Prevention Of Thromboembolic Complications After Spine Surgery By The Use Of Low-Molecular-Weight Heparin

OBJECTIVE:This study aimed to evaluate the effectiveness and safety of the use of low-molecular-weight heparin(LMWH)in the prevention of thromboembolic complications after spine surgery.We sought to assess the value of a newly designed risk assessment model(RAM)for the identification of patients who need spine surgery at risk of thromboembolic complications.METHODS:PART 1:We conducted a retrospective study on 2 groups of patients receiving spine surgery.A total of 947 patients admitted for surgery.from July 2009 to June 2012 were administered therapeutic dose of LMWH daily after the surgery(therapeutic group,Group B).Another 814 patients enrolled from July 2006 to June 2009 were not given any heparin treatment(control group,Group C).The wound drainage volume,the incidence rate of thrombosis and thromboembolic complications,and the occurrence of bleeding complications in 2 groups were statistically compared.PART 2:We designed a new thromboembolic risk assessment model(RAM)for the identification of patients who need spine surgery.And in this part,1098 consecutive patients(Group A)admitted to our department for spine surgery between November 2014 to November 2017 were classified as having a high(score ?4),moderate(score =3)or low risk(score<3)of thromboembolic complication according to the RAM,and were administered different prophylactic measurements.Meanwhile,we reassessed and reviewed the patients in Group B and C with the RAM.We compaired the three groups to assess the value of the newly designed risk assessment model(RAM)for the identification of patients who need spine surgery at risk of thromboembolic complications.RESULTS:1.The therapeutic group showed a lower rate of postsurgery thromboembolic complications when compared with the control group(therapeutic group,0.21%;control group,1.6%;P=0.002).Among the individual type of complications,the occurrence of cerebral infraction was the most significantly reduced(P=0.005).The overall rate of bleeding complications was higher in the therapeutic group compared with the control group,and the difference was marginally insignificant(therapeutic group,1.8%;control group,0.74%;P =0.051).2.The rate of thromboembolic comlication in Group A were the lowest in the 3 groups(Group A,B,C:0.09%,0.21%,1.6%,respectively;P<0.05).In Group C(without any thromboprophylactics),the rate were 0%in low disk subgroup,1.6%in moderate risk subgroup,and 5.7%in high risk subgroup.The thromboembolic comlication rate increased with the RAM grade of risk.The prophylactic LMWH was used both in Group A and B.But the LMWH related bleeding rate was statistically lower in Group A than Group B(Group A 0.09%;Group B 1.8%;P<0.05).And the LMWH related bleeding of Group B happened mainly in low risk subgroup(3.08%)and moderate risk subgroup(1.12%).CONCLUSIONS:The use of LMWH significantly decreases the incidence of thrombosis and thromboembolic complications after spine surgery,but increase the incision bleeding,leading to an elevated risk of symptomatic spinal epidural hematoma.The effectiveness and saftiveness can be improved by selecting proper prophylactic measurement according to the newly designed thromboembolic risk assessment model.