Surgical Treatment of Descending Aortic Aneurysms - Bypass, Shunting, or Simple Aortic Clamping -

下行性胸主動脈瘤之外科治療

張珩(Hang Chang) ； 王世名(Shih-Ming Wang) ； 洪啟仁(Chi-Ren Hung)

《慈濟醫學雜誌》 5卷1期 (1993/03) Pp. 1-8

https://doi.org/10.6440/TZUCMJ.199303.0001

摘要

進行下行性主動脈瘤(descending aortic aneurysm)之外科治療時需將動脈瘤之兩端夾起。此時，在夾起處之近心端會造成高血壓之狀態，而在其遠心端則會有低血壓之發生。在近心端有突發性血壓大幅增高時會引起左心室負荷增加、二尖瓣閉鎖不全、左心房壓增高、左心室壁失血、肺鬱血其或出血等現象；在遠心端有突發性的血壓大幅下降，則易造成脊柱、腎、內臟及下肢之缺血，導致續發性的傷害。本文討論的主題在 ”當進行下行性主動脈瘤手術” 時，我們應用何種方式來避免上述所提之併發症。
從王九六九年起一月到一九九○年十一月止，共有四十八位病人在台大醫院接受鑑行性胸主動脈瘤之外科治療。其中有二十六位病人(第一群)使用Gott分流手術；有十位病(第二群)使用人工心肺循環繞道(bypass)；十二位病人(第三群)則不使用任何分流或繞道的方法行動脈瘤手術。手術超果顯示第一群死率(19%)與第三群的已率(17%)類似，而第二群的死已率則高達80%。手術方法不同所造成之罹病率在各組無明顯差異。分析第二群死亡患者發現使用肝素(heparin)及廣泛動脈瘤剝離面(dissection surface)是此群高死亡率的主因。
由本文之分析可發現，使用分流手術(shunt)於主動脈瘤之外科手術中是較佳的選擇。但在慢性變化之動脈瘤患者群裡，在仔細監偵病人之血流，血壓及主動脈夾起時間(aortic cross-clamping time)之形下，只要患者本身側枝循環(collateral circulation)沒有問題，不用分流(shunt)或人工心肺繞(bypass)亦是可以接受的方法。由於人工心肺繞道(bypass)需使用肝素(heparin)，易引起手術後之出血，故我們建議其僅可使用於手術前血液力學不穩定之患者。

關鍵字

胸主動脈瘤 ； 分流手術 ； 人工心肺循環

並列摘要

We have reviewed our experience of resection of 48 aneurysms of the descending thoracic aorta during the past 2 decades. There were 11 atherosclerotic aneurysms, 34 aneurysms associated with aortic dissection, and 3 posttraumatic aneurysms. During repair, a temporary shunt was used in 26 patients (54%), partial (femorofemoral) cardiopulmonary hypass (CPB) in 10 patients (21%), and simple aortic cross-clamping in 12 patients (25%). For the group with a temporary shunt, 4 out of 17 patients (24%) undergoing emergency operation died, and 1 out of 9 patients (11%) undergoing elective surgery died. The aortic cross-clamping time ranged from 30 to 120 min with a mean of 54 min. For the group with partial cardiopulmonary bypass, 2 out of 4 patients (50%) undergoing elective surgery died; and all of the 6 patients (100%) undergoing emergency operations died. The aortic cross-clamp time ranged from 35 to 162 min with a mean of 99 min. For the group with simple aortic cross-clamping, all of the 6 patients undergoing elective surgery survived, and 2 out of 6 patients (33%) undergoing emergency operation died. The aortic cross-clamping time ranged from 28 to 74 min with a mean of 46 min. Considering the surgical morbidity, mortality and associated risk factors, a shunt procedure appeared to be the method of choice in surgical treatment of descending aortic aneurysm. Under the surveillance of blood pressure in both aortic segments proximal and distal to the aortic occlusion, direct aortic cross-clamping method can be safely applied to those who had adequate collateral perfusion. Bypass with systemic heparinization resulted in intraoperative coagulopathy, thus induced high surgical morbidity and mortality. We would like to confine the technique to those who had a ruptured aneruysm, an extensive aortic dissection or anticipated excessive hemorrhage during tissue dissection.

並列關鍵字

descending thoracic aorta ； thoracic aortic aneurysm ； bypass ； shunting ； simple aortic clamping