Discussion
Duodenal diverticula are found in 5–10% of patients undergoing radiological or endoscopic procedures and in 15–23% of patients at autopsy 1. The duodenum is the most common site for gastrointestinal diverticula after the colon, especially in the parapapillary region of Vater and the horizontal and ascending portions of the duodenum 4, 5. Unlike colon diverticulum, duodenal diverticulum is relatively asymptomatic. However, the risk of perforation should be kept in mind 6. Most of these perforations were seen within the second portion of the duodenum, mainly along the medial wall, within 2 cm of the ampulla of Vater. Duodenal diverticulitis was the most common cause of DDP, representing 69% of total associated cases 7. As perforation often occurs in the retroperitoneum, typical signs of peritonitis are often absent. Due to the lack of pathognomonic signs or symptoms, DDP is often clinically mistaken for acute cholecystitis, appendicitis, and perforated duodenal or gastric ulcers. Shimada et al. evaluated all 202 cases of DDP reported worldwide between 1907 and 2020. A total of 83% of all reported cases underwent surgical treatment 8. Simple closure of the perforated site is anatomically difficult when a duodenal diverticulum perforates the retroperitoneum. A pancreaticoduodenectomy must be performed to resect the duodenum that has the perforated site. However, this treatment appears to be highly invasive. Indeed, several cases in which surgical treatment was chosen reportedly involved only drainage for retroperitoneal perforation9, 10. In addition, these patients required a longer time to achieve postoperative cure. The morbidity and mortality rate for surgical options are reaching as high as 30% 11, including duodenal leak and fistulization; the option of conservative treatment has become more common. The success rate of conservative treatment, initially with broad-spectrum antibiotics, is very low. Given these facts, nonsurgical drainage from a retroperitoneal abscess is an option for treating perforated diverticula. However, percutaneous drainage can be technically challenging. Therefore, if the symptoms improve with endoscopic drainage, it is a valuable option.
Bezoars are composed of vegetable matter (phytobezoar), hair (trichobezoar), or other unusual materials. Previous gastric surgery (disturbance of pyloric function, gastric emptying, and hypoacidity), poor mastication, or overindulgence with foods with high fiber content are common predisposing factors for bezoar formation. There is only one report of laparoscopic resection of a bezoar in a duodenal diverticulum12, but duodenal diverticular perforation due to phytobezoar is rare.
We used the keywords “DDP” and “Endoscopic treatment” to conduct a PubMed search, there were several reports of endoscopic treatment of DDP. The information regarding the reported 7 patients and our case is summarized in Table 1 10, 13–17. Endoscopic treatment of DDP has increased since 2015. An ENBD catheter 17, stent 15, and endoscopic negative pressure16 were used for treatment. In all the cases, antibiotics were administered on admission, and endoscopic treatment was performed concurrently or secondarily. These reports demonstrated food debris and enteroliths in the duodenal diverticulum, which were removed using lithotomy 10 or a combination of a balloon catheter, Dormia basket, and an endoscopic retrograde cholangiopancreatography (ERCP) injection catheter 13. The symptoms improved immediately after endoscopic treatment. In this case, the retroperitoneal abscess was cleaned with the placement of an ENBD catheter in the diverticulum and endoscopic lithotripsy and was significantly effective. However, the bezoar was so hard and sticky that three endoscopic treatments were required to remove it. Flushing the ENBD catheter with saline was particularly useful because now the bezoar was smaller and softer. It has been reported that DDP can sometimes be relieved with fasting and antibiotics. However, in this case, there was no improvement in inflammatory findings or abdominal symptoms after starting antibiotics; therefore, endoscopy was performed. Endoscopic treatment was effective because the patient’s condition did not improve until the phytobezoar of the duodenal diverticulum was removed. Endoscopy can provide a more appropriate diagnosis, drainage, tube washing, and even stone removal. Endoscopic therapy, due to its therapeutic diversity, is valuable for the treatment of DDP.
In the current case, a previous CT scan revealed a duodenal diverticulum, which helped in the diagnosis of DDP. It remains difficult to distinguish DDP from duodenal perforation based on image studies and clinical findings. However, even if the presence of a duodenal diverticulum was not evident and CT showed a localized fluid collection around the duodenum and no peritoneal irritation symptoms; DDP should be suspected and endoscopic treatment considered.