title: Quantitative evaluation and assessment of peritoneal morphologic changes in peritoneal dialysis patients.
abstract: BACKGROUND
  Morphologic changes of the peritoneum such as peritoneal fibrosis and vasculopathy develop during peritoneal dialysis (PD). In 2002, Williams et al. reported microscopic characteristics of peritoneal changes in PD patients. These studies pointed out the importance of establishing a global standard for qualitative and quantitative histological evaluations. The objectives of the present study are (i) to verify the methods for assessing peritoneal thickness and classifying vasculopathy in peritoneal specimens using the assessment of Williams et al. and (ii) to propose a simple assessment that reflects clinical features such as PD duration and peritoneal function.
  
  
  METHODS
  Parietal peritoneal samples were obtained from 35 patients that included 27 patients with PD and 8 uraemic patients without PD. In all samples, the maximum and average thicknesses of the submesothelial compact (SMC) zone were measured to assess peritoneal interstitial fibrosis using KS400 imaging analysis. Vasculopathy was also assessed by calculation of patency rates of the vascular lumens using the diameter and area, and by measurement of dimensions of vascular wall hyalinization in each vessel specimen.
  
  
  RESULTS
  The median values of maximum and average thicknesses of the SMC zone exceeded 200 μm in uraemic patients without PD treatment. There was a significant relationship between the maximum and average thicknesses of the SMC zone (P < 0.0001). Four to 30 vessels were examined in each participant. Various grades of vasculopathy were observed in each specimen. According to the predominant vasculopathy found in each vessel, the prevalence of serious vasculopathy increased with increasing PD duration. Vascular patency calculated from wall thickness was significantly related to that calculated by the area and to the thickness of hyalinization. Average vascular patency assessed from 5 to 10 vessels in each patient having diameters ranging from 10 to 40 μm was related to PD duration and to peritoneal function (D4/P).
  
  
  CONCLUSIONS
  A random-points measurement of average SMC thickness provides a descriptive evaluation of the severity of peritoneal fibrosis that minimizes artefacts during processing and avoids human error. In addition, the average patency in post-capillary venules appears to accurately reflect clinical features such as PD duration and peritoneal permeability.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Tetsutaro
authors.initials: T
authors.lastname: Shimaoka
authors.forename: Chieko
authors.initials: C
authors.lastname: Hamada
authors.forename: Kayo
authors.initials: K
authors.lastname: Kaneko
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Io
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Sekiguchi
authors.forename: Seiki
authors.initials: S
authors.lastname: Aruga
authors.forename: Jiro
authors.initials: J
authors.lastname: Inuma
authors.forename: Yuko
authors.initials: Y
authors.lastname: Inami
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hotta
authors.forename: Satoshi
authors.initials: S
authors.lastname: Horikoshi
authors.forename: Toshio
authors.initials: T
authors.lastname: Kumasaka
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tomino
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005355:Fibrosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D010537:Peritoneum / Q000098:blood supply / Q000473:pathology*; D014652:Vascular Diseases / Q000209:etiology; D014654:Vascular Patency