Key-words:
Cystic craniopharyngioma - cystocisternostomy - endoscopic transcortical transventricular
- Ommaya - radiotherapy
Introduction
Craniopharyngiomas are benign neoplasm with malignant behavior and account for nearly
3% of all intracranial tumors.[[1]],[[2]],[[3]],[[4]],[[5]] About 60%–90% of all craniopharyngiomas have a cystic component and propensity
to extend into the anterior third ventricle, interpeduncular cistern, and retro and
parasellar region.[[1]],[[3]],[[6]] Gross total resection of this tumor is the gold standard surgical treatment, but
the preservation of neurological and hypothalamopituitary functions is also an important
facet in the management of this complex tumor.[[5]]
Microscopic surgical resection and endoscopic cyst fenestration along with intracystic
catheter placement of the Ommaya reservoir are the commonly performed surgical techniques.[[1]],[[7]],[[8]],[[9]],[[10]] Transcortical transventricular endoscopic surgery for cystic craniopharyngioma
has gained acceptance as a safe minimally invasive alternative to resection.[[11]],[[12]]
In this retrospective study, an outcome analysis of transcortical transventricular
endoscopically treated cystic craniopharyngioma over a period of 9 years was performed.
Materials and Methods
Records of 95 craniopharyngioma patients were retrieved from the departmental database,
who were operated between January 2009 and October 2017 in the Department of Neurosurgery
at King George's Medical University, Lucknow, India.
Thirty-two out of 95 patients had undergone endoscopic transcortical transventricular
decompression and drainage along with cerebrospinal fluid (CSF) diversionary procedure,
were included in this retrospective study. Ethical approval for conducting this study
was taken from the institutional ethics committee.
Demographic details, clinical presentations, radiological features, intraoperative
findings, details of CSF diversionary procedure, surgical complications, and follow-up
details were noted.
Surgical technique
All cases in this study had undergone neuroendoscopy by Karl Storz Lotta system 6°
ventriculoscope of diameter 6.1 mm with a working channel diameter of 2.9 mm (KARL
STORZ SE and Co. Tuttlingen/Germany). Patients were positioned supine and a linear
incision was given at coronal suture. A small precoronal burr hole 3 cm from the midline
and 1 cm anterior to coronal suture was made. Dura was opened either in a linear fashion
or a C-shaped flap. The lateral ventricle was entered with obturator and working sheath.
A freehand technique was used in all cases. The endoscope was introduced inside ventricle
and cystic craniopharyngioma was visualized at Foramen Monro. The cyst wall was coagulated,
fenestrated, and biopsy was taken from the wall. Dark green or machine oil colored
fluid was aspirated from the cyst. Irrigation and suction of the cyst was done and
inside of the cyst was visualized by the endoscope. Multiple calcified spots along
with friable, suckable contents were usually seen and taken out. In five cases, floor
of the third ventricle and interpeduncular cistern were well visualized though the
cyst for performing cystocisternostomy, this procedure was termed as double fenestration
(ventriculocystostomy and cystocisternostomy) [[Figure 1]]. Patients with significant hydrocephalus would also undergo endoscopic septostomy,
followed by a ventriculoperitoneal shunt performed through Keen's point in the same
sitting. A catheter was positioned in the cyst cavity under direct vision through
the scope and was connected to the Ommaya reservoir placed at burr hole [[Figure 2]]. The skin was closed in two layers.
Figure 1: Endoscopic cystic decompression and cystocisternostomy. (Patient no 13 [Table 2])
Top row images 1 and 2 - Magnetic resonance imaging T2 images show cystic craniopharyngioma
with extension to the 3rd ventricle. Top row images 3 and 4 - Endoscopic images of
cystic craniopharyngioma occluding the foramen of Monro and endoscopic intracavitary
image showing flecks of calcification. Bottom row image 1 - Fluid aspirated from cystic
craniopharyngioma -“Machine oil.” Bottom row images 2-4 - Computed tomography images
shows site of burr hole, shows decompression of cystic cavity and regression of ventriculomegaly
(follow-up computed tomography at 6 months)
Figure 2: Top row images 1-3 - Magnetic resonance imaging T2 images axial, coronal, and sagittal
section shows hyperintense cystic craniopharyngioma extending into the third ventricle
with ventriculomegaly. Bottom row image 1 and 2 - Computed tomography axial sections
show catheter tip into the cystic cavity and Ommaya reservoir at the burr hole site
Postoperative management
The patients were administered antibiotics according to our institute protocol. Postoperative
computed tomography (CT) scan was done to rule out any bleed and confirm the placement
of Ommaya catheter. Anti-epileptics (phenytoin 5 mg/kg in divided doses) was given
for 6 months if the patient remained seizure-free. In four patients, we witnessed
seizures in the postoperative period for which the dosage of anti-epileptic drug was
increased and no further episodes of seizures were reported.
Results
The age of the patients ranged from 3 years to 68 years (mean 16.28 ± 15.70). Seventy-five
percent of patients were below 16 years of age. There were 23 male and 9 female patients.
Headache was the most common presenting complaint, followed by the visual disturbance.
Presenting symptoms are enumerated in [[Table 1]].
Table 1: Presenting symptoms of the patients (n=32).
Investigations
CT and magnetic resonance imaging scans were performed in all patients preoperatively.
Fifty percent of the patients had hydrocephalus. All the patients had predominantly
cystic craniopharyngioma with cyst diameter ranged from 3 cm to 8 cm (mean 4.5 cm).
Calcification was seen in the wall of cyst in 70% of cases [[Table 2]].
Table 2: Clinicoradiological profile and outcome data of the study patients
Table 2: Contd...
Table 2: Contd...
Ophthalmological investigations showed papilledema in 53% (17/32) of patients which
improved significantly after surgical intervention, whereas 40% (13/32) of patients
had primary optic atrophy whose visual acuity status remained nearly same as preoperative
or had only slight improvement.
Outcome
All 32 patients were treated by endoscopic fenestration of craniopharyngioma cyst
along with a biopsy of cyst wall and complete drainage of cyst fluid. Ommaya reservoir
was placed in all cases [[Figure 4]]. Twelve patients required a ventriculoperitoneal shunt and six patients among them
also underwent septostomy who had significant hydrocephalus. In five patients, we
were able to perform cystocisternostomy (double fenestration) [[Table 2]] and [[Figure 3]].
Figure 3: The patient underwent cystocisternostomy. Top row images 1 and 2 - Magnetic resonance
imaging T1 contrast coronal and sagittal section shows contrast-enhancing cystic craniopharyngioma
reaching up to foramen of Monro with ventriculomegaly. Top row images 3 and 4 - Magnetic
resonance imaging T2 coronal and sagittal section shows hyperintense cystic craniopharyngioma
Bottom row images 1-3 - Magnetic resonance imaging T1 contrast sagittal, T2 coronal
and sagittal sections show reduction and regression of cystic cavity and improvement
of ventriculomegaly
Figure 4: Top row images 1 and 2 - Computed tomography axial and coronal sections show large
cystic suprasellar tumor with calcification. Bottom row image - catheter in situ in
cystic cavity with reduction in cyst volume
Headache improved in 92% (25/27) patients in whom headache was presenting symptom.
Nausea, vomiting, and confusion improved in all patients.
External beam radiotherapy was given to all the patients. No patient developed any
visual deterioration following radiotherapy. However, six patients showed clinical
and radiological recurrence in the follow-up with requirement of multiple Ommaya aspirations,
they were advised microsurgical intervention, but out of them, only two underwent
transcranial surgical excision. The recurrence rate in the study was 18.75% (6/32).
Remaining 26 patients (81%) had good tumor control on radiology, required no Ommaya
aspirations and were doing well at follow-ups.
Complications
Burr-hole site skin infection was seen in one case which was treated successfully
with antibiotics. Bacterial meningitis was seen in two cases (Case 1-Patient No. 9-both
VP shunt and Ommaya reservoir with catheter were removed and intravenous antibiotics
were given according to culture reports for 14 days, reinsertion of the shunt was
done from a fresh site after CSF culture reports turned sterile). (Case 2-Patient
No. 11-Ommaya reservoir with catheter was removed on the basis of positive culture
reports and was treated with intravenous antibiotics). One case each of intraventricular
hemorrhage and subdural collection was managed on conservative lines and fared well.
Burr hole site extradural hemorrhage was seen in 1 case and was evacuated. CSF leak
seen in two cases was due to shunt malfunction, which subsided on shunt revision.
Shunt complications were treated by reinserting fresh shunts from the changed side
[[Table 3]].
Table 3: Complications encountered in the study patients
Mortality
Three patients expired in the follow-up. The exact cause of death could not be ascertained
but telephonic conversation linked them to seizures due to poor compliance with anti-epileptics.
Follow-up
The patients were regularly followed up clinically and radiographically. CT scan was
initially done at 3 months thereafter at 6 months and then at yearly interval. The
mean follow-up was 22.7 ± 15.8 months (3–76 months) [[Table 2]].
Discussion
Craniopharyngiomas are commonly seen in two age groups (5–15 years) and (60–70 years).[[1]],[[5]],[[13]],[[14]] Similar observation was seen in our series. Majority of the patients were of pediatric
age group.[[1]],[[5]],[[13]],[[14]] The mean age of the patients in this study was 16.28 ± 15.70 which is close to
the reported mean age in other series.[[1]],[[5]],[[13]],[[14]] The clinical profile of patients in this series was similar to previously reported
other series. Features of raised intracranial pressure and visual disturbance were
commonly seen.[[5]],[[10]],[[13]],[[14]]
Gross total removal of cystic craniopharyngioma is considered as the gold standard
treatment, but this procedure is plagued with significant morbidity and mortality
following damage to the hypothalamus, optic apparatus, and stalk.[[1]],[[5]] To avoid the torrid postoperative course, surgical resection of cystic craniopharyngioma
has largely been replaced by cyst fenestration and drainage, and it has become one
of the commonly performed procedures for predominantly cystic craniopharyngioma.[[11]],[[12]],[[15]] Over the years, cyst fenestration along with Ommaya placement has evolved as a
less invasive and more accurate surgical procedure, while it was initially performed
percutaneously, or ultrasound-guided, but lately with endoscopy, it has led to better
visualization of tumor cavity, accurate placement of catheter, as well as minimal
damage to the hypothalamus or optic apparatus.[[3]],[[4]],[[9]],[[6]],[[16]],[[14]],[[17]] Rachinger et al. in their series concluded that cystic fenestration is as effective
as microsurgery with less hypothalamic damage.[[18]] The present study further reiterates the above fact.
Lauretti et al. analyzed and stated the superiority of neuroendoscopy over stereotactic
cyst aspiration as well as cyst CSF communication as a protective factor for recurrence.[[19]] In our series, patients had a collapse of cyst after cyst fenestration and widening
of the cyst opening along with aspiration. Ommaya catheter holes had communication
with both craniopharyngioma cyst and ventricle CSF. Patency of cyst and ventricle
communication due to widening of fenestration and catheter holes both in cyst and
ventricle is the probable reason which is believed to be the cause of no recollection
in these patients. The same explanation was mooted by Al-Abyad and El-Sheikh and Moussa
et al. in their series on cystic craniopharyngioma.[[13]],[[19]],[[20]],[[21]] In some series, chemical meningitis subsequent to spillage of cyst contents “machine
oil” was reported.[[22]],[[23]] No complication pertaining to the cyst-ventricle communication or spillage and
absorption was seen in this study and none were reported by the other series.[[7]],[[13]],[[20]],[[24]] The careful fenestration and aspiration of the cyst helps in avoiding the spillage
of cyst contents into the ventricle thus minimizing chances of chemical meningitis.
It was not seen in this study and has been rarely reported.[[13]],[[20]] No intracavitary treatment with bleomycin or interferon alpha was used in the present
study. There are no conclusive results described in the literature supporting the
use of intracavitary chemotherapy.[[2]],[[3]],[[23]],[[25]],[[26]],[[27]]
Complications noted in the series were similar to any series with procedures related
to endoscopic transcranial procedures and all were managed effectively.[[9]],[[28]],[[29]],[[30]],[[31]] They were far less as compared to those encountered in the resection procedures
and surely had lower morbidity.[[1]],[[29]],[[32]],[[33]],[[34]]
Transventricular endoscopic management begets superior results as compared to microsurgical
techniques in terms of less postsurgical morbidity and complications along with drastically
improved patient's symptomatology. It is also better than other techniques of cyst
drainage as it gives real-time direct visualization of the procedure and the catheter
placement in the cavity.
Radiotherapy's role in craniopharyngioma is controversial, and currently, adjuvant
radiotherapy is given in cases of residual tumors after resection to prevent relapse.[[35]],[[36]],[[37]] Though concerns regarding damage to optic apparatus and endocrinopathies as well
as inducing malignant transformation have been raised.[[38]],[[39]],[[40]] Rachinger et al. recommended to withhold or postpone radiotherapy in majority of
cystic craniopharyngioma.[[18]] Lauretti et al. suggested that radiotherapy can be avoided after cyst drainage
and should be given for recurrent or progressive cases[[41]] but several other series have conclusively prescribed radiotherapy for progression-free
survival in cystic craniopharyngioma [[Table 4]].[[20]],[[36]],[[37]],[[41]],[[42]] In the present study, external beam radiotherapy was given in all 32 patients with
good tumor control in follow-up with only 18.7% (6/32) patients showing recurrence.
Post radiotherapy, no visual deterioration was noted in the follow-up. Therefore,
we suggest radiotherapy to be given as adjuvant therapy following neuroendoscopic
fenestration and drainage.
Table 4: Summary of series describing endoscopic cyst drainage with Ommaya shunt placement
Limitation of the study
This study has few limitations. First, this is a retrospective single-institution
series which stands low on the pyramid of the level of evidence. Second, the sample
size is not large enough even though it is the largest series on the cystic craniopharyngioma
treated by neuroendoscopy.
Conclusions
Neuroendoscopic transcortical transventricular drainage of cystic craniopharyngioma
is a simple, safe, and effective treatment and lacks many risks associated with microsurgery.
Cyst ventricle communication in this procedure effectively prevents reaccumulation
and Ommaya reservoir catheter further reinforces this communication. Radiotherapy
is to be given as adjuvant modality following neuroendoscopic decompression. Consensus
on ideal management of craniopharyngioma is still far from over therefore multi-institutional
collaborative study involving all treatment modalities should be formulated for obtaining
more relevant statistical information to come to a definite conclusion.
