Ritter E F, Cronan J C, Rudner A M, Serafin D, Klitzman B
Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710, USA.
J Reconstr Microsurg. 1998 Jul;14(5):331-6. doi: 10.1055/s-2007-1000186.
Blood flow to a free flap may be impaired by thrombotic occlusion at the anastomosis or by microemboli occluding microvessels. The purpose of this study was to test the hypothesis that unfractionated heparin (UFH) or low molecular weight fractions of heparin (LMWH) could improve both the patency of microvascular anastomoses and microcirculatory perfusion. Sixty-six rats underwent orthotopic elevation of 3- x 10-cm epigastric free flaps. Animals received a single injection of either vehicle, UFH or LMWH, prior to microvascular clamp application and pedicle division. Anastomotic patency and tissue survival area were assessed on postoperative day 7. Anastomotic patency was significantly improved in both the UFH and LMWH groups. Total tissue survival area in those flaps with anastomotic patency was significantly improved in the UFH and the LMWH groups. Although both UFH and LMWH significantly elevated activated partial thromboplastin times (APTT) and anti activated clotting factor X (anti-Xa) activity over controls, UFH had its greatest effect on APTT, and LMWH on anti-factor Xa activity. Hematomas developed only in the UFH group. Thus, although both UFH and LMWH improved microcirculatory perfusion, as indicated by increased flap survival, only LMWH improved anastomotic patency while minimizing hemorrhage.
游离皮瓣的血流可能会因吻合口处的血栓形成阻塞或微血管被微栓子阻塞而受损。本研究的目的是验证以下假设：普通肝素（UFH）或肝素低分子片段（LMWH）可改善微血管吻合的通畅性和微循环灌注。66只大鼠接受了3×10厘米的腹壁游离皮瓣原位提升术。在应用微血管夹和切断蒂之前，动物接受单次注射赋形剂、UFH或LMWH。在术后第7天评估吻合口通畅性和组织存活面积。UFH组和LMWH组的吻合口通畅性均显著改善。UFH组和LMWH组中吻合口通畅的皮瓣的总组织存活面积显著增加。尽管UFH和LMWH均使活化部分凝血活酶时间（APTT）和抗活化凝血因子X（抗Xa）活性显著高于对照组，但UFH对APTT影响最大，而LMWH对抗因子Xa活性影响最大。仅在UFH组出现血肿。因此，尽管UFH和LMWH均改善了微循环灌注，如皮瓣存活增加所示，但只有LMWH改善了吻合口通畅性，同时将出血降至最低。
