Negative appendectomy rate in the era of computed tomography
DOI:
https://doi.org/10.18203/2349-2902.isj20261985Keywords:
Acute appendicitis, Negative appendectomy, Computed tomography, Diagnostic imagingAbstract
Background: Acute appendicitis remains a diagnostic challenge. Historically, a negative appendectomy rate (NAR) of up to 20% was considered acceptable to avoid missed diagnoses. With increasing use of computed tomography (CT), the impact of routine preoperative imaging on NAR warrants further evaluation. This study assessed the negative appendectomy rate among patients undergoing preoperative CT and evaluated its diagnostic contribution.
Methods: A retrospective study was conducted including all adult patients who underwent emergency open or laparoscopic appendectomy between January 2023 and April 2025 at King Fahad Hospital Hofuf, Kingdom of Saudi Arabia. Demographic data, preoperative CT findings, inflammatory markers, operative findings, and histopathological results were reviewed. Statistical analysis was performed using statistical package for the social sciences (SPSS) version 24.
Results: A total of 386 patients were included (62.2% male), with a mean age of 29 years. All patients underwent preoperative CT imaging. A normal appendix was identified intraoperatively in five patients (1.4%). Histopathological examination revealed catarrhal appendicitis in 66%, suppurative appendicitis in 18.7%, perforated or phlegmonous appendicitis in 13%, gangrenous appendicitis in 0.6%, and normal appendix in 1.4%. One case of appendiceal carcinoid tumor was identified. Normal leukocyte counts were present in 16.6% of patients.
Conclusions: Routine preoperative CT imaging was associated with a very low negative appendectomy rate. These findings support the role of CT in reducing unnecessary appendectomies.
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References
Ferris M, Quan S, Kaplan BS, Molodecky N, Ball CG, Chernoff GW, et al. The Global Incidence of Appendicitis: A Systematic Review of Population-based Studies. Ann Surg. 2017;266(2):237-41. DOI: https://doi.org/10.1097/SLA.0000000000002188
Hendriks IG, Langen RM, Janssen L, Verrijth-Wilms IM, Wouda S, Janzing HM. Does the Use of Diagnostic Imaging Reduce the Rate of Negative Appendectomy? Acta Chir Belg. 2015;115(6):393-6. DOI: https://doi.org/10.1080/00015458.2015.11681139
Baird DLH, Simillis C, Kontovounisios C, Rasheed S, Tekkis PP. Acute appendicitis. BMJ. 2017;357(312):1703. DOI: https://doi.org/10.1136/bmj.j1703
Humes DJ, Simpson J. Acute appendicitis. BMJ. 2006;333(7567):530-4. DOI: https://doi.org/10.1136/bmj.38940.664363.AE
Ohle R, O’Reilly F, O’Brien KK, Fahey T, Dimitrov BD. The Alvarado score for predicting acute appendicitis: A systematic review. BMC Med. 2011;9(3):139. DOI: https://doi.org/10.1186/1741-7015-9-139
Vadeboncoeur TF, Heister RR, Behling CA, Guss DA. Impact of helical computed tomography on the rate of negative appendicitis. Am J Emerg Med. 2006; 24(6):43-7.
Frei SP, Bond WF, Bazuro RK, Richardson DM, Sierzega GM, Reed JF. Appendicitis outcomes with increasing computed tomographic scanning. Am J Emerg Med. 2008;26(1):39-44. DOI: https://doi.org/10.1016/j.ajem.2007.06.027
McGory ML, Zingmond DS, Nanayakkara D, Maggard MA, Ko CY. Negative appendectomy rate: influence of CT scans. Am Surg. 2005;71(10):803-8. DOI: https://doi.org/10.1177/000313480507101001
Eng KA, Abadeh A, Ligocki C, Lee YK, Moineddin R, Adams-Webber T, et al. Acute Appendicitis: A Meta-Analysis of the Diagnostic Accuracy of US, CT, and MRI as Second-Line Imaging Tests after an Initial US. Radiology. 2018;288(3):717-27. DOI: https://doi.org/10.1148/radiol.2018180318
Drake FT, Florence MG, Johnson MG, Jurkovich GJ, Kwon S, Schmidt Z, et al. Progress in the diagnosis of appendicitis: a report from Washington State's Surgical Care and Outcomes Assessment Program. Ann Surg. 2012;256(4):586-94. DOI: https://doi.org/10.1097/SLA.0b013e31826a9602
Chooi WK, Brown JA, Zetler P, Wiseman S, Cooperberg P. Imaging of acute appendicitis and its impact on negative appendectomy and perforation rates: the St. Paul's experience. Can Assoc Radiol J. 2007;58(4):220-4.
D'Souza N, Marsden M, Bottomley S, Nagarajah N, Scutt F, Toh S. Cost-effectiveness of routine imaging of suspected appendicitis. Ann R Coll Surg Engl. 2018;100(1):47-51. DOI: https://doi.org/10.1308/rcsann.2017.0132
Lahaye MJ, Lambregts DM, Mutsaers E, Essers BA, Breukink S, Cappendijk VC, et al. Mandatory imaging cuts costs and reduces the rate of unnecessary surgeries in the diagnostic work-up of patients suspected of having appendicitis. Eur Radiol. 2015;25(5):1464-70. DOI: https://doi.org/10.1007/s00330-014-3531-0
Lehtimäki TT, Valtonen H, Miettinen P, Juvonen P, Paajanen H, Vanninen R. A randomised clinical trial of routine versus selective CT imaging in acute abdomen: Impact of patient age on treatment costs and hospital resource use. Eur J Radiol. 2017;87:1-7. DOI: https://doi.org/10.1016/j.ejrad.2016.11.031
SCOAP Collaborative; Cuschieri J, Florence M, Flum DR, Jurkovich GJ, et al. Negative appendectomy and imaging accuracy in the Washington State Surgical Care and Outcomes Assessment Program. Ann Surg. 2008;248(4):557-63. DOI: https://doi.org/10.1097/SLA.0b013e318187aeca
Raja AS, Wright C, Sodickson AD, Zane RD, Schiff GD, Hanson R, et al. Negative appendectomy rate in the era of CT: an 18-year perspective. Radiology. 2010;256(2):460-5. DOI: https://doi.org/10.1148/radiol.10091570
Coursey CA, Nelson RC, Patel MB, Cochran C, Dodd LG, Delong DM, et al. Making the diagnosis of acute appendicitis: do more preoperative CT scans mean fewer negative appendectomies? A 10-year study. Radiology. 2010;254(2):460-8. DOI: https://doi.org/10.1148/radiol.09082298
Doria AS, Moineddin R, Kellenberger CJ, Epelman M, Beyene J, Schuh S, et al. US or CT for Diagnosis of Appendicitis in Children and Adults? A Meta-Analysis. Radiology. 2006;241(1):83-94.
Lee SL, Walsh AJ, Ho HS. Computed tomography and ultrasonography do not improve and may delay the diagnosis and treatment of acute appendicitis. Arch Surg. 2001;136(3):556-62. DOI: https://doi.org/10.1001/archsurg.136.5.556
Flum DR, Morris A, Koepsell T, Dellinger EP. Has misdiagnosis of appendicitis decreased over time? A population-based analysis. JAMA. 2001;286(14):1748-53. DOI: https://doi.org/10.1001/jama.286.14.1748
Jose P, James E, Tyr OW, Dana J, Philip RC. Liberal use of computed tomography does not improve diagnostic accuracy in appendicitis. Am J Surg. 2003;185(3):194-7. DOI: https://doi.org/10.1016/S0002-9610(02)01364-8
Doria AS, Moineddin R, Kellenberger CJ, Epelman M, Beyene J, Schuh S, et al. US or CT for Diagnosis of Appendicitis in Children and Adults? A Meta-Analysis. Radiology. 2006;241(1):83-94. DOI: https://doi.org/10.1148/radiol.2411050913
Martin AE, Vollman D, Adler B, Caniano DA. CT scans may not reduce the negative appendectomy rate in children. J Ped Surg. 2004;39(2):886-90. DOI: https://doi.org/10.1016/j.jpedsurg.2004.02.034
Schuler JG, Shortsleeve MJ, Goldenson RS, Perez-Rossello JM, Perlmutter RA, Thorsen A. Is there a role for abdominal computed tomographic scans in appendicitis? Arch Surg. 1998;133(4):373-6. DOI: https://doi.org/10.1001/archsurg.133.4.373
Alfraih Y, Postuma R, Keijzer R. How do you diagnose appendicitis? An international evaluation of methods. Int J Surg. 2014;12(5):67-70. DOI: https://doi.org/10.1016/j.ijsu.2013.10.010
Keyzer C, Zalcman M, De Maertelaer V, Coppens E, Bali MA, Gevenois PA, et al. Comparison of US and unenhanced multi-detector row CT in patients suspected of having acute appendicitis. Radiology. 2005;236(2):527-34. DOI: https://doi.org/10.1148/radiol.2362040984
van Randen A, Bipat S, Zwinderman AH, Ubbink DT, Stoker J, Boermeester MA. Acute appendicitis: meta-analysis of diagnostic performance of CT and graded compression US related to prevalence of disease. Radiology. 2008;249(1):97-106. DOI: https://doi.org/10.1148/radiol.2483071652
van Rossem CC, Bolmers MD, Schreinemacher MH, van Geloven AA, Bemelman WA. Snapshot Appendicitis Collaborative Study Group Prospective nationwide outcome audit of surgery for suspected acute appendicitis. Br J Surg. 2016;103(1):144-51. DOI: https://doi.org/10.1001/jamasurg.2015.4236
Tseng J, Cohen T, Melo N, Alban RF. Imaging utilization affects negative appendectomy rates in appendicitis: an ACS-NSQIP study. Am J Surg. 2019;217(3):1094-8. DOI: https://doi.org/10.1016/j.amjsurg.2018.12.072
Lukenaite B, Luksaite-Lukste R, Mikalauskas S, Samuilis A, Strupas K, Poškus T. Magnetic resonance imaging reduces the rate of unnecessary operations in pregnant patients with suspected acute appendicitis: a retrospective study. Ann Surg Treat Res. 2021;100(1):40-6. DOI: https://doi.org/10.4174/astr.2021.100.1.40
Drake FT, Flum DR. Improvement in the diagnosis of appendicitis. Adv Surg. 2013;47(4):299-328. DOI: https://doi.org/10.1016/j.yasu.2013.03.003
National Surgical Research Collaborative. Multicentre observational study of performance variation in provision and outcome of emergency appendicectomy. Br J Surg. 2013;100(9):1240-52. DOI: https://doi.org/10.1002/bjs.9201
Bakker OJ, Go PM, Puylaert JB, Kazemier G, Heij HA. Guideline on diagnosis and treatment of acute appendicitis: imaging prior to appendicectomy is recommended. Ned Tijdschr Geneeskd. 2010;154:A303.
McDonald GP, Pendarvis DP, Wilmoth R, Daley BJ. Influence of preoperative computed tomography on patients undergoing appendectomy. Am Surg. 2001;67(11):1017-21. DOI: https://doi.org/10.1177/000313480106701101
Sugiura K, Miyake H, Nagai H, Yoshioka Y, Shibata K, Asai S, et al. Chronological Changes in Appendiceal Pathology Among Patients Who Underwent Appendectomy for Suspected Acute Appendicitis. World J Surg. 2020;44(9):2965-73. DOI: https://doi.org/10.1007/s00268-020-05509-y
Yeh DD, Eid AI, Young KA, Wild J, Kaafarani HMA, Ray-Zack M, et al. Multicenter Study of the Treatment of Appendicitis in America: Acute, Perforated, and Gangrenous (MUSTANG), an EAST Multicenter Study. Ann Surg. 2021;273(3):548-56. DOI: https://doi.org/10.1097/SLA.0000000000003661
Vadeboncoeur TF, Heister RR, Behling CA, Guss DA. Impact of helical computed tomography on the rate of negative appendicitis. Am J Emerg Med. 2006;24(1):43-7. DOI: https://doi.org/10.1016/j.ajem.2005.07.011
Petrosyan M, Estrada J, Chan S, Somers S, Yacoub WN, Kelso RL, et al. CT scan in patients with suspected appendicitis: clinical implications for the acute care surgeon. Eur Surg Res. 2008;40(2):211-9. DOI: https://doi.org/10.1159/000110863
Morse BC, Roettger RH, Kalbaugh CA, Dawn WB, William BH. Abdominal CT scanning in reproductive-age women with right lower quadrant abdominal pain: does its use reduce negative appendectomy rates and healthcare costs? Am Surg. 2007;73(6):580-4. DOI: https://doi.org/10.1177/000313480707300609
Dayawansa NH, Segan JDS, Yao HHI, Chong HI, Sitzler PJ. Incidence of normal white cell count and C-reactive protein in adults with acute appendicitis. ANZ J Surg. 2018;88(6):539-43. DOI: https://doi.org/10.1111/ans.13760