Neuronavigated endoscopic aqueductoplasty with panventricular stent plus septostomy for isolated fourth ventricle in complex hydrocephalus and syringomyelia associated with myelomeningocele

Acta Neurochirurgica (2023) 165:2333–2338

Isolated fourth ventricle (IFV) is a challenging entity to manage. In recent years, endoscopic treatment for aqueductoplasty has been on the rise. However, in patients with complex hydrocephalus and distorted ventricular system, its implementation can be complex.

Methods We present a 3-year-old patient with myelomeningocele and postnatal hydrocephalus treated by ventriculoperitoneal shunt. In follow-up, a progressive IFV and isolated lateral ventricle with symptoms of the posterior fossa developed. An endoscopic aqueductoplasty (EA) with panventricular stent plus septostomy guided with neuronavigation was decided due to the complexity of the ventricular system.

Conclusion In IFV associated with complex hydrocephalus with distortion of the ventricular system, navigation can be of great help for planning and as a guide for performing EA

The Aqueduct of Sylvius: Applied 3-T Magnetic Resonance Imaging Anatomy and Morphometry With Neuroendoscopic Relevance

Aqueduct of Sylvius MRI morphometry

Neurosurgery 73[ONS Suppl 2]:ons132–ons140, 2013

The aqueduct of Sylvius (AqSylv) is a structure of increasing importance in neuroendoscopic procedures. However, there is currently no clear and adequate description of the normal anatomy of the AqSylv.

OBJECTIVE: To study in detail hitherto unavailable normal magnetic resonance imaging morphometry and anatomic variants of the AqSylv.

METHODS: We retrospectively studied normal midsagittal T1-weighted 3-T magnetic resonance images in 100 patients. We measured widths of the AqSylv pars anterior, ampulla, and pars posterior; its narrowest point; and its length. We recorded angulation of the AqSylv relative to the third ventricle as multiple deviations of the long axis of the AqSylv from the Talairach bicommissural line. We statistically determined age- and sexrelated changes in AqSylv morphometry using the Pearson correlation coefficient. We measured angulation of the AqSylv relative to the fourth ventricle and correlated this to the cervicomedullary angle (a surrogate for head position).

RESULTS: Patients were 13 to 83 years of age (45% male, 55% female). Mean morphometrics were as follows: pars anterior width, 1.1 mm; ampulla width, 1.2 mm; pars posterior width, 1.4 mm; length, 14.1 mm; narrowest point, 0.9 mm; and angulation in relation to the third and fourth ventricles, 26 and 18, respectively. Age correlated positively with width and negatively with length of the AqSylv. There was no correlation between AqSylv alignment relative to the foramen magnum and the cervicomedullary angle.

CONCLUSION: Normative dimensions of the AqSylv in vivo are at variance with published cadaveric morphometrics. The AqSylv widens and shortens with cerebral involution. Awareness of these normal morphometrics is highly useful when stent placement is an option during aqueductoplasty. Reported data are valuable in guiding neuroendoscopic management of hydrocephalus and aqueductal stenosis.

Suboccipital endoscopic management of the entrapped fourth ventricle

Suboccipital endoscopic management of the entrapped fourth ventricle- technical note

Acta Neurochir (2013) 155:1957–1963

Entrapped fourth ventricle is the result of both inlet aqueduct and outlet fourth ventricular midline and lateral foraminae obstruction. It occurs as a sequalae of intracranial hemorrhagic or inflammatory disease condition. Usually it presents after previous shunting for communicating hydrocephalus with a period of improvement, after which manifestations of posterior fossa expanding process appear. The diagnosis of this rare condition is easy considering the patient past history and the recent clinical state, together with the midline CSF density of the dilated fourth ventricle in either the CT or MR images. The treatment options for this condition include open and endoscopic approaches together with the traditional ventricular to extracranial CSF diversionary procedures.

Objective The aim of the study was to adopt a procedure for treatment of entrapped fourth ventricle that carries the advantage of the minimally invasive technique thus avoiding the complications of the traditional opened and shunt surgeries as well as decreasing multiple procedures due to aqueduct restenosis or stent fall.

Methods Thirteen patients with symptomatic entrapped fourth ventricle underwent suboccipital endoscopic trans–fourth ventricular aqueductoplasty from May 2007 till November 2011. The Gabb endoscopic system was used and aqueductoplasty was performed using 3F Fogarty balloon followed by stent placement. Nine patients were females. The mean age was 3.6 years and the mean follow up period was 23 months. All cases had a previous one or two supratentorial VP shunt placement.

Results Short stent was used in eight patients. During the follow up, stent migration occurred in five of them. Three of these five patients developed posterior fossa compression manifestations due to aqueduct restenosis. Long stent from the aqueduct till the bur hole site for these three patients and the following five patients was used. All cases showed both clinical and radiologic improvement. Apart from the stent migration, no procedure-related complications were encountered.

Conclusion Endoscopic suboccipital paramedian aqueductoplasty with the use of a stent is a safe and effective surgical option that—in our opinion—should stand as the first line treatment for the entrapped fourth ventricle. Long stent is better used after aqueductoplasty to avoid the restenosis if no stent is used or stent fall after short stents. However, good case selection, familiarity with this fairly common endoscopic approach and longer follow-up is needed for obtaining an optimal result.

Efficacy and Safety of Endoscopic Transventricular Lamina Terminalis Fenestration for Hydrocephalus

Neurosurgery 71:464–473, 2012 DOI: 10.1227/NEU.0b013e31825b1e8d

Endoscopic third ventriculostomy (ETV) has become the procedure of choice in the treatment of obstructive hydrocephalus. In certain cases, standard ETV might not be technically possible or may engender significant risk.

OBJECTIVE: To present an alternative through the lamina terminalis (LT) by a transventricular, transforaminal approach with flexible neuroendoscopy and to discuss the indications, technique, neuroendoscopic findings, and outcomes.

METHODS: Between 1994 and 2010, all patients who underwent endoscopic LT fenestration as an alternative to ETV were analyzed and prospectively followed up. The decision to perform an LT fenestration was made intraoperatively.

RESULTS: Twenty-five patients, ranging in age from 7 months to 76 years (mean, 28.1 years), underwent endoscopic LT fenestration. Patients had obstructive hydrocephalus secondary to neurocysticercosis (11 patients), neoplasms (6 patients), congenital aqueductal stenosis (3 patients), and other (5 patients). Thirteen patients (52%) had had at least 1 ventriculoperitoneal shunt that malfunctioned; 6 patients (24%) had undergone a previous endoscopic procedure. Intraoperative findings that led to an LT fenestration were the following: ETV not feasible to perform, basal subarachnoid space not sufficient, or adhesions in the third ventricle. No perioperative complications occurred. The mean follow-up period was 63.76 months. Overall, 19 patients (76%) had resolutions of symptoms, had no evidence of ventriculomegaly, and did not require another procedure. Six (24%) required a ventriculoperitoneal shunt.

CONCLUSION: Endoscopic transventricular transforaminal LT fenestration with flexible neuroendoscopy is feasible with a low incidence of complications. It is a good alternative to standard ETV. Adequate intraoperative assessment of ETV success is necessary to identify patients who will benefit.

Endoscopic Treatment of Isolated Fourth Ventricle: Clinical and Radiological Outcome

Neurosurgery 70:847–859, 2012 DOI: 10.1227/NEU.0b013e318236717f

Treatment of an isolated fourth ventricle should be considered when clinical symptoms or a significant mass effect occur.

OBJECTIVE: To report clinical and radiographic outcomes after endoscopic transaqueductal or transcisternal stent placement into the fourth ventricle. METHODS: In 19 patients (age, 34th week of gestation-20 years; median age, 17.5 months), 22 endoscopic procedures were performed. Either an aqueductoplasty or, in cases with a supratentorially extended fourth ventricular component, an interventricular fenestration was performed. In all patients, a stent connected to the cerebrospinal fluid–diverting shunt was placed through the fenestration. Surgical complications and radiological and clinical outcomes are reported.

RESULTS: All 19 patients had a mean follow-up of 26.9 ± 18.2 months. No persisting neurological complications were observed; 27.3% of patients experienced complete resolution of presenting symptoms, whereas 68.3% demonstrated partial resolution. Symptoms with short duration (< 4 weeks) resolved completely, whereas long-standing symptoms partially improved. Short-term shunt complications (n = 2; insufficient catheter placement and subdural hygroma) and a need for long-term stent revisions (n = 3; stent retraction and shunt revision for other causes) were observed. The mean fourth ventricular volume was reduced after surgery (44.2 ± 25.8 to 23.1 ± 21.9 mL; P < .01). Pontine diameter increased from 0.9 ± 0.3 to 1.2 ± 0.3 cm (P < .01) after surgery. Both effects were still demonstrated on later radiological follow-up of 24.4 ± 14.2 months (fourth ventricular size, 24.7 ± 28.1 mL; P < .01; pontine diameter, 1.3 ± 0.3 cm; P < .01).

CONCLUSION: The clinical and radiological outcomes after endoscopic aqueductoplasty and interventriculostomy in children with an isolated fourth ventricle indicate that this procedure is feasible, effective, and safe.