Background and the aim of the study: A major feature of aortic stenosis is massive mineralization of the aortic valve, though the mechanism of the process remains unclear. The study aim was to characterize the chemical composition and morphology of inorganic deposits from surgically excised natural aortic valves and to seek similarities to minerals in bones and teeth.

Methods: Mineral deposits from 30 surgically excised natural aortic valves were examined. The control group consisted of autopsy samples (aortic valves, vertebral bodies) and teeth obtained after extraction. Micro-computed tomography (micro-CT) was used to describe the morphology and density of the minerals. X-ray fluorescence and Fourier transform infrared spectroscopy were applied to determine the chemical composition.

Results: A poorly crystalline, B-type carbonate-containing hydroxyapatite (HAP) was found to constitute the mineral phase of the aortic valve leaflets. No other chemical compounds were identified. The elemental composition of the minerals in aortic valves and bone/tooth did not differ markedly, except that the Mg concentration was fourfold higher in valve material. The aortic valve deposits were irregular in shape and occupied ca. 40% of the leaflet volume. The volume of the deposits were spread over a broad range (0.001-0.3 mm3), while the density ranged from that of dentine to enamel (average value 2.2 g/cm3), slightly higher than that of compact bone.

Conclusion: The aortic valve deposits were identified as B-type carbonate-containing HAP, and were not identical to those found in bones and teeth, the main difference being a fourfold elevated Mg content. Mg may have been deposited as a separate compound, as micro-CT results suggested that the formation of mineral deposits in aortic valves was a multi-factorial process. The morphological parameters and densities of the valve deposits were spread over a broad range (factor approximately 300). An unequivocal identification of the mechanism responsible for the aortic valve pathological calcification was not possible, however.

The main goal of aortic valve replacement (AVR) is to obtain relief from the fixed left ventricular (LV) obstruction by replacing the aortic valve with a prosthesis, either mechanical or biological, of adequate size. Most currently available prostheses provide satisfactory hemodynamic performance, but small-sized prostheses may be associated with high transvalvular gradients and suboptimal effective orifice area that result in prosthesis-patient mismatch (PPM), and thus are far from ideal for use in young, active patients. The avoidance of PPM is advisable as it has been repeatedly associated with increased mortality, decreased exercise tolerance and an impaired regression of LV hypertrophy after AVR for severe aortic stenosis. Enlargement of the aortic annulus (EAA) has proved to be a valuable method to prevent PPM in the presence of a diminutive aortic root. This review outlines the various techniques described for EAA, presenting technical details, long-term results and major procedure-related complications, and discussing the current role of EAA in patients requiring AVR.

During the past decades, replacement of the aortic valve (AVR) was considered a straightforward treatment of aortic valve disease. The technique is simple, with a relatively low perioperative mortality and morbidity (3-5%) and, as such, does not require a detailed knowledge of aortic root anatomy. However, with the renaissance of reconstructive procedures on the aortic root, an increased use of biological aortic valve prostheses (especially of stentless devices) and, finally, the revival of the Ross procedure, a more detailed understanding of aortic root function and morphology was required in the operating room.

Background and aim of the study: Aortic aneurysm size is known to portend a higher likelihood of aortic complications in patients with connective tissue disorders (CTD), but other objective tools are needed to determine which patients are at greatest risk of dissection, especially those which reflect the structural integrity and strength of the aortic wall.

Methods: The aortic wall pathology was evaluated in CTD patients with and without acute aortic dissection to identify parameters that affect the risk of dissection. A retrospective review was performed of aneurysm pathology from patients with Marfan syndrome (MFS; n = 53) without dissection undergoing prophylactic aortic root surgery, and acute type A aortic dissection patients (AAAoD; n = 16). Patients without a cardiovascular cause of death (n = 19) served as controls. The minimal aortic medial wall thickness was measured, and medial myxoid degeneration (MMD) and the degree of elastin loss and fragmentation were graded.

Results: The mean minimal aortic wall thickness was 1,625 +/- 364 microm in controls, and 703 +/- 256 microm and 438 +/- 322 microm for MFS and AAAoD patients, respectively. Aortic root diameters did not correlate with aortic wall thickness. A comparison of aortic medial thickness showed that the media was significantly thinner among acute dissection patients than either elective surgical patients (p = 0.02) or controls (p < 0.001). Aortic size, degree of MMD, and elastin loss did not vary significantly between CTD patients.

Conclusion: A diminished aortic wall medial thickness may be linked to aortic dissection. High-resolution imaging techniques in the future may lead to the morphological assessment of aortic medial wall thickness in vivo becoming a reality which, in theory, could provide a more refined risk prognostication for acute aortic dissection.

Background and aim of the study: The benefit of valve-sparing aortic root replacement compared to conventional aortic root replacement surgery remains unclear.

Methods: Between February 2009 and November 2010, a total of 112 patients underwent aortic root surgery at the Department of Cardiovascular and Thoracic Surgery, Heinrich-Heine-University, Dusseldorf, Germany. The valve-sparing technique was used when leaflets were grossly normal. In cases where the valve could not be saved, a prosthetic or biological substitute was used for the aortic root, according to existing guidelines. The patients were allocated to three groups: (i) valve-sparing aortic root replacement group using the David technique (VSR-David; n = 47); (ii) valve-replacing aortic root surgery with a prosthetic conduit using the Bentall-Kuchucus technique (VRR-Prosthetic; n = 31); and (iii) valve-replacing aortic root surgery with a biological stentless valve with the full root technique (VRR-Bio; n = 34).

Results: Intraoperative data revealed that, in the VSR-David group, the cardiopulmonary bypass and cross-clamp times were significantly longer (207 +/- 68 min and 140 +/- 38 min respectively; both p = 0.001). The VRR-Prosthetic patients were at highest risk (mean EuroSCORE 15.9%) compared to the VSR-David and VRR-Bio groups (10.8% and 10.4%, respectively). Postoperative analysis showed that patients in the VRR-Bio group had the lowest number of perioperative heart failures (p = 0.004). The perioperative 30-day mortality was significantly higher in the VRR-Prosthetic group (22.6%; p = 0.004). Transaortic flow velocities were significantly lower in the VSR-David group, followed by the VRR-Bio group and VRR-Prosthetic group (1.66 +/- 0.54, 1.98 +/- 0.45, and 2.29 +/- 0.39 m/s, respectively; p = 0.012). The univariate and multivariate analyses of perioperative risk factors showed that only open distal anastomosis was strongly associated with negative results, but not the valve-sparing technique.

Conclusion: Aortic valve-sparing root replacement must be considered as an excellent alternative for young patients requiring aortic root replacement when a biological valve is clinically indicated. For patients aged >65 years, or with a decreased life expectancy, the full root technique with a stentless valve should be used, given its technical simplicity and excellent postoperative results.

How to cite: Blehm, A., Schurr, P., Sorokin, V. A., Zianikal, I., Kamiya, H., Albert, A., & Lichtenberg, A. (2014). Comparison of different surgical techniques in 112 consecutive patients with aortic root operations: when should the valve be spared?. The Journal of heart valve disease, 23(1), 9–16.

Background and aim of the study: Recent evidence challenges the paradigm that left ventricular hypertrophy (LVH) is required to preserve left ventricular systolic performance in severe aortic stenosis (AS). The study aims were to determine the clinical, echocardiographic and prognostic implications in a cohort of patients with symptomatic severe AS, a preserved left ventricular ejection fraction (LVEF), and an absence of LVH.

Methods: Echocardiographic, clinical, aortic valve replacement (AVR)-related and all-cause death data were analyzed in 512 patients (253 males, 259 females; mean age 78.4 +/- 10.3 years) with severe AS and a preserved LVEF. Of these patients, 21% were enrolled prospectively, and the mean follow up was 40.4 +/- 32.5 months.

Results: By using the American Society of Echocardiography equation for left ventricular mass calculation, LVH was shown to be present in 330 patients (63%) and absent from 182 (36%). Typically, patients without LVH had a larger body surface area, were more often male, had a larger aortic valve area index (AVAi), and had similar LVEFs and rates of AVR as compared to those with LVH. A total of 59 deaths (32.4%) occurred among patients without LVH, and 134 (40.6%) among those with LVH (p = 0.07). When the left ventricular mass index (LVMi) was analyzed as a continuous variable, in both unadjusted and adjusted models for demographics, clinical characteristics, medications, AVAi, LVEF, and systemic vascular resistance, no association was found between LVMi and survival (p = 0.26). However, only patients with a normal LVMi and relative wall thickness had a survival benefit when compared to those with any pattern of abnormal left ventricular geometry (p = 0.01).

Conclusion: LVH was absent in more than one-third of patients with severe AS, and was not associated with worse outcomes. A normal left ventricular geometry was associated with lower mortality rates, while AVR was associated with prolonged survival, regardless of LVMi. Mechanisms other than compensatory hypertrophy appear capable of offsetting the adverse effects of afterload excess in AS.

How to cite: Barasch, E., Kahn, J., Petillo, F., Pollack, S., Rhee, P. D., & Reichek, N. (2014). Absence of left ventricular hypertrophy in severe isolated aortic stenosis and preserved left ventricular systolic function. The Journal of heart valve disease, 23(1), 1–8.