Bio

Clinical Focus


  • Robotics
  • Cancer > Urologic Oncology
  • Laparoscopic Surgical Procedures
  • Urology
  • Nerve Sparing Radical Prostatectomy
  • Laparoscopic Partial Nephrectomy
  • Robotic Partial Nephrectomy
  • Single Port Laparoscopy
  • Prostate Cancer - Robotic Radical Prostatectomy
  • Kidney Cancer - Urologic Oncology
  • Prostate Cancer
  • Adrenal Cancer
  • Urologic Cancers - Urologic Oncology

Academic Appointments


Administrative Appointments


  • Director, Robotic Surgery (2009 - Present)

Honors & Awards


  • Recognition, Who's Who in America (2007-present)
  • Third Place, Max K. Willscher Prize, New England Section, American Urological Association (2002)
  • First Place, Basic Science Research, Philadelphia Urologic Society (2002)

Professional Education


  • Residency:Massachusetts General Hospital (2001) MA
  • Fellowship:Cleveland Clinic Foundation (2006) OH
  • Internship:Massachusetts General Hospital (2000) MA
  • Board Certification: Urology, American Board of Urology (2008)
  • Fellowship, Cleveland Clinic, Laparoscopic and Robotic Surgery (2006)
  • Residency:Lahey Clinic Hospital (2005) MA
  • Medical Education:Jefferson Medical College (1999) PA
  • Residency, Lahey Clinic, Urology (2005)
  • Residency, Massachusetts General Hospital, Surgery (2001)
  • Internship, Massachusetts General Hospital, Surgery (2000)
  • M.D., Jefferson Medical College, Medicine (1999)
  • B.A., Amherst College, Classics (1995)

Research & Scholarship

Current Research and Scholarly Interests


Dr Chung is interested in outcomes and epidemiology of renal cell carcinoma and carcinoma of the prostate. He is also developing new technologies in the treatment of both prostate and kidney cancer. He is studying the efficacy of minimally invasive laparoscopic techniques for kidney tumors, including cryotherapy, and in developing robotic and laparoscopic novel therapies in the treatment of prostate cancer.

Current Clinical Interests


  • Robotics
  • Surgical Procedures, Minimally Invasive
  • Epidemiologic Studies
  • Renal Cell Carcinoma
  • Prostate Cancer

Clinical Trials


  • Prostate Active Surveillance Study Not Recruiting

    The Prostate Active Surveillance Study (PASS) is a research study for men who have chosen active surveillance as a management plan for their prostate cancer. Active surveillance is defined as close monitoring of prostate cancer with the offer of treatment if there are changes in test results. This study seeks to discover markers that will identify cancers that are more aggressive from those tumors that grow slowly.

    Stanford is currently not accepting patients for this trial. For more information, please contact Michelle Ferrari, (650) 725 - 5543.

    View full details

  • Quality of Life Following Radical Prostatectomy Recruiting

    This study will utilize the Expanded Prostate Cancer Index Composite questionnaire to learn what impact the surgery has upon the participant's sense of health, sexual and urinary quality of life.

    View full details

  • Pre-surgical Detection of Clear Cell Renal Cell Carcinoma (ccRCC) Using Radiolabeled G250-Antibody Not Recruiting

    This is a multicenter Phase III study to demonstrate the diagnostic utility of 124I-cG250 PET/CT pre-surgical imaging in patients with operable renal masses.

    Stanford is currently not accepting patients for this trial. For more information, please contact Denise Haas, (650) 736 - 1252.

    View full details

  • Photoacoustic Imaging (PAI) of the Prostate: A Clinical Feasibility Study Recruiting

    PRIMARY OBJECTIVE(S): The primary objective of this pilot study is to assess PAI-performance in a clinical setting to understand limitations of our current PAI instrumentation and to help improve the next-generation design. SECONDARY OBJECTIVE(S): To do preliminary evaluations of oxygen saturation in lesions based on PAI-measurements in order to distinguish malignant from benign prostatic tissue as a basis for future studies.

    View full details

Publications

Journal Articles


  • Editorial comment. Urology Liu, J., Chung, B. I. 2014; 83 (2): 356-?

    View details for DOI 10.1016/j.urology.2013.09.057

    View details for PubMedID 24468510

  • Risk factors for postoperative hemorrhage after partial nephrectomy. Korean journal of urology Jung, S., Min, G. E., Chung, B. I., Jeon, S. H. 2014; 55 (1): 17-22

    Abstract

    To evaluate the frequency and clinical characteristics of postoperative hemorrhage as a complication of partial nephrectomy.The demographics, physical statistics, tumor size, R.E.N.A.L. nephrometry score, operative method, warm ischemic time, and presence of postoperative hemorrhage and its severity and method of intervention were examined in 300 partial nephrectomy patients in two medical centers (Stanford Medical Center and Kyung Hee University Medical Center) between March 2000 and March 2012.Of the 300 subjects, 13 (4.3%) experienced postoperative hemorrhage severe enough to require intervention more invasive than transfusion (Clavien grade III or higher). Univariate analysis of the bleeding and nonbleeding groups showed that whereas age, ischemic time, tumor size and stage, body mass index, American Society of Anesthesiologists class, and operative method did not differ significantly, the exophyticity (E) score was significantly higher for severe postoperative hemorrhage (p=0.04). However, multivariate analysis showed none of the factors to differ significantly. In most of the cases requiring intervention, selective embolization was sufficient, but in one case explorative laparotomy and nephrectomy were required. Clinical characteristics varied significantly among severe hemorrhage cases, with time of onset ranging from the first to the 30th postoperative day and symptoms presenting in a diverse manner, such as gross hematuria and pleuritic chest pain. Computed tomography and angiographic findings were consistent with either arteriovenous fistula or pseudoaneurysms.Severe hemorrhage after partial nephrectomy is rare. Nonetheless, with the great variability in presenting symptoms and time of onset after surgery, surgeons should exercise great vigilance during the postoperative care of partial nephrectomy patients.

    View details for DOI 10.4111/kju.2014.55.1.17

    View details for PubMedID 24466392

  • The Impact of Surgeon Volume on the Morbidity and Costs of Radical Cystectomy in the United States: A Contemporary Population-Based Analysis. BJU international Leow, J. J., Reese, S., Trinh, Q. D., Bellmunt, J., Chung, B. I., Kibel, A. S., Chang, S. L. 2014

    Abstract

    To evaluate the relationship between surgeon volume of radical cystectomy (RC) and postoperative morbidity as well as the economic burden of bladder cancer in the United States.We captured all patients who underwent a RC (ICD-9 code 57.71) from 2003 to 2010, using a nationwide hospital discharge database. Patient, hospital, and surgical characteristics were evaluated. Annual volume of RC for surgeons was divided into quintiles. Multivariable regression models were developed adjusting for clustering and survey weighting to evaluate the outcomes including 90-day major complications (Clavien 3-5) and direct patient costs. We adjusted for clustering and weighting to achieve a nationally representative analysis.The weighted cohort included 49,792 RC patients with an overall 90-day major complication rate of 16.2%. Compared to surgeons performing one RC annually, surgeons performing ≥7 RC each year had a 45% decreased odds of major complications (OR: 0.55, p<0.001) and a reduction in costs by $1690 (p=0.02). Results were consistent when we analyzed surgeon volume as a continuous variable and when we examined the highest volume surgeons (≥28 cases annually), which found a marked decreased odds of major complications compared to the lowest volume surgeons (OR: 0.45, 95% CI: 0.31-0.67, p<0.0001). Compared to patients who did not have any complications, those who suffered a major complication had significantly higher 90-day median direct hospital costs ($43965 vs. $24341, p<0.0001).We demonstrate an inverse relationship between surgeon volume and the development of postoperative 90-day major complication rates as well as direct hospital costs. Centralization of RC to higher volume surgeons may reduce the development of postoperative major complications thereby decreasing the burden of bladder cancer on the health care system.

    View details for DOI 10.1111/bju.12749

    View details for PubMedID 24674655

  • Relating prognosis in chromophobe renal cell carcinoma to the chromophobe tumor grading system. Korean journal of urology Weinzierl, E. P., Thong, A. E., McKenney, J. K., Jeon, S. H., Chung, B. I. 2014; 55 (4): 239-44

    Abstract

    The chromophobe subtype of renal cell carcinoma (chRCC) has generally been associated with a better prognosis than the clear cell type; however, debate continues as to absolute prognosis as well as the significance of certain prognostic variables. We investigated the significance of pathologic stage and a recently proposed chromophobe tumor grading (CTG) scheme in predicting chRCC outcomes.All available chRCCs were identified from our surgical pathology archives from 1987-2010. Original slides were reviewed to verify diagnoses and stage, and each case was graded following a novel chromophobe tumor grade system criteria. Disease status was obtained from a clinical outcome database, and cancer specific deaths and recurrences were recorded.Eighty-one cases of chRCC were identified, and 73 had adequate follow-up information available. There were only 3 instances of cancer related recurrence or mortality, which included 1 disease specific mortality and 2 disease recurrences. Pathologic stage and CTG 3 were found to be significantly associated with the recurrences or death from chRCC, but there was no association with CTG 1 and CTG 2.chRCC is associated with a very low rate of cancer specific events (4.1%) even at a tertiary referral center. In our study, pathologic stage and CTG 3, but not CTG 1 or 2, were significantly associated with the development of these events.

    View details for DOI 10.4111/kju.2014.55.4.239

    View details for PubMedID 24741411

  • Utilization of Renal Mass Biopsy in Patients With Renal Cell Carcinoma. Urology Leppert, J. T., Hanley, J., Wagner, T. H., Chung, B. I., Srinivas, S., Chertow, G. M., Brooks, J. D., Saigal, C. S. 2014

    Abstract

    To examine the patient, tumor, and temporal factors associated with receipt of renal mass biopsy (RMB) in a contemporary nationally representative sample.We queried the Surveillance, Epidemiology, and End Results-Medicare data set for incident cases of renal cell carcinoma diagnosed between 1992 and 2007. We tested for associations among receipt of RMB and patient and tumor characteristics, type of therapy, and procedure type. Temporal trends in receipt of RMB were characterized over the study period.Approximately 1 in 5 (20.7%) patients diagnosed with renal cell carcinoma (n = 24,702) underwent RMB before instituting therapy. There was a steady and modest increase in RMB utilization, with the highest utilization (30%) occurring in the final study year. Of patients who underwent radical (n = 15,666) or partial (n = 2211) nephrectomy, 17% and 20%, respectively, underwent RMB in advance of surgery. Sixty-five percent of patients who underwent ablation (n = 314) underwent RMB before or in conjunction with the procedure. Roughly half of patients (50.4%) treated with systemic therapy alone underwent RMB. Factors independently associated with use of RMB included younger age, black race, Hispanic ethnicity, tumor size <7 cm, and metastatic disease at presentation.At present, most patients who eventually undergo radical or partial nephrectomy do not undergo RMB, whereas most patients who eventually undergo ablation or systemic therapy do. The optimal use of RMB in the evaluation of kidney tumors has yet to be determined.

    View details for DOI 10.1016/j.urology.2013.10.073

    View details for PubMedID 24529579

  • Reply. Urology Leppert, J. T., Hanley, J., Wagner, T. H., Chung, B. I., Brooks, J. D., Srinivas, S., Chertow, G. M., Saigal, C. S. 2014

    View details for DOI 10.1016/j.urology.2013.10.077

    View details for PubMedID 24529590

  • Propensity-Matched Comparison of Morbidity and Costs of Open and Robot-Assisted Radical Cystectomies: A Contemporary Population-Based Analysis in the United States. European urology Leow, J. J., Reese, S. W., Jiang, W., Lipsitz, S. R., Bellmunt, J., Trinh, Q. D., Chung, B. I., Kibel, A. S., Chang, S. L. 2014

    Abstract

    Radical cystectomy (RC) is a morbid procedure associated with high costs. Limited population-based data exist on the complication profile and costs of robot-assisted RC (RARC) compared with open RC (ORC).To evaluate morbidity and cost differences between ORC and RARC.We conducted a population-based, retrospective cohort study of patients who underwent RC at 279 hospitals across the United States between 2004 and 2010.Multivariable logistic and median regression was performed to evaluate 90-d mortality, postoperative complications (Clavien classification), readmission rates, length of stay (LOS), and direct costs. To reduce selection bias, we used propensity weighting with survey weighting to obtain nationally representative estimates.The final weighted cohort included 34 672 ORC and 2101 RARC patients. RARC use increased from 0.6% in 2004 to 12.8% in 2010. Major complication rates (Clavien grade ≥3; 17.0% vs 19.8%, p=0.2) were similar between ORC and RARC (odds ratio [OR]: 1.32; p=0.42). RARC had 46% decreased odds of minor complications (Clavien grade 1-2; OR: 0.54; p=0.03). RARC had $4326 higher adjusted 90-d median direct costs (p=0.004). Although RARC had a significantly shorter LOS (11.8 d vs 10.2 d; p=0.008), no significant differences in room and board costs existed (p=0.20). Supply costs for RARC were significantly higher ($6041 vs $3638; p<0.0001). Morbidity and cost differences were not present among the highest-volume surgeons (≥7 cases per year) and hospitals (≥19 cases per year). Limitations include use of an administrative database and lack of oncologic characteristics.The use of RARC has increased between 2004 and 2010. Compared with ORC, RARC was associated with decreased odds of minor but not major complications and with increased expenditures attributed primarily to higher supply costs. Centralization of ORC and RARC to high-volume providers may minimize these morbidity and cost differences.Using a US population-based cohort, we found that robotic surgery for bladder cancer decreased minor complications, had no impact on major complications and was more costly than open surgery.

    View details for DOI 10.1016/j.eururo.2014.01.029

    View details for PubMedID 24491306

  • Estimating the risk of chronic kidney disease after nephrectomy CANADIAN JOURNAL OF UROLOGY Ngo, T. C., Hurley, M. P., Thong, A. E., Jeon, S. H., Leppert, J. T., Chung, B. I. 2013; 20 (6): 7035-7041

    Abstract

    To identify factors associated with the development of chronic kidney disease (CKD) after nephrectomy and to create a clinical model to predict CKD after nephrectomy for kidney cancer for clinical use.We identified 144 patients who had normal renal function (eGFR > 60) prior to undergoing nephrectomy for kidney cancer. Selected cases occurred between 2007 and 2010 and had at least 30 days follow up. Sixty-six percent (n = 95) underwent radical nephrectomy and 62.5% (n = 90) developed CKD (stage 3 or higher) postoperatively. We used univariable analysis to screen for predictors of CKD and multivariable logistic regression to identify independent predictors of CKD and their corresponding odds ratios. Interaction terms were introduced to test for effect modification. To protect against over-fitting, we used 10-fold cross-validation technique to evaluate model performance in multiple training and testing datasets. Validation against an independent external cohort was also performed.Of the variables associated with CKD in univariable analysis, the only independent predictors in multivariable logistic regression were patient age (OR = 1.27 per 5 years, 95% CI: 1.07-1.51), preoperative glomerular filtration rate (GFR), (OR = 0.70 per 10 mL/min, 95% CI: 0.56-0.89), and receipt of radical nephrectomy (OR = 4.78, 95% CI: 2.08-10.99). There were no significant interaction terms. The resulting model had an area under the curve (AUC) of 0.798. A 10-fold cross-validation slightly attenuated the AUC to 0.774 and external validation yielded an AUC of 0.930, confirming excellent model discrimination.Patient age, preoperative GFR, and receipt of a radical nephrectomy independently predicted the development of CKD in patients undergoing nephrectomy for kidney cancer in a validated predictive model.

    View details for Web of Science ID 000328717300007

    View details for PubMedID 24331345

  • Reply. Urology Liu, J., Chung, B. I. 2013; 82 (3): 583-?

    View details for DOI 10.1016/j.urology.2013.03.083

    View details for PubMedID 23876587

  • Perioperative Outcomes for Laparoscopic and Robotic Compared With Open Prostatectomy Using the National Surgical Quality Improvement Program (NSQIP) Database UROLOGY Liu, J., Maxwell, B. G., Panousis, P., Chung, B. I. 2013; 82 (3): 579-583

    Abstract

    To examine contemporary outcomes of minimally invasive radical prostatectomy (MIRP) compared with open prostatectomy, using a national, prospective perioperative database reflecting diverse practice settings.The National Surgical Quality Improvement Program database was queried from 2005 to 2010 for laparoscopic or robotic prostatectomy (Current Procedural Terminology code 55866) and open retropubic prostatectomy (Current Procedural Terminology codes 55840, 55842, 55845). Perioperative outcomes examined were surgical and total operation duration, transfusion rates, length of stay, major morbidity (cardiovascular, pulmonary, renal, and infectious), and mortality.The study identified 5319 radical prostatectomies: 4036 MIRP and 1283 open. Although operative time was significantly longer in the MIRP group, there were significantly fewer perioperative blood transfusions and shorter mean length of stay. Major postoperative morbidity and mortality were 5% in the MIRP group and 9% in the open group (P <.001). Age, body mass index, presence of medical comorbidities, and open surgical technique were all independently predictive of major complications and mortality on multivariate analysis.In a nationwide database of diverse medical centers, MIRP was associated with longer operative time, but a significantly decreased rate of blood transfusions, length of stay, perioperative complication rate, and mortality compared with open prostatectomy. The minimally invasive surgical approach was independently associated with significantly fewer complications and deaths on multivariate analysis. Compared with other administrative databases that capture only inpatient events, the National Surgical Quality Improvement Program identifies complications up to 30 days postoperatively, providing more detailed characterization of complications after prostatectomy. These data reflect contemporary practice patterns and suggest that MIRP can be performed with low perioperative morbidity.

    View details for DOI 10.1016/j.urology.2013.03.080

    View details for Web of Science ID 000323790800031

    View details for PubMedID 23876584

  • Photoacoustic imaging of the bladder: a pilot study. Journal of ultrasound in medicine Kamaya, A., Vaithilingam, S., Chung, B. I., Oralkan, O., Khuri-Yakub, B. T. 2013; 32 (7): 1245-1250

    Abstract

    Photoacoustic imaging is a promising new technology that combines tissue optical characteristics with ultrasound transmission and can potentially visualize tumor depth in bladder cancer. We imaged simulated tumors in 5 fresh porcine bladders with conventional pulse-echo sonography and photoacoustic imaging. Isoechoic biomaterials of different optical qualities were used. In all 5 of the bladder specimens, photoacoustic imaging showed injected biomaterials, containing varying degrees of pigment, better than control pulse-echo sonography. Photoacoustic imaging may be complementary to diagnostic information obtained by cystoscopy and urine cytologic analysis and could potentially obviate the need for biopsy in some tumors before definitive treatment.

    View details for DOI 10.7863/ultra.32.7.1245

    View details for PubMedID 23804347

  • The unidirectional barbed suture for renorrhaphy during laparoscopic partial nephrectomy: stanford experience. Journal of laparoendoscopic & advanced surgical techniques. Part A Jeon, S. H., Jung, S., Son, H., Kimm, S. Y., Chung, B. I. 2013; 23 (6): 521-525

    Abstract

    Abstract Purpose: Using barbed suture represents a novel technical modification in the performance of minimally invasive partial nephrectomy. Our purpose of this study was to evaluate the safety and efficacy of this suture for renorrhaphy during laparoscopic partial nephrectomy (LPN). Patients and Methods: Thirteen consecutive patients underwent LPN using V-Loc™ 180 (Covidien, Dublin, Ireland) suture, and a nonconsecutive control group of 24 patients, matched according to tumor size and R.E.N.A.L. nephrometry score, underwent LPN using absorbable polyglactin suture. All 37 patients underwent LPN performed by a single surgeon. Perioperative and postoperative indicators of morbidity, estimated blood loss, and warm ischemia time (WIT) were compared between the groups. Results: Baseline characteristics including age, body mass index, American Society of Anesthesiologists score, tumor size, laterality, and R.E.N.A.L nephrometry score were identical between the groups. On multivariable analysis, there were no significant differences between the two groups with regard to operative time, estimated blood loss, transfusion rates, rates of surgical complications, and length of hospital stay. However, mean WIT was significantly shorter in the V-Loc group compared with the control group (24.5±5.3 minutes versus 31.9±8.9 minutes, P=.01). Conclusions: The use of V-Loc sutures for renorrhaphy during LPN is safe and feasible and, in our series, significantly reduces WIT. Further studies are needed to corroborate these findings, but these results indicate a promising development in reducing WIT during minimally invasive partial nephrectomy.

    View details for DOI 10.1089/lap.2012.0405

    View details for PubMedID 23414123

  • TEMPORAL TRENDS IN UTILIZATION OF CYTOREDUCTIVE NEPHRECTOMY AND PATIENT SURVIVAL IN THE TARGETED THERAPY ERA JOURNAL OF UROLOGY Conti, S. L., Hagedorn, J., Chung, B. I., Srinivas, S., Leppert, J. 2013; 189 (4): E753-E753
  • The Accordion Antiretropulsive Device Improves Stone-Free Rates During Ureteroscopic Laser Lithotripsy JOURNAL OF ENDOUROLOGY Wu, J. A., Ngo, T. C., Hagedorn, J. C., Macleod, L. C., Chung, B. I., Shinghal, R. 2013; 27 (4): 438-441

    Abstract

    The Accordion is a novel endoscopic device that prevents retropulsion of ureteral stones and their fragments during ureteroscopic laser lithotripsy. We describe our experience with its use focusing on three main endpoints: operating time, fluoroscopy time, and stone-free rates.Of 308 consecutive cases of unilateral ureteroscopic laser lithotripsy from 2006-2010, we analyzed 235 cases of ureteral stones. Chart review was performed to document patient demographics (age, sex, and race), stone characteristics (stone size, density, laterality, location, and multiplicity), operative characteristics (use of preoperative and/or postoperative stents, ureteral balloon dilators, ureteral access sheaths, the Holmium laser, and the Accordion device), and surgical outcomes (operative time, fluoroscopy time, stone-free status, and complications).The baseline characteristics between the Accordion and non-Accordion group were statistically similar. In univariate nonparametric tests of medians, Accordion device usage was not associated with a significant reduction in fluoroscopy time (median 1.68 vs. 1.95 minutes, p=0.28) or operating time (median 52.5 vs. 61 minutes, p=0.19). However, the stone-free rate for the Accordion group was significantly higher compared to the non-Accordion group (84.2% vs. 53.6%, p=0.001). In multivariate generalized linear models, Accordion usage was not associated with decreased operating or fluoroscopy times. Accordion use was associated with statistically significant greater odds of stone-free status (odds ratio 4.35, 95% confidence interval 2.36-8.00). Complication severity and rates were comparable between the two groups.The Accordion antiretropulsive device improves stone-free rates during ureteroscopic laser lithotripsy. Prospective studies are needed to validate these results.

    View details for DOI 10.1089/end.2012.0332

    View details for Web of Science ID 000317353000009

    View details for PubMedID 23387558

  • Surgical outcomes and complications associated with presurgical tyrosine kinase inhibition for advanced renal cell carcinoma (RCC) UROLOGIC ONCOLOGY-SEMINARS AND ORIGINAL INVESTIGATIONS Harshman, L. C., Yu, R. J., Allen, G. I., Srinivas, S., Gill, H. S., Chung, B. I. 2013; 31 (3): 379-385

    Abstract

    Tyrosine kinase inhibitors (TKI) have dramatically changed the management paradigm of advanced renal cell carcinoma (RCC) and are increasingly being used preoperatively to achieve cytoreduction.To review our case series of post-TKI surgical procedures to add to the current perioperative efficacy and complication profile.Between October 2006 and February 2010, 14 cytoreductive nephrectomies, radical nephrectomies, and metastectomies were performed after neoadjuvant sunitinib or sorafenib for advanced RCC. During the same time frame, a control group of 73 consecutive patients underwent radical nephrectomy, cytoreductive nephrectomy, or metastectomy in the absence of prior systemic therapy. We compared the incidence of perioperative complications and outcomes after surgical procedures between the two cohorts.Median preoperative renal mass size was 11 cm (6.7-24.2 cm). Primary tumor shrinkage was seen in 57%; median shrinkage was 18% (8%-25%). The median treatment period was 17 weeks, and the median time from TKI discontinuation was 2 weeks. Compared with a control group and after adjusting for confounding covariates, presurgical TKI use was not associated with a significant increase in perioperative complications (50% vs. 40%, P = 0.25) or perioperative bleeding (36% vs. 34%, P = 0.97) but was associated with increased incidence and grade of intraoperative adhesions (86% vs. 58%, P = 0.001; grade 3 vs. 1, P = 0.002).Compared with the published reports, we observed less hemorrhagic and wound healing issues but a significant increase in incidence and severity of intraoperative adhesions, which can present a formidable technical challenge. Potential reasons for our lower complication rate could be increased time from TKI discontinuation to surgery, longer time to postoperative TKI re-initiation, increased use of preoperative angioembolization, and the lack of preoperative bevacizumab administration. Presurgical TKI therapy can permit effective surgical cytoreduction with a safety and complication profile equivalent to that of non-TKI-nephrectomy; however safety data continue to evolve, and preoperative TKI use requires further prospective investigation.

    View details for DOI 10.1016/j.urolonc.2011.01.005

    View details for Web of Science ID 000317169500015

    View details for PubMedID 21353796

  • Prostate Cancer Risk Profiles in Asian Americans: Disentangling the Effects of Immigration Status and Race/Ethnicity. The Journal of urology Lichtensztajn, D. Y., Gomez, S. L., Sieh, W., Chung, B. I., Cheng, I., Brooks, J. D. 2013

    Abstract

    Asian-American men with prostate cancer have been reported to present with higher grade and later stage disease than White Americans. However, Asian Americans comprise a heterogeneous population with distinct health outcomes. We compared prostate cancer risk profiles among the diverse racial and ethnic groups in California.We used data from the California Cancer Registry for 90,845 Non-Hispanic White, Non-Hispanic Black, and Asian-American men diagnosed with prostate cancer between 2004 and 2010. Patients were categorized into low, intermediate, or high-risk groups based on clinical stage, Gleason score, and PSA value at diagnosis. Using polytomous logistic regression, we estimated adjusted odds ratios for the association of race/ethnicity and nativity with risk group.In addition to Non-Hispanic Blacks, six Asian-American groups (US-born Chinese, foreign-born Chinese, US-born Japanese, foreign-born Japanese, foreign-born Filipino, and foreign-born Vietnamese) were more likely to have an unfavorable risk profile compared to Non-Hispanic Whites. The odds ratios for high vs. intermediate-risk disease ranged from 1.23 (95% CI, 1.02-1.49) for US-born Japanese to 1.45 (95% CI, 1.31-1.60) for foreign-born Filipinos. These associations appeared to be driven by higher grade and PSA values, rather than advanced clinical stage at diagnosis.In this large, ethnically diverse population-based cohort, we found that Asian-American men were more likely to have unfavorable risk profiles at diagnosis. This association varied by racial/ethnic group and nativity, and was not attributable to later stage at diagnosis, suggesting that Asian men may have biological differences that predispose to the development of more severe disease.

    View details for DOI 10.1016/j.juro.2013.10.075

    View details for PubMedID 24513166

  • National Trends of Perioperative Outcomes and Costs for Open, Laparoscopic and Robotic Pediatric Pyeloplasty. The Journal of urology Varda, B. K., Johnson, E. K., Clark, C., Chung, B. I., Nelson, C. P., Chang, S. L. 2013

    Abstract

    We performed a population based study comparing trends in perioperative outcomes and costs for open, laparoscopic and robotic pediatric pyeloplasty. Specific billing items contributing to cost were also investigated.Using the Perspective database (Premier, Inc., Charlotte, North Carolina), we identified 12,662 pediatric patients who underwent open, laparoscopic and robotic pyeloplasty (ICD-9 55.87) in the United States from 2003 to 2010. Univariate and multivariate statistics were used to evaluate perioperative outcomes, complications and costs for the competing surgical approaches. Propensity weighting was used to minimize selection bias. Sampling weights were used to yield a nationally representative sample.A decrease in open pyeloplasty and an increase in minimally invasive pyeloplasty were observed. All procedures had low complication rates. Compared to open pyeloplasty, laparoscopic and robotic pyeloplasty had longer median operative times (240 minutes, p <0.0001 and 270 minutes, p <0.0001, respectively). There was no difference in median length of stay. Median total cost was lower among patients undergoing open vs robotic pyeloplasty ($7,221 vs $10,780, p <0.001). This cost difference was largely attributable to robotic supply costs.During the study period open pyeloplasty made up a declining majority of cases. Use of laparoscopic pyeloplasty plateaued, while robotic pyeloplasty increased. Operative time was longer for minimally invasive pyeloplasty, while length of stay was equivalent across all procedures. A higher cost associated with robotic pyeloplasty was driven by operating room use and robotic equipment costs, which nullified low room and board cost. This study reflects an adoption period for robotic pyeloplasty. With time, perioperative outcomes and cost may improve.

    View details for DOI 10.1016/j.juro.2013.10.077

    View details for PubMedID 24513164

  • Trends and perioperative outcomes for laparoscopic and robotic nephrectomy using the National Surgical Quality Improvement Program (NSQIP) database. Urologic oncology Liu, J. J., Leppert, J. T., Maxwell, B. G., Panousis, P., Chung, B. I. 2013

    Abstract

    We sought to examine the trends in perioperative outcomes of kidney cancer surgery stratified by type (radical nephrectomy [RN] vs. partial nephrectomy [PN]) and approach (open vs. minimally invasive).We queried the National Surgical Quality Improvement Program database to identify kidney cancer operations performed from 2005 to 2011. We examined 30-day perioperative outcomes including operative time, transfusion rate, length of stay, major morbidity (cardiovascular, pulmonary, renal, and infectious), and mortality.A total of 2,902 PN and 5,459 RN cases were identified. The use of PN increased over time, accounting for 39% of all nephrectomies in 2011. Minimally invasive approaches also increased over time for both RN and PN. Open surgery was associated with increased length of stay, receipt of transfusion, major complications, and perioperative mortality. Resident involvement and open approach were independent predictors of major complications for both PN and RN. Additionally, the presence of a medical comorbidity was also a risk factor for complications after RN. The overall complication rates decreased for all approaches over the study period.Minimally invasive approaches to kidney cancer renal surgery have increased with favorable outcomes. The safety of open and minimally invasive PN improved significantly over the study period. Although pathologic features cannot be determined from this data set, these data show that complications from renal surgical procedures are decreasing in an era of increasing use.

    View details for DOI 10.1016/j.urolonc.2013.09.012

    View details for PubMedID 24332644

  • Three differentiation states risk-stratify bladder cancer into distinct subtypes PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Volkmer, J., Sahoo, D., Chin, R. K., Ho, P. L., Tang, C., Kurtova, A. V., Willingham, S. B., Pazhanisamy, S. K., Contreras-Trujillo, H., Storm, T. A., Lotan, Y., Beck, A. H., Chung, B. I., Alizadeh, A. A., Godoy, G., Lerner, S. P., van de Rijng, M., Shortliffe, L. D., Weissman, I. L., Chan, K. S. 2012; 109 (6): 2078-2083

    Abstract

    Current clinical judgment in bladder cancer (BC) relies primarily on pathological stage and grade. We investigated whether a molecular classification of tumor cell differentiation, based on a developmental biology approach, can provide additional prognostic information. Exploiting large preexisting gene-expression databases, we developed a biologically supervised computational model to predict markers that correspond with BC differentiation. To provide mechanistic insight, we assessed relative tumorigenicity and differentiation potential via xenotransplantation. We then correlated the prognostic utility of the identified markers to outcomes within gene expression and formalin-fixed paraffin-embedded (FFPE) tissue datasets. Our data indicate that BC can be subclassified into three subtypes, on the basis of their differentiation states: basal, intermediate, and differentiated, where only the most primitive tumor cell subpopulation within each subtype is capable of generating xenograft tumors and recapitulating downstream populations. We found that keratin 14 (KRT14) marks the most primitive differentiation state that precedes KRT5 and KRT20 expression. Furthermore, KRT14 expression is consistently associated with worse prognosis in both univariate and multivariate analyses. We identify here three distinct BC subtypes on the basis of their differentiation states, each harboring a unique tumor-initiating population.

    View details for DOI 10.1073/pnas.1120605109

    View details for Web of Science ID 000299925000058

    View details for PubMedID 22308455

  • Laparoscopic Partial Nephrectomy for Completely Intraparenchymal Tumors JOURNAL OF UROLOGY Chung, B. I., Lee, U. J., Kamoi, K., Canes, D. A., Aron, M., Gill, I. S. 2011; 186 (6): 2182-2187

    Abstract

    Management for intraparenchymal renal tumors represents a technical challenge during laparoscopic partial nephrectomy since, unlike exophytic tumors, there are no external visual cues on the renal surface to guide tumor localization or excision. Also, hemostatic renorrhaphy and pelvicalyceal suture repair in these completely intrarenal tumors create additional challenges. We examined the safety and technical feasibility of this procedure in this cohort.Of 800 patients who underwent laparoscopic partial nephrectomy 55 (6.9%) had completely intraparenchymal tumors. Technical steps included intraoperative ultrasound guidance of tumor resection, en bloc hilar clamping, cold excision of tumor and sutured renal reconstruction.Mean tumor size was 2.3 cm (range 1.0 to 4.5), mean blood loss was 236 cc (range 25 to 1,000) and mean warm ischemia time was 29.9 minutes (range 7 to 57). There were no positive margins. When we compared laparoscopic partial nephrectomy for intraparenchymal tumors to the same procedure in another 3 tumor groups, including completely exophytic tumors, tumors infiltrating up to sinus fat and tumors infiltrating but not up to sinus fat, there were no statistically significant differences among the groups in complications, positive margin rate, blood loss, or tumor excision or warm ischemia time.Laparoscopic partial nephrectomy for completely intrarenal tumors is a technically advanced but effective, safe procedure. Facility and experience with the technique, effective use of intracorporeal laparoscopic ultrasound and adherence to sound surgical principles are the keys to success. Most recently we have performed laparoscopic and robotic partial nephrectomy for such completely intrarenal tumors using a zero ischemia technique.

    View details for DOI 10.1016/j.juro.2011.07.106

    View details for Web of Science ID 000296758600009

    View details for PubMedID 22014808

  • Editorial comment. journal of urology Chung, B. I. 2011; 186 (5): 1848-?

    View details for DOI 10.1016/j.juro.2011.07.120

    View details for PubMedID 21944988

  • Management of intraoperative splenic injury during laparoscopic urological surgery BJU INTERNATIONAL Chung, B. I., Desai, M. M., Gill, I. S. 2011; 108 (4): 572-576

    Abstract

    Study Type - Therapy (case series). Level of Evidence: 4. What's known on the subject? and What does the study add? The exact incidence of splenic injury during laparoscopic urologic procedures is not known; however, it is an uncommon occurrence. Also, the optimal treatment algorithm is not well delineated and the efficacy of successfully treating minor injuries to the spleen without resorting to splenectomy is not well described in the urologic literature. This study outlines the rate of splenic injury during a variety of laparoscopic urologic procedures and we outline a treatment algorithm that has been successfully employed in the management of these patients, which in all cases, did not lead to splenectomy. An important point is also that multiple adjunctive hemostatic measures should be used when a splenic injury is recognized and that a thorough search should ensue when suspicion of an occult splenic injury exists, as an unrecognized splenic injury may lead to severe post operative haemorrhagic complications.• To evaluate incidence, risk factors for, and management of intraoperative splenic injury in our laparoscopic patient cohort.• All patients undergoing laparoscopic urological upper tract procedures at two institutions between January 2001 and April 2006 and January 2000 and December 2008, respectively, were retrospectively examined for complications. • From these patients, those with intraoperative splenic injuries were selected and examined. • Possible factors predisposing patients to splenic injury were evaluated and the management plan for each patient was analysed to identify optimal treatment efficacy.• Of 2620 patients undergoing upper tract urological laparoscopic surgery, 14 patients (0.5%) sustained splenic injury and underwent left-sided surgery, 13 via a transperitoneal approach. • In 12 of the 14 patients, the splenic injury was recognized intraoperatively and all were effectively managed laparoscopically with a combination of argon beam coagulation, biological haemostatic agent FloSeal(TM) (Baxter, Deerfield, IL, USA), and bio-absorbable Surgicel® (Johnson and Johnson, Somerville, NJ, USA); none of these patients required splenectomy or developed any postoperative complications. • In two patients, the splenic injury was not recognized intraoperatively; both patients presented with delayed haemorrhage necessitating open splenectomy in each instance.• Splenic injuries are uncommon during laparoscopic urological surgery, but when a significant splenic injury occurs, it can be effectively managed laparoscopically, using conservative measures, without need for splenectomy. • If the splenic injury is not recognized intraoperatively, delayed haemorrhage is likely to occur necessitating emergent re-exploration and splenectomy. • Prompt and accurate intraoperative diagnosis of splenic injury is critical for achieving a good outcome.

    View details for DOI 10.1111/j.1464-410X.2010.09821.x

    View details for Web of Science ID 000294109500025

    View details for PubMedID 21062394

  • Cost-Effectiveness Analysis of Nephron Sparing Options for the Management of Small Renal Masses JOURNAL OF UROLOGY Chang, S. L., Cipriano, L. E., Harshman, L. C., Garber, A. M., Chung, B. I. 2011; 185 (5): 1591-1597

    Abstract

    A recent increase in the detection of contrast enhancing renal masses 4 cm or smaller suspicious for malignancy has led to the widespread use of nephron sparing options. Limited data exist to help clinicians decide which of these competing nephron sparing therapies is most appropriate. We performed a cost-effectiveness analysis to evaluate the relative clinical and economic merits of commonly available nephron sparing strategies for small renal masses.We developed a decision analytic Markov model estimating the costs and health outcomes of treating a healthy 65-year-old patient with an asymptomatic unilateral small renal mass using competing nephron sparing options of immediate intervention (ie open and laparoscopic partial nephrectomy as well as laparoscopic and percutaneous ablation), active surveillance with possible delayed intervention and nonsurgical management with observation. Benefits were measured in quality adjusted life-years. We used a societal perspective, lifetime horizon and willingness to pay threshold of $50,000 per quality adjusted life-year gained. Model results were assessed with sensitivity analyses.In the base case scenario the least costly option was observation and the optimal option was immediate laparoscopic partial nephrectomy, which had an incremental cost-effectiveness ratio of $36,645 per quality adjusted life-year gained compared to surveillance with possible delayed percutaneous ablation. Results were sensitive to age at diagnosis, health status and tumor size.Immediate laparoscopic partial nephrectomy is the preferred nephron sparing option for healthy patients younger than 74 years old with a small renal mass. Surveillance with possible delayed percutaneous ablation is a cost-effective alternative for patients with advanced age or significant comorbidities. Observation maximizes quality adjusted life-years in patients who are poor surgical candidates or with limited life expectancy (less than 3 years).

    View details for DOI 10.1016/j.juro.2010.12.100

    View details for Web of Science ID 000289279600013

    View details for PubMedID 21419445

  • Comparison of prostate cancer tumor volume and percent cancer in prediction of biochemical recurrence and cancer specific survival UROLOGIC ONCOLOGY-SEMINARS AND ORIGINAL INVESTIGATIONS Chung, B. I., Tarin, T. V., Ferrari, M., Brooks, J. D. 2011; 29 (3): 314-318

    Abstract

    Tumor volume and percent cancer (ratio of tumor volume/prostate volume) have been proposed as predictors of biochemical recurrence and cancer specific survival after radical prostatectomy. However, their relative merits as prognosticators have not been tested. We therefore evaluated and compared tumor volume and percent cancer as independent predictors of biochemical recurrence and prostate cancer specific death after radical prostatectomy.A retrospective review of 739 patients who underwent radical prostatectomy for prostate cancer between 1984 and 2004 was conducted. Median follow-up was 91.7 months, and 22 patients died of prostate cancer. Univariate and multivariate analysis evaluated the following factors in predicting biochemical recurrence and prostate cancer specific death: tumor volume, prostate volume, percent cancer, Gleason score, percentage of Gleason grade 4/5, margin status, capsular invasion status, seminal vesicle invasion status, preoperative PSA, and lymph node status.In univariate analysis, both tumor volume (P<0.001) and percent cancer (P<0.001) significantly correlated with biochemical recurrence. Since they are highly correlated, they did not predict outcome independently when included in the same model; however, both were highly predictive for biochemical recurrence in separate multivariate models (P=0.01 for both). Both also correlated with cancer specific survival as single variables; however, in separate multivariate models, only tumor volume (P=0.03) predicted death, while percent cancer did not (P=0.09).Tumor volume and percent cancer are independent predictors of recurrence after radical prostatectomy. However, in our series, tumor volume predicted cancer specific death better than percent cancer. Therefore, accurate determination of tumor volume, along with other accepted pathologic indices, is sufficient and preferred over percent cancer for prognostication after radical prostatectomy.

    View details for DOI 10.1016/j.urolonc.2009.06.017

    View details for Web of Science ID 000290779400016

    View details for PubMedID 19837617

  • Comparison of Holding Strength of Suture Anchors on Human Renal Capsule JOURNAL OF ENDOUROLOGY Kimm, S., Tarin, T., Chung, B., Shinghal, R., Reese, J. 2010; 24 (2): 293-297

    Abstract

    The use of surgical clips as suture anchors has made laparoscopic partial nephrectomy (LPN) technically simpler by eliminating the need for intracorporeal knot tying. However, the holding strength of these clips has not been analyzed in the human kidney. Therefore, the safety of utilizing suture anchors is unknown as the potential for clip slippage or renal capsular tears during LPN could result in postoperative complications including hemorrhage and urinoma formation. With the above in mind, we sought to compare the ability of Lapra-Ty clips and Hem-o-lok clips to function as suture anchors on human renal capsule.Fresh human cadaveric kidneys with intact renal capsules were obtained. A Lapra-Ty clip (Ethicon, Cincinnati, OH) or a Hem-o-lok clip (Weck, Raleigh, NC) was secured to a no. 1 Vicryl suture (Ethicon) with and without a knot, as is typically utilized during the performance of LPN. The suture was then placed through the renal capsule and parenchyma and attached to an Imada Mechanical Force Tester (Imada, Northbrook, IL). The amount of force required both to violate the renal capsule and to dislodge the clip was recorded separately.Six Lapra-Ty clips and six Hem-o-lok clips were tested. The mean force in newtons required to violate the renal capsule for the Lapra-Ty group was 7.33 N and for the Hem-o-lok group was 22.08 N (p < 0.001). The mean force required to dislodge the clip from the suture for the Lapra-Ty group was 9.0 N and for the Hem-o-lok group was 3.4 N (p < 0.001). When two Hem-o-lok clips were placed on the suture in series, the mean force required to dislodge the clips was 10.6 N.When compared with Lapra-Ty clips, using two Hem-o-lok clips may provide a more secure and cost-effective method to anchor sutures on human renal capsule when performing LPN.

    View details for DOI 10.1089/end.2009.0211

    View details for Web of Science ID 000274423500021

    View details for PubMedID 20050785

  • Laparoscopic Radical Nephrectomy in a Pelvic Ectopic Kidney: Keys to Success JSLS-JOURNAL OF THE SOCIETY OF LAPAROENDOSCOPIC SURGEONS Chung, B. I., Liao, J. C. 2010; 14 (1): 126-129

    Abstract

    Laparoscopic radical nephrectomy of a pelvic kidney for renal cell carcinoma is a procedure with little precedent, but one that offers the advantages of the minimally invasive approach. We present our experience with this unique procedure.A 64-year-old male with a history of end-stage renal disease was diagnosed with a 2.6-cm enhancing mass in a pelvic left kidney with 2 separate sources of blood supply. He was offered either an open radical nephrectomy or a laparoscopic radical nephrectomy and opted for the minimally invasive approach.The procedure was performed successfully without complications and with minimal blood loss. The case was marked both by difficulty in mobilizing the sigmoid colon and the limited working space of the pelvis, which made localization of the numerous hilar vessels challenging.Laparoscopic radical nephrectomy for a pelvic ectopic kidney appears to be safe and efficacious. Success is dependent on familiarity with pelvic anatomy, optimal port placement, and preprocedure knowledge of the often-complicated vascular anatomy of the ectopic kidney. Preoperative imaging to delineate anomalous vascular anatomy is mandatory, and ureteral catheter placement is helpful for intraoperative identification purposes.

    View details for DOI 10.4293/108680810X12674612765623

    View details for Web of Science ID 000278761200023

    View details for PubMedID 20529537

  • Laparoscopic radical nephrectomy after shrinkage of a caval tumor thrombus with sunitinib NATURE REVIEWS UROLOGY Harshman, L. C., Srinivas, S., Kamaya, A., Chung, B. I. 2009; 6 (6): 338-343

    Abstract

    A 57-year-old woman presented to the emergency department at a community hospital with a 2-month history of fatigue and right-sided flank and abdominal pain. Noncontrast CT of the abdomen and pelvis revealed a 9.1 cm right renal mass.Contrast CT of the chest, abdomen and pelvis, MRI of the abdomen and pelvis with gadolinium, radionuclide bone scan, lung nodule biopsy, complete blood count, comprehensive metabolic profile, and measurement of serum lactate dehydrogenase.Stage IV, T3bN0M1 clear cell renal cell carcinoma, with an associated tumor thrombus extending into the vena cava.The patient was treated with neoadjuvant sunitinib, which resulted in a marked response in the primary tumor and metastatic lesions as well as regression of the tumor thrombus well into the renal vein. Thus, laparoscopic radical nephrectomy was feasible and was achieved without hemorrhagic or wound healing complications. One month after surgery, she had evidence of disease progression in the lung and a periaortic lymph node. She was restarted on sunitinib with resultant disease stabilization, but discontinued the drug owing to toxicity. Eight months after cessation of sunitinib, she received a dendritic cell vaccine. She remains alive without evidence of disease progression 2 years after her diagnosis.

    View details for DOI 10.1038/nrurol.2009.84

    View details for Web of Science ID 000266773900012

    View details for PubMedID 19498412

  • Laparoscopic splenorenal venous bypass for nutcracker syndrome JOURNAL OF VASCULAR SURGERY Chung, B. I., Gill, I. S. 2009; 49 (5): 1319-1323

    Abstract

    Nutcracker syndrome is a rare entity caused by extrinsic compression on the left renal vein as it crosses between the superior mesenteric artery and the aorta. It can clinically present with flank pain and hematuria. Accepted treatments include open vascular bypass procedures or endoluminal stenting. We present the first description, to our knowledge, of a laparoscopic splenic vein-left renal vein bypass to relieve the outflow obstruction. The patient, a 29-year-old woman with debilitating left flank pain, presented with nutcracker syndrome. Left renal vein outflow was obstructed at the level of the intersection between the aorta and the superior mesenteric artery. The option of laparoscopic splenic to left renal vein bypass was discussed and performed. A five-port transperitoneal approach was used. Meticulous vascular control was achieved with numerous laparoscopic vascular bulldog clamps. With completely intracorporeal suturing techniques, the splenic vein was anastomosed to the superior aspect of the anterior left renal vein. Total warm ischemia time was 37 minutes. The anastomosis was watertight immediately upon unclamping. Interestingly, upon unclamping, the luminal diameter of the splenic vein appeared to increase to twice its native diameter. The proximal left renal vein appeared less distended, indicating preferential venous outflow through the newly created venous bypass. Blood loss was minimal, no intraoperative or postoperative complications occurred, and the patient's symptoms improved. This report continues to augment the indications for laparoscopic surgery in even complex, urologic vascular situations.

    View details for DOI 10.1016/j.jvs.2008.11.062

    View details for Web of Science ID 000265744700038

    View details for PubMedID 19307081

  • Perioperative Efficacy of Laparoscopic Partial Nephrectomy for Tumors Larger than 4 cm EUROPEAN UROLOGY Simmons, M. N., Chung, B. I., Gill, I. S. 2009; 55 (1): 199-208

    Abstract

    Laparoscopic partial nephrectomy (LPN) is typically reserved for kidney tumors < or = 4 cm in size. The use of LPN in patients with larger tumors (> 4 cm) has not been systematically evaluated.To examine technical feasibility and perioperative safety and efficacy of LPN for clinical stage pT1b-T2 tumors > 4 cm.This is a retrospective review of data from an Institutional Review Board-approved, prospectively maintained database of 425 LPN procedures over a 6-yr period (September 1999 through December 2005). Patients were grouped according to tumor size: control group 1: < 2 cm (n=89; 21% of patients); control group 2: 2-4 cm (n=278; 65% of patients); and study group 3: > 4 cm (n=58; 14% of patients).Retroperitoneal and transperitoneal LPN.Serum creatinine levels, estimated glomerular filtration rates.For groups 1, 2, and 3, mean tumor size was 1.5 cm, 2.9 cm, and 6 cm in diameter, respectively (p<0.001). Study group 3 patients more often had an American Society of Anesthesiologists score > or = 3 (p<0.05), central tumors (p<0.001), pelvicalyceal repair (p=0.004), and heminephrectomy (p<0.001). Total operative time, estimated blood loss, and duration of hospital stay were equivalent. Mean warm ischemia time was 30 min, 32 min, and 38 min in groups 1, 2, and 3, respectively (p=0.007). Tumor size > 4 cm did not increase significant risk for positive tumor margins, intraoperative complications, or postoperative genitourinary complications. In each group preoperative stage > or = 3 chronic kidney disease (CKD) was present in 31%, 35%, and 44% of patients in groups 1, 2, and 3, respectively (p=0.15); postoperatively, stage 3-5 CKD incidence increased to 52%, 52%, and 63% in groups 1, 2, and 3, respectively (p=0.20). Patients with tumor size > 4 cm and preoperative stage 3-5 CKD had an 8-fold increase in risk for CKD stage progression. Limitations of the study include retrospective analysis and a relatively low number of patients in group 3.Given laparoscopic expertise and appropriate patient selection, LPN is feasible and efficacious for kidney tumors > 4 cm. Indications for LPN should be expanded to include patients with amenable tumors > 4 cm in order to maximally preserve kidney function in these patients.

    View details for DOI 10.1016/j.eururo.2008.07.039

    View details for Web of Science ID 000262066700023

    View details for PubMedID 18684555

  • Laparoscopic Dismembered Pyeloplasty of a Retrocaval Ureter: Case Report and Review of the Literature EUROPEAN UROLOGY Chung, B. I., Gill, I. S. 2008; 54 (6): 1433-1436

    Abstract

    A retrocaval ureter is a rare entity that has traditionally been treated with open pyeloplasty techniques. In this paper, we describe the successful performance of a laparoscopic dismembered pyeloplasty for a retrocaval ureter and present important technical points. In reviewing the available literature about this technique, the laparoscopic approach should be considered to be first-line treatment for this anatomic anomaly due to the good track record, quick convalescence, and relative technical ease.

    View details for DOI 10.1016/j.eururo.2008.09.010

    View details for Web of Science ID 000261677600028

    View details for PubMedID 18805629

  • Fellowship in endourology, the job search, and setting up a successful practice: An insider's view JOURNAL OF ENDOUROLOGY Chung, B. I., Matin, S. F., Ost, M. C., Winfield, H. N. 2008; 22 (3): 551-557

    Abstract

    The field of endourology, which encompasses genitourinary endoscopy and percutaneous, laparoscopic, and robotic surgery, has advanced rapidly over the past quarter century, causing endourology to be considered a subspecialty of urology. The Endourological Society, which is recognized by the American Urological Association, offers numerous clinical and research fellowship opportunities throughout the world. The decision to seek postresidency fellowship training in endourology is complex as is the process of seeking subsequent employment. We offer guidance on the decision-making process to obtain fellowship training as well as on early steps into subsequent academic or private practice settings.

    View details for DOI 10.1089/end.2007.0144

    View details for Web of Science ID 000254829500030

    View details for PubMedID 18307381

  • Ureteroscopic versus percutaneous treatment for medium-size (1-2-cm) renal calculi JOURNAL OF ENDOUROLOGY Chung, B. I., Aron, M., Hegarty, N. J., Desai, M. M. 2008; 22 (2): 343-346

    Abstract

    To compare the outcomes of percutaneous nephrolithotomy (PCNL) and ureterorenoscopy (URS) for 1- to 2-cm renal calculi with specific reference to the stone clearance rate and morbidity.The records of 27 patients who underwent either PCNL (N = 15) or URS (N = 12) by standard techniques over an 8-month period for renal calculi between 1 and 2 cm were reviewed retrospectively. Demographic, intraoperative, and postoperative data were accrued and compared to identify any statistically significant differences. The median stone burden was slightly but not significantly higher in the PCNL group (1.8 cm v 1.25 cm; P = 0.19). Postoperative plain films were used to confirm stone clearance.The procedure was technically successful in all 27 patients. No patient in either group required a repeat session or ancillary procedure. All 15 PCNL procedures were completed through a single percutaneous tract. The PCNL and URS groups were equivalent with respect to operative time (79.0 minutes v 68.5 minutes) and incidence of complications (2 v 0). No patient in either group had significant hemorrhage or required blood transfusion. The overall stone-free rate was 87% for PCNL and 67% for URS (P = 0.36).Both PCNL and URS are effective options for renal calculi between 1 and 2 cm. The stonefree and complication rates for PCNL are higher, but the differences were not statistically significant in our series. The operative times are statistically equivalent, despite the potentially longer fragmentation times required for URS. The choice of treatment ultimately depends on the individual surgeon's preference and level of expertise.

    View details for DOI 10.1089/end.2006.9865

    View details for Web of Science ID 000253719900021

    View details for PubMedID 18294042

  • Second prize: 2006 endourological society essay competition - Preliminary experience with the Niris (TM) optical coherence tomography system during laparoscopic and robotic prostatectomy JOURNAL OF ENDOUROLOGY Aron, M., Kaouk, J. H., Hegarty, N. J., Colombo, J. R., Haber, G., Chung, B. I., Zhou, M., Gill, I. S. 2007; 21 (8): 814-818

    Abstract

    To evaluate the feasibility of high-resolution optical coherence tomography (OCT) in the identification of neurovascular bundles (NVBs) during laparoscopic and robotic radical prostatectomy (LRP).Between November 2005 and March 2006, 24 patients undergoing transperitoneal laparoscopic or robotic radical prostatectomy were enrolled in this study. Once the bladder was taken down and the prostate mobilized, the Niris imaging system was deployed. In each patient, in-vivo images were obtained to determine the image characteristics of NVBs, adipose tissue, prostate capsule, and endopelvic fascia. The NVB was imaged again in vivo, after the prostate was excised. Ex-vivo images were obtained from the prostate surface to look for the presence or absence of the NVBs and correlated with the surgeon's assessment of the adequacy of nerve sparing.From 24 patients, we obtained more than 300 OCT images of tissue structures including endopelvic fascia, prostate capsule, NVBs, fat, lateral pedicles, and lymphatics. These images were found to correlate independently with the surgeon's impression of the tissue being imaged. Preliminary comparison with parallel histologic evaluation was performed in four patients that suggested OCT could help to identify the NVBs and prostate capsule during LRP.In our preliminary experience with the Niris system during LRP, OCT was able to image the NVB in all patients. This could enhance surgical precision during nerve sparing and positively impact potency rates after radical prostatectomy. Further research will be needed, including parallel histologic evaluation and follow-up, to validate the findings of OCT imaging.

    View details for DOI 10.1089/end.2006.9938

    View details for Web of Science ID 000249550800003

    View details for PubMedID 17867934

  • The use of bowel for ureteral replacement for complex ureteral reconstruction: Long-term results JOURNAL OF UROLOGY Chung, B. I., Hamawy, K. J., Zinman, L. N., Libertino, J. A. 2006; 175 (1): 179-183

    Abstract

    Ileal and intestinal ureteral replacement remains a useful procedure for complex ureteral reconstruction. We examined the long-term safety and efficacy of this procedure, especially in regard to maintaining preoperative renal function and the avoidance of major complications.A total of 56 patients underwent intestinal ureteral substitution at our institution between 1979 and 2003, including 52 with an ileal ureteral replacement, 2 with colonic replacement alone and 2 with bilateral ureteral replacement, necessitating ileum and colon for 1 ureter each. The factors reviewed were indications for surgery, type of ureteral replacement, and the presence and type of complications. Followup data included excretory urogram or equivalent imaging results, and measurement of serum chloride, bicarbonate and creatinine before and after the procedure.Overall the complication rate remained low. Mean followup was 6.04 years (median 3.2). Most postoperative complications, which occurred in 10 patients (17.9%), were minor in nature, including pyelonephritis, fever of unknown origin, neuroma, hernia, recurrent urolithiasis and deep venous thrombosis. Major complications occurred in 6 patients (10.5%), including anastomotic stricture, ileal graft obstruction, wound dehiscence and chronic renal failure. Overall patients did not experience worsening renal function after the procedure with equivalent median creatinine before and after the procedure (1.0 mg/dl).During long-term followup major complications are rare and renal function remains preserved. Ileal and intestinal ureteral substitution remains a safe and efficacious procedure in patients with complex and difficult ureteral issues not amenable to more conservative measures.

    View details for DOI 10.1016/S0022-5347(05)00061-3

    View details for Web of Science ID 000234001100047

    View details for PubMedID 16406903

  • Laparoscopic Retroperitoneal Lymph Node Dissection for Stage I Nonseminomatous Germ Cell Tumors ? Do We Meet the Standards of Open Surgery? American Journal of Urology Review Chung BI, Tuerk IA 2005; 3 (9): 411-415
  • Laparoscopic Partial Nephrectomy : Alternative Surgical Approach for Renal Masses < 4 cm American Journal of Urology Review Chung BI, Tuerk IA 2004; 2 (10): 477-479
  • Expression of the proto-oncogene Axl in renal cell carcinoma DNA AND CELL BIOLOGY Chung, B. I., Malkowicz, S. B., Nguyen, T. B., Libertino, J. A., McGarvey, T. W. 2003; 22 (8): 533-540

    Abstract

    In this investigation, we examined the role of the Axl proto-oncogene in renal cell carcinoma (RCC). Axl is a tyrosine kinase receptor implicated in myeloid leukogenesis, and has been found to be overexpressed in lung cancers and breast cancers. Axl has been described to act as a mitogenic factor along with its ligand Gas-6. Axl has also shown to have a role in apoptosis, cell adhesion, and chemotaxis. The differential expression of the Axl RNA transcript was examined in 20 pairs of matched normal kidney and clear cell RCC patient samples. We found that there was a significant increase in the steady-state levels of Axl mRNA in the RCC compared with the normal kidney pair (Student's paired t-test P < 0.001). There was also a significant increase in Axl expression overall in RCC compared to normal kidney (P < 0.03). Western blotting was utilized to determine Axl protein levels in six out of the 20 pairs of the normal/RCC matched pairs. Overall, the level of expression was not significantly different between the paired normal kidneys and kidney tumors, but the detected Axl protein appeared to be at slightly different molecular weights. Primers were constructed for the two known Axl variant, RT-PCR performed, but no differences were observed in the expression of each variant. Next, we performed a gene silencing experiment utilizing double-stranded RNA constructed to silence the Axl gene in the 293 transformed kidney cell line. There was a 50% decrease in Axl gene expression in the RNAi transfected over control cells. In addition, flow cytometry performed to determine DNA content showed a 30% increase in G1/G0 cells, which were transfected with axl RNAi compared to control. Altogether, these findings suggest an overexpression of Axl as part of a proliferative phenotype in RCC.

    View details for Web of Science ID 000185482300007

    View details for PubMedID 14565870

  • The outcome of stopping prophylactic antibiotics in older children with vesicoureteral reflux JOURNAL OF UROLOGY Cooper, C. S., Chung, B. I., Kirsch, A. J., Canning, D. A., Snyder, H. M. 2000; 163 (1): 269-272

    Abstract

    Accepted management of vesicoureteral reflux includes surgical correction or prophylactic antibiotics with the hope for resolution as the child grows. The physician must consider surgery when reflux does not resolve despite uneventful years on prophylactic antibiotics. An alternative is cessation of the antibiotics. We report on the outcome of children taken off antibiotics with persistent reflux.During a 14-year period 51 children with documented reflux were taken off antibiotic prophylaxis. Selection criteria included children who were old enough to verbalize the symptoms of a urinary tract infection, and had normal voiding patterns, a minor history of infections and minimal or no renal scarring. Routine followup included nuclear cystography and renal sonography.A total of 40 girls and 11 boys maintained on antibiotics for a mean of 4.8 years were taken off prophylaxis and followed for an average of 3.7 years. Mean patient age when prophylactic antibiotics were stopped was 8.6 years. Reflux resolved in 10 children (19.6%). A urinary tract infection developed in 5 girls and 1 boy (11.8%) (mean age 11) an average of 2.3 years (range 4 months to 9.4 years) after antibiotic discontinuation. One child had symptoms consistent with cystitis and 5 had febrile urinary tract infections. All were treated with oral antibiotics and 5 had subsequent operations. No new renal scars developed.The majority of children did well following cessation of antibiotic prophylaxis despite persistent vesicoureteral reflux. Cessation of antibiotic prophylaxis is a reasonable option in a highly select patient population with reflux.

    View details for Web of Science ID 000084324900091

    View details for PubMedID 10604374

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