Temporary placement of a covered, retrievable, barbed stent for the treatment of hormone-induced benign prostatic hyperplasia: technical feasibility and histologic changes in canine prostates.
OBJECTIVE
To evaluate the technical feasibility of a covered, retrievable, barbed prostatic stent and to determine stent-induced histologic changes of the prostate in canine benign prostatic hyperplasia (BPH).


METHODS
BPH was induced in 8 male beagles by administration of dihydrotestosterone and beta-estradiol. Under fluoroscopy guidance, covered, retrievable, barbed stents were placed in the prostatic urethras. Urethrograms were obtained every three to 4 weeks until sacrifice. The stents were removed 8 weeks after placement. The dogs were sacrificed immediately (group A, n = 4) and 8 weeks after stent removal (group B, n = 4). Histologic changes of prostates were microscopically evaluated.


RESULTS
Stent placement was technically successful in all dogs. The diameters of the prostatic urethra were 14.1 mm + or - 0.5 and 13.7 mm + or - 0.5 on urethrograms obtained immediately after and 8 weeks after stent removal (P = .268). Stent removal was successful in all dogs except one, in which the stent was obstructed by stone formation. Small sandy stones were identified attached to the removed stents of two dogs. Histologic examination revealed extensive prostatic glandular atrophy involving 95.1% + or - 2.2 (group A) and 94.5% + or - 2.4 (group B) of entire prostate (P = .773).


CONCLUSIONS
A covered, retrievable, barbed prostatic stent seems to be feasible for use in hormone-induced canine BPH. The stent induced prostatic urethral dilatation, and extensive prostatic glandular atrophy persisted up to 8 weeks after stent removal.
Yoon
Chang Jin
CJ
Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap-2dong, Songpa-gu, Seoul, Republic of Korea, 138-736.
Song
Ho-Young
HY
Kim
Jin Hyung
JH
Park
Hyung Gyu
HG
Kang
Ho Seob
HS
Ro
Jae-Y
JY
Hong
Jun Hyuk
JH
D000818:Animals; D001284:Atrophy; D020099:Coated Materials, Biocompatible; D020878:Device Removal; D013196:Dihydrotestosterone; D004195:Disease Models, Animal; D004285:Dogs; D004958:Estradiol; D005240:Feasibility Studies; D005355:Fibrosis; D008297:Male; D011467:Prostate / Q000473:pathology*; D011470:Prostatic Hyperplasia / Q000139:chemically induced / Q000473:pathology / Q000628:therapy*; D011474:Prosthesis Design; D011859:Radiography; D015607:Stents; D013997:Time Factors; D014521:Urethra / Q000000981:diagnostic imaging; D014524:Urethral Obstruction / Q000209:etiology / Q000473:pathology / Q000628:therapy*
D020099:Coated Materials, Biocompatible; D013196:Dihydrotestosterone; D004958:Estradiol