Transventricular Off-Pump Tricuspid Valved Stent Implantation: Approach and Echocardiographic Guidance in an Acute Study
Jan P. Gundlach, Saskia Pokorny, Telse Bähr, Jawid Madjidyar, Huang D. Dai, Martin Marczynski-Bühlow, Jochen Cremer, Georg Lutter.
University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
OBJECTIVE: A transventricular approach is presented and evaluated for off-pump orthotopic tricuspid valved stent implantation under transesophageal echocardiographic (TEE) guidance.
METHODS: A nitinol valved stent was implanted in twelve pigs using a minimally invasive transventricular approach. Access was granted from the exposed right ventricular lateral wall close to the apex through a lower ministernotomy. A custom-made delivery system was used to implant a nitinol valved stent with an super absorbent polymer (SAP) pouch attached for better paravalvular sealing. Positioning of the stent was visualized using two-dimensional and more recently also three-dimensional TEE. Swan-Ganz catheter and echocardiographic measurements were performed before and 1h, 3h and 6h after implantation. Animals were observed for a period of six hours. Positioning of the valved stent and the SAP-pouch was evaluated during gross examination.
RESULTS: Implantation was successfully accomplished at first attempt in eight of twelve cases. Four pigs died of ventricular fibrillation (n=2) or stent migration (n=2) during implantation. TEE evaluation showed none or mild tricuspid valve regurgitation. 1h after implantation mild paravalvular leakage (PVL) was found in one and trace in the remaining animals. No PVLs were detected in two animals at the final evaluation. Eight animals maintained hemodynamic stability during the observation period (Table1). The heart rate increased after implantation and remained elevated during the follow-up period. The right ventricular function was stable and the enddiastolic pressure remained low with 3±3mmHg after six hours.
The transventricular approach was well suited for successful implantation of novel tricuspid valved stent into the tricuspid annulus allowing for a large diameter of the delivery system. This enables the use of large stents (≤57mm) and fitting of the SAP sealing pouch necessary for proper sealing within the tricuspid annulus.
CONCLUSIONS: The transventricular approach is feasible for minimally invasive off-pump implantation of tricuspid valved stents. It enables secure deployment of the valved stents with good valvular function. Sufficient paravalvular sealing was observed and was accredited to the stent size and adjacent SAP pouch.
|Pre Implantation||Post Implantation||3h||6h|
|Heart rate [bpm]||72 ± 14||108 ± 28||106 ± 26||105 ± 27|
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