Elective stenting of symptomatic middle cerebral artery stenosis

Percutaneous balloon angioplasty has been found to be useful for the treatment of intracranial atherosclerotic arterial stenosis. Nonetheless, an ongoing risk of this procedure is arterial dissection, which increases the hazards of acute closure, stroke, and restenosis. Stenting of the intracranial vasculature recently has been shown to be feasible in a variety of circumstances. To our knowledge, however, stenting of the middle cerebral artery has not been possible until now primarily because of difficulty with tracking stents across the carotid siphon. We describe the successful treatment of a symptomatic middle cerebral artery stenosis achieved using a balloon-expandable flexible coronary stent.     

Does coronary stenting following balloon angioplasty improve myocardial fractional flow reserve?

Purpose: Suboptimal distal coronary flow reserve after successful balloon angioplasty has been attributed to angiographically unrecognized inadequate lumen expansion, and adjunct coronary stenting has been shown to improve coronary flow reserve. The aim of this study was to investigate whether myocardial fractional flow reserve (FFRmyo) would increase further after coronary stenting compared with balloon angioplasty alone in the same patient group. Methods: FFRmyo and quantitative coronary angiography were obtained before and after pre-stent balloon dilation, and again after stent placement in 11 patients (7 left anterior descending artery, 3 right coronary artery and 1 left circumflex artery). FFRmyo was calculated as the ratio of Pd/Pa during intracoronary adenosine 5′-triphosphate (50 μg and 20 μg in the left and right coronary arteries, respectively)-induced maximum hyperemia, where Pd represents mean distal coronary pressure measured by a 2.1 Fr infusion catheter and Pa represents mean aortic pressure measured by the guiding catheter. Results: Percent diameter stenosis significantly decreased after balloon angioplasty (74% ± 15% vs 37% ± 17%, p < 0.001), and decreased further after stent placement (18% ± 10%, p < 0.001 vs baseline and balloon angioplasty). FFRmyo after coronary stenting (0.85 ± 0.09) was significantly higher than that at baseline (0.51 ± 0.16, p < 0.001) and after balloon angioplasty (0.77 ± 0.11, p < 0.05). There was a significant correlation between angiographic variables and FFRmyo. The increase in lumen dimensions after coronary stenting was followed by a further significant improvement of FFRmyo. Conclusion: These results suggest that coronary stenting may provide a more favorable functional status and lumen geometry of residual coronary stenosis compared with balloon angioplasty alone.     

Peri-stent aneurysm formation following a stent implant for stenotic intracranial vertebral artery dissection: a technical report of two cases successfully treated with coil embolization

Introduction

Although stenting for stenotic vertebral artery dissection (VAD) improves compromised blood flow, subsequent peri-stent aneurysm (PSA) formation is not well-known. We report two cases with PSA successfully treated with coil embolization.

Methods

Three patients with stenotic intracranial VAD underwent endovascular angioplasty at our institution because they had acute infarction in posterior circulation territory and clinical evidence of hemodynamic insufficiency. In two of three patients balloon angioplasty at first session failed to relieve the stenosis, and a coronary stent was implanted. Angiography immediately after stenting showed no abnormality in case 1 and minimal slit-like projection at proximal portion of the stent in case 2.

Results

Angiography obtained 16 months after the stenting revealed PSA in case 1. In case 2, angiography performed 3 months later showed that the projection at proximal portion enlarged and formed an aneurysm outside the stent. Because follow-up angiographies showed growth of the aneurysm in both cases, endovascular aneurysmal embolization was performed. We advanced a microcatheter into the aneurysm through the strut of existing stent and delivered detachable coils into the aneurysm lumen successfully in both cases. The post-procedural course was uneventful, and complete obliteration of aneurysm was confirmed on angiography in both cases.

Conclusion

Stenting for stenotic intracranial VAD may result in delayed PSA; therefore, follow-up angiographies would be necessary after stenting for stenotic intracranial arterial dissection. Coil embolization through the stent strut would be a solution for enlarging PSA.     

Stenting in the femoral superficial artery: an overview.

Stenting in the superficial femoral artery is still a controversial treatment in case of occlusive disease. Although the results of percutaneous treatment especially in the Hunter canal region are moderate, balloon angioplasty is nowadays an established technique. Many investigators tried to improve their results with additional stenting of the superficial femoral arteries after inappropriate results of balloon angioplasty and/or stenting. Although the figures of results after stenting are not consistent in literature even when using stent graft material I still feel that especially in the superficial femoral artery stenting procedures should not be performed on a routine basis. The main issue in stent failure is the extensive intima hyperplasia. Many investigators are working on this problem but as long as no real solution is available I feel that we have to act reluctantly in treating superficial femoral arteries with stents.     

Endovascular Stenting for Restenosis of the Intracranial Vertebrobasilar Artery After Balloon Angioplasty: Two Case Reports and Review of the Literature

Percutaneous transluminal balloon angioplasty (PTA) has been used in the treatment of critical stenosis of the intracranial vertebrobasilar artery (VBA). PTA of the intracranial VBA carries the risk of fatal complications such as arterial dissection or acute occlusion as well as postoperative restenosis. The estimated risk of periprocedural complications and restenosis were approximately 20% and 27%. The use of recently developed stents could prevent these problems of PTA. We present two cases of restenosis of the intracranial VBA after PTA which stenoses were successfully retreated with endovascular stenting using flexible coronary stents without any complications. Neither restenosis nor other recurrent symptoms were observed during the 4- and 6-month follow-up period. Reviewing the literature of 33 cases and our 2 cases, the overall complication rates related to stenting and restenosis were 5.6% and 7.8%. Endovascular stenting for the treatment of intracranial VBA can reduce the risk of arterial dissection and restenosis.     

Quantification of elastic recoil after balloon angioplasty in the iliac arteries.

PURPOSE: Elastic recoil of the arterial wall has been shown to be responsible for a significant loss of luminal area after balloon angioplasty in the coronary arteries, but it has not been well studied in the peripheral arteries. Because elastic recoil depends on the presence of elastin in the arterial wall, and the amount of elastin varies by artery and proximity to the aorta, the importance of this response to angioplasty may be different in peripheral arteries. The purpose of this study is to document the degree of elastic recoil in the iliac arteries, and analyze variables that might influence the results. MATERIALS AND METHODS: A series of 19 patients with 25 iliac artery stenoses underwent balloon angioplasty followed by placement of a Palmaz stent with the same-sized angioplasty balloon. The minimum luminal diameter of the lesion was measured before treatment, immediately after balloon angioplasty, and again after stent placement. The arterial diameter after stent placement was defined as the diameter of the inflated balloon. The degree of recoil was correlated with nine variables: patient age and sex, lesion location and length, lesion severity (as percent stenosis), the balloon:artery ratio, and three factors related to lesion morphology--complex versus simple, eccentric versus concentric, and calcified versus noncalcified. RESULTS: Elastic recoil averaged 36% +/- 11% and ranged from 19% to 54% in this series of patients. The only variable that significantly influenced the degree of elastic recoil was the balloon:artery ratio (P =.039), which was directly related. CONCLUSION: Elastic recoil is a significant limitation of balloon angioplasty in the iliac arteries. This study illustrates the importance of techniques that limit recoil, such as vascular stents, in angioplasty of the iliac arteries.     

Relief of Mesenteric Ischemia by Z-Stent Placement into the Superior Mesenteric Artery Compressed by the False Lumen of an Aortic Dissection

In a 58-year-old man acute aortic dissection compromised the origin of the superior mesenteric artery (SMA), resulting in mesenteric ischemia. After failed balloon angioplasty a Gianturco Z-stent was placed. The stenosis improved immediately, followed by resolution of the clinical signs of mesenteric ischemia. SMA flow was well preserved 1 year after stenting. Received: 0/00/00/Accepted: 0/00/00     

Randomized Trial of the SMART Stent versus Balloon Angioplasty in Long Superficial Femoral Artery Lesions: The SUPER Study

Purpose

To determine whether primary stenting reduces the rate of restenosis compared with balloon angioplasty alone in the endovascular treatment of long superficial femoral artery lesions; and to assess the effect of treatment on quality of life.

Methods

A total of 150 patients with superior femoral artery occlusion or severe stenosis of 5–22 cm length from 17 UK centers were randomized to either primary stenting with the SMART stent or balloon angioplasty (i.e., percutaneous transluminal angioplasty, PTA). Bailout stent placement was permitted in case of inadequate result from PTA. The primary end point was restenosis measured by duplex ultrasound at 1 year. Quality-of-life assessments were performed by the EuroQol (EQ)-5D questionnaire.

Results

Mean lesion length was 123.0 mm in the stent group and 116.8 mm in the PTA group. A total of 140 (93.3 %) of 150 had total occlusions. At 12 months’ follow-up, restenosis measured by Duplex ultrasound was not significantly different between the stent and PTA groups by intention-to-treat or as-treated analyses: 47.2 versus 43.5 % (p = 0.84) and 40.8 versus 46.7 % (p = 0.68), respectively. There were fewer target lesion revascularizations in patients randomized to stenting, but this did not reach statistical significance (12.5 vs. 20.8 %, p = 0.26). There was no difference in the rate of amputation. Patients in both groups reported improved quality of life.

Conclusion

Primary stenting of long lesions in predominantly occluded superficial femoral arteries does not reduce the rate of binary restenosis compared with balloon angioplasty and bailout stenting. Both treatment strategies conferred a meaningful and sustained improvement to the quality of life of patients with severe superficial femoral artery disease.     

Concurrent dissections of ascending aorta and right coronary artery during primary coronary angioplasty

We present a case of dissection in ascending aorta (AA) accompanying dissection of the right coronary artery (RCA) during transfemoral primary coronary angioplasty (PCA) for acute inferior myocardial infarction (MI). To our best knowledge, this is the first case of dissection both in AA and RCA during angioplasty for acute MI. The dissection in RCA was caused by balloon inflation during PCA. Most probably, an angiographically invisible retro-dissection in RCA resulted in the dissection in AA. A computed tomography (CT) confirmed the diagnosis of aortic dissection that was restrained in AA. The patient was treated conservatively. Five days after the event, a control CT demonstrated that the false lumen in AA disappeared and the dissection was healed entirely.     

MR measurement of coronary blood flow.

The functional significance of coronary arterial stenosis can be evaluated by measuring the pharmacological flow reserve. Magnetic resonance (MR) imaging has a unique potential for noninvasive measurement of coronary blood flow and flow reserve in the native coronary artery and bypass graft. Restenosis after coronary balloon angioplasty and stenting in the left anterior descending artery can be detected noninvasively with serial MR measurements of the coronary flow reserve. Further refinement of the MR pulse sequences to improve spatial and temporal resolutions may permit accurate quantification of blood flow volume and flow reserve in all major coronary arterial branches. MR assessments of blood flow volume and flow pattern allow noninvasive detection of significant stenosis in the coronary artery bypass graft as well. By integrating MR blood flow measurement in the coronary sinus and cine MR assessment of left ventricular myocardial mass, altered myocardial micro-circulation in patients with diffuse myocardial diseases, such as hypertrophic cardiomyopathy and cardiac transplant, has been documented. J. Magn. Reson. Imaging 1999;10:728-733.     

Dilatation Mechanism of Balloon Angioplasty in Children: Assessment by Angiography and Intravascular Ultrasound

Purpose: Little information is available about the dilatation mechanism in children. This prospective study aimed to (1) evaluate the dilatation mechanism of balloon angioplasty in children with arterial stenosis, and (2) compare the morphological changes seen by intravascular ultrasound (IVUS) and angiography. Methods: Twenty consecutive patients, who had undergone a total of 23 procedures, were examined before and immediately after balloon angioplasty with a 4.3 Fr, 30 MHz rotational tip IVUS system. The lesions for IVUS study had resulted from coarctation of the aorta in six patients, pulmonary arterial stenosis in five, Blalock-Taussig shunt stenosis in three, subclavian artery stenosis in two, renal artery stenosis in two, coronary artery stenosis in one and ductus arteriosus in one. Results: Four distinctive morphological types were identified: type I with arterial stretching, type IIa with superficial tearing, type IIb with deep intimal-medial tearing, type III with flap formation, and type IV with dissection. The diameter of the narrowest site before and after balloon angioplasty increased significantly from 2.1 ± 1.4 mm to 4.6 ± 3.4 mm (p < 0.001). Eighteen of the 23 angioplasty procedures (78%) were considered to be successful, with a dilatation ratio of more than 50%. In most patients with successful dilatation, non-stretch mechanisms such as tearing, flap formation, or dissection were found. The positive percent (70%) of non-stretch mechanisms seen by IVUS was significantly higher than the positive findings (39%) by angiography (Χ²= 6.47, p < 0.02). Conclusions: Non-stretch morphology of the arterial wall may be a common mechanism of dilatation after balloon angioplasty in children with arterial stenosis. IVUS is a useful modality for evaluating the effectiveness of balloon angioplasty and the mechanism of dilatation in individual cases.     

Cerebral angioplasty and stenting for intracranial vertebral atherosclerotic stenosis.

A 72-year-old man underwent cerebral angioplasty and stenting for a high-grade eccentric atherosclerotic stenosis (93%) of the right intracranial vertebral artery. The lesion was sufficiently and smoothly dilated very easily with the use of a highly flexible, balloon-expandable coronary stent. No complications occurred during or after the procedure. This therapeutic option may prove to be a safe and useful means to resolve an intracranial atherosclerotic stenosis.     

经皮球囊血管成形术与肾动脉支架术治疗肾动脉狭窄的疗效对比观察

目的观察经皮球囊血管成形术和肾动脉支架植入术治疗肾动脉狭窄的疗效。资料和方法 112例肾动脉狭窄患者随机分为2组:A组,经皮球囊血管成形术组;B组,肾动脉支架术组。比较两组的首次手术成功率、术后6个月并发症发生率、通畅率及术后即刻再狭窄率,术后6个月血压及血肌酐变化情况。结果 B组成功率高于A组(94.64%对76.79%,P<0.01),通畅率B组高于A组(73.21%对30.36%,P<0.01),再狭窄率B组低于A组(10.71%对28.57%,P<0.01),两组并发症发生率差异无统计学意义(P>0.05)。B组高血压治愈率较A组高(P<0.01),肾动脉支架术对动脉粥样硬化所致高血压的改善情况最好,而经皮球囊血管成形术对肌纤维结构不良所致肾血管性高血压的改善情况最好。术后血肌酐B组降低不明显(P>0.05),A组显著降低(P<0.05)。A组术后TGFR、RGFR较术前显著改善(P<0.05),B组术后TGFR较术前显著改善(P<0.05);A组术后TGFR改善更明显,较B组差异有统计学意义(P<0.05)。结论肾动脉支架术操作成功率高、通畅率高、再狭窄率低,对动脉粥样硬化引起的肾动脉狭窄所致高血压改善明显,较经皮球囊血管成形术有较大优势,可作为治疗肾动脉狭窄的一种重要的介入治疗方法。     

Aneurysm formation after dynamic catheter assisted balloon angioplasty

A male patient underwent recanalisation of a symptomatic popliteal artery occlusion using a dynamic angioplasty catheter, followed by balloon dilatation. A small subintimal dissection lead to an acute reocclusion. Repeat balloon angioplasty reopened the occlusion but was complicated by a distal embolus which was successfully treated by thrombolytic therapy followed by oral anticoagulation. Angiography 9 months later, demonstrated an aneurysm at the site of initial dissection. The artery remained patent and the patient free of claudication. A causal relationship between dynamic angioplasty and subsequent aneurysm formation is suggested and the possible predisposing factors discussed.     

急诊冠状动脉内支架置入治疗急性心肌梗死

目的 探讨急性心肌梗死患者急诊经皮冠状动脉内支架置入成形的安全性和有效性。资料与方法 22例急性心肌梗死患者,男16例,女6例,年龄48～90岁。其中2例合并心源性休克。梗死相关血管：左冠状动脉20支,右冠状动脉8支。22例患者25支血管(30处病变)施行了急诊经皮冠状动脉内支架置入成形术,3支血管行单纯经皮冠状动脉成形术(TPCA)治疗。结果 22例患者28支病变血管全部获得有效开通,其中25支血管(30处病变)一次性置入内支架,支架置入成功率loo％。除1例术后死亡外,2l例术前梗死相关血管平均狭窄95％,术后残余狭窄为6％,临床治疗成功率为95．5％,病死率为4．5％。对顺利出院的21例患者随访6个月．其间无心脏缺血症状发生。结论 急诊经皮冠状动脉内支架置入成形是治疗急性心肌梗死的安全有效措施,成功率高,并发症少,术后心肌再缺血发生率低,对改善患者的近期和远期预后有利。     

Perkutane Revaskulärisation von Nierenarterienstenosen Ballonangioplastie versus Stentimplantation

Renal artery stenosis (RAS) is the most common cause of secondary hypertension, with a prevalence of about 1% in the general population of people with hypertension. Severe arterial stenosis may also lead to impairment of excretory renal function. In experienced hands renal artery revascularization with or without stent implantation may be a safe and effective treatment in patients with sustained hypertension resistant to intensive antihypertensive treatment. Conventional balloon angioplasty of non-ostial RAS caused by fibromuscular dysplasia with a high technical and functional success rate may be the treatment of choice. However, there is continuous discussion concerning the utility of balloon angioplasty and renal stenting, respectively, in patients with atherosclerotic disease. At the time being, there are 3 randomized European trials ongoing to analyze the benefit of medical treatment versus percutaneous intervention. Several prospective studies dealing with renal artery stenting in ostial RAS found that the implantation of endoprostheses leads to much better morphologic longterm results as compared to those of balloon angioplasty alone and may be a safe and effective alternative to surgery. In addition, the functional results suggest that stent implantation in patients with mild or severe renal dysfunction may slow progression of renal failure and, thus delay the need for renal replacement therapy. It is to note that renal artery stenting does not impede any further surgical intervention. However, prior to any interventional treatment the indication of an eventual catheter procedure in patients with RAS should be discussed between experienced nephrologists and interventionalists based on clinical, functional and duplexsonographic data.     

Stent deployment resolves a petrous carotid artery angioplasty dissection.

A patient with a symptomatic petrous carotid artery stenosis underwent balloon angioplasty, which was complicated by a flow-limiting dissection. The problem was resolved by deploying a balloon-expandable coronary stent. The patient suffered no neurologic deficit, was discharged within 12 hours, and was asymptomatic at last follow-up, 5 months after the procedure, without warfarin therapy. This therapeutic option may prove useful as a means to correct endovascular procedural complications.     

Case report: perforation of angioplasty balloon by Palmaz stent.

Intravascular stents are recognized to be of value in maintaining patency in resistant stenoses, recanalized occlusions, and when intimal dissection has occurred during balloon angioplasty [1,2,3]. Apart from early thrombosis, complications are relatively infrequent. We report a case of perforation of an angioplasty balloon during iliac angioplasty by a Palmaz stent sited in the contralateral iliac artery.     

Primary stenting for high-grade basilar artery stenosis

We report two patients with symptomatic high-grade stenosis of the basilar artery refractory to appropriate maximal medical therapy in whom endovascular stenting was performed successfully without preliminary balloon angioplasty. Excellent angiographic results were achieved and there were no procedural or periprocedural complications. The patients were asymptomatic and neurologically intact at a mean clinical follow-up of 6.5 months. Primary stenting of basilar artery stenosis may be an alternative to balloon angioplasty for patients with symptomatic lesions refractory to medical therapy or in whom anticoagulation is contraindicated.     

Percutaneous transluminal angioplasty and stenting of the proximal vertebral artery for symptomatic stenosis

BACKGROUND AND PURPOSE: Percutaneous transluminal angioplasty (PTA) for significant stenosis involving the origin of the vertebral artery is now a well established treatment for selected patients when posterior cerebral arterial circulation is compromised. Arterial spasm, dissection, and restenosis may occur in some instances, with subsequent hemodynamic compromise. To prevent these potential complications, we combined PTA of the vertebral artery with primary stenting, using coronary stents, in seven patients. We herein present our short- and intermediate-term results. METHODS: A total of seven lesions affecting the origin of the vertebral artery were treated by primary trans-stenotic coronary stent placement. All patients were symptomatic, fulfilling the general criteria for vertebral artery angioplasty. Patients were followed for up to 36 months after treatment. RESULTS: All seven lesions were successfully dilated. Residual stenosis was never greater than 20% in diameter. No perioperative complications occurred. Clinical follow-up showed immediate resolution or improvement of symptoms in all patients. One patient's condition deteriorated 15 months after stent placement because of atheromatous stenosis of the prevertebral segment in the ipsilateral subclavian artery. CONCLUSION: Stent placement to treat significant stenosis involving the origin of the vertebral artery is safe and effective for alleviating symptoms and improving blood flow to the posterior cerebral circulation. Coronary stent design seems to be particularly well suited to cover atherosclerotic lesions of the origin of the vertebral artery. The stent mesh probably prevents elastic recoil and early restenosis after PTA, as it does in coronary arteries.