Volume 3, Case 16
Loren G. Yamamoto, MD, MPH
Kapiolani Medical Center For Women And Children
University of Hawaiʻi John A. Burns School of Medicine
This is a 1-month old male who was seen by his pediatrician in a rural town with poor feeding and occasional emesis. His weight gain was not satisfactory though his exact weight was not specified. He was hospitalized for observation in a rural hospital with a diagnosis of failure to thrive. His birth history was unremarkable. His birth weight was 2.9 kg (6 pounds, 7 ounces).
On the third day of hospitalization, his emesis became bilious. Radiographs of his abdomen were obtained.
View abdominal series: Flat (supine) view.
Upright view.
These radiographs show an obvious bowel obstruction. The bowel is distended. The bowel walls are smooth losing the normal plicae appearance due to distention. The upright view shows many obvious air fluid levels.
Intravenous fluids were started at a maintenance infusion. A nasogastric tube was inserted and transfer to a children's hospital was arranged. There was no history of fever.
Upon arrival at the children's hospital, he was evaluated by a surgical resident. Exam: VS T37.4 (rectal), P146, R42, BP 96/49. Weight 3.7 kg. Alert, not toxic. HEENT normal except for an NG tube in place. Mucosa moist. Neck supple. Heart regular without murmurs. Lungs clear. Abdomen soft, slightly distended, hypoactive bowel sounds. No masses. No hernias. Stool in the diaper (loose, brown), guaiac positive. Pulses good.
He was assessed as having a bowel obstruction due to intussusception or a malrotation. A barium enema was ordered. An abdominal series was repeated prior to the barium enema.
View second abdominal series.
This second abdominal series shows the same findings as the radiographs taken at the rural hospital. During the process of inserting the rectal tube for the barium enema, the infant was crying and the radiologist noticed an inguinal bulge. He contacted the surgeon to evaluate the patient. The surgeons at this point acknowledged that the infant had an incarcerated right inguinal hernia. This was reduced with moderate difficulty. The barium enema was then completed which failed to show any evidence of intussusception or malrotation. The infant's symptoms resolved. A follow-up abdominal series taken the next morning showed a normal abdominal gas pattern with resolution of the obstruction. The inguinal hernia was repaired and the infant was discharged home.
In retrospect, it is highly likely that the incarcerated hernia was present during the initial examinations since the obstruction resolved after the hernia was reduced. Specifically checking for inguinal hernias in any patient with vomiting would prevent one from missing this as a cause of the vomiting. In chubby infants, an incarcerated inguinal hernia may not be visibly obvious. Palpating the inguinal region would immediately reveal a hot-dog shaped mass in the inguinal region. A thickened cord can sometimes be appreciated, but this by itself would not indicate the presence of an incarcerated inguinal hernia. Female infants will often incarcerate an ovary instead of bowel. This would not yield a cylindrical mass, but a spherical mass of rubbery or grape-like consistency.
When bowel is incarcerated in an inguinal hernia, irritability and signs and symptoms of a bowel obstruction will develop. Radiographic signs of a bowel obstruction may be absent if the duration of the incarceration is short. Bowel gas may be visible in the groin region, but the absence of this does not rule out an incarcerated inguinal hernia. Review our patient's initial supine abdominal film again.
There is a pattern of air in the infant's left groin region. In this case, this air is probably due to a skin fold since clinically the infant's hernia was on the right. Additionally, this air does not show a pattern resembling bowel gas.
Most parents will seek medical attention when the inguinal bulge is noted before a bowel obstruction becomes obvious. Others will present with symptoms of a bowel obstruction. A delay in diagnosis can lead to bowel ischemia, necrosis, and perforation.
It is often difficult to distinguish a tense hydrocele from an incarcerated hernia. Hydroceles are commonly referred to pediatric centers because they are often difficult to distinguish from an incarcerated hernia or an acute scrotum. A hydrocele transilluminates fully. Typically, a spherical or oval mass is palpable in a hydrocele, while the mass is usually banana or hot-dog shaped in an incarcerated inguinal hernia. The hydrocele mass is within the scrotum, while the mass of an incarcerated inguinal hernia extends from the internal ring to varying depths into the scrotum.
Unless the child is very ill or bowel necrosis is suspected, a manual reduction of the incarcerated hernia is indicated. Rather than attempting to push the hernia through the ring, it is more optimal to squeeze gas or fluid out of it longitudinally from the tip back toward the abdominal cavity. If reduction is not attempted or unsuccessful, a surgeon should be consulted to perform the reduction or to repair the hernia.
References
Schnaufer L, Mahboubi S. Abdominal Emergencies. In: Fleisher GR, Ludwig S (eds). Textbook of Pediatric Emergency Medicine, third edition. Baltimore, MD, Williams and Wilkins, 1993, p. 1316-1317.