The combined aortic and mitral valve replacement with cardiac fibrous skeleton reconstruction (mitral-aortic continuity or curtain), commonly referred to as the “Commando procedure,” is a surgical technique designed to treat complex diseases of the heart’s fibrous skeleton, such as infective endocarditis with paravalvular extension to the mitral-aortic curtain or extensive calcification of the mitral-aortic continuity and adjacent valve annulus.

Although there are series describing the short-term morbidity and mortality of this procedure, data on long-term outcomes remain sparse.

The objective of this study was to evaluate the surgical and long-term outcomes of the Commando procedure. A total of 182 consecutive patients, operated on by a single surgeon between 1985 and 2020, underwent mitral-aortic curtain reconstruction, with posterior mitral annulus reconstruction in 63 cases. The median follow-up was 7.5 years (interquartile range 2.1-12.6 years), with 98% of the sample achieving complete follow-up. The mean age of patients was 62 years, with 69% having one or more previous valve surgeries, and 92% in NYHA functional class III or IV due to dyspnea. The indications for reconstruction were extensive calcification of the fibrous skeleton (34%), abscess (13%), tissue damage secondary to previous operations (39%), and mitral valve prosthesis-patient mismatch (13%). Bovine pericardium was used in two-thirds of cases, while a tailored Dacron conduit was employed in the remaining third. The operative mortality rate was 13.2%, with a high incidence of postoperative complications. Survival rates at 1, 10, and 20 years were 81.8%, 51.1%, and 23.7%, respectively. Fourteen patients required reoperation, and three underwent percutaneous intervention. The cumulative probability of reoperation at 1, 10, and 20 years was 3.3%, 5.8%, and 9.1%, respectively. Most patients experienced symptom improvement postoperatively.

Based on these results, the authors conclude that reconstruction of the heart’s fibrous skeleton is associated with high operative mortality, but the long-term outcomes are satisfactory, considering that most patients would not have survived without surgical intervention.

COMMENTARY:

David et al. from Toronto present the largest published series of patients undergoing combined aortic and mitral valve replacement with mitral-aortic continuity reconstruction, performed by a single surgeon. This series is not only notable for the large number of patients included but also provides, for the first time, long-term follow-up information for patients undergoing such an aggressive procedure. Initially, Tirone David described this technique in 1997, publishing a series of 43 patients; the subsequent series in 2005 included 73 patients, and this most recent series with 182 patients spans a 35-year period.

One notable point is the favorable short-term or in-hospital mortality rate of just 13.2%, a remarkable outcome considering that 69% of the procedures were reoperations, with 16% being third-time operations and even 7% fourth-time surgeries.

Tirone David’s team underscores that this series involved a complex learning curve and imparts technical lessons that cardiac surgeons should not overlook. Among the standout recommendations, they describe techniques for performing tension-free patch reconstruction between the medial and lateral fibrous trigones using individual sutures, measuring and positioning the mitral prosthesis to avoid left ventricular outflow tract obstruction, preoperative imaging guidelines, reconstructing the posterior mitral annulus, and when and what type of patch material to use. Regarding patch material, the authors report late calcification and fracture of bovine pericardium, which has sometimes led to late paravalvular leakage. Consequently, their team has recently preferred Dacron patches, especially for younger patients, although Dacron may be less versatile in the surgical field than bovine pericardium.

Several questions without clear answers remain, such as whether any preoperative imaging characteristics (computed tomography or echocardiography) or clinical factors contraindicated this procedure. Occasionally, particularly in cases of native valve endocarditis, the intraoperative findings of tissue destruction may exceed preoperative expectations, necessitating more radical debridement and, at times, a spontaneous shift to a Commando procedure. What percentage of these cases were unplanned, and did these unexpected scenarios impact outcomes?

This pioneering publication provides an exhaustive and exceptional technical surgical description, accompanied by excellent short- and long-term outcomes, setting the reference standard for Commando surgery.

REFERENCE:

David TE, Lafreniere-Roula M, David CM, Issa H. Outcomes of combined aortic and mitral valve replacement with reconstruction of the fibrous skeleton of the heart. J Thorac Cardiovasc Surg. 2022 Nov;164(5):1474-1484. doi: 10.1016/j.jtcvs.2021.09.011.