Current guidelines are supportive of bariatric surgery for those with obesity and T2D [13]. When considering the possibility of a surgical treatment for a disease that traditionally has a clinical approach, its pathophysiology must be considered, including genetic background and ethnicity. The median BMI of a T2D patient in this country is 29kg/m2. The BMI cutpoint for increased risk for T2D is much lower among Asian individuals groups, as well [14, 15].
Overweight and lean patients with diabetes may have an accelerated loss of pancreatic beta-cells, and there are studies demonstrating that patients with a higher BMI had lower HbA1c[16]. The importance of whether beta cell functioning is improved after surgery, not dependently of weight loss, may point to the risk of relapse with weight regain, by removing the effect of a better insulin sensitivity. RYGB causes profound changes in insulin sensitivity, improved in proportion to the weight loss. Targeting pancreatic β cells functioning would be of extreme importance for the indication of surgical treatment of patients with T2D and lower BMIs. Therefore, it is not clear to what extent the obesity model corresponds to the pathophysiology of T2D occurring in overweight or in non-obese patient [17]
The meta-analysis of Yu et al included 17 eligible studies and reported initial remission rate of 63.0% with relapse in 30.0% of T2D patients with obesity, after RYGB. They also concluded that the risk of recurrence of T2D was lower after RYGB than after sleeve gastrectomy [18].
Likewise, Scopinaro et al did not support RYGB weight loss-independent effect on beta-cell function in the T2D patients with obesity class I [10]
Ke et al studied 70 uncontrolled T2D patients who underwent laparoscopic RYGB, followed up above six months. The authors compared the remission rate according to the BMI and found that complete remission was 28.2% of the BMI < 30 kg/m2 group and 57.9% of the BMI > 30 kg/m2 group [19].
In 2006, DePaula et al described a new technique of sleeve gastrectomy associated with a jejunal ileal interposition, to treat obesity and its comorbidities, in 19 patients. After dividing the jejunum 50 cm from the ligament of Treitz, a 100-cm ileal segment was created, 50 cm proximal to the ileocecal valve, interposing it peristaltically in the proximal jejunum [20] Although ileal interposition was described in 1982, the association with SG was debuting [21]. The rationale for adding a gastric resection was based upon the ileal brake phenomenon, considering that the elevation of ileal hormones after contact with undigested food would increase gastric emptying time. Thus, it could be inferred that ileal procedures that aim to treat obesity and/or diabetes must be associated with gastric manipulation, under the risk of promoting gastroparesis. [22, 23]
The same authors, in 2010, demonstrated that if the ileal segment was interposed into the proximal duodenum, diabetes remission was higher [24]. In this paper, the authors did not completely discuss their findings, but in 2008, after finding that the AUC for total gastric inhibitory peptide (GIP) was greater compared with preoperative evaluation, they postulated that the reduction of the stimulus of the duodenum or even complete bypass of food transit would be able to reduce the characteristic GIP-resistant state of T2D. The explanation could be possible found by looking closely at the duodenum as an important organ in metabolic signaling, and its mucosal changes before and after the onset of T2D. [25][26]
Tinoco et al, in 2011, with a 18-month follow up, found remission of T2D in 80% of the patients after SGDII. [27]
De Paula et al demonstrated, in 94 patients, the efficacy of SGDII in patients with a BMI < 35 Kg/m2. The authors found that insulin sensitivity was restored and total insulin output increased ß-cell glucose sensitivity doubled, with a lower baseline insulin sensitivity as the only predictor of remission.[28]
Our choice for surgical treatment of obesity is RYGB (75%) and sleeve gastrectomy (25%), with 5144 procedures done, since 2000. For surgical treatment of T2D we have been using SGDII since 2011.
In the present study, 80% of patients had T2D remission after one year, 74.5% after three years, and 61.8% after five years. Folschi et al, comparing SGDII to medical treatment in T2D obese patients (BMI > 30), found, after five years, remission in 68% of the cases. [29]
Considering the duration of diabetes, more than four years, and the BMI, the rate of T2D remission after SGDII is higher than after RYGB (29%) with a five year follow up [30]
Parikh et al, on a systematic review with meta-analysis of diabetes remission among patients with a BMI < 35 kg/m2, found an overall rate of diabetes remission at 12 months of 54.7% of the cases, the highest one after ileal interposition (80.5% − 95% CI, 59.4–92.3%) [31]
The average BMI preoperatively was 33.43 kg/m2, and postoperatively it was 26.17 kg/m2, demonstrating that surgery does not promote excessive weight loss in non-obese patients.
The feasibility and safety of the procedure were analyzed according to the following criteria: operative time, need for conversion to laparotomy, early postoperative complications, and procedure-related mortality. SGDII can be considered a complex laparoscopic surgery, and reproducibility evaluation is critical. Possibly, this would be the most used argument limiting its use, despite the better results, regarding T2D remission, than those observed after consigned bariatric surgical techniques which had their indication extended to the surgical treatment of T2D. Another matter of debate would be the number of the mesenteric defects to be closed and the risk of internal hernias, complication not found on our series.
Postoperative complications (30 days) required surgical approach in 2.08% of the patients. As mentioned, two enteric fistulas, both in the duodenal stump, had a favorable outcome during the same hospital stay. We used an invaginating staple line to the sectioned duodenum, with 3 − 0 monofilament absorbable suture (Polydioxanone). Duodenal stump leaks have been reported in the surgical literature with a rate of approximately 1–6% [33]. The best comparison here would be with the duodenal switch operation, which carries a risk of 1.14% vs. 1.12% for RYGB [33]
Added to the challenge of approaching the duodenum, the presence of atherosclerosis, extensive in long lasting T2D, is associated with anastomotic leakage after abdominal surgery as well as other postoperative complications [34].
Postoperative bleeding occurred in four patients. All patients were treated conservatively with replacement of blood products and clinical support, with improvement of general symptoms. Bleeding rate (4.1%) was considered acceptable, especially when compared to RYGB, where most authors reported rates ranging from 1.5–4.1%. Once again, the severity of T2D should be considered, with many cases not suitable of discontinuing the prevention of atherothrombotic events.