Excessive Weight Loss and Hypoalbuminemia After SASI Bypass: the Need for Standardization of the Technique

TLDR: The authors based their recommendation to use SASI bypass selectively on the fact that two of their patients required conversion to sleeve gastrectomy due to excessive weight loss or severe protein malnutrition, and concur that these consequences can follow SASi bypass, certain points need to be highlighted.

Abstract: Dear Editor We read with great interest the article titled “1-Year Follow-up of Single Anastomosis Sleeve Ileal (SASI) Bypass in Morbid Obese Patients: Efficacy and Concerns” by Kermansaravi et al. [1]. Firstly, we would like to congratulate the authors on this important study and want to clarify a few issues with regard to the study and its conclusions. We think the conclusions of the study need to be restated as the authors started their conclusions in the abstract by describing SASI bypass as an investigational procedure which is not entirely true. Since it was first described, SASI bypass has been assessed in several studies, including a large multicenter study entailing 551 patients from seven countries [2] and a bicenter cohort study comparing SASI bypass with sleeve gastrectomy [3]. Hence, we could better describe the procedure as newly introduced, rather than an investigational procedure. The authors then recommended “to use SASI bypass only as a conversional surgery after sleeve failure or as a de novo procedure in carefully selected patients” [1]. We think this recommendation is not based on data of their study since none of the 24 patients in their series underwent SASI bypass as a revision after failed sleeve gastrectomy or other procedures. Moreover, the term “carefully selected patients” is not precisely defined for the readers. The patients selected for their series had either focal intestinal metaplasia and/or gastric atrophy, unresectable antral polyps, or family history of gastric cancer which are not the usual patient population on whom bariatric surgery is performed. The authors based their recommendation to use SASI bypass selectively on the fact that two of their patients required conversion to sleeve gastrectomy due to excessive weight loss or severe protein malnutrition. While we concur that these consequences can follow SASI bypass, certain points need to be highlighted. Although the previous studies that assessed the nutritional changes after SASI bypass reported a reduction of serum albumin levels postoperatively, the albumin levels remained within normal range and none of the patients required conversional surgery. The first published study by Mahdy et al. [4] reported that serum albumin levels showed insignificant changes from 3.8 ± 0.7 g/dl before surgery to 4.3 ± 0.4 g/dl at 6 months then was reduced to 4.1 ± 0.9 g/dl at 12 months postoperatively. Although the largest multicenter series on SASI bypass [2] and another study by Salama et al. [5] recorded a significant decrease in serum albumin levels at 12months after SASI bypass, the mean postoperative serum albumin level was 3.9 g/dl, within normal range, in both studies. Another randomized trial [6] that compared SASI bypass with sleeve gastrectomy did not observe any significant difference in the incidence of hypoalbuminemia between the two procedures (11% versus 8%). One important limitation of the study by Kermansaravi et al. [1] is the small number of patients included which can lead to type II error when analyzing the outcomes. This was readily apparent when assessing the improvement in comorbidities. Although the remission of diabetes mellitus and hypertension was recorded in about 89% and 86% of patients, this result was not statistically significant. However, we still concur that excessive weight loss and hypoalbuminemia, despite being infrequently recorded, are still possible after SASI bypass. To decipher the mechanism of these consequences after SASI bypass, one must comprehend the basic physiologic aspects of the procedure. As the procedure depends on the bipartition principle, certain technical aspects should be respected in order not to end with a complete diversion of food instead of bipartition. * Sameh Hany Emile sameh200@hotmail.com