Abstract
Introduction: Lymphedema is limb swelling secondary to lymphatic injury. Utilization of negative pressure therapy (NPT) has been shown to stimulate lymphatic vessel density, but the effect of NPT on secondary lymphedema is unknown. The purpose of this study is to evaluate the role of prophylactic negative pressure therapy in murine hindlimb lymphedema model. Methods: The murine hindlimb model of lymphedema was used. Mice underwent 20-Gy irradiation of one hindlimb. One week post-radiation, an incision in the proximal hindlimb was created to disrupt lymphatic vessels and remove popliteal lymph nodes. Mice were divided into two groups: Group 1 (NPT) and Group 2 (no NPT). Group 1 received a negative pressure of 75 mmHg on the lymphedema-induced hindlimb for 12 consecutive hours in the first 5 postoperative days (POD). Group 2 did not receive NPT. Paw thickness measurements and near-infrared laser lymphangiography were measured. Results: The study included 16 mice (Group 1 n=6, Group 2 n=10). Paw thickness on POD-21 in Group 1 was 2.9±0.3 mm compared to 3.3±0.3 mm in Group 2 (p=0.02). On postoperative day 35, the average paw thickness was 2.4±0.1 mm in Group 1 compared to 3.2±0.2 mm (p=0.001). Lymphangiography dye clearance was greater in Group 1 compared to Group 2 (p=0.008). Conclusions: Mice in the hindlimb lymphedema model that underwent NPT in the early postoperative period had less paw thickness swelling and better lymphatic function than mice that did not have NPT. NPT decreased lymphedema when used prophylactically following lymphatic injury.