Indigenous Inexpensive Practice Models for Skill Development in Neuroendoscopy

ABSTRACT Introduction: Neurosurgery is a branch having a tough learning curve. Residents generally get very less hands-on exposure for advanced procedures like neuroendoscopy. With the limited number of cadavers available and ethical issues associated with animal models, practice models, and simulators are becoming the able alternative. Most of these simulators are very costly. We tried to build indigenous inexpensive practice models that can help in developing most of the skills of neuroendoscopy. Materials and Methods: Models were built for learning hand-eye coordination, dexterity, instrument manipulation, cutting, fine dissection, keyhole concept, drilling, and simulation of laminectomy and ligamentum flavum resection. These were shown in the neuroendoscopic fellowship program conducted in authors’ institute, and trainees’ responses were recorded. Results: Both novice and experienced neuroendoscopic surgeons validated the models. There was no significant difference between their responses (P = 0.791). Conclusion: Indigenous innovative models can be used to learn and teach neuroendoscopic skills. The presented models were reliable, valid, eco-friendly, highly cost-effective, portable, easily made and can be kept in one’s chamber for practicing.

Quantitative verification of the keyhole concept: a comparison of area of exposure in the parasellar region via supraorbital keyhole, frontotemporal pterional, and supraorbital approaches

Object This study was designed to determine if the “keyhole concept,” proposed by Perneczky's group, can be verified quantitatively. Methods Fourteen (3 bilateral and 8 unilateral) sides of embalmed latex-injected cadaveric heads were dissected via 3 sequential craniotomy approaches: supraorbital keyhole, frontotemporal pterional, and supraorbital. Three-dimensional cartesian coordinates were recorded using a stereotactic localizer. The orthocenter of the ipsilateral anterior clinoid process, the posterior clinoid process, and the contralateral anterior clinoid process are expressed as a center point (the apex). Seven vectors project from the apex to their corresponding target points in a radiating manner on the parasellar skull base. Each 2 neighboring vectors border what could be considered a triangle, and the total area of the 7 triangles sharing the same apex was geometrically expressed as the area of exposure in the parasellar region. Results Values are expressed as the mean ± SD (mm2). The total area of exposure was as follows: supraorbital keyhole 1733.1 ± 336.0, pterional 1699.3 ± 361.9, and supraorbital 1691.4 ± 342.4. The area of exposure on the contralateral side was as follows: supraorbital keyhole 602.2 ± 194.7, pterional 595.2 ± 228.0, and supraorbital 553.3 ± 227.2. The supraorbital keyhole skull flap was 2.0 cm2, and the skull flap size ratio was 1:5:6.5 (supraorbital keyhole/pterional/supraorbital). Conclusions The area of exposure of the parasellar region through the smaller supraorbital keyhole approach is as adequate as the larger pterional and supraorbital approaches. The keyhole concept can be verified quantitatively as follows: 1) a wide area of exposure on the skull base can be obtained through a small keyhole skull opening, and 2) the side opposite the opening can also be visualized.

Tumors of the Lateral and Third Ventricle: Removal under Endoscope-assisted Keyhole Conditions

OBJECTIVE: Intraventricular tumors usually are managed by approaches and microsurgical techniques that need retraction and dissection of important brain structures. Minimally invasive endoscopic procedures achieve a remarkable alternative to conventional microneurosurgical techniques. Endoscope-assisted microneurosurgery may be a minimally invasive technique with maximally effective treatment. Using the keyhole concept for planning the surgical strategy, the reduction of the brain retraction is achieved, which is one of the main benefits of this technique. METHODS: We treated 35 patients (16 female patients and 19 male patients) with tumors in the lateral (n = 8) and the third (n = 27) ventricle. Patient age at the date of surgery ranged from 5 to 73 years. The follow-up period ranged from 6 to 83 months. The tumors were operated on using transcortical, transcallosal, or suboccipital transtentorial or infratentorial supracerebellar approaches after precise planning of the skin incision, the trephination, and the trajectory to the center of the tumor, performed earlier with a magnetic resonance imaging scan. RESULTS: Total removal of the tumor was achieved in 28 patients (78.5%). In 2 patients (6.5%), recurrent tumor occurred. In 5 patients (15%), parts of the tumors remained because of infiltration of eloquent areas. Overall clinical improvement was achieved in 31 patients (87%). Three patients (10%) were unchanged and 1 patient (3%) deteriorated. CONCLUSION: Endoscope-assisted keyhole neurosurgery seems to be a safe method of removing tumors in all regions inside the ventricular system with a low risk of permanent neurological deficits. The exact surgical corridor planning on the basis of the keyhole strategy offers less traumatic exposure of even deep-seated endoventricular tumors.