Complicated Diverticular Disease of the Small Bowel: A Rare Cause of Acute Abdomen in a Critically Ill Patient—A Case Report

Abstract

Diverticular disease of the small bowel is a rare, generally asymptomatic condition with a challenging diagnostic approach and the potential for life-threatening complications. While diverticular disease can manifest in any part of the gastrointestinal tract, its occurrence in the jejunum is exceptionally uncommon, with an incidence of up to 1%. Although rare, complications from diverticular disease of the small bowel can arise in up to 10% of cases, usually manifesting as signs and symptoms mimicking other etiologies or an acute abdomen. In this case report, we present the management of an elderly male patient with multiple comorbidities who developed an acute abdomen during his intensive care unit stay. The patient required surgical intervention, which revealed numerous complicated diverticula of the small bowel, affecting the jejunum, as the underlying cause of his symptoms.

Introduction

Diverticular disease of the small bowel (DDSB) refers to the presence of abnormal outpouchings (diverticula) located in the walls of the small bowel. These diverticula can be categorized histologically into 2 types: true diverticula, which involve all layers of the small bowel wall, and false diverticula, where the outpouchings consist solely of herniated mucosa and submucosa without affecting the muscular layer.^1,2

The incidence of DDSB varies depending on different factors, such as the affected segment of the small bowel, the patient’s age, and whether the diverticula are classified as true diverticula or not. ³ DDSB is more commonly found in the duodenum, where it has been incidentally discovered in up to 6% of imaging studies in the general population; interestingly, its incidence in the jejunum and ileum is much lower, ranging from 0.07% to 1.0%. ³

DDSB can present a wide array of nonspecific symptoms like bloating, abdominal cramping, and diarrhea, making its diagnosis a challenging one. ⁴ While DDSB can be discovered as an incidental finding in imaging studies, and most patients remain asymptomatic, complications like bleeding, perforation, peritonitis, and small bowel obstruction have been reported to arise in up to 10% of patients. ³ These complications can present as an acute abdomen or as abdominal pain that may mimic other intra-abdominal pathologies, like appendicitis, cholecystitis, and renal colic. ³

Here, we report a case of an 82-year-old male with several comorbidities presenting with multiple complicated diverticula of the small bowel, including the jejunum, requiring surgical intervention during his intensive care unit stay.

Case Presentation

An 82-year-old male patient with a medical history of hypertension, type 2 diabetes, and end-stage renal disease (ESRD), undergoing peritoneal dialysis for kidney replacement therapy for 5 years, with no other remarkable familial or personal medical history, was admitted to the intensive care unit (ICU). The admission was prompted by mixed diabetic ketoacidosis and hyperglycemic hyperosmolar syndrome.

Initial laboratory workup revealed elevated plasma glucose (800 mg/dl), acidosis (arterial pH 7.2), slightly reduced bicarbonate, urine ketones present, and an osmolality of 355 mOsm/kg.

During the next 4 days, the patient showed improvement in his overall condition due to effective ICU management, which included hemodialysis. The first evaluation for sepsis revealed no significant findings, with peritoneal catheter cultures returning negative.

His abdominal examination was within normal limits except for mild distention, without peritoneal irritation signs. At this moment, the patient was considered to show gradual improvement. The patient denied having chronic abdominal or gastrointestinal symptoms such as early satiety, bloating, chronic upper abdominal discomfort, or diarrhea.

On the fifth day of his ICU stay, the patient experienced an acute and progressive deterioration in his mental status and manifested moderate colicky pain localized to the left flank and iliac fossa. He also had an absence of bowel movements for the past 2 days.

The patient was severely obtunded with a Glasgow coma scale of 8/15, febrile, with a mean arterial pressure of 40 mmHg, a temperature of 38.4°C (101.12°F), tachycardic at 112 beats per minute, tachypneic with a respiratory rate of 22 per minute, and profusely diaphoretic. Upon physical examination, the patient grimaced during the deep palpation of the left iliac fossa and presented rebound tenderness. The rest of the physical examination was unremarkable.

Standard ICU care was started, including antibiotic therapy, advanced airway management, and vasopressors to keep adequate mean arterial pressures. At this point, the patient was considered to have a septic shock, with an elevated probability of the septic focus being intra-abdominal.

Later investigations revealed leukocytosis, with a WBC count of 25,000/µl, with 80% neutrophils. The CRP was elevated (>32 mg/dl). Creatinine and blood urea nitrogen (BUN) levels remained elevated at 5 and 40 mg/dl, respectively, without uremic findings. Arterial blood gas (ABG) results showed metabolic acidosis with hyperlactatemia (Table 1).

Table 1.

Initial laboratory workup and secondary evaluation for sepsis.

Initial laboratory workup	Sepsis laboratory workup
Blood glucose 800 mg/dl.	WBC 25,000/µl.
Arterial pH 7.2.	Neutrophils 80%.
Low serum bicarbonate.	CRP > 32 mg/dl.
Normal blood counts.	Low serum bicarbonate.
Urine ketones present.	Creatinine 5 mg/dl.
Osmolality 355 mOsm/kg.	Blood urea nitrogen (BUN) 40 mg/dl.
Arterial blood gas (ABG) results showed metabolic acidosis with hyperlactatemia.	Arterial blood gas (ABG) results showed metabolic acidosis with hyperlactatemia.

An abdominal ultrasound revealed the presence of ascites and cholelithiasis without signs of cholecystitis. Left colon Diverticulitis was included in the differential diagnosis, and an abdominal computed tomography (CT) scan was initially considered. However, due to the patient’s acute clinical deterioration and the strong suspicion of an intra-abdominal septic focus, a decision was made to proceed with an exploratory laparotomy.

An exploratory laparotomy, conducted through a median incision, revealed the presence of abundant ascitic fluid associated with complicated diverticular disease of the small bowel (jejunum). Specifically, 6 diverticula were found approximately 60 cm from the Treitz angle, displaying ischemic and necrotic signs (Figure 1).

Figure 1.

A segment of the jejunum that has been resected shows multiple diverticula. One of these diverticula is affected by necrotic changes (indicated by the red arrow).

Due to the characteristics of the lesions, a small bowel segment resection and a functional side-to-side antiperistaltic anastomosis employing mechanical sutures were performed. The complete resection amounted to 90 cm of the affected small bowel. Concurrently, an appendectomy was performed, culminating in the complete closure of the abdominal cavity. There were no complications associated with the procedure.

The histopathology report showed the presence of diverticula accompanied by acute and chronic inflammation, along with associated necrosis and diverticular perforation. Fibrous tissue was also present. Following the surgical intervention, the patient showed satisfactory improvement, was monitored in the ICU for 4 days, and was discharged 10 days later, experiencing an uneventful recovery. Three months later, during follow-up, he showed no signs of recurrent or chronic abdominal symptoms.

Discussion

DDSB is most commonly found in older adults, with an average presentation in the seventh decade of life, accounting for up to 80% of cases. ⁵ Although our patient was in his ninth decade, his age was still within the range reported by the literature, wherein DDSB is usually found (between 45 and 90 years of age). ⁵

Peritoneal dialysis has been associated with various gastrointestinal disorders; documented symptoms include constipation, abdominal pain, and gastroesophageal reflux. ⁶ Several studies have reported a link between peritoneal dialysis and diverticulosis, although the underlying pathophysiology is still poorly understood. ⁶ This association is thought to involve mechanisms such as increased intra-abdominal pressure and chronic constipation. ⁶

Although DDSB most commonly affects the duodenum, according to Mantas et al, its incidence is greater in the jejunum than the ileum, partly because of the larger diameter of the penetrating arteries found in the jejunum. ⁷ This is backed by the fact that the site where the diverticula protrude is generally found at the entry point of the vascular supply of the affected bowel segment. ⁷ Interestingly, although jejunal arteries tend to be larger, ileal arteries tend to have a more significant number of arcades, according to an anatomical study. ⁸ Risk factors, such as old age, constipation, and decreased dietary fiber, can be found early through screening. ⁹

Acute abdomen in the ICU admission could be classified as obstructive (47%), inflammatory (45%), vascular (4%), perforated (3%), traumatic (1%), or hemorrhagic (1%); acute diverticulitis is the main cause of inflammatory acute abdomen in the ICU. ¹⁰ Inflammatory causes, such as acute diverticulitis, were more commonly seen in older patients. ¹⁰ One-third of acute abdomen in the ICU may need surgery, and 13% will die during the hospital stay. ¹⁰

The absence of standardized diagnostic protocols or a definitive gold standard makes a prompt diagnosis of DDSB challenging. While diagnostic tools such as abdominal computed tomography (CT) scans and double balloon enteroscopy can assist in the diagnosis, abdominal radiography may be a faster option, which is particularly helpful in cases with a high suspicion of perforation. ¹¹ Regardless, in patients with acute abdomen and hemodynamic instability, urgent surgical management should not be delayed by diagnostics if the clinical suspicion is high, as evidenced in our case.

In limited resource settings, ultrasonography is the first-line imaging on nonspecific abdominal pain, the approach is clear: to perform a focused exploration of the area of maximum pain, led by the patient’s signs and symptoms. Key findings include hyperechogenic perilesional fat and fluid-filled collections with or without hyperechogenic spots of air. ¹² CT is considered the gold standard, with a diagnostic rate of 80% in the case of perforation and 36.7% in the case of diverticulitis. ¹² Key findings include peridiverticular edema and thickening, mesenteric inflammation in the mesenteric border, and anti-mesenteric involvement in severe cases. ¹² Other findings include fecalized diverticulum (51% of jejunum diverticulitis), luminal free and/or localized fluid collections. ¹²

Symptoms are nonspecific and may mimic other pathologies such as large bowel diverticular disease, intestinal inflammatory disease, foreign body ingestion, or cancer. ¹³ Therefore, inquiring about symptoms, as well as family and personal medical history, aids in making a first differential diagnosis. ¹³

While standardized guidelines for managing patients with suspected complicated DDSB are lacking, Abramov et al propose an approach based on the patient’s hemodynamic status. For hemodynamically stable patients, the proposed management strategy emphasizes identifying whether there is intestinal bleeding or a contained perforation; non-surgical approaches are viable options in these cases. ¹⁴ Surgical treatment is usually reserved for patients presenting with peritonitis, pneumoperitoneum, or hemodynamic instability, as in our patient’s case. ¹⁴

In cases where surgery is chosen to treat complicated DDSB, surgeons must be aware that there is a possibility of recurrence, even if the entire affected segment of the bowel is removed. ¹⁵ Additionally, there is a risk of developing short bowel syndrome after a resection is performed. ¹⁵ Therefore, it is recommended that resections be limited only to the affected segment and that extensive or unnecessary resections be avoided. ¹⁵ We removed the shortest possible segment of the affected jejunum, including all diverticula, and performed a functional anastomosis.

Based on our experience and the results reported in the literature, the segmental resection of the small bowel with a primary anastomosis remains the surgical technique yielding the best outcomes in patients with complicated DDSB. ¹⁵ For this reason, we opted for this technique in our patient. Additionally, we opted for functional side-to-side antiperistaltic anastomosis, as it has the lowest probability of an anastomotic leak (AL). ¹⁶

Contaminated surgical fields are considered a relative contraindication to perform a primary anastomosis; however, the likelihood of AL from this type of anastomosis in emergent abdominal surgeries associated with peritonitis is still a topic of debate. A systematic review by Skovsen et al. revealed heterogeneous results among different studies; while smaller studies suggest a higher risk of AL in “inflammatory” conditions like peritonitis, compared to “clean” conditions, larger trials do not identify peritonitis as a significant risk factor for anastomotic failure. ¹⁷ Instead, factors like preoperative hypoalbuminemia, hyponatremia, and intraoperative hypotension appear to have a greater impact on the likelihood of AL than the presence of a contaminated surgical field. ¹⁷

A retrospective single-center study by Zakrison et al. found that using vasopressors postoperatively in patients who underwent gastrointestinal anastomoses increases the risk of AL. ¹⁸ However, prolonged untreated hypotension is also believed to negatively affect oxygen delivery and tissue perfusion in the anastomosed area. ¹⁹ Therefore, while vasopressors are an important consideration when deciding to perform a primary intestinal anastomosis, their definitive role in determining the risk of AL remains unclear.

Conclusions

Although DDSB is a rare, generally asymptomatic condition primarily affecting patients in the seventh decade of life, it has the potential for life-threatening complications. Even though standardized guidelines for managing patients with complicated DDSB are lacking, non-surgical approaches show promise for hemodynamically stable patients with contained perforation or intestinal bleeding.

Surgical treatment is typically reserved for patients who have hemodynamic instability or an acute abdomen. When surgery is used to treat complicated DDSB, surgeons must be aware that recurrence is possible, even if the entire affected bowel segment is removed. Therefore, it is recommended that resections be limited and that extensive or unnecessary resections be avoided.

Although management recommendations exist, there are no international guidelines defining a standard of care. Further studies and case series are needed to help standardize the management of DDSB.