Outcome of renal stenting for renal artery coverage during endovascular aortic aneurysm repair
Received 10 September 2008; accepted 14 November 2008. published online 23 February 2009.
Objective
This study was conducted to determine the outcome of adjunctive renal artery stenting for renal artery coverage at the time of endovascular abdominal aortic aneurysm repair (EVAR).
Methods
Between August 2000 and August 2008, 29 patients underwent elective EVAR using bifurcated Zenith stent grafts (Cook, Indianapolis, Ind) and simultaneous renal artery stenting. Renal artery stenting during EVAR was performed with endograft “encroachment” on the renal artery ostium (n = 23) or placement of a renal stent parallel to the main body of the endograft (“snorkel,” n = 8). Follow-up included routine contrast-enhanced computed tomography (CT), multiview abdominal radiographs, and serum creatinine measurement at 1, 6, and 12 months, and then yearly thereafter.
Results
Thirty-one renal arteries were stented successfully in 29 patients. The 18 patients with planned renal artery stent placement had a proximal neck length <15 mm. Mean proximal neck length was shorter in patients who underwent the “snorkel” technique (6.9 ± 3.1 mm) compared with those with planned endograft encroachment (9.9 ± 2.6 mm). None of the patients with unplanned endograft encroachment had neck lengths <15 mm (mean length, 26.3 ± 10.2 mm). Mean proximal neck angulation was 42.8° ± 24.0° and did not differ between the groups. One patient had a type I endoleak on completion angiography, and two additional patients had a type I endoleak on the first postoperative CT scan. All type I endoleaks resolved by the 1-month postoperative CT scan. The primary assisted patency of renal artery stents was 100% at a median follow-up of 12.5 months (range, 2 days-77.4 months). In one patient near occlusion of a renal artery stent was noted on follow-up CT scan at 9 months; patency was restored by placement of an additional stent. One patient required dialysis after sustained hypotension from a right external iliac artery injury that resulted in prolonged postoperative bleeding. Mean serum creatinine was 1.1 ± 0.3 mg/dL at baseline, 1.2 ± 0.5 mg/dL at 1 month of follow-up, and 1.2 ± 0.5 mg/dL at 2 years of follow-up. There were no late type I endoleaks (>1 month postoperatively) or stent graft migrations.
Conclusions
Adjunctive renal artery stenting during endovascular AAA repair using the “encroachment” and “snorkel” techniques is safe and effective. Short- and medium-term primary patency rates are excellent, but careful follow-up is needed to determine the durability of these techniques.
Division of Vascular Surgery, University of California, San Francisco Medical Center, San Francisco, Calif
Correspondence: Jade S. Hiramoto, MD, UCSF Division of Vascular Surgery, 400 Parnassus Ave, A-581, San Francisco, CA 94143-0222
This publication was supported by NIH/NCRR/OD UCSF-CTSI Grant Number KL2 RR024130. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the National Institutes of Health.
Competition of interest: Dr. Chuter has licensed patents to Cook Inc, the manufacturer of the Zenith stent graft, and receives research and travel support from Cook Inc.
ABSTRACT