Description of the condition
Intussusception in children is a medical emergency that requires prompt diagnosis and management. It occurs when a segment of bowel (the intussusceptum) invaginates the lumen of another segment of bowel (the intussuscipiens). Both small and large bowel can be involved, but the most common kind of intussusception arises at the junction between the ileum and the caecum,-so-called ileocaecal intussusception (Loukas 2011). Untreated, intussusception may result in bowel perforation, peritonitis, and shock (Ko 2007). Mortality is increasingly rare (Buttery 2011; Davis 2003; Desai 2012; Parashar 2000) but remains a possibility (Iwase 2010; Meier 1996).
Intussusception is one of the most common abdominal emergencies for children less than the age of three (Applegate 2009). Its incidence varies from 0.33 to 2.4 per 1,000 live births (Bines 2002; Eng 2012; Fischer 2004; Huppertz 2006), though evidence suggests this rate is higher in developing countries (Ugwu 2000). Boys are more likely to be affected than girls (Bines 2002), and peak incidence occurs at ages between five and nine months (Daneman 2003; Samad 2012). Recent recipients of the current rotavirus vaccines (RotaTeq, Merck & Co; Rotarix, GlaxoSmithKline Biologicals) may be at slightly elevated risk for intussusception, as suggested by postlicensure monitoring in Mexico (Patel 2011) and Australia (Buttery 2011), but this elevated risk has not been observed in other countries (Ruiz-Palacios 2006; Shui 2012; Soares-Weiser 2012; Vesikari 2006; Yen 2012). A much stronger link between intussusception and an older rotavirus vaccine (RotaShield, Wyeth Laboratories) (Kramarz 2001; Murphy 2001; Peter 2002; Soares-Weiser 2004) led to its worldwide withdrawal 1999.
The cause of intussusception is often idiopathic (Staatz 1998), though any condition that produces pathological lead points (lesions in the bowel) can cause intussusception (Loukas 2011). Of these conditions, lymphoid hypertrophy seems to be the most common (Applegate 2009; Staatz 1998), implicating a viral or bacterial aetiology for most cases (Nylund 2010; Okimoto 2011; Parashar 2000; Staatz 1998). Other potential causes of pathological lead points include Meckel's diverticulum, duplication cyst, polyp, and lymphoma (Daneman 2003; Daneman 2004). Compared with idiopathic intussusception, intussusception caused by lead points is associated with poorer outcomes (Applegate 2009; Loukas 2011).
Diagnosis is challenging, since the symptoms of intussusception are wide-ranging and non-specific (Beasley 1988); the classic triad of symptoms most commonly associated with intussusception consists of vomiting, colicky abdominal pain, and bloody stool, but this triad occurs in less than half of cases (Blanch 2007; Lehnert 2009; Samad 2012). Three studies found that physicians correctly diagnosed intussusception in less than half of initial clinical encounters (Beasley 1988; Blanch 2007; Budwig 1994). Diagnostic delay increases the risk of surgical intervention (Lehnert 2009) and thus emphasizes the importance of prompt and effective management.
Description of the intervention
Non-surgical management of intussusception in children consists primarily of contrast enema (Applegate 2009; Daneman 2004; Ito 2012; Ko 2007). Contrast enema involves instilling contrast medium (usually air, saline, or barium) into the rectum via a rectal tube, with the aim of reducing the intussusceptum by increasing intraluminal pressure (Davis 2003). Fluoroscopy or, in the case of liquid contrast media, ultrasound can guide the procedure and monitor the reduction. Ultrasound avoids the radiation exposure associated with fluoroscopy and has the additional advantage of being an effective diagnostic tool (sensitivity = 98% to 100%, specificity = 88% to 100%) (Applegate 2009).
Pharmacological adjuvants can facilitate non-surgical management, but their efficacy remains controversial. For example, glucagon is an antispasmodic adjuvant used by 10% to 21% of surveyed practitioners (Cachat 2012; Katz 1992; Meyer 1992; Rosenfeld 1999). It provides analgesia (Lappas 1995) and reduces colonic muscle tone (Skucas 1994). However, a recent narrative review suggests that glucagon does not improve the rate of reduction in the non-surgical management of intussusception (Cachat 2012). Other commonly used adjuvants include antibiotics (Ein 2006; Moss 2000; Pepper 2012). Yet, one prospective study concludes that the actual risk of bacteraemia following fluoroscopically-guided air reduction is low (Somekh 1996). Two other studies found an elevated risk for intussusception following antibiotic administration (Hviid 2009; Spiro 2003), raising the concern for recurrence in cases where antibiotics are administered prophylactically.
Surgical management typically entails open laparotomy, though case-series and retrospective studies indicate laparoscopy may be just as effective and result in a shorter length of hospitalisation (Bailey 2007; Bonnard 2008; Kia 2005). Surgical management is generally indicated only if peritonitis, bowel perforation, or shock occurs; if appropriate radiological facilities are unavailable; or if contrast enema fails (American College of Radiology 2007; Daneman 2004). However, because non-surgical management is associated with lower morbidity and shorter hospitalisation (Bruce 1987), delayed repeat attempts at contrast enema may prove more beneficial than conversion to surgical management (Gonzalez-Spinola 1999; Navarro 2004; Sandler 1999; Saxton 1994).
Why it is important to do this review
Intussusception is a common abdominal emergency in children. Despite wide-spread agreement on the use of contrast enema for its non-surgical management, debate persists on the appropriate contrast medium, imaging modality, pharmacological adjuvant, and protocol for delayed repeat enema (i.e. duration of delay and number of repeated attempts) (Beasley 1998; Daneman 2004; Davis 2003; del-Pozo 1999; Littlewood 1998; Liu 1986; Schmit 1999). Debate also persists on the appropriate approach for its surgical management (i.e. open laparotomy versus laparoscopy). Prior reviews of non-surgical management exist (Al-Tokhais 2012; Applegate 2009; Cachat 2012; Daneman 2003; Ko 2007) but are narrative in nature and do not delineate the criteria used to assess studies. In contrast to narrative reviews, systematic reviews use transparent, objective, and reproducible methodology to locate and assess studies (Borenstein 2009). To the best of our knowledge, no systematic reviews of non-surgical or surgical management of intussusception currently exist.