The optimal surgical treatment in functional ischemic mitral regurgitation (FIMR) remains controversial. Recently, a posterior papillary muscle relocation (PMR) technique as adjunct procedure to ring annuloplasty has been proposed to prevent recurrent FIMR. We assessed the hypothesis that relocating both papillary muscles as adjunct procedure to down-sized ring annuloplasty improves mitral leaflet coaptation geometry in FIMR pigs. Eleven FIMR pigs were randomized to down-sized ring annuloplasty (RA, N=6) or RA combined with PMR (RA+PMR, N=5). In the RA+PMR group a 2– 0 Goretex suture was attached to each trigone, exteriorized through the corresponding papillary muscle, mounted on an epicardial pad and tightened to relocate the myocardium adjacent to the anterior and posterior papillary muscles 5 and 15 mm, respectively. Using 3D magnetic resonance imaging the impact from these interventions on leaflet geometry was assessed. Statistically significant (p<0.05) differences in postoperative leaflet geometry were observed at end-systole (RA vs. RA+PMR, mean ±SEM): Occlusional leaflet area (877 ±36 vs. 666 ±52 mm
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), tenting volume (1620 ±132 vs. 1064 ±198 mm
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), mean tenting height (5.9 ±0.2 vs. 4.9 ±0.3 mm), mean coaptation length (6.5 ±0.2 vs. 7.6 ±0.3 mm). Figure 1
shows coaptation length and tenting height of leaflet segments A1-P1, A2-P2 and A3-P3 at end-systole. Adding papillary muscle relocation to down-sized ring annuloplasty reduced leaflet tethering and improved coaptation geometry and therefore holds promise for reducing the prevalence of recurrent FIMR in patients.
Papillary muscle intervention vs mitral ring annuloplasty in ischemic mitral regurgitation
