Results of a European multicentre iliac stent trial with a flexible balloon expandable stent.

PURPOSE: to determine the 12 months success rate with a balloon expandable, flexible stainless steel stent in iliac artery obstructions. MATERIALS AND METHODS: one-hundred and twenty-six consecutive patients with iliac obstructive disease and who demonstrated an unsatisfactory angioplasty result with a post-dilatation gradient of at least 10 mmHg, or a primary occluded lesion were included in the study. Follow-up was by Doppler sonography, ankle pressures with and without exercise and clinical parameters. RESULTS: after stent placement, the mean percentage diameter stenosis decreased from 79 to 4%, with a mean intra-arterial pressure gradient of 3 mmHg. Primary stent patency was 94% at 6 months and 89% at 12 months. Primary clinical result at 6 months was 88% and at 12 months 81%. Primary assisted clinical result (after re-pta) at 6 and 12 months was 89 and 86%, respectively. The Ankle Brachial Index (ABI) after exercise at 1 month follow-up was reduced from 0.88 to 0.75, with minor deterioration at 6 months to 0.72, and at 12 months to 0.68. The 1, 6, and 12 months follow-up Piek Systolic Velocity (PSV) ratios across the stented lesions remained stable at a mean of 1.4, 1.6, and 1.6, respectively. However, respectively 44, 39 and 34% of the patients still experienced symptoms of claudication. CONCLUSIONS: the results presented here support the suggestion stenting to be an effective device in the treatment of iliac artery obstructive disease. This study also, confirms other study results concerning haemodynamic patency after iliac stenting on the indication of a 10 mmHg pressure gradient after pta and the discrepancy between good haemodynamic patency and clinical result.

Treatment of recurrent transplant renal artery stenosis with metallic stents.

PURPOSE: To evaluate the efficacy of stent deployment in the treatment of recurrent stenosis of transplant renal arteries (TRAs). PATIENTS AND METHODS: This retrospective study includes six consecutive patients who underwent a mean of 3.66 previous treatments of TRA stenosis per patient before stent implantation (20 angioplasties and two surgical procedures). The endoprostheses were a Wallstent in four patients and a Palmaz stent in two patients. Clinical, laboratory, and duplex scanning follow-up was performed every 6 months after stent placement in all patients. RESULTS: The procedure was a technical success in all patients. At 6 months, mean systolic blood pressure decreased from 179 to 152 mm Hg (P = .018) and mean diastolic blood pressure decreased from 102 to 90 mm Hg (P = .09). Mean serum creatinine level dropped from 269 to 182 mmol/L (P = .03) and the number of antihypertensive drugs per patient decreased from 2.5 to 1.6. At a mean follow-up of 34 months (range, 7-60 months), all TRAs were patent, with a stenosis less than 50% without clinical consequences in one patient. No secondary procedure was necessary. CONCLUSION: Stent placement seems to be an effective treatment of TRA recurrent stenosis. Midterm follow-up shows satisfactory clinical results and TRA patency rates. This technique might be considered as a valuable therapeutic option for the treatment of TRA recurrent stenosis.

Treatment of hemodialysis access rupture during PTA with Wallstent implantation.

PURPOSE: To report the authors' experience in treatment of ruptures complicating percutaneous transluminal angioplasty (PTA) of hemodialysis access with implantation of a Wallstent. MATERIALS AND METHODS: Between January 1, 1990, and October 1, 1995, the authors performed 2,414 PTAs of angioaccesses. A severe rupture occurred in 40 (1.7%) of these procedures and was treated by means of stent placement. Wallstents were implanted in 37 of these ruptures. The angioaccesses comprised 22 grafts and 15 fistulas. The indications for stent placement were four isolated pseudoaneurysms and 33 cases of bleeding: 15 major leaks, five moderate leaks that persisted despite prolonged inflation at low pressure, seven leaks associated with greater than 50% residual stenosis, four leaks associated with pseudoaneurysm, and two leaks associated with both greater than 50% residual stenosis and pseudoaneurysm. Seventeen ruptures were located on a vein, 19 on the venous anastomosis of a graft, and one on a graft itself. RESULTS: Stent placement stopped the bleeding immediately in 28 cases and after prolonged inflation within the stent in four cases. Residual bleeding required implantation of a covered Cragg stent within the Wallstent in one case. A pseudoaneurysm was still visible at the end of the intervention in 11 cases. Two complications occurred; one hematoma was drained surgically and one access occluded on day 2. Follow-up angiography showed a small pseudoaneurysm in only one patient with impaired platelet function. The primary and secondary patency of the angioaccesses were 48% and 86% at 1 year, respectively. CONCLUSION: Wallstent implantation is very effective for both immediate and long-term treatment of rupture of angioaccess during PTA.

Ostial renal artery stenosis angioplasty: immediate and mid-term angiographic and clinical results.

PURPOSE: To report the immediate results and the clinical and angiographic outcome of percutaneous angioplasty in patients with ostial renal artery stenosis. MATERIAL AND METHODS: Retrospective review of 52 percutaneous transluminal renal angioplasty (PTRA) procedures for strictly defined ostial atherosclerotic renal artery stenosis in 50 consecutive patients, selected among 670 PTRAs performed between 1983 and 1993. RESULTS: Immediate angiographic success was achieved in 30 arteries (58%) and improvement was achieved in 15 arteries (29%). The procedure was a failure in seven lesions (13%). PTRA was followed by a stent implantation in three lesions (6%). Two patients (4%) died within the first month after PTRA and a major complication occurred in seven other patients (13%). At a mean follow-up of 20.6 months, both systolic and diastolic blood pressure decreased significantly (P = .0006 and P = .0057 respectively). Renal function did not change significantly (P = .73). One patient was lost during follow-up. At angiographic control (mean, 11 months), restenosis occurred in 27% of the cases. There was no recurrence of pulmonary edema at a mean follow-up of 32 months in 50% of the 12 patients who experienced one episode or more before PTRA. CONCLUSIONS: True ostial renal artery stenosis is rare and often reflects severe and multifocal atheromatous disease. In these patients, PTRA might be considered an acceptable and relatively safe treatment that improves blood pressure and stabilizes renal function.

Abdominal aortic aneurysms in sheep: prevention of rupture with endoluminal stent-grafts.

PURPOSE: The authors evaluated the ability of an aortic balloon-expandable endovascular stent-graft to prevent rupture in a model of spontaneously rupturing abdominal aortic aneurysms in sheep. MATERIALS AND METHODS: Aneurysms were created in 16 sheep by inserting a 60 x 18-mm segment of the left internal jugular vein, end-to-end anastomosed, to the sectioned infrarenal abdominal aorta. The sheep were randomly assigned into two groups; eight animals underwent endovascular implantation of an 80 x 12-mm balloon expandable stent-graft (group A), and eight were only followed up (group B). RESULTS: In group B, seven of eight animals had died of aneurysmal rupture by 3 months. In group A, six of the eight aortic aneurysms were immediately excluded, and six animals were alive at 3 months without rupture. The 3-month survival rate was 100% in group A and 12% in group B (P = .0023). Macro- and microscopic analysis of the section of the aorta in which the stent-graft had been placed revealed rapid retraction of the aneurysmal sac. CONCLUSION: Placement of an endovascular stent-graft induced regression of a branchless aneurysm and prevented rupture.

Percutaneous treatment of acute iliac artery injury after intraaortic balloon counterpulsation.

We report on a novel approach to correcting iliac artery occlusions caused by aortic counterpulsation. Two patients who had leg ischemia after retrieval of an intraaortic balloon pump underwent angiograms that showed occlusion of the right external iliac artery because of dissection (one case) or thrombosis (one case). Percutaneous self-expandable stents were implanted in the occluded vessels, and they fully restored normal iliac patency with no complications and satisfactory midterm follow-up results. We conclude that iliac artery occlusion induced by aortic counterpulsation can be safely treated by implanting self-expandable stents in cases of acute iatrogenic dissection.

Self-expandable stents for the treatment of iliac artery obstructive lesions: long-term success and prognostic factors.

OBJECTIVE: The purpose of our study was to report long-term (more than 2 years of follow-up) angiographic patency after self-expandable stent implantation in the iliac artery and to identify patient- or procedure-related prognostic factors of angiographic patency. SUBJECTS AND METHODS: Ninety-five consecutive patients (101 arteries) underwent Wallstent implantation to treat claudication (n=95 limbs), rest pain (n=2), and nonhealing ulcer (n=3). Another patient was asymptomatic but was treated for acute occlusion of the iliac artery after coronary angioplasty. After implantation of self-expandable stents, we followed up by examining clinical and angiographic records at 6 months, 1 year, and annually thereafter. The Kaplan-Meier survival curve was used to determine primary and secondary patency rates. Primary patency was that achieved after the initial procedure only. Secondary patency was defined as that achieved after one or more successful additional percutaneous procedures within the stent or beyond the stent. Multivariate analysis using the Cox proportional hazard model was performed to identify predictive factors of angiographic failure, defined as restenosis of 50% or greater or occlusion. RESULTS: Four-year patency rates of 61% (primary) and 86% (secondary) were found (mean follow-up, 29 months). The following five factors were associated with long-term angiographic failure: occlusion of the superficial femoral artery (relative hazard = 5.21), absence of hypertension (relative hazard = 4.85), a stent diameter of less than 8 mm (relative hazard = 4.45), two or more stents implanted (relative hazard = 3.56), and current tobacco consumption (relative hazard = 2.46). CONCLUSION: Improved patency rates may be obtained by selecting patients for Wallstent implantation in the iliac artery based on five factors shown to be prognostically important.

Cragg covered stents in hemodialysis access: initial and midterm results.

PURPOSE: To report midterm follow-up after implantation of covered stents for hemodialysis access. PATIENTS AND METHODS: Over a 2-year period, a Cragg Endopro stent was placed in 14 patients (mean age, 66.6 years +/- 15) to treat angioplasty-induced ruptures (n = 3), pseudoaneurysm (n = 1), postangioplasty residual stenosis (n = 2), and early restenosis (n = 8, four of them in a Wallstent). RESULTS: Initial placement was successful in all cases. A clinical inflammatory reaction was observed in all three cases of placement in the forearm. When the covered stent was placed in a stenotic vessel, restenosis always occurred within 6 months. Primary and secondary patencies were 28.5% +/- 13.9 and 67.8% +/- 14.5, respectively, at 6 months. Covered stents were of undoubtable benefit in one case of rupture after Wallstent failure and in one case of restenosis in a Wallstent. CONCLUSION: Covered Cragg stents are effective in controlling angioplasty- induced rupture and sometimes for maintaining patency after restenosis in a Wallstent. They do not prevent restenosis and are responsible for an inflammatory reaction of unknown origin and long-term effect.

Iodixanol in leg phlebography: a randomized, double-blind parallel group phase III trial comparing iodixanol to ioxaglate.

PURPOSE: To evaluate the safety and efficacy of iodixanol (Visipaque) in phlebography in order to obtain experience from the use of this contrast medium in this i.v. indication. PATIENTS AND METHODS: Phlebography was performed in 150 patients, as a comparative prospective, double-blind, randomized parallel group study comparing iodixanol 270 mgI/ml with ioxaglate 320 mgI/ml. The tolerability was assessed from occurrence of discomfort, adverse events up to 30 min following injection and late adverse events. Efficacy was assessed by recording the diagnostic information on each venous segment. Statistical analysis was performed using the Cochran-Mantel-Haenszel test in order to correct for a possible centre effect. RESULTS: Frequency of patients reporting discomfort (P=0.002) or adverse events (P<0.001) was statistically significantly lower after the injection of iodixanol than after ioxaglate. There was no statistical difference regarding late adverse events and diagnostic information. CONCLUSION: Iodixanol 270 mgI/ml yielded the same diagnostic information as ioxaglate 320 mgI/ml and was associated with fewer patients reporting adverse events and discomfort.

Outcome of percutaneous intervention in iliac artery stents.

PURPOSE: To assess the safety and efficacy of secondary procedures in iliac artery stents. MATERIALS AND METHODS: Thirty-four patients (36 limbs) underwent one or more interventional procedures in iliac artery stents to treat restenosis (n = 30) or occlusion (n = 6). All patients were followed up by means of clinical and angiographic examination. Primary and secondary patency were assessed with angiography, duplex ultrasound, or both. Primary patency was determined after one interventional procedure, and secondary patency was determined at the end of the study (mean +/- standard deviation, 20.1 months +/- 17.5; range, 1-58 months). RESULTS: Immediate angiographic success was achieved in all cases. Four complications were observed. The primary and secondary cumulative patency rates were 77.5% +/- 7.6 and 94% +/- 4.1 at 6 months, 73% +/- 8.4 and 89.3% +/- 6 at 12 months, and 51.4% +/- 10.9 and 78.8% +/- 8.8 at 2 years. At the end of the study, 80% of the arteries were still nominally patent. CONCLUSION: Restenosis and chronic occlusion in iliac artery stents can be treated with percutaneous interventional procedures; however, stenosis can still recur.

Use of a snare-loop device as an adjunct to Palmaz stent placement.

A patient was treated by PTA for a tight excentric stenosis in the external iliac artery. Following angioplasty, appropriate placement of a Palmaz stent over the lesion was impossible because of arterial curves and irregular aspect of the residual stenosis. To overcome this problem, the stent was grasped and pulled over the lesion using a snare loop device by contralateral approach.

Strecker stent implantation in iliac arteries: patency and predictive factors for long-term success.

PURPOSE: To evaluate Strecker stent implantation in iliac arteries. MATERIALS AND METHODS: Sixty-four iliac arteries with Strecker stents were prospectively studied. Stents were placed for dissection (n = 31), total occlusion (n = 28), unsatisfactory results (n = 3) or restenosis (n = 1) after percutaneous transluminal angioplasty, and a calcified atherosclerotic lesion that bulged into the lumen (n = 1). RESULTS: Stent placement was successful in 63 arteries (98%). The overall complication rate was 12% (n = 8). During follow-up, three patients died. The stent was compromised in 18 cases because of hyperplasia (n = 10) or occlusion (n = 8). The primary patency rate was 84% at 1 year and 69% at 2 years; the secondary patency rate was 90% at 1 year and 81% at 2 years. Initial dissection (P = .046), a length of 60 mm or less for the stent region (P = .007), and total covering of the abnormal segment with the stent (P = .03) were significant predictive factors for good, long-term results. CONCLUSION: Use of the Strecker endoprosthesis appears useful but not ideal. Determination of predictive factors for long-term success may help identify indications for its use.

Renal artery stent placement: immediate and midterm technical and clinical results.

PURPOSE: The authors report their experience with implantation of self-expandable stents into renal arteries. PATIENTS AND METHODS: Twenty-five Wallstent endoprostheses were deployed into 18 renal arteries in 18 patients. Atheroma was the cause of the initial renal artery lesion in 15 patients (four ostial, 10 postostial, and one long occlusion). In these 15 patients, indications for stent placement were 12 immediate failures of percutaneous transluminal renal angioplasty (PTRA), two immediate PTRA complications (dissections), and one recurrent stenosis. The other renal artery lesions were three dissections (two spontaneous and one after catheterization). RESULTS: The procedure was technically successful in all patients, with residual stenosis less than 20%. However, five stents were slightly misplaced and a second stent was implanted to fully cover the lesion. Three complications occurred: one acute thrombosis 15 days after stent implantation that was successfully treated with local fibrinolysis, one asymptomatic occlusion due to early thrombosis or to delayed restenosis, and one segmental renal infarction related to extensive dissection after PTRA and not to stent placement. Following stent implantation, systolic blood pressure (P = .006) and diastolic blood pressure (P = .002) measured at 6 months decreased significantly. Angiographic follow-up was obtained in 16 patients (with intravenous technique in nine and intraarterial digital subtraction angiography in seven) at a mean of 11 months after stent placement, and ultrasonographic follow-up was obtained in the two others after 8 and 25 months, respectively. A normal patent renal artery was demonstrated in 16 patients (89%); there was one restenosis with a 75% reduction in diameter of the renal artery and the asymptomatic occlusion above mentioned. CONCLUSION: Self-expandable stent implantation is a promising technique in PTRA failures. Wallstent placement is technically feasible. Immediate results were satisfactory and the midterm restenosis rate was low in this series of patients.

Animal evaluation of the prototype omnicath atherectomy catheter.

A prototype directional atherectomy catheter (Omnicath) was evaluated in four Yucatan microswines. Atherectomy was performed on iliac or aortic target lesions. After control angiography, the animals were sacrificed and the target arteries were examined histologically. Atherectomy resulted in arterial ruptures in three cases, and the track of the blade was measured to be of an average depth of 0.38 mm. Maneuverability was satisfactory but aspiration was not efficient. Precise localization of the atherectomy window was difficult. We conclude that modification of the catheter seems mandatory before use in humans.

Percutaneous embolization of an arteriovenous fistula of the internal mammary pedicle following sternal wire insertion.

A case of traumatic arteriovenous fistula and false aneurysm of the internal mammary artery was encountered following sternal wire insertion during cardiac surgery. The diagnosis was suspected by echo-doppler and confirmed by arteriography allowing percutaneous embolization using cyanoacrylate in the same setting.

Femoropopliteal stent placement: long-term results.

Twenty-one patients who underwent percutaneous transluminal angioplasty (PTA) followed by attempted insertion of a self-expandable vascular endoprosthesis for femoropopliteal lesions were prospectively followed up for an average of 17.6 months with angiographic, Doppler ultrasound, and clinical examinations. Stents were placed bilaterally in one patient. Of the 22 lesions, 18 were total occlusions and four, stenoses. Stent placement was successful in 21 of 22 lesions. Nine occlusions occurred: four in the first 30 days and five 1-5 months after PTA. Three patients developed intrastent intimal hyperplasia that necessitated an additional percutaneous procedure. At 12 months, the patency rate without other interventions (the primary patency rate) was 49%. In patients who underwent secondary intervention (fibrinolysis, atherectomy, or PTA), the secondary patency rate was 67%, which fell to 56% after 18 months. At the end of the study, the overall rate of reocclusion was 43%. It is concluded that use of the self-expandable vascular endoprosthesis in the femoropopliteal region likely does not decrease the reocclusion rate after PTA alone. Its use is indicated for treatment of acute closures after femoropopliteal PTA.