LETTER TO Is It Time to Change Practice of Routine Colonoscopy After Acute Diverticulitis? To the Editor:
e read with interest the article by Sharma et al,1 a well-executed metaanalysis concerning the need for colonoscopy after acute diverticulitis. By studying a total of 1970 patients, they found that risk for colon cancer mimicking diverticulitis is approximately 10% in the case of complicated diverticulitis and 0.7% in uncomplicated diverticulitis. They conclude that routine colonoscopy may not be necessary after radiologically confirmed uncomplicated diverticulitis. Although we agree with their conclusions, we do have some comments. One study included in the metaanalysis used ultrasonography (US) to diagnose acute diverticulitis in 112 patients.2 This might be justified as US is recommended as a first-line diagnostic tool for all in some countries such as The Netherlands3 and for fertile-age women in others such as Denmark.4 However, few studies compare computed tomography (CT) to US in the diagnosis of acute diverticulitis. Farag et al5 and Pradel et al6 found excellent concordance of CT and US but made no distinction between uncomplicated and complicated diverticulitis, which is crucial considering the risk for colon cancer mimicking diverticulitis. On the contrary, a recent study by Nielsen et al7 found that US misclassifies CT-verified complicated diverticulitis in 79% of cases! As CT-diagnosed complicated diverticulitis has approximately a 10% risk of being colon cancer instead,1,8,9 it is of paramount interest to distinguish complicated diverticulitis from
uncomplicated one. We think that the diagnosis of diverticulitis should be made by CT. All diverticulitis that are diagnosed with US (or clinically) should still undergo colonoscopy to confirm diagnosis. There was a very low number of cases with complicated diverticulitis. Of the 11 studies included, only 8 studies classified patients into uncomplicated or complicated diverticulitis. Of these 8 studies, only 5 included patients with complicated diverticulitis. This led to a situation where only 79 of 1970 patients (4%) had complicated disease. This hardly represents the reality, as other reports indicate that approximately 20% to 30% of patients with acute diverticulitis present with an abscess.8,9 Because the risk for cancer is higher in complicated diverticulitis, underrepresentation of complicated disease will lead to underestimation of the risk for cancer in patients with any diverticulitis (in the meta-analysis by Sharma et al, estimated pooled risk was 1.6%). Sharma et al conclude that ‘‘in view of the overall paucity of high-quality data, further large-scale studies are needed before practice recommendations can be made.’’ Two new studies have emerged very recently that were not included in the metaanalysis.8,9 These studies include a total of 882 patients with CT-diagnosed diverticulitis and found cancer in 21 (risk for cancer was 2.4%). Diverticular abscess was present in 219 patients, whereas 663 patients did not have an abscess. Only one cancer case was found in patients without abscess (risk of cancer 0.15%), and even this patient had extraluminal pericolic air. Twenty cancer cases were found in patients with an abscess (risk of cancer 9.1%). We think that these 2 new studies, in addition to this meta-analysis, bring the needed high-quality data. As a matter of fact, in our institution, we have ceased routine colonoscopy in patients with
CT-diagnosed uncomplicated diverticulitis, who have no other indication for endoscopic evaluation of the colon. Ville Sallinen, MD, PhD Panu Mentula, MD, PhD Ari Leppa¨niemi, MD, PhD Department of Abdominal Surgery Helsinki University Central Hospital Helsinki, Finland [email protected]
REFERENCES 1. Sharma PV, Eglinton T, Hider P, et al. Systematic review and meta-analysis of the role of routine colonic evaluation after radiologically confirmed acute diverticulitis. Ann Surg. 2014;259:263–272. 2. van de Wall BJM, Reuling EMBP, Consten ECJ, et al. Endoscopic evaluation of the colon after an episode of diverticulitis: a call for a more selective approach. Int J Colorectal Dis. 2012;27:1145– 1150. 3. Diagnostiek en behandeling acute diverticulitis van het colon. 2011. Available at: http://www.mdl.nl/ uploads/240/996/NVvH-richtlijn_acute-diverticuli tis-van-het-colon_2010.pdf. Accessed January 1, 2014. 4. Andersen JC, Bundgaard L, Elbrønd H, et al. Danish national guidelines for treatment of diverticular disease. Dan Med J. 2012;59:C4453. 5. Farag Soliman M, Wu¨stner M, Sturm J, et al. [Primary diagnostics of acute diverticulitis of the sigmoid]. Ultraschall Med. 2004;25:342–347. 6. Pradel JA, Adell JF, Taourel P, et al. Acute colonic diverticulitis: prospective comparative evaluation with US and CT. Radiology. 1997;205:503–512. 7. Nielsen K, Richir MC, Stolk TT, et al. The limited role of ultrasound in the diagnostic process of colonic diverticulitis. World J Surg. 2014;38: 1814–1818. 8. Sallinen V, Mentula P, Leppa¨niemi A. Risk of colon cancer after computed tomography-diagnosed acute diverticulitis: is routine colonoscopy necessary? Surg Endosc. 2014;28:961–966. 9. Brar MS, Roxin G, Yaffe PB, et al. Colonoscopy following nonoperative management of uncomplicated diverticulitis may not be warranted. Dis Colon Rectum. 2013;56:1259–1264.
Disclosure: The authors declare there are no conflicts of interest. Copyright ß 2015 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0003-4932/14/26105-0821 DOI: 10.1097/SLA.0000000000000995
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Annals of Surgery Volume 262, Number 6, December 2015
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.