Midterm results of renal artery stenting.

Percutaneous transluminal angioplasty (PTA) has become the treatment of choice for major renal artery stenosis. Nonetheless, about 10% of renal artery stenoses cannot be properly dilated, and among the patients successfully dilated, 10%-15% had a recurrence. Renal artery stenting was used in 21 patients in cases of insufficient results after PTA: persisting significant stenosis after a primary or several PTAs (15 cases), recurrences (9 cases). Follow-up in all patients was from 12 months to 4 years. Implantation was performed without any problems but the low radioopacity of the stent makes placement difficult in obese patients, particularly for ostial lesions. There was no major complication except occlusion of a segmental branch of the renal artery in 1 case. Radiological controls have shown a preserved patency in all cases except 2, which present restenosis inside the stent by intimal hyperplasia. A significant clinical improvement was obtained in 90% of cases. These results suggest that the endovascular prosthesis represents an important adjunct to renal PTA.

[Long-term results of transluminal angioplasty in the treatment of stenosis of the renal artery]. / Résultats à long terme de l'angioplastie transluminale dans le traitement des sténoses de l'artère rénale.

MATERIALS AND METHODS. A multicenter study was undertaken to determine the long-term results of renal angioplasty. Five teams with considerable experience in the procedure replied to a computerized questionnaire concerning transluminal angioplasty (TLA) performed with immediate success from 1979 to 1985 and followed up regularly (minimum of four years). The main purpose of the study was to assess the long-term results, both anatomical results and clinical, of renal TLA. Consideration was given to anatomical of average quality and their possible correlation with long-term results, in an attempt to foresee and even prevent restenosis. The main points of the study are given in figure 1. Two hundred and forty-seven renal TLA performed in 210 patients were included (insofar as clinical and radiologic follow-up was adequate, with a minimum of one control angiography beyond six months). Patients who had immediate failure (dilatation not possible or ineffective dilatation) were excluded from the analysis of long-term results. Likewise, TLA of the renal artery of grafted kidneys were not included in this study. The histogram of patients ages shows a clear predominance of subjects 60 to 65 years of age, with extremes ranging from 10 to 80 years (mean 53 years). TLA were done mainly by the femoral route according to a technique using a balloon catheter positioned on a previously inserted guide at the level of the stenosis. The examination was performed under local anesthesia. Balloon size was determined according to the diameter of the renal artery upstream from the stenosis and that of the contralateral renal artery. A balloon of the same or slightly larger caliber was used. The indication of angioplasty was determined after multidisciplinary discussion according to two main criteria: First, treatment of hypertension presumed to be in relation with a stenosis of the renal artery (renovascular hypertension). Secondly, conservation of the nephrotic capacities of a patient with a renal stenosis possibly associated with arterial hypertension, in relation with a bilateral stenosis of the renal arteries or with a unilateral stenosis affecting a functionally or anatomically single kidney. In this latter case, the purpose of TLA was to avoid development toward thrombosis of the renal artery and worsening of renal insufficiency. RESULTS. Two hundred and forty-seven TLA in 210 patients were included in the study. Nineteen patients (9%) had bilateral TLA. The lesions treated are indicated in figure 3. These were most often simple atheromatous and truncal lesions of the renal artery (73%) which were significant (greater than 50%) in 99% of cases. TLA was indicated in 77% of cases for treatment of arterial hypertension presumed to be renovascular. In 23% of cases, treatment of the stenosis was intended to conserve, especially, kidney vascularization, i.e., an indication of nephrotic protection. There were 9.7% immediate failures...

[Usefulness of a percutaneous endoprosthesis in the treatment of renal artery stenoses]. / Utilité d'une endoprothèse percutanée dans le traitement des sténoses de l'artère rénale.

In approximately 10 p. 100 of the cases stenosis of the renal artery cannot be satisfactorily dilated by percutaneous transluminal angioplasty (PTA), and about 10 p. 100 of the patients successfully dilated have short-term restenosis. The excellent results obtained experimentally and clinically with the implantation of percutaneous intravascular stents have prompted us to use this material in the renal arteries. Stents were implanted in 10 patients who were followed up for periods of 1 to 16 months. Eight of them had restenosis after PTA; five of these stenoses were due to atheroma, 2 to fibromuscular dysplasia and 1 to Takayasu's disease. Two patients were implanted from the start owing to the insufficient results of PTA. Seven patients had severe arterial hypertension most probably of renovascular origin. Three patients had hypertension associated with moderate renal failure. Implantation was performed after a previous PTA. Adjuvant treatments and monitoring were the same in every case with, in particular, radiological control examination after one and six months. The implantations themselves were uneventful, and immediate control showed almost perfect anatomical restoration in all patients. On subsequent controls, arterial patency was preserved in all but one case. All patients showed significant clinical improvement. These results are most encouraging. They suggest that intravascular stents constitute an interesting solution when PTA is insufficient in the treatment of renal artery stenosis.