Gavriely N, 2008.
More than a third of patients undergoing TKA have a BMI greater than 30 (obese) with many of these patients having a BMI that is greater than 40 (morbidly obese). Operating on these patients present the surgeon and the OR team with special problems all around, not the least of which is achieving and maintaining a blood-free surgical field. The problems include the need for larger and wider specialty (curved) cuffs thereby dangerously decreasing the distance from the distal edge of the tourniquet to the incision; tourniquets tend to slide distally when inflated due to the taper of the thigh; occlusion of arterial flow in the obese patient requires higher pressures, thereby causing more tissue compression (crush injury) and skin damage (1). Additionally, the obese patient is more vulnerable to infection if non-sterile tourniquets are used; the ability to expel the blood from the operated limb prior to tourniquet inflation is difficult in the obese patient, time consuming and tedious and often suboptimal, leaving substantial volume of blood in the vessels. This blood clots over the course of the tourniquet “up” period and when the tourniquet is deflated these clots travel to the pulmonary circulation (PE). The blood left behind also obstruct the surgical field visibility and the imperfect field requires additional OR time for hemostasis (2). Nevertheless, tourniquets are used in obese patients and the overall long term outcome of TKA in obese patients is as positive as in the normal BMI patients. The HemaClear is a novel exsanguination tourniquet consisting of a rolling ring with an elastic stockinet and handles which can be applied quickly to the obese limb (picture). The HC90 is suitable for up to 90 cm of circumference which is suitable for most (but not all) obese patients. The HC provides a superior exsanguination, is a sterile, single patient use device and remains stable on the thigh (3). It applies safe levels of pressure to the limb and in more than 80,000 cases (all, not only obese) it has been used, proved to have an impeccable safety track record (no paralysis/paresis, no skin damage). The HC90 is avaluable addition to the tools designed to give the obese patient the same standard of care as the lean TKA recipient.