Abstract：
OBJECTIVE: A large proportion of infants with vallecular cyst (VC) have coexisting laryngomalacia (LM). Feeding difficulties, regurgitation, occasional cough, and sleep-disordered breathing are the common symptoms in moderate to severe cases. The surgical management of these cases is more challenging and remains controversial. The purpose of this study is to help surgeons select the effective surgical strategies by computer-aided design (CAD) and computational fluid dynamics (CFD) simulations of the upper airway flow characteristics.
METHODS: The three dimensional (3D) geometric model of the upper airway was reconstructed based on two dimensional (2D) medical images of the patient with VC accompanied with LM. Virtual surgeries were carried out preoperatively to simulate three possible post-operative states in silico. The different outcomes of virtual surgical strategies were predicted based on computational evaluations of airway fluid dynamics including pressure, resistance, velocity, and wall shear stress (WSS).
RESULTS: The CFD results of this study suggested the importance of the angle between the rim of epiglottis and arytenoid epiglottic (AE) fold. There was a small impact on the upper airway flow field while the VC was removed and the angle of epiglottis was unchanged. The partial lifting of epiglottis can further improve the flow field. With performing supraglottoplasty (SGP) and the marsupialization of VC, epiglottis was completely recovered, and the flow field was significantly improved. The clinical symptoms of this patient improved greatly after surgeries and no recurrence or growth retardation were noted during 1-year follow-up. The clinical prognosis was consistent with the prediction of the CFD results.
CONCLUSIONS: The state of epiglottis needs to be carefully checked to evaluate the necessity of performing further SGP in the patients with VC accompanied with LM. CFD and CAD could be developed as a new approach to help surgeons predict the post-operative outcomes through quantification of the airflow dynamics, and make the optimal and individualized surgical approaches for patients with airway obstruction.
METHODS: The three dimensional (3D) geometric model of the upper airway was reconstructed based on two dimensional (2D) medical images of the patient with VC accompanied with LM. Virtual surgeries were carried out preoperatively to simulate three possible post-operative states in silico. The different outcomes of virtual surgical strategies were predicted based on computational evaluations of airway fluid dynamics including pressure, resistance, velocity, and wall shear stress (WSS).
RESULTS: The CFD results of this study suggested the importance of the angle between the rim of epiglottis and arytenoid epiglottic (AE) fold. There was a small impact on the upper airway flow field while the VC was removed and the angle of epiglottis was unchanged. The partial lifting of epiglottis can further improve the flow field. With performing supraglottoplasty (SGP) and the marsupialization of VC, epiglottis was completely recovered, and the flow field was significantly improved. The clinical symptoms of this patient improved greatly after surgeries and no recurrence or growth retardation were noted during 1-year follow-up. The clinical prognosis was consistent with the prediction of the CFD results.
CONCLUSIONS: The state of epiglottis needs to be carefully checked to evaluate the necessity of performing further SGP in the patients with VC accompanied with LM. CFD and CAD could be developed as a new approach to help surgeons predict the post-operative outcomes through quantification of the airflow dynamics, and make the optimal and individualized surgical approaches for patients with airway obstruction.
摘要：
目的：大比例的瓣膜囊肿（VC）婴儿同时存在喉软化（LM）。喂养困难,返流,偶尔咳嗽,睡眠呼吸紊乱是中度至重度病例的常见症状。这些病例的手术治疗更具挑战性，仍然存在争议。本研究的目的是通过计算机辅助设计（CAD）和计算流体动力学（CFD）模拟上呼吸道流动特性，帮助外科医生选择有效的手术策略。
方法：基于伴有LM的VC患者的二维（2D）医学图像重建上气道的三维（3D）几何模型。术前进行虚拟手术，以模拟计算机中三种可能的术后状态。基于气道流体动力学的计算评估，包括压力，预测虚拟手术策略的不同结果。阻力,速度,和壁剪应力（WSS）。
结果：这项研究的CFD结果表明会厌边缘和类会厌（AE）褶皱之间的角度的重要性。去除VC且会厌角不变时，对上气道流场的影响很小。会厌的局部抬升可以进一步改善流场。进行声门上成形术（SGP）和VC的袋化，会厌完全康复,流场明显改善。该患者的临床症状在手术后大大改善，并且在1年的随访中没有发现复发或生长迟缓。临床预后与CFD结果的预测一致。
结论：需要仔细检查会厌的状态，以评估合并有LM的VC患者进一步进行SGP的必要性。CFD和CAD可以作为一种新的方法来帮助外科医生通过量化气流动力学来预测术后结果。并为气道阻塞患者制定最佳和个性化的手术方法。
方法：基于伴有LM的VC患者的二维（2D）医学图像重建上气道的三维（3D）几何模型。术前进行虚拟手术，以模拟计算机中三种可能的术后状态。基于气道流体动力学的计算评估，包括压力，预测虚拟手术策略的不同结果。阻力,速度,和壁剪应力（WSS）。
结果：这项研究的CFD结果表明会厌边缘和类会厌（AE）褶皱之间的角度的重要性。去除VC且会厌角不变时，对上气道流场的影响很小。会厌的局部抬升可以进一步改善流场。进行声门上成形术（SGP）和VC的袋化，会厌完全康复,流场明显改善。该患者的临床症状在手术后大大改善，并且在1年的随访中没有发现复发或生长迟缓。临床预后与CFD结果的预测一致。
结论：需要仔细检查会厌的状态，以评估合并有LM的VC患者进一步进行SGP的必要性。CFD和CAD可以作为一种新的方法来帮助外科医生通过量化气流动力学来预测术后结果。并为气道阻塞患者制定最佳和个性化的手术方法。
