Today, Sleeve Gastrectomy is the most frequently performed restrictive bariatric surgical procedure in the patient group with BMI≥50 since it is technically easier than other bariatric procedures and due to patient preference(18,19). SG was developed as the first stage of a 2-stage bariatric surgical procedure especially for the super obese patient group with BMI≥50(20,21). The consequent studies proved that SG on its own was also an effective bariatric surgical procedure (8,22,23). Some studies performed showed that SG provided more weight loss and caused less development of insulin sensitivity as compared to RYGB(24,25). On the other hand, recent randomized clinical studies showed that SG and RYGB were equally effective in weight loss and treatment of comorbidities(26,27). One of the most important methods used to assess the success of surgery is EWL%. In our study, we identified that the average EWL% was 67.58±13.37 in month 12 and 74.14± 10.03 in month 24. The mean values of all months were found significantly different (p<0.001). According to the Bonferroni multiple comparison test, in all possible binary comparisons (3rd, 6th, 12th, 18th, 24th), EWL% were significantly different (p<0.001), except for the 18th – 24th months. It was seen in the study performed that the process of weight loss continued until month 24, but there were no statistically significant difference between months 18 and 24. accepting the success rate as EWL%≥50 according to the Modified Reinhold criteria, it was found to be 93.55%, 96.8% and 92% in months 12, 18 and 24, respectively. When assessed according to the Biron criteria (BMI˂40), it was found to be 84.92%, 92.4% and 88% in months 12, 18 and 24.
As far as current studies are concerned, Bhandari et al performed a study with 514 super obese patients. In years 2 and 3 of this study, the EWL% was found to be 74.24% and 62.38% in the SG group and 71.4% and 69.55% in the RYBG group. Again, in the same study, this rate was identified as 87.88% and 85.11% in the Banded SG group (27). Rendo A et al. performed a study on 134 patients who received SG and their EWL% in years 1 and 2 were 61.3%, 62.6%, respectively (28). In a study conducted by Silva R et al. with 213 SO patients, the group that received SG had EWL% of 58.74 and 59.90 in years 1 and 2, respectively. In the RYGB group, these were 67.58 and 72.19, respectively (29). In a study performed by Arapis K et al. which included 210 SSO patients, the EWL% was 48.81 and 54.17 in the SG group in years 1 and 2, respectively. In the RYGB group, these were 53.96 and 60.64, respectively (10). Celio AC et al. conducted a study with 50987 SO patients, EWL% was 49% and %58 in the SG and RYBG group, respectively (30). In a study conducted by Uno K et al. consisting of 48 SO patients, the EWL% was reported as 57.7% and 65.1% in the SG group in years 1 and 2, respectively; in the RYGB group, it was reported as 73.4% and 73.7%, respectively (31). Wang Y et al. conducted a meta-analysis study comprising 12 studies, where they reported that RYGB was found superior in terms of EWL% in the first 12 months while the situation was equalized between SG and RYGB in month 24(32). Similarly, Bhandari et al. performed a study where they reported similar average EWL% values for RYGB and SG in year 3(27). Arapis K et al. also recommended SG as the primary surgical procedure in a study on a group of SSO patients. Once again, in the same study, it was reported that SG and RYGB produced similar results in terms of changes in EWL% and BMI in year 4(10). (Table 6)
More recently, a randomized Swiss Multicenter Bypass or Sleeve Study (SM-BOSS) which compared bariatric surgery patients that received SG and RYBG reported that no significant differences were seen between the SG and RYGB groups. The excessive Body Mass Index loss was found to be similar between LSG and LRYGB at each time point (1 year: 72.3±21.9% vs. 76.6±20.9%, P =0.139; 2 years: 74.7±29.8% vs. 77.7±30%, P = 0.513; 3 years:70.9±23.8% vs. 73.8±23.3%, P =0.316)(26).
The patients that were operated on were observed to have a significant improvement in comorbid diseases, as well. While full remission or improvements were noted in comorbidities such as DM, HT, Hyperlipidemia, OSA and GERD, full remission was not observed in patients with hyperlipidemia. It was observed that only 45.45% of patients with hyperlipidemia had improvement. There are studies which state that better results are obtained with RYGB in the improvement of comorbid diseases, especially Type 2 DM(32). A recent meta-analysis comparing SG and RYGB, which included 18455 patients and 62 studies to assess obesity-related comorbidities, found that RYGB had a statistically significant superiority in the remission of Hyperlipidemia and GERD. However, no statistically significant differences were seen in the DM and OSA remission(33). Singla V et al. conducted a study with 75 SO patients and found that the remission rate for Type 2 DM was 85.7% in the SG group and 77.7% in the RYGB group (p=0.59)(34). Silva et al. found that there were no differences in terms of the remission of diabetes in years 1 and 2 among RYGB, SG and AGB (p=0.91-p=0.13)(29). Different pathophysiological mechanisms other than weight loss also play a role in the correction of comorbidities following LSG. These include mechanisms such as increased gastric emptying and intestinal transit, increased GLP-1 hormone level and decreased ghrelin levels(35,36). Also in our study, Type 2 DM patients demonstrated a remission rate of 89.36% (n=42). The average HbA1c level of patients in the pre-operative period was 7.41±1.885 g/dL while it was identified as 5.482±0.687 g/dL in the post-operative period. As for the OSA patients, remission was observed in all of them. GERD following SG is an important problem. All patients that had reflux symptom and hiatal failure before surgery also received concomitant hiatal hernia repair. In all of these patients, the reflux symptoms disappeared in the post-operative period.
Especially in the SO patient group, SG can be performed more easily and safely than other surgical procedures given the large liver volume, limited intraabdominal operating space, increased abdominal wall thickness and increased abdominal fat tissue(37). Since the accompanying comorbidities are higher in number in super obese patients, their complications and mortality rates are also higher(28,30,38,39). As the risk of mortal progress is high when super obese patients develop complications, surgeries need to be performed with minimal complications especially in this patient group. Intervening on complications that develop in such patients is more difficult as compared to other patients. This is another factor that affects mortality. As per some studies performed, the rate of complications such as stapler line leaks, stricture, intraabdominal hemorrhage, abscess, PE, DVT, pneumonia, myocardial infarction and wound infection is in the range of 3.8-15.7%. The duration of surgery and hospital stay are also relatively long(5,28,30,40,41). According to the studies conducted, the mortality rate was in the range of 0.008-0.18% in the non-super obese patient group while the super obese patient group had mortality rates ranging up to 3.7%(28,30,39,40,42,43,44). No mortality and major complications were observed in our study. The concomitantly performed surgeries such as cholecystectomy and hiatal hernia repair did not have an effect on mortality and morbidity. One of the major complications that may be observed during SG surgery is stapler line leaks. The possibility of having a leak as a result of a technical error was checked via methylene blue leak test conducted during surgeries. It was ensured during surgery that the stapler line was straight and there were no twists in the stomach. The patients were recommended to avoid drinking liquids in one ago and to drink them slowly, in small sips so to prevent a leak secondary to increased intraluminal pressure in the post-operative period, as well.