Is the term "tricuspid atresia" appropriate?

The Journey of an Indian Pediatric Cardiologist : Dr. K. C. Chaudhuri Lifetime Achievement Award/Oration at AIIMS, New Delhi, September 2017

The life journey of an Indian pediatric cardiologist, who bestowed considerable attention to the development of new knowledge and train/teach physicians around the world while providing care of patients with heart disease over a 45-y period, is reviewed. This appraisal focuses particular attention on the scientific contributions to the literature. These include spontaneous closure of physiologically advantageous ventricular septal defects, various issues related to a congenital heart defect namely, tricuspid atresia and transcatheter and, interventional pediatric cardiac procedures.

Pulmonary Atresia with Intact Ventricular Septum

The prognosis for patients with pulmonary atresia with intact ventricular septum is poor with and without conventional surgical treatment. Because of this reason, a comprehensive program of medical, transcatheter, and surgical treatment is necessary to improve the long-term outlook of these infants. Algorithms of management plans should be developed based on the presence of right ventricular-dependent coronary circulation as well as size and morphology of the right ventricle. In a tripartite or bipartite right ventricle, transcatheter radiofrequency perforation is preferable. Alternatively, surgical valvotomy may be performed. Augmentation of pulmonary blood flow by prolonged infusion of prostaglandin E(1), stenting the ductus, or a surgical modified Blalock-Taussig shunt may be necessary in some of these patients. In patients with a unipartite or very small right ventricle or a right ventricular-dependent coronary circulation (Tricuspid valve Z score < -2.5), augmentation of pulmonary flow along with atrial septostomy should be undertaken. Follow-up studies to determine the feasibility of biventricular repair should be undertaken and, if feasible, surgical or transcatheter methods may be used to achieve the goals. If not suitable for biventricular repair, one-ventricle (Fontan) or one and one-half ventricular repair should be considered. Comprehensive and well-planned treatment algorithms may help improve survival rate.

Cardiac anatomy in patients undergoing the Fontan procedure

BACKGROUND

Controversies in nomenclature, especially of hearts with "single ventricle," have clouded discussion and understanding of the anatomy. Many patients with such malformations are submitted to the Fontan procedure as definitive surgical palliation. The spectrum of anatomy among these patients is wide and deserves analysis in an effort to provide a simple framework for description and to eliminate confusion.

METHODS

We reviewed 138 successive patients undergoing the Fontan operation at one institution to demonstrate the variability in pathology.

RESULTS

Only 89 patients (65%) had a univentricular type of atrioventricular connection. All but 5 patients had two ventricular chambers. Among the 49 patients with biventricular atrioventricular connections, 43 had a hypoplastic ventricle that precluded a biventricular repair.

CONCLUSIONS

Full understanding of the malformations that may preclude a "biventricular" repair and hence necessitate a Fontan procedure requires knowledge of the different forms of univentricular atrioventricular connection that, although usually associated with two ventricular chambers, are seldom amenable to a "two-pump repair." Understanding of those types of "biventricular heart" that preclude a two-pump repair (eg, severe hypoplasia of the left ventricle or the right ventricle) or are associated with high risks (eg, straddling atrioventricular valve) is also important.

Echocardiographic-morphologic correlations in tricuspid atresia

OBJECTIVES

Our aim was to clarify the anatomic substrate in hearts diagnosed as having tricuspid atresia by studying autopsy specimens and comparing the findings with those in two-dimensional echocardiograms.

BACKGROUND

Traditionally, tricuspid atresia was thought, and is still believed by some, to be due to an imperforate valvular membrane interposed between the floor of the blind-ending right atrium and the hypoplastic right ventricle. Others argued that the dimple, when present, pointed to the outflow tract of the left ventricle rather than to the right ventricle, making the lesion more akin to double-inlet left ventricle.

METHODS

We examined 39 autopsy specimens catalogued as having tricuspid atresia. We then studied 24 two-dimensional echocardiograms from patients with a primary diagnosis of tricuspid atresia.

RESULTS

Of the 39 specimens, 37 had a completely muscular floor to the right atrium (absent right atrioventricular [AV] connection). The dimple, when identified, was (except in one case) directed to the left ventricular outflow tract. Only two hearts had an imperforate tricuspid valve. Two-dimensional echocardiograms in all cases showed an echo-dense band, produced by the fibrofatty tissue of the AV groove and representing absence of the right AV connection, between the muscular floor of the morphologically right atrium and the ventricular mass.

CONCLUSIONS

Tricuspid atresia is usually, but not always, due to morphologic absence of one AV connection. In most cases, the ventricular mass then comprises a dominant left ventricle together with a rudimentary and incomplete right ventricle.

Corrective surgery for tricuspid atresia: which modification of Fontan-Kreutzer procedure should be used? A review

Various modifications of Fontan-Kreutzer procedure have evolved over the years. The available literature was reviewed in an attempt to evaluate whether one of these operations is preferable to others. Although there is no complete agreement, direct atriopulmonary anastomosis in the absence of a subpulmonary ventricular chamber, and atrioventricular connection via a homograft conduit in patients with a good-sized (greater than 30% of normal), well-formed (with both trabecular and outlet portions) right ventricle appear to be reasonable choices. In patients with more than the usual risk or at low risk for the Fontan-Kreutzer procedure, other alternatives (namely, total cavopulmonary connection for patients with asplenia/polysplenia syndrome and systemic venous anomalies and bidirectional cavopulmonary anastomosis or Fontan-Kreutzer with a small temporary atrial septal defect) could be considered. The role of experimental skeletal muscle augmentation or replacement of right heart chambers and cardiac transplantation in the corrective treatment of tricuspid atresia needs to be defined as more data become available.