Ventriculoperitoneal shunt complications: a local study at Qena University Hospital: a retrospective study

Hydrocephalus is an excess of cerebrospinal fluid (CSF) in the ventricular system due to the imbalance between formation and absorption of CSF which is referred to (i) obstruction of the CSF pathways, (ii) over production of CSF, and (iii) impaired venous drainage [1]. Hydrocephalus is the second most common congenital brain malformation [2]. To date, the standard treatment of hydrocephalus is ventriculoperitoneal shunt. The technique of using the peritoneal cavity for CSF absorption in ventriculoperitoneal shunting (VPS) was developed by Kausch in 1908 [3]. Although VPS insertion is a common neurosurgical procedure, complication rates in adults are poorly established with a reported range from 17 to 33% [2, 4–10]. Children demonstrated a higher rate of shunt complications than did adults at 5 years (48 versus 27%, P < 0.0001) [11]. The advent of endoscopic third ventriculostomy has gained popularity due to the high complication and failure rates of ventriculoperitoneal shunt [12]. The major disadvantage of VPS is the fact that it constitutes a foreign body and prone to complications such as mechanical blockage, shunt infection, shunt migration, and rarely shunt protrusion [13]. If a shunt system fails to be operated correctly, the patient’s life and cognitive functions are placed at risk. Thus, an urgent revision must be done [14]. Although developing countries face the problem of shunt complications more than other countries, much research is ongoing but still remains a common problem [15].

This is a retrospective observational study that was conducted at the Department of Neurosurgery, Qena University Hospital, South Valley University for a period of 5 years from January 2012 to December 2016. An informed signed consent was taken from the parents and guardians of patients before enrolling them into the study after the approval of the ethical committee of the Faculty of Medicine, South Valley University. During the study period, a complete clinical assessment including a detailed history and examination with a particular emphasis on neurological examination was done for all patients after admission. A medium-pressure PS medical valve systems were inserted for all patients. Patients with VP shunt complications operated at Qena University Hospital were included while patients operated before the study period were excluded. The investigations performed for all patients were complete blood count (CBC), erythrocyte sedimentation rate (ESR), complete urine analysis, X-ray chest, and brain computed tomography (CT) scan or MRI. Specific investigations such as CSF analysis, CSF culture and sensitivity, blood culture and sensitivity, urine culture and sensitivity, pus culture and sensitivity, ultrasound of abdomen, shunt series X-rays, and MRI of the brain were also performed when indicated. A final diagnosis was made on the basis of clinical findings, and investigations and treatment of individual patients were planned accordingly. All patients with VP shunts who had one or more complications were included in the study.

Although VP shunt is an effective treatment of hydrocephalus, it is plagued by shunt-related complications [16]. As VP shunt is lifelong commitment, multiple surgical procedures may be required during life time [17]. The incidence of VP shunt complications was reported by most studies to be slightly higher in males than females [18], which was consistent with the current study as males represent 73.3%. Among 30 patients who were operated by ventriculoperitoneal shunt, infants and children represented 93.3% whereas adults represented 6.6%. This is consistent with Abdul Munam et al. who conducted their study on 40 VP shunt complicated patients where children represented 85% [19]. In neonates, scalp necrosis is actually a common complication associated with VP shunts which is due to the inherent skin fragility and the superficial nature of the shunt [20, 21]. In agreement with this current study scalp, necrosis was presented in four (13.3%) patients. Lee et al. found shunt blockage in 12.2% of 246 shunt procedures in Seoul, Korea, and their infection rate was 4.1%. Shunt infection was found together with blockage in most instances in their series indicating that shunt malfunction could have been caused by infection in these patients [22]. Vanaclocha et al. observed that shunt malfunction occurred in infected shunts where some of which were clinically undetectable. They argued that the incidence of shunt infection might be higher than generally reported and that negative cultures of CSF taps did not exclude shunt infection in malfunctioning shunts [23]. Peacock and Currer found shunt blockage to be 20% in their series of 440 patients [24]. Mwan’gombe and Omulo reported an infection rate of 24.6% among children operated for non-tumor hydrocephalus in Nairobi [25]. In the current study, shunt obstruction was reported in approximately 13.4% of patients (6.7% proximal obstruction by debris and 6.7% distal obstruction by pseudo cyst). Infection was also reported in 13.4% of patients. Hamada and Abou Zeid found that misdirection of proximal catheter was founded in two (7.1%) patients of their shunt malfunction series which is approximately near to the result of this current study as proximal catheter misdirection was founded in three (10%) patients [26]. Aldrich and Harmann found that shunt disconnection and fracture accounted for 15% of their shunt malfunctions and that occipitally placed shunts had a higher tendency to dislocate than frontally placed shunts [27]. In agreement with this study, Shunt fracture was noted in 6.66% of shunt complication for occipitally placed shunts. Bierbauer et al. found no advantage of anteriorly placed shunts over posteriorly placed shunts in terms of shunt malfunction or infection [28]. However, in the current study, there was an advantage of anteriorly placed VP shunts over posteriorly placed shunts in terms of malfunction and infection. It was also noted that complications tend to occur more with occipitoparietal than with frontal VP shunts. In more details, incidence of complications with occipitoparietal VP shunt was 10.4% and with frontal type was 6%.

Abdominal complications of VP shunt are not rare and the main causes of distal catheter failure are related to extra peritoneal retraction of the catheter and subcutaneous or intra-abdominal cerebrospinal fluid (CSF) collections [29]. In the current study, intra-abdominal pseudo cyst was reported in two (6.66%) patients and extra peritoneal catheter in one (3.33%) patient.

A higher incidence of unobliterated processus vaginalis in pediatric patients than in adult patients leads to a higher likelihood of VP shunt distal catheter migration into the scrotum [30]. In the current study, one infant presented with scrotal swelling due to patent processus vaginalis (see Fig. 11) and this is consistent with the previous study. Sathyanarayana et al. documented a protrusion of distal catheter per anus without any complications such as obstruction or peritonitis [31]. This agrees with the current study where two patients were reported with a VP shunt distal catheter per rectum without any complications in the form of obstruction or peritonitis. Previous studies reported that age and principal diagnosis (etiology) are independent contributors to the risk of initial shunt failure [32–34]. In agreement with these studies, the current study demonstrated that age and etiology were significantly associated with shunt revision where 28 (93.33%) patients with VP shunt complications were congenital. Accordingly, there was a higher rate of complications related to congenital etiology.

Insertion of VP shunt is routinely done by all neurosurgeons. Great care and precautions should be taken during insertion of the shunt system starting from scrubbing to avoid complications such as infection. Implantation of VP shunt system should be done by well-qualified neurosurgeons in order to limit or avoid shunt complications. Despite complications, the VP shunt remains the main surgical procedure used for hydrocephalus management.