Toward an optimal cadaveric brain model for neurosurgical education: assessment of preservation, parenchyma, vascular injection, and imaging

OBJECTIVE

We assessed types of cadaveric head and brain tissue specimen preparations that are used in a high throughput neurosurgical research laboratory to determine optimal preparation methods for neurosurgical anatomical research, education, and training.

METHODS

Cadaveric specimens (N = 112) prepared using different preservation and vascular injection methods were imaged, dissected, and graded by 11 neurosurgeons using a 21-point scale. We assessed the quality of tissue and preservation in both the anterior and posterior circulations. Tissue quality was evaluated using a 9-point magnetic resonance imaging (MRI) scale.

RESULTS

Formalin-fixed specimens yielded the highest scores for assessment (mean ± SD [17.0 ± 2.8]) vs. formalin-flushed (17.0 ± 3.6) and MRI (6.9 ± 2.0). Cadaver assessment and MRI scores were positively correlated (P < 0.001, R2 0.60). Analysis showed significant associations between cadaver assessment scores and specific variables: nonformalin fixation (β = -3.3), preservation within ≤72 h of death (β = 1.8), and MRI quality score (β = 0.7). Formalin-fixed specimens exhibited greater hardness than formalin-flushed and nonformalin-fixed specimens (P ≤ 0.006). Neurosurgeons preferred formalin-flushed specimens injected with colored latex.

CONCLUSION

For better-quality specimens for neurosurgical education and training, formalin preservation within ≤72 h of death was preferable, as was injection with colored latex. Formalin-flushed specimens more closely resembled live brain parenchyma. Assessment scores were lower for preparation techniques performed > 72 h postmortem and for nonformalin preservation solutions. The positive correlation between cadaver assessment scores and our novel MRI score indicates that donation organizations and institutional buyers should incorporate MRI as a screening tool for the selection of high-quality specimens.

Clinical Anatomy and Medical Malpractice-A Narrative Review with Methodological Implications

Anatomical issues are intrinsically included in medico-legal methodology, however, higher awareness would be needed about the relevance of anatomy in addressing medico-legal questions in clinical/surgical contexts. Forensic Clinical Anatomy has been defined as "the practical application of Clinical Anatomy to the ascertainment and evaluation of medico-legal problems". The so-called individual anatomy (normal anatomy, anatomical variations, or anatomical modifications due to development, aging, para-physiological conditions, diseases, or surgery) may acquire specific relevance in medico-legal ascertainment and evaluation of cases of supposed medical malpractice. Here, we reviewed the literature on the relationships between anatomy, clinics/surgery, and legal medicine. Some methodological considerations were also proposed concerning the following issues: (1) relevant aspects of individual anatomy may arise from the application of methods of ascertainment, and they may be furtherly ascertained through specific anatomical methodology; (2) data about individual anatomy may help in the objective application of the criteria of evaluation (physio-pathological pathway, identification-evaluation of errors, causal value, damage estimation) and in final judgment about medical responsibility/liability. Awareness of the relevance of individual anatomy (risk of iatrogenic lesions, need for preoperative diagnostic procedures) should be one of the principles guiding the clinician; medico-legal analyses can also take advantage of its contribution in terms of ascertainment/evaluation.

Development of an Experimental Model for Studying the Nasosinusal and Skull Base Arterial and Venous Systems Using Iodinated Contrast and Latex in Cadavers

BACKGROUND

Cadaver dissection remains one of the most reliable and safest ways to study anatomy, whereas computed tomography angiography (CTA) is an essential technology for enabling students to become familiar with human anatomy and surgical planning. Thus, the convergence of both radiologic and anatomic information is important for surgical success, especially in regions of complex anatomy such as the nasosinusal and skull base regions. Here we propose an experimental model in formalinized cadaver heads consisting of intravascular injection of colored latex and iodinated contrast mixture, followed by CTA scans of the nasosinusal and skull base arterial and venous systems before dissection.

METHODS

Six cadaver heads that had been preserved for >5 years in 10% formaldehyde were immersed for 72 hours in a solution containing a dimethyldiethanol mono/dialkyloyl ester quaternary ammonium salt. In 5 of these heads, a mixture composed of latex, tissue ink, and iodinated contrast (Ultravist 300) was injected into the vascular system. CTA scans were performed sequentially after the injection, followed by endonasal and macroscopic dissections.

RESULTS

There was good radiologic and macroscopic vessel uptake in 4 specimens, allowing a detailed anatomic study.

CONCLUSIONS

An experimental model was made feasible by injecting iodinated contrast and colored latex into formalinized cadavers for CTA evaluation of the nasosinusal and skull base arterial and venous systems before performing dissections.

Step-up Establishment of Neurosurgical Laboratory Starting with Limited Resources-Tips and Tricks

BACKGROUND

Neurosurgical diseases have a devastating impact on society. It is estimated that approximately 14 million essential neurosurgical cases develop worldwide annually, of which more than 80% arise in low- and middle-income countries. Neurosurgical cadaveric dissection remains largely unexploited as a learning tool for the training of surgeons in developing countries, often because of the assumed high costs.

METHODS

The minimum requirements to establish a neurosurgical cadaver laboratory are the availability of minimally equipped environment to perform dissection, respecting safety requirements, fitting surgical instruments, anatomic samples, and materials to be used for preservation and preparation of anatomical specimens. Moving from these basic foundations, we established our Neurosurgical Dissection Laboratory at Fondazione Policlinico Universitario A. Gemelli IRCCS in Rome, Italy. The laboratory is located at the Institute of Public Health Section of Legal Medicine of University.

RESULTS

After reviewing relevant literature and discussing our experience, we provide advice for setting up a neurosurgical dissection cadaver laboratory with specific focus on suitable location identification, surgical equipment procurement, fresh cadaver and frozen specimen acquisition, and preparation and description of a step-up strategy to progressively enrich the laboratory.

CONCLUSIONS

Our study demonstrates the feasibility of establishing a neurosurgical cadaver dissection laboratory for training and research purposes even in presence of limited resources. The introduction of cost-effective guidelines and targeted funding could represent an added value to target the unmet neurosurgical disease need by promoting development of local neurosurgical expertise with the aim of providing health coverage for the treatment of common neurosurgical pathologies in developing countries.

Mastering Craniovertebral Junction Surgical Approaches: The Dissection Laboratory Experience at the Catholic University of Rome

The craniovertebral junction is an intricate anatomical region frequently affected by neoplastic, vascular, traumatic, congenital and degenerative pathology. Because the topography of this region is complex, direct knowledge and full mastery of craniocervical anatomy is mainly obtained through anatomical dissections performed in neuroanatomical laboratories.