Transcatheter pulmonic valve implantation: Techniques, current roles, and future implications

Right ventricular outflow tract(RVOT)obstruction is present in a variety of congenital heart disease states including tetralogy of Fallot,pulmonary atresia/stenosis and other conotruncal abnormalities etc.After surgical repair,these patients develop RVOT residual abnormalities of pulmonic stenosis and/or insufficiency of their native outflow tract or right ventricle to pulmonary artery conduit.There are also sequelae of other surgeries like the Ross operation for aortic valve disease that lead to right ventricle to pulmonary artery conduit dysfunction.Surgical pulmonic valve replacement(SPVR)has been the mainstay for these patients and is considered standard of care.Transcatheter pulmonic valve implantation(TPVI)was first reported in 2000 and has made strides as a comparable alternative to SPVR,being approved in the United States in 2010.We provide a comprehensive review in this space–indications for TPVI,detailed procedural facets and up-to-date review of the literature regarding outcomes of TPVI.TPVI has been shown to have favorable medium-term outcomes free of reinterventions especially after the adoption of the practice of pre-stenting the RVOT.Procedural mortality and complications are uncommon.With more experience,recognition of risk of dreaded outcomes like coronary compression has improved.Also,conduit rupture is increasingly being managed with transcatheter tools.Questions over endocarditis risk still prevail in the TPVI population.Head-to-head comparisons to SPVR are still limited but available data suggests equivalence.We also discuss newer valve technologies that have limited data currently and may have more applicability for treatment of native dysfunctional RVOT substrates.

In vitro bench testing using patient-specific 3D models for percutaneous pulmonary valve implantation with Venus P-valve

Background:Due to the wide variety of morphology,size,and dynamics,selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation(PPVI).This study aimed to report our experience with in vitro bench testing using patient-specific three-dimensional(3D)-printed models for planning PPVI with the Venus P-valve.Methods:Patient-specific 3D soft models were generated using PolyJet printing with a compliant synthetic material in 15 patients scheduled to undergo PPVI between July 2018 and July 2020 in Central China Fuwai Hospital of Zhengzhou University.Results:3D model bench testing altered treatment strategy in all patients(100%).One patient was referred for surgery because testing revealed that even the largest Venus P-valve would not anchor properly.In the remaining 14 patients,valve size and/or implantation location was altered to avoid valve migration and/or compression coronary artery.In four patients,it was decided to change the point anchoring because of inverted cone-shaped right ventricular outflow tract(RVOT)(n=2)or risk of compression coronary artery(n=2).Concerning sizing,we found that an oversize of 2-5 mm suffices.Anchoring of the valve was dictated by the flaring of the in-and outflow portion in the pulmonary artery.PPVI was successful in all 14 patients(absence of valve migration,no coronary compression,and none-to-mild residual pulmonary regurgitation[PR]).The diameter of the Venus P-valve in the 3D simulation group was significantly smaller than that of the conventional planning group(36[2]vs.32[4],Z=-3.77,P<0.001).Conclusions:In vitro testing indicated no need to oversize the Venus P-valve to the degree recommended by the balloon-sizing technique,as 2-5 mm sufficed.

Mechanism and Correlated Factors of SAM Phenomenon after Aortic Valve Replacement

To investigate the mechanism and correlated factors of systolic anterior motion （SAM） phenomenon after aortic valve replacement, 48 patients with severe aortic valvular stenosis were studied. Tested by echo-Doppler one week after aortic valve replacement, the patients were divided into two groups： SAM group and non-SAM group. The data of the left ventricular end-diastolic diameters, the left ventricular end-systolic diameters, the left ventricular outflow diameters, the thickness of the interventricular septum, the posterior wall of left ventricle, the blood velocities of left ventricular outflow and intra-cavitary gradients were recorded and compared. The results showed that no patients died during or after the operation. The blood velocities of left ventricular outflow was increased significantly in 9 patients （〉2.5 m/s）, and 6 of them developed SAM phenomenon. There was significant difference in all indexes （P〈0.05 or P〈0.01） except the posterior wall of left ventricle （P〉0.05） between two groups. These indicated that the present of SAM phenomenon after aortic valve replacement may be directly related to the increase of blood velocities of left ventricular outflow and intra-cavitary gradients. It is also suggested that smaller left ventricular diastolic diameters, left ventricular systolic diameters, left ventricular outflow diameters and hypertrophy of interventricular septum may be the anatomy basis of SAM phenomenon.

The effects of severe aortic stenosis and high pulmonary artery pressure on aortic valve replacement

Background: Pulmonary hypertension development in pure severe aortic stenosis is a situation that affects mortality and morbidity. Material and Methods: Data from files of 31 patients with systolic pulmonary artery pressure over 50 mm Hg and with pure severe aortic stenosis, and underwent aortic valve replacement in our clinic were examined retrospectively. Results: Preoperative effort capacities of the patients were evaluated as follows according to NYHA;4 patients class 1-2, 16 patients class 3, and 11 patients class 4. Twenty-five metal, and 6 biologic aortic valves were used. Postoperative hospital mortality was recorded as 12% with 4 patients. Patients were reevaluated on the postoperative 2nd and 12th months. Pulmonary arterial pressure of the patients was measured using echocardiography. Preoperative average pulmonary artery systolic pressure was measured as 55 ± 3 mmHg. The average pressure was measured as 41 ± 3 mmHg on the 2nd, and as 37.8 ± 4 mmHg on the 12th month. The effort capacity evaluation in the postoperative 2nd month was as follows: 11 patients class 1-2, 12 patients class 3, and 4 patients class 4. The effort capacity evaluation conducted in the 12th month was: 14 patients were class 1-2, 10 patients were class 3, and 2 patients were class 4. During the follow-up 1 year, survival rate of the patients was determined as 83.8% average, 5 year survival rate was determined as 61.5%. Conclusion: We believe that AVR may be performed in severe aortic stenosis cases with high pulmonary pressure with acceptable ortality, leading to a better quality and longer life.

Surgical left atrial appendage occlusion in patients with atrial fibrillation undergoing mechanical heart valve replacement

Background:Surgical left atrial appendage occlusion(SLAAO)may be associated with a lower risk of thromboembolism in patientswith atrial fibrillation undergoing cardiac surgery.However,evidence regarding the effectiveness of SLAAO in patients undergoingmechanical heart valve replacement(MHVR)is lacking.Therefore,we aimed to evaluate the association between SLAAO and thecardiovascular outcomes in patients with atrial fibrillation undergoing MHVR.Methods:We retrospectively analyzed data for 497 patients with atrial fibrillation;27.6%of the patients underwent SLAAO,andthe remainder of the patients did not(No-SLAAO group).The primary outcome was a composite of ischemic stroke,systemicembolism,and all-cause mortality.Cumulative event-free survival rates were estimated using Kaplan-Meier curves,and weperformed multivariate Cox analyses to evaluate the association between SLAAO and outcomes.We used one-to-one propensityscore matching to balance patients’baseline characteristics,and analyzed 120 matching pairs.Results:Five patients died within 30 days postoperatively,and there were no significant differences between the two groupsregarding in-hospital complications(all P>0.05).After a median follow-up of 14 months,14 primary events occurred.Kaplan-Meier curves showed no difference in the cumulative incidence of freedom from the primary outcome(log-rank P=0.830),hemorrhagic events(log-rank P=0.870),and the secondary outcome(log-rank P=0.730),between the two groups.MultivariableCox proportional hazards regression analysis showed no association between SLAAO and any outcome(all P>0.05).Afterpropensity score matching,cardiopulmonary bypass time and aortic cross-clamp time,and the postoperative length of stay weresignificantly longer in the SLAAO group(all P<0.05);results were similar to the unadjusted analyses.Conclusions:Concomitant SLAAO and MHVR was associated with longer length of stay,and cardiopulmonary bypass time andaortic cross-clamp time,but was not associated with additional protective effects against thromboembolic events and mortalityduring the 14-month follow-up.