Intracranial arachnoid cyst surgery

Controversy still exists regarding the optimal option for the surgical management of intracranial arachnoid cysts.


Neuroendoscopic fenestrations.

Microsurgical fenestrations +/- marsupialisation

Cystoperitoneal shunt.

In a retrospective case note review of all patients with intracranial arachnoid cysts treated surgically at the Department of Neurosurgery, Wessex Neurological Centre, Southampton General Hospital, over a 15 year period. Data on clinical presentations and outcomes was collected from the patient notes and the pre- and post-operative cyst volumes were calculated by creating 3-dimensional volumetric models.

Eighty-two patients were identified of which 45 were treated endoscopically, 34 microscopically and 3 underwent cysto-peritoneal shunting. The most common cyst location was the middle fossa (n = 25). Amongst the symptomatic patients, improvement or resolution of symptoms was seen in 35 out of 40 cysts treated endoscopically (88%), 28 out of 32 treated microsurgically (88%) and 3 out of 3 treated by shunting (100%, p = 0.79). The reoperation rate was not significantly different between the endoscopic and microsurgical groups (24.4% vs 14.7%, p = 0.49). The endoscopic and shunted groups had a shorter length of stay than the microsurgical group (3.0 vs 3.0 vs 4.5 days, p = 0.04). All three treatment modalities had a similar percentage reduction in cyst volume after surgery (30.0 vs 41.7 vs 30.9%, p = 0.98).

This cohort series shows that endoscopic and microsurgical approaches to treat intracranial arachnoid cysts produce comparable clinical and radiological outcomes. Endoscopic fenestration is associated with a shorter length of stay as would be expected from a minimally invasive procedure 1).

Open surgery advantages include, direct inspection of the cyst, biopsy sampling, fenestration in multilocular cysts and, in certain locations, cyst communication to basal cisterns 2).

Surgery for AC can be performed with a fairly low risk of complications and yields significant improvement in quality of life correlated to postoperative improvement in headache and dizziness. These findings may justify a more liberal approach to surgical treatment for AC 3).

Choi et al., analyzed pediatric patients under 18 years of age who underwent surgical management for intracranial AC between January 2000 and December 2011. Patients with a follow-up period of less than 1 year were excluded. A total of 75 patients were enrolled in this study. These patients were assessed by subjective symptoms and by a clinician’s objective evaluation. The radiological assessment of AC after surgery was also evaluated.

The median age of patients at the initial operation was 5 years. The median follow-up period was 38 months. The goal of surgery was achieved in 28% (21/75) of patients. The radiological alteration of AC after initial fenestration surgery was diverse. The results of the clinical and radiological assessments did not always coincide. A total of 35 complications occurred in 28 patients. Subdural fluid collection was the most common unexpected radiological complication.

The study showed that the fenestration procedure for AC produced unsatisfactory clinical improvements compared to the relatively high complication rate. Therefore, surgical treatment for AC should be strictly limited to patients who have symptoms directly related to AC 4).

A consecutive series of 68 adult patients (43 males, mean age 30.3 years, range 18-42 years) with IAC were surgically treated between January 2004 and January 2011 in the Department of Neurosurgery, West China Hospital of Sichuan University, Chengdu, China.

The cysts were supratentorial in location in 53 and infratentorial in 15 patients. Symptoms at presentation, location of the IAC, surgical treatment modalities, and postoperative complications were evaluated.

Of the 51 patients with headache, 44 (86.27%) patients had complete relief of the headache, five (9.80%) patients had significant improvement, and two (3.92%) had no worthwhile change. Three of the four patients with hydrocephalus and gait disturbances had relief of the symptoms and one patient had significant improvement. Of the five patients with cognitive decline and weakness, three (60.00%) patients showed improvement, and two (40.00%) patients had no significant change. Five (62.50%) of the eight patients with epilepsy had seizure remission, two (25.00%) patients had non-disabling seizures, and one had no change. Follow-up computed tomography (CT) scans showed variable change in the mass effect of IAC in 68 patients; cystic size was significantly reduced in 51 patients, no significant change in two patients of supratentorial arachnoid cysts. Cystic size was reduced in seven patients, but no significant change was observed in eight patients of infratentorial cysts. Three patients with enlarged head circumference had no further increase in the head circumference.

Adult patients with IAC symptoms should be treated efficiently. Surgical treatment is associated with significant improvement in the symptoms and signs 5).

Data from 69 patients with cerebral arachnoid cysts treated in our institution between 1997 and 2007 were reviewed.Cysts were located infratentorially in 20% (n = 14) and supratentorially in 80% (n = 55); of these 73% (n = 40) were in the middle cranial fossa. Mean cyst size was 61 mm (range 15-100 mm). The most common symptoms were headache (51%), dizziness (26%), cranial nerve dysfunction (23%), seizure (22%), nausea and vomiting (18%), and hemiparesis (13%). Surgery was performed in 83% (n = 57). First-line treatments were microsurgical fenestration (n = 30), endoscopic fenestration (n = 15), and cystoperitoneal/ventriculoperitoneal shunting (n = 11). More than one intervention was needed in 42% (n = 24). A particularly high rate of relapse (73%) was observed after endoscopic fenestration, following which 11 patients were admitted for reoperation. By comparison, only eight patients (28%) managed with microsurgical fenestration and four (36%) in the shunted group needed a second surgical procedure. Mean follow-up was 30 months. In the surgical series 79% (n = 45) had a good outcome.We conclude that the surgical treatment of arachnoid cysts has an overall good outcome. In our institution the best results were obtained with microsurgical decompression through craniotomy 6).



Hall S, Smedley A, Rae S, Mathad N, Waters R, Chakraborty A, Sparrow O, Tsitouras V. Clinical and radiological outcomes following surgical treatment for intra-cranial arachnoid cysts. Clin Neurol Neurosurg. 2018 Dec 27;177:42-46. doi: 10.1016/j.clineuro.2018.12.018. [Epub ahead of print] PubMed PMID: 30599313.

Saura Rojas JE, Horcajadas Almansa Á, Ros López B. [Microsurgical treatment of intracraneal arachnoid cysts]. Neurocirugia (Astur). 2015 Apr 16. pii: S1130-1473(15)00029-9. doi: 10.1016/j.neucir.2015.02.006. [Epub ahead of print] Spanish. PubMed PMID: 25891259.

Mørkve SH, Helland CA, Amus J, Lund-Johansen M, Wester KG. Surgical Decompression of Arachnoid Cysts Leads to Improved Quality of Life: A Prospective Study. Neurosurgery. 2016 May;78(5):613-25. doi: 10.1227/NEU.0000000000001100. PubMed PMID: 26540351.

Choi JW, Lee JY, Phi JH, Kim SK, Wang KC. Stricter indications are recommended for fenestration surgery in intracranial arachnoid cysts of children. Childs Nerv Syst. 2015 Jan;31(1):77-86. doi: 10.1007/s00381-014-2525-1. Epub 2014 Aug 16. PubMed PMID: 25123786.

Wang C, Liu C, Xiong Y, Han G, Yang H, Yin H, Wang J, You C. Surgical treatment of intracranial arachnoid cyst in adult patients. Neurol India. 2013 Jan-Feb;61(1):60-4. doi: 10.4103/0028-3886.108013. PubMed PMID: 23466842.

Holst AV, Danielsen PL, Juhler M. Treatment options for intracranial arachnoid cysts: a retrospective study of 69 patients. Acta Neurochir Suppl. 2012;114:267-70. doi: 10.1007/978-3-7091-0956-4_52. PubMed PMID: 22327706.

Insular glioma surgery

Shawn Hervey-Jumper and Berger from the UCSF Medical Center reviewed the literature for published reports focused on insular region anatomyneurophysiology, surgical approaches, and outcomes for adults with who grade II-IV gliomas.

While originally considered to pose too great a riskinsular glioma surgery can be performed safely due to the collective efforts of many individuals. Similar to resection of gliomas located within other cortical regions, maximal resection of gliomas within the insula offers patients greater survival time and superior seizure control for both newly diagnosed and recurrent tumors in this region. The identification and the preservation of M2 perforating and lateral lenticulostriate artery are critical steps to preventing internal capsulestroke and hemiparesis. The transcortical approach and intraoperative mapping are useful tools to maximize safety.

The insula’s proximity to middle cerebral and lenticulostriate arteries, primary motor areas, and perisylvian language areas makes accessing and resecting gliomas in this region challenging. Maximal safe resection of insular gliomas not only is possible but also is associated with excellent outcomes and should be considered for all patients with low- and high-grade gliomas in this area 1).

Advances in microsurgical anatomy and brain mapping techniques have allowed an increase in the extent of resection with acceptable morbidity rates. Transsylvian and transcortical approaches constitute the main surgical corridors, the latter providing considerable advantages and a high degree of reliability. Nevertheless, both surgical corridors yield remarkable difficulties in reaching the most posterior insular region.

see Insular tumor surgery.

Small deep infarcts constitute a well-known risk of motor and speech deficit in insulo-opercular glioma surgery. However, the risk of cognitive deterioration in relation to stroke occurrence in so-called silent areas is poorly known.

In a paper, Loit et al. propose to build a distribution map of small deep infarcts in glioma surgery, and to analyze patients’ cognitive outcome in relation to stroke occurrence.

They retrospectively studied a consecutive series of patients operated on for a diffuse glioma between June 2011and June 2017. Patients with lower-grade glioma were cognitively assessed, both before and 4 months after surgery. Areas of decreased apparent diffusion coefficient (ADC) on the immediate postoperative MRI were segmented. All images were registered in the MNI reference by ANTS algorithm, allowing to build a distribution map of the strokes. Stroke occurrence was correlated with the postoperative changes in semantic fluency score in the lower-grade glioma cohort.

One hundred fifteen patients were included. Areas of reduced ADC were observed in 27 out of 54 (50%) patients with a lower-grade glioma, and 25 out of 61 (41%) patients with a glioblastoma. Median volume was 1.6 cc. The distribution map revealed five clusters of deep strokes, corresponding respectively to callosal, prefrontal, insulo-opercular, parietal, and temporal tumor locations. No motor nor speech long-term deficits were caused by these strokes. Cognitive evaluations at 4 months showed that the presence of small infarcts correlated with a slight decrease of semantic fluency scores.

Deep small infarcts are commonly found after glioma surgery, but their actual impact in terms of patients’ quality of life remains to be demonstrated. Further studies are needed to better evaluate the cognitive consequences-if any-for each of the described hotspots and to identify risk factors other than the surgery-induced damage of microvessels 2).


Awake Brain Mapping in Dominant Side Insular Glioma Surgery: 2-Dimensional Operative Video 3).



Hervey-Jumper SL, Berger MS. Insular glioma surgery: an evolution of thought and practice. J Neurosurg. 2019 Jan 1;130(1):9-16. doi: 10.3171/2018.10.JNS181519. Review. PubMed PMID: 30611160.

Loit MP, Rheault F, Gayat E, Poisson I, Froelich S, Zhi N, Velut S, Mandonnet E. Hotspots of small strokes in glioma surgery: an overlooked risk? Acta Neurochir (Wien). 2018 Nov 10. doi: 10.1007/s00701-018-3717-3. [Epub ahead of print] PubMed PMID: 30415385.

Hameed NUF, Zhu Y, Qiu T, Wu J. Awake Brain Mapping in Dominant Side Insular Glioma Surgery: 2-Dimensional Operative Video. Oper Neurosurg (Hagerstown). 2018 Feb 16. doi: 10.1093/ons/opx299. [Epub ahead of print] PubMed PMID: 29471530
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