Objective: This study aimed to investigate the direction of tissue contraction after microwave ablation in ex vivo bovine liver models. Materials and Methods: Ablation procedures were conducted in a total of 90 sites in ex vivo bovine liver models, including the surface (n = 60) and parenchyma (n = 30), to examine the direction of contraction of the tissue in the peripheral and central regions from the microwave antenna. Three commercially available 2.45-GHz microwave systems (Emprint, Neuwave, and Surblate) were used. For surface ablation, the lengths of two overlapped square markers were measured after 2.5- and 5-minutes ablations (n = 10 ablations for each system for each ablation time). For parenchyma ablation, seven predetermined distances between the markers were measured on the cutting plane after 5- and 10-minutes ablations (n = 5 ablations for each system for each ablation time). The contraction in the radial and longitudinal directions and the sphericity index (SI) of the ablation zones were compared between the three systems using analysis of variance. Results: In the surface ablation experiment, the mean longitudinal contraction ratio and SI from a 5-minutes ablation using the Emprint, Neuwave, and Surblate systems were 28.92% and 1.04, 20.10% and 0.53, and 24.90% and 0.45, respectively (p < 0.001). A positive correlation between longitudinal contraction and SI was noted, and a similar radial contraction was observed. In the parenchyma ablation experiment, the mean longitudinal contraction ratio and SI from a 10-minutes ablation using the three pieces of equipment were 38.60% and 1.06, 32.45% and 0.61, and 28.50% and 0.50, respectively (p < 0.001). There was a significant difference in the longitudinal contraction properties, whereas there was no significant difference in the radial contraction properties. Conclusion The degree of longitudinal contraction showed significant differences depending on the microwave ablation equipment, which may affect the SI of the ablation zone.

Aortic rupture has a high mortality rate and can be considered a medical emergency. The standard treatment for aortic rupture is surgical repair. An aortic stent graft for a ruptured descending aorta is considered an effective alternative treatment. However, an aortic stent graft is difficult when the aortic aneurysm is in the aortic arch due to supra-aortic vessels. We report on a patient with a ruptured aortic arch aneurysm treated with a hybrid procedure, which involved a carotid to carotid bypass operation and an aortic stent graft. A 71-year-old male patient visited our cardiovascular center suffering from hemoptysis. The chest CT and aortography showed a 9 cm sized aortic arch aneurysm 0.5 cm distal to the left subclavian artery and a hemothorax in the left lung. The patient refused to undergo a full open operation. We performed a carotid to carotid bypass in advance, and two pieces of aortic stent grafts were placed across the left carotid artery and left subclavian artery. The follow up CT showed the aortic stent grafts, no endoleaks and no thrombus in the aortic arch aneurysm. The patient was discharged from the hospital without complication.
Aged ; Aneurysm ; Aorta, Thoracic ; Aortic Aneurysm ; Aortic Rupture ; Aortography ; Carotid Arteries ; Chimera ; Emergencies ; Endoleak ; Follow-Up Studies ; Hemoptysis ; Hemothorax ; Humans ; Lung ; Male ; Stents ; Stress, Psychological ; Subclavian Artery ; Thorax ; Thrombosis ; Transplants

Thoracic endovascular aortic repair (TEVAR) shows limitations in cases in which the aortic pathology involves the aortic arch. The study aims were to test a fenestrated aortic arch stent graft (FASG) with a preloaded catheter for the supraaortic arch vessels and to perform a preclinical study in swine to evaluate the safety and efficacy of this device. Six FASGs with 1 preloaded catheter and 5 FASGs with 2 preloaded catheters were advanced through the iliac artery in 11 swines. The presence of endoleaks and the patency and deformity of the grafts were examined with computed tomography (CT) at 4 weeks postoperatively. A postmortem examination was performed at 8 weeks. The mean procedure time for the one and two FASG groups was 30.2 (27.9-34.5) min and 43.1 (39.2-53.7) min. The mean time for the selection of the carotid artery was 4.8 (4.2-5.5) min and 6.2 (4.6-9.4) min. Major adverse event was observed in one of 11 pigs. One pig died at 4 weeks likely because of the effects of the high dose of ketamine, while the remaining 10 pigs survived 8-week. For both the one and two FASG groups, no endoleaks, no disconnection, no occlusion of the stent grafts were observed in the CT findings and the postmortem gross findings. The procedure with the FASG could be performed safely in a relatively short procedure time and involved an easy technique. The FASG is found to be safe and convenient in this preclinical study with swine.
Animals ; Aorta, Thoracic/*surgery ; Catheters ; Endovascular Procedures/adverse effects/*instrumentation ; *Stents ; Swine ; Tomography, X-Ray Computed