経カテーテル的大動脈弁留置術後9ヵ月の人工弁感染性心内膜炎に対する人工弁摘出

Surgical Explantation of a Bioprosthesis Nine Months After Transcatheter Aortic Valve Implantation

大動脈弁狭窄症に対する治療法として2013年に経カテーテル的大動脈弁留置術（TAVI）が日本国内で保険収載されて以降，その症例数は年々増加し，大動脈弁狭窄症の治療に革命をもたらした．しかしTAVI例数の増加とともに合併症も明らかになってきた．その中でも人工弁感染性心内膜炎（PVE）は依然として避けられない合併症の一つである．TAVI弁摘出手術の成績は不良であるが，われわれはTAVI後9ヵ月にPVEを発症し，外科的摘出を行い良好な転帰を得た1例を経験したので報告する．

Case：82-year-old female. In October 2020, the patient underwent transcatheter aortic valve implantation （TAVI）［Evolut PRO R 23 mm］ via left subclavian artery approach for severe aortic valve stenosis. The patient was discharged home without any issues. However, nine months after surgery, the patient was hospitalized at another hospital for a right upper arm fracture and developed a fever. The patient was transferred to our hospital and was diagnosed with Enterococcal bacteremia while receiving antibiotic treatment. Echocardiography revealed leaflet thickening and cord-like structure on the artificial valve, and a diagnosis of prosthetic valve endocarditis （PVE） was made. The patient then underwent surgical removal of the valve. The patient had a good postoperative course and completed 4 weeks of antibiotic treatment before being transferred back to the referring hospital 31 days after surgery. TAVI made unprecendented revolution in the treatment of aortic valve stenosis. TAVI is often used for elderly patients with comorbidities because of high perioperative risk is for surgical aortic valve replacement. Although TAVI is widely promoted for its benefits, it is not without limitations. In cases with more than one year of follow-up, there are many complications and the risk of surgery is high. There have been few reports of cases from Japan requiring surgical removal of TAVI valve. In this case, PVE was diagnosed nine months after TAVI and the patient had a good outcome.