頸動脈内膜剥離術における超音波検査による動脈壁形態の術中評価  [in Japanese] Intraoperative Evaluation of Vascular Wall and Hemodynalnics of the Carotid Artery by Ultrasonography in Carotid Endarterectorny  [in Japanese]

術中モニタリングを手技による術中および術後合併症を予防するためのフィードバックシステムととらえるならば,頸動脈内膜剥離術(CEA)において脳波,体性感覚誘発電位,経頭蓋ドップラー,などが術中脳虚血のチェックを含めた脳循環の評価として用いられている.しかし手術手技の直接の対象である頸部頸動脈については剥離術後の動脈内腔の形態の情報を得るために術中血管造影が主として行われてきたが,合併症の可能性と手技に時間と手間がかかることより必ずしも普及はしていない.それに対し超音波検査は安全でhandyに使用でき,動脈内腔の形態,血流情報を得ることができる.そこでわれわれはCEA術中に超音波検査を導入することにより動脈壁とくにプラークおよび剥離後の内皮断端の形態や血行動態を術中にモニタリングし手技の問題点をより早期に把握する試みを行ってきたので報告する.

Various kinds of intraoperative monitoring are used in carotid endarterectomy (CEA) such as somatosensory encephalogram or transcranial Doppler for detection of cerebral ischemia or microembolism. However, anatomical information about arterial wall, which is manipulated directly, is poorly monitored during operation. Postoperative ischemic complication and restenosis can be occasionally caused by failure of manipulation of intimal st,ump during CEA. Technical defects can be repaired if intramural problems are detected by ultrasonography (USG) during operation. In 24 cases of CEA between October 2001 and March 2004, we performed intraoperative USG to monitor the arterial wall and hemodynamics. Intraoperative digital angiography (DSA) was perfomned to compare USG findings. We were able to grasp characteristics and extension of plaque before arteriotomy. It was especially useful for the cases whose plaque end was obscure by DSA. An intimal stump on both sides after CEA could be recognized by B-mode scans. Peak systolic velocities measured by the pulse Doppler method were decreased in all cases after CEA. Three cases were repaired following recognition of technical defects by USG. One was an intimal flap over 2 mm; the others were due to residual common carotid artery lesion. In conclusion, intraoperative USG in CEA was useful in terms of grasping both information of vascular wall and intraluminal hemodynamics in real time, and allowed the detection of technical defects that required surgical repair. Intraoperative USG monitoring may improve operative results by reducing technical defects.