Renal stenting from the radial artery: a novel approach

PURPOSE: To describe the technique and feasibility of renal artery angioplasty and stenting from the radial artery. METHODS: A series of 19 patients were evaluated for transradial renal artery intervention. Procedures were performed using carbon dioxide gas (CO2) as the preferred angiographic contrast agent. Intervention was performed through a 5 Fr radial artery sheath using low-profile balloons and balloon-expandable stents. RESULTS: Nineteen patients with 26 stenosed renal arteries were considered for treatment via the radial route. A negative Allen's test precluded radial puncture in two (11%). In one patient the descending aorta could not be catheterized. Stenting from the radial route was successful in 22 renal arteries in 16 patients. On an intention-to-treat basis 16 of the 19 (84%) were treatable from the radial route. In the 17 patients with radial access technical success was 94% (16 of 17) patients and 91% (21 of 23) of renal arteries. One patient experienced a cerebrovascular event during intervention. CONCLUSION: Transradial renal artery intervention is technically feasible using low-profile angioplasty balloons and stents. This route offers advantages in renal arteries with a caudal angulation and in patients with diseases or tortuous iliac arteries.     

Percutaneous Endovascular Treatment of Chronic Iliac Artery Occlusion

Purpose: To evaluate the clinical and radiological long-term results of recanalization of chronic occluded iliac arteries with balloon angioplasty and stent placement. Methods: Sixty-nine occluded iliac arteries (mean length 8.1 cm; range 4–16 cm) in 67 patients were treated by percutaneous transluminal angioplasty and stent placement. Evaluations included clinical assesment according to Fontaine stages, Doppler examinations with ankle–brachial index (ABI) and bilateral lower extremity arteriograms. Wallstent and Cragg vascular stents were inserted for iliac artery recanalization under local anesthesia. Follow-up lasted 1–83 months (mean 29.5 months). Results: Technical success rate was 97.1% (67 of 69). The mean ABI increased from 0.46 to 0.85 within 30 days after treatment and was 0.83 at the most recent follow-up. Mean hospitalization time was 2 days and major complications included arterial thrombosis (3%), arterial rupture (3%) and distal embolization (1%). During follow-up 6% stenosis and 9% thrombosis of the stents were observed. Clinical improvement occurred in 92% of patients. Primary and secondary patency rates were 75% and 95%, respectively. Conclusion: The long-term patency rates and clinical benefits suggest that percutaneous endovascular revascularization with metallic stents is a safe and effective treatment for patients with chronic iliac artery occlusion.     

Angioplasty of the pelvic and femoral arteries in PAOD: Results and review of the literature

Purpose

Evaluation of percutaneous recanalization of obstructed iliac as well as superficial femoral arteries (SFAs) in patients with peripheral arterial obstructive disease (PAOD).

Material and methods

The data of 195 consecutive patients with 285 obstructions of the common and or external iliac artery as well as the data of 452 consecutive patients with 602 long occlusions (length > 5 cm) of the SFA were retrospectively analyzed. The lesions were either treated with percutaneous transluminal angioplasty (PTA) or Excimer laser assisted percutaneous transluminal angioplasty (LPTA). Overall 316 stents were implanted (Nitinol stents: 136; stainless steel stents: 180) in the iliac artery and 669 stents were implanted (Nitinol stents: 311; Easy Wallstents: 358) in the SFA. The follow-up period was 36-65 months (mean 46.98 ± 7.11 months) postinterventionally using clinical examination, ABI calculation, and color-coded duplex sonography. Patency rates were calculated on the basis of the Kaplan-Meier analysis.

Results

The overall primary technical success rate was 97.89% for the iliac arteries and 92.35% for the SFA. Minor complications (hematoma, distal emboli and vessel dissection) were documented in 11.79% for the iliac arteries and 7.97% for the SFA. The primary patency rate was 90.3% for the iliac and 52.8% for the SFA after 4 years. The secondary patency rate was 96.84% for the iliac and 77.8% for the SFA after 4 years.

Conclusion

Percutaneous recanalization of iliac and superficial femoral artery obstructions is a safe and effective technique for the treatment of patients with PAOD. By consequent clinical monitoring high secondary patency rates can be achieved. The use of a stents seems to result in higher patency rate especially in the SFA when compared to the literature in long-term follow-up.     

Neointima formation following arterial placement of self-expanding stents of different radial force: Experimental results

Purpose: Radial force delivered by self-expanding stents has been discussed as a factor affecting thickness of neointima formation. Methods: Two types of Wallstents were studied experimentally in vitro and in vivo. Due to an altered braiding angle of the stent filaments, one stent type (LS type) delivers half the radial force to the vascular wall than the conventional type. The radial force was evaluated in a compression-expansion test which related changes in stent length to the compressing force. Fourteen LS and 16 conventional stents were implanted into 15 femoropopliteal arteries of 10 dogs. Autopsy was performed after 4 weeks (14 stents) or 6 months (16 stents). Results: All stents remained patent over the follow-up period with no evidence of stenosis. Neointimal overgrowth was complete and smooth in all. Medial atrophy was a constant finding after placement of both types. Neointimal thickness did not exceed 100 m after 4 weeks and 6 months and did not significantly differ between LS stents and conventional stents. Conclusion: It is concluded that in normal dogs self-expanding stents of the Wallstent type do not induce neointimal buildup that exceeds 100 m in the femoropopliteal artery. A reduced radial force was not found to result in reduced neointima formation.     

Repeated intervention for in-stent restenosis of the renal arteries

PURPOSE: To assess the long-term technical success of repeated endovascular intervention in stenosed renal artery stents. MATERIALS AND METHODS: Fifteen patients with stenoses >or=50% in a renal stent placed because of an ostial atherosclerotic renal artery stenosis were included in this study. In the presence of increased blood pressure or decreased renal function, the in-stent restenosis was treated with percutaneous transluminal angioplasty (PTA) in the stent or placement of a second stent if the stenosis was located too distally in the stent. The results of these repeat interventions were evaluated by angiography. RESULTS: The 15 patients had a total of 20 stenosed stents. Eighteen of these in-stent stenoses were treated with PTA and two were treated with placement of a second stent. Angiographic follow-up was available in 16 arteries, showing in-stent restenosis in four (25%; mean follow-up, 11 mo). The cumulative patency rates after repeat endoluminal intervention were 93% (95% CI: 80%-106%) and 76% (95% CI: 52%-101%) after 6 and 12 months, respectively. Renal function remained stable or improved in most patients (80%) after repeated intervention in the stent, and hypertension was classified as improved or cured in 47% of patients after 1 year. CONCLUSION: Patients with stenosed renal artery stents can be treated successfully with PTA in a majority of cases, with a long-term success rate of 75% and stable renal function 1 year after repeated intervention.     

Renal artery entrapment by the diaphragmatic crus

The aim of this study is to describe renal artery entrapment (RAE) by the diaphragmatic crus and to elucidate the diagnostic and therapeutic approach to this entity. From 1995 to 2002, 15 patients (mean age 65) were found to have a RAE. They were investigated by CT scan (n=14) and/or MRA (n=2) for hypertension (n=7), chronic renal insufficiency (n=4) or aneurysms (n=4). The right (n=11) or the left (n=4) renal artery (RA) was involved. The compression was ostial (n=8) or truncal (n=7), and was 50% in eight cases. The course of the RA along the aorta on angiographic views (n=8) or a concentric ostial stenosis in a patient free of atheromatous lesions (n=7) were two findings suggestive of an RAE. Seven RAEs were indicated for treatment but only three were treated, by mean of stenting. Among the latter, two stents were patent at 6-month follow-up and one evolved to restenosis because of a stent fracture. RAEs may be suspected on angiographic views and proved by cross-sectional imaging because of specific imaging features. It is of importance to detect this etiology of RA stenosis because angioplasty with stenting is probably not always advisable.     

Long term results of endovascular treatment in renal arterial stenosis from Takayasu arteritis: Angioplasty versus stent placement

Purpose

To retrospectively evaluate and compare the long term patency and antihypertensive effect of angioplasty and stent insertion in renal artery stenosis caused by Takayasu arteritis, with CT angiography and clinical follow-up.

Materials and methods

We retrospectively analyzed and compared effects on hypertension and patency of renal artery in 16 patients (age ranging from 16 to 58 years, mean: 32.1 years) with renovascular hypertension caused by Takayasu arteritis who underwent endovascular treatment including angioplasty (n = 13) and stent placement (n = 9) for 22 stenotic renal arteries.

Results

Technical success was 95% (21/22) without major complications. In the last follow-up CT angiogram (mean 85 ± 41 months), restenosis was 8% (1/12) in angioplasty and 66% (6/9) in stent. Patency rates of angioplasty were 100%, 91.7%, 91.7% and primary unassisted and primary assisted patency rates of stent placement were 55.6%, 33.3%, 33.3% and 88.9%, 66.7%, 55.6% at 1-, 3- and 5-years, respectively. In clinical follow-up (mean 120 ± 37.8 months, range 48–183 months), beneficial effects on hypertension were obtained in 87% of patients (13/15) and there was no significant difference between the patients who were treated by only angioplasty and the patients who received stent placement in at least one renal artery, regardless of whether or not angioplasty had been performed in the other renal artery.

Conclusion

Compared with stent placement, angioplasty demonstrated better long term patency and similar clinical benefit on renovascular hypertension in renal artery stenosis of Takayasu arteritis. We suggest that stent placement should be reserved for obvious angioplasty failure.     

Flow Diversion with Low-Profile Braided Stents for the Treatment of Very Small or Uncoilable Intracranial Aneurysms at or Distal to the Circle of Willis

BACKGROUND AND PURPOSE:The endovascular treatment of aneurysms located at or distal to the circle of Willis and not amenable to coiling remains a challenge. We report our experience with flow-diversion treatment using low-profile braided stents as a stent monotherapy procedure for treating distally located very small or uncoilable aneurysms.MATERIALS AND METHODS:We retrospectively reviewed our data bases to identify patients with aneurysms located at or distal to the circle of Willis who were treated with stent monotherapy using low-profile braided stents. The immediate and follow-up angiographic findings and clinical status of the patients were assessed.RESULTS:Twenty aneurysms in 19 patients were included in the study. The mean size of the aneurysms was 4.7 ± 2.4 mm. Patients were treated via telescopic implantation of 2 stents for 11 aneurysms; single-stent placement was used for the remaining aneurysms. The technical success rate was 95%. We observed a technical complication in 1 case (5.3%) and a late ischemic event in another (5.3%). The final angiographies during a mean follow-up of 14.7 months showed complete aneurysm occlusion in 73.7%. The complete occlusion rate of the aneurysms treated with telescopic stent placement was 81.8%. The modified Rankin scale scores of all patients at the last follow-up were between 0 and 2.CONCLUSIONS:Flow diversion with low-profile braided stents as a stent monotherapy procedure for very small or uncoilable intracranial aneurysms located at or beyond the circle of Willis is a promising, relatively safe, and durable endovascular procedure.

In the past decade, several self-expandable stents dedicated to intracranial use have been introduced to treat wide-neck and complex aneurysms previously not amenable to coiling.^1–4 Stents create a mechanical scaffold, which prevents coil protrusion into the parent artery. In addition to this mechanical scaffolding effect, the implantation of stents also produces hemodynamic and biologic effects in the parent arteries that promote aneurysm occlusion. Stent deployment across the orifice of an aneurysm redirects the blood flow in the parent artery to decrease hemodynamic stress, which facilitates thrombosis in the aneurysmal sac.⁵ Furthermore, stents induce neointimal proliferation in the parent artery, which eventually leads to healing of the aneurysm neck.⁶ The hemodynamic and biologic effects of stents promote the progressive occlusion of partially coiled aneurysms and impede their recanalization.On the basis of the hemodynamic and biologic effects of stents, flow-diversion treatment as a stent monotherapy procedure using conventional stents has been proposed for the endovascular treatment of intracranial aneurysms not amenable to coiling or alternative open surgical procedures.⁷ Flow diversion as a stent monotherapy procedure consists of the implantation of a self-expandable stent or stents across the neck of an aneurysm, without coiling the aneurysm sac. A limited number of previous case series reported the application of stent monotherapy with balloon-expandable or conventional self-expandable stents and focused on the treatment of aneurysms located proximal to the circle of Willis.^7–10Low-profile braided stents have been recently introduced to treat aneurysms located at small-sized, distal parent arteries. Low-profile intracranial stents can be deployed into arteries with diameters between 1.5 and 3.5 mm, and they can be delivered through microcatheters with an internal diameter of 0.0165 inches, which allows easier navigation in small-sized, delicate vessels.¹¹ In this report, we present our experience with flow-diversion treatment as a stent monotherapy procedure for treating very small or uncoilable intracranial aneurysms located at or beyond the circle of Willis using low-profile braided stents. In this retrospective study, we investigated the feasibility, efficacy, and midterm durability of the stent monotherapy procedure with LEO Baby stents (Balt, Montmorency, France).     

The erasme study: A multicenter study on the safety and technical results of the palmaz stent used for the treatment of atherosclerotic ostial renal artery stenosis

Purpose: To assess, in a multicenter setting, safety, technical results, and restenosis rate of the Palmaz stent for treatment of atherosclerotic ostial renal artery stenosis. Methods: Ten centers enrolled 106 patients (120 treated renal artery stenoses) in the study. Patient selection was based on unsuccessful percutaneous transluminal renal angioplasty (residual stenosis ≥ 20%) performed for treatment of ostial stenosis ≥ 50%, in patients with hypertension and/or impaired renal function. Safety was assessed by means of the complication rate, and technical results by the number of successful stent placements and occurrence of restenosis (>50%) at intraarterial angiographic follow-up. Results: Stent placement was successful (n = 112) or partially successful (n = 5) in 117 (98%) arteries. Complications occurred in 19 procedures; seven were of serious clinical significance. Angiographic follow-up was performed in 89 of 117 (76%) cases, at a mean of 8 months (range 2.5–18 months). Fifteen stents (16.9%) showed restenosis (at a mean of 8.5 months), of which 10 were successfully redilated. Conclusion: Renal artery stenting has a high technical success rate, a complication rate comparable to percutaneous transluminal renal angioplasty, and a low rate of restenosis at 8 months angiographic follow-up.     

Combined Endovascular Treatment with Distal Radial Artery Coil Embolization and Angioplasty in Steal Syndrome Associated with Forearm Dialysis Fistula

Purpose

The present study was performed to define the results of the endovascular treatment with angioplasty and distal radial artery embolization in ischemic steal syndrome associated with forearm arteriovenous accesses.

Method

The cases referred to our interventional radiology unit with symptoms and physical examination findings suggestive of ischemic steal syndrome were retrospectively evaluated first by Doppler ultrasonography, and then by angiography. Cases with proximal artery stenosis were applied angioplasty, and those with steal syndrome underwent coil embolization to distal radial artery.

Results

Of 589 patients who underwent endovascular intervention for dialysis arteriovenous fistulae (AVF)-associated problems, 6 (1.01 %) (5 female, 1 males; mean age 62 (range 41–78) with forearm fistula underwent combined endovascular treatment for steal syndrome. In addition to steal phenomenon, there were stenosis and/or occlusion in proximal radial and/or ulnar artery in 6 patients concurrently. Embolization of distal radial artery and angioplasty to proximal arterial stenoses were performed in all patients. Ischemic symptoms were eliminated in all patients and the AVF were in use at the time of study. In one patient, ischemic symptoms recurring 6 months later were alleviated by repeat angioplasty of ulnar artery.

Conclusion

In palmar arch steal syndrome affecting forearm fistulae, combined distal radial embolization and angioplasty is also an effective treatment method in the presence of proximal radial and ulnar arterial stenoses and occlusions.

     

Safety and Efficacy of Stent-Assisted Coiling of Unruptured Intracranial Aneurysms Using Low-Profile Stents in Small Parent Arteries

BACKGROUND AND PURPOSE:Stent-assisted coiling of intracranial aneurysms arising from small vessels (≤ 2.0 mm) is a common procedure. However, data regarding its treatment outcomes are scarce. This study evaluated the clinical and radiologic outcomes of stent-assisted coiling using low-profile stents for aneurysms of small parent arteries.MATERIALS AND METHODS:From November 2015 to October 2020, sixty-four patients with 66 aneurysms arising from parent arteries of ≤2.0 mm were treated with stent-assisted coiling using a Low-Profile Visualized Intraluminal Support Junior (LVIS Jr) or the Neuroform Atlas stent in a single institution. The clinical and radiologic data were retrospectively reviewed, and the risk factors for procedure-related complications were evaluated.RESULTS:The LVIS Jr and Neuroform Atlas stents were used in 22 (33.3%) and 44 (66.7%) cases, respectively. Technical success was achieved in 66 cases (100%). Immediate postprocedural aneurysm occlusion grades assessed by the Raymond-Roy occlusion classification were I (57.6%), II (19.7%), and III (22.7%), respectively. Procedure-related complications occurred in 10 cases (15.2%), with 8 thromboembolic complications (12.1%) and 2 hemorrhagic complications (3.0%). Procedure-related morbidity was 4.5% without mortality. On multivariate analysis, current smoking (odds ratio = 7.1, P = .021) had a statistically significant effect on procedure-related complications.CONCLUSIONS:Stent-assisted coiling of intracranial aneurysms with low-profile stents in small vessels (≤ 2.0 mm) had a 100% success rate and a 15.2% overall complication rate with 4.5% morbidity. Current smoking was a significant risk factor associated with procedure-related complications.

In the past decade, development in neuroendovascular devices and techniques has facilitated the successful treatment of intracranial aneurysms that had been previously considered challenging or uncoilable lesions.¹ Above all, stent-assisted coiling (SAC) is widely accepted as an effective and safe treatment technique for wide-neck intracranial aneurysms^2,3 because it can also reduce recanalization and retreatment rates.⁴ However, previously used stent placement in small vessels was technically challenging due to the difficult navigation of larger (0.021- or 0.027-inch) delivery microcatheters to these small arteries.^5-7Recently, low-profile stents were introduced to improve the navigability and success rate of the procedure because they can be delivered via 0.0165- or 0.017-inch microcatheters to access tortuous and smaller vessels.^8-10 Although the recommended use of the low-profile stents is for a parent artery with a diameter of either ≥2.0  or ≥2.5 mm, their off-label use for the treatment of aneurysms arising from smaller parent arteries has become more common.^11,12 However, little is known about the efficacy and safety of SAC using low-profile stents in vessels smaller than 2.0 mm.In the present study, we aimed to investigate the clinical and radiologic outcomes of SAC using low-profile stents for the treatment of unruptured intracranial aneurysms arising from small vessels with a diameter of ≤2.0 mm.     

Fenestrated Stent Graft Repair of Abdominal Aortic Aneurysm: Hemodynamic Analysis of the Effect of Fenestrated Stents on the Renal Arteries

Objective

We wanted to investigate the hemodynamic effect of fenestrated stents on the renal arteries with using a fluid structure interaction method.

Materials and Methods

Two representative patients who each had abdominal aortic aneurysm that was treated with fenestrated stent grafts were selected for the study. 3D realistic aorta models for the main artery branches and aneurysm were generated based on the multislice CT scans from two patients with different aortic geometries. The simulated fenestrated stents were designed and modelled based on the 3D intraluminal appearance, and these were placed inside the renal artery with an intra-aortic protrusion of 5.0-7.0 mm to reflect the actual patients'' treatment. The stent wire thickness was simulated with a diameter of 0.4 mm and hemodynamic analysis was performed at different cardiac cycles.

Results

Our results showed that the effect of the fenestrated stent wires on the renal blood flow was minimal because the flow velocity was not significantly affected when compared to that calculated at pre-stent graft implantation, and this was despite the presence of recirculation patterns at the proximal part of the renal arteries. The wall pressure was found to be significantly decreased after fenestration, yet no significant change of the wall shear stress was noticed at post-fenestration, although the wall shear stress was shown to decrease slightly at the proximal aneurysm necks.

Conclusion

Our analysis demonstrates that the hemodynamic effect of fenestrated renal stents on the renal arteries is insignificant. Further studies are needed to investigate the effect of different lengths of stent protrusion with variable stent thicknesses on the renal blood flow, and this is valuable for understanding the long-term outcomes of fenestrated repair.     

Primary Stenting of Subclavian and Innominate Artery Occlusive Disease: A Single Center’s Experience

Purpose: To review immediate and midterm results of primary stenting for innominate and subclavian artery occlusive lesions.Methods: Retrospective data were collected from 48 consecutive symptomatic patients (27 men and 21 women, median age 64 years) having 49 subclavian and innominate artery lesions treated with stenting. Of the patients 52% had concomitant ischemic heart disease, and 30% had carotid and/or vertebral artery disease. Indication for treatment was vertebrobasilar insufficiency (VBI) in 16.6% of the patients; upper limb ischemia (ULI) in 31.3%; VBI and ULI in 12.5%; transient ischemic attack in 16.7%; angina in 12.5% before or after left internal mammary artery–to–coronary artery bypass grafting; and leg claudication in 10.4% before or after axillofemoral bypass grafting. Balloon-expandable stents were used in 44 lesions and self-expandable stents in 5 lesions. In total, 53 stents were placed in 48 patients.Results: Technical success was 96%, and clinical success 94%. We encountered four complications (two puncture site hematomas, one distal hand embolization and one transient cerebral ischemia). Two patients died within 30 days from other causes, and seven patients were lost to follow-up. Mean follow-up time was 16.7 months (range 0.3 to 68.2). Five patients had recurrent lesions treated by surgical (n = 2) or endovascular (n = 3) means. Cumulative primary patency rate was 91.7% and 77% at 12 and 24 months, respectively. Cumulative secondary patency rate was 96.5% and 91.7% at 12 and 24 months, respectively.Conclusion: Stenting of subclavian and innominate artery lesions resulted in immediate resolution of patients symptoms with durable midterm effect and few complications in a larger patient group with serious comorbid conditions.     

Brachial Artery Access for Percutaneous Renal Artery Interventions

Purpose: To evaluate the suitability of transbrachial access for endovascular renal artery interventions. Methods: During 37 consecutive endovascular renal artery interventions, the transbrachial approach was used on nine patients (mean age 63 years; range 41–76 years) for 11 renal artery procedures on native kidneys and one percutaneous transluminal angioplasty (PTA) on a transplanted kidney. The reason for using transbrachial access was a steep aorta-renal angle in five, and severe aorta-iliac atherosclerosis in the remaining patients. In addition to the intervention catheter in the left brachial artery, an additional nonselective catheter for controlling the procedure was inserted transfemorally (six patients) or via the contralateral brachial artery. Results: Eleven interventions (six PTAs, five stents) were successfully completed. The one failure resulted from impenetrable subclavian artery stenosis. The only major complication was a brachial artery pseudoaneurysm requiring surgical treatment. Conclusion: Transbrachial access is an effective and relatively safe technique for renal artery interventions when transfemoral access is not possible. Received: 0/00/00/Accepted: 0/00/00     

Post-stenting intravascular brachytherapy trials on hypercholesterolemic rabbits using 32P liquid sources: implications for prevention of in-stent restenosis

PURPOSE: Liquid sources of radiation delivered in angioplasty balloons may be a convenient self-centering device used for prevention of in-stent restenosis. To test the effectiveness of this method an intravascular brachytherapy study was performed using 32P liquid sources in an animal model. METHODS: The radial dose distribution around angioplasty balloons filled with solutions of Na 2H 32PO 4 was calibrated by thermoluminescence dosimetry. The animal experiments were performed in rabbits with induced hypercholesterolemia. The balloons containing 32P were introduced into iliac arteries immediately after stent implantation. Estimated 7-49 Gy doses required 30-100 min irradiations. Radiation effects were evaluated by comparing the thickness of various components of the artery wall. RESULTS: Doses of 7, 12, 16 or 49 Gy on the internal artery surface required 30-100 min of irradiation. The dose of 49 Gy at "zero" distance corresponding to 16 Gy at 1.0 mm from the balloon surface reduced hypertrophy in every layer of the arterial wall: in the intima the cross-sectional areas were 0.13 versus 0.91 mm 2, in the media were 0.5 versus 0.46 mm 2 and in the adventitia were 0.04 versus 0.3 mm 2 (p <0.05). A dose of 7 Gy at the balloon surface produced adverse irradiation effects: the intimal area of the artery was 2.087 versus 0.857 mm 2, the medial area was 0.59 versus 0.282 mm 2 and the adventitial area was 0.033 versus 0.209 mm 2 in treated and control arteries, respectively. CONCLUSION: Application of a 49 Gy irradiation dose to the internal arterial surface effectively prevented in-stent restenosis.     

Dual Stenting Using Low-Profile LEO Baby Stents for the Endovascular Management of Challenging Intracranial Aneurysms

BACKGROUND AND PURPOSE:Endovascular treatment of wide-neck, complex, and distally located cerebral aneurysms is a challenging issue. This study evaluated the safety and efficacy of dual stent placement by using a low-profile stent system (LEO Baby) for the treatment of challenging distal intracranial aneurysms.MATERIALS AND METHODS:We retrospectively reviewed patients in whom at least 1 LEO Baby stent was used in the context of dual stent placement for the treatment of intracranial aneurysms. Patients who were treated with dual stent-assisted coil embolization and telescopic implantation of LEO Baby stents were included in the study. Clinical and angiographic findings, procedural data, and follow-up are reported.RESULTS:Twelve patients were included in this study. Three patients presented with subarachnoid hemorrhage in the subacute-chronic phase, and the remaining patients had unruptured aneurysms. Nine patients were treated by using the dual stent-assisted coiling method. X- (nonintersecting), Y- (intersecting and reversible), T-, and parallel-stent configurations were performed for the dual stent-assisted coiling procedures. Three patients were treated by using telescopic stent placement for a flow diverter–like effect. The procedures were successful in all cases. Technical complications without a significant clinical adverse event developed in 2 patients. The 3- and 6-month control MRAs and DSAs demonstrated complete occlusion of the aneurysms in all patients except 1. All patients had good clinical outcomes on follow-up (mRS ≤1).CONCLUSIONS:The results of this small study showed the feasibility of dual stent placement by using low-profile LEO Baby stents to treat distally located complex intracranial aneurysms.

Coiling of intracranial aneurysms is safe and effective, but endovascular treatment of wide-neck and anatomically complex aneurysms remains challenging.¹ Self-expandable intracranial stents have been used in the past decade to achieve successful and durable coil embolizations of these aneurysms.^2–4 The placement of a stent bridging the ostium of a wide-neck aneurysm creates a scaffold, which prevents the protrusion or herniation of coils into the parent artery and results in denser coil packing. In addition to the mechanical effect, intracranial stents have hemodynamic and biologic effects.^5–8 Stent deployment across the orifice of an aneurysm is thought to redirect blood flow from the sac of the aneurysm toward the distal parent artery and decrease the hemodynamic stress that contributes to thrombosis of the aneurysmal sac.⁹ Furthermore, stent-induced neointimal overgrowth leads to the healing of the neck of the aneurysm.¹⁰ On the basis of these effects, stent monotherapy has been proposed as an alternative strategy for the endovascular treatment of uncoilable and complex intracranial aneurysms.^9–11 The telescopic placement of self-expandable intracranial stents can adequately divert the blood flow, especially for the treatment of blisterlike aneurysms.¹²Recently, low-profile, self-expandable, braided intracranial stents (LEO Baby [Balt, Montmorency, France] and LVIS Jr. [MicroVention, Tustin, California]) have been available for the endovascular treatment of complex and/or distal aneurysms.^13,14 These low-profile intracranial stents can be deployed into arteries with diameters of <3.5 mm and delivered through microcatheters with an internal diameter of 0.0165 inches, which allows easier navigation in small-sized, delicate vessels.A single stent may not suffice for the endovascular treatment of wide-neck and geometrically complex bifurcation aneurysms with involvement of 1 or both side branches. Endovascular treatment of these complex aneurysms often necessitates the implantation of 2 stents (ie, dual stent placement) in various configurations, such as Y-, X-, or parallel configurations.^14–16This retrospective study evaluated the safety and efficacy of dual stent placement by using a low-profile stent system (LEO Baby) for the treatment of challenging intracranial aneurysms.     

应用血管内支架治疗肾移植后肾动脉狭窄

目的：探讨肾移植后肾动脉狭窄应用血管内支架治疗的方法和疗效。方法：5例肾移植术后肾动脉狭窄的病人，经股动脉或腋动脉入路行狭窄肾动脉的球囊扩张加支架置入。结果：5例行球囊扩张并同时置入血管内支架的病人治疗后血压恢复正常，肾功能正常。经近5年的随访，1例病人术后9个月出现移植肾动脉再狭窄，给予球囊扩张，血流基本恢复，血压正常。结论：球囊扩张并血管内支架置入术仍然是移植肾动脉狭窄的安全有效的治疗方法之一,术后再狭窄的预防需要进一步探讨。     

不同类型支架治疗椎动脉开口狭窄的对照研究

【摘要】　目的?比较不同类型支架治疗椎动脉开口狭窄的有效性和安全性。方法?2018年1月至2018年12月73例椎动脉开口狭窄患者共86条病变血管接受支架成形术治疗,分别应用肾动脉支架23枚,Apollo支架26枚,冠状动脉裸支架19枚,药物洗脱支架（DES）18枚。回顾性分析患者临床资料,对比不同类型支架植入术疗效和支架内再狭窄发生率。结果?不同类型椎动脉开口支架成形术均获成功。术前影像显示椎动脉开口平均狭窄率为90.9%,术后即刻影像显示平均残余狭窄率为10.3%。围术期手术相关并发症发生率为1.2%（1/86）。术后平均随访（6.2±3.1）个月,患者临床症状得到改善。肾动脉枚架失访1枚,再发狭窄4枚（17%）;Apollo枚架失访2枚,再发狭窄8枚（31%）,1例患者术后第2日并发大面积后循环脑梗死;冠状动脉裸枚架无失访,再狭窄7枚（37%）,1例患者6个月时枚架断裂;DES组失访1枚,再狭窄2枚（11%）,与其他组再发狭窄差异有统计学意义（P＜0.05）。结论?不同类型枚架治疗椎动脉狭窄安全有效。DES在降低枚架内再狭窄发生方面最优,肾动脉枚架次之,Apollo枚架和冠状动脉裸枚架再狭窄率较高。     

Visceral and Renal Artery Complications of Suprarenal Fixation during Endovascular Aneurysm Repair

Background The effect of suprarenal fixation of endovascular grafts on renal and visceral artery function remains undefined. This study aimed to determine renal and visceral artery complications following suprarenal fixation during endovascular aneurysm repair (EVR). Methods Prospectively collected data from 112 patients who received suprarenal fixation (group SF) and 36 patients who received infrarenal fixation (group IF) in a single institution from December 1997 to April 2005 were reviewed retrospectively. Median follow-up was 26 months (range 0.1–101 months). Results Stent struts extended to or above the level of 106 (94.6%) right renal arteries, 104 (92.9%) left renal arteries, 49 (43.8%) superior mesenteric arteries (SMA), and 7 (6.3%) celiac arteries in group SF. This group had 2 (1.8%) unintentional main renal artery occlusions, of which 1 was successfully treated at the first procedure with a renal stent. There was 1 (0.9%) SMA occlusion which resulted in bowel infarction and death. Group IF had no renal or visceral artery complications. There were no late-onset occlusions or infarcts. There was no significant difference in median serum creatinine between groups SF and IF at 1 month (p = 0.18) and 6 months to 12 months (p = 0.22) follow-up. The change in serum creatinine over time was also not significantly different within each group (SF, p = 0.09; IF, p = 0.38). Conclusions In this study, suprarenal fixation was associated with a very small incidence of immediate renal and visceral artery occlusion. There did not appear to be any medium-term sequelae of suprarenal fixation.     

The Value of 320-Row Multidetector CT Bronchial Arteriography in Recurrent Hemoptysis after Failed Transcatheter Arterial Embolization

Purpose

To retrospectively assess the value of computed tomographic (CT) bronchial arteriography (BA) with 320-row multidetector CT in the management of patients with recurrent hemoptysis immediately after bronchial artery embolization (BAE).