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Title: Percutaneous Transcatheter One-Step Mechanical Aortic Disc Valve Prosthesis Implantation: A Preliminary Feasibility Study in Swine

Abstract

Purpose. To evaluate the feasibility of one-step implantation of a new type of stent-based mechanical aortic disc valve prosthesis (MADVP) above and across the native aortic valve and its short-term function in swine with both functional and dysfunctional native valves. Methods. The MADVP consisted of a folding disc valve made of silicone elastomer attached to either a nitinol Z-stent (Z model) or a nitinol cross-braided stent (SX model). Implantation of 10 MADVPs (6 Z and 4 SX models) was attempted in 10 swine: 4 (2 Z and 2 SX models) with a functional native valve and 6 (4 Z and 2 SX models) with aortic regurgitation induced either by intentional valve injury or by MADVP placement across the native valve. MADVP function was observed for up to 3 hr after implantation. Results. MADVP implantation was successful in 9 swine. One animal died of induced massive regurgitation prior to implantation. Four MADVPs implanted above functioning native valves exhibited good function. In 5 swine with regurgitation, MADVP implantation corrected the induced native valve dysfunction and the device's continuous good function was observed in 4 animals. One MADVP (SX model) placed across native valve gradually migrated into the left ventricle. Conclusion. The testedmore » MADVP can be implanted above and across the native valve in a one-step procedure and can replace the function of the regurgitating native valve. Further technical development and testing are warranted, preferably with a manufactured MADVP.« less

Authors:
 [1]; ;  [2]; ; ;  [3]
  1. Institute for Clinical and Experimental Medicine, Intensive Care Unit, Clinic of Cardiology (Czech Republic), E-mail: jan.sochman@medicon.cz
  2. Institute for Clinical and Experimental Medicine, Department of Diagnostic and Interventional Radiology (Czech Republic)
  3. Oregon Health and Sciences University, Dotter Interventional Institute (United States)
Publication Date:
OSTI Identifier:
21091276
Resource Type:
Journal Article
Resource Relation:
Journal Name: Cardiovascular and Interventional Radiology; Journal Volume: 29; Journal Issue: 1; Other Information: DOI: 10.1007/s00270-005-0029-9; Copyright (c) 2006 Springer Science+Business Media, Inc.; www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; FEASIBILITY STUDIES; INJURIES; NICKEL ALLOYS; SILICONES; SWINE; TITANIUM ALLOYS; VALVES

Citation Formats

Sochman, Jan, Peregrin, Jan H., Rocek, Miloslav, Timmermans, Hans A., Pavcnik, Dusan, and Roesch, Josef. Percutaneous Transcatheter One-Step Mechanical Aortic Disc Valve Prosthesis Implantation: A Preliminary Feasibility Study in Swine. United States: N. p., 2006. Web. doi:10.1007/S00270-005-0029-9.
Sochman, Jan, Peregrin, Jan H., Rocek, Miloslav, Timmermans, Hans A., Pavcnik, Dusan, & Roesch, Josef. Percutaneous Transcatheter One-Step Mechanical Aortic Disc Valve Prosthesis Implantation: A Preliminary Feasibility Study in Swine. United States. doi:10.1007/S00270-005-0029-9.
Sochman, Jan, Peregrin, Jan H., Rocek, Miloslav, Timmermans, Hans A., Pavcnik, Dusan, and Roesch, Josef. Wed . "Percutaneous Transcatheter One-Step Mechanical Aortic Disc Valve Prosthesis Implantation: A Preliminary Feasibility Study in Swine". United States. doi:10.1007/S00270-005-0029-9.
@article{osti_21091276,
title = {Percutaneous Transcatheter One-Step Mechanical Aortic Disc Valve Prosthesis Implantation: A Preliminary Feasibility Study in Swine},
author = {Sochman, Jan and Peregrin, Jan H. and Rocek, Miloslav and Timmermans, Hans A. and Pavcnik, Dusan and Roesch, Josef},
abstractNote = {Purpose. To evaluate the feasibility of one-step implantation of a new type of stent-based mechanical aortic disc valve prosthesis (MADVP) above and across the native aortic valve and its short-term function in swine with both functional and dysfunctional native valves. Methods. The MADVP consisted of a folding disc valve made of silicone elastomer attached to either a nitinol Z-stent (Z model) or a nitinol cross-braided stent (SX model). Implantation of 10 MADVPs (6 Z and 4 SX models) was attempted in 10 swine: 4 (2 Z and 2 SX models) with a functional native valve and 6 (4 Z and 2 SX models) with aortic regurgitation induced either by intentional valve injury or by MADVP placement across the native valve. MADVP function was observed for up to 3 hr after implantation. Results. MADVP implantation was successful in 9 swine. One animal died of induced massive regurgitation prior to implantation. Four MADVPs implanted above functioning native valves exhibited good function. In 5 swine with regurgitation, MADVP implantation corrected the induced native valve dysfunction and the device's continuous good function was observed in 4 animals. One MADVP (SX model) placed across native valve gradually migrated into the left ventricle. Conclusion. The tested MADVP can be implanted above and across the native valve in a one-step procedure and can replace the function of the regurgitating native valve. Further technical development and testing are warranted, preferably with a manufactured MADVP.},
doi = {10.1007/S00270-005-0029-9},
journal = {Cardiovascular and Interventional Radiology},
number = 1,
volume = 29,
place = {United States},
year = {Wed Feb 15 00:00:00 EST 2006},
month = {Wed Feb 15 00:00:00 EST 2006}
}
  • Purpose: Over the past 30 years there have been experimental efforts at catheter-based management of aortic valve regurgitation with the idea of extending treatment to nonsurgical candidates. A new catheter-based aortic valve design is described.Methods: The new catheter-delivered valve consists of a stent-based valve cage with locking mechanism and a prosthetic flexible tilting valve disc. The valve cage is delivered first followed by deployment and locking of the disc. In acute experiments, valve implantation was done in four dogs.Results: Valve implantation was successful in all four animals. The implanted valve functioned well for the duration of the experiments (up tomore » 3 hr).Conclusion: The study showed the implantation feasibility and short-term function of the tested catheter-based aortic disc valve. Further experimental studies are warranted.« less
  • The aim of this experimental study was to evaluate a newly designed cone-shaped aortic valve prosthesis (CAVP) for one-step transcatheter placement in an orthotopic position. The study was conducted in 15 swine using either the transcarotid (11 animals) or the transfemoral (4 animals) artery approach. A 12- or 13-Fr sheath was inserted via arterial cutdown. The CAVP was deployed under fluoroscopic control and its struts, by design, induced significant native valve insufficiency. CAVP function was evaluated by aortography and aortic pressure curve tracing. In 11 of 15 swine the CAVP was properly deployed and functioned well throughout the scheduled periodmore » of 2-3 h. In three swine the CAVPs were placed lower than intended, however, they were functional even in the left ventricular outflow tract position. One swine expired due to inadvertent low CAVP placement that caused both aortic regurgitation and immobilization of the anterior mitral valve leaflet by the valve struts. We conclude that this design of CAVP is relatively easy to deploy, works well throughout a short time period (2-3 h), and, moreover, seems to be reliable even in a lower-than-orthotopic position (e.g., infra-annulary space). Longer-term studies are needed for its further evaluation.« less
  • The purpose of this study was to report our initial experience with a swine model for biliary interventions by using a percutaneous transcholecystic access after suture anchor of the gallbladder. Telepaque tablets were given to five pigs to opacify the gallbladder. Under fluoroscopy, the opacified gallbladder was punctured percutaneously and three suture anchors were used to fix the anterior wall of the gallbladder to the abdominal wall. Two weeks later, the gallbladder was punctured and access into the distal common bile was obtained through the cystic duct. Balloon expandable stents were deployed into the distal common bile duct. Follow-up cholangiogramsmore » were obtained at 1 and 2 weeks. Necropsy was performed after 2 weeks to evaluate the relationship between the gallbladder and abdominal wall. Suture anchor placement was successful in all five pigs. One pig with a deep and highly positioned gallbladder developed fever, anorexia, and vomiting secondary to excessive stretch of the gallbladder. Placement of the guidewire through the extremely tortuous and small cystic ducts proved to be the most challenging step of the procedure. Metallic stents were successfully deployed in all four pigs in which it was attempted. Four animals tolerated the procedures without changes in their clinical conditions and no symptoms. Successful follow-up cholangiograms were performed at 1 and 2 weeks post-stent deployment without complications. All stents remained patent during the follow-up period. Necropsy demonstrated close attachment and adherence of the gallbladders to the antero-lateral abdominal wall in all four animals. Suture anchoring of the gallbladder is feasible in most pigs with superficially located gallbladders. This technique allows a safe and repeat access into the biliary system using a transcholecystic approach.« less
  • IntroductionSpastic patients often seek neurolysis, the permanent destruction of the sciatic nerve, for better pain management. MRI-guided high-intensity focused ultrasound (MRgHIFU) may serve as a noninvasive alternative to the prevailing, more intrusive techniques. This in vivo acute study is aimed at performing sciatic nerve neurolysis using a clinical MRgHIFU system.MethodsThe HIFU ablation of sciatic nerves was performed in swine (n = 5) using a HIFU system integrated with a 3 T MRI scanner. Acute lesions were confirmed using T1-weighted contrast-enhanced (CE) MRI and histopathology using hematoxylin and eosin staining. The animals were euthanized immediately following post-ablation imaging.ResultsReddening and mild thickening of themore » nerve and pallor of the adjacent muscle were seen in all animals. The HIFU-treated sections of the nerves displayed nuclear pyknosis of Schwann cells, vascular hyperemia, perineural edema, hyalinization of the collagenous stroma of the nerve, myelin sheet swelling, and loss of axons. Ablations were visible on CE MRI. Non-perfused volume of the lesions (5.8–64.6 cc) linearly correlated with estimated lethal thermal dose volume (4.7–34.2 cc). Skin burn adjacent to the largest ablated zone was observed in the first animal. Bilateral treatment time ranged from 55 to 138 min, and preparation time required 2 h on average.ConclusionThe acute pilot study in swine demonstrated the feasibility of a noninvasive neurolysis of the sciatic nerve using a clinical MRgHIFU system. Results revealed that acute HIFU nerve lesions were detectable on CE MRI, gross pathology, and histology.« less