No abstract

Chronic subdural hematoma (CSDH) is generally treated by twist drill, and one and two burr-hole craniostomy. We proposed new classification of the intraoperative condition of CSDH, and present a safer technique for aspiration of CSDH in one burr-hole surgery. The intraoperative condition of CSDH was classified according to the connections between the hematoma cavity and the extracranial space as follows. The``closed condition'' represents only a single route consisting of a tube inserted intraoperatively connecting the extracranial space to the hematoma cavity. The``open condition'' includes another route or space, which can freely pass air, saline, or old hematoma fluid, in addition to the tube inserted intraoperatively. Twist drill craniostomy and two burr-hole craniostomy clearly involve the intraoperative closed and open conditions, respectively. One burr-hole craniostomy may involve either condition due to the operative procedure. Aspiration and irrigation of the hematoma is basically free and safe in the open condition, but risky in the closed condition. All of the hematoma can be aspirated through one burr hole under certain open conditions with temporary replacement of the hematoma cavity with air followed by replacement of air with saline. Twenty-seven patients with symptomatic CSDH underwent one burr-hole craniostomy by the above mentioned aspiration technique. There were no special complications. The recurrence rate was average. The substitution of saline after complete aspiration of hematoma carries little risk only under the``open condition,'' shortens the operation time, and achieves good irrigation of the hematoma.

Stretching of the VIIIth nerve should be avoided to prevent postoperative hearing impairment. Adequate exposure of the lower cranial nerve roots and lateral medulla oblongata from the caudal side without using the brain retractor gives enough space for decompression with minimum stretching of the VIIIth nerve. Maximum preservation of the arachnoid membrane along the VIIIth nerve and shortening of the duration of microscopic manipulation may help in avoiding postoperative hearing impairment.

T rigeminal neuralgia is considered to be a type of neurovascular compression syndrome 4,7 typically caused by compression of the trigeminal nerve by the superior cerebellar artery (SCA) or other arteries branching from the vertebral and basilar arteries, and sometimes by veins or tumors. 2,3 We report a case of trigeminal neuralgia caused by an artery that had almost encircled the nerve, which was successfully decompressed surgically, and discuss the anatomy of the offending artery and trigeminal nerve root vasculature. Case ReportHistory and Presentation. This 31-year-old woman visited our hospital because of right facial pain. She first experienced a sharp pain in the right V 2 area of her face at age 16 years. The pain was triggered by brushing her teeth or washing her face. Treatment was initiated with oral medication (carbamazepine 600 mg per day), but the pain aggravated and the affected region enlarged to include the entire right V 1 to V 3 distribution and was even easily triggered by eating and conversation.Imaging. Gradient echo MRI indicated the presence of arteries along the right trigeminal nerve (Fig. 1); MR angiography showed 3 arteries on the right side of the upper part of the basilar artery (BA) (Fig. 2 left), and further gradient echo MRI showed bilateral thin anterior inferior cerebellar arteries (AICAs) branching from the lower portion of the BA (Fig. 2 right). The 3D fusion image from the caudal side revealed an artery arising from the BA and coursing toward the right trigeminal nerve, with neurovascular conflict observed at the proximal part of the nerve root, so this artery was identified as the offending artery (Fig. 3A). On the basis of this image and another 3D image from the posterior direction, it was confirmed that the duplicated SCAs and the offending artery directly branching from the BA were congruent with the 3 arteries identified on MR angiography (Fig. 3B). A surgical view of the 3D image allowed detailed evaluation of the neurovascular complex at the nerve root (Fig. 3C).Operation and Postoperative Course. After providing informed consent, the patient underwent microvascular decompression through a right suboccipital retrosig- This 31-year-old woman presented with typical right trigeminal neuralgia caused by a trigeminocerebellar artery, manifesting as pain uncontrollable with medical treatment. Preoperative neuroimaging studies demonstrated that the offending artery had almost encircled the right trigeminal nerve. This finding was confirmed intraoperatively, and decompression was completed. The neuralgia resolved after the surgery; the patient had slight transient hypesthesia, which fully resolved within the 1st month after surgery. The neuroimaging and intraoperative findings showed that the offending artery directly branched from the upper part of the basilar artery and, after encircling and supplying tiny branches to the nerve root, maintained its diameter and coursed toward the rostral direction of the cerebellum, which indicated that the artery supplied both the trigem...

but the complications of titanium cranioplasty for small skull defect caused by the lateral suboccipital approach, particularly microvascular decompression (MVD) surgery, have not been investigated.From April 2008 to November 2013, 417 titanium cranioplasties for small suboccipital craniectomy were performed in our institution. Four hundred and nine cases were treated with titanium cranioplasty after MVD primarily and eight cases were treated for repeated procedure after MVD. In this report, we present two cases of exposed titanium mesh. Both patients suffered from complications after repeated procedures. Case Reports I. Case 1A 62-year-old underweight female (height 157 cm, weight 45 kg, and BMI 18.3 kg/m 2 ), who had undergone MVD for left facial spasm and repair of cerebrospinal fluid leakage 5 years before at our hospital, visited again because she felt a strange projection under the left postauricular skin. The titanium mesh implanted at the second surgery was exposed from the operative scar (Fig. 1A). Computed tomography (CT) revealed exposure of the titanium mesh with no evidence of intracranial pathology (Fig. 1B, C), which indicated the need for removal of the titanium mesh. After obtaining informed consent, primary skin closure was completed after removal of the titanium mesh and debridement of the affected skin. No gross evidence of infection was observed. She was treated with intravenous cefazolin sodium hydrate (CEZ) 2 g/day for 5 days and discharged from our hospital with no evidence of further complication. II. Case 2A 75-year-old underweight female (height 150 cm, weight 38.6 kg, and BMI 17.2 kg/m 2 ), who had undergone MVD for right trigeminal neuralgia 10 years and 5 years before, visited our hospital again because she noticed mucus on the operative scar. The shape of titanium mesh that had been implanted at the second surgery was visible at the operative scar ( Fig. 2A). CT showed that the titanium mesh was exposed with partial absence of the skin. There was no evidence of subcutaneous or intracranial pathology (Fig. 2B, C). Removal of the titanium mesh was indicated and after obtaining informed consent, primary skin closure was completed using the same procedure as in the previous case. No definitive infection was observed around the affected wound Two cases of exposed titanium mesh occurred after implantation for cranioplasty after repeated procedures for microvascular decompression (MVD). Case 1 was a 62-year-old female who underwent MVD for left hemifacial spasm followed by repair of cerebrospinal fluid leak after the surgery, and Case 2 was a 75-year-old female who underwent MVD twice for right trigeminal neuralgia. Both patients visited our hospital again with complaints of postauricular lesion. Titanium mesh was visible through the operative scar and was successfully removed with no complication in both cases. Both patients were underweight females, and combined with multistep surgery may have contributed to the pathology. The present cases suggest that use of titanium mesh should be av...