CRP21.Mind the Gap: Open repair of Iatrogenic Cor Triatriatum Dexter After Prior Atrial Septal Defect Repair

Los Angeles Convention Center 

A membranous structure that divides the right atrium (RA) into two distinct chambers represents a congenital cardiac anomaly known as cor triatriatum dexter (CTD). Normal embryological development involves the regression of the right valve of the sinus venosus (SV); however, failure of regression can lead to CTD with varying clinical manifestations. Another embryological remnant that usually regresses after birth is the Eustachian valve (EV). Here, we present a case of an iatrogenic CTD, where the right atrium was divided into two chambers from a prior atrial septal defect (ASD) repair with persistent EV leading to liver cirrhosis.

A 55-year-old male presented with a history of a congenital ASD and no family history of prior congenital heart disease. He reported a cardiac murmur but was grossly asymptomatic and no further workup was obtained. At 15 he was diagnosed with an ASD. Right heart catherization showed an elevated Qp/Qs suggestive of left to right shunting. The patient underwent surgical repair by a world-renowned surgeon in Houston, TX. However, the details of the operation are unavailable. At age 45, he was found to have elevated liver enzymes, and his pathology suggested liver fibrosis due to venous congestion. His symptoms continued to progress. Imaging showed normal biventricular function and a possible obstructive membrane at the IVC/right atrium (RA) junction, consistent with CTD + SV defect versus a small residual ASD. Right heart catheterization and intracardiac echo (ICE) showed a thick band of tissue at the IVC/RA junction suggesting a prominent EV leading to CTD. ICE color doppler demonstrated flow acceleration at the opening of the CTD. An SV versus residual ASD was noted, with an agitated saline study confirming shunting.

A redo sternotomy was safely performed. No cannulation sites were identified, suggesting that the initial operation was likely completed under inflow occlusion. The RA was opened away from the prior transverse incision. There was a very thick EV, which had been sewn to the inferior edge of a sinus venosus ASD with near occlusion of the IVC orifice. A residual ASD at the top end of this lesion was seen. The thickened EV tissue was excised to expose the entire IVC orifice. The foramen ovale was opened, and the ASD was enlarged such that an adequately sized patch could be approximated without encroachment of the IVC orifice. A bovine pericardial patch was fashioned and sewn. TEE demonstrated no residual turbulence through the IVC opening, and the bubble study was negative.

The patient recovered well after surgery. Post-op echo showed no evidence of intracardiac shunting, as detected by Doppler and agitated saline. The remainder of his recovery was without complications, and the patient was discharged home on POD 5.

The rare nature of CTD due to iatrogenic causes can make the diagnosis difficult. This case report adds to the dearth of literature on this anomaly and demonstrates the complexities of managing patients with adult congenital heart disease – many of whom had early era repair techniques but have no operative records to inform future intervention. Symptoms of right-sided heart failure, including hepatic cirrhosis, and history of cardiac intervention may suggest a diagnosis of iatrogenic CTD. Although rare, clinicians should be aware of the causes and clinical manifestations of this cardiac pathology to facilitate earlier recognition, avoid delayed diagnosis