Can artifact mimic the pathology of the peritoneal mesothelium?

A peritoneal biopsy registry was established to examine morphological and functional changes to the peritoneum during peritoneal dialysis (PD). During the early stages of this study, it became clear that surgical trauma to the peritoneum at the time of biopsy could cause a variety of changes to the surface. We examined the effects of surgical trauma in a rat biopsy model.

Rat peritoneum was subjected to a variety of traumas that might occur at biopsy and compared with peritoneal biopsies that had been collected, using the suture method described here, from PD patients. Changes in the quality of non-PD biopsies taken before and after the development of the suture technique were evaluated.

In the rat model, external massaging of the peritoneum induced moderate loss of microvilli. Brief light touching caused distortion of the mesothelial surface. Pressing resulted in mesothelial denudation and thin strands of presumed cellular remains. Rubbing caused complete loss of mesothelial cells and their basement membrane. Air drying caused progressive loss of microvilli and eventual cellular distortion. Comparison with peritoneal biopsies from PD patients revealed similarities with certain types of trauma, namely, air drying and pressing. Collection of peritoneal biopsies using the suture method significantly improved specimen quality compared with specimens taken before its introduction (p < 0.025%).

These results illustrate the sensitivity of the mesothelium to mechanical trauma, the possibility of confusing trauma with genuine pathology, and, hence, the necessity of employing a trauma-free method of biopsy collection, such as the technique described here.