title: Application of stereology to study the effects of pneumoperitoneum on peritoneum.
abstract: BACKGROUND
  Scanning electron microscopy is unable to provide sufficient data to obtain definitive results for research into the morphologic effect of pneumoperitoneum on peritoneum. To overcome this difficulty, we adopted stereology to examine the effect of the type of gas insufflated, pressure, duration, and gas flow on morphologic alterations of peritoneum.
  
  
  METHODS
  Fifty SD rats were divided into ten groups. One group served as control. Pneumoperitoneum was established at 5 mmHg and 1.0 l/min gas flow for 1, 2 or 3 h with CO2 (in groups C1h, C2h, and C3h, respectively) or with He (in groups H1h, H2h, and H3h, respectively). CO2 pneumoperitoneum was further established at 8 mmHg and 1.0 l/min gas flow for 1 h (group C8p), at 5 mmHg and 2.0 l/min gas flow for 1 h (group C2f), and at 5 mmHg and 3.0 l/min gas flow for 1 h (group C3f). After the procedures, five specimens were sampled from anterior peritoneum and measured by stereological and electron-microscopic techniques.
  
  
  RESULTS
  Groups H1h and C1h, H2h and C2h, and H3h and C3h, respectively, were the same in terms of area fraction of basal lamina exposed and diameter of mesothelial cells (P>0.05). The magnitudes of peritoneal trauma in groups C2h, C3h, C8p, C2f, and C3f were significantly higher than that in group C1h (P<0.01), and the same result was observed in groups H2h and H3h against group H1h (P<0.01), and in group C3f against group C2f (P<0.01). Furthermore, the area fractions of basal lamina exposed in groups C3h and H3h were remarkably higher than those in groups C2h and H2h, respectively (P<0.01). The mechanism of basal lamina exposure comprises mesothelial cell desquamation and plasmatorrhexis.
  
  
  CONCLUSIONS
  Peritoneal morphologic trauma during pneumoperitoneum can be attributed to the pressure, duration, and gas flow instead of the type of gas insufflated.
authors.affiliation: Department of General Surgery and Center of Minimally Invasive Gastrointestinal Surgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Du
authors.forename: Pei-wu
authors.initials: PW
authors.lastname: Yu
authors.forename: Bo
authors.initials: B
authors.lastname: Tang
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002245:Carbon Dioxide / Q000009:adverse effects; D004195:Disease Models, Animal; D021621:Imaging, Three-Dimensional; D010535:Laparoscopy / Q000009:adverse effects / Q000379:methods; D008297:Male; D008855:Microscopy, Electron, Scanning; D010537:Peritoneum / Q000473:pathology* / Q000648:ultrastructure*; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects* / Q000379:methods; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D018709:Statistics, Nonparametric
chemical_list: D002245:Carbon Dioxide