Title:
‘Mitrabridge’ Strategy for a Patient with Fontan Failure Authors: Sabeeda Kadavath, Daniel E Clark, Angela Lowenstern, Angela Weingarten, Colin Barker
Introduction:
A 42 y.o. female with history of tricuspid atresia s/p left Blalock- Taussig-Thomas shunt as an infant (1979) for retrograde pulmonary blood flow and an additional R BTT shunt (1980) for progressive cyanosis and atrio-pulmonary Fontan (with pulmonary valve oversewing and septation of the common atrium) at 6 years old (complex, cyanotic, single ventricular physiology).
Clinical Case:
She has nearly a decade of failing Fontan physiology with an extremely inefficient hemodynamic circuit with right atrial stasis and prior intracardiac thrombosisclot, chronic atrial arrhythmias, and severe mitral regurgitation with poor forward flow. Her prognosis was extremely guarded given her years of not desiring advanced therapies/Fontan conversion, and chronic multi-organ failure with cardiogenic cirrhosis. Relevant Test Results Prior to Catherization: Mitraclip (Abbott Laboratories, Abbott Park, Illinois) therapy was determined to be a palliative endeavor to reduce her MR and help with functional improvement. Transesophageal echocardiogram showed severe mitral regurgitation from a coaptation defect between A2-P2 with EROA 0.65 cm 2 . The MVA was 4.5 cm2, flail gap of 3 mm, and flail width of 4 mm. Cardiac MRI showed a regurgitant volume of 44 mL, 55% regurgitant fraction, and EROA of 0.70 cm 2 . The patient underwent mitral transcatheter edge-to-edge repair (TEER) with the MitraClip System. Patient already had a massively dilated right atrium in the setting of prior atriopulmonary Fontan with ASD closure Gore-Tex patch making the transeptal puncture technically challenging. The puncture was performed using VersaCross RF Transseptal wire. We used a Evercross 10mmx40mm followed by a 12mmx40mm balloon to dilate the septum. The 22-F MitraClip delivery system was placed in the left atrium, and an XTW clip deployed with good leaflet insertion and good tissue bridge demonstration by 3D with a mean gradient of 4mmHg. The residual lateral moderate MR jet was then addressed. An NT clip was applied lateral to first clip with reduction in MR severity. Clip appeared to be subvalvular and patient had residual moderate MR so a third XT clip was deployed with a reduction in MR severity by more than 50% from 4+ to < 2+. Iatrogenic ASD noted with right-to-left shunt causing hypoxemia. Given worsening hypoxia and risk for paradoxical embolism without closure, aA 25mm Amplatzer septal occluder device was deployed across the ASD with residual, small peri-device interatrial shunting that was predominantly right-to-left.
Discussion:
In conclusion, for patients with severe MR on optimized medical therapy and with contraindications to surgery, MitraClip implantation is rather beneficial - especially in patients with complex cardiovascular anatomies and multiple staged reconstruction heart surgeries when re-sternotomy is not an option.