Complications Of Endoscopic Third Ventriculostomy Research Articles

Early Complications of Endoscopic Third Ventriculostomy in Obstructive Hydrocephalus

Obstructive hydrocephalus (HCP) occurs when cerebrospinal fluid is blocked leading to the enlargement of ventricular pathways stream resulting into increase pressure within skull. Endoscopic third ventriculostomy (ETV) is considered an effective management strategy for hydrocephalus especially for third/fourth ventricle level. Objective: To study the per-operative and post-operative early complications of endoscopic third ventriculostomy in obstructive hydrocephalus patients. Methods: This prospective study was conducted at Department of Neurosurgery, Liaquat University Hospital, Hyderabad, from 1st January 2020 to 31st December 2022. One hundred and fifty patients were included. All the cases, were underwent general anesthesia and elective surgery was performed in them. The patients were followed post operatively for 7 days in context to cerebrospinal fluid (CSF) leakage, wound infection, bleeding, seizures as well as meningitis. Results: Seventy six (50.7%) were males and 74 (49.3%) were female. Mean age was 5.5 ± 2.3 years with maximum number of patients (70.7%) were under or equal the age of 5 years. Complications occurred in 18 patients (12%) out of 150 patients. Cerebrospinal fluid leakage was the most common complication occurred in 5 (3.33%) patients, wound infection was seen in 2 (1.3%) patients, meningitis developed in 3 (2%) patients, minor bleeding was seen in 3 (2%) patients, seizures developed in 4 (2.6%) patients, in hospital mortality occurred in 1 (0.66%) patient on 3rd post-operative day. Conclusions: Ventriculostomy appeared to be the better surgical approach for obstructive hydrocephaly management. Minimum numbers of associated complications were observed in present study group.

Comparative Outcome Analysis of Endoscopic Third Ventriculostomy and Ventriculoperitoneal Shunt Surgery in Pediatric Hydrocephalus: An Experience of a Tertiary Care Center.

Background Endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt surgery (VPS) are used for the surgical management of pediatric hydrocephalus. There is controversy regarding the safety and efficacy of these procedures according to age, etiologies, and type of hydrocephalus. Objective The purpose of this study was to compare the outcomes and complications of ETV and VPS in pediatric hydrocephalus and to evaluate the better procedure. Material and Methods We retrospectively analyzed the pediatric hydrocephalus cases that were operated by ETV and VPS at our department from June 2016 to June 2019. Data were analyzed with respect to the etiology of hydrocephalus, age, and gender of the patients. We compared the outcomes (success and failure) depending on age at surgery, etiology, and type of hydrocephalus, complications at 12 months of follow-up. Fisher's exact test and chi-square test were applied to test the significance of difference. Results There were 195 pediatric hydrocephalus cases, which were operated by ETV ( n = 43; 22.05%) and VPS ( n = 152; 77.95%). The mean age of the cases was 53.63 ± 60.24 (ranged 0.5–204 months) in the ETV group and 53.44 ± 54.10 (ranged 0.3–210 months) in the VPS group. The male-to-female ratio was 1.41:1 in the ETV group and 1.21: 1 in the VPS group. Overall, ETV had successful outcomes in 30(69.77%) cases and VPS in 102(67.11%) cases at 12 months of follow-up. The complication rates were found in 7 (16.28%) cases in the ETV group and 38 (25.0%) cases in the VPS group. At initial 0.5 months of follow-up, ETV required revisions in 6 (13.95%) cases and VPS in 15 (9.87%) cases. Conclusion Although the success and failure of both the procedure vary according to the age at surgery, etiology and type of hydrocephalus, and complications, and failure rates on follow-up, there were no statistically significant differences between the two surgical groups in respect to these variables.

Does pre-resection endoscopic third ventriculostomy prevent the need for post-resection CSF diversion after pediatric posterior fossa tumor excision? A historical cohort study and review of the literature.

Children with posterior fossa tumors (PFTs) may present with hydrocephalus. Persistent (or new) hydrocephalus is common after PFT resection. Endoscopic third ventriculostomy (ETV) is sometimes performed prior to resection to 1) temporize hydrocephalus prior to resection and 2) prophylactically treat post-resection hydrocephalus. The objective of this study was to establish, in a historical cohort study of pediatric patients who underwent primary craniotomy for PFT resection, whether or not pre-resection ETV prevents the need for post-resection CSF diversion to manage hydrocephalus. The authors interrogated their prospectively maintained surgical neuro-oncology database to find all primary PFT resections from a single tertiary pediatric neurosurgery unit. These data were reviewed and supplemented with data from case notes and radiological review. The modified Canadian Preoperative Prediction Rule for Hydrocephalus (mCPPRH) score was retrospectively calculated for all patients. The primary outcome was the need for any form of postoperative CSF diversion within 6 months of PFT resection (including ventriculoperitoneal shunting, ETV, external ventricular drainage [EVD], and lumbar drainage [LD]). This was considered an ETV failure in the ETV group. The secondary outcomes were time to CSF diversion, shunt dependence at 6 months, and complications of ETV. Statistical analysis was done in RStudio, with significance defined as p < 0.05. A total of 95 patients were included in the study. There were 28 patients in the ETV group and 67 in the non-ETV group. Patients in the ETV group were younger (median age 5 vs 7 years, p = 0.04) and had more severe preoperative hydrocephalus (mean frontal-occipital horn ratio 0.45 vs 0.41 in the non-ETV group, p = 0.003) and higher mCPPRH scores (mean 4.42 vs 2.66, p < 0.001). The groups were similar in terms of sex and tumor histology. The overall rate of post-resection CSF diversion of any kind (shunt, repeat ETV, LD, or EVD) in the entire cohort was 25.26%. Post-resection CSF diversion was needed in 32% of patients in the ETV group and in 22% of the patients in the non-ETV group (p > 0.05). Shunt dependence at 6 months was seen in 21% of the ETV group and 16% of the non-ETV group (p > 0.05). The median time to ETV failure was 9 days. ETV failure correlated with patients with ependymoma (p = 0.02). Children who had ETV failure had higher mCPPRH scores than the ETV success group (5.67 vs 3.84, p = 0.04). Pre-resection ETV did not reliably prevent the need for post-resection CSF diversion. ETV was more likely to fail in children with ependymoma and those with higher mCPPRH scores. Based on the findings of this study, the authors will change the practice at their institution; pre-resection ETV will now be performed based on a newly defined protocol.

OBSTRUCTIVE HYDROCEPHALUS;

Introduction: Management of Hydrocephalus has always amazed and challenged clinicians throughout the history of medicine. The traditional treatment for all forms of hydrocephalus has been the implantation of Ventriculoperitoneal Shunt (VPS) system. Because of deployment of implant, this procedure inherently associated with certain common complications, infection approximately 24.6% of all shunt operations. Moreover, the risk of postoperative seizures is 25% and intracranial hemorrhage is 3.5%. Endoscopic Third Ventriculostomy (ETV) is a surgical procedure that allows the Cerebrospinal Fluid (CSF) to flow directly from the third ventricle to the basal cisterns and subarachnoid spaces, ETV has been established as a safe treatment for obstructive hydrocephalus because in this procedure there is no implant is deployed, that’s why rate of post operative complications is low as compare to VPS as intracranial infection found in 8% patient, intracranial hemorrhage in 5%and 1% patient developed seizure post ETV. Objectives: Objective of this study is to determine the frequency of short term complications of endoscopic third ventriculostomy in obstructive hydrocephalus. Study Design: Descriptive case series. Setting: Department of Neurosurgery, Lahore General Hospital, Lahore. Duration with Dates: Six months: from 01-07-2011 to 31-12-2011. Methods: This was a prospective study of in which 45 patients underwent Endoscopic third ventriculostomy for Obstructive hydrocephalus. The outcome of interest was to assess the frequency of complications like infection, hemorrhage and seizures following the ETV in patient with obstructive hydrocephalus. Data was collected on a specially designed Performa. Demographic details, signs and symptoms at presentation, details of post operative evaluation (mortality and neurological deficiency) were noted. Results: A total of 45 patients underwent in ETV for the treatment of obstructive hydrocephalus. Complications were observed in eight (17.8%) cases in which five patients had only one complication and three patients had multiple (two) complications. Regarding type of complication, Infection was observed in six (13.3%) cases, hemorrhage was observed in four (8.9%) cases and wound CSF leakages was seen in only one (2.2%) case. Conclusion: Endoscopic third ventriculostomy is recent advances in the management of obstructive hydrocephalus, it has lesser complications (Infection, Hemorrhage, seizures) and long term failure rate is low as compare to the traditional treatment of obstructive hydrocephalus.

Migration of Oxidized Cellulose to the Ventricle as a Complication of Endoscopic Third Ventriculostomy: A Case Report

AbstractEndoscopic third ventriculostomy (ETV) is an increasingly common neurosurgical procedure. Hemostatic agentes (porcine gelatin and oxidized cellulose) are normally placed to plug the cortical hole after ETV to avoid cerebral spinal fluid leakage, subdural hygroma, and hemorrhage. Here we report the case of a 6-year-old boy with hydrocephalus who underwent ETV and which oxidized cellulose was placed to plug the cortical hole. Magnetic resonance imaging of the head performed 3 months after the procedure showed the presence of oxidized cellulose in the ventricle. After an unsuccessful attempt to remove the cellulose, it was decided that the patient should be kept under observation. Two years later, the child is in good health and without any complaints. Hemostatic agents (especially oxidized cellulose) used on the cortical hole after ETV can migrate to the ventricle and compromise the procedure. Follow-up should be performed for such patients, and the main focus should be on not causing further injury.

Avoidance and management of perioperative complications of endoscopic third ventriculostomy: the Dhaka experience.

Although endoscopic third ventriculostomy (ETV) is a minimally invasive procedure, serious perioperative complications may occur due to the unique surgical maneuvers involved. In this paper the authors report the complications of elective and emergency ETV and their surgical management in 412 patients from July 2006 to October 2012 at Dhaka Medical College Hospital (a government hospital) and other private hospitals in Dhaka, Bangladesh. The authors attempted some previously undescribed simple maneuvers that may help to overcome the difficulties of managing complications. The complication rate was determined by recording intraoperative changes in pulse and blood pressure, bleeding episodes, serum electrolyte abnormalities, CSF leakage, and neurological deterioration in the immediate postoperative period. Intraoperative complications included hemodynamic alterations in the form of tachycardia, bradycardia, and hypertension. Bleeding was categorized as major in 2 cases and minor in 68 cases. Delayed recovery from anesthesia occurred in 14 cases, CSF leakage from the wound in 11 cases, and electrolyte imbalance in 5 cases. Postoperatively, 2 patients suffered convulsions and 1 had evidence of third cranial nerve injury. Three patients died as a result of complications. Complications during endoscopy can lead to serious consequences that may sometimes be very difficult to manage. The authors have identified and managed a large number of complications in this series, although the rate of complications is consistent with that in other reported series. These complications should be kept in mind perioperatively by both surgeons and anesthesiologists, as prompt detection and action can help minimize the risks associated with neuroendoscopic procedures.

Complications of endoscopic third ventriculostomy for hydrocephalus

To explore the complications of endoscopic third ventriculostomy (ETV) for hydrocephalus and examine their preventions. From September 2008 to September 2013, ETV was offered for obstructive hydrocephalus (n=15) and communicating hydrocephalus (n=5). And the prevention and treatment of common complications were analyzed. All had achieved satisfactory outcomes. For 16 cases, their symptoms and signs disappeared, ventricle returned to normal and interstitial edema resolved; for another 4 cases, there were improvements of symptoms and (or) signs, ventricular shrinking and/or interstitial edema lessening. And the postoperative complications included fever (n=5), poor healing of incision (n=2), scalp hydrops (n=2) and intracranial infection (n=1). The indications of ETV should be selected strictly according to the specific anatomical characteristics of bottom of third ventricle. And individualized methods of stoma are necessary. And early postoperative lumbar puncture and drainage may obviously reduce complications and improve surgical outcomes.

Third Ventriculocisternostomy for Shunt Failure

Our objective was to analyze the relevance, potential prognostic factors, and complications of endoscopic third ventriculostomy (ETV) in patients with shunt failures. Among 721 ETVs performed between 1999 and 2013, we studied 53 patients with shunts (31 men, 21 less than 18 years of age) who had an ETV performed for shunt failures as the result of various causes. We included all initial causes of hydrocephalus except adult chronic (i.e., "normal pressure") and pediatric communicant hydrocephalus. The mean duration between initial shunting for hydrocephalus and the ETV procedure was more than 11 years (137 months; range, 1 month to 34 years). Successful ETV procedure was defined as clinical improvement and shunt independence extending until the last follow-up visit. The success rate of the ETV procedure was 70% (37 of the 53 cases) with a mean follow-up of 51 months (from 3 to 157 months) and was not related to the age of the patient (P = 0.922), to the cause of hydrocephalus (P = 0.622), or to the number of shunt failures (P = 0.459). We also found no statistical difference (P = 0.343) between patients whose shunt had been in place for less than 5 years and those shunted more than 5 years. The presence of an infected shunt was not predictive of ETV failure (P = 0.395). No significant intraoperative or postoperative complications were noted. This study confirms that ETV should be considered as the first therapeutic option before shunt revision in cases of initial obstructive hydrocephalus.

A modified method to enhance the safety of endoscopic third ventriculostomy (ETV)—transendoscopic pulse-waved microvascular Doppler-assisted ETV, technical note

Endoscopic third ventriculostomy (ETV) is a simplified treatment relative to shunting for several types of hydrocephalus. The fatal complication of ETV is intraoperative hemorrhage due to arterial injury of the basilar artery, posterior cerebral arteries, and their perforators. Here, we present a modified technique of ETV by using a transendoscopic pulse-waved microvascular Doppler probe and videoscope head to avoid vascular injury behind the tuber cinereum (TC). The microvascular Doppler probe can detect the basilar artery complex through the TC. Ventriculostomy with the probe head helps prevent vascular injury by informing the presence of invisible vessels under endoscopic view during perforation, and the method introduced here is certain to prove invaluable for enhancing the safety of ETV.

Tuber cinereum proximity to critical major arteries: a morphometric imaging analysis relevant to endoscopic third ventriculostomy

Arterial bleeding in the interpeduncular fossa is a dreaded complication of endoscopic third ventriculostomy (ETV). When the "safe zone" of the tuber cinereum (TC) is fenestrated, the basilar artery tip (BT) or its branches may be encountered below the third ventriclular floor. Major arterial injuries might be avoided by careful preoperative planning. We aimed to establish previously unavailable normal magnetic resonance imaging (MRI) and MR angiographic (MRA) morphometry and configuration of the BT and posterior cerebral artery P1 segments relative to the TC. We analyzed images of 82 patients with non-dilated ventricles (mean Evans' index 0.26), and lying in a neutral head position (mean cervico-medullary angle 141°). We cross-referenced axial MRAs with sagittal MRIs to measure distances of BT and P1 segments from the TC, and to classify the location of the BT in the interpeduncular and suprasellar cisterns. We correlated the sagittal areas of these cisterns and patients' ages with the TC-to-artery distances using regression analysis. The BT, right P1 and left P1 segments were a mean 4.9 mm, 5.5 mm, and 5.7 mm respectively from the TC. Seventy-four percent of BTs were anterior to the mammillary bodies. These distances and locations did not correlate with age (mean 53 years) or size of basal cisterns. The normal BT and P1 segments are anatomically close to the TC and potentially at risk during ETV in adults of all ages. The new morphometric data presented, along with cross-referencing of preoperative multiplanar images, could help reduce vascular complications during ETV.

Growth Hormone Deficiency and Diabetes Insipidus as a Complication of Endoscopic Third Ventriculostomy

Endoscopic third ventriculostomy (ETV) has become the procedure of choice for the treatment of obstructive hydrocephalus in children and adults. Endocrinological complications of ETV in children are rare. Diabetes insipidus (DI) is the most common and accounts for only 0.5% of complications from ETV. The majority of documented cases are transient. To date, there are no documented cases of multiple pituitary hormone deficiencies. We present here a 6-year-old girl with growth hormone deficiency and permanent DI which developed as a complication of ETV. This patient is unique in both demonstrating multiple pituitary hormone deficiencies and the classical triphasic response of DI after ETV. We postulate that these complications were caused by compression of the pituitary stalk and hypothalamic injury during the procedure. We compare our case presentation to experimental studies conducted in rats. Conflict of interest:None declared.

Hyponatremia following endoscopic third ventriculostomy: a report of 5 cases and analysis of risk factors

Electrolyte and endocrinological complications of endoscopic third ventriculostomy (ETV) are infrequent but serious events, likely due to transient hypothalamic-pituitary dysfunction. While the incidence of diabetes insipidus is relatively well known, hyponatremia is not often reported. The authors report on a series of 5 patients with post-ETV hyponatremia. The records of patients undergoing ETV between 2008 and 2010 were reviewed. All ETVs were performed with a rigid neuroendoscope via a frontal bur hole, standard third ventricle floor blunt perforation, Fogarty catheter dilation, and intermittent normal saline irrigation. Postoperative MR images were evaluated for endoscope tract injury as well as the trajectory from the bur hole center to the fenestration site. Thirty-two patients (20 male and 12 female) underwent ETV. Their median age was 6 years (range 3 weeks-28 years). Hydrocephalus was most commonly due to nontumoral aqueductal stenosis (43%), nontectal tumor (25%), or tectal glioma (13%). Five patients (16%) had multicystic/loculated hydrocephalus. Five patients (16%) developed hyponatremia between 1 and 8 days following ETV, including 2 patients with seizures (1 of whom was still hospitalized at the time of the seizure and 1 of whom was readmitted as a result of the seizure) and 3 patients who were readmitted because of decline in their condition following routine discharge. No hypothalamic injuries were noted on imaging. Univariate risk factors consisted of age of 2 years or less (p = 0.02), presence of cystic lesions (p = 0.02), and ETV trajectory angle 10° or more from perpendicular (p = 0.001). Endoscopic third ventriculostomy is a well-tolerated procedure but can result in serious complications. Hyponatremia is rare and may be more likely in younger patients or those with cystic loculations. Patients with altered craniometry may be at particular risk with a rigid endoscopic approach requiring greater manipulation of subforniceal or hypothalamic structures.

Complications of endoscopic third ventriculostomy

Endoscopic third ventriculostomy (ETV) is an established treatment for hydrocephalus. Most studies focus on success rate, and complications are insufficiently documented. The aim of this study was to perform a systematic review of ETV complications. A Medline search discovered 34 series of ETV with detailed complications reports (17 series involving exclusively pediatric patient populations, 6 series involving exclusively adults, and 11 series involving mixed adult and pediatric populations). The analysis included 2985 ETVs performed in 2884 patients. The cause of hydrocephalus was aqueductal stenosis in 29.3% of patients, tumor in 37.6%, meningomyelocele in 7.6%, cysts in 2.6%, cerebellar infarct in 0.9%, Dandy-Walker malformation in 0.6%, and Chiari malformation Type I in 0.4%; 7.4% of the patients had posthemorrhagic hydrocephalus, 1.8% had postinfectious hydrocephalus, and 1.2% had normal pressure hydrocephalus. Hydrocephalus was due to other causes in 1.3% of cases and the cause was not reported in 9.8%. The overall complication rate was 8.5%. The rate of permanent morbidity was 2.38%; the rate of permanent neurological complications was 1.44% (hemiparesis, gaze palsy, memory disorders, altered consciousness), and the rate of permanent hormonal morbidity was 0.94% (diabetes insipidus, weight gain, precocious puberty). The rate of intraoperative hemorrhage rate was 3.7%; the rate of severe intraoperative hemorrhage was 0.6% (including a 0.21% rate of basilar rupture). The rate for intraoperative neural injury (thalamic, forniceal, hypothalamic, and midbrain injuries) was 0.24%. Central nervous system infections occurred in 1.81% of cases, CSF leak in 1.61%, and postoperative intracranial hematomas in 0.81% of cases. The early postoperative mortality rate was 0.21% (6 patients died; 2 of sepsis and 4 of hemorrhage). Another 2 children suffered delayed "sudden death" (one after 25 months and the other after 60 months), caused by acute hydrocephalus due to stoma occlusion. There were no significant differences between series involving pediatric or adult patient populations or series with fewer than 100 or more than 100 patients. All reported deaths were in series involving more than 100 patients. Endoscopic third ventriculostomy can be regarded as a low-complication procedure, with an overall complication rate of 8.5%, permanent morbidity rate of 2.4%, mortality rate of 0.21%, and delayed "sudden death" rate of 0.07%.

Endoscopic third ventriculostomy for hydrocephalus: A review of indications, outcomes, and complications

Endoscopic third ventriculostomy (ETV) has been in vogue for the past two decades, as a tool in the armamentarium of the neurosurgeon, for the management of hydrocephalus. Its utility has been proven consistently in congenital / acquired aqueductal stenosis, although the outcomes in communicating hydrocephalus as well as hydrocephalus secondary to other etiologies have not been as impressive. It is a relatively safe procedure with the appropriate selection of patients with a low rate of permanent morbidity. This review aims to define the current indications, management outcomes, and complications of ETV.

The distance between the posterior communicating arteries and their relation to the endoscopic third ventriculostomy in adults: An anatomic study.

Background:The diencephalic leaf of the Liliequist's membrane is a continuous structure that should be perforated in the endoscopic third ventriculostomy. Its lateral borders are penetrated by the third cranial nerve and the posterior communicating arteries. The most important complication of endoscopic third ventriculostomy is the vascular injury, such as the posterior communicating artery. The purpose of this study is to measure the distance between posterior communicating arteries located below the third ventricle floor and anterior of the mammillary bodies.Methods:In this observational prospective study 20 fresh brains from cadavers were utilized to measure the distance between the posterior communicating arteries in April 2008 at the Death Check Unit of our Institution. A digital photograph of the posterior communicating arteries was taken and the distance between the arteries was measured. The measurement was analyzed using descriptive statistics.Results:In the descriptive analysis of the 20 specimens, the posterior communicating arteries distance was 9 to 18.9 mm, a mean of 12.5 mm, median of 12.2 mm, standard deviation of 2.3 mm.Conclusion:The detailed knowledge of vascular structures involved in the endoscopic third ventriculostomy as to the posterior communicating arteries distance provides a safe lateral vascular border when performing such procedure.

Uncontrollable High-Frequency Tachypnea: A Rare and Nearly Fatal Complication of Endoscopic Third Ventriculostomy: Case Report and Literature Review

Endoscopic third ventriculostomy (ETV) is considered a safe procedure although it carries its rate of risks and complications that may occasionally be life-threatening. This is a report about a 48-year-old woman presenting with progressive gait unsteadiness, weakness of the lower extremities and cognitive impairment due to tri-ventricular hydrocephalus. This was treated with standard ETV. In the immediate post-operative period the patient developed a severe and uncontrollable tachypnea requiring sedation, intubation and mechanical ventilation. Tachypnea may be an early complication after standard ETV and although its mechanism remains yet unclear, we speculate that it may be related to excessive traction and/or surgical manipulation of the floor of the third ventricle. Supportive care with mechanical ventilation is the mainstay of treatment until spontaneous normalization of the respiratory mechanism occurs.

Posterior cerebral artery P1 segment at the stoma during endoscopic third ventriculostomy in adults

ObjectivesA serious catastrophic complication of endoscopic third ventriculostomy (ETV) is basilar artery (BA) damage. Although the BA has been discussed as the cause of haemorrhage and even pseudoaneurysm, variations of...

Incidence and pattern of intraoperative hemodynamic response to endoscopic third ventriculostomy

In patients undergoing endoscopic third ventriculostomy (ETV), various cardiovascular changes occur in the intraoperative period. We tried to determine a pattern in these changes and their relation to different surgical steps. A total of 260 patients were studied over a period of six years. Heart rate and mean arterial pressures were recorded before introduction of the endoscope and thereafter at various stages of the operation. Tachycardia was the predominant observed abnormality in 20% of patients, occurring mostly during manipulations and irrigation in the third ventricle (TV). Bradycardia was seen in 12% of patients, more often during fenestration of the floor of the third ventricle. Tachycardia observed during ETV may be related to hypothalamic stimulation or a rise in intracranial pressure and bradycardia may be due to stimulation of the hypothalamus or the third cranial nerve. Anticipation of these cardiovascular changes during the relevant steps of the operation can help in taking appropriate corrective action, thus preventing potentially serious complications of ETV.

P.146 Early and late complications of endoscopic third ventriculostomy

P.146 Early and late complications of endoscopic third ventriculostomy

Complications of endoscopic third ventriculostomy in previously shunted patients.

Endoscopic third ventriculostomy (ETV) is considered to be a safe and effective treatment in selected patients as an initial treatment for obstructive hydrocephalus and at the time of shunt malfunction in previously shunted patients. We compared the outcome and complications of ETV between patients with newly diagnosed hydrocephalus and those with previous shunting procedures. A retrospective review of patients undergoing ETV from 1996 to 2004 at Alberta's Childrens Hospital and Foothills Medical Centre was completed. Patient data included symptoms at clinical presentation, cause of hydrocephalus, age at initial shunt, number of previous shunt revisions, age at ETV, complications, and subsequent shunting procedures performed. A total of 131 patients were identified with a minimum follow-up duration of 1 year; 71 (82.5%) of 86 patients who underwent ETV as a primary procedure and 36 (80%) of 45 patients who had ETV at the time of shunt malfunction were shunt-free at the last follow-up evaluation. Patients younger than 1 year old who underwent ETV were more likely to require an additional procedure for control of their hydrocephalus (P < 0.01). Serious complications after ETV occurred more frequently in patients who presented at the time of shunt malfunction (14 of 45 patients, 31%) compared with patients who underwent primary ETV (seven of 86 patients, 8%) (P = 0.02). Previously shunted patients with a history of two or more revisions (P = 0.03) and who experienced a serious complication at the time of ETV (P = 0.01) were more likely to require shunt replacement. ETV is an effective treatment both in selected patients with newly diagnosed hydrocephalus and in patients with a previous shunting procedure who are presenting with malfunction. Complications of ETV occur more frequently in previously shunted patients than in patients treated for newly diagnosed hydrocephalus, and care must be taken in the selection and treatment of these patients.