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Dive into the research topics where Michael J. Phelan is active.

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Featured researches published by Michael J. Phelan.


Surgery for Obesity and Related Diseases | 2014

Impact of accreditation in bariatric surgery

Alana Gebhart; Monica Young; Michael J. Phelan; Ninh T. Nguyen

BACKGROUND Several studies have shown improved outcomes associated with accredited bariatric centers. The aim of our study was to examine the outcomes of bariatric surgery performed at accredited versus nonaccredited centers using a nationally representative database. Additionally, we aimed to determine if the presence of bariatric surgery accreditation could lead to improved outcomes for morbidly obese patients undergoing other general laparoscopic operations. METHODS Using the Nationwide Inpatient Sample database, for data between 2008 and 2010, clinical data of morbidly obese patients who underwent bariatric surgery, laparoscopic antireflux surgery, cholecystectomy, and colectomy were analyzed according to the hospitals bariatric accreditation status. RESULTS A total of 277,068 bariatric operations were performed during the 3-year period, with 88.4% of cases performed at accredited centers. In-hospital mortality was significantly lower at accredited compared to nonaccredited centers (.08% versus .19%, respectively). Multivariate analysis showed that nonaccredited centers had higher risk-adjusted mortality for bariatric procedures compared to accredited centers (odds ratio [OR] 3.1, P<.01). Post hoc analysis showed improved mortality for patients who underwent gastric bypass and sleeve gastrectomy at accredited centers compared to nonaccredited centers (.09% versus .27%, respectively, P<.01). Patients with a high severity of illness who underwent bariatric surgery also had lower mortality rates when the surgery was performed at accredited versus nonaccredited centers (.17% versus .45%, respectively, P<.01). Multivariate analysis showed that morbidly obese patients who underwent laparoscopic cholecystectomy (OR 2.4, P<.05) and antireflux surgery (OR 2.03, P<.01) at nonaccredited centers had higher rates of serious complications. CONCLUSION Accreditation in bariatric surgery was associated with more than a 3-fold reduction in risk-adjusted in-hospital mortality. Resources established for bariatric surgery accreditation may have the secondary benefit of improving outcomes for morbidly obese patients undergoing general laparoscopic operations.


Annals of Surgery | 2013

A decade analysis of trends and outcomes of partial versus total esophagectomy in the United States.

Jafari; Wissam J. Halabi; Brian R. Smith; Vinh Q. Nguyen; Michael J. Phelan; Michael J. Stamos; Ninh T. Nguyen

Objective:To examine the trends and outcomes of partial esophagectomy with an intrathoracic anastomosis compared with total esophagectomy with a cervical anastomosis. Background:Controversy exists regarding the optimal surgical approach in the management of esophageal cancer. Methods:Using the Nationwide Inpatient Sample database, yearly trends of patients with esophageal cancer who underwent partial and total esophagectomy were analyzed. Multivariate logistic regression analysis was used to analyze serious morbidity and in-hospital mortality between partial and total esophagectomy. In addition, outcomes were analyzed according to hospital volume, with low-volume centers defined as those with fewer than 10 cases per year and high-volume centers as those with 10 or more cases per year. Results:Between 2001 and 2010, 15,190 esophagectomies were performed for cancer. There was an overall increase in the number of esophagectomy procedures performed (1402 to 1975), with a concomitant reduction in the mortality rate (8.3% to 4.2%), particularly for partial esophagectomy. Partial esophagectomy was the predominant operation (76%). Most operations were performed at low-volume centers (62%), with a recent shift of cases to high-volume center. Compared with total esophagectomy, partial esophagectomy was associated with a shorter length of hospital stay (16 ± 6 vs 19 ± 9 days; P < 0.05), a lower in-hospital mortality rate (5.8% vs 8.3%; P < 0.05), and a lower hospital charge (


Diseases of The Colon & Rectum | 2015

Outcomes of open, laparoscopic, and robotic abdominoperineal resections in patients with rectal cancer

Zhobin Moghadamyeghaneh; Michael J. Phelan; Brian R. Smith; Michael J. Stamos

119,339 vs


Journal of Alzheimer's Disease | 2017

Down Syndrome, Partial Trisomy 21, and Absence of Alzheimer’s Disease: The Role of APP

Eric Doran; David B. Keator; Elizabeth Head; Michael J. Phelan; Ron Kim; Minodora Totoiu; Jorge R. Barrio; Gary W. Small; Steven G. Potkin; Ira T. Lott

138,496; P < 0.05). On multivariate regression analysis, total esophagectomy was associated with higher serious morbidity (odds ratio, 1.39; P < 0.01) and in-hospital mortality (odds ratio, 1.67; P = 0.03). There were no significant differences in risk-adjusted outcomes between low-volume centers and high-volume center. Conclusions:The number of esophagectomies performed for esophageal cancer has increased over the past decade accompanied by an overall reduction in mortality, particularly for the partial esophagectomy approach. The predominant operation in the United States continues to be partial esophagectomy with an intrathoracic anastomosis, which was associated with lower morbidity and in-hospital mortality than total esophagectomy. Hospital volume at a threshold of 10 cases per year was not a predictor of outcome.


Journal of The American College of Surgeons | 2016

A Decade Analysis of Trends and Outcomes of Male vs Female Patients Who Underwent Bariatric Surgery.

Monica T. Young; Michael J. Phelan; Ninh T. Nguyen

BACKGROUND: There are limited available data comparing open, laparoscopic, and robotic approaches for rectal cancer surgery. OBJECTIVE: We sought to investigate outcomes of different surgical approaches to abdominoperineal resection in patients with rectal cancer. DESIGN: The nationwide inpatient sample database was used to examine the clinical data of patients with rectal cancer who underwent elective abdominoperineal resection between 2009 and 2012 in the United States. Multivariate regression analysis was performed to compare outcomes of different surgical approaches. SETTINGS: A retrospective review according to the national inpatient sample database was designed. PATIENTS: We included patients with rectal cancer who underwent elective abdominoperineal resection between 2009 and 2012. MAIN OUTCOME MEASURES: Outcomes of different surgical approaches to abdominoperineal resection were investigated. RESULTS: We sampled 18,359 patients with rectal cancer who underwent elective abdominoperineal resections. Of these, 69.5% had open surgery, 25.8% had laparoscopic surgery, and 4.7% had robotic surgery. The rate of robotic procedures increased >4-fold, from 2.1% to 8.1%, from 2009 to 2012. The conversion rate in robotic surgery was significantly lower compared with laparoscopic surgery (5.7% vs 13.4%; p < 0.01). After risk adjustment, patients who underwent laparoscopic and robotic approaches had lower morbidity risks compared with those who underwent the open approach (adjusted OR = 0.77 (95% CI, 0.65–0.92), 0.57 (95% CI, 0.40–0.80); p < 0. 01). There were no significant differences in the morbidity rate of patients who underwent laparoscopic or robotic approaches (adjusted OR = 0.79 (95% CI, 0.55–1.14); p = 0.21). However, patients who underwent the robotic approach had significantly higher total hospital charges compared with those who underwent the laparoscopic approach (mean difference,


Clinical Infectious Diseases | 2015

Impact of Hospital Population Case-Mix, Including Poverty, on Hospital All-Cause and Infection-Related 30-Day Readmission Rates

Shruti K. Gohil; Rupak Datta; Chenghua Cao; Michael J. Phelan; Vinh Q. Nguyen; Armaan A. Rowther; Susan S. Huang

24,890; p < 0.01). LIMITATIONS: We could not adjust the results with some important factors, such as the tumor stage and BMI. CONCLUSIONS: The use of robotic and laparoscopic approaches to abdominoperineal resection have increased between 2009 and 2012. Both minimally invasive approaches decrease morbidity rates of patients undergoing abdominoperineal resection. The robotic approach has a significantly lower conversion rate compared with the laparoscopic approach. However, it had significantly higher total hospital charges compared with the laparoscopic approach.


Experimental Neurology | 2015

A meta-analysis of efficacy in pre-clinical human stem cell therapies for traumatic brain injury

Janessa Chang; Michael J. Phelan; Brian J. Cummings

Overexpression of the amyloid precursor protein (APP) gene on chromosome 21 in Down syndrome (DS) has been linked to increased brain amyloid levels and early-onset Alzheimers disease (AD). An elderly man with phenotypic DS and partial trisomy of chromosome 21 (PT21) lacked triplication of APP affording an opportunity to study the role of this gene in the pathogenesis of dementia. Multidisciplinary studies between ages 66-72 years comprised neuropsychological testing, independent neurological exams, amyloid PET imaging with 11C-Pittsburgh compound-B (PiB), plasma amyloid-β (Aβ) measurements, and a brain autopsy examination. The clinical phenotype was typical for DS and his intellectual disability was mild in severity. His serial neuropsychological test scores showed less than a 3% decline as compared to high functioning individuals with DS who developed dementia wherein the scores declined 17-28% per year. No dementia was detected on neurological examinations. On PiB-PET scans, the patient with PT21 had lower PiB standard uptake values than controls with typical DS or sporadic AD. Plasma Aβ42 was lower than values for demented or non-demented adults with DS. Neuropathological findings showed only a single neuritic plaque and neurofibrillary degeneration consistent with normal aging but not AD. Taken together the findings in this rare patient with PT21 confirm the obligatory role of APP in the clinical, biochemical, and neuropathological findings of AD in DS.


Alzheimer Disease & Associated Disorders | 2016

Cognitive Profiles on the Severe Impairment Battery Are Similar in Alzheimer Disease and Down Syndrome With Dementia.

Malcolm B. Dick; Eric Doran; Michael J. Phelan; Ira T. Lott

BACKGROUND Male obesity rates are now estimated to be equal to female obesity rates. Despite this, men constitute a minority of patients undergoing bariatric surgery. The aim of this study was to examine the national trends and outcomes of bariatric surgery in male patients compared with female patients. STUDY DESIGN The Nationwide Inpatient Sample database was reviewed for obese patients undergoing bariatric surgery between 2002 and 2011. Outcomes were analyzed according to sex. Main outcomes measures were patient demographics, length of stay, risk-adjusted inpatient morbidity and mortality, and hospital charge. RESULTS During the 10-year period, 810,999 patients underwent bariatric surgery; 19.3% were male and 80.7% were female. The percentage of male patients increased from 15.4% in 2002 to 21.7% in 2011. Mean age was significantly older for males (46 ± 11 years vs 43 ± 11 years; p < 0.01, respectively). Male patients had a higher proportion of moderate, major, and extreme severity of illness classifications and higher rates of comorbid conditions. Serious morbidity was significantly higher in male patients compared with female patients (7.58% vs 5.42%; p < 0.01). Mean hospital length of stay was longer for male patients (2.75 vs 2.61 days; p < 0.01) with a higher mean hospital charge (


Journal of The American College of Surgeons | 2017

Randomized Clinical Trial of Epidural Compared with Conventional Analgesia after Minimally Invasive Colorectal Surgery

Mark H. Hanna; Mehraneh D. Jafari; Fariba Jafari; Michael J. Phelan; Joseph Rinehart; Coral Sun; Joseph C. Carmichael; Steven Mills; Michael J. Stamos; Alessio Pigazzi

38,682 vs


Infection Control and Hospital Epidemiology | 2015

Substantial Variation in Hospital Rankings after Adjusting for Hospital-Level Predictors of Publicly-Reported Hospital-Associated Clostridium difficile Infection Rates

Rupak Datta; N. Neely Kazerouni; Jon Rosenberg; Vinh Q. Nguyen; Michael J. Phelan; John Billimek; Chenghua Cao; Patricia McLendon; Kate C. Cummings; Susan S. Huang

34,294; p < 0.01). Compared with the female group, the male group had higher risk-adjusted in-hospital mortality (odds ratio = 2.16; 95% CI, 1.62-2.88; p < 0.01) and serious morbidity (odds ratio = 1.23; 95% CI, 1.17-1.29; p < 0.01). CONCLUSIONS The number of male patients undergoing bariatric surgery in the past decade continues to be a small fraction compared with the number of female patients. Men undergoing bariatric surgery tend to have higher severity of illness, with higher risk-adjusted serious morbidity and mortality rates. Additional studies are necessary to examine barriers in obtaining treatment for obese men.

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Steven Mills

University of California

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Ninh T. Nguyen

University of California

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Mark H. Hanna

University of California

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