皮質下出血の出血原因からみた手術適応

Indications for Surgery to Determine the Etiology of Subcortical Hemorrhage

I．はじめに

　大脳皮質下出血の原因として，高血圧の頻度は31^9）-45^3）％と，他の部位の脳出血に比べ低い．これは脳動静脈奇形（AVM）や脳動脈瘤，脳腫瘍，出血性性素因など多くの原因があるためと思われる．原因不明の特発性のものは12^9）-27^3）％と報告されているが，この中には血腫量が少なくても出血原因検索の目的で手術が行われることもあり^7），その手術適応が問題となる．われわれは，皮質下出血の原因病変，再出血の有無および長期予後について調査し，その手術適応を検討した．

We studied the etiology of subcortical hemorrhage in 55 patients (30 males, 25 females), aged 19-83years (mean 60 years). CT scan was made in all patients on admission, with the use of intravenous infu-sion of contrast agent in 35 patients. Cerebral angiography was performed in 37 patients and MRI was per-formed in 22 patients. Forty-one patients underwent surgery and the other fourteen patients were treatedconservatively. The cause of bleeding had been discovered before surgery in 12 cases; 10 arteriovenousmalformations and 2 brain tumors. They were discovered by meticulous neuroradiological investigations in-cluding cerebral angiography, MRI, dynamic MRI, MRA and enhancing CT. The cause of bleeding wasnewly discovered after surgery in 7 cases; all of amyloid angiopathy. It remained unknown in the other 22surgical cases although hypertensive angiopathy was suspected in eleven of them. Among the 14 patientswho received conservative therapy, hemorrhagic diathesis including the use of Warfarin and DIC was thecause of bleeding in four cases and the etiology remained unknown in other ten, although hypertensiveangiopathy was suspected in eight of them. The 32 patients in whom the etiology remained unknown hadbeen observed as long as 12-120 months (mean, 40 months) and although bleeding has occurred at differ-ent locations in two of these patients, there has been no recurrence of bleeding at the same location in anyof them. In conclusion, surgery is not indicated to determine the etiology of subcortical hemorrhage whenmeticulous neuroradiological investigations fail to disclose any vascular or tumorous lesions.