Aortic root enlargement does not increase the surgical risk and short-term patient outcome?

Objective: To analyze the short-term outcome of aortic root enlargement (ARE) using death and adverse events as end points.

Methods: From January 1999 through December 2009, 3339 patients were subjected to aortic valve replacement (AVR). A total of 678 were considered to have small aortic roots (SARs) in which an aortic prosthesis size 21 mm or smaller was implanted. ARE using a bovine pericardial patch was performed in another 218 patients, who constitute the study population. This comprised 174 females (79.8%); the mean age was 69.4 ± 13.4 years (8-87, median 74 years), the body surface area (BSA) was 1.59 ± 0.15m² and the body mass index (BMI) 25.77 ± 3.16 k gm⁻², and 192 (88.5%) were in New York Heart Association (NYHA) II-III. Preoperative echocardiography revealed significant left ventricular (LV) dysfunction in 17 patients (8%), a mean aortic valve area of 0.57 ± 0.27 cm², and a mean gradient of 62.51 ± 21.25 mm Hg. A septal myectomy was performed in 129 subjects (59.2%), and other associated procedures, mostly coronary artery bypass grafting (CABG), in 60 (27.5%). Bioprostheses were implanted in 161 patients (73.9%). The mean valve size was 21.9 ± 1.0 (21-25). The mean extracorporeal circulation (ECC) and aortic clamping times were 82.8 ± 19.8 min and 56.8 ± 12.5 min, respectively.

Results: Hospital mortality was 0.9% (n=2) for ARE as compared with 0.6% (n=4) for the SAR group (p=0.8). Inotropic support was required in only 13 (5.9%) patients and the first 24-h chest drainage was 336.2 ± 202 ml. Other complications included pacemaker implantation (7.8%), acute renal failure (10.6%), respiratory (4.1%), and CVA/transient ischemic attack (CVA/TIA) (3.2%). Postoperative echocardiographic evaluation showed a significant decrease in peak and mean aortic gradients (23.7 ± 9.5 and 14 ± 6.2 mm Hg, respectively, p<0.0001). The mean indexed effective orifice area (iEOA) was 0.92 ± 0.01 cm² m⁻² (vs 0.84±0.07 cm² m⁻², in SAR, p<0.0001). Only 11% of patients (n=24) with ARE exhibited moderate patient-prosthesis mismatch (PPM) and none had severe PPM. Mean hospital stay was 9.7 ± 9.29 days (median 7 days).

Conclusions: With the growing number of patients with degenerative aortic valve pathology, mainly an older population, sometimes with calcified and fragile aortic wall, the issue of dealing with an SAR poses the dilemma of whether to implant a smaller prosthesis and admit some degree of PPM, or to enlarge the aortic root. This study demonstrates that the latter can be done in a safe and reproducible manner.