Discussion

Congenital ventricular diverticulum usually occurs (70%) as a part of complex cardiac syndromes, most commonly with the Pentalogy of Cantrell, and frequently associated with sternal, pericardial, diaphragmatic, and thoracoabdominal wall defects. ^{Reference Edgett, Nelson, Hall, Fishback and Jahnke1} It can originate from both ventricles while the left ventricular diverticulum is more frequently reported. ^{Reference Di Sessa, Howard and Salim2–Reference Ashraf, Gingell, Pieroni, Dhar and Subramanian4} Ventricular diverticula could be classified as fibrous or muscular. A muscular diverticulum is an outpouching originating usually from the apical part of the ventricle, contracting synchronously with it and containing all layers of heart tissue. ^{Reference Hoffman, Menon, Everitt and Burch3,Reference Ashraf, Gingell, Pieroni, Dhar and Subramanian4}

While the exact aetiology of this complex condition is not very clear, different theories have been proposed. A developmental failure in the differentiation of somatic and splanchnic mesoderm, the failure of ventral folding of the transverse septum, partial fusion of the ventral part of the septum transversum which is forming pericardium, and the primitive cardiac loop giving rise to the left ventricle are some of the theories explaining the possible causes of these complex defects. ^{Reference Ashraf, Gingell, Pieroni, Dhar and Subramanian4–Reference Pirasteh, Carcano, Kirsch and Mohammed6}

Syndromic association of ventricular diverticulum was described by Cantrell et al. ^{Reference Cantrell, Haller and Ravitch5} in 1958, and the syndrome was named as Pentalogy of Cantrell or Cantrell syndrome. The estimated incidence of this syndrome is approximately 1 per 65,000–200,000 live births ^{Reference Carmi and Boughman8} and classically consists of five congenital anomalies: intracardiac defect, lower sternal anomalies, pericardial defect, diaphragmatic defect, and epigastric omphalocele. ^{Reference Cantrell, Haller and Ravitch5} Intracardiac defects may include ventricular septal defect (most common), atrial septal defect, pulmonary atresia, ectopia cordis, patent ductus arteriosus, tetralogy of Fallot, and diverticulum. ^{Reference Mallula, Sosnowski and Awad9} The defects of the abdominal wall also vary from milder anomalies as umbilical hernia to the separation of recti, and even omphalocele. Therefore, the prognosis of the patient depends on the complexity of abnormalities.

As the complexity and expression of symptoms vary widely between patients, Toyama classified Cantrell’s syndrome into three different groups: class I presents with all five defects and is a definite diagnosis; class II is a probable diagnosis and presents with four defects, and class III is considered as an incomplete expression and presents with varying combinations of defects. ^{Reference Toyama10}

Differential diagnosis of ventricular diverticula may include ventricular aneurysms, ventricular clefts, and pseudoaneurysms. Congenital ventricular aneurysms are akinetic or dyskinetic ventricular out pouches, with no organised -or thin myocardium, connecting with a wide neck to the ventricular chamber. The main diagnostic features differentiating diverticulum from aneurysm are its synchronous contraction with heart, narrow connection to the ventricle, and composement of all myocardial layers. A myocardial cleft is an asymptomatic contractile protrusion within the myocardium that does not reach the epicardium and usually is accompanied with hypertrophic cardiomyopathy. Pseudoaneurysms are akinetic protrusions composed from pericardium and are caused by acute rupture of the ventricle wall due to infections or trauma. Therefore, pseudoaneurysms – being the potentially fatal conditions – must be differentiated from other pathologies of the ventricular wall.

In the present case, presence of both right and left ventricular diverticulum, large Patent ductus arteriosus (PDA), crossing pulmonary arteries, aberrant course of right subclavian artery, right-sided descending aorta, alterations in the ossification of the distal sternum; the presence of umbilical hernia leads to the diagnosis of a congenital biventricular diverticula as a part of the class III Cantrell’s syndrome. The patient was successfully operated at another heart centre for the surgical repair of both ventricular diverticula.