The dural flap is retracted anteriorly and reflected against the sinuses. None of these techniques differ from that of the conventional microscopic www.selleckchem.com/products/Erlotinib-Hydrochloride.html approach. Figure 1 Endoscopic view of burr hole/craniectomy site (a) with subsequent closure and placement of titanium mesh burr hole cover (b). At this point, however, the endoscope that is attached to the Mitaka Pneumatic Arm (Mitaka Kohki Co.) is brought in. Our preference is to use the 2.7mm zero-degree endoscope upfront (Storz; Culver City, CA, USA). This smaller diameter endoscope maximizes the amount of working space that is needed for the other instruments, thus minimizing instrument conflict and brain retraction (Figure 2). In conjunction with a high-definition camera, this system provides excellent visualization.
Angled endoscopes are also utilized to facilitate identification of vascular contacts at the root entry zone and to visualize the trigeminal nerve medial to a low and prominent petrous ridge. Figure 2 Endoscopic view of the vascular compression associated with cases of trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia. The left panel demonstrates compression of CN 5 by the superior cerebellar artery (top) with subsequent decompression … 2.2. Endoscopic Microvascular Decompression Next, the endoscope is inserted through the dural opening with minimal retraction on the cerebellum. The arachnoid sheath around the cranial nerve 9�C11 bundle is dissected with sharp scissors, and the cerebrospinal fluid is drained, enhancing visualization of structures within the CPA.
Using a combination of bipolar coagulation of minor vessels and blunt dissection, the arachnoid around the trigeminal nerve is then lysed, and the vascular anatomy is inspected. The offending vessel is then mobilized, and decompression is achieved with a Teflon pad placed between the offending vessel and trigeminal nerve. The 30-degree endoscope has been found to be the most useful in identifying occult vascular structures at the root entry zone (Figure 2), venous compression, as well as the nervus intermedius in the case of geniculate neuralgia. 3. Patient Population From September 2010 to November 2012, 70 patients (M/F: 24/46) with the diagnosis of medically refractory trigeminal neuralgia (TGN), hemifacial spasm (HFS), glossopharyngeal neuralgia (GPN), or geniculate neuralgia (GN) were seen in the neurosurgery clinic for preoperative evaluation.
Prior to this period, all patients who underwent microvascular decompression by the senior author (John Drug_discovery Y. K. Lee) had undergone a purely microscopic surgical procedure. In the first half of this experience (9/2010 to 12/2011), 14 MVDs, 8 endoscope-assisted (EA)-MVDs, and 16 purely E-MVDs were performed. In the next half of this experience (January 2012 to November 2012,) 9 MVDs, 1 EA-MVD, and 22 purely E-MVDs were performed. Hence, the great majority of procedures performed were purely endoscopic.