心筋梗塞に伴う左室内血栓症に対する外科治療成績

Surgical Results for Left Ventricular Thrombus Formation after Myocardial Infarction

左室内血栓症の有病率は1万人あたり7人であり，8割は虚血性心疾患に関連する1）．左室内血栓症はその形態から，左室壁に円盤状に強固に付着して可動性のないmural type，左室内に突出するprotruding type，左室壁と独立して動くmobile typeに分類され，protruding typeやmobile typeの場合，全身性塞栓症をきたすおそれがある2）．治療は冠状動脈血行再建および左室内血栓に対する治療であり，冠状動脈血行再建は経皮的冠状動脈形成術（PCI）および冠状動脈バイパス術（CABG），左室内血栓に対する治療は抗血栓療法および外科的血栓除去・左室形成術の選択肢がある．左室内血栓が前述のprotruding typeやmobile typeの場合，血栓塞栓症のリスクが高いため可及的除去が必要となり，緊急外科手術の適応となる．

We aimed to review the surgical results of left ventricular restoration for left ventricular thrombus after myocardial infarction.

A retrospective study was conducted on 5 patients who underwent thrombus removal and left ventricular restoration for left ventricular thrombus after myocardial infarction. Two patients were in an acute phase of myocardial infarction, and 3 in a chronic phase. Cerebral infarction occurred in 3 patients preoperatively.

Median observational period was 1.0 year. Left ventricular thrombus removal with septal anterior ventricular exclusion technique was performed. Concomitant procedure included 3 coronary artery bypass graftings and 1 left ventricular apex ablation. There was no perioperative bleeding event. The 30-day mortality occurred in 1 patient. There has been no systemic embolic complication, left ventricular dysfunction, nor recurrence of left ventricular thrombus during the observational period. The postoperative left ventricular volume reduced in 3 of the 4 survivors. The left ventricular ejection fraction increased postoperatively in 3 of the 4 survivors.

In conclusion, the septal anterior ventricular exclusion technique is an effective method for controlling perioperative bleeding, removing left ventricular thrombus completely, and preventing a recurrence of left ventricular thrombus and systemic embolism. This procedure also contributed to reducing the left ventricular volume, resulting in the improvement of the left ventricular function.