Damon, Aaron

Abstract Background Central venous catheterization (CVC) is a fundamental procedural competency in pulmonary and critical care medicine (PCCM). Although commercially available task trainers are effective for teaching CVC placement, their high cost and logistical requirements can limit access to repeated practice. Objective To evaluate learner and faculty perceptions and usability of a newly developed CVC simulation model compared with a standard commercial task trainer and detail the technical report of the novel model’s construction. Methods We conducted a prospective educational evaluation during the PCCM CVC workshop. Participants practiced CVC placement with both the standard commercial trainer and a locally constructed simulation model developed at our institution. Teaching faculty were asked to evaluate both models from an instructional standpoint. Results Eighteen participants (15 PCCM 1st year fellows and 3 faculty instructors) evaluated the novel CVC simulation model. All fellows (n = 15, 100%) preferred the new model over a standard commercial model, with 14 (93%) reporting improved understanding of CVC insertion steps and 11 (73%) noting ease of ultrasound landmark identification. All fellows (n = 15, 100%) endorsed inclusion of the model in future workshops. Additionally, faculty instructors preferred the novel model for teaching (n = 3, 100%). All faculty supported future use of the model. The initial model development cost was approximately $288.96 with most materials’ reusable. Conclusions The novel task-aligned CVC simulation model offers a realistic, reusable, and cost-effective alternative to commercial simulators, with high learner and faculty preference and strong educational value. Its functional alignment supports integration into fellowship training, with future studies needed to assess objective skill acquisition and retention.

BACKGROUND: Graduate surgical education is highly variable across regions and institutions regarding case volume and degree of trainee participation in each case. Dedicated educational curriculum using cadaveric tissue has been shown to enhance graduate surgical training, however with associated financial and utility burden to the institution. OBJECTIVE: To investigate the utility of educational and cost applications of a novel method of combining mixed organic hydrogel polymers and 3-dimensional printed anatomic structures to create a complete “start-to-finish” simulation for resident education in spinal anatomy, instrumentation, and surgical techniques. METHODS: This qualitative pilot study investigated 14 international participants on achievement of objective and personal learning goals in a standardized curriculum using biomimetic simulation compared with cadaveric tissue. A questionnaire was developed to examine trainee evaluation of individual anatomic components of the biomimetic simulators compared with previous experience with cadaveric tissue. RESULTS: A total of 210 responses were acquired from 14 participants. Six participants originated from US residency education programs and 8 from transcontinental residency programs. Survey results for the simulation session revealed high user satisfaction. Score averages for each portion of the simulation session indicated learner validation of anatomic features for the simulation compared with previous cadaveric experience. Cost analysis resulted in an estimated savings of $10 833.00 for this single simulation session compared with previous cadaveric tissue sessions. CONCLUSION: The results of this study indicate a strong potential of establishing biomimetic simulation as a cost-effective and high-quality alternative to cadaveric tissue for the instruction of fundamental spine surgical techniques.

Abstract BACKGROUND Brain mapping is the most reliable intraoperative tool for identifying surrounding functional cortical and subcortical brain parenchyma. Brain mapping procedures are nuanced and require a multidisciplinary team and a well-trained neurosurgeon. Current training methodology involves real-time observation and operation, without widely available surgical simulation. OBJECTIVE To develop a patient-specific, anatomically accurate, and electrically responsive biomimetic 3D-printed model for simulating brain mapping. METHODS Imaging data were converted into a 2-piece inverse 3D-rendered polyvinyl acetate shell forming an anatomically accurate brain mold. Functional and diffusion tensor imaging data were used to guide wire placement to approximate the projection fibers from the arm and leg areas in the motor homunculus. Electrical parameters were generated, and data were collected and processed to differentiate between the 2 tracts. For validation, the relationship between the electrical signal and the distance between the probe and the tract was quantified. Neurosurgeons and trainees were interviewed to assess the validity of the model. RESULTS Material testing of the brain component showed an elasticity modulus of 55 kPa (compared to 140 kPa of cadaveric brain), closely resembling the tactile feedback a live brain. The simulator's electrical properties approximated that of a live brain with a voltage-to-distance correlation coefficient of r 2 = 0.86. Following 32 neurosurgeon interviews, ∼96% considered the model to be useful for training. CONCLUSION The realistic neural properties of the simulator greatly improve representation of a live surgical environment. This proof-of-concept model can be further developed to contain more complicated tractography, blood and cerebrospinal fluid circulation, and more in-depth feedback mechanisms.

Abstract Neurosurgical training is being challenged by rigorous work-hour restrictions and the COVID-19 pandemic. 1 Now, more than ever, surgical simulation plays a pivotal role in resident education and psychomotor skill development. Three-dimensional (3D) printing technologies enable the construction of inexpensive, patient-specific, anatomically accurate physical models for a more convenient and realistic simulation of complex skull base approaches in a safe environment. 2 All stages of the surgical procedure can be simulated, from positioning and exposure to deep microdissection, which has an unparalleled educational value. The complex approach-specific anatomy, narrow working angles, and pathoanatomic relationships can be readily explored from the surgeon's perspective or point of view. 2,3 Furthermore, different thermoplastic polymers can be utilized to replicate the visual and tactile feedback of bone (cortical/cancellous), neurological, and vascular tissues. 4 Retrosigmoid craniectomies are widely used in neurosurgery with various applications, including microvascular decompressions in patients with trigeminal neuralgia. 5-7 Removal of the suprameatal tubercle (SMT) extends the retrosigmoid approach superiorly to the middle fossa and Meckel's cave, and anteriorly to the clivus. 8,9 This maneuver may be necessary in patients with prominent SMTs obstructing the view of the trigeminal nerve and in patients with a more anterosuperior neurovascular conflict. This video illustrates a microsurgical training tool for learning and honing the technique of retrosigmoid craniectomy and suprameatal drilling using an affordable (29.00 USD) biomimetic 3D-printed simulator that closely recapitulates not only the anatomy but also the tactile feedback of drilling and manipulating neurological tissues (see Table and Graph 1; minute 07:11) as it happens at the time of surgery.

Abstract Commercial central line vascular access trainers are available but have significant limitations including cost, size, and limited durability when used for the complete procedure. A unique central venous access trainer was constructed using silicone loaf pan, ballistic gel, copper pipe and aluminum rods as vessels conduits, with varying inserts including latex and silicone to simulate different vascular structures, and the use of camouflage. This trainer is inexpensive, portable, reusable, allows the complete procedure to be simulated, and may be customized to the specific needs of the learner. The assembled simulator demonstrated excellent ultrasound visualization, including varying size and vessel character, allowed modification to specific learner needs, while at the same time being light-weight, portable, inexpensive, and reusable. A moderate-fidelity central venous access simulator can be constructed in a cost-effective manner, which can be optimized to the learner skill level and allows the entire procedure to be completed on the simulator.

The recent decline in available personal protective equipment (PPE) due to the novel coronavirus (COVID-19) pandemic has given rise to a host of three-dimensional (3D) printed prototypes for facemask and respirator units. Many of these models have been made open access and publicly available for printing and use, and have been promoted by various media outlets. Although these desktop 3D printing measures have provided a possible venue for success in providing homemade and cost-effective PPE to health care workers, the rapid dissemination of these prototypes has been performed without reproducible methods of standardization and vetted safety in use. Although these methods have not been sanctioned by authoritative organizations as viable production approaches to address the PPE shortage, a concerted effort within the 3D printing community to adhere to scientific methodology and organized research efforts has the potential to provide a solution to this critical issue.

AbstractIntroductionThree‐dimensional (3D) printing of anatomical structures is a growing method of education for students and medical trainees. These models are generally produced as static representations of gross surface anatomy. In order to create a model that provides educators with a tool for demonstration of kinematic and physiologic concepts in addition to surface anatomy, a high‐resolution segmentation and 3D‐printingtechnique was investigated for the creation of a dynamic educational model.MethodsAn anonymized computed tomography scan of the cervical spine with a diagnosis of ossification of the posterior longitudinal ligament was acquired. Using a high‐resolution thresholding technique, the individual facet and intervertebral spaces were separated, and models of the C3–7 vertebrae were 3D‐printed. The models were placed on a myelography simulator and subjected to flexion and extension under fluoroscopy, and measurements of the spinal canal diameter were recorded and compared to in‐vivo measurements. The flexible 3D‐printed model was then compared to a static 3D‐printed model to determine the educational benefit of demonstrating physiologic concepts.ResultsThe canal diameter changes on the flexible 3D‐printed model accurately reflected in‐vivo measurements during dynamic positioning. The flexible model also was also more successful in teaching the physiologic concepts of spinal canal changes during flexion and extension than the static 3D‐printed model to a cohort of learners.ConclusionsDynamic 3D‐printed models can provide educators with a cost‐effective and novel educational tool for not just instruction of surface anatomy, but also physiologic concepts through 3D ex‐vivo modeling of case‐specific physiologic and pathologic conditions.

AbstractCervical radiculopathy from uncovertebral joint (UVJ) hypertrophy and nerve root compression often occurs anterior and lateral within the cervical intervertebral foramen, presenting a challenge for complete decompression through anterior cervical approaches owing to the intimate association with the vertebral artery and associated venous plexus. Complete uncinatectomy during anterior cervical discectomy and fusion (ACDF) is a controversial topic, many surgeons relying on indirect nerve root decompression from restoration of disc space height. However, in cases of severe UVJ hypertrophy, indirect decompression does not adequately address the underlying pathophysiology of anterolateral foraminal stenosis. Previous reports in the literature have described techniques involving extensive dissection of the cervical transverse process and lateral uncinate process (UP) in order to identify the vertebral artery for safe removal of the UP. Recent anatomical investigations have detailed the microanatomical organization of the fibroligamentous complex surrounding the UP and neurovascular structures. The use of the natural planes formed from the encapsulation of these connective tissue layers provides a safe passage for lateral UP dissection during anterior cervical approaches. This can be performed from within the disc space during ACDF to avoid extensive lateral dissection. In this article, we present our 10‐year experience using an anatomy‐based microsurgical technique for safe and complete removal of the UP during ACDF for cervical radiculopathy caused by UVJ hypertrophy.