Fontan術後における房室弁逆流と房室弁輪形態の関連：三次元イメージングを用いた検討

Naka Saito; 齊藤央; Katsuaki Toyoshima; 豊島勝昭; Sayaka Ikeda; 池田さやか; Rie Shibata; 芝田梨恵; Saki Shiraki; 白木沙紀; Sachie Yukiyoshi; 雪吉祥恵; Shin Ono; 小野晋; Sadamitsu Yanagi; 柳貞光; Hideaki Ueda; 上田秀明

doi:10.11272/jss.398

Fontan術後における房室弁逆流と房室弁輪形態の関連：三次元イメージングを用いた検討Impact of the Three-Dimensional Geometry of the Atrioventricular Valve Annulus on Atrioventricular Valve Regurgitation After Fontan Palliation

齊藤央¹，豊島勝昭²，池田さやか¹，芝田梨恵¹，白木沙紀¹，雪吉祥恵¹，小野晋³，柳貞光³，上田秀明³Naka Saito¹, Katsuaki Toyoshima², Sayaka Ikeda¹, Rie Shibata¹, Saki Shiraki¹, Sachie Yukiyoshi¹, Shin Ono³, Sadamitsu Yanagi³, Hideaki Ueda³

¹ 神奈川県立こども医療センター検査科Department of Clinical Laboratory, Kanagawa Children’s Medical Center

² 神奈川県立こども医療センター新生児科Department of Neonatology, Kanagawa Children’s Medical Center

³ 神奈川県立こども医療センター循環器内科Department of Pediatric Cardiology, Kanagawa Children’s Medical Center

受付日：2022年8月30日Received: August 30, 2022

受理日：2023年3月30日Accepted: March 30, 2023

発行日：2023年8月1日Published: August 1, 2023

目的：Fontan手術後における房室弁逆流は重要な予後規定因子である．しかし房室弁逆流の発生機序は不明確である．本研究の目的は，Fontan手術後における房室弁逆流と房室弁輪形態の関連性を評価することである．

対象と方法：経胸壁心エコー図検査で房室弁の三次元ボリュームデータを取得できた102例のFontan手術後患者を後向きに評価した．房室弁輪指標として，弁輪面積，弁輪の高さ，bending angleを三次元的に計測した．房室弁形態を共通房室弁，単一三尖弁，単一僧帽弁，二弁口房室弁の三尖弁，二弁口房室弁の僧帽弁に分類し，その5群で房室弁輪指標を比較した．またvena contracta幅で評価した逆流の重症度と房室弁輪指標との関連性を評価した．

結果と考察：対象102例の内，共通房室弁は33例，単一三尖弁は22例，単一僧帽弁は32例，二弁口房室弁は15例であった．共通房室弁および単一三尖弁では，他の房室弁形態と比較して，弁輪面積およびbending angleが大きく，弁輪の高さが低かった．中等度以上の房室弁逆流を認めた症例は共通房室弁および単一三尖弁で頻度が多かった．共通房室弁および単一三尖弁において，逆流の重症度は弁輪面積と機能的単心室サイズと相関していた．また弁輪面積は機能的単心室サイズで調整後も逆流の重症度と関連していた．

結論：Fontan手術後患者では共通房室弁および単一三尖弁を有する症例において有意に中等度以上の逆流の頻度が高かった．その逆流発生の機序として，弁輪面積や機能的単心室サイズが重要な因子であることが示唆された．

Purpose: Atrioventricular valve regurgitation is a known risk factor for adverse outcomes in patients who undergo Fontan palliation. However, the mechanism of atrioventricular valve regurgitation development has not been clarified in these patients. We aimed to assess the relationship between atrioventricular valve regurgitation and annulus morphology and examine the mechanism of atrioventricular valve regurgitation in Fontan palliation.

Patients and Methods: A total of 102 patients who underwent Fontan palliation and three-dimensional transthoracic echocardiography were retrospectively evaluated. The dataset of the atrioventricular valve obtained by three-dimensional transthoracic echocardiography and the following parameters were measured to characterize the three-dimensional geometry of the atrioventricular valve annulus: annulus area, annulus height, and bending angle. The atrioventricular valve was classified into the following five groups: common atrioventricular valve, single tricuspid valve, single mitral valve, tricuspid valve in two separate valves, and mitral valve in two separate valves. The atrioventricular valve annulus parameters were compared between the five groups. The atrioventricular valve regurgitation severity was assessed by the vena contracta width, and its relationship with the atrioventricular valve annulus parameters was evaluated.

Results and Discussion: Atrioventricular valve morphology was the common atrioventricular valve in 33 patients, single tricuspid valve in 22 patients, single mitral valve in 32 patients, and two separate valves in 15 patients. The common atrioventricular and single tricuspid valves had a larger annulus area, smaller height, and larger bending angle than the other atrioventricular valve morphologies. The frequency of greater than or equal to moderate atrioventricular valve regurgitation was higher in patients with the common atrioventricular and single tricuspid valves. In the common atrioventricular and single tricuspid valves, vena contracta width correlated with annulus area, and functional single ventricular size. The annulus area was an independent determinant of vena contracta width after adjustment for functional single ventricular size.

Conclusion: Atrioventricular valve regurgitation was observed significantly more frequently in patients with the common atrioventricular and single tricuspid valves than with the other atrioventricular valve morphologies after Fontan palliation. The increased annulus area and functional single ventricular size are suggested to be important features in the mechanism of atrioventricular valve regurgitation.

Key words: Fontan palliation; functional single ventricle; atrioventricular regurgitation; annulus geometry; three-dimensional echocardiography

超音波検査技術

原著Original Article

Fontan術後における房室弁逆流と房室弁輪形態の関連：三次元イメージングを用いた検討Impact of the Three-Dimensional Geometry of the Atrioventricular Valve Annulus on Atrioventricular Valve Regurgitation After Fontan Palliation