Management and Outcome of Infantile Hydrocephalus in a Tertiary Health Institution in Nigeria

INTRODUCTION

Hydrocephalus is the most common condition treated by pediatric neurosurgeons.[1] Ventriculoperitoneal shunt (VPS) remains the most common treatment for hydrocephalus world over even though it is associated with several short- and long-term complications.[2] As shunt system continues to evolve over the years to improve the outcome of the procedure; surgeons have also devised other alternative and safer techniques for the treatment of hydrocephalus. The advent of endoscopes ushered in the endoscopic third ventriculostomy (ETV) technique and later endoscopic choroid plexus cauterization (CPC) as alternatives to shunting for hydrocephalus in 1995.[123] Even then, there had been reported low success rate when used alone in some patients.[456] Hence, the recent popularization of combined ETV + CPC technique as a relatively safe means of increasing the overall treatment outcome success and avoiding the need for a shunt in infants with hydrocephalus.[2789]

Despite of the recent advances in technology, VPS remains the most widely performed procedure for hydrocephalus in infants. Various shunt valve designed have been developed to improve the success rate of shunting for hydrocephalus. The general trends in developed country are the use of programmable shunt valves. In low-income country like Nigeria, however, low cost, fixed pressure shunt valve system is widely used.

This study was undertaken as an audit of infant hydrocephalus management in our institutions where fixed-pressure slit-in spring Chhabra ventriculoperitoneal shunt device is traditionally used.

MATERIALS AND METHODS

This study included infants (<12 months) with hydrocephalus managed in our neurosurgical division over 3 years. Our institution has a facility for transcranial ultrasound, computed tomographic scan, and magnetic resonant imaging machines. The diagnosis of hydrocephalus was based on clinical and neuroradiologic evaluations. Data were collected retrospectively through review of case files, imaging reports, ward records, operative notes, and follow-up clinic charts. Information on demography, etiology, type and onset of hydrocephalus, treatment offered, complication, and outcome of care were retrieved using a predesigned pro forma. The main outcome measures were developmental milestones attained for age, complications, and death. Data were entered into 2011 IBM SPSS (Statistical Package for social sciences) software for windows, version 20; Armonk, NY (IBM Inc.). Frequency tables and figures were used to illustrate results.

RESULTS

Fifty-eight infants constituting 76% of a total of 76 patients with hydrocephalus were treated between 2012 and 2014. Case files of these infants were retrospectively studied. There were 33 males (57%) and 25 females (43%) with male to female ratio of 1.3:1. Age of patient ranged between 3 and 12 months with a median age of 3 months (±standard deviation of 4.2 ± 2 months). The most common age group in this study was 1–6 months 33 (57%), while the 7–12 months age group had the least frequency 9 (15%) [Table 1].

Table 1 Demographic and etiological distribution, cases (n=58)

A large proportion had an undetermined cause of their hydrocephalus 18 (31%). Of those with an identifiable congenital cause, the majority was due to Chiari II malformation 14 (24%) while intraventricular hemorrhage (IVH) was the most common acquired cause 10 (17%) [Table 1 and Figure 1]. In general, congenital hydrocephalus was more common 40 (69%) than acquired type 18 (31%) [Figures 2–4].

Close

Figure 1

Diagnosis and frequency of occurrence

Export to PPT

Close

Figure 2

Classification of hydrocephalus based on the time of onset

Export to PPT

Close

Figure 3

Typical hydrocephalus

Export to PPT

Close

Figure 4

Neglected congenital hydrocephalus

Export to PPT

The majority of the patients 27 (47%) had communicating hydrocephalus, whereas noncommunicating type was seen in 17 (29%). VPS was the neurosurgical treatment offered in most of the cases 53 (91%), followed by 3 (3.4%) ETV, and 2 (1.7%) ventriculosubgaleal (VSG) shunt [Figure 5], respectively [Table 2].

Close

Figure 5

(a) Subgaleal pouch following ventriculosubgalial shunt. (b) Postconversion of ventriculosubgaleal shunt to ventriculoperitoneal shunt

Export to PPT

Table 2 Type of hydrocephalus, surgical treatment, and complication, cases (n=58)

Infection was found to be the most common postoperative complication 7 (12%) in this series, followed by distal obstruction 5 (8.6%) while migration of shunt was the least complication experienced by patients 1 (1.7%). There were 2 perioperative deaths giving a mortality rate of 3.4%. One of the deaths was due to respiratory arrest in an infant with Chiari II malformation while the other patient was a preterm with IVH. The actual cause of death was not documented in the preterm. As at last follow up, most patients 38 (65.5%) were assessed has having satisfactory outcome based on developmental milestones attained for age.

DISCUSSION

A total of 76 patients with hydrocephalus were treated in our facility in 3 years between January 2012 and December 2014 under review. This figure is undoubted disproportionate to the incidence of the disease in the community. Poverty, stigmatization, traditional beliefs, and poor awareness of the amenability of hydrocephalus to orthodox medicine remain strong negative factors preventing hospital presentation in Sub-Sahara Africa. On the other hand, approximately 69,000 annual hospital admissions for hydrocephalus were recorded in the United States where awareness and access to health care are much better.[1011]

This series recorded a slight male preponderance in the incidence of hydrocephalus [Table 1] with a male to female ratio of 1.3:1 which is similar to the reports in other parts of Nigeria and America.[10121314] There was no obvious reason for this finding.

Hydrocephalus is predominantly a disease of infants; hence, the age range of 3–12 months with a median age of 3 months found in these studies. This is in keeping with findings in earlier studies.[1014] The most common age group in this study was 1–6 months 33 (57%), the cranial sutures are yet to fuse at this early age and pressure created by accumulation of cerebrospinal fluid (CSF) in the ventricles causes a back pressure effect on the cranium, widening the sutures, and expanding the head circumference (mega cranium); a feature pathognomonic of hydrocephalus in childhood.[15]

Chiari II malformation in infants with lumbosacral myelomeningocele was the most common cause of hydrocephalus, followed by IVH in these infants [Table 1 and Figure 1]. This is a reversal of the etiological pattern reported by Kulkarni et al. where IVH was the most common, followed by aqueductal stenosis.[2] In our series, however, the precise cause of the disease could not be determined in a significant number of cases 19 (32.7%). This is mostly due to financial constraints, which limited imaging and other necessary investigations that could have been done to confirm the diagnosis. In Nigeria, National Insurance scheme is yet to cover all citizens, especially the informal sector and the rural dwellers.[16] Hence, hospital bills are settled out of pocket with individual patient taking full responsibility for his or her hospital bills. For the same reason, indigent parents generally find it difficult to finance the care of their sick child [Figure 4]. Besides, hospital is usually the last point of call after exhausting their meager resources-seeking alternative healthcare at traditional homes and faith healing homes.[17]

In general, congenital hydrocephalus was more common than acquired type, and the majority of patients had communicating hydrocephalus, [Figure 2]. VPS was the neurosurgical treatment offered in most of the cases 53 (91%), followed by 3 (3.4%) ETV, and 2 (1.7%) VSG, respectively [Table 2]. VPS remains the most commonly performed treatment procedure for hydrocephalus despite all its pitfalls.[2] Endoscopic procedure is a relatively new technique in our practice, the 3 patients who had ETV had good outcome without complications. Good outcome from ETV among childhood hydrocephalus has been previously reported in Nigeria and other part of the world. There are on-going controversies on the efficacy of ETV in infant hydrocephalus management. A retrospective, multicenter North American study has suggested ETV + CPC as a relatively safe procedure with improve treatment success.[2] In Nigeria, a success rate of 75% has been reported with ETV + CPC in childhood hydrocephalus.[14] Our unit practice is likely to move toward ETV as preferred procedure in suitable infants following this audit. VSG procedure was undertaken for 3 of our patients with IVH as a temporizing measure. All of these were subsequently converted to VPS when the CSF became clear [Figure 5].

Infection was found to be the most common postoperative complication 7 (12%), in this series, followed by distal obstruction 5 (8.6%) while migration of shunt was the least complication experienced by 1 patient (1.7%). The prevalence of infection (12%) record in this study falls within the variable rates of 2.2%–39% reported in earlier studies.[1819] and it tallies with the overall infection rate of 11.7% reported by Simon et al. in a study of over 7000 children after shunt placement in America.[20] Even though it is higher than 6.98% observed by Wu et al. in a similar study in china.[21] The prevalence of infection is generally high in the developing tropical countries like Nigeria. However, Simon et al.'s study were done before the advent of antibiotics impregnated shunts which explain why the infection rate was close to our findings.[20] Aside from type of shunt implanted, other predisposing factors to shunt infection include age of patients at shunt insertion, cause of hydrocephalus and perioperative antibiotics, operative room traffic, duration of the shunt placement operation, experience of the neurosurgeon, and cause of hydrocephalus.[2223] Further studies of the role of these variables in etiology of shunt infections will be a valuable future research direction. Double gloving, prophylactic antibiotics, shunt impregnated with antibiotics usually rifampicin and clindamycin are reported to reduce shunt infections.[24] Most commonly implicated organisms in shunt-associated infections are coagulase-negative Staphylococcus and Staphylococcus aureus and other skin bacteria followed by Gram-negative bacteria.[21] Microbiology report was not studied in our series.

CONCLUSIONS AND RECOMMENDATION

There is need to improve surgical intervention in the form of ETV in suitable patients. Subsidizing cost of care may be considered for indigent patients.