**2.4 Investigations**

Cases of meconium ileus are usually evaluated with abdominal radiograph in which meconium might have a mottled appearance or be invisible [27].

Plain abdominal radiographs are routinely the first imaging done for cases of meconium ileus. They show numerous air-filled loops of bowel on the supine view with characteristic absence of air-fluid levels on the upright view due to the tenacious meconium and the abnormal mucous-gland secretion [5]. Although the absence of air-fluid levels strongly suggests meconium ileus, the presence of airfluid levels does not exclude it as it may occasionally be demonstrated in some cases. In some cases of meconium ileus, the admixture of meconium and bowel gas gives a soap-bubble appearance usually in the right lower quadrant (Neuhauser sign). The presence of calcification, free air, or multiple air-fluid levels suggests intestinal perforation [4].

A contrast enema examination is useful in confirming the diagnosis of meconium ileus in which microcolon is seen; this differentiates it from meconium plug syndrome in which a normal or dilated colon is seen [25]. The microcolon, which represents the underused colon, could also be seen in other congenital conditions causing complete intrauterine obstruction of the distal small bowel such as ileal atresia; however for cases of meconium ileus, the presence of meconium pellets distending the distal ileum is usually identified when the contrast refluxes into the small bowel, and the diagnosis is confirmed (**Figure 1**).

Water-soluble agents are typically used in contrast evaluation of meconium ileus, and several of such contrast agents have been used. The hyperosmolar meglumine (GastrografinRx) diluted at ratio 1:3 to water used to be the mainstay, but some radiologists have stopped using it because of the occurrence of deaths

**Figure 1.** *Contrast enema showing microcolon and meconium pellets in the terminal ileum [courtesy Radiopaedia].*

from fulminant colitis and dehydration sometimes reported with its use [28]. Also, the report of the Cystic Fibrosis Foundation Consensus Conference on gastrointestinal disorders concluded that there is no scientific evidence that hyperosmolar Gastrografin enema is any better than an iso-osmolar or hypo-osmolar enema. Nevertheless, many radiologists use it safely by ensuring appropriate dilution ratios. Adequate monitoring of fluid and electrolyte balance before, during, and after the contrast study is essential to avert potential fluid shifts with consequent hypovolemia which is worsened when bowel perforation and contrast leak occur. Nonionic contrast agents like Hypaque and Omnipaque are becoming popular with many radiologists since they have less risk of dehydration or colitis. Because of the tenacious and sticky nature of meconium, mucolytic agents like acetylcysteine are sometimes mixed with the contrast enema solution to aid passage of the meconium.

Meconium peritonitis may be an incidental abdominal radiograph finding in which the extruded meconium may be calcified or the radiograph may only suggest fluid in the abdomen when no calcification is present. When the calcification appears amorphous and curvilinear suggesting cystic loculation of the peritoneum, the term cystic or pseudocystic meconium peritonitis is used [5].

Prenatal ultrasound scan done at 17–18 weeks gestational age may show signs suggestive of meconium ileus; this include enlarged bowel loops or a mass with proximal bowel distention (likely cystic meconium peritonitis) [11, 12]. Also, calcified meconium may be seen if meconium peritonitis has already occurred. Also there might be polyhydramnios.

**75**

*Meconium Ileus*

outcome [29]:

**2.5 Treatment**

*DOI: http://dx.doi.org/10.5772/intechopen.85548*

the snowstorm configuration.

sweat chloride test should be done [25].

tive management is taken based on the presentation.

*2.5.1 Initial medical management*

*2.5.2 Nonoperative treatment*

Postnatal ultrasound scan is seldom necessary for meconium peritonitis, as the findings on plain radiographs are usually diagnostic. However, ultrasonography may be useful when cystic masses are present. The cystic masses often appear circumscribed and heterogeneous with sonolucent areas seen within the cyst suggestive of fluid. They demonstrate increased echogenicity resulting from debris and calcifications, and loops of fluid-filled bowel bound to the matrix of the associated adhesions may be noted. The cyst wall may be thick or thin. Multiple speckled echoes are seen with free-floating meconium in the abdomen, and these result in

Zangheri et al. created the following classification system related to perinatal

• Grade I: IAC and one of the following: ascites, pseudocyst, or bowel dilatation

• Grade II: IAC and two of the following: ascites, pseudocyst, or bowel dilatation

Patients diagnosed with meconium ileus should be tested for cystic fibrosis; the

Meconium ileus cases, both simple and complicated, are approached as intestinal obstruction and as such would require urgent initial resuscitative measures. These include intravenous fluid resuscitation, nasogastric decompression, urethral catheterization for hourly urinary monitoring, multiparameter vital sign monitoring, intravenous antibiotic therapy, laboratory evaluation of full blood count, coagulation work-up, and serum electrolytes, urea, and creatinine with necessary corrections instituted. Where necessary, mechanical respiratory support is provided. Once the infant has been optimized, the decision for nonoperative or opera-

Nonoperative management can be achieved by diatrizoate meglumine enemas as first described by Noblett in 1969 [30]. Variations on his approach have been established as effective first-line treatment for uncomplicated meconium ileus. Uncomplicated meconium ileus obstruction can be relieved by giving one or more dilute diatrizoate sodium or diatrizoate (gastrografin) enema (with N-acetylcysteine added) under fluoroscopic guidance. The hyperosmolar nature of this compound increases the influx of fluid into the bowel lumen to liquefy the viscid meconium and thus facilitate its expulsion with consequent large gastrointestinal water losses. While carrying out this procedure, therefore, adequate intrave-

nous fluid administration must be ensured to prevent hypovolemia.

• Grade III: all of the above (IAC, ascites, pseudocyst, and bowel dilatation)

• Grade 0: isolated intra-abdominal calcifications (IAC)
