Pulmonary anastomosis

This type of image analysis can be applied for flow pattern analysis as well as for quantitative flow measurements in other regions of the circulation. For example, to study the renal coronary, pulmonary or renal circulation or to determine the shunt volume through a aorto-pulmonary anastomosis (Figure 15,16,17) (Biirsch etaL, 1981,1983b, 1984 Bursch, 1982,1983). 

Next the pulmonary anastomosis is performed with a 4-0 polypropylene running suture. To avoid kinking of the new pulmonary trunk the proper length has to be measured and the vessels are trimmed. Again at the left lateral side of the recipient, pulmonary arterysuturing starts with first completing the back wall and finally the anterior wall. It is important to prevent rotation of the pulmonary artery. 

At this point we start systemic rewarming. The aortic anastomosis is carried out in the same fashion as the pulmonary anastomosis (Fig. 2.1.3c). The end-to-end anastomosis between donor aorta and patient aorta is made by continuous whipstitch (also 4-0 polypropylene). As there are often great size discrepancies, compensation is necessary either by opening the donor aorta for about 1 cm or by excision of a triangle on the anterior wall of the recipient aorta. 

After that air is removed from the heart and the aortic clamp is removed (Kirklin and Barratt-Boyes 1993). We do not perform the aortic anastomosis prior to the pulmonary anastomosis, as is carried out in many transplant units to reduce graft ischemic time. Instead, we accept a few extra minutes and perform the sometimes difficult pulmonary anastomosis in a bloodless operation field. 

The lack of response in the other patients suggests that pulmonary vasoconstriction is not the cause of the desaturation and that perhaps other factors, such as cerebral blood flow requirements, have a significant effect on pulmonary blood flow (superior vena cava flow) in these patients. We have delivered nitric oxide to two patients following the total cavopulmonary anastomosis (Fontan), with an elevated transpulmonary gradient in the presence of left atrial hypertension due to a restrictive atrial septal defect in one patient and pulmonary venous obstruction by the Fontan baffle in another. Inhaled nitric oxide produced a reliable decrease in transpulmonary gradient in both, with an increase in saturation in one (with a fenestrated... 

If the lungs are also retrieved, a modified heart-explantation technique is used. The left atrial incision is made in the middle, between the atrioventricular groove and the orifice of the left pulmonary veins. This incision is extended clockwise to the orifice of the right pulmonary veins in order to preserve enough left atrial tissue for the later left atrial anastomosis as well as enough tissue for the creation of atrial cuffs for the lung transplantation. In this case the pulmonary trunk is transected immediately in front of the bifurcation into the pulmonary arteries. 

Implantation of the heart starts with the anastomosis between the left atrial cuff and the corresponding orifice of the left donor atrium subsequently, the right pulmonary veins are anastomosed in the same manner to the corresponding right orifice of the left donor atrium. The following implantation is then performed in the usual fashion. 

The most common airway problems are anastomotic dehiscence and bronchial stenosis due to strictures. The reason is mostly a lack of perfusion of the bronchial tree, as the donor airways depend on a retrograde pulmonary-to-bronchial arterial circulation until revascularization of the bronchus wall occurs. Ischaemia is greater on the right main bronchus than on the left, therefore anastomotic healing is better on the left and early stenotic problems or dehiscence occur on the right anastomosis more frequently than on the left side. In the early years of transplantation the en bloc technique was mainly performed with a high incidence of tracheal dehiscence, which prompted the development of bilateral lung transplantation. 

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