Paradoxical Embolic Complications in Patient with a Previously Repaired Congenital Sinus

Paradoxical embolic complications in patient with a previously repaired congenital sinus venosus defect.

Mashhood kakroo¹, M.D, Saima Abbass¹, M.D, Rehana Qadir¹, M.D, Mujeeb Sheikh¹, M.D ¹University of Toledo Medical Center, Toledo, Ohio

Background: Atrial septal defect sinus venosus type (SVD) is a rare congenital anomaly, often diagnosed in adulthood, and usually presents with arrhythmia or pulmonary hypertension. The management involves Dacron patch closure of the defect at open heart surgery. Paradoxical embolism after repair of congenital SVD defects is very rarely seen or suspected. We describe a case of young man who presented with brain abscess and embolic stroke 34 years after the surgical repair of SVD and illustrate the management of this complication.

Case presentation A 47 year old male was admitted to the hospital with 2 weeks history of headache, fever, chills and visual disturbances. At age of 13 years, he had undergone repair of SVD and had remained symptom free for last 34 years. Clinical examination and baseline laboratory studies were normal. Magnetic resonance imaging (MRI) showed a large ring enhancing lesion in the occipital lobe and patient underwent craniotomy with drainage of brain abscess. Pus culture was positive for Ekinella Corrodens and intravenous antibiotics were administered and patient was subsequently discharged home. However, he was readmitted within 7 days, with a new onset left sided hemiparesis. A repeat MRI of brain was positive for a new embolic stroke in the left middle cerebral artery territory. Transthoracic imaging revealed an intact inter-atrial septum. Transesophageal echocardiogram demonstrated the presence of large right to left shunt on bubble study. Right heart catherization confirmed the presence of a large SVD and communication between the right superior pulmonary veins and superior vena cava (SVC). The clinical course was consistent with the diagnosis of back-to-back two paradoxical embolic processes in form of brain abscess and an embolic stroke. Patient underwent open heart surgery for repair of SVD and anomalous pulmonary venous drainage. Per-operative findings confirmed residual sinus venosus defect, drainage of right superior pulmonary veins into SVC. The SVD was closed by Dacron patch and pulmonary veins were re- routed into left atrium and a cavoplasty was performed for SVC stenosis. No thrombus or vegetation was visualized at the site of the defect and the tissue cultures were also negative. Post procedure patient did well and was discharged to rehabilitation facility, were on follow up at 2 months has no recurrence of symptoms. Conclusion: To our knowledge this the first case report of successful treatment of consecutive cerebral complications, paradoxical in nature, in a patient with an underlying occult residual sinus venosus defect. Our case highlights the importance of having high clinical suspicion for residual shunts in patients with history suggestive of paradoxical embolic phenomenon.