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Dive into the research topics where Colin O'Rourke is active.

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Featured researches published by Colin O'Rourke.


Liver Transplantation | 2014

Sanguineous normothermic machine perfusion improves hemodynamics and biliary epithelial regeneration in donation after cardiac death porcine livers

Qiang Liu; Ahmed Nassar; Kevin Farias; Laura D. Buccini; William M. Baldwin; Martin Mangino; Ana E. Bennett; Colin O'Rourke; Toshiro Okamoto; Teresa Diago Uso; John J. Fung; Kareem Abu-Elmagd; Charles M. Miller; Cristiano Quintini

The effects of normothermic machine perfusion (NMP) on the postreperfusion hemodynamics and extrahepatic biliary duct histology of donation after cardiac death (DCD) livers after transplantation have not been addressed thoroughly and represent the objective of this study. Ten livers (5 per group) with 60 minutes of warm ischemia were preserved via cold storage (CS) or sanguineous NMP for 10 hours, and then they were reperfused for 24 hours with whole blood in an isolated perfusion system to simulate transplantation. In our experiment, the arterial and portal vein flows were stable in the NMP group during the entire reperfusion simulation, whereas they decreased dramatically in the CS group after 16 hours of reperfusion (P < 0.05); these findings were consistent with severe parenchymal injury. Similarly, significant differences existed between the CS and NMP groups with respect to the release of hepatocellular enzymes, the volume of bile produced, and the levels of enzymes released into bile (P < 0.05). According to histology, CS livers presented with diffuse hepatocyte congestion, necrosis, intraparenchymal hemorrhaging, denudated biliary epithelium, and submucosal bile duct necrosis, whereas NMP livers showed very mild injury to the liver parenchyma and biliary architecture. Most importantly, Ki‐67 staining in extrahepatic bile ducts showed biliary epithelial regeneration. In conclusion, our findings advance the knowledge of the postreperfusion events that characterize DCD livers and suggest NMP as a beneficial preservation modality that is able to improve biliary regeneration after a major ischemic event and may prevent the development of ischemic cholangiopathy in the setting of clinical transplantation. Liver Transpl 20:987–999, 2014.


Journal of Bone and Joint Surgery, American Volume | 2015

Chronic Suppression of Periprosthetic Joint Infections with Oral Antibiotics Increases Infection-Free Survivorship.

Marcelo B. P. Siqueira; Anas Saleh; Alison K. Klika; Colin O'Rourke; Steven K. Schmitt; Carlos A. Higuera; Wael K. Barsoum

BACKGROUND The clinical benefit of chronic suppression with oral antibiotics as a salvage treatment for periprosthetic joint infection is unclear. The purpose of this study was to compare infection-free prosthetic survival rates between patients who received chronic oral antibiotics and those who did not following irrigation and debridement with polyethylene exchange or two-stage revision for periprosthetic joint infection. METHODS We reviewed the records on all irrigation and debridement procedures with polyethylene exchange and two-stage revisions performed at our institution from 1996 to 2010 for hip or knee periprosthetic joint infection. Of 625 patients treated with a total of 655 eligible revisions, ninety-two received chronic oral antibiotics for a minimum of six months and were eligible for inclusion in our study. These patients were compared with a matched cohort (ratio of 1:3) who did not receive chronic oral antibiotics. RESULTS The five-year infection-free prosthetic survival rate was 68.5% (95% confidence interval [CI] = 59.2% to 79.3%) for the antibiotic-suppression group and 41.1% (95% CI = 34.9% to 48.5%) for the non-suppression group (hazard ratio [HR] = 0.63, p = 0.008). Stratification by the type of surgery and the infecting organism showed a higher five-year survival rate for the patients in the suppression group who underwent irrigation and debridement with polyethylene exchange (64.7%) compared with those in the non-suppression group who underwent irrigation and debridement with polyethylene exchange (30.4%, p < 0.0001) and a higher five-year survival rate for the patients in the suppression group who had a Staphylococcus aureus infection (57.4%) compared with those in the non-suppression group who had a Staphylococcus aureus infection (40.1%, p = 0.047). CONCLUSIONS Chronic suppression with oral antibiotics increased the infection-free prosthetic survival rate following surgical treatment for periprosthetic joint infection. Patients who underwent irrigation and debridement with polyethylene exchange and those who had a Staphylococcus aureus infection had the greatest benefit.


The Spine Journal | 2014

Differences in the surgical treatment of recurrent lumbar disc herniation among spine surgeons in the United States

Thomas E. Mroz; Daniel Lubelski; Seth K. Williams; Colin O'Rourke; Nancy A. Obuchowski; Jeffrey C. Wang; Michael P. Steinmetz; Alfred J. Melillo; Edward C. Benzel; Michael T. Modic; Robert M. Quencer

BACKGROUND CONTEXT There are often multiple surgical treatment options for a spinal pathology. In addition, there is a lack of data that define differences in surgical treatment among surgeons in the United States. PURPOSE To assess the surgical treatment patterns among neurologic and orthopedic spine surgeons in the United States for the treatment of one- and two-time recurrent lumbar disc herniation. STUDY DESIGN Electronic survey. PATIENT SAMPLE An electronic survey was delivered to 2,560 orthopedic and neurologic surgeons in the United States. OUTCOME MEASURES The response data were analyzed to assess the differences among respondents over various demographic variables. The probability of disagreement is reported for various surgeon subgroups. METHODS A survey of clinical and radiographic case scenarios that included a one- and two-time lumbar disc herniation was electronically delivered to 2,560 orthopedic and neurologic surgeons in the United States. The surgical treatment options were revision microdiscectomy, revision microdiscectomy with in situ fusion, revision microdiscectomy with posterolateral fusion using pedicle screws, revision microdiscectomy with posterior lumbar interbody fusion/transforaminal lumbar interbody fusion (PLIF/TLIF), anterior lumbar interbody fusion (ALIF) with percutaneous screws, ALIF with open posterior instrumentation, or none of these. Significance of p=.01 was used to account for multiple comparisons. RESULTS Four hundred forty-five surgeons (18%) completed the survey. Surgeons in practice for 15+ years were more likely to select revision microdiscectomy compared with surgeons with fewer years in practice who were more likely to select revision microdiscectomy with PLIF/TLIF (p<.001). Similarly, those surgeons performing 200+ surgeries per year were more likely to select revision microdiscectomy with PLIF/TLIF than those performing fewer surgeries (p=.003). No significant differences were identified for region, specialty, fellowship training, or practice type. Overall, there was a 69% and 22% probability that two randomly selected spine surgeons would disagree on the surgical treatment of two- and one-time recurrent disc herniations, respectively. This probability of disagreement was consistent over multiple variables including geographic, practice type, fellowship training, and annual case volume. CONCLUSIONS Significant differences exist among US spine surgeons in the surgical treatment of recurrent lumbar disc herniations. It will become increasingly important to understand the underlying reasons for these differences and to define the most cost-effective surgical strategies for these common lumbar pathologies as the United States moves closer to a value-based health-care system.


American Journal of Transplantation | 2016

Comparing Normothermic Machine Perfusion Preservation With Different Perfusates on Porcine Livers From Donors After Circulatory Death.

Qiang Liu; Ahmed Nassar; Kevin Farias; Laura D. Buccini; Martin Mangino; William M. Baldwin; Ana E. Bennett; Colin O'Rourke; Giuseppe Iuppa; Basem Soliman; D. Urcuyo-Llanes; Toshiro Okamoto; Teresa Diago Uso; John J. Fung; Kareem Abu-Elmagd; Charles M. Miller; Cristiano Quintini

The utilization of normothermic machine perfusion (NMP) may be an effective strategy to resuscitate livers from donation after circulatory death (DCD). There is no consensus regarding the efficacy of different perfusates on graft and bile duct viability. The aim of this study was to compare, in an NMP porcine DCD model, the preservation potential of three different perfusates. Twenty porcine livers with 60 min of warm ischemia were separated into four preservation groups: cold storage (CS), NMP with Steen solution (Steen; XVIVO Perfusion Inc., Denver, CO), Steen plus red blood cells (RBCs), or whole blood (WB). All livers were preserved for 10 h and reperfused to simulate transplantation for 24 h. During preservation, the NMP with Steen group presented the highest hepatocellular injury. At reperfusion, the CS group had the lowest bile production and the worst hepatocellular injury compared with all other groups, followed by NMP with Steen; the Steen plus RBC and WB groups presented the best functional and hepatocellular injury outcomes, with WB livers showing lower aspartate aminotransferase release and a trend toward better results for most parameters. Based on our results, a perfusate that contains an oxygen carrier is most effective in a model of NMP porcine DCD livers compared with Steen solution. Specifically, WB‐perfused livers showed a trend toward better outcomes compared with Steen plus RBCs.


Liver Transplantation | 2015

Impact of Donor Age in Liver Transplantation from Donation after Circulatory Death Donors: A Decade of Experience at Cleveland Clinic

Daniel J. Firl; Koji Hashimoto; Colin O'Rourke; Teresa Diago-Uso; Masato Fujiki; Federico Aucejo; Cristiano Quintini; Dympna Kelly; Charles M. Miller; John J. Fung; Bijan Eghtesad

The use of liver grafts from donation after circulatory death (DCD) donors remains controversial, particularly with donors of advanced age. This retrospective study investigated the impact of donor age in DCD liver transplantation. We examined 92 recipients who received DCD grafts and 92 matched recipients who received donation after brain death (DBD) grafts at Cleveland Clinic from January 2005 to June 2014. DCD grafts met stringent criteria to minimize risk factors in both donors and recipients. The 1‐, 3‐, and 5‐year graft survival in DCD recipients was significantly inferior to that in DBD recipients (82%, 71%, 66% versus 92%, 87%, 85%, respectively; P = 0.03). Six DCD recipients (7%), but no DBD recipients, experienced ischemic‐type biliary stricture (P = 0.01). However, the incidence of biliary stricture was not associated with donor age (P = 0.57). Interestingly, recipients receiving DCD grafts from donors who were <45 years of age (n = 55) showed similar graft survival rates compared to those receiving DCD grafts from donors who were ≥45 years of age (n = 37; 80%, 69%, 66% versus 83%, 72%, 66%, respectively; P = 0.67). Cox proportional hazards modeling in all study populations (n = 184) revealed advanced donor age (P = 0.05) and the use of a DCD graft (P = 0.03) as unfavorable factors for graft survival. Logistic regression analysis showed that the risk of DBD graft failure increased with increasing age, but the risk of DCD graft failure did not increase with increasing age (P = 0.13). In conclusion, these data suggest that stringent donor and recipient selection may ameliorate the negative impact of donor age in DCD liver transplantation. DCD grafts should not be discarded because of donor age, per se, and could help expand the donor pool for liver transplantation. Liver Transpl 21:1494‐1503, 2015.


Journal of The American College of Surgeons | 2014

Conservative Axillary Surgery in Breast Cancer Patients Undergoing Mastectomy: Long-Term Results

Michael S. Cowher; Stephen R. Grobmyer; Joanne Lyons; Colin O'Rourke; Deborah Baynes; Joseph P. Crowe

BACKGROUND Recently, the American College of Surgeons Oncology Group Z0011 trial demonstrated that axillary lymph node dissection (ALND) could be safely avoided in selected breast cancer patients with limited nodal disease and having breast conservation therapy. However, for node positive (N+) mastectomy patients, full ALND remains the standard of care. Hypothesizing that omission of complete ALND is safe in many N+ breast cancer patients, a hybrid procedure called conservative axillary regional excision (CARE) was developed, consisting of removal of sentinel nodes and other palpable nodes (without intraoperative frozen section or reoperation for N+). STUDY DESIGN A retrospective review of patients undergoing mastectomy with CARE between 2002 and 2010 was performed. Data collected included demographics; staging; number of lymph nodes removed; adjuvant, antihormonal, and radiation therapies; recurrence; lymphedema; and survival data. Recurrence-free survival was estimated using the Kaplan-Meier method and compared using Cox proportional hazards. RESULTS Five hundred and eighty-seven patients underwent mastectomy with CARE. Mean follow-up was 5.1 years. A median of 8 nodes were removed. There were 7 patients with local recurrence, of which 3 were axillary recurrences. Lymphedema developed in 20 (3.4%) patients, 75% of which had neoadjuvant chemotherapy. Lymphedema development was associated with the number of lymph nodes removed (p = 0.05) and radiation therapy (p = 0.004). CONCLUSIONS Conservative axillary regional excision is an excellent model for understanding the role of limited axillary surgery in mastectomy patients. The locoregional recurrence rate among N1 patients having CARE is low (3.4%). Conservative axillary regional excision is also associated with low rates of lymphedema. These data support the use of limited ALND in selected N+ mastectomy patients.


Hpb | 2015

Estimating the need for hepato-pancreatico-biliary surgeons in the USA

Noaman Ali; Colin O'Rourke; Kevin El-Hayek; Sricharan Chalikonda; D. Rohan Jeyarajah; R. Matthew Walsh

BACKGROUND Hepato-pancreatico-biliary (HPB) fellowship training has risen in popularity in recent years and hence large numbers of graduating fellows enter the workforce each year. Studies have proposed that the increase in HPB-trained surgeons will outgrow demand in the USA. This study shows that the need for HPB-trained surgeons refers not to the meeting of demand in terms of case volume, but to improving patient access to care. METHODS The National Inpatient Sample (NIS) database for the years 2005-2011 was queried for CPT codes relating to pancreatic, liver and biliary surgical cases. These numbered 6627 in 2005 and increased to 8515 in 2011. Cases were then mapped to corresponding states. The number of procedures in an individual state was divided by the total number of procedures to give a ratio for each state. A similar ratio was calculated for the population of each state to the national population. These ratios were combined to give a ratio by state of observed to expected HPB surgical cases. RESULTS Of the 46 states that participate in the NIS, only 18 achieved ratios of observed to expected cases of >1. In the remaining 28 states, the number of procedures was lower than that expected according to each states population. CONCLUSIONS The majority of the USA is underserved in terms of HPB surgery. Given the growing number of HPB-trained physicians entering the job market, this sector should focus on bringing understanding and management of complex disease to areas of the country that are currently in need.


Clinical Nurse Specialist | 2014

Capture of knowledge work of clinical nurse specialists using a role tracking tool

Jennifer P. Colwill; Colin O'Rourke; Lydia Booher; Marian Soat; Deborah Solomon; Nancy M. Albert

Purpose: The aim of this study was to quantify clinical nurse specialist (CNS) work and determine if competencies are associated with personal characteristics, priorities, and quality outcomes. Background: The work of a CNS is difficult to quantify. Nurse leaders need quantifiable data to understand the impact of CNS work. Design: A prospective, single-center, correlational study with a convenience sample was conducted. Setting and Sample: The study was conducted in a 1200-bed quaternary care medical center in Northeast Ohio, using CNSs. Methods: The investigator-developed Role Tracker Tool (software) and a CNS questionnaire were used to collect baseline and monthly data for 5 months. Characteristics of the CNSs were summarized using descriptive statistics. Correlational statistics were used to measure associations. After mutually exclusive groups were created, tests for differences were completed using a Welch 2-sample t test and analysis of variance. Regression models were used to determine if relationships existed over time between competencies, priority ranking of competencies, and nursing characteristics. Findings: Among 14 CNSs, mean (SD) age was 45 (10.11) years; mean (SD) CNS experience was 5.57 (7.87) years. Of 6 competencies, CNSs ranked quality as most important, followed by clinical work. Research ranked low. Mean (SD) time spent in hours/8.5-hour workday over 5 months was highest for clinical work, at 1.9 (1) hours, and lowest for professional self-development, at 0.4 (0.4) hours. Time spent on specific competencies varied by specialty, years as a CNS and at current employer, and comfort in competencies and spheres after controlling for nurse characteristics and monthly trends. Of 9 quality initiative focuses, mean (SD) time in hours/8.5-hour workday was highest for heart failure, with 0.7(0.8) hours. Time spent on quality initiatives was not associated with changes in quality improvement outcomes. Clinical nurse specialist competency priorities, quality initiative focuses, and quality outcomes varied over time. Implications: The work of CNSs can be captured and analyzed to enhance understanding of unique and varied CNS contributions in the healthcare matrix.


Jsls-journal of The Society of Laparoendoscopic Surgeons | 2015

Paraesophageal Hernia Repair With Partial Longitudinal Gastrectomy in Obese Patients.

Matthew Davis; John Rodriguez; Kevin El-Hayek; Stacy A. Brethauer; Phillip R. Schauer; Zelisko A; Bipan Chand; Colin O'Rourke; Matthew Kroh

Background and Objectives: Treatment of gastroesophageal reflux disease (GERD) with hiatal hernia in obese patients has proven difficult, as studies demonstrate poor symptom control and high failure rates in this patient population. Recent data have shown that incorporating weight loss procedures into the treatment of reflux may improve overall outcomes. Methods: We retrospectively reviewed 28 obese and morbidly obese patients who presented from December 2007 through July 2013 with large or recurrent type 3 or 4 paraesophageal hernia. All of the patients underwent combined paraesophageal hernia repair and partial longitudinal gastrectomy. Charts were retrospectively reviewed, and the patients were contacted to determine symptomatic relief. Results: Mean preoperative body mass index was 38.1 ± 4.9 kg/m2. Anatomic failure of prior fundoplication occurred in 7 patients (25%). The remaining 21 had primary paraesophageal hernia, 3 of which were type 4. Postoperative complications included pulmonary embolism (n = 1), pulmonary decompensation (n = 2), and wound infection (n = 1). Mean hospital stay was 5 ± 3 days. Upper gastrointestinal esophagogram was performed in 21 patients with no immediate recurrence or staple line dehiscence. Mean excess weight loss was 44 ± 25%. All of the patients surveyed experienced near to total resolution of their preoperative symptoms within the first month. At 1 year, symptom scores decreased significantly. At 27 months, however, there was a mild increase in the scores. Return of severe symptoms occurred in 2 patients, both of whom underwent conversion to gastric bypass. Conclusions: Combined laparoscopic paraesophageal hernia repair with longitudinal partial gastrectomy offers a safe, feasible approach to the management of large or recurrent paraesophageal hernia in well-selected obese and morbidly obese patients. Short-term results were promising; however, intermediate results showed increasing rates of reflux symptoms that required medical therapy or conversion to gastric bypass.


Epilepsy & Behavior | 2016

Severity of self-reported insomnia in adults with epilepsy is related to comorbid medical disorders and depressive symptoms

Kwang ik Yang; Madeleine M. Grigg-Damberger; Noah Andrews; Colin O'Rourke; Nancy Foldvary-Schaefer

BACKGROUND Few studies have systematically investigated insomnia in adults with epilepsy. METHODS We performed a prospective cross-sectional investigation of the prevalence, severity, and comorbidities of insomnia in 90 adults with epilepsy using a battery of self-reported instruments and polysomnography. We quantified insomnia severity using the Insomnia Severity Index (ISI). RESULTS Fifty-nine of 90 (65.5%) adults with epilepsy reported insomnia (ISI≥8), moderate or severe (ISI≥15) in 28.9%. Good agreement between standard clinical diagnostic criteria and ISI was found for patients with ISI scores <8 and ≥15. Scores on the modified Beck Depression Inventory (mBDI) (r=0.25, p=0.021), the original BDI (r=0.32, p=0.002), and self-reported total sleep duration (TSD) (r=-0.3, p=0.006) were significantly related to ISI score. A multiple regression model found that decreased TSD (ß=-0.93, p=0.007), head trauma (ß=4.37, p=0.003), sedative-hypnotic use (ß=4.86, p=0.002), AED polytherapy (ß=3.52, p=0.005), and asthma/COPD (ß=3.75, p=0.014) were predictors of a higher ISI score. For 63 patients with focal epilepsy, an increased mBDI (ß=0.24, p=0.015), decreased TSD (ß=-1.11, p=0.008), asthma/COPD (ß=4.19, p=0.02), and epilepsy surgery (ß=5.33, p=0.006) were significant predictors of an increased ISI score. Patients with temporal lobe epilepsy (TLE) showed a trend for greater severity compared with those with extra-TLE (ß=-2.92, p=0.054). CONCLUSIONS Our findings indicate that severity of insomnia in adults with epilepsy is more likely to be associated with comorbid medical and depressive symptoms and less likely to be directly related to epilepsy. Good agreement between standard clinical diagnostic criteria for insomnia and the ISI for subjects without insomnia symptoms and for those with moderate-to-severe symptoms supports the use of this instrument in epilepsy research.

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