The Significant Hormonal Traits of Laparoscopic Sleeve Gastrectomy Are Further Supported Using Three-Dimensional MDCT Gastrography

Abstract

We read with great interest the article by El-Sayes et al. [1] evaluating the correlation of sleeve volume and weight loss following laparoscopic sleeve gastrectomy (LSG), using three-dimensional (3D) multidetector computed tomography (MDCT). Given the significance of the outcomes, we would like to further stress certain points. To begin with, LSG is generally considered as a restrictive procedure. Nonetheless, there is growing evidence highlighting the significant hormonal properties of the procedure [2]. In fact, LSG modulates the metabolic, lipidomic, and gut microbiota profile of patients, along with several intestinal hormones that are associated with the glucose homeostasis. In this context, LSG increases the postprandial secretion of GLP-1 and PYY, two hormones that have been associated with lower glucose and insulin levels, along with glucagon and ghrelin suppression [3]. The modulation of these hormones could be explained by the faster arrival of food in the ileum without being completely digested. Furthermore, it has been proposed that branched-chain amino acids (BCAAs) and trimethylamine-N-oxide (TMAO), which are associated with insulin resistance and cardiovascular pathophysiology [4, 5], were significantly modulated following LSG. All this evidence was further supported by the outcomes that El-Sayes et al. [1] provided, showing the non-significant correlation between preoperative/postoperative gastric volume and weight loss at 6 and 12 months postoperatively. However, future studies implementing dynamic imaging modalities showing gastric transit time of solid and liquid meal, along with a longer follow-up would provide additional evidence regarding the actual impact of LSG restrictive traits on weight loss. Performing 3D MDCT gastrography was another important aspect of the present study [1]. Despite the concerns regarding its utility during the perioperative pathway for primary uncomplicated bariatric surgery, the use of lowdose and locally oriented CT with 3D reconstruction represents an important evolution in CT imaging and provides a useful tool in the diagnosis, follow-up, and management of functional dysregulations/complications following bariatric surgery. In fact, the low dose of radiation exposure along with the enhanced imaging properties constitutes 3D MDCT gastrography superior, more feasible, and safer compared with other imaging modalities, such as the use of barium swallow or MRI, for complicated cases and revisional procedures. In addition, the right timing of MDCT is also crucial. In the present study [1], the MDCT gastrography was performed preoperatively and at 6 and 12 months postoperatively, a choice that was mainly based on concerns regarding safety and interpretation bias due to the potential pouch wall edema. Nonetheless, a comparison of the calculated gastric pouch volume with direct measurements of the actual resected part would be of real value to better evaluate the accuracy of 3D MDCT gastrography in measuring gastric volume. Taking everything into consideration, the present study highlights once more the significant hormonal traits of LSG, in addition to the restrictive characteristics of the procedure. Besides, the current study proves the value of 3D MDCT gastrography for assessing perioperative along with long-term anatomic and functional outcomes following LSG. * Dimitris Zacharoulis [email protected]