Novel multiparametric bulk and single EV pipeline for adipose cell-specific biomarker discovery in paired human biospecimens.

Obesity is a global health crisis that contributes to morbidity and mortality worldwide. Obesity's comorbid association with a variety of diseases, from metabolic syndrome to neurodegenerative disease, underscores the critical need to better understand the pathobiology of obesity. Adipose tissue, once seen as an inert storage depot, is now recognized as an active endocrine organ, regulating metabolic and systemic homeostasis. Recent studies spotlight the theranostic utility of extracellular vesicles (EVs) as novel biomarkers and drivers of disease, including obesity-related complications. Adipose-derived EVs (ADEVs) have garnered increased interest for their roles in diverse diseases, however robust isolation and characterization protocols for human, cell-specific EV subsets are limited. Herein, we directly address this technical challenge by establishing a multiparametric analysis framework that leverages bulk and single EV characterization, mRNA phenotyping and proteomics of human ADEVs directly from paired visceral adipose tissue, cultured mature adipocyte conditioned media, and plasma from obese subjects undergoing bariatric surgery. Importantly, rigorous EV phenotyping at the tissue and cell-specific level identified top 'adipose liquid biopsy' candidates that were validated in circulating plasma EVs from the same patient. In summary, our study paves the way toward a tissue and cell-specific, multiparametric framework for studying tissue and circulating adipose EVs in obesity-driven disease.

Mid-term Outcomes of Nissen Fundoplication Versus Roux-en-y Gastric Bypass for Primary Management of Gastroesophageal Reflux Disease in Patients With Obesity.

INTRODUCTION: The efficacy and outcomes of laparoscopic Nissen fundoplication (LNF) in patients with obesity is controversial. Specifically, concerns regarding long-term outcomes and recurrence in the setting of obesity has led to interest in laparoscopic Roux-en-Y gastric bypass (RYGB). METHODS: In this retrospective cohort study, we studied patients with obesity who underwent either LNF or RYGB for gastroesophageal reflux disease. Baseline demographics, clinical variables, operative outcomes, and symptom severity scores were compared. RESULTS: Baseline demographics, operative outcomes, and quality-of-life scores were similar. Proton pump inhibitor usage, quality-of-life, symptom severity scores, and satisfaction with the operation were similar between groups at mid-term follow-up. DISCUSSION: RYGB and LNF produced similar improvements in disease-specific quality of life with similar rates of complications, side effects, and need for reoperation. This demonstrates that RYGB and LNF represent possible options for surgical management of gastroesophageal reflux disease in obese patients.

Virtual Interviews for Surgical Fellowship are an Acceptable Alternative to In-Person Interviews for Applicants and Faculty Alike.

Background: In-person interviews have traditionally been an integral part of the fellowship application process to allow faculty and applicants to interact and evaluate the intangible aspects of the matching process. COVID-19 has forced a transition away from in-person interviews to a virtual platform. This study sought to track faculty and applicant perspectives on this transition. Study Design: Prospectively collected survey data was obtained from all participants after each of 3 consecutive virtual interview days for minimally invasive surgery fellowship at a single academic institution. Results: One hundred percent (27/27 applicants and 9/9 faculty) of interview participants completed the survey. Cost (100% applicants, 77.8% faculty) was perceived as the greatest barrier to in-person interviews, and "inability to get a feel for the program/applicant" was the largest concern for virtual interviews (66.7% applicants, 88.9% faculty). After interviews, most participants strongly agreed that they were able to assess education (66.7% applicants, 77.8% faculty), clinical experience (70.4% applicants, 77.8% faculty), and research potential (70.4% applicants, 88.9% faculty) through the virtual platform. Only 44.4% of each group strongly agreed that they could assess "overall fit" equally as well. Most faculty (6/9, 66.7%), but fewer applicants (10/27, 37.0%), were willing to completely eliminate in-person interviews. Conclusion: Virtual interviews may be an acceptable alternative to in-person interviews in times of COVID-19 and beyond. Offering a virtual format may help to eliminate costs associated with in-person visits while adequately assessing the fit of a program for both applicants and faculty, though applicants still desire an in-person option.

Epiregulin as an Alternative Ligand for Leptin Receptor Alleviates Glucose Intolerance without Change in Obesity.

The leptin receptor (LepR) acts as a signaling nexus for the regulation of glucose uptake and obesity, among other metabolic responses. The functional role of LepR under leptin-deficient conditions remains unclear. This study reports that epiregulin (EREG) governed glucose uptake in vitro and in vivo in Lepob mice by activating LepR under leptin-deficient conditions. Single and long-term treatment with EREG effectively rescued glucose intolerance in comparative insulin and EREG tolerance tests in Lepob mice. The immunoprecipitation study revealed binding between EREG and LepR in adipose tissue of Lepob mice. EREG/LepR regulated glucose uptake without changes in obesity in Lepob mice via mechanisms, including ERK activation and translocation of GLUT4 to the cell surface. EREG-dependent glucose uptake was abolished in Leprdb mice which supports a key role of LepR in this process. In contrast, inhibition of the canonical epidermal growth factor receptor (EGFR) pathway implicated in other EREG responses, increased glucose uptake. Our data provide a basis for understanding glycemic responses of EREG that are dependent on LepR unlike functions mediated by EGFR, including leptin secretion, thermogenesis, pain, growth, and other responses. The computational analysis identified a conserved amino acid sequence, supporting an evolutionary role of EREG as an alternative LepR ligand.

The Impact of Bariatric Surgery on Diverticulitis Outcomes and Risk of Recurrent Hospitalizations in Adults with Clinically Severe Obesity.

PURPOSE: Clinically severe obesity (SO) is a known risk factor for worsened outcomes and recurrence of acute diverticulitis. Paucity of data exist on outcomes of diverticulitis after bariatric surgery. METHODS: The Nationwide Readmissions Database was queried for diverticulitis hospitalizations between the years 2010 and 2014. We restricted analysis to patients with SO and those who had bariatric surgery (BRS). Outcomes of mortality, surgical events, and recurrent diverticulitis admissions were compared using multivariable analysis and one-to-one propensity score matching. RESULTS: Among 52,274 diverticulitis admissions, 91.2% (47,694) patients had SO and 8.8% (4580) had prior BRS. Patients with SO had higher odds of suffering mortality on index diverticulitis admission when compared to those with prior BRS [adjusted odds ratio (aOR): 10.55; 95%CI 1.45,76.75]. Patients with SO were also more likely to undergo emergency surgery (aOR: 1.71; 95%CI 1.25,2.34) and colectomy (aOR: 1.45; 95%CI 1.26,1.68). Rates of recurrent diverticulitis readmissions within 30 days and 6 months were also higher in patients with SO compared to BRS patients (aOR: 7.94; 95%CI 1.09,57.83 and aOR: 1.98; 95%CI 1.14,3.43, respectively). Propensity score matching confirmed our findings of increased rates of mortality (OR: 17.28; 95%CI 2.02,147.6), recurrent diverticulitis, and worsened surgical outcomes within 30 days in patients with SO compared to BRS. CONCLUSION: This study is first to show improved outcomes and less recurrent hospitalizations for diverticulitis after bariatric surgery compared to patients with clinically severe obesity. Further studies are needed to understand mechanisms leading to this improvement and the role of weight loss in prevention of severe diverticulitis.

SAGES primer for taking care of yourself during and after the COVID-19 crisis.

COVID-19 is a pandemic which has affected almost every aspect of our life since starting globally in November 2019. Given the rapidity of spread and inadequate time to prepare for record numbers of sick patients, our surgical community faces an unforeseen challenge. SAGES is committed to the protection and care of patients, their surgeons and staff, and all who are served by the medical community at large. This includes physical health, mental health, and well-being of all involved. The fear of the unknown ahead can be paralyzing. International news media have chronicled the unthinkable situations that physicians and other health care providers have been thrust into as a result of the COVID-19 pandemic. These situations include making life or death decisions for patients and their families regarding use of limited health care resources. It includes caring for patients with quickly deteriorating conditions and limited treatments available. Until recently, these situations seemed far from home, and now they are in our own hospitals. As the pandemic broadened its reach, the reality that we as surgeons may be joining the front line is real. It may be happening to you now; it may be on the horizon in the coming weeks. In this context, SAGES put together this document addressing concerns on clinician stressors in these times of uncertainty. We chose to focus on the emotional toll of the situation on the clinician, protecting vulnerable persons, reckoning with social isolation, and promoting wellness during this crisis. At the same time, the last part of this document deals with the "light at the end of the tunnel," discussing potential opportunities, lessons learned, and the positives that can come out of this crisis.

Redesigning a Department of Surgery during the COVID-19 Pandemic.

BACKGROUND: COVID-19 has created an urgent need for reorganization and surge planning among departments of surgery across the USA. METHODS: Review of the COVID-19 planning process and work products in preparation for a patient surge. Organizational and process changes, workflow redesign, and communication plans are presented. RESULTS: The planning process included widespread collaboration among leadership from many disciplines. The department of surgery played a leading role in establishing clinical protocols, guidelines, and policies in preparation for a surge of COVID-19 patients. A multidisciplinary approach with input from clinical and nonclinical stakeholders is critical to successful crisis planning. A clear communication plan should be implemented early and input from trainees, staff, and faculty should be solicited. CONCLUSION: Major departmental and health system reorganization is required to adapt academic surgical practices to a widespread crisis. Surgical leadership, innovation, and flexibility are critical to successful planning and implementation.

Endoscopic stent placement for treatment of sleeve gastrectomy leak: a single institution experience with fully covered stents.

BACKGROUND: Laparoscopic sleeve gastrectomy (SG) has risen in prevalence as a standalone surgical option for treating obesity over the last 15 years. One of the most worrisome complications is development of a leak at the gastrectomy staple line. OBJECTIVE: The objective of this report is to describe our single-institution experience in managing SG staple-line leaks with fully covered endoscopic stents. SETTING: Academic medical center, United States. METHODS: Data for all patients who underwent endoscopic stent placement for an SG leak between 2010 and 2016 at a single academic institution were retrospectively reviewed. Patient medical history, perioperative information, stent placement details, outcomes, and subsequent interventions were recorded. RESULTS: Twenty-four patients with SG staple-line leaks treated with fully covered endoscopic stents were identified. Leaks were identified at a median of 31.5 days postoperatively (range, 1-1615 d). The majority of patients underwent other treatment(s) for their leak before stent placement at our institution. Stents remained in place for an average of 28.8 ± 16.8 days. Migration occurred in 22% of all stent placements. Three patients were lost to follow-up, and 14 of the remaining 21 patients (66.7%) healed after stent placement. Five patients (23.8%) ultimately required operative revision with partial gastrectomy and Roux-en-Y esophagojejunostomy for management of persistent leaks. CONCLUSION: Endoscopic management using fully covered stents for staple-line leaks after SG is effective in the majority of patients. However, algorithms are needed for the management of chronic staple-line leaks, which are less likely to heal with stent placement.

Molecular Signaling and Dysfunction of the Human Reactive Enteric Glial Cell Phenotype: Implications for GI Infection, IBD, POI, Neurological, Motility, and GI Disorders.

BACKGROUND: Clinical observations or animal studies implicate enteric glial cells in motility disorders, irritable bowel syndrome, inflammatory bowel disease, gastrointestinal (GI) infections, postoperative ileus, and slow transit constipation. Mechanisms underlying glial responses to inflammation in human GI tract are not understood. Our goal was to identify the "reactive human enteric glial cell (rhEGC) phenotype" induced by inflammation, and probe its functional relevance. METHODS: Human enteric glial cells in culture from 15 GI-surgical specimens were used to study gene expression, Ca, and purinergic signaling by Ca/fluo-4 imaging and mechanosensitivity. A nanostring panel of 107 genes was designed as a read out of inflammation, transcription, purinergic signaling, vesicular transport protein, channel, antioxidant, and other pathways. A 24-hour treatment with lipopolysaccharide (200 µg/mL) and interferon-γ (10 µg/mL) was used to induce inflammation and study molecular signaling, flow-dependent Ca responses from 3 mL/min to 10 mL/min, adenosine triphosphate (ATP) release, and ATP responses. RESULTS: Treatment induced a "rhEGC phenotype" and caused up-regulation in messenger RNA transcripts of 58% of 107 genes analyzed. Regulated genes included inflammatory genes (54%/IP10; IFN-γ; CxCl2; CCL3; CCL2; C3; s100B; IL-1ß; IL-2R; TNF-α; IL-4; IL-6; IL-8; IL-10; IL-12A; IL-17A; IL-22; and IL-33), purine-genes (52%/AdoR2A; AdoR2B; P2RY1; P2RY2; P2RY6; P2RX3; P2RX7; AMPD3; ENTPD2; ENTPD3; and NADSYN1), channels (40%/Panx1; CHRNA7; TRPV1; and TRPA1), vesicular transporters (SYT1, SYT2, SNAP25, and SYP), transcription factors (relA/relB, SOCS3, STAT3, GATA_3, and FOXP3), growth factors (IGFBP5 and GMCSF), antioxidant genes (SOD2 and HMOX1), and enzymes (NOS2; TPH2; and CASP3) (P < 0.0001). Treatment disrupted Ca signaling, ATP, and mechanical/flow-dependent Ca responses in human enteric glial cells. ATP release increased 5-fold and s100B decreased 33%. CONCLUSIONS: The "rhEGC phenotype" is identified by a complex cascade of pro-inflammatory pathways leading to alterations of important molecular and functional signaling pathways (Ca, purinergic, and mechanosensory) that could disrupt GI motility. Inflammation induced a "purinergic switch" from ATP to adenosine diphosphate/adenosine/uridine triphosphate signaling. Findings have implications for GI infection, inflammatory bowel disease, postoperative ileus, motility, and GI disorders.

Pharmacotherapy in Conjunction with a Diet and Exercise Program for the Treatment of Weight Recidivism or Weight Loss Plateau Post-bariatric Surgery: a Retrospective Review.

BACKGROUND: Bariatric surgery is an effective therapeutic option for management of obesity. However, weight recidivism (WR) and weight loss plateau (WLP) are common problems. We present our experience with the use of two pharmacotherapies in conjunction with our standard diet and exercise program in those patients who experienced WR or WLP. METHODS: From June 2010 to April 2014, bariatric surgery patients who experienced WR or WLP after undergoing Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB), and who were treated with phentermine (Ph) or phentermine-topiramate (PhT), were reviewed retrospectively. Generalized estimating equations were used to compare patient weights through 90 days between initial surgery type and medication type. Patient weights, medication side effect, and co-morbidities were collected during the first 90 days of therapy. RESULTS: Fifty-two patients received Ph while 13 patients received PhT. Overall, patients in both groups lost weight. Among those whose weights were recorded at 90 days, patients on Ph lost 6.35 kg (12.8% excess weight loss (EWL); 95% confidence interval (CI) 4.25, 8.44) and those prescribed PhT lost 3.81 kg (12.9% EWL; CI 1.08, 6.54). Adjusting for baseline weight, time since surgery, and visit through 90 days, patients treated with Ph weighed significantly less than those on PhT throughout the course of this study (1.35 kg lighter; 95% CI 0.17, 2.53; p = 0.025). There were no serious side effects reported. CONCLUSIONS: Phentermine and phentermine-topirimate in addition to diet and exercise appear to be viable options for weight loss in post-RYGB and LAGB patients who experience WR or WLP.

ß-Nicotinamide adenine dinucleotide acts at prejunctional adenosine A1 receptors to suppress inhibitory musculomotor neurotransmission in guinea pig colon and human jejunum.

Intracellular microelectrodes were used to record neurogenic inhibitory junction potentials in the intestinal circular muscle coat. Electrical field stimulation was used to stimulate intramural neurons and evoke contraction of the smooth musculature. Exposure to ß-nicotinamide adenine dinucleotide (ß-NAD) did not alter smooth muscle membrane potential in guinea pig colon or human jejunum. ATP, ADP, ß-NAD, and adenosine, as well as the purinergic P2Y1 receptor antagonists MRS 2179 and MRS 2500 and the adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine, each suppressed inhibitory junction potentials in guinea pig and human preparations. ß-NAD suppressed contractile force of twitch-like contractions evoked by electrical field stimulation in guinea pig and human preparations. P2Y1 receptor antagonists did not reverse this action. Stimulation of adenosine A1 receptors with 2-chloro-N6-cyclopentyladenosine suppressed the force of twitch contractions evoked by electrical field stimulation in like manner to the action of ß-NAD. Blockade of adenosine A1 receptors with 8-cyclopentyl-1,3-dipropylxanthine suppressed the inhibitory action of ß-NAD on the force of electrically evoked contractions. The results do not support an inhibitory neurotransmitter role for ß-NAD at intestinal neuromuscular junctions. The data suggest that ß-NAD is a ligand for the adenosine A1 receptor subtype expressed by neurons in the enteric nervous system. The influence of ß-NAD on intestinal motility emerges from adenosine A1 receptor-mediated suppression of neurotransmitter release at inhibitory neuromuscular junctions.

Laparoscopic sleeve gastrectomy in morbidly obese patients with end-stage heart failure and left ventricular assist device: medium-term results.

BACKGROUND: Morbid obesity precludes patients with end-stage heart failure from becoming cardiac transplant candidates. This study evaluates the safety and efficacy of laparoscopic sleeve gastrectomy (LSG) as a means to transplant candidacy in such patients. METHODS: Morbidly obese patients with end-stage heart failure, who were ineligible for cardiac transplantation and underwent LSG between 2008 and 2013, were reviewed retrospectively. Demographic characteristics, perioperative details, percentage of excess weight loss (%EWL), and status of transplant candidacy were analyzed. RESULTS: Six patients (3 men) with end-stage heart failure and morbid obesity underwent LSG. Three patients (50%) had a left ventricular assist device (LVAD) in place at the time of surgery. Median age was 34 (31-66) years and mean preoperative body mass index (BMI) was 47.6±3.0 kg/m2. Median operative time was 90 (66-141) minutes, with a median length of stay of 7 (4-16) days. There were no perioperative deaths. One patient suffered a spontaneous flank hematoma. The same patient also had thrombosis of the LVAD pump at 3 weeks postoperatively, requiring an uneventful device exchange. At median follow-up of 22 (12-70) months, the mean %EWL was 51.4±10.3% with a decrease in BMI to 34.3±2.4 kg/m2 (P<.05). All patients had lost sufficient weight to become transplant eligible within 12 months of surgery. Two patients had undergone successful transplantation and another 2 were on the transplant list. CONCLUSION: LSG appears to be a safe, technically feasible, and effective method for obtaining adequate weight loss in morbidly obese patients with end-stage heart failure and mechanical circulatory support, subsequently improving their access to cardiac transplantation. This is the largest case series to date of this high-risk group of patients undergoing LSG.

Laparoscopic adjustable gastric banded plication: case-matched study from a single U.S. center.

BACKGROUND: Laparoscopic adjustable gastric banded plication (LAGBP) is a novel technique for weight loss surgery. This study evaluates the safety and short-term efficacy of LAGBP in a U.S. population. The setting was an academic medical center in the United States. METHODS: Patients who underwent LAGBP between 2012 and 2013 were reviewed retrospectively. Demographic characteristics, pre and perioperative details, body mass index (BMI), and percent excess weight loss (%EWL) were analyzed and compared to case-matched cohorts that had laparoscopic adjustable gastric banding (LAGB) or laparoscopic sleeve gastrectomy (LSG) during the same time period. RESULTS: Seventeen patients (14 females) underwent LAGBP during the study period and were case-matched based on age, sex, race, and preoperative BMI with patients having LAGB and LSG. Mean age and preoperative BMI for LAGBP cohort were 42.5±11.6 years and 47.7±6.5 kg/m2, respectively. Mean operative time and estimated blood loss were 72±16 minutes and 23±23 mL, respectively, compared to 49±16 minutes (P=.002) and 15±23 mL for LAGB, and 66±18 minutes and 36±22 mL for LSG. There were no perioperative deaths. Hospital length of stay was 1.1±.3 days for LAGBP, versus .7±.3 days (P=.004) for LAGB, and 2.7±1.4 days (P<.001) for LSG. At 12-month follow-up, patients in the LAGBP and LAGB groups had undergone similar number of band adjustments (4.7 versus 5.1; P=.68). The %EWL was 46.1±14.8% for the LAGBP cohort, compared to 38.9±20.6% for LAGB, and 57.7±16% for LSG. CONCLUSION: LAGBP is technically feasible and safe, and offers weight loss results positioned between LAGB and LSG at 1 year. To date, this is the largest U.S. series to compare this novel technique to more traditional weight loss procedures.

Near-infrared fluorescent cholangiography facilitates identification of biliary anatomy during laparoscopic cholecystectomy.

BACKGROUND: Intraoperative cholangiography (IOC) is the current gold standard for biliary imaging during laparoscopic cholecystectomy (LC). However, utilization of IOC remains low. Near-infrared fluorescence cholangiography (NIRF-C) is a novel, noninvasive method for real-time, intraoperative biliary mapping. Our aims were to assess the safety and efficacy of NIRF-C for identification of biliary anatomy during LC. METHODS: Patients were administered indocyanine green (ICG) prior to surgery. NIRF-C was used to identify extrahepatic biliary structures before and after partial and complete dissection of Calot's triangle. Routine IOC was performed in each case. Identification of biliary structures using NIRF-C and IOC, and time required to complete each procedure were collected. RESULTS: Eighty-two patients underwent elective LC with NIRF-C and IOC. Mean age and body mass index (BMI) were 42.6 ± 13.7 years and 31.5 ± 8.2 kg/m(2), respectively. ICG was administered 73.8 ± 26.4 min prior to incision. NIRF-C was significantly faster than IOC (1.9 ± 1.7 vs. 11.8 ± 5.3 min, p < 0.001). IOC was unobtainable in 20 (24.4 %) patients while NIRF-C did not visualize biliary structures in 4 (4.9 %) patients. After complete dissection, the rates of visualization of the cystic duct, common bile duct, and common hepatic duct using NIRF-C were 95.1, 76.8, and 69.5 %, respectively, compared to 72.0, 75.6, and 74.3 % for IOC. In 20 patients where IOC could not be obtained, NIRF-C successfully identified biliary structures in 80 % of the cases. Higher BMI was not a deterrent to visualization of anatomy with NIRF-C. No adverse events were observed with NIRF-C. CONCLUSIONS: NIRF-C is a safe and effective alternative to IOC for imaging extrahepatic biliary structures during LC. This technique should be evaluated further under a variety of acute and chronic gallbladder inflammatory conditions to determine its usefulness in biliary ductal identification.

Innervation of enteric mast cells by primary spinal afferents in guinea pig and human small intestine.

Mast cells express the substance P (SP) neurokinin 1 receptor and the calcitonin gene-related peptide (CGRP) receptor in guinea pig and human small intestine. Enzyme-linked immunoassay showed that activation of intramural afferents by antidromic electrical stimulation or by capsaicin released SP and CGRP from human and guinea pig intestinal segments. Electrical stimulation of the afferents evoked slow excitatory postsynaptic potentials (EPSPs) in the enteric nervous system. The slow EPSPs were mediated by tachykinin neurokinin 1 and CGRP receptors. Capsaicin evoked slow EPSP-like responses that were suppressed by antagonists for protease-activated receptor 2. Afferent stimulation evoked slow EPSP-like excitation that was suppressed by mast cell-stabilizing drugs. Histamine and mast cell protease II were released by 1) exposure to SP or CGRP, 2) capsaicin, 3) compound 48/80, 4) elevation of mast cell Ca²âº by ionophore A23187, and 5) antidromic electrical stimulation of afferents. The mast cell stabilizers cromolyn and doxantrazole suppressed release of protease II and histamine when evoked by SP, CGRP, capsaicin, A23187, electrical stimulation of afferents, or compound 48/80. Neural blockade by tetrodotoxin prevented mast cell protease II release in response to antidromic electrical stimulation of mesenteric afferents. The results support a hypothesis that afferent innervation of enteric mast cells releases histamine and mast cell protease II, both of which are known to act in a diffuse paracrine manner to influence the behavior of enteric nervous system neurons and to elevate the sensitivity of spinal afferent terminals.