治療に難渋した急性硬膜外血腫の2例と外減圧術併用に関する考察

Two Cases of Difficult-to-Treat Acute Epidural Hematoma and a Review of Decompressive Craniectomy with Hematoma Evacuation

Ⅰ．はじめに

　重症頭部外傷治療・管理のガイドラインによると，重症頭部外傷で脳ヘルニア徴候があるか，開頭術の適応のある症例，特に若年症例では外減圧術の併用を検討する¹⁵⁾とされている．しかし，難治性の頭蓋内圧亢進を伴う重症頭部外傷398症例を対象に，外減圧術群202例と内科的治療群196例に分け，転帰を比較したRESCUEicp Trialにおいて，死亡率は前者で有意に減少するものの，機能予後不良となるリスクは前者で有意に増加し，機能予後良好となった患者の割合に有意な差はなかったと報告されている¹⁰⁾．さらに，頭部外傷に対する外減圧術では数々の合併症を伴う可能性があるため，慎重な対応が必要とされている²¹⁾．

　急性硬膜外血腫（acute epidural hematoma：AEDH）に対する手術法としては，開頭血腫除去術が推奨されているが，脳浮腫や脳ヘルニア徴候を伴う場合は外減圧術の追加も考慮される^6,15)．AEDHを含め，重症頭部外傷に対する外減圧術の確固たる適応基準は未だなく，症例ごとにその適応を検討する必要がある．

　今回われわれは，治療に難渋したAEDHの2例をもとに，外減圧術併用にあたり注意すべき点について，若干の文献的考察を加えて報告する．

　INTRODUCTION:Decompressive craniectomy（DC）with craniotomy for acute epidural hematoma（AEDH）removal is controversial. Here, we summarized two difficult AEDH cases where DC was performed.

　CASE 1:A 26-year-old man sustained a head injury in a bicycle accident, with a Japan Coma Scale（JCS）score of 200, right pupil mydriasis, and a left decerebrate posture on admission. Computed tomography（CT）revealed right AEDH with a midline shift. Craniotomy was performed without DC. Postoperatively, his consciousness level and anisocoria improved（JCS score, 30). Furthermore, no cerebral infarction was observed on CT at 9 h after surgery;however, at 48 h after surgery, a cerebral infarction with a mild midline shift was evident in the right hemisphere. His consciousness level deteriorated（JCS score, 100), and we initiated glyceol infusion. Worsening of the midline shift was apparent on CT 100 h after surgery;thus, DC was immediately performed.

　CASE 2:A 15-year-old boy was injured in a fall. On admission, his JCS score was 10. Immediately afterward, he showed neurological deterioration（JCS score, 200), right pupil mydriasis, and a left decorticate posture. CT revealed right AEDH with a midline shift;thus, craniotomy was performed with DC. On hospitalization day 10, he had orthostatic headache and a JCS score of 1. CT revealed paradoxical midline shift to the opposite side of craniotomy, and syndrome of the trephined was considered. He was placed in the Trendelenburg position until cranioplasty was performed on hospitalization day 18.

　CONCLUSION:Patients with AEDH presenting severe consciousness issues should undergo hematoma removal. Although DC is controversial, surgeons should administer intensive and prompt treatment according to the circumstance and should consider DC for appropriate AEDH cases.