The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Jan M Macak - One of the best experts on this subject based on the ideXlab platform.
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mechanical properties of a biodegradable self expandable Polydioxanone monofilament stent in vitro force relaxation and its clinical relevance
PLOS ONE, 2020Co-Authors: Ales Bezrouk, Tomas Hosszu, Ludek Hromadko, Zuzana Zmrhalova, Martin Kopecek, Martin Smutny, Iva Selke Krulichova, Jan M MacakAbstract:Biodegradable stents are promising treatments for many diseases, e.g., coronary artery disease, urethral diseases, tracheal diseases, and esophageal strictures. The mechanical properties of biodegradable stent materials play a key role in the safety and efficacy of treatment. In particular, insufficient creep resistance of the stent material could result in premature stent collapse or narrowing. Commercially available biodegradable self-expandable SX-ELLA stents made of Polydioxanone monofilament were tested. A new, simple, and affordable method to measure the shear modulus of tiny viscoelastic wires is presented. The important mechanical parameters of the Polydioxanone filament were obtained: the median Young's modulus was [Formula: see text] = 958 (922, 974) MPa and the shear modulus was [Formula: see text] = 357 (185, 387) MPa, resulting in a Poisson's ratio of ν = 0.34. The SX-ELLA stents exhibited significant force relaxation due to the stress relaxation of the Polydioxanone monofilament, approximately 19% and 36% 10 min and 48 h after stent application, respectively. However, these results were expected, and the manufacturer and implanting clinician should be aware of the known behavior of these biodegradable materials. If possible, a biodegradable stent should be designed considering therapeutic force rather than initial force. Additionally, new and more advanced biodegradable shape-memory polymers should be considered for future study and use.
Yukihide Iwamoto - One of the best experts on this subject based on the ideXlab platform.
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Comparison of the mechanical properties of polyglycolide-trimethylene carbonate (Maxon) and Polydioxanone sutures (PDS2) used for flexor tendon repair and active mobilization.
Journal of Hand Surgery (European Volume), 2002Co-Authors: A. Wada, Hideaki Kubota, Mayuki Taketa, Hiromasa Miura, Yukihide IwamotoAbstract:Thirty-six canine flexor digitorum profundus tendons were repaired using 5-0 polyglycolide-trimethylene carbonate monofilament (Maxon) or Polydioxanone monofilament (PDS2). All the tendons healed without rupture or formation of gaps of more than 2 mm. Mechanically, all tendon repairs had sufficient tensile strength to enable active mobilization. Polyglycolide-trimethylene carbonate (Maxon) repairs were initially superior in gap and ultimate strength to Polydioxanone (PDS2) repairs. However, the gap and ultimate tensile strength of polyglycolide-trimethylene carbonate (Maxon) repairs had decreased significantly at day 14, whereas Polydioxanone (PDS2) repairs maintained their strength throughout the 28-day observation period.
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effect of absorbable Polydioxanone flexor tendon repair and restricted active mobilization in a canine model
Journal of Hand Surgery (European Volume), 2001Co-Authors: A. Wada, Hideaki Kubota, Hiromasa Miura, Takenori Akiyama, H Hatanaka, Yukihide IwamotoAbstract:Abstract We performed an experimental study to evaluate the mechanical and histologic healing process of flexor tendon repair using absorbable Polydioxanone monofilament followed by active mobilization. Sixty-four canine flexor digitorum profundus tendons were repaired using Polydioxanone monofilament or control braided polyester. Animals were evaluated 7, 14, 28, and 42 days after surgery with 12 day 0 control tendons. All repaired tendons healed without rupture or gap formation. Mechanically, all specimens had adequate tensile strength enabling active mobilization. The tendons that were repaired using braided polyester healed without initial tensile depression; however, the ultimate tensile strength values of Polydioxanone specimens showed a significant decrease at day 14. Histologically, an inflammatory response was observed around the Polydioxanone monofilament; this reaction increased from day 14 to day 42. However, the inflammatory response did not cause large adhesions or large tendon callus formation. This method of using absorbable suture material for tendon repair has the potential for use in the clinical setting. (J Hand Surg 2001;26A:398-406. Copyright © 2001 by the American Society for Surgery of the Hand.)
John A. Waldhausen - One of the best experts on this subject based on the ideXlab platform.
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end to end repair of aortic coarctation using absorbable Polydioxanone suture
The Annals of Thoracic Surgery, 1991Co-Authors: Juan D. Arenas, Alexander Vennos, Marie M. Gleason, Barry G. Baylen, John L. Myers, John A. WaldhausenAbstract:Abstract Based on previous laboratory work, we have used Polydioxanone absorbable suture in a variety of vascular and cardiac repairs in pediatric patients. However, some investigators have expressed concern about the potential for aneurysm formation at the anastomotic site. Between March 1983 and June 1989, 15 patients (7 male, 8 female) aged 2.5 months to 9.2 years (mean, 3.7 years) had resection of coarctation of the aorta and end-to-end anastomosis with Polydioxanone absorbable suture. Thirteen patients have returned for routine postoperative evaluation, the follow-up time ranging from 11 to 49 months (mean, 23 months). Noninvasive two-dimensional, pulsed-wave Doppler and color echocardiography and magnetic resonance imaging studies demonstrated good anatomical repair and no anastomotic aneurysm formation or residual coarctation of the aorta in any patient after end-to-end anastomosis with Polydioxanone. In summary, this intermediate follow-up study has revealed no vascular complications related to the repair of coarctation with absorbable Polydioxanone suture.
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results of aortic anastomoses made under tension using Polydioxanone suture
The Annals of Thoracic Surgery, 1990Co-Authors: Randy S. Haluck, Cynthia A Miller, John L. Myers, Wayne E. Richenbacher, John A. WaldhausenAbstract:Abstract After early repair of congenital cardiovascular defects, such as coarctation of the aorta, late stenosis may become a problem. Use of absorbable sutures has been shown to be superior to use of nonabsorbable sutures in allowing growth of an anastomotic site along with the individual. Some concern has been raised, however, about the potential for aneurysm formation at the site of anastomosis when absorbable sutures are used. This study was undertaken to observe the effects of longitudinal tension on anastomoses made with absorbable Polydioxanone suture in growing animals. Six piglets (aged 3 to 4 weeks) underwent a 1-cm resection of the infrarenal aorta and reanastomosis with Polydioxanone suture. One animal died prematurely of respiratory illness. The 5 remaining animals were killed after 6 months. The excised aortas demonstrated no stenosis, no dilatation, and no bursttest failure to 250 mm Hg. Histological examination showed disrupted elastic laminae without thinning of aortic wall in all samples of aorta. We conclude that Polydioxanone suture is a suitable suture material for vascular anastomoses made under tension where growth of the anastomotic site is expected.
Martina Vasakova - One of the best experts on this subject based on the ideXlab platform.
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biodegradable Polydioxanone stents in the treatment of adult patients with tracheal narrowing
BMC Pulmonary Medicine, 2015Co-Authors: Ludek Stehlik, Vladislav Hytych, Jana Letackova, Petr Kubena, Martina VasakovaAbstract:Biodegradable stents that disintegrate after a period of time are expected to be well tolerated and have advantages over other stents that are more commonly used in practice today. Polydioxanone is a biodegradable polymer that is widely used during surgery with absorbable sutures. We present cases from the first four patients to undergo a tracheal Polydioxanone stent insertion. Indications included significant non-malignant tracheal stenosis in cases where primary surgical treatment was not possible. The stents were implanted using rigid bronchoscopy and patients received regular follow-ups as needed. This use of biodegradable stents in adult patients was a novel, previously untested approach. The study was approved by the Institutional Ethics Committee and was based on a project entitled; “Biodegradable stents in the management of stenoses of large airways” (project NT 14146-3/2013). Six biodegradable stents were implanted in four patients with benign stenoses. No technical difficulties occurred and no serious or life-threatening events were recorded. All patients reported some benefit from treatment. Polydioxanone tracheal stents can be considered when a need for temporary support is expected, and as an alternative to other stents if the latter could compromise the patient. Owing to limited experience and observed disadvantages, further research is needed to fully assess this treatment. This work is based on project NT14146 - Biodegradable stents in the management of stenoses of the large airways (2013–2015, MZ0/NT), registered from May 1, 2013 in The Research and Development and Innovation Information System of the Czech Republic and in ClinicalTrials.gov, reg. no. NCT02620319 , December 2, 2015.
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Biodegradable Polydioxanone stents in the treatment of adult patients with tracheal narrowing.
BMC Pulmonary Medicine, 2015Co-Authors: Ludek Stehlik, Vladislav Hytych, Jana Letackova, Petr Kubena, Martina VasakovaAbstract:Background Biodegradable stents that disintegrate after a period of time are expected to be well tolerated and have advantages over other stents that are more commonly used in practice today. Polydioxanone is a biodegradable polymer that is widely used during surgery with absorbable sutures.
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Biodegradable Polydioxanone stents: Preliminary results in adult patients with tracheal narrowing
European Respiratory Journal, 2015Co-Authors: Ludek Stehlik, Vladislav Hytych, Sarka Lefnerova, Martina VasakovaAbstract:Background: Polydioxanone is biodegradable polymer widely used in surgery for absorbable sutures. Polydioxanone stents have successfully been used in humans as a mechanical support for tracheal transplants, in the treatment of obstructive airway complications after lung transplantation, and in children with airway stenosis. They have not been used in the treatment of tracheal stenosis in adults. Objectives: To assess the efficacy of Polydioxanone stents in the treatment of common types of tracheal narrowings. Methods: Indications included significant tracheal narrowing of various origin in cases where a primary surgical treatment was not possible. We used Polydioxanone stents (ELLA-CS Ltd., Hradec Kralove, Czech Republic) which were implanted during rigid bronchoscopy; patients received regular follow-up as needed. This study received Institutional Ethics Committee approval, it is based on the project entitled Biodegradable stents in the management of stenoses of the large airways (project NT 14146-3/2013) supported by the Internal Grant Agency of the Czech Republic9s Ministry of Health. Results: Between July 2013 and December 2014, we implanted 17 stents in 13 patients. One patient suffered from a malignant narrowing, every other had benign stenoses or tracheomalacia. No technical difficulties or life-threatening events occurred. Nine patients experienced benefit from treatment, the three did not register improvement or an early failure appeared, one patient is short time from procedure to be assessed. Conclusion: Polydioxanone tracheal stents can be considered when the need for temporary support is expected, further investigation is necessary.
A. Wada - One of the best experts on this subject based on the ideXlab platform.
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Comparison of the mechanical properties of polyglycolide-trimethylene carbonate (Maxon) and Polydioxanone sutures (PDS2) used for flexor tendon repair and active mobilization.
Journal of Hand Surgery (European Volume), 2002Co-Authors: A. Wada, Hideaki Kubota, Mayuki Taketa, Hiromasa Miura, Yukihide IwamotoAbstract:Thirty-six canine flexor digitorum profundus tendons were repaired using 5-0 polyglycolide-trimethylene carbonate monofilament (Maxon) or Polydioxanone monofilament (PDS2). All the tendons healed without rupture or formation of gaps of more than 2 mm. Mechanically, all tendon repairs had sufficient tensile strength to enable active mobilization. Polyglycolide-trimethylene carbonate (Maxon) repairs were initially superior in gap and ultimate strength to Polydioxanone (PDS2) repairs. However, the gap and ultimate tensile strength of polyglycolide-trimethylene carbonate (Maxon) repairs had decreased significantly at day 14, whereas Polydioxanone (PDS2) repairs maintained their strength throughout the 28-day observation period.
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effect of absorbable Polydioxanone flexor tendon repair and restricted active mobilization in a canine model
Journal of Hand Surgery (European Volume), 2001Co-Authors: A. Wada, Hideaki Kubota, Hiromasa Miura, Takenori Akiyama, H Hatanaka, Yukihide IwamotoAbstract:Abstract We performed an experimental study to evaluate the mechanical and histologic healing process of flexor tendon repair using absorbable Polydioxanone monofilament followed by active mobilization. Sixty-four canine flexor digitorum profundus tendons were repaired using Polydioxanone monofilament or control braided polyester. Animals were evaluated 7, 14, 28, and 42 days after surgery with 12 day 0 control tendons. All repaired tendons healed without rupture or gap formation. Mechanically, all specimens had adequate tensile strength enabling active mobilization. The tendons that were repaired using braided polyester healed without initial tensile depression; however, the ultimate tensile strength values of Polydioxanone specimens showed a significant decrease at day 14. Histologically, an inflammatory response was observed around the Polydioxanone monofilament; this reaction increased from day 14 to day 42. However, the inflammatory response did not cause large adhesions or large tendon callus formation. This method of using absorbable suture material for tendon repair has the potential for use in the clinical setting. (J Hand Surg 2001;26A:398-406. Copyright © 2001 by the American Society for Surgery of the Hand.)