ABSTRACT
Introduction: Vitamin B12 deficiency is more commonly found among patients who have undergone Roux-en-Y gastric bypass (RYGB) as compared to those with post-sleeve gastrectomies (SG). The major difference between SG and RYGB is that the latter greatly bypasses the stomach whereas the former simply reduces the gastric volume. Purpose: The aim of this article was to study the stomach and the distal ileum histologically in a cadaver with SG to explain the higher rate of incidences of vitamin B12 deficiency seen in patients post-RYGB relative to patients post-SG. Since the stomach is the major variable in these two procedures, we hypothesize that it has the ability to regenerate and increase its surface area to compensate for the loss of its volume in SG patients. Material and Methods: Tissue biopsies and hematoxylin and eosin stains were performed from various anatomical locations of the GI tract, specifically the gastric fundus, body, and antrum, and from the distal ileum of the small intestine of a cadaver with SG and another without SG (control). Results: Compared with the control, the SG cadaver's gastric tissue biopsies were significant for chronic gastritis and hypertrophy of the muscularis externa layer. More importantly, parietal cell hyperplasia and deeper mucosal glands were also noted in the SG cadaver supporting the hypothesis. Conclusions: The compensatory role of an intact stomach, given its ability to regenerate parietal cells and increase its numbers in the gastric fundus and body, can be better appreciated in a gastric-sparing procedure such as SG versus RYGB in terms of limiting vitamin B12 deficiencies.
Declaration of interest
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.
About the authors
Dwaipayan Muhuri, BSc, is a medical student at Ross University School of Medicine. His research interest ranges from gene therapy and bariatric surgery to pediatric endocrinology.
Gyorgy M. Nagy, MD, PhD, DSc, is a professor of anatomy and chair of the research committee at Ross University School of Medicine. His main research fields are neuroscience, neuroendocrinology, and endocrinology, in particular, cellular and molecular aspects of the regulation of pituitary function.
Velma Rawlins, PhD, is a core part of the laboratory services at Ross University School of Medicine.
Lisa Sandy, BSc, is the laboratory supervisor and a core part of the laboratory services at Ross University School of Medicine. She has special interest in public health and environmental toxicology.
Peter Bellot, MD, FACS, is a professor of pathology and the chair of the admissions committee at Ross University School of Medicine. He has particular interest and research experiences in cytology and surgical pathology.