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that should be closely inspected and if they are under or likely to become under tension should be coagulated and sharply cut. No veins are unnecessarily taken. Each vein that is cut leads to further possible complications of swelling. The arachnoid surrounding the cranial nerves is generously opened sharply to prevent traction on cranial nerves and blood vessels. The trigeminal complex is seen. The entire trigeminal complex from the brain stem to Meckel's cave needs to be inspected. It is important at this point to identify points of contact between vessels and the trigeminal complex. A disposable endoscope permits inspection of all sides of the nerve, the compression may be from underneath.
The vascular structures are sharply mobilized. Veins should not be taken unless they cannot be mobilized and isolated. Veins that are coagulated have been reported to recollateralize. Postoperative swelling when all other variables have been kept constant with the exception of dividing the venous structures can occur. The vascular structures using microsurgical techniques can be mobilized and held out of place with very small amounts of shredded Teflon felt or Ivalon sponge. A sling of Teflon felt can anchor the vessels away from the nerve however; the vessels should never be kinked. Additional shredded Teflon felt is needed to interpose between the vessels and the nerves to prevent re-approximation. The felt should also be placed in such a way that it is less likely to move during different patient position or when the CSF space is refilled. The Teflon should be placed in moderation so as not to produce a secondary mass effect. Any vasospasms caused by manipulation can be treated with topically applied papaverine. The craniotomy is closed with one cranial facial plate and the wound closed in multiple layers. The patient is ambulated early and watched in the ICU overnight. Patients usually have immediate relief of pain, while others improve over three months.
CONCLUSION
Minimally invasive neurosurgery results in the least trauma to the brain yet optimize exposure. The smaller opening facilitates a quicker recovery and reduces risks. Employing equipment such as the high-speed drill and implementing anatomical knowledge permits a "quarter" size craniotomy at the junction of the lateral and sigmoid sinuses.
Anatomical variation that may result in larger craniotomies can be minimized with a stereotactic system and a small endoscope. Microvascular decompression for trigeminal neuralgia is a minimally invasive procedure that can be performed with minimal complications if strict adherence to microneurosurgical principles is followed without exception by the skull base neurosurgeon.
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