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CHAPTER 62

Duodenal Atresia and Stenosis

Felicitas Eckoldt-Wolke
Afua A.J. Hesse
Sanjay Krishnaswami

Introduction Postnatal Symptoms and Signs
Congenital duodenal obstruction may be due to intrinsic or extrinsic Most women in Africa do not avail themselves of prenatal care, so the
lesions. Intrinsic duodenal obstruction may be caused by duodenal atre- majority of duodenal obstructions present only after birth. Furthermore,
sia, stenosis, diaphragm with or without perforation, or by a wind-sock because up to 60% of births occur outside health institutions, these
web or membrane that balloons distally. Extrinsic duodenal obstruction cases often present very late. The most common presenting features are
may be caused by malrotation with Ladd’s bands or a preduodenal por- bilious vomiting and feeding intolerance. Dehydration and electrolyte
tal vein or annular pancreas. The annular pancreas itself is not believed depletion rapidly ensue if the condition is not recognized and intrave-
to be the cause of obstruction, as there is usually an associated atresia nous therapy is not begun. Aspiration and respiratory failure may fol-
or stenosis in these patients. low. Repeated nonbilious vomiting is seen in cases of supra-ampullary
Duodenal obstructions usually occur in the second part of the obstruction (20%). Patients with a web or partial stenosis can survive
duodenum. They are believed to result from a developmental error to present in a much delayed fashion. 2
during early foetal life within the area of intense embryological activity Physical signs are nonspecific but can include upper-abdominal
involved in the creation of the biliary and pancreatic structures. Thus, distention with scaphoid lower abdomen. Additionally, in the
the obstruction usually occurs at or below the ampulla of Vater. appropriate clinical context, observation of typical Down syndrome
Duodenal obstruction is associated with prematurity (46%) and features should raise suspicion towards duodenal obstruction as the
maternal polyhydramnios (33%). In addition, there is a high incidence cause for neonatal intestinal obstruction. Finally, a careful physical
1
of specific associated anomalies, including Down syndrome (>30%), exam should concentrate on recognizing signs of significant congenital
malrotation (>20%), congenital heart diseases (20%), and other heart disease (e.g., cyanosis, murmurs), which could complicate
gastrointestinal tract (GIT) and renal anomalies. Along with prematurity perioperative management
and low birth weight, these associated anomalies are known to be Investigation
significant risk factors contributing to mortality in patients with In tertiary perinatal centres where a prenatal diagnosis has already been
duodenal atresia. Of note, the presence of Down syndrome itself does established, no further diagnostic work-up is typically necessary.
not influence the outcome of these babies.
In doubtful cases or in other settings, a plain abdominal x-ray
Demographics is the key method for diagnosis. An x-ray showing double-bubble
Although detailed statistics are not available in much of Africa, the gas shadows is essentially pathognomonic for duodenal obstruction
incidence of duodenal obstruction is reported to be 1 in 5,000–10,000 (Figure 62.1). If no double bubble is seen, instillation of 10–15 ml
2
births in most reports. Duodenal obstruction and jejunoileal atresia of air immediately prior to a plain abdominal radiograph may help
rank among the two most common causes of intestinal obstruction in to demonstrate these findings. In cases of stenosis or perforated
large series in the African population. 3 membranes, air may be seen in the distal GIT. Water-soluble contrast
Aetiology radiography is confirmatory, but it is generally needed only in cases of
incomplete obstruction. Radiographic findings of annular pancreas are
It has been demonstrated that from gestational weeks 5 to 10, the duodenum usually indistinguishable from other forms of duodenal obstruction.
is a solid chord. Intrinsic obstructions result from failure of vacuolization
and recanalization. An annular pancreas results from fusion of the anterior
and posterior anlage, forming a ring of pancreatic tissue that surrounds the
second part of the duodenum. Extrinsic obstructions result from a variety of
disorders of embryologic development specific to the pathology.
Clinical Presentation
Prenatal
Duodenal obstruction is readily diagnosed by prenatal ultrasound.
Antenatal care with prenatal ultrasonography should therefore be offered
to pregnant women in all circumstances. Duodenal obstruction presents
up to gestational week 20 with a double-bubble phenomenon due to the
simultaneous distention of the stomach and the first part of the duode-
num. In more than 30% of cases, maternal polyhydramnios is present,
and in some cases, serial amniotic aspiration has been reported as neces-
sary. In facilities where ultrasound is not available, a high index of suspi-
cion must be maintained in cases of maternal polyhydramnios. Pregnancy
can last near to maturity, and spontaneous delivery is usually the case.
Figure 62.1: Double-bubble sign on plain x-ray. Note the lack of distal gas.