[Incidence and risk factors of early deep venous thrombosis after knee arthroscopy operation under conventional tourniquet]

Abstract

Objective: To find out the incidence of early DVT in patients after knee arthroscopic surgery with routine use of tourniquet and discuss the associate risk factors.

Methods: Total 1 561 cases undertaken primary knee arthroscopic surgery was reviewed retrospectively from January 2013 to January 2017, including 651 males and 910 females with a mean age of (65.7±8.7) years old ranging from 62 to 81 years old. The cases were divided into DVT group and non-DVT group according to ultrasonic Doppler after surgery. The DVT occurrence rate was calculated and the basic information was analyzed to filter out the risk factors through univariate analysis and multivariate analysis. The cases of DVT group received 6 months anticoagulation therapy and were undertaken a follow-up of 1, 3, 6 months by ultrasonic Doppler.

Results: Out of the 1 561 cases, 226(14.5%) developed early DVTs following surgery, 32(2.0%) cases had the proximal DVTs, and 194(12.4%) cases had the isolated distal DVTs. The risk factors include the age(>=73 years), female sex and gastrocnemius vein dilation (GVD), hypertension, longer tourniquet time(>=74 min). The GVD and the length of tourniquet time was considered to be the best predictor of the early DVTs after surgery, with an odds ratio of 2.337 (95% CI, 1.644-3.611) and 2.112 (95%CI, 1.452-3.301). Twelve isolated distal DVTs(6.6%) and 11 proximal DVTs(36.7%) still showed thrombus at 6-month follow-up, but exhibit decreased size and at various stage of resolution.

Conclusions: The incidence of early DVTs after knee arthroscopic surgery is 14.5%. Out of all risk factors, the GVD and the length of tourniquet time have the best power for prediction of DVTs after surgery. Both proximal and distal DVTs received accepted outcomes after formal therapy.

Keywords: Arthroscopes; Deep venous thrombosis; Risk factors; Tourniquets.