Vulvar migration of the peritoneal end through the inguinal canal in a female infant: An unusual complication of the ventriculo-peritoneal shunt: A case report and review of literature.

Migration of the peritoneal end of the ventriculo-peritoneal shunt through the patent processus vaginalis has been described in preterm male infants with 26 such cases in the literature. The occurrence of this rare complication in the female preterm infants has not yet been reported. We report a 3-month-old premature female infant who presented with a gradual increase in head size since birth. Computed tomography revealed obstructive hydrocephalous secondary to the aqueductal stenosis and ventriculo-peritoneal shunt was performed. Ten days following the procedure she presented with swelling and other signs of inflammation over the right vulvar region. X-ray abdomen confirmed the migration of the peritoneal end into the vulva. Surgical obliteration of the patent processus vaginalis and replacement of the peritoneal end was performed. The patient had no recurrence at 6 months of follow-up. This report presents the unusual complication of a common procedure in a female infant with a review of the current literature.

Introduction

Ventriculo-peritoneal shunt is one of the routinely performed procedures in neurosurgical practice. A number of complications associated with the procedure such as blockage, obstruction, migration and malfunction of shunt have been mentioned in the literature. Migration of the catheter into the intestine, vagina, umbilicus and scrotum has been well described.[1] We report a rare case of the migration of the peritoneal end into the vulva of a premature female infant, which has not yet been reported in the literature.

Case Report

A 3-month-old premature female infant, first born issue of third degree consanguineous marriage presented with a gradual increase in the head size since birth. It was associated with persistence of downward gaze since birth. There was no history of fever, convulsions, vomiting, lethargy or refusal to feed. She was born at 7th month of gestation due to premature onset of labor in the hospital. Infant was kept in the incubator for 1 month in intensive care unit. There were no respiratory complications and baby recovered without sequelae. Immunization of the baby was up to date.

On examination, baby was conscious with spontaneous eye opening, playful and moving all four limbs. The baby was accepting feeds well. There was macrocephaly with head circumference of 43 cm and “sunset sign” was positive. Anterior fontanel was widely open and pulsations were felt on palpation. Fundus was showing grade 1 papilledema on both sides. Reflexes were normal in all the four limbs and plantars were upgoing.

CT scan [Figure 1] revealed obstructive hydrocephalous secondary to aqueductal stenosis. Cerebrospinal fluid examination (CSF) examination was normal.

Figure 1

CT scan (sagittal view) of the brain showing obstructive hydrocephalous secondary to the aqueductal stenosis

In view of above findings, ventriculo-peritoneal shunt (Chhabra shunt, Surgiwear Co., India) was performed through the right parietal burr hole (Keen′s point).

There were no complications in the immediate post-operative period. However, 10 days after this procedure, she again presented with swelling and redness over the left vulvar region of 1 day duration. On examination, the swelling was tender and the tip of the shunt tube could be palpated in the subcutaneous tissue.

X-ray abdomen [Figure 2a and b] showed the peritoneal end of the catheter in the left vulvar region, which had migrated through the patent processus vaginalis. This finding was also confirmed on ultrasound examination of the abdomen and inguinal region.

Figure 2

(a and b) X-ray of the abdomen showing the peritoneal end of the catheter in the left vulvar region through the patent processus vaginalis

Surgical obliteration of the patent processus vaginalis with replacement of the peritoneal end into the peritoneal cavity was performed by the pediatric surgeon.

In the post-operative period, the patient recovered well with no recurrence till the recent follow-up of 6 months.

Discussion

Although a number of complications associated with the ventriculo-peritoneal shunt procedure have been described in the literature, the common ones are malfunction, obstruction, blockage or migration of the shunt.[2-5] The occurrence of inguinal hernia or hydrocele following this procedure was first reported by Grosfeld and Cooney in 1974.[6] The incidence of this complication ranges from 3.8% to 16.8% in the literature.[35]

Migration of the peritoneal end into the scrotum have been reported in 26 male infants till date.[7]

The mean age of scrotal migration in these male infants was 17.1 months (4 days–5 years of life). Our patient′s age was within the given range. The interval between the shunt insertion and migration ranged from 1 day to 30 months (mean 3.8 months, median 1.0 month). The present case had migration about 10 days after the procedure.

According to the Kita et al. the migration of the shunt was more common on the right side as compared to the left.[7] Similar distribution of the inguinal hernias following shunt was described by Rowe et al.[8] in 1969. However our patient had migration of the peritoneal end on the left side.

Oktem et al.[9] postulated that the migration of the peritoneal end into the scrotum occurs through the “unobliterated processus vaginalis”. The processus vaginalis remains patent in 90% of male infants at birth, 50–60% at 1 year of age, 40% between 2 years and 16 years of age and 15% to 30% by adulthood.[7] The higher incidence of patent processus vaginalis at birth and more so in premature infant make this complication highly likely in preterm infants as in our case.

Moreover, the increase in the intraabdominal pressure due to the CSF inflow into the peritoneal cavity combined with the smaller peritoneal volumes (approx. 80 ml/m2 of the body surface area) can also contribute to maintain the patency of processus vaginalis is these premature infants.[67]

The management includes prompt surgical correction with obliteration of the processus vaginalis and replacement of the shunt catheters to avoid complications. However this complication rarely requires shunt revision.[10] Regular follow-up is required to ensure that the complication should not occur on the opposite side.

Conclusion

This rare case of the migration of the peritoneal end of the catheter into the vulva through the processus vaginalis in a female infant has not yet been described in the literature. This complication tends to occur in premature infants because of the higher incidence of patent processus vaginalis and smaller peritoneal cavity.