Endoscopic cystoventriculostomy
Endoscopic cystoventriculostomy is a neurosurgical procedure performed to treat certain types of brain cysts. It is a minimally invasive technique that involves using an endoscope to create a connection between the cyst and the ventricular system of the brain.
During the procedure, a small hole is made in the skull, and the endoscope is inserted through this opening. The endoscope allows the surgeon to visualize the cyst and surrounding structures. With the guidance of the endoscope, a small opening is made in the cyst wall, creating a passage for cerebrospinal fluid (CSF) to flow from the cyst into the ventricles of the brain. This helps to relieve pressure caused by the cyst or restore the normal circulation of CSF.
Endoscopic cystoventriculostomy is typically performed under general anesthesia and carries less risk and shorter recovery time compared to traditional open surgery. However, not all types of brain cysts are suitable for this procedure, and the decision to perform it depends on the specific characteristics of the individual case.
Tabakow et al. performed intraoperative magnetic resonance (iMR) cysternography was performed before and after the cystostomy. In each case, iMR cysternography was safe and could show clearly the cyst morphology and the effectiveness of performed endoscopic cystostomies. In six cases, iMR cysternography had a significant influence of the surgical decision (p = 0.027). The rate of inconsistency between the intraoperative observations and iMR imaging-based findings was 29%. A good contrast flow through the fenestrated cyst walls correlated with a good long-term clinical outcome (ρ = 0.54, p < 0.05) and good long-term radiological outcome (ρ = 0.72, p < 0.05). Intraoperative low-field MR cysternography is a safe and reliable method for assessment of the efficacy of performed endoscopic cystostomies and has significant influence on the surgical decision. It may be reliably used for prediction of the long-term clinical and radiological outcome 1)
Case series
Twelve pediatric patients (mean age 4.3 years) with symptomatic intraventricular ependymal cysts (IVECs) were the subject of this study. The cyst was located inside the lateral ventricle in all cases (100%), it was present in trigone (10 patients, 83.3%), and in the temporal horn (2 patients, 16.7%). Concomitant hydrocephalus was present in two patients (16.7%). All patients underwent operations through a purely endoscopic procedure. Communication of the cyst with the subarachnoid space was performed in six patients (50%); endoscopic cystocisternostomy was performed in four patients (33.3%), and endoscopic cystoventriculostomy in two patients (16.7%).
Postoperative clinical improvement associated with a postoperative reduction in cyst size was encountered in ten patients (83.3%). Improvement of hydrocephalus occurred in both patients who had hydrocephalus (100%). There were no deaths or permanent morbidity. During the follow-up period (mean 44.3 months), none of the patients required a repeat endoscopic procedure due to the recurrence of symptoms or an increase in cyst size.
Intraventricular ependymal cysts can be effectively treated by endoscopy. Endoscopic fenestration of the cyst wall into subarachnoid space, basal cisterns, or ventricular system can be used in the treatment of these patients with postoperative symptomatic improvement and reduction of cyst size. The procedure is simple, effective, minimally invasive, and associated with low morbidity and mortality rates 2).
In 11 cases, the arachnoid cysts were frontotemporoparietal and fenestration was performed into the lateral ventricle. In 1 case, the arachnoid cyst was located in the cerebellum and the cyst was fenestrated into the fourth ventricle. Neuronavigational guidance was used in all but 1 case. Endoscopic cystoventriculostomy was performed in all cases without complications. No stents were placed. The mean surgical time was 71 minutes (range 30-110 minutes). The mean follow-up period was 42.7 months (range 19-96 months) per surgical case and 48.8 months (range 19-127 months) per patient. Symptoms improved after 11 of the 12 procedures; 7 of the 11 patients became symptom-free and the others had only mild residual symptoms. The patient who did not experience clinical improvement suffered from depression and demonstrated a significant decrease of the cyst size on the postoperative MR imaging. After 11 of 12 procedures, a decrease in cyst size was observed. In 1 case, a subdural hematoma developed; it required surgical treatment 3 months after surgery. In another case, reclosure of the stoma required repeated endoscopic cystoventriculostomy more than 7 years after the initial procedure.
Overall, endoscopic cystoventriculostomy represents a useful treatment option for patients with paraxial arachnoid cysts in whom a standard cystocisternotomy is not feasible. Based on the results in this case series, stent placement appears not to be required. Despite the long mean follow-up of almost 4 years, however, a longer follow-up period seems to be required before definite conclusions can be drawn 3).
Case reports
Endoscopic cystoventriculostomy of an arachnoid cyst using a neuroendovascular stent to maintain patency 4).
Case report from the HGUA
Clinical presentation of forgetfulness and recent memory impairment of approximately 10 years of evolution. Additionally, it is associated with nonspecific dizziness without object rotation and gait instability that has caused several falls. This clinical picture is intermittent, but 2 years ago, progressive visual loss began, leading to a cerebral MRI that revealed a left occipital cyst.
Inferior right quadrantanopia on confrontation campimetry.
Left occipital cystic lesion. After gadolinium administration, no abnormal contrast enhancement is observed. The ventricles appear deformed due to the mass effect of the lesion, but there is no modification in the signal intensity of the parenchyma. The midline is not displaced.
Endoscopic cystoventriculostomy
The patient was positioned supine with a Mayfield skull clamp in place. The surgery was performed with the assistance of electromagnetic navigation. A left parietal incision was made, followed by an underlying minicraniotomy. The cyst was fenestrated endoscopically, targeting the ventricle and temporal horn. Hemostasis was achieved, and Spongostan was applied to the cerebral cortex. A hermetic dural closure was performed, and bone replacement was done using medilevel miniplates. The incision was closed in layers, and the skin was secured with surgical staples. The procedure proceeded without any complications.