Developmental Retrocerebellar Cysts: A New Classification for Neuroendoscopic Management and Systematic Review

Tetraventricular hydrocephalus with aqueductal flow void: an overlooked entity having consistent improvement following endoscopic third ventriculostomy

BACKGROUND

Tetraventricular Hydrocephalus (TetHCP) is a heterogeneous group of cerebrospinal fluid (CSF) flow disorders having varying success rates with Endoscopic third ventriculostomy (ETV). This is report on the efficacy and rationale of ETV in a specific subset of primary TetHCP with aqueductal CSF flow voids.

METHODS

Patients of primary acquired TetHCP presenting with increasing head size and/or headache having aqueductal CSF flow void on sagittal Magnetic Resonance Imaging (MRI) were included in this study. All of them underwent ETV. All patients were evaluated for clinical improvement & MRI at 3 months, and need for any additional procedure, in contrast to those without CSF flow void. The pathophysiology of hyperdynamic CSF circulation and its correlation to ETV was further reviewed.

RESULTS

Eleven patients had tetraventricular hydrocephalus and aqueductal flow void, with age ranging from 10 months to 59 years. Two patients who could undergo quantitative flow study confirmed the hyperdynamic flow across the aqueduct. Following ETV, all showed clinical improvement. MRI at 3 months showed CSF flow void across the third ventricular stoma in addition to across the aqueduct. None of these patients required any redo procedures for a mean follow-up of 39.2 months. In contrast, there was 30% failure rate after ETV among 10 patients of tetraventricular hydrocephalus without aqueductal flow void.

CONCLUSION

Tetraventricular hydrocephalus with aqueductal CSF flow void may be a unique entity with hyperdynamic CSF circulation and relative resistance at fourth ventricular outlets. ETV is highly efficacious in these patients, resulting in consistent clinico-radiological improvement.

Feasibility of awake endoscopic third ventriculostomy in selected patients of obstructive hydrocephalus

BACKGROUND

Endoscopic third ventriculostomy (ETV) is usually performed under general anesthesia (GA) with proper head immobilization. However a few patients with hydrocephalus (HCP) may not be suitable for GA. Once the surgeon is familiar with endoscopic ventricular anatomy and gains adequate surgical experience with the procedure, ETV can be attempted under local anesthesia (LA) in selected patients. Here we discuss our experience of treating 32 patients of HCP with ETV under LA.

METHODS

32 symptomatic HCP patients with in the age range of 13 and 65 years, conscious, alert, cooperative and at high risk for GA owing to deranged liver or renal function, associated co-morbidities, pregnancy were considered for ETV under scalp block. All patients were evaluated for any discomfort during the surgical intervention.

RESULT

All procedures were completed under LA. Four patients needed additional sedation prior to the scalp block to alleviate their apprehension. Four patients complained of bilateral orbital pain. In three it coincided with irrigation of fluid lower than body temperature. One patient had pain while touching the dorsum sella and needed analgesic supplement. All of them improved and none required additional CSF diversion within the average follow up of 9.5 months.

CONCLUSION

ETV can be performed under local anesthesia in conscious, alert and cooperative patients in experienced hands. Unnecessary stimulation of the painful structures should be avoided and fluid for irrigation should be at body temperature. This ensures patient comfort and safety of the procedure.

Single-entry two-stage rotational outside-in technique for simultaneous ventriculostomy and pineal region biopsy using traditional ventricular endoscope: technical note and comparative review

BACKGROUND

Many methods are reported for simultaneous endoscopic 3^rd ventriculostomy and posterior 3^rd ventricular biopsy with their pros and cons. We describe a novel single-entry two-stage rotational outside-in technique using the common 6° ventriculoscope and contrast this with others.

TECHNIQUE

Using a single burr hole, at the line extended from aqueduct through the larger foramen of Monro in parasagittal imaging, the ventricular endoscope is first inserted with 6° angled view anteroinferior, the tip of endoscope sheath just beyond the anterior part of the foramen, and ventriculostomy performed using flexible catheter's beveled cut end and balloon in a curvilinear trajectory using peripheral visualization. Keeping camera in the same orientation, it is then rotated 180° having 6° angled view postero-inferior, endoscope sheath traversing the posterior part of the foramen close to the posterior 3rd ventricular target, and biopsy obtained with rigid forceps. This technique overcomes some of the limitations of other methods by exploiting the flexible catheters and the rotational advantage of the 6° angle of the traditional ventriculoscope.

CONCLUSION

Our single burr hole two-stage rotational technique for simultaneous third ventriculostomy and posterior third ventricular biopsy seems to be an excellent alternative to other methods which can be used with both traditional 6° and greater angled ventriculoscopes without any significant deterrent.

Rigid versus flexible neuroendoscopy: a systematic review and meta-analysis of endoscopic third ventriculostomy for the management of pediatric hydrocephalus

OBJECTIVE

Endoscopic third ventriculostomy (ETV), with or without choroid plexus cauterization (±CPC), is a technique used for the treatment of pediatric hydrocephalus. Rigid or flexible neuroendoscopy can be used, but few studies directly compare the two techniques. Here, the authors sought to compare these methods in treating pediatric hydrocephalus.

METHODS

A systematic MEDLINE search was conducted using combinations of keywords: "flexible," "rigid," "endoscope/endoscopic," "ETV," and "hydrocephalus." Inclusion criteria were as follows: English-language studies with patients 2 years of age and younger who had undergone ETV±CPC using rigid or flexible endoscopy for hydrocephalus. The primary outcome was ETV success (i.e., without the need for further CSF diversion procedures). Secondary outcomes included ETV-related and other complications. Statistical significance was determined via independent t-tests and Mood's median tests.

RESULTS

Forty-eight articles met the study inclusion criteria: 37 involving rigid endoscopy, 10 involving flexible endoscopy, and 1 propensity scored-matched comparison. A cumulative 560 patients had undergone 578 rigid ETV±CPC, and 661 patients had undergone 672 flexible ETV±CPC. The flexible endoscopy cohort had a significantly lower average age at the time of the procedure (0.33 vs 0.53 years, p = 0.001) and a lower preoperatively predicted ETV success score (median 40, IQR 32.5-57.5 vs 62.5, IQR 50-70; p = 0.033). Average ETV success rates in the rigid versus flexible groups were 54.98% and 59.65% (p = 0.63), respectively. ETV-related complication rates did not differ significantly at 0.63% for flexible endoscopy and 3.46% for rigid endoscopy (p = 0.30). There was no significant difference in ETV success or complication rate in comparing ETV, ETV+CPC, and ETV with other concurrent procedures.

CONCLUSIONS

Despite the lower expected ETV success scores for patients treated with flexible endoscopy, the authors found similar ETV success and complication rates for ETV±CPC with flexible versus rigid endoscopy, as reported in the literature. Further direct comparison between the techniques is necessary.

Colloid cysts: Neuropsychological outcome, quality of life and long-term control after endoscopic gross total resection

BACKGROUND

Endoscopy is increasingly being adopted for removing colloid cysts. However, the neuropsychological outcome and quality of life (QOL) have not been studied in detail. This study is to evaluate the efficacy of endoscopic excision on cognitive measures and QOL.

METHODS

Patients with colloid cysts larger than 7 mm, undergoing endoscopy were prospectively studied concerning clinico-radiology, cognitive parameters (age and education adjusted), extent of resection and recurrence. A cross-sectional QOL assessment was additionally performed on endoscopic patients in comparison with cases who underwent microsurgery or standalone ventriculo-peritoneal (VP) shunt.

RESULTS

A total of 22 endoscopic patients with a mean age of 34 years and a mean cyst diameter of 19 mm were studied. Gross total resection(GTR) could be achieved in all. Over a mean follow-up of 53.4 months, none had a recurrence, ventriculomegaly, or retreatment. Among neuropsychological parameters, digit span was the most affected before surgery. There was a broad-based improvement in the mean global cognitive score from 40.63(±10.4) at baseline to 50.25(±5.8) after endoscopy with maximum improvement in 'immediate recall.' The change in scores also had a significant inverse correlation with cyst size, with cysts larger than 18 mm, resulting in lower scores following endoscopy(R=-0.9, P=0.01). QOL was significantly influenced by visual and cognitive impairments and was better among endoscopic patients than similar microsurgery or VP shunt controls, with a significant difference in social and environmental domains(P=0.02).

CONCLUSION

Endoscopy is effective in achieving GTR and long-term control, with neuropsychological improvement correlated with cyst size. This is probably the first report to show QOL is influenced by cognitive parameters and is better following endoscopy than after microsurgery or VP shunt.