title: Endoscopic obstruction is associated with higher risk of acute events requiring emergency operation in colorectal cancer patients.
abstract: BACKGROUND
  Unplanned emergency operations in colorectal cancers (CRC) are generally associated with increased risk of operative complications. This study aimed to examine the association, if any, between an endoscopic finding of obstructing tumor and the subsequent need for an emergency operation, with the aim of determining if this finding could be useful in identifying CRC cases who are more likely to require an emergency operation.
  
  
  METHODS
  The records of CRC cases operated on in our institute during the years 2002-2011 were retrospectively reviewed regarding an endoscopic obstruction (eOB), defined as a luminal obstruction of the colon or rectum severe enough to prevent the colonoscope from passing beyond the tumor. The eOBs were analyzed against outcomes in terms of need for emergency operation, surgical complications and overall survival (OS).
  
  
  RESULTS
  A total of 329 CRCs which had been operated on during the study period had complete colonoscopic data. eOB was diagnosed in 209 cases (64%). Occurrence of eOB was not correlated with clinical symptoms. Colon cancer had a higher incidence of eOB (70%) than rectal cases (50%) (p-value < 0.01). eOB was significantly associated with higher tumor size and more advanced T-stage (p < 0.01). Twenty-two cases (7%) had required an emergency operation before their scheduled elective surgery. The cases with eOB had a significantly higher risk of requiring an emergency operation while waiting for their scheduled procedure (p-value < 0.01), and these emergency surgeries had more post-operative complications (36%) than elective procedures (13%) (p-value 0.01) and poorer OS (p-value < 0.01).
  
  
  CONCLUSIONS
  Regardless of the presenting symptom, luminal obstruction severe enough to prevent further passage of a colonoscope should prompt the physician to consider an urgent surgery.
authors.affiliation: Department of Surgery, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand. surasak.sa@psu.ac.th.
authors.forename: Virote
authors.initials: V
authors.lastname: Chalieopanyarwong
authors.forename: Teeranut
authors.initials: T
authors.lastname: Boonpipattanapong
authors.forename: Paradee
authors.initials: P
authors.lastname: Prechawittayakul
authors.forename: Surasak
authors.initials: S
authors.lastname: Sangkhathat