The effect of aortic area measurement site on the energy loss coefficient: a comparison between echocardiography and cardiac computed tomography angiography in patients with aortic stenosis.

AIM: The energy loss coefficient (ELCo) has been suggested as a more accurate indicator of aortic stenosis (AS) severity as compared to transthoracic echocardiography (TTE) aortic valve area (AVA). There are little data regarding the optimal location for aortic area (Aa) measurement needed for ELCo calculation and the agreement of ELCo with direct anatomical AVA measurement. The aim of this study was to determine the optimal site of Aa measurement for calculation of the ELCo, using cardiac computed tomography angiography (CCTA) AVA planimetry as the reference standard. METHODS: We analyzed 69 patients with AS who underwent both CCTA and TTE. ELCo and CCTA planimetry AVA were compared using multiple sites for CCTA Aa measurement (sinus, sinotubular junction, or ascending aorta). RESULTS: CCTA AVA was 0.96±0.46 cm2 . ELCo was 0.95±0.43 cm2 using sinotubular junction Aa, 0.92±0.41 cm2 using sinus Aa, and 0.91±0.4 cm2 using the ascending aorta (P=.84, P=.13, and P=.08 compared to CCTA AVA). There was good agreement between CCTA AVA and ELCo using all Aa locations (0.89-0.90). On subgroup analysis of 16 patients most likely to be affected by pressure recovery (aortic diameter<3 cm and AVA ≥1 cm2 ), ELCo using the sinotubular junction Aa showed the best agreement with CCTA AVA as compared to the other Aa locations (0.84 vs 0.75-0.77). CONCLUSIONS: ELCo using Aa measurement at the sinotubular junction showed the best agreement with CCTA AVA. We therefore recommend using the sinotubular junction Aa for ELCo calculation.

Successful Endovascular Control of Renal Artery in a Transplant Kidney During Nephron Sparing Surgery (NSS) for Large Centrally Located Tumor.

Renal cell carcinoma in a transplant kidney is a rare condition. Nephron Sparing Surgery (NSS) is the treatment of choice. One of the main technical challenges is obtaining adequate vascular control. We present a rare case of large centrally located hillar tumor in a kidney 18 years after transplantation treated with NSS. Vascular control was achieved by using a novel approach. Post-operative course was uneventful with minimal decrease in renal function. We believe that this unique choice of treatment can be used in cases of NSS where the access to the renal pedicle is limited.

Three-dimensional imaging of the left ventricular outflow tract: impact on aortic valve area estimation by the continuity equation.

BACKGROUND: Measurement of left ventricular outflow tract (LVOT) area for estimation of aortic valve area (AVA) using two-dimensional (2D) transthoracic echocardiography (TTE) and the continuity equation assumes a round LVOT. The aim of this study was to compare measurements of LVOT area and AVA using 2D and three-dimensional (3D) TTE and cardiac computed tomographic angiography (CCTA) in an attempt to improve the accuracy of AVA estimation using TTE. METHODS: Fifty patients were prospectively studied, 25 with aortic stenosis and 25 without aortic stenosis (group 1). LVOT area and AVA were estimated using 2D TTE, and LVOT area and diameters were measured using 256-slice CCTA and 3D TTE. AVA was also planimetered using CCTA in midsystole. LVOT area and AVA estimated by 2D TTE were correlated with measurements by 3D TTE and CCTA. Findings from group 1 were then validated in 38 additional patients with aortic stenosis (group 2). RESULTS: LVOTs were oval in 96% of the patients in group 1, with a mean eccentricity index (diameter 2/diameter 1) of 1.26 ± 0.09 by CCTA. Compared with CCTA, 2D TTE systematically underestimated LVOT area (and therefore AVA) by 17 ± 16%. The correlation between CCTA and 3D TTE LVOT area was only moderate (r = 0.63), because of inadequate 3D transthoracic echocardiographic image quality. Mean AVA was 0.92 ± 0.44 cm(2) by 2D TTE and 1.14 ± 0.68 cm(2) by CCTA (P = .0015). After correcting AVA on 2D TTE by a factor of 1.17 (accounting for LVOT area ovality), there was no difference between 2D TTE and CCTA (0.06 ± 26 cm(2), P = .20, r = 0.86). In group 2, 2D TTE underestimated LVOT area and AVA by 16 ± 11%, similar to group 1, and AVA by TTE was 0.75 ± 0.14 cm(2) compared with 0.88 ± 0.21 cm(2) by CCTA (P < .0001). When the correction factor was applied to the group 2 results, the corrected AVA by 2D TTE (×1.17) was 0.87 ± 0.17 cm(2), similar to AVA by CCTA (P = .70). CONCLUSIONS: Three-dimensional imaging revealed oval LVOTs in most patients, resulting in underestimation of LVOT area and AVA on 2D TTE by 17%. This accounted for the difference in AVA between 2D TTE and CCTA. Current 3D TTE is inadequate to accurately measure LVOT area.

Hemodynamic analysis of descending versus ascending aortomyoplasty, and comparison with intra-aortic balloon pump.

OBJECTIVE: Descending and ascending aortomyoplasty are two surgical procedures intended to induce hemodynamic benefits similar to those of the intra-aortic-balloon-pump (IABP). To date, there have been no studies comparing the two surgical techniques. The objective of this study was to compare coronary blood flow augmentation and afterload reduction as produced by descending and ascending aortomyoplasty counterpulsation METHODS: Twenty-two mongrel dogs (18-35 kg) underwent IABP application (n=7), descending (n=8), or ascending (n=7) aortomyoplasty. Left anterior descending (LAD) coronary artery blood flow was measured using a Transonic Doppler flow probe. Left ventricular pressure as well as aortic pressures proximal and distal to either the aortomyoplasty site or the IABP position were monitored continuously. RESULTS: Descending aortomyoplasty induced higher elevation in the LAD blood flow during assisted beats (27% from 10.8+/-4 to 13.8+/-6 ml/min, P<0.001) than that induced by either ascending aortomyoplasty (19% from 11.7+/-5 to 14+/-5 ml/min, P<0.001) or IABP counterpulsation (18% from 8.6+/-3 to 10.2+/-4 ml/min, P<0.001). Conversely, while ascending aortomyoplasty reduced the left ventricular end-diastolic pressure by 16% (from 60+/-18 to 50+/-22 mmHg, P<0.001), similar to the 16% after load reduction achieved by the IABP counterpulsation, descending aortomyoplasty failed to induce afterload reduction. CONCLUSIONS: Descending aortomyoplasty produces higher coronary blood flow augmentation than either ascending aortomyoplasty or IABP. However, afterload reduction comparable to that achieved by IABP was observed only with ascending aortomyoplasty and not with descending aortomyoplasty.