Coil embolization of intracranial saccular aneurysms using the Low-profile Visualized Intraluminal Support (LVIS™) device

Introduction

The novel Low-profile Visualized Intraluminal Support (LVIS?, LVIS and LVIS Jr.) device was recently introduced for stent-supported coil embolization of intracranial aneurysms. Periprocedural and midterm follow-up results for its use in stent-supported coil embolization of unruptured aneurysms are presented herein.

Methods

In this prospective multicenter study, clinical and radiologic outcomes were analyzed for 55 patients with saccular aneurysms undergoing LVIS-assisted coil embolization between October 2012 and February 2013. Magnetic resonance angiography or digital subtraction angiography was performed to evaluate midterm follow-up results.

Results

The standard LVIS device, deployed in 27 patients, was more often used in internal carotid artery (ICA) aneurysms (n?=?19), whereas the LVIS Jr. (a lower profile stent, n?=?28) was generally reserved for anterior communicating artery (n?=?14) and middle cerebral artery (n?=?8) aneurysms. With LVIS-assisted coil embolization, successful occlusion was achieved in 45 aneurysms (81.8 %). Although no instances of navigation failure or stent malposition occurred, segmentally incomplete stent expansion was seen in five patients where the higher profile LVIS was applied to ICA including carotid siphon. Procedural morbidity was low (2/55, 3.6 %), limited to symptomatic thromboembolism. In the imaging of lesions (54/55, 98.2 %) at 6-month follow-up, only a single instances of major recanalization (1.9 %) occurred. Follow-up angiography of 30 aneurysms (54.5 %) demonstrated in-stent stenosis in 26 (86.7 %), with no instances of stent migration. Only one patient suffered late delayed infarction (modified Rankin Scale 1).

Conclusion

The LVIS device performed acceptably in stent-assisted coil embolization of non-ruptured aneurysms due to easy navigation and precise placement, although segmentally incomplete stent expansion and delayed in-stent stenosis were issues.     

Stents and flow diverters in the treatment of aneurysms: device deformation in vivo may alter porosity and impact efficacy

Introduction

High-porosity (HP) and flow-diverting (FD) stents are increasingly used to treat intracranial aneurysms. In vivo device deformations and their impact on the porosity of the segment of device lying over the aneurysm neck remain inadequately characterized.

Methods

Porosities of different braided FDs were studied in straight and 90° curved glass tubes. In vivo, 11 experimental lateral wall aneurysms were treated with FD (n?=?7) or HP (n?=?4) stents. At 3 months, the segment of FDs and HP stents over the aneurysm neck was analyzed, paying attention to changes in device diameter, metallic porosity, and neointimal closure of pores over the aneurysm or branch ostia. Device deformations were reproduced with benchtop experiments.

Results

In 90° curved tubes, FD porosity was higher (P?=?0.025) and pore density was lower (P?=?0.01) on convex compared to concave surfaces, but variations remained within 5–10 %. After in vivo deployment, a spindle-shaped deformation of FDs occurred, with focal expansion at the level of the aneurysm neck (P?=?0.004). This deformation translated into an accordion-like distribution of stent struts across the aneurysm neck, where porosity was not uniform. The midsection of the aneurysm ostium had more metal coverage than adjacent ostial areas (P?=?0.002). Mean porosity over the aneurysm neck was 78?±?9.4 and 32.6?±?12.1 % for HP and FD stents, respectively (P?=?0.008), decreasing to 13.0?±?10.1 and 1.4?±?0.6 % (P?=?0.022) following neointimal coverage, respectively. Spindle-shaped deformations and accordion effects were reproduced with benchtop manipulations; fluctuations in porosity and diameter changes correlated closely (R?=?0.81; P?=?0.005).

Conclusion

Alterations in porosity may occur following in vivo implantation.     

Treatment of carotid siphon aneurysms by use of the Willis stent graft: an angiographic and histopathological study

Objective

We designed a carotid siphon (CS) aneurysm model in dogs to test a new stent graft (the Willis covered stent) and compared tissue reaction over 12-month follow-up versus a comparison group with stents implanted in straight vessels.

Methods

Twenty-four saccular sidewall aneurysms (group A) and 12 CS aneurysms (group B) were created surgically. A Willis stent graft was implanted in each aneurysm. Angiography was performed immediately and at 1-, 3-, 6- and 12-month post-implantation to investigate aneurysm isolation, endoleak, stent angulation, parent artery (PA) patency and restenosis. Light and scanning electron microscopy were used to identify aneurysmal sac thrombi, intima hyperplasia and endothelial progress.

Results

Immediate angiography demonstrated mild endoleak in two aneurysms and three stent angulations in group B. Follow-up at 12 months revealed resolved endoleaks, occlusion in one PA and mild stenosis in three in group B. In group A, occlusion occurred in one PA and mild stenosis in two. Light microscopy revealed new intima, and all aneurysm sacs were filled with thrombi. In group B, endothelial progress was complete at 12 months, and closely correlated with haemodynamic changes.

Conclusions

Application of a Willis stent graft is a feasible method of treating CS aneurysms, and it exhibits a prolonged endothelial progress compared with that in straight vessels.     

Prevalence and prognosis of coronary stent gap detected by multi-detector CT: a follow-up study

Objectives

To evaluate the features of stent gap (SG) and the long-term impact of SG on in-stent restenosis (ISR) in patent stents.

Methods

A total of 347 consecutive patients with 781 stents who underwent MDCT were assessed for SG and ISR. Clinical and stent features were compared between the SG and non-SG groups. In the follow-up study, among 82 patients with 175 patent stents [26 assessed by conventional coronary angiography (CCA) including 6 contacted in a telephone survey, 46 assessed by computed tomography angiography (CTA) and 10 by both], the incidence of ISR was compared between stents with and without SG.

Results

Three patients and 13 stents were excluded. SG was observed in 12.5% of patients and 8.6% of stents. ISR detected by CTA was noted in 21.2% of SG, and SG accounted for 23.7% of ISR. Stent number, length, location, overlapping pattern, tortuosity and in-out angle were predisposing factors for SG. During a mean follow-up period of 15?months after detection of SG, the incidence of ISR was significantly higher in the SG group than in the non-SG group (43.8/14.9% by CCA, 33.3/10.1% by CTA and CCA).

Conclusion

Patent stents with SG detected by CTA had a higher incidence of late restenosis, indicating that long-term follow-up or further intervention is necessary.

Key Points

? Coronary artery computed tomographic angiography (CTA) is increasingly used following coronary intervention. ? Gaps within coronary stents detected by CTA correlate with in-stent restenosis. ? Patients with stent gaps have more late restenosis at follow-up. ? More attention should be given to patients with stent gaps.     

Endovascular treatment with flow diverters may fail to occlude experimental bifurcation aneurysms

Introduction

Animal models may explain how stents and flow diverters (FDs) may succeed or fail to treat bifurcation aneurysms.

Methods

In vitro studies were designed to anticipate device deformations in bifurcations. Large, wide-necked bifurcation aneurysms were constructed in 21 animals and treated 4–8 weeks later using stents and FDs in various combinations, forming four main groups: parent artery to right branch flow diversion (RBFD, n?=?6), parent artery to left branch flow diversion (LBFD, n?=?6), Y flow diversion (YFD, n?=?4), and compared with high-porosity Y-stenting (YHPS, n?=?4). The results include immediate and follow-up angiography at 3 months, followed by grading of the extent of neointimal coverage of devices at pathology.

Results

In vitro, all braided devices showed varying porosities according to characteristic zones. FDs can be compacted to decrease porosities, but a limiting factor is the constant presence of a more porous transition zone. In vivo, 3/6 RBFD, 4/6 LBFD, and 2/4 YFD treated aneurysms had decreased in size by 3 months, while those treated with YHPS increased in size (P?=?0.15). There was a significant correlation between device porosities and extent of neointimal coverage (r?=?0.639, P?=?0.002), and between porosities and angiographic evolution (r?=??0.655, P?=?0.002), but not between neointima formation and angiographic evolution (r?=??0.278, P?=?0.235). Failures could be explained in all cases by the presence of leaks or holes in the neointima at the level of the transition zones.

Conclusion

FDs did not successfully treat most bifurcation aneurysms, at least in this animal model.     

Angiographic and artefact-free computed tomography imaging of experimental aneurysms embolised with hydrogel filaments

Objectives

We compared experimental rabbit carotid bifurcation aneurysms embolised with platinum coils or hydrogel filaments by using digital subtraction angiography (DSA) and computed tomography angiography (CTA).

Methods

Embolisation was performed using platinum coils (n?=?2), hydrogel filaments loaded with iodine (n?=?3) and hydrogel filaments loaded with barium sulphate (n?=?3). In one case, a stent was deployed in the parent vessel to determine the effect of hydrogel filaments on stent visualisation. DSA evaluations occurred immediately post-treatment. CTA evaluations occurred at 0–13 weeks post-treatment. The DSA and CTA images were evaluated for the lack of artefacts and the visibilities of the embolic mass, individual coils and residual flow in the aneurysm sac and neck.

Results

The DSA results were largely concordant among the three groups. The embolic masses were readily evident with some individual coils being distinguished. In the aneurysms embolised with hydrogel filaments, visualisation of the individual coils, residual flow and stent with minor or no artefacts was possible using CTA. On the other hand, the beam hardening artefacts precluded analysis of aneurysms embolised with platinum coils.

Conclusion

CTA-compatible embolic devices could have wide applications in diverse locations throughout the vasculature, particularly in combination with stents or stent grafts.     

Early and midterm results of complex cerebral aneurysms treated with Silk stent

Introduction

Endovascular treatment of intracranial aneurysms has been an effective treatment option. In this paper, we report our experience with the Silk stent (SS) for endovascular treatment of complex intracranial aneurysms and present periprocedural events, immediate results, delayed complications, and imaging and clinical follow-up results.

Methods

We retrospectively examined angiographic images and clinical reports of 76 consecutive patients with 87 intracranial aneurysms who were treated with SSs between March 2008 and June 2011.

Results

All aneurysms could be successfully covered technically using implanted SSs, with an overall mortality of 6.6?%. Two transient morbidities (2.6?%) and three permanent morbidities due to embolic events (3.9?%) were observed. Unexpected procedural technical events occurred in 18 procedures (18/78, 23.1?%). Control angiographies were performed in all 71 patients with 82 aneurysms (100?%). Mean angiographic follow-up time was 17.5?±?11.1?months [range 2?C48?months]. Sixteen of the 71 patients with 19 aneurysms had only early angiographic controls in the first 6?months while remaining 55 patients with 63 aneurysms (77.5?%) had late controls after 6?months. Overall control angiographic occlusion rates were as follows: 87.8?% (72/82) total occlusion, 8.5?% residual aneurysm filling, and 3.7?% residual neck filling. The general in-stent stenosis rate in controls was 5.6?% and the stented parent artery occlusion rate was 4.2?%. Five (6.6?%) aneurysms ruptured after stent implantation in our series.

Conclusion

The Silk stent is an effective tool for the treatment of challenging aneurysms, which have previously demonstrated higher re-growth rates and technical problems, despite unexpected higher hemorrhage rates after treatment and deployment difficulties.     

Outcomes of Prosthetic Hemodialysis Grafts after Deployment of Bare Metal versus Covered Stents at the Venous Anastomosis

Purpose

To compare postintervention patency rates after deployment of bare metal versus covered stents across the venous anastomosis of prosthetic arteriovenous (AV) grafts.

Methods

Review of our procedural database over a 6?year period revealed 377 procedures involving stent deployment in an AV access circuit. After applying strict inclusion criteria, our study group consisted of 61 stent deployments in 58 patients (median age 58?years, 25 men, 33 women) across the venous anastomosis of an upper extremity AV graft circuit that had never been previously stented. Both patent and thrombosed AV access circuits were retrospectively analyzed. Within the bare metal stent group, 20 of 32 AV grafts were thrombosed at initial presentation compared to 18 of 29 AV grafts in the covered stent group.

Results

Thirty-two bare metal stents and 29 covered stents were deployed across the venous anastomosis. The 3, 6, and 12?months primary access patency rates for bare metal stents were not significantly different than for covered stents: 50, 41, and 22?% compared to 59, 52, and 29?%, respectively (p?=?0.21). The secondary patency rates were also not significantly different: 78, 78, and 68?% for bare metal stents compared to 76, 69, and 61?% for covered stents, respectively (p?=?0.85). However, covered stents demonstrated a higher primary stent patency rate than bare metal stents: 100, 85, and 70?% compared to 75, 67, and 49?% at 3, 6, and 12?months (p?Conclusion The primary and secondary access patency rates after deployment of bare metal versus covered stents at the venous anastomosis were not significantly different. However, bare metal stents developed in-stent stenoses significantly sooner.     

Safety and efficacy of radiological percutaneous jejunostomy for decompression of malignant small bowel obstruction

Objectives

This study aimed to evaluate the safety and efficacy of percutaneous radiological jejunostomy (PRJ) and stent placement in patients with malignant small bowel obstructions (MSBO).

Methods

A total of 21 patients (mean age 60 years) with single (n?=?4) or multiple (n?=?17) MSBO underwent PRJ following jejunopexy. The medical records and imaging studies were retrospectively reviewed to evaluate the technical/clinical success and complications. Clinical success was determined by symptomatic relief and radiologic bowel decompression.

Results

PRJ using a 12- or 14-F drainage catheter was technically successful in all patients. Eleven patients required placement of an 18-F nasogastric tube across one (n?=?3), two (n?=?6) and three (n?=?2) obstructions to achieve clinical success. Subsequently, self-expandable stents were placed through the PRJ tracts to recanalise MSBO in four patients. Clinical success was achieved in 18 patients (85.7 %). The median food intake capacity score improved from 4.0 to 2.0 (P?=?0.001). There were one major (peritonitis, 4.8 %) and six minor complications (28.6 %)

Conclusions

PRJ using a nasogastric tube across the obstructions is an effective palliative treatment for MSBO. The PRJ tract can be used as an approach route for stent placement to recanalise MSBO. However, dedicated devices should be developed to reduce frequent procedure-related complications.

Key Points

? Bowel decompression provides palliative treatment in malignant small bowel obstruction ? Percutaneous radiological jejunostomy (PRJ) is a safe and effective palliative treatment. ? Long tube placement across obstructions facilitates adequate drainage of multiple bowel obstructions. ? PRJ tract can be used for stent placement to approach MSBO recanalisation.     

The Interaction between Stent(s) Implantation,PICA Involvement,and Immediate Occlusion Degree Affect Symptomatic Intracranial Spontaneous Vertebral Artery Dissection Aneurysm (sis-VADA) Recurrence after Reconstructive Treatment with Stent(s)-Assisted Coiling

Objectives

We aimed to evaluate risk factors of sis-VADAs recurrence after reconstructive treatment based on 113 reconstructed lesions.

Methods

A total of 111 patients (M:F?=?68:43; median age, 47 years) with 113 sis-VADAs underwent reconstruction from October 2000 to March 2011, using stent(s) and coils. Treatments and predictors of recurrence were retrospectively analysed.

Results

Fifty-eight sis-VADAs underwent single-stent treatment, and the remaining 55 sis-VADAs underwent treatment with 2-4 overlapping stents. Follow-up angiography was available for 94 sis-VADAs 12 -78 months, with recurrence in ten patients, including seven angiographic recurrences and three post-treatment haemorrhagic recurrences. A higher rate of post-treatment recurrence was observed in the single stent group than in the multiple stents group (p?=?0.010). The interaction between stent (s) implantation and immediate occlusion degree (odds ratio [OR] =3.152; 95 % confidence interval [CI], 1.293-7.686; p?=?0.012), between stent (s) implantation and the posterior inferior cerebellar artery (PICA) involvement (OR?=?4.607; 95 % CI, 1.172-18.113; p?=?0.029), and between PICA involvement and immediate occlusion degree (OR?=?5.018; 95 % CI, 1.263-19.933; p?=?0.022) affect recurrence in the reconstructed sis-VADAs.

Conclusions

This single centre cohort study indicated that the interaction effect between stent (s) implantation, PICA involvement, and immediate occlusion degree were closely associated with recurrence after reconstructive treatment of sis-VADA.

Key Points

? The interaction between stent (s) and immediate occlusion degree affect aneurysmal recurrence ? The interaction between stent and PICA involvement affect aneurysmal recurrence ? The interaction between PICA involvement and immediate occlusion degree affect aneurysmal recurrence     

Coronary artery stent imaging with 128-slice dual-source CT using high-pitch spiral acquisition in a cardiac phantom: comparison with the sequential and low-pitch spiral mode

Objective

To evaluate coronary stents in vitro using 128-slice-dual-source computed tomography (CT).

Methods

Twelve different coronary stents placed in a non-moving cardiac/chest phantom were examined by 128-slice dual-source CT using three CT protocols [high-pitch spiral (HPS), sequential (SEQ) and conventional spiral (SPIR)]. Artificial in-stent lumen narrowing (ALN), visible inner stent area (VIA), artificial in-stent lumen attenuation (ALA) in percent, image noise inside/outside the stent and CTDIvol were measured.

Results

Mean ALN was 46% for HPS, 44% for SEQ and 47% for SPIR without significant difference. Mean VIA was similar with 31% for HPS, 30% for SEQ and 33% for SPIR. Mean ALA was, at 5% for HPS, significantly lower compared with ?11% for SPIR (p?=?0.024), but not different from SEQ with ?1%. Mean image noise was significantly higher for HPS compared with SEQ and SPIR inside and outside the stent (p?<?0.001). CTDIvol was lower for HPS (5.17 mGy), compared with SEQ (9.02 mGy) and SPIR (55.97 mGy), respectively.

Conclusion

The HPS mode of 128-slice dual-source CT yields fewer artefacts inside the stent lumen compared with SPIR and SEQ, but image noise is higher. ALN is still too high for routine stent evaluation in clinical practice. Radiation dose of the HPS mode is markedly (less than about tenfold) reduced.     

Early Results with the Use of Heparin-bonded Stent Graft to Rescue Failed Angioplasty of Chronic Femoropopliteal Occlusive Lesions: TASC D Lesions Have a Poor Outcome

Purpose

To evaluate early patency rate of the heparin-bonded stent grafts in atherosclerotic long femoropopliteal occlusive disease, and to identify factors that affect outcome.

Methods

Heparin-bonded Viabahn stent grafts were placed in 33 limbs in 33 patients during 2009–2010. The stents were deployed to rescue failed conventional balloon angioplasty. Mean age was 69 (range 44–88) years, and 67?% (22 of 33) were men. Most procedures (21 of 33, 64?%) were performed for critical limb ischemia (33?% for rest pain, 30?% tissue loss). Kaplan–Meier plots and Cox regression analysis were used to identify significant risk factors.

Results

The average length of lesions treated was 25?±?10?cm, and they were predominantly TASC (Transatlantic Intersociety Consensus) D (n?=?13) and C (n?=?17) lesions. The median primary patency was 5.0?months (95?% confidence interval 1.22–8.77). The mean secondary patency was 8.6?months (95?% confidence interval 6.82–10.42). Subsequently, 4 patients underwent bypass surgery and 5 patients underwent major amputation. One patient died. There were 5 in-stent or edge-stent stenoses. Cox multivariate regression analysis identified TASC D lesions to be a significant risk factor for early occlusion (p?=?0.035).

Conclusion

TASC D lesions of femoropopliteal occlusions have poor patency rates with the use of heparin-bonded stent grafts after failed conventional angioplasty. Alternative options should be considered for these patients.     

Evaluation of stent visibility by flat panel detector CT in patients treated for intracranial aneurysms

Introduction

This study aimed to evaluate the visibility of stents using high-resolution computed tomography (CT) acquisitions acquired with flat panel detector (XperCT, Allura series, Philips Healthcare, The Netherlands) for endovascular treatment of intracranial aneurysms.

Methods

On a 24-month period, 48 patients endovascularly treated by coiling and stenting (59 stents) for intracranial aneurysms were explored by flat panel detector CT technique. A sequence of 620 2D images was acquired over an angle of 240° using a 1,024?×?1,024 pixel matrix detector within a 48-cm field of view. The images were retrospectively analyzed independently by two neuroradiologists. Evaluation criteria were percentage of visualization of the stents and stent deployment (kinking or unsatisfactory deployment of the stent).

Results

Evaluation of the stent was feasible for all the patients. Stent visibility by XperCT was overall estimated at 76% of the stent length. Difficulties to analyze the stents were related to coil artifacts but not to packing density or aneurysm location. Stent length visualization was higher when the acquisition was performed before additional coiling (P?Conclusion XperCT technique provides multiplanar and 3D reconstructions that allows for a satisfying visualization of intracranial stents. This CT-like acquisition should be performed after the stent deployment and before coiling, in order to obtain better stent visualization.     

Next generation coronary CT angiography: in vitro evaluation of 27 coronary stents

Objectives

To evaluate in-stent lumen visibility of 27 modern and commonly used coronary stents (16 individual stent types, two stents at six different sizes each) utilising a third-generation dual-source CT system.

Methods

Stents were implanted in a plastic tube filled with contrast. Examinations were performed parallel to the system's z-axis for all stents (i.e. 0°) and in an orientation of 90° for stents with a diameter of 3.0 mm. Two stents were evaluated in different diameters (2.25 to 4.0 mm). Examinations were acquired with a collimation of 96?×?0.6 mm, tube voltage of 120 kVp with 340 mAs tube current. Evaluation was performed using a medium-soft (Bv40), a medium-sharp (Bv49) and a sharp (Bv59) convolution kernel optimised for vascular imaging.

Results

Mean visible stent lumen of stents with 3.0 mm diameter ranged from 53.3 % (IQR 48.9???56.7 %) to 73.9 % (66.7???76.7 %), depending on the kernel used at 0°, and was highest at an orientation of 90° with 80.0 % (75.6???82.8 %) using the Bv59 kernel, strength 4. Visible stent lumen declined with decreasing stent size.

Conclusions

Use of third-generation dual-source CT enables stent lumen visibility of up to 80 % in metal stents and 100 % in bioresorbable stents.

Key Points

? Blooming artefacts impair in–stent lumen visibility of coronary stents in CT angiography. ? CT enables stent lumen visibility of up to 80 % in metal stents. ? Stent lumen visibility varies with stent orientation and size. ? CT angiography may be a valid alternative for detecting in-stent restenosis.     

Ten Years of Experience with the GORE EXCLUDER? Stent-Graft for the Treatment of Aortic and Iliac Aneurysms: Outcomes from a Single Center Study

Purpose

This study was designed to assess the long-term outcome of selected patients with aortic, aortoiliac, and isolated common iliac aneurysms treated with the GORE EXCLUDER^? stent-graft.

Methods

Between December 1998 and June 2010, 121 nonconsecutive patients underwent insertion of a GORE EXCLUDER^? stent-graft to treat an aortic (n?=?80; 66%), aortoiliac (n?=?25; 21%), or isolated common iliac (n?=?16; 13%) aneurysm. Procedural and follow-up data were collected prospectively. Primary endpoints are overall survival, intervention-free survival, and freedom from aneurysm rupture. Secondary endpoints are device- and procedure-related complications, including all types of endoleaks or endotension, and reintervention.

Results

The mean follow-up is 4.98?years (standard deviation, 3.18; median follow-up, 4.05?years). The estimated percentage overall survival (with 95% confidence interval) after respectively 5 and 10?years of follow-up is 74.5% (65.8; 81.3) and 57.8% (47.7; 66.7). The estimated intervention-free survival after respectively 5 and 10?years is 90% (84.3; 96.1) and 77.7% (67; 88.4). There was no aneurysm rupture during follow-up. Early postoperative complications occurred in 16 patients (13%); none were fatal. Late reinterventions were performed in 18?patients (15%). Finally, throughout the follow-up period, endoleaks were identified: type I (n?=?4; 3%); type II (n?=?39; 32%); type?III (n?=?0; 0%); endotension was seen in 11 patients (9%).

Conclusions

Aneurysm exclusion with use of the GORE EXCLUDER^? stent-graft is durable through a mean follow-up of nearly 5?years. There was no postprocedural aneurysm rupture. Complications occurred throughout the follow-up period, requiring continued clinical and radiological surveillance.     

Correlation of aneurysm occlusion with actual metal coverage at neck after implantation of flow-diverting stent in rabbit models

Introduction

A remarkable curing rate has been achieved in the treatment of intracranial intractable aneurysms by using flow-diverting stents (FDS). An appropriate metal coverage (MC) of this device influences the hemodynamics of aneurysm significantly but little to branches in vitro. The MC changes after elongation or compression and the actual changes are still unknown in vivo. In this paper, we analyzed the correlation of aneurysm occlusion with actual MC after implantation of FDS in rabbit models.

Methods

FDS was implanted across the necks of 22 elastase-induced aneurysms in rabbits. Animals were performed for angiography at 4?weeks and sacrificed at 3?months after angiography for pathology. Tissue was explanted with stent for micro-computed tomography scan, and local shape of stent at neck was reconstructed. Actual MC at neck was calculated, and the correlations of aneurysm occlusion with effective factors were analyzed.

Results

Greater than 95% angiographic aneurysm occlusion rates for the FDS, which covered the neck of aneurysms, were 61.9% at 4?weeks and 57.9% by angiography at 3?months. Aneurysm occlusion was positively correlated with local MC of stent at neck (r _s?=?0.486; P?=?0.026). A 35% actual MC at the neck predicted greater than 95% angiographic aneurysm occlusion with a specificity of 100% and sensitivity of 53.8%.

Conclusion

Aneurysm occlusion was positively correlated with local MC of stent at the neck. The FDS with 35% MC can predict greater than 95% angiographic aneurysm occlusion.     

Biodegradable biliary stent implantation in the treatment of benign bilioplastic-refractory biliary strictures: preliminary experience

Objectives

To evaluate feasibility, safety, and outcome of patients treated with biodegradable biliary stents for benign biliary stenosis refractory to other treatments.

Methods

Between March 2011 and September 2012, ten patients (seven men, three women; age 59?±?7 years) with recurrent cholangitis due to postsurgical biliary stricture, previous multiple unsuccessful (two to five) bilioplasties, and unsuitability for surgical/endoscopic repair underwent percutaneous implantation of a biodegradable biliary stent. Patients were followed-up clinically and with ultrasound at 1, 3 and 6 months, and then at 6-month intervals.

Results

Stent implantation was always feasible. No immediate major or minor complications occurred. In all patients, 48-h cholangiographic control demonstrated optimal stent positioning and stenosis resolution. In a median follow-up time of 16.5 months (25th–75th percentiles = 11–20.25 months) no further invasive treatment was needed. Three patients experienced transient episodes of cholangitis. Neither re-stenosis nor dilatation of the biliary tree was documented during follow-up. No stent was visible at the 6-month follow-up.

Conclusions

Percutaneous placement of biodegradable biliary stents represents a new option in treating benign biliary stenoses refractory to treatment with bilioplasty. This technique seems to be feasible, effective and free from major complications. Further investigations are warranted to confirm our preliminary results.

Key Points

? Percutaneous biodegradable stents can be used to treat benign biliary stenosis. ? They can be used in patients refractory to bilioplasty. ? The procedure for insertion appears free from major complication. ? Biodegradable stents may represent an alternative device to covered expandable stents.     

Factors predicting retreatment and residual aneurysms at 1?year after endovascular coiling for ruptured cerebral aneurysms: Prospective Registry of Subarachnoid Aneurysms Treatment (PRESAT) in Japan

Introduction

Endovascular treatment of cerebral aneurysms includes follow-up imaging to identify aneurysms that may need retreatment. The aim of this study was to determine predictors of incomplete aneurysm occlusion at 1?year after endovascular coiling for ruptured cerebral aneurysms.

Methods

In 129 patients of the Prospective Registry of Subarachnoid Aneurysms Treatment cohort, ruptured aneurysms were coiled within 14?days of onset and both initial post-coiling and 1-year follow-up digital subtraction angiography or magnetic resonance angiography were obtained. Factors predicting 1-year incomplete aneurysm occlusion (retreatment within 1-year or residual aneurysms at 1?year) were determined using multivariate logistic regression analyses.

Results

One-year incomplete aneurysm occlusion was identified in 59 patients, including ten patients who were retreated within 1-year post-coiling. Dome size ≥7.5?mm (P?=?0.007, odds ratio (OR)?=?5.00, 95% confidence interval (CI)?=?1.55–16.15), pre-treatment aneurysm re-rupture (P?=?0.023, OR?=?3.50, 95% CI?=?1.19–10.31), non-small size/small neck aneurysm (dome size, ≥10?mm or neck size, ≥4?mm; P?=?0.022, OR?=?3.26, 95% CI?=?1.19–8.96), and residual aneurysms on immediate post-coiling angiograms (P?=?0.017, OR?=?1.43, 95% CI?=?1.07–1.93) significantly predicted incomplete aneurysm occlusion at 1-year post-coiling.

Conclusions

In addition to the characteristics of aneurysm and initially incomplete aneurysm occlusion, this study showed pre-treatment aneurysm re-rupture to be a predictor that favors closer imaging follow-ups for coiled aneurysms.     

How to design the optimal self-expandable oesophageal metallic stents: 22 years of experience in 645 patients with malignant strictures

Objectives

To evaluate the clinical efficacy and safety of self-expandable metallic stent (SEMS) placement for malignant oesophageal strictures and their relationship with stent designs.

Methods

Seven generations of SEMS were used to treat 645 consecutive patients with oesophageal strictures. Logistic regression models were constructed to identify predictive factors associated with complications.

Results

Stent placement was technically successful in 641 of 645 patients (99.4%). The clinical success rate was 95.5%. There were 260 (40.3%) complications after stent placement. Due to complications, 68 stents were removed; 66 of 68 stents (97.1%) were removed successfully. Stainless steel (SS) stents (odds ratio [OR] 4.18; 95% confidence interval [CI] 2.10, 8.32) and radiation therapy (RT) before stent placement (OR 4.23; CI 2.02, 8.83) were significantly associated with severe pain. Flared ends (OR 9.63; CI 3.38, 27.43), stricture length <6 cm (OR 2.01; CI 1.13, 3.60), and a stent diameter <18 mm (OR 3.00; CI 1.32, 6.84) were predictive factors of stent migration. Polyurethane membranes were associated with more frequent tumour ingrowth than polytetrafluoroethylene (PTFE) membranes (P?=?0.002).

Conclusions

Despite the relatively high complication rate, retrievable self-expandable PTFE-covered nitinol stents equipped with a head and a tail appeared to be an effective treatment for malignant oesophageal strictures.

Key Points

? Self-expandable metallic stents are now widely used for palliating unresectable oesophageal strictures ? Stents equipped with a head and a tail showed decreased stent migration rate ? Stainless steel stents and radiation therapy before stenting can cause severe pain ? Polyurethane membranes were associated with more frequent tumour ingrowth than polytetrafluoroethylene membranes ? Considering the high complication rate, stent retrievability is important for safety reasons     

Coil embolization of anterior circulation aneurysms supported by the Solitaire™ AB Neurovascular Remodeling Device

Introduction

The purpose of the study is to evaluate patients with wide-necked or complex aneurysms of the anterior circulation who underwent Solitaire? AB Neurovascular Remodeling Device-assisted coil embolization.

Methods

From February 2008 to March 2009, consecutive data were collected from 45 patients with anterior circulation aneurysms. Eighteen of the patients presented with acute subarachnoid hemorrhage. Forty-six aneurysms were treated with the aid of different applications (n?=?49) of the Solitaire? AB Remodeling Device followed by standard coiling procedure (n?=?43) using bioactive coils or/and bare coils.

Results

Successful positioning of the remodeling device was obtained in 95.9% of the cases. There were two thromboembolic complications (4.1%) and one severe vasospasm requiring retrieval of the device. Permanent procedural morbidity was observed in one patient (2%). The proportion of patients in whom Raymond class 1 occlusion was obtained was 53.5% (n?=?23). Raymond class 2 occlusion was achieved in 42% (n?=?18) and Raymond class 3 occlusion in 4.7% (n?=?2). Thirty-nine patients left the hospital with a good clinical status.

Conclusion

The initial technical and clinical results of Solitaire? AB device-assisted coiling of aneurysms in the anterior circulation are highly encouraging. This technique may enhance the possibilities of the endovascular treatment of these aneurysms in clinical routine.