Serial Observations after High Dose Talc Slurry in the Rabbit Model for Pleurodesis

Abstract

The mechanisms leading to a pleurodesis after the intrapleural injection of a sclerosing agent are not completely understood. The purpose of the present study was to make serial observations over 28 days on the pleural fluid findings and the gross and microscopic changes in the pleura after talc slurry administered intrapleurally at a high dose. Sixty-six rabbits received 400 mg/kg talc slurry. Ten to 12 rabbits were sacrificed 1, 2, 4, 7, 14, and 28 days after the intrapleural injection. At sacrifice the pleural fluid was measured and analyzed, and the pleural surfaces were studied grossly and microscopically. The intrapleural injection of 400 mg/kg talc slurry resulted in an acute exudative pleural effusion that persisted for 4 days. There was a progressive increase in the gross and microscopic fibrosis over the 28 days. Talc was present at the time of sacrifice in all animals. At 28 days there was a clinically significant pleurodesis in all rabbits; pleurodesis was not observed before this time. From this study we conclude that the intrapleural injection of 400 mg/kg talc slurry leads to an acute exudative pleural effusion and clinically significant pleurodesis that is present on day 28 but not day 14. It appears that the production of a pleurodesis requires higher doses of talc in rabbits without a chest tube than in humans with a chest tube.

Lung Damage in Experimental Pleurodesis Induced by Silver Nitrate or Talc

“…Talc is effective in humans (success rate, approximately 90%) 1 and in experimental studies. 2 However, serious concerns exist about its safety, and evidence is available that the intrapleural administration of talc induces ARDS in up to 8% of patients, 3 with an overall mortality rate of 1%. 4 Silver nitrate (SN) has been suggested in experimental studies 5 to be an effective agent for inducing pleurodesis.…”

Silver Nitrate Is Superior to Talc Slurry in Producing Pleurodesis in Rabbits

“…C urrently, talc is accepted by many as the agent of choice for creating a pleurodesis in patients with either a pneumothorax or a malignant pleural effusion. Talc became popular for several reasons: (1) in the experimental situation, it is effective in producing a pleurodesis 1 ; (2) in humans, it appears to be more effective than the tetracycline derivatives or chemotherapeutic agents 2 ; (3) in humans, its administration does not interfere with subsequent chemotherapy 3 ; (4) it is widely available 4 ; and finally, (5) it is less expensive than other sclerosing agents. 4 However, there are serious concerns about its safety.…”

Effectiveness of silver nitrate compared to talc slurry as pleural sclerosing agent in rabbits. Influence of concomitant intrapleural lidocaine

“…At gross examination, the diagnosis of hemothorax was made if there were blood clots in the pleural space. Atelectasis was classified as none (0), partial (1) or complete (2). Mediastinal shift was classified as none (0), slight (1), moderate (2) or severe (3).…”

“…Currently, talc is accepted by many as the agent of choice for patients with a malignant pleural effusion. Talc is popular for several reasons: a) it is effective in the experimental situation 2 , b) in humans it is apparently more effective than tetracycline derivatives 3 , c) its administration did not interfere with chemotherapy 4 , d) it is widely available 5 , and e) it is less expensive than other sclerosing agents 5 . However, there are concerns: a) acute respiratory distress syndrome develops in up to 8% of patients 6,7 , and b) the mortality due to the intrapleural administration is about 1% 6,7 .…”