Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


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

Publication


Featured researches published by Michael J. Bourke.


Gastroenterology | 2011

Endoscopic mucosal resection outcomes and prediction of submucosal cancer from advanced colonic mucosal neoplasia.

Alan Moss; Michael J. Bourke; Stephen J. Williams; Luke F. Hourigan; Gregor J. Brown; William Tam; Rajvinder Singh; Simon A. Zanati; Robert Chen; Karen Byth

BACKGROUND & AIMS Large sessile colonic polyps usually are managed surgically, with significant morbidity and potential mortality. There have been few prospective, intention-to-treat, multicenter studies of endoscopic mucosal resection (EMR). We investigated whether endoscopic criteria can predict invasive disease and direct the optimal treatment strategy. METHODS The Australian Colonic Endoscopic (ACE) resection study group conducted a prospective, multicenter, observational study of all patients referred for EMR of sessile colorectal polyps that were 20 mm or greater in size (n=479, mean age, 68.5 y; mean lesion size, 35.6 mm). We analyzed data on lesion characteristics and procedural, clinical, and histologic outcomes. Multiple logistic regression analysis identified independent predictors of EMR efficacy and recurrence of adenoma, based on findings from follow-up colonoscopy examinations. RESULTS Risk factors for submucosal invasion were as follows: Paris classification 0-IIa+c morphology, nongranular surface, and Kudo pit pattern type V. The most commonly observed lesion (0-IIa granular) had a low rate of submucosal invasion (1.4%). EMR was effective at completely removing the polyp in a single session in 89.2% of patients; risk factors for lack of efficacy included a prior attempt at EMR (odds ratio [OR], 3.8; 95% confidence interval, 1.77-7.94; P=.001) and ileocecal valve involvement (OR, 3.4; 95% confidence interval, 1.20-9.52; P=.021). Independent predictors of recurrence after effective EMR were lesion size greater than 40 mm (OR, 4.37; 95% confidence interval, 2.43-7.88; P<.001) and use of argon plasma coagulation (OR, 3.51; 95% confidence interval, 1.69-7.27; P=.0017). There were no deaths from EMR; 83.7% of patients avoided surgery. CONCLUSIONS Large sessile colonic polyps can be managed safely and effectively by endoscopy. Endoscopic assessment identifies lesions at increased risk of containing submucosal cancer. The first EMR is an important determinant of patient outcome-a previous attempt is a significant risk factor for lack of efficacy.


Gut | 2015

Long-term adenoma recurrence following wide-field endoscopic mucosal resection (WF-EMR) for advanced colonic mucosal neoplasia is infrequent: results and risk factors in 1000 cases from the Australian Colonic EMR (ACE) study

Alan Moss; Stephen J. Williams; Luke F. Hourigan; Gregor J. Brown; William Tam; Rajvinder Singh; Simon A. Zanati; Nicholas G. Burgess; Rebecca Sonson; Karen Byth; Michael J. Bourke

Objective Wide-field endoscopic mucosal resection (WF-EMR) is an alternative to surgery for treatment of advanced colonic mucosal neoplasia up to 120 mm in size, but has been criticised for its potentially high recurrence rates. We aimed to quantify recurrence at 4 months (early) and 16 months (late) following successful WF-EMR and identify its risk factors and clinical significance. Design Ongoing multicentre, prospective, intention-to-treat analysis of sessile or laterally spreading colonic lesions ≥20 mm in size referred for WF-EMR to seven academic endoscopy units. Surveillance colonoscopy (SC) was performed 4 months (SC1) and 16 months (SC2) after WF-EMR, with photographic documentation and biopsy of the scar. Results 1134 consecutive patients were enrolled when 1000 successful EMRs were achieved, of whom 799 have undergone SC1. 670 were normal. Early recurrent/residual adenoma was present in 128 (16.0%, 95% CI 13.6% to 18.7%). One case was unknown. The recurrent/residual adenoma was diminutive in 71.7% of cases. On multivariable analysis, risk factors were lesion size >40 mm, use of argon plasma coagulation and intraprocedural bleeding. Of 670 with normal SC1, 426 have undergone SC2, with late recurrence present in 17 cases (4.0%, 95% CI 2.4% to 6.2%). Overall, recurrent/residual adenoma was successfully treated endoscopically in 135 of 145 cases (93.1%, 95% CI 88.1% to 96.4%). If the initial EMR was deemed successful and did not contain submucosal invasion requiring surgery, 98.1% (95% CI 96.6% to 99.0%) were adenoma-free and had avoided surgery at 16 months following EMR. Conclusions Following colonic WF-EMR, early recurrent/residual adenoma occurs in 16%, and is usually unifocal and diminutive. Risk factors were identified. Late recurrence occurs in 4%. Overall, recurrence was managed endoscopically in 93% of cases. Recurrence is not a significant clinical problem following WF-EMR, as with strict colonoscopic surveillance, it can be managed endoscopically with high success rates. Trial registration number: NCT01368289.


The American Journal of Gastroenterology | 2006

Argon plasma coagulation in the management of symptomatic gastrointestinal vascular lesions: experience in 100 consecutive patients with long-term follow-up.

Kwan; Michael J. Bourke; Stephen J. Williams; Peter E. Gillespie; Murray Ma; Arthur J. Kaffes; Henriquez Ms; Chan Ro

BACKGROUND:The long-term efficacy of argon plasma coagulation (APC) in the management of gastrointestinal vascular lesions has not been evaluated in a large and well-defined series. The impact of APC on transfusion requirements and hemoglobin, and technical parameters including complications and number of treatment sessions, is assessed in this series.METHODS:Patients who underwent APC for bleeding gastrointestinal vascular lesions were identified via interrogation of an established endoscopic database, excluding patients with radiation proctitis, tumors, residual polypectomy tissue and acute ulcer bleeding. Follow-up data were collected via interview with patients and referring doctors, review of medical records, and follow-up blood tests.RESULTS:One hundred patients were enrolled, males = 46, median age = 74 yr (range: 19–99 yr). Median follow-up time was 16 months (range: 4–47 months). Lesions treated were arteriovenous malformations (n = 74) and gastric antral vascular ectasia (n = 26). Fifty-three patients required transfusion. In this group, median hemoglobin improved from 66 g/L (range: 35–114) to 111 g/L (range: 55–155, p < 0.001). Median transfusion velocity fell from 2 units/month (range: 0.1–6) to 0 units/month (range: 0–4, p < 0.001). Transfusion requirement was abolished in 77%. In non-transfusion-requiring patients, median hemoglobin improved from 105 g/L (range: 58–143) to 123 g/L (range: 79–158, p < 0.001). No complications occurred.CONCLUSIONS:APC is effective and safe in the management of gastrointestinal vascular lesions.


Endoscopy | 2008

A prospective randomized trial of cannulation technique in ERCP: effects on technical success and post-ERCP pancreatitis

A. A. Bailey; Michael J. Bourke; Stephen J. Williams; P. R. Walsh; M. A. Murray; Eric Y. Lee; Vu Kwan; P. M. Lynch

BACKGROUND AND STUDY AIMS Inadvertent injection of contrast agent into the pancreatic duct is believed to be an important contributor to pancreatitis occurring after endoscopic retrograde cholangiopancreatography (post-ERCP pancreatitis, PEP). Our aim was to examine whether primary deep biliary cannulation with a guide wire is associated with a lower rate of PEP than conventional contrast-assisted cannulation. PATIENTS AND METHODS From August 2003 to April 2006 all patients with an intact papilla who were referred for ERCP were eligible. Patients with pancreatic or ampullary cancer were excluded. Patients were randomized to undergo sphincterotomy biliary cannulation using either contrast injection or a guide wire. The ERCP fellow attempted initially for 5 minutes. If unsuccessful, the consultant attempted for 5 minutes using the same technique, followed by crossover to the other technique in the same sequence and then needle-knife sphincterotomy where appropriate. Patients were assessed clinically after the procedure, then followed up with telephone interviews after 24 hours and 30 days, and serum amylase and lipase tests after 24 hours. RESULTS Out of 1654 patients undergoing ERCP, 413 were included in the study. PEP occurred in 29/413 (7.0 %): 16 in the guide-wire arm, 13 in the contrast arm ( P = 0.48). The overall cannulation success rate was 97.3 %. Cannulation was successful without crossover in 323/413 patients (78.2 %): 167/202 (81.4 %) in the guide-wire arm and 156/211 (73.9 %) in the contrast arm ( P = 0.03). Multivariate analysis demonstrated female sex (OR = 2.7, P = 0.04), suspected sphincter of Oddi dysfunction (OR = 5.5, P = 0.01), and complete filling of the pancreatic duct with contrast agent (OR = 3.5, P = 0.02) to be independently associated with PEP. The risk of PEP increased incrementally with each attempt at the papilla (OR 1.4 per attempt, P = 0.04) to greater than 10 % after four or more attempts. CONCLUSIONS The guide-wire technique improves the primary success rate for biliary cannulation during ERCP but does not reduce the incidence of PEP compared to the conventional contrast technique. The incidence of PEP increases incrementally with each attempt at the papilla.


The American Journal of Gastroenterology | 2010

Endoscopic Resection for Barrett's High-Grade Dysplasia and Early Esophageal Adenocarcinoma: An Essential Staging Procedure With Long-Term Therapeutic Benefit

Alan C. Moss; Michael J. Bourke; Luke F. Hourigan; Saurabh Gupta; Stephen J. Williams; Kayla Tran; Michael P. Swan; Andrew Hopper; Vu Kwan; Adam A Bailey

OBJECTIVES: Patients with Barretts high‐grade dysplasia (HGD) or early esophageal adenocarcinoma (EAC) that is shown on biopsy alone continue to undergo esophagectomy without more definitive histological staging. Endoscopic resection (ER) may provide more accurate histological grading and local tumor (T) staging, definitive therapy, and complete Barretts excision (CBE); however, long‐term outcome data are limited. Our objective was to demonstrate the effect on histological grade or local T stage, efficacy, safety and long‐term outcome of ER for Barretts HGD/EAC and of CBE in suitable patients. METHODS: This prospective study at two Australian academic hospitals involved 75 consecutive patients over 7 years undergoing ER for biopsy‐proven HGD or EAC, using multiband mucosectomy or cap technique. In addition, CBE by 2–3‐stage radical mucosectomy was attempted for all Barretts segments ≤3 cm in length in patients aged <75 years with minimal comorbidities. RESULTS: Biopsy histology showed HGD in 89% of patients and EAC in 11%. However, ER histology resulted in altered grading or staging in 48% of patients (down 28%, up 20%), with HGD in 53%, low‐grade dysplasia (LGD) in 19%, mucosal adenocarcinoma in 13%, submucosal adenocarcinoma in 9%, and no dysplasia in 4% of patients. The CBE success rate was 94%. Complications were one aspiration (hospitalization with full recovery) and six strictures successfully dilated endoscopically. During the mean follow‐up of 31 months (range 3–89), there was no recurrence at ER sites, 11% developed metachronous lesions and five patients underwent esophagectomy for ER‐demonstrated submucosal invasion. Esophagectomy specimens were T0N0M0 in three and T1N0M0 in two patients. There were no deaths due to adenocarcinoma. CONCLUSIONS: ER alters histological grade or local T stage in 48% of patients and dramatically reduces esophagectomy rates by providing safe and effective therapy. ER has a high success rate (94%) for CBE in short segment Barretts esophagus.


Gastrointestinal Endoscopy | 2009

Large refractory colonic polyps: is it time to change our practice? A prospective study of the clinical and economic impact of a tertiary referral colonic mucosal resection and polypectomy service (with videos)

Michael P. Swan; Michael J. Bourke; Sina Alexander; Alan C. Moss; Stephen J. Williams

BACKGROUND Patients who have large, difficult, colorectal lesions not readily amenable to endoscopic resection are often referred directly to surgery. The application of advanced polypectomy and endoscopic mucosal resection (EMR) techniques undertaken by a tertiary referral colonic mucosal resection and polypectomy service (TRCPS) is not often considered but may be superior to surgery. OBJECTIVE To evaluate the safety, efficacy, and cost savings of a TRCPS for colorectal lesions. DESIGN Prospective intention-to-treat analysis. SETTING Tertiary academic referral center. PATIENTS In a 21-month period ending in April 2008, consecutive patients with large or complex colorectal polyps referred by other specialist endoscopists were prospectively enrolled on an intention-to-treat basis. INTERVENTION For sessile lesions, a standardized EMR approach was used. Pedunculated lesions were removed with or without pretreatment with an Endoloop procedure. MAIN OUTCOME MEASUREMENTS Complete resection, complications, recurrence, and potential cost savings comparing actual outcome of the cohort with a hypothetical analysis of surgical management. RESULTS This study included 174 patients (mean age 68 years) who were referred with 193 difficult polyps (186 laterally spreading, mean size 30 mm [range 10-80 mm]). We totally excised 173 laterally spreading lesions by EMR (115 piecemeal, 58 en bloc). Invasive adenocarcinoma was found in 6 lesions-5 treated successfully with EMR. Eleven patients were referred directly to surgery without an endoscopic attempt due to suspected invasive carcinoma. Seven >30-mm, pedunculated polyps were removed. There were no perforations. A total of 20 bed days was used because of endoscopic complications. Among all patients referred, 90% avoided the need for surgery. Excluding patients who were treated surgically for invasive cancer, the procedural success was 95% (157 of 168). By using Australian cost estimates applied to the entire group and compared with cost estimates assuming all patients had undergone surgery, we calculated the total medical cost savings was


Gastrointestinal Endoscopy | 2005

Impact of endoscopic intervention in 100 patients with suspected postcholecystectomy bile leak.

Arthur J. Kaffes; Luke F. Hourigan; Nicolas De Luca; Karen Byth; Stephen J. Williams; Michael J. Bourke

6990 (U.S.) per patient, or a total savings of


Endoscopy | 2011

Factors that predict bleeding following endoscopic mucosal resection of large colonic lesions.

A. J. Metz; Michael J. Bourke; Alan C. Moss; Stephen J. Williams; Michael P. Swan; Karen Byth

1,216,231 (U.S.). LIMITATION Not a randomized trial. CONCLUSIONS Colonoscopic polypectomy performed by a TRCPS on large or difficult polyps is technically effective and safe. This approach results in major cost savings and avoids the potential complications of colonic surgery. This type of clinical pathway should be developed to enhance patient outcomes and reduce health care costs.


Gastroenterology | 2014

Successful management of benign biliary strictures with fully covered self-expanding metal stents.

Jacques Devière; D. Nageshwar Reddy; Andreas Püspök; Thierry Ponchon; Marco J. Bruno; Michael J. Bourke; Horst Neuhaus; André G. Roy; Ferrán González-Huix Lladó; Alan N. Barkun; Paul P. Kortan; Claudio Navarrete; Joyce Peetermans; Daniel Blero; Sundeep Lakhtakia; Werner Dolak; Vincent Lepilliez; Jan Werner Poley; Andrea Tringali; Guido Costamagna

BACKGROUND Bile leak is a recognized complication of cholecystectomy. Endoscopic intervention is widely accepted as a treatment for this complication, but the optimal form is not well defined. METHODS An ERCP database was reviewed retrospectively to identify all cases of bile leak related to cholecystectomy. Patient records and endoscopy reports were reviewed, and structured telephone interviews were conducted to collect data. RESULTS A total of 100 patients (61 women, 39 men; mean age, 53 [17] years) with suspected postcholecystectomy bile leak were referred for ERCP. Cholecystectomy was commenced laparoscopically in 83 patients (with an open conversion rate of 30%). The most common symptoms were pain (n = 62) and fever (n = 37). Cholangiography was obtained in 96 patients. A leak was identified in 80/96 patients, the most common site being the cystic-duct stump (48), followed by ducts of Luschka (15), the T-tube site (7), and other sites (10). Treatment included stent insertion alone (40), sphincterotomy alone (18), combination stent/sphincterotomy (31), none (6), and other (1). Three patients with major bile-duct injuries were excluded from the analysis. Endoscopic therapy was unsuccessful in 7 patients (6 in the sphincterotomy alone group; p = 0.001). Four patients underwent surgery subsequent to ERCP to control the leak. All 4 were in the sphincterotomy alone group ( p = 0.001). Post-ERCP pancreatitis developed in 4 patients (3 mild, 1 moderate). CONCLUSIONS The optimal endoscopic intervention for postcholecystectomy bile leak should include temporary insertion of a biliary stent.


Gastrointestinal Endoscopy | 2011

The target sign: an endoscopic marker for the resection of the muscularis propria and potential perforation during colonic endoscopic mucosal resection

Michael P. Swan; Michael J. Bourke; Alan C. Moss; Stephen J. Williams; Andrew Hopper; Andrew J. Metz

BACKGROUND AND STUDY AIMS Endoscopic mucosal resection (EMR) for large colonic laterally spreading tumors (LSTs) is a safe, efficacious, and cost-effective treatment. The most common serious complication is delayed bleeding, which reduces these advantages, but consensus guidelines for large-polyp EMR do not exist. PATIENTS AND METHODS Data from two large prospective intention-to-treat studies of EMR for colonic LSTs 20 mm or greater in size were analyzed. Data collection was comprehensive, and included patient and lesion characteristics. EMR technique and cessation of anticoagulant and antiplatelet therapy was standardized. Clinically significant delayed bleeding was defined as that requiring hospital admission. RESULTS EMR was performed on 302 lesions in 288 patients. There was clinically significant delayed bleeding in 21 cases (7 %). Ten underwent colonoscopy. One required angiography. One required surgery after perforation following hemostatic clip placement. There were no deaths. Risk factors for bleeding on multivariate analysis were right colon location [adjusted odds ratio (OR) 4.4, P = 0.01], use of aspirin (OR 6.3, P = 0.005), and age (OR per decade of age 1.70). All bleeds occurred before aspirin was restarted. Patient characteristics, including ASA grade and co-morbidity type, were not predictive. Despite requiring more complex EMR, larger lesion size ( P = 0.2), multiple excisions rather than en bloc resection ( P = 0.1), polyp morphology ( P = 0.2), and previous attempts ( P = 0.5), were not associated with increased risk. CONCLUSIONS Proximal lesion location is a highly significant risk for clinically significant delayed bleeding following colonic EMR, and this knowledge could form the basis of a targeted therapeutic trial. Recent aspirin use also increases bleeding risk--specific consensus guidelines in this area are required for colonic EMR.

Collaboration


Dive into the Michael J. Bourke's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Luke F. Hourigan

Princess Alexandra Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Alan C. Moss

Beth Israel Deaconess Medical Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge