Cardiovascular evaluation and management of severely obese patients undergoing surgery: a science advisory from the American Heart Association.

Obesity is associated with comorbidities that may lead to disability and death. During the past 20 years, the number of individuals with a body mass index >30, 40, and 50 kg/m(2), respectively, has doubled, quadrupled, and quintupled in the United States. The risk of developing comorbid conditions rises with increasing body mass index. Possible cardiac symptoms such as exertional dyspnea and lower-extremity edema occur commonly and are nonspecific in obesity. The physical examination and electrocardiogram often underestimate cardiac dysfunction in obese patients. The risk of an adverse perioperative cardiac event in obese patients is related to the nature and severity of their underlying heart disease, associated comorbidities, and the type of surgery. Severe obesity has not been associated with increased mortality in patients undergoing cardiac surgery but has been associated with an increased length of hospital stay and with a greater likelihood of renal failure and prolonged assisted ventilation. Comorbidities that influence the preoperative cardiac risk assessment of severely obese patients include the presence of atherosclerotic cardiovascular disease, heart failure, systemic hypertension, pulmonary hypertension related to sleep apnea and hypoventilation, cardiac arrhythmias (primarily atrial fibrillation), and deep vein thrombosis. When preoperatively evaluating risk for surgery, the clinician should consider age, gender, cardiorespiratory fitness, electrolyte disorders, and heart failure as independent predictors for surgical morbidity and mortality. An obesity surgery mortality score for gastric bypass has also been proposed. Given the high prevalence of severely obese patients, this scientific advisory was developed to provide cardiologists, surgeons, anesthesiologists, and other healthcare professionals with recommendations for the preoperative cardiovascular evaluation, intraoperative and perioperative management, and postoperative cardiovascular care of this increasingly prevalent patient population.

Validation that a 1-year fellowship in minimally invasive and bariatric surgery can eliminate the learning curve for laparoscopic gastric bypass.

BACKGROUND: The concept that advanced surgical training can reduce or eliminate the learning curve for complex procedures makes logical sense but is difficult to verify and has not been tested for laparoscopic Roux-en-Y gastric bypass (LRYGB). We sought to determine if minimally invasive/bariatric surgery fellowship graduates (FGs) would demonstrate complication-related outcomes (CRO) equivalent to the outcomes achieved during their training experience under the supervision of experienced bariatric surgeons. METHODS: We compared CRO for the first 100 consecutive LRYGBs performed in practice by five consecutive minimally invasive/bariatric fellows at new institutions (total 500 cases) to CRO for the 611 consecutive LRYGBs performed during their fellowship training experience under the supervision of three experienced bariatric surgeons at the host training institution. RESULTS: The two patient groups did not differ demographically. The 18 types of major and minor complications identified after LRYGB did not differ among the five fellowship graduates. The mentors' CRO were compatible with published benchmark data. As compared with the training institution data, the overall incidence of complications for the combined experience of fellowship graduates did not differ statistically from that of the mentors. The fellowship graduates' early experience included zero non-gastrojejunostomy leaks (0% versus 1.5%) and a low rate of anastomotic stricture (0.8% versus 3.0%), incisional hernia (1% versus 4.4%), bowel obstruction (0% versus 3%), wound infection (0.3% versus 3.1%), and gastrointestinal hemorrhage (0.2% versus 1.6%). The rate of gastrojejunostomy leak (1.8% versus 2.6%) and, most importantly, mortality (0.8% versus 0.7%) did not differ between the two groups. CONCLUSIONS: Fellowship graduates achieved high-quality surgical outcomes from the very beginning of their post-fellowship practices, which are comparable to those of their experienced mentors. These data validate the concept that advanced surgical training can eliminate the learning curve often associated with complex minimally invasive procedures, specifically LRYGB.

Does diabetes affect weight loss after gastric bypass?

BACKGROUND: Weight loss in diabetics improves glycemic control. We investigated whether diabetes mellitus (DM) adversely affects postgastric bypass weight loss. METHODS: Our database was queried for the demographics and outcomes of patients with and without DM who had undergone gastric bypass surgery. DM was subdivided by severity: diet-controlled, oral hypoglycemic agents, and insulin. RESULTS: Of the 3193 patients, 655 (20%) had DM. The DM group was older (45.8 +/- 10.4 yr versus 39.1 +/- 9.9 yr, P <.0001), with more co-morbidities: hypertension (70.5% versus 44.2%, P <.0001), sleep apnea (36.7% versus 26.1%, P <.0001), and venous stasis (5.6% versus 2.6%, P <.0001). More men had DM (25.6% versus 19.3%, P = .0006). The age-adjusted, preoperative weight, and body mass index were equal. A direct relationship was found between DM severity and age, weight, and co-morbidities. At 1 year, the DM group had a lower percentage of excess weight loss (60.8% +/- 16.6% versus 67.6% +/- 16.7%, P <.0001) and greater body mass index (34.2 +/- 7.1 kg/m(2) versus 32.3 +/- 7.2 kg/m(2), P <.0001). The percentage of excess weight loss was 67.6% for those without DM, 63.5% for those with diet-controlled DM, 60.5% for those with DM controlled by oral hypoglycemic agents, and 57.5% for those requiring insulin. DM resolved in 89.8% of those with diet-controlled DM, 82.7% of those taking oral hypoglycemic medication, and 53.3% of those requiring insulin. Hypertension resolution was greatest in patients without DM (74.4% versus 63.5%, P <.0001). CONCLUSION: The results of our study have shown that those with DM typically have more co-morbidities, despite having no difference in preoperative weight compared with those without DM. Despite the lower weight loss, those with DM had significant resolution of their DM and hypertension and should not be deterred from undergoing gastric bypass surgery.

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical Practice for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient.

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical Practice are systematically developed statements to assist healthcare professionals in medical decision making for specific clinical conditions. Most of the content herein is based on literature reviews. In areas of uncertainty, professional judgment was applied. These guidelines are a working document that reflects the state of the field at the time of publication. Because rapid changes in this area are expected, periodic revisions are inevitable. We encourage medical professionals to use this information in conjunction with their best clinical judgment. The presented recommendations may not be appropriate in all situations. Any decision by practitioners to apply these guidelines must be made in light of local resources and individual patient circumstances. The American Society for Parenteral & Enteral Nutrition fully endorses sections of these guidelines that address the metabolic and nutritional management of the bariatric surgical patient.

Pulmonary embolism complicating bariatric surgery: detailed analysis of a single institution's 24-year experience.

BACKGROUND: Morbidly obese patients undergoing bariatric procedures are at risk for pulmonary embolism (PE). Because large series are required to analyze low-incidence complications, factors predictive of PE have not been clearly defined. Since 1992, short-course heparin prophylaxis, beginning immediately before operation, has been used in this center. STUDY DESIGN: Prospective data on 3,861 patients undergoing bariatric procedures between 1980 and 2004 were queried. Factors analyzed included age, gender, body mass index, interval between procedure and PE, inpatient versus outpatient status, mortality, access method (open versus laparoscopic), and comorbidities. RESULTS: PE within 60 days of operation occurred in 33 patients (23 women, 10 men), for an incidence of 0.85%. No difference in incidence was noted between open (0.84%) and laparoscopic (0.88%) groups, nor did routine prophylaxis with heparin since 1992 decrease the incidence. The interval between procedure and PE was 13.2+/-2.6 (mean +/- SEM) days (open=13.0+/-3.0 days, laparoscopic 14.1+/-6.49 days, p=0.9). One-third of PEs occurred after hospital discharge. Pulmonary embolism-related mortality was 27%. A statistically greater body mass index was noted in PE patients compared with non-PE patients (57.2+/-2.4 kg.m(2) versus 49.9+/-0.2 kg/m(2), p < 0.01, Wilcoxon rank test). Multivariate logistic regression confirmed a primary role for preoperative weight as a predictor of PE; univariate analysis suggested an increased PE risk with obesity hypoventilation syndrome, anastomotic leak, and chronic venous insufficiency. CONCLUSIONS: Data demonstrated persistence of PE risk in the anticoagulation, laparoscopic-access era at a rate similar to that in the preanticoagulation, open-access era. Because one-third of PEs occur after hospital discharge, consideration should be given to continuing anticoagulants longer and to adopting a more aggressive policy of inferior vena cava filter prophylaxis, particularly in patients with high body mass index, obese hyperventilation syndrome, and venous insufficiency.

Meta-analysis: surgical treatment of obesity.

BACKGROUND: Controversy exists regarding the effectiveness of surgery for weight loss and the resulting improvement in health-related outcomes. PURPOSE: To perform a meta-analysis of effectiveness and adverse events associated with surgical treatment of obesity. DATA SOURCES: MEDLINE, EMBASE, Cochrane Controlled Trials Register, and systematic reviews. STUDY SELECTION: Randomized, controlled trials; observational studies; and case series reporting on surgical treatment of obesity. DATA EXTRACTION: Information about study design, procedure, population, comorbid conditions, and adverse events. DATA SYNTHESIS: The authors assessed 147 studies. Of these, 89 contributed to the weight loss analysis, 134 contributed to the mortality analysis, and 128 contributed to the complications analysis. The authors identified 1 large, matched cohort analysis that reported greater weight loss with surgery than with medical treatment in individuals with an average body mass index (BMI) of 40 kg/m2 or greater. Surgery resulted in a weight loss of 20 to 30 kg, which was maintained for up to 10 years and was accompanied by improvements in some comorbid conditions. For BMIs of 35 to 39 kg/m2, data from case series strongly support superiority of surgery but cannot be considered conclusive. Gastric bypass procedures result in more weight loss than gastroplasty. Bariatric procedures in current use (gastric bypass, laparoscopic adjustable gastric band, vertical banded gastroplasty, and biliopancreatic diversion and switch) have been performed with an overall mortality rate of less than 1%. Adverse events occur in about 20% of cases. A laparoscopic approach results in fewer wound complications than an open approach. LIMITATIONS: Only a few controlled trials were available for analysis. Heterogeneity was seen among studies, and publication bias is possible. CONCLUSIONS: Surgery is more effective than nonsurgical treatment for weight loss and control of some comorbid conditions in patients with a BMI of 40 kg/m2 or greater. More data are needed to determine the efficacy of surgery relative to nonsurgical therapy for less severely obese people. Procedures differ in efficacy and incidence of complications.

Surgical management of obesity: a review of the evidence relating to the health benefits and risks.

Obesity continues to plague our society in epidemic proportions. Surgery for morbid obesity is considered by many as the most effective therapy for this complex disorder. Today, multiple surgical procedures for the treatment of obesity are available. As with most procedures, there are benefits and risks associated with open and laparoscopic gastric bypass surgery, as well as with laparoscopic adjustable gastric banding and partial biliopancreatic bypass with a duodenal switch. The risks and complications associated with bariatric surgery may be serious and in some cases life threatening. However, surgery for obesity has shown remarkable results in helping patients to achieve significant long-term weight control. In addition, it is associated with improvement and often resolution of co-morbid conditions, including type 2 diabetes mellitus, systemic hypertension, obesity hypoventilation, sleep apnea, venous stasis disease, pseudotumor cerebri, polycystic ovary syndrome, complications of pregnancy and delivery, gastroesophageal reflux disease, stress urinary incontinence, degenerative joint disease, and non-alcoholic steatohepatitis.

Lap-band failures: conversion to gastric bypass and their preliminary outcomes.

BACKGROUND: The LAP-BAND is designed to be an adjustable laparoscopically placed gastric restriction device for the treatment of severe obesity. The purpose of this study was to assess the outcome in patients who had failed to effectively lose weight with this device and were converted to a gastric bypass. METHODS: A retrospective chart review was performed of all LAP-BANDS placed in patients at our institution from March 1996 to June 1998. RESULTS: 36 LAP-BANDS were placed. To date, 18 of 36 (50%) have been removed. Fourteen of 18 were simultaneously converted to a gastric bypass. Indications for conversion included: failed weight loss (5), failed weight loss with esophageal dilatation (5), failed weight loss with leaking band (2), and symptomatic esophageal dilatation (1). Median time to conversion after LAP-BAND placement was 38.2 months. Median follow-up after conversion to gastric bypass was 8.3 months. Nineteen percent excess weight loss occurred after LAP-BAND placement. Forty-three percent excess weight loss occurred after conversion to gastric bypass (P =.025). CONCLUSIONS: In our experience, the LAP-BAND is associated with a high frequency of inadequate weight loss. Conversion to gastric bypass in this subset of patients is technically challenging but results in superior weight loss in a shorter time period.

Bariatric surgery for severely obese adolescents.

A 1991 National Institutes of Health Consensus Conference concluded that severely obese adults could be eligible for bariatric surgery if they had a body mass index (BMI) > or =35 kg/m(2) with or > or =40 kg/m(2) without obesity comorbidity. It was thought at that time that there were inadequate data to support bariatric surgery in severely obese adolescents. An estimated 25% of children in the United States are obese, a number that has doubled over a 30-year period. Very little information has been published on the subject of obesity surgery in adolescents. Therefore we reviewed our 20-year database on bariatric surgery in adolescents. Severely obese adolescents, ranging from 12 to less than 18 years of age, were considered eligible for bariatric surgery according to the National Institutes of Health adult criteria. Gastroplasty was the procedure of choice in the initial 3 years of the study followed by gastric bypass, which was found to be significantly more effective for weight loss in adults. Distal gastric bypass (D-GBP) was used in extremely obese patients (BMI > or =60 kg/m(2)) before 1992 and long-limb gastric bypass (LL-GBP) was used for superobese patients (BMI > or =50 kg/m(2)) after 1992. Laparoscopic gastric bypass was used after 2000. Thirty-three adolescents (27 white, 6 black; 19 females, 14 males) underwent the following bariatric operations between 1981 and June 2001: horizontal gastroplasty in one, vertical banded gastroplasty in two, standard gastric bypass in 17 (2 laparoscopic), LL-GBP in 10, and D-GBP in three. Mean BMI was 52 +/- 11 kg/m(2) (range 38 to 91 kg/m(2)), and mean age was 16 +/- 1 years (range 12.4 to 17.9 years). Preoperative comorbid conditions included the following: type II diabetes mellitus in two patients, hypertension in 11, pseudotumor cerebri in three, gastroesophageal reflux in five, sleep apnea in six, urinary incontinence in two, polycystic ovary syndrome in one, asthma in one, and degenerative joint disease in 11. There were no operative deaths or anastomotic leaks. Early complications included pulmonary embolism in one patient, major wound infection in one, minor wound infections in four, stomal stenoses (endoscopically dilated) in three, and marginal ulcers (medically treated) in four. Late complications included small bowel obstruction in one and incisional hernias in six patients. There were two late sudden deaths (2 years and 6 years postoperatively), but these were unlikely to have been caused by the bariatric surgical procedure. Revision procedures included one D-GBP to gastric bypass for malnutrition and one gastric bypass to LL-GBP for inadequate weight loss. Regain of most or all of the lost weight was seen in five patients at 5 to 10 years after surgery; however, significant weight loss was maintained in the remaining patients for up to 14 years after surgery. Comorbid conditions resolved at 1 year with the exception of hypertension in two patients, gastroesophageal reflux in two, and degenerative joint disease in seven. Self-image was greatly enhanced; eight patients have married and have children, five patients have completed college, and one patient is currently in college. Severe obesity is increasing rapidly in adolescents and is associated with significant comorbidity and social stigmatization. Bariatric surgery in adolescents is safe and is associated with significant weight loss, correction of obesity comorbidity, and improved self-image and socialization. These data strongly support obesity surgery for those unfortunate individuals who may have difficulty obtaining insurance coverage based on the 1991 National Institutes of Health Consensus Conference statement.

Impact of self-reported physical activity participation on proportion of excess weight loss and BMI among gastric bypass surgery patients.

Habitual physical activity is an important component of successful weight loss programs for morbidly obese individuals. This study examined self-reported physical activity (PA) participation in relation to excess weight loss and body mass index (BMI) reduction among gastric bypass surgery patients (GBS). PA participation was hypothesized to contribute to both greater excess weight loss (% EWL) and a greater reduction in BMI at 2 years postsurgery. PA participation was measured via self-report among 1585 GBS patients between 1988 and 2001. GBS patients were assigned to groups [PA (n = 1479)/no PA (n = 106)] and further stratified by presurgical BMI [35-49 kg/m2 (n = 897) and 50-70 kg/m2 (n = 688)]. Findings showed that GBS patients who reported PA participation were younger [P < 0.0001, PA (40.1 +/- 9.9) vs no PA (44.2 +/- 11.2)], had greater % EWL [P = 0.0081, PA (68.2 +/- 17.4%) vs no PA (63.9 +/- 19.5%)], and a greater decrease in BMI [P = 0.0011, PA (18.3 +/- 5.7 kg/m2) vs no PA (16.6 +/- 5.4 kg/m2)]. When stratified by presurgical BMI, only physically active patients with a BMI of 50-70 kg/m2 showed an increase in % EWL [P = 0.0444, PA (63.2 +/- 16.5) vs no PA (57.9 +/- 17.3)], whereas both BMI groups showed significant reductions in BMI at 2 years [BMI of 35-49 kg/m2 P = 0.0184, PA (16.0 +/- 4.0 kg/m2) vs no PA (14.4 +/- 4.0 kg/m2); and BMI of 50-70 kg/m2 P = 0.0221, PA (21.50 +/- 6.0 kg/m2) vs no PA (19.7 +/- 5.5 kg/m2)], respectively. PA had a favorable effect on % EWL and BMI among GBS patients at 2 years postsurgery, thus supporting the inclusion of habitual PA in a comprehensive GBS postsurgical weight maintenance program.

Type 2 diabetes after gastric bypass: remission in five models using HbA1c, fasting blood glucose, and medication status.

BACKGROUND: The remission rates of type 2 diabetes mellitus (T2DM) after Roux-en-Y gastric bypass (RYGB) vary according to the glycosylated hemoglobin A1c (HbA1c), fasting blood glucose (FG), and medication status. Our objectives were to describe remission using the American Diabetes Association standards for defining normoglycemia and to identify the factors related to the preoperative severity of T2DM that predict remission to normoglycemia, independent of weight loss, after RYGB. The setting was an urban not-for-profit community hospital. METHODS: We performed a retrospective analysis of prospectively collected data from a cohort of 2275 patients who qualified for bariatric surgery (2001-2008). Five different models for defining remission (no diabetes medication and a FG <100 mg/dL; no diabetes medication and HbA1c <6.0; no diabetes medication and HbA1c <5.7%; no diabetes medication, FG <100 mg/dL, and HbA1c <6.0%; and no diabetes medication, FG <100 mg/dL, and HbA1c <5.7%) were compared in 505 obese patients with T2DM 14 months after RYGB. The secondary aims were to determine the effects of preoperative insulin therapy and the duration of known T2DM on remission. RESULTS: Of the 505 patients, 43.2% achieved remission using the most stringent criteria (no diabetes medication, HbA1c <5.7%, and FG <100 mg/dL) compared with 59.4% using the most liberal definition (no diabetes medication and FG <100 mg/dL; P < .001). The remission rates were greater for patients not taking insulin preoperatively (53.8% versus 13.5%, P < .001) and for patients with a more recent preoperative T2DM diagnosis (8.9 versus 3.7 yr, P < .001). CONCLUSION: Remission, defined at a threshold less than what would be expected to result in microvascular damage, was achieved in 43.2% of diabetic patients by 14 months after RYGB. A more recent diagnosis of T2DM and the absence of preoperative insulin therapy were significant predictors, regardless of how remission was defined, independent of the percentage of excess weight loss.

Hypothesis: preeclampsia is a venous disease secondary to an increased intra-abdominal pressure.

It is hypothesized that in some women an excessively high intra-abdominal pressure (IAP) compresses the inferior vena cava, uterine veins, portal vein, hepatic veins, splenic vein and renal veins which lead to a decreased flow in these vascular beds, producing lower extremity edema, fetal-placental ischemia, a glomerulopathy with proteinuria and hypertension, hepatic ischemia and thrombocytopenia, increased uric acid, and hemolysis/elevated liver enzymes/low platelet known as the HELLP syndrome. There can be variability in the expression of these components. Placental-fetal ischemia could lead to expression of soluble fms-like tyrosine kinase1 (sFLT) and endoglin which have been shown to cause additional diffuse endovascular damage. A further increase in IAP pushes the diaphragm cephalad, increasing intrathoracic pressure leading to upper extremity edema, decreased internal jugular venous flow, cerebral vascular engorgement, raised intracranial pressure, and if unresolved, seizures. Placental/fetal ischemia and hepatic ischemic necrosis may lead to diffuse inflammation and a septic inflammatory response syndrome (SIRS) which may become a vicious cycle, perpetuating the ischemia. It is further hypothesized that application of an externally applied negative abdominal pressure device will lower IAP and possibly reverse the pathophysiology of preeclampsia. As the abnormal placental proteins develop weeks before clinical preeclampsia, early application of external negative abdominal pressure may prevent development of the syndrome.