Where can you find the tip of the appendix? - the anatomical variants and their clinical implications.

Transcription

1 Where can you find the tip of the appendix? - the anatomical variants and their clinical implications. Poster No.: C-0832 Congress: ECR 2018 Type: Educational Exhibit Authors: A. Zacharzewska-Gondek, A. A. Szczurowska, M. Guzi#ski, M. S#siadek, J. Bladowska; Wroc#aw/PL Keywords: Education and training, Education, CT, Gastrointestinal tract, Anatomy, Abdomen DOI: /ecr2018/C-0832 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 18

2 Learning objectives The learning objectives are: - to present a classification of the positions of the vermiform appendix, - to display the atypical locations of the tip of the appendix found on CT scans, - to describe possible misdiagnosis of appendicitis occurring in these locations. Page 2 of 18

3 Background The vermiform appendix has no constant position and is believed to be the most variable abdominal organ [1-3]. Unlike the base of the appendix which location is usually in the posteromedial aspect of the ceacum (about 2 cm under the ileocecal valve, in the confluence of three taenias) [4], the tip can be found in different areas due to variable length of the appendix. There are several classifications of the appendix positions in the relationship to the ceacum. Figure 1 shows a draft based on a few classifications described in the literature, there are the following positions distinguished[1,2,5]: - retrocaecal (or retrocolic when long) - appendix situated posteriorly and superiorly to the ceacum or ascending colon, - paracaecal - appendix located laterally to the ceacum and ascending colon, - subcaecal - under the ceacum, - pelvic - appendix directed inferiorly, 'pointing' the pelvis, - pre-ileal and post-ileal - located anteriorly and superiorly or posteriorly and superiorly to the ileum. The most common location of the appendix is still a controversial issue - in some studies conducted on cadavers or at laparoscopy the retrocaecal [1,2,5] or pelvic [3,6] position are the most frequent findings. It has been suggested that the location of the vermiform appendix could depend on age, gender, race or other demographic factors [1,3,6]. The length of the vermiform appendix usually ranges between 1.5cm and 25cm, with average length about 9cm[2,3,7]. A typical appendicitis presents clinically with pain in the right lower abdominal quadrant, however in case of a long appendix in an atypical location the symptoms of appendicitis occur in a different regions of the abdomen and may lead to the wrong diagnosis[3]. Page 3 of 18

4 Images for this section: Fig. 1: This picture shows a draft based on a few classifications of the positions of the vermiform appendix described in the literature[1,2,5] [1,2,5] Page 4 of 18

5 Findings and procedure details At first it is necessary to assess the localization of the ceacum. In order to find the vermiform appendix the area of the ceacum should be examined precisely. An unchanged appendix on a CT scan usually has a thin wall and possibly air in the lumen, its outer diameter is less than 6mm. (Fig.2.) We present the most unusual locations of the tip of the long appendix or normal appendix in case of atypically located caecum found by chance on CT in patients examined for other reasons in our department. One of our patients had the midgut malrotation with left-sided caecum and two patients had situs inversus - in these situations the appendix was located in the left inferior abdominal quadrant in pelvic position (Fig.3 and 4). In a few patients with long retrocaecal and consequently retrocolic appendix or in patients with a high position of the caecum the appendiceal tip was found subhepatically along the lower edge of the liver and/or next to the right kidney (Fig.5, 6 and 7). The tip of the long appendix may also be visualized next to descending part of the duodenum (Fig.8) or even horizontal part of duodenum (Fig.9.). Sometimes a long pelvic appendix may cross the right ureter (Fig.10.). The tip of the appendix can also be found in the midline inferiorly and in front of the aortic bifurcation (Fig.11.). The long pelvic located appendix may achieve the wall of the rectum (Fig. 12 and 13) or may encompass the appendages (Fig. 14). In case of a long pelvic appendix there is also a possibility to find the appendix in the scrotum as the content of an inguinal hernia (Fig.15.) Page 5 of 18

6 Images for this section: Fig. 2: Radiological features of normal vermiform appendix on computed tomography examination in two patients -thin wall and possibly air in the lumen (circle, left image), outer diameter less than 6mm (arrows, right image) Page 6 of 18

7 Fig. 3: Coronal CT reformation and axial CT scan of a patient with situs inversus and acute pancreatitis (fluid - triangle). The liver (star) and ceacum with the vermiform appendix (arrow) are located on the left side. The appendix is in a subcaecal position with normal length about 6.2cm. Fig. 4: Axial CT scan and sagittal CT reformation of a patient with midgut malrotation jejunum (star) is visualised on the right side, the caecum with the vermiform appendix (arrow) is located on the left side. The base of the appendix is visible atypically posterolaterally, length of the appendix about 8.5cm Page 7 of 18

8 Fig. 5: Axial CT scan and coronal CT reformation show an about 12.7cm long retrocolic appendix which is located next to the lateral aspect of the right kidney (circle) and near to the lower edge of the liver (arrows). The caecum in this patient was situated in normal position (not shown). Fig. 6: Coronal and sagittal CT reformations of a patient with a high position of the ceacum (star) and a 9.5cm long vermiform appendix (arrow) located along the lower edge of the liver, next to the right kidney (circle) and the descending part of the duodenum (triangle) Page 8 of 18

9 Fig. 7: Axial CT scan and sagittal CT reformation of a patient with a high position of the ceacum (star) and an about 13.8cm long vermiform appendix (arrow) located near to the lower edge of the liver and the right kidney (circle) Fig. 8: Sagittal and coronal CT reformations of a patient with a long (about 13.8cm), post-ileal situated, filled with barium vermiform appendix (circle), located medially and Page 9 of 18

10 anteriorly to the right kidney and its tip (arrow) achieves the descending part of the duodenum (star). Fig. 9: Coronal CT reformation and axial CT scan of a patient with a 11.1cm long postileal situated vermiform appendix, which distal part is located medially in mesogastric area and the tip (arrow) touches the wall of the horizontal part of the duodenum (star). Page 10 of 18

11 Fig. 10: Axial CT scan and sagittal CT reformation in the late phase of a patient with a 15 cm long, pelvic situated vermiform appendix (red arrow) which crosses the right urether (blue arrow) Fig. 11: Axial CT scan and coronal CT reformation of a patient with a 8.2cm long pelvic situated vermiform appendix which tip (arrows) is located in the midline beneath of the aortic bifurcation (star). Page 11 of 18

12 Fig. 12: Axial CT scan and coronal CT reformation of a patient with caecum located low in the pelvis (not shown) and with a 8,5cm long post-ileal vermiform appendix (arrow), which tip is situated next to the wall of the rectum (star). Page 12 of 18

13 Fig. 13: Axial scan and sagittal reformation of a patient with a short (about 6.4cm) vermiform appendix (arrow) in retrocaecal position which tip is located next to the wall of the rectum (star) Page 13 of 18

14 Fig. 14: Axial scan and coronal reformation of a 68-year-old woman with a 8.1cm long pelvic vermiform appendix (arrows), which distal part is located near to the right appendages and the right aspect of uterus (star) Fig. 15: Sagittal CT reformation and axial CT scan of a patient with a very long (at least 16.7cm, partially out of the scope of the examination) pelvic vermiform appendix as a content of a inguinal hernia. Page 14 of 18

15 Conclusion Variations in the position of the vermiform appendix are usually related to a complicated and changeable embryonic development of the ceacum [8-10] and/or to the variable length of the appendix [11,12]. It is important to be aware of variations of the vermiform appendix because the atypically situated inflamed appendix may produce symptoms mimicking other surgical and non-surgical acute abdominal diseases [2,13]. Moreover, a delay in final diagnosis of appendicitis may lead to complications incl. perforation, abscess and peritonitis [6]. Left-sided appendicitis in patients with midgut malrotation or situs inversus may be misinterpreted as acute diverticulitis [14]. Subhepatically located appendicitis can be clinically indistinguishable from cholecystitis, liver abscess, right renal colic or pyelonephritis [8, 9, 11, 15-18]. Inflammation of the tip of the appendix situated near to the wall of the duodenum may produce symptoms of duedenitis or duodenal ulcer. A long appendix crossing the right urether can cause hydronephrosis with renal colic symptoms due to inflammation or the development of an abscess [19, 20]. When the tip of appendix is situated in the midline an appendicitis may mimic enteritis [21]. Sometimes a long pelvic vermiform appendix is found in the contents of a scrotal hernia, therefore in case of appendicitis it may produce symptoms similar to orchitis or tortion of the testis [22, 23]. The multidetector computed tomography is a very useful and precise tool in the assessment of a normal appendix and its variations in terms of the length and positions [24-27]. CT allows to diagnose appendicitis in setting of atypical clinical presentation [18,28]. The awareness of atypical symptoms of appendicitis that result from its variable length and location of its tip may help to avoid the misdiagnosis and minimize the delay in applying the proper treatment. Page 15 of 18

16 References [1] J. O. Philip Mwachaka, Hemed El-busaidy, Simeon Sinkeet, "Variations in the Position and Length of the Vermiform Appendix in a Black Kenyan Population," ISRN Anat., vol. 2014, pp. 1-5, [2] S. Cilindro de Souza, S. R. M. Rodrigues da Costa, and G. I. Silva de Souza, "Vermiform appendix: positions and length - a study of 377 cases and literature review," J. Coloproctology, vol. 35, no. 4, pp , [3] I. Ahmed, K. S. Asgeirsson, I. J. Beckingham, and D. N. Lobo, "The position of the vermiform appendix at laparoscopy," Surg. Radiol. Anat., vol. 29, no. 2, pp , [4] Schumpelick V, Dreuw B, Ophoff K, Prescher A. Appendix and cecum. Embryology, anatomy, and surgical applications. Surg Clin North Am Feb;80(1): Review [5] C. P. G. Wakeley, "The Position of the Vermiform Appendix as Ascertained by an Analysis of 10,000 Cases," J. Anat., vol. 67, no. Pt 2, pp , [6] A. Ghorbani, M. Forouzesh, and A. M. Kazemifar, "Variation in Anatomical Position of Vermiform Appendix among Iranian Population: An Old Issue Which Has Not Lost Its Importance.," Anat. Res. Int., vol. 2014, p , [7] D. C. Collins, "The Length and Position of the Vermiform Appendix: A Study of 4,680 Specimens.," Ann. Surg., vol. 96, no. 6, pp , [8] W. R. Ball and A. Privitera, "Subhepatic appendicitis: A diagnostic dilemma," BMJ Case Rep., pp. 1-2, [9] J. Y. S. Ting and R. Farley, "Subhepatically located appendicitis due to adhesions: A case report," J. Med. Case Rep., vol. 2, pp. 1-3, [10] S. B. Nayak, B. M. George, S. Mishra, S. Surendran, P. Shetty, and S. D. Shetty, "Sessile ileum, subhepatic cecum, and uncinate appendix that might lead to a diagnostic dilemma," Anat. Cell Biol., vol. 46, no. 4, pp , [11] A. Alzaraa and S. Chaudhry, "An unusually long appendix in a child: a case report.," Cases J., vol. 2, p. 7398, [12] R. Ahmed Malik, S. Hussain Mir, I. Feroz, M. Yasir, K. M. Baba, and K. Alam, "An unusual case report - longest appendix in India (20.5 cm)," Oncol. Gastroenterol. Hepatol. Reports, vol. 2, no. 1, pp , Page 16 of 18

17 [13] I. Wani, "K-sign in retrocaecal appendicitis: A case series," Cases J., vol. 2, no. 10, pp. 1-3, [14] E. Ça#lar, B. Ariba#, R. Tiken, and S. Keskin, "Midgut malrotation presenting with leftsided acute appendicitis and CT inversion sign," BMJ Case Rep., pp , [15] H. C. Chong et al., "Malrotated Subhepatic Caecum with Subhepatic Appendicitis Diagnosis and Management," vol. 2016, pp. 3-5, [16] G. Rodrigues, "Subhepatic appendicitis masquerading as acute cholecystitis#: a lesson learnt#!," ANZ J. Surg., vol. 87, no. 11, pp. E208-E209, [17] E. M. W. Ong and S. K. Venkatesh, "Ascending retrocecal appendicitis presenting with right upper abdominal pain: Utility of computed tomography," World J. Gastroenterol., vol. 15, no. 28, pp , [18] A. M. Abougabal, A. Hafez, and M. I. Kasem, "Role of multidetector computed tomography ( MDCT ) in diagnosis of subhepatic appendicitis," Egypt. J. Radiol. Nucl. Med., vol. 43, no. 3, pp , [19] S. K. Okur, Y. S. Koca, #. Y#ld#z, and #. Barut, "Right Hydronephrosis as a Complication of Acute Appendicitis.," Case Rep. Emerg. Med., vol. 2016, p , [20] R. Moncada, D. Wasserman, and R. Freeark, "Hydronephrosis Secondary to Acute Appendicitis in Children," vol. 124, pp , [21] A. R. Azandaryani, M. Eftekharian, M. Mousavi, and L. Ebrahimi, "Huge Atypical Appendicitis in a 14-Year-Old Male: A Case Report," Case Reports Clin. Med., vol. 5, no. 11, pp , [22] S. Shumon, J. Bennett, G. Lawson, and P. Small, "Suppurative appendicitis presenting as acute scrotum confounded by a testicular appendage.," J. Surg. case reports, vol. 2016, no. 3, pp. 1-3, [23] Sharma SB, Gupta V. Acute appendicitis presenting as acute hemiscrotum in a boy. Indian J Gastroenterol Jul-Aug;23(4):150.] [24] H. Turkoglu, M. R. Onur, A. K. Poyraz, and E. Kocakoc, "Evaluation of normal appendix vermiformis in adults with multidetector computed tomography," Clin. Imaging, vol. 36, no. 6, pp , [25] S. Suwal, S. Karki, D. Mandal, and P. Rc, "Multi-Detector Computed Tomography Evaluation of Normal Appendix," vol. 14, no. 4, [26] A. Ma, M. Kumar, and K. Subedi, "Original article Visualization of Normal Appendix in Multidetector Computed Tomography Percent-," Page 17 of 18

18 [27] P. J. Pickhardt, J. Suhonen, E. M. Lawrence, A. Muñoz Del Rio, and B. D. Pooler, "Appendiceal length as an independent risk factor for acute appendicitis," Eur. Radiol., vol. 23, no. 12, pp , [28] D. Mandich, E. M. Chamorro, G. Ayala, V. Rueda, and S. B. Nacenta, "Diagnostic challenges in acute appendicitis#: atypical presentation and pitfalls," E. Exhibit, ECR Page 18 of 18