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Dive into the research topics where D. Wayne Overby is active.

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Featured researches published by D. Wayne Overby.


Surgical Endoscopy and Other Interventional Techniques | 2010

SAGES guidelines for the clinical application of laparoscopic biliary tract surgery

D. Wayne Overby; Keith N. Apelgren; William Richardson; Robert D. Fanelli

Laparoscopic cholecystectomy (LC) has become the standard of care for patients requiring removal of the gallbladder. In 1992, a National Institutes of Health (NIH) consensus development conference concluded that ‘‘laparoscopic cholecystectomy provides a safe and effective treatment for most patients with symptomatic gallstones, laparoscopic cholecystectomy appears to have become the procedure of choice for many of these patients’’ [1]. The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) first offered guidelines for the clinical application of laparoscopic cholecystectomy in May 1990. These guidelines have peri- odically been updated, and the last guideline in November 2002 expanded the guidelines to include all laparoscopic biliary tract surgery. This document updates and replaces the previous guideline. The current recommendations are graded and linked to the evidence utilizing the definitions in Appendices 1 and 2.


Surgical Endoscopy and Other Interventional Techniques | 2009

Clinical application of laparoscopic bariatric surgery: an evidence-based review

Timothy M. Farrell; Stephen P. Haggerty; D. Wayne Overby; Geoffrey P. Kohn; William Richardson; Robert D. Fanelli

BackgroundApproximately one-third of U.S. adults are obese. Current evidence suggests that surgical therapies offer the morbidly obese the best hope for substantial and sustainable weight loss, with a resultant reduction in morbidity and mortality. Minimally invasive methods have altered the demand for bariatric procedures. However, no evidence-based clinical reviews yet exist to guide patients and surgeons in selecting the bariatric operation most applicable to a given situation.MethodsThis evidenced-based review is presented in conjunction with a clinical practice guideline developed by the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES). References were reviewed by the authors and graded as to the level of evidence. Recommendations were developed and qualified by the level of supporting evidence available at the time of the associated SAGES guideline publication. The guideline also was reviewed and co-endorsed by the American Society for Metabolic and Bariatric Surgery.ResultsBariatric surgery is the most effective treatment for severe obesity, producing durable weight loss, improvement of comorbid conditions, and longer life. Patient selection algorithms should favor individual risk–benefit considerations over traditional anthropometric and demographic limits. Bariatric care should be delivered within credentialed multidisciplinary systems. Roux-en-Y gastric bypass (RGB), adjustable gastric banding (AGB), and biliopancreatic diversion with duodenal switch (BPD + DS) are validated procedures that may be performed laparoscopically. Laparoscopic sleeve gastrectomy (LSG) also is a promising procedure. Comparative data find that procedures with more dramatic clinical benefits carry greater risks, and those offering greater safety and flexibility are associated with less reliable efficacy.ConclusionsLaparoscopic RGB, AGB, BPD + DS, and primary LSG have been proved effective. Currently, the choice of operation should be driven by patient and surgeon preferences, as well as by considerations regarding the relative importance placed on discrete outcomes.


Surgery | 2009

Recent trends in bariatric surgery case volume in the United States.

Geoffrey P. Kohn; Joseph A. Galanko; D. Wayne Overby; Timothy M. Farrell

BACKGROUND Reports of increasing bariatric surgery volumes have driven resource allocation by health care systems and device manufacturers. Professional organizations and third-party payers have embraced credentialing systems to limit frivolous expansion. The underlying data upon which these reports are based are disparate and derived from imperfect methodologies. We queried the Nationwide Inpatient Sample (NIS) using several established search strategies to validate the current understanding of bariatric trends. METHODS NIS search algorithms capture bariatric admissions by the presence of International Classification of Disease, Ninth-Revision, Clinical Modification (ICD-9-CM) codes for obesity and bariatric procedures, with varying levels of inclusiveness for related foregut procedure codes. We applied 1 novel and 4 established algorithms to NIS data sets from 1998 to 2006 to generate contemporary case-volume curves, and we supplemented our data with industry estimates of ambulatory surgery volumes. RESULTS From 1998 to 2003, the number of bariatric operations increased markedly by all search strategies. Since then, a greater variation was observed in case volume estimates but no evidence of continuing growth was identified, irrespective of the search protocol employed. CONCLUSION Bariatric procedures peaked in 2003 and have since plateaued. The estimation of case volumes is limited by deficiencies in data and nonuniform search criteria. These factors should be considered by surgeons, professional organizations, hospitals, and third-party payers when planning for the future.


Journal of The American College of Surgeons | 2010

High Case Volumes and Surgical Fellowships are Associated with Improved Outcomes for Bariatric Surgery Patients: A Justification of Current Credentialing Initiatives for Practice and Training

Geoffrey P. Kohn; Joseph A. Galanko; D. Wayne Overby; Timothy M. Farrell

BACKGROUND Recent years have seen the establishment of bariatric surgery credentialing processes, center-of-excellence programs, and fellowship training positions. The effects of center-of-excellence status and of the presence of training programs have not previously been examined. The objective of this study was to examine the effects of case volume, center-of-excellence status, and training programs on early outcomes of bariatric surgery. STUDY DESIGN Data were obtained from the Nationwide Inpatient Sample from 1998 to 2006. Quantification of patient comorbidities was made using the Charlson Index. Using logistic regression modeling, annual case volumes were analyzed for an association with each institutions center-of-excellence status and training program status. Risk-adjusted outcomes measures were calculated for these hospital-level parameters. RESULTS Data from 102,069 bariatric operations were obtained. Adjusting for comorbidities, greater bariatric case volume was associated with improvements in the incidence of total complications (odds ratio [OR] 0.99937 for each single case increase, p = 0.01), in-hospital mortality (OR 0.99717, p < 0.01), and most other complications. Hospitals with a Fellowship Council-affiliated gastrointestinal surgery training program were associated with risk-adjusted improvements in rates of splenectomy (OR 0.2853, p < 0.001) and bacterial pneumonias (OR 0.65898, p = 0.02). Center-of-excellence status, irrespective of the accrediting entity, had minimal independent association with outcomes. A surgical residency program had a varying association with outcomes. CONCLUSIONS The hypothesized positive volume-outcomes relationship of bariatric surgery is shown without arbitrarily categorizing hospitals to case volume groups, by analysis of volume as a continuous variable. Institutions with a dedicated fellowship training program have also been shown, in part, to be associated with improved outcomes. The concept of volume-dependent center-of-excellence programs is supported, although no independent association with the credentialing process is noted.


Obesity Surgery | 2009

Risk-group targeted inferior vena cava filter placement in gastric bypass patients.

D. Wayne Overby; Geoffrey P. Kohn; Mitchell A. Cahan; Robert G. Dixon; Joseph M. Stavas; Stephan Moll; Charles T. Burke; Karen J. Colton; Timothy M. Farrell

BackgroundDespite a growing body of evidence guiding appropriate perioperative thromboprophylaxis in the general population, few data direct strategies to reduce deep venous thrombosis (DVT) and pulmonary embolism (PE) in the morbidly obese. We have implemented a novel protocol for venous thromboembolism (VTE) risk stratification in Roux-en-Y gastric bypass (RYGB) candidates at our institution, which augments clinical assessment with screening for thrombophilias, to guide retrievable inferior vena cava (IVC) filter utilization.MethodsA retrospective review of prospectively collected data from patients who underwent primary RYGB between 2001 and 2008 at the University of North Carolina at Chapel Hill was completed. During that time, clinical assessment of VTE risk was amplified by focused plasma screening for common thrombophilias (factors VIII, IX, and XI, d-dimer, fibrinogen). Preoperative prophylactic IVC filters were offered to high-risk patients. The database was reviewed for perioperative DVTs, PEs, and filter-related complications.ResultsOf 330 patients, in 162 attempts, 160 had prophylactic IVC filters placed with four complications overall (2.47%). No patient had symptoms of PE during the planned 6-week filter period, though one had a PE occur immediately after filter removal (0.63%); in contrast, five of 170 patients (2.94%) without prophylactic IVC filters presented with symptomatic PE (p = 0.216). In total, 147 (91.88%) prophylactic filters were removed.ConclusionsRisk-group targeted prophylactic inferior vena cava filter placement prior to RYGB is safe with a trend towards reduced occurrence of PE.


Obesity Surgery | 2009

Prevalence of Thrombophilias in Patients Presenting for Bariatric Surgery

D. Wayne Overby; Geoffrey P. Kohn; Mitchell A. Cahan; Joseph A. Galanko; Karen J. Colton; Stephan Moll; Timothy M. Farrell

BackgroundThe rise in bariatric surgery has driven an increased number of complications from venous thromboembolism (VTE). Evidence supports obesity as an independent risk factor for VTE, but the specific derangements underlying the hypercoagulability of obesity are not well defined. To better characterize VTE risk for the purpose of tailoring prophylactic strategies, we developed a protocol for thrombophilia screening in patients presenting for bariatric surgery at our institution.MethodsBetween April 2004 and April 2006, 180 bariatric surgery candidates underwent serologic screening for inherited thrombophilias (Factor V-Leiden mutation, low Protein C activity, low Protein S activity, Free Protein S deficiency) and acquired thrombophilias (D-Dimer elevation, Fibrinogen elevation, elevation of coagulation factors VIII, IX, and XI, elevation of Lupus anticoagulants and homocysteine level, and Antithrombin III deficiency). Prevalence rate of each thrombophilia in the subject group was compared to the actual prevalence rate of the general population.ResultsMost plasma markers of both inherited and acquired thrombophilias were identified in higher than expected proportions, including D-Dimer elevation in 31%, Fibrinogen elevation in 40%, Factor VIII elevation in 50%, Factor IX elevation in 64%, Factor XI elevation in 50%, and Lupus anticoagulant in 13%.ConclusionsObesity is a well-described demographic risk factor for VTE. In bariatric surgery candidates routinely screened for serologic markers, both inherited and acquired thrombophilias occurred more frequently than in the general population, and may therefore prove to be useful for individualized VTE risk assessment and prophylaxis.


Surgical Innovation | 2011

Treatment Options and Outcomes for Celiac Artery Compression Syndrome

Geoffrey P. Kohn; Raghid S. Bitar; Mark A. Farber; William A. Marston; D. Wayne Overby; Timothy M. Farrell

Background. Abdominal pain attributed to compression of the celiac artery at the level of the median arcuate ligament (MAL) of the diaphragm is an uncommon disorder. Although ultrasound investigation and arteriography can be suggestive of the diagnosis, no definitive criteria exist with only cases reports in the literature. This study presents the only known reported case series in which a combination of open and laparoscopic access techniques of MAL decompression are reported. Methods. A retrospective review of prospectively collected electronic databases of the University of North Carolina at Chapel Hill was performed for the period February 1999 until February 2009. Patients having undergone operation for celiac artery compression syndrome were identified and participated in a telephone interview. Questions were asked about the success of the operation, the recovery period, and patient satisfaction. Results. Six patients were identified, 3 were male; mean age was 37.7 years. Four underwent open MAL division and celiac ganglion neurolysis, and 2 underwent a laparoscopic approach. Mean follow-up was 48.6 months. All patients experienced symptomatic improvement and were satisfied with their outcome. No patient had symptoms recurrence. Conclusion. In this limited experience, MAL division with celiac ganglion neurolysis appears to be an effective treatment for celiac artery compression syndrome in appropriately selected patients. Both the open and laparoscopic approaches are safe with durable midterm follow-up results.


Surgery for Obesity and Related Diseases | 2014

Inferior vena cava filters and postoperative outcomes in patients undergoing bariatric surgery: a meta-analysis

Roop Kaw; Vinay Pasupuleti; D. Wayne Overby; Abhishek Deshpande; Craig I Coleman; John P. A. Ioannidis; Adrian V. Hernandez

Background: Pulmonary embolism(PE)accounts for almost 40% of perioperative deaths after bariatric surgery.Placement of prophylactic inferior vena cava(IVC) filter before bariatric surgery to improve outcomes has shown varied results. We performed a meta-analysis to evaluate post- operative outcomes associated with the preoperative placement of IVC filters in these patients. Methods: A systematic review was conducted by three investigators independently in PubMed, EMBASE, the Web of Science and Scopus until February 28,2013.Our search was restricted to studies in adult patients undergoing bariatric surgery with and without IVC filters. Primary outcomes were postoperative deep vein thrombosis(DVT),pulmonary embolism (PE),and postoperative mortality. Meta-analysis used random effects models to account for heterogeneity,and Sidik- Jonkman method to account for scarcity of outcomes and studies. Associations are shown as Relative Risks(RR) and 95% Confidence Intervals(CI). Results: Seven observational studies were identified (n=102,767), with weighted average inci- dences of DVT(0.9%),PE(1.6%),and mortality(1.0%)for a follow-up ranging from 3 weeks to 3 months. Use of IVC filters was associated with an approximately 3-fold higher risk of DVT and death that was nominally significant for the former outcome, but not the latter (RR2.81,95%CI 1.33-5.97, p=0.007; and RR 3.27,95%CI0.78-13.64, p=0.1, respectively);there was no difference in the risk of PE(RR1.02,95%CI0.31-3.77,p=0.9). Moderate to high heterogeneity of effects was noted across studies. Conclusions: Placement of IVC filter before bariatric surgery Is associated with higher risk of postoperative DVT and mortality. A similar risk of PE inpatients with and without IVC filter placement cannot exclude a benefit, given the potential large imbalance in risk at baseline.Ran- domized trials are needed before IVC placement can be recommended. (SurgObesRelatDis 2015;11:268-269.) r 2015 American Society for Metabolic and Bariatric Surgery.


Journal of Psychosomatic Research | 2013

Binge eating, body mass index, and gastrointestinal symptoms

Christine M. Peat; Lu Huang; Laura M. Thornton; Ann Von Holle; Sara E. Trace; Paul Lichtenstein; Nancy L. Pedersen; D. Wayne Overby; Cynthia M. Bulik

OBJECTIVE Symptoms of both gastroesophageal reflux disease (GERD) and irritable bowel syndrome (IBS) are frequently reported by individuals who binge eat. Higher body mass index (BMI) has also been associated with these disorders and with binge eating (BE). However, it is unknown whether BE influences GERD/IBS and how BMI might affect these associations. Thus, we examined the potential associations among BE, GERD, IBS, and BMI. METHODS Participants were from the Swedish Twin study of Adults: Genes and Environment (STAGE) and provided information on disordered eating behavior, BMI, gastrointestinal (GI) disorders, and commonly comorbid psychiatric and somatic illnesses. Key features of GERD and IBS were identified to create modified definitions of both disorders that were used as primary outcome variables. Logistic regression models were applied to determine the association between BE and each GERD/IBS both independently and in the context of BMI and other commonly comorbid psychiatric and somatic morbidities. RESULTS Prevalence estimates for GERD and IBS were higher among women than men (all p-values<.001). Only the association between BE and IBS was significant in both men and women after adjustment for BMI and the psychiatric/somatic morbidities. CONCLUSION BE appears to be an important consideration in the presence of IBS symptoms in both men and women, even when considering the impact of BMI and other commonly comorbid conditions. This association underscores the importance of routine assessment of BE in patients presenting with IBS to effectively manage the concurrent presentation of these problems.


Surgery for Obesity and Related Diseases | 2014

Choledocholithiasis after gastric bypass: a growing problem

D. Wayne Overby; William Richardson; Robert D. Fanelli

Q4 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 In their manuscript, DuCoin et al. address an important and growing problem, namely, access to and treatment of common bile duct stones in patients with Roux-en-Y reconstructions. Roux-en-Y gastric bypass (RYGB) comprises half of all weight loss procedures performed in the United States [1]. Given the current rate of approximately 100,000–200,000 bariatric procedures/year, an additional 500,000 to 1 million Americans/decade, who are at higher-than-average risk for symptomatic gallstones, will have access to their biliary trees complicated by surgically altered anatomy. The authors offer a single center’s experience with a laparoscopic approach to internal drainage for choledocholithiasis after gastric bypass. While their approach represents an interesting option, it is not likely to be the first choice for treatment of choledocholithiasis in Roux-en-Y patients by a majority of surgeons. There has been a national trend away from open or laparoscopic common bile duct exploration, and there has been an increase in the use of endoscopic retrograde cholangiopancreatography (ERCP) for treatment of choledocholithiasis. It is becoming more difficult to train new surgeons to perform common bile duct exploration and for practicing surgeons and their operating room staff to remain facile with it. In addition, surgeons are performing fewer intraoperative cholangiograms, lessening their ability to define biliary anatomy and guard against bile duct injury during cholecystectomy. The steadily increasing numbers of patients with difficult biliary access only adds to the necessity for increasing the experience general surgeons have with routine bile duct imaging, biliary anatomy, and performance of routine biliary surgery including common bile duct exploration. In the meantime, it is likely that the majority of surgeons will continue to rely on treatments offered by medical and surgical endoscopists for most bile duct stones, or to consider referral to a hepatobiliary surgeon for those not

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Timothy M. Farrell

University of North Carolina at Chapel Hill

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Geoffrey P. Kohn

University of North Carolina at Chapel Hill

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Joseph A. Galanko

University of North Carolina at Chapel Hill

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Karen J. Colton

University of North Carolina at Chapel Hill

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Craig I Coleman

University of Connecticut

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Joseph M. Stavas

University of North Carolina at Chapel Hill

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