RESUMO
Prosthetic and bioprosthetic materials currently in use lack growth potential and therefore must be repeatedly replaced in pediatric patients as they grow. Tissue engineering is a new discipline that offers the potential for creating replacement structures from autologous cells and biodegradable polymer scaffolds. In May 2000, we initiated clinical application of tissue-engineered vascular grafts seeded with cultured cells. However, cell culturing is time-consuming, and xenoserum must be used. To overcome these disadvantages, we began to use bone marrow cells, readily available on the day of surgery, as a cell source. Since September 2001, tissue-engineered grafts seeded with autologous bone marrow cells have been implanted in 44 patients. The patients or their parents were fully informed and had given consent to the procedure. A 3 to 10ml/kg specimen of bone marrow was aspirated with the patient under general anesthesia before the skin incision. The polymer tube serving as a scaffold for the cells was composed of a copolymer of lactide and ε-caprolactone (50: 50) which degrades by hydrolysis. Polyglycolic or poly-l-lactic acid woven fabric was used for reinforcement. Twenty-six tissue-engineered conduits and 19 tissue-engineered patches were used for the repair of congenital heart defects. The patients' ages ranged from 1 to 24 years (median 7.4 years). All patients underwent a catheterization study, CT scan, or both, for evaluation after the operation. There were 4 late deaths due to heart failure with or without multiple organ failure or brain bleeding in this series; these were unrelated to the tissue-engineered graft function. One patient required percutaneous balloon angioplasty for tubular graft-stenosis and 4 patients for the stenosis of the patch-shaped tissue engineered material. Two patients required re-do operation; one for recurrent pulmonary stenosis and another for a resulting R-L shunt after the lateral tunnel method. Kaplan-Meier analysis in relation to patients' survival was 95% within 3 years. There was only 1 patient (who underwent a total cavo-pulmonary connection procedure) requiring re-intervention in the tubular graft group and the material-related event-free rate was 96% within 3 years. This tissueengineering approach may provide an important alternative to the use of prosthetic materials in the field of pediatric cardiovascular surgery. As it is living tissue, these vascular structures may have the potential for growth, repair, and remodeling. However, this approach is still in its infancy, further studies to resolve the problems presented, and longer follow-up in patients are necessary to confirm the durability of this approach.
RESUMO
The approach for the heart and proximal aorta in a patient with a tracheostomy poses difficult problems such as mediastinitis and inadequate operative exposure. We report a case of successful surgical treatment for type A aortic dissection in a patient with tracheostomy using a Y shaped skin incision and median full-sternotomy. A 63-year-old woman with a tracheostomy was referred to our hospital because of type A thrombosed aortic dissection and cardiac tamponade. At first we treated the patient conseservatively, but follow-up CT taken on the 20th day after onset revealed that false lumen of the ascending aorta was patent and the size of ascending aorta had increased to 6cm in diameter. We therefore performed hemiarch replacement (24mm Hemashield gold graft) through a Y shaped skin incision and median full-sternotomy. The postoperative course was uneventful and she was discharged on the 19th postoperative day.
RESUMO
We reviewed 223 cases of surgical treatment for abdominal aortic aneurysm in octogenarians in this hospital between 1981 and 2000, and investigated the characteristic features, complications, and indications of the operation. The cases were divided into two age groups. Group O included 23 cases of octogenarians, and Group Y included 200 cases of patients under 80 years old. The average age was 68.6 years old in group Y (33-79 years old), and 83 years old in group O (80-93 years old). The hospital mortality rate was 0% in elective operation cases. In emergency operation case, Group O had a hospital mortality rate of 57.1%, significantly higher than the 6.1% for group Y. The hospital mortality rate was 17% in group O and 0.5% in group Y. The rate of emergency operation case was significantly higher in group O (30.4%) compared to group Y (16.5%). As for the preoperative complications, group O had more cases of renal dysfunction, COPD and gastrointestinal complication. As for the coronary artery disease and other cardiovascular complications, there were no significant differences between the groups. In the postoperative complication, group O had more cases of ileus, pneumonia, and cardiovascular disease. These complications were fatal in group O. These results suggest that surgical treatment for abdominal aortic aneurysm was performed safely in both groups for elective operations. Because the results of emergency operations are poor, early diagnosis and treatment seem to be important for the improvement of operative results.
RESUMO
A 40-year-old man was admitted because of coronary heart disease with a totally calcified ascending aorta and Leriche's syndrome. Establishing a cardiopulmonary bypass seemed to be difficult because neither the ascending aorta nor femoral artery was suitable as a cannulation site. It was not until a prosthetic conduit for revascularization of the lower extremities was anastomosed to the right axillary artery in preparation for the conversion from off-pump to on-pump that off-pump CABG was performed. Subsequently revascularization of the lower extremities was completed. The patient had a satisfactory postoperative course. Off-pump CABG is useful for patients with a severely calcified ascending aorta and occlusive lesions below the descending aorta.
