Key-words:
Blood patch - durotomy - epidural - pseudomeningocele
Introduction
Pseudomeningocele is an extradural cerebrospinal fluid (CSF) collection arising from
a dural defect that may be congenital, traumatic, or as a result of intraoperative
dural tear during spinal surgery. The incidence of dural tears during spinal surgeries
reported in the literature ranges from 1.7% to 16%.[[1]],[[2]] The exact incidence of postoperative pseudomeningocele is not known. Most cases
go underreported as they are asymptomatic and resolve either spontaneously or with
conservative methods. Surgeons are also reluctant to report this complication. Gerardi
et al. reported an incidence of 6.8% of dural tears which are inaccessible to repair
or go unrecognized during spinal surgeries.[[3]],[[4]] In cases of persistent CSF leak following dural repair, a multitude of consequences
such as postural headache, nausea, vomiting, neck or back pain, dizziness, and VI
cranial nerve palsy leading to diplopia, photophobia, and tinnitus may occur.[[5]],[[6]],[[7]] Persistence of these dural tears may result in chronic CSF leakage into the extradural
space with encapsulation causing a pseudomeningocele.
Various treatment options such as close observation for spontaneous resolution, conservative
measures such as bed rest, lumbar subarachnoid drainage, pressure dressings, hydration,
and use of abdominal binder have been recommended.[[8]],[[9]],[[10]],[[11]] Re-exploration and surgical repair of defect may be necessary in patients with
clinical features of intracranial hypotension, neurological deficit, external fistula,
or infection.[[12]],[[13]],[[14]],[[15]],[[16]] Epidural blood patches (EBPs) have been used successfully in postspinal headaches
and spontaneous intracranial hypotension. EBP was first described for postlaminectomy
pseudomeningocele by Lauer and Haddox in 1992.[[17]] We report the case of a 40-year-old female with postoperative pseudomeningocele
successfully treated with ultrasound (USG)-guided epidural blood patch application.
Case Report
A 48-year-old female presented at our hospital with a fluctuant, globular swelling
on her back 1 month postmicrodiscectomy for L4–L5 disc prolapse, operated elsewhere.
She also had back pain, left lower-limb radiculopathy, and postural headache. The
swelling was 4 cm × 3 cm in size at the previous surgical healed scar and increased
on standing and sitting. On examination, straight leg raising test was negative and
she had normal motor power. There was no history of visual disturbances, fever, and
bladder disturbances. Magnetic resonance imaging (MRI) showed a left L4 laminectomy
defect with a pseudomeningocele having an ill-defined CSF intensity collection in
the posterior paraspinal region [[Figure 1]] measuring 5.5 cm × 4.2 cm × 4 cm.
Figure 1: Postoperative pseudomeningocele - magnetic resonance imaging of the patient showing
post-L4-L5 discectomy pseudomeningocele measuring 5 cm x 4.2 cm x 4 cm, ill-defined
cerebrospinal fluid collection extending into the paraspinal region on the left side.
*Dural defect, Arrow: Cerebrospinal fluid collection. Sagittal T1-weighted (a), Sagittal
T2-weighted (b), Axial T2-weighted (c)
We treated the case by USG-guided CSF aspiration from the pseudomeningocele and application
of epidural blood patch. Under all aseptic precautions, L3–L4 and L4–L5 spaces were
identified and CSF was aspirated from the pseudomeningocele at L4–L5 space with a
Tuohy needle. At the same time, 20 ml of blood was drawn from the antecubital vein,
followed by 10 ml blood injection at L4–L5 and 10 ml at L3–L4 epidural space under
USG guidance. The patient was made to sit for 15 min. Her postural headache and lower-limb
radiculopathy were immediately relieved following the procedure.
On 1-year follow-up, the patient was completely symptom free and showed full resolution
of pseudomeningocele on 1-year follow-up MRI [[Figure 2]].
Figure 2: Magnetic resonance imaging of the patient showing complete resolution of pseudomeningocele
at 1-year follow-up. Sagittal T1-weighted (a), Sagittal T2-weighted (b), Axial T2
weighted (c)
Discussion
There is a reported incidence of 0.3%–2% of pseudomeningocoele after spinal surgery
in the literature.[[3]],[[4]] Pseudomeningoceles >5 cm have been characterized as “large,” while those >8 cm
are characterized as “giant."[[14]] The most common symptoms reported in patients with pseudomeningocele were neck
and back pain (64%), headaches (55%), and nausea and vomiting (36%). Sirlomask et
al.[[18]] suggest nonsurgical treatment in asymptomatic patients and use of subarachnoid
catheter in mildly symptomatic patients. Extirpation and dural repair should be reserved
for patients with severe symptoms or those with persisting symptoms beyond several
weeks postoperation. Re-exploration and closure procedures are not always effective,
sometimes requiring repeated repair procedures.
EBPs have long been used to relieve postdural puncture headaches in patients who do
not respond to conservative measures or in patients who present with spontaneous intracranial
hypotension.[[19]],[[20]] EBP was first described for postlaminectomy pseudomeningocele by Lauer and Haddox
in 1992.[[17]] EBP is a procedure in which a small volume of the patient's own blood is injected
into the epidural space in an attempt to “plug” any small dural openings.
Sandwell et al.[[21]] reported a success rate of 84% in resolution of headache and other symptoms. Successful
injections occurred as late as 184 days after development of pseudomeningocele. It
is thought that the blood forms a clot over the dural tear and allows healing of the
dura; furthermore, the clot in the epidural space raises extradural tissue pressure
relative to subarachnoid pressure and decreases the gradient for CSF efflux. An established
or chronic pseudomeningocele is thought of as extradural CSF leakage, which is completely
contained within the body and presents with no CSF drainage through the site of incision.
This procedure may reduce the need for surgical intervention.
There is difference of opinion regarding the level of blood patch application and
the amount of blood to be injected. The blood patch can be injected at the same level
as the laminectomy operation or at the epidural space one level above.[[19]] In postsurgical pseudomeningoceles, it is more practical to localize the epidural
space at a level higher than the laminectomy and introduce the blood while the patient
is maintained in the sitting position. The injected blood travels downward due to
gravity and creates a clot adherent, directly patching hole in it and preventing CSF
leak. The most common approach is to locate the epidural space at a level above operation
site. The volume of blood injected also varies from 5 to 30 ml in different studies
in the literature. In our patient, we injected 10 ml of blood in the cavity after
CSF aspiration from pseudomeningocoele and another 10 ml at one level above the laminectomy.
The CSF aspiration and blood patch at the level of pseudomeningocoele may help in
healing and fibrosis.
Although EBP is still not an established procedure for postlumbar surgery pseudomeningocoele,
it is worth trying this procedure to avoid second surgery as it may sometimes be unsuccessful.
Because of this reason in our case as the patient had a pseudomeningocoele but without
neurologic deficit, we decided to try epidural patch. Our patient was completely symptom
free postprocedure and after 1 year on follow-up visit. Furthermore, the MRI showed
complete resolution of pseudomeningocoele at 1-year follow-up. It can be safely concluded
that for all cases of pseudomeningocoeles postspinal surgery, we go for USG-guided
epidural blood patch application before opting for re-exploration.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms.
In the form, the patient has given her consent for her images and other clinical information
to be reported in the journal. The patient understands that name and initials will
not be published and due efforts will be made to conceal identity, but anonymity cannot
be guaranteed.
