Three dimensional evaluation of the aortic annulus using multislice computer tomography: are manufacturer's guidelines for sizing for percutaneous aortic valve replacement helpful?
ABSTRACT To evaluate the effects of applying current sizing guidelines to different multislice computer tomography (MSCT) aortic annulus measurements on Corevalve (CRS) size selection.
Multislice computer tomography annulus diameters [minimum: D(min); maximum: D(max); mean: D(mean) = (D(min) + D(max))/2; mean from circumference: D(circ); mean from surface area: D(CSA)] were measured in 75 patients referred for percutaneous valve replacement. Fifty patients subsequently received a CRS (26 mm: n = 22; 29 mm: n = 28). D(min) and D(max) differed substantially [mean difference (95% CI) = 6.5 mm (5.7-7.2), P < 0.001]. If D(min) were used for sizing 26% of 75 patients would be ineligible (annulus too small in 23%, too large in 3%), 48% would receive a 26 mm and 12% a 29 mm CRS. If D(max) were used, 39% would be ineligible (all annuli too large), 4% would receive a 26 mm, and 52% a 29 mm CRS. Using D(mean), D(circ), or D(CSA) most patients would receive a 29 mm CRS and 11, 16, and 9% would be ineligible. In 50 patients who received a CRS operator choice corresponded best with sizing based on D(CSA) and D(mean) (76%, 74%), but undersizing occurred in 20 and 22% of which half were ineligible (annulus too large).
Eligibility varied substantially depending on the sizing criterion. In clinical practice both under- and oversizing were common. Industry guidelines should recognize the oval shape of the aortic annulus.
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ABSTRACT: Precise measurements of aortic annulus dimensions are crucial for prosthesis size selection in patients undergoing transcatheter aortic valve implantation (TAVI). The so-called effective diameter (derived from area) measured in multislice computed tomography (MSCT) images has evolved to be the most precise measurement tool. Usually, the operator must manually adjust the aortic annular plane. Syngo Aortic ValveGuide (Siemens Healthcare) is a new software tool that allows for automatic aortic root reconstruction and annular plane detection. The aim of this study was to compare the effective diameter measured in automatically detected and manually adjusted annular plane. Seventy-three raw image datasets of preoperative TAVI MSCT scans were analysed using our institutional gold standard (3Mensio Valves™) with manual annular plane adjustment and using Aortic ValveGuide with automatic annular plane detection. The aortic annular circumference was manually marked for both software tools, and the effective diameter was calculated using the formula: effective diameter = 2 × √(circumferential area/π). Automatic annulus plane detection using Syngo Aortic ValveGuide worked well in all MSCT scans. Minor manual adjustment of the detected plane was necessary in only 3 patients. The mean effective aortic annulus diameter was 23.1 ± 2.4 mm for 3Mensio and 23.3 ± 2.4 mm for Syngo Aortic ValveGuide. Bland-Altman analysis of both imaging software tools showed good agreement (mean difference of 0.16 mm and limits of agreement of -0.48 to 0.80 mm). Effective aortic annulus diameter measured with Syngo Aortic ValveGuide, as a new imaging software that allows for automatic aortic annular plane detection, shows good agreement to gold standard measurements. Automatic annulus plane detection might reduce the effort for MSCT analysis and may lead to more reproducible aortic annulus measurements. Aortic ValveGuide is part of the DynaCT and in future aortic annulus dimension measurements may be feasible during intraoperatively acquired DynaCT.European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 01/2014; · 2.40 Impact Factor
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ABSTRACT: Transcatheter aortic valve implantation (TAVI) is a novel therapy, which has transformed the management of inoperable patients presenting with symptomatic severe aortic stenosis (AS). It is also a proven and less invasive alternative therapeutic option for high-risk symptomatic patients presenting with severe AS who are otherwise eligible for surgical aortic valve replacement. Patient age is not strictly a limitation for TAVI but since this procedure is currently restricted to high-risk and inoperable patients, it follows that most patients selected for TAVI are at an advanced age. Patient frailty and co-morbidities need to be assessed and a clinical judgment made on whether the patient will gain a measureable improvement in their quality of life. Risk stratification has assumed a central role in selecting suitable patients and surgical risk algorithms have proven helpful in this regard. However, limitations exist with these risk models, which must be understood in the context of TAVI. When making final treatment decisions, it is essential that a collaborative multidisciplinary "heart team" be involved and this is stressed in the most recent guidelines of the European Society of Cardiology. Choosing the best procedure is contingent upon anatomical feasibility, and multimodality imaging has emerged as an integral component of the pre-interventional screening process in this regard. The transfemoral route is now considered the default approach although vascular complications remain a concern. A minimal vessel diameter of 6 mm is required for currently commercial available vascular introducer sheaths. Several alternative access routes are available to choose from when confronted with difficult iliofemoral anatomy such as severe peripheral vascular disease or diffuse circumferential vessel calcification. The degree of aortic valve leaflet and annular calcification also needs to be assessed as the latter is a risk factor for post-procedural paravalvular aortic regurgitation. The ultimate goal of patient selection is to achieve the highest procedural success rate while minimizing complications and to choose patients most likely to derive tangible benefit from this procedure.Clinical Research in Cardiology 02/2014; · 3.67 Impact Factor
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ABSTRACT: The C-arm used for fluoroscopy during transcatheter aortic valve replacement (TAVR) may also be used to acquire 3-dimensional data sets similar to multidetector row CT (MDCT). The aim of this study was to evaluate the feasibility of C-arm CT (CACT) for aortic annulus and root (AoA/R) measurements in TAVR planning compared with MDCT. Twenty patients who were studied for TAVR underwent MDCT and CACT. Two independent observers measured predicted perpendicular projection to annular plane, diameters of the aortic annulus, sinus of Valsalva, sinotubular junction and ascending aorta, distance of coronary ostia to annular plane, sinus of Valsalva height, and leaflet length. Correlation between MDCT and CACT and interobserver variability were analyzed. MDCT and CACT showed strong correlation for all the measurements of the AoA/R (r ranging from 0.62 to 0.94; P between <.001 and .042) and also for the predicted perpendicular projection (left/right anterior oblique: r = 0.96, P = .002; cranial/caudal: r = 0.83, P = .043). Interobserver variability analysis showed disagreement for the measurements of the aortic annulus structures with CACT (intraclass correlation coefficient [ICC], <0.25) but not for the rest of the variables (ICC between 0.47 and 0.97). MDCT showed no interobserver variability for all the measurements (ICC between 0.45 and 0.93). CACT showed strong correlation with MDCT for the measurement of all AoA/R structures. However, CACT showed also important interobserver variability for the assessment of the aortic annulus. Therefore, valve sizing may not be reliably performed on the basis of CACT measurements alone.Journal of cardiovascular computed tomography 01/2014; 8(1):33-43. · 2.55 Impact Factor