MD is one of the most common congenital anomalies of the gastrointestinal tract, and was first characterised by Johann Friedrich Meckel. It becomes symptomatic in only 2–4% of cases, but its presentation can vary, making the correct diagnosis and the subsequent management difficult. For this reason, it is essential to identify patients at higher risk of complicated MD in order to diagnose and treat them promptly.
Generally, the current literature shows that the incidence of complicated MD is more common in males than females [8] with a variable rate from 2.3:1 [9] to 7.5:1 [10]. In the present study, the male-to-female ratio was 4:1, similarly to previous reported studies. A large proportion of complicated MD in childhood is reported to occur before 10 years of age [11] with the highest peak of occurrence under 5 years of age [4]. By contrast, in our case series, approximately half of the symptomatic cases (46.6%) were older than 10 years of age. We also found that the age distribution of patients in our cohort differed according to clinical presentation: patients with intestinal obstruction secondary to intussusception or volvulus were aged below 9 years in 5 out of 6 cases (p = 0.1), younger than patients with rectal bleeding who, in 67% (4/6) of cases, were 10 or older, although the difference was not statistically significant. This challenges the ‘rule of two’ stating that most complications, especially bleeding, occur before the age of 2. To the best of our knowledge, this is the first report that has examined the association between the clinical presentation and the age in children presenting with MD complications. Few other studies [8, 10] also reported a decreased frequency of complicated MD with age, but did not separately analyse each mode of clinical presentation and the age at onset of complications.
Traditional investigative modalities such as radiographic contrast studies, US, and computed tomography have many limitations in an accurate assessment of MD and its complications as they can mimic more common disorders that might cause an acute abdomen in children [12]. In case of bleeding episodes, a 99mTc-pertechnetate scintigraphy might be indicated; the principle is that a bleeding diverticulum consists of ulcerated ectopic gastric mucosa that can be revealed with 99mTc-pertechnetate. Indeed, it concentrates in the gastric tissue, leading to a reported sensitivity between 60% and 80% [13]. The problem is that, in cases of non-active bleeding, the sensitivity lowers further and, in any case, either a positive or negative examination would prompt a surgical exploration; for this reason, in our department, scintigraphy is not routinely used in cases of intestinal bleeding from a suspected MD.
Abdominal US has been considered the most effective tool to diagnose MD with high sensitivity and specificity [14]. MD is usually detected as a thick-walled tubular structure, with one blind end and the other end connected to the normal intestinal duct [15, 16]. Absence of peristalsis may allow the differentiation of MD from normal small bowel [17]. In our centre, abdominal US was performed routinely in all patients with acute abdominal pain and gastrointestinal bleeding. In a review by Higaki, it was reported that 88% of patients presenting with bleeding had a correct preoperative diagnosis, compared to just 11% of those with different symptoms [18]. This finding was confirmed in our study, in which more than 80% of patients presenting with gastrointestinal bleeding were properly diagnosed before surgery. However, in our series, abdominal US diagnosed up to 94% of patients correctly. This was likely due to the radiologist’s expertise in a paediatric referral centre. We believe that healthcare professionals with multidisciplinary expertise might be useful to standardise the management and therefore to improve prompt diagnosis, especially in case of rare diseases.
For the treatment of symptomatic MD, surgical resection has always been the treatment of choice.
In our study, more than 80% of cases underwent a trans-umbilical laparoscopic-assisted (TULA) approach, in which the small bowel is exteriorised through the extension of the umbilical port site, as described by previous studies [12, 19].
The traditional procedure is diverticulectomy or segmental bowel resection and subsequent anastomosis, depending on the length of the MD, thickening or ischemia at the base, severe small bowel obstruction or intraoperative suspicion of incomplete resection of heterotopic mucosa [20]. Some retrospective studies have previously suggested that diverticulectomy can be considered an appropriate therapeutic strategy for bleeding MD [21, 22] or symptomatic MD without basal thickening or ischemia [23]. By contrast, in our series, diverticulectomy was only performed in 2 cases (1 bleeding DM and 1 abscess). Our centre’s protocol includes a laparoscopic-assisted extracorporeal resection in case of complicated MD to ensure complete excision of any heterotopic mucosa and to verify intestinal vitality in case of intestinal obstruction. Postoperative complications after complicated MD resection are reported in literature to range from 5–12% in different series [24, 25]. In our study, the overall complications rate fell at the lower end of this range (5%) and the singular complication occurred after open surgery. Therefore, in our experience, TULA proved to be safe, feasible, and associated with low risks of postoperative complications even though it was not statistically significant, probably due to the small sample size. Postoperative histology revealed the presence of ectopic tissue from 41.1–85% in different series [26]. In our study, ectopic mucosa was confirmed in 46.6% of patients, with a higher percentage in children with intestinal bleeding compared to those with abdominal pain (p = 0.04), in line with previous reports [24].
The last several years have seen some debate about the proper management of asymptomatic Meckel's diverticula incidentally found during laparotomy or laparoscopy. Tauro et al. suggested resection of a normal-appearing MD in every case of appendectomy or laparotomy/laparoscopy for an acute abdomen to avoid secondary complications [27]. Conversely, Robijn et al. suggested a selective approach, recommending resection of MD in certain cases: male sex, younger than 45 years, diverticulum longer than 2 cm, presence of a fibrous band highlighted at the time of surgery [28]. A recent systematic review by Zani et al. demonstrated that leaving an incidentally-found MD in situ reduced the risk of postoperative complications without increasing late complications [29]. As a result, our institutional policy avoids prophylactic DM resection as this practice is not supported by sufficient evidence.