Abstract 2211: Right Ventricular Outflow Tract Characteristics can Predict Successful Outcome for Percutaneous Pulmonary Valve Implantation - A “Learning Curve” Analysis of a Novel Technique
Background: Our initial experience with the novel technique of percutaneous pulmonary valve implantation (PPVI) led us through a “learning curve”. We analysed this to devise a strategy for patient selection .
Methods We retrospectively analysed our database of all patients referred for PPVI between Sept 2000 and March 2006. Diagnosis, surgical history, right ventricular outflow tract(RVOT) morphology, RVOT size, RVOT calcification and haemodynamics assessed by non-invasive (echocardiography) and invasive (cardiac catherization) techniques were reviewed to evaluate the outcome measures related to implantation.
Results 222 patients (median age 28y,(7–58), median weight 63 kg(20 –117), (Tetralogy of Fallot variants(59%), transposition complex (10%) were referred for PPVI. We divided patients into three cohorts based on their outcome - successful implantation, failed implantation and unsuitable. 20/222 (9%) were unsuitable due to dynamic enlarged RVOT (> 22 mm ) with which precluded secure anchoring. 78/121 (64%) with successful implantation had Tetralogy of Fallot variants repaired by insertion of valved conduits (homograft 78 %) measuring 19.8mm (range 12 – 27) calcified (70%) and more than mild obstruction(RVOT velocity 3.6 ± 0.8 m/s, TR velocity 3.9 ± 0.7 m/s on echo) and gradient of 37.3 mm Hg mean(range 11 – 106) on catheterisation. Patients with failed implantation did not have a conduit repair (70%), minimal calcification in their RVOT(30%), and lower RVOT velocity (2.5 ± 0.8m/s). 10 patients with intention to treat were found unsuitable due to RVOT distensibility and presence of distal stents(8), angulation stenosis at ventriculo-conduit junction(1) and potential for coronary occlusion on balloon inflation(1) were responsible for abandoning the procedure.
Conclusion: Patients with calcified homograft conduits < 22 mm with a RVOT velocity of > 3.5m/s were most suitable for PPVI. Those with aneurysmal dynamic RVOT reconstructed using transannular patch with dimensions > 22 mm and minimal obstruction were least suitable. RVOT characteristics can be used to predict successful implantation of PPVI.