Sleeve Gastrectomy Protects Against Hypertension in Rats due to Changes in the Gut Microbiome.

INTRODUCTION: Sleeve gastrectomy (SG), results in improvement in hypertension. We have previously published that rodent SG improves hypertension independent of weight loss associated with unique shifts in the gut microbiome. We tested if the gut microbiome directly improves blood pressure by performing fecal material transfer (FMT) from post-SG rats to surgery-naïve animals. METHODS: We performed SG or Sham surgery in male, Zucker rats (n = 6-7) with obesity. Stool was collected postop from surgical donors for treatment of recipient rats. Three nonsurgical groups received daily, oral consumption of SG stool, sham stool, or vehicle alone (Nutella) for 10 wk (n = 7-8). FMT treatment was assessed for effects on body weight, food intake, oral glucose tolerance, and blood pressure. Genomic deoxyribonucleic acid of stool from donor and recipient groups were sequenced by 16S ribosomal ribonucleic acid and analyzed for diversity, abundance, and importance. RESULTS: Ten weeks of SG-FMT treatment significantly lowered systolic blood pressures in surgery-naïve, recipient rats compared to vehicle treatment alone (126.8 ± 13.3 mmHg versus 151.8 ± 12.2 mmHg, P = 0.001). SG-FMT treatment also significantly altered beta diversity metrics compared to Sham-FMT and vehicle treatment. In random forest analysis, amplicon sequence variant level significantly predicted FMT group, P = 0.01. CONCLUSIONS: We have found a direct link between gut microbial changes after SG and regulation of blood pressure. Future mechanistic studies are required to learn what specific gut microbial changes are required to induce improvements in obesity-associated hypertension and translation to clinical, metabolic surgery.

Bariatric Surgeon Ergonomics: A Comparison of Laparoscopy and Robotics.

INTRODUCTION: Bariatric surgery is routinely performed using laparoscopic and robotic approaches. Musculoskeletal injuries are prevalent among both robotic and laparoscopic bariatric surgeons. Studies evaluating ergonomic differences between laparoscopic and robotic bariatric surgery are limited. This study aims to analyze the ergonomic, physical, and mental workload differences among surgeons performing robotic and laparoscopic bariatric surgery. MATERIALS AND METHODS: All primary laparoscopic and robotic bariatric surgeries, Roux-en-Y gastric bypass, and sleeve gastrectomy between May and August 2022 were included in this study. Objective ergonomic analysis was performed by an observer evaluating each surgeon intraoperatively according to the validated Rapid Entire Body Assessment tool, with a higher score indicating more ergonomic strain. After each operation, surgeons subjectively evaluated their physical workload using the body part discomfort scale, and their mental workload using the surgery task load index. RESULTS: Five bariatric surgeons participated in this study. In total, 50 operative cases were observed, 37 laparoscopic and 13 robotic. The median total Rapid Entire Body Assessmentscore as a primary surgeon was significantly higher in laparoscopic (6.0) compared to robotic (3.0) cases (P < 0.01). The laparoscopic and robotic approaches had no significant differences in the surgeons' physical (body part discomfort scale) or mental workload (surgery task load index). CONCLUSIONS: This study identified low-risk ergonomic stress in surgeons performing bariatric surgery robotically compared to medium-risk stress laparoscopically. Since ergonomic stress can exist even without the perception of physical or mental stress, this highlights the importance of external observations to optimize ergonomics for surgeons in the operating room.

The Association of Preoperative Food Insecurity With Early Postoperative Outcomes After Bariatric Surgery.

INTRODUCTION: To assess the rate of food insecurity in patients undergoing bariatric surgery. To compare the rates of 30-d postoperative complications based on food security status. METHODS: Patients undergoing primary Roux-en-Y gastric bypass or sleeve gastrectomy between 7/2020 - 3/2022 were screened for food insecurity via telephone using questions from the Accountable Health Communities Health-Related Social Needs Screening Tool. Screens were matched to patient data and 30-d outcomes from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database. RESULTS: In total, 213 (59%) of the 359 bariatric surgery patients were screened with 81 (38%) screening positive for food insecurity. Evaluation of preoperative variables based on food security status showed comparable age, body mass index, and comorbidity status. Food insecure patients were found to have an increased length of stay following surgery compared to food secure patients (P = 0.003). Food insecurity was not associated with higher rates of Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program reported 30-d postoperative complications including emergency department/urgent care visits (P = 0.34) and hospital readmissions (P = 0.94). CONCLUSIONS: Food insecurity was prevalent at 38% of the bariatric surgical population. Food insecure patients had a statistically longer length of stay after primary bariatric surgery but were not associated with an increased risk of 30-d complications. Future studies are needed to determine the mid-term and long-term effects of food insecurity status on bariatric surgical outcomes and the potential impact of food insecurity on length of stay.

A single, peri-operative antibiotic can persistently alter the post-operative gut microbiome after Roux-en-Y gastric bypass.

INTRODUCTION: Roux-en-Y gastric bypass (RYGB) significantly alters the gut microbiome and may be a mechanism for post-operative cardiovascular disease improvement. We have previously found an association between the class of peri-operative, intravenous antibiotic administered at the time of RYGB and the resolution rate of hypertension suggesting the gut microbiome as a mechanism. In this study, we performed a prospective study of RYGB to determine if a single intravenous antibiotic could alter the gastrointestinal microbial composition. METHODS: Patients undergoing RYGB were randomized to a single, peri-operative antibiotic of intravenous cefazolin (n = 8) or clindamycin (n = 8). Stool samples were collected from four-time points: 2 weeks pre-op (- 2w), 2 days pre-op (- 2d), 2 weeks post-op (+ 2w) and 3 months post-op (+ 3m). Stool samples were processed for genomic DNA followed by Illumina 16S rRNA gene sequencing and shotgun metagenomic sequencing (MGS). RESULTS: A total of 60 stool samples (- 2w, n = 16; - 2d, n = 15; + 2w, n = 16; + 3m, n = 13) from 16 patients were analyzed. 87.5% of patients were female with an average age of 48.6 ± 12.2 years and pre-operative BMI of 50.9 ± 23.3 kg/m2. RYGB induced statistically significant differences in alpha and beta diversity. There were statistically significant differences in alpha diversity at + 2w and beta diversity at + 3m due to antibiotic treatment. MGS revealed significantly distinct gut microbiota with 11 discriminatory metagenomic assembled genomes driven by antibiotic treatment at 3 months post-op, including increased Bifidobacterium spp. with clindamycin. CONCLUSION: RYGB induces significant changes in the gut microbiome at 2 weeks that are maintained 3 months after surgery. However, the single peri-operative dose of antibiotic administered at the time of RYGB induces unique and persisting changes to the gut microbiome that are antibiotic-specific. Increased Bifidobacterium spp. with clindamycin administration may improve the metabolic efficacy of RYGB when considering gut-microbiome driven mechanisms for blood pressure resolution.

Transversus abdominis plane blocks for complex abdominal wall reconstruction decrease hospital length of stay compared to epidurals.

BACKGROUND: Complex abdominal wall reconstruction for ventral and incisional hernias can be quite painful with prolonged length of stay (LOS). There are a variety of options to manage post-operative pain after a ventral hernia repair, including epidural catheters, transversus abdominis plane (TAP) blocks, and intravenous narcotic pain medications (IVPM). We hypothesized that TAP blocks with liposomal bupivacaine decrease the LOS compared to epidurals and IVPM. METHODS: A retrospective review of all patients who underwent an open ventral hernia repair with retromuscular mesh between 2016 and 2020 was conducted. LOS was used as the primary outcome. Secondary outcomes included post-operative pain and 90-day post-operative complications. RESULTS: An epidural was used in 66 patients, a TAP block with liposomal bupivacaine in 18 patients, and IVPM in 11 patients. The epidural group was noted to have a significantly longer duration of surgery (251.11 vs. 207.94 min; P < 0.05) and larger area of mesh (461.85 vs. 338.17 cm2; P < 0.05) when compared to the TAP block group. Hospital LOS was significantly shorter for the TAP block group compared to the epidural group (4.22 vs. 5.62 days; P < 0.05). There were no differences in post-operative complications between the groups. The epidural group reported significantly lower post-operative day one (POD1) pain scores measured on a 10-point scale, compared to the IVPM and TAP block groups (5.00 vs. 6.91 vs. 7.50; P < 0.05). CONCLUSION: Patients who received a TAP block for post-operative pain management had a significantly shorter length of stay compared to those patients who received an epidural. While the TAP block group reported higher POD1 pain scores, they did not have a significant difference in post-operative complications. TAP blocks with liposomal bupivacaine should be considered for post-operative pain control in complex ventral hernia repairs.

Isolated left ventricular assist device implantation produces variable changes to patient body mass index.

BACKGROUND: Body mass index (BMI) is an important consideration for transplant-eligible left ventricular assist device (LVAD) recipients. LVAD therapy's impact on BMI is unclear. We evaluated BMI changes in patients who underwent LVAD implantation. The association between these patients' BMI and the transplant was studied. METHODS: This was a retrospective cohort study of patients who underwent LVAD implantation between January 1, 2012 and December 31, 2018 at our institution. Patients were stratified by preoperative BMI (kg/m2 ) into four groups: <30, 30-34.9, 34.9-39.9, and ≥40. BMI data were collected at 12 and 6 months prior to implantation, time of implantation, and 3- and 6- months postimplantation. RESULTS: A total of 107 patients underwent LVAD implantation at our institution. Data were available for 80 patients. Baseline characteristics included a mean age of 56.0 years, 69% male, and a mean implant BMI of 29.9 ± 6.8 kg/m2 . The mean BMI (kg/m2 ) for each of the BMI (kg/m2 ) groups <30, 30-34.9, 35-39.9, and ≥40 (n = 60, 25, 12, and 10, respectively) was 25.1, 32.5, 36.8, and 43.8, respectively. There was no consistent pattern with weight change across differing implant BMIs. No patient with a BMI of <30 gained sufficient weight to impact transplant candidacy. Twenty-three percent of patients with a BMI of 30-34.9 kg/m2 , 60% of patients with a BMI of 35-39.9 kg/m2 , and 87.5% of patients with a BMI of ≥40 kg/m2 had a 6-month BMI potentially affecting transplant. CONCLUSIONS: Associated weight changes during LVAD support may significantly impact transplant candidacy. Higher BMI groups may benefit from multimodal and multidisciplinary targeted weight-loss interventions.

The Impact of Hemoglobin A1c on Post-operative Outcomes in Bariatric Surgery Patients.

INTRODUCTION: Pre-operative hemoglobin (Hb) A1c levels ≥ 8% can lead to increased post-operative complications. In bariatric surgery patients, attaining a pre-operative HbA1c < 8% can be a challenge. The purpose of this study was to identify the association of pre-operative HbA1c on post-operative outcomes in bariatric surgery patients. MATERIAL AND METHODS: A retrospective chart review was conducted on diabetic patients (HbA1c ≥ 6.5%) who underwent primary bariatric surgery at a single institution between the years 2013 and 2019. Patients were divided into two groups based on their pre-operative HbA1c levels of < 8% and ≥ 8%. Univariate analyses were performed to determine an association between pre-operative HbA1c levels and post-operative outcomes. RESULTS: There were 351 primary diabetic bariatric surgery patients, 270 HbA1c <8%, and 81 HbA1c ≥ 8%. Procedure selection was significantly different between the HbA1c < 8% and HbA1c ≥ 8% group (49.3% sleeve, 50.4% bypass and 0.4% band versus 43.2% sleeve, 53.1% bypass and 3.7% band respectively, P < 0.04). There was no statistically significant difference in any 30-day post-operative outcome between the two groups. Post-operative HbA1c was significantly less in the HbA1c < 8% group at 3-6 month (6.0% ± 0.9 versus 7.4% ± 1.4, P <0.001) and 6-12 month (6.0% ± 1.1 versus 7.2% ± 1.4, P <0.001) follow-up. CONCLUSIONS: This study demonstrated no difference in post-operative outcomes of primary bariatric surgery patients based on a HbA1c cut-off of 8%. This highlights that bariatric surgery can be considered and safely performed in patients with a pre-operative HbA1c ≥ 8%.

Guidelines for the performance of minimally invasive splenectomy.

BACKGROUND: Minimally invasive splenectomy (MIS) is increasingly favored for the treatment of benign and malignant diseases of the spleen over open access approaches. While many studies cite the superiority of MIS in terms of decreased morbidity and length of stay over a traditional open approach, the comparative effectiveness of specific technical and peri-operative approaches to MIS is unclear. OBJECTIVE: To develop evidence-based guidelines that support clinicians, patients, and others in decisions on the peri-operative performance of MIS. METHODS: A guidelines committee panel of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) including methodologists used the Grading of Recommendations Assessment, Development and Evaluation approach to grade the certainty of evidence and formulate recommendations. RESULTS: Informed by a systematic review of the evidence, the panel agreed on eight recommendations for the peri-operative performance of MIS for adults and children in elective situations addressing six key questions. CONCLUSIONS: Conditional recommendations were made in favor of lateral positioning for non-hematologic disease, intra-operative platelet administration for patients with idiopathic thrombocytopenic purpura instead of preoperative administration, and the use of mechanical devices to control the splenic hilum. Further, a conditional recommendation was made against routine intra-operative drain placement.

The impact of nausea on post-operative outcomes in bariatric surgery patients.

INTRODUCTION: The evaluation and treatment of post-operative nausea in bariatric surgery patients has not been standardized. In this patient population, nausea can have a significant impact on quality outcomes. The primary objective of this study was to determine the impact of nausea on post-operative outcomes in bariatric surgery patients. METHODS: A retrospective chart review was conducted of adult patients who underwent a primary laparoscopic Roux-en-Y gastric bypass (LRYGB) or sleeve gastrectomy (LSG) between 2014 and 2017 at a single institution. Patients with post-operative nausea were identified. Post-operative nausea was defined as patients who had nausea that was documented by multiple providers, and which interfered with their oral intake. Demographic variables were identified for patients with and without documented nausea. Univariate analyses were performed to determine the impact of post-operative nausea on patients' length of stay, readmissions, reoperations, and overall complications. RESULTS: There were 449 primary bariatric surgery patients in the study period, 197 (43.9%) LRYGB and 252 (56.1%) LSG. Of these patients, 160 (35.6%) had documented post-operative nausea. Demographic factors that contributed to post-operative nausea included African-American race and undergoing a LSG (p = 0.004 and p = 0.01, respectively). Patients who underwent a LSG had a 2.0 times increased risk of post-operative nausea compared to LRYGB (p = 0.01). Patients with documented nausea had a statistically significant increased length of stay (2.4 ± 1.9 days vs. 1.6 ± 1.0 days; p ≤ 0.01). Documented nausea patients had an increased incidence of Emergency Department visits within 30 days post-operatively (p = 0.02). CONCLUSIONS: Post-operative nausea was more likely in patients who underwent a sleeve gastrectomy. Gastric bypass and sleeve gastrectomy patients with documented nausea had an increased length of stay and Emergency Department visits. These results highlight the need for a metric to more accurately measure post-operative nausea, as well as a standardized anti-emetic treatment pathway to improve quality outcomes.

Sleeve Gastrectomy in Obese Zucker Rats Restores Cardiac Function and Geometry Toward a Lean Phenotype Independent of Weight Loss.

OBJECTIVE: Bariatric surgery, including sleeve gastrectomy (SG), significantly improves cardiac geometry and function in patients with heart failure. In this study, we used the obese Zucker rat as an animal model of heart failure with preserved ejection fraction (HFpEF) to test the hypothesis that a SG will improve cardiac function independent of weight loss. METHODS AND RESULTS: Obese, male Zucker rats underwent SG, pair-fed sham, or ad-lib sham surgery. Lean Zucker rats also underwent ad-lib sham surgery. Echocardiograms were performed preoperatively and at 6 weeks postoperatively. Obese SG and obese pair-fed sham rats had similar body weights postoperatively. Obese SG and lean, ad-lib, sham rats had a significant increase in postoperative stroke volume, and left ventricular internal diameter in diastole and systole. SG preserved systolic function and significantly improved isovolumetric relaxation time (13.9 ± 2.4 to 11.1 ± 2.1 ms, P = .02) independent of weight loss. DISCUSSION: SG has a beneficial impact on both systolic and diastolic cardiac function in obese Zucker rats toward a lean phenotype independent of weight loss and caloric restriction. These findings may represent a weight-loss independent mechanism generated from the gastrointestinal tract that has the potential to improve diastolic dysfunction independent of obesity status and translate to patients with HFpEF.

Postoperative Urinary Retention After Bariatric Surgery: An Institutional Analysis.

BACKGROUND: Postoperative urinary retention (POUR) can impact quality outcomes, leading to urinary tract infections, longer lengths of stay, and increased healthcare costs. The incidence of POUR in bariatric patients is unknown. Our primary objective was to determine the incidence and risk factors contributing to POUR in primary bariatric surgery. METHODS: A retrospective review was conducted on patients who underwent a laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB) from 2013 to 2017. POUR was defined as the inability to urinate postoperatively, requiring urinary catheterization. Univariate and multivariate analyses were performed on perioperative variables and their correlation with POUR. RESULTS: During the study period, 603 patients underwent surgery: 317 (52.6%) LSG and 286 (47.4%) LRYGB. Overall, 49 (8.1%) patients developed POUR. There were no significant differences in preoperative demographics between patients with and without POUR. Patients who underwent an LSG had an increased incidence of POUR compared with LRYGB (P = 0.002). In both procedures, POUR was associated with decreased neostigmine, isolated nondepolarizing muscle relaxant, and reduced intraoperative fluid. LSG and congestive heart failure, as well as LSG and body weight, were independently associated with POUR. Female patients who experienced POUR had significantly increased length of stay. CONCLUSIONS: Risk factors associated with POUR after primary bariatric surgery include LSG, less intraoperative neostigmine and intravenous fluids, and isolated nondepolarizing muscle relaxants. These risk factors can help educate patients and providers, as well as identify quality initiatives that focus on perioperative and anesthetic management to reduce POUR and length of hospital stay.

C-Reactive protein as a predictor of post-operative complications in bariatric surgery patients.

BACKGROUND: The primary objective of this study was to evaluate the utility of CRP in early identification of post-operative complications after bariatric surgery. The ability of this marker to acutely predict post-operative complications in bariatric surgery patients has not been determined. METHODS: A retrospective chart review was conducted of adult patients who underwent a primary and revisional laparoscopic Roux-en-Y gastric bypass (LRYGB) or sleeve gastrectomy (LSG) between 2013 and 2017 at a single institution. Patients were identified using the prospective Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database. CRP levels were drawn on post-operative day one per standard protocol. Univariate analyses were performed to determine the predictive impact of CRP levels on post-operative complications, readmissions, and reoperations. RESULTS: There were 275 patients who underwent bariatric surgery, 222 primary and 53 revisional. Of the 275 patients, 36 (13.1%) had a complication. Bariatric surgery patients with a post-operative complication had higher CRP levels compared to those who did not (4.8 ± 4.6 vs. 2.9 ± 2.0; p = 0.02). A CRP ≥ 5 mg/dL had a sensitivity for a complication of 27% and a specificity of 88%. There was no difference in CRP levels for patients with a 30-day reoperation or readmission. There were no mortalities. CONCLUSIONS: Bariatric surgery patients with elevated post-operative CRP levels are at increased risk for 30-day complications. The low sensitivity of a CRP ≥ 5 mg/dL suggests that a normal CRP level alone does not rule out the possibility of a post-operative complication. However, with its high specificity, there should be an elevated clinical suspicion of a post-operative complication in patients with a CRP ≥ 5 mg/dL.

Linear vs. circular-stapled gastrojejunostomy in Roux-en-Y gastric bypass.

BACKGROUND: Various surgical techniques exist to create the gastrojejunostomy during laparoscopic Roux-en-Y gastric bypass (LRYGB). Linear-stapled anastomosis (LSA) and circular-stapled anastomosis (CSA) are two commonly employed techniques. We hypothesized that CSA is associated with an increased rate of surgical site infection (SSI) and gastrojejunostomy stenosis when compared to LSA. METHODS: This study is a retrospective review of patients who underwent LRYGB for morbid obesity at a single institution between 2012 and 2016. Three bariatric surgeons contributed patients to this series. Clinical information and perioperative outcomes were collected through 90 days after surgery. RESULTS: 171 patients met the inclusion criteria. Two patients did not complete 90-day follow-up and were excluded from the analysis (88 patients CSA, 81 LSA; 99% 90-day follow-up). Patient demographics did not differ between groups. The LSA technique was associated with a significantly reduced rate of SSI (0 (0%) vs. 6 (6.8%), p = 0.02) and stenosis (2 (2.5%) vs. 17 (19.3%), p < 0.01). The CSA technique demonstrated a greater number of endoscopic dilations per stenotic event (1.5 ± 0.8 vs. 1.0 ± 0, p = 0.03). CONCLUSION: In our experience, a gastrojejunostomy constructed with an LSA technique was associated with a significantly reduced rate of stenosis and SSI compared to the CSA technique. LSA is currently our anastomotic technique of choice in LRYGB.

Peri-operative, intravenous clindamycin may improve the resolution rate of hypertension after Roux-en-Y gastric bypass in morbidly obese patients.

BACKGROUND: Recent studies have suggested that potential aberrant alterations in the gastrointestinal microbiome contribute to the development of cardiovascular disease, specifically hypertension. Bariatric surgery produces significant sustained weight loss and hypertension resolution likely through multiple mechanisms which includes beneficial changes in the gut microbiome. We hypothesized that the type of prophylactic antibiotic given for bariatric surgery could impact the resolution rate of hypertension by altering the post-operative gastrointestinal microflora. METHODS: A retrospective analysis of adult bariatric patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) between 2012 and 2016 was conducted. The standard antibiotic prophylaxis was cefazolin, or clindamycin in patients with a penicillin allergy. Univariate analyses were performed comparing the differing peri-operative antibiotic treatments with resolution of hypertension at 2-week (± 1 week), 6-week (± 2 weeks), 3-month (± 2 weeks), 6-month (± 6 weeks), and 1-year (± 2 months) follow-up appointments. The criterion for resolution of hypertension was no longer requiring medication at time of follow-up. RESULTS: In total, 123 RYGB and 88 SG patients were included. No significant differences were found between cefazolin and clindamycin regarding hypertension resolution rates after SG. However, patients who underwent RYGB and received clindamycin had a significantly higher rate of hypertension resolution compared to cefazolin. This effect started at 2 weeks post-operatively (52.4% vs. 23.5% respectively, p = 0.008) and persisted up to the 1-year (57.9% vs. 44.0% respectively, p = 0.05). CONCLUSION: Prophylactic peri-operative, intravenous clindamycin was associated with significantly increased resolution of post-operative hypertension compared to cefazolin. This finding was not observed in SG patients. Future studies are needed to confirm the mechanism of action for this novel finding is due to the differing modifications of the gastrointestinal microflora after RYGB resulting from the specific peri-operative antibiotic administered.

Postoperative urinary retention after laparoscopic total extraperitoneal inguinal hernia repair.

BACKGROUND: Postoperative urinary retention (POUR) after laparoscopic inguinal hernia repair has an incidence of 2%-30%. POUR can lead to increased length of stay, decreased patient satisfaction, and increased health-care costs. The objective of this study was to determine the patient risk factors at our institution contributing to POUR after laparoscopic total extraperitoneal (TEP) inguinal hernia repair. METHODS: A retrospective chart review of patients who underwent a laparoscopic TEP inguinal hernia repair at our institution from 2009 to 2016. POUR is defined as the inability to urinate requiring urinary straight or indwelling catheterization in the postoperative period. Univariate analyses were performed on perioperative variables and their correlation with POUR. RESULTS: In total, 578 laparoscopic TEP inguinal hernia repair patients were included in the study: 277 (48%) indirect, 144 (25%) direct, 6 (1%) femoral, and 151 (26%) combination of direct, indirect, and/or femoral hernias. Of these, 292 (51%) were bilateral, and 286 (49%) were unilateral. Overall, 64 (11.1%) of the 578 patients developed POUR. POUR was significantly associated with benign prostatic hyperplasia, age 60 y or older, urinary tract infection within 30 d, and decreased body mass index. CONCLUSIONS: Patients aged greater than 60 y, with benign prostatic hyperplasia, and a decreased body mass index (≤25.8 kg/m2) were more likely to develop POUR after laparoscopic TEP inguinal hernia repair. In addition, these patients were more likely to develop a urinary tract infection within 30 d. Future quality initiatives can be explored to minimize the incidence of POUR in high-risk patient populations.

Increased glycine-amidated hyocholic acid correlates to improved early weight loss after sleeve gastrectomy.

BACKGROUND: Bile acids (BAs) are post-prandial hormones that play an important role in glucose and lipid homeostasis as well as energy expenditure. Total and glycine-amidated BAs increase after sleeve gastrectomy (SG) and correlate to improved metabolic disease. No specific bile acid subtype has been shown conclusively to mediate the weight loss effect. Therefore, the objective of this study was to prospectively evaluate the comprehensive changes in meal-stimulated BAs after SG and determine if a specific change in the BA profile correlates to the early weight loss response. METHODS: Patients were prospectively enrolled at the University of Nebraska Medical Center who were undergoing a SG for treatment of morbid obesity. Primary and secondary plasma bile acids and their amidated (glycine, G-, or taurine, T-) subtypes were measured at fasting, 30 and 60 min after a liquid meal performed pre-op, and at 6 and 12 weeks post-op. Area under the curve (AUC) was calculated for the hour meal test for each bile acid subtype. BAs that were significantly increased post-op were correlated to body mass index (BMI) loss. RESULTS: Total BA AUC was significantly increased at 6 (p < 0.01) and 12 weeks post-op (p < 0.01) compared to pre-operative values. The increase in total BA AUC was due to a statistically significant increase in G-BAs. Nine different BA AUC subtypes were significantly increased at both 6 and 12 weeks post-op. Increased total and G-chenodeoxycholic acid AUC was significantly correlated to the 6 week BMI loss (p = 0.03). Increased G-hyocholic acid was significantly correlated to increased weight loss at both 6 (p = 0.05) and 12 weeks (p = 0.006). CONCLUSIONS: SG induced an early and persistent post-prandial surge in multiple bile acid subtypes. Increased G-hyocholic consistently correlated with greater early BMI loss. This study provides evidence for a role of BAs in the surgical weight loss response after SG.

Chronic high-fat feeding increases GIP and GLP-1 secretion without altering body weight.

The incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), enhance postprandial insulin secretion, promote adipogenesis, and regulate gastrointestinal motility and food intake. To date, a consensus on how the incretin response is altered in obesity is lacking. We investigated the effects of chronic high-fat (HF) feeding on incretin secretion in the lymph fistula rat model. Male Sprague-Dawley rats (8 wk) were provided a semipurified AIN93M HF or low-fat (LF) diet ad libitum for 3 or 13 wk; a HF pair-fed (HF-PF) group was included as a control during the 3-wk feeding trial. Energy intake, body weight, and body composition were regularly monitored. At the culmination of the feeding period, an intestinal lymphatic duct cannula and duodenal infusion tube were installed. All animals were challenged with a 3-ml Ensure bolus (3.125 kcal/animal) to measure lymphatic incretin secretion. Despite a significantly higher energy intake, both the 3-wk and 13-wk HF-fed animals did not have an increase in body weight and only a slight increase in body fat compared with LF-fed rats. Following the duodenal Ensure challenge, the 3-wk and 13-wk HF-fed rats had significantly greater lymphatic GIP and GLP-1 secretion than the LF-fed animals. Additionally, the HF-PF group displayed a secretion profile similar to the HF-fed animals for GIP but a similar pattern to the LF-fed animals for GLP-1. The HF-PF data suggest that the increased GIP secretion is driven by the greater percentage of fat intake, whereas the increased GLP-1 secretion is driven by the excess caloric intake.

Bilirubin prevents acute DSS-induced colitis by inhibiting leukocyte infiltration and suppressing upregulation of inducible nitric oxide synthase.

Bilirubin is thought to exert anti-inflammatory effects by inhibiting vascular cell adhesion molecule-1 (VCAM-1)-dependent leukocyte migration and by suppressing the expression of inducible nitric oxide synthase (iNOS). As VCAM-1 and iNOS are important mediators of tissue injury in the dextran sodium sulfate (DSS) murine model of inflammatory colitis, we examined whether bilirubin prevents colonic injury in DSS-treated mice. Male C57BL/6 mice were administered 2.5% DSS in the drinking water for 7 days, while simultaneously receiving intraperitoneal injections of bilirubin (30 mg/kg) or potassium phosphate vehicle. Disease activity was monitored, peripheral blood counts and serum nitrate levels were determined, and intestinal specimens were analyzed for histological injury, leukocyte infiltration, and iNOS expression. The effect of bilirubin on IL-5 production by HSB-2 cells and on Jurkat cell transendothelial migration also was determined. DSS-treated mice that simultaneously received bilirubin lost less body weight, had lower serum nitrate levels, and exhibited reduced disease severity than vehicle-treated animals. Concordantly, histopathological analyses revealed that bilirubin-treated mice manifested significantly less colonic injury, including reduced infiltration of eosinophils, lymphocytes, and monocytes, and diminished iNOS expression. Bilirubin administration also was associated with decreased eosinophil and monocyte infiltration into the small intestine, with a corresponding increase in peripheral blood eosinophilia. Bilirubin prevented Jurkat migration but did not alter IL-5 production. In conclusion, bilirubin prevents DSS-induced colitis by inhibiting the migration of leukocytes across the vascular endothelium and by suppressing iNOS expression.