A 76-year-old woman with a history of double valve replacement (Aortic and mitral valves) for rheumatic heart disease, presented with acute dyspnea after a switch from Warfarin to LMWH before a planned bone marrow biopsy.
The investigations revealed a stuck aortic prosthetic valve ,that showed a prohibitive gradient of more than 50 mmhg. Since, she refused further surgery, a rare and risky effort was made to balloon dilate the prosthetic valve leaflet, though it is not a standard approved modality. It was decided to dilate the supero-lateral orifice and the central orifices by simultaneous kissing balloon. The results were dramatic.
The images and video are reproduced with courtesy of Dr. David Smith, Dr. Ayush Khurana, Department of Cardiology & Cardiac Surgery, Morriston Cardiac Centre, Swansea Bay University Health Board, Swansea, United Kingdom
The stuck valve
Twin balloon dilatation of bi-leaflet valve in between the superior and central orifice
There are few important lessons from this rare case report.
- The innovative double balloon catheter Inflation across the the mechanical prosthetic valve is possible. This technique is likely to emerge more useful in the post TAVI population as well.(JSCCAI 2023)
- Some times, a simple maneuvers like tapping , pushing or releasing stuck leaflet will solve the issue in few lucky patients. The reason is a clot less than 2mm can strategically sit on the hinge point and interfere with its motion. Dislodging a 2mm clot in all likely hood cause a benign TIA , or just vanish in the aortic stream down the hill,
- However , the risk of thromboembolism is genuine in those a clear thrombus is visualised. Hence distal protection by an Aortic sentinel device or its equivalent (FilterWire EZ, Tri-guard) is a must. If Aortic protection device is not available, proceeding with patient & family consent is not forbidden if circumstances demand.(In India ,we do PTMC with mini LA clots without any protection) A video on Sentinel aortic filter
4.It is to be noted if the obstruction is due to pannus , risk of thrombosis is almost nil and safety of prosthetic balloon valvuloplasty is almost ensured.(Of course with risk of device leaflet damage )
5.As on today, differentiating pannus from thrombus remains continues to be a learnt clinical guess game. CT and MRI can give more crucial inputs. To make things more difficult , a raw area over pannus could be the nidus for the thrombus.
6.Probably , the major learning point (rather a sort of mistake) is the decision to switch over to LMWH in lieu of OAC. Time and again we have seen LMWH is a weak anticoagulant, with erratic correlation of Anti X-a activity and efficacy.
7.I believe, in the above case. this complication might not have occurred if she had continued on OAC , if that was not possible , a switch to regular un-fractioned Heparin as a bridge during the surgery could have been the right choice. Generally, overestimation risk of bleeding viz a viz with life threatening thrombosis is quiet common especially in patients with prosthetic valve.
Current approach for prosthetic valve obstruction
A comprehensive review and surprise inclusion of leaflet release as an option.(Ref3)
Reference
3. A review on management of mechanical prosthetic valve
Dr.S.Venkatesan MD 