Factors Associated with the Decision to Complete Bariatric Metabolic Surgery among a Racially and Ethnically Diverse Sample of Adults: A Classification and Regression Tree Analysis

BACKGROUND

Less than 50% of eligible candidates who are referred complete Bariatric Metabolic Surgery (BMS). The factors influencing the decision to complete BMS, particularly how these factors vary across different racial and ethnic groups, remain largely unexplored.

METHODS

This prospective cohort study included adult patients referred to a bariatric surgeon or obesity medicine program between July 2019-September 2022. Sociodemographic characteristics, body mass index (BMI), anxiety, depression, body appreciation, and patient-physician relationship information were collected via survey and electronic health records. The association between BMS completion and potential decision-driving factors was examined using Classification and Regression Tree (CART) analysis.

RESULTS

A total of 406 BMS -eligible patients participated in the study (mean [SD] age: 47.5 [11.6] years; 87.2% women; 18.0% Hispanic, 39% non-Hispanic Black [NHB], and 39% non-Hispanic White [NHW]; mean [SD] BMI: 45.9 [10.1] kg/m2). A total of 147 participants (36.2%) completed BMS. Overall, the most influential factor driving the decision to complete BMS was younger age (< 68.4 years), higher patient satisfaction, and BMI (≥ 38.0 kg/m2). Hispanic participants prioritized age (< 55.4 years), female sex, and body appreciation. For NHB participants, the highest ranked factors were age < 56.3 years, BMI ≥ 35.8 kg/m2, and higher patient satisfaction. For NHW patients, the most influential factors were age (39.1 to 68.6 years) and higher body appreciation.

CONCLUSION

These findings highlight racial and ethnic group differences in the factors motivating individuals to complete BMS. By acknowledging these differences, healthcare providers can support patients from different backgrounds more effectively in their decision-making process regarding BMS.

Depression and Anxiety as Predictors of Metabolic and Bariatric Surgery Completion Among Ethnically Diverse Patients

BACKGROUND

Mental health conditions including depression and anxiety are often prevalent among metabolic and bariatric surgery (MBS) patients, but it is not known if these conditions predict the decision to complete the procedure and if this varies by race and ethnicity. This study aimed to determine if depression and anxiety are associated with MBS completion among a race/ethnically diverse sample of patients.

METHODS

This prospective cohort study included participants who were referred to an obesity program or two MBS practices between August 2019 and October 2022. Participants completed the Mini International Neuropsychiatric Interview (MINI) instrument to determine history of anxiety and/or depression, as well as MBS completion status (Y/N). Multivariable logistic regression models determined the odds of MBS completion by depression and anxiety status adjusting for age, sex, body mass index, and race/ethnicity.

RESULTS

The sample consisted of 413 study participants (87 % women, 40% non-Hispanic White, 39% non-Hispanic Black, and 18% Hispanic). Participants with a history of anxiety were less likely to complete MBS (aOR = 0.52, 95% CI = 0.30-0.90, p = 0.020). Women had increased odds of a history of anxiety (aOR = 5.65, 95% CI = 1.64-19.49, p = 0.006) and of concurrent anxiety and depression (aOR = 3.07, 95% CI = 1.39-6.79, p = 0.005) compared to men.

CONCLUSIONS

Results showed that participants with anxiety were 48% less likely to complete MBS compared to those without anxiety. Additionally, women were more likely to report a history of anxiety with and without depression versus men. These findings can inform pre-MBS programs about risk factors for non-completion.

Type 2 Diabetes and HbA1c Predict All-Cause Post-Metabolic and Bariatric Surgery Hospital Readmission

OBJECTIVE

The main goal of this analysis was to determine whether type 2 diabetes and hemoglobin A1c (HbA1c) predict all-cause 30-day hospital readmission after metabolic and bariatric surgery (MBS). It was hypothesized that a diagnosis of type 2 diabetes or high HbA1c values would predict all-cause hospital readmission rates post MBS.

METHODS

A retrospective analysis from the 2015-2018 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) cohort was completed (N = 744,776); 30,972 participants were readmitted during the 30 days post MBS.

RESULTS

Mean age of the MBSAQIP sample was 45.1 (11.5) years, and the majority were female (80.7%) and non-Hispanic White (59.4%). The all-cause hospital readmission rate was 4.2% and increased by 10% in those with uncontrolled type 2 diabetes (HbA1c > 7.5% [> 58 mmol/mol]); after adjustment, diabetes was not associated with increased readmission. Uncontrolled type 2 diabetes, type 2 diabetes, and prediabetes resulted in less weight loss 30 days post MBS.

CONCLUSIONS

These results based on a national MBS cohort showed that uncontrolled type 2 diabetes is associated with a greater likelihood of all-cause hospital readmission and reduced weight loss 30 days post MBS. Both type 2 diabetes and prediabetes were also associated with decreased weight loss 30 days post MBS. These findings highlight the need to classify and optimize glycemic control prior to MBS.

Identification and saturable nature of signaling pathways induced by metreleptin in humans: comparative evaluation of in vivo, ex vivo, and in vitro administration

Signaling pathways activated by leptin in metabolically important organs have largely been studied only in animal and/or cell culture studies. In this study, we examined whether leptin has similar effects in human peripheral tissues in vivo, ex vivo, and in vitro and whether the response would be different in lean and obese humans. For in vivo leptin signaling, metreleptin was administered and muscle, adipose tissue, and peripheral blood mononuclear cells were taken for analysis of signal activation. Experiments were also done ex vivo and with primary cultured cells in vitro. The signal activation was compared between male versus female and obese versus lean humans. Acute in vivo, ex vivo, and/or in vitro metreleptin administration similarly activated STAT3, AMPK, ERK1/2, Akt, mTOR, NF-κB, and/or IKKα/β without any differences between male versus female and obese versus lean subjects. All signaling pathways were saturable at ∼30-50 ng/mL, consistent with the clinical evidence showing no additional effect(s) in obese subjects who already have high levels of leptin. Our data provide novel information on downstream effectors of metreleptin action in humans that may have therapeutic implications.

Ventriculoperitoneal shunting: Laparoscopically assisted versus conventional open surgical approaches

OBJECTIVES

Ventriculoperitoneal shunting (VPS) is a mainstay of hydrocephalus therapy, but carries a significant risk of device malfunctioning. This study aims to compare the outcomes of laparoscopic ventriculoperitoneal shunting versus open ventriculoperitoneal shunting (OVPS) VPS-placement and reviews our findings in the pertinent context of the literature from 1993 to 2012.

MATERIALS AND METHODS

Between 2003 and 2012, a total of 232 patients underwent first time VPS placement at Beth Israel Deaconess Medical Center. Of those, 155 were laparoscopically guided and 77 were done conventionally. We analyzed independent variables (age, gender, medical history, clinical presentation, indication for surgery and surgical technique) and dependent variables (operative time, post-operative complications, length of stay in the hospital) and occurrence of shunt failure.

RESULTS

Mean operative time was 43.7 min (18.0-102.0) in the laparoscopic group versus 63.0 min (30.0-151.0) in the open group, (P < 0.05). Length of stay was similar, 5 days in the laparoscopic and in the open group, (P = 0.945). The incidence of shunt failure during the entire follow-up period was not statistically different between the two groups, occurring in 14.1% in the laparoscopic group and 16.9% in the open group, (P = 0.601). Kaplan-Meier analysis demonstrated no difference in shunt survival between the two groups (P = 0.868), with functionality in 85% at 6-months and 78.5% at 1-year.

CONCLUSION

According to our study, LVPS-placement results compare similarly to OVPS placement in most aspects. Since laparoscopic placement is not routinely indicated, we suggest a prospective study to assess its value as an alternate technique especially suitable in obese patients and patients with previous abdominal operations.

Effect of abdominal insufflation for laparoscopy on intracranial pressure

IMPORTANCE

Increased abdominal pressure may have a negative effect on intracranial pressure (ICP). Human data on the effects of laparoscopy on ICP are lacking. We retrospectively reviewed laparoscopic operations for ventriculoperitoneal shunt placement to determine the effect of insufflation on ICP.

OBSERVATIONS

Nine patients underwent insufflation with carbon dioxide (CO(2)) at pressures ranging from 8 to 15 mm Hg and ICP measured through a ventricular catheter. We used a paired t test to compare ICP with insufflation and desufflation. Linear regression correlated insufflation pressure with ICP. The mean ICP increase with 15-mm Hg insufflation is 7.2 (95% CI, 5.4-9.1 [P < .001]) cm H(2)O. The increase in ICP correlated with increasing insufflation pressure (P = .04). Maximum ICP recorded was 25 cm H(2)O.

CONCLUSIONS AND RELEVANCE

Intracranial pressure significantly increases with abdominal insufflation and correlates with laparoscopic insufflation pressure. The maximum ICP measured was a potentially dangerous 25 cm H(2)O. Laparoscopy should be used cautiously in patients with a baseline elevated ICP or head trauma.

Patient factors associated with undergoing laparoscopic adjustable gastric banding vs Roux-en-Y gastric bypass for weight loss

BACKGROUND

Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding are 2 commonly performed bariatric procedures in the US with different profiles for risk and effectiveness. Little is known about factors that might lead patients to proceed with one procedure over the other.

STUDY DESIGN

We recruited and interviewed patients seeking bariatric surgery from 2 academic centers in Boston (response rate 70%). We conducted multivariable analyses to identify patient perceptions and clinical and behavioral characteristics that correlated with undergoing gastric banding (n = 239) vs gastric bypass (n = 297).

RESULTS

After adjustment for socio-demographic and clinical factors, we found that older patients (odds ratio [OR] 1.03; 95% CI 1.00 to 1.05) and those with higher quality of life scores and higher levels of uncontrolled eating were more likely to undergo gastric banding as opposed to gastric bypass. In contrast, patients with type 2 diabetes (OR 0.46; 95% CI 0.28 to 0.77), those who desired greater weight loss, and those who were willing to assume higher mortality risk to achieve their ideal weight were less likely to proceed with gastric banding. After initial adjustment, male sex and lower body mass index were associated with a likelihood of undergoing gastric banding; however, these factors were no longer significant after adjustment for other significant correlates such as patients' perceived ideal weight, predilection to assume risk to lose weight, and eating behavior.

CONCLUSIONS

Patients' diabetes status, quality of life, eating behavior, ideal weight loss, and willingness to assume mortality risk to lose weight were associated with whether patients proceeded with gastric banding as opposed to gastric bypass. Other clinical factors were less important.

Expectations for weight loss and willingness to accept risk among patients seeking weight loss surgery

IMPORTANCE

Weight loss surgery (WLS) has been shown to produce long-term weight loss but is not risk free or universally effective. The weight loss expectations and willingness to undergo perioperative risk among patients seeking WLS remain unknown.

OBJECTIVES

To examine the expectations and motivations of WLS patients and the mortality risks they are willing to undertake and to explore the demographic characteristics, clinical factors, and patient perceptions associated with high weight loss expectations and willingness to assume high surgical risk.

DESIGN

We interviewed patients seeking WLS and conducted multivariable analyses to examine the characteristics associated with high weight loss expectations and the acceptance of mortality risks of 10% or higher.

SETTING

Two WLS centers in Boston.

PARTICIPANTS

Six hundred fifty-four patients.

MAIN OUTCOME MEASURES

Disappointment with a sustained weight loss of 20% and willingness to accept a mortality risk of 10% or higher with WLS.

RESULTS

On average, patients expected to lose as much as 38% of their weight after WLS and expressed disappointment if they did not lose at least 26%. Most patients (84.8%) accepted some risk of dying to undergo WLS, but only 57.5% were willing to undergo a hypothetical treatment that produced a 20% weight loss. The mean acceptable mortality risk to undergo WLS was 6.7%, but the median risk was only 0.1%; 19.5% of all patients were willing to accept a risk of at least 10%. Women were more likely than men to be disappointed with a 20% weight loss but were less likely to accept high mortality risk. After initial adjustment, white patients appeared more likely than African American patients to have high weight loss expectations and to be willing to accept high risk. Patients with lower quality-of-life scores and those who perceived needing to lose more than 10% and 20% of weight to achieve "any" health benefits were more likely to have unrealistic weight loss expectations. Low quality-of-life scores were also associated with willingness to accept high risk.

CONCLUSIONS AND RELEVANCE

Most patients seeking WLS have high weight loss expectations and believe they need to lose substantial weight to derive any health benefits. Educational efforts may be necessary to align expectations with clinical reality.

FNDC5 and irisin in humans: I. Predictors of circulating concentrations in serum and plasma and II. mRNA expression and circulating concentrations in response to weight loss and exercise

OBJECTIVE

In mouse, PGC1-α overexpression in muscle stimulates an increase in expression of FNDC5, a membrane protein that is cleaved and secreted as a newly identified hormone, irisin. One prior study has shown that FNDC5 induces browning of subcutaneous fat in mice and mediates beneficial effects of exercise on metabolism, but a more recent study using gene expression arrays failed to detect a robust increase in FNDC5 mRNA in human muscles from exercising subjects. No prior study has reported on the physiological regulation and role of circulating irisin and FNDC5 in humans.

MATERIALS/METHODS

A. FNDC5 gene expression studies: We first examined tissue distribution of FNDC5 in humans. B. Cross-sectional studies: Predictors of FNDC5 mRNA expression levels were examined in muscle tissues from 18 healthy subjects with a wide range of BMI. Assays were optimized to measure circulating FNDC5 and irisin levels, and their associations with anthropometric and metabolic parameters were analyzed in two cross-sectional studies that examined 117 middle-aged healthy women and 14 obese subjects, respectively. C. Interventional studies: The effect of weight loss on FNDC5 mRNA and/or circulating irisin levels was examined in 14 obese subjects before and after bariatric surgery. The effect of acute and chronic exercise was then assessed in 15 young healthy adults who performed intermittent sprint running sessions over an 8 week period.

RESULTS

Tissue arrays demonstrated that in humans, the FNDC5 gene is predominantly expressed in muscle. Circulating irisin was detected in the serum or plasma of all subjects studied, whereas circulating FNDC5 was detected in only a distinct minority of the subjects. Cross-sectional studies revealed that circulating irisin levels were positively correlated with biceps circumference (used as a surrogate marker of muscle mass herein), BMI, glucose, ghrelin, and IGF-1. In contrast, irisin levels were negatively correlated with age, insulin, cholesterol, and adiponectin levels, indicating a possible compensatory role of irisin in metabolic regulation. Multivariate regression analysis revealed that biceps circumference was the strongest predictor of circulating irisin levels underlying the association between irisin and metabolic factors in humans at baseline. Both muscle FNDC5 mRNA levels and circulating irisin levels were significantly downregulated 6 months after bariatric surgery. Circulating irisin levels were significantly upregulated 30 min after acute exercise and were correlated mainly with ATP levels and secondarily with metabolites related to glycolysis and lipolysis in muscle.

CONCLUSIONS

Similar to mice, the FNDC5 gene is expressed in human muscle. Age and muscle mass are the primary predictors of circulating irisin, with young male athletes having several fold higher irisin levels than middle-aged obese women. Circulating irisin levels increase in response to acute exercise whereas muscle FNDC5 mRNA and circulating irisin levels decrease after surgically induced weight loss in parallel to decrease in body mass. Further studies are needed to study the regulation of irisin levels and its physiological effects in humans and to elucidate the mechanisms underlying these effects.

Opioid-free single-incision laparoscopic (SIL) cholecystectomy using bilateral TAP blocks

A 30 year old woman who was 8 weeks postpartum with a history of cholelithiasis and gallstone pancreatitis, and who was status-post endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy, was treated with a single-incision laparoscopic (SIL) cholecystectomy. A transversus abdominis plane block (TAP) was performed after induction of anesthesia. The patient required no intraoperative or postoperative opioids.

Efficacy of metreleptin in obese patients with type 2 diabetes: cellular and molecular pathways underlying leptin tolerance

OBJECTIVE

Metreleptin has been efficacious in improving metabolic control in patients with lipodystrophy, but its efficacy has not been tested in obese patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We studied the role of leptin in regulating the endocrine adaptation to long-term caloric deprivation and weight loss in obese diabetic subjects over 16 weeks in the context of a double-blinded, placebo-controlled, randomized trial. We then performed detailed interventional and mechanistic signaling studies in humans in vivo, ex vivo, and in vitro.

RESULTS

In obese patients with diabetes, metreleptin administration for 16 weeks did not alter body weight or circulating inflammatory markers but reduced HbA(1c) marginally (8.01 ± 0.93-7.96 ± 1.12, P = 0.03). Total leptin, leptin-binding protein, and antileptin antibody levels increased, limiting free leptin availability and resulting in circulating free leptin levels of ∼50 ng/mL. Consistent with clinical observations, all metreleptin signaling pathways studied in human adipose tissue and peripheral blood mononuclear cells were saturable at ∼50 ng/mL, with no major differences in timing or magnitude of leptin-activated STAT3 phosphorylation in tissues from male versus female or obese versus lean humans in vivo, ex vivo, or in vitro. We also observed for the first time that endoplasmic reticulum (ER) stress in human primary adipocytes inhibits leptin signaling.

CONCLUSIONS

In obese patients with diabetes, metreleptin administration did not alter body weight or circulating inflammatory markers but reduced HbA(1c) marginally. ER stress and the saturable nature of leptin signaling pathways play a key role in the development of leptin tolerance in obese patients with diabetes.

Best practice updates for weight loss surgery data collection

To update evidence-based best practice guidelines for collection of data on weight loss surgery (WLS). Systematic search of English-language literature in MEDLINE and the Cochrane Library on WLS and data collection, registries, risk adjustment, accreditation, benchmarks, and administrative and outcomes databases published between April 2004 and May 2007. Use of key words to narrow the search for a selective review of abstracts, retrieval of full articles, and grading of evidence according to systems used in established evidence-based models. During our search, we identified 212 papers; the 63 most relevant were reviewed in detail. Most data collection on WLS has relied on administrative data sets, single-institution studies, and other sources that are not WLS specific. A six-center, nationwide study involving data collection has been started by the longitudinal assessment of bariatric surgery, but results are not yet available. Two WLS-specific, longitudinal, national data collection systems are about to be implemented. Key factors in patient safety include data collection for all weight loss procedures; prospective, risk-adjusted, universal, benchmarked, longitudinal data collection systems; and use of WLS-specific data points that track clinical effectiveness and complications following WLS. Data collection will need to include assessments of novel therapies and specific subgroups (e.g., adolescents, the elderly, and individuals who are at the greatest risk or have the most to gain from WLS). Quality indicators, including metrics on processes of care and determination of outliers, need to be established and monitored to advance patient safety and quality improvement.

Patients with neuroglycopenia after gastric bypass surgery have exaggerated incretin and insulin secretory responses to a mixed meal

CONTEXT AND OBJECTIVE

Hyperinsulinemic hypoglycemia is newly recognized as a rare but important complication after Roux-en-Y gastric bypass (GB). The etiology of the syndrome and metabolic characteristics remain incompletely understood. Recent studies suggest that levels of incretin hormones are increased after GB and may promote excessive beta-cell function and/or growth.

PATIENTS AND METHODS

We performed a cross-sectional analysis of metabolic variables, in both the fasting state and after a liquid mixed-meal challenge, in four subject groups: 1) with clinically significant hypoglycemia [neuroglycopenia (NG)] after GB surgery, 2) with no symptoms of hypoglycemia at similar duration after GB surgery, 3) without GB similar to preoperative body mass index of the surgical cohorts, and 4) without GB similar to current body mass index of the surgical cohorts.

RESULTS

Insulin and C-peptide after the liquid mixed meal were both higher relative to the glucose level achieved in persons after GB with NG compared with asymptomatic individuals. Glucagon, glucagon-like peptide 1, and glucose-dependent insulinotropic peptide levels were higher in both post-GB surgical groups compared with both overweight and morbidly obese persons, and glucagon-like peptide 1 was markedly higher in the group with NG. Insulin resistance, assessed by homeostasis model assessment of insulin resistance, the composite insulin sensitivity index, or adiponectin, was similar in both post-GB groups. Dumping score was also higher in both GB groups but did not discriminate between asymptomatic and symptomatic patients. Notably, the frequency of asymptomatic hypoglycemia after a liquid mixed meal was high in post-GB patients.

CONCLUSION

A robust insulin secretory response was associated with postprandial hypoglycemia in patients after GB presenting with NG. Increased incretin levels may contribute to the increased insulin secretory response.

Benchmarking hospital outcomes for laparoscopic adjustable gastric banding

BACKGROUND

Since the Food and Drug Administration (FDA) approval of laparoscopic adjustable gastric bands (LAGB) in June 2001, the number LAGB procedures performed in the United States has increased exponentially. This study aimed to benchmark the authors' initial hospital experience to FDA research trials and evidence-based literature.

METHODS

Over a 2-year period, 87 consecutive patients with a mean age of 43 years (range, 21-64 years) and a body mass index of 45.6 kg/m2 (range, 35-69 kg/m2) underwent an LAGB procedure at the authors' institution. The authors conducted a retrospective review of the outcomes including conversion, reoperation, mortality, perforation, erosion, prolapse, port dysfunction, excess weight loss, and changes in comorbidities, then compared the data with published benchmarks.

RESULTS

Gender, age, and body mass index were comparable with those of other series. Perioperative adverse events included acute stoma obstruction (n = 1) and respiratory complications (n = 2). Delayed complications included gastric prolapse (n = 4) and port reservoir malposition (n = 4). Five bands were explanted. The mean follow-up period was 14 months (n = 79). The mean percentage of excess weight loss was 30% (range, 4.7-69%) at 6 months, 41% (range, 9.6-82%) at 12 months, and 47% (range, 14-92%) at 24 months. Comorbidities resolved included diabetes (74%), hypertension (57%), gastroesophageal reflux disease (55%) and dyslipidemia (38%).

CONCLUSIONS

The short-term outcomes for LAGB were comparable with published benchmarks. With adequate weight loss, most patients achieve significant improvement in obesity-related illnesses. With new bariatric accreditation standards and mandates required for financial reimbursement, hospitals will need to demonstrate that their clinical outcomes are consistent with best practices. The authors' early experience shows that LAGB achieves significant weight loss with low mortality and morbidity rates. Despite a more gradual weight loss, most patients achieve excellent weight loss with corresponding improvement of comorbidities within the first 2 years postoperatively.

Anastomotic Leak following Antecolic versus Retrocolic Laparoscopic Roux-en-Y Gastric Bypass for Morbid Obesity

BACKGROUND

Laparoscopic Roux-en-Y gastric bypass (LRYGBP) is the most commonly performed operation for the treatment of morbid obesity in the United States. Previous reports suggest that postoperative complications may be influenced by Roux limb orientation (antecolic versus retrocolic), although this remains controversial. The aim of this study was to analyze our experience with anastomotic leaks following LRYGBP with an antecolic- versus retrocolic-routed Roux limb.

METHODS

During the 2-year period of June 2003 to June 2005, 353 patients underwent a LRYGBP. 135 were antecolic and 218 retrocolic. All cases were performed by one of three bariatric surgeons. The decision to perform antecolic versus retrocolic LRYGBP was left to the surgeon's preference. The primary outcome measure was anastomotic leak.

RESULTS

Mean follow-up was 28 weeks. There were no perioperative deaths. Overall complication rate was 16.9%. 17 gastrojejunal leaks (4.8%) were identified, consisting of 12 intraoperative leaks (3.4%) and 5 postoperative leaks (1.4%). Postoperative gastrojejunal leak rate was higher in the antecolic group (P=0.04).

CONCLUSION

Mortality and complication rates were consistent with reported benchmarks on the efficacy and safety of LRYGBP. Our review suggests that anastomotic leak may be more common after antecolic than after retrocolic LRYGBP for morbid obesity. A prospective randomized study is needed to determine whether antecolically-routed Roux limb is an independent predictor for anastomotic leak following LRYGBP.

Intussusception after Roux-en-Y gastric bypass for morbid obesity: case report and literature review of rare complication

Obstruction of the small intestine is a recognized complication after Roux-en-Y gastric bypass surgery for morbid obesity. Reported causes after bariatric surgery include volvulus, adhesion, internal hernia, hemorrhagic bezoar, incarcerated ventral hernia, and intussusception. Intussusception after Roux-en-Y gastric bypass for morbid obesity is rare. The etiology remains largely obscure. A delay in the diagnosis and management may result in catastrophic outcomes. Management should include the early involvement of a bariatric surgeon. We describe the clinical and radiologic presentation of a case of jejunojejunal intussusception 4 years after open Roux-en-Y gastric bypass.

Data collection systems for weight loss surgery: an evidence-based assessment

OBJECTIVE

To evaluate the existence and efficacy of data collection systems for weight loss surgery (WLS) and establish evidence-based guidelines for the development of a statewide WLS registry in Massachusetts.

RESEARCH METHODS AND PROCEDURES

We conducted two systematic searches of English language literature in MEDLINE. The first was on data collection registries related to WLS; the second was an expanded search encompassing other surgical fields (e.g., cardiac and thoracic surgery) and registries (i.e., cancer). Fourteen articles were found to be pertinent. Data were extracted, and evidence categories were assigned according to a grading system based on established evidence-based models. Recommendations were derived from these literature reviews and expert opinion.

RESULTS

This task group found that there are no standardized data collection systems for WLS in Massachusetts (or any other states) and no mandated reporting of WLS-specific outcomes. We described existing WLS databases and systems in other surgical fields. Recommendations focused on the importance and feasibility of data collection for WLS and the need to conduct a pilot study and explore options for creating a statewide WLS database.

DISCUSSION

A statewide WLS data collection system would optimize patient care by enabling the collection, analysis, and dissemination of best practice data. A broad-based effort is needed to meet challenges involved in defining and implementing such a system.

Heated and humidified insufflation during laparoscopic gastric bypass surgery: effect on temperature, postoperative pain, and recovery outcomes

BACKGROUND

Controversy exists regarding the efficacy of heated and humidified intraperitoneal gases in maintaining core body temperature. We performed a sham-controlled study to test the hypothesis that active warming and humidification of the insufflation gas reduces intraoperative heat loss and improves recovery outcomes.

PATIENTS AND METHODS

Fifty morbidly obese patients undergoing laparoscopic Roux-en-Y gastric bypass procedures using a standardized anesthetic technique were randomly assigned to either a control (sham) group receiving room temperature insufflation gases with an inactive Insuflow (Lexion Medical, St. Paul, MN) device, or an active (Insuflow) group receiving warmed and humidified intraperitoneal gases. Esophageal and/or tympanic membrane temperature was measured perioperatively. Postoperative pain was assessed at 15 minute intervals using an 11-point verbal rating scale, with 0 = none to 10 = maximal. In addition, postoperative opioid requirements, incidence of nausea and vomiting, as well as the quality of recovery, were recorded.

RESULTS

Use of the active Insuflow device was associated with significantly higher mean +/- standard deviation (SD) intraoperative core body temperatures (35.5 +/- 0.5 vs. 35.0 +/- 0.4 degrees C). Postoperative shivering (0 vs. 19%) and the requirement for morphine in the postanesthesia care unit (5 +/- 4 vs. 10 +/- 5 mg) were both significantly lower in the Insuflow vs. control groups. Patients in the Insuflow group also reported a higher quality of recovery 48 hours after surgery (15 vs. 13, P < 0.05).

CONCLUSION

The Insuflow device modestly reduced shivering and heat loss, as well as the need for opioid analgesics in the early postoperative period. However, it failed to improve laparoscopic visualization due to fogging, and provided improvement in the quality of recovery only on postoperative day 2.

Laparoscopic totally extraperitoneal versus Lichtenstein herniorrhaphy: cost comparison at teaching hospitals

Laparoscopic hernia repair is safe and effective and may result in less postoperative pain and faster recuperation compared with traditional open hernia repairs. Controversy exists as to the increased cost associated with laparoscopic repairs. The purpose of this study was to quantify and compare the cost of the totally extraperitoneal (TEP) laparoscopic repair and the tension-free Lichtenstein repair at teaching hospitals. The records of consecutive TEP (n = 28) and Lichtenstein (n = 28) repairs performed at Parkland Memorial Hospital and Zale-Lipshy University Hospital were reviewed. A detailed cost analysis was performed. Total patient charge (5,509 US dollars vs. 3,999 US dollars) and total cost (2,861 US dollars vs. 2,009 US dollars) were higher for TEP versus Lichtenstein repairs, respectively (P < 0.05). Operative time and complications were similar for both groups. Return to full activity (15 vs. 34 days) was faster for TEP versus Lichtenstein repairs, respectively (P < 0.05). Of 9 patients in the TEP group who had previously undergone an open hernia repair, 8 (89%) preferred the laparoscopic approach. The laparoscopic TEP repair costs 852 US dollars more than the Lichtenstein repair. The TEP repair results in faster recuperation. Patient preference and faster recuperation may offset the increased cost associated with laparoscopic hernia repair.

Differences in the capacity of reovirus strains to induce apoptosis are determined by the viral attachment protein sigma 1

Reoviruses are important models for studies of viral pathogenesis; however, the mechanisms by which these viruses produce cytopathic effects in infected cells have not been defined. In this report, we show that murine L929 (L) cells infected with prototype reovirus strains type 1 Lang (TIL) and type 3 Dearing (T3D) undergo apoptosis and that T3D induces apoptosis to a substantially greater extent than T1L. Using T1L x T3D reassortant viruses, we found that differences in the capacity of T1L and T3D to induce apoptosis are determined by the viral S1 gene segment, which encodes the viral attachment protein sigma 1 and the non-virion-associated protein sigma 1s. Apoptosis was induced by UV-inactivated, replication-incompetent reovirus virions, which do not contain sigma 1s and do not mediate its synthesis in infected cells. Additionally, T3D-induced apoptosis was inhibited by anti-reovirus monoclonal antibodies that inhibit T3D cell attachment and disassembly. These results indicate that sigma 1, rather than sigma 1s, is required for induction of apoptosis by the reovirus and suggest that interaction of virions with cell surface receptors is an essential step in this mechanism of cell killing.

The molecular basis of NMDA receptor subtypes: native receptor diversity is predicted by subunit composition

The relationship between four pharmacologically distinct NMDA receptor subtypes, identified in radioligand binding studies, and the recently identified NMDA receptor subunits (NR1a-g, NR2A-D) has not been determined. In this report, we demonstrate that the anatomical distribution of the four NMDA receptor subtypes strikingly parallels the distribution of mRNA encoding NR2A-D subunits. The distribution of NR2A mRNA was very similar to that of "antagonist-preferring" NMDA receptors [defined by high-affinity 3H-2-carboxypiperazine-4-yl-propyl-1-phosphonic (3H-CPP) binding sites; correlation coefficient = 0.88]. Agonist-preferring NMDA receptors localized to brain regions expressing both NR2B mRNA and NR1- mRNA (NR1 splice variant lacking insert 1). NR2C mRNA was largely restricted to the cerebellar granule cell layer, a region that displays a unique pharmacological profile. NR2D mRNA localized exclusively to those diencephalic nuclei that have a fourth, distinct pharmacological profile (typified by the midline thalamic nuclei). The pharmacology of native NMDA receptors was compared to that of heteromeric NMDA receptors expressed in Xenopus oocytes (NR1/NR2A, NR1/NR2B, NR1/NR2C). The oocyte-expressed NR1/NR2A receptor displayed a higher affinity for antagonists and a slightly lower affinity for agonists than the NR1/NR2B receptor. These patterns are analogous to those found for radioligand binding to native receptors in the lateral thalamus and medial striatum, respectively. NMDA receptors in the lateral thalamus (with a high density of NR2A subunit mRNA) displayed higher affinity for antagonists and a lower affinity for agonists than did NMDA receptors of the medial striatum (a region rich in NR2B mRNA). Relative to the NR1/NR2A and NR1/NR2B receptors, oocyte-expressed NR1/NR2C receptors had a lower affinity specifically for both D-3-(2-carboxypiperazin-4-yl)-1-propenyl-1-phosphonic acid (D-CPPene) and homoquinolinate (HQ). This pattern was identical to that observed for cerebellar (NR2C-containing) versus forebrain (NR2A- and NR2B-containing) NMDA receptors. Taken together, the data in this report suggest that the four previously identified native NMDA receptor subtypes differ in their NR2 composition. Furthermore, the NR2 subunits significantly contribute to the anatomical and pharmacological diversity of NMDA receptor subtypes.

Reassessment of verbal and visual analog ratings in analgesic studies

The relative performance of three analgesic rating scales--visual pain analog, verbal pain intensity, and verbal pain relief--was assessed in clinical trials with 1,497 patients and a variety of pain models. The scales correlated strongly with one another, with inconsistent and generally minimal differences in sensitivity. Overall, the verbal relief scale tended to be slightly more sensitive than the pain analog rating, which in turn showed a small advantage over the verbal pain intensity assessment. When the scores derived from the categorized ratings 1 hour after drug dosing (generally the time of peak effect) were analyzed, there was little difference whether a parametric or nonparametric approach was taken. When the cumulative measures of overall effect over 6 hours were considered, however, the nonparametric approach was decidedly more powerful. There was a similar pattern when the analog scores were analyzed. This unanticipated finding appears to be due to the cumulative measures (from all three scales) being more skewed toward the lower end of their respective ranges than are the 1-hour scores. A composite efficacy variable was defined, incorporating data from the three primary scales; this measure was found to be generally comparable in sensitivity to the individual scales and may be useful as a global summary of response. While our investigation provides evidence that any of the ratings considered will accurately reflect analgesic response, the verbal relief scale was the most sensitive and might be the best choice if a single measure is desired.

Effects of placebo versus guanabenz on hypertensive out-patients

The objectives of this study were two-fold: (1) 1 4-week multicentre, randomized, double-blind efficacy comparison of placebo and guanabenz acetate, a new centrally acting antihypertensive drug, in 168 hypertensive out-patients and (2) a more accurate determination of the incidence of drug-related, non-specific side-effects. Both treatment groups were comparable: 68% female, 63% black, mean age 53 years; 57% mild, 32% moderate, 11% moderately severe hypertensives. Seventy-six placebo patients completed 4 weeks and had a mean supine diastolic blood pressure (SDBP) decrease from 105 to 101 mm Hg (p < 0.01). Seventy-nine guanabenz patients completing 4 weeks had a mean SDBP decrease from 104 to 92 mm Hg (p < 0.01). All of the placebo responses and 10/12 mm Hg of the guanabenz response occurred during Week 1. Clinically significant individual SDBP decreases occurred in thirty-one (41%) placebo and fifty-five (70%) guanabenz-treated patients (p < 0.01). Mean daily guanabenz dose was 24 mg. Drug-related biochemical or electrocardiographic abnormalities were absent. Side-effects of sedation and dry mouth were recorded two and three times more frequently, respectively, in guanabenz as compared to placebo patients. Side-effects usually occurred within Week 1 and diminished in incidence thereafter. Consequently, in these patients it appeared that: (1) guanabenz was an effective, well-tolerated drug, (2) placebo effects on efficacy were significant, occurred early and remained stable, and (3) placebo and guanabenz side-effects were mainly sedation and dry mouth.