Network


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

Hotspot


Dive into the research topics where D.A. Howell is active.

Publication


Featured researches published by D.A. Howell.


Gut | 1998

Management of occluded biliary Wallstents

T.C.K. Tham; David L. Carr-Locke; J. Vandervoort; R.C.K. Wong; D R Lichtenstein; J Van Dam; F Ruymann; S. Chow; John J. Bosco; T. Qaseem; D.A. Howell; Douglas K. Pleskow; W Vannerman; E D Libby

Background—Wallstents (Schneider Stent, Inc., USA) used for the palliation of malignant biliary strictures, although associated with prolonged patency, can occlude. There is no consensus regarding the optimal management of Wallstent occlusion. Aims—To evaluate the efficacy of different endoscopic methods for managing biliary Wallstent occlusion. Methods—A multicentre retrospective study of patients managed for a biliary Wallstent occlusion. Results—Data were available for 38 patients with 44 Wallstent occlusions, all of which had initial endoscopic management. Twenty four patients had died and 14 were alive after a median follow up of 231 (30–1095) days following Wallstent occlusion. Occlusions were managed by insertion of another Wallstent in 19, insertion of a plastic stent in 20, and mechanical cleaning in five. Endoscopic management was successful in 43 (98%). Following management of the occlusion, bilirubin decreased from 6.0 (0.5–34.3) to 2.1 (0.2–27.7) mg/100 ml (p<0.05). No complications occurred. The median duration of second stent patency was 75 days (95% confidence interval 43 to 107) after insertion of another Wallstent, 90 days (71 to 109) after insertion of a plastic stent, and 34 days (30 to 38) after mechanical cleaning (NS). The respective median survivals were 70 days (22–118), 98 days (54–142), and 34 days (30–380) (NS). Incremental cost effective analysis showed that plastic stent insertion is the most cost effective option. Conclusion—Although all three methods are equally effective in managing an occluded Wallstent, the most cost effective method appears to be plastic stent insertion.


Gastrointestinal Endoscopy Clinics of North America | 2003

New technology for endoscopic retrograde cholangiopancreatography: improving safety, success, and efficiency.

Richard J. Farrell; D.A. Howell; Douglas K. Pleskow

Known and documented factors attributable to ERCP-related complications include the experience and technique of the endoscopist as well as anatomic and pathologic factors pertaining to the papilla. In an effort to minimize trauma, facilitate deep entry to the biliary system, and improve the efficiency of therapeutic ERCP, new cannulation, sphincterotomy, and guide wire devices have been developed, based on principles of safe and successful therapeutic ERCP learned over the years. By totally re-engineering familiar accessories into smaller, more flexible, and more versatile devices, the 0.025-inch guide wire-based DASH system attempts to minimize the trauma at deep CBD cannulation and thereby increase the safety and success of achieving deep cannulation and sphincterotomy. Limited clinical experience to date suggests that the DASH system can provide full-function ERCP while reducing risks and costs. Attention to cannulation has led to the development of the RX Biliary System which provides the endoscopist and the assistant with increased control of the guide wire and exchange compared with traditional devices, resulting in less stress, less hand and wrist force used for contrast injection, and easier guide wire management, all of which have been shown in clinical trials to improve the speed and efficiency of ERCP while reducing complications.


Gastrointestinal Endoscopy | 1996

Management of occluded biliary wallstents

T.C.K. Tham; J. Vandervoort; R.C.K. Wong; David L. Carr-Locke; S. Chow; John J. Bosco; T. Qaseem; D.A. Howell; Douglas K. Pleskow; B. Vannemann

BACKGROUNDnWallstents (Schneider Stent, Inc., USA) used for the palliation of malignant biliary strictures, although associated with prolonged patency, can occlude. There is no consensus regarding the optimal management of Wallstent occlusion.nnnAIMSnTo evaluate the efficacy of different endoscopic methods for managing biliary Wallstent occlusion.nnnMETHODSnA multicentre retrospective study of patients managed for a biliary Wallstent occlusion.nnnRESULTSnData were available for 38 patients with 44 Wallstent occlusions, all of which had initial endoscopic management. Twenty four patients had died and 14 were alive after a median follow up of 231 (30-1095) days following Wallstent occlusion. Occlusions were managed by insertion of another Wallstent in 19, insertion of a plastic stent in 20, and mechanical cleaning in five. Endoscopic management was successful in 43 (98%). Following management of the occlusion, bilirubin decreased from 6.0 (0.5-34.3) to 2.1 (0.2-27.7) mg/100 ml (p < 0.05). No complications occurred. The median duration of second stent patency was 75 days (95% confidence interval 43 to 107) after insertion of another Wallstent, 90 days (71 to 109) after insertion of a plastic stent, and 34 days (30 to 38) after mechanical cleaning (NS). The respective median survivals were 70 days (22-118), 98 days (54-142), and 34 days (30-380) (NS). Incremental cost effective analysis showed that plastic stent insertion is the most cost effective option.nnnCONCLUSIONnAlthough all three methods are equally effective in managing an occluded Wallstent, the most cost effective method appears to be plastic stent insertion.


Gastrointestinal Endoscopy | 1996

Diagnostic and therapeutic ERCP using a push enteroscope in long limb surgical gastroenterostomy patients

D.A. Howell; T. Qaseem; Willis G. Parsons


Gastrointestinal Endoscopy | 1996

Needle knife papillotomy (NKP) without stent insertion for the difficult sphincterotomy (ES): A standardized technique explained

D.A. Howell; T. Qaseem; Brian L. Hanson; Willis G. Parsons; E. Elton; John J. Bosco


Gastrointestinal Endoscopy | 1997

Use of the side arm adapter (SAA) for modifying ERCP accessories: Increased success at a lower cost

D.A. Howell; E. Elton; T. Qaseem; Willis G. Parsons


Gastrointestinal Endoscopy | 1996

Safe and successful ERCP in the billroth II (B-II) gastroenterostomy patient: Impact of recent advances

T. Qaseem; D.A. Howell; Willis G. Parsons; John J. Bosco


Gastrointestinal Endoscopy | 1996

Endoscopic placement of gianturco-rosch z-stents for the treatment of malignant biliary obstruction

D.A. Howell; T. Qaseem; John J. Bosco; E. Elton; Willis G. Parsons


Gastrointestinal Endoscopy | 1995

Reducing overall endoscopic sphincterotomy (ES) complications: The impact of needle knife papillotomy (NKP)

D.A. Howell; Brian L. Hanson; Willis G. Parsons; John J. Bosco; T. Qaseem


Successful Training in Gastrointestinal Endoscopy | 2011

ERCP Management of Malignancy: Tissue Sampling, Metal Stent Placement and Ampullectomy

D.A. Howell

Collaboration


Dive into the D.A. Howell's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

T. Qaseem

University of New Mexico

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

E. Elton

Rush University Medical Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Douglas K. Pleskow

Beth Israel Deaconess Medical Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Richard J. Farrell

Beth Israel Deaconess Medical Center

View shared research outputs
Researchain Logo
Decentralizing Knowledge