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Biomedical subjects

P L Redmond

Publications and source records attributed to P L Redmond.

11 recordsLinked to original sources
PubMed2005

Optical forces between metallic particles.

We calculate the optical attractive forces that occur between 30-nm Au or Ag nanocrystals when irradiated at visible wavelengths. These forces show resonances at dipolar plasmon wavelengths, similar to resonances in the near-field electromagnetic intensities. At MW/cm2 intensities, optical forces can be stronger than van der Waals forces and could be used to organize metallic particles. We also suggest that photonucleation of organic crystals from supersaturated liquid solutions may be caused by optical forces.

Journal Article↗
PubMed1997

Suprapapillary fistulosphincterotomy at ERCP: a prospective study.

BACKGROUND AND STUDY AIMS: The role of the needle knife at endoscopic retrograde cholangiopancreatography (ERCP) remains controversial, with conflicting views being held on the value and safety of this device. The aim of the present study was to assess prospectively the value and safety of suprapapillary fistulosphincterotomy (FS) in the endoscopic management of biliary disease. PATIENTS AND METHODS: Suprapapillary fistulosphincterotomy was performed when biliary cannulation had failed after attempting to opacify the bile duct for 30 minutes, initially with a standard diagnostic cannula and then by further attempts with a tapered cannula. The second indication for suprapapillary fistulosphincterotomy was inability to obtain satisfactory cannulation with the sphincterotome in patients in whom cholangiopancreatography showed pathology requiring endoscopic sphincterotomy. Using this technique, an opening was created into the intraduodenal segment of the common bile duct at a point on the vertical axis 3-5 mm proximal to the papillary orifice. The opening was then cannulated, and extended as required to facilitate clearance of stones or stent insertion. RESULTS: Of 531 consecutive patients, 83 (16%) underwent suprapapillary fistulosphincterotomy, and biliary cannulation was achieved in 74 of the 83 (89%). If suprapapillary fistulosphincterotomy had not been used, the diagnostic success rate would have fallen from 513 out of 531 (97%) to 451 out of 531 (85%) (P = 0.0001); the clearance rate for duct stones would have fallen from 150 out of 156 (96%) to 130 out of 156 (83%) (P = 0.0003); and successful stent insertion would have fallen from 52 out of 59 (88%) to 38 out of 59 (64%) (P = 0.0044). There were no fatalities following suprapapillary fistulosphincterotomy. Complications occurred in five of the 83 patients (6%) who underwent fistulosphincterotomy, compared with five of the 448 patients (1%) who did not undergo the procedure (P = 0.01). CONCLUSIONS: Our results suggest that suprapapillary fistulosphincterotomy is a valuable adjunct in the management of biliary disease at ERCP, but, in view of the increased risk of complications, it should be reserved for patients in whom the index of suspicion for biliary disease is high and further endoscopic treatment is likely.

Adolescent↗
PubMed1991

Planned delayed nephrectomy after ethanol embolization of renal carcinoma.

Planned delayed nephrectomy after preoperative ethanol infarction was done in 6 patients with renal carcinoma. Three patients had intracaval extension of tumor, 2 had renal vein but no vena caval extension and 1 had no renal vein or vena caval involvement. Nephrectomy was delayed 22 to 44 days after embolization. In the patients with inferior vena caval extension shrinkage of tumor thrombus after embolization allowed for easier surgical resection. Furthermore, delay of nephrectomy after preoperative infarction was of value in improving the clinical status of high risk patients.

Adult↗
PubMed1988

Embolization of an intrahepatic arterioportal fistula: case report and review of the literature.

An intrahepatic arterioportal fistula causing portal hypertension was successfully palliated with steel coils. The patient remains well 2 1/2 years after embolization. The 13 previously reported cases of transcatheter embolization of large intrahepatic arterioportal fistulae are reviewed. Percutaneous transcatheter embolization with suitable embolic material should be preferred to surgery in the treatment of these fistulae.

Arteriovenous Fistula↗
PubMed1988

Transhepatic venous collaterals in a patient with the Budd-Chiari syndrome.

A patient with large transhepatic venous collaterals between the right and middle hepatic veins bypassing a short inferior vena caval occlusion is described. Obstruction of the hepatic veins led to the development of the Budd-Chiari syndrome, ascites, and crural edema. A mesoatrial shunt was performed which resulted in complete recovery.

Adult↗
PubMed1987

Abdominal aortic aneurysm causing duodenal obstruction.

Two cases of abdominal aortic aneurysm presenting with duodenal obstruction following truncal vagotomy and pyloroplasty are described. Barium examination revealed the site and cause of obstruction in both. In one case the aneurysm was successfully resected.

Aged↗
PubMed1987

Mesoatrial shunts for Budd-Chiari syndrome and inferior vena cava thrombosis: angiographic and hemodynamic evaluations.

When inferior vena caval obstruction complicates the Budd-Chiari syndrome, conventional portosystemic shunts are not possible. The mesoatrial shunt has been devised to enable portal and sinusoidal decompression in these patients. Findings in 12 patients with Budd-Chiari syndrome and inferior vena caval obstruction in whom a mesoatrial shunt was performed are reported. Preoperative inferior vena cavography with pressure measurements is essential to determine the appropriate shunt procedure. Postoperatively, shunt patency is assessed with superior mesenteric arterial portography. Where possible, transvenous catheterization of the shunt is performed to confirm patency and assess hemodynamic function.

Adult↗
PubMedDate not supplied

Two balloon technique for disimpaction of intrahepatic biliary stones.

Considerable difficulty may be encountered when attempting, via a T-tube tract, to retrieve retained biliary stones situated in the intrahepatic ducts. This case illustrates a double balloon technique which was successfully used to dislodge a stone impacted at an intrahepatic ductal bifurcation.

Adult↗