ABSTRACT
Objective Stanford type A acute aortic dissection is a life-threatening medical condition with high rates of morbidity and mortality that requires surgical repair, on an emergency basis. The extent of aortic arch repair that should be carried out during emergency surgery of this type is controversial. This study was conducted to report clinical experience on aortic arch repair and determine surgical indication, optimal operative procedures and strategy for Stanford type A acute aortic dissection. Methods 210 consecutive patients with acute Stanford A aortic dissection who underwent aortic arch replacement combined with implantation of stented elephant trunk into the descending aorta between August 2005 and August 2010. Surgical procedures included hemi-aortic arch replacement in 92 patients, subtotal aortic arch replacement in 50 patients and total aortic arch replacement in 68 patients. All operations were performed with the aid of deep hypothermic circulatory arrest and selective antegrade cerebral perfusion (SACP). Enhanced computed tomography scanning was performed to evaluate the postoperative outcomes, particularly the fate of the false lumen remaining in the descending thoracic aorta by aortic arch replacement combined with implantation of stented elephant trunk during follow up. Results Average cardiopulmonary bypass time was (146 ±52) min. The average cross clamp time was(93 ±25)min and average selective cerebral perfusion and circulatory arrest time was(35 ±14)min. The overall in-hospital mortality was 4. 8% (10/210) and morbidity was 8. 6% ( 18/210). Postoperative complications included acute renal failure, stroke, mediastinitis and respiratory insufficiency. During the follow-up period [mean (27 ± 18) months, ranged 2 to 60 months], 1 patient underwent reoperation due to the descending thoracic and abdominal aortic aneurysm. There was no late death. Follow-up enhanced CT scanning showed about 74% false lumens obliterated at the level of the distal border of the stent graft post operation. Conclusion Open aortic arch replacement is an effective approach and provides acceptable outcomes for type A acute aortic dissection. Optimal treatment strategy is the key factor to success in emergency surgical intervention.
ABSTRACT
Objective Mechanisms for the dissection of aorta, a devastating disease, remain unknown. Studies showed that cytokine transforming growth factor (TGF)-131, a multifunctional regulator, was highly expressed in the aneurysms or dis-section of aorta and was responsible for the onset of the diseases. We try to explore the mechanisms of thoracic aortic dissection (TAD) by comparing the expression and distribution of TGF-β1 in the aortic wall and analyzing the association of TGF-β1 with extracellular matrix (ECM) in patients with TAD and control subjects. Methods Aortic specimens taken from surgical pa-tients with TAD( n = 20 ) at Zhongshao Hospital and organ donors ( n = 20, controls) were prepared with paraffin embedded tis-sue slide. ECM was investigated with hematoxylin-eosin, Verhoeff van-Giesen (EVG) and Maason's triehrome (MT) staining.Distribution and expression of TGF-β1 within aortic wall was examined with double immunofluoreseent staining and semi-quan-tiffed by fluoreseent intensity analysis. The expression of TGF-β1 in the two groups and among various layers of the arterial wall was compared. Results TAD was morphologically characterized by decreased and disrupted elastic fibers in the tunica media of the aorta wall with hyperplasia of the collagen fibers. TGF-β1 was expressed unevenly within aortic wall, with highest in the media, followed by intima and adventitia, in both TAD patients and eantrols. Specimen from TAD patients exhibited overall in-creased TGF-β1 expression by 9.56% as compared with that from the controls ( P <0.05 ). TGF-131 expression was increased by 16.09% (P<0.05) in the media and 16.75% (P<0.05) in the adventitia in TAD group as compared with those in the control group, but no difference was detected in intima between the two groups. TGF-β1 distribution histogram analysis dis-closed that TGF-β1 expression in the tunica media was evident in the elastic fibers, and was increased by 34.83% in TAD pa-tients as compared with that in the controls (P <0. 01 ). No significant associations between TGF-β1 expression and age, gen-der, maximal aortic diameter and type of dissection in TAD patients were detected. Conclusion TGF-β1 expression is up-reg-ulated and unevenly distributed in the dissected aortic wall of TAD patients. The finding that TGF-β1 was significantly up-regulated and condensed in the elastic fibers of the tuniea media suggested the crucial role of TGF-β1 in the development of TAD.