Comparison of Laparoscopic Sleeve Gastrectomy and Single Anastomosis Sleeve Ileal Bypass in Type 2 Diabetes Mellitus Remission Using International Criteria

Abstract

Introduction:

Single anastomosis sleeve ileal (SASI) bypass procedure is recommended in the treatment of patients with obesity, who have comorbidities such as type 2 diabetes mellitus (T2DM). Meanwhile, laparoscopic sleeve gastrectomy (LSG) has become the most preferred contemporary bariatric procedure. Research comparing these two techniques are scarce in the literature. In this study, we aimed to compare LSG and SASI procedures in terms of weight loss and diabetes remission.

Materials and Methods:

Thirty patients, who underwent LSG and 31 patients, who underwent SASI, with a body mass index (BMI) of 35 and above, and under unsuccessful medical treatment, in terms of T2DM, were included in the study. Patients' demographic data were recorded. Oral antidiabetic drugs and insulin use, HbA1c and fasting blood glucose values, and BMI values were recorded preoperatively, at thd sixth month and at first year. According to these data, patients were compared in terms of primarily diabetes remission and secondarily weight loss.

Results:

At the sixth month and first year, the mean excess weight loss (EWL) values of the SASI group were 55.2% ± 12.45% and 71.67% ± 15.75%, respectively, while EWL values of the LSG group were 57.41% ± 16.22% and 69.73% ± 16.65%, respectively (P > .05). T2DM evaluations revealed that in the SASI group, 25 (80.65%) patients at the sixth month and 26 (83.87%) patients at the first year had either clinical improvement or remission, whereas 23 (76.67%) patients at the sixth month and 26 (86,67%) patients at the first year in the LSG group had the same outcomes (P > .05).

Conclusion:

The short-term comparison of LSG and SASI procedures revealed similar results in terms of weight loss and T2DM remission. Hence, LSG can be considered as the first-step treatment of morbid obesity accompanied by T2DM, since it is a simpler surgical procedure.

Introduction

Obesity and its related diseases became not only a series of problems that negatively affect the health of individuals, but also a global problem that creates an enormous economic burden on societies. In fact, obesity became the third global problem caused by humans, which creates the most economic burden on humanity after smoking and wars in modern era.¹ In the face of this overwhelming global crisis, surgical treatments came to the fore, since they are attributed to more successful outcomes than other methods, and thus various surgical techniques were introduced.^2,3 However, the rapid evaluation of new different techniques rendered scientific studies in this field a must.

The most common comorbidity associated with obesity is type 2 diabetes mellitus (T2DM) due to insulin resistance, and remission of this condition became one of the main goals in patients undergoing bariatric and metabolic surgery (BMS). It is known that laparoscopic sleeve gastrectomy (LSG), which is the most frequently performed bariatric procedure all over the world, has positive effects on obesity-related diseases.⁴ The recently introduced single anastomosis sleeve ileal (SASI) procedure, which has promising short-term outcomes in terms of both weight loss and remission of obesity-related diseases, also became popular. However, due to lack of consensus on this BMS procedure, it is not considered as a standard surgical approach yet.⁵ In the light of these facts, we aimed to compare LSG and SASI procedures regarding T2DM remission and weight loss.

Materials and Methods

Ethics approval of the study was obtained from the Umraniye SUAM Clinical Research Ethics Committee (11/03/2021-54132726-000-5414). Thirty patients, who underwent LSG and 31 patients who underwent SASI at the Ümraniye Training and Research Hospital, University of Health Sciences, Turkey, between years 2015 and 2020, with a BMI of 35 and above, ages between 18 and 65, and under unsuccessful medical treatment, in terms of T2DM, were included in the study. The records of patients were extracted from the hospital database and reviewed retrospectively. Patients with a history of upper gastrointestinal system surgery, malignancy or type 1 diabetes, and patients who did not attend to their follow-ups regularly were excluded from the study.

Age, gender, and height (centimeter) of the patients in both groups were recorded. Body mass index (BMI), oral antidiabetic drugs (OAD)/insulin use, HbA1c, excess weight loss (EWL%), excess body mass index loss (EBMIL%), total weight loss (TWL), and fasting blood glucose (FBG) levels were recorded in three different time periods: preoperative, postoperative sixth month, and postoperative first year. Additionally, Framingham Offspring (FO) scoring was utilized to assess the risk of being diabetic again in patients who were in remission for diabetes.

Patients were assessed according to the American Society for Metabolic and Bariatric Surgery (ASMBS) and American Diabetes Association (ADA) criteria in terms of T2DM remission, and only ASMBS criteria for weight loss.^6,7 Accordingly, patients with FBG below 100 mg/dL, who discontinued OAD and insulin treatment, and meanwhile maintained their HbA1c values below 6% according to ASMBS or 5.7% according to ADA were considered in complete remission (CR). Patients with FBG of 100–125 mg/dL, who discontinued OAD and insulin treatment, and meanwhile maintained HbA1c values between 6% and 6.4% according to ASMBS or between 5.7% and 6.4% according to ADA were considered in partial remission (PR). Patients who did not meet the abovementioned criteria but had a reduction in OAD or insulin usage, or had a one point or more reduction in HbA1c values or whose FBG measurements were reduced by 25% or more under OAD and/or insulin treatment were considered in the clinical improvement (CI) state.

The sample size required for the study with 80% confidence interval and 5% alpha error was calculated using the statistical power analysis program G*Power V 3.1.9.6, and it was found that 31 patients in each group were sufficient.

Statistical Analysis

Descriptive statistics (frequency distributions, percentage, mean, standard deviation) were used in the analysis of the collected data. Whether the data were normally distributed or not was determined with the Kolmogorov–Smirnov test. In the analysis of continuous data, the t test was used for data with normal distribution, and the multifactor analysis of variance (Greenhouse–Geisser) method was used for repeated measurements, and the Mann–Whitney U test and Wilcoxon test, which are nonparametric tests, were used for data that were not normally distributed. The results were evaluated at 95% confidence interval and P < .05 significance level. To analyse the data, PSPP (PSPP is freesoftware; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or [at your option] any later version.) and Microsoft Excel programs were used.

Surgical preparation and technique

Low-molecular-weight heparin (enoxaparin 0.6 mL) was administered to all patients the night before the surgery and they were operated while wearing a pneumatic compression device. Additionally, cefazolin 2 gr/IV prophylaxis was administered.

Surgeries were carried out in French position. An imaginary line was drawn between the xiphoid bone and umbilicus. At its mid-distal 1/3 junction, a 10-mm camera trocar was placed into the abdomen, which was followed by a liver retractor placed below the xiphoid bone, a 12 mm trocar placed at the right midclavicular line and a 5 mm trocar placed at the left anterior axillary line. Finally, another 5 mm trocar was placed at the left midclavicular line for LSG, whereas a 12 mm trocar was placed in SASI patients instead. Then a 36 Fr orogastric calibration tube was advanced to the pylorus. Omental transection was started 5 cm proximal to the pylorus and carried out with an energy device until the entire lateral section of the stomach and fundus were mobilized from their attachments and left crus. The stomach was then transected with an Endo GIA stapler along the tube upward, starting from the beginning of the prepyloric dissection point while maintaining a 1 cm distance between the esophagogastric junction and the last staple line.

This step finalized the LSG procedure. Furthermore, a side-to-side anastomosis was done between the nonstapled prepyloric portion of the stomach and the small bowel 300 cm proximal to ileocecal junction in SASI procedure.

Results

The demographic findings, the mean weight, and BMI, and the changes in these parameters at the sixth month and first year are given in Table 1. Although weight loss and decrease in mean BMI were found to be statistically significant in both groups (P < .05), no significant difference was found between the groups (P > .05).

Table 1.

Demographic Findings

	Group 1-SASI		Group 2-LSG		P
	Mean ± SD	95% CI	Mean ± SD	95% CI
	Mean ± SD	min–max	Mean ± SD	min–max
Age	49.26 ± 7.72	46.43–52.09	48.4 ± 8.53	45.21–51.59	.68
Height(cm)	161.45 ± 8.8	158.22–164.68	162.47 ± 7.89	159.52–165.41	.64
Weight(kg)
Preop.	119.52 ± 15.55	113.81–125.22	123.6 ± 14.46	118.2–129	.29
Sixth month	90.19 ± 12.44	85.63–94.76	91.13 ± 13.65	86.04–96.23	.78
First year	80.65 ± 11.04	76.6–84.69	83.87 ± 11.75	79.48–88.25	.27
BMI
Preop.	45.93 ± 5.82	43.8–48.07	46.86 ± 4.96	45–48.71	.51
Sixth month	34.59 ± 4.57	32.92–36.27	34.43 ± 4.82	32.63–36.23	.89
First year	30.98 ± 4.3	29.4–32.56	31.79 ± 4.68	30.04–33.53	.49
Sex	N	Percentage	n	Percentage
M	6	19.40	7	23.30	.70
F	25	80.60	23	76.70	.70

BMI, body mass index; CI, confidence interval; F, female; LSG, laparoscopic sleeve gastrectomy; M, male; SASI, single anastomosis sleeve ileal bypass; SD, standard deviation.

Preoperative, sixth month, and first year EWL, EBMIL, and TWL percentages are given in Table 2. Although the changes in time within the groups were statistically significant for all three parameters (P < .05), there was no significant difference between the groups (P > .05).

Table 2.

Groups' Excess Weight Loss/Excess Body Mass Index Loss/Total Weight Loss Percentages

	Group 1-SASI		Group 2-LSG
	Mean ± SD	95% CI min–max	Mean ± SD	95% CI min–max	P
%EWL sixth month	55.2 ± 12.45	50.63–59.77	57.41 ± 16.22	51.35–63.47	.55
%EWL first year	71.67 ± 15.75	65.89–77.45	69.73 ± 16.65	63.51–75.95	.64
%EBMIL sixth month	55.97 ± 12.81	51.27–60.67	58.39 ± 15.64	52.55–64.23	.51
%EBMIL first year	73.28 ± 14.93	67.81–78.76	70.42 ± 16.89	64.12–76.72	.49
%TWL sixth month	24.47 ± 4.63	26.78–31.87	26.26 ± 6.72	28.91–36.02	.15
%TWL first year	32.37 ± 6.04	35.37–42.5	31.95 ± 6.81	35.76–43.57	.78

CI, confidence interval; EBMIL, excess body mass index loss; EWL, excess weight loss; LSG, laparoscopic sleeve gastrectomy; SASI, single anastomosis sleeve ileal bypass; SD, standard deviation, TWL, total weight loss.

All included patients were diagnosed with T2DM (Table 3). The preoperative median T2DM disease duration was 10 years in the SASI group, whereas LSG group had a 6-year median preoperative T2DM disease duration. It was observed that all patients in the SASI group and 96.7% of the patients in the LSG group used OAD in the preoperative period, and the difference between the groups was not statistically significant (P > .05).

Table 3.

Oral Antidiabetic Drugs Versus Insulin Usage

		Group 1 SASI		Group 2 LSG		P
		n	Percentage	N	Percentage	P
T2DM		31	100	30	100
OAD	N	0	0.0	1	3.3	.49
OAD	Y	31	100.0	29	96.7	.49
OAD sixth month	N	24	77.4	28	93.3	.15
OAD sixth month	Y	7	22.6	2	6.7	.15
OAD first year	N	21	67.7	26	86.7	.13
OAD first year	Y	10	32.3	4	13.3	.13
OAD Preop. sixth month	N	24	77.4	27	90.0	.301
OAD Preop. sixth month	Y	7	22.6	3	10.0	.301
OAD Preop. first year	N	21	67.7	25	83.3	.16
OAD Preop. first year	Y	10	32.3	5	16.7	.16
Insulin	N	1	3.2	14	46.7	.0001
Insulin	Y	30	96.8	16	53.3	.0001
Insulin sixth month	N	29	93.5	27	90.0	.67
Insulin sixth month	Y	2	6.5	3	10.0	.67
Insulin first year	N	29	93.5	28	93.3	.97
Insulin first year	Y	2	6.5	2	6.7	.97
Insulin preop sixth month	N	29	93.5	26	86.7	.43
Insulin preop sixth month	Y	2	6.5	4	13.3	.43
Insulin preop first year	N	29	93.5	28	93.3	.99
Insulin preop first year	Y	2	6.5	2	6.7	.99
OAD or Insulin sixth month	N	30	96.8	29	96.7	.98
OAD or Insulin sixth month	Y	1	3.2	1	3.3	.98
OAD or Insulin first year	N	30	96.8	26	86.7	.19
OAD or Insulin first year	Y	1	3.2	4	13.3	.19

LSG, laparoscopic sleeve gastrectomy; N, no; n, number of individuals; OAD, oral antidiabetic drug; SASI, single anastomosis sleeve ileal bypass; T2DM, type 2 diabetes mellitus; Y, yes.

It was found that 77.4% of the patients in the SASI group and 93.3% of the patients in the LSG group stopped using OAD at the end of the sixth month, and the difference between the groups was statistically insignificant (P > .05).

While all 31 patients in the SASI group were under OAD treatment in the preoperative period, 7 patients continued to use OAD at the end of the sixth month. While 29 of 30 patients in the LSG group were using OAD in the preoperative period, 2 patients continued to do so at the end of the sixth month. The temporal difference in OAD usage in both groups was statistically significant (P < .05). At the end of the first year, it was found that 67.7% of the patients in the SASI group and 86.7% of the patients in the LSG group stopped OAD usage, and no statistically significant difference was found between the groups (P > .05). Three patients in the SASI group and 2 patients in the LSG group, who stopped using OAD by the end of the sixth month, started using OAD again in their first year of follow-up. Nevertheless, the temporal change in OAD usage in both groups compared with the preoperative period remained statistically significant (P < .05).

The mean level of HbA1c was found to be higher in the SASI group than in the LSG group in preoperative, sixth-month, and first-year measurements (P > .05) (Table 4). The decrease in HbA1c values in both groups over time was statistically significant (P < .05). There was no statistically significant difference between the two groups in terms of decrease in HbA1c levels in the sixth-month and first-year evaluation (P > .05).

Table 4.

HbA1c Findings

	Group 1 SASI		Group 2 LSG
	Mean ± SD	95% CI min–max	Mean ± SD	95% CI min–max	P
HbA1c preop.	9.41 ± 1.54	8.84–9.98	8.62 ± 2.14	7.82–9.42	.090
HbA1c sixth month	6.7 ± 0.94	6.36–7.04	6.6 ± 1.19	6.15–7.04	.623
HbA1c first year	6.33 ± 0.98	5.97–6.69	6.06 ± 1.03	5.67–6.44	.163
P (preop sixth month)	.0001		.0001
P (preop first year)	.0001		.0001
P (sixth month–first year)	.010		.0001

CI, confidence interval, HbA1c, glycosylated hemoglobin; LSG, laparoscopic sleeve gastrectomy;P, P-value; SASI, single anastomosis sleeve ileal bypass; SD, standard deviation.

In the preoperative evaluation of FBG, the mean of the patients in the SASI group was found to be higher than the mean of the patients in the LSG group, with a statistically significant difference (P < .05; Table 5). In the sixth-month and first-year evaluations, the mean FBG of the SASI group was again found to be higher compared with the LSG group, but the difference was statistically insignificant (P > .05). The decrease in mean FBG values was found to be statistically significant both at the sixth month and first year in both groups (P < .05).

Table 5.

Fasting Blood Glucose Findings and Framingham Offspring Scores

	Group 1 SASI		Group 2 LSG
	Mean ± SD	95% CI min–max	Mean ± SD	95% CI min–max	P
FBG preoperative	208.71 ± 67.17	184.07–233.35	170.83 ± 60.59	148.21–193.46	.016
FBG 6. Ay	118.23 ± 30.44	107.06–129.39	111.4 ± 36.33	97.83–124.97	.209
FBG 1. Yıl	111.94 ± 31.2	100.49–123.38	107.67 ± 36.25	94.13–121.2	.348
P (preop sixth month)	.001		.0001
P (preop first year)	.001		.0001
P (sixth month–first year)	.135		.074
FO score sixth month	17.9 ± 6.33	15.02–20.79	16.22 ± 5.98	13.63–18.8	.209
FO score first year	12.29 ± 6.68	9.25–15.33	11.48 ± 4.48	9.54–13.42	.348
P	.001		.003

CI, confidence interval; FBG, fasting blood glucose; FO, Framingham offspring; LSG, laparoscopic sleeve gastrectomy; P, P-value; SASI, single anastomosis sleeve ileal bypass; SD, standard deviation.

Average FO scores were higher in the SASI group at the sixth month and first year, but the difference between the two groups was not statistically significant (P > .05; Table 5). The first-year evaluations of the average FO scores in both groups were found to be lower than the sixth-month evaluations, and the difference between the two measurement times was statistically significant (P < .05).

T2DM remission is divided into four groups as CR, PR, CI, and no remission (NR). According to ADA and ASMBS criteria, patients in both groups were evaluated at the sixth month and first year (Table 6).

Table 6.

Type 2 Diabetes Mellitus Remission

	SASI	LSG	P
ADA sixth-month CR	3	1	.612
ASMBS sixth-month CR	4	2	.671
ADA sixth-month PR + CR	12	16	.252
ASMBS sixth-month PR + CR	12	16	.252
ADA first-year CR	6	10	.215
ASMBS first-year CR	10	14	.249
ADA first-year PR + CR	16	19	.355
ASMBS first-year PR + CR	16	19	.355

ADA, American Diabetes Association; ASMBS, American Society for Metabolic & Bariatric Surgery; CR, complete remission; LSG, laparoscopic sleeve gastrectomy; PR, partial remission; SASI, single anastomosis sleeve ileal bypass; T2DM, type 2 diabetes mellitus.

The sixth-month assessment revealed that according to the ADA criteria, 3 patients were in CR and 9 patients were in PR and according to the ASMBS criteria, 4 patients were in CR and 8 patients were in PR in the SASI group. Thirteen patients had CI, while 6 patients did not show any improvement. According to ADA criteria, 1 patient was in CR and 15 patients were in PR and according to ASMBS criteria 2 patients were in CR and 14 patients were in PR in the LSG group. Seven patients had CI. However, 7 patients did not show any improvement. No statistically significant difference was found between the groups with regard to the sum of CR and PR (P > .05). Adding the number of patients with CI, the surgical procedure was effective in 25 (80.6%) patients in the SASI group and 23 (76.6%) patients in the LSG group. No statistically significant difference was found between the groups when all aspects of improvement were considered together (P > .05).

First-year assessment revealed that according to ADA criteria, 6 patients were in CR and 10 patients were in PR and according to ASMBS criteria 10 patients were in CR and 6 patients were in PR in the SASI group. Ten patients showed CI. Treatment failed in 5 patients. According to ADA criteria 10 patients were in CR and 9 patients were in PR, and according to ASMBS criteria 14 patients were in CR and 5 patients were in PR in the LSG group. The clinical condition of 7 patients improved. Four patients did not show any kind of improvement. No statistically significant difference was found between the groups with regard to the sum of CR and PR (P > .05). Adding the number of patients with CI, the surgical procedure was effective in 26 (83.8%) patients in the SASI group and 26 (86.6%) patients in the LSG group. No statistically significant difference was found between the groups when all aspects of improvement were considered together (P > .05).

Discussion

New approaches and technologies were developed over time in the global fight against obesity. However, the prevalence of obesity is increasing rapidly due to the increase in refined food consumption and broad availability of foods with high glycemic index. This led more surgeons and scientists to focus on this matter, and thus the development and improvement of surgical methods in the fight against obesity accelerated. While only laparoscopic adjustable gastric banding, Roux-en-Y gastric bypass, and biliopancreatic diversion techniques were available 30 years ago, today, aside from endoscopic procedures, at least 20 different surgical methods are defined. In this study, we investigated both the effectiveness of the SASI bypass operation, which is a newly proposed surgical method, on T2DM, as well as the effectiveness of LSG, which is a part of this surgery, on T2DM alone, and whether these two operations are superior to each other.

Sixth-month and first-year assessments revealed no significant difference between groups in terms of EWL, EBMIL, and TWL. In both groups, the average EWL and EBMIL percentages ranged between 55%–58% at the sixth month and 70%–75% at the first year. Different studies reported 64%–83% EWL at the first year for LSG.^6–8 In a systematic review conducted by Juodeikis et al. in 2017, a 5-year mean EWL percentage of 58.4% was reported.⁹ In another study conducted by Peterli et al., where a 35 Fr calibration tube was utilized, 72% EBMIL was reported at postoperative first year.¹⁰ Other studies reported 64%–87% EWL by the end of postoperative first year for SASI.^11–15 Khalaf et al. reported the rate of EWL at first year between 85% and 88% in their observational study of SASI, which included subgroups according to 3 or 4 cm anastomosis width and 250 or 300 cm common limb length.¹⁶ Another systematic review reported the average first-year EWL rate of SASI to be 90%.¹⁷ In two different observational studies comparing LSG and SASI bypass procedures, the rates of first year EWL were 60% and 72% for LSG, and 73% and 87.6% for SASI.^18,19

The SASI procedure was reported to have superior results in terms of weight loss compared with LSG in the literature. The SASI procedure in our study was performed by using a 36 Fr calibration tube, creating an anastomosis width of 3 cm and maintaining a 300-cm-long common limb. In this study, a lower weight loss rate was obtained in the SASI group than in most studies in the literature. We think that the longstanding history of T2DM in our patients in the SASI group may be the cause of this. Since EWL rates above 50%–70% can be considered as a success, both procedures are successful in terms of short-term weight loss with no significant difference in between. This finding is also consistent with the literature.

LSG and SASI groups were evaluated in terms of T2DM remission, which wa the main aim of the study, according to the ADA and ASMBS criteria stated above. In this study, no statistically significant difference was found between the groups in the sixth-month and first-year outcomes, in which both PR or CR and total success rates were considered. In a systematic review conducted by Gill et al. in 2010, including 26 studies, 16 of which were prospective, it was reported that the overall rates of both remission and CI considered together at the end of the first year of LSG ranged from 94% to 97%.²⁰ The remission criteria of this study were consistent with ours. In the STAMPEDE trial conducted by Schauer et al., 49 patients underwent LSG operation, and remission was observed in 26.5% of them at the end of the first year, which was consistent with the ASMBS CR criteria stated in our study.²¹ In the Oseberg study conducted by Hofsø et al., LSG operation was performed on 54 patients with T2DM diagnosis, a mean disease duration of 5 years, and preoperative mean HbA1c value of 7.9%, and CR was achieved at the end of the first year in 48% of patients according to ASMBS criteria.²²

This study also evaluated pancreatic β cell function, providing preoperative and postoperative basal insulin and C-peptide results. In an observational study published in 2020, Elgenaied et al. examined 230 patients with T2DM who underwent LSG and found CR in 42.2%, PR in 10.9%, and CI in 44.3%, according to ASMBS criteria.²³ In this study, it was reported that the preoperative mean HbA1c values of the patients were 8.1% and 64.4% of the patients had been treated for T2DM for >5 years. Additionally, in this study, CR was associated with shorter preoperative T2DM therapy, higher C-peptide levels, less OAD usage, younger age, and lower HbA1c levels. Nudotor et al. evaluated 2720 patients with T2DM who had undergone vertical sleeve gastrectomy in the United States between 2010 and 2016, and found that 67.9% of patients achieved remission, of which 22.8% recurred during follow-up.²⁴ However, in this study, only OAD or insulin usage were included in remission criteria, and remission was evaluated at the sixth month.

In a study published by Sha et al., the results of four randomized controlled trials, including only patients with a BMI below 35, were evaluated.²⁵

One of these studies had the same CR and PR criteria as our study, while the other three had similar definitions. This study evaluated a total of 118 patients with a diagnosis of T2DM who underwent LSG and reported a remission rate of 56.7%. In the SM-BOSS study conducted by Peterli, LSG operation was performed on 26 patients with T2DM, and a 61.5% remission rate and 15.4% CI rate were reported.²⁶ We found that the remission rates of T2DM following LSG were consistent with the literature. We also believe that the small differences between the total success rates may be due to the definition of CI.

Kermansaravi et al. reported CR at the first postoperative year in 8 of 9 patients who underwent SASI operation, and CI in the other patient.¹³ Madyan et al. performed SASI on 5 patients with T2DM, and reported CR in 4 patients and CI in 1 patient.¹² In this study, in contrast to the ASMBS and ADA criteria, the FBG values below 110 were accepted as the remission criteria.

In a study conducted by Mahdy et al., in which SASI was performed on 279 patients with T2DM and ASMBs' remission criteria were utilized, 83.9% CR and 15.4% PR were reported at the end of the first year.¹¹ In this study, C-peptide values of the patients were also evaluated preoperatively and at first year comparatively. In another study by Mahdy et al., in which, unlike ASMBS criteria, they accepted FBG values between 100 and 110 also as remission, they performed SASI operation on 29 patients with T2DM and reported a total rate of remission and CI of 82.7%.¹⁵ In a study by Khalaf et al. in which SASI was performed on a total of 111 patients with T2DM, which were divided into subgroups according to the preferred surgical technique, a remission rate of 97% and above and CI in the remaining patients were reported.¹⁶

In a study, Romero et al. performed SASI on 25 patients with T2DM and reported a CR of 96% and a CI of 4%.¹⁴ In a systematic review conducted by Emile et al., nearly 100% CR and PR rates were reported following SASI.¹⁷ In another retrospective study, a total of 95.8% remission and CI in T2DM were reported after SASI, and thus SASI procedure was found to be superior to LSG in this regard.¹⁹ In another study comparing LSG and SASI operations, a total remission and CI of 97.7% was reported in T2DM following SASI, and thus SASI was found to be superior to LSG in this regard.¹⁸

In our study, although the overall effect of SASI operation on T2DM was consistent with the abovementioned literature, remission rates were found to be lower. First of all, the concepts of remission and CI should be based on the internationally valid standards of institutions, such as ADA and ASMBS. Second, in the course of T2DM, there is a decrease in β cell counts and, as a result, the insulin secretory capacity is also diminished in direct proportion to the duration of the disease and the obesity rate.²⁷ For this reason, we believe that the severity of this disease plays a more important role in remission.

In none of the studies on SASI mentioned above, neither T2DM duration nor the necessity of insulin treatment was mentioned. For this reason, if this procedure was performed on a population that has been diabetic for maybe an average of 2 years in the aforementioned studies, the stated success rates might be realistic. However, due to the limitations in mentioned studies, it is not possible to conclude whether SASI operation has a short-term advantage over other surgical methods. In our study, the preoperative C-peptide values and insulin production capacities of the patients were not examined, only the preoperative medical treatment period was indicated.

Patients in remission in both groups were also evaluated for a possible recurrence of T2DM disease and the FO scoring was utilized in this regard. Although this scoring system examines the risk of developing this disease in individuals who have not been diagnosed with T2DM, it was preferred because it provides at least an idea for the development of T2DM again and to our knowledge, no other scoring system exists, which evaluates this risk during remission.²⁸ In this scoring system, lower scores represent lower risks, and the mean FO score of the LSG group at first year was found to be slightly lower.

In our study, LSG was found to be slightly more successful than SASI in terms of T2DM remission, although it was not statistically significant. However, the FBG values and preoperative insulin usage rates of the patients in the SASI group were significantly higher and the duration of preoperative medical treatment was longer than the LSG group. In our study, the median T2DM duration of the patients in the SASI group was 10 years, while it was 6 years in the LSG group. We believe that this is the most important factor in the absence of statistically significant difference in terms of T2DM remission in SASI operation, which also has a malabsorptive component. In the light of the contemporary literature and according to the results of this study, we believe that both procedures are effective in T2DM remission in short term. However, proving any kind of superiority either in short term or long term in this regard requires randomized controlled prospective trials, which also must be designed according to the abovementioned criteria and subgroups.

This study also has important limitations. First of all, despite prospective recording of patients' data, these data were evaluated retrospectively, which results in selection bias. The fact that SASI was preferred in patients with more severe T2DM disease inevitably affects the results. In addition, the insulin secretion capacity of the patients was not determined in the preoperative period. We believe that, despite all these limitations, our study is scientifically valuable because the number of patients is higher than other published articles comparing the two procedures, the patient data were recorded in a standard way at the preoperative, sixth month and first year, and the findings were reported according to the international standards.

Consequently, considering the weight loss and T2DM criteria in the short-term comparison, neither of these procedures was found to be superior to each other. Individuals with a diagnosis of T2DM, LSG may be preferred to SASI in the first step, since its outcomes are similar to SASI, is a simpler surgical procedure, and can be easily converted to a procedure like SASI in case of a possible failure.

Footnotes

Authors' Contributions

M.K.Y. and A.Ş. was the main contributors to study conception. All authors contributed to study design. Material preparation, literature search, and analysis were performed by M.K.Y., A.Ş., and M.T.D. The first version of the article was written by M.K.Y. and A.Ş. and all authors commented on this version. All authors read and approved the final version of the article.

Disclosure Statement

No competing financial interests exist.

Funding Information

No funding was received for this article.

References

Dobbs

, Sawers

, Thompson

, et al. Overcoming Obesity: An Initial Economic Analysis, McKinsey Global Institute: Jakarta, Indonesia; 2014.

Sjöström

, Lindroos

, Peltonen

, et al. Lifestyle, diabetes, and cardiovascular risk factors 10years after bariatric surgery. N Engl J Med, 2004; 351(26):2683–2693; doi: 10.1056/NEJMoa035622

Bhandari

, Fobi

MAL

, Buchwald

, et al. Standardization of bariatric metabolic procedures: World consensus meeting statement. Obes Surg, 2019; 29(Suppl 4):309–345; doi: 10.1007/s11695-019-04032-x

Switzer

, Prasad

, Debru

, et al. Sleeve gastrectomy and type 2 diabetes mellitus: A systematic review of long-term outcomes. Obes Surg, 2016; 26(7):1616–1621; doi: 10.1007/s11695-016-2188-y

American College of Surgeons (2022). Optimal Resources for Metabolic and Bariatric Surgery 2019-Revised. Available from: https://www.facs.org/-/media/fguhte1t/2022_cm_mbsaqip_standards_final_linked-toc.pdf [Last accessed: May 2, 2023].

Biter

, van Buuren

MMA

, Mannaerts

GHH

, et al. Quality of life 1 year after laparoscopic sleeve gastrectomy versus laparoscopic Roux-en-Y gastric bypass: A randomized controlled trial focusing on gastroesophageal reflux disease. Obes Surg, 2017; 27(10):2557–2565; doi: 10.1007/s11695-017-2688-4

Ignat

, Vix

, Imad

, et al. Randomized trial of Roux-en-Y gastric bypass versus sleeve gastrectomy in achieving excess weight loss. Br J Surg, 2017; 104(3):248–256; doi: 10.1002/bjs.10400

Seetharamaiah

, Tantia

, Goyal

, et al. LSG vs OAGB-1 year follow-up data-a randomized control trial. Obes Surg, 2017; 27(4):948–954; doi: 10.1007/s11695-016-2403-x

Juodeikis Ž, Brimas

. Long-term results after sleeve gastrectomy: A systematic review. Surg Obes Relat Dis, 2017; 13(4):693–699; doi: 10.1016/j.soard.2016.10.006

10.

Peterli

, Wölnerhanssen

, Vetter

, et al. Laparoscopic sleeve gastrectomy versus Roux-Y-Gastric bypass for morbid obesity-3-year outcomes of the prospective randomized Swiss multicenter bypass or sleeve study (SM-BOSS). Ann Surg, 2017; 265(3):466–473; doi: 10.1097/SLA.0000000000001929

11.

Mahdy

, Emile

, Madyan

, et al. Evaluation of the efficacy of single anastomosis sleeve ileal (SASI) bypass for patients with morbid obesity: A multicenter study. Obes Surg, 2020; 30(3):837–845; doi: 10.1007/s11695-019-04296-3

12.

Madyan

, Emile

, Abdel-Razik

, et al. Laparoscopic single anastomosis sleeve ileal (SASI) bypass for patients with morbid obesity: Technical description and short-term outcomes. Surg Laparosc Endosc Percutan Tech, 2020; 30(2):e13–e17; doi: 10.1097/SLE.0000000000000763

13.

Kermansaravi

, Kabir

, Pazouki

. 1-Year follow-up of single anastomosis sleeve ileal (SASI) bypass in morbid obese patients: Efficacy and concerns. Obes Surg, 2020; 30(11):4286–4292; doi: 10.1007/s11695-020-04781-0

14.

Romero

, Colorado-Subizar

, De Uriarte-Lorente

, et al. Single anastomosis sleeve ileal bypass (SASI bypass): Short-term outcomes and concerns. Obes Surg, 2021; 31(5):2339–2343; doi: 10.1007/s11695-020-05145-4

15.

Mahdy

, Emile

, Alwahedi

, et al. Roux-en-Y gastric bypass with long biliopancreatic limb compared to single anastomosis sleeve ileal (SASI) bypass in treatment of morbid obesity. Obes Surg, 2021; 31(8):3615–3622; doi: 10.1007/s11695-021-05457-z

16.

Khalaf

, Hamed

. Single-anastomosis sleeve ileal (SASI) Bypass: Hopes and concerns after a two-year follow-up. Obes Surg, 2021; 31(2):667–674; doi: 10.1007/s11695-020-04945-y

17.

Emile

, Mahdy

, Schou

et al. Systematic review of the outcome of single-anastomosis sleeve ileal (SASI) bypass in treatment of morbid obesity with proportion meta-analysis of improvement in diabetes mellitus. Int J Surg, 2021; 92:106024; doi: 10.1016/j.ijsu.2021.106024.

18.

Mahdy

, Gado

, Alwahidi

, et al. Sleeve gastrectomy, one-anastomosis gastric bypass (OAGB), and single anastomosis sleeve ileal (SASI) bypass in treatment of morbid obesity: A retrospective cohort study. Obes Surg, 2021; 31(4):1579–1589; doi: 10.1007/s11695-020-05159-y

19.

Emile

, Madyan

, Mahdy

, et al. Single anastomosis sleeve ileal (SASI) bypass versus sleeve gastrectomy: A case-matched multicenter study. Surg Endosc, 2021; 35(2):652–660; doi: 10.1007/s00464-020-07430-w

20.

Gill

, Birch

, Shi

, et al. Sleeve gastrectomy and type 2 diabetes mellitus: A systematic review. Surg Obes Relat Dis, 2010; 6(6):707–713; doi: 10.1016/j.soard.2010.07.011

21.

Schauer

, Kashyap

, Wolski

, et al. Bariatric surgery versus intensive medical therapy in obese patients with diabetes. N Engl J Med, 2012; 366(17):1567–1576; doi: 10.1056/NEJMoa1200225

22.

Hofsø

, Fatima

, Borgeraas

, et al. Gastric bypass versus sleeve gastrectomy in patients with type 2 diabetes (Oseberg): A single-centre, triple-blind, randomised controlled trial. Lancet Diabetes Endocrinol, 2019; 7(12):912–924; doi: 10.1016/S2213-8587(19)30344-4

23.

Elgenaied

, El Ansari

, Elsherif

, et al. Factors associated with complete and partial remission, improvement, or unchanged diabetes status of obese adults 1 year after sleeve gastrectomy. Surg Obes Relat Dis, 2020; 16(10):1521–1530; doi: 10.1016/j.soard.2020.05.013

24.

Nudotor

, Prokopowicz

, Abbey

, et al. Comparative effectiveness of Roux-en Y gastric bypass versus vertical sleeve gastrectomy for sustained remission of type 2 diabetes mellitus. J Surg Res, 2021; 261:407–416; doi: 10.1016/j.jss.2020.12.024

25.

Sha

, Huang

, Ke

, et al. Laparoscopic Roux-en-Y Gastric Bypass versus sleeve gastrectomy for type 2 diabetes mellitus in nonseverely obese patients: A systematic review and meta-analysis of randomized controlled trials. Obes Surg, 2020; 30(5):1660–1670; doi: 10.1007/s11695-019-04378-2.

26.

Peterli

, Wölnerhanssen

, Peters

et al. Effect of laparoscopic sleeve gastrectomy vs laparoscopic Roux-en-Y gastric bypass on weight loss in patients with morbid obesity: The SM-BOSS randomized clinical trial. JAMA, 2018; 319(3):255–265; doi: 10.1001/jama.2017.20897

27.

Ferrannini

, Mari

. β-Cell function in type 2 diabetes. Metabolism. 2014 Oct;63(10):1217–1227; doi: 10.1016/j.metabol.2014.05.012

28.

Wilson

, Meigs

, Sullivan

, et al. Prediction of incident diabetes mellitus in middle-aged adults: The Framingham Offspring Study. Arch Intern Med, 2007; 167(10):1068–1074; doi: 10.1001/archinte.167.10.1068