title: Myofibrotic malformation vessels: unique angiodysplasia toward the progression of hemorrhoidal disease.
abstract: BACKGROUND
  The etiology and pathogenesis of hemorrhoids is unclear, although hemorrhoids are a worldwide disease in men and women, with peak prevalence at 45-65 years of age. Hemorrhoidal cushions as the anal venous plexi are normal anatomical structures from infancy. This study attempts to reveal the angiodysplasia and other pathological changes in association with different degrees of symptomatic hemorrhoids.
  
  
  METHODS
  A total of 281 patients with internal hemorrhoids from degree I to IV underwent hemorrhoidectomy. The vascular changes were analyzed by microscopic assessment and software analysis, with Masson's trichrome, CD34, and smooth muscle actin.
  
  
  RESULTS
  The hemorrhoidal tissues exhibited abnormal vessels in the mucosae and submucosae that we termed them as myofibrotic malformation vessels (MMVs). MMVs are not ascribed to arteries or veins because they exhibit enlarged and tortuous lumens with smooth muscle dysplasia and fibrotic deposition in the walls without overlying mucosal ulceration. The muscularis mucosae also showed smooth muscle dysplasia and fibrosis, even if it were interrupted by the intruding MMVs. The statistical data indicated that the severity of all the changes correlate positively with the progression of hemorrhoids (P<0.001). Hemorrhoidal patients are prone for reoccurrence even with prolapsing hemorrhoid when compared with the conventional hemorrhoidectomy. Multiple logistic regression analysis showed that MMVs in mucosal propria, mean thickness of mucosal muscularis layer, and fibrotic changes in MMV were independent risk factors for MMVs in hemorrhoidal disease.
  
  
  CONCLUSIONS
  MMVs and muscularis mucosae dysplasia reciprocally contribute to hemorrhoidal exacerbation. The novel findings of this study propose that the characteristic features of MMVs and muscularis mucosae dysplasia of the anorectal tube ultimately cause symptomatic hemorrhoids, which could affect the clinical management of hemorrhoidal disease through the use of surgery to target the malformed vessels.
authors: Department of Anorectal Surgery, Nanfang Hospital, Zengcheng, Guangzhou, People's Republic of China.
authors: Sheng-Long
authors: SL
authors: Li
authors: Department of Anorectal Surgery, Nanfang Hospital, Zengcheng, Guangzhou, People's Republic of China ; Department of Pathology, Nanfang Hospital, Zengcheng, Guangzhou, People's Republic of China ; Department of Pathology, School of Basic Medical Sciences, Zengcheng, Guangzhou, People's Republic of China.
authors: Fang-Yan
authors: FY
authors: Jing
authors: Department of Pathology, Nanfang Hospital, Zengcheng, Guangzhou, People's Republic of China ; Department of Pathology, School of Basic Medical Sciences, Zengcheng, Guangzhou, People's Republic of China.
authors: Li-Li
authors: LL
authors: Ma
authors: Department of Pathology, Nanfang Hospital, Zengcheng, Guangzhou, People's Republic of China ; Department of Pathology, School of Basic Medical Sciences, Zengcheng, Guangzhou, People's Republic of China.
authors: Li-Li
authors: LL
authors: Guo
authors: Department of Pathology, Nanfang Hospital, Zengcheng, Guangzhou, People's Republic of China ; Department of Pathology, School of Basic Medical Sciences, Zengcheng, Guangzhou, People's Republic of China.
authors: Feng
authors: F
authors: Na
authors: Department of Biostatistics, Southern Medical University, Zengcheng, Guangzhou, People's Republic of China.
authors: Sheng-Li
authors: SL
authors: An
authors: Department of General Surgery, Xintang Hospital, Zengcheng, Guangzhou, People's Republic of China.
authors: Yan
authors: Y
authors: Ye
authors: Department of Anorectal Surgery, Nanfang Hospital, Zengcheng, Guangzhou, People's Republic of China.
authors: Jun-Ming
authors: JM
authors: Yang
authors: Department of Anorectal Surgery, Nanfang Hospital, Zengcheng, Guangzhou, People's Republic of China.
authors: Ming
authors: M
authors: Bao
authors: Department of Anorectal Surgery, Nanfang Hospital, Zengcheng, Guangzhou, People's Republic of China.
authors: Dong
authors: D
authors: Kang
authors: Department of Anorectal Surgery, Nanfang Hospital, Zengcheng, Guangzhou, People's Republic of China.
authors: Xiao-Lan
authors: XL
authors: Sun
authors: Department of Pathology, Nanfang Hospital, Zengcheng, Guangzhou, People's Republic of China ; Department of Pathology, School of Basic Medical Sciences, Zengcheng, Guangzhou, People's Republic of China.
authors: Yong-Jian
authors: YJ
authors: Deng
mesh_terms: D000199:Actins / Q000032:analysis; D000328:Adult; D001003:Anal Canal / Q000098:blood supply*; D016888:Angiodysplasia / Q000378:metabolism / Q000473:pathology*; D018952:Antigens, CD34 / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D001808:Blood Vessels / Q000737:chemistry / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D005355:Fibrosis; D061865:Hemorrhoidectomy; D006484:Hemorrhoids / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000473:pathology; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D012007:Rectum / Q000098:blood supply*; D012720:Severity of Illness Index
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D018952:Antigens, CD34; D015415:Biomarkers
keywords: anorectal disease; hemorrhoidal progression; internal hemorrhoids; muscularis mucosae dysplasia; myofibrotic malformation vessels