Keywords
meningeal carcinomatosis - neoplasm metastasis - hydrocephalus - cerebrospinal fluid
shunts - neurosurgery
Palavras-chave
carcinomatose meníngea - metástase neoplásica - hidrocefalia - derivações do líquido
cefalorraquidiano - neurocirurgia
Introduction
Leptomeningeal carcinomatosis (LC) occurs when a solid primary tumor infiltrates the
meninges, including the pia mater, arachnoid, and subarachnoid space. This rare complication
of breast cancer affects approximately 5% of patients. Given the high occurrence of
breast cancer globally, in terms of sheer numbers, it is the most prevalent cause
of LC.[1]
Patients with LC usually have a history of cancer, and most of them have already been
diagnosed with metastatic disease. The signs and symptoms commonly observed include
headache (80%), nerve pain that radiates from the spine, deficiencies in cranial nerves,
visual loss, loss of hearing, seizures, and a condition known as cauda equina syndrome.
Nausea, vomiting, headaches that worsen with changes in position, and even drowsiness,
are symptoms associated with obstructive or communicative hydrocephalus, which may
affect more than half of patients with LC due to impairment of the flow of cerebrospinal
fluid (CSF). An additional potential clinical manifestation is the development of
a new psychiatric disorder.[2]
[3]
The diagnosis is confirmed through positive (malignant) CSF cytology (gold standard),
radiological evidence (nodular changes on computed tomography [CT] or magnetic resonance
imaging [MRI] scans) that matches clinical observations, and symptoms indicating CSF
involvement in a patient who has a known malignancy.[4]
[5]
The primary management goals for LC are to improve the neurological function and quality
of life of the patients, prevent any further deterioration of neurological symptoms,
and ultimately extend their lifespan. This may include radiation therapy, the use
of bevacizumab, and ventriculoperitoneal shunt placement. In numerous cases, opting
for a palliative and comfort-oriented approach may be appropriate, even starting from
the initial diagnosis of leptomeningeal disease.[6]
[7]
Regarding CSF shunts, the current body of literature describes the possibility of
diversion procedures in as many as 36 different sites, including areas such as the
mastoid bone, the pleura, the right atrium, the peritoneum, the urinary tract (UT),
and the fallopian tubes.[8] According to the literature, the UT may be considered a potential alternative to
divert the CSF when the peritoneum or atrium is unavailable.[8]
[9] The primary advantage of using the UT as a diversion pathway for the CSF is that
it does not rely on the absorption properties of the tissue, which is a factor in
the case of the peritoneum. Moreover, the choice of this anatomical site for CSF diversion
is based on elimination via micturition instead of absorption.[9]
[10]
Case Report
A 40-year-old female patient had been under oncological follow-up for breast carcinoma
for 6 months. Due to the altered level of consciousness, nausea, and vomiting, a brain
MRI scan was requested, which showed diffuse leptomeningeal inflammatory tissue in
the posterior fossa ([Figure 1]) with perineural extension, as well as in the supratentorial compartment, notably
in the left frontotemporal region, with mild infiltration of the parenchyma edema
and hydrocephalus ([Figure 2]). Given the clinical context, the possibility of meningeal carcinomatosis, among
other inflammatory and infectious diseases, was considered. Therefore, we decided
to initiate radiation therapy.
Fig. 1 Contrast-enhanced inflammatory tissue covering the leptomeningeal surface, mainly
of the posterior fossa between the cerebellar folia, notably in the upper portion
of the cerebellar vermis and mesencephalic aqueduct, with some areas of parenchymal
infiltration causing local edema.
Fig. 2 Computed tomography (CT) scan showing hydrocephalus (white arrow) and transependymal
edema (red arrow)
Before the end of the radiation therapy, the patient was admitted to the emergency
department with a sudden decreased level of consciousness. Thus, a brain CT scan showed
supratentorial hydrocephalus and signs of transependymal transudation. Initially,
external ventricular drainage was performed, and the definitive treatment was postponed
until a discussion was held with the oncological team. Based on the clinical context,
conditions, and prognosis, ventriculovesical shunting with the interposition of a
low-pressure valve was proposed.
The technique for the placement of the ventriculovesical shunt follows the same principles
as those of ventriculoperitoneostomy. The patient must have an indwelling urinary
catheter, and it must be open. A median suprapubic incision and tunneling of the subcutaneous
tissue communicate with the cranial incision. The bladder wall is identified and repaired
with a catgut suture. A punctiform cystostomy is performed. The distal catheter is
introduced for 7 cm to 8cm, and the repair point is used to fix the catheter on the
bladder wall ([Figure 3]). Closure is performed conventionally, with sutures in layers. For the evaluation
of the correct positioning of the urinary catheter, the patient undergoes an abdominal
CT ([Figures 4] and [5]). The indwelling bladder catheter is maintained for five days.
Fig. 3 A punctiform cystostomy (red arrow) is performed. The distal catheter is introduced
for 7 cm to 8cm (black arrow).
Fig. 5 Abdominal CT scan (axial view): the distal catheter inside the bladder (red arrow).
Fig. 4 Abdominal CT scan (coronal view): the distal catheter inside the bladder (red arrow).
Discussion
The clinical manifestations of meningeal carcinomatosis are vast; patients may be
asymptomatic (a minority of cases), as the findings may be accidental (∼ 2% of the
cases), or patients may present with severe symptoms (most cases). When symptomatic,
the manifestations can be systemic and nonspecific, involving headache (present in
80% of the cases), alteration in the level of consciousness, nausea, and vomiting,
especially in cases in which there is hydrocephalus.[1]
[11] In the case herein reported, the patient was symptomatic, and her clinical history
corroborated the diagnostic hypothesis developed after the imaging exams.
Cases that present with hydrocephalus, are typically treated with ventriculoperitoneal
or ventriculoatrial shunts; however, due to the risks of dissemination of neoplastic
cells, they can be replaced by a ventriculovesical shunt.[10] The first surgery that enabled a connection between CSF and the genitourinary system
was performed in 1925 by Heinle, who connected the renal pelvis to the lumbar dura
mater, a urethrodural anastomosis.[12] In 1949, Matson performed what was described as a lumboureterostomy at the ureterovesical
junction using a polyethylene tube. This anatomical site has a valve mechanism that
prevents backward flow and consequent ascending infections, but an ipsilateral nephrectomy
was required.[13]
In 1980, West[14] reported the first ventriculovesical shunting, called ventriculovesicostomy. The
bladder was initially opened on its front wall, and the shunt was rerouted obliquely,
positioned above and to the side of the trigone. A suture was used to attach the catheter
to the back wall of the bladder via a connecting component. A significant portion
of the shunt tubing, measuring 15 cm in length, was left unsecured and hanging loosely
inside the bladder. The aurthor[14] reported that the complication of recurrent obstruction was relieved by urethral
instrumentation.
In 2001, Ames et al.[10] developed a new method of ventriculovesicostomy without sacrificing a kidney. They
altered the first procedure described by creating a distal shunt catheter using a
polyester cuff, which has antibacterial properties, at the end of a silicone catheter.
A nonabsorbable suture was employed to fix this apparatus onto the front wall of the
bladder. The authors[10] also created a deep tunnel running along the front wall of the bladder, which was
then stitched over the catheter. This addition was intended to position the shunt
slightly higher towards the dome of the bladder, thereby preventing trigonal irritation.
To complete the procedure, a minor incision was performed in the bladder wall to enable
the introduction of the distal shunt. There were no postoperative complications during
the first year of follow-up; however, they[10] highlighted the need of awareness regarding dehydration, ascending infection, and
the potential formation of encrustations on the shunt tube.
Conclusion
Ventriculovesical shunting is an alternative to other CSF diversion procedures, especially
when CSF absorption is not desired. This option is particularly useful in cases of
LC. More studies are necessary to define the incidence of complications and reoperations
in ventriculovesical shunts.
