ORIGINAL ARTICLES  VASCULAR AND ENDOVASCULAR PAPERS 

The Journal of Cardiovascular Surgery 2000 December;41(6):885-90

Copyright © 2009 EDIZIONI MINERVA MEDICA

language: English

Biological response to expandable metallic stents implanted into the portal vein. A histomorphometric study

Miyazaki K., Nishibe T. *, Watanabe S. **, Kudo F. *, Katoh H., Yasuda K. *, Tanabe T. ***

From the Second Department of Surgery Hokkaido University School of Medicine, Sapporo, Japan *Department of Cardiovascular Surgery Hokkaido University Hospital, Hokkaido University School of Medicine, Sapporo, Japan **Department of Anatomy, Graduate School Hokkaido University, School of Medicine, Sapporo, Japan ***Sapporo General Hospital of Nippon Telephone & Telegram, Sapporo, Japan

Background. This ­study was under­tak­en to inves­ti­gate the bio­log­i­cal ­response to an expand­able metal­lic ­stent implant­ed in the ­canine por­tal ­vein ­with a spe­cial ref­er­ence to the his­to­mor­pho­met­ric con­tri­bu­tion of cel­lu­lar and acel­lu­lar ele­ments to the inti­mal and medi­al ­growth.
Methods. In 11 ­dogs, the Gianturco Z ­stent was ­placed ­into the por­tal ­vein and was har­vest­ed at inter­vals of 4 (n=6) and 12 ­weeks (n=5). In 6 ­dogs, the nor­mal por­tal ­vein was har­vest­ed and ­used as a con­trol. The spec­i­mens ­were sub­ject­ed to his­to­mor­pho­met­ric exam­ina­tion.
Results. Mean inti­mal/medi­al thick­ness and ­total inti­mal/medi­al ­area sig­nif­i­cant­ly ­increased pro­gres­sive­ly by 12 ­weeks. Collagen inti­mal/medi­al ­area ­also sig­nif­i­cant­ly ­increased pro­gres­sive­ly by 12 ­weeks, ­while ­smooth mus­cle inti­mal/medi­al ­area sig­nif­i­cant­ly ­increased at 4 ­weeks but did not ­change ­from 4 ­weeks to 12 ­weeks. Collagen den­sity tend­ed to ­increase at 4 ­weeks and sig­nif­i­cant­ly ­increased at 12 ­weeks, ­while ­smooth mus­cle den­sity sig­nif­i­cant­ly ­decreased at 4 ­weeks and con­tin­ued to ­decrease at 12 ­weeks.
Conclusions. The ­total ­area or ­mean thick­ness of the inti­ma and ­media of the stent­ed por­tal ­vein con­tin­ued to ­increase by 12 ­weeks ­after ­stent place­ment. This phe­nom­e­non ­appeared to be due to pro­life­ra­tion of ­smooth mus­cle ­cells fol­lowed by accu­mu­la­tion of col­la­gen.