Ventriculosubgaleal shunting in the treatment of posthemorrhagic hydrocephalus of premature infants: case series

Introduction: Posthemorrhagic hydrocephalus(PHH) comprises the most common complication in  preterm infants (PTI) who suffered germinative matrix hemorrhage (GMH), and its treatment is still matter of controversies. These infants usually weigh less than 1,500g and a temporary CSF diversion  is needed. VSGS is preferred in those cases because it is a simple and rapid method, no need for repetitive aspiration for the evacuation of CSF, gives a permanent decompression without causing electrolyte and nutritional losses, and still protects the cerebral development of newborns with GMH.
Methods: We analyzed a series of 22 PTI who underwent VSGS for PHH, between July 2015 and April 2019, and minimum follow-up 6 months. The median gestation age was 28 weeks (range 23-32). The median weigh was 985g (range 625-1615). The mean period harboring de VSGS was 61,8 days (range 35-80). Results: The cases were studied for: 1) Shunt dependency: 11 children (50%) showed persistent hydrocephalus at further investigation and underwent to VP shunt after stable clinical condition. 2) Infection: 6 subjects (27,2%) showed positive cultures, and were converted to External Ventricular Device (EVD), and further VP shunt; 3) Outcome: the results were separated in Excellent/Good (GOS 5-4) 12 subjects (54%); Poor (GOS 3-2): 8 subjects (36%) and Death (GOS 1): 2 subjects (10%).
Conclusions: VSGS is a good alternative method to treat PHH, especially in a preterm infant who needs a temporary shunt device. The low rate of severe complications and encouraging results about persistent hydrocephalus should guide further investigation and larger cases series.


Introduction
Intraventricular hemorrhage (IVH) remains a serious complication of premature birth. Despite many treatment options, there is still no consensus on the management of post-hemorrhagic hydrocephalus (PHH) in the very low birth weight (VLBW) baby [1,2,5,8]. Preterm infants (PTI) are at risk for an extensive array of neurological complications, of which the most commonly observed and severe is intraventricular hemorrhage (IVH). Currently, IVH is seen in approximately 15%-20% of infants weighing below 1500 g and in 50% of infants weighing less than 750g. In 25%-50% of cases, progressive posthemorrhagic ventricular dilatation and posthemorrhagic hydrocephalus (PHH) develop as result of IVH. Symptomatic PHH has been associated with poor outcomes, including elevated rates of cognitive deficits, disability, and mortality [4]. Many reports have been showing VSGS as a beneficial tool in the management of PHH on premature infants before the placement of a permanent shunt and also comparing VSGS with Omaya Reservoir (OR) technique. The preference of these two techniques has been seen in different neurosurgical centers [5], although no significant statistical difference has been demonstrated in general outcomes between the both of them [6]. Since VSGS offers a less handling of the system and a constant control of intracranial hypertension, it remains to be the preferred protocol for the author, because puncturing the reservoir to control intracranial pressure daily does not seem necessary. Moreover, other authors have attempted to show that these VSGS patients were significantly older, had achieved greater weights and more optimal surgical candidacy at the time of VP shunt insertion [3,5]. We herein investigate the role of VSGS in the prognosis of the many complications it can occur.

Material and methods
We analyzed a series of 22 PTI who suffered Papile [7] grades III and IV of IVH and underwent VSGS for PHH, between July 2015 and April 2019. All

Diagnosis
GMH and PHH were diagnosed upon serial head ultrasounds (HU) performed by the senior author at side bed into de Neonatal ICU. All the cases were classified into Papile et al grade groups (table 1). The subjects were also studied pre-operatively for: gender, gestation weeks, weight at birth, age at surgery (in days), APGAR, and post-operatively for: days harboring the system, infection and shunt dependency. The follow-up protocol for IVH is summarized in figure 1. All the grades III and IV were seek with HU weekly, or sooner as it needed, as well daily for measurements of head circumference (HC), fontanel fashion, and clinical general status. Once the patients fit the profile established by the strict protocol (figure 1), the PTI had to be operated. We discussed the clinical status and coagulation exams with the ICU crew and if necessary, red blood cells or platelets transfusion were available.

Surgical Technique
All the PTI were transferred to the operation room and under general anesthesia, the skin was incised and subgaleal space undermined. A small trephination at Kocher point was made and the ventricular catheter inserted. A valveless system (HpBio® -neonatal) was then connected (figures 2) without a distal catheter (removing the valve). The skin was closed in one layer fashion with separated non-absorbable sutures.

Post-operative period
In the ICU, all the PTI were followed daily with HC measurements and wound inspection twice a day. We recommended the nurses to do a massage several times a day upon the system reservoir, to guarantee a good subgaleal pouch, especially in the first five days post-op. Effort was also taken not to put tight dressings over the wound, avoiding the stretch of the subgaleal pouch. Head Ultrasound continued to be done weekly to follow de ventricular size and brain arteries Doppler fashion [8].

Results/Discussion
The subjects are being followed at least for 9 months since each surgery. Every studied detail is summarized in table 2.

Shunt dependency
Six children (27.2%) developed some sort of complication in which was necessary to perform neuroendoscopic approaches such as septostomy, endoscopic third ventriculostomy, and cysts fenestrations. All of them needed to be converted to a further VP shunt. Other 6 subjects showed persistent hydrocephalus during their investigation and had to undergo a VP shunt after stable clinical condition.
To be prone to VP conversion all the following conditions were necessary: 1) weight higher than 2,000g, so that PTI's VP shunt would have its chances improved to work properly with less abdominal complications; 2) at least 2 serial negative CSF samples for bacteria, to guarantee that the CSF is free of pathogens 3) CSF protein content less than 1 g, expecting this could decrease the risk of mechanical VP shunt malfunctioning and eventually 4) persistent hydrocephalus and bulging subgaleal pouch, assuring the need of permanent shunting.

Infection and complications
Six subjects (27.2%) presented positive CSF cultures. They were converted to External Ventricular Device (EVD), received intravenous antibiotics tailored by the antibiograms, and subsequent VP shunt accordingly the above-noted conditions. 3 of those 6 subjects showed leakage from the pouch and then meningitis, which lead to further EVD. The other 3 developed pulmonary infection followed by sepsis and ventriculitis, and also required temporary EVD and were converted to VP shunt.
The . Infection rates seem to be related to the age and weight of children. In our series, the median weight was 985g, less than 1000g, and maybe one of the reasons in which led to being more prone to infections. In the same way, the median gestation weeks was 28 weeks, less than 30 weeks, another cut-off for poorer prognosis [11].
The most frequent complications of VSGS besides infection are: leakage, kinking of the shunt tubing, and wound breakdown with variables incidences [12].

Outcome
The results were separated among: Excellent/Good (Glasgow Outcome Scale -GOS -5-4) 12 subjects (54%). Children who are doing wellperforming, adequate or barely normal motor and cognitive skills for the age; Poor (GOS 3-2): 8 subjects (36%), in which include children who are underdeveloped, disabled, and shall be dependent to the caregivers for a significant span of life; and Death (GOS 1): 2 subjects (10%). One death occurred after severe pulmonary infection resulting in sepsis (patient n.4) and the other one (patient n.22) after respiratory distress during bronchospasms crises. Vaner et al observed 28% of mortality in the first month (25 cases of VSGS), related mainly to infection and sepsis [1]. Kutty et al found 14.2% of mortality (1 out of 7 children). The mortality is intrinsically related to the germinative matrix hemorrhage disease and related morbidly of prematurity.

Conclusions
VSGS is a safe and quick procedure and works as a good alternative method to treat PHH, moreover those PTI whose need a temporary shunt device [13,14,15,16]. A proactive IVH protocol should be conducted in each neonatal ICU in order to diagnose and treat these patients in advance these. Multidisciplinary teams should be encouraged to work on such cases since knowledge from different areas is required, as well as engagement from these professionals, who can face this common and challenging condition.
Ongoing multicenter prospective studies are being expected to answer many unsolved issues [17]. So far, we recommend VSGS as a useful tool considering its low rate of severe complications and good results about persistent hydrocephalus.

Disclosure Statement
The author reports no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.