Luminary Learning Gastrointestinal Disorder- Issue 1

Current Guidelines for Colonoscopy •  37 sporadic cancers require surveillance of their colon to rule out true anastomotic recurrence (<2% risk for colon, 5–20% for rectum); to detect and remove adenomata that have subsequently devel- oped or were missed on the initial examination. Surveillance after CRC is to be planned after 1 year, then after 3 years, and subsequently every 5 years if everything looks normal. In case of per- tinent findings as stated earlier, a tighter schedule would be entertained. CRC patients with high- risk constellations (particularly Lynch syndrome) who have only undergone segmental resections mandate continued annual surveillance of the residual. Contraindications to Colonoscopy Contraindications are defined by the factors related to either: (a) the condition of the colon, (b) the patient’s overall condition, or (c) denial of consent. In general, an intervention is contraindi- cated when the risks to the patient’s health or life outweigh the potential benefits. Absolute con- traindications to perform a colonoscopy include toxic megacolon, fulminant colitis, or a known free or concealed colonic perforation; furthermore, the list includes ASA IV/V, hemodynamic instability, or severe coagulopathy such as disseminated intravascular coagulation (DIC). Relative contraindications are situations in which the risk of the procedure (bleeding; perforation; extrin- sic organ injury, e.g., to spleen or aortic aneurysm) or of the conscious sedation/anesthesia is substantially increased. Nonetheless, it may on occasion still be deemed appropriate to proceed with at least a limited evaluation if the information that may be acquired would have a crucial impact on further treatment and management decisions. Routine screening is never indicated in pregnancy. Specific situations in pregnancy or management of patients on medications (platelet inhibitors, anticoagulation) are being discussed later. Effectiveness Analysis of the effectiveness of colonoscopy is difficult and can be based on a number of differ- ent factors, including: (a) the immediate procedural success and miss rates as well as accuracy and safety profile on an individual basis; (b) the population-based impact on CRC incidence and mortality; (c) the cost-effectiveness as measured, for example, by the number of gained patient years per invested direct and indirect dollar amount in comparison to other screening tools and interventions, or to no interventions at all. Even if there are likely other contributing factors, the simple observation of decreasing CRC incidence and mortality since introduction of routine use of colonoscopies seems to provide con- vincing evidence for its effectiveness and justification of its broad use. It is not easy, however, to draft high-quality prospective, randomized controlled trials over several decades. The implemen- tation of the National Polyp Study in the 1970s has, along with other large cohort studies, provided a flood of long-term data that demonstrate a lasting impact of interventions and polypectomies. Early reports of 76–90% reduction in colorectal cancer incidence have been recently supplement- ed with an observed long-term decrease of CRC mortality by 53% [10, 11, 17].