Impaired maturation of distal radio-cephalic fistula for haemodialysis: a review of treatment options.

Distal radio-cephalic arteriovenous fistula is the 'gold standard' vascular access for chronic hemodialysis. Its main drawback is early failure, which can complicate up to 50 % of this surgical procedure. Two scenarios of failure are possible: early post-operative thrombosis or impaired maturation. The first is mainly due to a defective preoperative evaluation or poor surgical procedure. The latter is a patent angioaccess unable to deliver adequately hemodialysis due to a persistently low blood flow or difficult cannulation. In this article, the causes of impaired maturation will be reviewed, ranging from the stenosis causing low flow to the deep location of the vein in the obese. Treatment options will be described in thorough technical detail, in order to allow the angioaccess team to master them in daily practice.

Interventional radiology in the preoperative management of stromal tumors causing intestinal bleeding.

PURPOSE: Our experienee in the preoperative diagnostic and therapeutic management of small bowel gastrointestinal stromal tumors, cause of intestinal bleeding, by means of interventional radiological procedures is reported. MATERIALS AND METHODS: From October 1999 to October 2001 6 patients admitted for melena due to bleeding of a gastrointestinal stromal tumor were treated. In all cases the lower and/or upper gastrointestinal endoscopy were the first diagnostic approaches. In two cases a Te 99m pertechnetate-labeled autologous red blood cells (TRBC) scintigraphic examination was also performed. All the patients underwent an abdominal angiography that was followed in two cases by preoperative trans-catheter arterial embolization. All the patients had the surgical resection of the bleeding neoplasm. RESULTS: In all patients, the endoscopic examinations weren't able to localize the exact site of bleeding. The TRBC scintigraphic examination performed in 2 patients was negative in one case, instead gave an incorrect localization of the bleeding site in the other one. The localization of the bleeding tumors was provided by the selective abdominal angiography that also suggested the presumable nature of the neoplasm on the basis of angiographic characteristics. The embolization of the two tumors was technically successful and was followed by surgical resection. CONCLUSIONS: On the basis of our data, we emphasize and confirm the predominant role of interventional radiological procedures in the detection and in the preoperative management of bleeding gastrointestinal stromal tumors of the small bowel.