Mitral valve repair with papillary muscle repositioning for functional mitral regurgitation (Type IIIb) with metal allergies: a case report

BACKGROUND: Prosthetic heart valves, rings, and clips commonly used in heart surgery may contain metals, such as nickel and cobalt, that can cause severe hypersensitivity reactions in allergic patients. These reactions can cause paravalvular leakage and valve dysfunction. Similarly, stainless steel sternal wires can cause contact dermatitis. We should select rings, valves, and wires that do not contain any metals known to cause allergies in patients undergoing cardiac surgery. CASE SUMMARY: We report the case of a 79-year-old man with severe functional mitral regurgitation (Type IIIb) and a history of nickel and cobalt allergies. We safely performed mitral valve repair with papillary muscle repositioning with nickel- and cobalt-free rings in this patient. He was discharged from the hospital on the 26th postoperative day without dialysis intervention. Two years after surgery, mitral and tricuspid regurgitation had not worsened. DISCUSSION: According to the 2020 American Heart Association guidelines, surgery for severe functional mitral valve insufficiency (Type IIIb) is considered class IIb. Meanwhile, transcatheter edge-to-edge repair is class IIa. Long-term regurgitation is difficult to control with valve replacement and annuloplasty alone; recurrence has been observed. Therefore, additional techniques were considered. Papillary muscle repositioning has been reported and shown good results. The method used in the present case made intervening in the subvalvular tissue easy and demonstrated technical feasibility, safety, and effectiveness.