Immune marker reductions in black and white Americans following sleeve gastrectomy in the short-term phase of surgical weight loss.

BACKGROUND: Surgical weight loss procedures like vertical sleeve gastrectomy (SG) are sufficient in resolving obesity comorbidities and are touted to reduce the burden of pro-inflammatory cytokines and augment the release of anti-inflammatory cytokines. Recent reports suggest a reduced improvement in weight resolution after SG in Black Americans (BA) versus White Americans (WA). The goal of this study was to determine if differences in immunoglobulin levels and general markers of inflammation after SG in Black Americans (BA) and White Americans (WA) may contribute to this differential resolution. METHODS: Personal information, anthropometric data, and plasma samples were collected from 58 participants (24 BA and 34 WA) before and 6 weeks after SG for the measurement of immunoglobulin A (IgA), IgG, IgM, C-reactive protein (CRP), and transforming growth factor (TGFß). Logistic regression analysis was used to determine the relationship of measures of body size and weight and inflammatory markers. RESULTS: Both IgG and CRP were significantly elevated in BA in comparison to WA prior to weight loss. Collectively, IgG, TGFß, and CRP were all significantly reduced at six weeks following SG. CRP levels in BA were reduced to a similar extent as WA, but IgG levels were more dramatically reduced in BA than WA despite the overall higher starting concentration. No change was observed in IgA and IgM. CONCLUSIONS: These data suggest that SG improves markers of immune function in both BA and WA. More diverse markers of immune health should be studied in future work.

Whole genome transcriptome analysis of the stomach resected in human vertical sleeve gastrectomy: cutting more than calories.

Vertical sleeve gastrectomy (VSG) is a surgical weight loss procedure that resects 80% of the stomach, creating a tube linking the esophagus to the duodenum. Because of the efficacy and relative simplicity of VSG, it is preferred in the United States, with VSG currently at >61% of bariatric surgeries performed. Surprisingly, there has never been a complete molecular characterization of the human stomach greater curvature's fundus and corpus. Here we compare and contrast the molecular makeup of these regions. We performed a prospective cohort study to obtain gastric tissue samples from patients undergoing elective VSG. Paired fundus and corpus samples were obtained. Whole genome transcriptome analysis was performed by RNA sequencing (N = 10), with key findings validated by qPCR (N = 24). Participants were primarily female (95.8%) and White (79.15%). Mean body mass index, body weight, and age were 46.1 kg/m2, 121.6 kg, and 43.29 yr, respectively. Overall, 432 gene transcripts were significantly different between the fundus and the corpus (P < 0.05). A significant correlation was found between the RNA sequencing dataset and qPCR validation, demonstrating robust gene expression differences between the fundus and the corpus. Significant genes included progastricsin, acidic chitinase, and gastokine 1 and 2 in both the fundus and the corpus. Of the very highly expressed genes in both regions, 87% were present in both the stomach's fundus and corpus, indicating substantial overlap. Despite significant overlap in the greater curvature gene signature, regional differences exist within the fundus and the corpus. Given that the mechanism of VSG is partly unresolved, the potential that the resected tissue may express genes that influence long-term body weight regulation is unknown and could influence VSG outcomes.

Elevated plasma endothelin-1 is associated with reduced weight loss post vertical sleeve gastrectomy.

BACKGROUND: Obesity and insulin resistance are positively correlated with plasma endothelin-1 (ET-1) levels; however, the mechanisms leading to increased ET-1 are not understood. Similarly, the full physiological complexity of ET-1 has yet to be described, especially in obesity. To date, one of the best treatments available for morbid obesity is bariatric surgery to quickly reduce body fat and the factors associated with obesity-related disease; however, the effects of vertical sleeve gastrectomy (SG) on plasma ET-1 have not been described. OBJECTIVES: To determine if SG will reduce plasma ET-1 levels and to determine if plasma ET-1 concentration is associated with weight loss after surgery. SETTING: The studies were undertaken at a University Hospital. METHODS: This was tested by measuring plasma ET-1 levels from 12 obese patients before and after SG. All data were collected from clinic visits before SG, 6 weeks after SG, and 6 months after surgery. RESULTS: At 6 weeks after SG, plasma ET-1 levels increased by 24%; however, after 6 months, there was a 27% decrease compared with presurgery. Average weight loss in this cohort was 11.3% ± 2.4% body weight after 6 weeks and 21.4% ± 5.7% body weight after 6 months. Interestingly, we observed an inverse relationship between baseline plasma ET-1 and percent body weight loss (R2 = .49, P = .01) and change in body mass index 6 months (R2 = .45, P = .011) post bariatric surgery. CONCLUSIONS: Our results indicate that SG reduces plasma ET-1 levels, a possible mechanism for improved metabolic risk in these patients. These data also suggest that ET-1 may serve as a predictor of weight loss after bariatric surgery.

Face, content, and construct validities of inanimate intestinal anastomoses simulation.

PURPOSE: Surgical simulation modules for "open" surgery are limited and not well studied or validated. Available simulation modules use either synthetic material, which is convenient but may not mimic what is observed or felt in the operating room, or live animal laboratories, which can simulate human tissue but are costly and not readily available. An intestinal anastomosis simulation was devised with thawed porcine intestine. In this study, the face, content, and construct validities of this simulation module were analyzed for both hand-sewn and stapled anastomoses. METHODS: Participants were timed on performing a 2-layered, hand-sewn anastomosis, as well as a side-to-side, functional, end-to-end, stapled anastomosis on thawed porcine small bowel. Anastomoses were examined for adequacy and measured for luminal narrowing and bursting pressure by intraluminal saline infusion. Questionnaires were answered regarding impressions with the simulation modules. Face, content, and construct validities were evaluated by comparing junior residents to senior residents and faculty. Data collected were analyzed with 2-sample t-tests. RESULTS: Both hand-sewn and stapled anastomoses showed strong face and content validity. Overall impressions of these inanimate simulation modules were a positive experience as reflected by the comments of participants. For hand-sewn anastomoses, a significant difference was found between junior and senior group times (50.0 +/- 17.2 vs 33.0 +/- 9.7 minutes, p = 0.013) as well as PGY-1 and faculty times (64.0 +/- 7.2 vs 28.0 +/- 3.8 minutes, p = 0.001). Bursting pressures varied between both groups and were not significant. For stapled anastomoses, no difference was noted between the various groups in completion time or bursting pressure. CONCLUSIONS: Hand-sewn and stapled inanimate intestinal anastomoses are a valid simulation of intraoperative experience based on the face and content validities. Although stapled anastomosis does not have good construct validity, the more challenging hand-sewn anastomosis does differentiate between various skill levels.

Incurable colorectal carcinoma: the role of surgical palliation.

About 20 per cent of patients with carcinoma of the colon or rectum present with metastatic disease. Surgeons are frequently asked to consider resection or other operative procedures in these patients for palliation. We performed this review to determine whether patients presenting with known metastatic colorectal cancer derive benefit from surgical intervention. We performed a retrospective review of all patients with M1 carcinoma of the colon or rectum who were identified from the University of Mississippi Medical Center Cancer Registry from April 1985 through February 2003. Patients who underwent hepatic and/or pulmonary resection with curative intent were excluded from analysis, as were patients with metachronous metastases. Eighty patients with M1 colorectal cancer who did not undergo surgery with curative intent were identified, and in 74 of these, complete medical records and follow-up were available. Forty-nine of the 74 patients (66%) underwent an operation, and 25 were managed nonoperatively. Indications for surgery included bowel obstruction, active hemorrhage, severe anemia from gastrointestinal bleeding with requirement for blood transfusions, intractable pain, and perforation of the colon. Average survival was 11.2 months for operative patients versus 6.5 months for nonoperative patients (P < 0.05). Thirty-six patients who underwent resectional procedures had a postoperative hospitalization of 7.5 days and a median survival of 11.5 months. Thirteen patients who had a nonresectional procedure had an average postoperative stay of 9 days and a median survival of 4 months. Median survival in those who did not undergo an operation was 4.8 months. Although metastatic colorectal carcinoma cannot usually be cured by surgical intervention, many patients who present with metastatic disease will benefit from palliative operations with relatively short hospitalizations and reasonable survival. Those who are not candidates for resection of the primary tumor have shorter survival times. Surgery can alleviate many of the distressing symptoms in patients with metastatic colorectal carcinoma.