The efficacy of mechanical abrasion and talc slurry as methods of pleurodesis in normal dogs.
OBJECTIVE
To determine the efficacy of mechanical abrasion and talc slurry as methods for pleurodesis in normal dogs.


METHODS
Experimental study.


METHODS
Ten normal beagle dogs.


METHODS
Group I dogs had mechanical abrasion (MA) of the pulmonary and costal pleurae performed in one hemithorax with a dry gauze sponge with a median sternotomy approach. Group II dogs had 100 mL of a 1 g talc slurry (TS) administered into one hemithorax through a tube thoracostomy. Administration of the TS was visualized by using video thoracoscopy. All dogs were evaluated at 2, 10, 20, and 30 days postoperatively by means of thoracic radiography and ultrasonographic thoracic wall measurement. The dogs were euthanatized 30 days postoperatively and a gross necropsy was performed. Hemithoraces were assigned a pleurodesis score (0-4) and an obliteration grade (0-6). Tissues were collected for histopathologic examination of pulmonary pleura, costal pleura, and pleural adhesions. Pulmonary and costal pleurae were graded for the degree of fibrosis (0-4).


RESULTS
Obliteration grade and costal pleural fibrosis score were significantly higher for the treated sides in the MA dogs compared with the TS dogs. MA Dogs: Mechanical abrasion dogs had pleurodesis, obliteration, and pleural fibrosis scores that were greater on the treated side than the untreated side, however, the differences were not statistically significant. Only two MA dogs had firm adhesion of the pulmonary pleura to the costal pleura in portions of the cranial and middle lung lobes in the treated hemithorax. Thoracic wall surface area covered with adhesions was 15% and 21% in each of these two dogs. The median pulmonary pleural fibrosis score of all MA dogs for the treated hemithorax was 3 compared to 0 on the untreated side. TS Dogs: There was no statistical difference for pleurodesis scores and obliteration grades between the treated and untreated sides. No dogs showed evidence of pulmonary to costal pleural adhesions. Histopathology showed talc crossover into the untreated side in all five dogs. Median pulmonary fibrosis score of the treated hemithorax was 1 compared with 0 on the untreated side.


CONCLUSIONS
Neither method of pleurodesis produced sufficient pleural adhesions to obliterate the pleural space. It is possible that the degree of pulmonary pleural fibrosis present in MA dogs may be sufficient to limit air leakage from pulmonary blebs and bullae resulting in successful treatment of spontaneous pneumothorax.
Jerram
R M
RM
Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station, USA.
Fossum
T W
TW
Berridge
B R
BR
Steinheimer
D N
DN
Slater
M R
MR
D000818:Animals; D015505:Chest Tubes / Q000662:veterinary; D004283:Dog Diseases / Q000628:therapy*; D004285:Dogs; D008297:Male; D010994:Pleura / Q000000981:diagnostic imaging / Q000473:pathology; D010995:Pleural Diseases / Q000209:etiology / Q000662:veterinary; D018700:Pleurodesis / Q000379:methods / Q000662:veterinary*; D011030:Pneumothorax / Q000628:therapy / Q000662:veterinary; D011859:Radiography; D011897:Random Allocation; D012597:Sclerosing Solutions / Q000008:administration & dosage*; D015503:Surgical Sponges / Q000662:veterinary; D013627:Talc / Q000008:administration & dosage*; D013906:Thoracoscopy / Q000662:veterinary; D013907:Thoracostomy / Q000662:veterinary; D000267:Tissue Adhesions / Q000209:etiology / Q000662:veterinary; D014463:Ultrasonography
D012597:Sclerosing Solutions; D013627:Talc