Cordeiro P G, Santamaria E, Hu Q Y, Heerdt P
Division of Plastic and Reconstructive Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Ann Plast Surg. 1997 Nov;39(5):524-31. doi: 10.1097/00000637-199711000-00013.
Pedicled flaps and microsurgical free tissue transfers are increasingly being used for reconstruction in the elderly and poorer risk patient. The use of systemically administered vasoactive agents to date has been avoided because of the fear that systemic levels of these agents perioperatively (particularly the vasopressors) might decrease blood flow and compromise the viability of the flap. There are no large-animal, real-time hemodynamic studies that support or disprove this belief. The objectives of this study were to (1) develop a musculocutaneous flap model in the pig that allows accurate, simultaneous monitoring of systemic and flap hemodynamic parameters such as flow and resistance and (2) identify the effects of commonly used vasoactive substances (dopamine, dobutamine, and phenylephrine) at clinically used levels on systemic and flap pressure/flow relationships. Vertically based rectus abdominis musculocutaneous flaps were raised in 8 anesthetized, 50- to 55-kg pigs, and a flow probe was placed around the artery. Catheters within the pulmonary artery and aorta were used to measure cardiac output and aortic root pressures. Measures of arterial blood pressure, cardiac output, and musculocutaneous flap flow were obtained at baseline and during the administration of varying doses of dopamine dobutamine and phenylephrine. Cardiac output increased significantly with low and high doses of dopamine and dobutamine, but decreased with increasing doses of phenylephrine. Flap flow, on the other hand, is increased only with dobutamine but remains unchanged with dopamine despite increased cardiac output. Flap flow decreases with high doses of phenylephrine. Flap flow also decreases relative to cardiac output with both dopamine and dobutamine. We conclude that (1) phenylephrine clearly affects flap flow adversely in a large-animal musculocutaneous model and therefore should be avoided, (2) dopamine does not affect total flap flow at either low or high doses despite increasing cardiac output, (3) dobutamine increases both flap flow and cardiac output, and (4) both dopamine and dobutamine should still be used with caution because the flap flow is not equally increased relative to total cardiac output. Possible changes in systemic and flap metabolic demand induced by these vasopressor drugs may therefore still be injurious to the flaps.
带蒂皮瓣和显微外科游离组织移植越来越多地用于老年及风险较高患者的重建手术。由于担心这些药物的全身水平在围手术期（尤其是血管加压药）可能会减少血流量并危及皮瓣的存活能力，所以迄今为止一直避免使用全身给药的血管活性药物。目前尚无大型动物实时血流动力学研究支持或反驳这一观点。本研究的目的是：（1）在猪身上建立一种肌皮瓣模型，以便准确、同时监测全身和皮瓣的血流动力学参数，如流量和阻力；（2）确定临床使用剂量的常用血管活性物质（多巴胺、多巴酚丁胺和去氧肾上腺素）对全身和皮瓣压力/流量关系的影响。在8头体重50至55千克、麻醉状态下的猪身上掀起垂直腹直肌肌皮瓣，并在动脉周围放置流量探头。使用肺动脉和主动脉内的导管测量心输出量和主动脉根部压力。在基线以及给予不同剂量的多巴胺、多巴酚丁胺和去氧肾上腺素期间，获取动脉血压、心输出量和肌皮瓣流量的测量值。低剂量和高剂量的多巴胺和多巴酚丁胺可使心输出量显著增加，但去氧肾上腺素剂量增加时心输出量降低。另一方面，皮瓣流量仅在使用多巴酚丁胺时增加，尽管心输出量增加，但使用多巴胺时皮瓣流量保持不变。高剂量去氧肾上腺素会使皮瓣流量降低。多巴胺和多巴酚丁胺都会使皮瓣流量相对于心输出量降低。我们得出以下结论：（1）在大型动物肌皮瓣模型中，去氧肾上腺素明显对皮瓣流量有不利影响，因此应避免使用；（2）多巴胺无论低剂量还是高剂量，尽管心输出量增加，但都不会影响皮瓣总流量；（3）多巴酚丁胺可增加皮瓣流量和心输出量；（4）多巴胺和多巴酚丁胺仍应谨慎使用，因为皮瓣流量相对于总心输出量并未同等增加。因此，这些血管加压药物引起的全身和皮瓣代谢需求的可能变化仍可能对皮瓣造成损害。
