Finite Element Simulation of Double-Stent Parallel Thrombectomy at Y-Shaped Bifurcation of Internal Carotid Artery / 医用生物力学

Objective To study the process of single stent and double-stent thrombectomy at the Y-shaped bifurcation of the ideal internal carotid artery by finite element simulation, analyze the stent-thrombus-vessel interaction during the thrombectomy process based on the simulation results, and provide guidance for improving the effect of stent thrombectomy at the bifurcation. Methods The CAD software was used to build the model and the finite element analysis software was used to simulate the process of single stent and double-stent thrombectomy. Results Thrombectomy was unsuccessful in single stent model and successful in double-stent model, and the maximum stress of thrombus during embolus retrieval was twice that of single stent, the maximum strain was 1.12 times that of single stent, and the maximum contact pressure on the surface of vessel was approximately twice that of single stent. Conclusions Double Solitaire stents can effectively prevent thrombus displacement at the bifurcation and successfully retrieve the thrombus, but there is a risk of fracture due to the high stress level in the middle section of the thrombus. The contact pressure of the vessel on the anterior artery side is higher during thrombectomy, and the risk of vessel damage is greater. Therefore, it is necessary to optimize the design of the stent-retriever to improve its flexibility.

Contact aspiration and stent retriever versus stent retriever alone following mechanical thrombectomy for patients of acute ischemic stroke: A recanalization success analysis

Abstract Objective Second-generation catheters used in mechanical thrombectomy have different advantages and disadvantages. The objective of this study was to evaluate the effectiveness and safety of the combination of contact aspiration and stent retriever technique on the rate of reperfusion after mechanical thrombectomy for large vessel occlusion. Methods Patients who underwent contact aspiration alone (CAA cohort, n = 150), stent retriever alone (SRA cohort, n = 129), or combined contact aspiration and stent retriever (CSR cohort, n = 122) techniques following mechanical thrombectomy were included in the analysis. A balloon guide catheter was used for all thrombectomies. Digital subtraction angiography was used to identify thrombolysis in cerebral infarction. Results The number of patients with thrombolysis in cerebral infarction score of ≥ 2c (near complete or complete antegrade reperfusion) was significantly higher in the CSR cohort than those in the CAA cohort (101 [83%] vs. 90 [60%], p < 0.0001) and those of SRA cohort (101 [83%] vs. 77 [59%], p = 0.0001). Arterial perforation was higher in patients in the CSR cohort than in those in the CAA (p < 0.0001) and SRA (p = 0.015) cohorts. Intracerebral hemorrhage was lower in patients in the CSR cohort than in those in the CAA (p = 0.0001) and SRA (p = 0.0353) cohorts. All-cause mortality at 1 year was fewer in the CSR cohort than in the CAA cohort (p = 0.018). Conclusions The combination of thrombo aspiration by large bore aspiration catheter and stent retriever is the most effective technique but has some related risks. Level of evidence IV. Technical efficacy stage 1.

Mechanical Properties of Optimized Stent Retrievers / 医用生物力学

Objective To analyze mechanical properties of stent retrievers with different structures, and provide theoretical support for the design and clinical selection of stent retrievers. Methods Three kinds of stent retrievers with different structures (B3, K4, X) were evaluated by finite element analysis and in vitro simulation experiment. The analytic parameters were radial support force, withdrawal force and thrombosis state during the thrombotomy test. Results The radial support forces of B3, K4, X stent retrievers obtained from the experiment were 0.48 N, 0.43 N, 0.51 N, respectively. The larger the crimping distance, the greater the radial support force of stent retrievers. The radial support force of the stent increased significantly when the crimping distance was larger than 3 mm. The simulated thrombus removal experiment results showed that the peak withdrawal forces of B3, K4, X stent retrievers were 0.410 N, 0.451N, 0.501 N, respectively. The experimental results were consistent with the finite element analysis results. Conclusion sBoth the experimental results and the finite element results showed that the X stent has better mechanical properties. This method can be used as an analytic method to evaluate performance of the stent retrievers, and provide references for performance improvement and development of the stent retrievers.

Biomechanical Study of the Open-Type Stent Retriever / 医用生物力学

Objective To simulate the process of thrombus removal from the open-type stent retrievers, so as to provide theoretical references for the design and clinical application of the open-type stent retrievers. Methods Finite element models of the open-type stent retrievers with 3,4,5 supporting units (K3,K4,K5), the crimping tools, simulated vessels and simulated thrombus (three types) were established. Radial displacement load was applied on the crimping tool until the stent was crimped to 0.5 mm, and the maximum principal strain (MPS) peak and radial force (RF)of the stent were analyzed. When displacement of the crimping tool was restored, the stent self-expanded and contacted with blood vessels, and MPS of the stent and von Mises stress (VMS) of blood vessels were analyzed. Axial displacement was applied to proximal end of the stents to allow the stent to drive the clots to migrate, and the blood vessel VMS and withdrawal force of the stents (the ability to capture thrombus) were analyzed. ResultsThe MPS peaks for 3 types of stent retrievers during crimping process were 6.94%, 8.30% and 5.48%, which were all smaller than the 12% fracture limit. When the outer diameter of the stent was 3 mm (equal to the inner diameter of blood vessels), the K4 stent had the largest RF. The results of self-expanding release process showed that the larger the number of support units, the greater the VMS of blood vessels. At the stage of thrombus migration and removal,the VMS of blood vessels was generally small and concentrated on the thrombus. The withdrawal force of the stent reached the maximum at the initial stage of thrombus migration and removal, then gradually decreased. The peak withdrawal force of the K4 stent was larger than that of the K5 and K3 stent. Conclusions Although the MPS and VMS for 3 types of open-type stent retrievers were within the safe range, the K4 stent showed better performance in RF and withdrawal force with the three types of thrombus. The research findings can provide the analysis methods and ideas for optimizing the open-type stent retrievers, to avoid clinical complications such as vascular injury and improve safety and effectiveness of the stent retrievers.

Trombectomía mecánica, aspirativa e intra-arterial. Primer caso en un paciente con stroke isquémico agudo de un hospital nacional / Intra-arterial, aspirate and mechanical thrombectomy. First case in a patient with an acute stroke in a hospital

Resumen El stroke isquémico agudo es una de las principales causas de morbilidad y mortalidad en el mundo. Si existe compromiso de vaso grande, la trombectomía mecánica es la técnica endovascular que ha demostrado los mejores resultados. Presentamos el caso de un paciente con trombosis de la arteria cerebral media izquierda de 5 horas de evolución, con afasia mixta y hemiplejía, la escala ASPECTS 7, score NIHSS 14 y escala de Rankin modificada (mRS) de 4. Se realizó trombectomía mecánica con stents Solitaire AB y ERIC, aspiración manual de coágulo con jeringa de 60cc e instilación de alteplase intra-arterial. La reperfusión inmediata fue total (TICI 3). El mRS posterior al tratamiento fue de 2.

Summary Acute stroke is one of the most common causes of morbidity and mortality worldwide. Mechanical thrombectomy is the endovascular procedure that has shown better results in patients with a large vessel involvement. We present here a case of a patient who had a five-hour history of thrombosis of the left mid cerebral artery who developed mixed aphasia and hemiparesis, ASPECTS scale of five, NIHSS score of 14 and a modified Rankin scale (mRS) of 4. A mechanical thrombectomy was performed with stents Solitaire AB and ERIC and manual aspiration of the clot with a 60cc syringe plus instillation of intra-arterial alteplase. Immediate reperfusion was complete (TICI 3). The mRS after the procedure was 2.

Efficacy of mechanical thrombectomy with stent-retriever for anterior circulation distal vessel occlusion / 第二军医大学学报

Objective To explore the therapeutic effect of mechanical thrombectomy with stent-retriever for the anterior circulation distal vessel occlusion. Methods Consecutive cases with anterior circulation distal vessel occlusion treated with mechanical thrombectomy in Stroke Center of Changhai Hospital of Navy Medical University (Second Military Medical University) from Sep. 2013 to May 2018 were enrolled. According to whether undergoing intravenous thrombolysis, the patients were divided into bridging group and direct thrombectomy group. The primary outcome was the neurological functional prognosis at 90 d after operation measured with modified Rankin Scale (mRS, mRS score≤2 reflected good prognosis). The secondary outcomes were the rate of recanalization (modified thrombolysis in cerebral ischemia [mTICI] grade≥2b), the National Institutes of Health stroke scale (NIHSS) score at 24 h after operation, complications and mortality. Results Totally 36 patients aged (68.3±13.6) years (ranging from 26 to 88 years) were included. There were 27 cases with middle cerebral artery (MCA) M2 segment occlusion, 5 cases with anterior cerebral artery (ACA) A1/A2 segment occlusion and 4 cases with MCA M2 segment accompanied with ACA A2 segment occlusion. The rate of recanalization of the occluded distal vessels was 91.7% (33/36) after mechanical thrombectomy with stent-retriever. The rate of good prognosis at 90 d after operation was 52.8% (19/36). The most common complication was vasospasm (33.3%, 12/36), followed by hemorrhagic transformation (16.7%, 6/36). The incidence of symptomatic intracranial hemorrhage was 5.6% (2/36) and the mortality was 8.3% (3/36). There were 14 cases in the brigding group and 22 cases in the direct thrombectomy group. The preoperative NIHSS score of the bridging group was significantly higher than that of the direct thrombectomy group (Z=3.025, P=0.002). While there were no significant differences in the NIHSS score at 24 h after operation, times of thrombectomy, the rate of recanalization, the rate of good prognosis at 90 d after operation, the incidence of hemorrhagic transformation or mortality between the bridging group and the direct thrombetomy group (all P>0.05). Conclusion The mechanical thrombectomy with stent-retriever for the anterior circulation distal vessel occlusion is likely safe and effective, and it is beneficial for vascular recanalization and good outcomes at 90 d.

Trombectomía mecánica en pacientes con ataque cerebrovascular isquémico: serie de casos en un centro de referencia colombiano / Mechanical Thrombectomy in patients with isquemic stroke: Case series in a Colombian reference center

RESUMEN OBJETIVO: Este artículo describe las características clínicas, indicaciones y desenlaces de mortalidad, eventos adversos e independencia funcional en pacientes con ataque cerebrovascular isquémico, ACVi, sometidos a trombectomía mecánica con stent Solitaire, TMSS. MATERIALES Y MÉTODOS: Estudio descriptivo, retrospectivo, de corte trasversal llevado a cabo entre abril de 2013 y abril de 2016. RESULTADOS: Durante el periodo de tiempo evaluado, se sometieron un total de 10 pacientes a TMSS. La edad media de los pacientes fue 62 años. Todos los pacientes tenían una buena clase funcional previa al ACVi, definida como una escala modificada de Rankin de 0 a 2. Al momento de la consulta, la escala de Rankin modificada fue 4. Los pacientes se sometieron a estrategia reperfusión combinada que consta de trombolisis intravenosa más trombectomía mecánica. Sin embargo, un 40 % de los pacientes tenía contraindicación para trombolisis. La mortalidad fue de 20 %, al igual que el sangrado cerebral que se presentó en 20 % de los pacientes y el Rankin modificado mejoró a lo largo del seguimiento en el 70 % de los pacientes, con un total de 50 % de pacientes que lograron independencia funcional significativa. CONCLUSIÓN: Parece haber impacto importante en la independencia funcional de pacientes sometidos a estrategia combinada de reperfusión cerebral con el uso de stents recuperadores, sin diferencia en la seguridad y mortalidad comparado con la estrategia estándar.

SUMMARY OBJECTIVE: This paper describes the clinical features, treatment indications, mortality and severity of global disability in the follow up outcomes in isquemic cerebrovascular stroke patients submitted to mechanical thrombectomy. MATERIALS AND METHODS: Retrospective, descriptive, cross-sectional study conducted from April 2013 to April 2016. RESULTS: During the study period, ten patients underwent mechanical thrombectomy. Mean age was 62, median modified Rankin Scale Score at acceptance was 4. Initially, all patients had a combined reperfusion approach, unless there were contraindications. Intravenous thrombolysis was contraindicated in 40% of patients. Mortality Trombectomía mecánica en pacientes con ataque cerebrovascular isquémico: serie de casos en un centro de referencia colombiano rate was 20% as well as intraparenchimal hemorrhage. Modified Rankin Scale improved during follow up in 70% of patients. Of these, functional independence was achieved by 50% of patients. CONCLUSION: it seems to be a functional independence impact on patients submitted to mechanical thrombectomy. There is not difference in safety and mortality outcomes.

Causes and Solutions of Endovascular Treatment Failure / 대한뇌졸중학회지

In a meta-analysis of individual patient data from 5 randomized controlled trials, endovascular treatment (EVT) mainly using a stent retriever achieved successful recanalization in 71.1% of patients suffering from acute stroke due to anterior circulation large artery occlusion (LAO). However, EVT still failed in 28.9% of LAO cases in those 5 successful trials. Stent retriever failure may occur due to anatomical challenges (e.g., a tortuous arterial tree from the aortic arch to a target occlusion site), a large quantity of clots, tandem occlusion, clot characteristics (fresh versus organized clots), different pathomechanisms (embolic versus non-embolic occlusion), etc. Given that recanalization success is the most important factor in the neurological outcome of acute stroke patients, it is important to seek solutions for such difficult cases. In this review, the basic technique of EVT is briefly summarized and then various difficult cases with diverse conditions are discussed along with suggested solutions.

Endovascular Stroke Therapy Focused on Stent Retriever Thrombectomy and Direct Clot Aspiration: Historical Review and Modern Application

Intravenous recombinant tissue plasminogen activator had been the only approved treatment for acute ischemic stroke since its approval in 1995. However, the restrictive time window, numerous contraindications, and its low recanalization rate were all limitations of this modality. Under those circumstances, endovascular stroke therapy went through a great evolution during the past two decades of intravenous thrombolysis. The results of the 2013 randomized trials for endovascular stroke therapy were neutral, although they were limited by insufficient imaging screening at enrollment, early-generation devices with less efficacy, and treatment delays. Huge progress was made in 2015, as there were five randomized clinical trials which all demonstrated the safety and efficacy of endovascular stroke treatment. Despite differences in detail patient enrollment criteria, all 5 trials employed key factors for good functional recovery; (1) screening with non-invasive imaging to identify the proximal occlusion and exclude a large infarct core, (2) using highly effective modern thrombectomy devices mainly with stent retriever, and (3) establishment of a fast workflow to achieve effective reperfusion. The results of those trials indicate that modern thrombectomy devices can allow for faster and more effective reperfusion, which can lead to improved clinical outcomes compared to intravenous thrombolysis alone. These advances in mechanical thrombectomy are promising in the global fight against ischemic stroke-related disability and mortality. Two current mainstreams among such mechanical thrombectomy techniques, “stent retriever thrombectomy” and “direct clot aspiration”, are the topic of this review. Stent retriever thrombectomy using Solitaire and Trevo retriever will be firstly discussed. And, the commonalities and the differences between two major clot aspiration thrombectomy techniques; a direct aspiration first pass technique (ADAPT) and forced arterial suction thrombectomy (FAST), will be additionally explained. Finally, details regarding the combination of direct clot aspiration and stent retriever thrombectomy, the switching strategy and the Solumbra technique, will be described.

Successful Cross-circulation Stent-Retriever Embolectomy Through Posterior Communicating Artery for Acute MCA Occlusion by Using Trevo XP ProVue / 신경중재치료의학

Acute ischemic stroke due to embolic occlusion of the middle cerebral artery (MCA) in patients with chronic ipsilateral internal carotid artery (ICA) occlusion is quite rare. Several previous reports demonstrated that intra-arterial (IA) thrombolytic therapy or aspiration thrombectomy using the cross-circulation technique via an alternative collateral pathway is feasible in acute stroke patients with an unfavorable direct route to the occluded sites. However, stent-retriever embolectomy via the cross-circulation approach has not been reported in the literature. The present paper reports the first case of successful stent-retriever embolectomy for acute MCA occlusion via the patent posterior communicating artery (PComA) by using Trevo XP ProVue stent-retriever in a patient with acute MCA stroke and chronic occlusion at the origin site of the ipsilateral ICA.

Angiographic and Clinical Factors Related with Good Functional Outcome after Mechanical Thrombectomy in Acute Cerebral Artery Occlusion

OBJECTIVE: The aim of this study is to investigate good prognostic factors for an acute occlusion of a major cerebral artery using mechanical thrombectomy. METHODS: Between January 2013 to December 2014, 37 consecutive patients with acute occlusion of a major cerebral artery treated by mechanical thrombectomy with stent retrievers were conducted. We analyzed clinical and angiographic factors retrospectively. The collateral flow and the result of recanalization were sorted by grading systems. Outcome was assessed by National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) at 90 days. We compared the various parameters between good and poor angiographic and clinical results. RESULTS: Twenty seven patients demonstrated good recanalization [Thrombolysis in Cerebral Infarction (TICI) 2b or 3] after thrombectomy. At the 90-day follow up, 19 patients had good (mRS, 0-2), 14 had moderate (3-4) and four had poor outcomes (5-6). The mRS of older patients (> or =75 years) were poor than younger patients. Early recanalization, high Thrombolysis in Myocardial Infarction risk score, and low baseline NIHSS were closely related to 90-day mRS, whereas high TICI was related to both mRS and the decrease in the NIHSS. CONCLUSION: NIHSS decreased markedly only when recanalization was successful. A good mRS was related to low initial NIHSS, good collateral, and early successful recanalization.

Mechanical Thrombectomy Using the Solitaire FR system for Occlusion of the Top of the Basilar Artery: Intentional Detachment of the Device after Partial Retrieval / 신경중재치료의학

Acute, distal, basilar artery occlusion is a challenging neurovascular emergency. There have been several reports regarding the successful application of the Solitaire FR device for treating this lesion. However, due to the lack of a suitable, balloon-tipped, guiding catheter for the vertebral artery, during this procedure we frequently experience the occurrence of clot fragmentation and distal migration. There may be some technical solutions to solve this problem. The purpose of this report is to present a technical variation of using the Solitaire FR, and which is referred to as the 'intentional device detachment technique.' As a clot tends to re-embolize during its passage through the tortuous cranio-cervical junction level of the vertebral artery or its passage through the tip of the guiding catheter, due to the lack of proximal flow arrest, we thought that not removing the stent segment of the device which is capturing the clot could avoid this problem. We were able to successfully apply this technique in two cases. We believe that this technique can be a possible technical option for using the Solitaire FR device when a patient has little concern regarding the subsequent use of antiplatelets.

Successful Mechanical Thrombectomy in a 2-Year-Old Male Through a 4-French Guide Catheter / 신경중재치료의학

A 2-year-old boy with hypoplastic left heart syndrome that required multiple cardiovascular surgeries and a heterozygous prothrombin G20210A mutation with resulting thrombophilia maintained on warfarin presented with acute right middle cerebral artery (MCA) infarction manifesting as a left hemiplegia. An MRI revealed a complete occlusion of the right M1 segment with an area of restricted diffusion in the right basal ganglia representing only a small area of acute infarction. Patchy areas of subacute infarction were also present in the right MCA territory. He underwent endovascular mechanical thrombectomy with a stent retriever. This is an account of a successful mechanical thrombectomy performed in the youngest patient reported in the English literature to date.

Application of Soehendra stent retriever in patients with pancreatic or bile duct stricture / 解放军医学杂志

Objective To evaluate the efficacy of Soehendra stent retriever as used as a dilator for the patients with high grade stricture of pancreatic or bile duct. Methods Forty-eight patients, who underwent endoscopic retrograde cholangiopancreatography (ERCP) from Jan. 2010 to Oct. 2012 in Endoscopy Department of General Hospital of Shenyang command, were found to have pancreatic or bile duct stricture. Dilation was then attempted using a dilating sound. Once the stricture could not be traversed, the Stent Retriever was inserted over the sound to dilate the stricture. Results A total of 554 patients were diagnosed to suffer from pancreatic or bile duct stricture with the aid of ERCP. Among them dilatation of stricture with catheter failed in 48 cases (8.7%) and Soehendra stent retriever was then used for dilatation. Of the 48 cases, ERCP revealed common bile duct stricture in 8 patients, common hepatic duct stricture in 6 patients, porta hepatis stricture in 5 patients, stricture at neck of pancreas stricture in 18, stricture at body of pancreas in 4, stoma stricture after liver transplant in 4, and occlusion of metallic stent in 3 patients. For these cases, Soehendra stent retriever was used to dilate the stricture prior to setting stent or endoscopic nasobiliary drainage (ENBD) with a success rate of 100%. No related complication was found. Conclusion Pancreatic and bile duct stricture can be dilated successfully with the Soehendra stent retriever. The procedure is of low risk and highly effective.

Endoscopic Approach via the Minor Papilla for the Treatment of Pancreatic Stones

BACKGROUND/AIMS: We aimed to evaluate whether the advanced techniques have influenced the minor papilla approach. METHODS: We studied the success rate of guide wire insertion by using ordinary techniques and advanced techniques (rendezvous method and precut method) in 30 patients via the minor papilla. We compared the selection of the access routes between before (52 patients) and after (28 patients) the introduction of the Soehendra stent retriever. RESULTS: In 19 out of 30 patients (63%), guide wire insertion via the minor papilla could be achieved by using ordinary techniques. In total, the guide wire could be inserted in 27 patients (90%) by using the advanced techniques. Before introduction of the Soehendra stent retriever, the major papilla approach was chosen in 38 cases (73%), and the minor papilla approach in 14 cases (27%). After introduction of the Soehendra stent retriever, the major papilla approach was used in 26 cases (93%) and the minor papilla in 2 cases (7%). The frequency of selecting the minor papilla approach has significantly decreased (p<0.05). CONCLUSIONS: The advanced techniques have contributed to the improvement of endoscopic approaches via the minor papilla, and decreased the frequency of selecting the minor papilla approach.

The Clinical Efficacy of Uisng a Soehendra Stent Retriever for Endoscopic Biliary Drainage in Malignant Biliary Obstruction / 대한소화기내시경학회지

BACKGROUND/AIMS: Endoscopic biliary drainage is widely used for the palliative treatment of malignant biliary obstruction. For the advanced stricture, the general treatments such as a dilating or balloon catheter can not fully expand a duct. The authors used a Soehendra Stent Retriever for these cases, and we evaluated the value of using this instrument for treating these patients. METHODS: From July 2006 to Jun 2008, we studied 12 patients with mailignant biliary obstruction (Klatskin's tumor=10, Gall bladder cancer=2) and who were failed at having a stent inserted with such general treatment such as using a dilating or balloon catheter (M: F=7:5, age=69.1 years old). For the bilateral biliary drainage of the duct, the "stent in stent" method was used and 12 patients were treated with a Soehendra Stent Retriever with clockwise rotation, as well as going forward to expand the target area of the intrahepatic bile duct obstruction and insert a metal stent. RESULTS: Ten patients among the 12 who were treated by a Soehendra Stent Retriever achieved successful insertion of a stent (technical success, 83.3%), and all 12 patients showed improvement of their jaundice. CONCLUSIONS: To insert bilateral stents for the advanced malignant biliary obstruction, expanding the strictured area with a Soehendra Stent Retriever can improve the success of inserting a stent.

Dilatation of Narrowed Pancreatic Duct Using a Soehendra Stent Retriever in Chronic Pancreatitis Patients / 대한소화기내시경학회지

BACKGROUND/AIMS: Endoscopic pancreatic ductal drainage may help alleviate the pain from chronic pancreatitis, but stricture dilatation may be technically difficult. Dilatation of high grade strictures of the pancreatic ducts with using dilating or balloon catheters may result in failure. We evaluated the efficacy of using the Soehendra stent retriever as a dilator. METHODS: Fourteen patients with pancreatic stricture had dilation performed with a Soehendra stent retriever. Each patient had sphincterotomy, guidewire placement and stent retriever dilatation. RESULTS: All procedures were successful and none of the patients had complications. Symptom relief was observed after dilation in all patients. There was no complication associated with the use of the stent retriever. None of the patients have relapsed for 6 months. CONCLUSIONS: The Soehendra stent retriever is safe and effective as a dilating device for the pancreatic strictures that are resistant to conventional dilation.

Endoscopic Biliary Drainage Using Soehendra Stent Retriever in Difficult Malignant Biliary Stricture / 대한소화기내시경학회지

BACKGROUND/AIMS: Endoscopic biliary drainage (EBD) has been used effectively as the palliative treatment for malignant biliary obstruction. In high grade strictures, endoscopic stenting can be achieved by dilating devices such as dilating or balloon catheters. Subgroup of malignant biliary obstructions are too stenotic to allow passage of plastic or metal stents. In cases of failure of conventional stenting, we evaluated the efficacy and safety of the 7-Fr Soehendra stent retriever (SSR) used as a dilator. METHODS: From January 1999 to September 2001, 14 patients with malignant pancreaticobiliary stirictures (2 pancreatic, 12 biliary) that could not be traversed with plastic or metal stents, underwent stricture dilation with SSR. An endoscopic sphincterotomy was performed and a guide wire was inserted beyond the stricture. Then the SSR was introduced over the guide wire via duodenoscope. Then the stricture was traversed by torquing the SSR clockwise while pushing it. The SSR was removed and then the plastic or metal stents were inserted above the stricture. RESULTS: Of the 14 patients, 13 patients (93%) underwent successful stenting using SSR. Symptom relief was observed in all patients after endoscopic biliary stenting. One patient (7%) went on to percutaneous biliary drainage because we failed to insert the metal stent into the stenotic left hepatic duct after traversing the stricture with SSR. There were no significant complications such as bile duct or duodenal perforation and bleeding. CONCLUSIONS: The Soehendra stent retriever is useful and safe for dilation with subsequent stent placement of malignant pancreaticobiliary stirictures resistant to conventional stenting. However, this device may be difficult to pass a tortuous or small-diameter hilar stricture.