Is a rigid tricuspid annuloplasty ring superior to a flexible band when correcting secondary tricuspid regurgitation?

A best evidence topic in adult valvular surgery was written according to a structured protocol. The question addressed was 'Is a rigid tricuspid annuloplasty ring superior to a flexible band when correcting secondary tricuspid regurgitation (TR)?' A total of 166 papers were found using the reported search, of which, 13 presented the best evidence to answer the clinical question. The authors, country, journal, date of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. All the 13 papers were retrospective studies, from which 4 were case-control studies comparing the rigid ring annuloplasty approach with the flexible band technique, eight case series and one case report. From the first three case-control studies, we conclude that more progression to moderate-to-severe TR in the flexible band group than rigid ring group. However, the fourth paper reported that both rigid and flexible systems provide acceptable early tricuspid valve repair results, but the use of a rigid ring increases risk of subsequent ring dehiscence. Another rare complication about the rigid ring was described by Galiñanes et al. We conclude that although there are relatively less risk of ring dehiscence or ring fracture in the flexible group, the rigid ring, particularly the new three-dimensional MC3 ring, is inclined to be better than the flexible band in terms of a sustained effect for maintaining stable postoperative regurgitation grade according to the current available evidences. However, due to the limited controlled studies and their retrospective design, the results should be confirmed by prospective studies with a large number of patients.