This work was funded and supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (2015R1C1A1A01051907). This work was also supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT &#38; Future Planning (NRF-2016M3A9E9941746).

This study was guided and approved by the Department of Laboratory Animal Resources, Yonsei Biomedical Research Institute, Yonsei University College of Medicine, accredited by the Association for Assessment and Accreditation of Laboratory Animal Care International. This study followed the guidelines for the Care and Use of Laboratory Animals of the Institute of Laboratory Animal Resources Commission on Life Sciences National Research Council. All Pigs were acclimated for One week before the operation.
1. Preparation
<ol>
	<li>Keep the pigs without food for over 12 h before general anesthesia with free access to water. 
	Note: Six female Yorkshire pigs were used weighing 25&#8211;30 kg each.</li>
	<li>Use a 16 Gauge Needle of 1 cm length to intramuscularly inject alfaxan (1 mg/kg), xylazine (2 mg/kg), and azaperone (2 mg/kg) behind and below the ear to initiate anesthesia.</li>
	<li>Shave the anterior midline of the neck and the abdominal wall of the pig using a surgical hair removal shaver.</li>
	<li>Secure an intravenous (IV) route through central or marginal ear vein on the posterior side of the auricle with a 22-G needle. Inject Ketorolac (1 mg/kg) via an IV line.</li>
	<li>Then inject atropine (0.04 mg/kg) intramuscularly as described in 1.2. Inject cefazolin (30 mg/kg) intramuscularly as described in 1.2.</li>
	<li>Put the pig lying down in a supine position over the Operating room table.</li>
	<li>Allow the pig to breath 2 L of oxygen with 5% of isoflurane through Swine anesthesia mask spontaneously.</li>
	<li>Expose the vocal cords through the mouth by using a laryngoscope and spray them with two puffs of 2% Lidocaine topical solution to prevent intubation-induced laryngospasm.</li>
	<li>Intubate with a 6.5 mm tube, inflate the tube cuff with 3-5 mL of air using a syringe without a needle attached to it. 
	Note: Perform capnometry to ensure that the tracheal tube, which is a part of the anesthesia machine, is in proper position and there is CO2 back to the machine as an indication of proper oxygenation.</li>
	<li>Maintain the anesthesia after the intubation with 2% isoflurane.</li>
	<li>Use the vet ointment on pig&#8217;s eyes and close it with an eye cover patch.</li>
</ol>
2. Procedure: Reception Site
<ol>
	<li>Disinfect the neck and the abdominal wall with the iodine-based scrub solution 1%.</li>
	<li>Start a vertical midline incision in the anterior neck using blade No. 23 up to the sternum.</li>
	<li>Dissect the strap muscles and retract it laterally using Kelly tissue scissor and Lahey retractor.</li>
	<li>Expose the trachea from the first ring to the thoracic inlet.</li>
	<li>Then, expose the common carotid artery and the internal jugular vein for the anastomosis.</li>
	<li>Create a window in the second or third tracheal cartilage, ~1 cm in width using blade no. 11.</li>
	<li>Look for the endotracheal tube through the tracheal defect created, and make sure the aeration through the tube is continued using the ventilator without a leak.</li>
</ol>
3. Procedure: Flap Site
Note: The superior epigastric artery perforator (SEAP) flap harvest can be performed, according to the method described by Frederic Bodin7.
<ol>
	<li>Design a flap on the upper abdomen by a surgical marker pen (Figure 1A).</li>
	<li>Create an elliptical Skin incision 4 x 3 cm using a No. 23 scalpel to the anterior sheath of the abdominal wall on the medial side of the drawn flap (Figure 1B).</li>
	<li>Elevate (peel) the Flap from the rectus abdominis muscle sheath looking for the perforators going to the skin flap while holding the fascia by the allis.</li>
	<li>Perform the intramuscular dissection and follow the perforators to the superior epigastric vessels (Figure 1B)</li>
	<li>Now perform the lateral skin incision on the designed flap (Figure 1A) using a No. 23 scalpel (Figure 1C)</li>
	<li>Clamp the superior epigastric vessels and venae comitantes with the hemostat superiorly and use Kelly tissue scissors to cut below the hemostat and ligate the vessel above the hemostat by 3-0 suture. Then take off the hemostat.</li>
</ol>
4. Anastomosis and Closure
<ol>
	<li>Put on a surgical loupe.</li>
	<li>Clamp the Carotid artery using two hemostats with 1-2 cm distance between them.</li>
	<li>Use micro-scissors to cut between the carotid artery and tie the superior part by double suture insure no oozing.</li>
	<li>Use the double clamp without the frame between the carotid artery and flap artery.</li>
	<li>Start anastomosis by using 10-0 suture simple full thickness interpreted.</li>
	<li>Place the first two stay sutures approximately 120 degrees apart on the vessel&#8217;s circumference then in between place 2-3 stitches.</li>
	<li>Release the clamp. If there is blood oozing do the similar suture at the oozing site.</li>
	<li>Look for the venous back flow from venae comitantes.</li>
	<li>Perform anastomosis as described in step 4.1 to 4.7 for the internal jugular vein and venae comitantes (Figure 1D).</li>
	<li>Use a syringe needle size 18 to prick the skin to ensure flap viability by seeing a blood drop.</li>
	<li>Close the tracheal window and suture it with the muscle fascia of the SEAP flap using 3-0 suture.</li>
	<li>Exteriorize and suture a skin paddle of the SEAP flap to the cervical midline skin incision (Figure 2A).</li>
	<li>Close the abdominal skin incision (Figure 2B).</li>
</ol>
5. Post-operative Care
<ol>
	<li>Get the pig back into the prone position.</li>
	<li>Stop the isoflurane and wean the pig from the ventilator.</li>
	<li>Allow the pig to recover in the animal cage and monitor it closely to ensure its smooth recovery from the procedure.</li>
	<li>Look for the flap at reconstruction site after healing (Figure 2C).</li>
	<li>Look at the donor site in the animal after healing (Figure 2D).</li>
	<li>Start Ringer&#39;s lactate at the rate of 150 mL/h until full recovery and administer 0.3 mg buprenorphine for analgesia.</li>
	<li>Following extubation, monitor the pig closely until it has regained sufficient consciousness to maintain position and breathing and is able to drink spontaneously.</li>
	<li>Keep the post-surgery pigs in separated place from no operated animals.</li>
	<li>Start intramuscular amoxicillin&#8211;clavulanate (14 mg/kg) for 1 week.</li>
	<li>Start intramuscular Meloxicam (0.2 mg/kg) for 1 week.</li>
</ol>
6. Euthanasia
<ol>
	<li>Start anesthesia for the pig by injecting propofol through i.v. (5-10 mL) and maintain it with isoflurane 5%.</li>
	<li>Intubate the pig as described on step (1.1, 1.2, 1.6-1.10).</li>
	<li>Induce the cardiac arrest by intravenous injection of 40 mmol KCl.</li>
</ol>

<ol>
	<li>Chen, C. L., Zenga, J., Roland, L. T., Pipkorn, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complications+of+double+free+flap+and+free+flap+combined+with+locoregional+flap+in+head+and+neck+reconstruction:+A+systematic+review.">Complications of double free flap and free flap combined with locoregional flap in head and neck reconstruction: A systematic review.</a> Head &amp; Neck journal of the Science and Specialties of the Head and Neck. 40 (3), 632-646 (2018).</li><li>Smith, R. K., Wykes, J., Martin, D. T., Niles, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Perforator+variability+in+the+anterolateral+thigh+free+flap:+a+systematic+review.">Perforator variability in the anterolateral thigh free flap: a systematic review.</a> Surgical and Radiologic Anatomy. 39 (7), 779-789 (2017).</li><li>Bauer, F., Koerdt, S., H&#246;lzle, F., Mitchell, D. A., Wolff, K. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Eight+free+flaps+in+24+hours:+a+training+concept+for+postgraduate+teaching+of+how+to+raise+microvascular+free+flaps.">Eight free flaps in 24 hours: a training concept for postgraduate teaching of how to raise microvascular free flaps.</a> British Journal of Oral and Maxillofacial. 54 (1), 35-39 (2016).</li><li>Schoeff, S., Hernandez, B., Robinson, D. J., Jameson, M. J., Shonka, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microvascular+Anastomosis+Simulation+Using+a+Chicken+Thigh+Model:+Interval+Versus+Massed+Training.">Microvascular Anastomosis Simulation Using a Chicken Thigh Model: Interval Versus Massed Training.</a> The Laryngoscope. 127 (11), 2490-2494 (2017).</li><li>Bodin, F., Diana, M., Koutsomanis, A., Robert, E., Marescaux, J., Bruant-Rodier, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Porcine+model+for+free-flap+breast+reconstruction+training.">Porcine model for free-flap breast reconstruction training.</a> Plastic and Reconstructive Surgery Journal. 68 (10), 1402-1409 (2015).</li><li>Rodriguez, J. R., Ya&#241;ez, R., Cifuentes, I., Varas, J., Dagnino, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microsurgery+Workout:+A+Novel+Simulation+Training+Curriculum+Based+on+Nonliving+Models.">Microsurgery Workout: A Novel Simulation Training Curriculum Based on Nonliving Models.</a> Plastic and Reconstructive Surgery Journal. 138 (4), 739e-747e (2016).</li><li>Carey, J. N., 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=Simulation+of+plastic+surgery+and+microvascular+procedures+using+perfused+fresh+human+cadavers.">Simulation of plastic surgery and microvascular procedures using perfused fresh human cadavers.</a> Plastic and Reconstructive Surgery journal. 67 (2), e42-e48 (2014).</li><li>Chan, W., Niranjan, N., Ramakrishnan, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structured+assessment+of+microsurgery+skills+in+the+clinical+setting.">Structured assessment of microsurgery skills in the clinical setting.</a> Plastic and Reconstructive Surgery Journal. 63 (8), 1329-1334 (2010).</li><li>Matsumura, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+newly+designed+training+tool+for+microvascular+anastomosis+techniques:+Microvascular+Practice+Card.">A newly designed training tool for microvascular anastomosis techniques: Microvascular Practice Card.</a> Surgical Neurology Journal. 71 (5), 616-620 (2010).</li><li>Kim, W. S., 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=Tracheal+reconstruction+with+a+free+vascularized+myofascial+flap:+preclinical+investigation+in+a+porcine+model+to+human+clinical+application.">Tracheal reconstruction with a free vascularized myofascial flap: preclinical investigation in a porcine model to human clinical application.</a> Scientific Reports. 7 (1), 10022 (2017).</li></ol>

The authors have nothing to disclose.

Significant morbidity and defects can occur in head and neck malignancy patients during surgical management. Microvascular free tissue transfer has become essential for reconstruction in most cases. The viability of the flap is a critical issue, requiring steadiness, precise handling of the pedicle, tactile sensation, visuospatial ability, and excellent operative flow from the surgeon8. To develop these skills, one needs extensive practice with a training model3,...

Reconstruction following surgery for the head and neck malignant diseases is a difficult procedure associated with significant morbidity. Microvascular free-flap reconstruction has been well established as the standard approach to reconstruction for over 20 years1,2,3. Free-flap transfer plays a significant role in improving the head and neck management in cancer patients and in post-traumatic injuries thereby pushing the boundaries of surgical excision of disease beyond previous techniques, resulting in greater patient quality of life and longer survival rates1,2,3. The various flaps for reconstruction include rotational, graft, and free flaps.
The role of free flaps in the head and neck reconstruction has expanded. It is the most difficult flap to work with, requiring skilled and delicate handling. Flap failure is a catastrophic event, with significant morbidity4,5. Thus, considerable training time is required to develop the precision necessary for the successful surgical outcomes3,4,5,6,7,8,9. The steep learning curve associated with such a surgery can influence the outcome for patients and affect treatment management3,4,5,6,7,8,9. To reduce the training time and learning curve for new surgeons, a training model is needed that mimics human biology and provides similar surgical field conditions8.
The goal of this study is to show the visibility of Porcine as a good training module for the head and neck microvascular reconstruction resembling the human case with improved skills in the active fashion.
This study investigated the use of a porcine model for training new colleagues in the head and neck microvascular reconstruction for free-flap transfer to provide a cost-effective and less stressful supplement to the clinical field training with reliably similar features for free-flap procedures. Pigs have been used for many studies and as teaching models for various surgical reconstructions, e.g., breast reconstruction;5 however, pigs have never been used for head and neck reconstruction except in our study for tracheal reconstruction due to tracheal stenosis10.
The idea was started after Frederic Bodin7, who describe the similar flap for breast reconstruction. The main advantage for the study over the other module of microvascular training is the active livening module with a real immediate result of the procedure.

<table><tbody><tr><td>Pigs XP Bio, Seoul, South Korea</td><td></td><td></td><td></td></tr><tr><td>Surgical Hair Removal shaver</td><td>3M</td><td></td><td></td></tr><tr><td>22 gage catheter</td><td>B.BRAUN</td><td></td><td></td></tr><tr><td>syring with needle size 18</td><td>Jung Rim Medical</td><td></td><td></td></tr><tr><td>Intramuscular alfaxan</td><td>Careside</td><td></td><td>10ml/VAL</td></tr><tr><td>Intramuscularxylazine</td><td>Bayer</td><td></td><td></td></tr><tr><td>Intramuscular azaperone</td><td>Sigma-aldrich</td><td></td><td>34223</td></tr><tr><td>Intramuscular atropine</td><td>Daewon</td><td></td><td>0.5mg/A</td></tr><tr><td>Intramuscular cefazolin</td><td>Yuhan</td><td></td><td>1g</td></tr><tr><td>intravenous Ketorolac</td><td>Hana Pharm</td><td></td><td>30mg</td></tr><tr><td>Swine ansthesia mask</td><td>DRE</td><td></td><td>1392</td></tr><tr><td>endotracheal cuff tube 6.5 mm</td><td>SMITH medical</td><td></td><td>100/150/065</td></tr><tr><td>ansthesia Machine</td><td>Dr&amp;auml;ger</td><td></td><td>PRIMUS IE</td></tr><tr><td>2% lidocaine topical solution</td><td>Taejoon</td><td></td><td></td></tr><tr><td>vet ointment</td><td>Pfizer</td><td></td><td>terramycin &lt;img alt=&quot;Misc&quot; src=&quot;/files/ftp_upload/58104/58104misc1.jpg&quot;/&gt;</td></tr><tr><td>eye cover patch</td><td>Innomed</td><td></td><td>S-universal010S</td></tr><tr><td>betadine solution 1%.</td><td>Korea Pharma</td><td></td><td></td></tr><tr><td>gauze 4*4</td><td>First Medical</td><td></td><td>22*30CM 320S</td></tr><tr><td>blade No. 23</td><td>Paragon</td><td></td><td>23</td></tr><tr><td>lahey retractor</td><td>V.Mueller</td><td></td><td>SU3960</td></tr><tr><td>kelly tissue scissors</td><td>SOLCO</td><td></td><td>05-1990</td></tr><tr><td>blade No. 11</td><td>Paragon</td><td></td><td>11</td></tr><tr><td>surgical marking pen</td><td>Aspen Surgical</td><td></td><td>Regular #2750</td></tr><tr><td>allis</td><td>V.Mueller</td><td></td><td>SU4055</td></tr><tr><td>tie suture</td><td>Covidein</td><td></td><td>non-needle</td></tr><tr><td>3.5&amp;times; surgical loupe</td><td>zeiss</td><td></td><td>eyemag smart</td></tr><tr><td>double clamp without frame</td><td>V.Mueller</td><td></td><td>CH7155</td></tr><tr><td>microscissors</td><td>AESCULAP</td><td></td><td>FD038R</td></tr><tr><td>Ringer&#039;s lactate</td><td>Daehan</td><td></td><td>500ml/1bag</td></tr><tr><td>amoxicillin&amp;ndash;clavulanate</td><td>Ilsung</td><td></td><td>0.6g/V</td></tr><tr><td>Meloxicam</td><td>Samil</td><td></td><td>7.5mg</td></tr><tr><td>propofol</td><td>Dong Kook</td><td></td><td>120mg/V</td></tr><tr><td>intravenous KCl solution</td><td>Daehan</td><td></td><td>20ml/50P</td></tr><tr><td>mosquito curved</td><td>SOLCO</td><td></td><td>013-0111</td></tr><tr><td>mosquito straight</td><td>SOLCO</td><td></td><td>05-1050</td></tr><tr><td>ethilone 10-0 suture</td><td>ethicone</td><td></td><td>10/0W1756</td></tr><tr><td>Vicryl 3-0.</td><td>ethicone</td><td></td><td>3/0W9890</td></tr><tr><td>buprenorphine</td><td>Hanlim</td><td></td><td>0.3mg</td></tr></tbody></table>

porcine as a training module for head and neck microvascular reconstruction

Live models that resemble surgical conditions of humans are needed for training free-flap harvesting and anastomosis. Animal models for training purposes have been available for years in many surgical fields. We used the female (because they are easy to handle for the procedure) Yorkshire pigs for the head and neck reconstruction by harvesting the deep inferior epigastric artery perforator or the superior epigastric artery perforator flap. The anastomosis site (neck skin defect or tracheal wall defect) was prepared via the dissection of the common carotid artery and the internal jugular vein, in which 3.5&#215; loupe magnification was used for anastomosis as we use on human cases in real life. This procedure demonstrates a new training method using a reliable learning model and provides a detailed anatomy in a live scenario. We focused on the ischemia time, harvesting, vessel anastomosis, and designing the flap to fit the defect site. This model improves tissue handling and with the use of proper instruments can be repeated many times so that the surgeon is fully confident before starting the surgery on humans.

We performed the procedure on six pigs: cervical skin defect reconstruction on two pigs, tracheal reconstruction on two pigs, and free flap to test vascular anastomosis device in two pigs. The pigs were monitored for 3 months and there was no clinical sign of neurological deficit.
The mean time for ischemia was 50 min (range, 35-80 min); the time decreased as the procedure was repeated. The mean harvest time of the six pigs was ...

Watch this Scientific Journal Video about Porcine As a Training Module for Head and Neck Microvascular Reconstruction at JoVE.com

Porcine As a Training Module for Head and Neck Microvascular Reconstruction

Here we present a protocol for the use of the pig superior epigastric artery perforator flap as a learning module for head and neck microvascular reconstruction.

Live models that resemble surgical conditions of humans are needed for training free-flap harvesting and anastomosis. Animal models for training purposes ...

porcine-as-training-module-for-head-neck-microvascular

Research

JoVE Journal

Medicine

7.7K Views.  King Abdullah Medical City. Deze methode kan helpen bij het beantwoorden van belangrijke vragen over het opzetten van een life training module voor microvasculaire hoofd-en nekreconstructie. Het belangrijkste voordeel van deze techniek is dat het vergemakkelijkt een de froment van microvasculaire reconstructieve chirurgie vaardigheden voor beginnende chirurgen. Begin met het gebruik van een laryngoscoop om de stembanden bloot te stellen door de mond van een 25 tot 30 gram vrouwelijke Yorkshire varken en spuiten de koord...

Video: Porcine As a Training Module for Head and Neck Microvascular Reconstruction

Autologous Endothelial Progenitor Cell-Seeding Technology and Biocompatibility Testing For Cardiovascular Devices in Large Animal Model

Implantable cardiovascular devices are manufactured from artificial materials (e.g. titanium (Ti), expanded polytetrafluoroethylene), which pose the risk of thromboemboli formation1,2,3. We have developed a method to line the inside surface of Ti tubes with autologous blood-derived human or porcine endothelial progenitor cells (EPCs)4. By implanting Ti tubes containing a confluent layer of porcine EPCs in the inferior vena cava (IVC) of pigs, we tested the improved biocompatibility of the cell-seeded surface in the prothrombotic environment of a large animal model and compared it to unmodified bare metal surfaces5,6,7 (Figure 1). This method can be used to endothelialize devices within minutes of implantation and test their antithrombotic function in vivo. 
Peripheral blood was obtained from 50 kg Yorkshire swine and its mononuclear cell fraction cultured to isolate EPCs4,8. Ti tubes (9.4 mm ID) were pre-cut into three 4.5 cm longitudinal sections and reassembled with heat-shrink tubing. A seeding device was built, which allows for slow rotation of the Ti tubes. 
We performed a laparotomy on the pigs and externalized the intestine and urinary bladder. Sharp and blunt dissection was used to skeletonize the IVC from its bifurcation distal to the right renal artery proximal. The Ti tubes were then filled with fluorescently-labeled autologous EPC suspension and rotated at 10 RPH x 30 min to achieve uniform cell-coating9. After administration of 100 USP/ kg heparin, both ends of the IVC and a lumbar vein were clamped. A 4 cm veinotomy was performed and the device inserted and filled with phosphate-buffered saline. As the veinotomy was closed with a 4-0 Prolene running suture, one clamp was removed to de-air the IVC. At the end of the procedure, the fascia was approximated with 0-PDS (polydioxanone suture), the subcutaneous space closed with 2-0 Vicryl and the skin stapled closed. 
After 3 - 21 days, pigs were euthanized, the device explanted en-block and fixed. The Ti tubes were disassembled and the inner surfaces imaged with a fluorescent microscope.
We found that the bare metal Ti tubes fully occluded whereas the EPC-seeded tubes remained patent. Further, we were able to demonstrate a confluent layer of EPCs on the inside blood-contacting surface.
Concluding, our technology can be used to endothelialize Ti tubes within minutes of implantation with autologous EPCs to prevent thrombosis of the device. Our surgical method allows for testing the improved biocompatibility of such modified devices with minimal blood loss and EPC-seeded surface disruption.

A method for seeding titanium blood-contacting biomaterials with autologous cells and testing biocompatibility is described. This method uses endothelial progenitor cells and titanium tubes, seeded within minutes of surgical implantation into porcine venae cavae. This technique is adaptable to many other implantable biomedical devices.

Implantable cardiovascular devices are manufactured from artificial materials (e.g. titanium (Ti), expanded polytetrafluoroethylene), which pose the risk ...

Bioengineering

Training a Sophisticated Microsurgical Technique: Interposition of External Jugular Vein Graft in the Common Carotid Artery in Rats

Neointimal hyperplasia is one the primary causes of stenosis in arterialized veins that are of great importance in arterial coronary bypass surgery, in peripheral arterial bypass surgery as well as in arteriovenous fistulas.1-5 The experimental procedure of vein graft interposition in the common carotid artery by using the cuff-technique has been applied in several research projects to examine the aetiology of neointimal hyperplasia and therapeutic options to address it. 6-8 The cuff prevents vessel anastomotic remodeling and induces turbulence within the graft and thereby the development of neointimal hyperplasia.
Using the superior caval vein graft is an established small-animal model for venous arterialization experiment.9-11 This current protocol refers to an established jugular vein graft interposition technique first described by Zou et al., 9 as well as others.12-14 Nevertheless, these cited small animal protocols are complicated.
To simplify the procedure and to minimize the number of experimental animals needed, a detailed operation protocol by video training is presented. This video should help the novice surgeon to learn both the cuff-technique and the vein graft interposition. Hereby, the right external jugular vein was grafted in cuff-technique in the common carotid artery of 21 female Sprague Dawley rats categorized in three equal groups that were sacrificed on day 21, 42 and 84, respectively. Notably, no donor animals were needed, because auto-transplantations were performed. The survival rate was 100 % at the time point of sacrifice. In addition, the graft patency rate was 60 % for the first 10 operated animals and 82 % for the remaining 11 animals. The blood flow at the time of sacrifice was 8&plusmn;3 ml/min. In conclusion, this surgical protocol considerably simplifies, optimizes and standardizes this complicated procedure. It gives novice surgeons easy, step-by-step instruction, explaining possible pitfalls, thereby helping them to gain expertise fast and avoid useless sacrifice of experimental animals.

Neointimal hyperplasia is the primary cause of stenosis in arterialized veins. We propose a new protocol whereby the right external jugular vein is grafted using the cuff technique in the common carotid artery of Sprague Dawley rats. The survival rate was 100 % at the time point of sacrifice.

Neointimal hyperplasia is one the primary causes of stenosis in arterialized veins that are of great importance in arterial coronary bypass surgery, in ...

A Modified Heterotopic Swine Hind Limb Transplant Model for Translational Vascularized Composite Allotransplantation (VCA) Research

Vascularized Composite Allotransplantation (VCA) such as hand and face transplants represent a viable treatment option for complex musculoskeletal trauma and devastating tissue loss. Despite favorable and highly encouraging early and intermediate functional outcomes, rejection of the highly immunogenic skin component of a VCA and potential adverse effects of chronic multi-drug immunosuppression continue to hamper widespread clinical application of VCA. Therefore, research in this novel field needs to focus on translational studies related to unique immunologic features of VCA and to develop novel immunomodulatory strategies for immunomodulation and tolerance induction following VCA without the need for long term immunosuppression.
This article describes a reliable and reproducible translational large animal model of VCA that is comprised of an osteomyocutaneous flap in a MHC-defined swine heterotopic hind limb allotransplantation. Briefly, a well-vascularized skin paddle is identified in the anteromedial thigh region using near infrared laser angiography. The underlying muscles, knee joint, distal femur, and proximal tibia are harvested on a femoral vascular pedicle. This allograft can be considered both a VCA and a vascularized bone marrow transplant with its unique immune privileged features. The graft is transplanted to a subcutaneous abdominal pocket in the recipient animal with a skin component exteriorized to the dorsolateral region for immune monitoring.
Three surgical teams work simultaneously in a well-coordinated manner to reduce anesthesia and ischemia times, thereby improving efficiency of this model and reducing potential confounders in experimental protocols. This model serves as the groundwork for future therapeutic strategies aimed at reducing and potentially eliminating the need for chronic multi-drug immunosuppression in VCA.

A Modified Heterotopic Swine Hind Limb Transplant Model for Translational Vascularized Composite Allotransplantation VCA Research

Vascularized Composite Allotransplantations (VCA) have become a clinical reality. However, broad clinical application of VCA is limited by chronic multi-drug immunosuppression. The authors present a reliable and reproducible large animal model to translate novel immunomodulatory strategies that can minimize or potentially eliminate the need of immunosuppression in VCA.

Vascularized Composite Allotransplantation (VCA) such as hand and face transplants represent a viable treatment option for complex musculoskeletal trauma ...

Step By Step: Microsurgical training method combining two nonliving animal models

The learning of microsurgical techniques and the maintenance of microsurgical skills have been traditionally based on the use of living animals, mainly laboratory rats. This method although extremely valuable can be economically demanding both for the surgeon and the sponsoring institution; it also requires special training facilities that may not always be available or accessible. Furthermore ethical concerns can limit the use of living animals for training purposes. Alternative training methods, such as inert tubes and gloves have not gained popularity among surgeons since they do not offer an experience similar to that of a clinical situation. Non-living animal models include the use of chicken thighs and wings; they offer a practice experience that resembles a clinical situation to a considerable extent. This type of training is relatively cheap and easily available. The microscope and instruments required can be acquired over the internet, and the chicken pieces can be bought at the local supermarket.
This approach allows a motivated trainee to rehearse different types of surgical techniques several times at a reasonable expense, helping to develop or maintain his surgical expertise if more complex facilities are not available. On the current manuscript we describe how to setup a small practice station, how to dissect the specimens, and how to practice both with the chicken thighs and with the chicken wings in a progressive fashion. This approach takes advantage on the versatility of the chicken thigh model and the small size of the chicken wing Brachial artery.

Here we describe how to set up a small microsurgical practice station and a simple and inexpensive method for the training of microsurgery with non-living animal models.

The learning of microsurgical techniques and the maintenance of microsurgical skills have been traditionally based on the use of living animals, mainly ...

Surgical Angiogenesis in Porcine Tibial Allotransplantation: A New Large Animal Bone Vascularized Composite Allotransplantation Model

Segmental bone loss resulting from trauma, infection malignancy and congenital anomaly remains a major reconstructive challenge. Current therapeutic options have significant risk of failure and substantial morbidity.
Use of bone vascularized composite allotransplantation (VCA) would offer both a close match of resected bone size and shape and the healing and remodeling potential of living bone. At present, life-long drug immunosuppression (IS) is required. Organ toxicity, opportunistic infection and neoplasm risks are of concern to treat such non-lethal indications.
We have previously demonstrated that bone and joint VCA viability may be maintained in rats and rabbits without the need of long-term-immunosuppression by implantation of recipient derived vessels within the VCA. It generates an autogenous, neoangiogenic circulation with measurable flow and active bone remodeling, requiring only 2 weeks of IS. As small animals differ from man substantially in anatomy, bone physiology and immunology, we have developed a porcine bone VCA model to evaluate this technique before clinical application is undertaken. Miniature swine are currently widely used for allotransplantation research, given their immunologic, anatomic, physiologic and size similarities to man. Here, we describe a new porcine orthotopic tibial bone VCA model to test the role of autogenous surgical angiogenesis to maintain VCA viability.
The model reconstructs segmental tibial bone defects using size- and shape-matched allogeneic tibial bone segments, transplanted across a major swine leukocyte antigen (SLA) mismatch in Yucatan miniature swine. Nutrient vessel repair and implantation of recipient derived autogenous vessels into the medullary canal of allogeneic tibial bone segments is performed in combination with simultaneous short-term IS. This permits a neoangiogenic autogenous circulation to develop from the implanted tissue, maintaining flow through the allogeneic nutrient vessels for a short time. Once established, the new autogenous circulation maintains bone viability following cessation of drug therapy and subsequent nutrient vessel thrombosis.

Currently any kind of vascularized composite allotransplantation depends on long-term-immunosuppression, difficult to support for non-life-critical indications. We present a new porcine tibial VCA model that can be used to study bone VCA and demonstrate the use of surgical angiogenesis to maintain bone viability without the need of long-term immune-modulation.

Segmental bone loss resulting from trauma, infection malignancy and congenital anomaly remains a major reconstructive challenge. Current therapeutic ...

A Reliable Porcine Fascio-Cutaneous Flap Model for Vascularized Composite Allografts Bioengineering Studies

Vascularized Composite Allografts (VCA) such as hand, face, or penile transplant represents the cutting-edge treatment for devastating skin defects, failed by the first steps of the reconstructive ladder. Despite promising aesthetic and functional outcomes, the main limiting factor remains the need for a drastically applied lifelong immunosuppression and its well-known medical risks, preventing broader indications. Therefore, lifting the immune barrier in VCA is essential to tip the ethical scale and improve patients&#39; quality of life using the most advanced surgical techniques. De novo creation of a patient-specific graft is the upcoming breakthrough in reconstructive transplantation. Using tissue engineering techniques, VCAs can be freed of donor cells and customized for the recipient through perfusion-decellularization-recellularization. To develop these new technologies, a large-scale animal VCA model is necessary. Hence, swine fascio-cutaneous flaps, composed of skin, fat, fascia, and vessels, represent an ideal model for preliminary studies in VCA. Nevertheless, most VCA models described in the literature include muscle and bone. This work reports&#160;a reliable and reproducible technique for saphenous fascio-cutaneous flap harvest in swine, a practical tool for various research fields, especially vascularized composite tissue engineering.

The present protocol describes the porcine fascio-cutaneous flap model and its potential use in vascularized composite tissue research.

Vascularized Composite Allografts (VCA) such as hand, face, or penile transplant represents the cutting-edge treatment for devastating skin defects, ...

Intra-Operative Neural Monitoring of Thyroid Surgery in a Porcine Model

Intraoperative injury to the recurrent laryngeal nerve (RLN) can cause vocal cord paralysis, which interferes with speech and can potentially interfere with breathing. In recent years, intraoperative neural monitoring (IONM) has been widely adapted as an adjunct technique to localize the RLN, detect RLN injury, and predict vocal cord function during the operations. Many studies have also used animal models to investigate new applications of IONM technology and to develop reliable strategies for preventing intraoperative RLN injury. The aim of this article is to introduce a standard protocol for using a porcine model in IONM research. The article demonstrates the procedures for inducing general anesthesia, performing tracheal intubation, and experimental design to investigate the electrophysiological characteristics of RLN injuries. Applications of this protocol can improve overall efficacy in implementing the 3R principle (replacement, reduction and refinement) in porcine IONM studies.

This study aims to develop a standard protocol of intra-operative neural monitoring of thyroid surgery in a porcine model. Here, we present a protocol to demonstrate general anesthesia, to compare different types of electrodes, and to investigate the electrophysiological characteristics of the normal and injured recurrent laryngeal nerves.

Intraoperative injury to the recurrent laryngeal nerve (RLN) can cause vocal cord paralysis, which interferes with speech and can potentially interfere ...

A Training and Testing System for Performing Vascular Reconstruction In Vitro

Manual vascular reconstruction training is essential for a beginner surgeon. However, an optimal training system for vascular reconstruction in vitro has yet to be developed. In this study, we introduce an in vitro training and testing system using a magnetic anchoring technique with which a trainee can practice manual vascular reconstruction individually. Additionally, this system can also be used to test the quality of the reconstruction. The described system includes a vascular reconstruction training machine, magnetic tractors, and a magnetic suture puller. In this manuscript, we detail an end-to-end vein anastomosis using porcine right and left iliac veins. To identify the potential damage caused by a magnetic suture puller on the suture, we created three groups with six segments of 4-0 polypropylene sutures each: a control group with no intervention on the polypropylene suture, a group in which the polypropylene suture is manually pulled with sterile gloves 20x, and a magnetic puller group in which the magnetic puller pulled the polypropylene suture 20x. These groups were tested by light microscopy and breaking strength tests, and the effect of reconstruction was assessed. In the light microscopy test, the control group was less likely to be damaged (p &#60; 0.05) and the number of damaged points of the manual group and magnetic puller group were similar (p &#62; 0.05). The results of the breaking strength test were compared across groups and no significant difference was observed (p &#62; 0.05). The end-to-end anastomosis of the porcine iliac veins was successfully performed using this training system, and the reconstructed veins could undergo 2.0 kPa perfusion pressure. Using this training and testing system the trainee can practice manual vascular reconstruction in vitro individually with the aid of magnetic tractors and a magnetic suture puller, and the quality of the reconstruction can be tested.

Here we present a training and testing system where a trainee can complete manual vascular reconstruction in vitro individually using a magnetic anchoring technique. The system can also be used to test the quality of reconstruction.

Manual vascular reconstruction training is essential for a beginner surgeon. However, an optimal training system for vascular reconstruction in vitro has ...

Swine Models of Aneurysmal Diseases for Training and Research

Large animal models, specifically swine, are widely used to research cardiovascular diseases and therapies, as well as for training purposes. This paper describes two different aneurysmal swine models that may help researchers to study new therapies for aneurysmal diseases. These aneurysmal models are created by surgically adding a pouch of tissue to carotid arteries in swine. When the model is used for research, the pouch must be autologous; for training purposes, a synthetic pouch suffices.
First, the right external jugular vein (EJV) and right common carotid artery (CCA) must be surgically exposed. The EJV is ligated and a vein pouch fashioned from a short segment. This pouch is then sutured to an elliptical arteriotomy performed in the CCA. Animals must be kept heparinized during model creation, and local vasodilators may be used to decrease vasospasms. Once the suture is completed, correct blood flow should be inspected, checking for bleeding from the suture line and vessel patency. Finally, the surgical incision is closed by layers and an angiography performed to image the aneurysmal model.
A simplification of this aneurysmal carotid model that decreases invasiveness and surgical time is the use of a synthetic, rather than venous, pouch. For this purpose, a pouch is tailored in advance with a segment of a polytetrafluoroethylene (PTFE) prosthesis, one end of which is sutured close using polypropylene vascular suture and sterilized prior to surgery. This "sac" is then attached to an arteriotomy performed in the CCA as described. 
Although these models do not reproduce many of the physiopathological events related to aneurysm formation, they are hemodynamically similar to the situation found in the clinical setting. Therefore, they can be used for research or training purposes, allowing physicians to learn and practice different endovascular techniques in animal models that are close to the human system.

Description of two different aneurysmal swine models for neuroradiology training courses and research studies. This study provides evidence of the feasibility of these aneurysm porcine model creations and the reproducible methods that are close to the clinical setting.

Large animal models, specifically swine, are widely used to research cardiovascular diseases and therapies, as well as for training purposes. This paper ...

Establishment and Evaluation of a Porcine Vein Graft Disease Model

Venous graft disease (VGD) is the leading cause of coronary artery bypass graft (CABG) failure. Large animal models of CABG-VGD are needed for the investigation of disease mechanisms and the development of therapeutic strategies. 
To perform the surgery, we enter the cardiac chamber through the third intercostal space and carefully dissect the internal mammary vein and immerse it in normal saline. The right main coronary artery is then treated for ischemia. The target vessel is incised, a shunt plug is placed, and the distal end of the graft vein is anastomosed. The ascending aorta is partially blocked, and the proximal end of the graft vein is anastomosed after perforation. The graft vein is checked for patency, and the proximal right coronary artery is ligated. 
CABG surgery is performed in minipigs to harvest the left internal mammary vein for its use as a vascular graft. Serum biochemical tests are used to evaluate the physiological status of the animals after surgery. Ultrasound examination shows that the proximal, middle, and distal end of the graft vessel are unobstructed. In the surgical model, turbulent blood flow in the graft is observed upon histological examination after the CABG surgery, and venous graft stenosis associated with intimal hyperplasia is observed in the graft. The study here provides detailed surgical procedures for the establishment of a repeatable CABG-induced VGD model.

In this protocol, novel pig vein bypass grafting was performed through a small incision in the left chest wall without cardiopulmonary bypass. A postoperative pathology study was done, which showed intimal thickening.

Porcine As a Training Module for Head and Neck Microvascular Reconstruction

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