Flexible tantalum stents for the treatment of renovascular hypertension: a10-year experience

The aim of this study was to determine long-term success of flexible tantal um stents for the treatment of ostial and truncal renal artery stenosis. Si nce 1989, flexible tantalum stents (type Strecker) were Implanted in 34 pat ients (36 arteries, 25 ostial lesions, 11 truncal lesions) with uncontrolla ble renal insufficiency. Stents were placed unilaterally in 32 patients, an d bilaterally in 2 patients for the treatment of renal artery stenosis. Thi rty-five of 36 lesions were atherosclerotic, including 5 recurrencies after previous percutaneous transluminal renal angioplasty (PTRA). One patient h ad Takayasu arteritis. Stents were implanted after unsuccessful PTRA of 11 truncal and 23 ostial lesions, and as a primary procedure in 2 ostial lesio ns. Follow-up examinations included blood pressure measurement, determinati on of serum creatinine level, color duplex sonography, or angiography. The technical success rate was 92%. Technical failure included incorrect stent placement (1 of 36 lesions, 2.8%), and stent dislocation (2 of 36 lesions, 5.6%), and two stents were retrieved percutaneously In one case of Takayasu arteritis, residual of 40% was observed. After technically successful sten t placement, 77% of patients became normotensive with or without medication . In the remaining patients there was partial improvement with blood pressu re between 140 and 180 mmHg. Renal function improved in 76% of patients (co mpletely in 3 of 8, 38%; and partially in 3 of 8, 38%). Primary patency rat e including all stented lesions and initial technical failures was 82.4% +/ - 6.8 (1 year) and;:82.4% +/- 9.2 (3 years). After technically successful s tent placement, patency rates were 89.9 +/- 5.6% (1 year), and 89.9 +/- 7.6 % (3 years). For ostial lesions, primary patency rate was 87.9 +/- 6.7% (1 year) and 87.9 +/- 9.2 % (3 years). Placement of flexible tantalum stents in renal arteries is technically demanding, especially in ostial lesions. O nce placed successfully, stent patency rate is excellent.