INCREASED PULMONARY FLOW VELOCITIES IN OVERSIZED HOMOGRAFTS IN PATIENTS AFTER THE ROSS PROCEDURE

Objective: Between September 1991 and July 1996, 60 patients (mean age 29.8 +/- 9 years; range 5-57) underwent aortic root replacement with pulmonary autograft, a viable biologic and nondegenerating substitute. The pulmonary root was replaced with cryopreserved homografts from ca rdiac transplant recipients. The aim of this study was to evaluate dif ferences in early valve function of viable and cryopreserved allograft s. Methods: All patients had Doppler echocardiographic examinations pr eoperatively, at discharge from hospital and 54 patients at 1 year fol low-up. We measured aortic and pulmonary peak flow velocities with con tinuous and pulsed-wave Doppler, and graded aortic and pulmonary insuf ficiency (AI, PI) with color Doppler flow (grade 0-IV). Intraoperative ly, the diameters of the pulmonary root and the pulmonary homograft we re measured with standard valve probes and matched to body surface are a. Results: Pulmonary peak how velocity (PVmax) increased significantl y from preoperative 0.87 +/- 0.11 m/s to 1.30 +/- 0.34 m/s postoperati vely (P < 0.001). The implanted homografts (mean 25.9 +/- 2.4 mm) were larger than their native pulmonary diameter (mean 23.3 +/- 1.8 mm) in all patients. Homograft size matched for body surface area (BSA) did not correlate with increased PVmax. There was a significant increase o f PVmax at follow-up (FU) since discharge, also 1.83 +/- 0.53 m/s; P < 0.001). Pulsed-wave Doppler demonstrates that increase of PVmax is lo cated directly at the homograft leaflets and not at the anastomoses. A ortic peak flow velocities (AV(max)) were normal postoperatively and a t FU (post = 1.35 +/- 0.35 m/s; FU = 1.17 +/- 0.27 m/s). There was no significant change in AI or PI since discharge (AI FU = 0.8 +/- 0.4; P I FU = 0.7 +/- 0.5. Eight patients with fever and symptoms diagnosed a s post-pericardiotomy syndrome had significantly higher PVmax at FU (P Vmax 2.41 +/- 0.40 m/s; P < 0.02). Conclusions: The Ross procedure lea ds to normal AV(max) but significant increase of PVmax even in oversiz ed cryopreserved homografts immediately after surgery. Further increas e of PVmax without changes in AV(max) in the first year demonstrates t hat changes in how velocities are valve related and not due to increas e in cardiac output. Further investigations will be necessary to deter mine whether this observation is due to valve rejection or early leafl et degeneration and treatment with immunosuppressive therapy is warran ted. (C) 1997 Elsevier Science B.V.