The effect of inguinal lymphatic manipulation on regional lymph flow patterns.

PURPOSE: Because of the proximity of the inguinal lymphatics and the femoral vessels, lymph vessel manipulation during inguinal dissection is unavoidable, and this project was undertaken to evaluate the consequences. METHODS: Thirty-five greyhound dogs underwent popliteal lymph node dissection, cannulation with microvascular silastic tubing, and infusion of 2.5% Patent blue violet (Sigma Chemical Co., St. Louis, Mo.) (visual enhancement) and technetium 99m-labeled human serum albumin (HSA). Animals underwent inguinal exploration with no manipulation (group 1; n = 9), local lymphatic ligation (group 2; n = 11), or radical excision and ligation (group 3; n = 15) of the inguinal lymph vessels. Lymphatic flow was calculated by 99mTc-HSA clearance (counts per minute) at the popliteal, inguinal, and iliac regions, before and after lymph vessel manipulation and was converted into percent change between the regions. RESULTS: There was statistically reduced intralymphatic radioactivity in groups 2 and 3 compared with group 1 (p < 0.001; Student t test), whereas there was no significant difference between groups 2 and 3. CONCLUSIONS: This demonstrates that lymphatic flow in this experimental model is significantly reduced when major channels are identified and ligated, although radical obliteration does not reduce flow more significantly than local ligation, implying that there is an alternate pathway for lymph flow.

Effects of verapamil on histamine-and carbachol-induced contraction of pulmonary tissues in vitro.

It has been hypothesized that calcium antagonists may be useful in the management of airway hyperreactivity. In these studies, we evaluated the effects of verapamil on guinea pig tracheal spirals and parenchymal lung strips in vitro. Preincubation of both tissues with verapamil caused concentration-dependent inhibition of contraction with significant effects noted at a 10 micromolar concentration. At this concentration of verapamil, approximately fivefold greater concentrations of either histamine or carbachol were required to produce contraction of tracheal spirals; and 21-fold greater concentrations of histamine and 630-fold greater concentrations of carbachol were required to contract parenchymal strips. We also assessed the ability of verapamil to reverse contraction. Significant reversal of both histamine- and carbachol induced contraction was observed with concentrations of 3 micromolar verapamil and contraction was nearly abolished with a 100 micromolar concentration. These data demonstrate that verapamil can both inhibit airway contraction and reverse contraction once it is present and further suggest that verapamil or other calcium antagonists may prove useful in the management of airway hyperreactivity.