Repair of truncus arteriosus and complete atrioventricular canal defect

Abstract

We report a case of the rare association of truncus arteriosus and complete atrioventricular (AV) canal defect in a neonate. Only 11 cases have been reported in the literature and all were postmortem cases. 1Van Praagh R Van Praagh S The anatomy of common aorticopulmonary trunk (truncus arteriosus communis) and its embryologic implications: a study of 57 necropsy cases.Am J Cardiol. 1965; 16: 406-425Abstract Full Text PDF PubMed Scopus (402) Google Scholar, 2Bharati S McAllister Jr, HA Rosenquist GC Miller RA Tatooles CJ Lev M The surgical anatomy of truncus arteriosus communis.J THORAC CARDIOVASC SURG. 1974; 67: 501-510Abstract Full Text PDF PubMed Google Scholar, 3Ceballos R Soto B Kirklin JW Bargeron Jr, LM Truncus arteriosus: an anatomical-angiographic study.Br Heart J. 1983; 49: 589-599Crossref PubMed Scopus (22) Google Scholar, 4Butto F Lucas RV Edwards JE Persistent truncus arteriosus: pathologic anatomy in 54 cases.Pediatr Cardiol. 1986; 7: 95-110Crossref PubMed Scopus (92) Google Scholar, 5Trowitzsch E Sluysmans T Perness IA et al.Anatomy and surgical outcome in infants with truncus arteriosus [Abstract].J Am Coll Cardiol. 1991; 17: 110ACrossref Google Scholar, 6Gumbiner CH McManus BM Latson LA Associated occurrence of persistent truncus arteriosus and asplenia.Pediatr Cardiol. 1991; 12: 192-195Crossref PubMed Scopus (18) Google Scholar, 7Kirklin JW Barratt-Boyes BG Cardiac surgery.in: 2nd ed. Churchill Livingstone, New York1993: 1131-1151Google Scholar After an uneventful pregnancy, a 3600 gm boy was born at term with global cardiac and respiratory failure, and anasarca necessitating intubation and mechanical ventilation. Disseminated intravascular coagulopathy related to fetal-maternal incompatibility led to total exsanguinous transfusion and repeated platelet transfusions. Diagnosis was made at birth by echocardiography, which showed type II truncus arteriosus with no truncal valve stenosis or regurgitation, good-sized pulmonary artery branches, normal aortic arch, and a complete AV canal defect with grade I to II AV valve regurgitation and a large inlet plus infundibular ventricular septal defect (Fig. 1). In the following days, hemodynamic deterioration necessitated infusion of inotropic drugs. Persistent high pulmonary vascular resistances necessitated artificial ventilation with an inspired oxygen fraction of more than 0.9 and prostaglandin E1 infusion in an attempt to improve arterial saturation. An operation was performed when the patient was 18 days of age and weighed 3100 gm. With bicaval cannulation and continuous cardiopulmonary bypass at 22° C, intracardiac analysis revealed (1) Rastelli type C complete AV canal with nearly fused left ventricular papillary muscles and an extremely large ventricular septal defect from the inlet to the truncal valve, (2) type II truncus arteriosus with a large branch from the right coronary artery crossing the anterior wall of the right ventricle and a small left anterior descending coronary artery. The left ventricular papillary muscle was split and the mitral cleft was left open because of a small mitral valve orifice. Ventricular septal defect closure was performed with a Dacron polyester fiber patch through a low infundibulotomy, avoiding the anomalous coronary artery, and through the right atrium. The ostium primum was closed with an autologous pericardial patch. After transection of the aorta and detachment of the pulmonary bifurcation, a Lecompte maneuver was performed. Right ventricle–pulmonary artery connection was established with an 8 mm cryopreserved aortic homograft. Total aortic crossclamp time was 95 minutes. Suprasystemic right ventricular pressures at discontinuation from bypass required reestablishment of cardiopulmonary bypass and placement of a pericardial patch to relieve stenosis of the origin of the right pulmonary artery, resulting in a right ventricular pressure 80% systemic. With sinus rhythm and a regimen of 0.1 μg/kg/min isoproterenol (Isuprel) and 0.05 μg/kg/min prostaglandin E1, the sternum was left open and the patient was transferred to the intensive care unit. The patient’s postoperative course was marked by gradual loss of preoperative edema and hemodynamic stability, allowing closure of the chest on postoperative day 7. Thrombocytopenia of unknown origin necessitated transfusion of several units of platelets. Doppler echocardiography showed a 20 mm Hg gradient at the origin of the right pulmonary artery, mild mitral regurgitation, and no residual shunt. The patient could be extubated on postoperative day 25 and was discharged from the hospital 35 days after the operation. Three months after the operation, the patient’s cardiac condition was good but with persistent leukopenia and thrombocytopenia that are under investigation. The association of truncus arteriosus and complete AV canal septal defect is rare. The literature reports only 11 such cases. 1Van Praagh R Van Praagh S The anatomy of common aorticopulmonary trunk (truncus arteriosus communis) and its embryologic implications: a study of 57 necropsy cases.Am J Cardiol. 1965; 16: 406-425Abstract Full Text PDF PubMed Scopus (402) Google Scholar, 2Bharati S McAllister Jr, HA Rosenquist GC Miller RA Tatooles CJ Lev M The surgical anatomy of truncus arteriosus communis.J THORAC CARDIOVASC SURG. 1974; 67: 501-510Abstract Full Text PDF PubMed Google Scholar, 3Ceballos R Soto B Kirklin JW Bargeron Jr, LM Truncus arteriosus: an anatomical-angiographic study.Br Heart J. 1983; 49: 589-599Crossref PubMed Scopus (22) Google Scholar, 4Butto F Lucas RV Edwards JE Persistent truncus arteriosus: pathologic anatomy in 54 cases.Pediatr Cardiol. 1986; 7: 95-110Crossref PubMed Scopus (92) Google Scholar, 5Trowitzsch E Sluysmans T Perness IA et al.Anatomy and surgical outcome in infants with truncus arteriosus [Abstract].J Am Coll Cardiol. 1991; 17: 110ACrossref Google Scholar, 6Gumbiner CH McManus BM Latson LA Associated occurrence of persistent truncus arteriosus and asplenia.Pediatr Cardiol. 1991; 12: 192-195Crossref PubMed Scopus (18) Google Scholar, 7Kirklin JW Barratt-Boyes BG Cardiac surgery.in: 2nd ed. Churchill Livingstone, New York1993: 1131-1151Google Scholar Surgical correction was performed only once,without success. 5Trowitzsch E Sluysmans T Perness IA et al.Anatomy and surgical outcome in infants with truncus arteriosus [Abstract].J Am Coll Cardiol. 1991; 17: 110ACrossref Google Scholar No details on the operative procedure or anatomy in this case are available. Gumbiner, McManus, and Ratson 6Gumbiner CH McManus BM Latson LA Associated occurrence of persistent truncus arteriosus and asplenia.Pediatr Cardiol. 1991; 12: 192-195Crossref PubMed Scopus (18) Google Scholar reported an autopsy subject with asplenia syndrome, truncus arteriosus, and complete AV canal with a small, left-sided ventricle. These authors' review assembled three other published cases but failed to mention the five cases of common AV orifice reported by Bharati and coworkers. 2Bharati S McAllister Jr, HA Rosenquist GC Miller RA Tatooles CJ Lev M The surgical anatomy of truncus arteriosus communis.J THORAC CARDIOVASC SURG. 1974; 67: 501-510Abstract Full Text PDF PubMed Google Scholar As pointed out by Van Praagh andVan Praagh, 1Van Praagh R Van Praagh S The anatomy of common aorticopulmonary trunk (truncus arteriosus communis) and its embryologic implications: a study of 57 necropsy cases.Am J Cardiol. 1965; 16: 406-425Abstract Full Text PDF PubMed Scopus (402) Google Scholar however, common AV valve seems infrequent in truncus arteriosus. 1Van Praagh R Van Praagh S The anatomy of common aorticopulmonary trunk (truncus arteriosus communis) and its embryologic implications: a study of 57 necropsy cases.Am J Cardiol. 1965; 16: 406-425Abstract Full Text PDF PubMed Scopus (402) Google Scholar A necropsy study of 66 cases of truncus arteriosus 8Crupi G Macartney FJ Anderson RH Persistent truncus arteriosus: a study of 66 autopsy cases with special reference to definition and morphogenesis.Am J Cardiol. 1977; 40: 569-578Abstract Full Text PDF PubMed Scopus (109) Google Scholar and a clinical report of 167 patients operated on 9Di Donato RM Fyfe DA Puga FJ et al.Fifteen-year experience with surgical repair of truncus arteriosus.J THORAC CARDIOVASC SURG. 1985; 89: 414-422Abstract Full Text PDF PubMed Google Scholar did not mention any cases of AV canal defect. The posterior limit of the ventricular septal defect in truncus arteriosus depends of the development of the ventriculoinfundibular fold and the posterior limb of the trabecula septomarginalis. 8Crupi G Macartney FJ Anderson RH Persistent truncus arteriosus: a study of 66 autopsy cases with special reference to definition and morphogenesis.Am J Cardiol. 1977; 40: 569-578Abstract Full Text PDF PubMed Scopus (109) Google Scholar In our case, the ventricular septal defect extended instead to the inlet septum below a common AV valve. The association of a complete AV canal defect can only increase the magnitude of left-to-right shunt, resulting in severe heart failure. Characteristic of our case was the persistence of high pulmonary vascular resistance before operation, necessitating assisted ventilation and prostaglandin infusion to ensure adequate oxygenation. Another feature of our case was the presence of a large branch of the right coronary artery coursing over the anterior right ventricular wall toward the anterior interventricular groove. This anomaly, already noted by Bharati and associates, 2Bharati S McAllister Jr, HA Rosenquist GC Miller RA Tatooles CJ Lev M The surgical anatomy of truncus arteriosus communis.J THORAC CARDIOVASC SURG. 1974; 67: 501-510Abstract Full Text PDF PubMed Google Scholar can be a source of difficulty in the location of ventriculotomy. The low right ventriculotomy led us to perform a Lecompte maneuver to facilitate homograft connection to the pulmonary artery bifurcation. Nearly fused left ventricular papillary muscles with potential for inflow obstruction (parachute-type mitral valve) were split and a mitral cleft was left open, resulting in satisfactory postoperative mitral continence. Reconstruction of the right ventricle–pulmonary artery continuity with a valved conduit offers improved results 10Lacour-Gayet F Bruniaux J Serraf A Sousa-Uva M Roux D Planché C Influence of pulmonary valve competence on truncus arteriosus repair.Cardiol Young. 1993; 3: 13Google Scholar compared with nonvalved conduits, and a cryopreserved homograft is used whenever available. Precarious hemodynamic and respiratory conditions dictated early, semiurgent repair in our patient. These conditions were also responsible for slowly progressive postoperative recovery. Associated cardiac defects have been shown to be an incremental risk factor for death after repair of truncus arteriosus. 5Trowitzsch E Sluysmans T Perness IA et al.Anatomy and surgical outcome in infants with truncus arteriosus [Abstract].J Am Coll Cardiol. 1991; 17: 110ACrossref Google Scholar, 6Gumbiner CH McManus BM Latson LA Associated occurrence of persistent truncus arteriosus and asplenia.Pediatr Cardiol. 1991; 12: 192-195Crossref PubMed Scopus (18) Google Scholar, 7Kirklin JW Barratt-Boyes BG Cardiac surgery.in: 2nd ed. Churchill Livingstone, New York1993: 1131-1151Google Scholar Palliative operations consisting of separate banding of the pulmonary arteries offer no advantage, however, and are responsible for their own complications. To the best of our knowledge, this is the first report of successful repair in a neonate of truncus arteriosus and complete AV canal defect.