Name: designing cad/cam surgical guides for maxillary reconstruction using an in-house approach
Uploaded: 2018-08-24T13:00:00
Description: Watch this Scientific Journal Video about Designing CAD/CAM Surgical Guides for Maxillary Reconstruction Using an In-house Approach at JoVE.com

This work was partly supported by JSPS KAKENHI Grant Number JP17K11914.

This study was approved by the authors&#39; institutional review board, and written consent forms were completed by all patients.
1. Preparation of Materials
<ol>
	<li>Use a personal computer, computed tomographic (CT) data of facial bone and fibula, conversion software such as InVesalius20, and three-dimensional (3-D) CAD software (e.g., Blender21). 
	NOTE: A maximum thickness of 1 mm slices of CT data is recommended for an accur...

<ol>
	<li>Hirsch, D. L., 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=Use+of+computer-aided+design+and+computer-aided+manufacturing+to+produce+orthognathically+ideal+surgical+outcomes:+A+paradigm+shift+in+head+and+neck+reconstruction.">Use of computer-aided design and computer-aided manufacturing to produce orthognathically ideal surgical outcomes: A paradigm shift in head and neck reconstruction.</a> Journal of Oral and Maxillofacial Surgery. 67 (10), 2115-2122 (2009).</li><li>Hanasono, M. M., Skoracki, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computer-assisted+design+and+rapid+prototype+modeling+in+microvascular+mandible+reconstruction.">Computer-assisted design and rapid prototype modeling in microvascular mandible reconstruction.</a> The Laryngoscope. 123 (3), 597-604 (2013).</li><li>Roser, S. M., 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=The+accuracy+of+virtual+surgical+planning+in+free+fibula+mandibular+reconstruction:+Comparison+of+planned+and+final+results.">The accuracy of virtual surgical planning in free fibula mandibular reconstruction: Comparison of planned and final results.</a> Journal of Oral and Maxillofacial Surgery. 68 (11), 2824-2832 (2010).</li><li>Ayoub, 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=Evaluation+of+computer+assisted+mandibular+reconstruction+with+vascularized+iliac+crest+bone+graft+compared+to+conventional+surgery:+A+randomized+prospective+clinical+trial.">Evaluation of computer assisted mandibular reconstruction with vascularized iliac crest bone graft compared to conventional surgery: A randomized prospective clinical trial.</a> Trials. 15, 114 (2014).</li><li>Stirling, C. 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=Simulated+surgery+and+cutting+guides+enhance+spatial+positioning+in+free+fibular+mandibular+reconstruction.">Simulated surgery and cutting guides enhance spatial positioning in free fibular mandibular reconstruction.</a> Microsurgery. 35 (1), 29-33 (2015).</li><li>Schepers, R. H., 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=Accuracy+of+fibula+reconstruction+using+patient-specific+CAD/CAM+reconstruction+plates+and+dental+implants:+a+new+modality+for+functional+reconstruction+of+mandibular+defects.">Accuracy of fibula reconstruction using patient-specific CAD/CAM reconstruction plates and dental implants: a new modality for functional reconstruction of mandibular defects.</a> Journal of Cranio-Maxillofacial Surgery. 43 (5), 649-657 (2015).</li><li>Tarsitano, A., 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=Mandibular+reconstructions+using+computer-aided+design/computer-aided+manufacturing:+a+systematic+review+of+a+defect-based+reconstructive+algorithm.">Mandibular reconstructions using computer-aided design/computer-aided manufacturing: a systematic review of a defect-based reconstructive algorithm.</a> Journal of Cranio-Maxillofacial Surgery. 43 (9), 1785-1791 (2015).</li><li>Wilde, F., 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=Multicenter+study+on+the+use+of+patient-specific+CAD/CAM+reconstruction+plates+for+mandibular+reconstruction.">Multicenter study on the use of patient-specific CAD/CAM reconstruction plates for mandibular reconstruction.</a> International Journal of Computer Assisted Radiology and Surgery. 10 (12), 2035-2051 (2015).</li><li>Huang, J. 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=Preliminary+clinic+study+on+computer+assisted+mandibular+reconstruction:+the+positive+role+of+surgical+navigation+technique.">Preliminary clinic study on computer assisted mandibular reconstruction: the positive role of surgical navigation technique.</a> Maxillofacial Plastic and Reconstructive Surgery. 37 (1), 20 (2015).</li><li>Numajiri, T., Nakamura, H., Sowa, Y., Nishino, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-cost+design+and+manufacturing+of+surgical+guides+for+mandibular+reconstruction+using+a+fibula.">Low-cost design and manufacturing of surgical guides for mandibular reconstruction using a fibula.</a> Plastic and Reconstructive Surgery - Global Open. 4 (7), 805 (2016).</li><li>Numajiri, T., Tsujiko, S., Morita, D., Nakamura, H., Sowa, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+fixation+guide+for+the+accurate+insertion+of+fibular+segments+in+mandibular+reconstruction.">A fixation guide for the accurate insertion of fibular segments in mandibular reconstruction.</a> Journal of Plastic, Reconstructive &amp; Aesthetic Surgery. Open. 12 (8), 1-8 (2017).</li><li>Toto, J. M., 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=Improved+operative+efficiency+of+free+fibula+flap+mandible+reconstruction+with+patient+specific,+computer-guided+preoperative+planning.">Improved operative efficiency of free fibula flap mandible reconstruction with patient specific, computer-guided preoperative planning.</a> Head &amp; Neck. 37 (11), 1660-1664 (2015).</li><li>Avraham, 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=Functional+outcomes+of+virtually+planned+free+fibula+flap+reconstruction+of+the+mandible.">Functional outcomes of virtually planned free fibula flap reconstruction of the mandible.</a> Plastic and Reconstructive Surgery. 134 (628), 634 (2014).</li><li>Sieira, G. R., 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=Surgical+planning+and+microvascular+reconstruction+of+the+mandible+with+a+fibular+flap+using+computer-aided+design,+rapid+prototype+modeling,+and+precontoured+titanium+reconstruction+plates:+A+prospective+study.">Surgical planning and microvascular reconstruction of the mandible with a fibular flap using computer-aided design, rapid prototype modeling, and precontoured titanium reconstruction plates: A prospective study.</a> British Journal of Oral and Maxillofacial Surgery. 53 (1), 49-55 (2015).</li><li>Seruya, M., Fisher, M., Rodriguez, E. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computer-assisted+versus+conventional+free+fibula+flap+technique+for+craniofacial+reconstruction:+An+outcomes+comparison.">Computer-assisted versus conventional free fibula flap technique for craniofacial reconstruction: An outcomes comparison.</a> Plastic and Reconstructive Surgery. 132 (5), 1219-1225 (2013).</li><li>Metzler, P., 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=Three-dimensional+virtual+surgery+accuracy+for+free+fibula+mandibular+reconstruction:+Planned+versus+actual+results.">Three-dimensional virtual surgery accuracy for free fibula mandibular reconstruction: Planned versus actual results.</a> Journal of Oral and Maxillofacial Surgery. 72 (12), 2601-2604 (2014).</li><li>Numajiri, 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=Using+an+in-house+approach+to+CAD/CAM+reconstruction+of+the+maxilla.">Using an in-house approach to CAD/CAM reconstruction of the maxilla.</a> Journal of Oral and Maxillofacial Surgery. 76 (6), 1361-1369 (2018).</li><li>Bosc, R., 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=Mandibular+reconstruction+after+cancer:+An+in-house+approach+to+manufacturing+cutting+guides.">Mandibular reconstruction after cancer: An in-house approach to manufacturing cutting guides.</a> International Journal of Oral and Maxillofacial Surgery. 46 (1), 24-29 (2017).</li><li>Ganry, L., 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=Three-dimensional+surgical+modeling+with+an+open-source+software+protocol:+Study+of+precision+and+reproducibility+in+mandibular+reconstruction+with+the+fibula+free+flap.">Three-dimensional surgical modeling with an open-source software protocol: Study of precision and reproducibility in mandibular reconstruction with the fibula free flap.</a> International Journal of Oral and Maxillofacial Surgery. 46 (8), 946-950 (2017).</li><li>. InVesalius Available from: <a target="_blank" href="https://www.cti.gov.br/en/invesalius">https://www.cti.gov.br/en/invesalius</a> (2018)</li><li>. Blender Available from: <a target="_blank" href="https://www.blender.org/">https://www.blender.org/</a> (2018)</li><li>. Free3D Available from: <a target="_blank" href="https://free3d.com/3d-models/human">https://free3d.com/3d-models/human</a> (2018)</li><li>. MakerBot Replicator+ Available from: <a target="_blank" href="https://www.makerbot.com/replicator/">https://www.makerbot.com/replicator/</a> (2018)</li><li>. Artec Eva Lite Available from: <a target="_blank" href="https://www.artec3d.com/portable-3d-scanners/artec-eva-lite">https://www.artec3d.com/portable-3d-scanners/artec-eva-lite</a> (2018)</li><li>Guerrero-de-Mier, A., Espinosa, M. M., Dominguez, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bricking:+A+new+slicing+method+to+reduce+warping.">Bricking: A new slicing method to reduce warping.</a> Procedia Engineering. 132, 126-131 (2015).</li><li>Petropolis, C., Kozan, D., Sigurdson, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accuracy+of+medical+models+made+by+consumer-grade+fused+deposition+modeling+printers.">Accuracy of medical models made by consumer-grade fused deposition modeling printers.</a> Plastic Surgery. 23 (2), 91-94 (2015).</li><li>Alsoufi, M. S., Elsayed, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Warping+deformation+of+desktop+3D+printed+parts+manufactured+by+open+source+fused+deposition+modeling+(FDM)+system.">Warping deformation of desktop 3D printed parts manufactured by open source fused deposition modeling (FDM) system.</a> International Journal of Mechanical and Mechatronics Engineering (IJMME) - International Journal of Engineering and Sciences (IJENS). 17 (4), 7-16 (2017).</li><li>Maschio, F., Pandya, M., Olszewski, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+validation+of+plastic+mandible+models+produced+by+a+"low-cost"+3-dimensional+fused+deposition+modeling+printer.">Experimental validation of plastic mandible models produced by a "low-cost" 3-dimensional fused deposition modeling printer.</a> Medical Science Monitor. 22, 943-957 (2016).</li><li>Rendon-Medina, M. A., Andrade-Delgado, L., Telich-Tarriba, J. E., Fuente-Del-Campo, A., Altamirano-Arcos, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dimensional+error+in+rapid+prototyping+with+open+source+software+and+low-cost+3D-printer.">Dimensional error in rapid prototyping with open source software and low-cost 3D-printer.</a> Plastic and Reconstructive Surgery - Global Open. 6 (1), 1646 (2018).</li><li>Nizam, A., Gopal, R. N., Naing, L., 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=Dimensional+accuracy+of+the+skull+models+produced+by+rapid+prototyping+technology+using+stereolithography+apparatus.">Dimensional accuracy of the skull models produced by rapid prototyping technology using stereolithography apparatus.</a> Archives of Orofacial Sciences. 1, 60-66 (2006).</li></ol>

CAD/CAM reconstruction is considered to contribute to the attainment of an accurate osteotomy length, width, and angle in cutting bones while using cutting guides4,5,6,7,8,9,10,11,12,13<s...

The use of CAD/CAM techniques has recently increased in dental and denture work. Following this evolution of CAD/CAM, osteocutaneous flap transfers using CAD/CAM are now used in the field of mandibular reconstruction after an oncologic wide resection of malignant tumors1,2,3. Several companies in Western countries have begun to supply and sell a CAD/CAM cutting guide for the mandible region. A CAD/CAM reconstruction of the mandible is considered to have an advantage in terms of accuracy4,5,6,7,8,9,10,11. However, a disadvantage is that this technique is available in limited areas worldwide and it is very expensive12. Thus, CAD/CAM reconstruction for maxillary lesions has not yet become popular. The number of the cases of maxillary reconstruction is lower than that for the mandible, and commercial guides are not common.
Because commercial maxillary CAD/CAM guides are not sold in Japan, we have developed CAD/CAM surgical guides using an in-house approach. The clinical effectiveness of the CAD/CAM guides has already been reported13,14,15,16,17,18,19, but there is no report of how to design them. The purpose of the present report is to show the CAD/CAM design method using a low-cost in-house approach.

<table border="0" cellpadding="0" cellspacing="0" style="width:1292px;" width="1291">
	<tbody>
		<tr height="66">
			<td height="66" style="height:66px;width:523px;">Information Technology Center, Renato Archer, Campinas, Brazil</td>
			<td style="width:316px;">InVesalius</td>
			<td style="width:383px;">Free software https://www.cti.gov.br/en/invesalius</td>
			<td style="width:71px;"></td>
		</tr>
		<tr height="66">
			<td height="66" style="height:66px;">The Blender Foundation, Amsterdam, Netherlands</td>
			<td>Blender</td>
			<td style="width:383px;">Free software https://www.blender.org/</td>
			<td></td>
		</tr>
		<tr height="66">
			<td height="66" style="height:66px;">TurboSquid, Inc. 935 Gravier St., Suite 1600, New Orleans, LA.</td>
			<td>Free 3D skeletal data file</td>
			<td style="width:383px;">Free3D https://free3d.com/3d-models/human</td>
			<td></td>
		</tr>
		<tr height="66">
			<td height="66" style="height:66px;">MakerBot Industries, LLC One MetroTech Center, 21st Fl, Brooklyn, NY.</td>
			<td>MakerBot Replicator+</td>
			<td>https://www.makerbot.com/replicator/</td>
			<td></td>
		</tr>
		<tr height="66">
			<td height="66" style="height:66px;width:523px;">YouTube (Google, Inc.), 901 Cherry Ave. San Bruno, CA</td>
			<td>video sharing website.</td>
			<td>https://www.youtube.com/results?search_query=invesalius+dicom+to+stl</td>
			<td></td>
		</tr>
		<tr height="66">
			<td height="66" style="height:66px;">Artec 3D, 2, rue Jean Engling, Luxembourg</td>
			<td>Artec Eva Lite</td>
			<td>https://www.artec3d.com/portable-3d-scanners/artec-eva-lite</td>
			<td></td>
		</tr>
		<tr height="66">
			<td height="66" style="height:66px;">CloudCompare</td>
			<td>CloudCompare</td>
			<td>http://www.danielgm.net/cc/</td>
			<td></td>
		</tr>
	</tbody>
</table>

designing cad/cam surgical guides for maxillary reconstruction using an in-house approach

Computer-aided design/computer-assisted manufacturing (CAD/CAM) is now being evaluated as a preparative technique for maxillofacial surgery. Because this technique is expensive and available in only limited areas of the world, we developed a novel CAD/CAM surgical guide using an in-house approach. By using the CAD software, the maxillary resection area and cutting planes and the fibular cutting planes and angles are determined. Once the resection area is decided, the necessary faces are extracted using a Boolean modifier. These superficial faces are united to fit the surface of the bones and thickened to stabilize the solids. Not only the cutting guides for the fibula and maxilla but also the location arrangement of the transferred bone segments is defined by thickening the superficial faces. The CAD design is recorded as .stl files and three-dimensionally (3-D) printed as actual surgical guides. To check the accuracy of the guides, model surgery using 3-D-printed facial and fibular models is performed. These methods may be used to assist surgeons where commercial guides are not available.

Using the procedure presented here, the resection area was determined first. Using CAD software, the resection area was completely circumscribed by the faces. This area was subtracted from the facial bone by a Boolean operation. The fibula image was placed on the defect, and fibular cutting faces were placed in the appropriate reconstructed points. All fibular cutting faces were linked to the fibula in a parent setting. These faces were made smaller and were united to make solids. The fib...

Watch this Scientific Journal Video about Designing CAD/CAM Surgical Guides for Maxillary Reconstruction Using an In-house Approach at JoVE.com

Designing CAD/CAM Surgical Guides for Maxillary Reconstruction Using an In-house Approach

Methods for designing a computer-aided design/computer-aided manufacturing (CAD/CAM) surgical guide are shown. Cutting planes are separated, united, and thickened to easily visualize the necessary bone transfer. These designs can be three-dimensional printed and checked for accuracy.

Computer-aided design/computer-assisted manufacturing (CAD/CAM) is now being evaluated as a preparative technique for maxillofacial surgery. Because this ...

This method can help answer key questions in the head and neck reconstruction field about computer assisted design on the modeling reconstruction of the maxilla. The main advantage of this technique is that CAD and CAM simulations are accessible to everyone. The implications of this technique extended to a reconstructive surgery therapy as these surgeries are typically performed using a free-hand approach.After selecting the area of bone to be excised, make a large plane and place the plane on the border of the area for removal in the appropriate computer aided design software. Continue to place more planes until the entire area for removal has been surrounded and select the vertices of the planes. Connect the plates by adjusting edges and faces of the planes in the edit mode to surround the area for removal.Then use a boolean modifier to subtract the receptable solid from the facial bone to generate a shaved facial bone for the maxillary defect model. Boolean modifiers sometimes fail. If this happens, don't panic.And try again. Next, place a fibula into the maxillary defect area, and mark the fibula with one small green cube eight centimeters distal to the fibular head and one small green cube five centimeters proximal to the lateral malleolus. For the maxilla, place red cubes for the identification of the reconstructed points.Using a parent setting in the object mode, link the small cubes to the fibula and place more small marker cubes over the areas in the maxillary lesion where reconstruction is necessary to increase the visibility of the necessary reproduction points. If the fibula is displaced from the midline, fit the fibula to the front margin of the alveolar bone and use the previous plane of the midline maxillary osteotomy as a first fibular osteotomy plane. Place a new osteotomy plane where appropriate.And link this new plane to the fibula as a parent setting. Copy the fibula and two planes of osteotomy as a parent setting in the object mode. And move the copied fibula with the first block area with two cutting planes on both ends to the secondary area where reconstruction is necessary to plan the second fibula block.Then, add a new plane in the object mode to place the second cutting plate. To design the fibular cutting guide, visualize only the fibula and cutting planes and make each cutting plane smaller so that each plane occupies only half of the area of the fibula cutting section. Unite two end planes to build a solid shape in the object mode and select the vertices of all of the planes to form a solid rectangle.Use a boolean modifier to subtract the fibula from the rectangle and unite each subtracted solid in the object mode. Place a cube near the subtracted solids and extrude the faces to make pillars. Then unite the pillars to the subtracted solids to generate the fibular cutting guide.To design the maxillary cutting guide, add the maxillary and zygomatic planes for the original remaining surface after the maxillary removal and extrude the faces to thicken the plane. Use the solidify modifier to solidify the plates in the edit mode and delete the thickened object over the resection planes on both ends of the maxilla to generate the maxillary cutting guide. To generate the fibular segment fixation guide, use cutting planes on both ends to remove the intersecting area between the fibula and the solid construct for each fibular block in the boolean modifier.Extract half of the superficial surface of each fibular block and unite all of the superficial surfaces in the object mode. Then, use a knife cut to delete any small faces to secure the spaces for the metal plate fittings and use the solidifying modifier to thicken the surfaces. For 3D printing, export the designs of the guides in STL format and print all of the guides and bones.Then, fit the maxillary cutting guide to the facial bone model and use a saw to cut the facial bone along the cutting plane. Attach the fibular cutting guide to the fibular bone model and cut the bone into pieces. Then, attach the fibular blocks to the fixation guide and use screws and plates to fix the resulting fixation guide complex to the maxillary defect.Then, fix the fibular segments to the maxilla where the fixation guide does not attach with additional screws and plates and remove the fixation guide. The reconstruction is now complete. The designs for these representative fibular cutting, maxillary cutting, and fibular fixation guides were created and exported in STL format as demonstrated for 3D printing.The maxillary cutting and fibular cutting guides were then completely fitted to the facial bone and fibular bone models. The models were cut with a saw and the resulting model was fixed with titanium plates and screws. A 3D reconstructed image was then determined by a 3D scanner within an approximately two millimeter deviation.While attempting this procedure, it's important to remember to check that each object does not interfere with the surrounding tissues and that the vascular pedicles are not compressed or kinked by the printed object and transverse tissues. Using these computer guided surgery approaches, the accuracy of free-handed, reconstructive surgery techniques can be improved.

designing-cadcam-surgical-guides-for-maxillary-reconstruction-using

Research

JoVE Journal

Medicine

Surgical Procedures for a Rat Model of Partial Orthotopic Liver Transplantation with Hepatic Arterial Reconstruction

Orthotopic liver transplantation (OLT) in rats using a whole or partial graft is an indispensable experimental model for transplantation research, such as studies on graft preservation and ischemia-reperfusion injury 1,2, immunological responses 3,4, hemodynamics 5,6, and small-for-size syndrome 7. The rat OLT is among the most difficult animal models in experimental surgery and demands advanced microsurgical skills that take a long time to learn. Consequently, the use of this model has been limited. Since the reliability and reproducibility of results are key components of the experiments in which such complex animal models are used, it is essential for surgeons who are involved in rat OLT to be trained in well-standardized and sophisticated procedures for this model.
While various techniques and modifications of OLT in rats have been reported 8 since the first model was described by Lee et al. 9 in 1973, the elimination of the hepatic arterial reconstruction 10 and the introduction of the cuff anastomosis technique by Kamada et al. 11 were a major advancement in this model, because they simplified the reconstruction procedures to a great degree. In the model by Kamada et al., the hepatic rearterialization was also eliminated. Since rats could survive without hepatic arterial flow after liver transplantation, there was considerable controversy over the value of hepatic arterialization. However, the physiological superiority of the arterialized model has been increasingly acknowledged, especially in terms of preserving the bile duct system 8,12 and the liver integrity 8,13,14.
In this article, we present detailed surgical procedures for a rat model of OLT with hepatic arterial reconstruction using a 50% partial graft after ex vivo liver resection. The reconstruction procedures for each vessel and the bile duct are performed by the following methods: a 7-0 polypropylene continuous suture for the supra- and infrahepatic vena cava; a cuff technique for the portal vein; and a stent technique for the hepatic artery and the bile duct.

Orthotopic liver transplantation in rats is an indispensable experimental model for biomedical research. Here we present our surgical procedures for orthotopic rat liver transplantation with hepatic arterial reconstruction using a 50% partial graft.

Orthotopic liver transplantation (OLT) in rats using a whole or partial graft is an indispensable experimental model for transplantation research, such as ...

The Mouse Round-window Approach for Ototoxic Agent Delivery: A Rapid and Reliable Technique for Inducing Cochlear Cell Degeneration

Investigators have utilized a wide array of animal models and investigative techniques to study the mammalian auditory system. Much of the basic research involving the cochlea and its associated neural pathways entails exposure of model cochleae to a variety of ototoxic agents. This allows investigators to study the effects of targeted damage to cochlear structures, and in some cases, the self-repair or regeneration of those structures. Various techniques exist for delivery of ototoxic agents to the cochlea. When selecting a particular technique, investigators must consider a number of factors, including the induction of inadvertent systemic toxicity, the amount of cochlear damage produced by the surgical procedure itself, the type of lesion desired, animal survivability, and reproducibility/reliability of results. Currently established techniques include parenteral injection, intra-peritoneal injection, trans-tympanic injection, endolymphatic sac injection, and cochleostomy with perilymphatic perfusion. Each of these methods has been successfully utilized and is well described in the literature; yet, each has various shortcomings. Here, we present a technique for topical application of ototoxic agents directly to the round window niche. This technique is non-invasive to inner ear structures, produces rapid onset of reliably targeted lesions, avoids systemic toxicity, and allows for an intra-animal control (the contra-lateral ear). Results stemming from this approach have helped deeper understanding of auditory pathophysiology, cochlear cell degeneration, and regenerative capacity in response to an acute injury. Future investigations may use this method to conduct interventional studies involving gene therapy and stem cell transplantation to combat hearing loss.

Various methods exist for introducing ototoxic agents to the cochleae of animal models. Presented is a surgical protocol for delivery of ototoxic agents to the round window niche. The procedure is reliable, creates targeted intra-cochlear lesions, and avoids mechanical damage to the microarchitecture. Examination of cochlear self-repair/regeneration is possible.

Investigators have utilized a wide array of animal models and investigative techniques to study the mammalian auditory system. Much of the basic research ...

Surgical Approach for Middle Cerebral Artery Occlusion and Reperfusion Induced Stroke in Mice

Stroke is a leading cause of death worldwide and continues to be one of the major causes of long-term adult disabilities. About 87% of strokes are ischemic in origin and occur in the territory of the middle cerebral artery (MCA). Currently the only Food and Drug Administration (FDA) approved drug for the treatment of this devastating disease is tissue plasminogen activator (tPA). However, tPA has a small therapeutic window for administration (3 - 6 hr), and is only effective in 4% of the patients who actually receive it. Current research focuses on understanding the pathophysiology of stroke in order to find potential therapeutic targets. Thus, reliable models are crucial, and the MCA occlusion (MCAo) model (also termed the intraluminal filament or suture model) is deemed to be the most clinically relevant surgical model of ischemic stroke, and is fairly non-invasive and easily reproducible. Typically the MCAo model is used with rodents, especially with mice due to all the genetic variations available for this species. Here we describe (and present in the video) how to successfully perform the MCAo model (with reperfusion) in mice to generate reliable and reproducible data.

In order to understand the pathophysiology of stroke, it is important to use reliable models. This paper will describe one of the most frequently used stroke models in mice, termed the middle cerebral artery occlusion (MCAo) model (also termed the intraluminal filament or suture model) with reperfusion.

Stroke is a leading cause of death worldwide and continues to be one of the major causes of long-term adult disabilities. About 87% of strokes are ...

Intravital Microscopy of Tumor-associated Vasculature Using Advanced Dorsal Skinfold Window Chambers on Transgenic Fluorescent Mice

Tumor and tumor vessel development, as well as tumor response to therapeutics, are highly dynamic biological processes. Histology provides static information and is often not sufficient for a correct interpretation. Intravital evaluation, in which a process is followed in time, provides extra and often unexpected information. With the creation of transgenic animals expressing cell-specific markers and live cell tracers, improvements to imaging equipment, and the development of several imaging chambers, intravital microscopy has become an important tool to better understand biological processes. This paper describes an experimental design for the investigation of tumor vessel development and of therapeutic effects in a spatial and temporal manner. Using this setup, the stage of vessel development, tip cell and lumen formation, blood flow, extravasation, an established vascular bed, and vascular destruction can be visualized and followed. Furthermore, therapeutic effects, intratumoral fate, and the localization of chemotherapeutic compounds can also be followed.

This protocol describes the intravital imaging of transgenic mice expressing cell-specific fluorescent markers. Intravital imaging provides a non-invasive method for high-resolution observations in living animals using implantable windows through which the microscopic visualization of processes is possible. This method is especially useful to study longitudinal processes.

Tumor and tumor vessel development, as well as tumor response to therapeutics, are highly dynamic biological processes. Histology provides static ...

Using In Vitro Live-cell Imaging to Explore Chemotherapeutics Delivered by Lipid-based Nanoparticles

Conventional imaging techniques can provide detailed information about cellular processes. However, this information is based on static images in an otherwise dynamic system, and successive phases are easily overlooked or misinterpreted. Live-cell imaging and time-lapse microscopy, in which living cells can be followed for hours or even days in a more or less continuous fashion, are therefore very informative. The protocol described here allows for the investigation of the fate of chemotherapeutic nanoparticles after the delivery of doxorubicin (dox) in living cells. Dox is an intercalating agent that must be released from its nanocarrier to become biologically active. In spite of its clinical registration for more than two decades, its uptake, breakdown, and drug release are still not fully understood. This article explores the hypothesis that lipid-based nanoparticles are taken up by the tumor cells and are slowly degraded. Released dox is then translocated to the nucleus. To prevent fixation artifacts, live-cell imaging and time-lapse microscopy, described in this experimental procedure, can be applied.

Using In Vitro Live-cell Imaging to Explore Chemotherapeutics Delivered by Lipid-based Nanoparticles

Live-cell imaging is a powerful tool to visualize dynamic processes. The examination of fixed cells provides only static pictures, which can lead to misinterpretation and confusion about the process. This work presents a method to study uptake, drug release, and intracellular localization of liposomal nanoparticles in living cells.

Conventional imaging techniques can provide detailed information about cellular processes. However, this information is based on static images in an ...

A Rat Model of Orthotopic Liver Transplantation Using a Novel Magnetic Anastomosis Technique for Suprahepatic Vena Cava Reconstruction

The rat model of orthotopic liver transplantation (OLT) is essential for transplant research. It is a very sophisticated animal model and requires a steep learning curve. The introduction of the cuff technique for anastomosis of the portal vein (PV) and infrahepatic vena cava (IHVC) has significantly simplified the transplant procedure in rats. However, due to the short anterior wall of the recipients' suprahepatic vena cava (SHVC), the cuff technique is very difficult to use for the reconstruction of the SHVC. Most researchers in this field still use the hand-suture technique for SHVC reconstruction, which makes it the bottleneck step in rat orthotopic liver transplantation. The magnetic anastomosis technique (i.e., magnamosis) is a method of connecting two vessels using the attractive force between two magnets. Our recent study has shown that the magnetic anastomosis technique is superior to the hand-suture technique for SHVC reconstruction in rats. In this article, we show a step-by-step protocol for SHVC reconstruction in rats using the novel magnetic anastomosis technique. In this model, the reconstruction of the PV and IHVC was performed by the standard cuff technique, while the reconstruction of the bile duct (BD) was performed by a stent technique. The hepatic re-arterialization was not performed. The magnetic anastomosis technique made SHVC reconstruction much easier and significantly shortened the anphepatic phase. After a reasonable learning curve, even researchers without advanced microsurgical skills can produce reliable and reproducible results using this rat model of OLT.

The reconstruction of the suprahepatic vena cava (SHVC) remains a difficult step in rat orthotopic liver transplantation. In this article, we show a step-by-step protocol for SHVC reconstruction in rats using a novel magnetic anastomosis technique.

The rat model of orthotopic liver transplantation (OLT) is essential for transplant research. It is a very sophisticated animal model and requires a steep ...

Orthotopic Rat Kidney Transplantation: A Novel and Simplified Surgical Approach

Kidney transplantation offers increased survival rates and improved quality of life for patients with end-stage renal disease, as compared to any type of renal replacement therapy. Over the past few decades, the rat kidney transplantation model has been used to study the immunological phenomena of rejection and tolerance. This model has become an indispensable tool to test new immunomodulatory pharmaceuticals and regimens prior to proceeding with expensive preclinical large animal studies.
This protocol provides a detailed overview of how to reliably perform orthotopic kidney transplantation in rats. This protocol includes three distinctive steps that increase the probability of success: perfusion of the donor kidney by flushing through the portal vein and the use of a cuff system to anastomose the renal veins and ureters, thereby decreasing cold and warm ischemia times. Using this technique, we have achieved survival rates beyond 6 months with normal serum creatinine in animals with syngeneic or tolerant kidney transplants. Depending on the aim of the study, this model can be modified by pre- or posttransplant treatments to study the acute, chronic, cellular, or antibody-mediated rejection. It is a reproducible, reliable, and cost-effective animal model to study different aspects of kidney transplantation.

The purpose of this manuscript and protocol is to explain and demonstrate in detail the surgical procedure of orthotopic kidney transplantation in rats. This method is simplified to achieve the correct perfusion of the donor kidney and shorten the reperfusion time by using the venous and ureteral cuff anastomosis technique.

Kidney transplantation offers increased survival rates and improved quality of life for patients with end-stage renal disease, as compared to any type of ...

Whole-Mount Immunofluorescence Staining, Confocal Imaging and 3D Reconstruction of the Sinoatrial and Atrioventricular Node in the Mouse

The electrical signal physiologically generated by pacemaker cells in the sinoatrial node (SAN) is conducted through the conduction system, which includes the atrioventricular node (AVN), to allow excitation and contraction of the whole heart. Any dysfunction of either SAN or AVN results in arrhythmias, indicating their fundamental role in electrophysiology and arrhythmogenesis. Mouse models are widely used in arrhythmia research, but the specific investigation of SAN and AVN remains challenging.
The SAN is located at the junction of the crista terminalis with the superior vena cava and AVN is located at the apex of the triangle of Koch, formed by the orifice of the coronary sinus, the tricuspid annulus, and the tendon of Todaro. However, due to the small size, visualization by conventional histology remains challenging and it does not allow the study of SAN and AVN within their 3D environment.
Here we describe a whole-mount immunofluorescence approach that allows the local visualization of labelled mouse SAN and AVN. Whole-mount immunofluorescence staining is intended for smaller sections of tissue without the need for manual sectioning. To this purpose, the mouse heart is dissected, with unwanted tissue removed, followed by fixation, permeabilization and blocking. Cells of the conduction system within SAN and AVN are then stained with an anti-HCN4 antibody. Confocal laser scanning microscopy and image processing allow differentiation between nodal cells and working cardiomyocytes, and to clearly localize SAN and AVN. Furthermore, additional antibodies can be combined to label other cell types as well, such as nerve fibers.
Compared to conventional immunohistology, whole-mount immunofluorescence staining preserves the anatomical integrity of the cardiac conduction system, thus allowing the investigation of AVN; especially so into their anatomy and interactions with the surrounding working myocardium and non-myocyte cells.

We provide a step-by-step protocol for whole-mount immunofluorescence staining of the sinoatrial node (SAN) and atrioventricular node (AVN) in murine hearts.

The electrical signal physiologically generated by pacemaker cells in the sinoatrial node (SAN) is conducted through the conduction system, which includes ...

Surgical Approach, Challenges, and Resolutions for Uterus Transplantation in Rats

Uterine transplantation (UTx) is a new approach for treating women with absolute uterine factor infertility (AUFI). An estimated 3%-5% of women suffer from AUFI. These women were deprived of the option to have children until the advent of UTx. The clinical application of UTx was driven by experimental studies in animals, and the first successful UTx was achieved in rats. Given their physiological, immunological, genetic, and reproductive characteristics, rats are a suitable model system for such transplants. In particular, their short gestation period is a clear advantage, as the usual endpoint of experimental UTx is successful pregnancy with live birth. The biggest challenge for rat models remains the small anatomy, which requires advanced microsurgical skills and experience. Although UTx has led to pregnancy in the clinic, the procedure is not established and requires continuous experimental optimization. Here, a detailed protocol is presented, including essential troubleshooting for rat UTx, which is expected to make the entire procedure easier to grasp for those without experience in this type of microsurgery.

The present protocol describes all the essential steps for successful uterine transplantation (UTx) in rats. The rat model has proven suitable to promote the clinical implementation of UTx; however, rat UTx is a highly complex procedure requiring careful instructions.

Uterine transplantation (UTx) is a new approach for treating women with absolute uterine factor infertility (AUFI). An estimated 3%-5% of women suffer ...

3D Reconstruction for the Diagnosis and Treatment of Pulmonary Nodules

A 3D Digital Model for the Diagnosis and Treatment of Pulmonary Nodules

The three-dimensional (3D) reconstruction of pulmonary nodules using medical images has introduced new technical approaches for diagnosing and treating pulmonary nodules, and these approaches are progressively being acknowledged and adopted by physicians and patients. Nonetheless, constructing a relatively universal 3D digital model of pulmonary nodules for diagnosis and treatment is challenging due to device differences, shooting times, and nodule types. The objective of this study is to propose a new 3D digital model of pulmonary nodules that serves as a bridge between physicians and patients and is also a cutting-edge tool for pre-diagnosis and prognostic evaluation. Many AI-driven pulmonary nodule detection and recognition methods employ deep learning techniques to capture the radiological features of pulmonary nodules, and these methods can achieve a good area under-the-curve (AUC) performance. However, false positives and false negatives remain a challenge for radiologists and clinicians. The interpretation and expression of features from the perspective of pulmonary nodule classification and examination are still unsatisfactory. In this study, a method of continuous 3D reconstruction of the whole lung in horizontal and coronal positions is proposed by combining existing medical image processing technologies. Compared with other applicable methods, this method allows users to rapidly locate pulmonary nodules and identify their fundamental properties while also observing pulmonary nodules from multiple perspectives, thereby providing a more effective clinical tool for diagnosing and treating pulmonary nodules.

Author Spotlight: A 3D Digital Model for the Diagnosis and Treatment of Pulmonary Nodules  

The objective of this study is to develop a novel 3D digital model of pulmonary nodules that serves as a communication bridge between physicians and patients and is also a cutting-edge tool for pre-diagnosis and prognostic evaluation.

The three-dimensional (3D) reconstruction of pulmonary nodules using medical images has introduced new technical approaches for diagnosing and treating ...