Homero Rivas, MD, MBA, FACS, FASMBS is an Assistant Professor of Surgery, and the Director of Innovative Surgery at Stanford University. He is also the Co-Director of the Stanford Fellowship in Minimally invasive Surgery. As a digestive and bariatric surgeon, he has 15 years of experience. After his training in general surgery at the University of North Dakota, he completed two one-year fellowships in Minimally Invasive Surgery at the University of Louisville and also at the Hospital Clinic in Barcelona, Spain. He is certified by the American Board of Surgery. He is a pioneer and leader in numerous state-of-the art innovative techniques of minimal access surgery including: scarless surgery; natural orifice surgery; robotic surgery, and more. He successfully implemented a program for Per Oral Endoscopic Myotomy (POEM) for achalasia at Stanford, and presently he is one of few surgeons in the US doing this sophisticated technique. He has been involved in minimal access surgery both nationally in the US and internationally in nearly all continents, as a surgeon-in-training, a practicing surgeon and also as teacher of other expert surgeons. Dr. Rivas is the Co-Chair of the International Committee for the American Society of Metabolic and Bariatric Surgery, and he has been inducted as Honorary Fellow for both, the Brazilian College of Surgeons and the Brazilian College of Digestive Surgery.

Additionally, Dr. Rivas has been involved in Digital Health and Telemedicine for many years. He has several research projects using wearables to improve safety in the operating room, medical simulation and education implementing augmented and virtual reality, among others. He is a strong proponent of novel technologies such as 3D printing, Drones, artificial intelligence engines, etc., in healthcare. He is a co-director of Stanford’s massive-open-online-course on mHealth, with over 20,000 registered students from all over the world. He is a Senior Fellow with the Center for Innovation in Global Health (CIGH) at Stanford University School of Medicine. He is advocate of Hispanics in the USA and he champions mHealth and telemedicine among them and internationally. He is a founding member and Vice-President of the Society of Wearable Technology in Healthcare (WATCH). Dr. Rivas holds an MBA from the Cox School of Business at the Southern Methodist University in Dallas, TX.

Clinical Focus

  • General Surgery
  • Digestive Surgery
  • Bariatric Surgery
  • Minimally Invasive Surgery
  • Achalasia and POEM
  • Robotic Surgery
  • Digital Health

Academic Appointments

Honors & Awards

  • Winner of the Benito Juarez Award for Highest Academic Average, Universidad Juarez del Estado de Durango, School of Medicine (1993)
  • Honor Graduate, Mexican Medical Licensing Examination (June, 1994)
  • Distinguished Business Leader Award, Southern Methodist University, Edwin Cox School of Business (April, 2008)
  • Resident Achievement Award, General Surgery Program, University of North Dakota (June, 2000)
  • Junior Faculty of the Year Teaching Award, General Surgery Residency Program, University of Texas Southwestern Medical Center at Dallas (June, 2006)
  • Honorary Fellow, Brazilian College of Digestive Surgery (July, 2011)
  • Honorary Fellow, Brazilian College of Surgery (October, 2012)
  • Honorable Mention, POEM for Achalasia at Stanford, General Surgery Scientific MIS Week / Society of Laparoendoscopic Surgeons, Annual Congress (September, 2014)
  • Get Inspired by mHealth Leaders. Homero Rivas, one of top 25 mHealth leaders, Mobile Health Global, Barcelona, Spain (2014)
  • Senior Fellow with the Center for Innovation in Global Health (CIGH), Stanford University School of Medicine (2015)

Boards, Advisory Committees, Professional Organizations

  • Co-Chair, International Committee of American Society of Bariatric and Metabolic Surgery (2015 - Present)

Professional Education

  • Residency:University of North Dakota Office of the Registrar (2000) ND
  • Board Recertification, American Board of Surgery, General Surgery (2010)
  • Professional Education:Southern Methodist University Cox School of Business (2008) TX
  • Fellowship, Hospital Clinic Barcelona, Laparoscopic Digestive Surgery (2003)
  • Fellowship:University of Louisville Department of Surgery (2002) KY
  • Board Certification: General Surgery, American Board of Surgery (2001)
  • Medical Education:Universidad Juarez del Estado de Durango (1994) Mexico

Research & Scholarship

Current Research and Scholarly Interests

-Per Oral Endoscopic Myotomy (POEM) for patients with esophageal achalasia
-Use of wearables technologies in the operating room
-Subjective and Objective Experience of Mobile Applications Used in Different Contexts of Daily Life
-Use of a massive open online course (MOOC) platform in medical educationUse of =Augmented Reality through Google Glass and other wearables for teaching novel surgeons in the operating room
-Understanding leadership profiles among Hispanic International Medical Graduates in the US
-The Role of Online Communities in Supporting Patient Care


2017-18 Courses


All Publications

  • Capnoperitoneum During Peroral Endoscopic Myotomy-Recognition and Management: A Case Report. A & A case reports Lee, E., Brodsky, J. B., Rivas, H., Zheng, K., Brock-Utne, J. G. 2017


    Peroral endoscopic myotomy (POEM) is a minimally invasive procedure for treating esophageal achalasia. During POEM, carbon dioxide is insufflated under pressure into the esophagus and stomach, which can cause clinically significant capnoperitoneum, capnomediastinum, or capnothorax. We present a case in which gas accumulation in the abdomen during POEM had adverse effects on ventilation. Once the cause was recognized, needle decompression of the abdomen led to immediate improvement in ventilation.

    View details for DOI 10.1213/XAA.0000000000000449

    View details for PubMedID 28114155

  • Buttressing of the EEA stapler during gastrojejunal anastomosis decreases rate of bleeding-related complications for laparoscopic gastric bypass. Surgery for obesity and related diseases Ichter, Z. A., Voeller, L., Rivas, H., Khoury, H., Azagury, D., Morton, J. M. 2017


    Bariatric surgery is a well-tolerated and effective treatment for severe obesity. Newer surgical techniques and equipment have improved safety standards surrounding bariatric surgery. In particular, buttressing of the staple line in sleeve gastrectomy has decreased rates of clinically significant postoperative bleeding. The present study investigates the effectiveness of buttressing the circular stapled anastomosis during laparoscopic Roux-en-Y gastric bypass (LRYGB).Academic, accredited hospital.A total of 253 patients undergoing LRYGB at a single academic institution were included in this retrospective study between 2014 and 2015. Buttressing material was used in 125 of these cases. Demographic information was collected from both groups preoperatively. Surgical characteristics were also obtained analyzed using unpaired t or χ(2) tests.Patients in both buttressing and nonbuttressing groups were on average 46 years old and predominantly female (79.2% versus 74.2% female, respectively), with a body mass index of approximately 48 kg/m(2). Postoperative weight loss did not significantly differ between groups at any time point (buttressing versus nonbuttressing percentage of excess weight loss: 39.5% versus 41.5% at 3 mo, P = .3860; 56.4% versus 56.7% at 6 mo, P = .9341). There were no significant differences for operating time, length of stay, readmissions, or reoperations. Complications due to strictures were found to be lower for the buttressing group (0% buttressing versus 2.3% nonbuttressing, P = .0851). Specific rates of bleeding-related complications were significantly lower for the group in which buttressing was used (0% buttressing versus 3.1% nonbuttressing, P = .0463).Buttressing of the gastrojejunal anastomosis during LRYGB significantly reduces bleeding-related complications and increases tolerability of the procedure.

    View details for DOI 10.1016/j.soard.2017.01.019

    View details for PubMedID 28325504

  • Adipose tissue macrophages impair preadipocyte differentiation in humans. PloS one Liu, L. F., Craig, C. M., Tolentino, L. L., Choi, O., Morton, J., Rivas, H., Cushman, S. W., Engleman, E. G., McLaughlin, T. 2017; 12 (2)


    The physiologic mechanisms underlying the relationship between obesity and insulin resistance are not fully understood. Impaired adipocyte differentiation and localized inflammation characterize adipose tissue from obese, insulin-resistant humans. The directionality of this relationship is not known, however. The aim of the current study was to investigate whether adipose tissue inflammation is causally-related to impaired adipocyte differentiation.Abdominal subcutaneous(SAT) and visceral(VAT) adipose tissue was obtained from 20 human participants undergoing bariatric surgery. Preadipocytes were isolated, and cultured in the presence or absence of CD14+ macrophages obtained from the same adipose tissue sample. Adipocyte differentiation was quantified after 14 days via immunofluorescence, Oil-Red O, and adipogenic gene expression. Cytokine secretion by mature adipocytes cultured with or without CD14+macrophages was quantified.Adipocyte differentiation was significantly lower in VAT than SAT by all measures (p<0.001). With macrophage removal, SAT preadipocyte differentiation increased significantly as measured by immunofluorescence and gene expression, whereas VAT preadipocyte differentiation was unchanged. Adipocyte-secreted proinflammatory cytokines were higher and adiponectin lower in media from VAT vs SAT: macrophage removal reduced inflammatory cytokine and increased adiponectin secretion from both SAT and VAT adipocytes. Differentiation of preadipocytes from SAT but not VAT correlated inversely with systemic insulin resistance.The current results reveal that proinflammatory immune cells in human SAT are causally-related to impaired preadipocyte differentiation, which in turn is associated with systemic insulin resistance. In VAT, preadipocyte differentiation is poor even in the absence of tissue macrophages, pointing to inherent differences in fat storage potential between the two depots.

    View details for DOI 10.1371/journal.pone.0170728

    View details for PubMedID 28151993

    View details for PubMedCentralID PMC5289462

  • Characterizing Readmissions After Bariatric Surgery. Journal of gastrointestinal surgery Garg, T., Rosas, U., Rogan, D., Hines, H., Rivas, H., Morton, J. M., Azagury, D. 2016; 20 (11): 1797-1801


    Readmissions are an important quality metric for surgery. Here, we compare characteristics of readmissions across laparoscopic Roux-en-Y gastric bypass (LRYGB), sleeve gastrectomy (LSG), and adjustable gastric band (LAGB).Demographic, intraoperative, anthropometric, and laboratory data were prospectively obtained for 1775 patients at a single academic institution. All instances of readmissions within 1 year were recorded. Data were analyzed using STATA, release 12.For the 1775 patients, 113 (6.37 %) were readmitted. Mean time to readmission was 52.1 days. Of all the readmissions, 64.6 % were within 30 days, 22.1 % from 30 to 90 days, 1.77 % from 90 to 180 days, and 11.5 % from 180 to 365 days. Incidence of 30-day readmissions varied across surgeries (LRYGB: 7.17 %; LAGB: 3.05 %; LSG: 4.25 %, p = 0.04). Time to readmission varied as well, with 90.0 % of LSG and 80.0 % of LABG patients within the first 30 days, versus 60.8 % of LRYGB (p = 0.02). The most common causes of readmissions were gastrointestinal issues related to index procedure (34.5 %) and did not vary across surgeries. In multivariable logistic regression, index hospital length of stay (LOS) was associated with readmission (OR = 1.07, 95 % CI 1.02-1.13, p = 0.01).Readmissions after bariatric surgery are associated with high index hospital LOS, and a measureable proportion of procedure-related readmissions can occur up to 1 year, especially for LRYGB.

    View details for PubMedID 27613733

  • Magnetic Surgery: Results from First Prospective Clinical Trial in 50 Patients. Annals of surgery Rivas, H., Robles, I., Riquelme, F., Vivanco, M., Jiménez, J., Marinkovic, B., Uribe, M. 2016: -?


    To evaluate a new magnetic surgical system during reduced-port laparoscopic cholecystectomy in a prospective, multicenter clinical trial.Laparoscopic instrumentation coupled by magnetic fields may enhance surgeon performance by allowing for shaft-less retraction and mobilization. The movements can be performed under direct visualization, generating different angles of traction and reducing the number of trocars to perform the procedure. This may reduce well-known associated complications of trocars, including incisional pain, scarring, infection, bowel, and vascular injuries, among others.A prospective, multicenter, single-arm, open-label study was performed to assess the safety and performance of a magnetic surgical system (Levita Magnetics' Surgical System). The investigational device was used during a 3-port laparoscopic technique. The primary endpoints evaluated were safety and feasibility of the device to adequately mobilize the gallbladder to achieve effective exposure of the targeted surgical site. Patients were followed for 30 days postprocedure.Between January 2014 and March 2015, 50 patients presenting with benign gallbladder disease were recruited. Forty-five women and 5 men with an average age of 39 years (18-59), average body mass index of 27 kg/m (20.4-34.1) and an average abdominal wall thickness of 2.6 cm (1.8-4.6). The procedures were successfully performed in all 50 patients. No device-related serious adverse events were reported. Surgeons rated as "excellent" (90%) or "sufficient" (10%) the exposure of the surgical site.This clinical trial shows that this new magnetic surgical system is safe and effective in reduced-port laparoscopic cholecystectomy.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

    View details for PubMedID 27759614

  • Influence of Weight Loss Attempts on Bariatric Surgery Outcomes. American surgeon Deb, S., Voller, L., Palisch, C., Ceja, O., Turner, W., Rivas, H., Morton, J. M. 2016; 82 (10): 916-920


    Many payors require an additional attempt at nonsurgical weight loss before approval of bariatric procedures. This study evaluates this requirement by characterizing the prior weight loss attempts (WLAs) undergone by bariatric surgery patients and correlating those attempts to postoperative weight loss outcomes. Number and duration of WLAs were obtained from a preoperative clinic assessment. Body mass index (BMI) and percentage of excess weight loss (%EWL) were used to assess weight loss. Kruskal-Wallis and Spearman Correlation tests were performed to analyze data using GraphPad Prism 6. Mean number of WLAs before surgery was 3.5 ± 0.2 attempts, with an average duration of 15.2 ± 1.1 years. There was a significant negative correlation between duration of WLAs and preoperative BMI (r = -0.2637, P = 0.0025). No significant difference was found for preoperative BMI or mean 12-month %EWL among any WLA groups. The number and duration of dietary attempts before surgery do not significantly affect long-term weight loss outcomes after bariatric surgery. Given these data, an additional preoperative WLA may not be efficacious in improving patients' chances at weight loss.

    View details for PubMedID 27779973

  • National prevalence, causes, and risk factors for bariatric surgery readmissions AMERICAN JOURNAL OF SURGERY Garg, T., Rosas, U., Rivas, H., Azagury, D., Morton, J. M. 2016; 212 (1): 76-80


    Readmissions are often used as a quality metric particularly in bariatric surgery.Laparoscopic Roux en Y gastric bypass, laparoscopic adjustable gastric banding, and laparoscopic sleeve gastrectomy were identified using Current Procedure Terminology codes in the 2012 National Surgical Quality Improvement Program public use file.A total of 18,296 patients were included, 10,080 (55.1%) were laparoscopic Roux en Y gastric bypass, 1,829 (10.0%) were laparoscopic adjustable gastric banding, and 6,387 (34.9%) were laparoscopic sleeve gastrectomy. Among all patients, 955 (5.22%) were readmitted. Patients with readmissions had a higher proportion of body mass index greater than 50 (30.2% vs 24.6%, P < .001), higher index operative time (132 minutes vs 115, P < .001) and greater proportion with length of stay greater than 4 days (9.57% vs 3.36%, P < .001). Readmitted patients were more likely to have diabetes (31.1% vs 27.7%, P = .02), chronic obstructive pulmonary disease (2.63% vs 1.72%, P = .04), and hypertension (54.5% vs 50.8%, P = .03). Overall, 40.6% of readmitted patients had a complication. Common readmissions were gastrointestinal-related (45.0%), dietary (33.5%), and bleeding (6.57%). Readmission was independently associated with African-American race (odds ratio [OR] = 1.53, P = .02), complication (OR = 11.3, 95%, P < .001), and resident involvement (OR = .53, P = .04).A 30-day readmission after bariatric surgery is prevalent and closely associated with complications.

    View details for DOI 10.1016/j.amjsurg.2016.01.023

    View details for Web of Science ID 000378063100011

    View details for PubMedID 27133197

  • A postoperative nutritional consult improves bariatric surgery outcomes. Surgery for obesity and related diseases Garg, T., Birge, K., Ulysses Rosas, Azagury, D., Rivas, H., Morton, J. M. 2016; 12 (5): 1052-1056


    Bariatric surgery is the most effective treatment for obesity. Guidelines for optimizing postoperative care are emerging, and roles of the surgeon and registered dietician (RD) have opportunities for coordination.The study objective was to better define the appropriate guidelines for postoperative care by investigating whether a combined surgeon and RD follow-up for the initial postoperative visit within 2 to 6 weeks after surgery improves patient outcomes.The setting was an accredited bariatric hospital in an academic setting.A retrospective analysis of a prospective database was performed on patients who underwent bariatric surgery and were followed up by either a surgeon alone or by a surgeon and RD for initial postoperative visit.There were 302 patients in the surgeon follow-up group and 268 in the RD follow-up. Patients in the RD follow-up group had significantly fewer readmissions due to dietary-related problems (9 versus 0; P = .004), more favorable 3-month change in serum thiamine (-30.5 versus-4.04; P = .002), high-density lipoprotein (-3.42 versus-1.67; P = .053), and triglycerides (-17.5 versus-31.5; P = .03), and trended lower number of minor complications (16 versus 6; P = .08). No significant differences in percent excess weight loss were observed at all time points after surgery. Multivariate logistic models controlling for demographic features found that RD follow-up predicted 3-month increase in thiamine (odds ratio = 2.49; P<.000) and high-density lipoprotein cholesterol (OR = 1.73; P = .01), and decrease in total cholesterol (OR = 1.58; P = .03) and triglycerides (OR = 1.55; P = .03).Follow-up with a surgeon and RD for the initial postoperative visit may help improve patient outcomes.

    View details for DOI 10.1016/j.soard.2016.01.008

    View details for PubMedID 27220825

  • The Influence of Resected Gastric Weight upon Weight Loss after Sleeve Gastrectomy AMERICAN SURGEON Rosas, U., Hines, H., Rogan, D., Rivas, H., Morton, J. 2015; 81 (12): 1240-1243
  • Mesenteric defect closure in laparoscopic Roux-en-Y gastric bypass: a randomized controlled trial. Surgical endoscopy Rosas, U., Ahmed, S., Leva, N., Garg, T., Rivas, H., Lau, J., Russo, M., Morton, J. M. 2015; 29 (9): 2486-2490


    Internal herniation is a potential complication following laparoscopic Roux-en-Y gastric bypass (LRYGB). Previous studies have shown that closure of mesenteric defects after LRYGB may reduce the incidence of internal herniation. However, controversy remains as to whether mesenteric defect closure is necessary to decrease the incidence of internal hernias after LRYGB. This study aims to determine if jejeunal mesenteric defect closure reduces incidence of internal hernias and other complications in patients undergoing LRYGB.105 patients undergoing laparoscopic antecolic RYGB were randomized into two groups: closed mesenteric defect (n = 50) or open mesenteric defect (n = 55). Complication rates were obtained from the medical record. Patients were followed up to 3 years post-operatively. Patients also completed the gastrointestinal quality of life index (GI QoL) pre-operatively and 12 months post-operatively. Outcome measures included: incidence of internal hernias, complications, readmissions, reoperations, GI QoL scores, and percent excess weight loss (%EWL).Pre-operatively, there were no significant differences between the two groups. The closed group had a longer operative time (closed-153 min, open-138 min, p = 0.073). There was one internal hernia in the open group. There was no significant difference at 12 months for decrease in BMI (closed-15.9, open-16.3 kg/m(2), p = 0.288) or %EWL (closed-75.3%, open-69.0%, p = 0.134). There was no significant difference between the groups in incidence of internal hernias and general complications post-operatively. Both groups showed significantly improved GI QoL index scores from baseline to 12 months post-surgery, but there were no significant differences at 12 months between groups in total GI QoL (closed-108, open-112, p = 0.440).In this study, closure or non-closure of the jejeunal mesenteric defect following LRYGB appears to result in equivalent internal hernia and complication rates. High index of suspicion should be maintained whenever internal hernia is expected after LRYGB.

    View details for DOI 10.1007/s00464-014-3970-3

    View details for PubMedID 25480607

  • Mesenteric defect closure in laparoscopic Roux-en-Y gastric bypass: a randomized controlled trial SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Rosas, U., Ahmed, S., Leva, N., Garg, T., Rivas, H., Lau, J., Russo, M., Morton, J. M. 2015; 29 (9): 2486-2490
  • Quality of Life Technologies Experiences from the Field and Key Challenges IEEE INTERNET COMPUTING Wac, K., Fiordelli, M., Gustarini, M., Rivas, H. 2015; 19 (4): 28-35
  • Do adverse childhood experiences affect surgical weight loss outcomes? Journal of gastrointestinal surgery Lodhia, N. A., Rosas, U. S., Moore, M., Glaseroff, A., Azagury, D., Rivas, H., Morton, J. M. 2015; 19 (6): 993-998


    Bariatric surgery is an effective and enduring treatment for obesity; however, variation in weight loss may occur following surgery. Many factors beyond technical considerations may influence postoperative outcomes. A better understanding of the influence of adverse childhood experiences (ACE) on surgical weight loss may improve preoperative care. Demographic and preoperative and postoperative data were prospectively obtained for 223 patients undergoing bariatric surgery. All cases were completed laparoscopically without serious complication. Patients completed the ACE questionnaire, which assesses childhood maltreatment. Patients had an average age of 48 years and 77 % were female. There was a significant reduction from preoperative to 12-month postoperative BMI (45 to 31 kg/m(2), p ≤ 0.01). The average ACE score was 2.9 and these patients were more likely than population norms to have an ACE score ≥4 (35.9 vs. 12.5 %, p < 0.001). There was a positive correlation between the number of preoperative comorbidities and preoperative ACE score (R = 0.112, p = 0.09). Patients with a high ACE score (≥6) vs. patients low ACE scores had a higher postoperative BMI at 6-months (36.9 vs. 33.4 kg/m(2), p = 0.03) and 12-months postoperatively (34.5 vs. 30.5 kg/m(2), p = 0.07). High ACE patients had higher total cholesterol (191 vs. 169 mg/dL, p = 0.02) and LDL cholesterol (116 vs. 94 mg/dL, p = 0.02) than low ACE patients 12-months postoperatively. A high preoperative ACE score decreases weight loss following bariatric surgery and may warrant an increased preoperative counseling.

    View details for DOI 10.1007/s11605-015-2810-7

    View details for PubMedID 25832488

  • T-cell profile in adipose tissue is associated with insulin resistance and systemic inflammation in humans. Arteriosclerosis, thrombosis, and vascular biology McLaughlin, T., Liu, L., Lamendola, C., Shen, L., Morton, J., Rivas, H., Winer, D., Tolentino, L., Choi, O., Zhang, H., Hui Yen Chng, M., Engleman, E. 2014; 34 (12): 2637-2643


    The biological mechanisms linking obesity to insulin resistance have not been fully elucidated. We have shown that insulin resistance or glucose intolerance in diet-induced obese mice is related to a shift in the ratio of pro- and anti-inflammatory T cells in adipose tissue. We sought to test the hypothesis that the balance of T-cell phenotypes would be similarly related to insulin resistance in human obesity.Healthy overweight or obese human subjects underwent adipose-tissue biopsies and quantification of insulin-mediated glucose disposal by the modified insulin suppression test. T-cell subsets were quantified by flow cytometry in visceral (VAT) and subcutaneous adipose tissue (SAT). Results showed that CD4 and CD8 T cells infiltrate both depots, with proinflammatory T-helper (Th)-1, Th17, and CD8 T cells, significantly more frequent in VAT as compared with SAT. T-cell profiles in SAT and VAT correlated significantly with one another and with peripheral blood. Th1 frequency in SAT and VAT correlated directly, whereas Th2 frequency in VAT correlated inversely, with plasma high-sensitivity C-reactive protein concentrations. Th2 in both depots and peripheral blood was inversely associated with systemic insulin resistance. Furthermore, Th1 in SAT correlated with plasma interleukin-6. Relative expression of associated cytokines, measured by real-time polymerase chain reaction, reflected flow cytometry results. Most notably, adipose tissue expression of anti-inflammatory interleukin-10 was inversely associated with insulin resistance.CD4 and CD8 T cells populate human adipose tissue and the relative frequency of Th1 and Th2 are highly associated with systemic inflammation and insulin resistance. These findings point to the adaptive immune system as a potential mediator between obesity and insulin resistance or inflammation. Identification of antigenic stimuli in adipose tissue may yield novel targets for treatment of obesity-associated metabolic disease.

    View details for DOI 10.1161/ATVBAHA.114.304636

    View details for PubMedID 25341798

  • T-Cell Profile in Adipose Tissue Is Associated With Insulin Resistance and Systemic Inflammation in Humans ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY McLaughlin, T., Liu, L., Lamendola, C., Shen, L., Morton, J., Rivas, H., Winer, D., Tolentino, L., Choi, O., Zhang, H., Chng, M. H., Engleman, E. 2014; 34 (12): 2637-2643
  • Increasing access to specialty surgical care: application of a new resource allocation model to bariatric surgery. Annals of surgery Leroux, E. J., Morton, J. M., Rivas, H. 2014; 260 (2): 274-278


    To calculate the public health impact and economic benefit of using ancillary health care professionals for routine postoperative care.The need for specialty surgical care far exceeds its supply, particularly in weight loss surgery. Bariatric surgery is cost-effective and the only effective long-term weight loss strategy for morbidly obese patients. Without clinically appropriate task shifting, surgeons, hospitals, and untreated patients incur a high opportunity cost.Visit schedules, time per visit, and revenues were obtained from bariatric centers of excellence. Case-specific surgeon fees were derived from published Current Procedural Terminology data. The novel Microsoft Excel model was allowed to run until a steady state was evident (status quo). This model was compared with one in which the surgeon participates in follow-up visits beyond 3 months only if there is a complication (task shifting). Changes in operative capacity and national quality-adjusted life years (QALYs) were calculated.In the status quo model, per capita surgical volume capacity equilibrates at 7 surgical procedures per week, with 27% of the surgeon's time dedicated to routine long-term follow-up visits. Task shifting increases operative capacity by 38%, resulting in 143,000 to 882,000 QALYs gained annually. Per surgeon, task shifting achieves an annual increase of 95 to 588 QALYs, $5 million in facility revenue, 48 cases of cure of obstructive sleep apnea, 44 cases of remission of type 2 diabetes mellitus, and 35 cases of cure of hypertension.Optimal resource allocation through task shifting is economically appealing and can achieve dramatic public health benefit by increasing access to specialty surgery.

    View details for DOI 10.1097/SLA.0000000000000656

    View details for PubMedID 24743608

  • Increasing Access to Specialty Surgical Care Application of a New Resource Allocation Model to Bariatric Surgery ANNALS OF SURGERY Leroux, E. J., Morton, J. M., Rivas, H. 2014; 260 (2): 274-278
  • Comparison of robotic and laparoendoscopic single-site surgery systems in a suturing and knot tying task SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Eisenberg, D., Vidovszky, T. J., Lau, J., Guiroy, B., Rivas, H. 2013; 27 (9): 3182-3186


    BACKGROUND: Laparoendoscopic single-site (LESS) surgery has been established for various procedures. Shortcomings of LESS surgery include loss of triangulation, instrument collisions, and poor ergonomics, making advanced laparoscopic tasks especially challenging. We compared a LESS system with a robotic single-site surgery platform in performance of a suturing and knot-tying task under clinically simulated conditions. METHODS: Each of five volunteer minimally invasive surgeons was tasked with suturing a 5 cm longitudinal enterotomy in porcine small intestine with square knots at either end, using a laparoendoscopic or da Vinci robotic single-site surgery platform, within a 20 min time limit. A saline leak test was then performed. Each surgeon performed the task twice using each system. The time to completion of the task and presence of a leak were noted. Fisher's exact test was used to compare the overall completion rate within the defined time limit, and a Wilcoxon rank test was used to compare the specific times to complete the task. A p value of <0.05 was considered significant. RESULTS: All surgeons were able to complete the task on the first try within 20 min using the robot system; 60 % of surgeons were able to complete it after two attempts using the LESS surgery system. Time to completion using the robot system was significantly shorter than the time using the standard LESS system (p < 0.0001). There were no leaks after closure with the robot system; the leak rate following the standard LESS system was 90 %. CONCLUSIONS: Surgeons demonstrated significantly better suturing and knot-tying capabilities using the robot single-site system compared to a standard LESS system. The robotic system has the potential to expand single-site surgery to more complex tasks.

    View details for DOI 10.1007/s00464-013-2874-y

    View details for Web of Science ID 000323621500016

    View details for PubMedID 23443484

  • Single-Incision Laparoscopic Cholecystectomy Is Associated with Improved Cosmesis Scoring at the Cost of Significantly Higher Hernia Rates: 1-Year Results of a Prospective Randomized, Multicenter, Single-Blinded Trial of Traditional Multiport Laparoscopic Cholecystectomy vs Single-Incision Laparoscopic Cholecystectomy JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS Marks, J. M., Phillips, M. S., Tacchino, R., Roberts, K., Onders, R., Denoto, G., Gecelter, G., Rubach, E., Rivas, H., Islam, A., Soper, N., Paraskeva, P., Rosemurgy, A., Ross, S., Shah, S. 2013; 216 (6): 1037-1048


    Minimally invasive techniques have become an integral part of general surgery with recent investigation into single-incision laparoscopic cholecystectomy (SILC). This study presents the final 1-year results of a prospective, randomized, multicenter, single-blinded trial of SILC vs multiport cholecystectomy (4PLC).Patients with biliary colic and documented gallstones or polyps or with biliary dyskinesia were randomized to SILC vs 4PLC. Data measures included operative details, adverse events, and conversion to 4PLC or laparotomy. Patients were followed for 12 months.Two hundred patients underwent randomization to SILC (n = 119) or 4PLC (n = 81). Enrollment ranged from 1 to 50 patients with 4 sites enrolling >25 patients. Total adverse events were not significantly different between groups (36% 4PLC vs 45% SILC; p = 0.24), as were severe adverse events (4% 4PLC vs 10% SILC; p = 0.11). Incision-related adverse events were higher after SILC (11.7% vs 4.9%; p = 0.13), but all of these were listed as mild or moderate. Total hernia rates were 1.2% (1 of 81) in 4PLC patients vs 8.4% (10 of 119) in SILC patients (p = 0.03). At 1-year follow-up, cosmesis scores continued to favor SILC (p < 0.0001).Results of this trial show SILC to be a safe and feasible procedure when compared with 4PLC, with similar total adverse events but with an identified significant increase in hernia formation. Cosmesis scoring and patient preference at 12 months continue to favor SILC, and more than half of the patients were willing to pay more for a single-site surgery over a standard laparoscopic procedure. Additional longer-term population-based studies are needed to clarify if this increased rate of hernia formation as compared with 4PLC will continue to hold true.

    View details for DOI 10.1016/j.jamcollsurg.2013.02.024

    View details for Web of Science ID 000319039900002

    View details for PubMedID 23619321

  • Present and future advanced laparoscopic surgery. Asian journal of endoscopic surgery Rivas, H., Díaz-Calderón, D. 2013; 6 (2): 59-67


    Modern laparoscopy, starting with Kurt Semm's insufflators and the first successful appendectomies, has only been around for approximately 30 years. Since those early successes, the technology has grown from the inception of basic laparoscopy to endoscopic surgery through natural orifices, and it continues to evolve by leaps and bounds with computer-assisted surgery and improved robotics in surgery. Without question, laparoscopy has revolutionized the way we perform standard surgery, especially relative to the techniques that had been used for hundreds of years. Despite the development of multiple novel technologies since the 1980s, very little has changed with regard to basic conceptualizations and practice of laparoscopy. In this review article, we will describe the highlights of recent advanced laparoscopic surgery procedures, their potential applications within the field of surgery, and how these advances may impact and improve future quality and patient outcomes.

    View details for DOI 10.1111/ases.12028

    View details for PubMedID 23601993

  • Consensus statement of the consortium for LESS cholecystectomy SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Ross, S., Rosemurgy, A., Albrink, M., Choung, E., Dapri, G., Gallagher, S., Hernandez, J., Horgan, S., Kelley, W., Kia, M., Marks, J., Martinez, J., Mintz, Y., Oleynikov, D., Pryor, A., Rattner, D., Rivas, H., Roberts, K., Rubach, E., Schwaitzberg, S., Swanstrom, L., Sweeney, J., Wilson, E., Zemon, H., Zundel, N. 2012; 26 (10): 2711-2716


    Many surgeons attempting Laparo-Endoscopic Single Site (LESS) cholecystectomy have found the operation difficult, which is inconsistent with our experience. This article is an attempt to promote a standardized approach that we feel surgeons with laparoscopic skills can perform safely and efficiently. This is a four-trocar approach consistent with the four incisions utilized in conventional laparoscopic cholecystectomy. After administration of general anesthesia, marcaine is injected at the umbilicus and a 12-mm vertical incision is made through the already existing anatomical scar of the umbilicus. A single four-trocar port is inserted. A 5-mm deflectable-tip laparoscope is placed through the trocar at the 8 o'clock position, a bariatric length rigid grasper is inserted through the trocar at the 4 o'clock position (to grasp the fundus), and a rigid bent grasper is placed through the 10-mm port (to grasp the infundibulum). This arrangement of the instruments promotes minimal internal and external instrument clashing with simultaneous optimization of the operative view. This orientation allows retraction of the gallbladder in a cephalad and lateral direction, development of a window between the gallbladder and the liver which promotes the "critical view" of the cystic duct and artery, and provides triangulation with excellent visualization of the operative field. The operation is concluded with diaphragmatic irrigation of marcaine solution to minimize postoperative pain. Standardization of LESS cholecystectomy will speed adoption, reduce intraoperative complications, and improve the efficiency and safety of the approach.

    View details for DOI 10.1007/s00464-012-2478-y

    View details for Web of Science ID 000309175200002

    View details for PubMedID 22936433

  • Intermediate results of a prospective randomized controlled trial of traditional four-port laparoscopic cholecystectomy versus single-incision laparoscopic cholecystectomy Annual Meeting of the Society-of-American-Gastrointestinal-and-Endoscopic-Surgeons (SAGES) Phillips, M. S., Marks, J. M., Roberts, K., Tacchino, R., Onders, R., Denoto, G., Rivas, H., Islam, A., Soper, N., Gecelter, G., Rubach, E., Paraskeva, P., Shah, S. SPRINGER. 2012: 1296–1303


    Minimally invasive techniques have become an integral part of general surgery, with recent investigation into single-incision laparoscopic cholecystectomy (SILC). This study presents a prospective, randomized, multicenter, single-blind trial of SILC compared with four-port cholecystectomy (4PLC) with the goal of assessing safety, feasibility, and factors predicting outcomes.Patients with biliary colic and documented gallstones or polyps or with biliary dyskinesia were randomized to SILC or 4PLC. Data measures included operative details, adverse events, and conversion to 4PLC or laparotomy. Pain, cosmesis, and quality-of-life scores were documented. Patients were followed for 12 months.Two hundred patients were randomized to SILC (n = 117) or 4PLC (n = 80) (3 patients chose not to participate after randomization). Patients were similar except for body mass index (BMI), which was lower in the SILC patients (28.9 vs. 31.0, p = 0.011). One SILC patient required conversion to 4PLC. Operative time was longer for SILC (57 vs. 45 min, p < 0.0001), but outcomes, including total adverse events, were similar (34% vs. 38%, p = 0.55). Cosmesis scores favored SILC (p < 0.002), but pain scores were lower for 4PLC (1 point difference in 10-point scale, p < 0.028) despite equal analgesia use. Wound complications were greater after SILC (10% vs. 3%, p = 0.047), but hernia recurrence was equivalent for both procedures (1.3% vs. 3.4%, p = 0.65). Univariate analysis showed female gender, SILC, and younger age to be predictors for increased pain scores, while SILC was associated with improved cosmesis scores.In this multicenter randomized controlled trial of SILC versus 4PLC, SILC appears to be safe with a similar biliary complication profile. Pain scores and wound complication rates are higher for SILC; however, cosmesis scores favored SILC. For patients preferring a better cosmetic outcome and willing to accept possible increased postoperative pain, SILC offers a safe alternative to the standard 4PLC. Further follow-up is needed to detail the long-term risk of wound morbidities, including hernia recurrence.

    View details for DOI 10.1007/s00464-011-2028-z

    View details for Web of Science ID 000303103900015

    View details for PubMedID 22083331

  • Prospective randomized controlled trial of traditional laparoscopic cholecystectomy versus single-incision laparoscopic cholecystectomy: Report of preliminary data AMERICAN JOURNAL OF SURGERY Marks, J., Tacchino, R., Roberts, K., Onders, R., Denoto, G., Paraskeva, P., Rivas, H., Soper, N., Rosemurgy, A., Shah, S. 2011; 201 (3): 369-373


    This study presents preliminary data from a prospective randomized multicenter, single-blinded trial of single-incision laparoscopic cholecystectomy (SILC) versus standard laparoscopic cholecystectomy (4PLC).Patients with symptomatic gallstones, polyps, or biliary dyskinesia (ejection fraction <30%) were randomized to SILC or 4PLC. Data included operative time, estimated blood loss, length of skin and fascial incisions, complications, pain, satisfaction and cosmetic scoring, and conversion.Operating room time was longer with SILC (n = 50) versus 4PLC (n = 33). No differences were seen in blood loss, complications, or pain scores. Body image scores and cosmetic scores at 1, 2, 4, and 12 weeks were significantly higher for SILC. Satisfaction scores, however, were similar.Preliminary results from this prospective trial showed SILC to be safe compared with 4PLC although operative times were longer. Cosmetic scores were higher for SILS compared with 4PLC. Satisfaction scores were similar although both groups reported a significantly higher preference towards SILC.

    View details for DOI 10.1016/j.amjsurg.2010.09.012

    View details for Web of Science ID 000288408600019

    View details for PubMedID 21367381

  • Modified single-incision laparoscopic adjustable gastric band SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Scott, D. J., Castellvi, A. O., Varela, J. E., Rivas, H. 2010; 24 (9): 2314-2315


    This video describes a modified single-incision laparoscopic approach for adjustable gastric band placement.The patient was a 28-year-old female with a BMI of 48.75 with no prior surgery but with numerous comorbidities. With the patient placed in a split-leg position and in steep reverse Trendelenburg, a 12-mm optical trocar is placed 12 cm distal to the xiphoid process in the left paramedian location. A Nathanson liver retractor is placed through a midepigastric 5-mm incision. Two 5-mm low-profile trocars are placed next to the 12-mm trocar through separate incisions (this maintains stability of each cannula) and a 5-mm 45 ° laparoscope is used. Using an automated suturing device, a stay suture is placed high on the fundus and externalized for retraction. An articulating band passer dissects the phrenogastric attachments at the angle of His. The 12-mm port is removed and the gastric band is inserted. The GE junction fat pad is excised and the Pars Flaccida membrane is divided using conventional instruments. A second traction suture is placed to retract the lesser curve fat and right crus fat pad. A peritoneal bite is also taken in the left lateral subcostal area such that when this suture is externalized, it acts as a pulley. An articulating 5-mm grasper is used to develop the retrogastric tunnel. Then the band is fed into position and its buckle is locked. Three interrupted sutures are placed to create an anterior gastric plication and a fourth antislippage suture is placed below the band along the lesser curve. The band tubing is externalized and the port is implanted by joining the three working trocar incisions into a single 4.5-cm incision.The patient did well postoperatively with no complications.A modified single incision approach for laparoscopic gastric band placement is feasible and provides patients with improved cosmesis.

    View details for DOI 10.1007/s00464-010-0910-8

    View details for Web of Science ID 000281776400038

    View details for PubMedID 20422429

  • Cost Consciousness and Medical Education NEW ENGLAND JOURNAL OF MEDICINE Rivas, H., Morton, J. M., Krummel, T. M. 2010; 363 (9): 888-889

    View details for Web of Science ID 000281196600019

    View details for PubMedID 20738193

  • Single-incision laparoscopic cholecystectomy: initial evaluation of a large series of patients SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Rivas, H., Varela, E., Scott, D. 2010; 24 (6): 1403-1412


    Findings have shown that single-incision laparoscopic cholecystectomy (SILC) is feasible and reproducible. The authors have pioneered a two-trocar SILC technique at the University of Texas Southwestern. Their results for 100 patients are presented.From January 2008 to March 2009, 100 patients with symptomatic gallbladder disease underwent SILC through a 1.5- to 2-cm umbilical incision using a two-port (5-mm) technique. For nearly all the patients, a 30 degrees angled scope was used. The gallbladder was retracted, with two or three sutures placed along the gallbladder. These sutures were either fixated internally or placed through the abdominal wall to obtain a critical view of Calot's triangle. The SILC procedure was performed using standard technique with 5-mm reticulating or conventional laparoscopic instruments. The cystic duct and artery were well visualized, clipped, and divided. Cholecystectomy was completed with electrocautery, and the specimen was retrieved through the umbilical incision.In this series, 80 women (85%) and 15 men (15%) with an average age of 33.8 years (range, 17-66 years) underwent SILC. Their mean BMI was 29.8 kg/m(2) (range, 17-42.5 kg/m(2)), and 39% of these patients had undergone previous abdominal surgery. The mean operative time was 50.8 min (range, 23-120 min). The mean estimated blood loss was 22.3 ml (range, 5-125 ml), and 5% of the patients had an intraoperative cholangiogram. There were no conversions of the SILC technique. A two-trocar technique was feasible for 87% of the patients. For the remaining patients, either a three-channel port or three individual trocars were required. A SILC technique was used for 5% of the patients to manage acute cholecystitis or gallstone pancreatitis.The SILC technique with a two-trocar technique is safe, feasible, and reproducible. The operating times are reasonable and can be lessened with experience. Even complex cases can be managed with this technique. Excellent exposure of the critical view was obtained in all cases. The SILC procedure is becoming the standard of care for most of the authors' elective patients with gallbladder disease. Clinical trials are warranted before the SILC technique is adopted universally.

    View details for DOI 10.1007/s00464-009-0786-7

    View details for Web of Science ID 000277713800027

    View details for PubMedID 20035355

  • Consensus statement of the consortium for laparoendoscopic single-site surgery SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Gill, I. S., Advincula, A. P., Aron, M., Caddedu, J., Canes, D., Curcillo, P. G., Desai, M. M., Evanko, J. C., Falcone, T., Fazio, V., Gettman, M., Gumbs, A. A., Haber, G., Kaouk, J. H., Kim, F., King, S. A., Ponsky, J., Remzi, F., Rivas, H., Rosemurgy, A., Ross, S., Schauer, P., Sotelo, R., Speranza, J., Sweeney, J., Teixeira, J. 2010; 24 (4): 762-768

    View details for DOI 10.1007/s00464-009-0688-8

    View details for Web of Science ID 000276076100005

    View details for PubMedID 19997938

  • Single-incision laparoscopic surgery: case report of SILS adjustable gastric banding SURGERY FOR OBESITY AND RELATED DISEASES Oltmann, S. C., Rivas, H., Varela, E., Goova, M. T., Scott, D. J. 2009; 5 (3): 362-364

    View details for DOI 10.1016/j.soard.2009.03.003

    View details for Web of Science ID 000266670600012

    View details for PubMedID 19460675

  • Laparoscopic Esophagomyotomy for Achalasia: How I Do It JOURNAL OF GASTROINTESTINAL SURGERY Rivas, H., Rege, R. V. 2009; 13 (3): 542-549


    The pathophysiology, diagnosis, and treatment options for achalasia are briefly discussed, followed by a description of the minimally invasive surgical approaches to this disease, as practiced by the authors.Laparoscopic myotomy is performed routinely at our institution in the lithotomy position under endoscopic control. The techniques for performing the myotomy, the use of fundoplication, and the adaptation of this approach to use the surgical robot are described. Laparoscopic esophagomyotomy has been highly effective, durable, safe, and widely accepted by patients. There is less data about the robotic approach, but increased degrees of freedom afforded by articulation in the instruments promises finer control and possibly lower perforation rates.

    View details for DOI 10.1007/s11605-008-0574-z

    View details for Web of Science ID 000263877100025

    View details for PubMedID 18594931

  • Single Port Laparoscopy. The new evolution of endoscopic surgery. Asian J Endosc Surg Rivas H 2009; Dec 2 (3): 77-88
  • Endoscopic hemostasis using endoclip in early gastrointestinal hemorrhage after gastric bypass surgery OBESITY SURGERY Tang, S., Rivas, H., Tang, L., Lara, L. F., Sreenarasimhaiah, J., Rockey, D. C. 2007; 17 (9): 1261-1267


    Roux-en-Y gastric bypass (RYGBP) is the most commonly performed bariatric operation in the USA. In the early postoperative stage, gastrointestinal (GI) bleeding is an infrequent but potentially serious complication that usually results from bleeding at the gastrojejunostomy staple-line. Observant management with transfusion for stable patients and surgical exploration for unstable patients is typically recommended for early GI bleeding. We hypothesized that use of endoclips, which do not cause thermal injury to the surrounding tissues (or anastomosis), may be preferable to thermal approaches which could cause tissue injury. We report 2 cases of early GI bleeding after RYGBP that were successfully managed with endoclip application to bleeding lesions. Emergent endoscopy was performed, and major stigmata such as active spurting vessel and adherent clot were noted at the gastrojejunostomy staple-lines. Endoscopic hemostasis using endoclips was readily applied to bleeding lesions at staple-lines. Primary hemostasis was achieved, and there was no recurrent bleeding or complication. We conclude that therapeutic endoscopy can be performed safely for early bleeding after RYGBP. In patients with early bleeding after RYGBP, use of endoclips is mechanistically preferable to other options.

    View details for Web of Science ID 000249112000020

    View details for PubMedID 18074504

  • Endoclip closure of jejunal perforation after balloon dilatation OBESITY SURGERY Tang, S., Tang, L., Gupta, S., Rivas, H. 2007; 17 (4): 540-543


    Endoscopy is commonly used in patients undergoing Roux-en-Y gastric bypass (RYGBP) for diagnosis and intervention. Stomal stricture at the gastrojejunostomy occurs in approximately 3% to 17% of patients after laparoscopic RYGBP. The incidence of iatrogenic perforation during stomal balloon dilatation is reported to be 3% to 12% among these patients. Surgery has typically been required for iatrogenic perforation. With the availability of the endoclip, endoscopists are able to manage iatrogenic perforation non-operatively. We report a patient who had jejunal perforation during balloon dilatation after RYBGP, who was successfully closed with endoclip applications and managed non-operatively.

    View details for Web of Science ID 000245515000018

    View details for PubMedID 17608268

  • Current attitudes to the laparoscopic bariatric operations among European surgeons OBESITY SURGERY Rivas, H., Martinez, J. L., Delgado, S., Vidal, J., Lacy, A. M. 2004; 14 (9): 1247-1251


    The current attitudes among European bariatric surgeons toward the laparoscopic bariatric operations were examined.150 questionnaires were sent to recognized bariatric surgeons in Europe, and 60% responded.47% of respondents perform laparoscopic Roux-en-Y gastric bypass (LRYGBP), 81% laparoscopic adjustable gastric banding (LAGB), and 29% laparoscopic biliopancreatic diversion with or without duodenal switch (L-BPD/BPDDS). For BMI <40, 57% of respondents would only perform LAGB, 7% LRYGBP, 2% vertical banded gastroplasty (VBG), 3% L-BPD/BPDDS, and 2% intra-gastric balloon. For BMI 40-50, 43% of respondents prefer LAGB, 11% LRYGBP, 8% VBG, 5% L-BPD/BPDDS, and 33% contemplate several operations. For BMI 50-60, 30% prefer LAGB, 23% LRYGBP, 5% VBG, 16% L-BPD/BPDDS, and 26% tailor each patient's treatment. For BMI >60, 20% prefer LAGB, 24% LRYGBP, 37% L-BPD/BPDDS, 2% VBG, and 17% consider more than one operation. Although important, BMI and patient eating habits are not significant in choosing an operation for 25% of respondents. Interestingly, 39% of the surgeons offer laparoscopic bariatric surgery to so-called pediatric patients (<18). Of these, 76% favor LAGB, 8% LRYGBP, 8% L-BPD and 4% other procedures.The overall body of respondents prefers laparoscopic procedures. The responses suggest that at lower BMI there is a higher trend for restrictive operations. However, as BMI increases, combined and malabsorptive operations are preferred. At least one-third of surgeons offer bariatric surgery to patients with age <18 years, and here LAGB is greatly preferred.

    View details for Web of Science ID 000224972600019

    View details for PubMedID 15527643

  • Image of the month. Slippage of stomach through an adjustable gastric lap-band. Archives of surgery Rivas, H., Cacchione, R., Allen, J. W. 2004; 139 (10): 1127-1128

    View details for PubMedID 15492155

  • Laparoscopic assisted colectomies in kidney transplant recipients with colon cancer JOURNAL OF LAPAROENDOSCOPIC & ADVANCED SURGICAL TECHNIQUES-PART A Rivas, H., Martinez, J. L., Delgado, S., Lacy, A. M. 2004; 14 (4): 201-204


    Kidney transplant recipients have increased operative risks for major abdominal surgery. The purpose of this study is to present the results of laparoscopic assisted colectomies (LAC) in patients who have received a kidney transplant, and evaluate the difficulty and potential benefits or hazards inherent in this approach.From September 1993 to March 2003, 820 patients underwent LAC in our service. We studied all patients with kidney transplant and LAC.Three kidney transplantation recipients were included. Two patients were female and one male. The mean age was 65 years (range, 54-73 years). The average time elapsed since transplantation was 8 years (range, 6-10 years), and no patient had experienced problems with rejection. All patients had colon cancer. All of the allografts were contralateral to the side of the colon resection. The mean operative time was 103 minutes (range, 100-105 minutes). There were no complications, renal function remained intact, and there was no need to stop immunosuppression. The average length of hospital stay was 5 days (range, 4-7 days). The mean followup time has been 17 months (range, 3-40 months). Since surgery there have been no episodes of rejection and the patients have been free of cancer.The benefits of minimal access surgery seem to be shared by kidney transplant recipients. A key feature may be to avoid stopping immunosuppression perioperatively, therefore lowering the potential risk of rejection. Also, lessening the number of wound-related problems appears important for these patients. LAC in experienced hands must be considered a safe alternative for elective colon resections in highly selected patients with kidney transplants.

    View details for Web of Science ID 000223572700002

    View details for PubMedID 15345155

  • Laparoscopic-assisted colectomy in patients with liver cirrhosis SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Martinez, J. L., Rivas, H., Delgado, S., Castells, A., Pique, J. M., Lacy, A. M. 2004; 18 (7): 1071-1074


    Nonhepatic abdominal surgery, and especially colorectal surgery, is associated with high rates of morbidity and mortality among cirrhotic patients. With proper patient selection and preoperative optimization of the patient's condition, laparoscopic-assisted colectomy could become effective and safe for patients with compensated liver cirrhosis. The aim of this study was to evaluate the safety and feasibility of minimal-access surgery in these patients.Between September 1993 and March 2003, 820 patients underwent laparoscopic-assisted colectomy at our hospital. We studied all patients with liver cirrhosis who underwent this operation.Seventeen patients with cirrhosis were included in the study. Twelve were Child's A and five were Child's B. The mean operative time was 150 min (ranges 75-280), mean estimated blood loss was 245 ml (ranges 100-250). The conversion rate to open surgery was 29% (five patients). Median length of hospital stay was 5 days. The morbidity rate was 29% (five patients). There were no anastomotic leaks or operative-related deaths. The median follow-up was 21 months.Laparoscopic-assisted colorectal surgery can be performed in compensated cirrhotic patients with low morbidity and mortality. Adequate patient selection and expertise in advanced minimal-access surgery are essential to obtain such good results.

    View details for DOI 10.1007/s00464-003-9222-6

    View details for Web of Science ID 000222826800012

    View details for PubMedID 15156381

  • Jaundice due to extrabiliary gallstones. JSLS : Journal of the Society of Laparoendoscopic Surgeons / Society of Laparoendoscopic Surgeons Stevens, S., Rivas, H., Cacchione, R. N., O'Rourke, N. A., Allen, J. W. 2003; 7 (3): 277-279


    Cholecystectomy is one of the most common general surgical procedures performed today. The laparoscopic approach is beneficial to patients in terms of length of stay, postoperative pain, return to work, and cosmesis. Some drawbacks are associated with the minimal access form of cholecystectomy, including an increased incidence of common bile duct injuries. In addition, when the gallbladder is inadvertently perforated during laparoscopic cholecystectomy, retrieval of dropped gallstones may be difficult. We present a case in which gallstones spilled during cholecystectomy, causing near circumferential, extraluminal common hepatic duct compression, and clinical jaundice 1 year later.The patient experienced jaundice and pruritus 12 months after laparoscopic cholecystectomy. A computed tomographic scan was interpreted as cholelithiasis, but otherwise was normal (despite a previous cholecystectomy). Endoscopic retrograde cholangiopancreatography was performed and a stent placed across a stenotic common hepatic duct.The results of brush biopsies were negative. The stent rapidly occluded and surgical intervention was undertaken. At exploratory laparotomy, an abscess cavity containing multiple gallstones was encountered. This abscess had encircled the common hepatic duct, causing compression and fibrosis. The stones were extracted and a hepaticojejunostomy was tailored. The patient's bilirubin level slowly decreased and she recovered without complication.Gallstones lost within the peritoneal cavity usually have no adverse sequela. Recently, however, numerous reports have surfaced describing untoward events. This case is certainly one to be included on the list. A surgeon should make every attempt to retrieve spilled gallstones due to the potential later complications described herein.

    View details for PubMedID 14558721

  • Laparoscopic management of Meckel's diverticulum in adults SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Rivas, H., Cacchione, R. N., Allen, J. W. 2003; 17 (4): 620-622


    Meckel's diverticulum is an uncommon entity. A high index of suspicion is necessary for opportune diagnosis and prompt treatment. Technetium (TC) 99m pertechnetate scintigraphy is a sensitive and specific test for Meckel's diverticulum. In adults, the scan contributes little to clinical decision making and often will not change the need for surgical intervention. We describe our experience with four patients.Between August 2000 and August 2001, four patients were seen with Meckel's diverticula. Three were male and one was female. The mean age was 39 years (range, 18-64). Three patients presented with anemia and one with an acute abdomen. A 99mTc pertechnetate scan was performed at a cost of 900 dollars in the three anemic patients after other endoscopic and radiographic tests were nondiagnostic. Only one patient had a positive scan. All four patients underwent exploratory laparoscopy and small bowel resection. In one patient, a minilaparatomy had to be performed.All patients had a satisfactory outcome without complications. Three patients were discharged within 3 days of surgery. The remaining patient had a prolonged hospital stay because of ongoing chemotherapy for small cell lung cancer. In the three anemic patients who underwent enterectomy, ulcerated small bowel outside the diverticulum was found by the pathologist.Laparoscopy is safe, cost-effective, and efficient for the diagnosis and definitive management of Meckel's diverticulum. Technetium 99m pertechnetate scintigraphy scanning adds considerable time and expense to the care of the patient without significant benefits in adults. The practice of exploratory laparoscopy rather than scintigraphy is recommended.

    View details for DOI 10.1007/s00464-002-8613-4

    View details for Web of Science ID 000182269100035

    View details for PubMedID 12582775

  • Intracorporeal suturing and knot tying broadens the clinical applicability of laparoscopy. JSLS : Journal of the Society of Laparoendoscopic Surgeons / Society of Laparoendoscopic Surgeons Allen, J. W., Rivas, H., Cocchione, R. N., Ferzli, G. S. 2003; 7 (2): 137-140


    As surgeons become more experienced with basic laparoscopic procedures like cholecystectomy, they are able to expand this approach to less common operations. However, without laparoscopic suturing skills, like those obtained with Nissen fundoplication, many operations cannot be completed laparoscopically. We present a series of 10 patients with less common surgical illnesses who were successfully treated with minimal access techniques and intracorporeal suturing.Over a 6-month period at 2 medical centers, 10 patients underwent operations with laparoscopic intracorporeal suturing and knot tying. Diagnoses included bowel obstruction due to gallstone ileus (n=1), perforated uterus from an intrauterine device (n=1), urinary bladder diverticulum (n=1), bleeding Meckel's diverticulum (n=3), and perforated duodenal ulcer (n=4).Each patient was treated with standard surgical interventions performed entirely laparoscopically with intracorporeal suturing. No morbidity or mortality occurred in any patient due to the operation.Although each of these operations has been previously reported, as a series, they point out the importance of mastering laparoscopic suturing. Although devices are commercially available to facilitate certain suturing scenarios, we encourage residents and fellows to sew manually. We believe that none of these operations could have been completed as effectively by using a suture device. The ability to suture laparoscopically markedly broadens the number of clinical scenarios in which minimal access techniques can be used.

    View details for PubMedID 12856844

  • Totally laparoscopic management of gallstone ileus SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Allen, J. W., McCurry, T., Rivas, H., Cacchione, R. N. 2003; 17 (2)


    Gallstone ileus is an uncommon disease of elderly patients who present with bowel obstruction. Mortality and severe complications are common, even in modern series, due to the comorbidities in the affected patient population. A number of less invasive ways to treat this disease are described. We report on a case where enterolithotomy was performed laparoscopically. The patient is a 60-year-old diabetic woman who presented with a bowel obstruction and pneumobilia on abdominal radiographs. She underwent exploratory laparoscopy using three reusable ports, an enterolithotomy, and her remaining bowel was examined. The benefits to a minimal access approach to this rare disorder are discussed. The ability to suture laparoscopically is emphasized.

    View details for DOI 10.1007/s00464-002-4518-5

    View details for Web of Science ID 000180932600039

    View details for PubMedID 12404050

  • A simple technique for decompression of distended gallbladder during laparoscopic cholecystectomy SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Rivas, H., MaCcoll, C. 2002; 16 (11): 1640-1640

    View details for DOI 10.1007/s00464-002-8567-6

    View details for Web of Science ID 000179050000027

    View details for PubMedID 12444447

  • Understanding and optimizing laparoscopic videosystems SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Rivas, H., Cacchione, R., ALLEN, J. N. 2002; 16 (9): 1376-1376

    View details for DOI 10.1007/s00464-001-8269-5

    View details for Web of Science ID 000177925200027

    View details for PubMedID 12296317

  • Medical events during airline flights NEW ENGLAND JOURNAL OF MEDICINE Rivas, H. 2002; 347 (7): 535-536

    View details for Web of Science ID 000177674400028

    View details for PubMedID 12182189