Abstract
While a salutary effect of pneumatic compression upon thoracic duct lymph flow has previously been documented,1, 2 the effects of such interventions upon lymph flow have not been demonstrated within an experimental model of the human disease of lymphedema. In the current issue of Lymphatic Research and Biology, Prajapati and colleagues publish the results of their examination of the effects of pneumatic compression upon lymph flow in the thoracic duct of instrumented conscious dogs in the presence of edema produced by constriction of the inferior vena cava. 3 Their investigation demonstrated that edema produced by elevated inferior vena cava pressure greatly increased flow in the thoracic lymph duct of conscious, instrumented dogs. Lymphatic pump treatment further augmented this flow. However, the additional flow generated by four minutes of this treatment was not large.
In a related series of interventions, 4 the same group of investigators examined the effect of exercise upon lymph flow, as a function of exercise intensity. Dogs were surgically instrumented with an ultrasonic flow transducer on the thoracic lymph duct and a catheter in the descending thoracic aorta. After recovery from surgery, the dogs ran on a treadmill at speeds that varied stepwise from 0 to 10 mph and from 10 to 0 mph. The investigators were thus able to demonstrate that, indeed, lymph flow in the thoracic duct correlates positively with exercise intensity.
It is through such medically relevant physiological investigations that we will, increasingly, substantiate the validity of current, and future, medical interventions designed to improve the health, well-being, and function of individuals who suffer from lymphatic vascular insufficiency.