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[A midline vertebral artery aneurysm operated via transoral transclival approach (author's transl)].

A detail of an unsuccessful trial of transoral transclival operation for an aneurysm arising from the left vertebral artery was reported. The patient was 66 years old male who had bronchial asthma and difficulty in phonation and swallowing. The angiograms showed that the aneurysm, 1.5X1.5X2.0 cm in size, was situated in the midline at the level of caudal one-third of the clivus. A transoral transclival operation was performed following preoperative tracheostomy and gastrostomy to improve his pulmonary and nutritional condition. A midline incision on the palate was followed by the removal of the posterior half of palatal bone. The upper part of incision on the retropharyngeal mucosa was placed approximately 1 cm off the midline to facilitate closure afterwords. A caudal 1/3 of the clivus, anterior arch of the atlas and a part of the odontoid process were removed. The aneurysm, fusiform in shape, was then collapsed by needle puncture after the left vertebral artery was trapped between the posterior inferior cerebellar artery and the vertebro-basilar junction. Closure of the dura with a fascial patch was incomplete due to an extensive incision and coagulation of the dura. Closure of the retropharyngeal mucosa around the orifice of the Eustachian tube was also incomplete in spite of the paramedian incision described above. Postoperative course was complicated by an frequent occurrence of the attack of bronchial asthma causing loss of gastic juice from the gastrostomy and resultant hypoproteinemia, although the recovery of lower cranial nerve palsy was good. There was no signs of infection until the 21st postoperative day when meningitis developed. The patient died in the 28th postoperative day. The importance of complete closure of the dura and retropharyngeal mucosa to prevent meningial infection was discussed. Since the mucosa around the orifice of Eustachian tube was extremely friable and the closure was almost impossible, the risk of meningial infection was considered to be high, especially when the intradural procedure was necessary through transoral high clivotomy.