1. Laparoscopic appendectomy When the unexpected unveils… Dr. Grace KY Hung Kwong Wah Hospital

2. Case scenario 60/M Right lower quadrant pain and fever Physical examination –Stable vitals with temperature 38.5C –Tenderness over right lower quadrant

3. Laparoscopic appendectomy offered…

5. Background Acute appendicitis –Lifetime risk ~ 7% 1 –One of the most commonly encountered emergency surgical condition –Peak incidence towards 30 years old

6. Background Pathology –Bacterial infection secondary to blockage of the lumen –Could be due to faecolith, caecal tumor, appendiceal tumor, enlargement of lymphoid aggregate, parasites

7. Background Clinical presentation –Typical presentation: fever, right lower quadrant pain, leukocytosis

8. Scenarios Negative appendectomy Appendiceal neoplasm (Intra- operative/histopathological)

9. Negative appendectomy Negative appendectomy rate: –15% - 25% 2,3,4 Female patient of reproductive age are at higher risk

10. Negative appendectomy pic

15. Differential diagnosis Gynecological problem Colonic diverticulitis Colitis, ileitis Meckels diverticulitis Inflammatory bowel disease Neoplasm (colonic, appendiceal) Perforated peptic ulcer Acute cholecystitis Mesenteric adenitis Others

16. Can pre-operative imaging help to decrease negative appendectomy rate?

17. Pre-operative CT scan Sensitivity 83-99% 5 Specificity 86-100% 5 Krajewski et al (Meta analysis) 6 NAR (CT): 8.7% NAR (no CT): 16.7% Use of CT was associated with a delay in time to surgery, yet the appendiceal perforation rates were unchanged

18. Depends on –Availability –Expertise in interpretation

19. CT criteria for infalmmed appendix 7 Diameter greater than 6mm Appendiceal wall thickness greater than 1mm Appendiceal gas Periappendiceal fat stranding Caecal arrow-head sign Caecal bar sign

20. CT scan of patient with acute appendicitis

21. Even with pre-operative CT scan the NAR is 8.7% Does pre-operative CT scan has a role? –Yes –Provides additional information for planning subsequent management

22. Differential diagnosis Gynecological problem Colonic diverticulitis Colitis, ileitis Meckels diverticulitis Inflammatory bowel disease Neoplasm (colonic, appendiceal) Perforated peptic ulcer Acute cholecystitis Mesenteric adenitis Others

23. Differential diagnosis Gynecological problem Colonic diverticulitis Colitis, ileitis Meckels diverticulitis Inflammatory bowel disease Neoplasm (colonic, appendiceal) Perforated peptic ulcer Acute cholecystitis Mesenteric adenitis Others

24. Periappendiceal abscess maybe drained percutaneously

25. Pre-operative USG Rander A et al 8 Mean sensitivity of USG: 78% Diagnostic accuracy inferior to CT Still plays a role in patients in whom radiation exposure is a concern (e.g. pregnant patients)

26. Sonographic findings in USG Compressed diameter greater than 6mm Brightly echogenic periappendiceal fat Periappendiceal fluid collection Hypervascularity on color Doppler

27. Scenarios Negative appendectomy Appendiceal neoplasm (Intra- operative/histopathological)

28. Tumor recognized at time of surgery Tumor <2cm Base and mesoappendix: clear Evidence of perforation Evidence of mucinous ascites Right hemicolectomy Appendectomy Appendectomy or, if not possible, tissue biopsy, cytology on mucus Peritoneal lavage Analysis of tumor markers (CEA, CA-125, CA 19.9) and CT abd + pelvis Colonoscopy Appendectomy or, if not possible, tissue biopsy, cytology on mucus Peritoneal lavage Analysis of tumor markers (CEA, CA-125, CA 19.9) and CT abd + pelvis Colonoscopy YES No

29. Appendiceal neoplasm Accounts for 1% of all GI malignancies 9 Usually present as acute appendicitis Incidental finding at operation/ on histopathological examination Carcinoid tumors are most common 10

30. Classification of appendiceal neoplasms 9 PrimarySecondary Epithelial Benign Hyperplastic polyp and diffuse mucosal hyperplasia Serrated adenoma Colonic type adenoma Malignant Low-grade mucinous neoplasms Adenocarcinoma/ High-grade mucinous neoplasms Non-epithelial Carcinoid tumors Classical carcinoid Globet cell carcinoids/adenocarcinoids Mesenchymal tumors Gastrointestinal stromal tumors Neuroma Leiomyoma/sarcoma Kaposi’s sarcoma Lymphoma Ovarian Colonic Melanoma

31. Carcinoid tumors Arise from neuroendocrine cells Usually located at the tip or distal third of the appendix Adverse prognostic feature: size >2cm, mesoappendiceal extension 11 Simple appendectomy for tumor less than 2cm and does not involve the resection margin or mesoappendix 12 Right hemicolectomy for tumor more than 2cm or when there is involvement of the base of the appendix or mesoappendix 12

32. Malignant epithelial lesions Range from low grade mucinous neoplasms to adenocarcinomas Prognosis depends on whether they have perforated and whether mucin and epithelial cells are present outside the appendix 13 May spread to peritoneal cavity, giving rise to pseudomyxoma peritonei Treatment: –Not perforated tumor not involving the mesoappendix/base: Appendectomy –Perforated tumor: complete cytoreduction with intraperitoneal chemotherapy

33. Synchronous appendiceal and colonic neoplasm Associates with a significant incidence of both synchronous and metachronous colorectal neoplasms. 14 10% of appendiceal carcinoid 50% of appendiceal malignant epithelial tumors Screening and surveillance colonoscopy should be advocated

34. Conclusion Laparoscopic appendectomy is one of the most commonly performed surgical procedure which carries a negative appendectomy rate of around 15%-25% Pre-operative CT scan could decrease the negative appendectomy rate and provide more information for better planning if available.

35. Conclusion Rarely, appendiceal neoplasms are found incidentally during operation/on histopathological examinations Tumor less than 2cm without involvement of the resection margin and mesoappendix can be treated by simple appendectomy Screening and surveillance colonoscopy should be performed for all patients with appendiceal neoplasm

36. Reference 1.Korner, H., J. A. Soreide, E. J. Pedersen, T. Bru, K. Sondenaa, and L. Vatten. "Stability in Incidence of Acute Appendicitis. A Population-Based Longitudinal Study." Dig Surg 18, no. 1 (2001): 61-6. 2.Flum, D. R., and T. Koepsell. "The Clinical and Economic Correlates of Misdiagnosed Appendicitis: Nationwide Analysis." Arch Surg 137, no. 7 (2002): 799-804; discussion 804. 3.Humes, D. J., and J. Simpson. "Acute Appendicitis." BMJ 333, no. 7567 (2006): 530-4. 4.Humes, D. J., and J. Simpson. "Acute Appendicitis." BMJ 333, no. 7567 (2006): 530-4. 5.Musunuru, S., H. Chen, L. F. Rikkers, and S. M. Weber. "Computed Tomography in the Diagnosis of Acute Appendicitis: Definitive or Detrimental?" J Gastrointest Surg 11, no. 11 (2007): 1417-21 6.Susan Krajewski, Jacqueline Brown, P. Terry Phang, Manoj Raval, Carl J. Brown. "Impact of Computed Tomography of the Abdomen on Clinical Outcomes in Patients with Acute Right Lower Quadrant Pain: A Meta-Analysis." Can J Surg 54, no. 1 (2011): 43-53. 7.Joshua D. Hawkins, Richard C. Thirlby. "The Accuracy and Role of Cross Sectional Imaging in the Diagnosis of Acute Appendicitis." Advances in Surgery 43, (2009): 13-22. 8.van Randen A, Bipat S, Zwinderman A. "Acute Appendicitis: Meta-Analysis Od Diagnostic Performance of Ct and Graded Compression Us Related to Prevalence of Disease." Radiology 249, no. 1 (2008): 97-106. 9.Murphy, E. M., S. M. Farquharson, and B. J. Moran. "Management of an Unexpected Appendiceal Neoplasm." Br J Surg 93, no. 7 (2006): 783-92. 10.Connor, S. J., G. B. Hanna, and F. A. Frizelle. "Appendiceal Tumors: Retrospective Clinicopathologic Analysis of Appendiceal Tumors from 7,970 Appendectomies." Dis Colon Rectum 41, no. 1 (1998): 75-80.

37. Reference 11. Connor, S. J., G. B. Hanna, and F. A. Frizelle. "Appendiceal Tumors: Retrospective Clinicopathologic Analysis of Appendiceal Tumors from 7,970 Appendectomies." Dis Colon Rectum 41, no. 1 (1998): 75-80. 12.Goede, A. C., M. E. Caplin, and M. C. Winslet. "Carcinoid Tumor of the Appendix." Br J Surg 90, no. 11 (2003): 1317-22. 13.Misdraji, J., R. K. Yantiss, F. M. Graeme-Cook, U. J. Balis, and R. H. Young. "Appendiceal Mucinous Neoplasms: A Clinicopathologic Analysis of 107 Cases." Am J Surg Pathol 27, no. 8 (2003): 1089-103. 14.Fujiwara, T., A. Hizuta, H. Iwagaki, T. Matsuno, M. Hamada, N. Tanaka, and K. Orita. "Appendiceal Mucocele with Concomitant Colonic Cancer. Report of Two Cases." Dis Colon Rectum 39, no. 2 (1996): 232-6.

38. Thank you