Yoo Byung Won, Park Han Ki
Department of Clinical Pharmacology, Clinical Trial Center, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Korean J Pediatr. 2013 Jun;56(6):235-41. doi: 10.3345/kjp.2013.56.6.235. Epub 2013 Jun 21.
Repair of tetralogy of Fallot (TOF) has shown excellent outcomes. However it leaves varying degrees of residual hemodynamic impairment, with severe pulmonary stenosis (PS) and free pulmonary regurgitation (PR) at both ends of the spectrum. Since the 1980s, studies evaluating late outcomes after TOF repair revealed the adverse impacts of residual chronic PR on RV volume and function; thus, a turnaround of operational strategies has occurred from aggressive RV outflow tract (RVOT) reconstruction for complete relief of RVOT obstruction to conservative RVOT reconstruction for limiting PR. This transformation has raised the question of how much residual PS after conservative RVOT reconstruction is acceptable. Besides, as pulmonary valve replacement (PVR) increases in patients with RV deterioration from residual PR, there is concern regarding when it should be performed. Regarding residual PS, several studies revealed that PS in addition to PR was associated with less PR and a small RV volume. This suggests that PS combined with PR makes RV diastolic property to protect against dilatation through RV hypertrophy and supports conservative RVOT enlargement despite residual PS. Also, several studies have revealed the pre-PVR threshold of RV parameters for the normalization of RV volume and function after PVR, and based on these results, the indications for PVR have been revised. Although there is no established strategy, better understanding of RV mechanics, development of new surgical and interventional techniques, and evidence for the effect of PVR on RV reverse remodeling and its late outcome will aid us to optimize the management of TOF.
法洛四联症（TOF）修复术已显示出极佳的效果。然而，它会留下不同程度的残余血流动力学损害，从严重的肺动脉狭窄（PS）到两端的自由肺动脉反流（PR）不等。自20世纪80年代以来，评估TOF修复术后远期结果的研究揭示了残余慢性PR对右心室（RV）容积和功能的不利影响；因此，手术策略发生了转变，从积极的右心室流出道（RVOT）重建以完全缓解RVOT梗阻，转变为保守的RVOT重建以限制PR。这种转变引发了一个问题，即保守的RVOT重建后可接受的残余PS程度是多少。此外，随着因残余PR导致RV功能恶化的患者进行肺动脉瓣置换（PVR）的情况增多，人们担心何时应进行该手术。关于残余PS，多项研究表明，除PR外的PS与较少的PR和较小的RV容积相关。这表明PS与PR相结合可使RV舒张特性通过RV肥厚来防止扩张，并支持保守的RVOT扩大，尽管存在残余PS。同样，多项研究揭示了PVR后RV容积和功能恢复正常的RV参数的PVR前阈值，并基于这些结果修订了PVR的适应症。尽管尚无既定策略，但更好地理解RV力学、开发新的手术和介入技术，以及PVR对RV逆向重构及其远期结果影响的证据，将有助于我们优化TOF的管理。
