Pulmonary homograft morphology after the Ross procedure: a computed tomography study

In patients undergoing the Ross procedure the autograft morphological characteristics have been well studied, but those of the homograft are less clear. The study aim was to describe the radiomorphological homograft characteristics in Ross patients, and to compare them with such characteristics in normal (control) subjects.

A total of 79 Ross patients (68 males, 11 females; mean age 43 +/- 12.3 years) underwent a computed tomography (CT) scan at a mean of 31 +/- 26 months after surgery. A group of 123 patients without cardiovascular disease served as controls. Cryopreserved homografts were implanted in all Ross patients, with the majority being obtained from a single source.

The mean donor age was 47 +/- 11 years, and the mean homograft diameter 25.4 +/- 1.3 mm (as provided at source). Electrocardiographic-gated CT reconstructions were used for the measurements. The smallest diameters were at the proximal anastomosis, and maximum diameters at the distal anastomosis (p <0.001). In controls, the minimum diameter was just proximal to the pulmonary valve annulus. In Ross patients, the homograft diameters were significantly smaller at all levels compared to controls. This effect persisted after taking into consideration patient age, height, gender, body surface area, and time since surgery. Notably, the measured homograft diameters were significantly smaller than those provided at source.

The study results provided evidence of homograft shrinkage at all levels after the Ross procedure but, most prominently, at the level of the proximal suture line. This may have implications for novel preservation methods, as well as homograft size selection and implantation techniques.