Histopathology of stapled haemorrhoidectomy specimens: a cautionary note.

Abstract

Stapled haemorrhoidectomy is a new technique with encouraging early results. The aim of this study was to examine the tissue removed during stapled haemorrhoidectomy, in particular to check on the presence or absence of transitional or squamous anal canal mucosa and internal anal sphincter muscle. Twenty-six consecutive patients undergoing stapled haemorrhoidectomy were studied. Resected tissue was examined histologically according to a standardized histological protocol. All 26 specimens contained columnar mucosa. Twelve specimens also contained anal transitional and stratified squamous epithelium. Two specimens contained columnar and transitional mucosa. Twenty-two of 26 specimens contained smooth muscle as well as mucosa (median maximum diameter 7.5 mm, range 2-20 mm). In 11 specimens this was circular muscle only; in 11 circular and longitudinal smooth muscle were present. In 10 specimens smooth muscle was seen to be lying beneath stratified squamous or transitional epithelium, suggesting that it was from the internal anal sphincter. Stapled haemorrhoidectomy results in resection of stratified squamous mucosa or part of the internal anal sphincter in a significant proportion of patients. Surgeons should be aware that this technique may result in damage to the internal anal sphincter.