Manual Instruments as an Alternative to Drilling for Bony Exposure in Skull Base Surgery: Concept and Technique

Background  Drilling in neurosurgery is an integral part of surgical exposure, especially in skull base approaches and craniovertebral junction (CVJ) surgeries. Most of such drillings are done in close proximity to the neurovascular structures in skull base surgeries and cervical-medullary junction or facet/pedicle in CVJ surgeries. Reluctance to drilling among young neurosurgeons is due to less hands-on experience during training and also, in the early part of the career, due to fear of injury to neurovascular structures. Methods  Five commonest bone removals for skull base region and CVJ surgeries that can be safely done using manual instruments were identified based on experiences of senior authors. The authors highlight key technical nuances to widen surgical corridors using manual instruments safely for skull base surgical approaches. Results  Basic neuroanatomical concepts and basic physics help in using manual instruments safely for bone removals in various skull base surgical approaches. Conclusions  Manual instruments may be used for bone removals in selected skull base surgical approaches, which help young neurosurgeons to perform these surgeries in limited-resource settings.

Primary Diffuse Leptomeningeal Melanomatosis in an Indian Child With Review of Literature

BACKGROUND

Primary diffuse leptomeningeal melanomatosis (PDLM) is an extremely rare, aggressive malignant neoplasia of the central nervous system. We report the first case of pediatric PDLM from India.

METHODS

A review of literature was done to describe the 15 pediatric cases reported so far.

RESULTS

A 12-year-old male child presented with fever, vomiting, and headache for 2 months. Cerebrospinal fluid examination was normal. An MRI of the brain revealed hydrocephalus, for which antitubercular therapy was started and external ventricular drainage followed by ventriculoperitoneal shunt was done. Repeat MRI revealed a suprasellar lesion, nodular enhancement of cranial nerves along with dural enhancement of spinal cord with arachnoiditis, and long-segment myelomalacia. Repeat cerebrospinal fluid examination was negative for malignant cells. During biopsy, blackish dura with diffuse blackish deposits in ventricle were noted. Histopathological examination revealed tumor cells with intracytoplasmic coarse brown pigment melanoma, frequent mitotic figures, and immunohistochemistry testing was positive for human melanoma black-45 and MelanA, suggestive of PDLM. He expired 4 months after the diagnosis.

CONCLUSION

Diagnosing PDLM can be daunting in light of its slow but malignant progression mimicking TBM leading to improper management. However, the absence of any supportive microbiological evidence and failure to respond to the standard antitubercular therapy with subsequent progression of the symptoms should prompt the need for finding an alternative diagnosis. A targeted molecular diagnosis and precision medicine may provide a favorable outcome in children with PDLM.

Setting Up a Department of Neurosurgery in a Government Hospital in an LMIC: Jodhpur, India

BACKGROUND

The number of government institutes offering affordable super specialty and tertiary healthcare in India has traditionally not been able to keep pace with the growth in population, most of whom are too poor to be able to afford private healthcare services. To meet this mandate, 6 new institutes built on the template of the premier institute of the country-the All India Institute of Medical Sciences, New Delhi-were founded and began operations in 2012. Using the progress of our department as an example, the aim of this report is to outline the principles that were followed to set up the department of neurosurgery.

METHODS

The Department of Neurosurgery at All India Institute of Medical Sciences, Jodhpur, began providing services in August 2017. Data related to the inception and development of the department were collected.

RESULTS

The department has grown during the past 5 years from 400 outpatients and 79 inpatients in 2017 to 11,144 outpatients and 1624 inpatients in 2022. Only 59 surgeries were performed in 2017 compared with 597 routine and 311 emergency procedures performed in 2022. Currently, the department has 7 faculty members performing all forms of complex skull base, craniovertebral junction, vascular, endovascular, epilepsy, and functional surgeries. A total of 134 studies have been reported in national and international journals, and 8 patents have been granted.

CONCLUSIONS

We report the unique experiences of one department that could be useful as a template and as guidelines for the establishment process of a new department.

Skull base dural reflection models: tool for teaching neuroanatomy at resource-scarce centers

Skull base dural reflections are complex, and along with various ligaments joining sutures of the skull base, are related to most important vessels like internal carotid arteries (ICA), vertebral arteries, jugular veins, cavernous sinus, and cranial nerves which make surgical approaches difficult and need thorough knowledge and anatomy for a safe dissection and satisfactory patient outcomes. Cadaver dissection is much more important for the training of skull base anatomy in comparison to any other subspecialty of neurosurgery; however, such facilities are not available at most of the training institutes, more so in low- and middle-income countries (LMICs). A glue gun (100-Watt glue gun, ApTech Deals, Delhi, India) was used to spread glue over the superior surface of the bone of the skull base over desired area (anterior, middle, or lateral skull base). Once glue was spread over the desired surface uniformly, it was cooled under running tap water and the glue layer was separated from the skull base. Various neurovascular impressions were colored for ease of depiction and teaching. Visual neuroanatomy of the inferior surface of dural reflections of the skull base is important for understanding neurovascular orientations of various structures entering or exiting the skull base. It was readily available, reproducible, and simple for teaching neuroanatomy to the trainees of neurosurgery. Skull base dural reflections made up of glue are an inexpensive, reproducible item that may be used for teaching neuroanatomy. It may be useful for trainees and young neurosurgeons, especially at resource-scarce healthcare facilities.

Suction cannula design for safe microneurosurgery

INTRODUCTION

Suction cannula (SC) is an important instrument for a neurosurgeon. Currently used suction control valves, kept in the sterile field, are controlled by the surgeon, for which he needs to leave the surgical dissection or by assistant or by operation room personnel to adjust the pressure of the equipment (suction machine or central suction), which lies in the unsterile field. Authors studied relationships of the different diameters of SC and the thumb hole (TH) of the SC and present their findings.

METHODS

Seven SC with various diameters of their lumen and TH were used for the study. Suction pressures were measured with suction tip open, immersed in saline and TH open and closed. TH of 2 SC were made smaller using adhesive tape over the TH and making smaller hole over the tape and two additional measurements were taken using changed SC with modified TH. SPSS Statistics 23.0 (IBM India Pvt Ltd, Bangaluru, India) was used for statistical analysis of the pressure recordings and SC features.

RESULTS

Pressure and diameter of ST or TH were related in opposite direction. As the diameter increases the pressure decreases. A strong negative association was observed between the diameter of TH and the pressure.

CONCLUSION

TH diameter of SC is important to control suction pressure with any size of SC. One should use tear-drop type TH or appropriate diameter of the circular type of TH to contemplate safe microneurosurgery.

Simulation of surgery for supratentorial gliomas in virtual reality using a 3D volume rendering technique: a poor man's neuronavigation

OBJECTIVE

Different techniques of performing image-guided neurosurgery exist, namely, neuronavigation systems, intraoperative ultrasound, and intraoperative MRI, each with its limitations. Except for ultrasound, other methods are expensive. Three-dimensional virtual reconstruction and surgical simulation using 3D volume rendering (VR) is an economical and excellent technique for preoperative surgical planning and image-guided neurosurgery. In this article, the authors discuss several nuances of the 3D VR technique that have not yet been described.

METHODS

The authors included 6 patients with supratentorial gliomas who underwent surgery between January 2019 and March 2021. Preoperative clinical data, including patient demographics, preoperative planning details (done using the VR technique), and intraoperative details, including relevant photos and videos, were collected. RadiAnt software was used for generating virtual 3D images using the VR technique on a computer running Microsoft Windows.

RESULTS

The 3D VR technique assists in glioma surgery with a preoperative simulation of the skin incision and craniotomy, virtual cortical surface marking and navigation for deep-seated gliomas, preoperative visualization of morbid cortical surface and venous anatomy in surfacing gliomas, identifying the intervenous surgical corridor in both surfacing and deep-seated gliomas, and pre- and postoperative virtual 3D images highlighting the exact spatial geometric residual tumor location and extent of resection for low-grade gliomas (LGGs).

CONCLUSIONS

Image-guided neurosurgery with the 3D VR technique using RadiAnt software is an economical, easy-to-learn, and user-friendly method of simulating glioma surgery, especially in resource-constrained countries where expensive neuronavigation systems are not readily available. Apart from cortical sulci/gyri anatomy, FLAIR sequences are ideal for the 3D visualization of nonenhancing diffuse LGGs using the VR technique. In addition to cortical vessels (especially veins), contrast MRI sequences are perfect for the 3D visualization of contrast-enhancing high-grade gliomas.

Congenital skull anomaly with multiple brain stones and symptomatic meningioma of medial sphenoid wing

Intracranial calcifications are not uncommon and are mostly seen with intracerebral hematomas, tuberculomas, and brain tumors. These lesions may be intra- or extra-axial and occasionally pose challenge in the diagnosis. We report a case of multiple intracranial extra-axial calcifications with congenital skull anomaly and multiple meningiomas. Authors could not find similar case reported in the literature and present their findings and discuss relevant literature.