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TOTS: SG associated with fewer complications vs GB and OAGB

Tue, 07/21/2020 - 17:46
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The two-year outcomes from the Tehran obesity treatment study (TOTS), which is comparing the effectiveness and safety of sleeve gastrectomy (SG) and gastric bypass (GB), has reported that both surgical procedures are effective in the control of obesity and remission of its comorbidities. However, since SG was associated with a lower rate of complications, it seems that SG should be considered as a suitable procedure for obese patients, especially those with a healthier metabolic profile, the authors report. The outcomes were featured in the paper, ‘Two-year outcomes of sleeve gastrectomy versus gastric bypass: first report based on Tehran obesity treatment study (TOTS)’, published in BMC Surgery.

The study authors from Tehran Obesity Treatment Center, Shahed University and Obesity Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran, claim TOTS is the first comprehensive report of a prospective cohort study evaluating a broad spectrum of outcomes in a two-year follow-up in the Middle East (MENA) regions. TOTS is a prospective cohort study of patients with morbid obese, including 2,202 patients who underwent laparoscopic SG and 1,085 patients who underwent laparoscopic GB (160 underwent RYGB and 925 underwent one-anastomosis gastric bypass [OAGB). The follow-up rate was 86, 91, and 64% at six, 12, and 24 months after surgery, respectively, which was not significantly different between the SG and GB groups.

Three major obesity-associated comorbidities - type 2 diabetes mellitus (T2DM), hypertension (HTN), and dyslipidaemia, were assessed. Each comorbidity was followed-up according to standardized outcome reporting in metabolic and bariatric surgery. Major complications were defined as those requiring the patient’s return to the operating room, prolonged hospital stay beyond seven days and need for re-admission. All other complications were regarded as minor. The primary endpoints in this study were early (<30 days) and late (>30 days) complications, major and minor complications, length of hospital stay and surgery duration. Quality of life was assessed using the Iranian version of Short-Form Health Survey (SF-36), which measures eight health-related components, including physical, mental, and social aspects of health.

Outcomes

A total of 3,287 patients (78.6% female) were included in the analysis, the 2,202 patients undergoing SG a mean age of 38.0±11.8 years and the mean BMI44.6±5.7 vs 1,085 patients undergoing GB who had a mean age of 39.4±10.7 years and mean BMI45.5±6.1. The baseline characteristics showed no significant difference between the two surgery groups regarding metabolic indices, except for fasting plasma glucose (FPG), HbA1c%, and LDL-C. Patients in the SG group had lower FPG (105.8±28.5 vs. 117.9±49.9, p<0.001) and HbA1c%, compared to the GB group. The prevalence of T2DM and insulin therapy were significantly lower in the SG group, compared to the GB group (24.1 vs. 35.9%, p<0.001; 8.7 vs. 22.9%, p<0.001, respectively). Based on the findings, the serum level of LDL-C was higher in the SG group, compared to the GB group (112.3±31.5 vs. 109.5±32.2, p=0.023).

BMI was not significantly different between the two groups, except in the 24-month follow-up, when the SG group had a higher BMI than the GB group (Figure 1a). Based on the results, EWL% was 61.9±15.7, 74.8±19.1 and 75.0±21.9 in the SG group and 62.7±15.3, 77.5±18.4 and 80.1±20.8 in the GB group at 6-, 12- and 24-month follow-ups, respectively. EWL% was lower in the SG group, compared to the GB group in 12- and 24-month follow-ups (p=0.002 for both) (Figure 1b). Despite the lower fat mass in the SG group compared to the GB group at baseline (59.7±11.6 vs. 60.7±11.6, p=0.020), it was higher in the SG group at 12 months after surgery (30.3±9.7 vs. 28.2 ± 9.8, p<0.001) (Figure 1c). Changes in fat percentage and its comparison between the groups showed the same trend during the follow-ups (Figure 1d). The GB group showed more significant results regarding TC and LDL reduction in all follow-ups, whereas HDL increased in both groups, although the SG group showed higher levels of HDL throughout the follow-up.

Figure 1: The anthropometric and body composition indices over time: a) BMI; b) EWL (%); c) fat mass (kg); and d) fat percentage (%)
Figure 1: The anthropometric and body composition indices over time: a) BMI; b) EWL (%); c) fat mass (kg); and d) fat percentage (%)
 

 

T2DM

The prevalence of T2DM at baseline was 439 (24.1%) and 376 (35.9%) in the SG and GB groups, respectively, which was significantly higher in the GB group (p<0.001). Of all patients with T2DM, 671 cases were followed-up for two years and remission and medication reduction were evaluated in these individuals. Out of 671 patients, 364 (54.2%) and 307 (45.8%) underwent SG and GB, respectively. The results showed that T2DM duration, mean FPG, and HbA1c% were significantly lower in the SG group, compared to the GB group.

At baseline, 118 (33.2%) and 57 (18.9%) patients did not use any T2DM medications, while 31 (8.7%) and 69 (22.9%) patients required insulin alone or in combination with other drugs, respectively, which was significantly lower in the SG group, compared to the GB group (p<0.001). Insulin therapy significantly reduced in both groups during the follow-up, and it was found to be lower than 2% in the 24-month follow-up. The number of patients with no T2DM medications in the SG group versus the GB group was 262 (87.3%) versus 215 (84.6%), 214 (89.9%) versus 262 (91.3%), and 95 (91.3%) versus 97 (90.7%) at 6-, 12-, and 24-month follow-ups, respectively.

The rate of T2DM remission was 73.3, 71.9 and 53.3% in the SG group and 56, 65.3 and 63.8% in the GB group at 6-, 12-, and 24-month follow-ups, respectively. Additionally, T2DM improvement was reported in 18.6, 26.8 and 38.7% of subjects in the SG group and 42.4, 33.8 and 35% of subjects in the GB group at 6-, 12-, and 24-month follow-ups, respectively. After PS-adjusted multivariable analysis, the surgical techniques were found to be similar regarding T2DM remission at all three time points of the follow-up.

Hypertension

At baseline, 622 (30.2%) subjects in the SG group and 329 (32.0%) subjects in the GB group had HTN, which was not significantly different between the two groups. Of all patients with HTN (n=734), 466 (63.4%) patients undergoing SG and 268 (36.6%) patients undergoing GB were followed-up for two years, and HTN remission and reduction of anti-HTN medication use were evaluated in these individuals.

At baseline, 353 (75.7%) and 226 (84.3%) patients used HTN medications in the SG and GB groups, respectively. The number of patients using anti-HTN medications in the SG group versus the GB group was 93 (23.7%) versus 67 (29.0%), 70 (18.7%) versus 46 (21.9%) and 38 (24.8%) versus 11 (11.9%) at 6-, 12- and 24-month follow-ups, respectively. Medication use was higher in the SG group, compared to the GB group only in the 24-month follow-up (p=0.010).

The prevalence of HTN remission was 50.4, 52.2 and 39.1% in the SG group and 46.3, 52.6 and 54.7% in the GB group at 6-, 12- and 24-month follow-ups, respectively. HTN improvement was estimated at 43.1, 44 and 54.7% in the SG group and 45.4, 40.9 and 40.0% in the GB group at 6-, 12- and 24-month follow-ups, respectively. After PS-adjusted multivariable analysis, the GB group showed a higher rate of HTN remission, compared to the SG group only in the 24-month follow-up (p=0.007).

Dyslipidaemia

The prevalence of dyslipidaemia at baseline was 1,820 (85.5%) and 926 (87.0%) in the SG and GB groups, respectively, which was not significantly different between the groups. Of all patients with dyslipidaemia, 2,116 cases were followed-up for two years and dyslipidaemia remission and medication use reduction were evaluated in these individuals. Out of 2,116 patients, 1,349 (63.7%) underwent SG and 767 (36.3%) underwent GB.

At baseline, 302 (22.3%) and 246 (32.0%) patients used dyslipidaemia medications in the SG and GB groups, respectively. The number of patients using dyslipidaemia medications in the SG group versus the GB group was 29 (2.6%) versus 14 (2.2%), 26 (2.8%) versus 12 (2.0%) and 16 (5.6%) versus 3 (1.5%) at 6-, 12- and 24-month follow-ups, respectively. Medication use was higher in the SG group, compared to the GB group only in the 24-month follow-up (p=0.022).

The prevalence of dyslipidaemia remission was 25.4, 27.7 and 14.2% in the SG group and 24.7, 37.1 and 29.8% in the GB group at 6-, 12- and 24-month follow-ups, respectively. Based on the findings, dyslipidaemia improvement was estimated at 73.7, 71.7 and 82.1% in the SG group and 74.4, 62.6 and 70.2% in the GB group at 6-, 12- and 24-month follow-ups, respectively. Based on the adjusted multivariable analysis, the GB group had a significantly higher rate of dyslipidaemia remission, compared to the SG group in all follow-ups.

Nutritional deficiencies

The most common deficient micronutrients in both SG and GB groups were vitamin D, vitamin B12, haemoglobin and serum iron. In general, nutritional deficiencies were less prevalent in the SG group, compared to the GB group. Haemoglobin and haematocrit deficiencies were significantly lower in the SG group, compared to the GB group in all follow-ups. Moreover, in the 12-month follow-up, iron (5.2% vs. 12.2%), ferritin (15.7% vs. 25.0%), copper (5.8% vs. 8.5%) and calcium (0.6% vs. 3.7%) deficiencies were significantly less prevalent in the SG group, compared to the GB group. There was no case of hypoalbuminemia in the SG group, whereas in the GB group, its prevalence was 1.5 and 1.0% at 12- and 24-month follow-ups, respectively.

Complications

The mean length of hospital stay was 2.5 days in both surgery groups. The mean surgery time and anaesthesia duration were significantly shorter in the SG group, compared to the GB group (56.5±16.2 and 105.2±22.9 vs. 72.7±24.3 and 121.8±30.4 min, respectively; p<0.001). There was only one case of early mortality in the GB group, while two and four late mortalities were reported in the SG and GB groups, respectively. Overall, 122 patients returned to the operating room, including 55 (2.4%) patients in the SG group and 67 (6.0%) patients in the GB group (p<0.001). In general, the rate of early and late complications was lower in the SG group, compared to the GB group (4.6 and 2.2% vs. 11.7 and 5.2%, respectively; p<0.001).

A total of 560 patients were asked to complete SF-36 before and 12 months after surgery. Of these patients, 372 (66.4%) and 188 (33.6%) underwent SG and GB, respectively. There was no significant difference between the two groups in terms of physical and mental health components of quality of life at baseline and 12 months after surgery. However, both groups improved significantly in all subdomains of quality of life after the operation.

“According to the findings of the present study, both SG and GB are effective in terms of weight loss, remission of obesity-associated comorbidities, and quality of life improvement. Since SG is associated with fewer complications and nutritional deficiencies, it can be considered a valid treatment for obesity and its associated comorbidities in eligible patients,” the authors concluded. “However, further RCTs, with comorbidity remission as the primary endpoint, are needed to shed more light on the existing discrepancies regarding the decision to choose between different bariatric surgeries, especially SG and GB.”

To access this paper, please click here