Hydrocephalus and racemose cysticercosis: surgical alternative by endoscopic third ventriculostomy

BACKGROUND AND PURPOSE: Hydrocephalus is a frequent and potentially serious complication of neurocysticercosis. Its treatment often requires ventricular shunting. The complication rate is high due to obstruction or material infection, which may justify endoscopic third ventriculostomy (ETV). OBSERVATION: We report a case of obstructive hydrocephalus in a 46-year-old man in the context of racemose cysticercosis, presenting with headaches and transient disorders of consciousness. Imaging showed cystic lesions of the cisterna magna, responsible for hydrocephalus which was treated effectively by ETV. Treatment with albendazole decreased the volume of the cisterna magna cysts. RESULTS: The patient was followed for 6 years after ETV with no recurrence of hydrocephalus despite two more symptomatic episodes of the disease with extension of the cysts into the lumen of the fourth ventricle and into the perispinal subarachnoid spaces, effectively treated by albendazole each time. CONCLUSIONS: Treatment of obstructive hydrocephalus secondary to cerebral racemose cysticercosis by ETV seems to be an effective and safety technique. The role of ETV should be evaluated in this indication.     

Use of a microvascular Doppler probe to avoid basilar artery injury during endoscopic third ventriculostomy. Technical note.

Basilar artery (BA) injury has been reported in a number of cases as a major complication of third ventriculostomy for hydrocephalus. This report describes the deployment of a pulsed-wave microvascular Doppler probe through the endoscope to locate the BA complex and subsequently to select a safe zone for perforation of the third ventricular floor. This procedure is quick and easily learned, and it is hoped that it can decrease the risk of vascular injury during third ventriculostomy.     

Endoscopic neurosurgery "around the corner" with a rigid endoscope. Technical note.

Endoscopically "working around the corner" is presently restricted to the use of flexible endoscopes or an endoscope-assisted microneurosurgical (EAM) technique. In order to overcome the limitations of these solutions, endoscopic equipment and techniques were developed for "working around the corner" with rigid endoscopes. A steering insert with a 5 French working channel is capable of steering instruments around the corner by actively bending the guiding track and consecutively the instrument. A special fixation device enables strict axial rotation of the endoscope in the operating field. Endoscopic procedures "around the corner", including aqueductal stenting, pellucidotomy, third ventriculostomy and biopsy were performed in human cadavers. Special features of the used pediatric neuroendoscope system, i.e., reliable fixation, axial rotation, and controlled steering of instruments, increase the safety and reduce the surgical traumatization in selected cases, such as obstructive hydrocephalus due to a mass lesion in the posterior third ventricle, since endoscopic third ventriculostomy and biopsy can be performed through the same burr hole trephination. Limitations of this technique are given by the size of the foramen of Monro and the height of the third ventricle as well as by the bending angle of the instruments (40-50 degrees).     

Endoscopy of spinal cord and posterior fossa by a lumbar percutaneous approach: endoscopic anatomy in cadavers.

Endoscopy has a long history and is used extensively today following recent technical improvements. Endoscopy has been used in neurosurgery to examine ventricles, cisterns, and intra-arteries. In this study, we evaluated the possibility of endoscopic examination and treatment in the narrow confines of the subarachnoid space of the spine and the posterior fossa. Endoscopes with external diameters of 0.5, 1.4, and 2.2 mm were used. While the first two endoscopes had rigid tips, the 2.2-mm endoscope had a directable tip. Each endoscope was inserted percutaneously in the lumbar region in five cadavers and was advanced cranially into the posterior fossa under endoscopic monitoring. Arteries, veins and nerve roots upon the surface of the spinal cord could be distinguished readily with all endoscopes. All endoscopes could be inserted under direct observation, avoiding these vessels and nerve roots. Further rostral advancement of the endoscope permitted visualization of the upper spinal cord, cisterna magna at the foramen magnum, and the fourth ventricle. The lower aspect of the cerebellum, the foramen of Magendie, and the cerebral aqueduct could be observed from below. When the endoscope was advanced ventrolaterally, the vertebral artery and lower cranial nerves were observed. From this preliminary cadaver study, endoscopy via lumbar puncture appeared useful for inspection of structures surrounding the spinal cord and posterior fossa, and for some simple treatments.     

Traumatic subependymal hematoma during endoscopic third ventriculostomy in a patient with a third ventricle tumor: case report.

Endoscopic third ventriculostomy has become a routine intervention for the treatment of non-communicating hydrocephalus. This technique is largely considered safe and a very low incidence of complications is reported. However, hemorrhage in the course of neuroendoscopy is still a problem difficult to manage. The authors present a case in which endoscopic third ventriculostomy and tumor biopsy were performed in a young patient with a huge tumor growing in the posterior part of the third ventricle. The surgical approach to realize the stoma was difficult because the tumor size reduced the third ventricle diameter. Surgical manipulation produced a traumatic subependymal hematoma. This hematoma drained spontaneously after few minutes into the ventricle and the blood was washed away. The postoperative neurological course was uneventful and the ventriculostomy showed to work well by reducing the size of the lateral ventricles and the intracranial pressure in three days. This complication during endoscopic third ventriculostomy has never been reported before. We emphasize the difficulty of endoscopic procedures in patients with huge tumors in the third ventricle. Where reduction in size of the third ventricle and of the foramen of Monro ist present we suggest a careful approach to the third ventricle.     

Death after late failure of endoscopic third ventriculostomy: a potential solution

OBJECTIVE: Late failure after successful third ventriculostomy is rare, and death caused by failure of a previously successful third ventriculostomy has been reported on four occasions. We describe a simple innovation that adds little morbidity and has the potential to reduce the advent of death after late failure of endoscopic third ventriculostomy. METHODS: After endoscopic fenestration of the floor of the third ventricle, a ventricular catheter and subcutaneous reservoir are placed via the endoscope path. With acute blockage and neurological deterioration, cerebrospinal fluid can be removed via needle puncture of the reservoir until consultation with a neurosurgeon. RESULTS: From 1979 to 2003, more than 240 endoscopic third ventriculostomies have been performed at our institution, with one death after late failure. The revised technique was devised after this death and has been performed on 21 patients to date. CONCLUSION: The addition of a reservoir adds little time and morbidity to the procedure and offers the potential to sample cerebrospinal fluid, measure intracranial pressure, and reduce mortality associated with late failure of endoscopic third ventriculostomy.     

Interhemispheric Endoscopic Fenestration of the Lamina Terminalis through a Single Frontal Burr Hole

Objective We evaluate the feasibility and safety of performing a novel interhemispheric endoscopic fenestration of the lamina terminalis (IEFLT) through a single frontal burr hole immediately lateral to the superior sagittal sinus. Methods Five cadaveric heads underwent IEFLT. Sequential burr holes were made beginning above the glabella and progressed cranially to caudally until the frontal sinus. An endoscope was inserted, and interhemispheric dissection of the arachnoid membranes was completed with endoscopic instruments in a straight direction from the point of entry to the lamina terminalis (LT). Angled optics (0 and 30 degrees) were used to study the neurovascular structures and surgical landmarks. Results The IEFLTs were successfully completed in all specimens and allowed for good visualization of the inferior portion of the LT. The arachnoid dissections were achieved uneventfully. The endoscope provided good surface control of the LT and excellent stereoscopic visualization of the neurovascular complexes. Improved circumferential visualization of the superior part of the anterior portion of the third ventricle was attained. Conclusion IEFLT is a potential alternative to the classic endoscopic third ventriculostomy and a simpler alternative to the subfrontal EFLT, although surgical maneuverability is still limited due to the size of the probe in relation to the narrow surgical corridor.     

Endoscopic surgery for large posterior fossa arachnoid cysts.

The authors report two cases of large arachnoid cysts of the posterior fossa treated by endoscopic surgery. One patient underwent a successful endoscopic cyst fenestration by burr hole approach after several procedures of shunt revision. In another an endoscope-assisted microsurgical intervention was necessary. Lateral (cerebellar or cerebellopontine angle) cysts, as two reported cases, may be treated through a lateral retromastoid approach by fenestration into the prepontine cistern and eventually into the cisterna magna. We advise to start the operation through a burr hole and to try to realize the fenestration by endoscopy only. If this attempt fails, an endoscope-assisted microsurgical technique may be performed by enlarging the craniectomy. In this last instance the endoscope is useful particularly deeply to fenestrate the anterior cyst wall in the prepontine or ambient cisterns, where it provides more illumination and helps to identify the nervous and vascular structures.     

Endoscopy of Meckel's cave, cisterna magna, and cerebellopontine angle. Technical note.

A new 1.45-mm endoscope is described that can be inserted through a thin-walled No. 16 needle. The instrument was used in 10 cadavers for endoscopic exploration of the cisterna magna, the C1-2 space, Meckel's cave, and the cerebellopontine angle. Its potential clinical application is discussed.     

The combined use of image-guided frameless stereotaxy and neuroendoscopy for the surgical management of occlusive hydrocephalus and intracranial cysts

The objective of the study was to report the initial experiences with the combined use of an infrared-based frameless stereotactic navigation device and neuroendoscopy. Ten hydrocephalic patients underwent endoscopic third ventriculostomy and two patients with intracranial cysts underwent cystoventriculostomy. The trajectory of the rigid endoscope and target point were planned by frameless stereotaxy. An articulated arm served to maintain the predetermined trajectory during the surgery and to guide the endoscope. Endoscopic surgery was successfully performed in 11 of the 12 patients. In one patient with a small third ventricle the ventriculostomy had to be abandoned. We observed no surgical morbidity. In none of the cases was it necessary to correct the predetermined trajectory of the endoscope to reach the planned target area. The planning of the trajectory and the target area, as well as the maintenance of the trajectory during endoscopy reduce the risk of inadvertent damage to vital structures. The combined use of frameless stereotaxy and neuroendoscopy might contribute to a decrease of procedure-related morbidity.     

Endoscopic third ventriculostomy for hydrocephalus.

The authors report on 125 patients who underwent endoscopic third ventriculostomy for obstructive hydrocephalus in three Italian Neurosurgical Centers. The series includes 77 cases of primary aqueductal stenosis, 33 with triventricular hydrocephalus due to external tumor compression, and 15 with tetraventricular hydrocephalus. The operations were carried out mainly under general anesthesia, using a flexible endoscope. Decrease of size of the third ventricle and the presence of a signal void at the level of the fenestration are the main postoperative MRI findings. Signs of intracranial hypertension, increased head circumference and Parinaud syndrome respond more frequently to the endoscopic treatment. The overall rate of good results (shunt-independent patients) in this series is 86.4%; primary aqueductal stenosis (93.5%) and triventricular hydrocephalus due to external compression (84.8%) are associated to the higher rate of good postoperative results than tetraventricular hydrocephalus (53.3%). Because of the very low invasivity of this technique, the absence of postoperative mortality and the scarce and usually transient postoperative complications, the authors advise to enlarge the indications for endoscopic third ventriculostomy to all patients with obstructive hydrocephalus when the third ventricle is large enough and there are no alterations of the CSF resorption.     

Endovascular management of a basilar artery false aneurysm secondary to endoscopic third ventriculostomy: case report

OBJECTIVE AND IMPORTANCE: Third ventriculostomy for the management of noncommunicating hydrocephalus is a commonly performed procedure with a 5% complication rate. One of the known complications is basilar artery injury. CLINICAL PRESENTATION: We report a case of basilar artery injury, intraventricular hemorrhage, and false aneurysm formation in a 30-month-old boy after third ventricle floor fenestration. INTERVENTION: The false aneurysm was managed with endovascular trapping by use of Guglielmi detachable coils without morbidity. CONCLUSION: Endovascular therapy can be used successfully to manage vascular injury after third ventriculostomy.     

Endoscopic third ventriculostomy with cystoventricular stent placement in the management of dandy-walker malformation: technical case report of three patients

OBJECTIVE AND IMPORTANCE: Dandy-Walker malformation has conventionally been managed with placement of cystoperitoneal or ventriculoperitoneal shunts. However, associated aqueductal obstruction requires simultaneous drainage of both the supratentorial and infratentorial compartments. CLINICAL PRESENTATION: Three children with Dandy-Walker malformation and aqueductal obstruction were managed with endoscopic third ventriculostomy and placement of a stent from the third ventricle to the posterior fossa cyst. INTERVENTION: After an endoscopic third ventriculostomy was performed, the stent was placed from the third ventricle to the posterior fossa cyst through the thinnest part of the posteroinferior wall of the aqueduct. There was no operative morbidity. In one patient, the stent was malpositioned, requiring a repositioning. The endoscopic third ventriculostomy was successful in two patients, whereas it failed in one, requiring a ventriculoperitoneal shunt placement. CONCLUSION: Cystoventricular stent placement with endoscopic third ventriculostomy is a promising alternative in patients with Dandy-Walker malformation with aqueductal obstruction.     

经前额纵裂入路的神经内镜与显微解剖学及临床应用

目的通过对经前额纵裂入路的内镜解剖与显微解剖学研究,为临床提供解剖学参考。方法8例成人尸头,取经前额纵裂入路,在显微镜和内镜下对其内部结构进行全程观察。采用经前额纵裂入路手术22例。结果通过显微镜及不同角度内镜,能够观察到鞍区和第三脑室结构。22例中,动脉瘤5例均成功夹闭,肿瘤全切13例,近全切除3例,大部切除1例,无死亡病例,无严重并发症的发生。结论内镜辅助显微镜经前额纵裂入路对鞍区及第三脑室前部暴露良好,对周围组织损伤小,是切除鞍区和第三脑室前部肿瘤的较佳入路。     

Fatal subarachnoid hemorrhage after endoscopic third ventriculostomy. Case report.

In recent years, endoscopic third ventriculostomy has become a well-established procedure for the treatment of various forms of noncommunicating hydrocephalus. Endoscopic third ventriculostomy is considered to be an easy and safe procedure. Complications have rarely been reported in the literature. The authors present a case in which the patient suffered a fatal subarachnoid hemorrhage (SAH) after endoscopic third ventriculostomy. This 63-year-old man presented with confusion and drowsiness and was admitted in to the hospital in poor general condition. Computerized tomography scanning revealed an obstructive hydrocephalus caused by a tumor located in the cerebellopontine angle. An endoscopic third ventriculostomy was performed with the aid of a Fogarty balloon catheter. Some hours postoperatively, the patient became comatose. Computerized tomography scanning revealed a severe perimesencephalic-peripontine SAH and progressive hydrocephalus. Despite emergency external ventricular drainage, the patient died a few hours later. Although endoscopic third ventriculostomy is considered to be a simple and safe procedure, one should be aware that severe and sometimes fatal complications may occur. To avoid vascular injury, perforation of the floor of the third ventricle should be performed in the midline, halfway between the infundibular recess and the mammillary bodies, just behind the dorsum sellae.     

Minimally invasive treatment of posterior fossa craniopharyngioma by means of navigated endoscopy.

The aim of the paper is to present an unusual case of ectopic posterior fossa craniopharyngioma after repeated surgeries for primary suprasellar tumor. The clinical condition of the patient favored minimally invasive neuroendoscopic surgery. After presurgical planning with the help of neuronavigation system a trajectory from the contralateral side through the cisterna magna was chosen. Endoscopic cyst fenestration and cyst wall resection were safely performed with an excellent outcome. The possible origin of this posterior fossa craniopharyngioma is discussed together with tumor dissemination pathways. The endoscopic contralateral approach to the tumor utilized the wide working space provided by the cisterna magna and the great versatility of the navigated neuroendoscopic approach was proven.     

Endoscopic third ventriculostomy: a study of intracranial pressure vs. haemodynamic changes.

Fourteen paediatric patients with obstructive hydrocephalus were studied. They underwent endoscopic third ventriculostomy under general anaesthesia. Their ages ranged from 1 to 144 weeks (mean 34+/-36 weeks) and weight from 2 to 22 kg (mean 10.2+/-5.4 kg). In an attempt to identify the possible mechanisms of the intraoperative haemodynamic changes associated with endoscopic third ventriculostomy, we studied the intracranial pressure measured in the third ventricle versus the haemodynamic changes. The intracranial pressure was measured using a pressure transducer attached at one end to the endoscope and the other end to the monitor. The mean third ventricle pressure value was 10.2 mmHg (+/-3.5). Bradycardia occurred in six (43%) of our patients. The mean value of the lowest heart rate reading intraoperatively was 81 beats/min (+/-31.8). Negative correlation was obtained between the intracranial pressure and the haemodynamic changes. Alerting the surgeon to perforate the floor of the third ventricle or withdraw the scope away from it was sufficient to resolve the bradycardia. We concluded that serious dysrhythmias might occur during endoscopic third ventriculostomy, the majority of which can be resolved without medications.     

Endoscopic methods of hydrocephalus treatment

This article discusses the use of the endoscope in treatment of hydrocephalus without shunting. The selection of candidates for third ventriculostomy and choroid plexus coagulation are described together with the overall published rates of success with each technique. A summary of the nature and frequency of complications of third ventriculostomy are given after reviewing published data on over a thousand patients who have had the operation to date. The role of other endoscopic techniques, such as septal fenestration and decompression of obstructing cysts, also are discussed.     

Neuronavigation-guided endoscopic surgery for pineal tumors with hydrocephalus.

We have applied the neuronavigation system to endoscopic biopsy and third ventriculostomy in the management of patients with a pineal tumor with hydrocephalus. With the guidance of neuronavigation, the two optimal sites of burr hole and trajectories were planned preoperatively, and the advancing endoscopic device was monitored in real time during the procedure. In our five patients, the diameters of the tumors were 2-3 cm, and the mean systemic accuracy of registration with neuronavigation was 1.2 mm. The biopsy and third ventriculostomy were performed successfully via the respective optimal burr hole and the trajectory determined using preoperative neuronavigation. There were no procedure-related complications, and none of the patients needed another procedure for CSF diversion during the follow-up periods. We present our technique which includes the application of the neuronavigation system to the biopsy and third ventriculostomy in pineal tumor with associated hydrocephalus. This technique can be performed using a simple rigid endoscope via the determined optimal entries and trajectories. The optimal preoperative planning and the intraoperative guidance by neuronavigation are thought to be able to give more chances to minimize the brain injury related to movements or deviation of endoscopic device.     

Treatment of posterior third ventricular central neurocytoma with endoscopic biopsy, endoscopic third ventriculostomy and stereotactic radiosurgery.

Central neurocytomas of the posterior third ventricle are rare. These typically benign lesions have recently been shown to respond well to Gamma knife stereotactic radiosurgery (SRS). We present the case of a posterior third ventricle central neurocytoma presenting with aqueduct obstruction. The patient was treated with endoscopic biopsy and endoscopic third ventriculostomy, followed by Gamma knife radiosurgery. At 2 years the tumor has diminished in size and the patient is neurologically intact. This treatment strategy may avoid the risk of open ventricular surgery and the need for shunts in patients with central neurocytomas of appropriate size and location.