Name: creation of a high-fidelity, low-cost, intraosseous line placement task trainer via 3d printing
Uploaded: 2022-08-17T12:40:00
Description: Watch this Scientific Journal Video about Creation of a High-Fidelity, Low-Cost, Intraosseous Line Placement Task Trainer via 3D Printing at JoVE.com

The funding for this project was provided solely from institutional or departmental resources.

NOTE: The University of Nebraska Medical Center Institutional Review Board determined that our study did not constitute human subject research. The local IRB obtained ethical approval and waiver of informed consent. Complete anonymization of imaging data was done before analysis per the hospital de-identification protocol.
1. Data
<ol>
	<li>Obtain a CT scan capturing the anatomy of interest for the planned task trainer. Be careful to take into consideration the working volume limitations of ...

<ol>
	<li>Farrow, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reducing+the+risks+of+military+aircrew+training+through+simulation+technology.">Reducing the risks of military aircrew training through simulation technology.</a> Performance and Instruction. 21 (2), 13-18 (1982).</li><li>Lateef, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simulation-based+learning:+Just+like+the+real+thing.">Simulation-based learning: Just like the real thing.</a> Journal of Emergencies, Trauma, Shock. 3 (4), 348-352 (2010).</li><li>Gaba, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Crisis+resource+management+and+teamwork+training+in+anaesthesia.">Crisis resource management and teamwork training in anaesthesia.</a> British Journal of Anaesthesia. 105 (1), 3-6 (2010).</li><li>Al-Elq, A. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simulation-based+medical+teaching+and+learning.">Simulation-based medical teaching and learning.</a> Journal of Family &amp; Community Medicine. 17 (1), 35-40 (2010).</li><li>Hays, R. T., Singer, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Simulation fidelity in training system design: Bridging the gap between reality and training. , (2012).</li><li>Green, M., Tariq, R., Green, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improving+patient+safety+through+simulation+training+in+anesthesiology:+Where+are+we.">Improving patient safety through simulation training in anesthesiology: Where are we.</a> Anesthesiology Research and Practice. , 4237523 (2016).</li><li>Olympio, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simulation+saves+lives.">Simulation saves lives.</a> American Society of Anesthesiologists Newsletter. , 15-19 (2001).</li><li>Murphy, 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=Simulation-based+multidisciplinary+team+training+decreases+time+to+critical+operations+for+trauma+patients.">Simulation-based multidisciplinary team training decreases time to critical operations for trauma patients.</a> Injury. 49 (5), 953-958 (2018).</li><li>Jensen, A. 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=Simulation-based+training+is+associated+with+lower+risk-adjusted+mortality+in+ACS+pediatric+TQIP+centers.">Simulation-based training is associated with lower risk-adjusted mortality in ACS pediatric TQIP centers.</a> Journal of Trauma and Acute Care Surgery. 87 (4), 841-848 (2019).</li><li>Gupta, A., Peckler, B., Schoken, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Introduction+of+hi-fidelity+simulation+techniques+as+an+ideal+teaching+tool+for+upcoming+emergency+medicine+and+trauma+residency+programs+in+India.">Introduction of hi-fidelity simulation techniques as an ideal teaching tool for upcoming emergency medicine and trauma residency programs in India.</a> Journal of Emergencies, Trauma, and Shock. 1 (1), 15-18 (2008).</li><li>Risser, D. 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=The+potential+for+improved+teamwork+to+reduce+medical+errors+in+the+emergency+department.">The potential for improved teamwork to reduce medical errors in the emergency department.</a> Annals of Emergency Medicine. 34 (3), 373-383 (1999).</li><li>Shapiro, M. J., 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+based+teamwork+training+for+emergency+department+staff:+Does+it+improve+clinical+team+performance+when+added+to+an+existing+didactic+teamwork+curriculum.">Simulation based teamwork training for emergency department staff: Does it improve clinical team performance when added to an existing didactic teamwork curriculum.</a> Quality and Safety in Health Care. 13 (6), 417-421 (2004).</li><li>Schebesta, K., 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=Degrees+of+reality:+Airway+anatomy+of+high-fidelity+human+patient+simulators+and+airway+trainers.">Degrees of reality: Airway anatomy of high-fidelity human patient simulators and airway trainers.</a> Anesthesiology. 116 (6), 1204-1209 (2012).</li><li>Crofts, J. 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=Training+for+shoulder+dystocia:+A+trial+of+simulation+using+low-fidelity+and+high-fidelity+mannequins.">Training for shoulder dystocia: A trial of simulation using low-fidelity and high-fidelity mannequins.</a> Obstetrics and Gynecology. 108 (6), 1477-1485 (2006).</li><li>Cox, R. 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=A+(sort+of)+new+image+data+format+standard:+NiFTI-1.">A (sort of) new image data format standard: NiFTI-1.</a> 10th Annual Meeting of the Organization for Human Brain Mapping. , 22 (2004).</li><li>Bude, R., Adler, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+easily+made,+low-cost,+tissue-like+ultrasound+phantom+material.">An easily made, low-cost, tissue-like ultrasound phantom material.</a> Journal of Clinical Ultrasound. 23 (4), 271-273 (1995).</li><li>Fisher, J., 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=Clinical+skills+temporal+degradation+assessment+in+undergraduate+medical+education.">Clinical skills temporal degradation assessment in undergraduate medical education.</a> Journal of Advances in Medical Education &amp; Professionalism. 6 (1), 1-5 (2018).</li><li>Buzink, S. N., Goossens, R. H., Schoon, E. J., de Ridder, H., Jakimowicz, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Do+basic+psychomotor+skills+transfer+between+different+image-based+procedures.">Do basic psychomotor skills transfer between different image-based procedures.</a> World Journal of Surgery. 34 (5), 933-940 (2010).</li></ol>

In this protocol we detail a 3D task trainer's development process to train the infrequently performed and life-saving procedure of IO line placement. This self-guided protocol uses 3D printing to produce the bulk of the model structures, while the remainder of the components used to assemble the task trainer are ubiquitous, easily obtainable, and non-toxic materials that may be reclaimed and reused. The 3D task trainer is low-cost and requires minimum expertise to create and assemble. We have successfully used our 3D IO...

Patient care competency of procedural skills is a critical component for developing trainees in civilian and military healthcare1,2 environments. Procedural skills development is particularly important for procedure-intensive specialties such as anesthesiology3 and front-line medical personnel. Task trainers may be used to rehearse numerous procedures with skill levels ranging from those of a first-year medical student or medical technician to a senior resident or fellow. While many medical procedures require significant training to complete, the task presented here-placement of an interosseous (IO) line-is straightforward and requires less technical skill. Successful placement of an IO line can be accomplished after a relatively short period of training. The use of simulation during medical training, which includes the use of task trainers, is recognized as a tool to gain technical procedural skills through the repetition and the rehearsal of a clinical procedure in a safe, low-stress environment, before ultimately performing the procedure on patients2,4,5.
Understandably so, simulation training in medical education environments has become widely accepted and appears to be a mainstay, despite the paucity of data regarding any impact on patient outcomes6,7. Additionally, recent publications demonstrate that simulation improves team performance and patient outcomes as the result of improved team dynamics and decision-making. Still, there is little data to suggest that simulation improves the time or success rate to perform critical, life-saving procedures8,9 suggesting that simulation is complex and multifaceted in the education of health care providers. In patients where standard intravenous access is not possible or indicated, IO line placement may be used to achieve vascular access quickly, requiring minimal skill. Timely and successful performance of this procedure is critical, particularly in the perioperative environment or a trauma scenario10,11,12. Because IO line placement is an infrequently performed procedure in the perioperative area and can be a life-saving procedure, training in a non-clinical environment is critical. An anatomically accurate task trainer specific to IO line placement is an ideal tool for offering predictable training frequency and skills development for this procedure.
Although widely used, currently available commercial task trainers suffer from several significant drawbacks. First, task trainers that allow for multiple attempts of a procedure are costly, not only for the initial purchase of the task trainer but also for replenishing the replaceable parts such as silicone skin patches. The result is often infrequently replaced parts, leaving prominent landmarks that provide the trainee a suboptimal training experience; patients will not come pre-marked where one should do the procedure. Another drawback is that the high cost of traditional task trainers can result in limited access by users when the devices are &#39;locked up&#39; in protected storage locations to prevent loss or damage to the devices. The result is requiring more rigorously and less available scheduled practice time, limiting their use can certainly make unscheduled training difficult. Finally, most trainers are considered low-fidelity5,13,14 and use only representative anatomy, potentially leading to inappropriate psychomotor skills development or training scars. Low-fidelity trainers also make the thorough assessment of skill acquisition, mastery, and degradation very difficult as training on a low-fidelity device may not adequately mimic the actual real-world procedure.
Representative anatomy also impedes the proper evaluation of the acquisition and mastery of psychomotor skills. Moreover, assessing the transfer of psychomotor skills between simulated medical environments to patient care becomes nearly impossible if some of the psychomotor skills are not reflected in the clinical task. This results in the prevention of consensus on the ability of medical simulation and training to affect patient outcomes. To overcome the challenges of cost, anatomical accuracy, and access, we have developed a low-cost, high-fidelity IO line task trainer. The task trainer is designed from an actual patient&#39;s CT scan, resulting in accurate anatomy (Figure 1). The materials used are ubiquitous and easy to obtain, with components that are relatively easy to reclaim. Compared to many other commercially available trainers, the modest cost of the task trainer design described here dramatically reduces the desire to sequester the trainers in a less accessible, protected location and makes multiple repetitions without leading landmarks possible.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>3D printer filament, poly-lactic acid (PLA), 1.75 mm</td>
			<td>N/A / Hatchbox</td>
			<td></td>
			<td>Base for 3D printing molds, bone structures, and bone / mold hardware</td>
		</tr>
		<tr>
			<td>3D printer, Original Prusa i3 MK3</td>
			<td>Prusa</td>
			<td></td>
			<td>To print molds, bone structures, and bone / mold hardware</td>
		</tr>
		<tr>
			<td>bleach, household (6% sodium hypochlorite)</td>
			<td>Clorox</td>
			<td></td>
			<td>Animicrobial additive for tissue media</td>
		</tr>
		<tr>
			<td>bolts, 1/4&#8221;, flat / countersunk or round head, various lengths</td>
			<td>N/A</td>
			<td></td>
			<td>Hardware used to hold mold casing halves together during casting</td>
		</tr>
		<tr>
			<td>Bucket, 5 gallon, plastic</td>
			<td>N/A</td>
			<td></td>
			<td>To hold tissue media during media preparation</td>
		</tr>
		<tr>
			<td>chlorhexidine, 4% solution w/v</td>
			<td></td>
			<td></td>
			<td>Animicrobial additive for tissue media</td>
		</tr>
		<tr>
			<td>drill, household 3/8&#8217; chuck</td>
			<td>N/A</td>
			<td></td>
			<td>To stir tissue media during media preparation</td>
		</tr>
		<tr>
			<td>food coloring, red (optional)</td>
			<td>N/A</td>
			<td></td>
			<td>Coloring additive for simulated bone marrow</td>
		</tr>
		<tr>
			<td>gelatin, unflavored</td>
			<td>Knox</td>
			<td></td>
			<td>Base for tissue media</td>
		</tr>
		<tr>
			<td>hex nuts, 1/4&#8221;</td>
			<td>N/A</td>
			<td></td>
			<td>Hardware used to hold mold casing halves together during casting</td>
		</tr>
		<tr>
			<td>Non-stick cooking spray</td>
			<td>N/A</td>
			<td></td>
			<td>Mold releasing agent</td>
		</tr>
		<tr>
			<td>plastic bags, ziplock</td>
			<td>Ziplock</td>
			<td></td>
			<td>To store tissue media</td>
		</tr>
		<tr>
			<td>psyllium husk fiber, finely ground, orange flavored, sugar free (optional)</td>
			<td>Procter &#38; Gamble</td>
			<td>Metamucil</td>
			<td>Opacity / Echogenicity additive for tissue media</td>
		</tr>
		<tr>
			<td>screwdriver, flat / Phillips (matching bolt hardware)</td>
			<td>N/A</td>
			<td></td>
			<td>To tighten mold casing hardware</td>
		</tr>
		<tr>
			<td>silicone gasket cord stock, 3mm, round, various lengths</td>
			<td>N/A</td>
			<td></td>
			<td>Gasket media for mold casings</td>
		</tr>
		<tr>
			<td>spray adhesive, Super 77 (optional)</td>
			<td>3M</td>
			<td></td>
			<td>Agent used to improve bed adhesion during 3D printing</td>
		</tr>
		<tr>
			<td>stirring paddle / rod</td>
			<td></td>
			<td></td>
			<td>To stir tissue media during media preparation</td>
		</tr>
		<tr>
			<td>turkey baster, household, ## mL</td>
			<td>N/A</td>
			<td></td>
			<td>To inject simulated bone marrow into bone marrow cavity</td>
		</tr>
		<tr>
			<td>ultrasound gel</td>
			<td></td>
			<td></td>
			<td>Base for simulated bone marrow</td>
		</tr>
		<tr>
			<td>water, tap</td>
			<td></td>
			<td></td>
			<td>Used in both tissue media and simulated bone marrow</td>
		</tr>
	</tbody>
</table>

creation of a high-fidelity, low-cost, intraosseous line placement task trainer via 3d printing

The description of procedural task trainers includes their use as a training tool to hone technical skills through repetition and rehearsal of procedures in a safe environment before ultimately performing the procedure on a patient. Many procedural task trainers available to date suffer from several drawbacks, including unrealistic anatomy and the tendency to develop user-created &#39;landmarks&#39; after the trainer tissue undergoes repeated manipulations, potentially leading to inappropriate psychomotor skill development. To ameliorate these drawbacks, a process was created to produce a high-fidelity procedural task trainer, created from anatomy obtained from computed tomography (CT) scans, that utilize ubiquitous three-dimensional (3D) printing technology and off-the-shelf commodity supplies.
This method includes creating a 3D printed tissue mold capturing the tissue structure surrounding the skeletal element of interest to encase the bony skeletal structure suspended within the tissue, which is also 3D printed. A tissue medium mixture, which approximates tissue in both high-fidelity geometry and tissue density, is then poured into a mold and allowed to set. After a task trainer has been used to practice a procedure, such as intraosseous line placement, the tissue media, molds, and bones are reclaimable and may be reused to create a fresh task trainer, free of puncture sites and manipulation defects, for use in subsequent training sessions.

Following the protocol, the modeling of the task trainer utilized a CT scan of a de-identified patient. Segmentation of the CT images utilized 3D Slicer software and Auto Meshmixer for 3D modeling. For 3D printing, both 3D Simplify and the Prusa i3 MK3 were used (Figure 1). Subsequently, we completed the assembly of the 3D-printed parts, prepared the tissue media mixture, and poured the media mixture into the assembled task trainer mold. Following a training period with the task trainer, the...

Watch this Scientific Journal Video about Creation of a High-Fidelity, Low-Cost, Intraosseous Line Placement Task Trainer via 3D Printing at JoVE.com

Creation of a High-Fidelity, Low-Cost, Intraosseous Line Placement Task Trainer via 3D Printing

We describe a procedure to process computed tomography (CT) scans into high-fidelity, reclaimable, and low-cost procedural task trainers. The CT scan identification processes, export, segmentation, modeling, and 3D printing are all described, along with the issues and lessons learned in the process.

The description of procedural task trainers includes their use as a training tool to hone technical skills through repetition and rehearsal of procedures ...

Here we created a high fidelity 3D printed task trainer derived from CT scans of normal human anatomy The task trainers created using this protocol, help in performing all critical aspects of a chosen task or procedure, various anatomically correct models can be created with this protocol. It's important to find a CT scan containing the desired anatomic section for the model we are creating, as part of the process used to transform the anatomic scans into 3D models it's important to close the natural openings in the bone to create a final product that permits the addition of features to hold the bone in the correct orientation and to have a space for the simulated marrow. To begin, confirm the correct triangle normal orientation of the imported SDL files, if the triangle orientation is incorrect flip the triangle normal by clicking select, modify and select all.Next, click select, then edit and flip models to eliminate the unwanted structures and refine the models, to create the task trainer, click on select then select the triangles on the undesired structures and click edit and discard. Select the edit and plane card tool to crop the model to fit within the confines of the 3D printer build volume. Reduce the computational overhead by clicking on select and double clicking anywhere on the mesh to select the entire mesh, then select edit and reduce.For reduced target, reduce the triangle budget under approximately 10, 000 faces. Once the triangles of the mesh around the defect are selected click on select, then select edit and erase and fill, to improve the surface holes and irregularities. Export and save the finished models using the SDL file type, open the Autodesk Fusion 360 software select insert and then insert mesh command to import the SDL files of bone and tissue models in the workspace as a mesh.For converting the imported meshes into B-rep Solids disabled the Fusion 360 timeline, reduce the number of triangles in the target mesh to less than 10, 000, select the imported mesh body, then right click to open the menu and select the mesh to B wrap option. After the meshes have been converted to B wrap solids resume the fusion 360 timeline and modify the solid to create the task trainers mold by splitting the rectangular solid along the long axis of the tissue B wrap. Select two to three locations for support pins and place the pre designed assembly group components, to fix the task trainer's bones, import and position a bone plug onto the open marrow space of the bone B rep to prevent tissue media from entering the marrow space and draining the simulated bone marrow.Generate an opening of four to six centimeters through the molds in the space represented by the tissue B rep solid for pouring the liquid tissue media into the mold, perform the mirror of the objects to make the task trainer for the isolateral side. Once the components of the pre designed assembly groups are positioned to fix the bones in space click bullion combined to either add or cut the various assembly groups in the models. Select the desired body within the workspace and right click, then select Save as STL to export the final components for printing, position the STL file on the bed of the 3D printer and orient the bone vertically.For printing user raft full support material, a 0.4 millimeter nozzle layer height at 0.2 millimeters with four top and bottom layers, three perimeter shells infill at 20%and hot end temperature of 210 degrees Celsius. Orient the mold components with the tissue surface facing up and print without a raft, set the layer height at 0.3 millimeters infill at 15%and use full support material. Arrange the support pins and other components to minimize support material, print all pin support parts with a raft and set the layer height at 0.2 millimeters and infill at 20%Print the threaded components without support material at a reduced speed, once each component's parameters are selected, prepare and export the G code file generated by the software to SD card.Open the 3D printer software select the saved G code file from the SD card and 1.75 millimeter polylactic acid 3D printer media filament for printing. Measure the gelatin cilium husk fiber chlorhexidine solution and sodium hypochlorite, to prepare the tissue media and set aside heat one liter of water to 85 degrees Celsius. Add the heated water in a mixing container several times larger than the volume of the ingredients while vigorously shaking the tissue medium solution, add the measured ingredients one by one.Heat the mixture in a water bath at 71 degrees Celsius for a minimum of four hours for dissipating the bubbles, prepare the simulated bone marrow solution by measuring 100 grams of cold water, 100 grams of ultrasound gel and five milliliters of red food color, then thoroughly mix the ingredients. Spray the inner surfaces of the mold with a non silicone based releasing agent, secure the bone using support pins to maintain the correct position within the tissue space. Then secure the bone to the bottom of the mold and assemble the mold, verify the position of the bone plug to prevent the tissue medium from entering the marrow space during pouring.Position the mold with the opening facing up and pour 46 degrees Celsius warm tissue medium into the mold cavity. Secure any leakage of the tissue medium from the mold by spraying it with an inverted air duster canister, transfer the filled mold to four degrees Celsius for a minimum of six hours or until the tissue medium has been set. Disassemble the mold and removed the task trainer and support pins remove the bone plug, fill the simulated bone marrow solution in the marrow space and replace the bone plug.Store the task trainer in a plastic bag at four degrees Celsius or minus 20 degrees Celsius until use. Once the task trainer reaches room temperature instruct the trainees to place the IO needle and aspirate the simulated bone marrow solution. Next, disassemble the task trainers to recover the tissue medium and the bones, disassemble the task trainer and place the gelatin into a container to be remelted for additional use, the model can be reformed and the gel once melted can be reused to create another model.This protocol was used for modeling and printing the three-dimensional tissue mold and the tissue structures surrounding the skeletal element, using the CT scan of a patient's left knee joint the designed tibia resulted in a very close replica after printing. An opening made to expose the tissue cavity facilitated the pouring of the tissue medium, the mold was designed with two supporting pin assembly groups to support and suspend the bone structures within the tissue cavity. The task trainer was customized for the humorous and tibia using an opaque and transparent tissue medium which allows varying levels of visualization of skeletal structures or landmarks.The anatomical similarity was achieved between the CT scan data used to create the task trainer and the fully assembled humorous task trainers with respect to bone thickness, skin depth and tendon groove the time and cost required to print the top of the mold were highest followed by the bottom of the mold, the bones and the hardware. When 3D printing the molds, we have found it's important to use a strong adhesive to prevent warping at the base. Another critical aspect is the use of a releasing spray applied to the inner service of the mold prior to adding the gel.This prevents the gel from sticking to the 3D printed material. These trainers permit skill transfer from the training environment to the clinical environment because of their anatomic similarity with patients, repetition helps a learner to perform the critical steps of a procedure.

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Research

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Medicine

Creation of Abdominal Adhesions in Mice

Abdominal adhesions consist of fibrotic tissue that forms in the peritoneal space in response to an inflammatory insult, typically surgery or intraabdominal infection. The precise mechanisms underlying adhesion formation are poorly understood. Many compounds and physical barriers have been tested for their ability to prevent adhesions after surgery with varying levels of success. The mouse and rat are important models for the study of abdominal adhesions. Several different techniques for the creation of adhesions in the mouse and rat exist in the literature. Here we describe a protocol utilizing abrasion of the cecum with sandpaper and sutures placed in the right abdominal sidewall. The mouse is anesthetized and the abdomen is prepped. A midline laparotomy is created and the cecum is identified. Sandpaper is used to gently abrade the surface of the cecum. Next, several figure-of-eight sutures are placed into the peritoneum of the right abdominal sidewall. The abdominal cavity is irrigated, a small amount of starch is applied, and the incision is closed. We have found that this technique produces the most consistent adhesions with the lowest mortality rate.

Abdominal adhesions that form after surgery are a major cause of pain, infertility, and hospitalization and reoperation for small bowel obstruction. Our surgical procedure for creating abdominal adhesions in mice is a reliable tool to study the mechanisms underlying the formation of adhesions.

Abdominal adhesions consist of fibrotic tissue that forms in the peritoneal space in response to an inflammatory insult, typically surgery or ...

Expression of Exogenous Cytokine in Patient-derived Xenografts via Injection with a Cytokine-transduced Stromal Cell Line

Patient-derived xenograft (PDX) mice are produced by transplanting human cells into immune deficient mice. These models are an important tool for studying the mechanisms of normal and malignant hematopoiesis and are the gold standard for identifying effective chemotherapies for many malignancies. PDX models are possible because many of the mouse cytokines also act on human cells. However, this is not the case for all cytokines, including many that are critical for studying normal and malignant hematopoiesis in human cells. Techniques that engineer mice to produce human cytokines (transgenic and knock-in models) require significant expense before the usefulness of the model has been demonstrated. Other techniques are labor intensive (injection of recombinant cytokine or lentivirus) and in some cases require high levels of technical expertise (hydrodynamic injection of DNA). This report describes a simple method for generating PDX mice that have exogenous human cytokine (TSLP, thymic stromal lymphopoietin) via weekly intraperitoneal injection of stroma that have been transduced to overexpress this cytokine. Use of this method provides an in vivo source of continuous cytokine production that achieves physiological levels of circulating human cytokine in the mouse. Plasma levels of human cytokine can be varied based on the number of stromal cells injected, and cytokine production can be initiated at any point in the experiment. This method also includes cytokine-negative control mice that are similarly produced, but through intraperitoneal injection of stroma transduced with a control vector. We have previously demonstrated that leukemia cells harvested from TSLP-expressing PDX, as compared to control PDX, exhibit a gene expression pattern more like the original patient sample. Together the cytokine-producing and cytokine-negative PDX mice produced by this method provide a model system that we have used successfully to study the role of TSLP in normal and malignant hematopoiesis.

Described here is a method for producing exogenous cytokine in patient-derived xenograft (PDX) mice via weekly intraperitoneal injection of a cytokine-transduced stromal cell line. This method broadens the utility of PDX and provides the option for transient or sustained exogenous cytokine delivery in a multitude of PDX models.

Patient-derived xenograft (PDX) mice are produced by transplanting human cells into immune deficient mice. These models are an important tool for studying ...

Creation of a Rodent Model of Abdominal Aortic Aneurysm by Blocking Adventitial Vasa Vasorum Perfusion

The adventitial vasa vasorum (VV) provides oxygen and nourishment to the aortic wall. Hypoxia in the aortic wall can cause enlarged abdominal aortic aneurysms (AAAs). This article introduces and describes a standard protocol used to induce AAAs through adventitial VV hypoperfusion created with a combination of polyurethane catheter insertion into the aortic lumen and suture ligation of the infrarenal abdominal aorta.
The protocol involves the use of male rats weighing 300-400 g, which are provided food and water ad libitum. After laparotomy with a ventral midline abdominal incision, exfoliation of the aorta is performed, which blocks blood flow from the perivascular tissue. Aortotomy involving a small incision adjacent to the renal artery branches is performed, and a polyurethane catheter is inserted using an 18-gauge indwelling needle. After repairing the incision, tight ligation of the aorta over the catheter blocks VV blood flow from the proximal direction through the aortic wall without disturbing the aortic blood flow. This technique can induce an AAA with progressive aortic dilatation.
The greatest benefit of this model is that VV hypoperfusion causes tissue hypoxia and the development of an infrarenal AAA, which has morphological and pathological characteristics similar to those of a human AAA.

Polyurethane catheter insertion into the aortic lumen and suture ligation of the aorta induce chronic hypoxia due to hypoperfusion of the adventitial vasa vasorum. This article describes a novel animal model of abdominal aortic aneurysm (AAA) with characteristics similar to those of AAA in humans.

The adventitial vasa vasorum (VV) provides oxygen and nourishment to the aortic wall. Hypoxia in the aortic wall can cause enlarged abdominal aortic ...

Three-Dimensional Printing of a Complex Aortic Anomaly

Complex congenital aortic anomalies include diverse types of malformations that may be clinically asymptomatic or present with respiratory or esophageal symptoms. These anomalies may be associated with other congenital heart diseases. It is hard to identify the accurate anatomic vessel location from two-dimensional imaging data, such as computed tomography. As an additive manufacturing method, three-dimensional (3-D) printing can covert the acquired imaging data into 3-D physical models. This protocol describes the procedure for modeling the volumetric DICOM imaging into 3-D data and printing it as an anatomically realistic 3-D model. Using this model, surgeons can identify the vessel location of complex aortic anomalies, which is helpful for pre-operative planning and intra-operative guidance.

Here, we present a protocol to use three dimensional printed models for pre-operative planning and intra-operative reorganization of complicated vascular locations when handling a congenital aortic anomaly.

Complex congenital aortic anomalies include diverse types of malformations that may be clinically asymptomatic or present with respiratory or esophageal ...

Creation of Colonic Anastomosis in Mice

Intestinal anastomoses are commonly performed in both elective and emergent operations. Even so, anastomotic leaks are a highly feared complications of colonic surgeries and can occur in up to 26% of surgical anastomoses, with mortality being up to 39% for patients with such a leak. Currently, there remains a paucity of data detailing the cellular mechanisms of anastomotic healing. Devising preventative strategies and treatment modalities for anastomotic leak could be greatly potentiated by a better understanding of appropriate anastomotic healing.
A murine model is ideal as previous studies have shown that the murine anastomosis is the most clinically similar to the human case as compared with other animal models. We offer an easily reproducible murine model of colonic anastomosis in mice that will allow for further illustration of anastomotic healing.

Anastomotic leak or breakdown after surgery is a major cause of postoperative morbidity and mortality. Our surgery for creating a colonic anastomosis is a reliable and reproducible method for studying the healing mechanisms of anastomoses.

Intestinal anastomoses are commonly performed in both elective and emergent operations. Even so, anastomotic leaks are a highly feared complications of ...

Manufacture of a Multi-Purpose Low-Cost Animal Bench-Model for Teaching Tracheostomy

Tracheostomy is one of the most frequent procedures, performed through various techniques in the intensive care unit and emergency situations. Despite this, there is a lack of training on this procedure that affects its outcome, which is also dependent on operator's dexterity. Here, we take the specific training and simulation into consideration. This article aims to describe every step of the manufacture of a new multi-purpose low-cost animal bench-model, with the support of video and images, and to obtain an opinion about the quality of this model by administering a questionnaire to professionals with experience in the procedures. 
Ten experts in the technique were enrolled. The model scored an average of 3.45/5 for its anatomical realism; 4.75/5 for its usefulness as a training tool for simulation courses and assessments. The time necessary to build the model was 15 minutes, and the cost amounted to 10&#8364;. The animal bench-model was considered a very useful simulator for tracheostomy training and assessments. Therefore, it could be used as a tool for medical courses and residencies.

This article illustrates every step of the manufacture of a new multi-purpose low-cost animal bench-model for subglottic airway access management. All the procedures are shown in the video. The model's realism and its suitability for training the given clinical maneuvers were assessed by independent senior otolaryngologists and anesthesiologists.

Tracheostomy is one of the most frequent procedures, performed through various techniques in the intensive care unit and emergency situations. Despite ...

Multicolor 3D Printing of Complex Intracranial Tumors in Neurosurgery

Three-dimensional (3D) printing technologies offer the possibility of visualizing patient-specific pathologies in a physical model of correct dimensions. The model can be used for planning and simulating critical steps of a surgical approach. Therefore, it is important that anatomical structures such as blood vessels inside a tumor can be printed to be colored not only on their surface, but throughout their whole volume. During simulation this allows for the removal of certain parts (e.g., with a high-speed drill) and revealing internally located structures of a different color. Thus, diagnostic information from various imaging modalities (e.g., CT, MRI) can be combined in a single compact and tangible object.
However, preparation and printing of such a fully colored anatomical model remains a difficult task. Therefore, a step-by-step guide is provided, demonstrating the fusion of different cross-sectional imaging data sets, segmentation of anatomical structures, and creation of a virtual model. In a second step the virtual model is printed with volumetrically colored anatomical structures using a plaster-based color 3D binder jetting technique. This method allows highly accurate reproduction of patient-specific anatomy as shown in a series of 3D-printed petrous apex chondrosarcomas. Furthermore, the models created can be cut and drilled, revealing internal structures that allow for simulation of surgical procedures.

The protocol describes the fabrication of fully colored three-dimensional prints of patient-specific, anatomical skull models to be used for surgical simulation. The crucial steps of combining different imaging modalities, image segmentation, three-dimensional model extraction, and production of the prints are explained.

Three-dimensional (3D) printing technologies offer the possibility of visualizing patient-specific pathologies in a physical model of correct dimensions. ...

Combining Augmented Reality and 3D Printing to Display Patient Models on a Smartphone

Augmented reality (AR) has great potential in education, training, and surgical guidance in the medical field. Its combination with three-dimensional (3D) printing (3DP) opens new possibilities in clinical applications. Although these technologies have grown exponentially in recent years, their adoption by physicians is still limited, since they require extensive knowledge of engineering and software development. Therefore, the purpose of this protocol is to describe a step-by-step methodology enabling inexperienced users to create a smartphone app, which combines AR and 3DP for the visualization of anatomical 3D models of patients with a 3D-printed reference marker. The protocol describes how to create 3D virtual models of a patient&rsquo;s anatomy derived from 3D medical images. It then explains how to perform positioning of the 3D models with respect to marker references. Also provided are instructions for how to 3D print the required tools and models. Finally, steps to deploy the app are provided. The protocol is based on free and multi-platform software and can be applied to any medical imaging modality or patient. An alternative approach is described to provide automatic registration between a 3D-printed model created from a patient&rsquo;s anatomy and the projected holograms. As an example, a clinical case of a patient suffering from distal leg sarcoma is provided to illustrate the methodology. It is expected that this protocol will accelerate the adoption of AR and 3DP technologies by medical professionals.

Presented here is a method to design an augmented reality smartphone application for the visualization of anatomical three-dimensional models of patients using a 3D-printed reference marker.

Augmented reality (AR) has great potential in education, training, and surgical guidance in the medical field. Its combination with three-dimensional (3D) ...

3D Planning and Printing of Patient Specific Implants for Reconstruction of Bony Defects

We are in the midst of the 3D era in most aspects of life, and especially in medicine. The surgical discipline is one of the major players in the medical field using the constantly developing 3D planning and printing capabilities. Computer-assisted design (CAD) and computer assisted manufacturing (CAM) are used to describe the 3D planning and manufacturing of the product. The planning and manufacturing of 3D surgical guides and reconstruction implants is performed almost exclusively by engineers. As technology advances and software interfaces become more user-friendly, it raises a question regarding the possibility of transferring the planning and manufacturing to the clinician. The reasons for such a shift are clear: the surgeon has the idea of what he wants to design, and he also knows what is feasible and could be used in the operating room. It allows him to be prepared for any scenario/unexpected results during the operation and allows the surgeon to be creative and express his new ideas using the CAD software. The purpose of this method is to provide clinicians with the ability to create their own surgical guides and reconstruction implants. In this manuscript, a detailed protocol will provide a simple method for segmentation using segmentation software and implant planning using a 3D design software. Following the segmentation and stl file production using segmentation software, the clinician could create a simple patient specific reconstruction plate or a more complex plate with a cradle for bone graft positioning. Surgical guides can be created for accurate resection, hole preparation for proper reconstruction plate positioning or for bone graft harvesting and re-contouring. A case of lower jaw reconstruction following plate fracture and nonunion healing of a trauma sustained injury is detailed.

This protocol describes the use of 3D planning and printing for reconstruction of bony defects. We use segmentation tools to create 3D models followed by 3D design software to create patient specific implants for reconstruction purposes concomitant to ablative surgery or as a second stage.

We are in the midst of the 3D era in most aspects of life, and especially in medicine. The surgical discipline is one of the major players in the medical ...

Treatment of Facial Deformities using 3D Planning and Printing of Patient-Specific Implants

Technological advancements in surgical planning and patient-specific implants are constantly evolving. One can either adopt the technology to achieve better results, even in the less experienced hand, or continue without it. As technology develops and becomes more user-friendly, we believe it is time to allow the surgeon the option to plan his/her operations and create his/her own patient-specific surgical guides and fixation plates allowing him full control over the process. We present here a protocol for 3D planning of the operation followed by 3D planning and printing of surgical guides and patient-specific fixation implants. During this process we use two commercial computer-assisted design (CAD) software. We also use a fused deposition&#160;modeling printer for the surgical guides and a selective laser sintering printer for the titanium patient-specific fixation implants. The process includes computed tomography (CT) imaging acquisition, 3D segmentation of the skull and facial bones from the CT, 3D planning of the operations, 3D planning of patient-specific fixation implant according to the final position of the bones, 3D planning of surgical guides for performing an accurate osteotomy and preparing the bone for the fixation plates, and 3D printing of the surgical guides and the patient-specific fixation plates. The advantages of the method include full control over the surgery, planned osteotomies and fixation plates, significant reduction in price, reduction in operation duration, superior performance and highly accurate results. Limitations include the need to master the CAD programs.

As technology develops and becomes more user-friendly, planning of operations and patient-specific surgical guides and fixation plates should be performed by the surgeon. We present a protocol for 3D planning of orthognathic skeletal movements and 3D planning and printing of patient-specific fixation plates and surgical guides.

Technological advancements in surgical planning and patient-specific implants are constantly evolving. One can either adopt the technology to achieve ...