Microvascular decompression for trigeminal neuralgia

In 1967, Jannetta discovered that in the patients with primary trigeminal neuralgia in the area where the nerve roots entered the brainstem, the compression of abnormal vasospasm at the cerebral pons was the main cause of the disease. After the nerves in this area are subjected to pulsatile compression of abnormal vasospasm, the myelin sheath and axons can be denatured, and the efferent fibers and the pain afferent fibers are short-circuited, or the normal tactile afferent impulses also cause pain. According to a large case report, in the case of trigeminal neuralgia, 78.8% to 88.3% of the nerve roots were compressed by the vascular, and 5.2% to 9.8% were caused by the tumor, of which arterial compression accounted for 58.9%, and venous compression accounted for 13.9%. The intravenous mixed oppression accounted for 2%. The superior cerebellar artery and the inferior cerebellar artery are the main arteries. Treating diseases: trigeminal neuralgia Indication Trigeminal neuralgia microvascular decompression is suitable for patients with severe pain after treatment with drugs, ethanol injection or radiofrequency thermocoagulation. Contraindications Elderly patients and patients with severe organs should be considered carefully. Preoperative preparation According to the routine preparation of the posterior cranial fossa. For patients with local anesthesia, it should be explained how to cooperate. Surgical procedure Incision Under the occipital occipital, 2cm behind the mastoid to make a straight skin incision; or after the mastoid to make a barb-shaped cane incision; or in the upper part of the posterior mastoid to make a transverse incision, about 4cm. 2. The bone window Make a bone window with a diameter of 3 ~ 4cm, the upper edge reaches the transverse sinus, and the outer side reaches the edge of the sigmoid sinus. 3. Dural valvular incision The basal ligament is connected to the transverse sinus, and the dura mater is turned upward to expose the outer upper part of the posterior fossa. 4. Exposing the trigeminal nerve root The cerebellar hemisphere is pulled down to the inner side, and the cerebrospinal fluid is released. After the cerebellum sinks, the rock vein is carefully peeled off with a micro-stripping, and if necessary, it is cut off after electrocoagulation. Recognize the face, listen to the nerves, and reveal the trigeminal nerve roots. Cut the arachnoid attached to the nerve root, separate it to the nerve root near the pons, and carefully explore it. 5. Free compression of nerve root vessels After the arterial spasm or abnormal blood vessels are pressed to compress the nerve roots, the blunt microscopic stripper is inserted into the gap between the artery and the nerve root for free. If there is adhesion, it can be cut with micro scissors, and the artery and nerve root are separated. Insert a small piece of Teflon cotton lint or gasket between them (Fig. 4.12.4-3). In the case of venous compression, the vein is freely separated from the surface of the nerve root, and the bipolar is coagulated and then cut. 6. Suture the dura mater and routinely close the skull. complication Dura mater and muscle suture are not strict, the operation area is not tightly wrapped, can cause cerebrospinal fluid leakage or pseudocyst, can cause intracranial and / or intraoperative infection, the mouth does not heal, the treatment is very difficult. Once found, the leak should be sutured in time. The posterior cranial nerve injury can cause hoarseness, coughing, and difficulty swallowing. According to statistics, 85% of postoperative pain disappeared; 2% to 4% suffered from secondary surgery due to pain; 5% to 13% of pain recurred, and 1% still had severe pain.