Radio-frequency electrocautery ablation of mammary tissue in swine.
OBJECTIVE
To establish the size, configuration, and histopathologic features of acute, subacute, and chronic radio-frequency (RF) electrocautery of mammary tissue in swine.


METHODS
Eighteen RF treatments were performed in the mammary tissue of three domestic swine under ultrasonographic (US) guidance. Histopathologic examination was performed immediately after (acute animal); 2 weeks after (subacute animal); and 4 weeks after (chronic animal) treatment.


RESULTS
In the acute animal, lesions were firm nodules on palpation and had a distinct line of demarcation between necrotic and viable mammary tissue (mean lesion volume, 14.24 cm(3); largest volume, 29.06 cm(3)). In the subacute animal, there was diffuse coagulation necrosis with neutrophilic infiltrates at the periphery (mean lesion volume, 6.46 cm(3); largest volume, 9.47 cm(3)), and two treatment areas had a secondary bacterial infection. In the chronic animal, lesions were still palpable and firm (mean lesion volume, 11.67 cm(3); largest volume, 25.5 cm(3)), and five of six treatment sites had an area of gray to white fibrotic tissue that blended with the surrounding tissue. However, one site had a pale yellow area of central necrosis surrounded by a fibrotic area. In both the subacute and chronic animals, two and one treatment site, respectively, had minimal areas of skin necrosis.


CONCLUSIONS
RF ablation of breast tissue is feasible in this animal model. Problems included minimal skin erythema, residual firm treatment regions at 4 weeks, slightly variable margins of coagulation necrosis, and occasional bacterial infection.
McGahan
J P
JP
Department of Radiology, University of California-Davis Medical Center, Sacramento 95817, USA. john.mcgahan@ucdmc.ucdavis.edu
Griffey
S M
SM
Schneider
P D
PD
Brock
J M
JM
Jones
C D
CD
Zhan
S
S
D000818:Animals; D017115:Catheter Ablation / Q000009:adverse effects; D005260:Female; D008321:Mammary Glands, Animal / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D013552:Swine; D018084:Ultrasonography, Interventional