title: Colonoscopic perforation leading to a diagnosis of Ehlers Danlos syndrome type IV: a case report and review of the literature.
abstract: BACKGROUND
  Colonoscopic perforation is a rare but serious complication of colonoscopy. Factors known to increase the risk of perforation include colonic strictures, extensive diverticulosis, and friable tissues. We describe the case of a man who was found to have perforation of the sigmoid colon secondary to an undiagnosed connective tissue disorder (Ehlers-Danlos syndrome type IV) while undergoing surveillance for hereditary non-polyposis colorectal cancer.
  
  
  METHODS
  A 33-year-old Caucasian man presented to our hospital with an acute abdomen following a colonoscopy five days earlier as part of hereditary non-polyposis colorectal cancer screening. His medical history included bilateral clubfoot. His physical examination findings suggested left iliac fossa peritonitis. A computed tomographic scan revealed perforation of the sigmoid colon and incidentally a right common iliac artery aneurysm as well. Hartmann's procedure was performed during laparotomy. The patient recovered well post-operatively and was discharged. Reversal of the Hartmann's procedure was performed six months later. This procedure was challenging because of dense adhesions and friable bowel. The histology of bowel specimens from this surgery revealed thinning and fibrosis of the muscularis externa. The patient was subsequently noted to have transparency of truncal skin with easily visible vessels. An underlying collagen vascular disorder was suspected, and genetic testing revealed a mutation in the collagen type III, α1 (COL3A1) gene, which is consistent with a diagnosis of Ehlers-Danlos syndrome type IV.
  
  
  CONCLUSIONS
  Ehlers-Danlos syndrome type IV, the vascular type, is a rare disorder caused by mutations in the COL3A1 gene on chromosome 2q31. It is characterized by translucent skin, clubfoot, and the potentially fatal complications of spontaneous large vessel rupture, although spontaneous uterine and colonic perforations have also been reported in the literature. The present case presentation describes the identification of Ehlers-Danlos syndrome type IV in a patient with a non-spontaneous colonic perforation secondary to an invasive investigation for another hereditary disorder pre-disposing him to colorectal cancer. Invasive procedures such as arteriograms and endoscopies are relatively contra-indicated in Ehlers-Danlos syndrome type IV. Alternatives with a lower risk of perforation, such as computed tomographic colonography, need to be considered for patients requiring ongoing colorectal cancer surveillance. Furthermore, management of vascular aneurysms in patients with Ehlers-Danlos syndrome type IV requires consideration of the risks of endovascular stenting, as opposed to open surgical intervention, because of tissue friability. Genetic and reproductive counseling should be offered to affected individuals and their families.
authors.affiliation: Division of Surgery, Department of Surgery and Cancer, Imperial College London, St Mary's Hospital, South Wharf Road, London W2 1NY, UK. mariam.rana02@imperial.ac.uk.
authors.forename: Mariam
authors.initials: M
authors.lastname: Rana
authors.forename: Omer
authors.initials: O
authors.lastname: Aziz
authors.forename: Sanjay
authors.initials: S
authors.lastname: Purkayastha
authors.forename: Josephine
authors.initials: J
authors.lastname: Lloyd
authors.forename: John
authors.initials: J
authors.lastname: Wolfe
authors.forename: Paul
authors.initials: P
authors.lastname: Ziprin