Lymphatic Pump Treatment Increases Thoracic Duct Lymph Flow in Conscious Dogs with Edema Due to Constriction of the Inferior Vena Cava

Abstract Background: Osteopathic lymphatic pump treatments (LPT) are used to treat edema, but their direct effects on lymph flow have not been studied. In the current study, we examined the effects of LPT on lymph flow in the thoracic duct of instrumented conscious dogs in the presence of edema produced by constriction of the inferior vena cava (IVC). Methods and Results: Six dogs were surgically instrumented with an ultrasonic flow transducer on the thoracic lymph duct and catheters in the descending thoracic aorta and in IVC. After postoperative recovery, lymph flow and hemodynamic variables were measured 1) pre-LPT, 2) during 4 min LPT, 3) post-LPT, in the absence and presence of edema produced by IVC constriction. This constriction increased abdominal girth from 60 ± 2.6 to 75 ± 2.9 cm. Before IVC constriction, LPT increased lymph flow (P < 0.05) from 1.9 ± 0.2 ml/min to a maximum of 4.7 ± 1.2 ml/min, whereas after IVC constriction, LPT increased lymph flow (P < 0.05) from 7.9 ± 2.2 to a maximum of 11...