A retrospective study of intravascular ultrasound use in patients undergoing endovascular aneurysm repair: its usefulness and a description of the procedure.

OBJECTIVES: To verify the usefulness and limitation of intravascular ultrasound (IVUS) in endovascular aneurysm repair (EVAR). METHODS: A total of 112 consecutive patients, who underwent EVAR to treat abdominal aortic aneurysms, were examined retrospectively. Of these, 33 patients were assigned to the IVUS group because of renal failure, a suspected allergy to contrast agents or anatomical difficulties; the remaining 79 patients were assigned to the non-IVUS group. RESULTS: Patients in the IVUS group required fewer intra-arterial contrast agents (IACAs) than those in the non-IVUS group (67±34ml vs. 123±50ml; p<0.01). Blood loss and operation time were comparable between the two groups. No patients died within 30 days of the operation. Three major renal complications occurred in the non-IVUS group. Renal deterioration evaluated by chronic kidney disease (CKD) stage was found to a greater extent in the non-IVUS group. CONCLUSIONS: IVUS is a powerful auxiliary method in EVAR for reducing the required volume of contrast agents. The combination of IVUS and IACA usage showed good overall performance; thus, we propose the routine use of IVUS in EVAR procedures.

Middle-term results of endovascular aneurysm repair in Japan: does intraoperative endovascular management against the hostile aneurysmal neck prevent the proximal type I endoleak?

AIM: Endovascular aneurysm repair (EVAR) was first approved in Japan in 2007. In order to avoid the learning curve generally seen in the initial stages of implementation, we have aimed for procedural perfection. As the proximal type I endoleak (EL) is associated with a higher risk of late conversion and rupture, so we have treated the intraoperative type I EL scrupulously. The hostile neck, which is known to be a risk for perigraft leakage, is the focus of this study. We showed both the middle-term results of EVAR in our country and the possible necessity of intraoperative management for the hostile neck. METHODS: From a consecutive series of 134 patients who underwent EVAR of abdominal aortic aneurysms, 129 cases in which contrast agent was used intraoperatively were selected. All cases had at least 12-month follow-up postoperatively (12-40 months). Of the 129 selected cases, 49 cases (37%) that did not fulfill the commercially recommended criteria of the aneurysmal neck (length <15 mm and angle >60° of the aneurysm or >45° of the suprarenal aorta) were assigned to the off-label group. The other 80 cases were assigned to the on-label group. We carefully observed the completion angiography and when we found or suspected a type I EL, we performed a re-touch up, changed to a non-compliant balloon, and used a supportive device, such as a PalmazTM stent or aortic cuffs, in sequence. RESULTS: No postoperative type I ELs were detected within the follow-up period. Intraoperative type I ELs were detected more frequently in the off-label group (51%) than the on-label group (20%) (P<0.01). The rate of type I EL in the off-label group in terms of the neck length criteria (11/14 cases) was higher than that in the on-label group (30/115 cases) (P<0.01). In terms of the neck angle, patients in the off-label group had a greater tendency to develop the type I EL than those in the on-label group (18/42 vs. 23/87 cases) (P=0.06). CONCLUSION: Off-label usage regarding aneurysmal neck length and angle tends to be incomplete without additional procedures. Conversely, various techniques, including non-compliant balloon usage and aortic stenting or cuffs, produce good results for the intraoperative type I EL. We found a relationship between the neck condition and the intraoperative type I EL, and showed the importance of strictly obeying our simple algorithm against the proximal type I EL.