A novel, rapid, and low cost method for preparing tissues with metallic stents for routine histology.

Abstract

Coronary artery stenting has become a common procedure and cardiovascular pathology specimens containing these metallic stents are accordingly becoming common. Histologic examination of stented vessels is imperative, but special techniques are needed due to the presence of metal within the tissue. We describe a rapid and inexpensive method for preparing stented vascular specimens for routine histology suitable for use in almost any histology laboratory. After formalin fixation and decalcification, stented vascular segments were freeze-embedded and sectioned using a handheld power micro cutoff wheel tool into ~1mm slices. Sections were allowed to thaw and the strut shards removed with fine forceps. No longer containing metal, the sections were processed for routine paraffin embedding, microtomy and staining. Histologic sections showed only minor tissue disruption around the stent struts. In our experience with 25 stented arteries (mean interval from implantation 5.6 years), the mean subjective section quality score was 4.1 out of 5. The position of each strut could easily be determined, along with neointimal in-stent restenosis and thrombosis. Local reaction to each strut could be surmised even if minor tissue disruption occurred. The entire process was completed in 2-3 days. The incremental cost over that of routine histology is nominal. This method for examining stented vascular segments histologically could readily be applied in most pathology laboratories and serves as a highly practical solution to dilemma of examining stents histologically.