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Background and Objective: Vascular endothelial growth factor (VEGF) is known to increase vascular permeability and promote angiogenesis. It is expressed in most types of pleural effusions. However, the exact role of VEGF in the development of pleural effusions has yet to be determined. The anti-VEGF mAb, bevacizumab, has been used in the treatment of cancer to reduce local angiogenesis and tumour progression. This study describes the acute effects of VEGF blockade on the expression of inflammatory cytokines and pleural fluid accumulation., Methods: One hundred and twelve New Zealand rabbits received intrapleural injections of either talc or silver nitrate. In each group, half the animals received an intravenous injection of bevacizumab, 30 min before the intrapleural agent was administered. Five animals from each subgroup were sacrificed 1, 2, 3, 4 or 7 days after the procedure. Twelve rabbits were used to evaluate vascular permeability using Evans's blue dye. Pleural fluid volume and cytokines were quantified., Results: Animals pretreated with anti-VEGF antibody showed significant reductions in pleural fluid volumes after talc or silver nitrate injection. IL-8 levels, vascular permeability and macroscopic pleural adhesion scores were also reduced in the groups that received bevacizumab., Conclusions: This study showed that bevacizumab interferes in the acute phase of pleural inflammation induced by silver nitrate or talc, reinforcing the role of VEGF as a key mediator in the production of pleural effusions. The results also suggest that bevacizumab should probably be avoided in patients requiring pleurodesis.

Background and Objective: Both talc and 0.5% silver nitrate have been shown to induce effective pleurodesis. However, acute adverse systemic inflammatory effects have been described with both agents. The aim of this study was to assess in rabbits the systemic effects associated with a new technique of pleurodesis using repeated low doses of 0.1% silver nitrate., Methods: Rabbits were injected intrapleurally through a chest tube with 0.1% silver nitrate at 0, 24 and 48 h. Other groups received a single injection of 0.5% silver nitrate or 400 mg/kg of talc. Blood samples were collected at 24, 48 and 72 h, and at 7 days, and cytological and biochemical measurements were performed. After 28 days, the presence of macroscopic pleural adhesions and microscopic pleural fibrosis in the pleural cavity were evaluated., Results: Both talc and 0.5% silver nitrate caused significant increases in blood neutrophils, serum LDH, IL-8, transforming growth factor-beta and CRP in comparison with control at almost all time points, whereas sequential doses of 0.1% silver nitrate only increased LDH and CRP in the first 24 h and transforming growth factor-beta at all time points. All groups showed efficient pleurodesis, with no differences in pleural adhesions or fibrosis., Conclusions: Sequential doses of 0.1% silver nitrate produced efficient pleurodesis in rabbits, with a low systemic inflammatory response in comparison with 400 mg/kg of talc or 0.5% silver nitrate.

Objective: To compare the efficacy and toxicity of 1% silver nitrate, 0.2% povidone iodine and 50% dextrose in renal pelvic instillation sclerotherapy (RPIS) for chyluria., Patients and Methods: In a prospective randomized comparative study from January 1999 to June 2003, 106 patients (61 males and 45 females; mean age 36 years, sd 12, range 14-65) were randomized to receive 1% silver nitrate, 0.2% povidone iodine or 50% dextrose as RPIS. In all, nine doses were given at 8-h intervals, and patients followed at 6 weeks and then at 3-monthly intervals. Patients with 'persistence' or 'recurrence' of chyluria were treated with second course of RPIS using same sclerosant., Results: The dextrose treatment was discontinued at mid-term because of poor success (one of 21 patients, P < 0.001). Of 85 patients, 44 received silver nitrate and 41 povidone iodine; both groups were well-matched and the mean follow-up was 28.4 and 23.3 months, respectively. 'Immediate clearance' was recorded in 91% and 98%, and recurrence in 21% and 22% of patients after the first course of RPIS, after silver nitrate and povidone, respectively; Kaplan-Meier estimates of 'disease-free duration' in the two groups (23.6 vs 20.1 months) were also similar (P = 0.7906). The cumulative success rate after two courses of RPIS was 82% (silver nitrate) and 83% (povidone; P = 1.0). Five (11%) patients in the silver nitrate and one (2%) in the povidone group had significant flank pain during treatment., Conclusions: Povidone iodine 0.2% is as effective for RPIS as 1% silver nitrate.