Makihata S, Tanimoto M, Yamamoto T, Mihata S, Konishiike A, Ohyanagi M, Yasutomi N, Yamazaki K, Kawai Y, Iwasaki T
J Cardiogr. 1985 Mar;15(1):181-95.
Cross-sectional echocardiography facilitates recognizing dissecting aortic aneurysms, but the diagnosis of abnormalities of the descending aorta in the retrocardiac portion is difficult. We prospectively designed to assess the usefulness of a new echocardiographic technique in defining the retrocardiac descending thoracic aorta in its long and short axes. Two patients with dissecting aneurysms involving the retrocardiac descending aorta were studied in the 90 degrees right lateral position using a Toshiba SSH-11A or SSH-40A cross-sectional echocardiographic apparatus. The transducer was positioned in the third or fourth intercostal space closely to the left of the thoracic vertebrae, and the ultrasonic beam was directed toward the retrocardiac descending aorta from the patient's back. The descending thoracic aorta was identified in its long axis as a straight tubular structure with parallel walls. The transducer was then rotated approximately 90 degrees, to visualize the descending aorta in its short axis as a circular structure. This "paravertebral approach" has not previously been reported. In both patients, the retrocardiac descending thoracic aorta was clearly visualized in its long and short axes, and the oscillating intimal flap was visualized within the descending aorta in the paravertebral approach. Pulsed Doppler echocardiography (PDE) using the long-axis paravertebral approach identified the flow in the false and true lumens of the descending thoracic aorta. Flow patterns including the peak flow velocity and the velocity profile obviously varied between the true and false lumens. The peak flow velocities in the former were extremely high compared to those in the latter. The former exhibited laminar profiles, but the latter showed some spectral broadening. By the same approach, the entrance tear was explored and the jet flow through the tear was detected in Case 1 by PDE, which had high flow velocity with wide spectral broadening and aliasing in systole and also had relatively low flow velocity with some spectral broadening in diastole. To our knowledge, there has been no previous report of detecting flow at the entrance tear by PDE. These cross-sectional echocardiographic studies suggest that the paravertebral approach may prove helpful in initially evaluating patients with symptoms or signs suggestive of acute dissecting aneurysms. However, comprehensive studies are necessary to define the sensitivity and specificity of these echocardiographic techniques in recognizing all types of dissecting aneurysms.
横断面超声心动图有助于识别主动脉夹层动脉瘤，但诊断心后区降主动脉异常较为困难。我们前瞻性地设计了一项研究，以评估一种新的超声心动图技术在确定心后区降主动脉长轴和短轴方面的实用性。使用东芝SSH - 11A或SSH - 40A横断面超声心动图仪，对两名累及心后区降主动脉的夹层动脉瘤患者在右侧90度卧位进行了研究。将换能器置于第三或第四肋间，紧靠胸椎左侧，超声束从患者背部指向心后区降主动脉。降主动脉在其长轴上被识别为具有平行壁的直管状结构。然后将换能器旋转约90度，以在短轴上观察降主动脉为圆形结构。这种“椎旁入路”此前尚未见报道。在两名患者中，心后区降主动脉在其长轴和短轴上均清晰可见，且在椎旁入路中可在降主动脉内观察到摆动的内膜瓣。使用长轴椎旁入路的脉冲多普勒超声心动图（PDE）确定了降主动脉真假腔内的血流。包括峰值流速和速度剖面在内的血流模式在真假腔之间明显不同。前者的峰值流速与后者相比极高。前者呈现层流剖面，而后者显示出一些频谱增宽。通过相同的入路，在病例1中通过PDE探查了入口撕裂并检测到通过撕裂的射流，其在收缩期具有高流速、宽频谱增宽和混叠，在舒张期也具有相对较低的流速和一些频谱增宽。据我们所知，此前尚无通过PDE检测入口撕裂处血流的报道。这些横断面超声心动图研究表明，椎旁入路可能有助于初步评估有急性夹层动脉瘤症状或体征的患者。然而，需要进行全面研究以确定这些超声心动图技术在识别所有类型夹层动脉瘤方面的敏感性和特异性。
