Intracranial pressure patterns after endoscopic third ventriculostomy. Preliminary experience

Summary. Background. Endoscopic Third Ventriculostomy (ETV) has become the treatment of choice for non-communicating hydrocephalus as it is able to couple high success rate (60–80%) with rare complications (about 5%). Nevertheless, which is the best postoperative care standard and whether or not it is possible to predict the success of the procedure is still discussed. Traditional neuro-imaging techniques show several limitations in the early postoperative period. Indeed, a decrease of the ventricular size is often minimal and not visible before three weeks, while, MRI visualization of a flow void signal through the third ventricle floor, seems to have a significant incidence of false positives. The use of postoperative ICP measurement after ETV has been suggested as a valid monitoring method, mostly in the early postoperative period. In previously unpublished data the authors observed the existence of different ICP patterns following ETV. This finding prompted the authors to search for a relationship among ICP patterns, stoma functioning and prediction of success.Method. At our institution 26 consecutive patients affected by obstructive triventricular hydrocephalus underwent ETV. Among them there were 11 primitive aqueductal stenosis (AS), 5 shunt malfunctions, 2 third ventricle mass, 3 intraventricular cysts, and 5 patients with different lesions (1 quadrigeminal cistern arachnoidal cyst, 1 pineal region mass, 2 tectal tumours, and 1 supracerebellar abscess) compressing the aqueduct of Sylvius from outside named ab estrinseco aqueductal stenosis. All patients underwent postoperative Intra Cranial Pressure (ICP) monitoring by means of a ventricular catheter.Findings. Transient ICP rises of any grade, mostly responsive to periodical liquoral subtractions, occurred shortly after ETV in as many as 50% of our patients. No major complications occurred. The effect of ETV on ICP trend was found to be variable among groups of patients thus identifying different ICP patterns. Patients with ab estrinseco Sylvian aqueduct compression showed the best effect on ICP, whilst, patients with intraventricular mass lesions causing triventricular hydrocephalus and shunt-dependent patients, revealed a clear trend to develop a more severe intracranial hypertension after ETV.Conclusions. Patients with shunt malfunction and patients with intraventricular mass lesions, showing a more pronounced trend to develop severe intracranial hypertension after ETV, should always be considered for postoperative ICP monitoring in order to detect and, eventually, treat any ICP rises which may occur. Unfortunately, it is still difficult to assign a predictive value to the different postoperative ICP patterns. The authors encourage postoperative ICP monitoring in all patients in order to define all the possible ICP patterns following ETV.     

Neuroendoscopy in pineal region tumor with obstructive hydrocephalus

Objective : Pineal region tumours are composed of a variety of tumour pathologies, for example germinoma, teratoma, pinealocytoma, pinealoblastoma, meningioma and benign pineal glial cyst. They commonly present with mass effect causing obstructive hydrocephalus or Parinaud’s Syndrome. This paper reviews seven patients with pineal region tumour who presented with obstructive hydrocephalus and who received neuroendoscopy as part of the management of their clinical condition. Method : Neuroendoscopic techniques include endoscopic third ventriculoscopy (ETV) and endoscopic third ventriculo‐cisternostomy (ETVC). Diagnostic ETV allows direct visualization, localization and biopsy of the lesion, as well as sampling of cerebrospinal fluid (CSF). Endoscopic third ventriculo‐cisternostomy allows CSF diversion for relief of obstructive hydrocephalus. Results and Conclusion : Four out of seven of the third ventriculoscopy cases had lesions successfully located and biopsy was performed in two cases. Endoscopic third ventriculo‐cisternostomy was performed in all 7 patients. Two patients with unknown pathology relied on ETVC as the only therapeutic procedure. Three patients were followed with subsequent definitive treatment (radiotherapy or surgery). All these patients showed clinical improvement or radiological relief of obstructive hydrocephalus. Minimal complications were recorded among these cases.      

Diagnostic method for differentiating external hydrocephalus from simple subdural hygroma

OBJECT: The various terms used to describe subdural fluid collection--"external hydrocephalus", "subdural hygroma", "subdural effusion", "benign subdural collection", and "extraventricular obstructive hydrocephalus"-reflect the confusion surrounding the diagnoses of these diseases. Differentiating external hydrocephalus from simple subdural hygroma may be difficult, but the former appears to be a distinct clinical entity separate from the latter. In this report, the authors present a diagnostic method for differentiating external hydrocephalus from simple subdural hygroma, based on their clinical experience in treating subdural fluid collection after mild head trauma. METHODS: Twenty patients with subdural fluid collection after mild head trauma were included in this study. Ventricle size was measured using a modified frontal horn index (mFHI); that is, the largest width of the frontal horns divided by the bicortical distance in the same plane, instead of the inner table distance. Bur hole trephination was performed on the appearance of a subdural fluid collection thicker than 15 mm on computed tomography (CT), persistent (longer than 4 weeks) or increasing in size, and accompanied by neurological symptoms (confusion or memory impairment). During the procedure, subdural pressure was measured using a manometer before opening the dura mater. Subdural pressure varied among the patients, ranging from 3 to 27.5 cm H2O. Four patients with a subdural pressure greater than 15 cm H2O had hydrocephalus after surgery (p < 0.05). Hydrocephalus developed in a pediatric patient (2 years old) with a subdural pressure of 12 cm H2O. All of the patients in whom hydrocephalus developed after bur hole trephination had had enlarged ventricles (mFHI > 33%) on preoperative CT scans. CONCLUSIONS: Monitoring subdural pressure may be a valuable tool for differentiating subdural hygroma from external hydrocephalus in patients with mild head trauma. Additionally, the mFHI reflects the nature of the subdural collection more accurately than the standard frontal horn index.     

Laser-assisted endoscopic third ventriculostomy for obstructive hydrocephalus: technique and results in a series of 40 consecutive cases

BACKGROUND AND OBJECTIVES: To report a case series of endoscopic third ventriculostomy (ETV) using laser in 40 consecutive patients with obstructive hydrocephalus. STUDY DESIGN/MATERIALS AND METHODS: Under stereotactic and endoscopic guidance, multiple perforations in the ventricular floor using a 1.32 microm neodymium-yttrium/aluminum/garnet (Nd-YAG) or a 0.805 microm diode laser unit and removal of intervening coagulated tissue ensued with a 4-6 mm opening between third ventricle and basilar cisterns. RESULTS: The procedure could be completed in all cases. A transient complication occurred in five cases. In 39 patients (mean follow-up 28 months), 31 (79%) had a favorable outcome. Failure occurred in six patients, requiring permanent shunting leading to complete recovery, and two patients remained in a poor clinical status despite ETV. CONCLUSIONS: Laser-assisted ETV is a safe and efficient procedure for the treatment of obstructive hydrocephalus. Laser is advantageous in cases of distorted anatomy and may reduce technical failures.     

Third Ventriculostomy in Late-onset Idiopathic Aqueductal Stenosis Treatment: A Focus on Clinical Presentation and Radiological Diagnosis

Endoscopic third ventriculostomy (ETV) is considered the gold standard treatment for obstructive hydrocephalus due to partial or complete obstruction of cerebrospinal fluid (CSF) ventricular pathways caused by mass lesions. However long-term efficacy of this procedure remains controversial as treatment of chronic adult hydrocephalus due to stenosis of Sylvian acqueduct [late-onset idiopathic aqueductal stenosis (LIAS)]. The authors describe clinical presentation, diagnostic investigations in patients affected by LIAS, and define their clinical and radiological outcome after ETV. From January 2003 to December 2008, 13 consecutive LIAS patients treated by ETV were retrospectively reviewed. Pre- and post-operative clinical and radiological findings, including conventional and phase-contrast (PC) cine magnetic resonance imaging (MRI) were investigated. ETV was successfully performed in all patients. Patient''s neurological condition improved. No one required a second ETV procedure or shunt implantation. Clinical and radiological results reveal a satisfactory outcome of LIAS patients treated by ETV. At follow-up a clinical improvement could be demonstrated in all cases. Selection criteria of LIAS patients seem to be crucial to obtain satisfactory and long-lasting results. Even in elderly patients with chronic hydrocephalus, ETV can be considered the treatment of choice.     

Endoscopic third ventriculostomy in the presence of large or giant basilar artery aneurysms

Background  

Endoscopic third ventriculostomy (ETV) is an effective treatment of obstructive hydrocephalus (OH). However, the presence of a large or giant basilar aneurysm is generally considered a contra-indication to ETV for treating hydrocephalus. We report the feasibility and efficacy of ETV for the treatment of hydrocephalus in the presence of such aneurysms.     

Neuroendoscopy: one year of experience--personal results, observations and limits.

After reading reports of successful neuroendoscopic treatment of hydrocephalus, colloid cysts and arachnoid cysts as well as tumor biopsy, we started using endoscopic procedures in our Department, one year ago. One surgeon (E.S.) skilled in the Decq Endoscope, performed a series of sixteen procedures, from January 2001 to March 2002 (in patients aged 28 to 69 years). The most common pathology was obstructive hydrocephalus (14 cases), one was colloid cyst, and the last case was tumor biopsy. The surgical treatment consisted of third ventriculostomy, cyst opening and shrinking and tumor biopsy. In fourteen patients treated for hydrocephalus with third ventriculostomy (ETV), one required a definitive shunt. Complication occurred in one case with chronic subdural collection. We further report one case of aqueductal restoration after third ventriculostomy. Our results, with no neurological deficits or deaths, confirmed our opinion that neuroendoscopy is a safe surgical technique in well-selected patients and we believe it is the ideal treatment in obstructive hydrocephalus.     

Endoscopic third ventriculostomy: anesthetic implications.

Endoscopic third ventriculostomy (ETV) is one of the recent neurosurgical advances for the treatment of obstructive hydrocephalus. There has been number of publications, which have established the role of ETV in neurosurgical practice, particularly in hydrocephalus. ETV has developed into a therapeutic alternative to shunting for the management of patients with non-communicating hydrocephalus. This procedure requires a general anesthetic and necessitates violation of the brain parenchyma and manipulation via neural structures to access the floor of the third ventricle. This discussion will focus on the anesthetic implications during ETV.     

Is endoscopic third ventriculostomy superior to shunts in patients with non-communicating hydrocephalus? A systematic review and meta-analysis of the evidence

Background

Endoscopic third ventriculostomy (ETV) and shunts are both utilized in the treatment of non-communicating hydrocephalus. The objective of this study was to review the evidence comparing the effectiveness of these two techniques.

Methods

The Cochrane Central Register of Controlled Trials (CENTRAL) and Medline databases were searched between 1990 and August 2012. We included all studies comparing the failure rate of patients with non-communicating hydrocephalus treated with ETV and shunts. Two authors (HJM and FTR) appraised quality and extracted data independently.

Results

Of 313 articles identified, 12 were selected for further review. Of these, 6 were included for qualitative analysis, and 5 for quantitative analysis (n?=?504). ETV was associated with a non-statistically significant reduction in failure using the random-effects model (OR 0.58, 95 % CI 0.29-1.13).

Conclusions

Both ETV and shunts are associated with a relatively high failure rate. At present there is insufficient proof to unequivocally recommend one mode of treatment above the other. However, there is some evidence that ETV may confer long-term survival advantage over shunts in the treatment of non-communicating hydrocephalus, particularly in patients with certain aetiologies such as aqueductal stenosis. Prospective randomized controlled trials are currently underway and may provide more robust evidence to answer this important question and better guide future management.     

A prospective randomised study to compare the utility and outcomes of subdural and subperiosteal drains for the treatment of chronic subdural haematoma

Background

The usage of a drain following evacuation of a chronic subdural haematoma (CSDH) is known to reduce recurrence. In this study we aim to compare the clinical outcomes and recurrence rate of utilising two different types of drains (subperiosteal and subdural drain) following drainage of a CSDH.

Methods

Prospective randomised single-centre study analysing 50 patients who underwent CSDH treatment. Two types of drains, subperiosteal (SPD) and subdural (SDD), were utilised on consecutive alternate patients following burr-hole craniostomy, with a total of 25 patients in each group. The drains were left in for 48-h duration and then removed. The modified Rankin Scale (mRS) was used for outcome measurement at 3 and 6?months.

Results

Data analysis was performed by unpaired t test with Welch’s correction. It was observed that none of the patients in either group had haematoma recurrence during a 6-month follow-up, and a significant difference in outcome was noted at 6?months (p?=?0.0118) more than at 3?months (p?=?0.0493) according to the statistical analysis. Postoperative seizure and inadvertent placement of the subdural drain into the brain parenchyma were the two complications noted in this study. Anticoagulant use prior to the surgery did not affect the outcome in either group.

Conclusions

We conclude there was no recurrence of CSDH utilising the SDD and SPD following burr-hole craniostomy. The mRS measurement at the 6-month follow-up was found to be statistically significant, with better outcomes with utilisation of the SPD. The SPD may thus prove to be more beneficial than the SDD in the treatment of CSDH. A multi-centre study with a larger group of patients is recommended to reinforce the results from our study.     

Long-term outcome of endoscopic third ventriculostomy in obstructive hydrocephalus.

This multicentric study reports on 140 patients who underwent endoscopic third ventriculostomy for obstructive hydrocephalus in four Italian neurosurgical centers between 1994 and 1999. Its aim is to define the long-term outcome of these patients many years (6-12) after the initial procedure. The study includes both children and adults; the etiology of the hydrocephalus was malformative aqueductal stenosis in 88 cases (62.8%), compression by tumors of the mesencephalic and pineal regions and posterior fossa in 45 (32.2%) and post-infection aqueductal stenosis in 7 (5%). The ETV was performed by using the standard technique. The overall rate of good results (shunt-independent patients with clinical remission or improvement) was 87.1%. Eighteen patients (12.9%) required a shunt because of ETV failure. The long-term outcome of ETV in this study was not influenced by the patient's age and the etiology of the hydrocephalus (although cases secondary to cisternal hemorrhage and infections are not included). Other series including cases with long follow-up are analyzed. In conclusion, ETV results in a high rate of good long-term outcome in patients with obstructive hydrocephalus. Because postoperative failures occur early, clinical and radiological control studies must be performed particularly in the first years after the neuroendoscopic procedure.     

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.     

Association between antithrombotic drug use before chronic subdural haematoma and outcome after drainage: a systematic review and meta-analysis

In view of their age and vascular co-morbidities, people are often taking an antithrombotic drug when diagnosed with chronic subdural haematoma (CSDH). It is unclear whether antithrombotic use at CSDH diagnosis, or resumption afterwards, is associated with recurrent CSDH or vaso-occlusive events. We systematically reviewed the literature for studies reporting CSDH recurrence or vaso-occlusive events after drainage of CSDH associated with antithrombotic drug use. We searched Medline 1946–2016 and Embase 1974–2016 inclusive for cohort studies reporting the risk of CSDH recurrence or vaso-occlusive events after CSDH associated with antithrombotic (anticoagulant or antiplatelet) drug use. We meta-analysed outcome data using a random effect model and assessed inconsistency between studies using the I-squared (I ²) statistic. We found 20 studies reporting outcome after drainage of CSDH associated with antithrombotic drug use. Before CSDH drainage, 337 (11.5%) of 2941 patients in 12 studies used an anticoagulant drug and 600 (19%) of 3150 patients in 11 studies used an antiplatelet drug. The association between antithrombotic drug use and CSDH recurrence was significant for antiplatelet drug use (relative risk [RR] 1.36, 95% CI 1.05 to 1.75; I ² = 36.3%), but marginally significant for anticoagulant drug use (RR 1.38 95% CI 1.00–1.91; I ² = 37.5%). Two studies including 30 patients reported one vaso-occlusive outcome event after CSDH?. Antithrombotic drug use at CSDH diagnosis may be associated with post-operative CSDH recurrence. It is unclear whether this is attributable to confounding factors, antithrombotic reversal strategies or antithrombotic drug resumption. Further observational studies and randomised controlled trials of antithrombotic drug resumption are needed.     

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.Commentaries on this paper are available at and     

Chronic subdural hematoma following bypass surgery--report of three cases.

Bypass surgery is a safe procedure with low mortality and morbidity, and few reported surgical complications. Three patients developed postoperative chronic subdural hematoma (CSDH): two with stroke after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis and one with moyamoya disease after STA-MCA anastomosis combined with encephalomyosynangiosis. The factors inducing CSDH after revascularization in the seven reported and present cases included postoperative subdural effusion associated with brain atrophy, and postoperative anticoagulant therapy such as aspirin. CSDH may occur in patients with pre-existing brain atrophy and postoperative subdural effusion. Anticoagulant therapy should be avoided at the early postoperative stage after bypass surgery.     

Endoscopic third ventriculostomy in obstructive hydrocephalus due to giant basilar artery aneurysm

OBSTRUCTIVE: hydrocephalus due to giant basilar artery (BA) aneurysm is a rare finding, and endoscopic treatment has not been reported. Here the authors present their experience with endoscopic third ventriculostomy (ETV) in obstructive hydrocephalus due to giant BA aneurysm. Between December 2000 and March 2007, 3 patients (2 men and 1 woman; age range 32-80 years) underwent an ETV for the treatment of obstructive hydrocephalus caused by a giant BA aneurysm. All 3 patients presented with cephalgia, nausea, vomiting, and a variable decrease in consciousness. An obstructive hydrocephalus caused by a giant BA aneurysm was found in each case as the underlying pathological entity. Intraoperatively, a narrowing of the third ventricle by upward displacement of the tegmentum was found in all 3 patients. A standard ETV was performed and included an inspection of the prepontine cisterns. The endoscopic treatment was successful in all patients with respect to clinical signs and radiological ventricular enlargement. No complications were observed. In all, the endoscopic ventriculostomy was proven to be a successful treatment option in obstructive hydrocephalus even if it is caused by untreated giant BA aneurysm.     

Volume and densities of chronic subdural haematoma obtained from CT imaging as predictors of postoperative recurrence: a prospective study of 107 operated patients

Background

Chronic subdural haematoma (CSDH) is a common entity in neurosurgery with a considerable postoperative recurrence rate. Computerised tomography (CT) scanning remains the most important diagnostic test for this disorder. The aim of this study was to characterise the relationship between the recurrence of CSDH after treatment with burr-hole irrigation and closed-system drainage technique and CT scan features of these lesions to assess whether CT findings can be used to predict recurrence.

Methods

We investigated preoperative and postoperative CT scan features and recurrence rate of 107 consecutive adult surgical cases of CSDH and assessed any relationship with univariate and multivariate regression analyses.

Results

Seventeen patients (15.9 %) experienced recurrence of CSDH. The preoperative haematoma volume, the isodense, hyperdense, laminar and separated CT densities and the residual total haematoma cavity volume on the 1st postoperative day after removal of the drainage were identified as radiological predictors of recurrence. If the preoperative haematoma volume was under 115 ml and the residual total haematoma cavity volume postoperatively was under 80 ml, the probability of no recurrence was very high (94.4 % and 97.4 % respectively).

Conclusions

These findings from CT imaging may help to identify patients at risk for postoperative recurrence.     

Effectiveness of kampo medicine gorei-san-ryo for chronic subdural hematoma in very elderly patients

Chronic subdural hematoma (CSDH) is mainly a disease of the elderly. Widespread use of CT and MRI has resulted in the discovery of CSDH cases with no or minimum symptoms in the elderly. Treatment is by surgical evacuation, although small hematoma may resolve spontaneously. Treatment of CSDH in elderly patients of more than 80 years of age with minimum symptoms is still undetermined. Many conservative treatments such as those with steroids and diuretics have been reported with some good results. Conservative treatment cannot become the procedure of choice for fear of side effects. We report successful treatment for CSDH cases among the very elderly with a Kampo medicine (Japanese traditional herbal medicine). Among a total eleven cases, four were recurrent after surgical evacuation and seven showed significant hematoma with minimal symptoms. Gorei-san-ryo, a Kampo medicine, was administered for 3 to 12 months. Some cases showed rapid hematoma resolution after administration. Only one of them required subsequent surgical intervention. This conservative treatment with Kampo medicine for CSDH may be a potential alternative to surgery especially for the elderly.     

Endoscopic third ventriculostomy in the management of obstructive hydrocephalus: an outcome analysis

OBJECT: The purpose of this paper is to elucidate the safety and efficacy of, and indications and outcome prognosis for endoscopic third ventriculostomy (ETV) in 58 patients with obstructive hydrocephalus. METHODS: Between September 1999 and April 2003, 58 ETVs were performed in 58 patients with obstructive hydrocephalus (36 male and 22 female patients) at the authors' institution. The ages of the patients ranged from 5 to 67 years (mean age 35 years) and the follow-up period ranged from 3 to 41 months (mean duration of follow up 24 months). Patients were divided into four subgroups based on the cause of the obstructive hydrocephalus: 21 with intracranial tumors; 11 with intracranial cysts; 18 with aqueductal stenosis: and eight with intracranial hemorrhage or infection. Both univariate and multivariate statistical analyses were performed to assess the prognostic relevance of the cause of the obstructive hydrocephalus, early postoperative clinical appearance, and neuroimaging findings in predicting the result of the ETV. The survival rate was 87% at the end of the 1st year and 84% at the end of the 2nd year post-ETV. One month after ETV an overall clinical improvement was observed in 45 (77.6%) of 58 patients. If we also consider the successful revision of ETV in two patients, a success rate of 78.3% (47 of 60 patients) was reached. The ETV was successful in 17 (81%) of 21 patients with intracranial tumors, nine (82%) of 11 with cystic lesions, 16 (88.9%) of 18 with aqueductal stenosis, and three (38%) of eight with intracranial hemorrhage or infection. A Kaplan-Meier analysis illustrates that the percentage of functioning ETVs stabilizes between 75 and 80% 1 year after the operation. In a comparison of results 1 year after ETV, the authors found that the aqueductal stenosis subgroup had the highest proportion of functioning ETV (89%). The proportions of the tumor and cyst subgroups were 84 and 82%, respectively, whereas the proportion was only 50% in the ventriculitis/intracranial hemorrhage subgroup (strata log-rank test: chi2 = 7.93, p = 0.0475). In the present study, ETV failed in eight patients (13.8%) and the time to failure after the procedure was a mean of 3.4 months (median 2 months, range 0-8 months). The logistic regression analysis confirmed an early postoperative improvement (within 2 weeks after ETV, significance [Sig] of log likelihood ratio [LLR] < 0.0001) and a patent stoma on cine phase-contrast magnetic resonance (MR) images (Sig of LLR = 0.0002) were significant prognostic factors for a successful ETV. The results demonstrated the multivariate model (B = -53.7309, standard error = 325.1732, Wald = 0.0273, Sig = 0.8688) could predict a correct result in terms of success or failure from ETV surgery in 89.66% of observed cases. The Pearson chi-square test demonstrated that little reliance could be placed on the finding of a reduced size of the lateral ventricle (chi2 = 5.305, p = 0.07) on neuroimaging studies within 2 weeks after ETV, but it became a significant predictive factor at 3 months (chi2 = 8.992, p = 0.011) and 6 months (chi2 = 10.586, p = 0.005) post-ETV. Major complications occurred in seven patients (12.1%), including intraoperative venous bleeding in three, arterial bleeding in one, and occlusion of the stoma in three patients. The overall mortality rate was 10.3% (six patients). One of these patients died of pulmonary infection and another of ventriculitis. Four additional patients died of progression of malignant tumor during the follow-up period. CONCLUSIONS: The results indicate that ETV is a most effective treatment in cases of obstructive hydrocephalus that is caused by aqueductal stenosis and space-occupying lesions. For patients with infections or intraventricular bleeding, ETV has considerable effects in selected cases with confirmed CSF dynamic studies. Early clinical and cine phase-contrast MR imaging findings after the operation play an important role in predicting patient outcomes after ETV. The predictive value of an alteration in ventricle size, especially during the early stage following ETV, is unsatisfactory. Seventy-five percent of ETV failures occur within 6 months after surgery. A repeated ventriculostomy should be considered to be a sufficient treatment option in cases in which stoma dysfunction is suspected.