Palliative ventriculoperitoneal shunting in dogs with obstructive hydrocephalus caused by tumors affecting the third ventricle

Abstract

Background Hypertensive or obstructive hydrocephalus is a common complication in dogs with tumors affecting the third ventricle for which few therapeutic options are available. Objectives To describe signalment, neurological status, and pre‐ and postsurgical findings, complications and survival time in 4 dogs with obstructive hydrocephalus caused by third ventricle tumors that were palliatively treated using ventriculoperitoneal shunting (VPS). Animals Four client‐owned dogs with obstructive hydrocephalus caused by tumors affecting the third ventricle. Methods Medical records were reviewed for dogs diagnosed with third ventricular tumors. Inclusion criteria were complete medical record, advanced diagnostic imaging for review, and VPS as sole surgical treatment. Results At the time of diagnosis, all patients displayed acute onset and rapidly progressive diffuse intracranial clinical signs. On advanced imaging, all dogs had a homogeneously enhancing mass occupying or collapsing the third ventricle as well as obstructive hydrocephalus. All of the dogs underwent VPS of the most dilated lateral ventricle. In 2 of the patients, intracranial hypertension followed by normotension after VPS placement was confirmed intraoperatively by means of direct intracranial pressure monitoring. Excellent clinical improvement was observed in all dogs immediately after surgery. Three patients required a second VPS in the contralateral lateral ventricle 3, 7 and 11 months after the first surgery, all of them with renewed improvement in clinical signs. Conclusion and Clinical Importance Ventriculoperitoneal shunting is a rapid and effective treatment for patients with obstructive (hypertensive) hydrocephalus caused by tumors located within the third ventricle.

Case Report: Ventriculoperitoneal Shunting and Radiation Therapy Treatment in a Cat With a Suspected Choroid Plexus Tumor and Hypertensive Hydrocephalus

“…Choroid plexus tumors are rare tumors in cats, and the reported clinical signs are variable including seizures, blindness and altered mental status ( 1 , 9 ). Although not mentioned if the cats in these studies had increased ICP, in people and dogs choroid plexus tumors are widely associated with raised ICP ( 2 , 10 ). Ventricular shunt placement has been shown to significantly improve clinical symptoms of human patients with increased ICP secondary to brain tumors ( 11 ).…”

“…A comparison between dogs with congenital hydrocephalus treated with VPS or medical management showed similar outcomes, although the median follow up time was only 9 months for medical and 15 months for surgical management ( 31 ). However, a case series with dogs with hydrocephalus secondary to tumors of the third ventricle found that the ICP measured considerably higher (28 mmHg and 31 mmHg) than the intracranial pressures found in dogs with communicating internal hydrocephalus (mean 8.8 mmHg, range from 3 to 18 mmHg) ( 2 , 32 ). In these dogs with hydrocephalus secondary to III ventricle tumors, their clinical signs were not improved by medical management but significantly improved after being treated with VPS placement ( 2 ).…”

“…Ventricular shunt placement has been shown to significantly improve clinical symptoms of human patients with increased ICP secondary to brain tumors ( 11 ). A retrospective case series describing four dogs with brain tumors affecting the III ventricle reported that clinical signs such as abnormal mental status, unlocalizable pain, decreased menace response and impaired vision improved after VPS placement, demonstrating that these clinical signs were likely due to the raised ICP rather than the brain tumors themselves ( 2 ). Furthermore, a retrospective study reporting 45 dogs treated with VPS due to hypertensive hydrocephalus found that decreases in ventricular volume and increases in brain parenchyma after VPS placement have been associated with improvement in one or more pre-operative clinical signs in dogs ( 12 ).…”

“…Placement of a VPS is often the preferred option for hydrocephalus treatment, although this too comes with various complications such as mechanical shunt failure, infection, hemorrhage and over drainage ( 2 , 21 ). In human medicine, rarely metastatic spread of neoplastic cells in the CSF through the VPS from the brain to the abdomen have been reported ( 29 ).…”

“…Radiation therapy (RT) is an established treatment choice for inoperable intracranial tumors in cats ( 1 ). Ventriculoperitoneal shunt (VPS) placement has been described for the treatment of obstructive hypertensive hydrocephalus secondary to intraventricular tumors ( 2 – 4 ). To the best of the authors' knowledge, this is the first report of successful VPS placement and subsequent RT treatment in a cat with III ventricle tumor causing hypertensive obstructive hydrocephalus.…”