Sheath System Research Articles

Abstract TP44: Trans-Radial Approach in Mechanical Thrombectomy in Anterior Circulation Large Vessel Stroke; Two Center Experience

Background: Trans-femoral access (TFA) is used conventionally for mechanical thrombectomy (MT) for large vessel occlusion (LVO) stroke. Trans-radial access (TRA) is not only an alternative access route when TFA is not successful but has been shown to significant advantages over TFA in cardiac interventions in large prospective studies. In LVO stroke also, TRA may have several advantages over TFA, including greater technical ease of selection of great vessels at the arch in Type 2 & 3 arches in older stroke patients, avoidance of aorto-illiac disease and less frequency of access complications. We assessed the technical feasibility and safety of TRA for MT in Anterior Circulation LVO in 2 large tertiary care hospitals. Methods: This is a retrospective two-center study of patients undergoing MT for anterior LVO via a TRA from January 2015 through June 2017. From the institutional database of patients receiving MT we identified consecutive patients in whom a TRA was performed for MT for anterior circulation Large vessel occlusion. A 6F guide sheath and 6F Guide-catheter system introduced through the radial artery with or without balloon at distal tip was used for the MT procedure with a standard microcatheter MT technique. We measured workflow metrics, complications and feasibility and safety in this cohort. Results: 27 out of 390 (6.9%) MT patients underwent TRA MT for anterior LVO during the study period. There were 8 males (29.6%) and 19 females (70%). There were 9 patients (33.3%) in whom a TFA was attempted initially and had to be converted to a TRA due to inability to catheterize the great vessels via TFA. In rest of the patients, TRA was the first line approach. The mean age of patients was 80 ±12, females 84.5±9.6 years, males 74.1±16.2 years. Median time from access to reperfusion was 60 minutes (IQR 37 to 94). 22 (81.4%) had excellent rates of revascularization (TICI 2b, 3). Symptomatic ICH was observed in 3 patients (11.1%). There were no access related complications were noted in any of the patients. Conclusion: TRA for MT in patients with anterior circulation LVOs is feasible, safe and achieves rapid reperfusion similar to TFA for MT. Apart from being an alternative when TFA is not feasible, it should be studied further as a first line approach for MT in LVO stroke.

Submucosal Inferior Turbinoplasty Using a New Continuous Suction Irrigation Method.

Numerous surgical techniques for inferior turbinate hypertrophy (ITH) have been reported, each with advantages and disadvantages. Submucosal turbinoplasty with removal of the bony component of the inferior turbinate (IT) is an excellent procedure to expand the nasal cavity. However, this procedure requires a large incision to remove the inferior turbinate bone (ITB) and is associated with hemorrhage, crust formation, and adhesion. A smaller incision would avoid such complications. We developed a continuous suction irrigation method that maintains a clear view of the limited surgical field of the IT. Only a single small incision is needed to insert the rigid endoscope. The surgeon can flush blood with continuous water flow and perform IT surgery without difficulty. We performed this method in 39 cases from January 2016 to January 2017. This video article demonstrates our new submucosal inferior turbinoplasty technique. Submucosal turbinoplasty using a continuous suction irrigation method was performed under general anesthesia. An irrigation-suction straw sheath system was used to create an underwater surgical field. The ITB was removed safely with no severe complications. An expanded common nasal cavity was confirmed postoperatively on computed tomographic images. We resected the ITB safely using a continuous suction irrigation method without difficulty or complications. We believe that this method may become one of the best surgical options for ITH.

A Novel External Carotid Arterial Sheath System for Intra-arterial Infusion Chemotherapy of Head and Neck Cancer.

The purpose of this study was to describe a novel system for treating advanced head and neck cancer consisting of an external carotid arterial sheath (ECAS) and a microcatheter to inject drugs retrogradely into multiple feeding arteries through the superficial temporal artery (STA). Four consecutive patients with head and neck cancer that had more than one feeding artery were enrolled in this study. The ECAS was made of polyurethane and surface-coated with heparin resin to prevent thrombus formation, allowing it to remain in place for a prolonged period of time. The ECAS was inserted through the STA, and its tip was placed between the maxillary artery and facial artery. The tumor-feeding arteries were selected using a hooked-shaped microcatheter through the ECAS. A total of 13 target arteries were selected in the four patients. The microcatheter inserted via the ECAS was used to catheterize ten arteries (five lingual arteries and five facial arteries). The remaining three lingual arteries were directly selected by the catheter without ECAS. All of the target arteries were able to be catheterized superselectively. The technical success rate was 100%. Vascular occlusion, which might have been caused by the ECAS, was observed in one patient. No neurologic toxicities occurred. This ECAS system is a new approach for retrograde superselective intra-arterial chemotherapy that covers the entire tumor with anticancer drugs. It has the potential to increase the effectiveness of therapy for advanced head and neck cancer. Level 4, Case Series.

Online Monitoring and Diagnosis of HV Cable Faults by Sheath System Currents

Cross-bonded metal sheath connection is applied in sectioned single-core power cables to reduce or eliminate the voltages that are induced in the sheath over long distances. However, cross-bonded cables present an opportunity as well as a challenge for online measurement and diagnosis of cable conditions. In this paper, a methodology to identify cable sheath faults through analysis of the sheath system currents in a cross-bonded cable system is presented. First, a numerical model is established to simulate the sheath currents in cross-bonded cable systems. Second, analyses of several faults, which happen frequently with serious consequences, are presented on the basis of current measurement at the link cable. Simulations of normal and fault conditions are given to determine the feasibility of fault diagnosis. A case study using field data from a cable tunnel in China considering the normal condition is presented to verify the numerical model. Results in normal condition show good consistency with field data with error less than 5%. Simulation results of fault conditions show that analysis of readings from six current sensors can distinguish different fault types and fault positions using the method proposed. Based on the analyses, criteria are established for sheath loop fault type diagnosis.

Anteromedial Portal Anterior Cruciate Ligament Reconstruction With Tibialis Anterior Allograft

In an effort to better restore normal joint function and kinematics, recent emphasis has been placed on surgical techniques that provide a more anatomic reconstruction of the anterior cruciate ligament (ACL). With femoral tunnel placement shown to play a vital role in the biomechanics, stability, and clinical outcomes after ACL reconstruction, approaches that better approximate the ACL's native femoral origin have been adopted. The independent anteromedial portal technique is thought to better position the femoral tunnel within the native ACL footprint and leave the graft more posteroinferior on the wall of the lateral femoral condyle than the more traditional transtibial approach. This article outlines the surgical technique for an anteromedial portal ACL reconstruction with a tibialis anterior allograft fixed with the Mitek Femoral and Tibial Intrafix sheath and screw system (DePuy Synthes, Raynham, MA).

Pulley Reconstruction to Correct the Dynamic Direction of the Finger for Treatment of IIB Cleft Hand

Purpose: Manske IIB cleft hand is the most common type, which is characterized by severely narrowed first web and rotation of index finger. Some patients suffered from ulnar displacement of flexor tendon system. However, the ulnar displacement was poorly corrected during index to middle transposition during previous procedures and would usually lead to dysfunction of pinch and grip. Here, we developed a new method to correct finger dynamic direction by pulley transposition. Method: In 15 cases with Type IIB cleft hand, incisions from A1 to A2 pulleys were made with pedicle transposition of the flexor tendon and sheath system to the central. A1 pulleys of index and ring fingers were separated to reconstruct transverse ligament. Snow-Littler procedures were performed to reconstruct the first web. Postoperative assessment included subjective considerations of appearance, parent satisfaction, and ability to perform daily activities. Objective assessment included measurement of first web space, index-ring metacarpal separation, pinch strength, and rotation of the index finger. Results: All the patients and parents claimed to be satisfied with the surgery. Pinch grip reached 72% of the opposite hand when that was normal. The radiological measurement of the angle between the first and second metacarpals was 60.8º and the distance between the adjacent metacarpals across the closed cleft was 8 mm. Index rotation was only 1º and the mean thumb-index pinch was 5.6 kg. Conclusions: Pulley transposition can correct the ulnar displacement of flexor tendon system and improve pinch grip strength in Manske IIB cleft hand, which is a supplemental method for physiological and aesthetic reconstruction of cleft hand.

The feasibility of transradial laser atherectomy for chronic total occlusion using the 5 Fr sheath system

We present a case of chronic total occlusion (CTO) approached with LASER endovascular intervention by radial artery approach using a 5 French sheath. A 57-year-old man presented to our hospital having had retrosternal chest pain for two days. Physical examination was normal at the time of presentation. The laboratory tests were within normal limits, including cardiac enzymes except the lipid panel which showed hypertriglyceridemia. The patient underwent a myocardial perfusion scintigraphy stress test that revealed inferior wall ischemia, with normal left ventricular ejection fraction. A 5-French vascular sheath was placed in the right radial artery. Selective coronary artery angiography was performed, which showed right coronary artery (RCA) CTO. A 5-French JR4 guide catheter successfully engaged the RCA and Laser angioplasty was performed across the CTO into the RCA. A marked improvement of flow was evident thereafter. To best of our knowledge this is the first case report showing the feasibility of laser atherectomy using the 5 French sheath system in a coronary arterial CTO.

Evaluation of lead extraction procedures using the Evolution Mechanical Dilatator Sheath lead extraction system: A single centre experience

In recent years, there has been an increase in clinical situations requiring extraction of leads of implanted cardiac devices. This study aimed to evaluate the Evolution Mechanical Dilator Sheath system, presently in use in our clinic for lead extraction procedures. Lead extraction procedures carried out on 20 patients (14 men, 6 women; mean age 61±19; range 23 to 85 years) between 2008 and 2013 using the Evolution system were retrospectively evaluated. Procedural success, and major and minor complications were determined by previously published guidelines. Mean implantation duration of the leads was 97±65 months (8-204). Fifteen (75%) patients had undergone pacemaker implantation and 5 (25%) had been implanted with a defibrillator. A total of 35 leads were removed from the patients. Seventeen (49%) were ventricular and 12 (34%) were atrial. Five (14%) were defibrillator coils and 1 a coronary sinus lead. Indications for lead extraction were device infection in 18 (90%) patients and lead dysfunction in 2 (10%). Complete procedural success was 95%. Failure occurred in 1 patient. The major complication rate was 5% and minor complications were seen in 25% of patients. No case of mortality was present. In this single centre study, it was shown that extraction of pacemaker and defibrillator leads of longer implant duration may be successfully carried out using the Evolution system. However, due to potentially serious complications it is advised that extraction be done by an experienced operator in centres with cardiovascular surgery facilities.

A balloon-expandable sheath facilitates transfemoral TAVR in patients with peripheral vascular disease and tortuosity.

We sought to perform transcatheter aortic valve replacement (TAVR) via the transfemoral approach in patients with peripheral arterial disease (PAD), small caliber ileofemoral vessels and vascular tortuosity. For patients with increased surgical risk, TAVR is associated with a higher 1-year survival rate than surgical aortic valve replacement (SAVR). Transfemoral vascular access for TAVR results in superior outcomes versus procedures performed via other routes in terms of mortality, morbidity and healthcare economics. In many patients, the ability to safely perform the procedure via the transfemoral approach is limited by narrow, diseased and tortuous ileofemoral vasculature. We employed the SoloPath Balloon Expandable TransFemoral Access System (Terumo Med. Corp., Tokyo, Japan) to perform transfemoral TAVR in five patients with PAD, small caliber ileofemoral vessels and vascular tortuosity. We report our experience using this balloon-expandable sheath during 5 cases of transfemoral TAVR in patients with inhospitable ileofemoral vasculature of mean diameter ⩽ 5.8 mm. The unexpanded sheath's malleable structure and hydrophilic coating permitted deployment despite severe stenoses and tortuosity. Subsequent inflation to 18 Fr facilitated successful TAVR. Postprocedural angiography demonstrated no significant vascular access complications. In one case, the entire procedure was performed percutaneously, without common femoral artery surgical cutdown. The SoloPath sheath system permits transfemoral TAVR in patients with PAD small caliber ileofemoral vessels and vascular tortuosity. The transfemoral balloon-expandable sheath allowed these patients to avoid the increased morbidity and mortality risks associated with direct aortic or transapical access.

The Design and Simulated Analysis of Sheath Flow System for the Flow Cytometry

Flow cytometry is a examination method which can analyse and sort unicellular or biological particles . For the requirement of the width and the flowage of sample flow in the laser detection area , this paper designs a sheath flow system of flow cytometry through solidworks software based on the theory of hydrodynamic focusing. Simulating and calculating this model through solidworks flow simulation software, the simulated results meet fully the actual experiment for unicellular and biological particles. The simulated results can verify the correctness of the sheath flow system, and it has certain theoretical significance for actual design of sheath system about flow cytometry.

Electron emission in a source-collector sheath system: A kinetic study

The classical source-collector sheath system describes a plasma that forms between a Maxwellian source and an absorbing wall. The plasma is assumed to be collisionless and without ionization. Two distinct areas are being formed: the collector sheath, an ion-rich region in contact with the absorbing boundary, and the source sheath, which is an electron-rich area near the Maxwellian source. In this work, we study a modified version of the classical source-collector sheath system, where the wall is no longer absorbing but emits electrons. As a result, we have two different types of collector sheath, one where a potential well is formed and one without a potential well. We examine the effect of electron emission for a range of conditions for the plasma and the emitted electrons. In the first part of this work, we study the problem analytically, and in the second, using our kinetic Vlasov code, Yggdrasil. The simulation results are in very good agreement with the predictions of our theoretical model.

DIRECT VESSEL VISUALIZATION WITH ARTERIAL CUT-DOWN REDUCES VASCULAR COMPLICATION RATES IN TRANSCATHETER AORTIC VALVE IMPLANTATION: BACK TO THE FUTURE

Transfemoral (TF) transcatheter aortic valve implantation (TAVI) using a purely percutaneous approach is associated with significant rates of major vascular complications, even in the most contemporary published data series. The rate of major vascular complications in the TAVI group in the US CoreValve High Risk Study was 5.9%. Since 2010 our institution has adopted a routine surgically performed vascular cut-down for all TF TAVI procedures with deployment of a balloon expandable sheath (SoloPath, Onset Medical Corp, Irvine, CA) under direct arterial visualization. The purpose of this retrospective observational study was to document the rate of vascular complications using this approach. Records on patients who underwent TF TAVI with the CoreValve system (Medtronic, Minneapolis, MN) between January 2010 to March 2014 at our centre were retrospectively reviewed. Data on patient demographics, STS scores, femoral artery size, procedure duration, mortality, vascular complications, transfusions, wound infections, length of stay and discharge location were collected. Vascular complications were defined according to the Valve Academic Research Consortium definitions. Descriptive statistics were performed. Sixty-three patients underwent TF TAVI from January 2010 to March 2014. The mean age was 80 years. Seventy percent were male. The mean STS score for morbidity and mortality was 27.7 ± 13%. The mean STS PROM score was 7.5 ± 5.5%. The mean diameter of the common femoral artery was 8.8 ± 1.6mm. All patients had a TF approach with direct arterial visualization via cut-down. The mean procedural duration was 132 ± 53mins. There was a 4.8% 30-day mortality rate. One vascular complication (1.6%, 1/63) was observed. A localized sub-intimal lower descending thoracic aortic dissection was identified following sheath insertion which necessitated aborting the procedure. This healed uneventfully and a subsequent successful transapical TAVI was undertaken 6 weeks later. There were no complications of leg ischemia, hemorrhage, or iliofemoral rupture. Four patients (6.3%) required transfusions of at least 1 unit due to peri-procedural blood loss. One patient (1.6%) experienced a pseudomonas wound infection that resolved with intravenous inpatient antibiotic treatment. Mean length of stay was 6.4 ± 3.5days and 94% (59/63) were discharged to their own homes. Use of direct arterial visualization and a balloon expandable sheath system for obtaining femoral vascular access for TAVI was associated with a vascular complication rate substantially lower than that seen in published studies using a purely or default percutaneous approach while maintaining a comparable length of hospital stay.

Minimally invasive evacuation of parenchymal and ventricular hemorrhage using the Apollo system with simultaneous neuronavigation, neuroendoscopy and active monitoring with cone beam CT

IntroductionThe Apollo system is a low profile irrigation–aspiration system which can be used for the evacuation of intracranial hemorrhage. We demonstrate the feasibility of using Apollo to evacuate intracranial hemorrhage...

Elongation Modeling and Compensation for the Flexible Tendon--Sheath System

In tendon-driven systems, the elongation of the tendon would result in inaccuracy in the position control of the system. This becomes a critical challenge for those applications, such as surgical robots, which require the tendon-sheath system with flexible and even time-varying configurations but lack of corresponding sensory feedback at the distal end due to spatial restrictions. In this paper, we endeavor to address this problem by modeling the tendon elongation in a flexible tendon-sheath system. Targeting at flexibility in practical scenarios, we first derived a model describing the relationship between the overall tendon elongation and the input tension with arbitrary route configurations. It is shown that changes in the route configuration would significantly affect the tendon elongation. We also proposed a remedy to enhance the system tolerance against potential unmodeled perturbations along the transmission route during operation. A scaling factor S was introduced as a design guideline to determine the scaling effect. A dedicated platform that was able to measure the tensions at both ends and the overall tendon elongation was designed and set up to validate the new findings. Discussions were made on the performance and the future implementation of the proposed models and remedy.

Design of Dividable Colonoscope Sheath1

Design of Dividable Colonoscope Sheath1

Renal sympathetic denervation with long steerable sheath and mapping system — First-in-man experience in three consecutive patients

system — First-in-man experience in three consecutive patients Bruno Rustum Andrea ⁎, Edvaldo Xavier , Marcio Galindo Kiuchi , Simone Farah , Shaojie Chen , Jocemir Ronaldo Lugon , Eduardo Andrea a,c a Corritmo Group, Electrophysiology Department, Rio de Janeiro, Brazil b Renal Division, Department of Medicine, Universidade Federal Fluminense, Niteroi, RJ, Brazil c Department of Cardiology, Regional Darcy Vargas Hospital, Rio Bonito, Brazil d Department of Cardiology, Santa Casa de Misericordia de Maceio Hospital, Maceio, Brazil e Nucleo de Consultoria Cardiologica, Secretaria Estadual de Saude do Rio de Janeiro, Brazil f The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China

Variable stiffness outer sheath with “Dragon skin” structure and negative pneumatic shape-locking mechanism

Natural orifice transluminal endoscopic surgery (NOTES) offers the possibility of surgery without visible scars. To overcome the limitations of NOTES, we developed a novel surgical device called the rigid and flexible outer sheath with multi-piercing surgery (MPS). This sheath can switch between flexible and rigid modes using a novel "Dragon skin" structure and a negative pneumatic shape-locking mechanism. In addition, it has an integrated bending structure that enables it to flex in four directions at the distal end. The insertion part of the prototype is 575mm long with a 20 mm outer diameter. The rigid and flexible shaft is separated into two parts. The primary and secondary shape-locking shafts are 300 and 200 mm long, respectively. The two parts of shape-locking shaft can be locked independently, including both being locked simultaneously. In addition, the model was equipped with one 7- and 1.7-mm-diameter, and three 3-mm-diameter working channels. When the sheath approaches the target, the surgeon locks the shape and then easily inserts flexible instruments through the path created by the sheath. In this study, we evaluated the stiffness of the prototype. Furthermore, an in vivo partial gastrectomy experiment was also performed. The experimental results regarding the shape property suggest that the rigidity of the shaft was considerably increased using this mechanism. An in vivo partial gastrectomy experiment performed using a swine was successfully performed using the outer sheath for assistance. The outer sheath was inserted through a percutaneous route during the in vivo experiment. The evaluation results show that the advanced outer sheath system has great promise for solving access and stability problems with NOTES.

Feasibility and safety of a virtual 3‐Fr sheathless‐guiding system for percutaneous coronary intervention

To evaluate the feasibility and safety of a virtual 3-Fr system [5-Fr sheathless-guiding catheter (GC)] for percutaneous coronary intervention (PCI). The use of miniaturized devices for PCI is gaining popularity because of increased patient comfort and decreased risk of access site complications. From July 2010 to December 2012, consecutive patients who underwent elective PCI (planned or ad hoc PCI) at our hospital were enrolled. PCI using the virtual 3-Fr system was attempted as our initial strategy, unless a 6-Fr or larger GC was considered to be suitable [lesions with heavy calcification, large (>2 mm) side branches, or chronic total occlusion]. Five hundred sixty-six patients underwent elective PCI during the study period, and 132 patients who met the criteria underwent PCI using the virtual 3-Fr system. Procedures using the virtual 3-Fr system were successful in 126 patients (95%); 111 (84%) were performed using the transradial approach, 110 (83%) were ad hoc procedures, and 45 (31%) were complex coronary lesions (type B2 or C). Six patients required conversion to a conventional 5- or 6-Fr sheath and catheter system. No intraoperative complications occurred, and radial artery patency was achieved in all patients who underwent transradial procedures. PCI using the virtual 3-Fr system is a feasible and viable alternative to conventional procedures that use a sheath and GC in appropriately selected patients. This small-caliber system may minimize endovascular trauma, particularly during transradial coronary procedures.

Considerations in the surgical use of the flexor sheath and pulley system

The use of the digital flexor sheath to reconstruct damaged structures in the fingers is an intriguing but under-investigated subject. The sheath is anchored firmly to the phalanges and palmar plates and has well-vascularized outer and synovial inner layers. The middle layer is strong and fibrous and not all of it is required for its main biomechanical function of maintaining the moment arm of the flexor tendons. These characteristics have led to several descriptions of different reconstructive uses. In sheath reconstruction, flaps can be used to repair damaged A2 and A4 pulleys. As an anchor, the sheath is useful for tenodeses and tendon transfers. It has been used in the correction of ulnar claw and swan neck deformities. In ligament reconstruction, the A1 pulley has been used to reconstruct the transverse intermetacarpal ligament in cleft hand and ray amputations. The sheath has also been used to cover tendon repairs and periosteal defects with the aim of decreasing adhesions. There is potential for further use of the flexor sheath in reconstructive surgery. The digital flexor sheath can be used to restore various finger functions providing its physiological roles are recognized and preserved. This review considers the different techniques described and their potential uses.

An investigation of friction-based tendon sheath model appropriate for control purposes

The tendon sheath mechanism plays an important role in many robotic systems from surgical devices to robot hands. However, many unexpected properties such as nonlinear hysteresis and backlash, which appear in the tendon sheath system, cause major losses in force transmission. This report deals with the characterization of hysteresis phenomenon, which is attributed to the presence of frictional effects on its elements, in a tendon-sheath driven surgical robot. Unlike various approaches presented in the literature that utilized multiple lumped mass elements, this proposed approach models the tendon sheath as one element. A new dynamic friction model that allows accurate description of friction lag and hysteresis behavior in two regimes, i.e. presliding and sliding regimes, for a sheath in arbitrary configuration such as helical and spatial shape has been developed.In both regimes, an advanced set of velocity and acceleration dependent functions in a form of the Stribeck function and the modified normalized Bouc–Wen model are used to model friction characteristics between the tendon and the sheath. The smooth transition between the two regimes is also assured. The proposed model is subsequently validated using experimental data. It shows a high degree of accuracy and fidelity in predicting the friction force in a tendon-sheath mechanism. The proposed model overcomes the current drawbacks in tendon sheath friction modeling approach when dealing with discontinuity as the system operates near areas of zero velocity. The new structure of this new model allows a simplified calculation, bringing more valuable practicability and providing an accurate prediction for haptic feedback and control purposes.