Sigaudo-Roussel D, Evans D H, Naylor A R, Panerai R B, London N L, Bell P, Gaunt M E
Department of Medical Physics, Leicester Royal Infirmary, Cambridge, UK.
J Vasc Surg. 2002 Oct;36(4):793-8.
Blood pressure instability after carotid endarterectomy (CEA) has been associated with a disturbance of the baroreflex control mechanism caused by the surgery in the carotid sinus region. The purpose of this study was to determine if a deterioration in carotid baroreceptors occurs during the surgery.
Heart rate (HR) and blood pressure (BP) were recorded continuously in 60 patients undergoing CEA as well as preoperatively and postoperatively at 2 days and 6 weeks. The baroreflex sensitivity was determined by cross-spectral analysis of HR and systolic blood pressure (SBP). During the surgery, three tests were used to assess the baroreflex response. The first test simulated a sudden fall in systemic blood pressure by clamping the common carotid artery. The second test simulated a rise in systemic blood pressure by applying pressure by using a rubbing action on the luminal surface of the carotid sinus region. The rub test was performed twice, once with the atheromatous plaque in situ and once when the plaque had been removed. The third test is clamp removal and restoration of blood flow through the carotid sinus.
Carotid cross-clamping increased mean +/- standard error of the mean SBP from 117 +/- 3 mm Hg before clamping to 125 +/- 3 mm Hg (P <.05) at 30 beats after clamping. The first rub test with the plaque in situ decreased SBP from 121 +/- 3 mm Hg to 117 +/- 3 mm Hg (P <.01) at 10 beats after the rub test, indicating a functioning baroreceptor reflex. The second rub test increased SBP from 126 +/- 3 mm Hg to 128 +/- 3 mm Hg (P <.05). SBP dropped (P <.01) when unclamping suggesting a selective alteration of the baroreflex sensitivity. The baroreflex sensitivity was significantly reduced 2 days postoperatively when compared to preoperative values (P <.05).
These findings suggest that the act of plaque removal could be associated with a partial disruption of baroreceptor mechanism in the carotid artery. This could affect type I baroreceptors.
颈动脉内膜切除术（CEA）后血压不稳定与手术导致的颈动脉窦区域压力感受器控制机制紊乱有关。本研究的目的是确定手术过程中颈动脉压力感受器是否会恶化。
连续记录60例接受CEA手术患者术前、术后2天和6周时的心率（HR）和血压（BP）。通过对HR和收缩压（SBP）进行交叉谱分析来确定压力感受器敏感性。手术过程中，使用三项测试来评估压力感受器反应。第一项测试通过夹闭颈总动脉模拟全身血压突然下降。第二项测试通过在颈动脉窦区域管腔内表面施加摩擦动作模拟全身血压升高。摩擦测试进行两次，一次在动脉粥样硬化斑块原位时进行，一次在斑块切除后进行。第三项测试是松开夹子并恢复通过颈动脉窦的血流。
颈动脉夹闭使夹闭前平均±平均标准误差SBP从117±3mmHg在夹闭后30次心跳时增加到125±3mmHg（P<.05）。斑块原位时的第一次摩擦测试使摩擦测试后10次心跳时SBP从121±3mmHg降至117±3mmHg（P<.01），表明压力感受器反射功能正常。第二次摩擦测试使SBP从126±3mmHg增加到128±3mmHg（P<.05）。松开夹子时SBP下降（P<.01），提示压力感受器敏感性有选择性改变。与术前值相比，术后2天压力感受器敏感性显著降低（P<.05）。
这些发现表明，斑块切除行为可能与颈动脉中压力感受器机制的部分破坏有关。这可能会影响I型压力感受器。
