Preoperative computed tomography in the planning of median resternotomy in children

Abstract

The capabilities of computed tomography (CT) in the diagnosis of mediastinal adhesions and measuring the density of adhesions when planning midline resternotomy in children were assessed, and the effect of preoperative CT on the incidence of surgical complications was studied. According to several authors, the frequency of resternotomies in cardiac surgery is up to 20% of the total number of surgeries per year and is accompanied by significant difficulties in the isolation of the heart and vessels. In pediatric cardiac surgery, complex congenital heart disease (CHD) mostly requires a staged approach. The staging of complex CHD correction and the need for repeated surgeries in most cardiac defects make the problem of safe repeated surgical access urgent. Postoperative adhesions are one of the most acute problems in modern cardiac surgery. The formation of adhesions is an inevitable reaction of the body after primary cardiac surgery. Massive adhesions that develop after surgery most commonly lead to adhesion of the heart and major great vessels to the posterior surface of the sternum. These changes are especially pronounced in children due to the high reactivity of the body and the lack of technical possibility and expediency of pericardial suturing after surgery. Rough adhesions during resternotomy complicate the cardiac surgeons task and increase the risk of complications. The main dangers are damage to various structures in the thorax such as the right and left heart, aorta, coronary arteries, pulmonary artery, and brachiocephalic vein. The diagnosis of postoperative adhesions in the mediastinum before resternotomy is difficult. CT has the widest diagnostic capabilities for assessing mediastinal adhesions. When performing CT as a part of preoperative resternotomy planning, it is important to examine the mediastinal topography, assess the degree of adjacency of the pericardium and mediastinal structures, determine the presence and density of adhesions, and assess patency and diameter of great vessels to select cannulas and cannulation methods necessary for emergency start of cardiopulmonary bypass (CPB) in cardiac trauma. These criteria are important when planning midline resternotomy to reduce the risks of traumatization of cardiac structures and great vessels and allow correction of surgical tactics and timely preventive surgical measures. Depending on the density, extent, and localization of adhesions, the cardiolysis technique and cannulation of great vessels required for initiation of emergency CPB may be changed. The use of preoperative CT when planning midline resternotomy in children allows to predict the risks of damage of cardiac structures and great vessels and visualize adhesive bands and measure their density, which helps the surgeon to adjust surgical tactics regarding the method and volume of cardiolysis and assess patency and diameter of great arteries and veins, thus determining the cannulation method and cannula diameter in advance if urgent CPB is needed. Therefore, standardization of CT description protocols for midline resternotomy planning with assessment of key criteria is an urgent task and requires further development.