Thrombolytic Therapy as the Management of Mitral Transcatheter Valve-in-Valve Implantation Early Thrombosis

A case of early thrombosis following a percutaneous tricuspid valve in valve implantation managed by thrombolysis

Bioprosthetic valve thrombosis (BPVT) is a growing recognized entity, especially with the increasing use of the valve in vale procedures and the advent of new detection technologies (e.g., 4D CT and 4D echocardiography). The incidence of BPVT is higher in transcatheter valves than surgically implanted bioprosthetic valves. However, the best thromboprophylaxis regimen and optimal management strategy in the acute context remain unknown. This paper presents a case of early thrombosis following the percutaneous tricuspid valve in vale procedure that was successfully managed with thrombolysis.

Transcatheter mitral valve thrombosis: A case report and literature review

Transcatheter mitral valve replacement (TMVR) is an exciting alternative therapy for complex patients with mitral valve disease. Experience with TMVR is new and there is a lot yet to discover about their durability, long-term outcomes, and complications including mitral transcatheter heart valve (THV) thrombosis. Many factors have been speculated to increased risk of THV thrombosis. Here, we report a case of a 72-year-old woman who developed mitral THV thrombosis after undergoing TMVR for severe mitral regurgitation with mitral annular calcification. We reviewed 42 TMVR papers with 1,484 patients, including 60 with mitral THV thrombosis. We discussed the most common strategies used for mitral THV thromboprophylaxis and treatment.

Transcatheter mitral valve implantation for degenerated mitral bioprostheses or failed surgical annuloplasty rings: A systematic review and meta-analysis

BACKGROUND

Transcatheter mitral valve-in-valve (TMVIV) and valve-in-ring (TMVIR) implantation for degenerated mitral bioprostheses and failed annuloplasty rings have recently emerged as treatment options for patients deemed unsuitable for repeat surgery.

METHODS

A systematic literature review was conducted to summarize the data regarding the baseline characteristics and clinical outcomes of patients undergoing TMVIV and TMVIR procedures.

RESULTS

A total of 245 patients (172 patients who underwent TMVIV surgery and 73 patients who underwent TMVIR surgery) were included in the study; 93.5% of patients experienced successful TMVIV or TMVIR implantation. The mortality rates at discharge, 30 days, and 6 months were 5.7%, 8.1%, and 23.4%, respectively. The transapical (TA) access route was used in most procedures (55.2%). The TA and transseptal (TS) access routes resulted in similar outcomes. No significant differences were observed in the short-term outcomes between the patients who developed mitral stenosis versus mitral regurgitation as the mode of failure.

CONCLUSIONS

TMVIV and TMVIR implantation for degenerated mitral bioprostheses and failed annuloplasty rings are safe and effective. Both procedures, via TA or TS access, can result in excellent short-term clinical outcomes in patients with mitral stenosis or regurgitation, but long-term follow-up data are currently lacking to determine the durability of these procedures.

Valve thrombosis following transcatheter aortic valve replacement: significance of blood stasis on the leaflets

OBJECTIVES

Leaflet thrombosis following transcatheter aortic valve replacement (TAVR) and valve-in-valve (ViV) procedures has been increasingly recognized. However, the factors affecting the post-TAVR/ViV thrombosis are not fully understood. This study aimed to investigate the effect of the geometric confinement of transcatheter aortic valve (TAV) on blood residence time (BRT) on the TAV leaflets and in turn on the post-TAVR valve thrombosis.

METHODS

Two computational models, representing a surgical bioprosthesis and a TAV, were developed to study the effect of the geometric confinement on BRT on the leaflets in ViV setting/TAVR Intra-annular positioning. 3D flow fields were obtained via a one-way fluid-solid interaction modelling approach validated by experimental testing. BRT was compared between the two models by quantification and statistical analysis of the residence time of randomly distributed particles in close proximity of the leaflets.

RESULTS

Significantly longer BRT on the leaflets was observed in the TAV compared to the surgical valve during different stages of the cardiac cycle. During forward flow, the mean value of BRT was found to be 39% higher in the TAV compared to the surgical bioprosthesis ( P <  0.0001). During diastole, specifically from end-systole to mid-diastole and from mid-diastole to the beginning of systole, the amount by which the mean BRT was higher for TAV compared to the surgical valve was 150% and 40%, respectively ( P <  0.0005).

CONCLUSIONS

The geometric confinement of TAV by the failed bioprosthesis or the calcified native valve increases the BRT on the TAV leaflets. This may act as a permissive factor in valve thrombosis.

Surface heparinization and blood compatibility modification of small intestinal submucosa (SIS) for small-caliber vascular regeneration

OBJECTIVES

This study aims to investigate the small intestinal submucosal (SIS) surface after heparinization with the hypothermia plasma technique, to improve the blood compatibility of SIS, and to explore the possibility of construction of small-caliber vascular grafts with modified SIS scaffolds in vivo.

METHODS

SIS films prepared from jejunums of pigs were processed for surface treatment at different time periods with the argon plasma initiation technique under vacuum, and were then immediately immersed in 4% (m/v) heparin sodium solution for 24-h heparinization. The surface morphologies of heparinized SIS were observed under a scanning electron microscope (SEM). The antithrombogenicity of the modified SIS films was tested by measuring the water contact angle, blood coagulation time, activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), and observation of platelet adherence by SEM. Heparinized SIS films were sewn into a small caliber (3-mm) tube and implanted into the defect of a canine femur by anastomosis as a vascular graft. The efficiency of the SIS graft was evaluated according to the patency for the circulation of blood with Doppler color ultrasonography and hematoxylin-eosin staining.

RESULTS

Heparinized SIS showed a significantly different surface morphology compared with that of untreated SIS. The SIS surface resembles wrinkled film, but the heparinized SIS surface is uniformly coated with microdots, and appears to have a layer of heparin adhesion.

CONCLUSION

Heparin was attached to the SIS surface after hypothermia plasma treatment. Hydrophilicity and antithrombogenicity of heparinized SIS were clearly increased. The heparinized SIS vascular graft showed great potential for replacement of defective small-caliber vessels.