Introduction

Meckel’s diverticulum (MD) represents the most common congenital anomaly of the gastrointestinal tract [1]. A prevalence of 2% has been reported in the general population [2] and the lifetime risk of related complications is estimated to be 4—40% [3]. The name was attributed to the German anatomist Johann Friedrich Meckel, who established the embryonic origin in 1809 [4].

Clinically, it may remain silent for life or become complicated and debut as an acute abdomen. Causes may be associated with inflammation and haemorrhage. Other less common presentations are hernia, malignancy or obstruction; some of these may even be life-threatening [5]. Nevertheless, there are other rarer complications such as diverticular perforation by a foreign body [6]. We present a case of a patient with perforation of a MD by an intact fishbone that simulated acute appendicitis who was operated on for this diagnosis.

Case report

The patient was an 18-year-old male, who presented with abdominal pain in the right iliac fossa, of 48 hours’ evolution, of a lying down type, with abrupt onset and increasing intensity and associated with nausea. There was no history of chronic diseases or previous abdominal surgery. On physical examination, the patient had a blood pressure of 100/70 mmHg, heart rate of 66 bpm, axillary temperature of 36.5°C and oxygen saturation of 97%. On abdominal examination, McBurney, Blumberg, Rovsing sign was found. Laboratory analysis revealed a white blood cell count of 15,160 per mm³ (normal range 4,500 to 10,000 per mm³) with 89% neutrophils (normal range 50—75%); haemoglobin, glucose, creatinine and coagulation times within normal ranges. An abdominal ultrasound was performed, which reported scant free fluid and thickening of the intestinal wall of the intestinal loops located in the right lower quadrant; an acute appendicitis was therefore conjectured as a diagnosis, and the patient was scheduled for a laparoscopic appendectomy.

Under laparoscopic vision, a paracecally oriented cecal appendix was identified, with no inflammatory signs; however, the scarce seropurulent free fluid near the cecum attracted attention, so it was decided to perform an incidental appendectomy and exploration of the terminal ileum, from the ileocecal valve upwards. At 50 cm from it, a Meckel’s diverticulum was identified with fibrin adhering to its surface, as well as erythema at the base and a foreign body perforating the diverticulum near its base. It was an intact fishbone (figure). It was decided to convert to open surgery as there was no material available to complete the surgery laparoscopically. The perforated Meckel’s diverticulum was resected and then the ileo-ileal end-to-end anastomosis was performed in 2 planes. The first plane, with 4/0 vicryl, with Schmieden stitches; and the second plane, with 3/0 vicryl, with Lembert stitches. The postoperative period was uneventful. He was discharged after two days; a check-up was carried out at one week and one month, without any complications.

Meckel’s diverticulum perforated by fish bone.

Discussions

MD is caused by incomplete obliteration of the omphalomesenteric duct, which connects the yolk sac to the small intestine, specifically the ileum, in the developing embryo [7]; it is considered the most common congenital anomaly of the gastrointestinal tract, with a prevalence of approximately 2% in the general population [8]. Most MDs are asymptomatic and are discovered incidentally through imaging studies or during abdominal surgery. An Italian study showed an incidental finding of 60% in a sample of 65 patients with MD [9]. An epidemiological study in Taiwan on MD reported that 50% of patients were symptomatic and bowel obstruction was the most common preoperative diagnosis, followed by acute abdominal pain and gastrointestinal bleeding. Bowel obstruction was the most common presenting symptom of MD in the age groups 0—10 years (young children) and >20 years (adults), while acute abdominal pain was most common in the age group 11—20 years (adolescents) [10].

MD historically follows the “rule of two”: 2% frequency, diagnosed mostly in children under 2 years of age, 2 times more frequent in males, located in the small intestine 60 cm from the ileocaecal valve, with a length of up to 5 cm and a diameter of up to 2 cm, with two types of heterotopic mucosa [11, 12]. The cells lining the vitelline canal are pluripotent and, as the MD is a remnant of the vitelline canal, it contains heterotopic gastric tissue (50%), pancreatic tissue (5%) and, more rarely, hepatobiliary tissue and duodenal, colonic, endometrial or Brunner’s glands [13]. The presence of heterotopic tissues results in severe and even fatal complications such as gastrointestinal haemorrhage (31%), inflammation (25%), intestinal obstruction (16%), hernial involvement (11%), intussusception (11%), fistula or umbilical sinus (4%) and tumours (2%) [14].

In relation to the causes of intestinal perforation, fish bones, chicken bones and toothpicks have generally been reported. Other rarer causes are pens, fingernails, nail clippers, batteries and pins [15]. Of these, ingested fish bones are the most common cause of gastrointestinal perforation due to their elongated configuration and sharp tip. In our case, perforation of the MD by a fishbone occurred, probably due to a combination of the peristalsis, the angulation and blind termination of the diverticulum on one side and the linear shape of the fishbone. All this increases the possibility of impaction and perforation.

Patients with foreign body perforation in areas close to the cecum such as the MD will present with acute abdominal pain that simulates, in most cases, acute appendicitis, as was the case here. This is often overlooked in the diagnosis, as it is a rare condition, and they usually do not recall ingestion of fish bones [16]. As a consequence of MD perforation, patients may have different complications, some very mild and self-limited, as in our case, to more severe ones, such as localized abdominal abscess, colorectal, colovesical and enterovesical fistula, inflammatory mass, chronic or acute intestinal obstruction, haemorrhage, among others. In situations other than MD perforation by a foreign body but acute, a delay in diagnosis could reach a mortality of 6%, especially in the elderly [17].

Imaging is limited in making the diagnosis of foreign body perforation of the MD. Plain abdominal radiography has a detection sensitivity of 32%; and abdominal ultrasound has been shown to be useful in the identification of foreign bodies, thanks to its high reflectivity and variable back shadowing [18]. Abdominal CT, among all studies, represents the radiological examination of choice for the detection of foreign bodies and their complications [19]. Radiological findings will show acute and focal inflammatory changes around the site of perforation, as well as thickening of the bowel wall, free fluid and ileus; and, depending on the time course, even self-limiting masses through the omentum or adjacent structures may be evident.

A MD perforated by a foreign body should be treated like any other complication of the diverticulum. There are two surgical interventions: simple diverticulectomy and segmental bowel resection, with subsequent primary anastomosis [17], which is the technique of choice; the latter is reserved for perforated or inflamed cases, as in the present case. On the other hand, there are conventional and laparoscopic surgical interventions [20], both of which are safe, although for the latter, all the necessary logistics for adequate resection and primary anastomosis must be in place.

Conclusions

Perforation of a Meckel’s diverticulum by a fishbone is exceptionally rare and could simulate acute appendicitis. Imaging has its limitations; however, among all of them, abdominal CT, carefully evaluated, leads to a correct preoperative diagnosis. Laparoscopy is a safe diagnostic and also therapeutic procedure to treat complicated Meckel’s diverticulum.

Conflicts of Interest and Source of Funding

The authors declare that they have no known competing financial or personal relationships that could be viewed as influencing the work reported in this paper. This work did not receive any grant from funding agencies in the public, commercial, or not-for-profit sectors

Authorship

All persons listed as authors have been actively involved in one or more key aspects of the reported study. All authors attest that they meet the current International Committee of Medical Journal Editors (ICMJE) criteria for Authorship. The full responsibility for the content of this article lies in the authors.

Ethics

All procedures performed were in accordance with the ethical standards of the 1964 Helsinki Declaration and its later amendments.