Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Ranjan Sudan is active.

Publication


Featured researches published by Ranjan Sudan.


Surgery for Obesity and Related Diseases | 2014

Systematic review on reoperative bariatric surgery: American Society for Metabolic and Bariatric Surgery Revision Task Force.

Stacy A. Brethauer; Shanu N. Kothari; Ranjan Sudan; Brandon Williams; Wayne J. English; Matthew Brengman; Marina Kurian; Matthew M. Hutter; Lloyd Stegemann; Kara J. Kallies; Ninh T. Nguyen; Jaime Ponce; John M. Morton

BACKGROUND Reoperative bariatric surgery has become a common practice in many bariatric surgery programs. There is currently little evidence-based guidance regarding specific indications and outcomes for reoperative bariatric surgery. A task force was convened to review the current evidence regarding reoperative bariatric surgery. The aim of the review was to identify procedure-specific indications and outcomes for reoperative procedures. METHODS Literature search was conducted to identify studies reporting indications for and outcomes after reoperative bariatric surgery. Specifically, operations to treat complications, failed weight loss, and weight regain were evaluated. Abstract and manuscript reviews were completed by the task force members to identify, grade, and categorize relevant studies. RESULTS A total of 819 articles were identified in the initial search. After review for inclusion criteria and data quality, 175 articles were included in the systematic review and analysis. The majority of published studies are single center retrospective reviews. The evidence supporting reoperative surgery for acute and chronic complications is described. The evidence regarding reoperative surgery for failed weight loss and weight regain generally demonstrates improved weight loss and co-morbidity reduction after reintervention. Procedure-specific outcomes are described. Complication rates are generally reported to be higher after reoperative surgery compared to primary surgery. CONCLUSION The indications and outcomes for reoperative bariatric surgery are procedure-specific but the current evidence does support additional treatment for persistent obesity, co-morbid disease, and complications.


Obesity Surgery | 2004

Altered Olfactory Acuity in the Morbidly Obese

Brynn E. Richardson; Eric A. Vander Woude; Ranjan Sudan; Jon S. Thompson; Donald A. Leopold

Background: Obese individuals have been reported to have a heightened desire for and ability to identify sweets when compared with leaner persons. Smell, like taste, may also be altered in obese persons compared with leaner subjects. This study was designed to determine if the sense of smell is different between morbidly obese and moderately obese individuals. Methods: 101 adult volunteers undergoing preoperative evaluation completed the 12-item Cross-Cultural Smell Identification Test (CC-SIT) before surgical intervention. Age, BMI, and smoking history were also obtained. Results: 101 subjects completed the preoperative CC-SIT (87 female, 14 male). Mean age of the subjects was 40 ± 12 years. Mean BMI was 42.5 ± 12.5 kg/m2. 46 subjects (46%) had a BMI >45. 21 were smokers (21%). 9 subjects (9%), all female non-smokers, had a CC-SIT score representing olfactory dysfunction. Subjects with BMI >45 were more likely to have olfactory dysfunction than subjects with BMI <45 (16% vs 4%, P <0.05). Conclusion: Morbidly obese individuals are more likely than moderately obese individuals to demonstrate CC-SIT scores consistent with olfactory dysfunction. The reason for this is unclear but is probably related to metabolic changes occurring in morbidly obese individuals.


Surgery for Obesity and Related Diseases | 2016

American Society for Metabolic and Bariatric Surgery estimation of bariatric surgery procedures in 2015 and surgeon workforce in the United States

Jaime Ponce; Eric J. DeMaria; Ninh T. Nguyen; Matthew M. Hutter; Ranjan Sudan; John M. Morton

American Society for Metabolic and Bariatric Surgery estimation of bariatric surgery procedures in 2015 and surgeon workforce in the United States Jaime Ponce, M.D.*, Eric J. DeMaria, M.D., Ninh T. Nguyen, M.D., Matthew Hutter, M.D., Ranjan Sudan, M.D., John M. Morton, M.D. Chattanooga Bariatrics, Chattanooga, Tennessee Bon Secours Health System, Hampton Roads, Virginia Department of Surgery, University of California Irvine Medical Center, Orange, California Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts Department of Surgery, Duke University Medical Center, Durham, North Carolina Department of Surgery, Stanford University, Palo Alto, California Received August 22, 2016; accepted August 22, 2016


Journal of Endourology | 2003

Laparoscopy-Assisted Robotic Radical Cystoprostatectomy with Ileal Conduit Urinary Diversion for Muscle-Invasive Bladder Cancer: Initial Two Cases

Paulos Yohannes; Varun Puri; Bing Yi; A. Khan; Ranjan Sudan

BACKGROUND AND PURPOSE The use of the da Vinci robot is being investigated in the discipline of urologic surgery. We describe our experience with its use during radical cystoprostatectomy in two patients with organ-confined bladder cancer. PATIENTS AND METHODS Laparoscopic radical cystoprostatectomy with ileal conduit urinary diversion was performed using the da Vinci robot. Both patients were informed about this new approach, and informed consent was obtained. RESULTS There were no intraoperative or postoperative complications. The operative time was 10 and 12 hours. A clear liquid diet was started on the third postoperative day. Final histopathology examination in both patients revealed T(3a)N(0)M(0) transitional-cell carcinoma. The hospital stay was 6 days. Both patients returned to normal activity within 2 weeks. CONCLUSION Robot-assisted laparoscopic radical cystoprostatectomy with ileal conduit urinary diversion for muscle-invasive bladder cancer is feasible.


Surgical Endoscopy and Other Interventional Techniques | 2007

Robotically assisted biliary pancreatic diversion with a duodenal switch: a new technique

Ranjan Sudan; Varun Puri; Debra Sudan

BackgroundMinimally invasive surgical techniques decrease the length of hospitalization and the morbidity for general surgery procedures. Application of minimally invasive techniques to obesity surgery had previously been limited to stapled techniques used primarily for the Roux-en-Y gastric bypass and laparoscopic band placement. The authors present the technique for totally intracorporeal robotically assisted biliary pancreatic diversion with a duodenal switch (BPD/DS) using five ports.MethodsAfter development of the technique in animal and human cadaver models, the da Vinci robot was first used in October 2000 to perform BPD/DS using five ports and a totally intracorporeal technique. Patient selection was based on standard surgery guidelines for the morbidly obese.ResultsThis technique was applied for 47 patients with a mean body mass index (BMI) of 45 kg/m2 and a mean age of 38 ± 10 years. The median operating time was 514 min (range, 370–931 min). The median operative time for the last 10 patients was 379 min (range, 370–582 min). Three patients underwent conversion to open surgery, and four patients experienced postoperative leaks with no mortality.ConclusionThe safety, feasibility, and reproducibility of a minimally invasive robotic surgical approach to complex abdominal operations such as BPD/DS is demonstrated. The BPD/DS allows for a sutured bowel anastomosis similar to the open technique using a minimal number of small access ports.


Transplantation | 2000

Long-term outcome of simultaneous kidney-pancreas transplantation: analysis of 61 patients with more than 5 years follow-up.

Debra Sudan; Ranjan Sudan; Robert J. Stratta

BACKGROUND The long-term outcome of simultaneous kidney pancreas transplant recipients is not well established. METHODS We retrospectively reviewed all patients who underwent simultaneous kidney-pancreas transplantation with bladder drainage at our center between January 1989 and December 1991. A total of 57 patients (93%) were alive with functioning grafts 1 year after transplantation and were followed for a minimum of 5 years. These patients formed the study group. RESULTS Five-year actual patient, kidney and pancreas survival rates were 95%, 85%, and 88%, respectively. Fasting serum glucose fell from 198 mg/dL preoperatively to 94 mg/dL and remained stable thereafter. Glycohemoglobin levels decreased from 9.8% preoperatively to 4.8% 1 year after transplantation and remained normal thereafter. Kidney function remained good, with mean serum creatinine of 2.0 and creatinine clearance of 56 ml/min throughout the follow-up period. Hospital admissions decreased significantly with increasing time after transplantation from a mean of 1.2 admissions per patient in the 1st year to a mean of 0.2 admissions per patient 6 years after transplantation. Of the readmissions, 42% were for <48 hr and the most common reasons for readmission were infection, surgery, and dehydration. Mean systolic blood pressure decreased from 166 mm Hg before the transplant to 142 mm Hg 1 year after the transplant. CONCLUSIONS Simultaneous kidney pancreas transplantation is a safe and effective method to treat advanced diabetic nephropathy and is associated with stable metabolic function, decreased cholesterol, improved hypertension control, improved rehabilitation over time, and little morbidity or mortality after the 1st year.


Annals of Surgery | 2012

Multifactorial analysis of the learning curve for robot-assisted laparoscopic biliopancreatic diversion with duodenal switch

Ranjan Sudan; Kyla M. Bennett; Danny O. Jacobs; Debra Sudan

Objective:To assess the impact of surgeon, patient, and case-specific factors on the learning curve of robot-assisted laparoscopic biliopancreatic diversion with duodenal switch (RA-LBPD/DS). Background:The BPD/DS has better resolution of diabetes and hypercholesterolemia, and the best long-term weight loss compared to the laparoscopic gastric band or the Roux-en-Y gastric bypass. Despite excellent results, the BPD/DS is least commonly performed because of greater malabsorption, longer operative duration, and higher technical complication rates. A reduction in technical complications and operative duration will enable the BPD/DS to be offered more frequently. Methods:Consecutive patients (N = 120) undergoing RA-LBPD/DS between October 2000 and August 2008 were analyzed using univariate and multivariate logistic regression to determine the influence of surgeon and patient factors on complications and operative duration. Independent variables were case number, age, gender, body mass index, American Society of Anesthesiologists (ASA) score, difficult anatomy, and need for extensive adhesiolysis. Dependent variables were complications (leaks, bleeding, and conversion) and operative duration. The best-fit model predicted the risk factors for complications, and a risk-adjusted cumulative sum analysis estimated the learning curve. Results:Operative duration decreased an average of 3 minutes with each successive case (P < 0.001, R2 = 0.63) and with patients female gender. Adhesiolysis, difficult anatomy, liver biopsy, and higher ASA score increased operative duration. The incidence of high blood loss (13.3%), conversion (2.2%), and leaks (5.8%) were experienced by a total of 22 patients (18.3%). There was no mortality. Complications declined after 50 cases and were strongly predicted by increasing surgeon case number. Conclusions:The learning curve for the RA-LBPD/DS is 50 cases. Risk factors influencing outcomes were identified.


Journal of Gastrointestinal Surgery | 2014

Rectal prolapse: an overview of clinical features, diagnosis, and patient-specific management strategies.

Liliana Bordeianou; Caitlin W. Hicks; Andreas M. Kaiser; Karim Alavi; Ranjan Sudan; Paul E. Wise

Rectal prolapse can present in a variety of forms and is associated with a range of symptoms including pain, incomplete evacuation, bloody and/or mucous rectal discharge, and fecal incontinence or constipation. Complete external rectal prolapse is characterized by a circumferential, full-thickness protrusion of the rectum through the anus, which may be intermittent or may be incarcerated and poses a risk of strangulation. There are multiple surgical options to treat rectal prolapse, and thus care should be taken to understand each patient’s symptoms, bowel habits, anatomy, and pre-operative expectations. Preoperative workup includes physical exam, colonoscopy, anoscopy, and, in some patients, anal manometry and defecography. With this information, a tailored surgical approach (abdominal versus perineal, minimally invasive versus open) and technique (posterior versus ventral rectopexy +/− sigmoidectomy, for example) can then be chosen. We propose an algorithm based on available outcomes data in the literature, an understanding of anorectal physiology, and expert opinion that can serve as a guide to determining the rectal prolapse operation that will achieve the best possible postoperative outcomes for individual patients.


Methods in Enzymology | 1988

[6] Long-term implantation of voltammetric oxidase/peroxide glucose sensors in the rat peritoneum

Leland C. Clark; Linda K. Noyes; Robert B. Spokane; Ranjan Sudan; Marian L. Miller

Methods for designing, fabricating, testing in vitro and in vivo, and improving chronically implantable oxidase/peroxide-type polarographic glucose sensors are described. Voltammetric means to evaluate oxygen supply to the sensor and to measure the nearby microcirculation with hydrogen washout techniques using the implanted glucose sensor are outlined. Because some peritoneally implanted sensors have, perhaps surprisingly, remained functional for months, such devices may prove with further development to be useful as the sensing components in artificial pancreatic beta cells for the control of diabetes.


World Journal of Surgery | 2013

The evolution of robotic bariatric surgery.

Erik B. Wilson; Ranjan Sudan

IntroductionThe growth of bariatric surgery has resulted in varying types of procedures with increasing complexity. Robotic digital platforms are employed in bariatric surgery to address this increasing complexity in the high-risk obese patient population with difficult anatomy.Materials and MethodsThis review explores the literature and examines the reported outcomes and complications in using robotics for bariatric surgery. Robotic approaches to adjustable gastric banding, sleeve gastrectomy, gastric bypass, and biliopancreatic diversion with duodenal switch are examined. Revisional cases, learning curves, and cost effectiveness are reviewed, with an eye toward the future of bariatric surgery as the use of robotics is adopted.ConclusionDigital platforms are showing great promise as enabling technology which advance bariatric outcomes. With increasingly complex bariatric cases being performed and revised, the insertion of digital information between the surgeon and the patient leads to better operations for the patient and the surgeon.

Collaboration


Dive into the Ranjan Sudan's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ninh T. Nguyen

University of California

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Andreas M. Kaiser

University of Southern California

View shared research outputs
Top Co-Authors

Avatar

Jaime Ponce

Memorial Hospital of South Bend

View shared research outputs
Top Co-Authors

Avatar

Karim Alavi

University of Massachusetts Medical School

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge