Study objective: The ideal agent for producing
pleurodesis has not been identified. Although talc is the agent most
commonly used at the present time, there are concerns about its safety.
Silver nitrate is a possible alternative agent. The purpose of the
present study was to compare the effectiveness of intrapleural silver
nitrate and talc slurry in producing pleurodesis in rabbits.
Additionally, the total amount of pleural collagen and the distribution
of thick and thin collagen fibers were studied.
Design: Two groups of 10 rabbits received either 0.50%
silver nitrate or 400 mg/kg talc in a total volume of 2 mL
intrapleurally. The animals were killed 28 days after injection, and
the pleural spaces were assessed grossly for evidence of pleurodesis
and microscopically for evidence of inflammation and fibrosis. Collagen
was assessed with the van Gieson’s and picrosirius stains.
Results: The macroscopic pleurodesis (scale, 0 to 4;
mean ± SEM) resulting from the intrapleural injection of silver
nitrate (3.4 ± 0.2) was significantly better (p < 0.001) than
that resulting from talc (1.6 ± 0.1). The mean degree of microscopic
pleural fibrosis induced by silver nitrate (3.3 ± 0.3) was
significantly higher (p = 0.003) than that induced by talc
(1.8 ± 0.1). The mean amount of microscopic pleural collagen (van
Gieson’s) was significantly greater (p < 0.001) in the rabbits that
received silver nitrate (3.0 ± 0.2) than in those that received talc
(1.6 ± 0.2). The distribution of thick and thin collagen fibers did
not differ between the groups.
conclude that, in our rabbit model, intrapleural silver nitrate was
more effective than talc in producing a pleurodesis.