Tissue Shrinkage of Resected Specimens in Hirschsprung's Disease: Why Pediatric Surgeons Think the Bowel Specimen was Longer Than Indicated in the Pathology Report.

BACKGROUND: Hirschsprung disease (HD) is an aganglionosis of variable length starting at the rectosigmoid colon with surgery as sole therapeutic option. The length of the resected bowel segment is a crucial information for the treating surgeons and influences the prognosis of the patient. It is often artificially altered due to post operative tissue shrinkage. The objective of this study is to quantify the extent tissue shrinkage of HD specimens.

MATERIAL AND METHODS: Colorectal HD specimens were measured at the time of surgery and at the time of cut-up, either fresh or after formalin fixation and statistically analyzed.

RESULTS: Sixteen colorectal specimens were included. Following formalin fixation the specimen length decreased by 22.7% ( P  < .001). Without formalin fixation the specimens shrank by an average of 24.9% ( P  = .05). There was no significant difference in the extent of tissue shrinkage with or without formalin fixation ( P  = .76).

CONCLUSION: This study showed that there is significant tissue shrinkage in HD specimens. The 2 different cohorts revealed that tissue shrinkage is mostly caused by tissue retraction/alteration after organ removal but also to a lesser extent by fixation with formalin. Surgeons and (neuro-)pathologists should be aware of the sizeable shrinking artifact to avoid unnecessary confusion.