Edwards Jeff T, Brown D Mark, Worrall Neil K
Northwest Heart and Lung Surgical Associates, Spokane, Washington 99204, USA.
J Extra Corpor Technol. 2004 Sep;36(3):245-9.
The incidence of ischemic complications associated with repair of descending and thoracoabdominal aortic aneurysms has been significantly reduced by the use of distal aortic perfusion with moderate hypothermia, cerebral spinal fluid drainage, and segmental sequential clamping techniques. However, because the maintenance of proximal perfusion, the adequacy of left heart bypass (LHB), and the ability to ventilate patients on only one lung are all dependent on ventricular and pulmonary function, high-risk patients with descending and/or thoracoabdominal aortic aneurysms in the presence of cardiopulmonary insufficiency or instability present a difficult challenge for the surgical team. Traditional closed LHB circuits become nonfunctional in the event of cardiac arrest or refractory arrhythmias that create hemodynamic instability and are unable to provide necessary pulmonary support if the patient fails to ventilate adequately on one lung during thoracotomy. Furthermore, converting a patient from closed LHB to traditional venoarterial cardiopulmonary bypass (CPB) is frequently difficult, especially when the perfusionist works without the benefit of extra personnel to assist during such crises. Consequently, a modified extracorporeal circuit was designed to provide closed LHB with desired therapeutic adjuncts while also satisfying the additional need for a rapid infusion device, a source of supplemental ventilation/oxygenation, and, if necessary, the ability to convert the patient to venoarterial CPB conveniently in the event of cardiac and/or pulmonary failure during surgery to repair descending and/or thoracoabdominal aortic aneurysms.
通过采用远端主动脉灌注、中度低温、脑脊液引流和节段性顺序钳夹技术,降主动脉和胸腹主动脉瘤修复相关缺血性并发症的发生率已显著降低。然而,由于近端灌注的维持、左心旁路(LHB)的充分性以及仅单肺通气患者的能力均依赖于心室和肺功能,存在心肺功能不全或不稳定的降主动脉和/或胸腹主动脉瘤高危患者对手术团队构成了严峻挑战。在心脏骤停或难治性心律失常导致血流动力学不稳定时,传统的闭合式LHB回路会失去功能,并且在开胸手术期间如果患者单肺通气不足,该回路无法提供必要的肺支持。此外,将患者从闭合式LHB转换为传统的静脉动脉体外膜肺氧合(CPB)通常很困难,尤其是当灌注师在没有额外人员协助应对此类危机的情况下工作时。因此,设计了一种改良的体外循环回路,以在提供闭合式LHB的同时具备所需的治疗辅助手段,同时还满足对快速输注装置、补充通气/氧合源的额外需求,并且在修复降主动脉和/或胸腹主动脉瘤的手术过程中,如有必要,能够在心脏和/或肺功能衰竭时方便地将患者转换为静脉动脉CPB。