Adjunct brachytherapy: a new concept to prevent intimal hyperplasia after surgical endarterectomy?
OBJECTIVE
Endarterectomy represents a therapeutical option for patients with advanced coronary artery disease. The mid-term results are compromised by restenosis due to neointima formation. The aim of this study was to evaluate a new treatment concept - endarterectomy with consecutive gamma-irradiation - in a rat model.


METHODS
Male Sprague-Dawley rats underwent left carotid endarterectomy with removal of intima: control (n=10) or were irradiated with 15 Gray (Gy) (n=13) or 20 Gy (n=10) postoperatively and compared with sham-operated rats (n=10). After 3 weeks, carotid arteries were perfusion-fixed and vessel compartment areas were measured. Transmission electron microscopy and immunohistochemical staining were used to confirm neointima formation.


RESULTS
Three weeks after endarterectomy, neointimal hyperplasia was found in the control group (0.07+/-0.04 mm(2)). After irradiation, a dose-dependent reduction of neointima was observed (0.003 mm(2) at 15 Gy and 0.0007 mm(2) at 20 Gy, P<0.0001). However, immunohistochemical staining revealed that thin re-endothelialization after irradiation was not inhibited.


CONCLUSIONS
Gamma-irradiation significantly suppressed neointimal hyperplasia in a rat model of surgical endarterectomy. Despite inhibition of intimal hyperplasia, re-endothelialization after adjuvant brachytherapy was present. Adjuvant brachytherapy may be therefore a new concept to prevent restenosis after endarterectomy in patients.
Beller
Carsten J
CJ
Department of Cardiac Surgery, University of Heidelberg, INF 110, 69120 Heidelberg, Germany. Carsten.Beller@urz.uni-heidelberg
Kosse
Jens
J
Radovits
Tamás
T
Krempien
Robert
R
Gross
Marie-Luise
ML
Berger
Irina
I
Hagl
Siegfried
S
Szabó
Gábor
G
D000818:Animals; D001918:Brachytherapy / Q000379:methods*; D002339:Carotid Arteries / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D004195:Disease Models, Animal; D004307:Dose-Response Relationship, Radiation; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D004730:Endothelium, Vascular / Q000502:physiology; D005720:Gamma Rays / Q000627:therapeutic use; D006133:Growth Substances / Q000378:metabolism; D006965:Hyperplasia / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008854:Microscopy, Electron; D018714:Radiotherapy, Adjuvant; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration / Q000528:radiation effects; D055502:Secondary Prevention; D017539:Tunica Intima / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D014666:Vasomotor System / Q000528:radiation effects
D006133:Growth Substances