Cytokine, Chemokine, and Cytokine Receptor Changes Are Associated With Metabolic Improvements After Bariatric Surgery.

Context: Altered cytokine levels and chronic low-grade inflammation contribute to metabolic dysfunction in obesity. The extent of cytokine changes and their impact on metabolic improvements after bariatric surgery have not been fully explored. Objective: To compare 76 circulating cytokines, chemokines, and secreted cytokine receptors in subjects with obesity and lean subjects and determine how these cytokines are altered by bariatric surgery. Design, Setting, and Participants: A total of 37 patients with obesity and 37 lean patients in a cross-sectional study at an academic medical center. We also investigated cytokine changes in 25 patients with obesity after bariatric surgery. Intervention: Bariatric surgery (Roux-en-Y gastric bypass and vertical sleeve gastrectomy). Main Outcome Measures: Quantification of 76 circulating cytokines, chemokines, and secreted cytokine receptors. Results: A total of 13 cytokines were significantly higher, and 4 lower, in patients with obesity relative to lean controls. Soluble vascular endothelial growth factor receptor 2 (sVEGFR2), soluble TNF receptor (sTNFR) 1, and sTNFR2 were positively correlated, and soluble receptor for advanced glycation end-products was inversely correlated, with weight and body mass index. sTNFR2 was positively correlated with fasting glucose, homeostatic model assessment of insulin resistance, and hemoglobin A1c. After bariatric surgery, adiponectin increased, and leptin decreased. Elevated sVEGFR2 levels in patients with obesity were decreased (P = 0.01), whereas reduced chemokine (C-X-C motif) ligand (CXCL) 12 levels in patients with obesity increased (P = 0.03) after surgery. Patients with higher soluble interleukin receptor (sIL) 1R2 and sIL-6R levels before surgery had greater weight loss after surgery (P < 0.05). Conclusions: We demonstrate that chemokine (C-C motif) ligand (CCL) 14, sVEGFR2, and platelet-derived growth factor BB are elevated in obesity, and CXCL12, CCL11, and CCL27 are lower in obesity. We found clinically concordant directionality between lean and patients with obesity and before vs after surgery for six cytokines, suggesting that bariatric surgery shifted the cytokine profiles of patients with obesity toward that of lean controls.

The Role of Laboratory Testing in Differentiating Type 1 Diabetes from Type 2 Diabetes in Patients Undergoing Bariatric Surgery.

BACKGROUND: It may be difficult to distinguish between adults with type 1 diabetes and type 2 diabetes by clinical assessment. In patients undergoing bariatric surgery, it is critical to correctly classify diabetes subtype to prevent adverse perioperative outcomes including diabetic ketoacidosis. This study aimed to determine whether testing for C-peptide and islet cell antibodies during preoperative evaluation for bariatric surgery could improve the classification of type 1 versus type 2 diabetes compared to clinical assessment alone. METHODS: This is a retrospective analysis of the Improving Diabetes through Lifestyle and Surgery trial, which randomized patients with clinically diagnosed type 2 diabetes and BMI 30-40 kg/m2 to medical weight loss or bariatric surgery; one participant was discovered to have type 1 diabetes after experiencing postoperative diabetic ketoacidosis. Using blood samples collected prior to study interventions, we measured islet cell antibodies and fasting/meal-stimulated C-peptide in all participants. RESULTS: The participant with type 1 diabetes was similar to the 11 participants with type 2 diabetes in age at diagnosis, adiposity, and glycemic control but had the lowest C-peptide levels. Among insulin-treated participants, fasting and stimulated C-peptide correlated strongly with the C-peptide area-under-the-curve on mixed meal tolerance testing (R = 0.86 and 0.88, respectively). Three participants, including the one with type 1 diabetes, were islet cell antibody positive. CONCLUSIONS: Clinical characteristics did not correctly identify type 1 diabetes in this study. Preoperative C-peptide testing may improve diabetes classification in patients undergoing bariatric surgery; further research is needed to define the optimal C-peptide thresholds.

Inversion Technique for the Removal of Partially Covered Self-Expandable Metallic Stents.

BACKGROUND AND AIMS: Partially covered self-expandable metallic stents (PCSEMS), although an effective treatment for anastomotic/staple line leaks and strictures, can be difficult to remove. This study examines the effectiveness of the inversion technique for the removal of PCSEMS in the treatment of leaks and strictures that occurred post-sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB). METHODS: Consecutive patients who underwent PCSEMS removal for a leak and/or stricture post-SG or RYGB between July 2013 and December 2016 at the Johns Hopkins Medical Institutions were reviewed. All PCSEMS removals were first attempted via the inversion technique, which involves grasping the distal end of the stent and inverting it through itself. RESULTS: Fourteen patients (four males) underwent PCSEMS removal via the inversion technique for an anastomotic/staple line leak (50%), stricture (29%) or both (21%) post-SG (79%) or RYGB (21%). Technical success (successful removal of the stent) was achieved in one endoscopic session for 13 of the 14 PCSEMS (93%). One PCSEMS required the use of the stent-in-stent technique for removal. The median dwell time was 47 days (range 5-72). A distal partial occlusion developed in five patients (35%) due to tissue overgrowth and one PCSEMS (7%) migrated, necessitating premature removal. Eight patients (57%) experienced clinical success at follow-up, and six patients (43%) required subsequent treatment due to persistence or recurrence of the pathology. CONCLUSIONS: The inversion technique is a safe, effective, and efficient method of removing PCSEMS placed to correct anastomotic/staple line leaks and strictures post-SG and RYGB.

Vitamin D status and supplementation before and after bariatric surgery: a comprehensive literature review.

BACKGROUND: Bariatric surgery is the most effective long-term weight loss method. The most common procedures are Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG). Bariatric patients are at high risk of vitamin D deficiency (VDD) and insufficiency (VDI), which are associated with skeletal and nonskeletal ailments. There is no consensus regarding the optimal treatment for VDD/VDI in bariatric patients. OBJECTIVES: To critically examine the literature on vitamin D status (serum 25[OH]D concentrations) pre- and postbariatric surgery as well as supplementation regimens currently used. METHODS: We searched PubMed, Embase, and Cochrane from inception to May 2015 for articles relating to vitamin D, RYGB, and VSG. Of 208 citations retrieved, 30 were included. RESULTS: Preoperative VDD (<20 ng/mL) ranged from 13% to 90%, while VDI (<30 ng/mL) was found in up to 98%. Prevalence remained similar postoperatively and was highest after RYGB. Most studies found dosages<800 IU daily insufficient postbariatric surgery. Other studies examined the effectiveness of dosages between 1000 and 5000 IU daily, reaching similar conclusions. Several studies suggested using 50,000 IU weekly plus a daily dose. No studies reported optimization. CONCLUSIONS: It is widely accepted that serum 25(OH)D concentrations above 30 ng/mL are optimal; however, current postbariatric vitamin D supplementation fails to raise 25(OH)D above that level universally. This review highlights both the great need and the lack of consensus on the optimal supplementation regimen (dosage and frequency) for pre- and postbariatric patients. Future studies should investigate multiple regimens and attempt to identify methods for personalizing these regimens if found necessary.

C1q/TNF-Related Protein-9 (CTRP9) Levels Are Associated With Obesity and Decrease Following Weight Loss Surgery.

CONTEXT: C1q/TNF-related protein-9 (CTRP9) is a novel adipokine that has beneficial metabolic and cardiovascular effects in various animal models. Alterations in circulating CTRP9 have also been observed in patients with cardiovascular disease and diabetes, but little is known about the impact of obesity and bariatric surgery on CTRP9 concentrations. OBJECTIVE: The aim of this study was to compare CTRP9 levels in obese and lean subjects and to determine whether circulating CTRP9 levels in morbidly obese patients are altered by bariatric surgery. DESIGN, SETTING, AND PARTICIPANTS: Fifty-nine obese bariatric surgical patients and 62 lean controls were recruited to participate in a cross-sectional study at an academic medical center. The obese patients were further invited to participate in a cohort study, and 21 returned for analysis at 3 and 6 months postsurgery. INTERVENTION: Bariatric surgery (Roux-en-Y gastric bypass and vertical sleeve gastrectomy) was the intervention for this study. MAIN OUTCOME MEASURES: Fasting serum was obtained from all subjects on entry to the study and was analyzed in the core laboratory for hemoglobin A1c, glucose, aspartate aminotransferase, alanine aminotransferase, total cholesterol, high- and low-density lipoprotein cholesterol, and triglycerides; CTRP9, insulin, adiponectin, and leptin were measured by ELISA. Serum from the patients in the cohort study was also analyzed at 3 and 6 months. RESULTS: Serum CTRP9 was significantly higher in the obese group compared to the lean group. CTRP9 was associated with obesity, even after controlling for age, gender, and ethnicity. Following bariatric surgery, there was a significant decrease in weight at 3 and 6 months postprocedure, accompanied by decreases in CTRP9, hemoglobin A1c and leptin, and an increase in serum adiponectin. CONCLUSIONS: CTRP9 levels are elevated in obesity and significantly decrease following weight loss surgery. Our data suggest that CTRP9 may play a compensatory role in obesity, similar to that of insulin, and is down-regulated following weight loss surgery.

Treatment for Vitamin D Deficiency Prior to Bariatric Surgery: a Prospective Cohort Study.

BACKGROUND: Since obesity increases vitamin D deficiency (VDD) risk, bariatric surgery candidates are high-risk. Previously, we documented 71.4% VDD at our center. OBJECTIVES: To investigate diagnosis and treatment for VDD in our bariatric candidates. METHODS: 25(OH)D, if pending, and supplementation (form, dosing, frequency) were prospectively documented in 265 candidates. RESULTS: Candidates were 83.0% female, 48.9% white, age 43 ± 13 years and BMI 46.3 ± 10.5 kg/m(2). 25(OH)D was available for 18.5%: 35.7% VDD 39.3% insufficiency. VDD history did not differ by demographics or procedure, as with those tested versus not. CONCLUSION: VDD testing was lower than clinically-indicated. Of those tested, 35.7% were deficient and 39.3% insufficient. We previously reported higher rates: 71.4% deficiency, 92.9% insufficiency. Thus, many candidates are untested but high-risk.

Early hospital readmission after bariatric surgery.

BACKGROUND: With the rise in bariatric procedures being performed nationwide and the growing focus on quality and outcome measures, reducing early hospital readmission (EHR) rates has garnered great clinical interest. The aim of this study was to identify the incidence, reasons, and risk factors for EHR after bariatric surgery. METHODS: Using American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) dataset (2012-2013), patients with a diagnosis of obesity and body mass index ≥35 who underwent bariatric surgery were identified. EHR was defined as at least one hospitalization within 30 days of bariatric procedure. The association between readmission and patient factors was assessed using multivariable logistic regression analysis. In addition, reasons for readmission were sought. RESULTS: A total of 36,042 patients were identified. The overall EHR rate was 4.70 % [laparoscopic (lap) adjustable band 1.87 %, lap gastric bypass (GBP) 5.94 %, open GBP 7.86 %, and sleeve gastrectomy 3.73 %], and it occurred at the median of 11 days postoperatively. The rate of EHR significantly decreased from 2012 to 2013 (5.15 vs. 4.32 %, p < 0.001). The median age and BMI were 44 years and 44.7 kg/m(2), respectively, 78.99 % were female, and 70.78 % were white. The most common reason for readmission was nausea/vomiting (12.95 %), followed by abdominal pain (11.75 %) and dehydration (10.54 %). On multivariable analysis, factors most strongly associated with readmission were procedure type (lap band: reference; open GBP: OR 3.78, 95 % CI 2.47-5.80; lap GBP 3.18, 2.39-4.22; sleeve gastrectomy: 2.03, 1.52-2.71; all p < 0.001), steroid use (1.82, 1.33-2.48, p < 0.001), pre-discharge complication (1.64, 1.20-2.24, p < 0.001), and black population (1.51, 1.34-1.71, p < 0.001). CONCLUSIONS: Bariatric centers should consider implementing standardized protocols for outpatient monitoring of patients identified to be at high risk of experiencing early readmission, which in turn would decrease overall costs and improve quality of care.

Malnutrition in Bariatric Surgery Candidates: Multiple Micronutrient Deficiencies Prior to Surgery.

BACKGROUND: Over 78 million American adults have obesity. Bariatric surgery is the leading means of durable weight loss. Nutritional deficiencies are commonly treated post-operatively but are often undiagnosed pre-operatively. Malnutrition is correlated with adverse surgical outcomes. OBJECTIVES: The aim of this study is to assess pre-operative nutritional status in our bariatric surgery candidates in a cross-sectional study. METHODS: We recruited 58 bariatric candidates approved to undergo the Roux-en Y gastric bypass. Nutritional status was determined for vitamins A, B12, D, E-α, and E-ß/γ as well as thiamine, folate, and iron. We used clinical as well as frank deficiency cut-offs based on the Institute of Medicine and the World Health Organization guidelines. RESULTS: This cohort was largely female (77.6%) and white (63.8%). Median age was 42.2 years. Median body mass index (BMI) was 46.3 kg/m(2). Multiple comorbidities (MCM) were present in 41.4%, 54.0% hypertension, 42.0% diabetic, 34.0% sleep apnea. Men had more comorbidities, 69.2 % with MCM. Folate and iron saturation varied significantly by sex. Vitamins A, D, E-α, and thiamine significantly varied by race. Vitamin D negatively correlated with BMI (p = 0.003) and age (p = 0.030). Vitamin A negatively correlated with age (p = 0.001) and number of comorbidities (p = 0.003). These pre-operative bariatric candidates had significant malnutrition, particularly in vitamin D (92.9%) and iron (36.2 to 56.9 %). Multiple micronutrient deficiency (MMND) was more common in blacks (50.0 versus 39.7% overall). Number of comorbidities did not correlate with MMND. CONCLUSIONS: Malnutrition in one or multiple micronutrients is pervasive in this pre-operative bariatric cohort. The effect of pre-operative supplementation, especially vitamin D and iron, should be explored.

Lower Circulating C1q/TNF-Related Protein-3 (CTRP3) Levels Are Associated with Obesity: A Cross-Sectional Study.

PURPOSE: C1q/TNF-related protein-3 (CTRP3) is a novel adipokine that lowers blood glucose levels, reduces liver triglyceride synthesis, and is protective against hepatic steatosis in diet-induced obese mouse models. We hypothesized that higher circulating serum levels of CTRP3 would be associated with a lean body mass index (BMI) and a more favorable metabolic profile in humans. The aim of this study was to investigate CTRP3 levels in lean individuals compared to obese individuals. METHODS: This was a cross-sectional study of obese (n=44) and lean control patients (n=60). Fasting metabolic parameters were measured in all patients and serum CTRP3 levels were measured by ELISA. RESULTS: BMI of the lean group was 21.9 ± 0.2 kg/m2 and obese group was 45.2 ± 1.1 kg/m2. We found significantly lower circulating levels of CTRP3 in obese individuals (405 ± 8.3 vs. 436 ± 6.7 ng/mL, p=0.004) compared to the lean group. Serum CTRP3 levels were inversely correlated with BMI (p=0.001), and triglycerides (p<0.001), and significantly associated with gender (p<0.01), ethnicity (p=0.05), HDL-cholesterol (p<0.01), and adiponectin (p<0.01). We found BMI (p<0.01), gender (p<0.01), and ethnicity (p<0.05) to be significant predictors of CTRP3 levels when controlling for age in multiple regression analysis. CONCLUSIONS: CTRP3 is a beneficial adipokine whose circulating levels are significantly lower in obese individuals. Obesity causes dysregulation in adipokine production, including the down-regulation of CTRP3. Lower CTRP3 levels may contribute to the pathophysiology of metabolic disorders associated with obesity. Optimizing CTRP3 levels through novel therapies may improve obesity and its comorbidities.

Assessment of postdischarge complications after bariatric surgery: A National Surgical Quality Improvement Program analysis.

BACKGROUND: Little is reported about postdischarge complications after bariatric surgery. We sought to identify the rates of postdischarge complications, associated risk factors, and their influence on early hospital readmission. METHODS: Using the database of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) (2005-2013), we identified patients ≥18 years of age who underwent a bariatric operation with a primary diagnosis of morbid/severe obesity and a body mass index ≥35. The incidence of postdischarge complication was the primary outcome, and hospital readmission was the secondary outcome. The association between postdischarge complications and various patient factors was explored by the use of multivariable logistic regression. RESULTS: A total of 113,898 patients were identified with an overall postdischarge complication rate of 3.2% within 30 days of operation. The rates decreased from 2005 to 2006 (4.6%) to 2013 (3.0%) (P < .001). On average, postdischarge complications occurred 10 days postoperatively, with wound infection (49.4%), reoperation (30.7%), urinary tract infection (16.9%), shock/sepsis (12.4%), and organ space surgical-site infection (11.0%) being the most common. Patients undergoing open gastric bypass had the greatest postdischarge complication rate of 8.5%. Of those patients experiencing postdischarge complications, 51.6% were readmitted. The overall readmission rate was 4.9%. The factors associated most strongly with increased odds of postdischarge complications were body mass index ≥ 50, use of steroids, procedure type, predischarge complication, prolonged duration of stay, and prolonged operative time. CONCLUSION: Postdischarge complications after bariatric surgery represent a substantial source of patient morbidity and hospital readmissions. The majority of postdischarge complications are infection-related, including surgical-site infections and catheter-associated urinary tract infections. Adopting and implementing standardized pre- and postoperative strategies to decrease perioperative infection may help to decrease the rate of postdischarge complications and associated readmissions and enhance overall quality of care.

Lysyl Oxidase as a Serum Biomarker of Liver Fibrosis in Patients with Severe Obesity and Obstructive Sleep Apnea.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is associated with the progression of nonalcoholic fatty liver disease (NAFLD). We hypothesized that the hypoxia of OSA increases hepatic production of lysyl oxidase (LOX), an enzyme that cross-links collagen, and that LOX may serve as a biomarker of hepatic fibrosis. DESIGN: Thirty-five patients with severe obesity underwent liver biopsy, polysomnography, and serum LOX testing. A separate group with severe OSA had serum LOX measured before and after 3 mo of CPAP or no therapy, as did age-matched controls. LOX expression and secretion were measured in mouse hepatocytes following exposure to hypoxia. SETTING: The Johns Hopkins Bayview Sleep Disorders Center, and the Hypertension Unit of the Heart Institute at the University of São Paulo Medical School. MEASUREMENTS AND RESULTS: In the bariatric cohort, the apnea-hypopnea index was higher in patients with hepatic fibrosis than in those without fibrosis (42.7 ± 30.2 events/h, versus 16.2 ± 15.5 events/h; P = 0.002), as was serum LOX (84.64 ± 29.71 ng/mL, versus 45.46 ± 17.16 ng/mL; P < 0.001). In the sleep clinic sample, patients with severe OSA had higher baseline LOX than healthy controls (70.75 ng/mL versus 52.36 ng/mL, P = 0.046), and serum LOX decreased in patients with OSA on CPAP (mean decrease 20.49 ng/mL) but not in untreated patients (mean decrease 0.19 ng/mL). Hypoxic mouse hepatocytes demonstrated 5.9-fold increased LOX transcription (P = 0.046), and enhanced LOX protein secretion. CONCLUSIONS: The hypoxic stress of obstructive sleep apnea may increase circulating lysyl oxidase (LOX) levels. LOX may serve as a biomarker of liver fibrosis in patients with severe obesity and nonalcoholic fatty liver disease.

Decreased Escitalopram Concentrations Post-Roux-en-Y Gastric Bypass Surgery.

BACKGROUND: There is a high coincidence between obesity and psychiatric disorders including depression. Depressive disorders are commonly treated with antidepressants, including the selective serotonin reuptake inhibitor Lexapro (escitalopram). Although candidates for elective Roux-en-Y gastric bypass (RYGB) surgery may be treated with escitalopram, drug dosing strategies are typically not adjusted postoperatively. Therefore, studies are needed to better characterize escitalopram drug concentrations in a postsurgical setting. METHODS: Turbulent flow-liquid chromatographic-tandem mass spectrometric methods were used to quantify escitalopram concentrations in serum in study participants approved for RYGB. Blood was collected from study subjects 2 weeks before surgery, and 2 and 6 weeks postoperatively, to assess the impact of RYGB on systemic drug concentrations. RESULTS: Twelve samples from 4 study participants were collected and analyzed for serum escitalopram concentrations. Two weeks post-RYGB, although there were minimal changes in each participant's body mass index (<5%), drug concentrations were 33% (4%-71%) decreased as compared with presurgical serum concentrations. There were further decreases in drug concentrations 6 weeks postsurgery. All clinical laboratory values were within normal reference intervals. CONCLUSIONS: RYGB significantly alters the gastrointestinal tract and impacts escitalopram drug concentrations, even shortly after surgery.

Effect of Mandatory Centers of Excellence Designation on Demographic Characteristics of Patients Who Undergo Bariatric Surgery.

IMPORTANCE: From February 21, 2006, through September 24, 2013, the Centers for Medicare & Medicaid Services (CMS) required, via the National Coverage Determination manual, that bariatric surgery be performed only in hospitals that had been designated as a Center of Excellence (COE). The effect of this certification requirement on access to bariatric surgery has been reported only anecdotally. OBJECTIVE: To investigate whether the COE certification requirement proved to be a barrier to patients' access to bariatric surgical procedures. DESIGN, SETTING, AND PARTICIPANTS: Using the National Inpatient Sample, we retrospectively identified patients who underwent bariatric surgery from January 1, 2006, through December 31, 2011. EXPOSURE: Bariatric surgery. MAIN OUTCOMES AND MEASURES: Logistic regression and χ² tests were used to examine differences in patients' sociodemographic characteristics over time. RESULTS: A total of 134,227 bariatric surgical patients were identified. The proportion of the population who were older than 64 years increased from 2.9% in 2006 to 7.0% in 2011 (P < .001) and there was a decrease in the proportion of patients who were 49 years and younger (P < .001). The percentage of female patients who underwent bariatric surgery decreased from 80.4% to 78.1% (P < .001) and the percentage of patients who were classified as black, Hispanic, or Asian or Pacific Islander increased from 12.3% to 15.1% (P < .001), 9.7% to 12.5% (P < .001), and 0.3% to 0.4% (P < .001), respectively. The proportion of patients with Medicare increased from 8.5% to 16.3% (P < .001) and those with Medicaid from 6.6% to 11.8% (P < .001). The percentage of patients with private insurance declined from 72.4% to 63.3% (P < .001). The proportion of patients in the lowest income quartile increased from 20.7% to 22.9% (P < .001) while those in the highest income quartile decreased from 25.8% to 23.9% (P < .001). CONCLUSIONS AND RELEVANCE: The COE certification requirement by CMS did not appear to limit access to bariatric surgery. Future studies should determine whether CMS's recent (2013) change in policy (ie, removing the mandatory COE certification for bariatric surgical insurance coverage) might sacrifice patient safety without addressing the real cause of limited access to health care.

Preoperative warm-up the key to improved resident technique: a randomized study.

BACKGROUND: The ACGME has required that a skills lab be incorporated into the surgical residency curriculum. While the value of warm-up is generally accepted in other areas requiring complex motor skills, there is little evidence to support the benefits of warm-up prior to performing surgery. We are conducting this study in an attempt to identify whether a warm-up period prior to operating impacts operative technique. METHODS: All general surgery residents and MIS fellows were included in this IRB-approved randomized study. Participants were randomized to either warm-up or no warm-up groups. Participants randomized to the warm-up group completed a 10 min practice session in the simulation lab within 1 h of starting the case, using an FLS training box. At the conclusion of the operation, the participant was evaluated by the attending surgeon using the validated global rating scales of Reznick and Vassiliou. The attending surgeons were blinded to the use of pre-procedure warm-up. The results of the questionnaire were analyzed using student's t test with p < 0.05 for significance. RESULTS: Pilot data were obtained after completing 40 cases that were randomized to warm-up (19) or no warm-up (21). There was a statistically significant improvement in depth perception (p = 0.02), bimanual dexterity (p = 0.01), and efficiency of movements (p = 0.03) for those randomized to warm-up. There was statistical improvement when we preformed a composite scoring of the attending evaluations for each of the Reznick (p = 0.008) and the Vassiliou (p = 0.01) global rating scales. CONCLUSIONS: Preoperative warm-up significantly improves depth perception, bimanual dexterity, and efficiency of movements, as well as improvement in composite scores as judged by the attending surgeon. The lack of self-perceived improvement by the residents may be a reflection of the high standards and intense self-critique that is common among surgical trainees. We believe that our findings, while preliminary, reflect that surgical performance can be enhanced through structured warm-up activities.

The effect of warm-up on surgical performance: a systematic review.

BACKGROUND: The concept of warming-up before a performance has been accepted across many disciplines including sports and music. In contrast, it is uncommon for a surgeon to "warm-up" prior to operating. OBJECTIVE: To date, few studies from various specialties have attempted to answer this question whether warm-up improved the intraoperative performance of the surgeon. However, there has not been a systematic review of these studies. The aim of our systematic review is to assess the effect of warming-up preoperatively on the laparoscopic performance of the surgeon. METHODS: Pubmed and scopus were searched to identify all published prospective observational studies, which involved either residents, fellows or attending surgeons. We excluded case reports, reviews, non-English studies, and medical student participation. Study risk of bias were assessed regarding sequence generation, allocation concealment, blinding, incomplete outcome data, selective outcome reporting, and other biases, using a validated Cochrane Collaboration's tool. RESULTS: Out of 241 studies, 6 met the inclusion criteria. All included studies were randomized with half of them being randomized controlled studies and the rest randomized crossover studies. The total number of operative cases was 196, including 98 warm-up and 98 non warm-up. The total number of participants was 87, with the largest number in a single study being 38 and the average sample size of all studies was 14. All six studies assessed various aspects of laparoscopic surgical performances. Significant improvement in the intraoperative laparoscopic performance was observed with warming-up preoperatively in five out of six studies (p < 0.05). The sixth study failed to reach statistical significance (p > 0.05). CONCLUSION: Warming-up before an operative procedure improve a trainee's technical, cognitive, and psychomotor performance. Further studies are necessary to assess the ways in which warm-up could impact a surgeon's performance, and to identify the optimal timing and duration of warm-up prior to operating.

Hospital-acquired conditions after bariatric surgery: we can predict, but can we prevent?

BACKGROUND: Centers for Medicare and Medicaid Services initiated a non-payment policy for certain hospital-acquired conditions (HACs) in 2008. This study aimed to determine the rate of the three most common HACs (surgical site infection (SSI), urinary tract infection (UTI), and venous thromboembolism (VTE)) among bariatric surgery patients. Additionally, the association of HACs with patient factors and the effect of HACs on post-operative outcomes were investigated. METHODS: Patients over 18 years with a body mass index (BMI) ≥ 35 who underwent bariatric surgery were identified using the American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) database (2005-2012). Patients were grouped into two categories: HAC versus no HAC patients and baseline characteristics and outcomes, including 30-day mortality, reoperation, and mean length of stay (LOS) were compared. Multivariable logistic regression analysis was performed to identify the risk factors for developing a HAC. RESULTS: 98,553 patients were identified, 2,809 (2.9%) developed at least one HACs. SSI was the most common HAC (1.8%), followed by UTI (0.7%) and VTE (0.4%). The rate of these HACs significantly decreased from 4.6% in 2005-2006 to 2.5% in 2012 (p < 0.001). Laparoscopic gastric banding was associated with the lowest rates of HAC (1.3%) and open gastric bypass with the highest (8.0%). HAC patients had significantly higher rates of in-hospital mortality (0.8 vs. 0.1%, p < 0.001) and LOS (3.9 vs. 2.1 days, p < 0.001). On adjusted analysis, open GBP patients had 5.36-fold higher odds of developing a HAC. Interestingly, the presence of a resident surgeon 7-11 years post graduation was associated with significantly increased odds of HACs (1.86, 1.50-2.31, p < 0.001). CONCLUSION: Our data demonstrate a strong correlation between these three HACs following bariatric surgery and factors intrinsic to the bariatric patient population. This calls into question the non-payment policy for inherent patient factors on which they cannot have impact. These findings are important to help inform health care policy decisions regarding access to care for bariatric surgery patients.

A single institutional comparison of endoscopic and open abdominal component separation.

BACKGROUND: The authors analyzed surgical factors and outcomes data in the largest single institutional study comparing endoscopic (ECS) and open component separation (OCS) in ventral hernia repairs (VHR). METHODS: A prospectively maintained database was reviewed, identifying 76 patients who underwent component separation for VHR with mesh from 2010 to 2013: 34 OCS and 42 ECS. Comparisons were made for demographics, surgical risk factors, and peri-operative outcomes. Wound complications and hernia occurrence post-operatively were reviewed. Risk analyses were performed to determine the association of pre-operative risk factors with surgical site occurrences. RESULTS: Twenty-five ECS patients underwent subsequent laparoscopic hernia repair, and 17 underwent open repair. Operative time for ECS was longer than OCS (334 vs. 239 min; P < 0.001); however, there was no difference in length of stay (4 days in both groups, P = 0.64) and estimated blood loss (ECS: 97 vs. OCS: 93 cc, P = 0.847). In a sub-analysis of ECS patients, those who underwent laparoscopic hernia repair had a 96 min shorter operative time (P < 0.001) and lower EBL (63 vs. 147 cc, P < 0.001) than open repair. Wound complications were 24% in the ECS (n = 10) and 32% in OCS group (n = 11). There was one midline hernia recurrence in the ECS group (mean follow-up of 8 months, range 0.5-34.5 months) and no hernia recurrences in the OCS group (mean follow-up 10 months, range 0.5-30 months). Three of the patients in the ECS group developed new lateral abdominal wall hernias post-operatively. CONCLUSIONS: The ECS group had a significantly longer operative time than the OCS group. Post-operative wound complications were similar between ECS and OCS groups. Patients in the ECS group who underwent subsequent laparoscopic VHR had a shorter operative time and blood loss than open repair.

Hormonal response to a mixed-meal challenge after reversal of gastric bypass for hypoglycemia.

CONTEXT: Severe hypoglycemia is a rare and challenging complication of Roux-en-Y gastric bypass (RYGB), which is characterized by hypersecretion of insulin and incretin hormones in the postprandial state. OBJECTIVE: The objective of the study was to determine the clinical and hormonal responses to a mixed-meal challenge after the reversal of RYGB in 2 patients with post-RYGB hypoglycemia. We hypothesized that the reversal of RYGB would lead to clinical improvement in hypoglycemia through the attenuation of incretin hormone secretion. DESIGN/SETTING/SUBJECTS/OUTCOME MEASURES: Two patients with post-RYGB hypoglycemia underwent a standardized meal tolerance test prior to and 8 and 18 months after RYGB reversal, respectively, with the measurement of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), insulin, and glucose levels. Gastric bypass was reversed by reattaching the small gastric pouch to the bypassed distal stomach and resecting the Roux limb to restore the normal flow of food bolus. RESULTS: Both subjects showed persistent evidence of hypoglycemia with marked hyperinsulinemia after the RYGB reversal. GLP-1 levels after the RYGB reversal decreased by 76% and 70%, respectively, from their prereversal levels and to the level of nonhypoglycemic post-RYGB controls. In contrast, GIP levels after the RYGB reversal increased by 3-10 times the level before the reversal and 8-26 times that of the nonhypoglycemic post-RYGB controls. CONCLUSIONS: Reversal of RYGB did not alleviate hyperinsulinemic hypoglycemia upon a mixed-meal challenge in our patients, thus suggesting its limited clinical benefit as treatment of post-RYGB hypoglycemia. The marked increase in GIP levels and concurrent decrease in GLP-1 levels in our patients suggest a possible role of GIP in persistent hyperinsulinemic hypoglycemia after the reversal of RYGB.

Clinical outcomes after bariatric surgery: a five-year matched cohort analysis in seven US states.

BACKGROUND: Bariatric surgery is the most effective weight loss treatment, yet few studies have reported on short- and long-term outcomes postsurgery. METHODS: Using claims data from seven Blue Cross/Blue Shield health plans serving seven states, we conducted a non-concurrent, matched cohort study. We followed 22,693 persons who underwent bariatric surgery during 2003-2007 and were enrolled at least 6 months before and after surgery. Using logistic regression, we compared serious and less serious adverse clinical outcomes, hospitalizations, planned procedures, and obesity-related co-morbidities between groups for up to 5 years. RESULTS: Relative to controls, surgery patients were more likely to experience a serious [odds ratio (OR) 1.9; 95% confidence interval (CI) 1.8-2.0] or less serious (OR 2.5, CI 2.4-2.7) adverse clinical outcome or hospitalization (OR 1.3, CI 1.3-1.4) at 1 year postsurgery. The risk remained elevated until 4 years postsurgery for serious events and 5 years for less serious outcomes and hospitalizations. Some complication rates were lower for patients undergoing laparoscopic surgery. Planned procedures, such as skin reduction, peaked in postsurgery year 2 but remained elevated through year 5. Surgery patients had a 55% decreased risk of obesity-related co-morbidities, such as type 2 diabetes, in the first year postsurgery, which remained low throughout the study (year 5: OR 0.4, CI 0.4-0.5). CONCLUSIONS: While bariatric surgery is associated with a higher risk of adverse clinical outcomes compared to controls, it also substantially decreased obesity-related co-morbidities during the 5-year follow-up.

The long-term risk of venous thromboembolism following bariatric surgery.

BACKGROUND: Venous thromboembolism (VTE) is a leading cause of morbidity and mortality following bariatric surgery. The exact duration and magnitude of post-surgery risk for VTE, however, is unclear. We analyzed a large administrative database to determine the long-term risk and predictors for VTE in patients undergoing bariatric surgery. METHODS: A private insurance claims database was used to identify 17,434 patients who underwent bariatric surgery. Longitudinal data were available for each patient for up to 12 months post-surgery. We used logistic regression to identify independent predictors for VTE events. RESULTS: The incidence of VTE during the index surgical hospitalization was .88%. This cumulative rate rose to 2.17% at 1 month and 2.99% by 6 months post-surgery. Over 74% of VTE events occurred after discharge. Risk factors identified for VTE developing by 6 months post-surgery included male sex (odds ratio (OR) = 1.68; confidence limits (CL) = 1.37-2.07), age ≥ 55 years (OR = 2.18; CL = 1.56-3.03), smoking (OR = 1.86; CL = 1.06-3.27), and previous VTE (OR = 7.48; CL = 5.78-9.67). The laparoscopic adjustable gastric band was less likely to result in VTE compared to open or laparoscopic gastric bypass (OR = .31; CL = .13-.75). CONCLUSIONS: The period of increased risk for VTE following bariatric surgery extends well beyond the initial hospital discharge and 30 days after surgery. The high frequency of VTE up to 6 months following bariatric surgery suggests that more aggressively extended prophylaxis should be considered in patients at higher risk for VTE.