Endoscopic surgery for obstructive hydrocephalus

The relationship between semantic and episodic memory: evidence from a case of severe anterograde amnesia

It is increasingly being recognized that new declarative, consciously accessible information can be learned in anterograde amnesia, but it is not clear whether this learning is supported by episodic or semantic memory. We report a case of a 55-year-old man who experienced severe amnesia after limited damage to the medial temporal lobe following neurosurgical complications. His general cognitive performance and knowledge of new French words and public events that occurred before and after the onset of amnesia were assessed. Performance remained satisfactory on post-morbid vocabulary and public events, with a drop in performance observed for very recent public events only, while knowledge of very recent vocabulary was comparable to that of the control subjects. The implications of these findings for our understanding of the underlying learning mechanisms are discussed. This is the first report of acquisition of consciously accessible postmorbid knowledge of public events in a patient with severe amnesia.

Fourth Ventricular Outflow Obstruction in an Infant with Ileal Atresia and Laryngomalacia: Endoscopic Management

Fourth ventricle outflow obstruction (FVOO) is a rare cause of obstructive hydrocephalus. In this study, we described a case of idiopathic FVOO with ileal atresia and laryngomalacia which was managed with endoscopic third ventriculostomy (ETV) and re-endoscopy. We also described the techniques of fenestration of Liliequist membrane and partial removal of arachnoid membrane over dorsum sella (DS) to prevent closure of fenestration and recurrence of hydrocephalus. The patient was a 4-month-old infant presented with progressively increasing head size, feeding difficulty, respiratory distress, and tense fontanel. The infant had a history of laparotomy for ileal atresia. CT scan showed panventriculomegaly due to FVOO. ETV with fenestration of Liliequist membrane was done on emergency basis. After operation, the patient improved clinically and radiologically. Four weeks later, the patient returned with recurrent hydrocephalus. Endoscopic reoperation showed closure of fenestration in arachnoid membrane (Lilieqiest membrane). Endoscopic refenestration with partial excision of arachnoid on DS was done. The patient again recovered radiologically and clinically till last follow-up. In idiopathic FVOO, ETV with wide fenestration of Liliequist membrane, preferably with partial removal of arachnoid on DS, may be very useful in treating hydrocephalus (HCP) and preventing recurrent HCP even in infants.

The effect and evolution of patient selection on outcomes in endoscopic third ventriculostomy for hydrocephalus: A large-scale review of the literature

Endoscopic third ventriculostomy (ETV) has become a popular technique for the treatment of hydrocephalus, but small sample size has limited the generalizability of prior studies. We performed a large-scale review of all available studies to help eliminate bias and determine how outcomes have changed and been influenced by patient selection over time. A systematic literature search was performed for studies of ETV that contained original, extractable patient data, and a meta-analytic model was generated for correlative and predictive analysis. A total of 130 studies were identified, which included 11,952 cases. Brain tumor or cyst was the most common hydrocephalus etiology, but high-risk etiologies, post-infectious or post-hemorrhagic hydrocephalus, accounted for 18.4%. Post-operative mortality was very low (0.2%) and morbidity was only slightly higher in developing than in industrialized countries. The rate of ETV failure was 34.7% and was higher in the first months and plateaued around 20months. As anticipated, ETV is less successful in high-risk etiologies of hydrocephalus and younger patients. Younger patient age and high-risk etiologies predicted failure. ETVs were performed more often in high-risk etiologies over time, but, surprisingly, there was no overall change in ETV success rate over time. This study should help to influence optimal patient selection and offer guidance in predicting outcomes.

Outcome of Endoscopic Third Ventriculostomy in Pediatric Patients at Zewditu Memorial Hospital, Ethiopia

OBJECTIVE

To determine short-term outcome of endoscopic third ventriculostomy (ETV) in pediatric patients.

METHODS

This was a hospital-based retrospective study of outcome of ETV performed with or without choroid plexus cauterization (CPC) in pediatric patients at Zewditu Memorial Hospital, Addis Ababa, Ethiopia, between January 2012 and December 2014. Medical records were used to complete a structured questionnaire. Outcomes were graded as success or failure. The difference in proportions was examined using χ(2) test.

RESULTS

Of 122 children, 26 underwent a combined ETV and CPC procedure, and 96 underwent ETV alone. The mean and median ages were 1.89 months and 2.0 months, respectively. Most patients were <6 months old (45.1%); 35.2% were >1 year old. The cause of hydrocephalus was myelomeningocele in 42 (34.4%) patients and aqueductal stenosis in 41 (33.6%) patients. The mean and median follow-up periods were 7.2 months and 3.0 months, respectively. The success rate for combined ETV and CPC (66%) was superior to the success rate for ETV alone (47%) among infants <1 year old (P < 0.0001). The overall surgical mortality rate was 2.4%, and the infection rate was 7%.

CONCLUSIONS

In resource-limited countries, ETV can be performed with acceptable results and less mortality and morbidity. Myelomeningocele and aqueductal stenosis were the most common causes of hydrocephalus. In patients <1 year old, the outcome success in patients undergoing combined ETV and CPC (53%) was significantly better compared with patients undergoing ETV alone (25%).

Endoscopic third ventriculostomy for obstructive hydrocephalus: Outcome analysis of 120 consecutively treated patients from a developing country

OBJECTIVES

Endoscopic third ventriculostomy (ETV) for the treatment of obstructive hydrocephalus is a relatively new concept amongst neurosurgeons of the developing world. Therefore, this study was conducted to report our experience, patient selection, success rates and complications of ETV and compare our results with the literature from the developed countries.

METHODS

We performed ETV on 120 patients at our centre and prospectively collected their clinical data on pre designed questionnaires. Success was defined as clinical improvement on 3rd month post operative clinic visit. The data was analyzed using SPSS version 20.

RESULTS

There were 79 male and 41 female patients. The mean age was 36.1 ± 14.3 years. Overall, ETV was successful in 107 (89.2%) of patients. 4 patients had intra operative bleeding, 4 patients developed CSF leaks while 1 patient had a transient gaze palsy. There was no mortality.

CONCLUSION

ETV is a very effective treatment modality for treating obstructive hydrocephalus in well selected patients and can be successfully practiced by neurosurgeons in the developing countries.

Idiopathic fourth ventricle outlet obstruction successfully treated by endoscopic third ventriculostomy: a case report

Introduction

Fourth ventricle outlet obstruction (FVOO) is a rare cause of obstructive hydrocephalus. We describe a case of idiopathic FVOO that was successfully treated with endoscopic third ventriculostomy (ETV).

Case report

A 3-year old boy without any remarkable medical history presented with a headache and vomiting. Computed tomography (CT) images, which had incidentally been taken 2 years previously due to a minor head injury, showed no abnormality. Magnetic resonance imaging on admission showed tetra-ventricular hydrocephalus associated with the dilatation of the fourth ventricle outlets, without any obstructive lesions. However, CT ventriculography, involving contrast medium injection through a ventricular catheter, suggested mechanical obstruction of the cerebrospinal fluid (CSF) at the fourth ventricle outlets. Thus, the patient was diagnosed with FVOO and ETV was performed; the hydrocephalus was subsequently resolved. Although hydrocephalus recurred 1 year postoperatively, re-ETV for the highly stenosed fenestration successfully resolved this condition.

Conclusions

ETV should be considered for FVOO treatment, particularly in idiopathic cases without CSF malabsorption.

A morphologic study of the transcallosal-interventricular foramen approach in endoscopic third ventriculostomy with magnetic resonance imaging

There is a very wide range of applications in neurosurgery for the treatment of obstructive hydrocephalus by third ventriculostomy. To facilitate the operation, we measured the related data of transcallosal-interventricular foramen approach in endoscopic third ventriculostomy with the magnetic resonance images of the third ventricle from 103 healthy adults. We calculated the mean and standard deviation as well as the 95% confidence interval for the mean value of the measured data, which conformed to normal distribution. We used median and interquartile range to show its concentration and the level of variation when it does not.

Current state and future development of intracranial neuroendoscopic surgery

Since the introduction of the modern, smaller endoscopes in the 1960s, neuroendoscopy has become an expanding field of neurosurgery. Neuroendoscopy reflects the tendency of modern neurosurgery to aim towards minimalism; that is, access and visualization through the narrowest practical corridor and maximum effective action at the target point with minimal disruption of normal tissue. Transventricular neuroendoscopy allows the treatment of several pathologies inside the ventricular system, such as obstructive hydrocephalus and intra-/paraventricular tumors or cysts, often avoiding the implantation of extracranial shunts or more invasive craniotomic approaches. Endoscopic endonasal transphenoidal surgery allows the treatment of pathologies of the sellar and parasellar region, with the advantage of a wider vision of the surgical field, less traumatism of the nasal structures, greater facility in the treatment of possible recurrences and reduced complications. However, an endoscope may be used to assist microsurgery in virtually any kind of neurosurgical procedures (endoscope-assisted microsurgery), particularly in aneurysm and tumor surgery. Basic principles of optical imaging and the physics of optic fibers are discussed, focusing on the neuroendoscope. The three main chapters of neuroendoscopy (transventricular, endonasal transphenoidal and endoscope-assisted microsurgery) are reviewed, concerning operative instruments, surgical procedures, main indications and results.

Usefulness of intraoperative magnetic resonance ventriculography during endoscopic third ventriculostomy

BACKGROUND

Endoscopic third ventriculostomy (ETV) is the preferred method for the treatment of noncommunicating hydrocephalus. The different success rates of ETV indicate the difficulties in predicting the success of this procedure.

OBJECTIVE

To show the usefulness of intraoperative ventriculography performed by the low-field 0.15-T magnetic resonance imager Polestar N20 during ETV.

METHODS

The study was conducted in 11 patients with noncommunicating hydrocephalus caused by tumors or cysts of the third ventricle (n = 5), nontumoral stenosis of the sylvian aqueduct (n = 3), and fourth ventricle outlet obstruction (n = 3). Intraoperative magnetic resonance (iMR) ventriculography was performed before and after the ETV.

RESULTS

In each case, iMR-ventriculography was a safe procedure and determined the exact site of obstruction of cerebrospinal fluid flow. In all cases, iMR-ventriculography performed after ETV showed with the greatest accuracy the patency of the performed fenestrations, demonstrating in 9 patients good flow of the contrast from the third ventricle to the basal cisterns, restricted flow in 1 patient, and no flow in 1 patient. The results of ventriculography were consistent with the postoperative neurological status of operated-on patients. In 3 patients, the opinion of the surgeons about the patency of endoscopic fenestration, based on intraoperative observation of the third ventricle floor, was inconsistent with the results from iMR-ventriculography.

CONCLUSION

Low-field iMR-ventriculography is a safe procedure that can be successfully applied during ETV to determine the site of obstruction in hydrocephalus and the patency of performed ventricle fenestration.

Endoscopic management of complex hydrocephalus

BACKGROUND

The management of complex hydrocephalus is challenging. There is no consensus of the best treatment for isolated fourth ventricles, arachnoid cysts, and multiloculated hydrocephalus, although the avoidance of multiple shunts is desirable. We reviewed our experience with the use of endoscopic techniques to simplify complex multicompartmental hydrocephalus to determine its efficacy and safety.

METHODS

We performed a retrospective study of 114 consecutive adults and children undergoing endoscopic management of hydrocephalus by a single surgeon. The type of hydrocephalus and endoscopic procedure performed were recorded. The management algorithm for simplification of complex hydrocephalus is reviewed. All patients were followed up in the office or by telephone.

RESULTS

A total of 143 endoscopic procedures were performed on 114 patients with a mean age of 4.4 years (4 weeks to 32 years). The endoscopic procedures performed included cyst fenestration, septum pellucidotomy, endoscopic third ventriculostomy, aqueductal plasty with and without stent, and removal of cystercicotic cysts. Twenty-two (19.3%) patients had planned staged endoscopic procedures. Mean follow up was 65 months (range 33-122 months). Eighty-two (72%) patients were reduced to 1 shunt, shunt independence was achieved in 32 (28%) patients, and only 8 (11%) patients required shunt revision in the follow-up period.

CONCLUSIONS

Endoscopic simplification of complex hydrocephalus enables dependence on only a single shunt in the majority of patients, and a significant proportion achieve shunt independence. Endoscopic management should be considered before the placement of a second shunt, and some cases require staged endoscopic procedures to adequately communicate multicompartmental hydrocephalus.

Outcome of endoscopic third ventriculostomy and Chhabra shunt system in noncommunicating non-tumor childhood hydrocephalus

Background:

Endoscopic third ventriculostomy (ETV) the main alternative to ventriculoperitoneal shunt (VPS) is just beginning to have a foothold in West Africa. It provides a great opportunity for a hydrocephalic child to be shunt free. The purpose of this paper is to compare outcome following ETV and VPS (using the cheap Chhabra shunt) in children with noncommunicating non-tumoral hydrocephalus in an environment where late presentation is the norm.

Materials and Methods:

Sixty-three pediatric patients (< 6 years) with hydrocephalus who underwent a VPS or ETV at our hospital were included in this study. The study period was of 30 months (January 2006 till June 2008). Clinically successful outcome was defined as no event occurring during or after surgery that resulted in an alternate surgical procedure, or significant post-operative complication that includes death. All complications related to the procedures were also analyzed.

Results:

The outcome of surgical intervention was not significantly related to the gender, age of the patient at surgery, or type of surgery. The post-operative complication rate was similar in both groups.

Conclusions:

The clinical outcome of ETV is comparable to that of VPS, with the added benefit of no shunt-related problems; and being a short procedure, patient anesthesia and operation time, hospital stay, and cost are significantly reduced. We consider ETV to be the procedure of choice for the treatment of noncommunicating nontumoral hydrocephalus in the pediatric population.

Endoscopic third ventriculostomy: outcome analysis in 368 procedures

OBJECT

Although endoscopic third ventriculostomy (ETV) has been accepted as a procedure of choice for the treatment of obstructive hydrocephalus, the outcome of this treatment remains controversial with regard to age, cause, and long-term follow-up results. The goal of this study was to assess the risk of failure associated with these factors in a retrospective cohort study.

METHODS

Between 1999 and 2007, 368 ETVs were performed in 350 patients (165 patients < 18 years of age) with hydrocephalus at the University Hospital of Toulouse. Failure of ETV was defined as cases requiring any subsequent surgical procedure for CSF diversion or death related to hydrocephalus management.

RESULTS

Tumors (53%), primary aqueductal stenosis (18%), and intracranial hemorrhage (13%) were the most common causes of hydrocephalus. The median follow-up period was 47 months (range 6-106 months), and the overall success rate was 68.5% (252 of the 368 procedures). Patients < 6 months of age had a 5-fold increased risk of ETV failure than older patients (adjusted hazard ratio [HRa] 5.0; 95% CI 2.4-10.4; p < 0.001). Hemorrhage-related (HRa 4.0; 95% CI 1.9-8.5; p < 0.001) and idiopathic chronic hydrocephalus (HRa 6.3, 95% CI 2.5-15.0, p < 0.001) had a higher risk of failure than other causes. Most failures (97%) occurred within 2 months of the initial procedure. The overall morbidity rate was 10%, although most complications were minor. Finally, the introduction of ETV in the authors' department reduced the number of shunt insertions and hospital admissions for shunt failures by half and was a source of cost savings.

CONCLUSIONS

Endoscopic third ventriculostomy is a safe procedure and an effective treatment option for hydrocephalus. Factors indicating potential poor ETV outcome seem to be very young children and hemorrhage-related and chronic hydrocephalus in adults.

Aqueductal stenosis presenting as isolated tremor: case report and review of the literature

Essential tremor is rare in children, particularly in the absence of a significant family history. We report the case of a child with compensated hydrocephalus secondary to aqueductal stenosis whose sole presenting symptom was tremor. An otherwise healthy 6-year-old male developed a fine hand tremor, which over the course of 4 years both increased in intensity and spread to involve the lower limbs and head. After an MRI had confirmed hydrocephalus due to aqueductal stenosis, the patient underwent an endoscopic third ventriculostomy. His tremor improved markedly, but did not completely resolve. Occult hydrocephalus should be considered in the differential diagnosis of new-onset tremor. Progression of the tremor should halt with treatment of the hydrocephalus, and clinical improvement may be seen.

Endoscopic third ventriculostomy for obstructive hydrocephalus due to intracranial hemorrhage with intraventricular extension

Object

Endoscopic third ventriculostomy (ETV) is well accepted for obstructive hydrocephalus of various etiologies. Nevertheless, it is seldom considered in intracranial hemorrhage even in cases involving obstruction of the CSF circulation.

Methods

Between May 1993 and April 2008, 34 endoscopic procedures were performed for hemorrhage-related obstructive hydrocephalus with an intraventricular component. All patients were prospectively followed up. Special attention was paid to presurgical clinical status, type of hemorrhage, type of surgery, postsurgical clinical status, postsurgical ventricular size, and necessity of ventriculoperitoneal shunt implantation.

Results

An ETV was performed for treatment of obstructive hydrocephalus due to intracranial hemorrhage in 34 patients (15 male, 19 female; mean age 60.8 years [range 3 months–83 years]). Hydrocephalus was caused by 17 cerebellar, 6 thalamic, 5 intraventricular, 3 basal ganglia, 2 subarachnoid, and 1 pontine hemorrhage. Thirty-three patients (97.1%) presented with impaired consciousness. Intraventricular blood was present in all cases. In 16 cases (47.1%), blood clots had to be evacuated to achieve access to the third ventricle floor. The mean operation time was 58.2 minutes (range 25–120 minutes). Three complications occurred (rate of 8.8%) with 2 being asymptomatic (5.9%) and 1 being transient (2.9%). There was no procedure-related permanent morbidity, and no procedure-related mortality. After surgery, there was clinical improvement in 17 cases (50.0%) and radiological evidence of improvement in 22 cases (64.7%). Two patients required postoperative ventriculoperitoneal shunting (5.9%). Seven patients died of hemorrhage while in the hospital (20.6%), and another 4 died during follow-up (11.8%). Fifteen patients (44.1%) showed a persistent clinical improvement at the final follow-up (mean 12.2 months after surgery).

Conclusions

Endoscopic third ventriculostomy represents a safe treatment option in intraventricular hemorrhage–related obstructive hydrocephalus yielding similar results as an external drainage but with less risk of infection and a very low subsequent shunt placement rate. In cases with a predominant obstructive component, ETV should be considered in hydrocephalus due to intracerebral hemorrhage. However, performing an ETV with a blurred field of vision and distorted ventricular anatomy is a challenge for any endoscopic neurosurgeon and should be reserved for experienced neuroendoscopists.

Measurements of burr-hole localization for endoscopic procedures in the third ventricle in children

OBJECTIVE

In a retrospective study, we measured the localization for the burr hole for neuroendoscopic procedures in the third ventricle, which are determined by anatomical landmarks like the foramen of Monro (FM) and the respective targets.

PATIENTS AND METHODS

In 48 children, thin-sliced T2-weighted magnetic resonance images were analyzed within an imaging software tool to determine the trajectory between the FM to the floor of the third ventricle (F3V) or the entrance of the sylvian aqueduct (SA). The crossing point at the skull convexity defined the entry points. Coordinates are given relative to nasion and midline. A mean virtual entry point to reach both targets was compared to the burr-hole localization used in the respective surgeries. The tissue shift at the FM was quantified for the trajectories.

RESULTS

The entry point to reach the F3V or the SA measured 119.7+/-26.4 mm (to nasion)-20.5+/-11.5 mm (to midline) and 57.4+/-26.5-18.8+/-8.3 mm, respectively. The virtual mean entry point to reach both targets was located at 86.5+/-25.3-20.9+/-9.8 mm. There was a statistical difference in the entry point localization relative to nasion of the virtual mean trajectory compared with the burr-hole localization used in these patients. The tissue shift at the level of the FM using the mean virtual trajectory was significantly lower than by using the actual burr hole to the SA.

CONCLUSIONS

Planning an optimal burr-hole localization is important in neuroendoscopic procedures in children, especially where the target is located around the sylvian aqueduct.

Three-dimensional constructive interference in steady-state magnetic resonance imaging in obstructive hydrocephalus: relevance for endoscopic third ventriculostomy and clinical results

Object

Endoscopic third ventriculostomy is the treatment of choice in patients with obstructive hydrocephalus caused by aqueductal stenosis. The authors examined the clinical course and results of surgical treatment for obstructive hydrocephalus with pre- and postoperative refined constructive interference in steady-state (CISS) MR imaging.

Methods

Forty patients with obstructive hydrocephalus underwent pre- and postoperative 3D-CISS imaging and clinical evaluation. Radiological findings were correlated with intraoperative observations of the thickness and transparency of the floor of the third ventricle and the patient's postoperative clinical course.

Results

Three-dimensional CISS MR imaging provides precise visualization of the basilar/posterior cerebral artery, its distance to the clivus, the diameter of the foramen of Monro, and the extension of and thickness of the floor of the third ventricle. In 71% of patients a flow void was detectable postoperatively on the ventriculostomy. In this group 81.5% had strong and 14.8% moderate clinical benefit, and 3.7% required secondary shunt placement. In the remaining 29% of the patients without a visible flow void, strong improvement was seen in 54.5%, moderate improvement in 18.2%, and stoma failure occurred in 27.3% (p = 0.094). Radiological measurements of the thickness of the third ventricle floor correlated with intraoperative findings (r = 0.35, p = 0.029). Comparison of outcomes showed a statistically significant tendency for a better outcome in patients with thin and easily perforated third ventricle floors (p = 0.04).

Conclusions

Endoscopic ventriculostomy in patients with obstructive hydrocephalus is safe and mostly successful, and 3D-CISS MR imaging seems to be a valuable diagnostic method for precisely identifying the anatomy of relevant structures. Furthermore, 3D-CISS MR imaging allows judgment of the thickness of the third ventricle floor and display of the ventriculostomy/flow void, which are predictive for intraoperative course and clinical outcome.

Complications of endoscopic third ventriculostomy

OBJECTS

Although endoscopic third ventriculostomy (ETV) is considered as the first choice in the management of noncommunicating hydrocephalus, it is not without risk or complication.

METHODS

The patients who had undergone ETV only between 1998 and 2005 were retrospectively reviewed. There were 85 males and 70 females, and 173 ETVs were performed in 155 patients. The patients' age ranged from 2 months to 77 years. Complications were categorized as (1) intraoperative, (2) early postoperative (<1 month), and (3) late postoperative (>1 month). Follow-up of the patients ranged from 1 to 86 months.

RESULTS

Overall complication rate per patient was 15.4%, and complication per procedure was 18%. Complication rate significantly varied with the etiology of hydrocephalus (P = 0.013). The patients with Chiari type I malformation and tumor had no or very low complication rates. The complication risk was significantly higher in repeat endoscopic procedure (55.5%) than in the first procedure (10%; P = 0.0001).

CONCLUSION

ETV should be the first choice in the management of noncommunicating hydrocephalus. Training, experience, and meticulous technique will decrease the complication rate. Patients undergoing ETV should be followed in a similar manner to patients with cerebrospinal fluid shunts.

LASER-ASSISTED ENDOSCOPIC THIRD VENTRICULOSTOMY

OBJECTIVE

Endoscopic third ventriculostomy is a well-known surgical option in the treatment of noncommunicating hydrocephalus. We studied complications and long-term success in 202 patients to demonstrate the safety and efficacy of laser-assisted endoscopic third ventriculostomy (LA-ETV) using a unique “black” fiber tip/diode laser combination for controlled tissue ablation.

METHODS

We studied 213 LA-ETVs, which were performed in 202 patients. Patients' ages ranged from 2 days to 83 years (mean age, 27 yr). The mean follow-up period for all patients was 2.7 years (range, 2 d to 12 yr). Hydrocephalus was caused by aqueductal stenosis in 65 patients, tumors in 67 patients, hemorrhages in 24 patients, myelomeningoceles in 20 patients, cysts in 15 patients, and other causes in 11 patients. The long-term effectiveness of LA-ETV was studied with Kaplan-Meier analysis.

RESULTS

Technically successful LA-ETVs were accomplished in 196 of the 202 patients (97%). The overall success rate for a functional LA-ETV was 68% at the 2-year follow-up evaluation. LA-ETV was more effective in patients aged 1 year and older (70% success rate) than in younger patients (59% success rate). Success rates were greater in patients with aqueductal stenosis or tumors as compared to other etiologies. Complications occurred in 22 procedures (10.3%). Only one patient (0.5%) experienced a major complication. No surgical mortalities or laser-related complications occurred.

CONCLUSION

This study demonstrates that LA-ETV is a safe and effective procedure that is comparable to other techniques for ETV. LA-ETV is most effective in patients aged 1 year and older and in patients with aqueductal stenosis and tumors, with a low major complication rate.

Complications following endoscopic intracranial procedures in children

BACKGROUND

The significant technological improvement of endoscopic instrumentation has allowed, in the last 10 years, a widespread diffusion of neuroendoscopic procedures. Nevertheless, severe, sometimes life-threatening, complications may occur during neuroendoscopic surgery, and the incidence and age specificity of complications in children have been underdescribed so far.

MATERIALS AND METHODS

Complications recorded in a prospectively collected database of pediatric patients undergoing neuroendoscopic procedures were analysed; the medical histories of the patients and the surgical procedures were reviewed.

RESULTS

Complications occurred in 32 out of 231 (13.8%) procedures performed for the management of obstructive hydrocephalus (137), multiloculated hydrocephalus (53), arachnoid cysts (29) and intraventricular tumors (12). Subdural hygroma occurred in 11 cases, seven requiring subdural shunting. In one of these cases, infection of the subdural space occurred and required a craniotomy. Cerebrospinal fluid (CSF) infection occurred in 11 cases. In one case, a frontal abscess developed and was managed with craniotomy. CSF leak occurred in nine cases, intraventricular haemorrhages in two, technical failures in seven, subcutaneous CSF collection (managed with lumbo-peritoneal shunt) in one, thalamic contusion and post-operative transient akinetic mutism in one. This patient suddenly died 6 months later, probably as a consequence of closure of the stoma. Two patients developed secondary compartmentalisation of the ventricles after complicated endoscopic third ventriculostomy. In nine cases, these complications were associated. Overall, no patient died after the procedure (operative mortality 0), one patient died 6 months after the procedure for unexplained events (sudden death rate 0.4%), and three patients presented permanent disability as a consequence of surgical complication (permanent morbidity 1.3%).

CONCLUSIONS

Complication rate of neuro-endoscopic procedures is not negligible even in experienced hands. The majority are minor complications which do not affect the final outcome, but sporadically major events may occur, leading to significant problems in surgical management and, occasionally, to permanent disabilities. Careful selection of patients on pre-operative imaging studies and intensive training of surgeons are mandatory to improve results.

Shunts vs endoscopic third ventriculostomy in infants: are there different types and/or rates of complications? A review

INTRODUCTION

The decision-making process when we compare endoscopic third ventriculostomy (ETV) with shunts as surgical options for the treatment of hydrocephalus in infants is conditioned by the incidence of specific and shared complications of the two surgical procedures.

REVIEW

Our literature review shows that the advantages of ETV in terms of complications are almost all related to two factors: (a) the avoidance of a foreign body implantation and (b) the establishment of a 'physiological' cerebrospinal fluid (CSF) circulation. Both these kinds of achievements are particularly important in infants because of the relative high rate of some intraoperative (i.e. abdominal) and late (secondary craniosynostosis, slit-ventricle syndrome) shunt complications in this specific subset of patients. On the other side, the main factor which is claimed against ETV is the relatively high risk of immediate mortality and neurological complications. Clinical manifestations of neurological structure damage seem to be more frequent in infants, probably due to the more relevant effect of parenchymal and vascular damage in this age group; however, both the immediate mortality and neurological damage risk of ETV procedures should be weighted against the long-term mortality and the late neurological damage which is not infrequently described as a consequence of shunt malfunction and proximal shunt revision procedures. Infections are possible in both ETV and extrathecal CSF procedures, especially in infants. However, the incidence of infective complications is significantly lower in case of ETV (1-5% vs 1-20%). Moreover, different from shunting procedures, infections in children with third ventriculostomy have a more benign course, being generally controlled by antibiotic treatment alone.

Endoscopic Third Ventriculostomy for Occlusive Hydrocephalus Caused by Cerebellar Infarction

OBJECTIVE:

The surgical management of occlusive hydrocephalus caused by massive cerebellar infarction remains controversial. The procedures that are more commonly used to avoid progressive neurological deterioration are based on transient external ventricular drainage or the placement of permanent shunt systems. To our knowledge, this is the first report regarding using endoscopic third ventriculostomy (ETV) in patients with an occlusive hydrocephalus caused by cerebellar ischemic stroke. We report our experience of 10 reviewed cases.

METHODS:

Between 1997 and 2004, 10 patients with a resulting hydrocephalus caused by a space-occupying cerebellar infarction were managed with ETV. Glasgow Coma Scale score on admission, cause of stroke, and computed tomographic signs, including the ischemic vascular territory involved and brain edema, were noted. Clinical outcome was evaluated using the Glasgow Outcome Scale.

RESULTS:

In all patients, there was a mean interval of 4 days from the onset of deterioration of consciousness to operation. Mean Glasgow Coma Scale score on admission was 11.2. In nine patients, ETV was the initial procedure of ventricular drainage. One patient was primarily treated with an external ventricular drainage, but the device dislocated and ETV was performed. In one patient, an external ventricular drainage became necessary 7 days after the initial ETV because of a malfunction of the stoma. One patient showed a progressive brain edema 2 days after ETV, and suboccipital decompression was performed. Eight successfully treated patients demonstrated an improvement in the level of consciousness after ETV. Mean Glasgow Outcome Scale score on discharge of all patients was 3.4.

CONCLUSION:

Occlusive hydrocephalus caused by cerebellar infarction is infrequent. When occlusive hydrocephalus is observed, ETV can be used successfully with minimal risks, especially with avoidance of a higher rate of infectious complications caused by external drainage systems.

Abdominal actinomycosis associated with a sigmoid colon perforation in a patient with a ventriculoperitoneal shunt

Abdominal actinomycosis causing hydronephrosis in a patient with a ventriculoperitoneal shunt is very rare. A 27- year-old female patient was admitted complaining of lower abdominal pain. She had undergone ventriculoperitoneal shunt surgery 10 years ago. Abdominal Ultrasonography and a CT scan demonstrated an inflammatory mass in the lower left quadrant of the abdomen causing obstructive hydroureter and hydronephrosis. Laparotomy revealed a diffusely infiltrating mass involving the small bowel, mesentery, and sigmoid colon, and a 1cm perforation in the sigmoid colon. Actinomycosis was diagnosed upon histological examination. After treatment with antibiotics and surgery, the patient's condition improved.

Endoscopic third ventriculostomy in children: early and late complications and their avoidance

INTRODUCTION

Endoscopic third ventriculostomy (ETV) is considered by many authors the initial surgical procedure of choice for the treatment of non-communicant hydrocephalus. However, this procedure has early and late complications that neurosurgeons must be aware of when performing it.

MATERIALS AND RESULTS

A retrospective study of infants and children treated with ETV at Children's Memorial Hospital (Chicago, IL) between 1993 and 2004 is presented. A total of 136 ETVs in 122 patients were performed with 8.8% early complication rate (hemorrhage, CSF leak, infection, diabetes insipidus, and seizures). There were no fatalities but one patient had severe neurological disturbances due to intracranial hemorrhage at the second ETV. We identified several significant factors that influence the late ETV failure rate: age under 12 months (p=0.012), cases performed early in our experience (p=0.009), patients with hydrocephalus without expansive lesions (p=0.026), patients that had an external ventricular drain (EVD) after ETV (p<0.005), and patients who developed early complications (p=0.035).

CONCLUSION

A careful patient selection and preoperative planning lead to better results of ETV. A higher early and late complication rate in children younger than 1-year-old were noted in our series. There is definitely a learning curve for this technique, and several technical considerations are helpful to avoid adverse events. Most of the early complications are transient, while potential devastating injuries can occur. Long-term follow-up is needed to identify delayed closure of the fenestration. Ventricular access devise is helpful for diagnostic and therapeutic purposes during the follow-up.

Anesthesia for Minimally Invasive Cranial and Spinal Surgery

The field of minimally invasive neurosurgery has evolved rapidly in its indications and applications over the last few years. New, less invasive techniques with low morbidity and virtually no mortality are replacing conventional neurosurgical procedures. Providing anesthesia for these procedures differs in many ways from conventional neurosurgical operations. Anesthesiologists are faced with the perioperative requirements and risks of newly developed procedures. This review calls attention to the anesthetic issues in various minimally invasive neurosurgical procedures for cranial and spinal indications. Among the procedures specifically discussed are endoscopic third ventriculostomy, endoscopic transsphenoidal hypophysectomy, endoscopic strip craniectomy, deep brain stimulation, video-assisted thorascopic surgery, vertebroplasty and kyphoplasty, cervical discectomy and foraminectomy, and laparoscopically assisted lumbar spine surgery.

Endoscopic third ventriculostomy in the treatment of hydrocephalus in pediatric patients

Advances in surgical instrumentation and technique have lead to an extensive use of endoscopic third ventriculostomy in the management of pediatric hydrocephalus. The aim of this work was to point out the leading aspects related to this technique. After a review of the history, which is now almost one century last, the analysis of the endoscopic ventricular anatomy is aimed to detail normal findings and possible anatomic variations which might influence the correct conclusion of the procedure. The overview of modern endoscopic instrumentation helps to understand the technical improvements that have contributed to significantly reduce the operative invasiveness. Indications are analysed from a pathogenetic standpoint with the intent to better understand the results reported in the literature. A further part of the paper is dedicated to the neuroradiological and clinical means of outcome evaluation, which are still a matter of debate. Finally a review of transient and permanent surgical complications is performed looking at their occurrence in different hydrocephalus etiologies.

Long-term Reliability of Endoscopic Third Ventriculostomy

OBJECTIVE:

To describe the short-term operative success and the long-term reliability of endoscopic third ventriculostomy (ETV) for treatment of hydrocephalus and to examine the influence of diagnosis, age, and previous shunt history on these outcomes.

METHODS:

We retrospectively analyzed 203 consecutive patients from a single institution who had ETV as long as 22.6 years earlier. Patients with hydrocephalus from aqueduct stenosis, myelomeningocele, tumors, arachnoid cysts, previous infection, or hemorrhage were included.

RESULTS:

The overall probability of successfully performing an ETV was 89% (84–93%). There was support for an association between the surgical success and the individual operating surgeon (odds ratios for success, 0.44–1.47 relative to the mean of 1.0, P = 0.08). We observed infections in 4.9%, transient major complications in 7.2%, and major and permanent complications in 1.1% of 203 procedures. Age was strongly associated with long-term reliability. The longest observed reliability for the 13 patients 0 to 1 month old was 3.5 years. The statistical model predicted the following reliability at 1 year after insertion: at 0 to 1 month of age, 31% (14–53%); at 1 to 6 months of age, 50% (32–68%); at 6 to 24 months of age, 71% (55–85%); and more than 24 months of age, 84% (79–89%). There was no support for an association between reliability and the diagnostic group (n = 181, P = 0.168) or a previous shunt. Sixteen patients had ETV repeated, but only 9 were repeated after at least 6 months. Of these, 4 procedures failed within a few weeks, and 2 patients were available for long-term follow-up.

CONCLUSION:

Age was the only factor statistically associated with the long-term reliability of ETV. Patients less than 6 months old had poor reliability.

How should primary aqueductal stenosis in adults be treated? A review

In 10% of adult patients with hydrocephalus, the cause is because of aqueductal stenosis (AS), causing enlargement of the lateral and third ventricles. There are currently two alternate forms of surgical treatment for AS; shunt surgery and ventriculostomy. Shunt surgery is associated with high complication rates and many patients need revisions, but the effectiveness is high. Endoscopic third ventriculostomy (ETV), re-establishing a physiological route of CSF dynamics, has become the treatment of choice for AS in most neurosurgical centers. ETV has fewer complications and revisions are rare, but some patients need shunt surgery to improve despite a patent ventriculostomy. There are today no common criteria for patient selection to either ETV or ventriculo-peritoneal shunt surgery.

Endoscopic third ventriculostomy for obstructive hydrocephalus

The indications for neuroendoscopy are not only constantly increasing, but even the currently accepted indications are constantly being adjusted and tailored. This is also true for one of the most frequently used neuroendoscopic procedures, the endoscopic 3rd ventriculostomy (ETV) for obstructive hydrocephalus. ETV has gained popularity and widespread acceptance during the past few years, but little attention has been paid to the techniques of the procedure. After a short introduction describing the history of ETV, an overview is given of all the different techniques that have been and still are employed to open the floor of the 3rd ventricle. The spectrum of indications for ETV has been widely enlarged over the last years. Initially, the use of this procedure was restricted to patients older than 2 years, to patients with an obvious triventricular hydrocephalus, and to those with a bulging, translucent floor of the 3rd ventricle. Nowadays, indications include all kinds of obstructive hydrocephalus but also communicating forms of hydrocephalus. The results of endoscopic procedures in treating these pathologies are given under special consideration of shunt technologies. In summary, from the review of the publications since the first ETV performed by Mixter in 1923, this technique is the treatment of choice for obstructive hydrocephalus caused by different etiologies and is an alternative to cerebrospinal fluid shunt application.

Long-term complications and definition of failure of neuroendoscopic procedures

OBJECTS

A lot has been published about neuroendoscopic procedures over the last decade. Most of these publications are about the effectiveness of endoscopic third ventriculostomy, the most frequently performed neuroendoscopic procedure. Little is published about the effectiveness of other, less frequently performed neuroendoscopic procedures. Over the years more reports about the complications of endoscopic procedures are published, but again most of these publications are about endoscopic third ventriculostomy and only a little is presented about the complications of all other neuroendoscopic procedures. Furthermore, most reports are about intraoperative and immediate postoperative complications; only a few reports evaluated the long-term complications of neuroendoscopic procedures. There are also a few publications that analyse the failures of neuroendoscopic procedures but a good definition of failure is not given. The reports mention, again, mainly endoscopic third ventriculostomy procedures, and are mostly directed at the short-term failure rates, defined as the need for a shunt to be placed. Less attention is paid to the effects of the endoscopic procedures in the longer term. Looking at longer terms emphasises the need for a better definition of failure.

METHODS

To get more insight into the long-term complications and failures of neuroendoscopic procedures, we reviewed the literature and evaluated our own series of 485 different cranial endoscopic procedures. With the information gathered we tried to answer the questions mentioned above.

CONCLUSIONS

Most of the complications of neuroendoscopic procedures are transient, either spontaneously or by medical intervention. Only a few permanent complications are known, in our series 1.6%, and most of them are not typically related to the endoscopic procedure itself but are due to the ventricular approach necessary for and the management of the endoscopy. Mortality rates are less than 1%. A uniform definition of failure cannot be given for all neuroendoscopic procedures, because the procedures are too heterogeneous and the indications are widespread. Failures are mainly diagnosed within a few months of the procedure but neurosurgeons must be aware of failure in the longer term, because if not diagnosed they can give rise to increased morbidity and probably mortality.

Epidural hematoma as a complication of endoscopic biopsy and shunt placement in a patient harboring a third ventricle tumor

Although some complications have been reported when using endoscopic techniques, epidural hematoma (EDH) has rarely been caused. The authors report a case of EDH complicating a concomitant endoscopic biopsy procedure with ventricular shunt placement in a young, 14-year-old boy harboring a third ventricle tumor with a hydrocephalus. Few cases have been reported; however, the authors warn that there is a risk that EDH may develop following an endoscopic procedure and shunt placement.

History of neuroendoscopy

Since the beginnings of medicine, physicians have sought minimally invasive ways to peer into body cavities. It is only in the last several decades that the promises of endoscopy have begun to be answered. What follows is a brief outline of the development of endoscopic technology and its application to the nervous system both for diagnostic and therapeutic procedures.

Comparison of revision rates following endoscopically versus nonendoscopically placed ventricular shunt catheters

BACKGROUND

Endoscopic placement of ventriculoperitoneal (VP) shunt catheters in pediatric patients has been increasingly used in an attempt to minimize the unacceptably high rates of revision. Although this procedure carries an increased expense, there is currently no evidence to support an improved long-term outcome. This paper compares the rates of revision following ventricular catheter placement for shunted hydrocephalus with and without the use of endoscopy.

METHODS

We retrospectively reviewed the records of all pediatric patients who had undergone shunt placement for hydrocephalus between April 1992 and February 1998. All shunts placed before March 1995 were performed without the endoscope; all subsequent shunts were placed endoscopically. The independent effect of endoscopic versus nonendoscopic shunt placement on subsequent shunt failure was analyzed via multivariate proportional hazards regression model. Multiple logistic regression analyses were used to determine the independent effect of endoscopic placement on subsequent etiology of failure (infection, proximal obstruction, distal malfunction) in the 511 failing shunts.

RESULTS

There were 447 pediatric patients who underwent a total of 965 shunt placements or revisions. Six hundred and five (63%) catheters were placed with the use of the endoscope. Three hundred and sixty (37.3%) were placed without the use of the endoscope. Neuroendoscopy did not independently affect the risk of subsequent shunt failure [Hazard Ratio (95% Confidence Interval) = 1.08 (0.84-1.41)]. Endoscopic placement independently decreased the odds [Odds Ratio (95% Confidence Interval) = 0.56 (0.32-0.93)] of proximal obstruction, increased the odds of distal malfunction [1.52 (1.02-2.72)], and was not associated with infection [1.42 (0.78-2.61)].

CONCLUSIONS

Endoscopic assisted ventricular catheter placement decreased the odds of proximal obstruction but failed to improve overall shunt survival in this 6 year experience.

Complications of endoscopic third ventriculostomy

OBJECT

The purpose of this prospective investigation was to determine the rate of complications associated with endoscopic third ventriculostomy (ETV).

METHODS

Between March 1993 and October 2001, 193 ETVs were performed in 188 patients at a single institution. The age of the patients ranged from 1 month to 85 years (mean age 39 years). One procedure had to be abandoned because a severe venous hemorrhage blurred the surgeon's view; however, third ventriculostomy was successfully accomplished in that patient 14 days later. In addition, there were two cases in which significant venous hemorrhages could be controlled endoscopically by using irrigation. Postoperative imaging revealed three subdural collections, one tiny thalamic contusion, one cortical hemorrhage at the puncture site, and one severe subarachnoid hemorrhage (SAH). There were two deaths (1% mortality rate) related to the endoscopic procedure; causes of death were one SAH from a torn basilar perforating artery and one wound infection leading to meningitis and septic multiorgan failure. Three permanent deficits occurred (confusion, oculomotor palsy, and diabetes insipidus [1.6% permanent morbidity rate]). Transient deficits included four cases of meningitis, three cases of cerebrospinal fluid leak, two cases of herniation syndrome, two cases of confusion, one case in which there was a decrease of consciousness, two cases of oculomotor palsy, and one case in which there was loss of thirst (7.8% transient morbidity rate). Misplacement of the fenestration was the main reason for severe complications. During the course of the study, the complication rate dropped significantly (no incidences of mortality or permanent morbidity occurred during the last 100 procedures).

CONCLUSIONS

All permanent and fatal complications occurred during the authors' very early experience, indicating that a steep learning curve was associated with the procedure. Endoscopic third ventriculostomy, if performed correctly, is a safe, simple, and effective treatment option for various forms of noncommunicating hydrocephalus.