Commentary: Devil is in the details…and good judgment!

T. K. Susheel Kumar, MD, and Christopher J. Knott-Craig, MD

The cone operation for Ebstein anomaly of the tricuspid valve nearly restores the anatomy and function of the valve. Good outcomes hinge on attention to minor details and optimal patient selection.

See Article page 269.

The relative rarity of the disease and the wide spectrum of valve malformation combine to make Ebstein anomaly of the tricuspid valve a surgical enigma. In 2004, Da Silva described a new technique, termed the “cone operation,” to repair the tricuspid valve in Ebstein anomaly. This operation restored the tricuspid valve anatomy and function better than any other previously described technique. Dearani and his group at the Mayo Clinic further refined this technique (“Mayo modification”) and have performed it in a large number of patients with impressive outcomes. In a recent series of 235 patients that included children, with a median age of 15.6 years, there was just 1 early mortality and 98% freedom from late reoperation at 6 years. A sustained improvement in tricuspid valve function and reduction in right ventricle volume was also noted during follow-up.

In this article on surgical techniques, Dr Joseph Dearani provides exemplary insight into the nuances of cone technique for repair of Ebstein anomaly. The description of the operation stands out for its clarity and attention to minor details, with the author providing stitch-to stitch guidance through the operation. There is little to add or edit to what he has already described beautifully. In our experience, we have found that marking the external course of the right coronary artery with ink before myocardial arrest can help avoids inadvertent injury. Dissection of the superior vena cava and right pulmonary artery, including high cannulation of the superior vena cava should be done in all cases in anticipation of a bidirectional Glenn procedure.

We would like to sound a word of caution to the readers. The success of an operation depends not only on surgical finesse, but also on patient selection. Not every patient with Ebstein anomaly is a good candidate for the cone operation. Extremes of age, pulmonary hypertension, significant left ventricular dysfunction, severe enlargement of the tricuspid valve, severe enlargement of the right ventricle, and extremely poor delamination of the tricuspid valve leaflets are risk factors for poor outcomes. The cone technique works well in the older children and adults with Ebstein anomaly, in whom the valve tissue is mature and the functional right ventricle is of reasonable size. The technique cannot be applied in symptomatic neonates with Ebstein anomaly, for several reasons. The functional right ventricle is often diminutive, with severe apical displacement of the tricuspid valve. Either it is not amenable to biventricular repair or the valve tissue is too delicate to withstand extensive suturing intrinsic to cone repair. In addition, the backup option of the bidirectional Glenn procedure is not available for neonates. Other options, such as monocusp repair based on the anterior tricuspid valve with ligation of patent ductus arteriosus, should be considered. A Starnes single-patch palliation also remains an excellent option in the neonate with a diminutive functional right ventricle.

Dr Dearani once again needs to be congratulated for an excellent step-by-step rendition of the surgical technique for a successful cone repair. Maintaining the integrity of the anteroseptal commissure, avoiding closure of the natural clefts in the tricuspid valve leaflets, and creating a complete cone of tissue before attachment to the annulus are important steps borne out of years of experience.