Abstract
INTRODUCTION
The efficacy and safety of the tourniquet are discussed, in particular with regard to the blood saving and tissue damage induced by ischemia. The quality of exsanguination and tissue necrosis in the compression zone are significant prognostic factors. The objective of this study was to evaluate the efficacy and safety of a new tourniquet system combining efficient and controlled exsanguination (figure 1) and ischemia maintained by pressure on a minimal surface (figure 2). The hypothesis tested was that the new system allowed tourniquet to reduce blood loss compared to conventional withers without increasing the risk of complications.
MATERIAL
Two groups of 30 patients undergoing total knee arthroplasty (TKA) were compared. There were 39 women and 21 men with a mean age of 67 years and a mean BMI of 34. The study group was operated with the innovative tourniquet and followed prospectively. The control group was operated with the traditional tourniquet and analyzed retrospectively.
METHODS
Operating time was measured between skin incision and dressing application. Blood loss was calculated with the Gross formula. Blood transfusion requirements were collected. Rehabilitation course was appreciated by the time to discharge. Complications, whether related or not to the tourniquet used, were recorded. Data were compared in both groups with the appropriate statistical tests at a 0.05 level of significance. The sample size was calculated to allow detecting a 300 ml decrease in mean blood loss with a power of 0.80.
RESULTS
Both groups were comparable for all pre-operative data (age, gender, BMI, severity of the pre-operative deformation, pre-operative hematocrit level). Calculated blood loss was not significant different in the two groups (968 ml in the study group versus 1,022 ml in the control group, p<0.05). Operating time was not significantly decreased in the study group. Blood transfusion requirements were not significant different in the two groups (4 units versus 6 units). The complication rate was significantly decreased in the study group (no case versus 4 cases), especially for skin complications (3 cases of persistent bleeding or skin ischemia in the study group). The mean discharge time was significantly shorter in the study group (3rd post-operative day versus 5th post-operative day, p<0.05).
DISCUSSION
The tested hypothesis was not confirmed. This preliminary study did not show any advantage of the new technology of tourniquet when analyzing blood loss. However, the decreased rate of local skin complications may be in relationship with a decreased intra-operative skin ischemia. This might lead to an earlier discharge.
CONCLUSION
A prospective, randomized study is necessary to confirm these preliminary results.
