Dynamic Perfused Cadaver: Diverse Solution to Surgical Simulation Needs

Human cadavers have re-emerged in surgical simulations for military, civilian and medical school training. Anthony Bitar, Ezekiel Kapusciak and Dr. Joss Fernandez describe the use of perfused cadavers for a more ‘realistic training experience’.

Training, of any magnitude, should be geared at preparing the trainee in a manner that produces the best results. A mainstay of effective training in the healthcare industry is simulating real life scenarios. “Simulation offers an immersive, realistic way of learning technical skills.” (Agha and Fowler, 2015)[1] Some universities now own full functioning simulation hospitals. The idea behind this is simple; the closer to real life a simulation can be made the better prepared a trainee will be when it counts. The diversity of simulation training is vast. New technologies are coming out with great frequency. The result is many different specialized simulators but without one that meets all the wide-ranging needs of today’s trainees. With all these different types of simulators it is estimated the average simulation center will spend between $200,000 to $1.2 million in startup cost with $15,000 annual expenditures which excludes personnel costs. Despite these great monetary outlays many of these simulation centers are under-utilized for the simple fact that they lack realism.

Exploratory laparotomy. Modern techniques prevent bowel bleeding during perfusion of dynamic cadaver. All Images: Maximum Fidelity Surgical Simulations.

In response, companies have leveraged there-emergence of human cadavers in surgical simulations. The Dynamic cadavermakes use of new techniques and developments in cadaver handling, perfusion andventilation to provide a cadaver with a reconstituted circulation andrespirations. Dynamic cadavers have been utilized by military personnel,paramedics, physicians and researchers in different degrees all showing theversatility of this new simulation training.

Currently four broad categories forsurgical simulations exist.

Success

Skills that have been taught numerousdifferent ways in the past are now finding great success with the dynamiccadaver. Take lifesaving tourniquets for example. Although mannequins may playa role in initial training, there is no substitute for a perfused cadaver toevaluate the effectiveness of the trainee’s technique. The presence of a pulsein the perfused cadaver is a unique feature that adds to the immersion oftraining. By having a pulsing model with the exact anatomy of a live human thetraining experience is as life like as possible. This situation can be alteredin several ways with a perfused cadaver. The most basic of which is simplypracticing a tourniquet on an intact cadaver. This allows the user a chance tofamiliarize themselves with the equipment and proper techniques withrepetition. A perfused cadaver can maintain a pulse for hours with an unlimitedsupply of artificial blood, allowing first responders and military members thechance to master basic tourniquet skills.

Perfused cadavers have the capability tobleed similarly to that of humans. This allows users to practice tourniquetplacement on an actual bleeding model that responds in a fashion analogous tothat of real life. These labs can be altered in many ways to provide a varyingrange of experiences, from car crashes to mass casualty situations. Perfusedcadavers offer a training experience that brings the user closer to real life.

The benefits to using a dynamic cadaverdon’t stop with first responders and tourniquets. Many hospitals and medicalschools have started using perfused cadavers for training physicians. In thisaspect, perfused cadavers again show their versatility. From placement ofcentral venous catheters to endoscopic surgery to microvascular procedures;perfused cadavers have shown great success as training models.

Aresearch team out of the San Antonio Military Medical Center, department ofsurgery, recently published a paper speaking to the benefits of perfusedcadavers in catheterization training. Eighty-seven physicians of differentspecialties took part in the trials. All of them received a didactic lecturefollowed by a simulation using a commercially available simulator and thenattempted catheterization on a perfused cadaver. The participants were thensurveyed.

“Results of the survey demonstrated that91% of the participating physicians found the perfused cadaveric model to be atrue simulation of conditions that exist in live patients, and 98% reportedthat the use of this model promoted acquisition of technical skills.” (Varga,Smith, Minneti, Carey, Zakaluzny, Noguchi, Demetriades, and Talving, 2015)[2]This example demonstrates the usefulness of perfused cadavers as a trainingmodel in a controlled scenario. Perfused cadavers have also been used tosimulate catastrophes to prepare trainees for the unexpected.

Military training session that is utilizing perfused cadaver to simulate real life battlefield injuries.

Realistic

Medical education personnel, residents andresearchers out of Keck School of Medicine of the University of SouthernCalifornia, department of neurosurgery, developed a lab in which residents andjunior faculty could practice responding to arterial injuries during endoscopicendonasal surgeries. All of the trainees from this lab reported a realisticexperience that was enhanced by the perfusion of the cadaver. The team thereconcluded, “The addition of an arterial perfusion system to fresh tissuecadavers is among the most realistic training models available. This enablesthe simulation of rare intraoperative scenarios such as ICA injury.” (Pharm,Kale, Marquez, Winer, Lee, Harris, Minnetti, Carey, Giannotta and Zada, 2014)[3].

Another research team out of Keck School ofMedicine of the USC, department of plastic surgery, tested a multitude ofdifferent surgeries on perfused cadavers in an attempt to determine how closelysimulated perfused cadavers surgeries mimicked real life. They attemptedthirty-eight procedures with varying degrees of difficulty. All of which,including the most complex microsurgical flap transfer, were reportedsuccessful.

The perfused cadaver model has been makingan impact in education and training. “We anticipate utilization of this modelprior to entering the operating room will enhance surgical ability and offer avaluable resource in plastic surgical education.” (Carey, Rommer, Sheckter,Minneti, Talving, Wong, Garner and Urata, 2014)[4] The benefits ofperfused cadavers have been demonstrated for educational purposes but that isnot their only purpose.

Perfused cadavers offer a uniqueopportunity for researchers and product developers to test theories and tryproducts on a model that very nearly mimics real life. Not only are users ableto practice tourniquets using a perfused model but users are also able to testnew products.

The Junctional Emergency Treatment Tool(JETT) is a novel device with the goal of reducing preventable death on thebattlefield from groin bleeds. This research would have been difficult tocomplete without the use of a perfused cadaver model. The JETT was testedagainst the gold standard femoral artery tourniquet tool and was found to be aseffective at stopping blood flow with a much more rapid application time.Having a perfused cadaver model to test this product allowed for a realisticrepresentation of this new product. Many other companies used perfused cadaverswhen developing products. From tourniquets to boviee tools, perfused cadavershave offered a distinct advantage in research and development. There is evenresearch being conducted currently to enhance the perfused cadaver experience.

Typically these cadavers are perfused usinga synthetic blood. While having a pulse and moving blood there are still somecomponents of real life that have not been replicated, one of which isclotting. New research in this area hopes to provide advancement to theperfused cadaver model. Soon there may be perfused cadavers that not only havea pulsatile blood flow but also can offer the same clotting dynamics as aliving individual. This novel idea may increase the usefulness and versatilityof perfused cadavers, opening up more training experiences and newer researchopportunities.

While all the aforementioned benefits grantvaluable experience and information to trainees and researchers the benefits gofar beyond. Greater expectations along with greater training modules will leadto better outcomes for patients. New products being developed with the aid ofperfused cadavers will save lives and institute a new standard of care. Whilethe average citizen may never be a part of a perfused cadaver learningexperience they may gain benefit from them.

Reducing Medical Errors

Within the medical community there has beena huge push to reduce medical errors. Simulations and training experiences canaid in this pursuit of perfection. In surgery training, a lot is changing.Historically, surgical residents have gained a majority, if not all, of theirtraining from experience. Unfortunately, limitations on training hours andchanges in practice partners have hampered the surgical training experience.The Society of Vascular Surgery estimates that by 2020 fellows training invascular surgery will have been exposed to only, on average, five aorticsurgeries. This is a far cry from the 30-50 aortic surgeries needed to becredentialed. The use of simulations, including perfused cadaver models, hasbeen pushing surgical training in a different direction. This new school ofthought is based more on capability. Dr. Agha from Pinderfields Hospital,department of plastic surgery, spoke to this fact stating, “surgery has movedaway from its traditional apprenticeship model and toward a competency basedone.” (Agha and Fowler, 2015)[ibid] Not only have simulations been used astraining techniques they can also be a means of assessing health care providersabilities. “Simulation can be a standardized and safe method for training andassessing surgeons.” (Agha and Fowler, 2015)[ibid] These changes will lead tobetter patient care and improved outcomes.

In conclusion, studies have shown the effectiveness of perfused cadavers and its impact on surgical training by providing a real life experience that current institutions are starting to utilize. Data shows and agrees that perfused cadavers are an alternative to expensive surgical simulating tools and mannequins, and allows fellows to gain the necessary experience to be competent and credentialed. Additionally, having the ability to manipulate situations and recreate different scenarios during training, whether it be practicing with a tourniquet or any other surgical tools, allows trainees to identify their weaknesses and improve their skills. Finally, perfused cadavers are a relatively new technology that has only begun to be utilized and hold great potential for the future of surgical training and healthcare education.

About the Authors

Anthony Bitar and Ezekiel Kapusciak aremedical students at University of Missouri School of Medicine. They both havetremendous experience working with perfused cadavers. During their school yearthey travel to perform dynamic cadavers labs and have worked with MaximumFidelity Surgical Simulations developing new products and new technologies tothe field of surgery simulations. They have conducted research in boneregeneration utilizing bioactive glass scaffolds as well as on patient outcomesof colorectal cancer resections.

Dr. Joss Fernandez is a leadingcardiothoracic surgeon. Through his many years of surgery he has gainedexperience that allowed him to build Maximum Fidelity Surgical Simulations fromthe ground up. He has been a part of revolutionizing the realm of perfusedcadavers and holds several patents and publications regarding dynamic cadaversand is a leader in this field.

References

1. Agha, Riaz A., and Alexander J. Fowler. 2015. "The Role And Validity Of Surgical Simulation". International Surgery 100 (2): 350-357. International College of Surgeons. doi:10.9738/intsurg-d-14-00004.1.
2. Varga S, et al. 2018. "Central Venous Catheterization Using A Perfused Human Cadaveric Model: Application To Surgical Education. - Pubmed - NCBI ". Ncbi.Nlm.Nih. Gov. Accessed August 31 2018. https://www.ncbi.nlm.nih.gov/pubmed/25129205.
3. Pham, Martin, Aydemir Kale, Yvette Marquez, Jesse Winer, Brian Lee, Brianna Harris, Michael Minnetti, Joseph Carey, Steven Giannotta, and Gabriel Zada. 2014. "A Perfusion-Based Human Cadaveric Model For Management Of Carotid Artery Injury During Endoscopic Endonasal Skull Base Surgery". Journal Of Neurological Surgery Part B: Skull Base 75 (05): 309-313. Georg Thieme Verlag KG. doi:10.1055/s-0034-1372470.
4. Carey, Joseph N., Elizabeth Rommer, Clifford Sheckter, Michael Minneti, Peep Talving, Alex K. Wong, Warren Garner, and Mark M. Urata. 2014. "Simulation Of Plastic Surgery And Microvascular Procedures Using Perfused Fresh Human Cadavers". Journal Of Plastic, Reconstructive & Aesthetic Surgery 67 (2): e42-e48. Elsevier BV. doi:10.1016/j.bjps.2013.09.026.

Originally published in  Issue 4, 2018 of MT Magazine.