Acute Abdominal Pain Presenting as Appendiceal Duplication
Acute Abdominal Pain Presenting as Appendiceal Duplication
There have been two classification systems proposed to categorize appendiceal duplication. The first classification system was described by Waugh in 1941 and consisted of three categories. The first category described appendiceal duplication where both appendices originated from one cecum. The appendiceal lumens were juxtaposed to each other, with submucosal fibrous communication arising at various lengths from the cecal base. The second type of duplication was depicted by two appendices, located on two distinct and polar sides of the ileocecal valve. The last category described one appendix arising from the normal anatomical point with a second appendix originating from a distal point along the tenia.
A second system to categorize appendiceal duplication was introduced in 1963 by Wallbridge, which interestingly also consisted of three classifications. Type A described two appendices arising from one cecum, with one appendix smaller and shorter than its counterpart, appropriately classified as a partial appendix. Type B described two complete appendices, each stemming from a single cecum. This category was further subdivided into B1 and B2. B1 depicted the two appendices arising from either side of the cecum, approximately 180 degrees apart, at a fixed anatomical point. B2 described one appendix arising from the cecum and the second appendix originating from the tenia, distal from the cecum. Type C was used to categorize two appendices, along with two cecums, one appendix arising from each respective cecum, although this category is exceedingly rare.
It is important to distinguish appendiceal duplication from other differential diagnoses of bowel etiology. Ultrasound is often used to diagnose or visualize the appendix; however, should the ultrasound be negative and the index of suspicion remain high, for acute appendicitis, we recommend computed tomography of the abdomen and pelvis with oral and intravenous contrast. Barium enemas have been used to diagnose appendiceal duplication; however, we do not recommend this-particularly as there is a risk of perforation in the presence of potential appendiceal inflammation and subsequent complicated peritonitis. The diagnosis of appendiceal duplication can be confirmed with pathological and histological examination. The presence of lymphoid tissue within the wall of the appendix does differentiate it from bowel diverticulum. Although the disease is associated with several abnormalities, it is not pathognomonic to a specific disorder. Skeletal surveys, bone biopsies or investigation of the genitourinary system do not supercede prompt evaluation of the appendix.
Management of acute appendicitis, in the clinical scenario of appendiceal duplication, warrants complete appendectomy. Obviously this has to be performed for Waugh type1 duplication and for Wallbridge (later renamed Cave-Wallbridge) Type A; however, we advocate this for all symptomatic cases of acute appendicitis with appendiceal duplication, irrespective of only single appendiceal inflammation. Our patient did not have any evidence of inflammatory changes; hence she was discharged without operative intervention with a working diagnosis of bowel gas pain versus gynecological physiologic pain.
Appendiceal duplication found incidentally when operating for other abdominal pathology does not immediately warrant a complete appendectomy. In the setting of an acute inflammatory disease, such as Crohn's disease, an appendectomy should not be performed.
Discussion
There have been two classification systems proposed to categorize appendiceal duplication. The first classification system was described by Waugh in 1941 and consisted of three categories. The first category described appendiceal duplication where both appendices originated from one cecum. The appendiceal lumens were juxtaposed to each other, with submucosal fibrous communication arising at various lengths from the cecal base. The second type of duplication was depicted by two appendices, located on two distinct and polar sides of the ileocecal valve. The last category described one appendix arising from the normal anatomical point with a second appendix originating from a distal point along the tenia.
A second system to categorize appendiceal duplication was introduced in 1963 by Wallbridge, which interestingly also consisted of three classifications. Type A described two appendices arising from one cecum, with one appendix smaller and shorter than its counterpart, appropriately classified as a partial appendix. Type B described two complete appendices, each stemming from a single cecum. This category was further subdivided into B1 and B2. B1 depicted the two appendices arising from either side of the cecum, approximately 180 degrees apart, at a fixed anatomical point. B2 described one appendix arising from the cecum and the second appendix originating from the tenia, distal from the cecum. Type C was used to categorize two appendices, along with two cecums, one appendix arising from each respective cecum, although this category is exceedingly rare.
It is important to distinguish appendiceal duplication from other differential diagnoses of bowel etiology. Ultrasound is often used to diagnose or visualize the appendix; however, should the ultrasound be negative and the index of suspicion remain high, for acute appendicitis, we recommend computed tomography of the abdomen and pelvis with oral and intravenous contrast. Barium enemas have been used to diagnose appendiceal duplication; however, we do not recommend this-particularly as there is a risk of perforation in the presence of potential appendiceal inflammation and subsequent complicated peritonitis. The diagnosis of appendiceal duplication can be confirmed with pathological and histological examination. The presence of lymphoid tissue within the wall of the appendix does differentiate it from bowel diverticulum. Although the disease is associated with several abnormalities, it is not pathognomonic to a specific disorder. Skeletal surveys, bone biopsies or investigation of the genitourinary system do not supercede prompt evaluation of the appendix.
Management of acute appendicitis, in the clinical scenario of appendiceal duplication, warrants complete appendectomy. Obviously this has to be performed for Waugh type1 duplication and for Wallbridge (later renamed Cave-Wallbridge) Type A; however, we advocate this for all symptomatic cases of acute appendicitis with appendiceal duplication, irrespective of only single appendiceal inflammation. Our patient did not have any evidence of inflammatory changes; hence she was discharged without operative intervention with a working diagnosis of bowel gas pain versus gynecological physiologic pain.
Appendiceal duplication found incidentally when operating for other abdominal pathology does not immediately warrant a complete appendectomy. In the setting of an acute inflammatory disease, such as Crohn's disease, an appendectomy should not be performed.
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