Mid-term results
The survival rate was 94.8% at a mean follow-up time of 26.4 months in our study. In comparison to Ozaki’s study, the survival rate of 850 patients was 85.9%,11 at a mean follow-up time of 53.5 months, and it was 98.1% at a mean follow-up time of 14 months after surgery according to Krane et al.17 In our study, 02 patients died from ascending aortic pseudoaneurysm rupture at 3 and 8 months after surgery, respectively. These patients were admitted to the hospital with a diagnosis of postoperative sternitis and both underwent an operation for stainless steel suture removal and debridement. However, the infection progressed to spread into the mediastinum and caused a pseudoaneurysm at the aorta incision site and then rupture. During Ozaki’s procedure, the extensive dissection and harvest of the anterior pericardium could be a risk factor infection from the sternum to spread into the anterior mediastinum.
The cumulative incidence of reoperation was 2.8%, including 02 patients who required reoperation for endocarditis. As reported by Ozaki in 850 patients, there were 13 patients reoperated due to endocarditis.11 The incidence of reoperation due to degeneration and calcification was extremely low. In our study, no patient had valvular degeneration during follow-up despite the relatively low mean age (52.9). The procedure of harvesting the pericardium, treatment with glutaraldehyde, and rinsing all required absolute sterility.
The cumulative incidence of aortic regurgitation was 4.2%, including 01 patient who had moderate regurgitation immediately after surgery without progression at 42 months follow up and 02 patients who had severe regurgitation due to endocarditis that underwent reoperation after 03 and 06 months, respectively. In comparison, the incidences of moderate or higher aortic regurgitation reported by Ozaki and Krane were 7.3% (the follow-up of 53.6 months) and 3% (the follow-up of 14 months), respectively.11,17 In Ozaki’s procedure, the height of the cusps are elevated to the level of the sinotubular junction in the aorta which increases the aortic cusp coaptation than that with the natural valve, thus limiting the risk of cusp prolapse and subsequent aortic regurgitation.
Aortic valve hemodynamics were favorable, with a post-operative peak gradient pressure of 16.1 to 17.1 mmHg. All patients have been prescribed aspirin 100 mg only if in sinus rhythm after surgery and no bleeding or thromboembolic complications were observed.
In conclusion, aortic valve reconstruction surgery by Ozaki procedure was a safe approach, with a low mortality rate and a high technical success rate. This technique could be implemented in various types of aortic valve diseases and morphology. Hemodynamics of reconstructed valves were favorable with a low cumulative incidence of aortic regurgitation without prosthesis-patient mismatch. However, this technique is limited by a longer aortic cross-clamp time, cardiopulmonary bypass time than in prosthetic valve replacement. The longest follow-up time was 42 months; therefore, it is necessary to continue the follow-up to evaluate long-term outcomes.