Efficacy of simultaneous single-trajectory endoscopic tumor biopsy and endoscopic cerebrospinal fluid diversion procedures in intra- and paraventricular tumors.

OBJECT: Intraventricular and paraventricular tumors resulting in hydrocephalus commonly require a CSF diversion procedure. A tumor biopsy can often be performed concurrently. Although the tissue samples obtained during endoscopic biopsy procedures are small, a diagnosis can be made in most cases. In the present study the authors analyzed the efficacy of concurrent endoscopic biopsy and CSF diversion procedures using a single bur hole and trajectory. METHODS: Eighty-seven patients with intraventricular and paraventricular tumors were treated with endoscopic biopsy and CSF diversion procedures using a rigid rod-lens endoscope or a rigid fiberscope during a 10-year period. All patients underwent a tumor biopsy and an endoscopic third ventriculostomy (ETV), aqueductal stenting (AS), or ventriculoperitoneal (VP) shunting, depending on the tumor location and site of obstruction. A single bur hole for both procedures was used in all patients. RESULTS: Among the 87 patients, the biopsy was diagnostic in 72 (83%) and merely suggestive in 7 (8%); in 8 patients (9%) the sample was nondiagnostic. Among the 22 patients who underwent an initial endoscopic biopsy and subsequent procedures, the specimen obtained at the second surgery was concordant with the initial endoscopic biopsy sample in 13 patients; it was somewhat similar in 4 patients. In the other 5 patients, either a microsurgical or stereotactic approach was used to correctly diagnose the pathology. Fifty-five patients were considered for endoscopic CSF diversion procedures; an ETV was performed in 52 patients and AS in 2. An ETV could not be performed in 3 patients for technical reasons. A VP shunt was inserted in 32 patients, with 25 undergoing shunt placement at the same time as the ETV and 7 at a later date. Significant bleeding was encountered in 3 patients during the tumor biopsy and in 1 patient during the ETV. The ETV failed in 1 patient during the follow-up, and a repeat ETV was required. CONCLUSIONS: Endoscopic biopsy sampling and a concurrent CSF diversion procedure through a single bur hole and trajectory can be considered for intraventricular tumors. The overall success rates of 83% for the biopsy procedure and 86% for the ETV indicate that the procedures are beneficial in the majority of cases. A concordance rate of 75% was found in patients who underwent an initial biopsy procedure and a subsequent microsurgical approach for tumor excision.

Efficacy of endoscopic third ventriculostomy in fourth ventricular outlet obstruction.

OBJECTIVE: Fourth ventricular outlet obstruction (FVOO), an uncommon cause of obstructive hydrocephalus, is most commonly associated with prior intraventricular hemorrhage or intraventricular infection in children. There have been few reports of FVOO in an adult population. METHODS: Twenty-two patients with FVOO treated with endoscopic third ventriculostomy (ETV) were analyzed retrospectively. RESULTS: Of the 22 patients, 10 were younger than 2 years, 6 were between 2 and 18 years, and 6 were older than 18 years of age. Predisposing factors included tubercular meningitis (1 patient), ventriculitis (2 patients), and intraventricular hemorrhage (3 patients). Twelve patients (mostly >2 years of age) had no prior significant history. The third ventricular floor and the adhesions in the basal cisterns were individually graded (I-IV). An inflamed floor was encountered in 3 patients. ETV was successfully performed in 20 patients. Fourth ventricular exploration was carried out in 5 patients, with outlet membrane fenestration in 2 patients. The follow-up period was 1 to 8 years (mean, 4.2 years). The ETV failed in 7 patients, requiring shunt insertion. The overall success rate was 65%; 91% success was achieved in patients who were more than 2 years of age, whereas the procedure failed in all patients younger than 6 months of age. The cerebrospinal fluid yielded a positive bacterial culture (1 patient), antitubercular antibody (1 patient), anticysticercal antibody (1 patient), and cryptococcosis (1 patient). With a successful procedure, lateral ventricular size was reduced in all patients, whereas fourth ventricular size decreased in 12 patients. The extent of adhesions in the basal cisterns directly correlated with failure. None of the patients demonstrated isolated fourth ventricle on follow-up magnetic resonance imaging. In 4 of the 7 patients with failure, endoscopic exploration was performed, and a patent stoma was observed in all of these patients. CONCLUSION: ETV is a viable option for treatment of patients with FVOO. The high failure rate in infants younger than 6 months of age suggests that ventriculoperitoneal shunting is a favorable option in this age group, rather than ETV. Isolated fourth ventricle is uncommon after ETV in hydrocephalus attributable to FVOO.

Endoscopic options in management of posterior third ventricular tumors.

OBJECTIVE: A spectrum of both radiosensitive and radio-resistant lesions occurs in the region of the posterior third ventricle (PTV). Most of these are associated with hydrocephalus requiring a cerebrospinal fluid diversion procedure. The present study aims to assess the effectiveness of endoscopic biopsy and third ventriculostomy (ETV) in these patients. MATERIALS AND METHODS: Twenty-four patients with PTV lesions with moderate to severe hydrocephalus were managed prospectively. All patients underwent ETV and biopsy of the lesion during the same procedure. The ETV could be performed in all patients, where as in 23, a successful biopsy could be obtained. The ETV was successful in 22 patients; it failed in 2 patients requiring shunt insertion. A positive biopsy was obtained in all the patients (pinealocytoma 4, pinealoblastoma 10, embryonal cell carcinoma 1, germinoma 2, oligodendroglioma 1, astrocytoma 2, tuberculoma 4). All patients were subsequently managed with further surgery, radiation, and chemotherapy either alone or in combination depending on the pathology. One patient with a tumor bed hematoma required clot evacuation. The follow-up period ranged from 12 to 36 months. Two patients died, one during hospital stay with a tumor bed hematoma and another at 6 months follow-up due to extensive leptomeningeal spread. CONCLUSIONS: The high yield of endoscopic biopsy (100%) and success of ETV (91%) emphasizes its role in management of the diverse group of PTV lesions in arriving at the optimal definitive management.

Treatment options for Dandy-Walker malformation.

OBJECT: The aim of this study was to assess the efficacy of various treatment options available for children with Dandy-Walker malformation (DWM) and to evaluate the role of endoscopic procedures in the treatment of this disorder. METHODS: The authors conducted a retrospective review of 72 children who underwent surgical treatment for DWM during a 16-year period. All patients underwent computed tomography scanning, and 26 underwent magnetic resonance (MR) imaging. The initial surgical treatment included ventriculoperitoneal (VP) shunt placement in 21 patients, cystoperitoneal (CP) shunt placement in 24, and combined VP and CP shunt insertion in three. Twenty-one patients underwent endoscopic procedures (endoscopic third ventriculostomy [ETV] alone in 16 patients, ETV with aqueductal stent placement in three, and ETV with fenestration of the occluding membrane in two). Three patients underwent membrane excision via a posterior fossa craniectomy. In the 26 patients who had undergone preoperative MR imaging, aqueductal patency was noted in 23 and aqueductal obstruction in three. These three patients underwent placement of a stent from the third ventricle to the posterior fossa cyst in addition to the ETV procedure. During the follow-up period, 12 patients with a CP shunt and four with a VP shunt experienced shunt malfunctions that required revision. Four patients with a CP shunt also required placement of a VP shunt. In addition, five of the 21 ETVs failed, requiring VP shunt insertion. A reduction in ventricle size noted on postoperative images occurred more frequently in patients with a VP shunt, whereas a reduction in cyst size was more appreciable in patients with a CP shunt. Successful ETV resulted in a slight decrease in ventricle size and varying degrees of reduction in cyst size. CONCLUSIONS: Endoscopic procedures may be considered an acceptable alternative in children with DWM. The authors propose a treatment protocol based on preoperative MR imaging findings of associated aqueductal stenosis.

Endoscopic third ventriculostomy in the management of Chiari I malformation and syringomyelia associated with hydrocephalus.

BACKGROUND: Chiari malformation with syringomyelia is conventionally managed with foramen magnum decompression and duroplasty. In presence of hydrocephalus, a ventriculoperitoneal shunt insertion has been the initial preferred mode of treatment. METHODS: Two patients of Chiari I malformation with syringomyelia who had associated hydrocephalus were initially treated with endoscopic third ventriculostomy (ETV). RESULTS: At follow up, both the patients symptomatically improved. Repeat MRI studies revealed collapse of the syrinx cavity and reduction of the Chiari malformation. CONCLUSIONS: Chiari malformation and syrinx associated with hydrocephalus may be effectively managed with endoscopic third ventriculostomy.