Use of a Tentorial Sling for Microvascular Decompression of the Trigeminal Nerve in Patients with Trigeminal Neuralgia: A Novel Operative Technique and Report of Clinical Outcomes

Intro: Trigeminal neuralgia is a debilitating pain disorder characterized by excruciating facial pain. Although atypical forms exist, classic trigeminal neuralgia is caused by arterial compression of the trigeminal nerve at the nerve root entry zone. Microvascular decompression (MVD) remains the most definitive treatment for the disease, with reported cure rates between 60–80% at five years. Traditional decompression methods involve a standard retrosigmoid craniotomy with placement of an inert foreign material (e.g., Teflon, Avalon sponge) between the nerve and compressive vessel. For some patients, recurrence of trigeminal neuralgia after MVD has been associated with migration of arterial vessel back against the nerve, adhesion formation around the nerve, or arterial pulsation against the Teflon abutting the nerve. Additionally, foreign materials may cause inflammatory responses that can trigger delayed recurrence of trigeminal pain. Although Teflon is considered an inert material, it has been associated with granuloma formation in 1–7% of cases in which it is used for microvascular decompression.

An alternative method for decompression involves the use of a sling to transpose the compressive vessel away from the nerve. Results of various sling techniques as a decompressive strategy are limited to small series and case reports. In this study we present our institutional experience utilizing a tentorial sling for microvascular decompression in patients with trigeminal neuralgia.

Methods: The tentorial sling technique involves creation of a split thickness vascularized dural flap (~3 mm wide × 1.5 cm in length) from the underside of the tentorium. The sling is then wrapped around the compressive vessel, transposing the vessel away from the nerve, and secured in place by applying a Weck clip to appose the proximal and distal ends of the dural sling.

Results: The tentorial sling technique was performed in 37 consecutive patients undergoing MVD for trigeminal neuralgia, in which the anatomy was favorable.

The cure rate in this cohort was 76% (Barrow Facial Outcome Pain scale of 1) with a mean follow up time of 16 months. Two patients developed CSF leaks and one developed a small cerebellar stroke resulting in mild dysmetria.

Conclusions: This represents the first large study to describe the utilization of a tentorial sling for microvascular decompression in patients with trigeminal neuralgia. The technique represents a novel method for decompression of the trigeminal nerve by transposition of the offending vessel without use of foreign material. Although our preliminary results parallel the historical cure rate, further outcome data are required to assess long-term durability of this method.