Ulrich Frank

Predictors of Improved Renal Function After Percutaneous Stent-Supported Angioplasty of Severe Atherosclerotic Ostial Renal Artery Stenosis

Background—Percutaneous stent-supported angioplasty is a treatment option for atherosclerotic ostial renal artery stenosis. Improvement of renal function by such intervention, however, is controversial and thought to be limited to specific subsets, such as nondiabetic patients and bilateral stenoses. In this prospective study, we investigated predictors for improvement of renal function and blood pressure after renal artery stent placement. Methods and Results—The study included 215 consecutive patients with ostial renal artery stenosis of ≥70% diameter stenosis undergoing stent-supported angioplasty. The primary end point was decrease in serum creatinine concentration at 1 year; the secondary end point, decrease in average mean arterial blood pressure assessed by 24-hour monitoring. One-year follow-up was complete in 191 surviving patients. In 52% (99/191) of the patients, serum creatinine concentration decreased during 1-year follow-up. Median serum creatinine concentration dropped significantly from 1.21 mg/dL (quartiles: 0.92, 1.60 mg/dL) at baseline to 1.10 mg/dL (quartiles: 0.88, 1.50 mg/dL) at 1 year (P =0.047). On average, mean arterial blood pressure decreased significantly, from 102±12 mm Hg (mean±SD) at baseline to 92±10 mm Hg at 1 year (P <0.001). Significant independent predictors of improved renal function were baseline serum creatinine (odds ratio [95% CI], 2.58 [1.35 to 4.94], P =0.004) and left ventricular function (OR 1.51 [1.04 to 2.21], P =0.032). Female sex, high baseline mean blood pressure, and normal renal parenchymal thickness were independent predictors for decreased mean blood pressure. Conclusions—Stent-supported angioplasty for severe ostial renal artery stenosis improves renal function and blood pressure in a broader spectrum of patients than previously thought.

Percutaneous Peripheral Atherectomy of Femoropopliteal Stenoses Using a New-Generation Device: Six-Month Results from a Single-Center Experience

Purpose: To report the early and 6-month results after atherectomy of femoropopliteal lesions using a new atherectomy device compatible with a 7-F sheath. Methods: Fifty-two patients (36 men; mean age 67±7 years) with stable, chronic lower limb occlusive disease were enrolled prospectively in a study of percutaneous directional atherectomy using the SilverHawk Atherectomy Catheter. The 71 femoropopliteal stenoses were grouped for analysis according to pathology: 30 (42%) primary stenoses, 27 (38%) native vessel restenoses, and 14 (20%) in-stent restenoses. The overall average stenosis length was 48±64 mm (range 10–300). There were more diabetics in the primary lesion cohort, whereas the lesion length of the in-stent restenoses was nearly twice as long as the other groups. Results: After atherectomy alone, residual stenosis was ≤50% in 68 (96%) lesions and ≤30% in 54 (76%). Additional balloon angioplasty was used in 41 (58%) lesions, primarily to smooth the arterial contour; stents were implanted in 4 (6%) arteries. Acute results after atherectomy and additional therapy were identical for the 3 groups (mean residual stenosis 15% in primary lesions, 8% in restenoses, and 14% in in-stent lesions). At the beginning of the study, 5 cases of tissue embolism were successfully treated with aspiration (device modification solved this problem). Restenosis rates after 6 months were not significantly lower in primary lesions (27%) compared with the other groups (41% for restenoses and 36% for in-stent restenoses). Reintervention after 6 months was also lowest for primary lesions (20% versus 37% for restenoses and 29% for in-stent lesions; p = NS). The ankle-brachial index was significantly improved after 6 months in all groups. At the 6-month follow-up, >80% of all patients were symptom free or had no lifestyle-limiting claudication. Conclusions: Short and medium-length femoropopliteal lesions can be treated successfully and safely in most cases with this new atherectomy catheter. Technical and 6-month clinical outcomes seem to favor primary lesions compared with restenoses.

Stent angioplasty of severe atherosclerotic ostial renal artery stenosis in patients with diabetes mellitus and nephrosclerosis

Atherosclerotic renal artery stenosis (ARAS) may lead to deterioration of renal function or hypertension. The clinical outcome after stent angioplasty of ARAS on renal function and blood pressure control in patients with diabetes and nephrosclerosis is the subject of some controversy. We have analyzed the results of our single‐center experience with stent angioplasty for severe (≥ 70%) ostial ARAS and present here the results of a subgroup analysis of those patients who had diabetes mellitus and nephrosclerosis. From 1996 to 2001, 241 patients underwent stent angioplasty for the treatment of ARAS at our center. Of these, 99 patients had diabetes mellitus (41%) and 176 patients (73%) had nephrosclerosis defined as intrarenal resistance index (RI) ≥ 0.7 diagnosed by duplex ultrasound. All lesions (n = 355) were treated successfully. Mean blood pressure at baseline was comparable and significantly improved immediately after the intervention in all groups (nondiabetics: 102 ± 12 to 93 ± 10 mm Hg; diabetics: 102 ± 14 to 93 ± 11 mm Hg; RI < 0.7: 105 ± 13 to 95 ± 10 mm Hg; RI = 0.7–0.8: 100 ± 12 to 92 ± 10 mm Hg; RI > 0.8: 102 ± 15 to 92 ± 11 mm Hg; P < 0.0001 each). Baseline serum creatinine was not significantly lower in nondiabetics compared to diabetics (1.46 ± 0.9 vs. 1.62 ± 1.2 mg %; P < 0.05) and increased in patients with nephrosclerosis (RI < 0.7: 1.18 ± 0.6 mg %; RI = 0.7–0.8: 1.57 ± 1.1 mg %; RI > 0.8: 1.96 ± 1.6 mg %). Except for patients without nephrosclerosis who had a normal baseline creatinine, serum creatinine decreased significantly in all subgroups during follow‐up. Stent angioplasty of ARAS offers favorable acute and long‐term clinical results for the preservation of the renal function and for blood pressure control in patients with diabetes mellitus and nephrosclerosis. Cathet Cardiovasc Intervent 2003;58:510–515.

Stent-Supported Angioplasty of Severe Atherosclerotic Renal Artery Stenosis Preserves Renal Function and Improves Blood Pressure Control: Long-Term Results from a Prospective Registry of 456 Lesions

Purpose: To report a prospective study evaluating the long-term impact of stent-supported angioplasty on renal function and blood pressure control. Methods: In a 6-year period, 456 hemodynamically significant de novo renal artery stenoses ≥70% were treated in 340 consecutive hypertensive patients (223 men; mean age 66±10 years, range 44–84) with or without impaired renal function. Baseline data on serum creatinine (sCr), intrarenal resistance index, ambulatory 24-hour blood pressure monitoring, and documentation of the number and dose of antihypertensive drugs were compared to values obtained during follow-up. The primary endpoint was a 10% decrease in sCr; the glomerular filtration rate and changes in blood pressure control were additional outcome measures. Results: During a mean follow-up of 34±20 months, sCr decreased significantly from 1.45±0.87 to 1.39±0.73 mg/dL (p=0.048). In 34% of the patients, sCr decreased >10%, 39% were unchanged, and 27% had an increase >10%. Glomerular filtration rate increased from 59±26 to 62±26 mL/min/1.73 m2 (p=0.6). Systolic, diastolic, and mean blood pressure measurements significantly improved immediately after the intervention (132/72/93 versus 144/79/102 mmHg at baseline, p<0.0001) and remained improved during follow-up (p<0.0001). Blood pressure control was improved in 46%, unchanged in 43%, and deteriorated in 11%. Baseline sCr, bilateral intervention, percent diameter stenosis, and 3-vessel coronary disease were independent predictors of improved renal function during follow-up; the number of antihypertensive drugs taken before the intervention predicted improved blood pressure control. Conclusions: Stent-supported angioplasty of renal artery stenoses preserves renal function and improves blood pressure control in a broader spectrum of patients than previously thought.

Two-year results after directional atherectomy of infrapopliteal arteries with the SilverHawk device.

Purpose: To report the 12- and 24-month results after directional atherectomy (DA) of below-the-knee (BTK) arterial lesions with the SilverHawk device. Methods: Forty-nine BTK lesions in 36 patients (58% men; mean age 70611 years) with peripheral occlusive disease of the lower limbs were treated with DA; 19 (53%) of the limbs were classified with Rutherford-Becker 4 or 5 ischemia. Target lesions were in the popliteal artery (n=6, 12%), tibioperoneal trunk (n=25, 51%), peroneal artery (n=10, 20%), anterior tibial artery (n=5, 10%), and posterior tibial artery (n=3, 6%). Nine (18%) lesions were located in a stent. Twelve lesions extended to 2 artery segments. The average degree of diameter stenosis was 89%±10% (range 70%–100%); there were 11 (22%) occlusions. The mean lesion length was 48±28 mm. Results: Sixteen (33%) lesions were treated after predilation; 33 (67%) lesions were treated with primary DA. All but 1 (2%) lesion could be treated with DA. In 19 (39%) lesions, additional balloon angioplasty was performed, and 2 (4%) lesions required stent implantation as a result of dissection. The mean stenosis diameter after DA was 12%±18% (range 0%–100%). After additional therapy, the mean stenosis diameter was 8%±9% (range 0%–100%). A residual stenosis ≤30% was achieved in 48 (98%) lesions. The mean ankle-brachial index significantly increased from 0.48±0.26 to 0.81±0.32 (p<0.05) before discharge and remained improved during follow-up. Primary and secondary patency rates were 67% and 91% after 1 year and 60% and 80% after 24 months. The 12-and 24-month cumulative event-free survival rates (primary patency) by Kaplan-Meier analysis were 58%±8% and 46%±9%; at the same time intervals, the cumulative survival rates (secondary patency) were 88%±6% and 73%±9%, respectively. Conclusion: BTK lesions can be treated successfully and safely with DA. Midterm clinical results are encouraging.

Midterm Results after Atherectomy-assisted Angioplasty of Below-Knee Arteries with Use of the Silverhawk Device

PURPOSE Prospective evaluation of the 3- and 6-month results after atherectomy of below-knee arterial lesions with a reference diameter of at least 2.0 mm with use of the Silverhawk device. MATERIALS AND METHODS Fifty-two below-knee lesions in 33 patients (61% men; mean age, 70 years +/- 11) with chronic peripheral occlusive disease of the lower limbs were treated with directional atherectomy. Target lesions were the popliteal artery (segment 3), n = 4 (8%); tibioperoneal trunk, n = 22 (42%); peroneal artery, n = 18 (34%); anterior tibial artery, n = 5 (10%); posterior tibial artery, n = 3 (6%); and in-stent lesions, n = 8 (16%). All interventions were performed via a 6-F sheath. The average degree of diameter stenosis was 89% +/- 10% (range, 70%-100%; n = 12 [23%] occlusions) and the mean lesion length was 48 mm +/- 28. RESULTS All but one lesion (2%) could be treated with the atherectomy catheter. After additional balloon angioplasty, all but one lesion was treated, with a residual stenosis no greater than 30% (98%), with 7.2 passes per lesion +/- 2.8 (range, 1-12) performed with the device. Fifteen lesions (29%) were treated after predilation and 37 (71%) were treated with primary atherectomy. In 15 lesions (29%), additional balloon angioplasty was performed, and two lesions required stent implantation as a result of dissection. The mean stenosis diameter after atherectomy was 12% +/- 18% (range, 0-100%). After additional therapy, the mean stenosis diameter was 6% +/- 9% (range, 0%-30%). A residual stenosis no greater than 30% was achieved in 50 lesions (96%). The mean ankle-brachial index significantly increased from 0.46 +/- 0.27 to 0.80 +/- 0.34 before discharge and remained improved during follow-up. One procedural complication (3%) was observed in which an intermittent occlusion of the target vessel occurred after an unsuccessful attempt to cross the lesion with the atherectomy device; this was then treated successfully with local lysis. One patient with one treated lesion died during follow-up. The rates of restenosis of at least 70% (diagnosed by duplex ultrasonography) were 14% (seven of 51 lesions) after 3 months and 22% (11 of 51) after 6 months. The 3-month and 6-month cumulative event-free survival were 91% +/- 4.1% and 76.9% +/- 5.8% and the 3-month and 6-month cumulative patency rates were 98% +/- 1.9% and 94.1% +/- 3.3%, respectively. CONCLUSION Below-knee native vessel lesions with a diameter of at least 2.0 mm can be treated with the Silverhawk catheter with a high success rate and a low complication rate. Midterm technical and clinical results are encouraging. Additional balloon angioplasty might be necessary in selected cases.

Endovascular treatment of common femoral artery disease: medium-term outcomes of 360 consecutive procedures.

OBJECTIVES The purpose of this study was to evaluate the technical feasability, safety, and 1-year efficacy of the endovascular treatment of atherosclerotic common femoral artery (CFA) obstructions. BACKGROUND Atherosclerotic CFA obstruction is a known cause of symptomatic peripheral arterial disease. Although surgical endarterectomy is considered the therapy of choice for this condition, little is known about the percutaneous options. METHODS Using a prospectively maintained single-center database, we retrospectively analyzed the outcomes of 360 consecutive percutaneous interventions of the CFA for atherosclerotic disease and assessed procedural success, in-hospital complications, and 1-year patency and target lesion revascularization rates. RESULTS Ninety-seven procedures (26.9%) were isolated CFA interventions, whereas 157 (43.6%) and 152 (42.2%) also involved inflow and outflow vessels, respectively. Bifurcation lesions were present in 140 cases (38.9%), and concomitant treatment of the profunda femoral artery was performed on 93 occasions (25.8%). Chronic total CFA occlusions were recanalized in 60 cases (16.7%). Balloon angioplasty was performed as the primary intervention in virtually all cases (98.6%), whereas stenting was needed for suboptimal angioplasty results in 133 procedures (36.9%). Failures-defined as a final angiographic result with a >30% residual stenosis-were observed on 26 occasions (7.2%). In-hospital major (i.e., requiring surgery) and minor (i.e., treated percutaneously or conservatively) complications occurred in 5 (1.4%) and 18 (5.0%) procedures, respectively. One-year follow-up data were available for 281 patients (87.5%). Restenosis >50% by duplex scanning and target lesion revascularization were observed in 74 of 268 (27.6%) and 64 of 322 (19.9%) procedures, respectively. CONCLUSIONS This large series suggests that the percutaneous approach may be a valid alternative to surgery for CFA atherosclerotic obstructions.

Results after balloon angioplasty or stenting of atherosclerotic subclavian artery obstruction

Endovascular therapy is an accepted treatment strategy in occlusive disease of the subclavian artery. The purpose of this study was to evaluate the technical and clinical long‐term outcome following either balloon angioplasty (plain balloon angioplasty (PTA)) or stenting.

Acute and Long-Term Outcome of Endovascular Therapy for Aortoiliac Occlusive Lesions Stratified According to the TASC Classification: A Single-Center Experience

Purpose: To compare acute and long-term outcomes of endovascular therapy for TASC (TransAtlantic Inter-Society Consensus) A and B lesions versus TASC C and D lesions. Methods: Based on a prospectively maintained database, a retrospective analysis was conducted of 375 symptomatic patients (335 men; mean age 63±8 years) who underwent 438 interventions for aortoiliac arterial obstructions. Lesions were stratified according to the TASC II classification: 259 (59%) procedures involved TASC A/B lesions, while 113 (26%) were for TASC C and 66 (15%) for TASC D lesions. Results: The baseline characteristics of patients with TASC A/B lesions differed significantly in the ankle-brachial index (ABI), occurrence of renal insufficiency, and lesion characteristics from those with TASC C or D lesions. Acute treatment success, defined as residual stenosis <30%, was 100%, 96%, 93%, and 100% for TASC A, B, C, and D lesions, respectively. The primary 1-year patency rate, which was 86% for the entire study cohort, was similar for all TASC classifications (89%, 86%, 86%, 85% for TASC A to D lesions, respectively). In the TASC A/B cohort, the 5-year event-free survival (70%) was not significantly better than in the C/D cohort (57%, p=0.124). The clinical outcome, as measured by Rutherford stage and ABI, improved significantly in all TASC subgroups after successful intervention and was maintained up to 1 year. Stenting was an independent predictor for lower restenosis rates (HR 0.517, 95% CI 0.317 to 0.842; p=0.008). Conclusion: In experienced hands, endovascular therapy of aortoiliac lesions can be successfully performed with sustained long-term outcome independent of the TASC II classification, even in class D lesions.

Gold coating and restenosis after primary stenting of ostial renal artery stenosis

Predictors of restenosis after stent angioplasty of ostial renal artery stenosis (RAS) and long‐term technical success, particularly the influence of gold coating, are unknown. During a 4‐year period (1996–2000), we treated 156 consecutive patients with 219 ostial RAS of ≥ 70% diameter stenosis. Gold‐coated stents were used in 29% of RAS (n = 64); the vessel diameter ranged from 3 to 9 mm. The restenosis rate was 11.4% at 12 months, 12.2% for gold‐coated stents and 11.1% for noncoated stents. Restenosis rates were 16% for ≤ 4 mm, 17% for 5 mm, 10% for 6 mm, and 0% for ≥ 7 mm (P ≤ 0.05). In a backward stepwise logistic regression analysis including gold coating, vessel diameter, gender, diabetes, smoking status, as well as lesion diameter stenosis before and after stenting, vessel diameter was found the only independent predictor of restenosis (odds ratio = 0.57; 95% CI = 0.35–0.93; P = 0.02, for an increase in vessel diameter of 1 mm). Gold coating was not a significant predictor (odds ratio = 1.09; 95% CI = 0.39–3.03; P = 0.87). Seven major (4.5%) complications occurred. There were no procedural fatalities. The restenosis rate after stent angioplasty of ostial RAS is influenced by the vessel diameter but not by gold coating. Catheter Cardiovasc Interv 2003;60:1–6.