4-finger technique for retrograde cardioplegia cannula insertion

Despite the widespread use of retrograde cardioplegia in most institutions, some surgeons continue to encounter technical difficulties during insertion of the retrograde cardioplegia cannula. We introduce the 4-finger technique to facilitate identification, accurate localization, and palpation of the coronary sinus at the left atrioventricular groove during cannula insertion prior to the initiation of cardiopulmonary bypass. The aim of this study was to describe the four-finger technique, evaluate its efficacy, and assess the learning curve among individual surgeons using this approach.

We conducted a prospective observational study involving 200 consecutive adult patients undergoing cardiac surgery requiring retrograde cardioplegia cannulation using the four-finger technique. The little finger palpates the posterior aspect of the IVC, Ring finger palpates the posterior LA wall, index finger palpates the LV wall, and the middle finger positioned over the left AV groove to align with the advancing tip of the RCC. The primary outcome was successful first-attempt cannulation of the coronary sinus. Secondary outcomes included time to successful cannulation, intraoperative hemodynamic disturbances, and the need for conversion to an alternative cannulation method. Learning-curve visualization was analysed for individual surgeons and for overall single-centre performance.

First-attempt cannulation was successful in 188/200 cases (94%). Mean cannulation time improved from 54 ± 20 s in the initial phases to 33 ± 12 s in later cases, demonstrating a clear learning curve. The 4-finger technique was associated with a low incidence of hemodynamic instability during cannulation. Transient hypotension or bradycardia occurred in 8 patients (4%), these events occurring early in the series and resolving spontaneously within 30 s. No conversion to open or direct visualization techniques were reported. Learning Curve Visualization was reported and analysed for the individual surgeons separately and then across the one centre performance.

The four-finger technique achieved a high success rate, reduced cannulation time, and demonstrated a short learning curve across operators.