Failure to decrease blood pressure during sleep: non-dippers are among us.

OBJECTIVE: To test the hypothesis that major aorto-pulmonary collaterals (MAPCAs) have the same anatomy as bronchial arteries. METHODS: Two hundred and thirty-eight angiographies performed on 61 patients with pulmonary atresia, ventricular septal defect (VSD), and MAPCAs constituted the basis for this study. This represented all available angiographies performed on this patient group at our institution during the period 1972-2001. MAPCA anatomy was compared to bronchial artery anatomy as described in previous publications. RESULTS: Each patient had one to five MAPCAs (mean 3.2+/-0.94). A mean of 2.6+/-0.66 MAPCAs came from the descending aorta. MAPCAs with anatomy similar to right intercosto-bronchial arteries were found in 87% of the patients. Fifty percent of the patients had MAPCAs originating from the subclavian artery regions. These numbers were all similar to those previously described for bronchial arteries. All MAPCAs had anatomy similar to bronchial arteries. The distribution in different branching patterns of MAPCAs arising from the aorta was similar to the distribution of bronchial arteries described in previous angiographic studies (p=0.32 and p=0.24). CONCLUSIONS: In patients with pulmonary atresia and VSD, MAPCAs are likely to be dilated bronchial arteries. Bronchial arteries may have limited growth potential and their known vasoreactivity might preclude any long-term beneficial effects of unifocalization procedures.

Aorta, Thoracic↗

PubMed2006

Endovascular clamping of porcelain aorta in aortic valve surgery using Foley Catheter.

Unclampable calcified aorta is an uncommon condition that all cardiac surgeons may encounter and performing aortic valve surgery in this condition with a non cross-clamping technique of using Foley Catheter has rarely been reported. Aortic valve surgery invariably becomes a high-risk, challenging procedure to cardiac surgeon or even a contraindication to surgery when the ascending aorta cannot be clamped due to extensive calcification precluding safe dissection and clamping. We describe and recommend a non cross-clamping technique of using Foley Catheter and report it successful use in two patients who underwent aortic valve replacement with "porcelain" unclampable aorta.

Aorta, Thoracic↗

PubMed2006

Smooth muscle cell injury after cryopreservation of human thoracic aortas.

The cryopreservation protocol we use for arterial reconstructive surgery has been studied to evaluate smooth muscle cell (SMC) structural integrity and viability before implantation. Samples of human thoracic aortas (HTA) were harvested from five multi-organ donors. Sampling included unfrozen and cryopreserved specimens. Cryopreservation was performed using RPMI with human albumin and 10% Me(2)SO in a controlled-rate freezing apparatus. Thawing was accomplished by submerging bags in a water bath (39 degrees C) followed by washings in cooled saline. In situ cell preservation as investigated by light and transmission electron microscopy showed that SMCs from cryopreserved HTA had nuclear and cytoplasmic changes. A TUNEL assay, performed to detect DNA fragmentation in situ, showed increased SMC nuclear positivity in cryopreserved HTA when compared to unfrozen samples. 7-AAD flow cytometry assay of cells derived from cryopreserved HTA showed that an average of 49+/-16% cells were unlabeled after cryopreservation. Organ cultures aimed to study cell ability to recover cryopreservation damage showed a decreasing number of SMCs from day 4 to day 15 in cryopreserved HTA. In conclusion, the cryopreservation protocol applied in this study induces irreversible damage of a significant fraction of arterial SMCs.

Aorta, Thoracic↗