Does the morphology of mitral paravalvular leaks influence symptoms and hemolysis?

Prosthetic mitral valve replacement (MVR) is associated with paravalvular leak in up to 12.5% of patients. The influence of the morphology and location of paravalvular leaks on clinical symptoms and degree of leak-related hemolysis is unknown.

Morphology, size, location and number of paravalvular leaks were analyzed in 96 consecutive patients with primary mitral paravalvular leaks.

Mitral leak was diagnosed a median of 119 days after primary MVR. A small (1-2 mm) paravalvular leak was found in 41 patients (43%), an intermediate leak (3-5 mm) in 26 (27%), and a large leak (6-15 mm) in 29 (30%). Single leaks were observed in 70 patients (73%), whilst 26 (27%) had multiple leaks. Paravalvular leaks occurred around the entire prosthetic circumference, but were seen predominantly around the mitral commissural areas (76%). The larger the size of the leak, the more symptomatic the patient (p = 0.006); 80% of patients with small leaks were in NYHA classes I and II, whilst 62% with intermediate/large leaks were in NYHA classes III and IV. The number of leaks was not correlated with severity of clinical symptoms. Multiple leaks were more likely to cause significant hemolysis. Patients with preoperative chronic renal insufficiency, postoperative infection or large (>5 cm) left atria were more likely to develop multiple leaks. The size and location of the leaks was surgeon-dependent.

Intraoperative transesophageal echocardiography is mandatory to detect possible small leaks and technical errors. Strict monitoring of all MVR patients is necessary for prolonged periods, as the appearance of paravalvular leaks is not necessarily correlated with clinical symptoms. Small paravalvular leaks, in particular, may go unnoticed. As the location and size of the leaks were significantly surgeon-dependent, self-monitoring should be mandatory for all surgeons.