Jegger David, Chassot Pierre-Guy, Bernath Marc-Andre, Horisberger Judith, Gersbach Philippe, Tozzi Piergiorgio, Delay Dominique, von Segesser Ludwig K
Department of Cardiovascular Surgery, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne, Switzerland.
Eur J Cardiothorac Surg. 2006 Apr;29(4):525-9. doi: 10.1016/j.ejcts.2005.12.050. Epub 2006 Feb 14.
Transthoracic echocardiography (TTE) has been used clinically to disobstruct venous drainage cannula and to optimise placement of venous cannulae in the vena cava but it has never been used to evaluate performance capabilities. Also, little progress has been made in venous cannula design in order to optimise venous return to the heart lung machine. We designed a self-expandable Smartcanula (SC) and analysed its performance capability using echocardiography.
An epicardial echocardiography probe was placed over the SC or control cannula (CTRL) and a Doppler image was obtained. Mean (V(m)) and maximum (V(max)) velocities, flow and diameter were obtained. Also, pressure drop (DeltaP(CPB)) was obtained between the central venous pressure and inlet to venous reservoir. LDH and Free Hb were also compared in 30 patients. Comparison was made between the two groups using the student's t-test with statistical significance established when p<0.05.
Age for the SC and CC groups were 61.6+/-17.6 years and 64.6+/-13.1 years, respectively. Weight was 70.3+/-11.6 kg and 72.8+/-14.4 kg, respectively. BSA was 1.80+/-0.2 m(2) and 1.82+/-0.2 m(2), respectively. CPB times were 114+/-53 min and 108+/-44 min, respectively. Cross-clamp time was 59+/-15 min and 76+/-29 min, respectively (p=NS). Free-Hb was 568+/-142 U/l versus 549+/-271 U/l post-CPB for the SC and CC, respectively (p=NS). LDH was 335+/-73 mg/l versus 354+/-116 mg/l for the SC and CC, respectively (p=NS). V(m) was 89+/-10 cm/s (SC) versus 63+/-3 cm/s (CC), V(max) was 139+/-23 cm/s (SC) versus 93+/-11 cm/s (CC) (both p<0.01). DeltaP(CPB) was 30+/-10 mmHg (SC) versus 43+/-13 mmHg (CC) (p<0.05). A Bland-Altman test showed good agreement between the two devices used concerning flow rate calculations between CPB and TTE (bias 300 ml+/-700 ml standard deviation).
This novel Smartcanula design, due to its self-expanding principle, provides superior flow characteristics compared to classic two stage venous cannula used for adult CPB surgery. No detrimental effects were observed concerning blood damage. Echocardiography was effective in analysing venous cannula performance and velocity patterns.
经胸超声心动图（TTE）已在临床上用于疏通静脉引流插管并优化静脉插管在腔静脉中的放置，但从未用于评估其性能。此外，为优化心肺机的静脉回流，静脉插管设计方面进展甚微。我们设计了一种可自扩张的智能插管（SC），并使用超声心动图分析其性能。
将心外膜超声心动图探头置于SC或对照插管（CTRL）上方，获取多普勒图像。记录平均速度（V(m)）、最大速度（V(max)）、流量和直径。同时，获取中心静脉压与静脉储液器入口之间的压力降（DeltaP(CPB)）。还比较了30例患者的乳酸脱氢酶（LDH）和游离血红蛋白（Free Hb）。两组间比较采用学生t检验，p<0.05时具有统计学意义。
SC组和CC组的年龄分别为61.6±17.6岁和64.6±13.1岁。体重分别为70.3±11.6 kg和72.8±14.4 kg。体表面积分别为1.80±0.2 m²和1.82±0.2 m²。体外循环时间分别为114±53分钟和108±44分钟。主动脉阻断时间分别为59±15分钟和76±29分钟（p=无显著性差异）。CPB后SC组和CC组的游离血红蛋白分别为568±142 U/l和549±271 U/l（p=无显著性差异）。LDH分别为335±73 mg/l和354±116 mg/l（p=无显著性差异）。V(m)为89±10 cm/s（SC）对63±3 cm/s（CC），V(max)为139±23 cm/s（SC）对93±11 cm/s（CC）（均p<0.01）。DeltaP(CPB)为30±10 mmHg（SC）对43±13 mmHg（CC）（p<0.05）。Bland-Altman检验显示，用于CPB和TTE流量计算的两种装置之间具有良好的一致性（偏差300 ml±700 ml标准差）。
这种新型智能插管设计因其自扩张原理，与用于成人CPB手术的传统两级静脉插管相比，具有更优越的血流特性。未观察到对血液的有害影响。超声心动图在分析静脉插管性能和速度模式方面有效。
