Name: polytetrafluoroethylene (ptfe) as a suture material in tendon surgery
Uploaded: 2022-10-06T13:00:00
Description: Watch this Scientific Journal Video about Polytetrafluoroethylene PTFE as a Suture Material in Tendon Surgery at JoVE.com

The study was conducted with funds from the Sana Hospital Hof. Furthermore, authors want to thank Ms Hafenrichter (Serag Wiessner, Naila) for her untiring help with the experiments.

This article does not contain any studies with human participants or animals performed by any of the authors. The use of the human material was in full compliance with the university policy for use of cadavers and recognizable body parts, Institute of Anatomy, University of Erlangen.
1. Harvest the flexor tendons
<ol>
	<li>Harvesting the flexor digitorum profundus
	<ol>
		<li>Place a fresh cadaveric upper limb on the dissecting table with the ventral-palmar side facing the s...

<ol>
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An experimental and clinical study.</a> Acta Orthopaedica Scandinavia. 40 (5), 587-601 (1969).</li><li>Waitayawinyu, T., Martineau, P. A., Luria, S., Hanel, D. P., Trumble, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+biomechanic+study+of+flexor+tendon+repair+using+FiberWire.">Comparative biomechanic study of flexor tendon repair using FiberWire.</a> The Journal of Hand Surgery. 33 (5), 701-708 (2008).</li><li>Polykandriotis, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flexor+tendon+repair+with+a+polytetrafluoroethylene+(PTFE)+suture+material.">Flexor tendon repair with a polytetrafluoroethylene (PTFE) suture material.</a> Archives of Orthopaedic and Trauma Surgery. 139 (3), 429-434 (2019).</li><li>Polykandriotis, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polytetrafluoroethylene+(PTFE)+suture+vs+fiberwire+and+polypropylene+in+flexor+tendon+repair.">Polytetrafluoroethylene (PTFE) suture vs fiberwire and polypropylene in flexor tendon repair.</a> Archives of Orthopaedic and Trauma Surgery. 141 (9), 1609-1614 (2021).</li><li>Polykandriotis, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Individualized+wound+closure-mechanical+properties+of+suture+materials.">Individualized wound closure-mechanical properties of suture materials.</a> Journal of Personalized Medicine. 12 (7), 1041 (2022).</li><li>Edsfeldt, S., Rempel, D., Kursa, K., Diao, E., Lattanza, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+flexor+tendon+forces+generated+during+different+rehabilitation+exercises.">In vivo flexor tendon forces generated during different rehabilitation exercises.</a> Journal of Hand Surgery. 40 (7), 705-710 (2015).</li><li>Amadio, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Friction+of+the+gliding+surface.+Implications+for+tendon+surgery+and+rehabilitation.">Friction of the gliding surface. Implications for tendon surgery and rehabilitation.</a> Journal of Hand Therapy. 18 (2), 112-119 (2005).</li><li>Wieskotter, B., Herbort, M., Langer, M., Raschke, M. J., Wahnert, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+impact+of+different+peripheral+suture+techniques+on+the+biomechanical+stability+in+flexor+tendon+repair.">The impact of different peripheral suture techniques on the biomechanical stability in flexor tendon repair.</a> Archives of Orthopaedic and Trauma Surgery. 138 (1), 139-145 (2018).</li><li>Savage, R., Tang, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=History+and+nomenclature+of+multistrand+repairs+in+digital+flexor+tendons.">History and nomenclature of multistrand repairs in digital flexor tendons.</a> Journal of Hand Surgery. 41 (2), 291-293 (2016).</li><li>Lawrence, T. M., Davis, T. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+biomechanical+analysis+of+suture+materials+and+their+influence+on+a+four-strand+flexor+tendon+repair.">A biomechanical analysis of suture materials and their influence on a four-strand flexor tendon repair.</a> Journal of Hand Surgery. 30 (4), 836-841 (2005).</li><li>Lawrence, T. M., Davis, T. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Locking+loops+for+flexor+tendon+repair.">Locking loops for flexor tendon repair.</a> Annals of the Royal College of Surgeons of England. 87 (5), 385-386 (2005).</li><li>Kannas, S., Jeardeau, T. A., Bishop, A. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rehabilitation+following+zone+II+flexor+tendon+repairs.">Rehabilitation following zone II flexor tendon repairs.</a> Techniques in Hand and Upper Extremity Surgery. 19 (1), 2-10 (2015).</li><li>Tang, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+developments+are+improving+flexor+tendon+repair.">New developments are improving flexor tendon repair.</a> Plastic and Reconstructive Surgery. 141 (6), 1427-1437 (2018).</li><li>Dang, M. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Some+biomechanical+considerations+of+polytetrafluoroethylene+sutures.">Some biomechanical considerations of polytetrafluoroethylene sutures.</a> Archives of Surgery. 125 (5), 647-650 (1990).</li><li>Abellan, D., Nart, J., Pascual, A., Cohen, R. E., Sanz-Moliner, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physical+and+mechanical+evaluation+of+five+suture+materials+on+three+knot+configurations:+an+in+vitro+study.">Physical and mechanical evaluation of five suture materials on three knot configurations: an in vitro study.</a> Polymers. 8 (4), 147 (2016).</li><li>Silva, J. M., Zhao, C., An, K. N., Zobitz, M. E., Amadio, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gliding+resistance+and+strength+of+composite+sutures+in+human+flexor+digitorum+profundus+tendon+repair:+an+in+vitro+biomechanical+study.">Gliding resistance and strength of composite sutures in human flexor digitorum profundus tendon repair: an in vitro biomechanical study.</a> Journal of Hand Surgery. 34 (1), 87-92 (2009).</li><li>Chauhan, A., Palmer, B. A., Merrell, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flexor+tendon+repairs:+techniques,+eponyms,+and+evidence.">Flexor tendon repairs: techniques, eponyms, and evidence.</a> Journal of Hand Surgery. 39 (9), 1846-1853 (2014).</li><li>Tolerton, S. K., Lawson, R. D., Tonkin, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Management+of+flexor+tendon+injuries+-+Part+2:+current+practice+in+Australia+and+guidelines+for+training+young+surgeons.">Management of flexor tendon injuries - Part 2: current practice in Australia and guidelines for training young surgeons.</a> Hand Surgery. 19 (2), 305-310 (2014).</li><li>Tang, J. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strong+digital+flexor+tendon+repair,+extension-flexion+test,+and+early+active+flexion:+experience+in+300+tendons.">Strong digital flexor tendon repair, extension-flexion test, and early active flexion: experience in 300 tendons.</a> Hand Clinics. 33 (3), 455-463 (2017).</li><li>Gray, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Grays Anatomy. , (2013).</li><li>McGregor, A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Fundamental Techniques of Plastic Surgery. 10th editon. , (2000).</li><li>Tsuge, K., Yoshikazu, I., Matsuishi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Repair+of+flexor+tendons+by+intratendinous+tendon+suture.">Repair of flexor tendons by intratendinous tendon suture.</a> Journal of Hand Surgery. 2 (6), 436-440 (1977).</li><li>Croog, A., Goldstein, R., Nasser, P., Lee, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+biomechanic+performances+of+locked+cruciate+four-strand+flexor+tendon+repairs+in+an+ex+vivo+porcine+model.">Comparative biomechanic performances of locked cruciate four-strand flexor tendon repairs in an ex vivo porcine model.</a> Journal of Hand Surgery. 32 (2), 225-232 (2007).</li><li>Tang, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Indications,+methods,+postoperative+motion+and+outcome+evaluation+of+primary+flexor+tendon+repairs+in+Zone+2.">Indications, methods, postoperative motion and outcome evaluation of primary flexor tendon repairs in Zone 2.</a> Journal of Hand Surgery. 32 (2), 118-129 (2007).</li><li>Head, W. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adhesion+barriers+in+cardiac+surgery:+A+systematic+review+of+efficacy.">Adhesion barriers in cardiac surgery: A systematic review of efficacy.</a> Journal of Cardiac Surgery. 37 (1), 176-185 (2022).</li><li>Pressman, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Teflon+or+Ivalon:+a+scoping+review+of+implants+used+in+microvascular+decompression+for+trigeminal+neuralgia.">Teflon or Ivalon: a scoping review of implants used in microvascular decompression for trigeminal neuralgia.</a> Neurosurgery Reviews. 43 (1), 79-86 (2020).</li><li>Pillukat, T., van Schoonhoven, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nahttechniken+und+Nahtmaterial+in+der+Beugesehnenchirurgie.">Nahttechniken und Nahtmaterial in der Beugesehnenchirurgie.</a> Trauma und Berufskrankheit. 18 (3), 264-269 (2016).</li><li>Dudenhoffer, D. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+biocompatibility+of+a+novel+expanded+polytetrafluoroethylene+suture+for+annuloplasty.">In vivo biocompatibility of a novel expanded polytetrafluoroethylene suture for annuloplasty.</a> The Thoracic and Cardiovascular Surgeon. 68 (7), 575-583 (2018).</li><li>Dy, C. J., Daluiski, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Update+on+zone+II+flexor+tendon+injuries.">Update on zone II flexor tendon injuries.</a> Journal of the American Academy of Orthopaedic Surgeons. 22 (12), 791-799 (2014).</li><li>Killian, M. L., Cavinatto, L., Galatz, L. 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In this line of experiments, a PTFE strand was evaluated as suturing material for flexor tendon repair. The protocol reproduces conditions that are like the in vivo situation in all but two aspects. First, the loads applied in vivo are repetitive, so a cyclically repeated type of loading might be better suitable. Second, over the first 6 weeks postoperatively, the significant shift from biomechanics toward biology as tendon healing progresses, which is a process that cannot be adequately addressed under...

The treatment of flexor tendon injuries of the hand has been an issue of controversy for over half a century. Until the 1960s, the anatomical area between the middle phalanx and the proximal palm was named "no man's land", to express that attempts of primary tendon reconstruction in this area were futile, producing very poor results1. However, in the 1960s, the issue of primary tendon repair was revisited by introducing new concepts for rehabilitation2. In the 1970s, with advances in neurosciences, new concepts of early rehabilitation could be developed, including dynamic splints3, but thereafter only marginal improvements could be achieved. Recently, new materials were introduced with significantly improved integral stability4,5 so that technical issues other than the failure of the suture materials came into focus, including cheese wiring and pullout6. 
Until recently, polypropylene (PPL) and polyester were widely used in flexor tendon repairs. A 4-0 USP (United States Pharmacopeia) strand of polypropylene corresponding to a diameter of 0.150-0.199 mm exhibits a linear tensile strength of less than 20 Newton (N)6,7, whereas flexor tendons of the hand can develop in vivo linear forces of up to 75 N8. After trauma and surgery, because of edema and adhesions, the resistance of the tissue advances more9. Classical techniques of tendon repair included two-strand configurations that had to be reinforced with additional epitendinous running sutures3,10. Newer polyblend polymer materials with substantially higher linear strength have brought about technical developments4; a single polyblend strand with a core of long chain ultra-high molecular weight polyethylene (UHMWPE) in combination with a braided jacket of polyester in the same diameter as PPL can withstand linear forces of up to 60 N. However, extrusion technologies can manufacture monofilamentous polymer strands exhibiting comparable mechanical properties6. 
Repair techniques have also evolved in the last decade. Two-strand tendon repair techniques have given way to more elaborate four- or six-strand configurations11,12. By the use of a looped suture13, the number of knots can be diminished. By combining newer materials with newer techniques, an initial linear strength of over 100 N can be achieved4. 
An individualized rehabilitation regimen should be advocated in any case, taking into account special patient attributes and tendon repair techniques. For instance, children and adults unable to follow complex instructions for a long time should be subjected to delayed mobilization. Less strong repairs should be mobilized by passive motion alone14,15. Otherwise, early active motion regimens should be the golden standard. 
The overall goal of this method is to evaluate a novel suture material for flexor tendon repair. To commend on the rationale of the protocol, this technique is an evolution of formerly validated protocols found in the literature4,10,12,16 as a means of assessment of suture materials under conditions that resemble clinical routine. Using a modern servohydraulic materials testing system, a traction velocity of 300 mm/min can be set resembling in vivo stress, in contrast to earlier protocols using 25-180 mm/min4,10, accounting for limitations in software and measurement equipment. This method is suitable for ex vivo studies on flexor tendon repairs, and in a wider sense for evaluation of the application of suture materials. In materials sciences, such experiments are routinely used to evaluate polymers and other classes of materials17. 
Phases of the study: The studies were performed in two phases; each was divided into two or three subsequent steps. In the first phase, a polypropylene (PPL) strand and a polytetrafluoroethylene (PTFE) strand were compared. Both 3-0 USP and 5-0 USP strands were utilized to mimic the real clinical conditions. The mechanical properties of the materials themselves were first investigated, although being medical devices, these materials have been extensively tested already. For these measurements, N = 20 strands were measured for linear tensile strength. Knotted strands were also investigated since knotting alters linear tension strength and produces a potential breaking point. The main part of the first phase was about testing the performance of the two different materials under clinical conditions. In addition, 3-0 core repairs (two-strand Kirchmayr-Kessler with the modifications of Zechner and Pennington) were performed and tested for linear strength. For an additional wing of the investigation, an epitendinous 5-0 running suture was added to the repair for additional strength18,19. 
In a subsequent phase, a comparison between three suturing materials was performed, including PPL, UHMWPE and PTFE. For all comparisons, a USP 4-0 strand was used, corresponding to a diameter of 0.18 mm. For a complete list of the materials used, refer to the Table of Materials. For the final step, an Adelaide20 or a M-Tang21 core repair was performed as described earlier.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Chirobloc</td>
			<td>AMT AROMANDO Medizintechnik GmbH</td>
			<td>CBM</td>
			<td>Hand Fixation</td>
		</tr>
		<tr>
			<td>Cutfix Disposable scalpel</td>
			<td>B. Braun Medical Inc, Germany</td>
			<td>5518040</td>
			<td>Safety one use blade</td>
		</tr>
		<tr>
			<td>Coarse paper/ Aluminium Oxide Rhynalox</td>
			<td>Indasa</td>
			<td>440008</td>
			<td>abrasive with a grit size of ISO P60&#160;</td>
		</tr>
		<tr>
			<td>Fiberloop 4-0</td>
			<td>Arthrex GmbH</td>
			<td>AR-7229-20</td>
			<td>Ultra-high molecular weight polyethylene with a braided jacket of polyester 4-0</td>
		</tr>
		<tr>
			<td>G20 cannula Sterican</td>
			<td>B Braun</td>
			<td>4657519</td>
			<td>100 Pcs package</td>
		</tr>
		<tr>
			<td>Isotonic Saline 0.9% Bottlepack 500 mL&#160;</td>
			<td>Serag Wiessner GmbH</td>
			<td>002476</td>
			<td>Saline 500 mL</td>
		</tr>
		<tr>
			<td>KAP-S Force Transducer</td>
			<td>A.S.T. &#8211; Angewandte System Technik GmbH</td>
			<td>AK8002</td>
			<td>Load cell</td>
		</tr>
		<tr>
			<td>Metzenbaum Scissors (one way, 14 cm)</td>
			<td>Hartmann</td>
			<td>9910846</td>
			<td></td>
		</tr>
		<tr>
			<td>Screw grips, Type 8133, Fmax 1 kN</td>
			<td>ZwickRoell GmbH &#38; Co. KG,</td>
			<td>316264</td>
			<td></td>
		</tr>
		<tr>
			<td>Seralene 3-0</td>
			<td>Serag Wiessner GmbH</td>
			<td>LO203413</td>
			<td>Polypropylene Strand 3-0</td>
		</tr>
		<tr>
			<td>Seralene 4-0</td>
			<td>Serag Wiessner GmbH</td>
			<td>LO151713</td>
			<td>Polypropylene Strand 4--0</td>
		</tr>
		<tr>
			<td>Seralene 5-0</td>
			<td>Serag&#160; Wiessner GmbH</td>
			<td>LO103413</td>
			<td>Polypropylene Strand 5-0</td>
		</tr>
		<tr>
			<td>Seramon 3-0</td>
			<td>Serag Wiessner GmbH</td>
			<td>MEO201714</td>
			<td>Polytetrafluoroethylene 3-0</td>
		</tr>
		<tr>
			<td>Seramon 4-0</td>
			<td>Serag Wiessner GmbH</td>
			<td>MEO151714</td>
			<td>Polytetrafluoroethylene 4-0</td>
		</tr>
		<tr>
			<td>Seramon 5-0</td>
			<td>Serag Wiessner GmbH</td>
			<td>MEO103414</td>
			<td>Polytetrafluoroethylene 5-0</td>
		</tr>
		<tr>
			<td>testXpert III testing software (Components following)</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>See following points for components</td>
			<td>testing software</td>
		</tr>
		<tr>
			<td>Results Editor</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035615</td>
			<td></td>
		</tr>
		<tr>
			<td>Layout Editor</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035617</td>
			<td></td>
		</tr>
		<tr>
			<td>Report Editor</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035620</td>
			<td></td>
		</tr>
		<tr>
			<td>Export Editor</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035618</td>
			<td></td>
		</tr>
		<tr>
			<td>Organization Editor</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035614</td>
			<td></td>
		</tr>
		<tr>
			<td>Virtual testing machine VTM</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035522</td>
			<td></td>
		</tr>
		<tr>
			<td>Language swapping</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035622</td>
			<td></td>
		</tr>
		<tr>
			<td>Upload/download</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035957</td>
			<td></td>
		</tr>
		<tr>
			<td>Traceability</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035624</td>
			<td></td>
		</tr>
		<tr>
			<td>Extended control mode</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035959</td>
			<td></td>
		</tr>
		<tr>
			<td>Video Capturing</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035575</td>
			<td></td>
		</tr>
		<tr>
			<td>Plus testControl II</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1033655</td>
			<td></td>
		</tr>
		<tr>
			<td>Temperature control</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035623</td>
			<td></td>
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			<td>HBM connection</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035532</td>
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			<td>National Instruments connection</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035524</td>
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			<td>Video Capturing multiCamera I</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1035574</td>
			<td></td>
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			<td>Video Capturing multiCamera II</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1033653</td>
			<td></td>
		</tr>
		<tr>
			<td>Measuring system related measuring uncertainty to CWA 15261-2</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>1053260</td>
			<td></td>
		</tr>
		<tr>
			<td>Zwick Z050 TN servohydraulic materials testing system&#160;</td>
			<td>ZwickRoell GmbH &#38; Co. KG, Ulm, Germany</td>
			<td>58993</td>
			<td>servohydraulic materials testing system</td>
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polytetrafluoroethylene (ptfe) as a suture material in tendon surgery

With the evolution of suture materials, there has been a change in paradigms in primary and secondary tendon repair. Improved mechanical properties allow more aggressive rehabilitation and earlier recovery. However, for the repair to hold against higher mechanical demands, more advanced suturing and knotting techniques must be assessed in combination with those materials. In this protocol, the use of polytetrafluoroethylene (PTFE) as a suture material in combination with different repair techniques was investigated. In the first part of the protocol, both linear tension strength and elongation of knotted against not-knotted strands of three different materials used in flexor tendon repair were evaluated. The three different materials are polypropylene (PPL), ultra-high molecular weight polyethylene with a braided jacket of polyester (UHMWPE), and polytetrafluoroethylene (PTFE). In the next part (ex vivo experiments with cadaveric flexor tendons), the behavior of PTFE using different suture techniques was assessed and compared with PPL and UHMWPE.
This experiment is comprised of four steps: harvesting of the flexor tendons from fresh cadaveric hands, transection of the tendons in a standardized manner, tendon repair by four different techniques, mounting, and measurement of the tendon repairs on a standard linear dynamometer. The UHMWPE and PTFE showed comparable mechanical properties and were significantly superior to PPL in terms of linear traction strength. Repairs with four- and six-strand techniques proved stronger than two-strand techniques. Handling and knotting of PTFE are a challenge due to very low surface friction but fastening of the four- or six-strand repair is comparatively easy to achieve. Surgeons routinely use PTFE suture material in cardiovascular surgery and breast surgery. The PTFE strands are suitable for use in tendon surgery, providing a robust tendon repair so that early active motion regimens for rehabilitation can be applied.

Tendon repairs: When a two-strand Kirchmayr-Kessler technique was used alone, there was a high rate of slippage with repairs reaching a linear strength of approximately 30 N (Figure 2 and Figure 5A)5. In vivo, the tendon of the flexor digitorum profundus can develop linear traction of up to 75 N8. Under post-traumatic conditions, this value can be even higher due to friction, swelling, and...

Watch this Scientific Journal Video about Polytetrafluoroethylene PTFE as a Suture Material in Tendon Surgery at JoVE.com

Polytetrafluoroethylene PTFE as a Suture Material in Tendon Surgery

The present protocol illustrates a method for assessing the biophysical properties of tendon repairs ex vivo. A polytetrafluoroethylene (PTFE) suture material was evaluated by this method and compared to other materials under different conditions.

Polytetrafluoroethylene (PTFE) as a Suture Material in Tendon Surgery

With the evolution of suture materials, there has been a change in paradigms in primary and secondary tendon repair. Improved mechanical properties allow ...

With this protocol, we were able to assess the mechanical properties of a flexor tendon repair. Novel developments, such as linear tension strength, can be reliably evaluated this way. Even slight differences can be detected.To begin, place a fresh cadaveric upper limb on the dissecting table, with the ventral palmar side facing the surgeon. Using a number 15 scalpel, place a median longitudinal incision at the index finger on the palmar side, beginning from the distal phalanx, distally toward the A1 pulley over the metacarpophalangeal joint. Sever the A1 and A2 pulleys longitudinally without injuring the flexor tendons, and then sever the flexor digitorum profundus at the level of the distal interphalangeal joint using a scalpel.Use a tendon retractor to set the tendon under traction and retrieve the flexor digitorum profundus at the level of the A1 pulley. Then, make a six centimeter transversal incision on the rasceta crease, using a number 15 scalpel. Make another transversal incision 10 centimeters proximal to the rasceta.Next, make a longitudinal incision at the median of the palmar side of the forearm, connecting the two transversal incisions. Develop two opposing skin flaps at the level of the forearm fascia to expose the flexor tendons. The flexor tendons are readily identifiable under the skin.Again, use a tendon retractor to place the flexor digitorum tendon under traction, and retract the tendon proximal to the wrist. Sever the tendon at the musculotendinous junction for maximal tendon length with a number 11 scalpel, and place the tendon specimen into 500 milliliters of 0.9%saline solution. Repeat these steps for the third to fifth fingers.Fix the tendon specimen on an expanded polystyrene plate with pins or 18-gauge cannulas, and transect the tendon in the middle, using a scalpel with a number 11 blade. Next, for the Adelaide"cross lock 4-strand core repair, insert the needle into the left stump of the transected tendon, and follow the path of the tendon on the surgeon's side for 1.5 centimeters, and exit at the surface of the tendon. Insert the needle three millimeters to the left and take a bite of three millimeters, exiting toward the surgeon.Then, insert the needle three millimeters to the right, next to the exit point of the first path, and follow the tendon to the very side until the left stump. Insert the needle into the right stump in a path at the very outer part of the tendon, and exit approximately 1.5 centimeters to the right of the stump. Then, insert the needle again at three millimeters to the right.Take a grasp, and exit at the side of the tendon. Insert the needle back toward the right stump, entering approximately three millimeters to the left. Exit at the right stump, and enter again into the left stump for 1.5 centimeters.Grasp a portion of the tendon of three millimeters with the suture, and exit near the midline. Reinsert the needle three millimeters nearer to the stump, and follow the direction of the tendon to the right, making sure to exit at the stump. Insert the needle into the right stump, and follow the tendon fibers approximately 1.5 centimeters to the right.Exit at the surface. Re-enter the tendon further to the right and take a grasp, aiming to the far side. Insert the needle three millimeters to the left, and follow the tendon, exiting at the stump.Now, tie a surgical knot with eight throws, alternating the direction manually. For M-Tang 6-strand core repair, insert the needle of the loop approximately 1.5 centimeters from the right stump of the tendon, and grasp a portion of the tendon of approximately three millimeters in size. Then, pass the needle through the loop and insert the needle into the surface of the tendon.Follow the path of the tendon and exit between the stumps. Re-insert the needle into the opposite stump and follow the tendon in the deep plane for 1.8 centimeters. Exit at the surface of the tendon.Next, enter three millimeters near the stump. Follow a transversal path to the far side of the tendon and exit there. Insert the needle bearing the loop three millimeters to the left, further away from the stumps.Follow the path of the tendon and exit between the stumps. Re-enter at the opposite stump and exit 1.5 centimeters to the right at the surface of the tendon. Cut one of the two strands arming the needle with scissors.Then, insert the needle and grasp a three millimeter portion of the tendon. Manually tie a surgical knot with eight throws, alternating the direction. Take another loop suture and perform a Tsuge suture by grasping a portion of the tendon of approximately three millimeters at 1.5 centimeters to the right.Re-insert the needle and follow the path of the tendon to the left. Exit between the stumps. Re-enter into the left stump and follow the path of the tendon for 1.5 centimeters.Exit at the surface of the tendon. Cut one of the two strands arming the needle with a pair of scissors, and re-insert the needle, grasping three millimeters of the tendon. Finally, tie a surgical knot manually with eight throws, alternating the direction.The linear tensile strength of polypropylene and polytetrafluoroethylene, when using the Kirchmayr-Kessler technique, is shown here. There was no difference between the two materials in terms of linear tensile strength, although polytetrafluoroethylene was somewhat weaker due to slippage. When an epitendinous running suture was used, slippage was less of a problem for the polypropylene repairs, but the repair broke down at approximately 50 Newton.On the contrary, repairs with polytetrafluoroethylene failed at around 70 Newton due to slippage. With the combination of a stronger repair, such as 4-strand Adelaide"or 6-strand M-Tang, and a stronger suture material, such as polytetrafluoroethylene or multistrand, a linear tension strength of 75 Newton or more could be achieved. No significant advantage of the 4-strand versus the 6-strand technique was observed.A summary of the results from the flexor tendon repairs is shown here. Repairs with polytetrafluoroethylene displayed a peak tensile strength comparable to multistrand. Both the repairs were significantly stronger than those with polypropylene.The repairs should be performed symmetrically at both stumps of the severed tendon. The multistrand suture should be rinsed in order for the suture to slip evenly through the fibers of the tendon. The knots of the repair poses some problems.Maybe in the future, some knotless kind of repair can be developed.

polytetrafluoroethylene-ptfe-as-a-suture-material-in-tendon-surgery

Research

JoVE Journal

Medicine

A Strategy to Identify de Novo Mutations in Common Disorders such as Autism and Schizophrenia

There are several lines of evidence supporting the role of de novo mutations as a mechanism for common disorders, such as autism and schizophrenia. First, the de novo mutation rate in humans is relatively high, so new mutations are generated at a high frequency in the population. However, de novo mutations have not been reported in most common diseases. Mutations in genes leading to severe diseases where there is a strong negative selection against the phenotype, such as lethality in embryonic stages or reduced reproductive fitness, will not be transmitted to multiple family members, and therefore will not be detected by linkage gene mapping or association studies. The observation of very high concordance in monozygotic twins and very low concordance in dizygotic twins also strongly supports the hypothesis that a significant fraction of cases may result from new mutations. Such is the case for diseases such as autism and schizophrenia. Second, despite reduced reproductive fitness1 and extremely variable environmental factors, the incidence of some diseases is maintained worldwide at a relatively high and constant rate. This is the case for autism and schizophrenia, with an incidence of approximately 1% worldwide. Mutational load can be thought of as a balance between selection for or against a deleterious mutation and its production by de novo mutation. Lower rates of reproduction constitute a negative selection factor that should reduce the number of mutant alleles in the population, ultimately leading to decreased disease prevalence. These selective pressures tend to be of different intensity in different environments. Nonetheless, these severe mental disorders have been maintained at a constant relatively high prevalence in the worldwide population across a wide range of cultures and countries despite a strong negative selection against them2. This is not what one would predict in diseases with reduced reproductive fitness, unless there was a high new mutation rate. Finally, the effects of paternal age: there is a significantly increased risk of the disease with increasing paternal age, which could result from the age related increase in paternal de novo mutations. This is the case for autism and schizophrenia3. The male-to-female ratio of mutation rate is estimated at about 4&#x2013;6:1, presumably due to a higher number of germ-cell divisions with age in males. Therefore, one would predict that de novo mutations would more frequently come from males, particularly older males4. A high rate of new mutations may in part explain why genetic studies have so far failed to identify many genes predisposing to complexes diseases genes, such as autism and schizophrenia, and why diseases have been identified for a mere 3% of genes in the human genome. Identification for de novo mutations as a cause of a disease requires a targeted molecular approach, which includes studying parents and affected subjects. The process for determining if the genetic basis of a disease may result in part from de novo mutations and the molecular approach to establish this link will be illustrated, using autism and schizophrenia as examples.

Molecular genetic strategy for finding de novo mutations causing common disorders such as autism and schizophrenia.

There are several lines of evidence supporting the role of de novo mutations as a mechanism for common disorders, such as autism and schizophrenia. First, ...

The In ovo CAM-assay as a Xenograft Model for Sarcoma

Sarcoma is a very rare disease that is heterogeneous in nature, all hampering the development of new therapies. Sarcoma patients are ideal candidates for personalized medicine after stratification, explaining the current interest in developing a reproducible and low-cost xenotransplant model for this disease. The chick chorioallantoic membrane is a natural immunodeficient host capable of sustaining grafted tissues and cells without species-specific restrictions. In addition, it is easily accessed, manipulated and imaged using optical and fluorescence stereomicroscopy. Histology further allows detailed analysis of heterotypic cellular interactions.
This protocol describes in detail the in ovo grafting of the chorioallantoic membrane with fresh sarcoma-derived tumor tissues, their single cell suspensions, and permanent and transient fluorescently labeled established sarcoma cell lines (Saos-2 and SW1353). The chick survival rates are up to 75%. The model is used to study graft- (viability, Ki67 proliferation index, necrosis, infiltration) and host (fibroblast infiltration, vascular ingrowth) behavior. For localized grafting of single cell suspensions, ECM gel provides significant advantages over inert containment materials. The Ki67 proliferation index is related to the distance of the cells from the surface of the CAM and the duration of application on the CAM, the latter determining a time frame for the addition of therapeutic products.

The In ovo CAM-assay as a Xenograft Model for Sarcoma

The in ovo chorioallantoic membrane (CAM) is grafted with fresh sarcoma-derived tumor tissues, their single cell suspensions, and permanent and transient fluorescently labeled established sarcoma cell lines. The model is used to study graft- (viability, Ki67 proliferation index, necrosis, infiltration) and host (fibroblast infiltration, vascular ingrowth) behavior.

Sarcoma is a very rare disease that is heterogeneous in nature, all hampering the development of new therapies. Sarcoma patients are ideal candidates for ...

Oxygen-Glucose Deprivation and Reoxygenation as an In Vitro Ischemia-Reperfusion Injury Model for Studying Blood-Brain Barrier Dysfunction

Ischemia-Reperfusion (IR) injury is known to contribute significantly to the morbidity and mortality associated with ischemic strokes. Ischemic cerebrovascular accidents account for 80% of all strokes. A common cause of IR injury is the rapid inflow of fluids following an acute/chronic occlusion of blood, nutrients, oxygen to the tissue triggering the formation of free radicals.
Ischemic stroke is followed by blood-brain barrier (BBB) dysfunction and vasogenic brain edema. Structurally, tight junctions (TJs) between the endothelial cells play an important role in maintaining the integrity of the blood-brain barrier (BBB). IR injury is an early secondary injury leading to a non-specific, inflammatory response. Oxidative and metabolic stress following inflammation triggers secondary brain damage including BBB permeability and disruption of tight junction (TJ) integrity.
Our protocol presents an in vitro example of oxygen-glucose deprivation and reoxygenation (OGD-R) on rat brain endothelial cell TJ integrity and stress fiber formation. Currently, several experimental in vivo models are used to study the effects of IR injury; however they have several limitations, such as the technical challenges in performing surgeries, gene dependent molecular influences and difficulty in studying mechanistic relationships. However, in vitro models may aid in overcoming many of those limitations. The presented protocol can be used to study the various molecular mechanisms and mechanistic relationships to provide potential therapeutic strategies. However, the results of in vitro studies may differ from standard in vivo studies and should be interpreted with caution.

Oxygen-Glucose Deprivation and Reoxygenation as an In Vitro Ischemia-Reperfusion Injury Model for Studying Blood-Brain Barrier Dysfunction

Ischemia-Reperfusion (IR) injury is associated with a high rate of morbidity and mortality. The goal of the in vitro model of oxygen-glucose deprivation and reoxygenation (OGD-R) described here is to assess the effects of ischemia reperfusion injury on a variety of cells, particularly in blood-brain barrier (BBB) endothelial cells.

Ischemia-Reperfusion (IR) injury is known to contribute significantly to the morbidity and mortality associated with ischemic strokes. Ischemic ...

Murine Flexor Tendon Injury and Repair Surgery

Tendon connects skeletal muscle and bone, facilitating movement of nearly the entire body. In the hand, flexor tendons (FTs) enable flexion of the fingers and general hand function. Injuries to the FTs are common, and satisfactory healing is often impaired due to excess scar tissue and adhesions between the tendon and surrounding tissue. However, little is known about the molecular and cellular components of FT repair. To that end, a murine model of FT repair that recapitulates many aspects of healing in humans, including impaired range of motion and decreased mechanical properties, has been developed and previously described. Here an in-depth demonstration of this surgical procedure is provided, involving transection and subsequent repair of the flexor digitorum longus (FDL) tendon in the murine hind paw.&#160;This technique can be used to conduct lineage analysis of different cell types, assess the effects of gene gain or loss-of-function, and to test the efficacy of pharmacological interventions in the healing process. However, there are two primary limitations to this model: i) the FDL tendon in the mid-portion of the murine hind paw, where the transection and repair occur, is not surrounded by a synovial sheath. Therefore this model does not account for the potential contribution of the sheath to the scar formation process. ii) To protect the integrity of the repair site, the FT is released at the myotendinous junction, decreasing the mechanical forces of the tendon, likely contributing to increased scar formation. Isolation of sufficient cells from the granulation tissue of the FT during the healing process for flow cytometric analysis has proved challenging; cytology centrifugation to concentrate these cells is an alternate method used, and allows for generation of cell preparations on which immunofluorescent labeling can be performed. With this method, quantification of cells or proteins of interest during FT healing becomes possible.

Flexor tendons in the hand are commonly injured, leading to impaired hand function. However, the scar-tissue healing response is not well characterized. A murine model of flexor tendon healing is demonstrated here. This model can enhance overall understanding of the healing process and assess therapeutic approaches to improve healing.

Tendon connects skeletal muscle and bone, facilitating movement of nearly the entire body. In the hand, flexor tendons (FTs) enable flexion of the fingers ...

Use of Two Intracorporeal Ventricular Assist Devices As a Total Artificial Heart

Mechanical circulatory support (MCS) has been introduced as a viable alternative to heart transplantation primarily through the use of intracorporeal ventricular assist devices (VADs) for support of the left ventricle. However, certain clinical scenarios warrant biventricular mechanical support. One strategy for some patients is the excision of both ventricles and the implantation of two VAD pumps as a total artificial heart (TAH). This has recently been made possible by the improvements in device design and the small profile of centrifugal devices. This TAH approach remains experimental with many important challenges such as the device settings to balance the right and left circulation, the orientation of the devices and the outflow graft with their influence on hemolysis and stability, and the outcome of chronic support using such an orientation. This protocol aims to provide a reproducible approach for total artificial heart replacement with two intracorporeal centrifugal VADs in a cow model.

Here, we present a protocol using two centrifugal pumps as a total artificial heart replacement.

Mechanical circulatory support (MCS) has been introduced as a viable alternative to heart transplantation primarily through the use of intracorporeal ...

Evaluation of Stem Cell Therapies in a Bilateral Patellar Tendon Injury Model in Rats

Regenerative medicine provides novel alternatives to conditions that challenge traditional treatments. The prevalence and morbidity of tendinopathy across species, combined with the limited healing properties of this tissue, have prompted the search for cellular therapies and propelled the development of experimental models to study their efficacy. Umbilical cord matrix-derived mesenchymal stem cells (UCM-MSC) are appealing candidates because they are abundant, easy to collect, circumvent the ethical concerns and risk of teratoma formation, yet resemble primitive embryonic stem cells more closely than adult tissue-derived MSCs. Significant interest has focused on chitosan as a strategy to enhance the properties of MSCs through spheroid formation. This paper details techniques to isolate UCM-MSCs, prepare spheroids on chitosan film, and analyze the effect of spheroid formation on surface marker expression. Consequently, creation of a bilateral patellar tendon injury model in rats is described for in vivo implantation of UCM-MSC spheroids formed on chitosan film. No complication was observed in the study with respect to morbidity, stress rising effects, or tissue infection. The total functional score of the operated rats at 7 days was lower than that of normal rats, but returned to normal within 28 days after surgery. Histological scores of tissue-healing confirmed the presence of a clot in treated defects evaluated at 7 days, absence of foreign body reaction, and progressing healing at 28 days. This bilateral patella tendon defect model controls inter-individual variation via creation of an internal control in each rat, was associated with acceptable morbidity, and allowed detection of differences between untreated tendons and treatments.

This paper describes the preparation and evaluation of umbilical cord matrix-derived mesenchymal stem cells spheroids with a bilateral patellar tendon defect model in a rat. This model was associated with an acceptable morbidity and was found to detect differences between untreated and treated tendons, and between the two treatments tested.

Regenerative medicine provides novel alternatives to conditions that challenge traditional treatments. The prevalence and morbidity of tendinopathy across ...

Tachycardia-Induced Cardiomyopathy As a Chronic Heart Failure Model in Swine

A stable and reliable model of chronic heart failure is required for many experiments to understand hemodynamics or to test effects of new treatment methods. Here, we present such a model by tachycardia-induced cardiomyopathy, which can be produced by rapid cardiac pacing in swine.
A single pacing lead is introduced transvenously into fully anaesthetized healthy swine, to the apex of the right ventricle, and fixated. Its other end is then tunneled dorsally to the paravertebral region. There, it is connected to an in-house modified heart pacemaker unit that is then implanted in a subcutaneous pocket. 
After 4 - 8 weeks of rapid ventricular pacing at rates of 200 - 240 beats/min, physical examination revealed signs of severe heart failure - tachypnea, spontaneous sinus tachycardia, and fatigue. Echocardiography and X-ray showed dilation of all heart chambers, effusions, and severe systolic dysfunction. These findings correspond well to decompensated dilated cardiomyopathy and are also preserved after the cessation of pacing.
This model of tachycardia-induced cardiomyopathy can be used for studying the pathophysiology of progressive chronic heart failure, especially hemodynamic changes caused by new treatment modalities like mechanical circulatory supports. This methodology is easy to perform and the results are robust and reproducible.

Here, we present a protocol to produce tachycardia-induced cardiomyopathy in swine. This model represents a potent way to study the hemodynamics of progressive chronic heart failure and the effects of applied treatment.

A stable and reliable model of chronic heart failure is required for many experiments to understand hemodynamics or to test effects of new treatment ...

Emergency Undocking in Robotic Surgery: A Simulation Curriculum

The following is a training platform to allow robotic surgeons to develop the skills necessary to lead an interprofessional team in emergency undocking of a robotic system. In traditional robotic training for surgeons, a brief web based overview of performing an emergency undocking is provided during initial introductory training to the robotics system. During such a process, there is no training in delineation of interdisciplinary roles for operating room (OR) personnel. The training presented here uses formative simulation and debriefing followed by a lecture. For the simulation, a modified gynecologic simulator is draped in a steep trendelenburg position consistent with most gynecologic laparoscopic surgery. The training torso is modified using tubing hooked to pressure bags of red food colored IV fluid used to simulate a catastrophic vessel injury on demand. Positioned throughout the operating room setting is an interprofessional team consisting of embedded standardized persons (ESPs) to fulfill the roles of a circulating nurse, scrub nurse, anesthesiologist, and bedside assist surgeon. Robotic surgeons are presented a case scenario necessitating emergency undocking, and given control of the robotic instruments. The scenario is terminated following either successful completion of an emergency undock, or at five minutes due to the emergent nature of the case. A debriefing session with hands on training of the steps to emergency undocking, necessary equipment, troubleshooting techniques, and operating room personnel roles follows the simulation. The learners are presented with a short lecture reemphasizing the material presented in the debriefing for their own self-study. This training results in improved time accessing the patient, improved knowledge, confidence, and completion of critical actions, and can be replicated in most institutions. All robotic surgeons should be able to demonstrate competence in this crucial intervention. A limitation of the curriculum is ability to access the in-situ environment for training purposes.

This training platform is designed to allow robotic surgeons to develop the skills necessary to lead an interprofessional team in emergency undocking of the robotic system. Training includes the utilization of the technology and equipment to perform an emergency undocking, as well as delineation of roles for such a scenario.

The following is a training platform to allow robotic surgeons to develop the skills necessary to lead an interprofessional team in emergency undocking of ...

A Saline/Bipolar Radiofrequency Energy Device As an Adjunct for Hemostasis in Solid Organ Injury/Trauma

Solid organ (liver, spleen, and kidney) hemorrhage is often life-threatening and can be difficult to stop in critically ill patients. Traditional techniques for arresting this ongoing bleeding include coagulation by high voltage electrocautery, topical hemostatic application, and the delivery of ignited argon gas. The goal of this study/video was to demonstrate the efficacy of a new energy device for arresting persistent solid organ hemorrhage.A novel instrument utilizing bipolar radiofrequency (RF) energy which acts to ignite/boil dripping saline from a simple handpiece is employed to arrest ongoing bleeding from solid organ injuries in a porcine model. This instrument is extrapolated from experience within elective hepatic resections. An escalating series of injuries to solid organs within a porcine model will be created. This will be followed by arresting hemorrhage with this novel energy device in sequence. A standard suction device will also be employed. This simple saline/RF energy instrument has the potential to arrest ongoing solid organ surface/capsular bleeding, as well as moderate hemorrhage associated with deep lacerations.

The goal of this publication is to demonstrate the potential application of a novel device using simulated solid organ injuries in a porcine model.

Solid organ (liver, spleen, and kidney) hemorrhage is often life-threatening and can be difficult to stop in critically ill patients. Traditional ...

Murine Cervical Aortic Transplantation Model using a Modified Non-Suture Cuff Technique

With the introduction of powerful immunosuppressive protocols, distinct advances are possible in the prevention and therapy of acute rejection episodes. However, only minor improvement in the long-term results of transplanted solid organs could be observed over the past decades. In this context, chronic allograft vasculopathy (CAV) still represents the leading cause of late organ failure in cardiac, renal and pulmonary transplantation.
Thus far, the underlying pathogenesis of CAV development remains unclear, explaining why effective treatment strategies are presently missing and emphasizing a need for relevant experimental models in order to study the underlying pathophysiology leading to CAV formation. The following protocol describes a murine heterotopic cervical aortic transplantation model using a modified non-suture cuff technique. In this technique, a segment of the thoracic aorta is interpositioned in the right common carotid artery. With the use of the non-suture cuff technique, an easy to learn and reproducible model can be established, minimizing the possible heterogeneity of sutured vascular micro anastomoses.

Here, we present a protocol of heterotopic aortic transplantation in mice using the non-suture cuff technique in a cervical murine model. This model can be used to study the underlying pathology of chronic allograft vasculopathy (CAV) and can help evaluate new therapeutic agents in order to prevent its formation.

With the introduction of powerful immunosuppressive protocols, distinct advances are possible in the prevention and therapy of acute rejection episodes. ...