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We examined the blood supply of a cryopreserved tracheal allograft and its morphohistologic changes after transplantation.In each of 22 dogs, a five-ring tracheal segment was replaced by one of the following tracheal grafts: fresh autografts (n = 8), cryopreserved tracheal allografts (n = 8), or fresh allografts (n = 6). The cryopreserved tracheal allografts were preserved at -196 degrees C for 60 days. No immunosuppressant was given to any of the animals. All grafts were retrieved at 1 and 12 weeks and assessed by microangiography and histology.The epithelial denudation and the revascularization of the transverse intercartilaginous arteries were recognized within 7 days as common to each of the three types of grafts. In the cryopreserved tracheal allografts, neither cartilage degradation nor graft shrinkage occurred at 7 days. However, the recanalized transverse intercartilaginous arteries completely disappeared at 12 weeks, and marked shrinkage occurred; the cartilage cells were accompanied by karyolysis and were significantly decreased in number (p0.05). Recanalization of the transverse intercartilaginous arteries was also demonstrated in the fresh allografts; however, necrosis abruptly occurred as a result of acute rejection responses.Cryopreservation of a tracheal allograft provided sufficient reduction of the acute rejection responses, and blood supply to the cryopreserved tracheal allograft was established through the recanalized transverse intercartilaginous arteries within 7 days; however, subsequent chronic rejection responses resulted in occlusion of the transverse intercartilaginous arteries and atrophy.

Background . We evaluated human and canine internal thoracic arteries (ITAs) to determine whether the latter is valid for studies relevant to clinical use. Methods . We studied 19 human ITAs obtained from 1 female and 14 male victims of recent fatal accidents who had no evidence of cardiovascular disease (mean age=39 ± 19 years; range=15 to 79 years), and ITAs of 21 randomly-selected mongrel dogs of both sexes, weighing 18–40 kg (average = 24.3 ± 5.7 kg). Specimens were fixed in formalin at a controlled pressure of 120 mm Hg, before extensive assessment that included intimal thickening, condition of the internal elastic lamina, and number of medial elastic lamellae and vasa vasorum. Results . The canine morphology and histology were similar to the human ITAs, but there was no intimal hyperplasia, and the media and adventitia were thinner (ITAs of humans older than 40 years had significant increases in medial thickness, as well as in overall length). Morphologically and histologically, the left and right canine ITAs were almost completely the same. Conclusions . Canine ITAs are valid for bilateral comparative studies and are a useful tissue source and model for clinically-relevant experimental studies.

We present 3 cases of pediatric post-sternotomy mediastinitis treated by a vacuum-assisted closure (VAC). The patients 2 girls, aged 6 months and 10 months, and a 2-year-old boy. The onset of infection was at 9, 14, and 32 postoperative days. The culture examination detected coagulase-negative Staphylococci strains in 2 cases, and Staphylococcus aureus in 1 case. A VAC was performed at −50 mm Hg for 10, 12, and 7 days. The wounds were closed without vascularized soft tissue. A VAC under a low negative pressure is a useful and safe procedure for the management of pediatric post-sternotomy mediastinitis.

Background . Skeletonization of the internal thoracic artery (ITA) produces greater length for coronary bypass grafting. We studied the effect of skeletonization on the morphology, histology, and tissue viability of the ITA wall. Methods . Six mongrel dogs underwent unilateral ITA dissection; the contralateral ITA was the control. Study periods were 3 weeks (n = 3) and 12 weeks (n = 3). At sacrifice, the entire anterior chest wall was removed and dynamically fixed with formalin. Extensive histologic comparisons were performed on three tissue blocks taken from each ITA, 2, 8, and 24 cm from their origin. Results . Flows at the end of the study were comparable to measurements taken during operation, immediately after skeletonization. Grossly, the ITA wall was not injured by skeletonization and there was no adventitial hematoma or bleeding from the sealed branch ends. Microscopic observations showed intact, normal wall structures. Histologic data showed no major significant difference between controls and skeletonized ITAs. Conclusions . Careful skeletonizing dissection is not detrimental to the integrity of ITAs, which justifies their use for myocardial revascularization.

ELSEVIER, Goh, K; Yamamoto, H; Tsuda, N; Sasajima, T, ANNALS OF THORACIC SURGERY, 69(4), 1264-1266, 2000. author, The Konno procedure was performed to replace the aortic valve and the sinus of Valsalva in a 1-year-old child with pneumococcal infective endocarditis. A Dacron (C.R. Bard, Haverhill, PA) graft and a 16 mm ATS valve (ATS Medical Inc., Minneapolis, MN) was used. Adequate debridement could be easily performed. Postoperative recovery was uneventful. The procedure, originally developed for narrow aortic annulus, could be a good option for treatment of a young individual with aortic valve endocarditis.

A 42-year-old woman with isolated right ventricular hypoplasia underwent operation. To determine the optimal procedure, we temporarily occluded the atrial septal defect with a balloon catheter that was introduced through the right atrial appendage. The hemodynamics were stable throughout the occlusion test. Simple closure of the atrial septal defect was safely accomplished. Intraoperative occlusion test with the balloon catheter was a good alternative to preoperative occlusion test.

Right-sided aortic arch accompanied by an aberrant origin of the left subclavian artery is rare and seen in 0.05% approximately 0.1% of the population. A 73-year-old woman with this anomaly was admitted to our institution because of the enlargement of the distal aortic arch aneurysm. She also had mild dysphagia. The size of the aneurysm was 70 mm in diameter and she underwent total arch replacement using selective cerebral perfusion through a median sternotomy. Additional right thoracotomy was not required and four cervical vessels were reconstructed. The postoperative course was uneventful. This case report shows median sternotomy alone may provide sufficient access for this pathology.

Background . Anastomotic complications associated with bronchoplastic procedures cannot be completely avoided despite the improvements made in surgical techniques and suture materials. Thus, the present study attempted to clearly define the significant factors influencing anastomotic complications. Methods . Between 1978 and 1998, 47 patients with primary nonsmall cell lung cancer underwent bronchoplastic procedures. The incidences of anastomotic complications were calculated according to each of the following clinical factors: primary site, age, pathologic type, pT factor, pN factor, pulmonary arterioplasty, surgical procedure, suture material, coverage of the anastomotic line, positive resection margin, and preoperative chemotherapy. The results were analyzed using univariate and multiple logistic regression analysis. Results . Anastomotic complications occurred in 8 patients. Four had anastomotic dehiscence and 4 had stenosis. Of these 8 patients, the resection margin was diagnosed as being positive in 6 patients. Three showed metastasis of the most distal mediastinal lymph node whereas the others had a residual tumor at the bronchial resection margin. According to multiple logistic regression analysis, only pN factor ( p = 0.04) and positive resection margin ( p = 0.02) had a significant influence on the complications. Conclusions . Thus, pN2 patients, especially those with metastasis of the most distal mediastinal lymph node and patients with a residual tumor at the bronchial resection margin, have a significantly higher risk of anastomotic complications.

A soft vascular clamp was used for hemostasis and stabilization of the operative field during minimally invasive direct coronary artery bypass (MIDCAB). The instrument was gently applied so that it clamps the coronary artery by grasping the adjacent myocardium. The method offered dry and stable operative field without a special instrument or technique. The surgical results have been satisfactory. We found application of the vascular clamp to be very helpful for MIDCAB.

The technique of placing an inverted graft into the descending thoracic aorta facilitates and secures the distal anastomosis in aortic arch replacement, especially in the anastomosis beyond the transverse arch. We developed a simple technique using a pair of thin-walled tubes to enable the arch graft, with its four branches, to be smoothly inserted into the flaccid, normal-caliber descending aorta. The use of these tubes simplified the procedure, resulting in time saving.