Studies involving human cadaver tissues can be a valuable resource for companies developing new medical devices. Human cadaver labs allow an entrepreneur to gather integral information about a medical device or procedure including:
Cadaver labs can involve the use of standard surgical or interventional supplies, imaging equipment and/or mechanical testing equipment to gather information about the device/tissue interface, device placement, device failure under loading conditions, etc. There are many situations where feasibility and product development testing, as well as, physician and clinical bioskills training in human cadaver models supplement or replace the need for preclinical testing or training in animal models. As a resource, Surpass and Scientific and Engineering consulting firm, Exponent, have compiled some of the most common reasons for performing preclinical testing in human cadaver labs below.
Even with many similarities in size and structure of organ systems in humans and animals, there are cases where the human anatomy is different or more arduous to navigate than the animal. Human cadaver testing can be valuable for providing tortuous anatomy to challenge vascular devices. Although preclinical models such as the porcine carotid pin model or vessels in the gastric region can be used to simulate challenging human anatomy, there are times when testing in actual human anatomy is desirable. With devices targeting an ear, nose, and throat (ENT) indication, typical research models vary anatomically in size and shape from humans so a large portion of research is done in the human cadaver model. One can also encounter situations where the target anatomy mimics humans (in size and structure) but the surrounding structures do not, causing a need to vary the mode of delivery of the device in the research model from that intended in the clinic. One example of this is vascular devices treating the superficial femoral artery (SFA). In this situation, safety testing may be done in animals to evaluate the response to the implant but performance evaluations in human cadaver labs can help supplement performance assessments from in vivo testing.
Although disease models exist in animals and can provide valuable information, they do not perfectly represent the physiological disease state in humans. Companies wanting to evaluate their device by delivering or deploying them in the presence of disease pathology, may choose to perform cadaver studies. Cadaver lab testing is common for cardiovascular medical devices, where evaluating the device in calcified vasculature or heart valves is desirable. For example, a transcatheter aortic heart valve can be deployed in a diseased human heart to determine if a diseased aortic root affects device deployment and appropriate device placement.
Behavior differences exist between the human and medical research models. Humans are bipeds and most models used in preclinical research are quadrupeds. The loading characteristics and consequently the shape of anatomical structures (e.g. hip joint and spine) are different between quadrupeds and bipeds, so human cadaver models are commonly used in orthopedic research.
For certain types of devices, cadaver labs can provide equally as much, if not more, predictability of a device's performance in the human clinical setting than an animal study, thus making them a better choice than using in vivo models.
Cadaver tissue specimens can be used to better understand how a medical device interfaces directly with the human body in a healthy or diseased state, and can be used to characterize the device's in vivo performance. For example, the pullout force of bone screws, which can be used for fixation of fractures and is subjected to high in vivo loads, and can be measured to determine its fixation strength. The bone screws are inserted in healthy or osteoporotic bone and the force to pull out the screw from the bone is measured using a mechanical test system. Other biomechanical examinations of a medical device can be conducted by loading the device under various conditions (i.e., cyclic, axial compression/tension, or torsional loading) based on the clinical application. One example of this is examination of the behavior of spinal motion preserving implants in human lumbar spine specimens loaded in flexion, extension, rotation, and lateral bending loads.
As we have highlighted many of the benefits of human cadaver testing in this post, it is important to note that there are also limitations when using cadaver models (live tissue interactions can't be evaluated, only limited functional assessments can be performed, there is no interaction with live blood components, and cadavers are not appropriate for drug evaluations). Should you need to conduct further experiments within animal models to supplement your cadaver lab data, the Surpass research team is here to support you along the way.
Surpass has been successfully conducting human cadaver labs for research and development (R&D) and biokills trainings for over a decade. Whether you are planning a single specimen station for R&D testing or need to have 6 consecutive stations running for a physician training event, our staff is here to make your project successful. We can assist with anatomy review, source specimens with specific disease conditions, discuss procedures for isolating target anatomy to allow for efficient use of your physician's time, and more. At Surpass, Our People are Your Team.
Exponent has utilized human cadaveric models for evaluating spinal, cardiovascular and orthopaedic technologies at Exponent's Biomedical Engineering Laboratories, which are fully compliant with CFR 21 Part 58, U.S. FDA Good Laboratory Practices (GLP). Characterization of the medical device's interaction with the cadaver tissue can be accomplished, for example, by mechanical testing using servo-hydraulic and electromechanical frames, or imaging by optical microscopy, fluoroscopy, microCT, and ESEM.