Juvonen T, Ergin M A, Galla J D, Lansman S L, McCullough J N, Nguyen K, Bodian C A, Ehrlich M P, Spielvogel D, Klein J J, Griepp R B
Departments of Cardiothoracic Surgery and Biomathematics, Mount Sinai School of Medicine, New York, USA.
J Thorac Cardiovasc Surg. 1999 Apr;117(4):776-86. doi: 10.1016/S0022-5223(99)70299-0.
This study was an attempt to determine risk factors for rupture and to improve management of patients with type B aortic dissection who survive the acute phase without operation.
We studied 50 patients by means of serial computer-generated 3-dimensional computed tomographic scans. All patients who did not undergo operative treatment before the completion of at least 2 computed tomographic scans a minimum of 3 months apart after an acute type B dissection were included in the study. The median duration of follow-up was 40 months (range 0.9-112 months). Only 1 patient died of causes unrelated to the aneurysm during follow-up. Nine patients had fatal rupture (18%); 10 patients underwent elective aneurysm resection because of rapid expansion or development of symptoms, and 31 patients remained alive without operation or rupture. Possible risk factors for rupture in patients in the rupture, operative, and event-free groups were compared, as were dimensional data from first follow-up and last computed tomographic scans.
Older age, chronic obstructive pulmonary disease, and elevated mean blood pressures were unequivocally associated with rupture (rupture versus event-free survival, P <.05), and pain was marginally significantly associated. Analysis of dimensional factors contributing to rupture was complicated by the fact that patients who underwent elective operation had significantly larger aneurysms and faster expansion rates than did either of the other groups, leaving comparisons of aneurysmal diameter between groups with and without rupture showing only marginal statistical significance. The last median descending aortic diameter before rupture in the rupture group was 5.4 cm (range 3.2-6. 7 cm).
In an environment in which patients with large and rapidly expanding aneurysms are usually referred for surgical treatment, older patients with chronic type B dissections, especially if they have uncontrolled hypertension and a history of chronic obstructive pulmonary disease, are significantly more likely to have rupture than are younger, normotensive patients without lung disease. Neither the presence of a persistently patent false lumen nor a large abdominal aortic diameter appears to increase the risk of rupture. Overall, our nondimensional data strikingly resemble the natural history of patients with nondissecting aneurysms, suggesting that calculations derived from data on chronic descending thoracic and thoracoabdominal aneurysms would provide an overly conservative individual estimate of rupture risk for patients with chronic type B dissection, who tend toward earlier rupture of smaller aneurysms. A more aggressive surgical approach toward treatment of patients with chronic type B dissection seems warranted.
本研究旨在确定破裂的危险因素，并改善急性期未经手术治疗而存活的B型主动脉夹层患者的管理。
我们通过系列计算机生成的三维计算机断层扫描对50例患者进行了研究。所有在急性B型夹层后至少间隔3个月完成至少2次计算机断层扫描之前未接受手术治疗的患者均纳入本研究。随访的中位时间为40个月（范围0.9 - 112个月）。随访期间只有1例患者死于与动脉瘤无关的原因。9例患者发生致命破裂（18%）；10例患者因动脉瘤快速扩张或出现症状而接受择期动脉瘤切除术，31例患者存活且未发生手术或破裂。比较了破裂组、手术组和无事件组患者破裂的可能危险因素，以及首次随访和最后一次计算机断层扫描的尺寸数据。
年龄较大、慢性阻塞性肺疾病和平均血压升高与破裂明确相关（破裂与无事件生存，P <.05），疼痛与之有边缘性显著相关。由于接受择期手术的患者动脉瘤明显更大且扩张速度比其他两组更快，这一事实使对导致破裂的尺寸因素的分析变得复杂，导致有破裂和无破裂组之间动脉瘤直径的比较仅显示出边缘统计学意义。破裂组破裂前降主动脉的最后中位直径为5.4 cm（范围3.2 - 6.7 cm）。
在通常将大的且快速扩张的动脉瘤患者转诊进行手术治疗的情况下，患有慢性B型夹层的老年患者，尤其是如果他们有未控制的高血压和慢性阻塞性肺疾病史，比年轻、血压正常且无肺部疾病的患者发生破裂的可能性显著更高。持续存在的假腔或较大的腹主动脉直径似乎均未增加破裂风险。总体而言，我们的非尺寸数据与非夹层动脉瘤患者的自然病史惊人地相似，这表明从慢性降胸段和胸腹主动脉瘤数据得出的计算结果将为慢性B型夹层患者的破裂风险提供过于保守的个体估计，而慢性B型夹层患者倾向于较小动脉瘤更早破裂。对于慢性B型夹层患者，似乎有必要采取更积极的手术治疗方法。
