在宅中心静脈栄養法患者へ心外膜パッチリードを用いた植込み型除細動器移植例―経静脈性到達困難例への工夫

Implantable Cardioverter Defibrillator Implantation using Epicardial Patch Electrodes for a Home Total Parenteral Nutrition Patient with Poor Venous Access

要旨　患者は68歳，男性，広範囲小腸切除術後で在宅中心静脈栄養法を実施中であり，経静脈型心室ペースメーカ移植術後であった．発熱と右下肢深部静脈血栓症で前医に入院中，高熱時に心室細動を来して電気的除細動治療を要し，植込み型除細動器移植目的で転院した．ペーシングシステムを除去して心筋リードでペースメーカを再移植した．感染は消退したが，電気生理学的検査で心室細動が誘発され，植込み型除細動器移植術を行った．経静脈リード使用は感染再発が危惧され，両下肢深部静脈血栓と左無名静脈狭窄症のために経静脈到達法は困難と考えた．胸骨正中切開し，心筋リードを右心房と右心室表面に移植し，左右の心囊膜外側に心外膜パッチリード(Medtronic社)を縫着し，本体は左上腹部皮下に移植した．移植後1年6カ月では致死的不整脈の再発や除細動の作動はなく，日常生活に復帰している．

　A 68-year-old man was referred to our institution for removal of a ventricular pacing system using an endocardial electrode with bacterial infection, and treatment of repeated ventricular fibrillation accompanied with high fever. He also had a past history of home total parenteral nutrition because of short bowel syndrome, and deep venous thrombus of both lower extremities and stenosis of the left innominate vein. Initially, his ventricular pacing system was removed for treatment of bacteremia and a new dual pacing system was implanted with epicardial electrodes through the subxiphoid approach. After treatment of the infection, we planned to implant an implantable cardiovertor defibrillator(ICD) with extrapericardial defibrillator patches for reducing the risk of repeated bacteremia and increasing the chance of venous approach for home total parenteral nutrition.

　Under general anesthesia, the patient was placed in a spine position. Defibrillation pads were placed on the right and left lateral chest for transthoracic rescue shocks. All surgical manipulations were performed through a full sternotomy. The pericardium over the left ventricle and right atrium was easily grasped and opened anteriorly to the phrenic nerve. A large sized epicardial patch electrode(Medtronic, model 6921L) was placed extrapericardially over the posterolateral and anterior left ventricle and fixed to the pericardium with seven stitches. A medium sized epicardial patch(Medtronic, model 6921M) was secured extrapericardially over the right atrium with six-point sutures on the pericardium. The epicardial leads were placed at the right atrium and ventricle as the pace sense lead. All leads were tunneled to a subcutaneous generator pocket in the left upper quadrant of the abdomen. The ICD(Medtronic, model D164AWG) was then activated and tested. Defibrillation threshold testing was successful twice at 25J. The patient is doing well without recurrence of life-threatening ventricular arrhythmias and bacteremia, 18 months after the ICD implantation.