globally , the body mass index ( bmi ) has been increasing over the last 30 years . currently , more than 20% of the world population is overweight and approximately 10% are obese . in particular , the world health organization estimates that over 1.5 billion individuals are overweight and 500 million are obese . in canada , an estimated 60% of the population was classified as overweight and 24% as clinically obese [ 47 ] . currently , bariatric surgery is the only evidence - based approach shown to be effective at achieving marked and sustained weight loss in obese individuals . in addition , resolution of comorbidities , such as type 2 diabetes mellitus ( t2 dm ) and hypertension commonly , occurs following bariatric surgery . roux - en - y gastric bypass ( rygb ) is the most commonly performed bariatric surgical procedure in north america . weight loss was thought to occur by malabsorption ; however , this may not be the primary mechanism of action . recently , there has been a suggestion that rapid nutrient delivery to the jejunum and ileum may trigger a hormonal response ( involving glp1 and pyy ) that alters satiety and hunger [ 10 , 11 ] . a number of studies have shown significant and sustained weight loss following rygb in severely obese individuals . however , to date , there have only been a small number of studies that have looked at rygb outcomes in a publically funded canadian healthcare system [ 1215 ] . the objective of this study was to analyze the outcomes of laparoscopic rygb performed as part of a comprehensive weight management program in a publically funded canadian hospital . this was a retrospective observational study to investigate the outcomes following rygb as part of a comprehensive weight management strategy . weight wise is a multidisciplinary adult weight management program , which includes physicians , nurses , dieticians , and other healthcare professionals . obese patients are enrolled and followed in the weight wise clinic , with bariatric surgery offered to patients as part of an overall treatment strategy by the multidisciplinary team . ethics approval was obtained from human research ethics board at the university of alberta . a total of 293 patients who underwent laparoscopic rygb since the inception of a bariatric program were reviewed from jan 2005 to june 2011 . the hospital was a canadian , publically funded , level 2 trauma center with 750 inpatient beds . the center was located in the inner city and had university - based teaching services , including an accredited minimally invasive surgery / bariatric program . three generalist surgeons performed all the operations with the mis fellow present at each surgery since 2010 . the presence of preoperative medical conditions was also recorded , including t2 dm , hypertension , sleep apnea , and gastroesophageal reflux disease ( gerd ) . operative details were extracted including operative time , position of roux limb , use of orvil stapler ( covidien ; massachusetts , usa ) , perioperative complications , and use of hemostatic agents . patient records at the weight wise medical program were used to extract postoperative outcomes , including change in weight , complications , reoperations , change in medications , resolution of medical conditions , and diagnostic investigations . the postoperative time points were 1 month , 3 months , 6 months , 1 year , 2 years , and 3 years . the data was analyzed to determine changes in absolute weight , body mass index , and excess body weight . weight values at the initial entry into the weight wise program were compared to preoperative and postoperative weights . resolution or improvement of obesity - related comorbidities following rygb was recorded . for t2 dm , improvement in t2 dm was defined as any decrease in the amount or number of oral hypoglycemic agents or insulin compared to the preoperative period . for hypertension improvement was defined as any decrease in the amount or number of antihypertensives compared to the preoperative period . median time to resolution was calculated based on the postoperative time of visit at which a change in comorbidity status was first recorded in the clinic . the mean operative time was compared among rygb performed near the inception of the program and those performed recently . the perioperative complication rate was calculated for gastrointestinal hemorrhages , anastomotic leaks , stricture formation , ulceration , reoperation , and mortality . perioperative gastrojejunal ( gj ) leaks were diagnosed with an intraoperative methylene blue leak test . patients with symptoms of gastric outlet obstruction were evaluated with a gastrografin upper gi series followed by esophagoduodenoscopy for definitive diagnosis and treatment . length of hospital stay was calculated from the date of surgery to the date of discharge . the use of an orvil stapler was compared to suturing for the gj anastomosis with respect to postoperative stricture development . cost analysis was performed with a sample year of 2010 and values were adjusted by 5% for inflation per year . weight wise clinic costs are an average value for either a preoperative or postoperative visit . the average cost of a rygb surgery is based on the supply cost per case and labour cost for average or time . length of stay cost is based on the total average inpatient cost per day at the royal alexandra hospital . the overall cost analysis is based on the average uncomplicated patient who required no additional investigation due to postoperative complications or reoperations . all patients were enrolled in an adult weight management program called weight wise . the program consisted of a multidisciplinary team of physicians , nurses , dieticians , and counselors who were experienced in the treatment of obesity . the clinic assisted with diet and lifestyle modifications and provided follow - up care after the surgery . weight management plans involved diet and behavior modification , counseling , education , advice on exercise , and pharmacologic treatment . when patients showed progress in the clinic , they were presented with the option of surgery . patients were presented with multiple surgical options according to their unique situation ; rygb was only one of the options . following the canadian guidelines , patients older than 18 years of age with a bmi > 40  kg / m or a bmi > 35  kg / m with comorbidities were selected for surgery . although in practice , due to limited resources and a large population that the clinic serves , patients with a higher bmi are prioritized , leading to increased wait times for others . all patients are nonpaying in the publically funded system , and thus resource allocation remains an important issue . after surgery , the patients were followed up with the program at specific intervals to monitor their postoperative progress . when patients achieved adequate weight loss without complications , they were transitioned from the clinic to the care of their family doctor . patients returned to the clinic if they had subsequent complications or other failures of treatment relating to their weight . the gastrojejunal ( gj ) anastomosis was created either by intracorporeal suturing ( hand - sewn ) or the use of circular eea ( orvil ) stapler . the roux limb was approximately 100  cm in length and was placed either antecolic or retrocolic depending on the judgment of the surgeon . methylene blue injected through a gastroscope or nasogastric tube was used to test the integrity of the gj anastomosis . excess weight was calculated as the amount of weight over a bmi of 24.9  kg / m preoperatively . excess weight loss ( ewl ) was determined by the weight loss at a specific postoperative time point . wilcoxon signed rank test and paired t - test were used for continuous variables according to data normality . the median number of visits to the weight wise program prior to surgery was 9 , over a median period of 13 months . the preoperative bmi was significantly lower than the initial bmi ( 51.6  9.4 versus 55.3  10.0  kg / m , p - value < 0.001 ) . the median follow - up time was 1 year postoperatively ; 94.5% of the patients were followed up with the weight wise program at some point postoperatively . at 1 year , 69.3% of the patients were followed up with the bariatric program . at 3 years follow - up , however , patients normally transition to general practitioner care around 2 years postoperatively if they experienced consistent weight loss and minimal complications . there was no significant difference in operative times among the first hundred and the second hundred cases or the last 93 cases . the majority of rygb surgeries were teaching cases , and since 2010 , an mis fellow has been present and performing a portion of the operation . furthermore , the addition of a third generalist surgeon and the change to the orvil stapler for gj anastomosis ( which occurred at the same time ) did not significantly affect operative times . the seven patients ( 2.4% ) had a gj leak , 4 patients ( 1.4% ) had a stomach stapler line bleed , and 3 patients ( 1.0% ) had abdominal bleeds . surgeon preference determined whether the antecolic or retrocolic positioning of the roux limb was chosen , with an increased frequency of retrocolic positioning ( 60% ) . a percentage of 5.3 of the patients had gastrointestinal obstruction after retrocolic positioning versus 7.9% of the patients who had antecolic roux limb positioning . both the 21  mm and 25  mm orvil staplers were used in the study , but the stapler group does not differentiate between the two . the sewn group had significantly more gj leaks when compared to the stapler group ( 8.8% versus 0% , p - value < 0.001 ) . there were no differences in the rates of gj stricture , abdominal bleeds , staple - line bleeds , or upper gi obstruction when comparing the two groups . as shown in figure 1 , bmi significantly decreased from the initial visit at the weight wise to the preoperative assessment with only lifestyle modifications . there was a significant decrease in the mean bmi at 1 month after rygb compared to preoperative assessment ( p - value < 0.001 ) . furthermore , there was a statistically significant decrease in bmi at each postoperative time point when compared to the preoperative value ( p - value < 0.001 ) the average decrease in bmi was 16.7  1.4  kg / m for the patients who were followed up for 3 years postoperatively . as shown in figure 2 , the absolute weight ( kg ) showed significant decreases at all postoperative time points when compared to the preoperative value ( p - value < 0.001 ) . this was comparable to the change in bmi seen in figure 1 . on average , patients lost 56.1  17.7  kg or 35.5  8.6% of the initial weight at 12 months after rygb . this was equivalent to an excess weight loss of 63.4  20.4% at 12 months after rygb . as with bmi , there was no significant increase in the weight from 2 years to 3 years postoperatively . there were two deaths ( 0.7% ) postoperatively that were related to ongoing sepsis , 15.4% of the patients experienced a complication within the first 3 months postoperatively , 4.8% of the patients experienced a gj leak , and 6.5% of the patients experienced a gj stricture after laparoscopic rygb . a percentage of 4.7 of the patients required surgical revision of the rygb . these included bowel resection due to obstruction ( 1.7% ) , gastrogastric fistula repair ( 1.4% ) , gj anastomosis revision secondary to anastomotic leak ( 1.0% ) , enteroenterostomy repair ( 0.3% ) , and stomach repartitioning ( 0.3% ) . fifty - eight patients ( 19.8% ) underwent a subsequent panniculectomy at a medium of 24 months after rygb to remove excess skin after their significant weight loss . table 5 summarizes the prevalence of obesity - related comorbidities before and after rygb surgery . improvement , resolution , and development of these complications were previously defined ( see section 2 ) . the average cost for a patient to go through the preoperative visits , rygb surgery , and the postoperative visits is $ 24,742.88 . our study demonstrates that rygb can be performed safely and effectively on super obese individuals in a publically funded canadian academic center as part of a comprehensive weight management strategy . super obese patients at our institution had marked and sustained weight loss at three years post - rygb , with acceptable morbidity . the weight wise obesity program is unique in that it services a very large region due to limited centers in its proximity . patients are nonpaying , and those selected for surgery tend to have a higher bmi . patients with higher bmis are preferentially selected because they are deemed more likely to benefit from bariatric surgery . this biases the surgical candidates towards those with more significant comorbidities and likely impacts the results we obtain . additionally , nearly 25% of our patients are unemployed , on social assistance , or on long term disability . this is in contrast to private centers where these same patients would not be able to afford multidisciplinary treatment and rygb surgery . however , even with a unique patient population , this study shows that a multidisciplinary program in a public system can still obtain good results . the mean bmi just prior to surgery in our study was 50  kg / m , which is demonstrative of the bias mentioned previously . in fact , one - fifth of the patients in this study had a bmi greater than 60  kg / m . in contrast , adams et al . reported a mean preoperative bmi of 44.9    7.6 regardless of this difference , we were still able to obtain significant and comparable weight loss . the mean weight loss and decrease in bmi following rygb in our series were comparable to the literature [ 12 , 18 , 19 ] . kothari et al . recently reported data from a similar institution in the private american sector . over a seven - year period , their academic center performed 700 rygb surgeries and reported excess weight loss of 72.4% at 12 months postoperatively , which was comparable to our 63.4% . these authors also reported a weight gain trend in the latter years , nearly 60 months of follow - up . this was similar in our study , in which a plateau was observed at approximately 12 months postoperatively . additionally , welch et al . reported a mean excess weight loss of 59.1% and a decrease in bmi of 15.7  kg / m , which was comparable to our 16.7  kg / m decrease after 36 months . therefore , in comparison to american academic centers , our study demonstrates that similar effectiveness of rygb can be achieved in a publically funded canadian health care system . the mean operating time to perform laparoscopic rygb in our series was similar to that previously reported in the literature [ 13 , 19 , 20 , 22 , 23 ] ; however , considerable variability exists between studies [ 18 , 24 , 25 ] . furthermore , a number of studies have suggested that a learning curve exists and influences operating times [ 13 , 25 , 26 ] . the canadian study by schaeffer et al . reported that their operative time was significantly lower in their second cohort of 60 patients , with a mean time of 146  min . this may be related to the frequent turnover of residents and fellows commonly participating in the operating room at an academic center . in terms of the bariatric surgeons at our institution , they all have received fellowship training , which may influence operative times . supportively , oliak et al . suggest that fellowship training in laparoscopic rygb surgery appears to decrease operating times . overall , our complication rates following rygb were comparable to other laparoscopic rygb series [ 13 , 25 , 26 ] . however , we observed an overall gj stricture rate of 6.5% , compared to a 24% rate reported in the literature [ 2732 ] . interestingly , the rate of gj stricture was lower at 4.7% in the patients whose gj anastomosis was secured with a circular stapler . this is comparable to the recent american study by dolce et al . who reported a gj stricture rate of 9.4% after using a circular stapler for the gj anastomosis . furthermore , our rate was comparable to the swiss study by suter et al . who reported a gj stricture rate of 5.8% after 466 rygb surgeries . the most important complication following rygb remains to be the anastomotic leakage , specifically the gj anastomosis . et al . identified 580 patients who underwent rygb surgery at a privately funded institution . moreover , their mortality rate was 0.7% for the laparoscopic rygb group , which was comparable to our mortality rate . therefore , our study has comparable serious complication and mortality rates to a privately funded institution . this is comparatively low in relation to the large american study by schauer et al . , where they found that 80% of their 191 diabetic patients showed improvement after laparoscopic rygb . improvement in their study was defined as a decrease in oral antidiabetic agents , which is similar to our definition . in contrast , the canadian study by schaeffer et al . reported a 16% decrease in the rate of t2 dm after rygb . interestingly , the rate of improvement of hypertension in our study was 50% , which was higher than that reported by batsis et al . at a privately funded institution . the canadian study by schaeffer et al . also reported a 19% decrease in the rate of hypertension after rygb , which was approximately a 40% improvement rate . so , there is discrepancy in the improvement rates for both t2 dm and hypertension . the variations in reported rates in the literature likely relate to variation of the definition of improvement , and how intensively these improvements are searched for . for instance , our study did not systematically assess comorbidities at each follow - up visit , which may have led to underestimation of the actual improvement rates . nonetheless , it is widely accepted that rygb surgery can improve obesity - related comorbidities . cost analysis is a very important aspect of surgeries performed in a publically funded health care system . a recent study by martin et al . reported that private clinics in canada were charging an average of $ 16,000.00 to patients for a rygb procedure . compared to our average cost however , it is important to consider that their number of preoperative visits ( 2.7 ) and postoperative visits ( 3.7 ) was less than our clinic . this translates into fewer visits with the multidisciplinary team ( including dieticians , psychologists , and education classes ) . consequently , patients receive more comprehensive care through our clinic compared to private canadian clinics . salem et al . performed a cost analysis of both rygb and adjustable gastric banding surgeries . their reported cost ranged from $ 18,000 to $ 36,000 for one patient to undergo rygb surgery and postoperative follow - up . additionally , they found that rygb had a $ 14,680/qaly ( quality adjusted life year ) . based on the assumption that < $ 25,000/qaly defines cost effectiveness , then rygb is a cost effective procedure . their qaly analysis took into account the benefits of rygb on the overall health and the resulting future cost savings . consequently , at our current cost per patient we can offer a cost effective , publically funded rygb surgery . firstly , the retrospective nature of our study may lead to selection bias . secondly , at a 3-year follow - up after rygb , only 23.5% of the patients remained . however , patients normally transition to their general practitioner 's care if they experienced consistent weight loss and minimal complications . thirdly , it is difficult to consider all the possible variables in a public system that may influence our patients and this study . consequently , the overall effectiveness of the program can be influenced by variables not considered in this study . the surgeons in the study do have fellowship training , but they have diverse practices within the trauma center as general surgeons in addition to performing bariatric surgery . however , even with the limitations identified , this study demonstrates that significant short and intermediate term weight loss is achieved for super obese patients following rygb . in conclusion , our study demonstrates that rygb performed in a publically funded bariatric program , in the setting of a teaching hospital , whose surgeons have diverse practices outside of bariatric surgery , is still effective in producing significant and sustainable weight loss .
background . there is limited literature assessing the outcomes of bariatric surgery in a publically funded , north american , multidisciplinary bariatric program . 
 our objective was to assess outcomes of roux - en - y gastric bypass ( rygb ) in a publically funded bariatric program through a retrospective review of patient records . 
 methods . 
 293 patients spent a median of 13 months attending a multidisciplinary obesity clinic prior to undergoing laparoscopic rygb surgery . 
 the hospital was a canadian , publically funded , level 2 trauma center with university teaching services . results . 
 79% of the patients were female and the average bmi at first visit to clinic was 55.3 kg / m2 . 
 the average decrease in bmi was 19.2  0.9  kg / m2 . 
 this was an average absolute weight loss of 56.1 kg or 35.5% of initial weight . 
 the average excess weight loss was 63.4  20.4% . 
 improvement or resolution of obesity related comorbidities occurred in 65.9% of type 2 diabetics and in 50% of hypertensive patients . conclusion . despite this being an unconventional setting of a publically funded program in a large canadian teaching hospital , 
 early outcomes following rygb were appropriate in severely obese patients 
 . ongoing work will identify areas of improvement for enhanced efficiencies within this system .