Prior studies have indicated that neuroendoscopy is a safe and effective method for treating patients with intracranial cysts [1, 18–22]. However, only a few studies have investigated the use of neuroendoscopy for treating cysts located in the lateral ventricles [12–15]. In this study, patients treated with neuroendoscopy had generally better clinical outcomes than patients treated with non-neuroendoscopic procedures. The total resection rate was higher for neuroendoscopy versus non-neuroendoscopy (P <0.05). We attribute this to the endoscopic approach improving visualization in tight spaces, especially within the lateral ventricle, and to the degree of freedom in creating surgical corridors, etc. Neuroendoscopy was also associated with less operation-related blood loss, shorter surgical time, and greater improvement in symptoms compared with non-neuroendoscopy. Moreover, the proportion of patients with post-operative hydrocephalus was higher in the non-neuroendoscopy group.
Neuroendoscopy is an important option for the treatment of intracranial cysts. Microsurgical approaches that include craniotomy and fenestration, and cystoperitoneal shunting are valuable techniques, however, endoscopy which allows closer direct cyst or tumor visualization, is less invasive, and decreases severe complications associated with other surgical methods. These properties are particularly important in treating young patients with different types of benign tumors [1, 21]. Neuroendoscopy has been recommended as the first choice of therapy for treating intracranial cysts [8, 18, 21–23], including cysts located in the lateral ventricles [12, 24]. It has been recommended that when the manipulations are done through the endoscope that neuroendoscopy is best performed on deep-seated cysts such as those in the lateral ventricles as it is relatively less traumatic to the brain parenchyma and provides good visualization . Also, once the endoscope is fixed in position, instruments and optics can be changed readily without damage to brain structures along the approach. Also, endoscopic cyst fenestration from the lateral or third ventricle based on cyst extension presents no risk with regard to damaging the deep incisural and quadrigeminal veins . A disadvantage of this method is the limited range of motion and the size of the instruments that fit into the working channel of the endoscope . Our study supports the idea of removing cysts located in the lateral ventricles by neuroendoscopy where cyst removal is performed through the endoscope itself. In our study, no patients treated with neuroendoscopy had cyst recurrence while cysts recurred in 20.5% of patients treated by non-neuroendoscopic techniques. Gangemi et al. reported that neuroendoscopy was associated with a greater frequency of cyst recurrence compared with other surgical techniques . Our results differed. The reason for this difference is not clear. We used rigid neuroendoscopy to resect arachnoid membrane cysts in the lateral ventricles. Rigid neuroendoscopy was also reported to have been used successfully for the treatment of cerebral aneurysms  and colloid cysts . Successful use of flexible neuroendoscopy has been reported for the treatment of supracellar arachnoid cysts  and shunt malfunction .
Our findings are mostly similar to those of other studies that compared the efficacy and safety of neuroendoscopy to microsurgical resection in treating intraventricular cysts. Several studies reported that neuroendoscopy resulted in less morbidity and shorter hospital stay for adults and children, and more rapid return of the patients to work [5–8, 15, 18]. King and colleagues reported their experiences with endoscopic resection of colloid cysts. The results showed that the average hospital stay following treatment of colloid cysts of the lateral and third ventricles by neuroendoscopy was 2.3 days compared to 5 days following craniotomy . However, in our study, the length of hospital stay was the same for both the neuroendoscopy and non-neuroendoscopy groups (10 days).
The use of neuroendoscopy to treat intraventricular cysts is also associated with marked improvement in symptoms that include headache, nausea, vomiting, double vision, and paresis [8, 9, 15]. We found that the majority of patients (64.3%) treated with neuroendoscopy had marked improvement in their symptoms, whereas only 5.1% of patients treated with a non-neuroendoscopy method had marked symptom improvement.
Many complications have been reported for non-neuroendoscopy and neuroendoscopy cyst treatment options. Complications of fenestration/resection and shunting procedures include meningitis, hemiparesis, oculomotor palsy, subdural hematomas, new epileptic seizure, hemorrhages, transient diabetes insipidus, psychosyndrome, and death [22, 23]. In our study, neuroendoscopy compared with non-neuroendoscopy was associated with a greater proportion of patients having post-operative fever or subdural fluid accumulation. But these complications soon resolved.
Limitations of this study include its retrospective design and small sample size. Larger prospective studies are necessary to more fully compare the different methods for treating lateral ventricular cysts. Median follow-up duration was only 2 years; a longer follow-up period is needed for more complete assessment. This study also did not evaluate potential differences in the functional impairment of patients following neuroendoscopy versus non-neuroendoscopic surgery. This is of interest since a large trial (N =714) that assessed the clinical outcomes and quality-of-life of patients with ventricular and paraventricular cysts (12.7% of whom had lateral ventricular cysts) found that the Karnofsky performance score significantly improved with neuroendoscopy (from 80 to 90; P < 0.0001) .