Gersak Borut, Gartner Urska, Antonic Miha
Department of Cardiovascular Surgery, University Medical Center, Ljubljana, Slovenia.
J Heart Valve Dis. 2011 Jul;20(4):401-6.
Stentless biological valves have proven advantages in hemodynamic performance and left ventricular function compared to stented biological valves. Following a marked postoperative fall in the platelet count of patients after implantation of the Freedom SOLO valve, the study aim was to confirm clinical observations that this effect was more severe in patients receiving Freedom SOLO valves than in those receiving St. Jude Medical (SJM) mechanical aortic valves.
Preoperative and postoperative platelet counts were compared in two groups of patients who underwent aortic valve replacement (AVR) without any concomitant procedures between January and December 2007. Patients received either a Freedom SOLO valve (n = 28) or a SJM mechanical valve (n = 41). Mean values of platelet counts were compared using three multiple linear regression models.
Platelet counts were significantly lower in the Freedom SOLO group than in the SJM group from the first postoperative day (POD 1) up to POD 6 (p <0.001). In three patients of the Freedom SOLO group the platelet count fell below 30x10(9)/l, while the lowest level in the SJM group was 75x10(9)/l. Based on multiple linear regression models, the type of valve implanted had a statistically significant influence on postoperative platelet counts on POD 1, POD 3, and POD 5 (p <0.001).
Whilst the reason for this phenomenon is unknown, the use of consistent monitoring should prevent severe falls in platelet count from becoming dangerous for the patient. Further studies are required to investigate the phenomenon since, despite a shorter cardiopulmonary bypass time, the fall in platelet count was more profound in the Freedom SOLO group.
与有支架生物瓣膜相比，无支架生物瓣膜在血流动力学性能和左心室功能方面已被证明具有优势。在植入Freedom SOLO瓣膜的患者术后血小板计数显著下降之后，本研究的目的是证实临床观察结果，即这种效应在接受Freedom SOLO瓣膜的患者中比接受圣犹达医疗（SJM）机械主动脉瓣膜的患者更为严重。
比较2007年1月至12月期间两组接受主动脉瓣置换术（AVR）且未进行任何伴随手术的患者术前和术后的血小板计数。患者分别接受Freedom SOLO瓣膜（n = 28）或SJM机械瓣膜（n = 41）。使用三个多元线性回归模型比较血小板计数的平均值。
从术后第一天（POD 1）到POD 6，Freedom SOLO组的血小板计数显著低于SJM组（p <0.001）。Freedom SOLO组有3名患者的血小板计数降至30×10⁹/L以下，而SJM组的最低水平为75×10⁹/L。基于多元线性回归模型，植入瓣膜的类型对POD 1、POD 3和POD 5的术后血小板计数有统计学显著影响（p <0.001）。
虽然这种现象的原因尚不清楚，但持续监测应可防止血小板计数严重下降对患者造成危险。由于尽管体外循环时间较短，但Freedom SOLO组的血小板计数下降更为明显，因此需要进一步研究来调查这一现象。
