failure to achieve satisfactory weight loss has been reported in several series of morbidly obese patients who underwent bariatric procedures . the result of inferior weight loss after roux - en - y gastric bypass ( rygb ) in high body mass index ( bmi ) patients has led to the development of biliopancreatic diversion with duodenal switch ( bpd / ds ) . the technical complexity of bpd / ds and its significant perioperative risks in the supermorbidly obese patients have resulted in a two - stage approach . in this method , a vertical sleeve gastrectomy ( vsg ) is initially performed , followed by a second - stage malabsorptive procedure after the initial weight loss and resolution of the obesity - related comorbidities . in the early era of minimally invasive surgery , laparoscopic vsg was proposed as a staged approach to the bpd / ds for high - risk super morbidly obese patients . in the last decade , however , laparoscopic vsg has been increasingly considered by many bariatric surgeons as definitive procedure because of its promising early and midterm outcomes . the technical simplicity and more modest learning curve of laparoscopic vsg have contributed to its rapid adoption among bariatric surgeons . as techniques in minimally invasive surgery improve , the previously high - risk bpd / ds is now performed as a single - stage operation with minimal complications and excellent outcomes . to our knowledge , there have been no reports that compare the complications and outcomes between laparoscopic vsg and laparoscopic single - stage bpd / ds . in this study , we investigated the outcomes of laparoscopic vsg as a stand - alone procedure and compare them with those of single - stage laparoscopic bpd / ds in morbidly obese patients . a prospectively maintained database of 100 consecutive patients who underwent laparoscopic vsg ( group 1 ) and 100 consecutive patients who underwent laparoscopic bpd / ds ( group 2 ) by two bariatric surgeons in a large independent teaching hospital was retrospectively reviewed . patient demographics ( age , gender , bmi , and number of obesity - related comorbidities ) , intraoperative details , perioperative complications , length of hospital stay ( los ) , weight loss outcome at 1- , 3- , 6- , 9- , 12- , 18- month intervals , and mortality were compared . major complications were defined as potentially life - threatening events that were directly related to the operation . these include anastomotic or staple line leak , hemorrhage , intestinal obstruction , inadvertent injury to other organs , venous thromboembolism , and all events that required return to the operating room . minor complications were defined as nonlife - threatening events that result in prolongation of the typical postoperative recovery course . these include superficial skin or soft tissue infection , minor incisional hematoma , urinary tract infection , or musculoskeletal problems . the standard criteria for bariatric surgery selection included bmi above 40 kg / m without comorbidities , or bmi above 35 kg / m with at least one obesity - related comorbidity . all patients underwent comprehensive preoperative medical evaluation , detailed psychological assessment , relevant laboratory , and radiologic testing , as well as esophagogastroduodenoscopy . a sleep apnea test was performed in patients with clinical suspicion of obstructive sleep apnea . all patients were counseled about other surgical options , including laparoscopic rygb and laparoscopic adjustable gastric banding . postoperatively , patients were encouraged to maintain an exercise program and regularly attend the bariatric patient - support group meetings . standard postoperative follow - up included visits to the outpatient clinic at 1- , 3- , 6- , 9- , 12- , 18- month intervals and then annually thereafter . , statistical analysis was performed using student 's t - test with p  0.05 considered statistically significant . patients in group 1 were older than those in group 2 ( 50.8 vs. 46.4 years ; p < 0.05 ) , although gender distribution ( female predominance ) , average bmi ( 48.8 vs. 51.9 kg / m ; p > 0.05 ) , and number of obesity - related comorbidities ( 7.1 vs. 6.8 ; p > 0.05 ) were comparable [ table 1 ] . patients demographics one patient in each group required open conversion because of dense intraabdominal adhesions from prior laparotomy . compared to the bpd / ds group , the vsg group had a significantly shorter mean operative time ( 107 vs. 296.8 min , p < 0.05 ) . average blood loss was minimal ( < 50 ml ) in both groups , without intraoperative complications . in the bpd / ds group , one patient developed a staple line leak , which resulted in perigastric air - fluid collection 14 days postoperatively . this patient experienced significant postoperative nausea and hematemesis , which required placement of a decompressive nasogastric tube and blood transfusion . the bleeding resolved on postoperative day 2 , without the need for endoscopic or surgical intervention [ table 2 ] . 30-day perioperative outcomes and complications one patient in the vsg group was returned to the operating room for surgical hemostasis , related to a port - site hemorrhage . in the bpd / ds group , two patients were returned to the operating room , one on postoperative day 1 for an endoscopic release of a nasogastric tube that had been inadvertently sutured during the robotically - assisted creation of the duodenoileal anastomosis , and the other patient returned on postoperative day 2 because of port - site infection . the average los after vsg and bpd / ds was statistically comparable . in the vsg group , two patients had an extended hospital stay because of prosthetic heart valve complications , as well as urologic complications related to recurrent hematuria and urinary retention . in the bpd / ds group , two other patients stayed longer in the hospital because of the exacerbation of carpal tunnel syndrome and skin / soft tissue infection at one of the trocar insertion sites ( 9 and 13 days , respectively ) . in the first 3 months postoperatively , patients in the vsg group and bpd / ds group achieved a comparable percentage of excess weight loss . the weight loss , however , promptly reached statistical difference at the 6-month interval ( 45.4 vs. 52.4% , p < 0.05 ) , with the bpd / ds served as the more effective weight loss operation . the difference became even more significant at 9 , 12 , and 18 months , postoperatively [ table 3 ] . percentage of patients who reached bmi < 35 kg / m at 18-months postoperatively ( final weight loss ) was 60% in the vsg group and 85% in the bpd / ds group . at the end of study ( 18 months postoperatively ) , approximately 35% of vsg patients were lost to follow - up . in the bpd / ds group , it is a modification of the original biliopancreatic diversion operation described by scopinaro et al . , in 1979 and the ds operation described by demeester et al . , in 1987 . ideally , bariatric procedure should be technically simple with acceptable low morbidity and mortality , sustained weight loss , as well as excellent resolution of obesity - related comorbidities . greater technical challenges and perioperative risks associated with the bpd / ds have led to the adoption of vsg as the initial and potentially definitive procedure for treatment of morbid obesity . patients with unsatisfactory weight loss and poor resolution of obesity - related comorbidities after vsg then proceeded with the ds during a second operation . many of the superobese and high - risk patients underwent the second stage within 2 years with improved comorbidities and surgical risk status . in contrast , patients with sufficient weight loss and excellent resolution of obesity - related comorbidities after vsg do not require the second stage of the bpd / ds . the primary goal of bariatric surgery is to find a technically simple , safe , and effective operation for the treatment of morbid obesity . when perioperative variables were compared between the two groups , the vsg group had a significantly shorter operative time , which correlated to its technical simplicity . literature showed that the operative mortality rate in the first reported laparoscopic bpd / ds series was 2.5% and specifically in a subgroup of patients with preoperative bmi greater than 60 kg / m , the mortality rate reached 6.5% . when compared to the 0% mortality rate reported by mukherjee et al . , after laparoscopic vsg , bpd / ds was clearly a procedure with significant risks of death . additionally , in two large open bpd / ds series in 1993 and 2007 by marceau et al . , the anastomotic leak rate was 2.7% and 3.75% , respectively . in our series of vsg and bpd / ds , however , the overall morbidity ( 1% staple line leak and 1% bleeding rate after bpd / ds , vs. 0% after vsg ) and mortality ( 0% after both procedures ) are significantly lower , compared with those reported in the literature . these findings suggested that in the current era of widely used minimally invasive approach , both vsg and single - stage bpd / ds can be performed laparoscopically , with a low complication rate and a relatively equal safety profile . our patients experienced excess weight loss of 18% and 31.4% at 1 and 3 months after the vsg , respectively . this early result was comparable with that achieved after the bpd / ds . at 6 months postoperatively , however , the bpd / ds group showed a significantly higher percentage of weight loss compared with the vsg . this difference may represent the role of malabsorptive component in medium and long - term weight reduction in postbariatric surgery patients . the third national health and nutrition examination survey 1999 reported that morbidly obese patients with bmi greater than 35 kg / m were found to have relative risks ( rrs ) of 1.97 , 6.16 , and 3.77 to experience heart diseases , diabetes mellitus , and hypertension , respectively , when compared to the nonobese population . in addition to a higher prevalence of obesity - related medical comorbidities , a significant increased risk of mortality was observed in patients with bmi > 35 kg / m ( rr = 1.36 , p < 0.05 ) . this information led us to conclude that although modest weight loss has been shown to improve many of the metabolic complications of obesity , greater degree of weight loss ( target bmi < 35 kg / m ) is necessary to achieve all of the benefits of bariatric surgery . our study demonstrated that the vsg group experienced a 64% excess weight loss , while bpd / ds group experienced 79.6% excess weight loss at 18 months postoperatively . there have been different opinions among bariatric surgeons on the degree of postoperative excess weight loss to be considered adequate , but we believe that bmi should fall below 35 kg / m , in order to optimally benefit from a bariatric operation , based on the published third national health and nutrition survey data . hypothetically , if a morbidly obese male with bmi of 57 kg / m and body weight of 400 lbs were to undergo a laparoscopic vsg , his bmi would only fall to 36 kg / m at 18 months postoperatively . with this degree of weight loss ( postoperative bmi still above 35 kg / m ) , the patient will continue to have an increased risk for developing heart disease , diabetes mellitus , and hypertension , compared to their nonobese counterparts , as mentioned above . when the same patient were to undergo laparoscopic bpd / ds , his bmi would fall to 31 kg / m postoperatively , which gives him the maximum benefit of the bariatric surgery . in this study , we found that after bpd / ds , a significantly higher percentage of patients were able to reach final bmi of < 35 kg / m compared with the vsg group ( 85% vs. 60% , respectively ) . therefore , we believe a higher percentage of excess weight loss to achieve final bmi less than 35 kg / m using bpd / ds , should be sought in an appropriate clinical setting . there are several limitations in this study , such as its retrospective nature with relatively small sample size . our follow - up rate at 18 months postoperatively was only approximately 65%-70% , as described previously . , where 22% of their patients were unavailable for medium - term follow - up , even in a country using socialized medical care system . laparoscopic vsg is a lower - risk and a technically simpler operation with promising weight loss outcome . the single - stage laparoscopic bpd / ds , however , produces superior weight loss with acceptable complication rates . the statistically significant difference in weight loss between the two operations became evident at 6 months postoperatively and persisted thereafter . we , therefore , recommend single - stage laparoscopic bpd / ds in patients with a high bmi , in an attempt to achieve the target bmi of less than 35 kg / m postoperatively .
background : vertical sleeve gastrectomy ( vsg ) was originally performed as the first - stage of biliopancreatic diversion with duodenal switch ( bpd / ds ) for superobesity as a strategy to reduce perioperative complications and morbidity . 
 vsg is now considered a definitive procedure because of its technical simplicity and promising outcomes.aims:to analyze the outcomes of laparoscopic vsg and to compare them with those of single - stage laparoscopic bpd / ds.materials and methods : a retrospective review of 200 consecutive patients who underwent vsg and bpd / ds between 2008 and 2011.results:a total of 100 patients underwent laparoscopic vsg and 100 patients underwent laparoscopic bpd / ds . 
 the patients in vsg group were older , but gender distribution and body mass index were comparable . 
 mean operative time for vsg was significantly shorter compared with that of bpd / ds . 
 a single patient in each groups required open conversion . 
 staple line leak ( n = 1 ) and intraluminal hemorrhage into the newly - created sleeve ( n = 1 ) occurred in the bpd / ds group . 
 mean length of stay was shorter after vsg ( 3.1 vs. 3.9 days ) . at 6 months 
 postoperatively , excess weight loss between the two groups revealed statistically significant difference , favoring bpd / ds.conclusions : despite promising outcomes and technical simplicity of vsg , bpd / ds provides significantly superior excess weight loss in morbidly obese patients .