Medium-Term Results of Laparoscopic Sleeve Gastrectomy: a Matched Comparison with Gastric Bypass

Transcription

1 DOI /s ORIGINAL CONTRIBUTIONS Medium-Term Results of Laparoscopic Sleeve Gastrectomy: a Matched Comparison with Gastric Bypass Wei-Jei Lee & Eng-Hong Pok & Abdullah Almulaifi & Ju Juin Tsou & Kong-Han Ser & Yi-Chih Lee # Springer Science+Business Media New York 2015 Abstract Background Laparoscopic sleeve gastrectomy () is considered a primary bariatric surgery and is increasingly being performed worldwide; however, long-term data regarding the durability of this procedure are inadequate. Here, we report the long-term results of s in comparison to those of gastric bypass surgeries. Methods A prospectively collected bariatric database from Ming-Shen General Hospital was retrospectively studied. Five hundred nineteen morbidly obese patients (mean age 36.0± 9.1 years old (14 71), 74.6 % female, mean body mass index (BMI) 37.5±6.1 kg/m 2 ) underwent as a primary bariatric procedure from 2006 to 2012 at our institute. The operative parameters, weight loss, laboratory data, and quality of life were followed. Another two matched groups of laparoscopic Roux-en-Y gastric bypass (RYGB) and laparoscopic single anastomosis (mini-) gastric bypass (SAGB) patients who were matched in terms of age, sex, and BMI were recruited for comparisons. Results The mean surgical time for was 113.5± 31.3 min, and the mean blood loss was ml. The rate of major complications was 1.6 %, and the average length of the postoperative stay was 3.0±1.7 days. The operation times of the RYGB patients were longer than those of both the and SAGB patients. The RYGB and SAGB patients W.<J. Lee (*): A. Almulaifi : J. J. Tsou : K.<H. Ser Department of Surgery, Min-Sheng General Hospital, No. 168, Chin Kuo Road, Tauoyan, Taiwan, Republic of China wjlee_obessurg_tw@yahoo.com.tw E.<H. Pok Department of Surgery, University Malaysia Medical Center, University of Malaysia, Kuala Lumpur, Malaysia Y.<C. Lee Department of International Business, Chien Hsin University of Science and Technology, Zhongli City, Taoyuan County, Taiwan experienced higher major complication rate than the patients. The weight loss of the patient at 5 years was %, and the mean BMI was The RYGB patients exhibited a 5-year weight loss similar to the patients, and the SAGB patients exhibited greater weight loss than both of the other groups. Both the RYGB and SAGB patients exhibited significantly better glycemic control and lower blood lipids than the patients, but the patients exhibited a lesser micronutrient deficiency than the RYGB and SAGB groups. All three of the groups exhibited improved quality of life at 5 years after surgery, and there was no significant between-group difference in this measure. Conclusions appears to be an ideal bariatric surgery, and the efficacy of this surgery is not inferior to that of gastric bypass. Keywords Sleeve gastrectomy. Gastric bypass. Long-term result Introduction Sleeve gastrectomy (SG) is a vertical gastrectomy that leaves a narrow gastric tube along the lesser curvature of the stomach and is first described as a part of a duodenal switch (DS) bariatric surgery at 1990 [1]. Laparoscopic sleeve gastrectomy () was subsequently performed by Dr. Gagner and proposed as a stage of a bariatric protocol for high-risk patients to reduce the risk profile of laparoscopic DS [2]. However, rapidly became a stand-alone bariatric surgery worldwide because of its simplicity and efficacy [3]. Several International Consensus Summit of Sleeve Gastrectomy meetings have been held to discuss the technique and its effectiveness [4 7]. The American College of Surgeons Bariatric Surgery

2 Center Network has put in the intermediate position between the other two commonly performed bariatric procedures, laparoscopic adjustable gastric banding and laparoscopic gastric bypass, in term of surgical risk, weight loss, and resolution of obesity-related illness [8]. However, the long-term outcome is currently regarded as inadequate, and the widespread acceptance of this procedure might have resulted from a tendency toward faddism that gravitated to the latest surgical option [3, 9]. The aim of this study was to evaluate the long-term outcomes and efficacy of and compare with the results to those of the gold standard in bariatric surgery, gastric bypass. Patients and Methods We performed a retrospective review of patients who underwent from 2006 to 2012 and completed at least 12 months of follow-up. All patients provide consent, and the data were collected into a prospective database, which was then analyzed retrospectively. Prior approval for the performance of this study was obtained from the ethics committee of the Hospital. A total of 519 consecutive patients who underwent as a primary bariatric procedure were included. The mean patient age was 36.0±9.1 years old (range 14 71), and females dominated this cohort at 74.6 %. The preoperative mean mean body mass index (BMI) was 37.5±6.1 kg/ m 2 (range ). Patients with previous bariatric operations were excluded. Two matched groups were selected from a prospectively collected bariatric patient database from our center: 519 of these patients received laparoscopic Roux-en-Y gastric bypasses (RYGBs), and 519 received laparoscopic single anastomosis (mini-) gastric bypasses (SAGBs). The group and the matched gastric bypass groups were similar in terms of the baseline characteristics including age (±2 years), BMI (±1 kg/m 2 ), and gender (same). The three groups were compared in terms of operation time, blood loss, days of hospital stay, analgesic usage, postoperative complications, weight loss percentage (WL%), excess weight loss percentage (EWL%), laboratory data, and quality of life. Surgical Technique Laparoscopic Sleeve Gastrectomy Our surgical technique for SG has evolved over the years to include a reinforcement suture and the invagination of the stapler line, which were introduced in 2006 [10], and reduced ports access surgery that began in 2009 as previously reported [11]. Subsequently, we used the transumbilical 2-site modified single incision laparoscopic surgery (SILS) technique for all s. The important surgical techniques are briefly described as follows. All procedures were completed laparoscopically. Three skin incisions were placed at two sites of the abdomen, including two skin incisions along the natural fold of the umbilicus for the video scope and stapler working port and 15- mm skin incision on the left lateral abdominal wall for another working port. A 2-mm Kircher wire was inserted through a subxyphoid skin puncture as the liver retractor to expose the angle of His. The operation began with the dissection of the greater omentum, and short gastric arteries using a 5-mm blunt tip laparoscopic Ligasure (Covidien, Norwalk, CT, USA) system begin from the pylorus and continuing to the angle of His while sparing the sling fibers near the cardioesophageal junction and the gastroepiploic vessels. The large fat pads of Belsey at the angle of His were dissected to provide a clean field for fundal resection. Meticulous dissection was performed at the angle of His with full mobilization of the gastric fundus. The posterior wall of the stomach was freed from the pancreatic adhesion if present. Once the stomach was completely mobilized, an orogastric tube (size 36 Fr) was placed along the lesser curvature of the stomach directed toward the pylorus as a calibrator prior to beginning the gastric resection. Vertical transection of the stomach was accomplished with 5 6 firings of a 60-mm linear stapler (Endo GIA, Covidien, Norwalk, CT, USA). After gastric resection, the long gastric remnant stapler line was invaginated with a 3 0 vicryl suture to prevent leakage and hemorrhage. The gastric tube was then fixed to the posterior peritoneal tissue to prevent gastric volvulus. The resected stomach was extracted through the umbilical incision after dilatation. Drains were not routinely used. The fascial defect was closed with vicryl suture or plugged with surgicel [12]. Laparoscopic Gastric Bypass The surgical procedures performed included two types of gastric bypass procedures, RYGB and laparoscopic SAGB: the details of these procedures have been published [13]. Briefly, LRYGB was performed with standard 5-port laparoscopic technique via the antecolic and antegastric routes with a 100-cm Bilio-pancreatic limb and a 15-cm alimentary limb. The gastric pouch was approximately 20 cc, and the gastrojejunostomy was created by the stapler technique with a 1.2-cm diameter anastomosis. SAGB was performed by first creating a long sleeved gastric tube using a 36-Fr size bougie along the lesser curvature from the antrum to the angle of His. Next, a Billroth II type loop gastroenterostomy was created with the intestine at 200 cm distal to the ligament of Trietz. Quality of Life Measure All patients received a quality of life questionnaire evaluation at their preoperative assessments and at their postoperative

3 follow-up. Quality of life was measured with the Gastrointestinal Quality-of-Life Index (GIQLI), which is a 36- item questionnaire [14]. In the analysis, the results of the questionnaire were divided into four domains: symptoms (19 items), physical status (7 items), psychological emotions (6 items), and social functioning (4 items). Each item was scored on a scale from 0 to 4 (from the worst to the best options). The maximum score was 144. This questionnaire has been shown to have good validity for use across different countries and different gastrointestinal surgeries [15 18]. The range of normal scores is from 118 to 125 [18, 19]. Statistical Analysis All statistical analyses were performed using SPSS version (SPSS Inc., Chicago, Illinois). The baseline comparisons were made with chi-square test and ANOVA t test. Continuous variables are expressed as the mean (standard deviation). A two-sided P value below 0.05 was considered statistically significant. Results Basic Characters of the Three Groups There were no significant differences between the three groups in basic characteristics (Table 1). The mean age of the whole study was 36.0 years, and BMI was 37.5 kg/m 2.Morethan70%ofthepatientswerefemale. Approximately 60 % of the patients had metabolic syndrome. Surgical Outcome of The mean surgical time for was 113.5±31.3 min, and the mean blood loss was ml. The average hospital stay length was 3.0±1.7 days. The overall postoperative 30-day rates of minor and major morbidities were minor 5.8 % (n=30) and major 1.6 % (n=8), respectively, as shown in Table 2. Seven cases required reoperation due to leakage (n=5), major bleeding (n=1), and port site hernia (n=1). There were six postoperative leaks detected in our large series (1.2 %). However, the risk of leak was highly influenced by the learning curve of the surgeons, as the majority of the leaks occurred in the first 100 cases performed (5 %), then one (1 %) in the second 100 cases and dropped to 0 % for the last 319 operations performed. Table 1 surgery Clinical characteristics of the morbidly obese patients prior to (n=519) RYGBP (n=519) Comparison of the Surgical Outcomes SAGB (n=519) The comparisons of the operative parameters between and the other two types of gastric bypass are shown in Table 2. The operation time for the RYGB group was significantly longer ( min; P<0.001) than those of the other two groups. SAGB and had a similar operation time. The group experienced quicker flatus passage and a shorter hospital stay than did the other two groups. The major complication rate was lowest in the group (1.6 %) followed by the SAGB (1.9 %) and RYGB (2.3 %) groups, although these differences were statistically nonsignificant. Weight Loss and Comorbidity Outcomes of P value Age (mean+sd) 36.0± ± ± Sex ratio (F:M) 387: / / BMI (kg/m 2 ) 37.5± ± ± Metabolic syndrome 314 (60.5) 312 (60.1) 308 (59.3) (%) Waist circumference 112.6± ± ± (cm) TG, mg/dl 167.2± ± ± CHO, mg/dl 196.6± ± ± FPG, mg/dl 108.0± ± ± HbA1c, % 6.4± ± ± SBP, mm-hg 136.8± ± ± DBP, mm-hg 88.1± ± ± Uric acid (mg/dl) 6.7± ± ± Albumin (mg/dl) 4.4± ± ± WBC (10 3 /μl) 8.4± ± ± Hemoglobin (g/dl) 14.4± ± ± Ca, μg/dl 9.3± ± ± Iron, μg/dl 85.7± ± ± MCV (fl) 84.8± ± ± *P<0.05 BMI body mass index, TG triglyceride, CHO cholesterol, FPG fasting plasma glucose, SBP systematic blood pressure, DBP diastolic blood pressure, WBC white blood cell count, Hb hemoglobin Postoperatively, the mean BMI at 6 months, 1 year, 2 years, 3 years, 4 years, and 5 years were 28.9, 27.3, 26.5, 27.2, 27.3, and 27.1 kg/m 2, and the mean WL% at these points were 24.6, 28.3, 30.0, 28.1, 28.3, and 28.8 %, respectively. The evolution of the BMIs is depicted in Fig. 1. The maximal weight loss was achieved within 2 years and minor weight regain occurred thereafter. At 5 years after surgery, one hundred sixteen

4 Table 2 Operative characters of the three techniques RYGB SAGB P-1 vs RYGB P-2 vs SAGB p-3 SAGB vs RYGB Mean Op time 113.5± ±32.4* 117.2±33.3# <0.001* <0.001* Blood loss (ml) 49.1± ± ±26.6# * Flatus passage (day) 1.6± ± ± Hospital stay (days) 3.0± ±1.9* 3.4±2.4* 0.011* 0.045* Analgesic dosage (morphine mg) 2.5± ± ±2.3* * Complications n (%) major 8 (1.6) 12 (2.3) 10 (1.9) minor 30 (5.8) 36 (6.9) 39 (7.6) *P<0.05, comparing to #P<0.05, comparing with RYGB Op operation patients (75.3 %) of the 154 eligible patients had follow-up data. All of the obesity-related comorbidities decreased significantly after surgery at the fifth year (Table 3). However, 14.7 % (17 of 116) of the patients developed de novo GERD at 5 years of follow-up and required long-term proton-pump inhibitors. A total of 16 patients (3.1 %) required surgical Fig. 1 BMI progress post-, RYGB, and SAGB

5 Table 3 Weight loss and laboratory data at 5 years after surgery N=116 RYGB N=218 SAGB N=499 P-1 vs RYGB P-2 vs SAGB p-3 SAGB vs RYGB BMI 27.1± ± ±5.6*# <0.001* <0.001# Weight loss (%) 28.3± ± ±9.5*# <0.001* <0.001# Excess WL (%) 68.7± ± ±19.7*# * <0.001# FPG, mg/dl 90.5± ± ± HbA1c, % 5.7± ± ±0.5*# * <0.001# TG, mg/dl 80.4± ± ± CHO, mg/dl 193.3± ±31.8* 155.4±30.4* <0.001* <0.001* LDL-C, mg/dl 110.9± ±26.8* 92.1±24.2* <0.001* <0.001* HDL-C, mg/dl 62.7± ±13.3* 53.9±11.9* 0.008* <0.001* SBP, mm-hg 118.4± ± ± DBP, mmh-g 85.2± ± ± Albumin, gm/dl 4.4± ±03 4.4± Ca, μg/dl 9.0± ± ±1.0*# <0.001* <0.001# Iron, μg/dl *# * <0.001# WBC 5.7± ± ± Hb 12.5± ± ±2.7*# <0.001* 0.009# *P<0.05, comparing to #P<0.05, comparing with RYGB BMI body mass index, Op operation, TG triglyceride, CHO cholesterol, LDL low-dense cholesterol, HDL high-dense lipoprotein, FPG fasting plasma glucose, SBP systematic blood pressure, DBP diastolic blood pressure, WBC white blood cell count, Hb hemoglobin revision due to the following: weight regain (n=6), persistent type 2 diabetes (n=1), stricture (n=1), and GERD (n=8). Comparisons of Outcomes At year 5, 116 in the, 218 in the RYGB, and 399 in the SAGB group had follow-up data because was started later in the series. The SAGB patients exhibited the greatest weight loss (WL 31.2 %), and there was no significant difference in weight loss between the (WL 27.1 %) and RYGB (WL 27.0 %) patients. At year 5, the patients exhibited higher HbA1c (5.7 vs 5.5 and 5.3 %) and blood lipid levels (cholesterol 193 vs and mg/dl; LDL vs 87.9 and 92.1 mg/dl) but better micronutrient nutritional statuses calcium and iron than both the SAGB and RYGB (Table 3). SAGB patients had significant lower hemoglobin (10.8 gm/ dl) than the RYGB group (11.8 gm/dl) and the group (12.5 gm/dl). Quality of Life Comparison All three groups experienced improvement in quality of life at 5 years after surgery. The improvements were mainly in general quality of life, including the physical, emotional, and social domains (Table 4). However, all of the groups exhibited similar deteriorations in the score in the domain of symptoms Table 4 The gastrointestinal quality-of-life index (GIQLI) at 5 years after surgery GIQLI All (n=1104 ) (pre-op) (n=75 ) (post-op 5-y) RYGB (n=49 ) (post-op 5-y ) SAGB (n=133) (post-op 5-y ) P-1 vs RYGB P-2 vs SAGB p-3 SAGB vs RYGB Overall 106.5± ±14.7* 113.0±20.2* 109.8±17.6* Symptoms 63.5± ±8.4* 58.0±11.3* 57.9±9.9* Physical 16.6± ±4.9* 23.0±2.6* 20.0±5.1* Emotional 11.9± ±1.8* 15.3±4.0* 15.1±3.3* Social 14.6± ±2.4* 16.8± ±3.7* *P<0.05 compared to the pre-op data #P<0.05 between each group

6 because some specific symptoms can present after bariatric surgery. Discussion This study confirmed the medium-term efficacy of as a primary bariatric procedure. Our medium-term results over 5 years showed that primary resulted in 28.3 % WL and up to 70 % EWL. These results concur with recent reports of the long-term results of [20 22]. Several randomized trials have also demonstrated that has weight reduction efficacy similar to that of RYGB in the short- to mid-term [17, 23, 24]. This study is the first to provide long-term data supporting that notion that the weight loss efficacy of is similar or greater than that of RYGB. The preferred bariatric surgery has evolved in the past decades. RYGB had been regarded as the gold standard procedure since However, given the similar weight loss efficacies and the lower risk of surgical complications and long-term micronutrient deficiencies of, we expect that will be the first choice bariatric surgery in the future. Another important advantage of compared to RYGB or SAGB is the avoidance of the risk of gastric cancer that arises from the excluded remnant stomach [25]. RYGB or SAGB precludes the option of screening the stomach and raises strong concerns in countries with high incidences of gastric cancer, such as countries in Asia, South American, and some parts of Europe. Therefore, it is not surprising that is particularly welcomed in Asia because of the concern of remnant gastric cancer. SG now accounts for more than 50 % of the bariatric surgeries in Asia and more than 70 % of the surgeries in Japan where gastric cancer is the leading cancer-related cause of death [26]. Although resulted in weight reductions that were similar to those that resulted from gastric bypass, was found to be inferior to RYGB and SAGB in terms of glycemic control and lowering blood lipid levels. Several randomized trials have shown that procedures that include duodenal exclusion have higher rates in diabetes remission and patients being able to go off medication than do those without duodenal exclusion, especially for diabetes patients with lower BMIs [27 29]. The reason for these findings is that duodenal exclusion might have a significant role in the treatment diabetes apart from weight reduction. A recent study comparing and RYGB identified some duodenal factors that are possibly related to duodenal exclusion supported the duodenal exclusion theory [30]. In this study, the patients who received gastric bypass had significant lower HbA1c and LDL levels than did those who received at 5 years after surgery. Therefore, although might be the first choice for bariatric surgery, gastric bypass might be the preferred metabolic surgery for the treatment of T2DM in patients with BMI <35 kg/m 2. Another main drawback of is the development of reflux esophagitis. In this study, 15 % of the patients exhibited symptomatic reflux esophagitis at 5 years after surgery. The result concurs with the reported incidence of reflux rate of % [20, 31 34]. The possible explanations for this high incidence include an increased prevalence of hiatal hernia, increased intra-abdominal pressure, delayed gastric emptying, and dysfunction of the lower esophageal sphincter. However, the relationship between SG and reflux esophagitis is intriguing because various studies have reported either improvements or worsening of reflux symptoms following surgery [35]. Therefore, it is currently recommended to be avoided for patients with pre-existing reflux esophagitis symptoms and that hiatal defect should be searched for and repaired when found during SG in patients without preexisting reflux symptoms. In patients with severe reflux esophgitis after, the only definite treatment is conversion to RYGB. In this study, two types of gastric bypass were performed, RYGB and SAGB. SAGB, or mini-gastric bypass, is a simplified gastric bypass involving a long narrowed sleeve gastric tube with single-loop anastomosis. With a biliopancreatic limb of up to 200 cm, SAGB can be regarded as a malabsorption procedure. In a previous study, SAGB was demonstrated to have a lower complication and result in greater weight loss than RYGB; however, a higher incidence of micronutrient malabsorption was found with this procedure [36]. Although controversy regarding bile reflux exists, SAGB has gained a wider acceptance in recent year [3]. In the present study, and SAGB had similar mean operation time and lower rates of major complications. The weight loss efficacy of was not inferior to that of SAGB at 5 years, and avoids the risk for micronutrient malabsorption associated with SAGB. Therefore, is now preferred over SAGB in our practice with the exception of patients with severe metabolic disorders. The mechanisms by which works are intriguing. Previously, two restrictive type surgeries, vertical banded gastroplasty and adjustable gastric banding, were both found to be nonideal bariatric surgeries. might be the first restrictive procedure to be superior to gastric bypass procedures. However, is not purely a restrictive bariatric procedure because some complex gut hormone changes are involved with. First, marked reductions in ghrelin levels occur after complete removal of the gastric fundus, which is the site of the production of the hormone ghrelin, and such reduction would aid weight loss [37]. Second, quick elevations of the postmeal GLP-1 and PYY responses are induced by the rapid bowel transit time that occurs following after, and these factors might aid weight reduction and metabolic control [23, 38]. However, a recent study in mice by Ryan et al. showed that neither ghrelin nor GLP-1 plays an essential role in. These authors demonstrated that bile acid is the key player in weight loss following

7 and was probably due to the increase in circulating bile acids and associated changes to the gut microbial milieu [39]. Further studies are needed to elucidate this intriguing question about the mechanism of. This study has some limitations. This study was not a randomized trial, although all data was prospectively collected. However, a relative large numbers and long-term follow-ups might provide further useful knowledge. Another limitation of this study is that it was not a functional study. Awell-designed functional study that includes measurements of gut hormones might provide answers regarding the significance of duodenum exclusion to the differences between the and gastric bypass. In conclusion, as has evolved to become as safe and effective as a bariatric surgery, some concerns about the longterm effect of reflux esophagitis still exists. This approach has begun to appear to be an ideal bariatric surgery with an efficacy that is not inferior to that of gastric bypass. might be the recommended treatment option for morbidly obese patients without severe metabolic disorders and in areas in which gastric cancer is not an uncommon disease. Conflict of Interest All authors report no conflict of interest. Ethical Approval Informed consent was obtained from all individual participants included in the study. For this type of study, for- Statement of Human and Animal Rights mal consent is not required. References 1. Hess DS, Hess DW. Biliopancreatic diversion with a duodenal switch. Obes Surg. 1998;8(3): Regan JP, Inabnet WB, Gagner M, et al. Early experience with twostage laparoscopic Roux-en-Y gastric bypass as an alternative in the super-super obese patient. Obes Surg. 2003;13(6): Buchwald H, Oien DM. Metabolic/bariatric surgery worldwide Obes Surg. 2013;23: Deitel M, Crosby RD, Gagner M. The First International Consensus Summit for Sleeve Gastrectomy (SG), New York City, October 25-27, Obes Surg. 2008;18(5): Gagner M, Deitel M, Kalberer TL, et al. The Second International Consensus Summit for Sleeve Gastrectomy, March 19-21, Surg Obes Relat Dis. 2009;5(4): Deitel M, Gagner M, Erickson AL, et al. Third International Summit: current status of sleeve gastrectomy. Surg Obes Relat Dis. 2011;7(6): Rosenthal RJ, Diaz AA, Arvidsson D, et al. International Sleeve Gastrectomy Expert Panel Consensus Statement: best practice guidelines based on experience of >12,000 cases. Surg Obes Relat Dis. 2012;8: Hutter MM, Schirmer BD, Jones DB, et al. First report from the American College of Surgeons Bariatric Surgery Center Network: laparoscopic sleeve gastrectomy has morbidity and effectiveness positioned between the band and the bypass. Ann Surg. 2011;254(3): discussion Himpens J, Dobbeleir J, Peeters G. Long-term results of laparoscopic sleeve gastrectomy for obesity. Ann Surg. 2010;252: Ser KH, Lee WJ, Lee YC, et al. Experience in laparoscopic sleeve gastrectomy for morbidly obese Taiwanese: staple-line reinforcement is important for preventing leakage. Surg Endosc. 2010;24(9): Lee WJ, Chen JC, Yao WC, et al. Transumbilical 2-site laparoscopic Roux-en-Y gastric bypass: initial results of 100 cases and comparison with traditional laparoscopic technique. Surg Obes Relat Dis. 2012;8(2): Chiu CC, Lee WJ, Wang W, et al. Prevention of trocar-wound hernia in laparoscopic bariatric operations. Obes Surg. 2006;16(7): Lee WJ, Yu PY, Wang W, et al. Laparoscopic Roux-en-Yversus minigastric bypass for the treatment of morbid obesity: a prospective randomized controlled clinical trial. Ann Surg. 2005;242: Espasch E, Williams JL, Wood-Dauphinee S. Gastrointestinal quality of life index: development validation and application of new instrument. Br J Surg. 1995;82: Slim K, Bousquet J, Kwiatkowski F. Quality of life before and after laparoscopic fundoplication. Am J Surg. 2001;180: Decker G, Borie F, Bouamrirene D. Gastrointestinal quality of life before and after laparoscopic Heller myotomy with partial posterior fundoplication. Ann Surg. 2002;236: Peterli R, Wolnerhanssen B, Peters T, et al. Improvement in glucose metabolism after bariatric surgery: comparison of laparoscopic Rouxen-Y gastric bypass and laparoscopic sleeve gastrectomy: a prospective randomized trial. Ann Surg. 2009;250: Overs SE, Freeman RA, Zarshenas N, et al. Food tolerance and gastrointestinal quality of life following three bariatric procedures: adjustable gastric banding, Roux-en-Y gastric bypass, and sleeve gastrectomy. Obes Surg. 2012;22: Yu PR, Tsou JJ, Lee WJ, et al. Impairment of gastrointestinal quality of life in severely obese patients. World J Gastroenterol. 2014;20(22): Strain GW, Saif T, Gagner M, et al. Cross-sectional review of effects of laparoscopic sleeve gastrectomy at 1, 3, and 5 years. Surg Obes Relat Dis. 2011;7(6): Transtulli S, Desiderio J, Guarino S, et al. Laparoscopic sleeve gastrectomy compared with other bariatric surgical procedures: a systematic review of randomized trials. Surg Obes Relat Dis. 2013;9: Diamanis T, Apostolou KG, Alexandrou A, et al. Review of longterm weight loss results after laparoscopic sleeve gastrectomy. Surg Obes Relat Dis. 2013;10: Karamanakos SN, Vagenas K, Kalfarentzos F, et al. Weight loss, appetite suppression, and changes in fasting and postprandial ghrelin and peptide-yy levels after Roux-en-Y gastric bypass and sleeve gastrectomy: a prospective, double blind study. Ann Surg. 2008;247: Peterli R, Borbely Y, Ker B, et al. Early results of the Swiss multicentre bypass or sleeve study (SM-BOSS): A prospective randomized trial comparing laparoscopic sleeve gastrectomy and Rouxen-Y gastric bypass. Ann Surg. 2013;258: Wu CC, Lee WJ, Ser KH, et al. Gastric cancer after mini-gastric bypass surgery: a case report and literature review. Asian J Endosc Surg. 2013;6: Sasaki A, Wakabayashi G, Yonei Y. Current status of bariatric surgery in Japan and effectiveness in obesity and diabetes. J Gastroenterol. 2014;49(1): Lee WJ, Chong K, Ser KH, et al. Gastric bypass vs sleeve gastrectomy for type 2 diabetes mellitus: a randomized controlled trial. Arch Surg. 2011;146:143 8.

8 28. Schauer PR, Kashyap SR, Wolski K, et al. Bariatric surgery versus intensive medical therapy in obese patients with diabetes. N Engl J Med. 2012;366: Schauer PR, Bhatt DL, Kirwan JP, et al. Bariatric surgery versus intensive medical therapy for diabetes. N Engl J Med Jullg M, Yip S, Xu A, et al. Lower Fetulin-A retinol binding protein 4 and several metabolites after gastric bypass compared to sleeve gastrectomy in patients with type 2 diabetes. PLoS One. 2014;9(5): e Himpens J, Dobbeleir J, Peeters G. Long-term results of laparoscopic sleeve gastrectomy for obesity. Ann Surg. 2010;252(2): D'Hondt M, Vanneste S, Pottel H, et al. Laparoscopic sleeve gastrectomy as a single-stage procedure for the treatment of morbid obesity and the resulting quality of life, resolution of comorbidities, food tolerance, and 6-year weight loss. Surg Endosc. 2011;25(8): Sarela AI, Dexter SP, O'Kane M, et al. Long-term follow-up after laparoscopic sleeve gastrectomy: 8-9-year results. Surg Obes Relat Dis. 2012;8(6): Rawlins L, Rawlins MP, Brown CC, et al. Sleeve gastrectomy: 5-year outcomes of a single institution. Surg Obes Relat Dis. 2013;9(1): Soricelli E, Iossa A, Casella G, et al. Sleeve gastrectomy and crural repair in obese patients with gastroesophageal reflux disease and/or hiatal hernia. Surg Obes Relat Dis. 2013;9(3): Bohdjalian A, Langer FB, Shakeri-Leidenmuhler S, et al. Sleeve gastrectomy as sole and definitive bariatric procedure: 5-year results for weight loss and ghrelin. Obes Surg. 2010;20(5): Lee WJ, Ser KH, Lee YC, et al. Laparoscopic Roux-en-Y vs. minigastric bypass for the treatment of morbid obesity: a 10-year experience. Obes Surg. 2012;22: Melissas J, Leventi A, Klinaki I, et al. Alterations of global gastrointestinal motility after sleeve gastrectomy: a prospective study. Ann Surg Ryan KK, Tremaroli V, Clemmensen C, et al. FXR is a molecular target for the effects of vertical sleeve gastrectomy. Nature. 2014;509: