Performance of the Occlutech® Atrial Flow Regulator Device in Patients With Either Failing Fontan Circulations or Irreversible Pulmonary Hypertension

BACKGROUND: The presence of an atrial level right to left shunt may be desirable in patients with severe pulmonary hypertension (PH) or failing Fontan circulation. The Occlutech Atrial Flow Regulator (AFR) was originally designed to create an atrial shunt for left heart failure and is currently being used off-label in patients with PH or failing Fontan circulation. There is limited evidence supporting AFR use for these indications. AIMS AND METHODS: We performed a retrospective review of consecutive patients with Fontan circulation or severe irreversible PH who underwent AFR implantation. Comprehensive data were collected and analyzed. RESULTS: Sixteen Fontan and eight PH patients underwent AFR implantation. Median age and weight at implantation were 7.5 years (range 2-34) and 22.3 kg (range 11.3-80), respectively. Twenty-eight devices were implanted in 24 patients during 27 procedures. Successful deployment was achieved in all. The device proved versatile and durable across diverse anatomic substrates, even after multiple repositioning attempts. There were no deaths or urgent surgical interventions. Transseptal puncture or Fontan baffle perforation using a Brockenbrough needle or radiofrequency before AFR implantation was required in 10 patients (42%). The most serious complication was a hemorrhagic stroke related to anticoagulation therapy. Thrombotic events occurred in three Fontan patients (11% of all implantations). CONCLUSIONS: AFR appears to be a promising adjunctive option for PH and failing Fontan patients, with acceptable safety and clinically effective results. Device thrombosis remains a risk, particularly with smaller devices in Fontan circulation, likely related to the Fontan patients' underlying hypercoagulable state.