The authors have no acknowledgements.

1. Preparation:
<ol>
	<li>Obtain a tabletop stereo microscope, with a variable 3,5 x to 45x zoom, 200 mm working distance, 55 to 75 mm variable inter-pupillary distance and an accessory led ring light. Any similar microscope is adequate, it can be set up on a small table and is not extremely expensive.</li>
	<li>Gather and prepare a set of microsurgical instruments with two microsurgical pickups, one dissecting scissor, and one needle-driver; this is the minimum required, it must be taken into account that these are practice instruments, and high end quality instruments are not needed.</li>
	<li>Use 9/0 monofilament micro-suture for all the practices. Buy commercially available chicken thighs or wings and food colorant at the local supermarket.</li>
	<li>A 20 G angio-catheter is used for the patency tests on the chicken femoral arteries. For the Brachial arteries a thinner 27 G catheter is needed. These can be acquired over the internet at a local Pharmacy or with the instruments set. Buy a commercially available syringe to inject the food colorant.</li>
</ol>
2. Macroscopic dissection techniques:
<ol>
	<li>The approach to the femoral vessels is straightforward. For chicken thighs, perform a blunt dissection technique just medial to the femoral shaft, separate the femoral muscle from the bone and expose the femoral artery, vein and nerve. The nerve can be further dissected into two separate fascicles for different types of nerve repair practices.</li>
	<li>In order to access the chicken Brachial artery in the chicken wings, incise the skin longitudinally with a scissor, from the shoulder up to the tip of the wing. Observe the artery running between the biceps and triceps brachii.</li>
</ol>
3. Recommended training regimen:
<ol>
	<li>Training with the femoral artery. 
	NOTE: The first step in the training regimen is to practice with the chicken femoral artery.</li>
</ol>

<ol>
	<li>Place the piece under the microscope and start the microsurgical dissection. Free the femoral artery from the underlying tissues; and divide it horizontally. Perform an adventicectomy. Use the micro-pickups and micro-scissors to trim any adventicia overlying the arterial lumen. Rinse the inner lumen with regular tap water. Write down the starting time</li>
	<li>Perform an end to end anastomosis.
	<ol>
		<li>Start on the back wall of the artery on the side opposite to the operator. Place the first stitch; start on the left side if working horizontally, on the lower side if working vertically. Pass the needle from the outside of the artery towards the lumen and then from the lumen to the outside of the artery.</li>
		<li>Tie the stitch, perform a double knot first, and then two single throws alternating directions. Complete the whole back wall with the above described technique.</li>
		<li>Starting on the right hand side if you are working horizontally or the upper side if you are working vertically, place a single stitch from the outside to the lumen and then from the lumen to the outside. Tie the knot as described above. Complete the front wall repeating the procedure described in 3.1.2.2.</li>
		<li>Write down the final time this will allow you to keep a time record, so you can control your progression. 
		NOTE: The authors prefer a one way up technique; but any type of microsurgical suture can be rehearsed. It is recommendable that the trainee completes around 25 microsurgical anastomoses in this manner before he can try other clinical scenarios. These include vein grafting for arterial gaps, end to end nerve repairs, and the use of vein conduits for the treatment of nerve gaps. An important technique in microvascular surgery, that can be learned with this training method is the continuous or running suture, to perform this technique the trainee proceeds as 3.1.2.1 but the stich is not cut, continue to perform stitches as in 3.1.2.1 without cutting them until you complete the whole suture and tie it to the original stitch at the end.</li>
	</ol>
	</li>
</ol>

<ol start="2">
	<li>Training with the Brachial artery
	<ol>
		<li>Place the piece under the microscope. Complete the procedure as described above for the femoral artery. 
		NOTE: The only difference is the size. The Brachial artery is much smaller than the femoral artery and the anastomosis is considerably more challenging.</li>
	</ol>
	</li>
	<li>Patency tests
	<ol>
		<li>Cross a smooth 20 or 27 G angio-catheter through the anastomosis, to check for obstructions caused by stitches suturing both vessel walls together.</li>
		<li>Apply a syringe with commercial food colorant to the end of the angio-catheter, and perfuse dye into the artery to test for jet leakage</li>
		<li>Open the artery longitudinally to visualize the stitches, their parallelism and the amount of wall taken.</li>
	</ol>
	</li>
</ol>

<ol><li>Lee, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Historical+events+on+development+of+experimental+microsurgical+organ+transplantation%5BTitle%5D)+AND+%22Yonsei+Med+J%22%5BJournal%5D)">Historical events on development of experimental microsurgical organ transplantation.</a> Yonsei Med J. 45 (6), 1115-1120 (2004).</li>
<li>Shurey, S., Akelina, Y., Legagneux, J., Malzone, G., Jiga, L., Ghanem, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+rat+model+in+microsurgery+education%3A+classical+exercises+and+new+horizons%5BTitle%5D)+AND+%22Arch+Plast+Surg%22%5BJournal%5D)">The rat model in microsurgery education: classical exercises and new horizons.</a> Arch Plast Surg. 41 (3), 201-208 (2014).</li>
<li>Olabe, J., Olabe, J., Sancho, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Human+cadaveric+infusi%C3%B3n+model+for+neurosurgical+training%5BTitle%5D)+AND+%22Surg+Neurol%22%5BJournal%5D)">Human cadaveric infusión model for neurosurgical training.</a> Surg Neurol. 72, 700-702 (2009).</li>
<li>Peled, I. J., Kaplan, H. Y., Wexler, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microsilicone+anastomoses%5BTitle%5D)+AND+%22Ann+Plast+Surg%22%5BJournal%5D)">Microsilicone anastomoses.</a> Ann Plast Surg. 10 (4), 331-332 (1983).</li>
<li>Gluer, N. M., Rao, G. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Canniesburn+%E2%80%9Cever-ready%E2%80%9D+model+to+practise+microsurgery%5BTitle%5D)+AND+%22Br+J+Plast+Surg%22%5BJournal%5D)">Canniesburn “ever-ready” model to practise microsurgery.</a> Br J Plast Surg. 43 (3), 381-382 (1990).</li>
<li>Hino, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Training+in+microvascular+surgery+using+a+Chicken+wing+artery%5BTitle%5D)+AND+%22Neurosurgery%22%5BJournal%5D)">Training in microvascular surgery using a Chicken wing artery.</a> Neurosurgery. 52 (6), 1495-1498 (2003).</li>
<li>Marsh, D. J., Norton, S. E., Mok, J., Patel, H. D., Chen, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microsurgical+training+the+Chicken+thigh+model%5BTitle%5D)+AND+%22Ann+Plast+Surg%22%5BJournal%5D)">Microsurgical training the Chicken thigh model.</a> Ann Plast Surg. 59 (3), 355-356 (2007).</li>
<li>Jeong, H. S., Moon, M. S., Kim, H. S., Lee, H. K., Yi, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microsurgical+training+with+fresh+chicken+legs+and+their+histological+characteristics%5BTitle%5D)+AND+%22Ann+Plast+Surg%22%5BJournal%5D)">Microsurgical training with fresh chicken legs and their histological characteristics.</a> Ann Plast Surg. 70 (1), 57-61 (2013).</li>
<li>Couceiro, J., Ozyurekoglu, T., Sanders, S., Tien, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microsurgical+training+regimen+with+nonliving+chicken+models%5BTitle%5D)+AND+%22Microsurgery%22%5BJournal%5D)">Microsurgical training regimen with nonliving chicken models.</a> Microsurgery. 33 (3), 251-252 (2013).</li>
<li>Phoon, A. F., Gumley, G. J., Rtshiladze, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microsurgical+training+using+a+pulsatile+membrane+pump+and+chicken+thigh%3A+A+new%2C+realistic%2C+practical%2C+nonliving+educational+model%5BTitle%5D)+AND+%22Plast+Reconstr+Surg%22%5BJournal%5D)">Microsurgical training using a pulsatile membrane pump and chicken thigh: A new, realistic, practical, nonliving educational model.</a> Plast Reconstr Surg. 126 (5), 278e-279e (2010).</li>
<li>Zhou, Y., Gu, X., Xiang, J., Qian, S., Chen, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+comparative+study+on+suture+versus+cuff+anastomosis+in+mouse+cervical+cardiac+transplant%5BTitle%5D)+AND+%22Exp+Clin+Transplant%22%5BJournal%5D)">A comparative study on suture versus cuff anastomosis in mouse cervical cardiac transplant.</a> Exp Clin Transplant. 8 (3), 245-249 (2010).</li>
</ol>

The authors have nothing to disclose.

The clinical practice of microsurgery requires a continuous practice and a high level of expertise; it&#8217;s applications include free flaps, replantation and revascularization procedures, intracranial &#8211; extracranial anastomoses for neurosurgical procedures, peripheral nerve surgery and others. In spite of the wide variety of procedures that require microsurgical techniques, some of them are seldom performed in many centers. The surgeons therefore need sometimes to maintain their skill level rehearsing the surgeries on different practice models. 
The most widely spread training model is currently the rat 1,2; it is considered by many to be the &#8220;gold standard&#8221; in microsurgical instruction. Rats are indeed a very valuable tool in the teaching and learning of microsurgery. They provide a very similar environment to that of the clinical situation. This approach however exhibits some intrinsic limitations. The use of living animals presents an ethical dilemma; and is generally subjected to institutional review board approval. Furthermore they require anesthesia, and dedicated technicians and facilities. All These factors imply important economic costs; this restricts training on living animals to specific teaching units, experimental surgery departments and hospitals with similar resources. 
The use of nonliving animal models described in this protocol, has the advantage of not raising any ethical concerns; it does not require institutional review board approval. Economically it compares favorably to living animal training. The required equipment is limited and can be acquired over the internet for a reasonable price; the author&#8217;s tabletop stereomicroscope was bought for around 450 United States Dollars (USD) and the set of practice microsurgical instruments was purchased for around 150 USD. The author uses microsurgical sutures provided by his sponsoring institution; the price of sutures varies greatly and high quality sutures are not needed, a box of twelve sutures can be bought for around 70 USD on the internet. A microsurgical training station can be set up on a very limited area at home or at work; Jeong et al.8 Placed their microscope at the residents&#8217; office; whilst we9 used an available microscope close to the hand surgery fellows&#8217; quarters. 
The most critical point in the application of this protocol is the need for the trainee to be constant and to stay motivated with his training, it is therefore very important that he starts training with the bigger vessels first and then proceed to the smaller chicken wing vessels to avoid frustration. The limitations of training with nonliving models involve primarily the lack of bleeding and the inexistence of hemodynamic phenomena like vasospasm and clotting. The advantages and disadvantages of this type of training are summarized on Table 1. The three tests detailed in section three are aimed to help the trainee check the vessel&#8217;s patency in the absence of the earlier mentioned phenomena; they provide information on the quality of the trainee&#8217;s suture, leaking, suture misalignment, and lumen obstruction caused by stitches suturing the front and back wall together. 
The protocol can potentially be improved by the addition of a peristaltic pump10 to simulate vessel flow or by flooding the field with liquid to simulate superficial tension. It is the authors opinion that this would result in the production of an even more realistic training environment and this should be the direction of future research. 
Another possible field for development is the application of this training method to help the trainee learn more complex procedures, such as the cuff anastomosis technique11 before it&#8217;s actual application on animal research. The authors have however no experience with such techniques at present time. 
In conclusion the protocol described in the present manuscript allows a determined trainee to setup a small practice station and use it to learn, perfect and maintain microsurgical skills progressively and sustainably; without the need for special facilities and minimizing animal deaths.

An ample array of training models have been described for the learning and maintenance of both basic and advanced microsurgical skills. These include living animals1,2, human cadaveric specimens3, inert models4,5 and non-living animal models6-9.The Living animal models, specifically those using rats have been extensively used in the teaching of microsurgery 1,2; and they are considered the current gold standard of training. In spite of their remarkable instructive value, when an intensive or prolonged training is required; economical and ethical concerns can hinder their practical usage. 
Cadaveric models3 offer the opportunity to practice in an environment similar to that of the actual clinical situation; they are unfortunately restricted to anatomy labs and similar facilities, a microscope must be available at the lab as well; these models are therefore not widely available. Inert models such as rubber tubes, or gloves4,5 are cheap, and easily accessible, the required equipment for their application is minimal. The resemblance to a clinical situation is tenuous however; and their application is generally limited to the introductory stages of training, before the trainee starts practicing on rats. To the best of our knowledge Hino6 was the first to propose the use of non-living chicken for the development and maintenance of clinical microsurgical skills. His model is based on the extraction and subsequent usage of the chicken brachial artery from commercial chicken wings. This approach does not need institution review board approval, rodent anaesthesia, laboratory technicians or postoperative care. 
Following Hino&#180;s description of the chicken wing artery model numerous other nonliving animal models were published. The use of commercial chicken thighs was first suggested by Marsh et al.7 who reported the use of the femoral artery, vein and nerve for didactic purposes. This particular model expands the possibilities of training including structures different from the arteries; it permits the trainee to perform a variety of complex procedures such as vein grafts, nerve grafts or fascicular repairs. Jeong et al.8 Further studied Marsh&#8217; chicken thigh model and its applications to the teaching of resident doctors. The authors analysed chicken tissue samples histologically and found that it presented similarities to human tissues. The time to perform an anastomosis by the trainee was significantly reduced by practice in their study. They concluded that &#8220;the femoral neurovascular bundles of chicken are an appropriate and effective model for teaching and practicing microsurgery&#8221;. In 2013 my colleagues and I9 published a microsurgical training regimen that combined both the chicken thigh and the chicken wing models; this approach benefits from the versatility of the chicken thighs and from the limited size of the chicken wing artery which can represent more of a challenge than the femoral vessels for the more advanced trainees. 
On the current manuscript we describe step by step the process of setting up a microsurgical practice station; the materials required, how to dissect the neurovascular structures of each model and how to effectively apply the training regimen.

<table><tbody><tr><td>Stereomicroscope</td><td>Amscope</td><td>SM-1BX</td><td>Microscope</td></tr><tr><td>Led light</td><td>Amscope</td><td>LED-80S-YA</td><td>illumination system</td></tr><tr><td>Microsurgical instruments set</td><td>Chen hen microsurgical instruments</td><td>HC- X803-1</td><td>Microsurgical instruments</td></tr><tr><td>Microsurgical sutures</td><td>S/T microsurgical</td><td>9/0 Suture</td><td>Sutures</td></tr></tbody></table>

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.

The authors have chronometered their times with the present training method and have seen it to significantly reduce the anastomosis times for a femoral artery at the end of the third week. The trainee can control the improvements on his technique by checking his times, his patency percentages and the alignment of his stitches. The system described in this manuscript is depicted in Figure 1 it includes a tabletop microscope and a set of microsurgical instruments. The macroscopic dissections are shown in Figures 2 and 3. An example of a femoral artery microsurgical anastomosis is shown in Figure 4. Figure 5 shows a Brachial artery microsurgical anastomosis. Figure 6 shows a femoral artery repair with a vein graft. The patency tests are shown in Figure 7.

<img alt="Figure 1" src="/files/ftp_upload/52625/52625fig1.jpg" /> 
Figure 1: The corresponding author&#8217;s own microsurgical practice station. It includes a tabletop microscope and a set of training microsurgical instruments. It can be set up on a very limited space at the office or at home.
<img alt="Figure 2" src="/files/ftp_upload/52625/52625fig2.jpg" /> 
Figure 2 A: A macroscopic dissection of a chicken thigh, The femoral vessels and sciatic nerve can be easily exposed running a finger just medial to the femoral shaft. The horizontal arrow marks the femoral head. The dissection plane is marked by the vertical arrow just parallel to the femoral shaft B: The femoral artery (a) vein (v) and sciatic nerve (n) are shown here in detail.
<img alt="Figure 3" src="/files/ftp_upload/52625/52625fig3.jpg" /> 
Figure 3 A and B: A macroscopic dissection of a chicken wing. The brachial artery runs between the Biceps and Triceps Brachii. The artery is marked with an arrow on both photographs it is quite superficial and the approach is simple; it can be achieved with commercial cooking scissors.
<img alt="Figure 4" src="/files/ftp_upload/52625/52625fig4.jpg" /> 
Figure 4: Microscopic image of a femoral artery end to end suture, here a one way up technique with single stitches was performed. Any other type of suture can be practiced at the trainee&#8217;s discretion.
<img alt="Figure 5" src="/files/ftp_upload/52625/52625fig5.jpg" /> 
Figure 5: End to end suture of a chicken Brachial artery. This arteries are much smaller than the femoral ones and the procedure is much more technically demanding.
<img alt="Figure 6" src="/files/ftp_upload/52625/52625fig6.jpg" /> 
Figure 6: A femoral artery repair with a vein graft harvested from the femoral vein. The chicken thigh model is very versatile allowing for different types of practice exercises.
<img alt="Figure 7" src="/files/ftp_upload/52625/52625fig7.jpg" /> 
Figure 7: The patency tests. A: An angio-catheter of the appropriate diameter is crossed through the anastomosis to check for obstructions caused by stiches suturing both of the vessel&#8217;s walls. B: Dye is perfused through the anastomosis to test for leakage. C: The anastomosis is opened longitudinally to visualize the suture alignment.

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

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 ...

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Medicine

15.2K Views.  POVISA Hospital. 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. 

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

Murine Cervical Heart Transplantation Model Using a Modified Cuff Technique

Mouse models are of special interest in research since a wide variety of monoclonal antibodies and commercially defined inbred and knockout strains are available to perform mechanistic in vivo studies. While heart transplantation models using a suture technique were first successfully developed in rats, the translation into an equally widespread used murine equivalent was never achieved due the technical complexity of the microsurgical procedure. In contrast, non-suture cuff techniques, also developed initially in rats, were successfully adapted for use in mice1-3. This technique for revascularization involves two major steps I) everting the recipient vessel over a polyethylene cuff; II) pulling the donor vessel over the formerly everted recipient vessel and holding it in place with a circumferential tie. This ensures a continuity of the endothelial layer, short operating time and very high patency rates4.
Using this technique for vascular anastomosis we performed more than 1,000 cervical heart transplants with an overall success rate of 95%. For arterial inflow the common carotid artery and the proximal aortic arch were anastomosed resulting in a retrograde perfusion of the transplanted heart. For venous drainage the pulmonary artery of the graft was anastomosed with the external jugular vein of the recipient5.
Herein, we provide additional details of this technique to supplement the video.

The murine cervical heart transplantation model is well suited for immunological as well as ischemia reperfusion injury studies. We modified the procedure using a non-suture cuff technique and performed more than 1,000 successful transplants with this approach.
Herein, we provide additional details of this technique to supplement the video.

Mouse models are of special interest in research since a wide variety of monoclonal antibodies and commercially defined inbred and knockout strains are ...

Real-Time Tracking of Nanoparticles in Brain Tumors Using 2P-IVM in Mice

Two-Photon Intravital Microscopy of Glioblastoma in a Murine Model

The delivery of intravenously administered cancer therapeutics to brain tumors is limited by the blood-brain barrier. A method to directly image the accumulation and distribution of macromolecules in brain tumors in vivo would greatly enhance our ability to understand and optimize drug delivery in preclinical models. This protocol describes a method for real-time in vivo tracking of intravenously administered fluorescent-labeled nanoparticles with two-photon intravital microscopy (2P-IVM) in a mouse model of glioblastoma (GBM).
The protocol contains a multi-step description of the procedure, including anesthesia and analgesia of experimental animals, creating a cranial window, GBM cell implantation, placing a head bar, conducting 2P-IVM studies, and post-surgical care for long-term follow-up studies. We show representative 2P-IVM imaging sessions and image analysis, examine the advantages and disadvantages of this technology, and discuss potential applications.
This method can be easily modified and adapted for different research questions in the field of in vivo preclinical brain imaging.

Author Spotlight: Multimodal Imaging Strategies for Optimizing Drug Delivery and Early Detection in Glioblastoma Treatment

We present a novel approach for two-photon microscopy of the tumor delivery of fluorescent-labeled iron oxide nanoparticles to glioblastoma in a mouse model.

The delivery of intravenously administered cancer therapeutics to brain tumors is limited by the blood-brain barrier. A method to directly image the ...

Cancer Research

Common Carotid Artery Repair After Injection in a Mouse Model 

Facilitating Repeat Intracarotid Injections in Mouse Models by a Novel Injection Site Repair Technique

Given recent advances in the delivery of novel antitumor therapeutics using endovascular selective intraarterial delivery methods in neuro-oncology, there is an urgent need to develop methods for intracarotid injections in mouse models, including methods to repair the carotid artery in mice after injection to allow for subsequent injections. We developed a method of intracarotid injection in a mouse model to deliver therapeutics into the internal carotid artery (ICA) with two alternative procedures. 
During injection, the needle is inserted into the common carotid artery (CCA) after tying a suture around the external carotid artery (ECA) and injected therapeutics are delivered into the ICA. Following injection, the common carotid artery (CCA) can be ligated, which limits the number of intracarotid injections to one. The alternative procedure described in this article includes a modification where intracarotid artery injection is followed by injection site repair of the CCA, which restores blood flow within the CCA and avoids the complication of cerebral ischemia seen in some mouse models. 
We also compared the delivery of bone marrow-derived human mesenchymal stem cells (BM-hMSCs) to intracranial tumors when delivered through intracarotid injection with and without injection site repair following the injection. Delivery of BM-hMSCs does not differ significantly between the methods. Our results demonstrate that injection site repair of the CCA allows for repeat injections through the same artery and does not impair the delivery and distribution of injected material, thus providing a model with greater flexibility that more closely emulates intracarotid injection in humans.

Author Spotlight: Advancing Glioblastoma Treatment Through Intraarterial Delivery Strategies for Oncolytic Viruses and MicroRNAs

Repair of the intracarotid artery in a mouse model after injection returns blood flow to the artery without negatively impacting the distribution of the injected material. Injection site repair facilitates subsequent injections through the same artery and prevents cerebral ischemia in mouse strains that lack a complete Circle of Willis.

Given recent advances in the delivery of novel antitumor therapeutics using endovascular selective intraarterial delivery methods in neuro-oncology, there ...

A Novel Microsurgical Model for Heterotopic, En Bloc Chest Wall, Thymus, and Heart Transplantation in Mice

Exploration of novel strategies in organ transplantation to prolong allograft survival and minimizing the need for long-term maintenance immunosuppression must be pursued. Employing vascularized bone marrow transplantation and co-transplantation of the thymus have shown promise in this regard in various animal models.1-11 Vascularized bone marrow transplantation allows for the uninterrupted transfer of donor bone marrow cells within the preserved donor microenvironment, and the incorporation of thymus tissue with vascularized bone marrow transplantation has shown to increase T-cell chimerism ultimately playing a supportive role in the induction of immune regulation. The combination of solid organ and vascularized composite allotransplantation can uniquely combine these strategies in the form of a novel transplant model. Murine models serve as an excellent paradigm to explore the mechanisms of acute and chronic rejection, chimerism, and tolerance induction, thus providing the foundation to propagate superior allograft survival strategies for larger animal models and future clinical application. Herein, we developed a novel heterotopic en bloc chest wall, thymus, and heart transplant model in mice using a cervical non-suture cuff technique. The experience in syngeneic and allogeneic transplant settings is described for future broader immunological investigations via an instructional manuscript and video supplement.

To study combined solid organ and vascularized composite allotransplantation, we describe a novel heterotopic en bloc chest wall, thymus, and heart transplant model in mice using a cervical non-suture cuff technique.

Exploration of novel strategies in organ transplantation to prolong allograft survival and minimizing the need for long-term maintenance immunosuppression ...

Surgical Training for the Implantation of Neocortical Microelectrode Arrays Using a Formaldehyde-fixed Human Cadaver Model

This protocol describes a procedure to assist surgeons in training for the implantation of microelectrode arrays into the neocortex of the human brain. Recent technological progress has enabled the fabrication of microelectrode arrays that allow recording the activity of multiple individual neurons in the neocortex of the human brain. These arrays have the potential to bring unique insight onto the neuronal correlates of cerebral function in health and disease. Furthermore, the identification and decoding of volitional neuronal activity opens the possibility to establish brain-computer interfaces, and thus might help restore lost neurological functions. The implantation of neocortical microelectrode arrays is an invasive procedure requiring a supra-centimetric craniotomy and the exposure of the cortical surface; thus, the procedure must be performed by an adequately trained neurosurgeon. In order to provide an opportunity for surgical training, we designed a procedure based on a human cadaver model. The use of a formaldehyde-fixed human cadaver bypasses the practical, ethical and financial difficulties of surgical practice on animals (especially non-human primates) while preserving the macroscopic structure of the head, skull, meninges and cerebral surface and allowing realistic, operating room-like positioning and instrumentation. Furthermore, the use of a human cadaver is closer to clinical daily practice than any non-human model. The major drawbacks of the cadaveric simulation are the absence of cerebral pulsation and of blood and cerebrospinal fluid circulation. We suggest that a formaldehyde-fixed human cadaver model is an adequate, practical and cost-effective approach to ensure proper surgical training before implanting microelectrode arrays in the living human neocortex.

We designed a procedure in which a formaldehyde-fixed human cadaver is used to assist neurosurgeons in training for the implantation of microelectrode arrays into the neocortex of the human brain.

This protocol describes a procedure to assist surgeons in training for the implantation of microelectrode arrays into the neocortex of the human brain. ...

Model Surgical Training: Skills Acquisition in Fetoscopic Laser Photocoagulation of Monochorionic Diamniotic Twin Placenta Using Realistic Simulators

Fetoscopic laser coagulation of arterio-venous anastomoses (AVA) in a monochorionic placenta is the standard of care for twin-twin transfusion syndrome (TTTS), but is technically challenging and can lead to significant complications. Acquiring and maintaining the necessary surgical skills require consistent practice, a critical caseload, and time. Training on realistic surgical simulators can potentially shorten this steep learning curve and enables several proceduralists to acquire procedure-specific skills simultaneously. Here we describe realistic simulators designed to allow the user familiarity with the equipment and specific steps required in the surgical treatment of TTTS, including fetoscopic handling, approaches to anterior and posterior placenta, recognition of anastomoses, and efficient coagulation of vessels. We describe the skills that are especially important in conducting placental laser coagulation that the surgeon can practice on the model and apply in a clinical case. These models can be adapted easily depending on the availability of materials and require standard fetoscopy equipment. Such training systems are complementary to traditional surgical apprenticeships and can be useful aids for fetal medicine units that provide this clinical service.

Practicing the specific skills required for fetoscopic laser coagulation of monochorionic placental anastomoses on realistic models can aid less experienced surgeons in overcoming the steep learning curve associated with this procedure that is now regarded as the standard of care for twin-twin transfusion syndrome.

Fetoscopic laser coagulation of arterio-venous anastomoses (AVA) in a monochorionic placenta is the standard of care for twin-twin transfusion syndrome ...

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.

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 ...

Learning Modern Laryngeal Surgery in a Dissection Laboratory

Surgery for laryngeal malignancies requires millimetric accuracy from the different endoscopic and open techniques available. Practice of this surgery is almost completely reserved to a few referral centers that deal with a large proportion of this pathology. Practice on human specimens is not always possible for ethical, economic, or availability reasons. The aim of this study is to provide a reproducible method for the organization of a laryngeal laboratory on ex vivo animal models where it is possible to approach, learn, and refine laryngeal techniques. Porcine and ovine larynges are ideal, affordable, models to simulate laryngeal surgery given their similarity to the human larynx in their anatomical layout and tissue composition. Herein, the surgical steps of transoral laser surgery, open partial horizontal laryngectomy, and total laryngectomy are reported. The merging of endoscopic and exoscopic views guarantees an inside-out perspective, which is vital for the comprehension of the complex laryngeal anatomy. The method was successfully adopted during three sessions of a dissection course &#34;Lary-Gym&#34;. Further perspectives on robotic surgical training are described.

The purpose of this paper is to illustrate how to organize a reproducible laboratory for laryngeal surgery on affordable and closely similar animal laryngeal models in order to improve anatomical and surgical knowledge and skills.

Surgery for laryngeal malignancies requires millimetric accuracy from the different endoscopic and open techniques available. Practice of this surgery is ...

A Revised Method for Inducing Secondary Lymphedema in the Hindlimb of Mice

Animal models are of paramount importance in the research of lymphedema in order to understand the pathophysiology of the disease but also to explore potential treatment options. This mouse model allows researchers to induce significant lymphedema lasting at least 8 weeks. Lymphedema is induced using a combination of fractioned radiotherapy and surgical ablation of lymphatics. This model requires that the mice get a dose of 10 Gray (Gy) radiation before and after surgery. The surgical part of the model involves ligation of three lymph vessels and extraction of two lymph nodes from the mouse hindlimb. Having access to microsurgical tools and a microscope is essential, due to the small anatomical structures of mice. The advantage of this model is that it results in statistically significant lymphedema, which provides a good basis for evaluating different treatment options. It is also a great and easily available option for microsurgical training. The limitation of this model is that the procedure can be time consuming, especially if not practiced in advance. The model results in objectively quantifiable lymphedema in mice, without causing severe morbidity and has been tested in three separate projects.

This animal model enables researchers to induce statistically significant secondary lymphedema in the hindlimb of mice, lasting at least 8 weeks. The model can be used to study the pathophysiology of lymphedema and to investigate novel treatment options.

Animal models are of paramount importance in the research of lymphedema in order to understand the pathophysiology of the disease but also to explore ...

Modeling Stroke in Mice: Focal Cortical Lesions by Photothrombosis

Stroke is a leading cause of death and acquired adult disability in developed countries. Despite extensive investigation for novel therapeutic strategies, there remain limited therapeutic options for stroke patients. Therefore, more research is needed for pathophysiological pathways such as post-stroke inflammation, angiogenesis, neuronal plasticity, and regeneration. Given the inability of in vitro models to reproduce the complexity of the brain, experimental stroke models are essential for the analysis and subsequent evaluation of novel drug targets for these mechanisms. In addition, detailed standardized models for all procedures are urgently needed to overcome the so-called replication crisis. As an effort within the ImmunoStroke research consortium, a standardized photothrombotic mouse model using an intraperitoneal injection of Rose Bengal and the illumination of the intact skull with a 561 nm laser is described. This model allows the performance of stroke in mice with allocation to any cortical region of the brain without invasive surgery; thus, enabling the study of stroke in various areas of the brain. In this video, the surgical methods of stroke induction in the photothrombotic model along with&#160;histological analysis are demonstrated.

Described here is the photothrombotic stroke model, where a stroke is produced through the intact skull by inducing permanent microvascular occlusion using laser illumination after administration of a photosensitive dye.

Stroke is a leading cause of death and acquired adult disability in developed countries. Despite extensive investigation for novel therapeutic strategies, ...