Background

Lower gastrointestinal bleeding can be caused by colonic diverticular bleeding, ischemic enteritis, and anorectal lesions such as hemorrhoids, tumors, and inflammatory bowel disease, but the appendix is very rarely the source of bleeding. We describe a case of emergency laparoscopic appendectomy performed in a patient diagnosed as having appendiceal bleeding by lower gastrointestinal endoscopy.

Case presentation

A 71-year-old man with no specific medical history had constipation for 3 days, and bloody stools containing blood clots were observed one day before he visited the hospital. He continued to have bloody stools the next morning, so he visited our hospital. Abdominal findings were normal. Blood tests showed a hemoglobin of 10.5 g/dL and progressive anemia. Lower gastrointestinal endoscopy was performed because a rectal examination revealed the presence of fresh bloody stools with clots. The endoscopic examination revealed fresh blood from the anus to the cecum and active bleeding from the appendiceal orifice (Fig. 1). Hemostatic clips were used to stop the bleeding, but as hemostasis could not be achieved, we decided to perform an appendectomy. A plain CT scan performed before the endoscopic examination showed no significant findings, and the appendix was not swollen (Fig. 2).

Fig. 1
figure 1

Explanation of the lower gastrointestinal findings. Bleeding is observed from the orifice of the appendix

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Fig. 2
figure 2

Histopathological examination findings. An appendiceal diverticulum is present, but no obvious source of bleeding can be identified. An artery was found near the appendiceal diverticulum, and it was determined to be the likely cause of the appendiceal diverticulum bleeding

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Surgery was performed laparoscopically. The operation time was 36 min and blood loss was minimal. The appendix was normal with no enlargement. Because the clip used for hemostasis was located at the base of the appendix, an appendectomy was performed using an automatic suturing device to partially resect the cecum, taking care not to entrap the clip. The patient had a good postoperative course and was discharged on the third postoperative day.

Histopathological examination showed no inflammatory cell infiltration in the appendix. A diverticulum was observed in the appendix, but there was no vascular malformation or disruption, and the source of the bleeding could not be identified. An artery ran in close proximity to the appendiceal diverticulum, and we determined that appendiceal diverticular bleeding was the most likely cause of the appendiceal bleeding.

Discussion

There are many causes of lower gastrointestinal bleeding, including tumors, inflammatory bowel disease, infectious bowel disease, ischemic enteritis, and other blood flow disorders, but the responsible site is very rarely the appendix. The appendix is reported to be responsible for 0.4% of all lower gastrointestinal bleeding [1]. In this case, the cause of the appendiceal bleeding was not clear from the histopathological results, but an artery ran in close proximity to the appendiceal diverticulum, suggesting that the cause was appendiceal diverticular bleeding. Appendiceal diverticulum was first described by Kelynack in 1893 [2], and Lim et al. reported that 1.74% of patients who underwent appendectomy had an appendiceal diverticulum [3]. Appendiceal diverticulum is classified into true diverticulum, which has a full-layered structure, and pseudodiverticulum, which lacks the intrinsic muscular layer. True diverticula are thought to be related to deformity due to the duplication of the appendix, a remnant of the yolk duct, or adhesions [4], but they occur congenitally and the details of their cause have not yet been clarified. Pseudodiverticula are thought to be formed by increased appendiceal luminal pressure, and pseudodiverticula account for more than 95% of all diverticula [5]. Therefore, the perforation rate is high in appendiceal diverticulitis, and complicated appendicitis often follows. A search on PubMed revealed a few cases of appendiceal hemorrhage caused by an appendiceal diverticulum [6,7,8], but nine cases have been reported in Japan, including the present case (Table 1). The median patient age was 62.7 years. All patients were male, which may be due in part to the fact that the male-to-female ratio of appendiceal diverticulum is 1.8:1 [3], indicating that the incidence is higher in males.

Table 1 Cases of appendiceal bleeding reported in Japan
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We found 36 cases of appendiceal bleeding reported in Japan [9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41], including the present case. The causes were the aforementioned appendiceal diverticulum in 9 cases (25%), ulcer in 5 cases (13.9%), appendiceal tumor in 2 cases (5.6%), angiodysplasia in 2 cases (5.6%), appendicitis in 2 cases (5.6%), and dietary appendiceal tear, aneurysm, ectopic endometriosis, and ulcerative colitis in 1 case (2.7%) each. The cause of appendiceal bleeding in the remaining 12 cases was unknown. As initial treatment, 29 patients underwent surgical appendectomy, 6 patients underwent endoscopic hemostasis [14, 19, 25, 29, 31, 40], and 1 patient underwent interventional radiology to confirm hemostasis. However, 2 of the 6 patients who underwent endoscopic hemostasis required emergency surgery due to rebleeding [19, 25]. As in the present case, the presence of the hemostatic clip at the base of the appendix forced the area of resection to be expanded to resect a portion of the cecum. Even if hemostasis is achieved with a clip, appendicitis may occur due to obstruction of the appendiceal orifice. Similarly, the possibility of appendicitis is increased when hemostasis is obtained by injecting contrast media such as barium. Therefore, surgical appendectomy should be the first-line treatment for appendiceal bleeding. There is insufficient evidence regarding the use of barium filling for hemostasis of diverticular hemorrhage, and because of the risk of perforation, it is preferable not to use this technique. The Japanese Guideline for Colonic Diverticular Bleeding [42] does not recommend barium filling for the purpose of hemostasis for diverticular bleeding.

Interventional radiology is also a treatment option, but there have been reports of rebleeding [12], and even when hemostasis is achieved, it is desirable to perform appendectomy as soon as possible.

Conclusion

We report a case of laparoscopic appendectomy for appendiceal bleeding, which should be treated with surgical resection as soon as possible.