漏斗胸的術前評估：針對納氏手術（Nuss Procedure）的軟體開發及臨床之應用

Pre-Operation Evaluation of Pectus Excavatum : The Development and Clinical Application of Modeling Software for Nuss Procedure

漏斗胸是胸壁最常見的先天性畸型。漏斗胸的患者在外觀上呈現前胸壁向內凹陷情形，使胸腔空間變小，並且壓迫到心臟及肺臟，而心肺的功能受到影響。漏斗胸的矯治不僅只是外觀的整復，更重要的是心肺功能的增進，在兒童期早期矯治，可以得到最好的效果。漏斗胸的手術方法，傳統治療漏斗胸必須進行大傷口的手術；自1998年Dr. Nuss首先發表他的納氏手術（Nuss procedure），顯示此種手術的優越性及可接受性。這種手術標榜的是簡單、迅速，手術過程中會將一條不鏽鋼矯正板由腋下植入而置放於胸骨後方，利用此矯正鋼板將內凹之胸骨向外推出來做矯正手術。這種微創的納氏手術要把這內凹的前胸往外恢復到甚程度，並沒有一定的標準，只能靠手術醫師術中的模擬及即興創作。本研究之目的主要針對漏斗胸的病人，透過病患的胸部電腦斷層檢查影像，重建出其有缺陷的胸型外觀，再以自創的數位模型塑型軟體，編修出理想的胸型，取得手術矯正板的外型，作為進行真實手術時的參考。此一方法可在術前模擬出病人接受胸部矯正板矯正後的胸形，在病人未接受開刀前即可和病人及其家屬直接在電腦影像上，討論大家可接受的胸型，增加手術結果的可接受性及減少醫療糾紛。此計畫發展過程中接受96年國科會小產學計畫（NSC96-2622-B-214-001-CC3；EDP J96015），及義大醫院98年院內計畫（EDAH-P98021）補助開發此一軟體且取得臨床數據。

Pectus excavatum is an unbalanced growth in the costochondral regions resulting in depression deformity of the anterior chest wall. The surgical indications of such deformity are the physiologic and the psychological (cosmetic) effects. The minimal invasive Nuss procedure is the operation most adapted in recent years with the advantage of less invasion, short operation time and simple method. This procedure utilized a stainless Pectus bar, which is shaped as needed and put into the thoracic cavity, to push outward the depressed sternum. The main limitation of this procedure is that the operated surgeon makes the shape of the Pectus bar subjectively during the operation. If the chest wall deformity is complex or the experience of the surgeon is limited, it is then difficult for a surgeon to shape the Pectus bar satisfactorily. Therefore, it is our design that we can develop a computer-software to imitate the post-operative chest wall contour based on the pre-operative chest computer tomography of the patient. And we can shape the pectus bar pre-operatively according to the picture that the software figures out. Using this pre-shaped chest contour, we can show it to the patient before operation. Using the imitated picture of the chest contour we can discuss with the patient and the family about the most satisfactory chest wall contour they want and, thus, to avoid many post-operative legal problem. The software has been applied to 10 patients with acceptable results regarding to the estimated transverse chest wall length, antero-posterior chest wall length, the pectus index and the type of pectus bar we need. Nevertheless, there are some defects of the software and we will correct it in the near future.