Thoracic Endovascular Aortic Repair for Type B Aortic Dissection Associated with Retrograde Type A Intramural Hematoma.

PURPOSE: To evaluate feasibility and efficacy of thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) associated with retrograde type A intramural hematoma (IMH). MATERIALS AND METHODS: From April 2013 to January 2017, 15 consecutive patients with TBAD associated with retrograde type A IMH who underwent TEVAR were reviewed retrospectively. There was no cardiac tamponade, aortic regurgitation, involvement of coronary artery, or sign of cerebral ischemia in these patients. Enhanced CT was used in 4 patients to diagnose malperfusion of abdominal visceral arteries or lower extremity artery and underwent emergent TEVAR. For the remaining 11 patients, repeated enhanced CT after initial medical treatment within 24 hours from onset of pain showed expansion of IMH in 8 patients or presence of periaortic hematoma in 3 patients. Delayed TEVAR was scheduled for these cases. RESULTS: Successful deployment of the stent graft was achieved in all patients. There were no severe postoperative complications, such as retrograde type A aortic dissection or aortic rupture. Sudden death occurred in 1 patient 3 months after the procedure. Thrombosis of the false lumen, shrinkage of the diameter of the aorta, and complete absorption of the IMH were observed in the remaining patients at a mean follow-up of 19.8 months ± 6.57. CONCLUSIONS: TEVAR for treatment of TBAD with retrograde type A IMH is feasible and effective. It represents a treatment option for patients with TBAD associated with type A IMH with a proximal entry tear located in the descending aorta.

Experimental computed tomography-guided vena cava puncture in pigs for percutaneous brachytherapy of middle mediastinal lymph node metastases / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Percutaneous brachytherapy is a valuable method for the treatment of lung cancer and mediastinal lymph nodes metastasis. However, in some of the metastatic lymph nodes in the middle mediastinum, the percutaneous approach cannot be used safely due to possible damage to surrounding anatomical structures. We established an animal model (group of 12 pigs) to assess the safety and feasibility of computed tomography (CT)-guided vena cava puncture.</p><p><b>METHODS</b>Under CT guidance, an 18G needle was used to puncture the anterior wall of the anterior vena cava (AVC) in 12 pigs. The 18G needle was chosen as it is similar in size to the needles employed for clinical application in brachytherapy. The incidence of complications and vital signs was monitored during the procedure. Thoracotomy was performed to remove AVC specimens, which were analyzed for histological evidence of vessel wall damage and repair.</p><p><b>RESULTS</b>Following postoperative enhanced CT, two animals were found to have a small pneumothorax (one being hemopneumothorax). The intraoperative oxygen saturation of both animals was not significantly decreased and was maintained at 93-100%. No animals developed mediastinal hematoma. Preoperative, intraoperative, and postoperative changes in blood pressure, heart rate, hemoglobin, and blood oxygen saturation were not significant. Histological evaluation of AVC specimens showed that by 7 days following the procedure, the endothelial layer was smooth with notable scar repair in the muscularis layer.</p><p><b>CONCLUSIONS</b>CT performed after the procedure and histological preparations confirmed the safety of the procedure. This indicates that percutaneous brachytherapy for metastatic middle mediastinal lymph nodes can be carried out via the superior vena cava.</p>