Dr. Liou is a local product, having grown up in Salinas and graduated from U.C. Berkley with a degree in Molecular and Cell Biology. He received his M.D. from New York Medical College and completed his General Surgery training at Cedars-Sinai Medical Center in Los Angeles. At Cedars, he was recognized for his excellence in clinical care and research with numerous awards and publications. Dr. Liou recently completed his 2 years of Thoracic Surgery training at Stanford, during which time he proved to be an outstanding physician and surgeon and a dedicated clinical researcher.

Dr. Liou?s expertise includes all surgical diseases of the lung, mediastinum, esophagus, chest wall, and diaphragm, with particular interest in thoracic oncology and minimally invasive surgical techniques. He has extensive experience with minimally invasive and open management of lung and esophageal cancer, mediastinal tumors, and benign esophageal disease. Dr. Liou's primary research focus has been on clinical outcomes in thoracic oncology and quality improvement.

Dr. Liou practices out of Stanford Hospital main campus and Stanford Health Care-ValleyCare Hospital in Pleasanton, where he is starting Stanford's Thoracic Surgery program in the East Bay.

Clinical Focus

  • Thoracic Surgery (Cardiothoracic Vascular Surgery)

Academic Appointments

Professional Education

  • Fellowship: Stanford University Thoracic Surgery Fellowship (2018) CA
  • Board Certification: American Board of Surgery, General Surgery (2017)
  • Residency: Cedars Sinai Medical Center General Surgery Residency (2016) CA
  • Medical Education: New York Medical College Registrar (2010) NY


All Publications

  • Stereotactic Body Radiotherapy Versus Delayed Surgery for Early-stage Non-small-cell Lung Cancer. Annals of surgery Mayne, N. R., Lin, B. K., Darling, A. J., Raman, V., Patel, D. C., Liou, D. Z., D'Amico, T. A., Yang, C. J. 2020


    OBJECTIVE: To evaluate the overall survival of patients with operable stage IA non-small-cell lung cancer (NSCLC) who undergo "early" SBRT (within 0-30 days after diagnosis) versus "delayed" surgery (90-120 days after diagnosis).SUMMARY OF BACKGROUND DATA: During the COVID-19 pandemic, national guidelines have recommended patients with operable stage IA NSCLC to consider delaying surgery by at least 3 months or, alternatively, to undergo SBRT without delay. It is unknown which strategy is associated with better short- and long-term outcomes.METHODS: Multivariable Cox proportional hazards modeling and propensity score-matched analysis was used to compare the overall survival of patients with stage IA NSCLC in the National Cancer Data Base from 2004 to 2015 who underwent "early" SBRT (0-30 days after diagnosis) versus that of patients who underwent "delayed" wedge resection (90-120 days after diagnosis).RESULTS: During the study period, 570 (55%) patients underwent early SBRT and 475 (45%) underwent delayed wedge resection. In multivariable analysis, delayed resection was associated with improved survival [adjusted hazard ratio 0.61; 95% confidence interval (CI): 0.50-0.76]. Propensity-score matching was used to create 2 groups of 279 patients each who received early SBRT or delayed resection that were well-matched with regard to baseline characteristics. The 5-year survival associated with delayed resection was 53% (95% CI: 45%-61%) which was better than the 5-year survival associated with early SBRT (31% [95% CI: 24%-37%]).CONCLUSION: In this national analysis, for patients with stage IA NSCLC, extended delay of surgery was associated with improved survival when compared to early treatment with SBRT.

    View details for DOI 10.1097/SLA.0000000000004363

    View details for PubMedID 33074904

  • Commentary: Two decades of innovation, leadership, and overcoming challenges, but more lies ahead. The Journal of thoracic and cardiovascular surgery Liou, D. Z. 2020

    View details for DOI 10.1016/j.jtcvs.2020.09.080

    View details for PubMedID 33069423

  • Cancer diagnoses and survival rise as 65-year-olds become Medicare eligible. Patel, D. C., He, H., Berry, M. F., Yang, C., Trope, W., Lui, N., Liou, D. Z., Backhus, L., Shrager, J. B. AMER SOC CLINICAL ONCOLOGY. 2020
  • Sub-solid lung adenocarcinoma in Asian versus Caucasian patients: different biology but similar outcomes JOURNAL OF THORACIC DISEASE Lui, N. S., Benson, J., He, H., Imielski, B. R., Kunder, C. A., Liou, D. Z., Backhus, L. M., Berry, M. F., Shrager, J. B. 2020; 12 (5): 2161?71
  • Sub-solid lung adenocarcinoma in Asian versus Caucasian patients: different biology but similar outcomes. Journal of thoracic disease Lui, N. S., Benson, J., He, H., Imielski, B. R., Kunder, C. A., Liou, D. Z., Backhus, L. M., Berry, M. F., Shrager, J. B. 2020; 12 (5): 2161?71


    Asian and Caucasian patients with lung cancer have been compared in several database studies, with conflicting findings regarding survival. However, these studies did not include proportion of ground-glass opacity or mutational status in their analyses. Asian patients commonly develop sub-solid lung adenocarcinomas that harbor EGFR mutations, which have a better prognosis. We hypothesized that among patients undergoing surgery for sub-solid lung adenocarcinomas, Asian patients have better survival compared to Caucasian patients.We identified Asian and Caucasian patients who underwent surgical resection for a sub-solid lung adenocarcinoma from 2002 to 2015 at our institution. Sub-solid was defined as ?10% ground-glass opacity on preoperative CT scan or ?10% lepidic component on surgical pathology. Time-to-event multivariable analysis was performed to determine which characteristics were associated with recurrence and survival.Two hundred twenty-four patients were included with median follow up 48 months. Asian patients were more likely to be never smokers (76.3% vs. 29.0%, P<0.01) and have an EGFR mutation (69.4% vs. 25.6% of those tested, P<0.01), while Caucasian patients were more likely to have a KRAS mutation (23.5% vs. 4.9% of those tested, P<0.01). There was a trend towards Asian patients having a higher proportion of ground-glass opacity (38.8% vs. 30.5%, P=0.11). Time-to-event multivariable analysis showed that higher proportion of ground-glass opacity was significantly associated with better recurrence-free survival (HR 0.76 per 20% increase, P=0.02). However, mutational status and race did not have a significant impact on recurrence-free or overall survival.Asian and Caucasian patients with sub-solid lung adenocarcinoma have different tumor biology, but recurrence-free and overall survival after surgical resection is similar.

    View details for DOI 10.21037/jtd.2020.04.37

    View details for PubMedID 32642121

    View details for PubMedCentralID PMC7330405

  • Does size matter? A national analysis of the utility of induction therapy for large thymomas. Journal of thoracic disease Liou, D. Z., Ramakrishnan, D., Lui, N. S., Shrager, J. B., Backhus, L. M., Berry, M. F. 2020; 12 (4): 1329?41


    Tumor size of 8 cm or greater is a risk factor for recurrence after thymoma resection, but the role of induction therapy for large thymomas is not well defined. This study tested the hypothesis that induction therapy for thymomas 8 cm and larger improves survival.The use of induction therapy for patients treated with surgical resection for Masaoka stage I-III thymomas in the National Cancer Database between 2006-2013 was evaluated using logistic regression, Kaplan-Meier analysis, and Cox-proportional hazards methods.Of the 1,849 patients who met inclusion criteria, 582 (31.5%) had tumors ?8 cm. Five-year survival was worse in patients with tumors ?8 cm compared to smaller tumors [84.6% (95% CI: 81.2-88.1%) vs. 89.4% (95% CI: 87.2-91.7%), P=0.003]. Induction therapy was used in 166 (9.0%) patients overall and was more likely in patients with tumors ?8 cm [adjusted odds ratio (AOR) 3.257, P<0.001]. Induction therapy was not associated with improved survival in the subset of patients with tumors ?8 cm in either univariate [80.9% (95% CI: 72.6-90.1%) vs. 85.4% (95% CI: 81.8-89.3%), P=0.27] or multivariable analysis [hazard ratio (HR) 1.54, P=0.10]. Increasing age (HR 1.56/decade, P<0.001) and Masaoka stage III (HR 1.76, P=0.04) were associated with worse survival in patients with tumors ?8 cm.Survival after thymoma resection is worse for tumors 8 cm or larger compared to smaller tumors and is not improved by induction therapy. Size alone should not be a criterion for using induction therapy prior to thymoma resection.

    View details for DOI 10.21037/jtd.2020.02.63

    View details for PubMedID 32395270

    View details for PubMedCentralID PMC7212162

  • Paradoxical Motion on Sniff Test Predicts Greater Improvement Following Diaphragm Plication. The Annals of thoracic surgery Patel, D. C., Berry, M. F., Bhandari, P., Backhus, L. M., Raees, S., Trope, W., Nash, A., Lui, N. S., Liou, D. Z., Shrager, J. B. 2020


    Diaphragm plication (DP) improves pulmonary function and quality of life for those with diaphragm paralysis/dysfunction. It is unknown whether differing degrees of diaphragm dysfunction as measured by sniff testing impact results after plication.Patients who underwent minimally invasive DP from 2008-2019 were dichotomized based on sniff test results: paradoxical motion (PM) vs. no paradoxical motion (NPM) - the latter including normal/decreased/no motion. Preoperative and postoperative pulmonary function testing (PFT) after DP was compared between the two groups. The impact of diaphragm height index (DHI), a measure of diaphragm elevation, was also assessed.Twenty-six patients underwent preoperative sniff testing, DP, and postoperative PFTs. Including all patients, DP resulted in a 17.8 ± 5.5% (p<0.001) improvement in forced expiratory volume at 1 second (FEV1), a 14.4 ± 5.3% (p<0.001) improvement in forced vital capacity (FVC), and a 4.7 ± 4.6% (p=0.539) improvement in diffusing capacity (DLCO). There were greater improvements in the PM group (n=16) vs. NPM group (n=10) for FEV1 (27.2 ± 6.0% vs. 3.9 ± 6.2%, p=0.017) and FVC (28.1 ± 5.3% vs. -0.5 ± 3.3%, p=0.001). There was no difference in ?DLCO between groups. There were no differences between patients with PM and NPM in postoperative course/complications. No value for DHI predicted improvement in PFTs following DP.Patients with PM on sniff test have dramatically greater objective improvements in pulmonary function following plication than those without PM. Most patients without PM do not demonstrate improvement in standard PFTs. Improvements in dyspnea require additional study.

    View details for DOI 10.1016/j.athoracsur.2020.07.049

    View details for PubMedID 33031777

  • A National Analysis of Treatment Patterns and Outcomes for Patients 80 Years or Older with Esophageal Cancer. Seminars in thoracic and cardiovascular surgery Yang, C. J., Wang, Y., Raman, V., Patel, D., Lui, N., Backhus, L., Shrager, J., Berry, M. F., Liou, D. 2020


    The purpose of this study was to evaluate practice patterns and outcomes for patients 80 years or older with esophageal cancer using a nationwide cancer database. Practice patterns for patients 80 years or older with stage I-IV esophageal cancer in the National Cancer Database from 2004-2014 were analyzed. Overall survival associated with different treatment strategies were evaluated using the Kaplan-Meier method and multivariable Cox proportional hazard models. In the study period, 40.5% and 46.2% of patients with stage I adenocarcinoma and squamous cell carcinoma, respectively, did not receive any treatment at all. Less than 11% (196/1,865) of patients with stage I-II disease underwent esophagectomy, even though surgery was associated with a better 5-year survival compared to no treatment (stage I: 47.3% [95% CI 36.2%-57.6%] vs 14.9% [95% CI: 11.2%-19.1%]; stage II: 29.3% [95% CI 20.1%-39.1%] vs 1.2% [95% CI: 0.1%-5.5%]). Of the 1,596 (37.7%) patients with stage III disease who received curative-intent treatment (surgery or chemoradiation), the 5-year survival was significantly better than that of patients who received no treatment (11.9% [95% CI: 9.7%-14.4% vs 4.3% [95% CI: 1.9%-8.3%]). In this national analysis of patients 80 years and older with esophageal cancer, over 40% of patients with stage I disease did not receive treatment. Patients with stage I-III disease had better survival and risks and benefits of treatment for elderly patients should be discussed in a multidisciplinary setting.

    View details for DOI 10.1053/j.semtcvs.2020.09.004

    View details for PubMedID 32977014

  • National Evaluation of Short-Term and Intermediate-Term Readmission after Esophagectomy Yang, C. J., Wang, Y., He, H., Liou, D., Lui, N., Berry, M. F., Shrager, J., Backhus, L. ELSEVIER SCIENCE INC. 2019: S279?S280
  • Management of Benign Esophageal Perforation in the National Inpatient Sample Lui, N., Bhandari, P., Backhus, L., Liou, D., Shrager, J., Berry, M. F. ELSEVIER SCIENCE INC. 2019: E209
  • The influence of hormone replacement therapy on lung cancer incidence and mortality. The Journal of thoracic and cardiovascular surgery Titan, A. L., He, H., Lui, N., Liou, D., Berry, M., Shrager, J. B., Backhus, L. M. 2019


    Data regarding the effects of hormone replacement therapy (HRT) on non-small cell lung cancer (NSCLC) are mixed. We hypothesized HRT would have a protective benefit with reduced NSCLC incidence among women in a large, prospective cohort.We used data from the multicenter randomized Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (1993-2001). Participants were women aged 50 to 74 years followed prospectively for up to 13 years for cancer screening. The influence of HRT on the primary outcome of NSCLC incidence and secondary outcomes of all-cause and disease-specific mortality were assessed with Kaplan-Meier analysis and Cox proportional hazard models adjusting for covariates.In the overall cohort of 75,587 women, 1147 women developed NSCLC after a median follow-up of 11.5 years. HRT use was characterized as 49.4% current users, 17.0% former users, and 33.6% never users. Increased age, smoking, comorbidities, and family history were associated with increased risk of NSCLC. On multivariable analysis, current HRT use was associated with reduced risk of NSCLC compared with never users (hazard ratio, 0.80; 95% confidence interval, 0.70-0.93; P = .009). HRT or oral contraception use was not associated with significant differences in all-cause mortality or disease-specific mortality.These data represent among the largest prospective cohorts suggesting HRT use may have a protective effect on the development of NSCLC among women; the physiological basis of this effect merits further study; however, the results may influence discussion surrounding HRT use in women.

    View details for DOI 10.1016/j.jtcvs.2019.10.070

    View details for PubMedID 31866083

  • A national analysis of open versus minimally invasive thymectomy for stage I to III thymoma. The Journal of thoracic and cardiovascular surgery Yang, C. J., Hurd, J., Shah, S. A., Liou, D., Wang, H., Backhus, L. M., Lui, N. S., D'Amico, T. A., Shrager, J. B., Berry, M. F. 2019


    The oncologic efficacy of minimally invasive thymectomy for thymoma is not well characterized. We compared short-term outcomes and overall survival between open and minimally invasive (video-assisted thoracoscopic and robotic) approaches using the National Cancer Data Base.Perioperative outcomes and survival of patients who underwent open versus minimally invasive thymectomy for clinical stage I to III thymoma from 2010 to 2014 in the National Cancer Data Base were evaluated using multivariable Cox proportional hazards modeling and propensity score-matched analysis. Predictors of minimally invasive use were evaluated using multivariable logistic regression. Outcomes of surgical approach were evaluated using an intent-to-treat analysis.Of the 1223 thymectomies that were evaluated, 317 (26%) were performed minimally invasively (141 video-assisted thoracoscopic and 176 robotic). The minimally invasive group had a shorter median length of stay when compared with the open group (3 [2-4] days vs 4 [3-6] days, P < .001). In a propensity score-matched analysis of 185 open and 185 minimally invasive (video-assisted thoracoscopic + robotic) thymectomy, the minimally invasive group continued to have a shorter median length of stay (3 vs 4 days, P < .01) but did not have significant differences in margin positivity (P = .84), 30-day readmission (P = .28), 30-day mortality (P = .60), and 5-year survival (89.4% vs 81.6%, P = .20) when compared with the open group.In this national analysis, minimally invasive thymectomy was associated with shorter length of stay and was not associated with increased margin positivity, perioperative mortality, 30-day readmission rate, or reduced overall survival when compared with open thymectomy.

    View details for DOI 10.1016/j.jtcvs.2019.11.114

    View details for PubMedID 32245668

  • Induction therapy for locally advanced distal esophageal adenocarcinoma: Is radiation Always necessary? Liou, D. Z., Backhus, L. M., Lui, N. S., Shrager, J. B., Berry, M. F. MOSBY-ELSEVIER. 2018: 2697?2705
  • Induction therapy for locally advanced distal esophageal adenocarcinoma: Is radiation Always necessary? The Journal of thoracic and cardiovascular surgery Liou, D. Z., Backhus, L. M., Lui, N. S., Shrager, J. B., Berry, M. F. 2018


    OBJECTIVE: To compare outcomes between induction chemotherapy alone (ICA) and induction chemoradiation (ICR) in patients with locally advanced distal esophageal adenocarcinoma.METHODS: Patients in the National Cancer Database treated with ICA or ICR followed by esophagectomy between 2006 and 2012 for cT1-3N1M0 or T3N0M0 adenocarcinoma of the distal esophagus were compared using logistic regression, Kaplan-Meier analysis, and Cox proportional hazards methods.RESULTS: The study group included 4763 patients, of whom 4323 patients (90.8%) received ICR and 440 patients (9.2%) received ICA. There were no differences in age, sex, race, Charlson Comorbidity Index, treatment facility type, clinical T or N status between the 2 groups. Tumor size ?5cm (odds ratio, 1.46; P=.006) was the only factor that predicted ICR use. Higher rates of T downstaging (39.7% vs 33.4%; P=.012), N downstaging (32.0% vs 23.4%; P<.001), and complete pathologic response (13.1% vs 5.9%; P<.001) occurred in ICR patients. Positive margins were seen more often in ICA patients (9.6% vs 5.5%; P=.001), but there was no difference in 5-year survival (ICR 35.9% vs ICA 37.2%; P=.33), and ICR was not associated with survival in multivariable analysis (hazard ratio=1.04; P=.61).CONCLUSIONS: ICR for locally advanced distal esophageal adenocarcinoma is associated with a better local treatment effect, but not improved survival compared with ICA, which suggests that radiation can be used selectively in this clinical situation.

    View details for PubMedID 29530567

  • Thoracic Surgery Considerations in Obese Patients THORACIC SURGERY CLINICS Liou, D. Z., Berry, M. F. 2018; 28 (1): 27-+


    The obesity epidemic in the United States has increased greatly over the past several decades, and thoracic surgeons are likely to see obese patients routinely in their practices. Obesity has direct deleterious health effects such as metabolic disorder and cardiovascular disease, and is associated with many cancers. Obese patients who need thoracic surgery pose practical challenges to many of the routine elements in perioperative management. Preoperative assessment of obesity-related comorbid conditions and risk stratification for surgery, thorough intraoperative planning for anesthesia and surgery, and postoperative strategies to optimize pulmonary hygiene and mobility minimize the risk of adverse outcomes.

    View details for PubMedID 29150035

  • Predictors of Failure to Rescue After Esophagectomy. Ann Thorac Surg. Liou, D. Z., Serna-Gallegos, D., Mirocha, J., Bairamian, V., Alban, R. F., Soukiasian, H. J. 2018; 105 (3): 871-878
  • Survival Difference in Patients with Malignant Pleural Effusions Treated with Pleural Catheter or Talc Pleurodesis. The American surgeon Liou, D. Z., Serna-Gallegos, D., Chan, J. L., Borgella, J., Akhmerov, S., Soukiasian, H. J. 2016; 82 (10): 995?99


    Malignant pleural effusions (MPE) are commonly managed with either pleural catheter (PC) or talc pleurodesis (TP). The aim of this study was to compare survival in MPE patients treated with either PC or TP. A retrospective review of our cancer center database was performed. Patients with metastatic cancer and MPE were analyzed. Demographic and clinical data were tabulated and compared. A total of 238 patients with MPE treated by either PC or TP were included. Of these, 79 patients comprised the PC group and 159 the TP group. PC had a higher incidence of advanced disease (stage III or IV) at initial diagnosis compared with TP (70.9% vs 57.2%, P = 0.05). TP had a longer postprocedure length of stay compared with PC (7.1 vs 5.0 days, P = 0.02); however, overall length of stay was similar (9.7 vs 11.1 days, P = 0.34). Readmissions were significantly lower in TP (11.9% vs 22.8%, P = 0.04). Mean survival was higher in TP compared with PC (18.7 vs 4.1 months, P < 0.001). Patients with metastatic cancer and MPE treated with TP had significantly higher survival compared with PC. This is likely related to a greater disease burden in PC, as 70 per cent of patients in this group had stage III or IV disease on initial presentation.

    View details for PubMedID 27779992

  • Recovery of Native Renal Function in Patients with Hepatorenal Syndrome Following Combined Liver and Kidney Transplant with Mercaptoacetyltriglycine-3 Renogram: Developing a Methodology World journal of nuclear medicine Aparici, C. M., Bains, S. N., Qian, L., Liou, D., Wojciechowski, D., Werner, J., Khan, S., Kroll, C., Sandhu, M., Nguyen, N., Hawkins, R. 2016; 15 (1)
  • Insulin-dependent diabetes and serious trauma. European journal of trauma and emergency surgery : official publication of the European Trauma Society Liou, D. Z., Singer, M. B., Barmparas, G., Harada, M. Y., Mirocha, J., Bukur, M., Salim, A., Ley, E. J. 2016; 42 (4): 491?96


    Trauma patients with diabetes mellitus (DM) represent a unique population as the acute injury and the underlying disease may both cause hyperglycemia that leads to poor outcomes. We investigated how insulin-dependent DM (IDDM) and noninsulin-dependent DM (NIDDM) impact mortality after serious trauma without brain injury.The National Trauma Data Bank (NTDB) version 7.0 was queried for all patients with moderate to severe traumatic injury [injury severity score (ISS) >9]. Patients were excluded if missing data, age <10 years, severe brain injury [head abbreviated injury scale (AIS) >3], dead on arrival or any AIS = 6. Logistic regression modeled the association between DM and mortality as well as IDDM, NIDDM and mortality.Overall 166,103 trauma patients without brain injury were analyzed. Mortality was 7.6 and 4.4 % in patients with and without DM, respectively (p < 0.01). Mortality was 9.9 % for patients with IDDM and 6.7 % for NIDDM (p < 0.01). The increased mortality associated with DM was only significantly higher for DM patients in their forties (5.6 vs. 3.3 %, p < 0.01). Regression analyses demonstrated that DM (AOR 1.14, p = 0.04) and IDDM (AOR 1.46, p < 0.01) were predictors of mortality compared to no DM, but NIDDM was not (AOR 1.02, p = 0.83).While DM was a predictor for higher mortality after serious trauma, this increase was only observed in IDDM and not NIDDM. Our findings suggest IDDM patients who present after serious trauma are unique and attention to their hyperglycemia and related insulin therapy may play a critical role in recovery.

    View details for DOI 10.1007/s00068-015-0561-5

    View details for PubMedID 26253885

  • Thromboelastography After Murine TBI and Implications of Beta-Adrenergic Receptor Knockout. Neurocritical care Liou, D. Z., Ko, A., Volod, O., Barmparas, G., Harada, M. Y., Martin, M. J., Salim, A., Dhillon, N., Thomsen, G. M., Ley, E. J. 2016; 25 (1): 145?52


    The source of coagulopathy in traumatic brain injury (TBI) is multifactorial and may include adrenergic stimulation. The aim of this study was to assess coagulopathy after TBI using thromboelastography (TEG), and to investigate the implications of ?-adrenergic receptor knockout.Adult male wild type c57/bl6 (WT) and ?1/?2-adrenergic receptor knockout (BKO) mice were assigned to either TBI (WT-TBI, BKO-TBI) or sham injury (WT-sham, BKO-sham). Mice assigned to TBI were subject to controlled cortical impact (CCI). At 24 h post-injury, whole blood samples were obtained and taken immediately for TEG.At 24 h after injury, a trend toward increased fibrinolysis was seen in WT-TBI compared to WT-sham although this did not reach significance (EPL 8.1 vs. 0 %, p = 0.18). No differences were noted in fibrinolysis in BKO-TBI compared to BKO-sham (LY30 2.6 vs. 2.5 %, p = 0.61; EPL 3.4 vs. 2.9 %, p = 0.61). In addition BKO-TBI demonstrated increased clot strength compared to BKO-sham (MA 76.6 vs. 68.6, p = 0.03; G 18.2 vs. 11.3, p = 0.03).In a mouse TBI model, WT mice sustaining TBI demonstrated a trend toward increased fibrinolysis at 24 h after injury while BKO mice did not. These findings suggest ?-blockade may attenuate the coagulopathy of TBI and minimize progression of intracranial hemorrhage by reducing fibrinolysis and increasing clot strength.

    View details for DOI 10.1007/s12028-015-0223-9

    View details for PubMedID 26666545

  • Bicycle trauma and alcohol intoxication INTERNATIONAL JOURNAL OF SURGERY Harada, M. Y., Gangi, A., Ko, A., Liou, D. Z., Barmparas, G., Li, T., Hotz, H., Stewart, D., Ley, E. J. 2015; 24: 14?19


    As bicycling has become more popular, admissions after bicycle trauma are on the rise. The impact of alcohol use on bicycle trauma has not been well studied. The aim of this study was to examine the effect of alcohol intoxication on injury burden following bicycle-related crashes.A retrospective review of trauma patients presenting to a Level I trauma center after bicycle-related crashes from January 2002 to December 2011 was conducted. Demographics, injury data, alcohol intoxication, helmet use, and clinical outcomes were reviewed. Blood alcohol level (BAL) was considered positive if >0.01 g/dL. Variables were compared between patients based on BAL: negative, 0.01-0.16 g/dL, and >0.16 g/dL.During the 10 year study period, 563 patients met study criteria; mean age was 33.5 ± 16.5 years, 87% were male, and mortality was 1%. On average, bicycle crashes increased over the study period by 4.4 collisions per year. BAL was tested in 211 (38%) patients. Mean BAL was 0.24 g/dL, with 37% of these patients being intoxicated (BAL ? 0.010 g/dL). Intoxicated patients were significantly less likely to wear a helmet (4.7% vs. 22.2%, p = 0.002) and to be involved in motor vehicle crash (59.0% vs. 81.2%, p < 0.001). There was no difference noted in the injury burden including ISS ? 16 (14.3% vs. 19.5%, p = 0.335) and AIS Head ? 3 (17.9% vs. 21.8%, p = 0.502). When comparing patients according to their BAL, there was a decreasing risk of motor vehicle collision with increasing BAL (81.2% for undetected, 76.5% for BAL ? 0.16 g/dL and 54.1% for BAL >0.16 g/dL, p < 0.001). The risk for a severe head injury (AIS Head ? 3) was significantly lower in helmeted patients (8.4% vs. 15.8%, p = 0.035).The incidence of bicycle-related crashes is increasing and more than a third of patients tested for alcohol after bicycle-related crashes are found to be intoxicated. The injury burden in intoxicated patients, including head trauma, was not different compared to non-intoxicated patients. In addition, the risk for a collision with a motor vehicle was significantly lower. Nonetheless, these patients rarely utilize a helmet. The findings from this study can be used for the development and implementation of preventive strategies to minimize the injury burden associated with bicycle crashes and intoxicated cyclists.

    View details for DOI 10.1016/j.ijsu.2015.10.013

    View details for Web of Science ID 000366662600004

    View details for PubMedID 26493212

  • Work Hour Reduction: Still Room for Improvement. Journal of surgical education Liou, D. Z., Barmparas, G., Harada, M., Chung, R., Melo, N., Ley, E. J., Salim, A., Bukur, M. 2015; 73 (1): 173?79


    The effect of resident duty hour restrictions continues to yield conflicting results on patient outcomes. Failure to rescue (FTR), or death after a major complication, has become a topic of increasing quality assessment. The aim of this study is to evaluate the effect of duty hour restrictions on in-hospital mortality, complication rates, and FTR in patients suffering traumatic injuries.Data from the National Trauma Data Bank (NTDB) were retrospectively reviewed (Research Data Set 2007-2008 and version 7.2). Patients admitted to Level I or II teaching institutions were dichotomized into pre-duty hour restriction (2002-2003) and post-duty hour restriction (2007-2008) time periods. Patients who had nonsurvivable injuries (any region Abbreviated Injury Scale score = 6), died within 48 hours, or had missing data were excluded. Multivariate logistic regression was used to adjust for differences in patient characteristics and derive adjusted outcomes.Level I and II teaching institutions in the NTDB.All patients with trauma admitted to a Level I or II teaching institution between January 1, 2002 and June 30, 2003 and between January 1, 2007 and December 31, 2008.Although overall adjusted in-hospital mortality was decreased (adjusted odds ratio [AOR] = 0.7, p < 0.001) in the post-duty hour restriction era, overall complications (AOR = 2.0, p < 0.001) and FTR (AOR = 2.0, p < 0.001) were significantly higher.Although there may be some benefit to resident duty hour restrictions, there is still room for improvement in patient care. Individual institutions should carefully review their own complication data to identify preventable systems issues, such as poor handoffs, and opportunities for increased resident supervision.

    View details for DOI 10.1016/j.jsurg.2015.07.016

    View details for PubMedID 26319104

  • Prospective derivation of a clinical decision rule for thoracolumbar spine evaluation after blunt trauma: An American Association for the Surgery of Trauma Multi-Institutional Trials Group Study. The journal of trauma and acute care surgery Inaba, K., Nosanov, L., Menaker, J., Bosarge, P., Williams, L., Turay, D., Cachecho, R., de Moya, M., Bukur, M., Carl, J., Kobayashi, L., Kaminski, S., Beekley, A., Gomez, M., Skiada, D. 2015; 78 (3): 459?65; discussion 465?67


    Unlike the cervical spine (C-spine), where National Emergency X-Radiography Utilization Study (NEXUS) and the Canadian C-spine Rules can be used, evidence-based thoracolumbar spine (TL-spine) clearance guidelines do not exist. The aim of this study was to develop a clinical decision rule for evaluating the TL-spine after injury.Adult (?15 years) blunt trauma patients were prospectively enrolled at 13 US trauma centers (January 2012 to January 2014). Exclusion criteria included the following: C-spine injury with neurologic deficit, preexisting paraplegia/tetraplegia, and unevaluable examination. Remaining evaluable patients underwent TL-spine imaging and were followed up to discharge. The primary end point was a clinically significant TL-spine injury requiring TL-spine orthoses or surgical stabilization. Regression techniques were used to develop a clinical decision rule. Decision rule performance in identifying clinically significant fractures was tested.Of 12,479 patients screened, 3,065 (24.6%) met inclusion criteria (mean [SD] age, 43.5 [19.8] years [range, 15-103 years]; male sex, 66.3%; mean [SD] Injury Severity Score [ISS], 8.8 [7.5]). The majority underwent computed tomography (93.3%), 6.3% only plain films, and 0.2% magnetic resonance imaging exclusively. TL-spine injury was identified in 499 patients (16.3%), of which 264 (8.6%) were clinically significant (29.2% surgery, 70.8% TL-spine orthosis). The majority was AO Type A1 282 (56.5%), followed by 67 (13.4%) A3, 43 (8.6%) B2, and 32 (6.4%) A4 injuries. The predictive ability of clinical examination (pain, midline tenderness, deformity, neurologic deficit), age, and mechanism was examined; positive clinical examination finding resulted in a sensitivity of 78.4% and a specificity of 72.9%. Addition of age of 60 years or older and high-risk mechanism (fall, crush, motor vehicle crash with ejection/rollover, unenclosed vehicle crash, auto vs. pedestrian) increased sensitivity to 98.9% with specificity of 29.0% for clinically significant injuries and 100.0% sensitivity and 27.3% specificity for injuries requiring surgery.Clinical examination alone is insufficient for determining the need for imaging in evaluable patients at risk of TL-spine injury. Addition of age and high-risk mechanism results in a clinical decision-making rule with a sensitivity of 98.9% for clinically significant injuries.Diagnostic test, level III.

    View details for DOI 10.1097/TA.0000000000000560

    View details for PubMedID 25710414

  • Impact of body mass index on injury in abdominal stab wounds: implications for management. The Journal of surgical research Bloom, M. B., Ley, E. J., Liou, D. Z., Tran, T., Chung, R., Melo, N., Margulies, D. R. 2015; 197 (1): 162?66


    Although it is assumed that obese patients are naturally protected against anterior abdominal stab wounds, the relationship has never been formally studied. We sought to examine the impact of body mass index (BMI) on severity of sustained injury, need for operation, and patient outcomes.We conducted a review of all patients presenting with abdominal stab wounds at an urban level I trauma center from January 2000-December 2012. Patients were divided into groups based on their BMI (<18.5, 18.5-29.9, 30-35, and >35). Data abstracted included baseline demographics, physiologic data, and characterization of whether the stab wound had violated the peritoneum, caused intra-abdominal injury, or required an operation that was therapeutic. The one-sided Cochran-Armitage trend test was used for significance testing of the protective effect.Of 281 patients with abdominal stab wounds, 249 had complete data for evaluation. Chest and abdomen abbreviated injury scale trends decreased with increasing BMI, as did overall injury severity score, the percent of patients severely injured (injury severity score ? 25), and length of intensive care unit stay. Rates of peritoneal violation (100%, 84%, 77%, and 74%; P = 0.077), visceral injury (83%, 56%, 50%, and 30%; P = 0.022), and injury requiring a therapeutic operation (67%, 45%, 40%, and 20%; P = 0.034) all decreased with increasing BMI. Patients in the thinnest group required an operation three times more often than those in the most obese.Increased BMI protects patients with abdominal stab wounds and is associated with lower incidence of severe injury and need for operation. Heavier patients may be more suitable to observation and serial examinations, whereas very thin patients are more likely to require an operation and be critically injured.

    View details for DOI 10.1016/j.jss.2015.03.052

    View details for PubMedID 25891677

  • Alcohol intoxication may be associated with reduced truncal injuries after blunt trauma. American journal of surgery Liou, D. Z., Barmparas, G., Zaw, A., Bukur, M., Salim, A., Ley, E. J. 2015; 210 (1): 87?92


    Prior studies suggest that positive blood alcohol concentration (BAC) is associated with lower mortality after motor vehicle collisions (MVCs). We investigated the relationship between increasing BAC and mortality after MVC.A retrospective review of the Los Angeles County trauma database from January 2003 to December 2008 was performed. MVC patients greater than or equal to 16 years of age with admission BAC were considered. Patients were stratified by BAC as follows: BAC0 (<.01), BAC1 (.01 to .08), BAC2 (.09 to .16), BAC3 (.17 to .24), BAC4 (.25 to .32), and BAC5 (>.32). Logistic regression was used to determine predictors of mortality.A total of 12,540 patients were included. Overall mortality rate was 2.2%. Mortality was lowest in BAC3 (1.6%) and BAC4 (1.3%), although the difference among all groups was not statistically significant (P = .07). Decreased rates of Injury Severity Score greater than or equal to 16 were noted with increasing BAC, which was largely because of reduced chest and abdomen/pelvis Abbreviated Injury Scale. Adjusted mortality was lower in BAC3 and BAC4 (both adjusted odds ratio .4, P < .001).A protective effect of alcohol after MVC may be related to decreased truncal injury burden rather than protection after head injury.

    View details for DOI 10.1016/j.amjsurg.2014.11.015

    View details for PubMedID 25921093

  • Defining early trauma-induced coagulopathy using thromboelastography. The American surgeon Liou, D. Z., Shafi, H., Bloom, M. B., Chung, R., Ley, E. J., Salim, A., Tcherniantchouk, O., Margulies, D. R. 2014; 80 (10): 994?98


    Early trauma-induced coagulopathy (ETIC) is abnormal coagulation detected on presentation, but a clear description is lacking. We used thromboelastography (TEG) to characterize ETIC. Data were prospectively collected on high-acuity trauma activations at an urban Level I trauma center between July 2012 and May 2013. Patients with admission TEG before any blood transfusion were stratified by Injury Severity Score (ISS): mild (less than 16), moderate (16 to 24), severe (25 or greater). TEG parameters were compared between groups. ETIC was defined as any abnormality detected on TEG. Fifty-two patients were included; mean age was 49 years and mean time to the emergency department was 26 minutes. Mean ISS for the cohort was 17 with 28 patients in mild, eight in moderate, and 16 in severe. Glasgow Coma Score was lower and head Abbreviated Injury Scale was higher in severe (P < 0.001). Forty-three (83%) patients had an abnormal TEG. Shortened reaction (R) time was noted in 42 patients. There were no differences in any TEG parameters between the injury severity groups. Hyperfibrinolysis was detected in four (8%) patients. ETIC was present in over 80 per cent of high-acuity trauma activations irrespective of injury severity and characterized primarily by shortened R time, indicating ETIC is initially described by a hypercoagulable state as a result of thrombin generation.

    View details for PubMedID 25264646

  • Breast-conserving therapy for triple-negative breast cancer. JAMA surgery Gangi, A., Chung, A., Mirocha, J., Liou, D. Z., Leong, T., Giuliano, A. E. 2014; 149 (3): 252?58


    The aggressive triple-negative phenotype of breast cancer (negative for estrogen and progesterone receptors and v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2 [ERBB2] [formerly human epidermal growth factor receptor 2 (HER2)]) is considered by some investigators to be a relative contraindication to breast-conserving therapy.To compare outcomes of breast-conserving therapy for patients with triple-negative breast cancer (TNBC) with those of patients with the luminal A, luminal B, and ERBB2 subtypes.Prospective database review at an academic tertiary medical center with a designated breast cancer center. We included 1851 consecutive patients ages 29 to 85 years with stages I to III invasive breast cancer who underwent breast-conserving therapy at a single institution from January 1, 2000, through May 30, 2012. Of these patients, 234 (12.6%) had TNBC; 1341 (72.4%), luminal A subtype; 212 (11.5%), luminal B subtype; and 64 (3.5%), ERBB2-enriched subtype.Breast-conserving therapy.The primary outcome measure was local recurrence (LR). Secondary outcome measures included regional recurrence, distant recurrence, and overall survival. RESULTS Triple-negative breast cancer was associated with younger age at diagnosis (56 vs 60 years; P =?.001), larger tumors (2.1 vs 1.8 cm; P

    View details for DOI 10.1001/jamasurg.2013.3037

    View details for PubMedID 24382582

  • To swab or not to swab? A prospective analysis of 341 SICU VRE screens. The journal of trauma and acute care surgery Liou, D. Z., Barmparas, G., Ley, E. J., Salim, A., Tareen, A., Casas, T., Lee, D., Bukur, M. 2014; 76 (5): 1192?1200


    Vancomycin-resistant Enterococcus (VRE) screening is routine practice in many intensive care units despite the question of its clinical significance. The value of VRE screening at predicting subsequent VRE or other hospital-acquired infection (HAI) is unknown. The purpose of this investigation was to examine the rate of subsequent VRE HAI in patients undergoing VRE screening.This study was conducted in a 24-bed surgical intensive care unit (SICU) at a Level I trauma center. Patients admitted to the SICU between February and August 2011 who had rectal swab for VRE screening within 72 hours were followed prospectively for the development of VRE and other HAIs. Demographics, clinical characteristics, and infection rates were compared between VRE-positive and VRE-negative patients. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of VRE screening for predicting subsequent VRE HAI were calculated.A total of 341 patients had VRE screening within 72 hours of SICU admission, with 32 VRE-positive (9%) and 309 VRE-negative (91%) patients. VRE-positive patients had a higher incidence of any HAI (78% vs. 35%, p < 0.001). Eight VRE-positive patients (25%) developed VRE HAI compared with only 3 VRE-negative patients (1%) (p < 0.001). VRE screening had a 73% sensitivity, 93% specificity, 25% PPV, and 99% NPV for determining subsequent VRE HAI.VRE colonization was present in 9% of SICU patients at admission. Negative VRE screen result had a high specificity and NPV for the development of subsequent VRE HAI. Empiric treatment of VRE infection may be unnecessary in VRE-negative patients.Prognostic/epidemiologic study, level III. Therapeutic study, level IV.

    View details for DOI 10.1097/TA.0000000000000203

    View details for PubMedID 24747448

  • Impact of positive fluid balance on critically ill surgical patients: a prospective observational study. Journal of critical care Barmparas, G., Liou, D., Lee, D., Fierro, N., Bloom, M., Ley, E., Salim, A., Bukur, M. 2014; 29 (6): 936?41


    The purpose of this study is to determine the effect of postoperative fluid balance (FB) on subsequent outcomes in acute care surgery (ACS) patients admitted to the surgical intensive care unit (ICU).Acute care surgery patients admitted to the surgical ICU from 06/2012 to 01/2013 were followed up prospectively. Patients were stratified by FB into FB-positive (+) and FB-negative (-) groups by surgical ICU day 5 or day of discharge from the surgical ICU.A total of 144 ACS patients met inclusion criteria. Although there was no statistically significant difference in crude mortality (11% for FB [-] vs 15.5% for FB [+]; P=.422], after adjusting for confounding factors, achieving an FB (-) status by day 5 during the surgical ICU stay was associated with an almost 70% survival benefit (adjusted odds ratio [95% confidence interval], 0.31 [0.13, 0.76]; P=.010). In addition, achieving a fluid negative status by day 1 provided a protective effect for both overall and infectious complications (adjusted odds ratio [95% confidence interval], 0.63 [0.45, 0.88]; P=.006 and 0.64 [0.46, 0.90]; P=.010, respectively).In a cohort of critically ill ACS patients, achieving FB (-) status early during surgical ICU admission was associated with a nearly 70% reduction in the risk for mortality.

    View details for DOI 10.1016/j.jcrc.2014.06.023

    View details for PubMedID 25085510

  • Prehospital hypertension is predictive of traumatic brain injury and is associated with higher mortality. The journal of trauma and acute care surgery Barmparas, G., Liou, D. Z., Lamb, A. W., Gangi, A., Chin, M., Ley, E. J., Salim, A., Bukur, M. 2014; 77 (4): 592?98


    The purpose of the current study was to investigate the effect of early adrenergic hyperactivity as manifested by prehospital (emergency medical service [EMS]) hypertension on outcomes of traumatic brain injury (TBI) patients and to develop a prognostic model of the presence of TBI based on EMS and admission (emergency department [ED]) hypertension.This study is a retrospective review of the 2007 to 2008 National Trauma Data Bank including blunt trauma patients 15 years or older with available EMS and ED vital signs. Patients with head Abbreviated Injury Scale (AIS) score of 3 or greater were selected, and mortality was examined within EMS systolic blood pressure (SBP) groups: lower than 100 mm Hg, 110 mm Hg to 150 mm Hg, 160 mm Hg to 180 mm Hg, and 190 mm Hg to 230 mm Hg. A forward logistic regression model including the EMS heart rate, EMS SBP, EMS Glasgow Coma Scale (GCS) score, ED heart rate, and ED SBP was used to identify predictors of a TBI in patients with ED GCS score of less than or equal to 8, 9 to 13, and 14 to 15.For the 5-year study period, 315,242 patients met inclusion criteria. Adjusted odds for mortality increased in a stepwise fashion with increasing EMS SBP compared with patients with normal EMS SBP (adjusted odds ratio [95% confidence interval], 1.33 [1.22-1.44], p < 0.001, for EMS SBP of 160-180 mm Hg and 1.97 [1.76-2.21], p < 0.001, for EMS SBP of 190-230 mm Hg). A 7-point scoring system was developed for each ED GCS score group to predict the presence of a TBI. EMS SBP of greater than 150 mm Hg and ED SBP of greater than 150 mm Hg were both predictive of the presence of a TBI in patients with ED GCS score of 8 or less and in patients with ED GCS score of 9 to 13 or 14 to 15, respectively.Prehospital hypertension in TBI is associated with a higher mortality risk. Early hypertension in the prehospital setting and at admission can be used to predict the presence of such injuries. These findings may have important early triage and treatment implications.Prognostic study, level III.

    View details for DOI 10.1097/TA.0000000000000382

    View details for PubMedID 25250599

  • Gastric Adjustable Band as a Retained Foreign Object: A Case Report BARIATRIC SURGICAL PRACTICE AND PATIENT CARE Felder, S. I., Liou, D. Z., Gangi, A. 2013; 8 (4): 166?68
  • Gender impacts mortality after traumatic brain injury in teenagers JOURNAL OF TRAUMA AND ACUTE CARE SURGERY Ley, E. J., Short, S. S., Liou, D. Z., Singer, M. B., Mirocha, J., Melo, N., Bukur, M., Salim, A. 2013; 75 (4): 682?86


    Gender may influence outcomes following traumatic brain injury (TBI) although the mechanism is unknown. Animal TBI studies suggest that gender differences in endogenous hormone production may be the source. Limited retrospective clinical studies on gender present varied conclusions. Pediatric patients represent a unique population as pubescent children experience up-regulation of endogenous hormones that varies dramatically by gender. Younger children do not have these hormonal differences. The aim of this study was to compare pubescent and prepubescent females with males after isolated TBI to identify independent predictors of mortality.We performed a retrospective review of the National Trauma Data Bank Research Data Sets from 2007 and 2008 looking at all blunt trauma patients 18 years or younger who required hospital admission after isolated, moderate-to-severe TBI, defined as head Abbreviated Injury Scale (AIS) score 3 or greater. We excluded all individuals with AIS score of 3 or greater for any other region to limit the confounding effect of comorbidities. Based on the median age of menarche, we defined two age groups as follows: prepubescent (0-12 years) and pubescent (>12 years). Analysis was performed to compare trauma profiles and outcomes between groups. Our primary outcome measure was in-hospital mortality.A total of 20,280 patients met inclusion criteria; 10,135 were prepubescent, and 10,145 were pubescent. Overall mortality was 6.9%, and lower mortality was noted among prepubescent patients compared with pubescent (5.2% vs. 8.6%, p < 0.0001). Although female gender did not predict reduced mortality in the prepubescent cohort (adjusted odds ratio, 1.05; 95% confidence interval, 0.85-1.30; p = 0.63), female gender was associated with reduced mortality in the pubescent (adjusted odds ratio, 0.78; 95% confidence interval, 0.65-0.93; p = 0.007).In contrast to prepubescent female gender, pubescent female gender predicts reduced mortality following isolated, moderate-to-severe TBI. Endogenous hormonal differences may be a contributing factor and require further investigation.Prognostic study, level III.

    View details for DOI 10.1097/TA.0b013e31829d024f

    View details for Web of Science ID 000330457400020

    View details for PubMedID 24064883

  • Emergency department blood transfusion: the first two units are free JOURNAL OF SURGICAL RESEARCH Ley, E. J., Liou, D. Z., Singer, M. B., Mirocha, J., Melo, N., Chung, R., Bukur, M., Salim, A. 2013; 184 (1): 546?50


    Studies on blood product transfusions after trauma recommend targeting specific ratios to reduce mortality. Although crystalloid volumes as little as 1.5 L predict increased mortality after trauma, little data is available regarding the threshold of red blood cell (RBC) transfusion volume that predicts increased mortality.Data from a level I trauma center between January 2000 and December 2008 were reviewed. Trauma patients who received at least 100 mL RBC in the emergency department (ED) were included. Each unit of RBC was defined as 300 mL. Demographics, RBC transfusion volume, and mortality were analyzed in the nonelderly (<70 y) and elderly (?70 y). Multivariate logistic regression was performed at various volume cutoffs to determine whether there was a threshold transfusion volume that independently predicted mortality.A total of 560 patients received ?100 mL RBC in the ED. Overall mortality was 24.3%, with 22.5% (104 deaths) in the nonelderly and 32.7% (32 deaths) in the elderly. Multivariate logistic regression demonstrated that RBC transfusion of ?900 mL was associated with increased mortality in both the nonelderly (adjusted odds ratio 2.06, P = 0.008) and elderly (adjusted odds ratio 5.08, P = 0.006).Although transfusion of greater than 2 units in the ED was an independent predictor of mortality, transfusion of 2 units or less was not. Interestingly, unlike crystalloid volume, stepwise increases in blood volume were not associated with stepwise increases in mortality. The underlying etiology for mortality discrepancies, such as transfusion ratios, hypothermia, or immunosuppression, needs to be better delineated.

    View details for DOI 10.1016/j.jss.2013.03.043

    View details for Web of Science ID 000323609400088

    View details for PubMedID 23578753

  • Surgical management of advanced adrenocortical carcinoma: a 21-year population-based analysis. The American surgeon Tran, T. B., Liou, D., Menon, V. G., Nissen, N. N. 2013; 79 (10): 1115?18


    Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with a dismal prognosis. When diagnosed in advanced stages of the disease, the outcomes of surgical resection are not well understood. The objective of this study is to determine the impact of surgery in patients with advanced ACC. Using the Surveillance, Epidemiology and End Results database, we identified patients diagnosed with Stage III and IV ACC between 1988 and 2009. A total of 320 patients with Stage III and IV disease were included in our analysis. In patients treated with surgical resection, the Stage III 1- and 5-year survival rates were 77 and 40 per cent, respectively, whereas the Stage IV 1- and 5-year survival rates were 54 and 27.6 per cent, respectively. Patients treated without surgery had poor survival at 1 year for both Stage III (13%) and Stage IV (16%) (P < 0.01 compared with the surgical groups). Lymph node dissection was performed in 26 per cent of the patients with advanced ACC and was associated with improved survival in univariate analysis of Stage IV patients. Overall, our results indicate that favorable survival outcomes can be achieved even in patients with Stage III and IV disease and surgery should be considered in patients with advanced ACC.

    View details for PubMedID 24160811

  • Midodrine: a novel therapeutic for refractory chylothorax. Chest Liou, D. Z., Warren, H., Maher, D. P., Soukiasian, H. J., Melo, N., Salim, A., Ley, E. J. 2013; 144 (3): 1055?57


    Thoracic duct injury is a rare but serious complication following surgery of the neck or chest that leads to uncontrolled chyle leak. Conventional management includes drainage, nutritional modification, or aggressive surgical interventions such as thoracic duct ligation, flap coverage, fibrin glue, or talc pleurodesis; few successful medical therapeutics are available. We report a case of a high-output chylothorax refractory to aggressive medical and surgical interventions. Chyle output decreased substantially after initiating midodrine, an ?1-adrenergic agonist that causes vasoconstriction of the lymph system, reducing chyle flow. This case report suggests that midodrine may be a novel therapeutic for refractory chyle leaks.

    View details for DOI 10.1378/chest.12-3081

    View details for PubMedID 24008957

  • Acute kidney injury in elderly trauma: not associated with admission IV contrast. J Trauma Treat Liou, D. Z., Berry, C., Singer, M. B., Rudd, S., Torbati, S. S., Silka, P. A., Bukur, M., Salim, A., Ley, E. J. 2013; 2 (172)
  • Insurance-and race-related disparities decrease in elderly trauma patients. The journal of trauma and acute care surgery Singer, M. B., Liou, D. Z., Clond, M. A., Bukur, M., Mirocha, J., Margulies, D. R., Salim, A., Ley, E. J. 2013; 74 (1): 312?16


    Little focus is on health care disparities in the elderly, a population largely covered by public insurance. We characterized insurance type and race in elderly trauma patients to determine if lack of insurance or minority status predict increased mortality.The National Trauma Data Bank (version 7.0) was queried for all adult blunt trauma patients. We divided patients into two cohorts (15-64 or ? 65 years) based on age for universal Medicare eligibility. Our primary outcome measure was in-hospital mortality. Multiple logistic regression was used to control for confounding variables.A total of 541,471 patients met inclusion criteria. Among younger patients, the most common insurance type was private (41.0%), with 26.9% uninsured. In contrast, the most common insurance type among older patients was Medicare (64.6%), with 6.0% uninsured. Within the younger cohort, private insurance (adjusted odds ratio [AOR], 0.6; p < 0.01) and other insurance (AOR, 0.8; p < 0.01) predicted reduced mortality, while Medicare predicted similar mortality (AOR, 1.1; p = 0.18) compared with no insurance. Black race (AOR, 1.4; p < 0.01) and Hispanic ethnicity (AOR, 1.4; p < 0.01) predicted higher mortality compared with white race. Within the older cohort, no insurance predicted similar mortality as Medicare (AOR, 1.0; p = 0.43), private insurance (AOR, 1.0; p = 0.51), and other insurance (AOR, 1.0; p = 0.71). Hispanic ethnicity predicted increased mortality (AOR, 1.4; p < 0.01), while Asian race was protective (AOR, 0.7; p = 0.01) compared with white race.Elderly trauma patients present primarily with Medicare, while younger trauma patients are mostly privately insured; elderly patients are four times more likely to be insured. Disparities caused by lack of insurance and minority race are reduced in elderly trauma patients.Epidemiologic/prognostic study, level III.

    View details for DOI 10.1097/TA.0b013e31826fc899

    View details for PubMedID 23147178

  • Does a history of postoperative ileus predispose to recurrent ileus after multistage ileal pouch-anal anastomosis? Techniques in coloproctology Le, Q., Liou, D. Z., Murrell, Z., Fleshner, P. 2013; 17 (4): 383?88


    Although postoperative ileus (POI) is a common complication after major abdominal colorectal surgery, it is unknown whether a history of POI predisposes to recurrent POI in subsequent surgeries. In the present retrospective case-control study, conducted at the colorectal surgery division of a tertiary care center, we attempted to identify factors that may predict recurrent POI in ulcerative colitis (UC) patients undergoing three-stage ileal pouch-anal anastomosis (IPAA).Charts of UC patients undergoing three-stage IPAA were reviewed. All patients received a standardized accelerated postoperative care pathway. Patients were assigned to one of 3 categories: Group A patients did not have POI after either initial subtotal colectomy (STC) or subsequent IPAA, Group B patients developed POI only after initial STC, and Group C patients developed POI after both STC and IPAA.The study group consisted of 91 patients. There were 71 (78 %) patients in Group A, 14 (15 %) patients in Group B, and 6 (7 %) patients in group C. There was no significant difference in any demographic or clinical features among patients that developed no POI, those that developed POI only after STC, and those that developed POI after both STC and IPAA.POI is difficult to predict after first- and second-stage IPAA. Clinical factors and a history of POI from first-stage IPAA do not predict POI after second-stage IPAA. Patients with a history of POI after STC do not have an increased risk of developing recurrent POI.

    View details for DOI 10.1007/s10151-012-0942-2

    View details for PubMedID 23183687

  • Insurance type, not race, predicts mortality after pediatric trauma. The Journal of surgical research Short, S. S., Liou, D. Z., Singer, M. B., Bloom, M. B., Margulies, D. R., Bukur, M., Salim, A., Ley, E. J. 2013; 184 (1): 383?87


    In adult trauma, mortality varies with race and insurance status. In the elderly, insurance type has little impact on mortality after trauma and the influence of race is reduced. How race and insurance affect pediatric trauma requires further attention. We hypothesized that mortality after pediatric trauma is influenced by insurance type and not race.We reviewed all cases of blunt trauma in children ?13 y requiring admission, using the National Trauma Data Bank Research Data Sets for 2007 and 2008. Exclusions included an Abbreviated Injury Score of 6 for any body region, dead on arrival, and missing data. Our primary outcome measure was in-hospital mortality.We identified 831 Asian (1.2%), 10,592 black (15.5%), 45,173 white (66.2%), and 8498 Hispanic (12.5%) children, and 3161 children (4.6%) classified as other race. Mean age was 7.4 ± 4.5 y, 11.9% were uninsured, and overall in-hospital mortality was 1.4%. Multivariable modeling indicated that race was not associated with increased mortality (Asian versus white, adjusted odds ratio [AOR] 1.05, P = 0.88; black versus white, AOR 0.92, P = 0.42; Hispanic versus white, AOR 0.87, P = 0.26; and other race versus white, AOR 1.01, P = 0.96). In contrast, insurance status (any insurance versus no insurance, AOR 0.6, P < 0.01) and insurance type (private insurance versus no insurance, AOR 0.47, P < 0.01; Medicaid versus no insurance, 0.67, P < 0.01) predicted reduced mortality.Insurance status and insurance type are important predictors of mortality after pediatric trauma while, in contrast, race is not.

    View details for DOI 10.1016/j.jss.2013.03.042

    View details for PubMedID 23582228

  • Supratherapeutic vancomycin levels after trauma predict acute kidney injury and mortality. The Journal of surgical research Ley, E. J., Liou, D. Z., Singer, M. B., Mirocha, J., Srour, M., Bukur, M., Margulies, D. R., Salim, A. 2013; 184 (1): 501?6


    High-dose vancomycin is increasingly prescribed for critically ill trauma patients at risk for methicillin-resistant Staphylococcus aureus pneumonia. Although trauma patients have multiple known risk factors for acute kidney injury (AKI), a link between vancomycin and AKI or mortality has not been established. We hypothesize that high vancomycin trough concentration (VT) after trauma is associated with AKI and increased mortality.This was a retrospective analysis from a single institution Level I trauma center. Data were reviewed for all adult trauma patients who were admitted between 2006 and 2010. Patients were included if they received intravenous vancomycin, had serum creatinine levels before and after vancomycin administration, and had at least one recorded VT. Patients were stratified by VT into four groups: VT1 = 0-10 mg/L, VT2 = 10.1-15 mg/L, VT3 = 15.1-20 mg/L, VT4 >20 mg/L. Multivariable logistic regression was performed to determine the association between VT, AKI, and mortality.Of the 6781 trauma patients reviewed, 263 (3.9%) fit inclusion criteria. Ninety-seven (36.9%) patients developed AKI and 25 (9.5%) died. AKI and mortality increased progressively with VT. Ninety-one patients (34.6%) had troughs >20 mg/L and VT4 was independently associated with AKI (AOR 4.7, P < 0.01) and mortality (AOR 4.8, P = 0.05).AKI is common in trauma patients who receive intravenous vancomycin. A supratherapeutic trough level of >20 mg/L is an independent predictor of AKI and mortality in trauma patients.

    View details for DOI 10.1016/j.jss.2013.04.047

    View details for PubMedID 23731689

  • Increasing intent to donate in Hispanic American high school students: results of a prospective observational study. Transplantation proceedings Salim, A., Berry, C., Ley, E. J., Liou, D. Z., Schulman, D., Navarro, S., Zheng, L., Chan, L. S. 2012; 45 (1): 13?19


    High school students are an important target audience for organ donation education. A novel educational intervention focused on Hispanic American (HA) high school students might improve organ donation rates.A prospective observational study was conducted in five Los Angeles High Schools with a high percentage of HA students. A "culturally sensitive" educational program was administered to students in grades 9 to 12. Preintervention surveys that assessed awareness, knowledge, perception, and beliefs regarding donation as well as the intent to become an organ donor were compared to postintervention surveys.A total of 10,146 high school students participated in the study. After exclusions, 4876 preintervention and 3182 postintervention surveys were analyzed. A significant increase in the overall knowledge, awareness, and beliefs regarding donation was observed after the intervention, as evidenced by a significant increase in the percentage of correct answers on the survey (41% pre- versus 44% postintervention, P < .0001). When specifically examining HA students, there was a significant increase in the intent to donate organs (adjusted odds ratio 1.21, 95% confidence interval: 1.09, 1.34, P = .0003).This is the first study to demonstrate a significant increase in the intent to donate among HA high school students following an educational intervention.

    View details for DOI 10.1016/j.transproceed.2012.08.009

    View details for PubMedID 23375270

    View details for PubMedCentralID PMC3564055

  • Support for blood alcohol screening in pediatric trauma. American journal of surgery Ley, E. J., Singer, M. B., Short, S. S., Liou, D., Bukur, M., Malinoski, D. J., Margulies, D. R., Salim, A. 2012; 204 (6): 939?43; discussion 943


    Alcohol intoxication in pediatric trauma is underappreciated. The aim of this study was to characterize alcohol screening rates in pediatric trauma.The Los Angeles County Trauma System Database was queried for all patients aged ? 18 years who required admission between 2003 and 2008. Patients were compared by age and gender.A total of 18,598 patients met the inclusion criteria; 4,899 (26.3%) underwent blood alcohol screening, and 2,797 (57.1%) of those screened positive. Screening increased with age (3.3% for 0-9 years, 15.1% for 10-14 years, and 45.4% for 15-18 years; P < .01), as did alcohol intoxication (1.9% for 0-9 years, 5.8% 10-14 years, and 27.3% for 15-18 years; P < .01). Male gender predicted higher mortality in those aged 15 to 18 years (adjusted odds ratio, 1.7; P < .01), while alcohol intoxication did not (adjusted odds ratio, .97; P = .84).Alcohol intoxication is common in adolescent trauma patients. Screening is encouraged for pediatric trauma patients aged ?10 years who require admission.

    View details for DOI 10.1016/j.amjsurg.2012.05.018

    View details for PubMedID 23026384

  • Preoperative FDG-PET for axillary metastases in patients with breast cancer. Archives of surgery (Chicago, Ill. : 1960) Chung, A., Liou, D., Karlan, S., Waxman, A., Fujimoto, K., Hagiike, M., Phillips, E. H. 2006; 141 (8): 783?88; discussion 788?89


    Fludeoxyglucose F 18 (FDG) positron emission tomography (PET) can be used to predict axillary node metastases.Case series.Comprehensive breast care center.Fifty-one women with 54 biopsy-proven invasive breast cancers.Whole-body FDG-PET performed before axillary surgery and interpreted blindly.Axillary FDG activity, quantified by standardized uptake value (SUV); axillary metastases, quantified histologically; and tumor characteristics.There was PET activity in 32 axillae (59%). The SUVs ranged from 0.7 to 11.0. Twenty tumors had an SUV of 2.3 or greater, and 34 had an SUV of less than 2.3. There were no significant differences between these 2 groups except in axillary metastasis size (SUV /=2.3): mean age, 53 vs 58 years (P = .90); mean modified Bloom-Richardson score, 7.7 vs 7.6 (P = .20); lymphovascular invasion present, 25% vs 36% (P = .40); mean Ki-67 level, 25% vs 32% (P = .20); mean tumor size, 2.9 vs 3.2 cm (P = .05); and axillary metastasis size, 0.9 vs 1.7 (P = .001). By adopting an SUV threshold of 2.3, FDG-PET had a sensitivity of 60%, a specificity of 100%, and a positive predictive value of 100%.Patients with an SUV greater than 2.3 had axillary metastases. This finding obviates the need for sentinel lymph node biopsy or needle biopsy to diagnose axillary involvement. Surgeons can proceed to axillary node dissection to assess the number of nodes involved, eliminate axillary disease, or perhaps provide a survival benefit if preoperative FDG-PET has an SUV greater than 2.3.

    View details for DOI 10.1001/archsurg.141.8.783

    View details for PubMedID 16924086

  • Selective nonoperative management of abdominal stab wounds: prospective, randomized study. World journal of surgery Leppäniemi, A. K., Haapiainen, R. K. 1996; 20 (8): 1101?5; discussion 1105?6


    In a prospective, randomized trial the safety and cost-effectiveness of selective nonoperative management was compared to mandatory laparotomy in patients with abdominal stab wounds not requiring immediate laparotomy for hemodynamic instability, generalized peritonitis, or evisceration of abdominal contents. Fifty-one patients were randomly assigned to mandatory laparotomy or expectant nonoperative management and compared for early (<90 days) mortality and morbidity, length of hospital stay, and hospital costs. There was no early mortality. The morbidity rate was 19% following mandatory laparotomy and 8% after observation (p = 0.26). Four patients (17%) managed nonoperatively required delayed laparotomy. The hospital stay was shorter in the observation group (median 2 days versus 5 days;p = 0.002). About $2800 (US) was saved for every patient who underwent successful nonoperative management. It is concluded that selective nonoperative management of abdominal stab wounds, although resulting in delayed laparotomy in some patients, is safe and the preferred strategy for minimizing the days in hospital with concomitant savings in hospital costs. Mandatory laparotomy detects some unexpected organ injuries earlier and more accurately but results in a high nontherapeutic laparotomy rate and surgical management of minor injuries that in many cases could be managed nonoperatively.

    View details for PubMedID 8798372

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