Metallic stent placement for iliac artery occlusive disease

Since 1991, we have performed stent placement for 35 iliac artery lesions in 31 patients. The etiologic diseases were atherosclerotic in 34 patients and traumatic dissection in one. The indications of placement were total occlusion in 3, late restenosis after angioplasty in 5, dissection in 5, and residual stenosis due to inadequate angioplasty in 21. We also performed direct stent placement for one traumatic dissection. The stents used were Wallstents in 10, Palmaz stents in 14, Strecker stents in 9, and Memotherm stents in 2 lesions. Follow-up was performed clinically or angiographically with measurement of the ankle/arm pressure index. Stent placement was successful in all cases, and relief or improvement of symptoms was achieved. The follow-up period ranged from 6-85 months (mean, 37.3 months). Late stent stenosis or occlusion occurred in 6 cases, among which 4 occluded lesions were successfully recanalized by thrombolytic therapy with angioplasty or second stent placement. In total, the primary patency rates were 88% and 77% at two and four years, respectively, while the secondary patency rates were 94% and 94%. In conclusion, metallic stent placement may offer extended application of intravascular treatment for iliac artery occlusive disease, and good long-term patency rates can be expected.     

Strecker vascular prostheses. The median- and long-term results]

Between September 1989 and October 1991, 37 patients were treated with percutaneous transluminal angioplasty (PTA) and the insertion of a Strecker stent. The patients--35 men and 2 women, mean age 61 years, range 41-47--had 39 lesions in 39 arteries--30 iliac arteries, 8 femoral arteries and 1 popliteal artery. The lesions included 19 dissections after PTA (48%), 13 residual stenoses > 30% after PTA (34%), 7 restenoses (18%) and 4 total occlusions (10%). The stents were successfully inserted in 37/39 cases (95%). Complications occurred in 4 patients: 2 acute thromboses (resolved with local infusion of urokinase), 1 distal embolization and 1 pseudoaneurysm. Distal embolization, despite aspiration and local fibrinolysis, required leg amputation after about 1 month. The max follow-up period was 2 years (average 15 months): patency was 97% at 1 and 3 months, 100% at 6 and 12 months, 95% at 18 months and 100% at 24 months. Total patency was 85% at 24 months. Four patients were lost to follow-up, and 1 patient died. Four stents failed: 2 of them at 1 and 3 months, and surgery was performed, and 2 at 18 months. Intimal hyperplasia of minimum grade occurred in 2 vessels. There was no evidence of stent migration. The authors believe that the placement of Strecker stents is a valuable approach to the treatment of PTA complications.     

The strecker stent: Indications and results in iliac and femoropopliteal arteries

We have implanted more than 100 Strecker stents in the iliac and femoral arteries. In iliac arteries, follow-up is available from 8 to 48 months (mean 20 months) and in peripheral arteries, from 8 to 32 months (mean 19 months). In iliac and proximal femoral arteries there was a patency rate of 98% (mean 20 months after stent implantation) whereas in peripheral arteries the patency rate was 70.8% (mean 19 months after stent implantation). Besides careful selection of patients, anticoagulation is very important for successful stenting. Because of the excellent results of stents in iliac vessels there is a wide range of good indications, including primary stenting after recanalization of occlusions. In contrast, stent implantation in peripheral vessels should be restricted to special cases such as acute dissection or reocclusion after successful recanalization.     

Primary stent placement for recanalization of iliac artery occlusions: Using a self-expanding spiral stent

Purpose: To report the clinical results for recanalizations of an occluded iliac artery by a self-expanding spiral stent. Methods: We attempted to recanalize 36 iliac artery occlusions in 34 patients [33 men, 1 woman, aged 51–75 years (average 61.6 years)]. The average lesion length was 6.92 cm (range 1–14 cm). The patients' chief complaints were intermittent claudication and resting pain. Fontaine classification was assigned before and after the procedure. Technical and clinical success were also analyzed. Results: Forty-five stents were successfully deployed in 34 patients. All 36 lesions (13 in the external iliac artery, 12 in the common iliac artery, and 11 in both) were patently recanalized on angiography. The follow-up period ranged from 6 months to 36 months (mean 11.9 months). Fourteen stents (39%) with incomplete expansion were dilated with a balloon catheter. Good technical (100%) and clinical (94%) results were obtained. The only complication was one hematoma at the puncture site. Reocclusions were noted in two lesions (5%) at 1 week and 15 months, respectively. Conclusion: A self-expanding spiral stent is a safe and effective device for recanalization of an iliac artery occlusion as the primary stent without any previous intervention.     

Hemodynamics and wall mechanics after stent placement in swine iliac arteries: comparative results from six stent designs.

PURPOSE: To compare the hemodynamics and wall mechanics of swine iliac arteries after placement of six types of stent. MATERIALS AND METHODS: Stents were placed in the iliac artery of 18 pigs (three pigs each underwent placement with one of six types of stent); 16 untreated pigs served as control animals. Iliac arterial hemodynamics and wall mechanics were measured 4 days after placement. RESULTS: Four stents (Palmaz-Schatz, Cordis, Warren, NJ; and Strecker, Cragg, and Symphony, Boston Scientific/Vascular, Natick, Mass) caused decreased pulsatile flow rate in the treated and contralateral iliac arteries; one (Memotherm; Bard, Covington, Ga) caused increased flow pulsatility; and one (Wallstent; Schneider, Plymouth, Minn) had no effect. No compliance mismatching was noted for the Cragg, Symphony, and Memotherm stents, whereas a decrease in compliance was noted for the Palmaz-Schatz, Strecker, and Wallstent designs. The Palmaz-Schatz and Strecker stents caused increased arterial wall rigidity, the Symphony and Wallstent designs had no effect, and the Memotherm and Cragg stents caused decreased wall rigidity. Stents made of stiff metal yielded different early results than did stents made of the less rigid nitinol. CONCLUSION: Soon after implantation, the six stent designs elicited varying changes in blood flow, arterial compliance, and arterial wall mechanics. Contralateral arterial flow also was affected.     

Arterial stent placement with use of the Wallstent: midterm results of clinical experience

Self-expandable stents of the Wallstent type were used in 26 iliac and 15 femoropopliteal artery lesions of 31 patients to treat stenoses or occlusions. The indications were confined to complex lesions, including residual stenoses and dissections after percutaneous procedures or previous surgery in the iliac artery lesions, and long-segment (mean, 13.5 cm) occlusions with inadequate response to percutaneous recanalization in the femoropopliteal artery lesions. In the iliac artery group, after stent placement, 96% of the lesions were patent at a mean follow-up of 16 months (range, 6-30 months). In the femoropopliteal artery group, of 11 patients available for follow-up, only six had patent stents at 7-26 months (mean, 20 months). Four of these six patients required one to three secondary interventions. Self-expanding endoprostheses are of great value in complex iliac artery lesions where simple balloon dilation is insufficient. Stent placement for long femoral artery lesions should be performed with utmost reserve, and the extent of stent placement should be as short as possible.     

Effects of nitinol Strecker stent placement on vascular response in normal and stenotic porcine iliac arteries

PURPOSE: This experimental study was conducted to evaluate neointimal thickness, lumen diameters, and histologic changes in normal and stenotic porcine iliac arteries following placement of self-expanding nitinol Strecker stents. MATERIALS AND METHODS: Neointimal trauma causing slight vascular stenosis was induced unilaterally within external iliac arteries of 12 swines by means of endothelial abrasion and high cholesterol diet. Nitinol Strecker stents were placed within the stenotic and the normal contralateral vascular segments. For histopathologic evaluation, the pigs were killed 12 or 24 weeks after stent placement and luminal diamters were evaluated angiographically. RESULTS: Excluding one occlusion, 15% narrowing of the lumen diameter was induced unilaterally (P = .002). Initial luminal gain after stent placement was greater for stenotic than for normal arteries. The amount of neointima thickness was not different between stenotic and normal vessels (P > .05). Comparing vascular diameters before stent placement and at follow-up, luminal loss due to neointima proliferation was 22% within normal arteries (P = .0002), while a luminal gain by 15% was found within the stenotic arteries (P = .008). Maturation of neointima and endothelial coverage were complete after 24 weeks. CONCLUSIONS: Even though nitinol Strecker stents induce excessive neointimal proliferation, stenotic arteries seem to profit from great early luminal gain resulting in 15% of vascular expansion at follow-up while slight stenosis is induced within normal iliac arteries.     

Heparin-coated balloon-expandable stent reduces intimal hyperplasia in the iliac artery in baboons

PURPOSE: To examine the effect of heparin-coated balloon-expandable iliac stent placement on intimal hyperplasia in a baboon model. MATERIALS AND METHODS: Balloon-expandable (Palmaz-Schatz) stents were placed in bilateral common iliac arteries in 20 male baboons (mean weight: 8.8 kg). In each animal, a heparin-coated iliac stent was placed on one side and the contralateral iliac artery received an uncoated stent that served as a control. The iliac artery stents were harvested at 30 days (n = 10) and 90 days (n = 10). Arteriography was performed to assess iliac patency and intravascular ultrasonography was used to determine neointimal and luminal areas. Histologic and morphometric analysis and scanning electron microscopy were performed in the stent-implanted iliac arteries. RESULTS: One animal was excluded in the 30-day group because of premature death. In the remaining nine surviving animals, seven control stents (78%) and nine heparin-coated stents (100%) remained patent. Morphometric analysis showed that the iliac arteries with heparin-coated stents had larger luminal areas (17%, P <.05), less neointimal area (26%, P <.05), lower neointima-to-media ratios (32%, P <.05), and equivalent medial areas (P =.92) compared to the control group at 30 days. In contrast, all control and heparin-coated stents were patent (100%) in the 90-day group. In that group, the heparin-coated stent group had less neointimal area (28%, P <.05), lower neointima-to-media ratios (42%, P <.05), and equivalent medial area (P =.92) and luminal area (P =.07) compared to the control group. CONCLUSIONS: The data demonstrate that heparin-coated balloon-expandable stents reduce intimal hyperplasia after iliac artery stent placement. This approach may represent a useful strategy for prolonging luminal patency after iliac stent placement.     

应用覆膜支架治疗自发性外周动脉夹层9例

目的 探讨应用覆膜支架腔内隔绝自发性外周动脉夹层的安全性及有效性.方法 收集9例自发性外周动脉夹层患者,病变在髂动脉6例,锁骨下动脉3例.术前均行CTA检查,明确外周动脉夹层的部位和程度,预定覆膜支架.所有患者经Seldinger穿刺股动脉后进一步造影明确病变,依据造影结果植入覆膜支架.结果 9例患者中,病变在右侧髂总动脉3例,右侧髂外动脉l例,左侧髂总动脉2例,左侧锁骨下动脉3例.夹层长度0.9～3.3 cm,平均1.7 cm.动脉夹层起始部距靶血管开口距离0.5～5,6 cm,平均2.3 em.所有患者均成功植入覆膜支架,1例覆膜支架覆盖左侧非优势椎动脉,术中无明显并发症发生.随访3～32个月,平均18个月,所有患者均无相关并发症发生,彩色多普勒超声复查示支架通畅.结论 应用覆膜支架腔内隔绝自发性外周动脉夹层是一种安全有效的治疗方法.     

Renal artery stenosis: preliminary results of treatment with the Strecker stent.

Use of the Strecker flexible balloon-expandable tantalum stent for treatment of renal artery stenosis after failed angioplasty or transaortic thromboendarterectomy was evaluated in 10 patients (nine hypertensive, one normotensive). Left (n = 3) and right (n = 5) renal arteries were involved; renal artery stenosis in two patients had developed after kidney transplantation. Indications for stent placement were inadequate immediate postangioplasty response (n = 7), development of considerable restenosis after angioplasty (n = 1), and obstructing intimal flaps following transaortic endarterectomy (n = 2). Stent placement was technically successful (less than 20% residual stenosis) and patency was preserved in eight patients. Of the seven hypertensive patients with successful implantation, two were cured, three had improvement, and two had no change at latest follow-up evaluation (mean, 10.6 months; range, 6-12 months). The Strecker stent may be helpful in treating restenosis after failed revascularization procedures, although the precise indication, true safety, and long-term efficacy of stent placement in renal arteries will not be known until trials with more subjects and longer follow-up periods are completed.     

Influence of stent type on hemodynamic depression after carotid artery stent placement

PURPOSE: To assess the effect of stent type on hypotension and bradycardia after carotid artery stent placement. MATERIALS AND METHODS: A retrospective analysis on a prospectively maintained database was conducted in 256 patients (126 men; mean age, 71.8 years +/- 8.6; 194 de novo lesions) undergoing carotid artery stent placement between January 1996 and January 2007 by using self-expanding stents. Braided Elgiloy stents (Wallstents) were used in 44 of the 256 patients (17.2%) and slotted-tube nitinol stents were deployed in 212 (82.8%). Bivariate and multivariable logistic regression models were used to determine the influence of stent design on procedural and 24-hour hypotension and bradycardia. RESULTS: Procedural hemodynamic depression (HD) was encountered in 73 of the 256 patients (28.5%) due to hypotension in 24 (9.4%), bradycardia in 12 (4.7%), or both in 37 (14.5%) patients. Rates of procedural hypotension were 11.3% with nitinol stents and 0% with braided Elgiloy stents (P = .0188). Persistent postprocedural HD occurred in 91 of the 256 patients (35.5%) due to hypotension in 40 patients (15.6%), bradycardia in 23 (9.0%), or both in 28 (10.9%). Within a multivariable analysis adjusted for clinically relevant factors affecting rates of HD, the use of braided Elgiloy stents was associated with a decreased rate of procedural hypotension (odds ratio: 0.165; 95% confidence interval: 0.038, 0.721; P = .017). Procedural hypotension and bradycardia were not correlated to incidence of major adverse events but were associated with an increased duration of hospital stay (P = .0059 and P = .0335, respectively). CONCLUSIONS: Nitinol stents are associated with a higher risk of hypotension as compared to braided Elgiloy stents during carotid artery stent placement.     

国产硅酮覆膜支架血液相容性的实验研究

目的评价国产硅酮覆膜支架在犬髂动脉内的血液相容性。方法实验犬9只。18条正常髂动脉,先行大球囊经皮腔内血管成形术(PTA)术后置人支架,继而置人硅酮覆膜支架10枚和镍钛合金编织型裸支架8枚(对照组)。术后第1、4、12周,两组分别抽取一定数量支架段血管行DSA观察通畅率和支架内再狭窄程度;其后处死动物,取出支架段血管,作苏木精-伊红染色及组织学检查,并对两组支架急性血栓形成情况、支架的内膜覆盖和新生内膜增生程度等作出评价。结果术后第1、4、12周DSA所见：①裸支架组各段时间造影均显示通畅,12周时支架段血管狭窄平均为36．7％;②硅酮膜支架组有2支血管闭塞(通畅率为80％),12周时支架段血管狭窄平均为72．3％。结论本组实验用国产硅酮膜支架的血液相容性不优于裸支架。     

Flexible tantalum stents for the treatment of renovascular hypertension: a 10-year experience

The aim of this study was to determine long-term success of flexible tantalum stents for the treatment of ostial and truncal renal artery stenosis. Since 1989, flexible tantalum stents (type Strecker) were implanted in 34 patients (36 arteries, 25 ostial lesions, 11 truncal lesions) with uncontrollable renovascular hypertension, 9 of them in association with renal insufficiency. Stents were placed unilaterally in 32 patients, and bilaterally in 2 patients for the treatment of renal artery stenosis. Thirty-five of 36 lesions were atherosclerotic, including 5 recurrencies after previous percutaneous transluminal renal angioplasty (PTRA). One patient had Takayasu arteritis. Stents were implanted after unsuccessful PTRA of 11 truncal and 23 ostial lesions, and as a primary procedure in 2 ostial lesions. Follow-up examinations included blood pressure measurement, determination 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 stenosis of 40 % was observed. After technically successful stent placement, 77 % of patients became normotensive with or without medication. In the remaining patients there was partial improvement with blood pressure between 140 and 180 mmHg. Renal function improved in 76 % of patients (completely in 3 of 8, 38 %; and partially in 3 of 8, 38 %). Primary patency rate 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 stent 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. Once placed successfully, stent patency rate is excellent. Received: 8 December 1999; Accepted: 23 February 2000     

Five-Year Outcomes of the Bioresorbable Peripheral Remedy Stent in the Treatment of Iliac Artery Disease

PurposeTo evaluate the 5-year performance of a bioresorbable vascular scaffold, the Remedy stent, for the treatment of iliac artery atherosclerotic disease.Materials and MethodsThis prospective, multicenter, single-arm clinical study evaluated 97 patients (97 lesions) with symptomatic TransAtlantic Inter-Society Consensus II A/B iliac artery lesions for 5 years after stent placement. The primary efficacy end point was 12-month primary patency compared with the prespecified standard derived from historical data with metallic stents, and the primary safety end point was the occurrence of major adverse clinical events within 5 years. All angiographic and computed tomography angiographic findings were evaluated by an independent core laboratory for quantitative vessel analysis.ResultsThe 12-month primary patency rate was 88.6% (95% CI, 80.1%–94.4%), which was lower than the prespecified standard. No significant difference was noted between the diameter stenosis at 9 and 12 months. There were no device- or procedure-related deaths, major amputation, or distal embolization during the follow-up period. The ankle-brachial index maintained significant improvement through the 5-year period compared with that at baseline. The Kaplan–Meier estimates of freedom from target lesion revascularization (TLR), major adverse cardiovascular events, and major adverse cardiovascular and limb events were 95.8%, 91.7%, and 87.5% at 12 months and 85.4%, 72.1%, and 62.5% at 5 years, respectively.ConclusionsThe 5-year follow-up outcomes, including freedom from TLR, of the Remedy stent in iliac artery lesions were satisfactory, with a good safety profile. Nevertheless, the 12-month primary patency did not meet the expected standard compared with that of contemporary metallic stents.     

Iliac artery stenosis or obstruction after unsuccessful balloon angioplasty: treatment with a self-expandable stent.

Obstruction or stenosis of the iliac artery was treated by placement of a self-expandable stent in 91 patients. A total of 100 lesions was treated. All patients had had poor results of balloon angioplasty including residual stenosis, iliac occlusion, and dissection. The stent used in all cases was a self-expandable stainless steel endoprosthesis mounted on a 7- or 9-French catheter and covered by an invaginated tubular rolling membrane. The diameter of the expanded stent varied from 7 to 12 mm. A total of 129 stents was placed. Technical success was 97%. Thromboses occurred immediately after placement in two patients and within the first month in six; these were mainly due to residual obstruction. Eighty-two (93%) of 88 patients with a follow-up longer than 3 months had no recurrent symptoms. Restenosis caused by intimal hyperplasia inside the stent occurred in 10 patients; these required repeated intervention in only four cases. In the remaining six patients, no further complications occurred. Our results show that self-expanding endoprostheses are of value for improving the results of inadequate percutaneous transluminal angioplasty.     

Chronic iliac artery occlusion: treatment with the Strecker stent after PTA

The purpose of this retrospective study was to evaluate the use of percutaneous transluminal angioplasty (PTA) and subsequent Strecker stent implantation for the treatment of chronic iliac artery occlusions. A total of 39 patients were subjected to this procedure. The occluded vessels were catheterized, dilated and subjected to stenting in all patients: the length of occlusion varied from 4.5 to 10.5 cm (mean 5.9), lesions were located in common iliac arteries (25), external iliac arteries (10) and in combinations of both (4). Twenty-five patients presented stage II according to Fontaine classification, nine patients stage III and five patients stage IV. The stent was mounted on balloon catheter and introduced through a 9 French sheet (for 8–10 mm stent diameter). After this procedure, 37 out of 39 patients showed a statistically significant increase in the Doppler sonographic ankle-arm index (AAI) (P=0.001) and improvement of clinical symptoms, while in two patients a complete occlusion resulted due to long dissection not covered by the stent in one case and to stent misplacement in the other case. After stenting, 27 patients improved to stage I, ten patients to stage IIa and two patients showed no changes. Two complications were observed: one groin hematoma and one distal embolization. At a 6-month follow-up, a 89.7% of patency was observed. This study shows that Strecker stent can be successfully employed in addition to PTA to treat occlusions of the iliac arteries.     

Metallic stents for treatment of benign biliary obstruction: a long-term study comparing different stents

PURPOSE: To investigate the role of metallic stents in the treatment of benign biliary strictures and analyze the differences in primary patency associated with the various types of stents deployed. MATERIALS AND METHODS: Between 1990 and 1997, 21 patients with benign obstructive jaundice were treated with transhepatic placement of metallic stents (11 Wallstents in 10 patients, nine Palmaz stents in seven patients, and four tantalum Strecker stents in four patients). Nineteen patients presented with strictures not responding to balloon angioplasty (postsurgical, n = 13; cholangitis, n = 5; unknown, n = 1). Estimates for cumulative patency, patency rate in the different stent groups, and survival were calculated with use of life-table analysis; the log-rank test was used to compare the different stent groups. The prognostic relevance of the selected variables-stent type, stent length, etiology, and location-were modeled with respect to patency according to Weibull distribution. RESULTS: The median follow-up time was 80.5 months (range, 2-116 months). The median survival time was 91 months. One patient was lost to follow-up after 3 months. Repeat intervention for recurrent obstructive jaundice was necessary in 11 patients (55%), and the median patency rate was 26 months (range, 2-96 months). The Palmaz stent was the most effective in achieving long-term patency, with a median patency duration of 36 months (range, 22-96 months), versus 9 months (range, 3-67 months) for the Wallstent and 6 months (range, 2-15 months) for the tantalum Strecker stent. The cumulative patency rate with the Palmaz stent was significantly higher than for the tantalum Strecker stent (log-rank test, P = .017) and nonsignificantly higher compared with the Wallstent (log-rank test, P = .07). Multivariate analysis showed that the type of stent (Wald test, P = .003) and stent length (Wald test, P < .0001) influenced the patency rate. CONCLUSIONS: These results suggest that the type of stent and the stent length have a significant influence on the patency rate. In this series, the Palmaz stent was most effective in achieving long-term patency in benign biliary strictures.     

Twelve-month Results of the EverFlex Stent in the Superficial Femoral Artery

PurposeTo evaluate the clinical efficacy of EverFlex stents (length, 6–20 cm) for the treatment of peripheral artery disease (PAD) in the superficial femoral artery (SFA).Material and MethodsOver a period of 18 months, 56 SFA lesions in 53 patients were treated with an EverFlex stent. The following parameters were documented before the intervention, immediately afterward, and 12 months later: clinical stage, ankle-brachial index, and peak systolic velocity ratio (PSVR). The primary study endpoint was the primary patency rate after 12 months (defined as a PSVR < 2.5).ResultsIn 18% of the 56 lesions, complete occlusions were present. Mean lesion length was 9.4 cm ± 5.3, and mean stent length was 12.6 cm ± 5.6. Of the 53 patients enrolled in the study, a 12-month follow-up was performed in 46. The primary patency rate after 12 months was 71.7%. In-stent restenosis or occlusion occurred in 13 patients. Compared with the total study group, the mean stent length in these 13 patients was greater (14.0 cm ± 7.3) and the incidence of de novo lesions was lower. In the patient group with stents less than 10 cm in length (n = 24), six patients (25%) required a repeat intervention, compared with seven patients (32%) in the group with stents longer than 12 cm.ConclusionsAlthough the primary patency rate associated with the EverFlex stent is comparable to those in published data, the present results demonstrate a higher percentage of in-stent stenoses in patients in whom longer SFA stents were implanted.     

Directional atherectomy in iliac stent failure: Clinical technique and histopathologic correlation

Purpose: To assess the feasibility and efficacy of directional atherectomy in the treatment of iliac stent stenosis or occlusion and to evaluate the histologic composition of excised atherectomy specimens. Methods: Directional atherectomy of six occluded and 10 severely stenosed iliac stents was undertaken in 12 patients at a mean interval of 28 months (range 3–69 months) after stent insertion for occlusive aortoiliac disease. In cases of stent occlusion, atherectomy was preceded by low-dose thrombolysis. In all patients stent clearance with return of femoral pulses was achieved within 24 hr and there were no significant complications. All excised specimens were sent for histologic examination. Results: Eleven patients (92%) remain symptom free with unlimited walking distance at a mean follow-up interval of 11.5 months (range 3–31 months) after treatment. Histologic examination revealed typical myointimal hyperplasia at three excision sites, intimal fibrosis at three sites, atheroma at four sites and organized thrombus at six sites. Conclusion: Atherectomy offers an effective treatment in iliac stent occlusion and restenosis with no significant adverse effects. Debulking of these lesions seems to offer a more logical approach than simple balloon angioplasty. Clinical and duplex follow-up confirms satisfactory outcome within the first year but longer-term results are not yet known. The histologic data obtained demonstrate that stent restenosis and occlusion are likely to be multifactorial, and challenge the assumption that myointimal hyperplasia is the sole cause of iliac stent occlusion.     

Iliac artery stent placement: clinical experience and short-term follow-up regarding a self-expanding nitinol stent

PURPOSE: To evaluate the effectiveness, safety, and short-term patency rates of a self-expandable nitinol stent (JostentSelfX; Abbott Laboratories, Chicago, IL) for treatment of iliac artery stenoses. MATERIALS AND METHODS: In a prospective study, 34 chronic iliac artery stenoses were primarily treated in 27 patients (mean age, 61.7 years +/- 9.4) by placement of a JostentSelfX. Handling and visibility of the stent was scored on a 4-point scale. Before stent placement, within 3 days after stent placement and at 6 months follow-up, the clinical history, clinical stage according to the Rutherford classification, and the ankle-brachial index (ABI) were assessed. Intra-arterial digital subtraction angiography including measurement of the mean pressure gradient was performed at the time of stent placement and at 6 months follow-up or in case of recurrence of symptoms. The Wilcoxon signed rank test and Kaplan-Meier method were applied for statistical analysis. RESULTS: The immediate technical success rate was 94%. The clinical success rate immediately after the procedure was 96% and 85% at 6 months follow-up. Stent placement significantly decreased the severity of stenoses as well as the mean pressure gradients and significantly increased the ABI. Handling of the stent was judged good. No misplacement occurred. Foreshortening during deployment was negligible and no stent migration was seen. However, visibility of the stent during fluoroscopy was ranked as moderate to bad. Follow-up at 6 months revealed the cumulative angiographic primary patency rate (<50% restenosis and <10 mm Hg mean pressure gradient) to be 0.96. CONCLUSION: The evaluated self-expandable nitinol stent is an effective tool in treating iliac artery stenoses. Apart from poor visibility, handling was good. The angiographic patency rate is comparable with data reported in other stent trials.