Academic Editor: Rafael Franco
Despite a relatively high risk of complication and failure, ventriculoperitoneal shunting (VPS) is the most common approach to surgically treat chronic hydrocephalus [1, 2]. Although hydrocephalic patient mortality has been significantly reduced by introducing ventricular shunt systems, a wide variety of mid and long-term complications principally related to valve-regulated shunts are encountered and these underscore the complex pathophysiology of this condition [3, 4].
Shunt malfunctions have been classified into three groups: (1) Mechanical failure related to improper functioning of the device, including obstructions, ruptures, migrations, and disconnection; (2) Infections related to colonization of implanted materials and development of clinical infection either of the CSF inside the shunt or the soft tissue around it; and (3) Functional issues related to the hydrodynamic properties of the shunt [5].
We have evaluated the long-term results of shunt therapy in patients with
idiopathic normal pressure hydrocephalus (iNPH) with a follow-up period spanning
ten years [1], this represents the most extended follow-up study conducted to
date in the literature. We showed that VPS is a safe modality capable of
improving symptoms in most patients, including long-term symptom management.
Compared with other symptoms, gait disturbance showed sustained improvement
following shunting, VPS displays a low complication rate, and this approach has
met with long-term therapeutic success over for
Shunt overdrainage is a common complication following VPS. This was first reported by Dandy in 1932 where an account of sudden drainage of cerebrospinal fluid (CSF) after surgery lead to intracranial hypotension with ventricular collapse [15] was detailed. In 1982, Hyde-Rowan et al. [16] described this condition, termed slit ventricle syndrome, that is characterized by intermittent headache (from 10 to 90 min), small ventricles on imaging studies, and slow filling of the valve reservoir on palpation due to the postural changes of CSF drainage. To date, shunt overdrainage is associated with severe headaches that interfere with activities of daily living in patients with CSF diversion systems and those with smaller or normal cerebral ventricles [17].
Pathophysiology of shunt overdrainage and slit ventricle syndrome has not been
completely established and several theories are actively under investigation
including acquired craniocerebral disproportion [18], periventricular gliosis
[19], capillary absorption laziness [20], and pulsatile vector theory [21].
Moreover, the siphon effect is primarily associated with CSF overdrainage. In the
supine position, the intracranial pressure is equivalent to that of the
subarachnoid spinal space, however in the standing position, intracranial
pressure falls to 0 mm H
Panagopoulos D et al. [24] conducted a narrative literature review focused on an analysis of shunt overdrainage and slit ventricle syndrome. The authors also reported technological advancements aimed in counteracting these treatment side effects. Moreover, they described CSF hydrodynamics in patients who undergo CSF flow diversion and reported evidence supporting a role for internal jugular vein collapse as a result of a moderate decrease of intracranial pressure when patients adopt a vertical position. Further, this report described the most relevant clinical and radiological criteria associated with slit ventricle syndrome, specifically, the most accepted pattern of overdrainage stemming from negative pressure, an on-off symptom complex, recurring proximal ventricular dysfunction, chronic subdural collections due to shunt overdrainage, and headaches unrelated to shunt function.
Overall, this study sought to clarify a complex and poorly understood condition which often influences patient prognosis. The authors are to be commended for bringing these issues to light as additional tailored preclinical and clinical studies are necessary to provide a set of best management principles for hydrocephalus-affected patients.
FT—Writing – original draft, Conceptualization. GG—Writing – original draft, Supervision.
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This research received no external funding.
The authors declare no conflict of interest. GG is serving as one of the Editorial Board members of this journal. We declare that GG had no involvement in the peer review of this article and has no access to information regarding its peer review. Full responsibility for the editorial process for this article was delegated to RF.
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