Lymphatic and transcapillary forces in patients with edema following operation for lower limb atherosclerosis.

Intralymphatic end pressure and Starling pressures (interstitial fluid pressure (Pif), plasma and interstitial fluid colloid osmotic pressures (COPpl and COPif)) were measured in leg subcutaneous tissue in 5 patients with local leg edema following femoropopliteal reconstruction for lower limb atherosclerosis. Superficial lymphatics were cannulated proximal to the ankle and the catheter was connected to either syringes for determination of lymph flow and colloid osmotic pressure (COPl), or to a pressure transducer for measurement of intralymphatic end pressure. Samples of interstitial fluid were collected by implantation of nylon wicks and Pif was measured by the "wick-in-needle" technique. In all patients normal end pressure waves with maximum values ranging between 30 and 40 mmHg were recorded, indicating that the ischemia prior to surgery had not significantly affected the intrinsic mechanism for lymph propulsion. COPif of the operated leg averaged 5.7 mmHg +/- 1.0 which was 0.9 mmHg +/- 0.7 higher than the corresponding COPl. This supports the theory of "preferential channels" between the capillaries and the lymphatics. There was a statistically significant correlation between lymph flow and estimated capillary pressure (reabsorption pressure), capillary filtration coefficient, calf blood flow and Pif. According to this study the capillary pressure should at least be 11 mmHg before production of lymph occurs.