Rare aetiology of abdominal pain: contained abscess secondary to perforated jejunal diverticulitis

Abstract

A patient with a history of multiple jejunal diverticulosis (JD) presented with a non-peritonitic abdominal pain and leucocytosis. CT scan showed a thick-walled interloop collection within the left mid-abdomen with dilated bowels and mild diffuse air-fluid levels. Exploratory laparotomy revealed multiple diverticular outpouchings in the mid-jejunum, one of which was perforated, contained within the mesentery. Resection of the contained abscess and primary anastomosis were performed subsequently.

Background

Non-specific abdominal pain has numerous differential diagnoses. Majority of reported jejunal diverticulosis (JD) present with acute abdominal presentation. Here we present a rare case of non-specific abdominal pain caused by a contained abscess due to a perforated JD. While, it has been previously reported that JD may cause a variety of symptoms, it should be considered when faced with non-specific abdominal pain.

Case presentation

An 83-year-old woman with a medical history of type 2 diabetes, diabetic neuropathy and hypertension presented to the emergency department with a 2-day history of vague epigastric abdominal pain and loss of appetite. She denied any fever, chills, nausea or vomiting. She presented 2 months prior with similar symptoms and was discharged after a course of antibiotic therapy. The patient is a non-drinker and non-smoker with no previous abdominal surgeries. Vital signs were within normal limits. Her physical examination revealed a mild, diffuse abdominal tenderness without rebound or signs of peritonitis.

Investigations

Laboratory workup was significant for leucocytosis (24×10⁹/L), normal liver and kidney function tests and normal lactic acid levels. She had a normal urinalysis. CT scan showed a left mid abdomen interloop abscess measuring 5.5×5.0×5.5 cm (figure 1A, B). Interestingly, during her previous hospital visit, CT scan showed an inflammatory process in the right lower quadrant with a collection of debris and gas measuring at 3.4×3.3×3.3 cm. In addition, there were some mild inflammatory changes showed at the right lower quadrant (figure 1A, B). It could be related to the interloop abscess. We clarified with radiologist for the final reads. There were no obvious radiological pathologies over the right lower quadrant. It was the radiographical representation related to the perforated JD. The patient had been put on intravenous antibiotics and bowel rest prior to the surgical intervention for the contained abscess. Neither imaging showed any signs of free air, free fluid, mesenteric ischaemia, appendicitis or bowel perforation.

Figure 1.

CT scan showing a thick-walled interloop collection within the left mid-abdomen and mild-diffuse dilation of a fluid-filled small bowel without transition point. (A) Coronal view. (B) Axial view (yellow arrow, interloop collection; red arrow, related inflammatory changes).

Differential diagnosis

The differential diagnosis for acute epigastric pain is broad and includes many pathologies of gastric, pancreatic or hepatobiliary origins. Medical causes such as myocardial infarction or pneumonia were also considered. Initial investigations should address these common surgical and medical causes of acute epigastric pain with specific tests and lab data. Medical causes could be investigated with a chest X-ray, ECG and troponins while a complete metabolic blood analysis would offer insight into both the hepatobiliary system along with any acute pancreatic pathology. An ultrasound is an ideal initial imaging choice to evaluate the biliary tree while an upper endoscopy can offer insight to a potential gastric pathology. In an otherwise haemodynamically stable patient with no explanation for their acute epigastric pain, a CT scan should be obtained to better elucidate the source of the patient’s symptoms. If the patient is haemodynamically unstable, despite adequate resuscitation, immediate surgical intervention should be considered.

Treatment

She was admitted to the surgical service and was started on intravenous antibiotics. Interventional radiology was consulted for potential percutaneous drainage of the interloop collection; however, this collection was unamenable to percutaneous drainage. She continued to have worsening abdominal pain and was subsequently taken to the operating room on hospital day 5. Diagnostic laparoscopy was initiated; however, due to numerous interloop JD, the operation was converted to open laparotomy. On investigating the bowel loops, multiple JD were noted along a 65 cm portion of jejunum (figure 2A, B), with a single perforated diverticulum being the source of the mesenteric abscess (figure 3A, B). Considering the above findings, a small bowel resection was performed to include all JD followed by a single primary small bowel anastomosis. Postoperative pathological studies showed small intestinal mucosa with diverticula formation and associated inflammation, abscess, perforation and marked serosal inflammation.

Figure 2.

Intraoperative photos showed diverticulosis in the mid-jejunum. (A). Multiple diverticular pouches (yellow arrow). (B) Perforation noted over the diverticulum (yellow arrow).

Figure 3.

Specimen photos. (A) Multiple diverticular pouches (yellow arrow). (B) Perforation noted over the diverticulum (yellow arrow).

Outcome and follow-up

Postoperatively, the patient recovered well. Her antibiotics were continued for 4 postoperative days. She had a return of bowel function on postoperative day 5, at which point she was placed on a clear liquid diet. Her diet was gradually progressed and she was discharged home on postoperative day 7. She was seen in the clinic 2 weeks after discharge and was doing well without any abdominal pain, nausea or vomiting. Her appetite has returned to the normal level.

Discussion

Small bowel diverticula was first described by Locallo and Stahl 1967.¹ These may manifest as true, involving all layers of the bowel, or false, involving the outpouching of mucosal and submucosal layers through the muscularis layer. While duodenal diverticular disease is quite common, JD is quite rare with unknown aetiology.² The incidence ranges from about 0.5% to 2.3%.³ The mean age of detection is at the age of 60s–70s and have a slightly higher male to female predominance.⁴ There is quite a variety of sizes of these diverticula ranging from a few millimetres to greater than 5–10 cm.⁵ There are a few postulated hypotheses regarding aetiology of JD, including irregular intestinal muscular contractions leading to increased intraluminal pressure.⁶ Krishnamurthy et al suggested that the abnormality of smooth muscle or myenteric plexus causing intestinal dyskinesia subsequently results in herniation of diverticulosis.⁷ Some studies associated the formation of diverticulosis with the pre-existing intestinal dysmotility due to systemic diseases such as amyloidosis, systemic sclerosis and other rare neuromuscular disorders namely Ehlers-Danlos syndrome.^{8 9}

JD often has an asymptomatic presentation, found incidentally on CT scans.¹⁰ It can also present with non-specific acute abdominal pain, mimicking peptic ulcer disease or large bowel diverticulitis.¹¹ Perforation of JD has been reported to occur at a rate of 2%–6%.^12–14 In this case study, the perforated diverticulitis appeared contained in the mesenteric wall, which is a rare presentation that can lead to small bowel obstruction proximal to the obstruction.¹⁵

While many reports have described acute abdomen and peritonitis secondary to diverticular perforation, our patient presented with no such symptoms.^{16 17} Interestingly, the patient has been taking over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) for osteoarthritis. It has been reported that long term use of NSAIDs therapy may induce silent enteropathy leading to elevated intestinal inflammatory response and intestinal permeability. Such a chronic inflammatory response can potentially lead to pathological changes that could lead to contained bowel perforation.¹⁸ Unfortunately, there is not a reliable diagnostic test for JD considering its rare incidence and variable clinical presentation.¹⁹ Both CT scan imaging and balloon/capsule endoscopy have been described as diagnostic tools, with the latter being costly with limited use in urgent settings.^{20 21} In our case, CT showed an interloop abscess, while likely from a perforation, while her exam and clinical presentation were not consistent with a perforation. Given the high mortality of small bowel perforation, reaching as high as 40%, we believe it was in the best interest of the patient to have an exploratory laparotomy to aid in diagnosis.²²

Treatment for jejunal diverticulitis can be divided into conservative and operative management.

In general, asymptomatic JD does not require bowel resection. Patients with chronic symptoms such as mild intermittent epigastric discomfort can be treated conservatively. A surgical resection is suggested only in patients with persistent symptoms refractory to conservative management. In perforated JD, surgical intervention is recommended due to the high mortality and morbidity of bowel perforation. Prophylactic surgery was not recommended in asymptomatic individual.²³ In jejunal diverticulitis with abscess formation but without perforation, non-operative management includes antibiotics and bowel rest with possible image-guided drainage.²⁴ However, in perforated jejunal diverticulum causing peritonitis prompted surgical management, including laparoscopic approach, has often been reported in acute settings.^{13 25–27} Bowel resection with primary anastomosis would be the surgery of choice in most of the cases.²⁸ Given the nutritional capacity of the jejunum, caution has to be taken to avoid malnutrition and short gut syndrome as a result of extensive resection.^{29 30} Elective surgical management with small bowel resection has also been suggested to avoid emergent surgery and higher postoperative morbidity.³¹

JD is a rare intestinal pathology. It is more prevalent in the aged population and the mortality rate from perforation is significant. We report an unusual presentation of contained perforated JD which highlights the importance of including JD as one of the differential diagnoses in the patient presented with atypical abdominal symptoms.

Learning points.

• A contained abscess due to perforated jejunal diverticulosis (JD) is very rare. But it is an important diagnosis in non-specific abdominal pain. We recommend general surgeon to also include it as one of the important differential diagnosis.

• Some related aetiology, such as connective tissue disease and long term use NSAIDs may prompt the consideration of possible small bowel diverticulosis pathology. We recommend the use of NSAID and known history of JD should raise a suspicion of potential complication from jejunal diverticulitis.

• A sound clinical judgement for the need for exploratory laparotomy is crucial in an ambiguous presentation of abdominal pathology. We recommend considering a prompt surgical intervention in a perforated JD as a definitive treatment to reduce the related mortality and morbidity.