ORIGINAL ARTICLES  VASCULAR PAPERS 

The Journal of Cardiovascular Surgery 2000 October;41(5):725-35

Copyright © 2009 EDIZIONI MINERVA MEDICA

language: English

Canine carotid allograft changes after photochemotherapy and external polyester sheathing

Donovan T. J., Lena C. M., Knibbs D. R., Shapiro D. S., Lavitt S. E.

From the Hartford Hospital, Surgical Research Hartford, Ct. (USA)

Back­ground. The pur­pose of ­this ­study is to ­define and ­refine the ­changes in ­canine ­carotid allo­grafts ­after pho­to­chem­o­therapy and poly­ester ­sheathing. Pho­to­chem­o­therapy ­with 8-­methoxy pso­ralen (8MOP) and UVA (PUVA) was ­given ­alone or com­bined ­with intra­lu­minal vis­ible ­light (VL) 450 nm in ­proper dos­ages to ­speed the depop­u­la­tion of endo­the­lial (EC) and ­smooth ­muscle ­cells (SMC) and to mod­ulate the ­immune ­response.
­Methods. ­Novel appa­rati ­were ­made for pho­to­chem­o­therapy of 19 ­right ­canine ­carotid arte­rial allo­grafts ­with 19 ­paired ­untreated con­trols in the ­left ­carotid. ­External UVA and internal vis­ible ­light (VL 450 nm) ­were ­used ­with 8-­methoxy pso­ralen (8-MOP) as a sen­si­tizer.
­Results. ­With mod­erate ­dosage of 8-MOP (1 μg/cc) and 2-4 J/cm2 of ­external UVA (­PUVA), ­smooth ­muscle ­cells (SMC) dis­ap­peared ­faster ­from the ­media and fibro­blasts (FB) ­appeared ear­lier in the adven­titia of the ­treated ­right allo­grafts, ­reducing but not elim­i­nating the ­immune ­response. Intra­lu­minal VL did not ­enhance the ­PUVA ­effect. At 68 ­days, ­treated and con­trol allo­grafts ­showed sim­ilar dimen­sions ­with sub­sided ­immune reac­tions. The ­media thick­ness was ­reduced ­from 0.38 mm to 0.18 mm and the ­host adven­titia ­increased ­from 0.22 to 0.60 mm. Var­i­able reac­tions ­peaked ­between two and ­three ­weeks and sub­sided ­after one ­month. All allo­grafts ­remained ­open ­with ­canine ­carotid i.d.s of 2-3 mm and 80 to 100 cc/ minute arte­rial ­flows. ­Although the UVA ­dosage was mod­erate) sim­ilar ­doses ster­il­ized log 7 of ­staph ­aureus cul­tures in ­saline. The allo­grafts ­without ­smooth ­muscle ­showed mod­erate but ­stable cylin­drical dil­a­ta­tion ­without ­spasm or sten­osis and ­with an ade­quate adven­ti­tial but­tress for a ­small ­vessel. A poly­ester ­sleeve ­around ­four ­treated ­grafts was insep­a­rable ­from the allo­graft in ­less ­than 3 ­weeks and tol­er­ated ­well ­over a 70-day ­period.
Con­clu­sions. Bio­de­grad­able ­graft ­sheaths ­with bio­erod­ible hydro­gels ­with ­growth fac­tors (FGF) for ­local ­delivery may pro­vide a ­faster and ­more com­plete ­matrix remod­eling for a ­superior con­duit in the ­future.