Aortico-Left Ventricular Tunnel: The Case for Early Treatment

Abstract

Communications between the aorta and left ventricle that bypass the aortic valve have come to be known as aortico-left ventricular tunnels. Such communications may be acquired or congenital in nature. The acquired ones are usually secondary to bacterial endocarditis and, classically, make their appearance in adult life. The congenital variety is rare. Okoroma and associates1Okoroma EO Perry LW Scott III, LP et al.Aortico-left ventricular tunnel: Clinical profile, diagnostic features, and surgical considerations.J Thorac Cardiovasc Surg. 1976; 71: 238PubMed Google Scholar found two cases among 1,700 examples of congenital heart disease. The pecularity of the congenital aortico-left ventricular tunnel is that it makes its presence known early in infancy. In the case reported by Nichols and associates in this issue of Chest (page 74), a to-and-fro murmur was noted when the patient was only 15 days old, and surgical closure of this fistula was accomplished when the patient was five months of age. Okoroma and associates1Okoroma EO Perry LW Scott III, LP et al.Aortico-left ventricular tunnel: Clinical profile, diagnostic features, and surgical considerations.J Thorac Cardiovasc Surg. 1976; 71: 238PubMed Google Scholar emphasized that the young age at which a murmur is detected leads to distinguishing congenital aortico-left ventricular tunnel from other conditions in which there is abnormal runoff from the aorta associated with murmurs both in the systolic and diastolic periods, conditions such as ruptured congenital aortic sinusal aneurysm, ventricular septal defect associated with aortic insufficiency, and fistulas involving the coronary arteries. The uncommonly great degree of dilatation of the ascending aorta seen in congenital aortico-left ventricular tunnel is yet another characteristic. Several authors, including Nichols and associates, have observed that in patients undergoing surgical correction of aortico-left ventricular tunnel, there is a disturbing incidence of postoperative aortic valvular insufficiency. This functional state has been charged, in part, to the prominent dilatation of the aortic root.2Sommerville J English T Ross DN Aorto-left ventricular tunnel: Clinical features and surgical management.Br Heart J. 1974; 36: 321Crossref PubMed Google Scholar Another cause of aortic insufficiency mentioned are the valvular changes secondary to turbulence caused by flow through the tunnel. Also, it has been pointed out that as the tunnel passes close to the aortic valve, surgical obliteration of it may result in distortion of aortic valvular orientation with consequent incompetence of the valve. It should also be pointed out that in some cases, there is a congenital deformity of the aortic valve. At present, it is not possible to identify with certainty which of the previously mentioned factors is responsible for the demonstrated postoperative aortic insufficiency which occurs in some cases, and it may be a fact that in a given case, multiple causes apply. Nevertheless, it is clear that one effect of the functioning tunnel is left ventricular hypertrophy. This, coupled with the relative ease of closing the tunnel, supports the view that the tunnel should be closed at an early age, as accomplished by Nichols and associates.