The surgical management of arachnoid cysts includes various techniques as open craniotomy and cyst resection, cystoperitoneal shunting, and others. Recently, the advantages and disadvantages of endoscopy have been described in the literature .
In this study, 18 cases with arachnoid cysts were treated with different endoscopic techniques; Sylvian fissure arachnoid cysts were excluded, as they have the lowest success rate and the highest complication rates when managed endoscopically. Ortel found only 52% radiological success rate in Sylvian fissure cysts treated endoscopically; Choi has a 60% success rate while Karabatso and Pardilla have 9% and 27% success rates, respectively. Although the clinical success rates were much better in these studies, the failure of regression in size was significant and raised the possibility of the recurrence of manifestation on long-term follow-up .
The most common types of arachnoid cysts in this study were the suprasellar arachnoid cysts (7 cases) followed by the quadrigeminal cysts (5 cases). The endoscopic technique applied differed according to the site of the cyst.
Regarding Suprasellar arachnoid cysts, different studies described different endoscopic techniques including endoscopic VC alone or combined endoscopic VC+C. In this study, we performed combined VC+C, which is consistent with El Ghandour  who concluded that VC+C is the treatment of choice in these cases .
Applying endoscopic VC+C to all suprasellar cases in this study allowed the decrease of the cyst s size in 100% of cases and control of manifestations in 85% of cases.
In Quadrigeminal cysts, three different endoscopic approaches and procedures were described in the literature, including cyst fenestration and removal through a suboccipital supracerebellar approach, lateral VC, and third ventricle−cystostomy . In a study published by Gangemi, the most commonly used approach was the lateral VC approach . In this study, the lateral VC technique was performed for all 5 cases, as they were all huge in size and bulging inside the lateral ventricle. Fenestration was established through the floor of the body of the lateral ventricle. The role of added ETV in these cases in order to treat the associated hydrocephalus is questionable. It is not easy to conclude whether an added ETV is mandatory or the cyst fenestration with recanalization of the aqueduct is usually enough for clinical improvement? .
In a single case in this study, VC and endoscopic ETV were performed as there was associated marked hydrocephalus. Unfortunately, this case developed subdural hygroma that was managed conservatively and showed spontaneous resolution over 3 months. Overtreatment in targeting the cyst and the associated hydrocephalus may have been the result of this complication.
In two cases of intraventricular cysts in this study, the VC technique was performed safely.
In parietal supratentorial paraxial cysts and posterior fossa cysts, CV was performed, and they were opened directly to the ventricular system with free hands in the absence of neuronavigation. This is contrary to Ortel  who recommended neuronavigation to facilitate the entry from the cyst to the ventricle. In all 4 cases in this study, it was easy to identify the underlying ventricular cavity through the cyst wall knowing it by its transparency. Also, the absence of thick brain parenchyma facilitated the procedure without neuronavigation. Although these cysts were close to the cortical surface, none of these cases was complicated with CSF fistula.
Regarding complications, we have a single case that developed subdural hygroma (5.5%) and was managed conservatively; Copley , in his study with a larger number of cases, had a complication rate of 20% but all of them as he mentioned were treated easily without subsequent morbidity and mortality. El Ghandour , in his series, had a single case of subdural hygroma (4%), single case of hemorrhage (4%), and a single case of CSF leakage (4%). These complications were the most frequent complications reported in literature; however, the risk of seizures and deficits were extremely rare .
Clinical improvement was found in 94% of the cases, only one case showed no improvement in the clinical manifestations despite the decrease in the cyst size, and this could be explained by the short period of follow-up (6 months).
The cysts’ size decreased in 94% of the cases; only one posterior fossa case remained the same size on follow-up although improvement of the clinical manifestation was stated, supporting the hypothesis that claims that the manifestations are mainly due to the pressure effect rather than the size of the cyst. This needs further research involving a larger sample size and longer follow-up periods to prove such theory.
In the present study, none of the cases showed recurrences nor increased in the size of the cysts; however, the follow-up period is short and requires longer follow-up to document the patency of the established stoma. On the opposite side, Copley  declared that 41% of children in his study required revision surgery at a certain time due to symptom recurrence and that his results are consistent with literature that announced the need for further surgery, including shunt insertion, following endoscopic fenestration and that the studies reporting a 100% success rate following a single endoscopic procedure were typically limited by smaller patient numbers and/or shorter follow-up periods.
No stents were used in this study to maintain the patency of the stoma, which is in agreement with Ortel  who showed evidence that even a small stoma without stent insertion might be sufficient for adequate cyst drainage, in contrary to previous reports denoting the importance of the size of cyst fenestration and stent insertion for avoidance of cyst recurrence . However, this suggestion needs well-designed studies with longer follow-up period to prove its validity.