Dissection Thoracic Aneurysm After Type A Surgical Repair: “Kick-Off registry”

Abstract

Introduction - The success of aortic dissection surgery depends upon complete resection of the primary intimal tear with attempted obliteration of the false lumen; in this concept the major goal for acute type A aortic dissection (AAAD) after surgical aortic replacement is to have a living patient.” This motto is always the directive for the cardiac-surgeon. However, the extent of the “A” dissection and surgical management could lead to “chronic dissection B”; which may eventually require additional treatments during follow-up. The traditional approach of open distal anastomosis is associated with high rates of persistent false lumen patency which exposes the patient to the formation of complex thoraco-abdominal dissection aneurysms. Kick-Off is a registry which evaluates the results of “cardiac-surgery” performed on patients with AAAD, in acute phase as well as during follow-up (the need of intervention surgery or endovascular aortic repair for dissection thoracic aneurysm > 55 mm). Methods - Between January 2010 and December 2017, in Santa Maria Hospital - Terni data concerning acute type A aortic dissection was collected in a registry: “Kick-Off Registry”. Urgent admissions with the diagnosis of acute A dissection were selected. Surgical outcomes were evaluated in terms of operative mortality and morbidity. Furthermore the development of thoracic dissection aneurysm was analysed, during follow-up. The following anatomic conditions like entry tear (patent / non patent); entry tear localization (inner or external), diameter of entry tear (major or minor 10 mm); initial aortic diameter (major or minor 40 mm), false lumen thrombosis (yes or not), shape of true lumen (elliptical or circular) and type of dissecton (linear or spiral) were taken into consideration. Moreover the type of surgical approach was evaluated. Statistical analyses were carried out using SPSS statistics version 22. Results - 196 patients underwent emergency repair for AAAD using a standard approach. 66% patients required replacement of the dissected ascending aorta, 27% required an emiarch replacement and 7% required total aortic root replacement. The mean age was 65.7 (146 male – 50 female). Median-follow-up was 29 months. Overall operative mortality was 21%. Multivariate analysis revealed that older age, stroke and malperfusion increased the risk of operative death. During follow-up the overall need for any kind of intervention (surgery, TEVAR or Hybrid intervention) was 19%. In multivariate analysis (Cox regression) a patent primary entry tear (P<0.05), initial diameter (superior to 40 mm - P<0.05)were predictors of thoraco-abdominal dissection aneurysm superior to 55 mm. Multivariate analysis showed that the type of required repair (emiarch replacement) was the primary factor associated with the development of dissection aneurysm (P<0.001). Conclusion - The anatomic conditions of AAAD and an unsuitable surgical strategy could bring about the development of thoraco-abdominal dissection aneurysm. The “Kick-Off” registry is helpful to understand the mechanisms that lead to dissection aneurysm; in the future we hope to categorization the risk patients for aneurysm disease. Furthermore, treatment options in acute phase and suggest preventive strategies to reduce the occurrence of this dissection aneurysm to a minimum would be define.