4.1 Surgical management
Open heart surgery is a gold standard treatment provided for significant and complex PVLs; it either aims to repair or replace the valve27. The surgical strategy is decided based on factors such as patient status, the aetiology, the condition of the native annulus, the size and location of the leak and whether the area is accessible27. The use of open surgery is reduced primarily due to the high morbidity and mortality rates28. The rate of recurrence of paravalvular leaks is also common as the underlying pathology is not really treated. Open-heart surgery is, therefore, performed in cases where: the execution of percutaneous treatment is contraindicated (e.g. if the patient presents with active endocarditis), where the prosthetic valve is dysfunctional 28, or in those who have severe PVLs (where performing an open-heart surgery has shown improved survival and reduced symptoms in patients) 27.
Transcatheter aortic valve closure
The use of percutaneous catheter-based methods and other minimally invasive procedures have developed a great deal of curiosity and interest with regards to treating PVL and resultant regurgitation as not only do they treat the PVL but also reduce risk of further re-operation. To perform the percutaneous method, you need special occlusive devices and access to the site. The access to the site varies according to what type of PVL is present; mitral or aortic PVL. Aortic PVL is accessed through the femoral artery with a retrograde approach. Mitral PVL is accessed through the femoral vein and a transseptal puncture28. Whilst performing these procedures, it is important that the patient is administered general anaesthesia for their comfort and because there may be long-lasting equipment dwell27. PVL closures can be performed using three approaches (transseptal, retrograde transaortic or left ventricle transapical approaches) and the approach taken is decided based on the location of leak, the valve involved, presence of any hinderance or calcification. Aortic paravalvular leaks are treated using the retrograde transaortic approach.
A hydrophilic guidewire, supported by a catheter, is initially directed towards the PVL and either echocardiography or fluoroscopy is used to confirm paravalvular position. The catheter is then inserted into the left ventricle through the defect. Whilst taking extra precautions, the hydrophilic wire is subsequently replaced with an extra support wire; the precautions are necessary to prevent cardiac perforation risk. A delivery sheath for the device is introduced into the left ventricle and then pulled into the defect. The correct placement of the device is confirmed by using TOE27. An overview of a protocol can be seen pictorially in Figure 3 .
Despite the retrograde transaortic approach being the most ideal for an aortic PVL, in some cases the transapical approach may be used. The transapical approach may be necessary when a mitral or aortic mechanical prosthesis is present or when the retrograde transaortic approach is not successful. The antegrade transseptal approach requires an exteriorized arteriovenous (AV) for support and control of the device and sheath during delivery. When the crossing wire is inserted into the descending aorta, snared, and then exteriorized through the femoral arterial sheath, the AV rail is created. It’s important to avoid putting too much pressure on the left ventricle loop, which can entrap the anterior mitral leaflet and produce severe mitral regurgitation27.
Outcomes of PVL management
Surgical treatment of mild and moderate PVLs with no adverse effects is successful in almost 80-90% of patients29. Complications due to treatment using the transcatheter method is rare. Studies that investigated the emergence of adverse effects in 115 patients noticed that in a 30-day period post treatment, 1.7% had an unexplained or sudden death, 2.6% had a stroke, 0.9% required an emergency surgery and 5.2% required treatment for periprocedural bleeding30 31. Two studies had also noticed that 2.5% of patients had experienced device embolism and death was seen in approximately 0.5% of patients 3031.
The transcatheter method may not be successful in some patients. This can be due to impingement of the prosthetic leaflet and the inability to guide the catheter or cross the defects of the wire. Although it is more common for impingement to occur in patients with mechanical valves, it can occur with any prosthesis. Impingement can be prevented with the use of smaller devices but can still be challenging with the nature of the shape of occluders and the location, with regards to the surgical annular ring. Clinical success and the symptoms experienced by patients is dependent upon the degree of regurgitation; it is also seen that those who have heart failure suffer a greater deal of symptoms compared to those with haemolysis 32.
In a study looked at the risk of death and developing heart failure with rehospitalization in 1661 patients after 1-year post-TAVR. A 9.3% of the patients had died within the year whilst approximately 15% of the patients had hospitalized with heart failure. Those with the least moderate form of PVL also had the highest mortality rate. It was also seen that the degree of PVL had decreased by one class/group in almost 80% of patients33. Another study evaluated the outcomes seen after 3 years and saw that there was a survival rate of 64%, cardiac-associated death rate of 9.5%, non-cardiac associated death rate of approximately 10%. 72% of those who survived were symptom free and did not require any other surgery32.