Myocardial revascularization by CO2 laser.

An original method of myocardial revascularization using CO2 laser has been studied in a pig model with acute myocardial infarction. Transparietal channels were created by myocardial vaporization, using a CO2 laser beam. A comparative evaluation was made against a control group using as parameters survival rate, ECG changes, anatomopathologic findings, and angiographic studies. With the exception of favorable changes in the ECG there was no other evidence of improved regional perfusion. No evidence of long-term patency of the transmyocardial channels could be demonstrated by angiographic and histologic studies.

[Surgical treatment of aortic subvalvular obstruction. Experimental study of a new approach]. / Le traitement chirurgical des obstacles sous-valvulaires aortiques. Etude expérimentale d'une voie d'abord nouvelle.

The aortic subvalvular region is difficult to approach. The results after resection through a pure transaortic approach are often unsatisfactory. An aorto-septal approach derived from the Konno-Rastan aortoventriculoplasty was experimented in animals. This technique involves opening the ascending aorta and the pulmonary infundibulum, section of the aortic annulus at the left anterior commissure and incising the muscular interventricular septum. The results of this aorto-septal approach show: - that the whole left ventricular ejection tract can be exposed; - that the incision can be closed without damage to the heart, i.e. creation of atrioventricular block, and with reconstruction of an intact interventricular septum and a normally functioning aortic valve. This approach could therefore be used for the treatment of diffuse subvalvular aortic stenosis: - subaortic fibromuscular tunnel without hypoplasia of the aortic ring (one personal case has already been reported); - severe forms of hypertrophic obstructive cardiomyopathy with asymmetric septal hypertrophy.

Surgical transposition of the atria: A new procedure for repairing transposition of the great vessels.

The proposed procedure consists of interchanging the positions of the atria by means of an incision used in heart transplantation. After frontal sectioning of the atrial body, the heart is turned up on its pedicle, the interatrial septum is divided in its posterior part, and the vena cavae are extensively freed from their mediastinal and diaphragmatic attachments. The posterior parts of the atria can then be transposed: the right atrium and vena cava are repositioned to the left of the left atrium, and a new septum is constructed by joining the external atrial walls. The heart can then be replaced and the walls of the transposed atria repaired by edge-to-edge sutures. Cadaver experiments have indicated that this procedure is applicable in infants and young people. Casts and radiologic examinations have shown no strictures in the vena cavae, and the possibility of postoperative arrhythmias has been evaluated by means of electrocardiographic studies in dogs surviving for long periods after heart autotransplantation.

[Experimental study of a biodegradable micro-arterial prosthesis (author's transl)]. / Etude expérimentale d'une prothèse micro-artérielle biodégradable.

An experimental study of a micro-arterial prosthesis prepared from biological materials was carried out in the rat. The results obtained after two months were analysed in terms of permeability of the biochemical constituants of the vessel and of the neighbouring scar tissue, and endothelial healing. These studies showed the association with a process of proteolysis of the implanted vessel, of a process of reconstruction. They show moreover the quality of the endothelial scar on the internal surface of the vessel.