title: [Expression of collagen and elastin fibers in the rectum of patients with obstructed defecation syndrome and its significance].
abstract: OBJECTIVE
  To detect the expression of collagen and elastin fibers in the rectum of patients with obstructive defecation syndrome (ODS), and to explore the possible role of these fibers in the pathogenesis of ODS.
  
  
  METHODS
  The rectum specimens of 20 patients with ODS were collected. These patients had undergone stapled transanal rectal resection (STARR) surgery in our hospital since 2012. Full-thickness rectal specimens were stained with Masson and EVG staining to show collagen and elastin fibers. As the control, rectum specimens of 20 patients with severe prolapsed hemorrhoids also undergoing STARR surgery in our hospital during the same period were collected.
  
  
  RESULTS
  Masson staining showed that the structure of collagen fibers in submucosa was slender, area decreased [(13.88±7.02)% vs. (30.98±3.46)%, P<0.01], and the expression level was significantly lower in ODS group compared with control group. EVG staining also showed that collagen fiber area of ODS patients was reduced compared with control group [(17.18±7.24)% vs. (27.04±9.65)%, P<0.01]. Meanwhile EVG staining revealed that elastic fibers were fragmented in ODS group and the expression level was lower compared with control group [(1.20±1.39)% vs. (1.47±1.06)%], whereas the difference was not statistically significant(P>0.05).
  
  
  CONCLUSIONS
  The expression level of collagen fibers in patients with ODS is significantly reduced, which may play an important role in the pathogenesis of ODS.
authors.affiliation: Department of Chinese Integrative Medicine Anorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510655, China. rendl111@163.com.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Hongcheng
authors.initials: H
authors.lastname: Lin
authors.forename: Donglin
authors.initials: D
authors.lastname: Ren
mesh_terms: D003094:Collagen; D003248:Constipation; D003672:Defecation; D013505:Digestive System Surgical Procedures; D004549:Elastin; D006484:Hemorrhoids; D006801:Humans; D012007:Rectum
chemical_list: D003094:Collagen; D004549:Elastin