Search Results

You are looking at 1 - 7 of 7 items for

  • Author or Editor: Aaron Mohanty x
Clear All Modify Search
Restricted access

Aaron Mohanty

✓Isolation of the fourth ventricle is occasionally observed after shunt treatment of the lateral ventricles for obstructive panventricular hydrocephalus. Of the various surgical options currently available, placement of shunts in the fourth ventricle has remained as the mainstay of treatment. These shunts are difficult to place, however, and have been associated with higher complication rates. With the advent of neuroendoscopic techniques, the treatment of this condition has shifted from shunt therapy to endoscopic third ventriculostomy (ETV) and aqueductal reconstruction. The authors report on four patients (age range 11–28 years old) who had undergone fourth ventricular shunt placement earlier in childhood to treat panventricular hydrocephalus and who presented with an isolated fourth ventricle (IFV) during the follow-up period. All patients underwent magnetic resonance imaging to identify the extent of the stenosed aqueduct. Symptoms improved in all and the size of the fourth ventricle decreased as well, indicating a functioning stent. The ETV failed in two patients, however, and they required placement of a ventriculoperitoneal (VP) shunt. Aqueductal stenting with an ETV or a VP shunt is a promising option in the management of IFVs.

Restricted access

Aaron Mohanty, Arundhati Biswas, Satyanarayana Satish, Shanti Shankar Praharaj and Kolluri V. R. Sastry

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.

Full access

Aaron Mohanty, Vani Santosh, B. Indira Devi, Satyanarayana Satish and Arundhati Biswas

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.

Full access

Xavier G. Kocherry, Thimappa Hegde, Kolluri V. R. Sastry and Aaron Mohanty

Object

Intracranial abscesses located deep in the cerebral parenchyma and in eloquent regions are often difficult to manage surgically. The authors have attempted to analyze the efficacy of stereotactic aspiration in the management of these abscesses.

Methods

Cases involving 22 patients (including 9 children) with deep-seated and/or eloquent-region intracranial abscesses who underwent CT- or MR imaging–guided stereotactic aspiration between January 1995 and July 2001 were analyzed.

Results

A definite source of infection could be identified only in 9 of the cases. In 18 patients, the abscess was deep seated, whereas in the rest it was located in the eloquent cortex. Five patients had abscesses located in multiple sites. In 17 patients only 1 aspiration was required; in 5 others subsequent procedures were required. In the initial postaspiration CT, minor hemorrhage was noted in 3 patients not requiring further intervention. Antibiotics were administered for a period varying from 4 to 8 weeks following aspiration. An early recurrence (within 2 weeks of initial aspiration) was evident in 5 patients. All recurrent abscesses were reaspirated. In 2 patients new abscesses developed while the patients were still receiving antibiotic therapy. There were no late recurrences. In 1 patient ventriculitis developed, with subsequent hydrocephalus requiring a shunt insertion. Follow-up CT scans showed complete resolution of the abscess in all patients. There were no deaths.

Conclusions

Stereotactic aspiration is a useful management option for abscesses located in eloquent or inaccessible regions. Repeated aspiration should be considered in patients in whom the initial aspiration proves ineffective or partially effective. Complete resolution may require repeated stereotactic aspirations and continued antibiotic therapy.

Restricted access

Leonardo Rangel-Castilla, Jaime Torres-Corzo, Roberto Rodriguez Della Vecchia, Aaron Mohanty and Haring J. W. Nauta

Object

Arachnoid cysts are congenital lesions that arise during development by splitting of the arachnoid membrane. Large cysts can be adjacent to CSF pathways causing a marked midline shift and hydrocephalus. The association between a large arachnoid cyst and hydrocephalus has been commonly described as being due to a mass effect, but these previous reports have not focused closely on any associated intraventricular abnormalities.

Methods

Seven patients who were previously treated with a cystoperitoneal shunt presented with shunt failure, hydrocephalus, and/or cyst expansion. All of these patients had giant arachnoid cysts extending to the periventricular region from the original site, which was the sylvian fissure in 4 patients, and the suprasellar cistern, quadrigeminal cistern, and interhemispheric fissure in 1 patient each. Endoscopic exploration of the ventricular system and cyst fenestration was then performed in all patients.

Results

The endoscopic findings were obstruction of the cerebral aqueduct by a membrane not related to the cyst in 5 patients, occlusion of the foramen of Monro in 6, septum pellucidum hypoplasia in 2, and occlusion of the cerebral aqueduct by a quadrigeminal arachnoid cyst in 1. Endoscopic procedures performed were septum pellucidum fenestration and/or foraminoplasty in 5 patients, aqueductoplasty in 2, endoscopic third ventriculostomy in 5, fenestration of the lamina terminalis in 1, and direct cystocisternostomy in 1. After the endoscopic procedure, signs and symptoms of increased intracranial pressure and hydrocephalus improved in all patients, with a reduction in size of the cyst and the ventricle.

Conclusions

Ventricular abnormalities contributing to hydrocephalus may be associated with arachnoid cysts. These abnormalities may more likely reflect a common origin than a casual relation. Foramen of Monro stenosis and cerebral aqueduct occlusion associated with an arachnoid cyst can be more frequent than has been previously believed. In cases of periventricular giant arachnoid cysts, endoscopic exploration is a good alternative for examining the ventricular system and identifying and treating CSF obstructions caused by and/or related to arachnoid cysts.

Restricted access

Shlomi Constantini, Aaron Mohanty, Samuel Zymberg, Sergio Cavalheiro, Conor Mallucci, Dieter Hellwig, Yusuf Ersahin, Hiroshi Mori, Carmelo Mascari, José Aloysio Costa Val, Wolfgang Wagner, Abhaya V. Kulkarni, Spyros Sgouros and Shizuo Oi

Object

Analysis of the safety and morbidity of neuroendoscopic biopsies (NEBs), as well as the reliability in obtaining an accurate diagnosis, has until now been based on studies with relatively small sample sizes. Through the cooperative efforts of several international medical centers, authors of the present study collected data on a large number of patients to obtain better insight into this issue. When possible, they compared pathology obtained through an NEB with the “gold-standard” pathology obtained in open surgery.

Methods

Thirteen randomly chosen medical centers in 9 countries collected data for patients who had undergone NEB, which were then analyzed for universal complications, bleeding, navigation technique, pathology, mismatch between biopsy results and final diagnosis, and a number of other potentially influential factors.

Results

Data for 293 patients were analyzed. Sixty percent of the patients were male, and patient ages ranged from 0.1 to 78.7 years (median age 20.4 years). The most common tumor locations were pineal (33.1%), thalamic (16.7%), tectal (13%), and hypothalamic (4.4%). Fifty percent of the tumors were larger than 20 mm, 36% were between 10 and 20 mm, and 14% were smaller than 10 mm. Intraoperative bleeding was seen in 275 patients (94%). The amount of blood was noted as mild in 75%, moderate in 13%, and severe in 6%. Infection occurred in 8 patients (3%). Death occurred in 1 patient (0.3%), which was caused by severe intraoperative bleeding. Biopsies were informative in 265 patients (90.4%). Seventy-eight patients (26.6%) had open surgery following the NEB. For these patients, the pathology results from the NEB were compared with those from the open surgery that followed. In 14 cases (17.9%) there was disagreement on the pathology. Of these cases, a meaningful mismatch, in which the erroneous NEB pathology could have led to an inappropriate management decision, occurred in 9 cases (11.5%). Most of these meaningful mismatches were lesions diagnosed as low-grade or pilocytic astrocytoma on the NEB and later proved to be high-grade astrocytoma (4 cases) and 1 case each of meningioma, cavernoma, primitive neuroectodermal tumor, neurocysticercosis, and pineocytoma.

Conclusions

In experienced hands, NEBs can be performed with low morbidity and mortality, providing meaningful pathological data for the majority of patients with a wide range of tumor types, locations, and presentations. These biopsies also offer other advantages, such as the ability to perform concomitant endoscopic third ventriculostomy and septum pellucidotomy. However, due caution must be maintained, since pathology obtained from an NEB, as with stereotactic biopsies, may be subject to sampling errors, especially when the results seem to indicate a low-grade glial tumor.