Print this pageIntra operative Quality Control with Duplex Ultrasound during Renal Artery Revascularization
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Michele Carmo, MD, Thomas C. Bower, MD, Geza Mozes, MD, PhD, Thanila A. Macedo, MD, Ryan D. Nachreiner, MD, Alessandra Puggioni, MD, Manju Kalra, MBBS, Audra A. Noel, MD, Timothy M. Sullivan, MD, Peter Gloviczki, MD.
Mayo Clinic, Rochester, MN, USA.
Purpose: To review our experience with the use of intra operative duplex ultrasonography (IODUS) during open renal artery (RA) reconstruction.
Methods: All patients who had open RA revascularization from 1998 to 2002 were reviewed. IODUS was classified according to the presence of any abnormal image and flow velocity changes. We defined successful outcome as freedom from arterial occlusion or recurrent stenosis < 60% during follow-up. A major defect with IODUS was arterial occlusion, >60% residual stenosis, or other lesions which caused dampened distal RA blood flow.
Results: 375 RAs (324 main and 51 accessory RA) were reconstructed in 225 patients. One hundred and ninety-three patients had atherosclerosis (329 arteries) and 18 had fibromuscular dysplasia (22 arteries). The other 14 required 22 RAs to be reconstructed during aortic replacement. The technique of RA reconstruction was endarterectomy for 248 arteries, bypass for 117, and reimplantation for 10. Aortic replacement was done for AAA in 58 patients and for aorto-iliac occlusive disease in 84 .
335 arteries(198 patients) were interrogated by IODUS. 232 arteries were normal, 49 had major defects, and 51 had minor defects. IODUS records were inadequate in 3 cases. 42 arteries were revised for 39 major and 3 minor defects and 33 of these had another US. Ten arteries with a major defect were not revised. After revision, 250 arteries were normal, 15 had a major residual defect (10 not revised plus 5 after revision), 59 had a minor defect, and the other 11 were not reimaged.
At least 1 follow-up imaging study was available for 294 arteries (78.4%) with a median of 3 for each operated artery (range:0-13).645 US scans were done but 92 were nondiagnostic, 69.3% of them because an accessory RA could not be imaged well. Overall [[Unable to Display Character: "]]success[[Unable to Display Character: "]](as defined above) was 87.7±2.1% at 1 year, 79.6±2.9 at 3 years, and 70.1±4.3 at 5 years. Success for patients with normal arteries by IODUS was 91.1±2.3 and 85.1±3.2 at 1 and 3 years. Similar outcomes were seen in those with minor defects. The presence of a major defect had success rates of only 56%±17.1 and 42±17.6 at 1 and 3 years. One third of arteries that were not rescanned after revision had either occluded or had a > 60% recurrent stenosis by 3 years.[[Unable to Display Character: "]]Success[[Unable to Display Character: "]] occurred in 69.8±9.6% and 37.5±14% at 1 and 3 years for those not receiving an IODUS. There was a significant difference in outcome when arteries with normal or minor defects were compared to those with major defects or those that were not imaged by IODUS.(log rank tests p<0.001 in all cases).
Conclusions: The use of intra operative duplex ultrasonography improves long- term success of renal artery reconstructions as long as major residual arterial defects are corrected during the operation. Patients who have normal arteries or minor arterial defects have similar long term outcomes.