Orbital Rim Sparing Single-piece Fronto-orbital Keyhole Craniotomy Through Eyebrow Incision: A Technical Report and Comparative Review

Giant skull base mass need not be a tumor - a rare presentation of IgG4-related disease

BACKGROUND

Giant intracranial 'IgG4-related' lesions are uncommon. They may present as pachymeningitis or localized mass. Here we report, probably, the largest IgG4 skull base mass ever to be reported.

CASE

A 40-year male presented with headache, diplopia, right-sided sensori-neuronal hearing loss, and left spastic hemiparesis. Magnetic resonance imaging showed a lesion of 8.5 cm extending from the paranasal sinuses to the right petroclival region with uniform contrast enhancement and T2 hypointensity. Endonasal biopsy revealed respiratory epithelium with fibrosis, and lymphoplasmacytic infiltrate having IgG4 positive cells >30/HPF suggestive of 'IgG4-related' disease. Serum IgG4 was within normal levels. With oral prednisolone 60 mg given daily for 6 weeks and then tapered off over 8 weeks, he improved symptomatically.

CONCLUSION

Though rare, 'IgG4-related' disease can also present as a giant skull base mass and should be kept as a differential to fungal granulomas and meningiomas. As they improve dramatically with medical management, extensive skull base resection should not be planned before obtaining a tissue biopsy, especially when there is extension into paranasal sinuses and T2 hypointensity.

Novel freehand frontal ventriculostomy in the supraorbital keyhole approach: technical note

BACKGROUND AND OBJECTIVES

The narrow surgical passage provided by the supraorbital keyhole craniotomy restricts the instrument's maneuverability and presents a number of technical challenges. Inadequate brain relaxation may eventually result in unavoidable brain retraction and neurological impairments. The article aims to provide a novel intraoperative ventriculostomy to assist in overcoming the barrier of a narrow surgical corridor and assess its feasibility and safety compared to other techniques.

METHODS

The craniometric point was planned on one normal computed tomography (CT) brain. The coordinates were verified on 43 magnetic resonance imaging (MRI) brain images uploaded on the neuronavigation system (StealthStation S8 version 1.0; Medtronic, Louisville, USA). The ventriculostomy point was 3 cm superior to glabella, 2 cm lateral to midline, 6 cm deep to the brain surface in the perpendicular direction, and parallel to the floor of the anterior cranial fossa. Subsequently, the abovementioned radiologically calculated ventriculostomy trajectory was confirmed on 32 consecutive patients (without neuronavigation) of suprasellar mass undergoing supraorbital craniotomy between February 2022 and April 2023. The technical issues, feasibility, and outcomes were assessed.

RESULTS

Out of 32 patients, in 29 patients, ventricular hit was attained in a single attempt, and the rest 3 patients needed two attempts. The intraoperative ventricular hit rate was 100% with 90.6% success in a single attempt. No ventriculostomy-related complications occurred. Compared to ELD (external lumbar drainage), performing an intraoperative ventriculostomy had no discernible difference in the perception of the brain retraction force. Intraoperative ventriculostomy fully eliminated the low back pain or radiculopathy that patients with ELD rarely have even after drain removal.

CONCLUSION

The novel intraoperative frontal ventriculostomy is a safe trajectory and is a valid alternative to Menovsky's ventriculostomy or external lumbar drainage. The authors recommend this technique be generally utilized in supraorbital keyhole approaches to optimize brain relaxation and minimize secondary adverse events.

Supraorbital Keyhole Approach—A Minimally Invasive Versatile Approach to Skull Base Lesions

Context Over the last two decades, there have been development of approaches that are minimally invasive but achieve maximum effective results with minimal morbidity. The supraorbital keyhole approach (SOKHA) through the transciliary incision is minimally invasive approach that permits effective management of skull base lesions with minimal injury to the soft tissue and surrounding brain.

Aims The aim of this study was to evaluate the efficacy and safety of SOKHA for skull base lesions.

Settings and Design This is a prospective study in a tertiary neurosurgical teaching institute in a metropolitan city.

Materials and Methods Twenty-one patients of various pathology were operated using the SOKHA through the “eye-brow incision.” The pathologies included pituitary adenoma, craniopharyngioma, epidermoid, tuberculum sella, and planum sphenoidale meningioma. The authors describe in detail the surgical approach employed by them for these various pathologies.

Results All neoplastic lesions in this series could be addressed effectively with near total or total excision. No fresh postoperative deficits were noted except a case who developed ipsilateral anterior cerebral artery infarction that resulted in lower limb weakness. One patient developed postoperative abscess requiring surgical excision. At follow-up, all patients revealed a cosmetic scar hidden by the eye brow.

Conclusions The SOKHA is an effective minimally invasive procedure with proven safety for the management of anterior, selected middle skull base lesions and to provide excellent cosmesis with minimal trauma to the adjacent brain. The authors, however, feel that it is technically demanding and surgeons should employ a stepwise progression from simple to more complex lesions.

Supraorbital Keyhole Craniotomy in Pediatric Neurosurgery: A Systematic Review of Clinical Outcomes and Cosmetic Outcomes

BACKGROUND

Supraorbital keyhole craniotomy is a minimally invasive approach used to access the parasellar region with advantages of decreased cortical exposure, simple closure, and decreased risk of postoperative cerebrospinal fluid leak. The incision of this approach, however, has raised cosmetic concerns, especially for pediatric patients. The aim of this study is to assess postoperative complications and cosmeses of the supraorbital keyhole approach for resection of intracranial lesions in pediatric patients.

METHODS

A literature search of PubMed, Scopus, and Web of Science databases was performed on June 1, 2021, searching for all studies of pediatric patients undergoing supraorbital keyhole craniotomy for surgical resection of lesions in the anterior fossa/sellar region.

RESULTS

Of 729 unique hits, 15 supraorbital keyhole studies reporting on 177 pediatric cases were included in the final review. Quality of all included studies was moderate. Overall, the surgery was well tolerated with a low number of severe adverse events. A wide variety of pathologies were treated with this approach. Complications of surgery included changes in vision, epidural hematoma, subdural hematoma, cerebrospinal fluid leak, and wound infection. At 6 weeks of follow-up, surgical scars in most patients were noted to be minimally detectable. At 3-6 months of follow-up, scars were no longer visible. Cosmetic complications included 5 bone defects, 1 split eyebrow, and 1 case of ptosis.

CONCLUSIONS

This study suggests that supraorbital keyhole craniotomy is a safe and effective approach to access the parasellar region in pediatric patients with excellent cosmetic outcomes reported across multiple institutions.

How Safe and Effective Is Shifting from Pterional to Supraorbital Keyhole Approach for Clipping Ruptured Anterior Circulation Aneurysms? A Surgeon's Transition Phase Comparative Study

Background  Comparative studies between standard pterional and supraorbital keyhole approaches for aneurysms had potential biases with the heterogeneity of patient selection, differences among surgeons, or varying expertise across the surgeon’s learning curve. This is a study of a surgeon’s transition from pterional to keyhole approach for early clipping of selected consecutive ruptured anterior circulation aneurysms.

Methods  Patients more than 18 years, presenting within 72 hours of ictus, in good clinical grades 1 to 3, no midline shift, with saccular aneurysms less than 25 mm at either communicating segment of internal carotid artery, anterior communicating artery, or middle cerebral artery segment till bifurcation were studied between the last 25 cases of pterional and first 25 cases of the keyhole, for the intraoperative and postoperative surgical outcome parameters.

Results  There was no significant difference among baseline parameters, including the location of aneurysms across both groups. While only four cases of pterional had an intraoperative ventricular puncture, the lumbar drain was electively inserted in all keyhole patients. The intraoperative parameters, such as a dural tear, adequate parent vessel exposure, temporary clipping, and intraoperative rupture, did not show any significant difference. None had immediate postoperative deficits. While delayed cerebral ischemia and wound complaints were similar in both groups, temporal hollowing and chewing difficulty were significantly more in pterional patients( p = 0.01).

Conclusion  A surgeon experienced in pterional approach can comfortably and safely shift to the keyhole for early clipping of selected ruptured aneurysms less than 25 mm, with a comparable surgical outcome but better cosmesis and mastication.