Vascular access stenosis and central vein obstruction interventions: five years of experience in Ramathibodi Hospital.

OBJECTIVE: To evaluate initial post-treatment and six months outcome of patients sent to the intervention radiology unit with vascular access malfunctions. MATERIAL AND METHOD: A retrospective study of venoplasty, venoplasty with stenting, and venoplasty with thrombolysis for vascular access failure patients, included 53 patients with 67 interventional radiology procedures at the intervention radiology unit of Ramathibodi Hospital between January 2004 and June 2009. RESULTS: Sixty-seven intervention procedures were performed in 53 patients. Two patients had severe stenosis of AVF anastomosis with a resulting in failure to perform venoplasty. There were 34 lesions of central venous obstruction. The lesions were usually short and 79% shorter than 4.0 cm. In the group of central venous obstruction that performed venoplasty alone, the degree of stenosis was 58.7 +/- 18.6% (mean +/- SD) with 69.2% technical success and 84.6% clinical successes. However the technical success was increased to 71.4% and clinical success was increased to 100% in the stent placement group. At the six-month follow-up, there was no significant clinical re-obstruction. Fair to good outcomes of interventional procedures of vascular access and peripheral venous stenosis were achieved. Within the group of 14 lesions of patients who underwent AVBG, the degree of stenosis was 64.4 +/- 14.4% with 57.1% technical success and 100% clinical successes. In the other group of 19 lesions that underwent native AVF the degree of stenosis was 61 +/- 9.4% with 52.6% technical success and 89% clinical successes. Two patients had re-stenosis and thrombosis in AVBG six months after treatment procedure. CONCLUSION: Percutaneous interventional radiology procedure continues to play a beneficial role in treatment, and remains the first treatment of choice in vascular access malfunction and corollary complications of central venous obstruction. The technical success rate of treatments is determined by morphologic features of each lesion, with the identification of these features helping in proper planning and the use of appropriate instruments.

Three-dimensional aortic aneurysm model and endovascular repair: an educational tool for surgical trainees.

OBJECTIVES: Endovascular aortic aneurysm repair (EVAR) is a current valid treatment option for patients with abdominal aortic aneurysms (AAAs). The success of EVAR depends on the selection of appropriate patients, which requires detailed knowledge of the patient's vascular anatomy and preoperative planning. Three-dimensional (3D) models of AAA using a rapid prototyping technique were developed to help surgical trainees learn how to plan for EVAR more effectively. METHOD: Four cases of AAA were used as prototypes for the models. Nine questions associated with preoperative planning for EVAR were developed by a group of experts in the field of endovascular surgery. Forty-three postgraduate trainees in general surgery participated in the present study. The participants were randomly assigned into two groups. The 'intervention' group was provided with the rapid prototyping AAA models along with 3D computed tomography (CT) corresponding to the cases of the test, while the control group was provided with 3D CTs only. RESULTS: Differences in the scores between the groups were tested using the unpaired t test. The mean test scores were consistently and significantly higher in the 3D CT group with models compared with the 3D CT group without models for all four cases. Age, year of training, sex and previous EVAR experience had no effect on the scores. CONCLUSION: The 3D aortic aneurysm model constructed using the rapid prototype technique may significantly improve the ability of trainees to properly plan for EVAR.