Commentary: Second verse, same as the first: Biatrial versus bicaval anastomosis in cardiac transplantation.

David D. Yuh, MD, FACS, FACC

Despite the purported advantages of the bicaval anastomotic technique in cardiac transplantation, tricuspid distortion and functional tricuspid insufficiency can be reduced with the still-popular biatrial technique.

See Article page 25.

The relatively high prevalence of functional tricuspid insufficiency (TI) after orthotopic cardiac transplantation has been attributed to numerous factors (eg, endomyocardial biopsies, pulmonary hypertension, donor-recipient size mismatch, graft ischemic times) but most commonly to tricuspid annular distortion, which can result from the abnormal atrial dimensions and geometries associated with the “standard” biatrial cuff technique originally described by Shumway and Lower in the 1960s. Despite several studies demonstrating significant reduction of functional TI with the bicaval anastomotic technique introduced in the late 1980s, and others suggesting significant negative consequences of moderate to severe functional TI on morbidity and mortality among heart transplant recipients,4, 5, 6 the technically simpler biatrial technique is still widely performed today, with excellent results. The persistent comparisons of the 2 anastomotic techniques among multiple transplantation centers with widely varying rates of functional TI and inconsistent correlations with long-term survival7, 8, 9, 10 have perpetuated controversy regarding these techniques' relative impacts on short- and long-term clinical outcomes.

The primary value of the analysis of a large cohort of biatrial cardiac transplant recipients reported by Hajiyev and colleagues in this issue of the Journal lies in its acceptance of the propensity for distorting tricuspid annular geometry and functional TI using the biatrial technique and identifying a technical benchmark—maintaining a donor-to-recipient (D/R) right atrial anterior wall ratio <1—that mitigates this distortion by reducing tension on the anterior wall of the right atrium. The technique used by the authors' institution to achieve this benchmark appears to have resulted in a low incidence of early moderate to severe functional TI of 19%, compared with 42.8% in a contemporary pooled meta-analysis and even higher rates in other series. The impact of right atrial proportions on functional TI was corroborated in an earlier study by Dandel and colleagues, who observed that patients without TI had a D/R atrial dimensional ratio <1, whereas those with moderate to severe TI had a D/R ratio >1.

This technical benchmark for the biatrial technique illustrated by Hajiyev and colleagues provides a useful, reproducible refinement of a simple, time-tested technique for transplantation surgeons who are reluctant to change to an arguably more technically complicated bicaval technique despite its purported (yet still-controversial) benefits. Furthermore, the growing use of biventricular/AICDs and ventricular assist devices in patients awaiting transplantation and the improved survival may present more situations in which a biatrial anastomosis is more technically favorable (eg, reoperative transplant, abnormal caval veins).

Certainly, among cardiac transplant recipients there are more prevalent causes of morbidity and mortality than functional TI, regardless of its many possible etiologies (including anastomotic technique). Consistently mitigating the other risk factors identified by this analysis—number of endomyocardial biopsies and end-stage renal disease necessitating dialysis—would seem to be difficult. Nevertheless, there appears to be a significant opportunity to reduce the morbidity and mortality associated with functional TI after transplantation with improved surveillance and proactive medical and surgical interventions that includes reoperative and even prophylactic tricuspid annuloplasty during transplantation. Further validation and refinement of such measures would seem worthwhile.