Quantitative Anatomical Comparison of Surgical Approaches to Meckel's Cave

Temporoparietal Fascia Flap (TPFF) in Extended Endoscopic Transnasal Skull Base Surgery: Clinical Experience and Systematic Literature Review

Background and Objectives: The temporoparietal fascia flap (TPFF) has recently emerged as an option for skull base reconstruction in endoscopic transnasal surgery when vascularized nasal flaps are not available. This study provides a systematic literature review of its use in skull base surgery and describes a novel cohort of patients. Methods: PRISMA guidelines were used for the review. Patients undergoing skull base reconstruction with TPFF in our center from May 2022 to April 2024 were retrospectively included. Data were collected on pre- and post-operative clinical and radiological features, histology, surgical procedures, and complications. Results: Sixteen articles were selected, comprising 42 patients who underwent TPFF reconstruction for treatment of complex skull base pathologies. In total, 5 of 358 patients (0.9%) who underwent tumor resection via endoscopic transanal surgery in the study period in our institution required TPFF. All had been previously treated with surgery and radiation therapy for different pathologies (three chordomas, one giant pituitary neuroendocrine tumor (PitNET), and one sarcoma). Post-operative complications included CSF leak, which resolved after flap revision, and an internal carotid artery pseudoaneurysm requiring endovascular embolization. Conclusions: TPFF is an effective option for skull base reconstruction in complex cases and should be part of the armamentarium of the skull base surgeon.

Endoscopic Transpterygoid Approach to Meckel's Cave: Technical Considerations and Retrospective Analysis of a Clinical Series

OBJECTIVE

Tumors located within the Meckel's cave (MC) pose a significant surgical challenge. Although several corridors to access this complex region have been described, the endoscopic transpterygoid approach (ETPA) and the endoscopic transorbital superior eyelid approach (ETOA) have emerged in recent years, as viable alternatives to traditional microsurgical transcranial approaches (MTA). To date, there is a limited literature on surgical series considering endoscopic-assisted approaches to the MC.

METHODS

We conducted a retrospective analysis of patients with primary MC tumors treated at our Institution between 2015 and 2022, specifically those managed via the ETPA assisted by intraoperative Endoscopic Diving Technique (EDT). Lesion resection extent was evaluated using pre- and post-intervention radiological images and surgical videos. Moreover, a literature review on ETPA was performed.

RESULTS

This series comprises 7 patients affected by 4 trigeminal schwannomas, 1 benign notochordal cell tumor, 1 dermoid cyst and 1 mesenchymal tumor. In 71 % of cases, trigeminal neuralgia was the presenting symptom. Post-operative clinical improvement was observed in all but one case. Notably, 85.7 % of patients achieved total or near-total resection (NTR), with the remaining case undergoing subtotal resection (STR). No significant intraoperative complications occurred, and no recurrences were observed during the mean follow-up period of 41 months.

CONCLUSIONS

In selected cases, the ETPA offers a direct and safe path to lesions located into the MC. This approach circumvents complications and constraints associated with ETOA or MTA. Moreover, the use of the EDT reduces manipulation of critical neurovascular structures, enhancing the efficacy of the ETPA.

Treating Trigeminal Schwannoma through a Transorbital Approach: A Systematic Review

Background: Trigeminal schwannomas (TSs) are uncommon tumors found along any segment of the fifth cranial nerve (CN V). Typically located at the skull base, these benign tumors carry substantial morbidity due to the extent of traditional surgical methods. Minimally invasive endoscopic surgery such as the endoscopic transorbital approach (ETOA) presents promising new avenues for treatment, with the transorbital approach emerging as a potentially successful alternative. Methods: This review systematically assesses the application of the ETOA in treating TSs. PubMed, Ovid MEDLINE, and Embase were thoroughly searched for articles detailing the use of the ETOA in clinical case studies. The outcomes of interest encompassed epidemiological profiling, surgical results, and complication rates. Results: This study included 70 patients with TSs (from six studies), with 22 males (31.4%) and 58 females (68.6%). Patients averaged 55 years and were monitored for around 16.4 months (on average). In most tumors, the middle cranial fossa was involved to some degree. The majority (87.2%) were large (3-6 cm) and underwent gross total resection (GTR) or near-total resection in 87.2% of patients. Preoperatively, sensory alterations were common, along with proptosis, neuropathic pain, and diplopia. Postoperatively, complications included ptosis, diplopia, sensory impairment, corneal keratopathy, masticatory difficulty, and neuralgia. The pure ETOA was the primary surgical technique used in 90% of cases, with no recurrence observed during the follow-up period. Conclusions: Using the ETOA to treat TSs demonstrated an oncologic control rate of 87.2%. Postoperative complications including ptosis, diplopia, and sensory disturbances have been observed, but careful monitoring and management can mitigate these problems. The ETOA emerges as a viable surgical option, especially for tumors involving the middle cranial fossa, capable of adapting to individual patient needs and demonstrating efficacy in TS management.