Case one
Institutional review board approved case reports at our institution. A 64-year-old woman was referred to our department for PTRA. She underwent patch plasty of bilateral renal arteries using autologous saphenous veins for fibromuscular dysplasia in her twenties. Around 30 years after the operation, bilateral renal artery aneurysms were detected. Bilateral renal artery bypass grafting was performed using autologous saphenous vein grafts (Figure 1). Two harvested saphenous veins were anastomosed at each end to be shaped as pouch, and the pouch was anastomosed directly to her abdominal aorta distal to the renal artery branches. Two years after the bypass operation, follow-up renal ultrasonography revealed significant stenosis at the left renal bypass graft (peak systolic velocity: 474.2 cm/sec, renal aortic ratio: 5.5, and resistive index: 0.47-0.63), and renal perfusion scintigraphy revealed that left renal perfusion was decreased. Before PTRA, blood pressure was 148/86 with three types of antihypertensive drugs (Amlodipine Besylate 5 mg/day, Candesartan Cilexetil 8 mg/day, Atenolol 25 mg/day). Creatinine clearance was 81.1 ml/min, and resistive index of the left renal artery was mentioned above. Therefore, her renal function was thought to be maintained, and this case was indicated for PTRA.
We started PTRA with left femoral approach and placed a 6-F long sheath. To keep the root of the reconstructed venous graft, we used a 6-F guiding catheter (ENVOY, Cordis, Bridgewater, NJ, USA) which shape of the tip was relatively straight (Multipurpose D). Two sites of stenosis were detected at the left renal bypass graft (Figure 2a). We passed a 0.014-inch microguidewire (Cruise, St. Jude Medical, St. Paul, MN, USA) through the stenotic region, and performed a predilation at 8 atm using a 2.6-F balloon (3 mm × 40 mm, IKAZUCHI PAD, KANEKA MEDIX, Osaka, Japan). After the predilation, two stents were deployed with the mounted balloons (Amiia, Cordis, Bridgewater, NJ, USA) at 12 atm respectively. One stent (6 mm × 15 mm, PALMAZ Genesis, Cordis, Bridgewater, NJ, USA) was on the distal stenosis and the other stent (6 mm × 18 mm, PALMAZ Genesis, Cordis, Bridgewater, NJ, USA) was on the proximal stenosis. The mounted balloons were 6-F balloons with a rated burst pressure of 12 atm. Because residual stenoses were significant despite those stents were deployed at the rated burst pressure of the mounted balloon (Figure 2b), another slightly higher pressure balloon with a rated burst pressure of 14 atm (6 mm × 20 mm, Aviator Plus, Cordis, Bridgewater, NJ, USA) was inserted using double wire technique (Chetcuti and Moscucci 2004) and additional dilations twice at 14 atm with the Aviator Plus achieved adequate dilation (Figure 2c). We used double wire technique because we could not insert the balloon with a single wire. Two years after the PTRA, blood pressure is 128/72 with antihypertensive drugs (Amlodipine Besylate 2.5 mg/day, Candesartan Cilexetil 4 mg/day). Creatinine clearance is 69.3 ml/min, and follow-up computed tomography reveals no restenosis.
Case two
The second case is very similar with the first case mentioned above. A 59-year-old man was referred to our department for PTRA. He underwent right nephrectomy and patch plasty of left renal artery using an autologous saphenous vein for fibromuscular dysplasia and induced right renal complete dysfunction in his twenties. Around 30 years after the operation, a left renal artery aneurysm was detected. Left renal artery bypass grafting was performed using autologous saphenous vein grafts (Figure 3). Two harvested saphenous veins were anastomosed at each end to be shaped as pouch, and the pouch was anastomosed directly to his abdominal aorta distal to the left renal artery branch. Three years after the bypass operation, follow-up renal ultrasonography revealed significant stenosis at the posterior branch of the left renal bypass graft (peak systolic velocity: 527.3 cm/sec, renal aortic ratio: 6.2, and resistive index: 0.38-0.63), and PTRA was planned. Blood pressure was 130/76 before the PTRA with two types of antihypertensive drugs (Amlodipine Besylate 2.5 mg/day, Losartan potassium 50 mg/day). Creatinine clearance was 60.6 ml/min and his renal function was thought to be maintained.
We started PTRA with left femoral approach and placed a 6-F long sheath. To keep the root of the reconstructed venous graft, we used a 6-F guiding catheter (Mach1, Boston Scientific, Natick, MA, USA) which shape of the tip was straight. Stenosis was detected at the proximal region of the posterior branch of the left renal bypass graft (Figure 4a). We passed a 0.014-inch microguidewire (Agosal XS 0.8, St. Jude Medical, St. Paul, MN, USA) through the stenotic region, and performed a predilation at 8 atm using a balloon (4 mm × 20 mm, Aviator Plus, Cordis, Bridgewater, NJ, USA). After the predilation, a stent (6 mm × 16 mm, PALMAZ Genesis, Cordis, Bridgewater, NJ, USA) was deployed with the mounted balloon (Amiia, Cordis, Bridgewater, NJ, USA) at 12 atm. Because the mounted balloon could not achieve adequate dilation (Figure 4b), another balloon (6 mm × 15 mm, Aviator Plus, Cordis, Bridgewater, NJ, USA) was inserted and additional dilation at 14 atm achieved adequate dilation (Figure 4c). Two months after the PTRA, blood pressure is 126/66 and antihypertensive drugs which have been taken for 11 years can be ceased. Creatinine clearance is 61.5 ml/min, and follow-up renal ultrasonography reveals no restenosis.
