Effect of Intraoperative Blood Pressure Regulation on Postoperative Hemorrhage After Bariatric Surgery.

INTRODUCTION: With a rising number of bariatric procedures, the absolute number of postoperative complications is increasing, too. Postoperative bleeding, particularly along the staple line, is a recognized challenge. Numerous strategies including reinforcement of the staple line (SLR) have been proposed to improve bleeding rates, but no single technique has shown superiority over the others. In our bariatric center, we have implemented intraoperative blood pressure regulation alone, without SLR, to reduce hemorrhagic complications postoperatively. METHODS: This retrospective observational analysis compares the incidence of postoperative bleeding in two groups of consecutive patients (total n = 438 patients), one with and one without intraoperative blood pressure elevation to 150 mmHg systolic without the additional use of staple line reinforcement. This intervention was integrated into our standard bariatric surgical procedure, no randomization or matching was conducted. Significant postoperative bleeding was defined as drop of hemoglobin of more than 2.5 mg/dl in 48 h and one of the following symptoms: lactate ≥ 2 mmol/L, bloody drainage, quantity of drainage more than 200 ml and/or radiological signs. RESULTS: Defined postoperative bleeding occurred in 33 (7.5%) patients. We observed a decrease in bleeding rates from 10% to 5% (n = 22 vs. n = 11) after introducing intraoperative blood pressure increase (p = 0.034). The rate of revisional surgery for bleeding also decreased from 2.7% to 0.5% (n = 6 vs. n = 1). In multivariate analysis, the intervention with blood pressure elevation showed a significant decrease on bleeding rates (p = 0.038). CONCLUSION: The use of increased intraoperative blood pressure alone, without staple line reinforcement, appears to be an effective and suitable method for reducing post-bariatric hemorrhagic complications.

Long-Term Diabetes Improvement After Duodenal Exclusion in Zucker Diabetic Fatty Rats Is Associated with Prevention of Strain-Specific Pancreatic Remodeling and Increased Beta Cell Proliferation.

BACKGROUND: Response to metabolic surgery is heterogeneous and the metabolic states that underpin weight loss and metabolic improvement are still unclear. In this study, we investigate parameters of post-bariatric fasting glucoregulation and leverage artificial intelligence-assisted whole-slide image analyses to characterize associated immunohistologic features of the pancreas. MATERIALS AND METHODS: We performed either loop duodeno-jejunostomy (DJOS) with exclusion of 1/3 of total intestinal length, loop duodeno-ileostomy with exclusion of 2/3 of total intestinal length (DiOS), or a sham operation on 8-week-old male obese ZDF rats. Six months post-operative, we measured blood metabolites and hormones. Subsequently, pancreatic and intestinal tissue was removed, formalin fixed, and paraffin embedded. Immunohistologic (IHC) analyses included proliferating cell nuclear antigen (PCNA) to visualize the proliferation fraction and pancreatic and duodenal homeobox 1 (PDX 1) as a measure of pancreatic cell differentiation. For IHC quantification, all slides were digitalized and analyzed using QuPath. All analyzed slides were reviewed by two independent pathologists for correctness. RESULTS: DJOS and DiOS were associated with preserved fasting insulin production compared to sham. Histopathologic evaluation showed significantly higher numbers of beta cells and specifically of clustered cell organization in DJOS and DiOS compared to sham. Cell proliferation (PCNA) was significantly elevated in DJOS and DiOS compared to sham. CONCLUSION: In this interventional model of bariatric surgery in severe genetic diabetes, we demonstrate post-operative histologic and immunohistologic features of the pancreas associated with improved fasting glucose homeostasis.

Putting the Hindgut Hypothesis to the Test in a Diabetic Zucker Rat Model.

BACKGROUND: The hindgut theory hypothesizes a key role of differential hindgut stimulation following metabolic procedures in ameliorating diabetes mellitus. We used two strategies to remove the hindgut from intestinal continuity in order to analyze its impact on diabetes mellitus. METHODS: Loop duodeno-jejunostomy (DJOS) with exclusion of one-third of total intestinal length was performed in 3 groups of 9-week-old Zucker diabetic fatty rats. In group 1, no further alteration of the intestinal tract was made. Group 2 received additional ileal exclusion (IE). Group 3 underwent additional resection of 50% of the ileum with side-to-side ileocecal anastomosis (IR). One, 2, and 4 months after surgery, fasting blood glucose levels, oral glucose tolerance tests (OGTT), and glucose-stimulated hormone analyses were conducted, and bile acid blood levels were compared. Body weight was documented weekly. RESULTS: In relation to DJOS, glucose control was not impaired in IR or IE. On the contrary, only IR could maintain preOP glucose values until 4 months. There were no significant weight differences between the groups. Confirming effective ileal diversion, bile acid blood levels were significantly higher in the DJOS group compared with both IR and IE (p = 0.0025 and p = 0.0047). Operative interventions had no impact on GLP-1 levels at any time point (ANOVA p > 0.05 for all). Insulin secretion was preserved in all groups. CONCLUSION: This data supports the hypothesis that the mechanisms driving amelioration of diabetes mellitus are complex and cannot be reduced to the ileum.

Duodenal Exclusion but Not Sleeve Gastrectomy Preserves Insulin Secretion, Making It the More Effective Metabolic Procedure.

INTRODUCTION: There is an ongoing debate on which procedure provides the best treatment for type 2 diabetes. Furthermore, the pathomechanisms of diabetes improvement of partly anatomically differing operations is not fully understood. METHODS: A loop duodenojejunostomy (DJOS) with exclusion of one third of intestinal length, a sleeve gastrectomy (SG), or a combination of DJOS + SG was performed in 8-week-old male ZDF rats. One, three, and six months after surgery, an oral glucose tolerance test and measurements of GLP-1, GIP, insulin, and bile acids were conducted. RESULTS: After an initial (4 weeks) equal glucose control, DJOS and DJOS + SG showed significantly lower glucose levels than SG 3 and 6 months after surgery. There was sharp decline of insulin levels in SG animals over time, whereas insulin levels in DJOS and DJOS + SG were preserved. GIP levels were significantly larger in both groups containing a sleeve at all three time points, whereas GLP-1 was equal in all groups at all time. Bile acid levels were significantly higher in the DJOS compared to the SG group at all time points. Interestingly, the additional SG in the DJOS + SG group led to lower bile acid levels 1 and 6 months postoperatively. CONCLUSION: The effect of SG on glucose control was transient, whereas a duodenal exclusion was the more effective procedure in this model due to a sustained pancreatic function with a preserved insulin secretion.

Common Channel Length in Bypass Surgery Does Not Impact T2DM in Diabetic Zucker Rats.

INTRODUCTION: Metabolic surgery is known to impact glucose tolerance but the exact mechanism is still unclear. Based on recently-published data, especially the role of the hindgut may require redefinition. METHODS: Either a loop duodeno-jejunostomy (DJOS) with exclusion of one third of total intestinal length, a loop duodeno-ileostomy (DiOS, exclusion of two thirds), or SHAM operation was performed in 9-week-old Zucker diabetic fatty rats. One, 3, and 6 months after surgery, an oral glucose tolerance test (OGTT) and glucose-stimulated hormone analyses were conducted. Body weight was documented weekly. RESULTS: DJOS and DiOS animals showed significantly better glucose control in all OGTTs than the SHAM group (two-way ANOVA p < 0.0001). Body weight developed largely parallel in both intervention groups; SHAM animals had gained significantly less weight after 6 months (Mann-Whitney DJOS/DiOS vs. SHAM p < 0.05, DJOS vs. DiOS p > 0.05). Operative interventions had no impact on GLP-1 and GIP levels at any time point (Mann-Whitney p > 0.05 for all). DJOS/DiOS operations could preserve insulin production up to 6 months, while there was already a sharp decline of insulin levels in the SHAM group (Mann-Whitney: DJOS/DiOS vs. SHAM p < 0.05 for all time points). Additionally, insulin sensitivity was improved significantly 1 month postoperative in both intervention groups compared to SHAM (Mann-Whitney DJOS/DiOS vs. SHAM p < 0.05). CONCLUSION: The data of the current study demonstrate a sharp amelioration of glucose control after duodenal exclusion with unchanged levels of GLP-1 and GIP. Direct or delayed hindgut stimulation had no impact on glucose control in our model.