The role of sacral laminoplasty in the management of spina bifida and sacral cystic lesions: case series.

OBJECTIVE: Although laminae are not viewed as essential structures for spinal integrity, in the sacrum the anatomical weakness and gravity makes it a vulnerable area for CSF accumulation and expansion. The congenital or postoperative defects of sacral laminae, such as in patients with spina bifida, make this area more susceptible to forming progressive dural ectasia, pseudomeningocele, or expansile arachnoid cyst (Tarlov cyst). In addition, adhesions between the dura and surrounding soft tissue after laminectomy can cause some local symptoms, which are difficult to relieve. The authors propose that sacral laminoplasty with titanium mesh can provide a rigid support and barrier to resolve these sacral lesions and local symptoms. METHODS: From January 2016 to December 2017, patients with progressive CSF-containing lesions in the sacral area and defective sacral laminae were included in the study. After repair of the lesion, the authors performed sacral laminoplasty with titanium mesh in each patient. Subsequently, the soft tissue and skin were closed primarily. RESULTS: A total of 6 patients were included. Four patients with repaired myelomeningocele had progressive dural ectasia. One patient with lipomyelomeningocele previously underwent detethering surgery and developed postoperative pseudomeningocele. One patient had a symptomatic Tarlov cyst. Four of these 6 cases presented with low-back pain and local tenderness. During follow-up, ranging from 13 to 37 months, all 6 patients experienced no recurrence of dural ectasia or pseudomeningocele and were free from local symptoms. CONCLUSIONS: Sacral laminoplasty with titanium mesh is a safe and effective procedure for treating progressive sacral dural ectasia and refractory pseudomeningocele, preventing CSF leakage as well as relieving local symptoms that may occur years after previous surgery for spina bifida.

Using the keystone design perforator island flap in large myelomeningocele closure.

OBJECTIVE: Many repair techniques have been proposed to treat large myelomeningocele (MMC), and although effective in many cases, some of these techniques can be complex and time consuming, with complications such as cerebrospinal fluid (CSF) leakage, flap loss, tip necrosis, and wound dehiscence. The purpose of this study was to analyze cases of large skin defects and the methods applied and to report the outcomes of the keystone design perforator island flap (KDPIF) technique for large MMC closure. METHODS: The authors performed a retrospective review of all neonatal patients who had undergone KDPIF for MMC closure in the period from 2013 to 2018. All patients had a diagnosis of lumbosacral MMC based on obstetric ultrasound. The neurosurgeons and plastic surgeons had selected the cases after concluding that primary closure would be unlikely. The design of the flap is based on the randomly located vascular perforators, creating two identical opposing flaps to fashion a double keystone flap. During wound closure, V-Y advancement of each end of the double flap in the longitudinal axis creates redundancy in the central portion of the flap and reduces the horizontal tension. After discharge, both the neurosurgery and plastic surgery teams followed up all patients, tracking the results with photography. RESULTS: No skin flap dehiscence or necrosis, infection, or CSF leakage was detected, proving the reliability of the flap. One of the patients required further surgery for the large skin defects after insufficient intrauterine closure of the MMC and successfully underwent KDPIF treatment. Another patient (14.3%) had severe neonatal sepsis, which ultimately led to death. A ventriculoperitoneal shunt was required after the skin defect repair in 5 (83.3%) of the 6 surviving patients. Exceptional aesthetic results were achieved for all patients during the follow-up. CONCLUSIONS: The KDPIF technique is based on well-known vascular perforators of the intercostal, lumbar, and gluteal regions. Wound tension is widely distributed by the flap and, as a consequence, relevant tissue bulk, reliable vascularity, and important geometrical versatility are provided. In addition, most of the muscles and fascia are preserved, which is another advantage in terms of minimizing secondary morbidity to local tissue rearrangement. The use of KDPIF closure was successfully shown to be a viable alternative for more complex MMCs that present with large skin defects.

Progressive hydrocephalus despite early complete reversal of hindbrain herniation after prenatal open myelomeningocele repair.

OBJECTIVE: Open prenatal myelomeningocele (MMC) repair is typically associated with reversal of in utero hindbrain herniation (HBH) and has been posited to be associated with a reduction in both postoperative prenatal and immediate postnatal hydrocephalus (HCP) risks. However, the long-term postnatal risk of HCP following HBH reversal in these cases has not been well defined. The authors describe the results of a long-term HCP surveillance in a cohort of patients who underwent prenatal MMC repair at their institution. METHODS: A retrospective review of all prenatal MMC repair operations performed at the Mayo Clinic between 2012 and 2017 was conducted. Pertinent data regarding the clinical courses of these patients before and after MMC repair were summarized. Outcomes of interest were occurrences of HBH and HCP and the need for intervention. RESULTS: A total of 9 prenatal MMC repair cases were identified. There were 7 cases in which MRI clearly demonstrated prenatal HBH, and of these 86% (6/7) had evidence of HBH reversal after repair and prior to delivery. After a mean postnatal follow-up of 20 months, there were 3 cases of postnatal HCP requiring intervention. One case that failed to show complete HBH reversal after MMC repair required early ventriculoperitoneal shunting. The other 2 cases were of progressive, gradual-onset HCP despite complete prenatal HBH reversal, requiring endoscopic third ventriculostomy with choroid plexus cauterization at ages 5 and 7 months. CONCLUSIONS: Although prenatal MMC repair can achieve HBH reversal in a majority of well-selected cases, the prevention of postnatal HCP requiring intervention appears not to be predicated on this outcome alone. In fact, it appears that in a subset of cases in which HBH reversal is achieved, patients can experience a progressive, gradual-onset HCP within the 1st year of life. These findings support continued rigorous postnatal surveillance of all prenatal MMC repair patients, irrespective of postoperative HBH outcome.

Contemporary management and outcome of myelomeningocele: the Rotterdam experience.

OBJECTIVE: Myelomeningocele (MMC) is the most common form of spina bifida, with a lifelong impact on the quality of life for infants born with this condition. In recent decades, fetal surgery has evolved from an experimental therapy to standard of care for many centers in the world. In this study, the authors aimed to provide an overview of the current management and outcomes for infants with MMC managed at their institution. This then provides a center-specific historical cohort for comparison with future antenatal-treated MMC cases. METHODS: This is a retrospective, single-institution cohort study including all consecutive MMC cases between January 1, 2000, and June 1, 2018, at Erasmus MC. Outcome data included closure of the defect (location, timing, and surgical parameters), hydrocephalus management, Chiari malformation type II (CMTII) management, incidence of spinal cord tethering and outcome, motor outcomes, and continence. RESULTS: A total of 93 patients were included with predominantly lumbosacral lesions. Two patients died during follow-up. Hydrocephalus was present in 84%, with a 71% ventriculoperitoneal shunt reoperation rate. Surgery was performed in 12% for a tethered spinal cord at a mean age of 8 years. Decompression surgery was performed in 3 patients for CMTII. Special education in 63% was significantly associated with hydrocephalus (p < 0.015). Nineteen percent of patients were able to walk independently, and 47% were nonambulators. Social continence for urine was obtained in 75% of patients, 4% had fecal incontinence. CONCLUSIONS: This study provides an overview of current MMC outcomes at the authors' center and will serve as a historical cohort for comparison with future fetal surgery cases operated on at the center in the coming years. Apart from a relatively low surgical untethering rate, the authors' outcome data are comparable to those in the literature. Hydrocephalus is highly prevalent in postnatally treated MMC patients; in this study as in much of the literature, hydrocephalus is correlated with a low cognitive function. Fetal surgery for MMC halves the need for shunt treatment in a select group of MMC pregnancies, constituting a major indication for us to undergo the transition to a fetal surgery center. The fetal benefits of open antenatal surgery for MMC are well established, yet long-term data on especially tethered spinal cord are eagerly awaited.

Pediatric neurosurgeons' views regarding prenatal surgery for myelomeningocele and the management of hydrocephalus: a national survey.

OBJECTIVE: The Management of Myelomeningocele Study (MOMS) compared prenatal with postnatal surgery for myelomeningocele (MMC). The present study sought to determine how MOMS influenced the clinical recommendations of pediatric neurosurgeons, how surgeons' risk tolerance affected their views, how their views compare to those of their colleagues in other specialties, and how their management of hydrocephalus compares to the guidelines used in the MOMS trial. METHODS: A cross-sectional survey was sent to all 154 pediatric neurosurgeons in the American Society of Pediatric Neurosurgeons. The effect of surgeons' risk tolerance on opinions and counseling of prenatal closure was determined by using ordered logistic regression. RESULTS: Compared to postnatal closure, 71% of responding pediatric neurosurgeons viewed prenatal closure as either "very favorable" or "somewhat favorable," and 51% reported being more likely to recommend prenatal surgery in light of MOMS. Compared to pediatric surgeons, neonatologists, and maternal-fetal medicine specialists, pediatric neurosurgeons viewed prenatal MMC repair less favorably (p < 0.001). Responders who believed the surgical risks were high were less likely to view prenatal surgery favorably and were also less likely to recommend prenatal surgery (p < 0.001). The management of hydrocephalus was variable, with 60% of responders using endoscopic third ventriculostomy in addition to ventriculoperitoneal shunts. CONCLUSIONS: The majority of pediatric neurosurgeons have a favorable view of prenatal surgery for MMC following MOMS, although less so than in other specialties. The reported acceptability of surgical risks was strongly predictive of prenatal counseling. Variation in the management of hydrocephalus may impact outcomes following prenatal closure.

Facial nerve outcome and extent of resection in cystic versus solid vestibular schwannomas in radiosurgery era.

OBJECTIVE Cystic vestibular schwannomas (CVSs) are a subgroup of vestibular schwannomas (VSs) that are reported to be associated with unpredictable clinical behavior and unfavorable postoperative outcomes. The authors aimed to review their experience with microsurgical treatment of CVSs in terms of extent of resection and postoperative facial nerve (FN) function and compare these outcomes with those of their solid counterparts. METHODS Two hundred-eleven VS patients were treated surgically between 2006 and 2017. Tumors were defined as cystic when preoperative neuroimaging demonstrated cyst formation that was confirmed by intraoperative findings. Solid VS (SVSs) with similar classes were used for comparison. Clinical data of the patients were reviewed retrospectively, including clinical notes and images, as well as operative, pathology, and neuroradiology reports. RESULTS Thirty-two patients (20 males and 12 females) with a mean age of 52.2 years (range 17-77 years) underwent microsurgical resection of 33 CVSs (mean size 3.6 cm, range 1.5-5 cm). Forty-nine patients (26 males and 23 females) with a mean age of 49.9 years (range 21-75 years) underwent microsurgical resection of 49 SVSs (mean size 3 cm, range 2-4.5 cm). All operations were performed via either a retrosigmoid or a translabyrinthine approach. Gross-total resection was achieved in 30 cases in the CVS group (90.9%) and 37 in the SVS group (75.5%). The main reason for subtotal and near-total resection was adherence of the tumor to the brainstem and/or FN in both groups. None of the patients with subtotal or near-total resection in the CVS group demonstrated symptomatic regrowth of the tumor during the mean follow-up period of 41.6 months (range 18-82 months). The FN was anatomically preserved in all patients in both groups. Good FN outcomes were achieved in 15 of CVS (grade I-II; 45.5%) and 35 of SVS (71.4%) surgeries at discharge. Good and fair FN functions were noted in 22 (grade I-II; 81.5%) and 5 (grade III only; 18.5%) of the CVS patients, respectively, at the 1-year follow-up; none of the patients showed poor FN function. CONCLUSIONS Surgery of CVSs does not necessarily result in poor outcomes in terms of the extent of resection and FN function. Special care should be exercised to preserve anatomical continuity of the FN during surgery, since long-term FN function outcomes are much more satisfactory than short-term results. High rates of gross-total resection and good FN outcomes in our study may also suggest that microsurgery stands as the treatment of choice in select cases of large CVSs and SVSs in the era of radiosurgery.

Neural tube defects in Uganda: follow-up outcomes from a national referral hospital.

OBJECTIVE: Children with neural tube defects (NTDs) require timely surgical intervention coupled with long-term management by multiple highly trained specialty healthcare teams. In resource-limited settings, outcomes are greatly affected by the lack of coordinated care. The purpose of this study was to characterize outcomes of spina bifida patients treated at Mulago National Referral Hospital (MNRH) through follow-up phone surveys. METHODS: All children presenting to MNRH with NTDs between January 1, 2014, and August 31, 2015, were eligible for this study. For those with a documented telephone number, follow-up phone surveys were conducted with the children's caregivers to assess mortality, morbidity, follow-up healthcare, and access to medical resources. RESULTS: Of the 201 patients, the vast majority (n = 185, 92%) were diagnosed with myelomeningocele. The median age at presentation was 6 days, the median length of stay was 20 days, and the median time to surgery was 10 days. Half of the patients had documented surgeries, with 5% receiving multiple procedures (n = 102, 51%): 80 defect closures (40%), 32 ventriculoperitoneal shunts (15%), and 1 endoscopic third ventriculostomy (0.5%). Phone surveys were completed for 53 patients with a median time to follow-up of 1.5 years. There were no statistically significant differences in demographics between the surveyed and nonrespondent groups. The 1-year mortality rate was 34% (n = 18). At the time of survey, 91% of the survivors (n = 30) have received healthcare since their initial discharge from MNRH, with 67% (n = 22) returning to MNRH. Hydrocephalus was diagnosed in 29 patients (88%). Caregivers reported physical deficits in 39% of patients (n = 13), clubfoot in 18% (n = 6), and bowel or bladder incontinence in 12% (n = 4). The surgical complication rate was 2.5%. Glasgow Outcome Scale-Extended pediatric revision scores were correlated with upper good recovery in 58% (n = 19) of patients, lower good recovery in 30% (n = 10), and moderate disability in 12% of patients (n = 4). Only 5 patients (15%) reported access to home health resources postdischarge. CONCLUSIONS: This study is the first to characterize the outcomes of children with NTDs that were treated at Uganda's national referral hospital. There is a great need for improved access to and coordination of care in antenatal, perioperative, and long-term settings to improve morbidity and mortality.

Real-time ultrasound-guided external ventricular drain placement: technical note.

In the United Kingdom, ultrasound-guided external ventricular drain (EVD) insertion is becoming the standard of care to mitigate the morbidity associated with catheter malposition and multiple passes. Many neurosurgeons routinely use ultrasound to check the preinsertion trajectory, although real-time visualization of ventricular cannulation is preferable since minor deviations can be significant in patients with smaller ventricles, and live visualization further enables the catheter tip to be adjusted away from the choroid plexus. Such real-time ultrasound navigation has traditionally been limited by technical factors including the challenge of simultaneously manipulating the probe and inserting the catheter within the same image plane. The authors here describe a simple technique for precise EVD placement using a readily available bur hole ultrasound transducer attached to a 10-gauge needle guide channel (principally used for biopsy procedures) to accommodate a ventriculostomy catheter. The anticipated trajectory line is then projected onto the display and followed into the ipsilateral lateral ventricle. This is illustrated with a representative case and video demonstrating this rapid, user-friendly, and reliable technique. The authors invite others to consider this useful technique to minimize the risks of catheter misplacement or multiple cannulation attempts, which can be of particular benefit to junior neurosurgeons performing difficult cases under pressured conditions.

Overshunting-associated myelopathy: report of 2 cases.

The authors present 2 cases of cervical myelopathy produced by engorged vertebral veins due to overshunting. Overshunting-associated myelopathy is a rare complication of CSF shunting. Coexisting cervical degenerative disc disease may further increase the difficulty of diagnosing the condition. Neurosurgeons and others who routinely evaluate patients with intracranial shunts should be familiar with this rare but possible diagnosis.

Laparoscopy versus mini-laparotomy peritoneal catheter insertion of ventriculoperitoneal shunts: a systematic review and meta-analysis.

OBJECTIVE Ventriculoperitoneal (VP) shunt treatment is the main treatment method for hydrocephalus. The traditional operative approach for peritoneal catheter insertion is mini-laparotomy. In recent years, laparoscopy-assisted insertion has become increasingly popular. It seems likely that use of an endoscope could lower the incidence of shunt malfunction. However, there is no consensus about the benefits of laparoscopy-assisted peritoneal catheter insertion. METHODS A systematic search was performed using the PubMed, Embase, ScienceDirect, and Cochrane Library databases. A manual search for reference lists was conducted. The protocol was prepared according to the interventional systematic reviews of the Cochrane Handbook, and the article was written on the basis of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. RESULTS Eleven observational trials and 2 randomized controlled trials were included. Seven operation-related outcome measures were analyzed, and 3 of these showed no difference between operative techniques. The results of the meta-analysis are as follows: in the laparoscopy group, the rate of distal shunt failure was lower (OR 0.41, 95% CI 0.25-0.67; p = 0.0003), the absolute effect is 7.11% for distal shunt failure, the number needed to treat is 14 (95% CI 8-23), operative time was shorter (mean difference [MD], -12.84; 95% CI -20.68 to -5.00; p = 0.001), and blood loss was less (MD -9.93, 95% CI -17.56 to -2.31; p = 0.01). In addition, a borderline statistically significant difference tending to laparoscopic technique was observed in terms of hospital stay (MD -1.77, 95% CI -3.67 to 0.13; p = 0.07). CONCLUSIONS To some extent, a laparoscopic insertion technique could yield a better prognosis, mainly because it is associated with a lower distal failure rate and shorter operative time, which would be clinically relevant.

Stereotactic laser ablation for hypothalamic and deep intraventricular lesions.

OBJECTIVE Laser ablation is a novel, minimally invasive procedure that utilizes MRI-guided thermal energy to treat epileptogenic and other brain lesions. In addition to treatment of mesial temporal lobe epilepsy, laser ablation is increasingly being used to target deep or inoperable lesions, including hypothalamic hamartoma (HH), subependymal giant cell astrocytoma (SEGA), and exophytic intrinsic hypothalamic/third ventricular tumors. The authors reviewed their early institutional experience with these patients to characterize clinical outcomes in patients undergoing this procedure. METHODS A retrospective cohort (n = 12) of patients undergoing laser ablation at a single institution was identified, and clinical and radiographic records were reviewed. RESULTS Laser ablation was successfully performed in all patients. No permanent neurological or endocrine complications occurred; 2 (17%) patients developed acute obstructive hydrocephalus or shunt malfunction following treatment. Laser ablation of HH resulted in seizure freedom (Engel Class I) in 67%, with the remaining patients having a clinically significant reduction in seizure frequency of greater than 90% compared with preoperative baseline (Engel Class IIB). Treatment of SEGAs resulted in durable clinical and radiographic tumor control in 2 of 3 cases, with one patient receiving adjuvant everolimus and the other receiving no additional therapy. Palliative ablation of hypothalamic/third ventricular tumors resulted in partial tumor control in 1 of 3 patients. CONCLUSIONS Early experience suggests that laser ablation is a generally safe, durable, and effective treatment for patients harboring HHs. It also appears effective for local control of SEGAs, especially in combination therapy with everolimus. Its use as a palliative treatment for intrinsic hypothalamic/deep intraventricular tumors was less successful and associated with a higher risk of serious complications. Additional experience and long-term follow-up will be beneficial in further characterizing the effectiveness and risk profile of laser ablation in treating these lesions in comparison with conventional resective surgery or stereotactic radiosurgery.

Optimizing ventriculoperitoneal shunt placement in the treatment of idiopathic intracranial hypertension: an analysis of neuroendoscopy, frameless stereotaxy, and intraoperative CT.

OBJECTIVE: Cerebrospinal fluid shunting can effectively lower intracranial pressure and improve the symptoms of idiopathic intracranial hypertension (IIH). Placement of ventriculoperitoneal (VP) shunts in this patient population can often be difficult due to the small size of the ventricular system. Intraoperative adjuvant techniques can be used to improve the accuracy and safety of VP shunts for these patients. The purpose of this study was to analyze the efficacy of some of these techniques, including the use of intraoperative CT (iCT) and frameless stereotaxy, in optimizing postoperative ventricular catheter placement. METHODS: The authors conducted a retrospective review of 49 patients undergoing initial ventriculoperitoneal shunt placement for the treatment of IIH. The use of the NeuroPEN Neuroendoscope, intraoperative neuronavigation, and iCT was examined. To analyze ventricular catheter placement on postoperative CT imaging, the authors developed a new grading system: Grade 1, catheter tip terminates optimally in the ipsilateral frontal horn or third ventricle; Grade 2, catheter tip terminates in the contralateral frontal horn; Grade 3, catheter terminates in a nontarget CSF space; and Grade 4, catheter tip terminates in brain parenchyma. All shunts had spontaneous CSF flow upon completion of the procedure. RESULTS: The average body mass index among all patients was 37.6 ± 10.9 kg/m2. The NeuroPEN Neuroendoscope was used in 44 of 49 patients. Intraoperative CT scans were obtained in 24 patients, and neuronavigation was used in 32 patients. Grade 1 or 2 final postoperative shunt placement was achieved in 90% of patients (44 of 49). In terms of achieving optimal postoperative ventricular catheter placement, the use of iCT was as effective as neuronavigation. Two patients had their ventricular catheter placement modified based on an iCT study. The use of neuronavigation significantly increased time in the operating room (223.4 ± 46.5 vs. 190.8 ± 31.7 minutes, p = 0.01). There were no shunt infections in this study. CONCLUSIONS: The use of iCT appears to be equivalent to the use of neuronavigation in optimizing ventricular shunt placement in IIH. Additionally, it may shorten operating room time and limit overall costs.

Global surgery for pediatric hydrocephalus in the developing world: a review of the history, challenges, and future directions.

OBJECTIVE Pediatric hydrocephalus is one of the most common neurosurgical conditions and is a major contributor to the global burden of surgically treatable diseases. Significant health disparities exist for the treatment of hydrocephalus in developing nations due to a combination of medical, environmental, and socioeconomic factors. This review aims to provide the international neurosurgery community with an overview of the current challenges and future directions of neurosurgical care for children with hydrocephalus in low-income countries. METHODS The authors conducted a literature review around the topic of pediatric hydrocephalus in the context of global surgery, the unique challenges to creating access to care in low-income countries, and current international efforts to address the problem. RESULTS Developing countries face the greatest burden of pediatric hydrocephalus due to high birth rates and greater risk of neonatal infections. This burden is related to more general global health challenges, including malnutrition, infectious diseases, maternal and perinatal risk factors, and education gaps. Unique challenges pertaining to the treatment of hydrocephalus in the developing world include a preponderance of postinfectious hydrocephalus, limited resources, and restricted access to neurosurgical care. In the 21st century, several organizations have established programs that provide hydrocephalus treatment and neurosurgical training in Africa, Central and South America, Haiti, and Southeast Asia. These international efforts have employed various models to achieve the goals of providing safe, sustainable, and cost-effective treatment. CONCLUSIONS Broader commitment from the pediatric neurosurgery community, increased funding, public education, surgeon training, and ongoing surgical innovation will be needed to meaningfully address the global burden of untreated hydrocephalus.

An improved reservoir for the flushing test to diagnose shunt insufficiency.

OBJECTIVE Reservoirs integrated into hydrocephalus shunts are commonly used for the removal of CSF and for intra-ventricular pressure measurement. Pumping with the reservoir to diagnose shunt sufficiency is still a matter of controversy. The authors describe an improved flushing device and its characteristic features in vitro and in vivo. METHODS The flushing reservoir is constructed with a sapphire ball in a cage as a nonresistance valve to also enable the detection of distal occlusions. The most important reservoir parameters were investigated in vitro, simulating total and partial proximal and distal shunt occlusions. Then the expected advantages were assessed in vivo by evaluating the pump test data of 360 implanted reservoirs. The results were compared with those found in the literature. RESULTS The optimization of the technical parameters of the device, such as the high stroke volume in combination with moderate suction force, are obvious advantages compared with other flushing devices. Total occlusion of the ventricular catheter and the valve could be assessed with high certainty. The detection of a total obstruction of the peritoneal catheter or any partial obstruction is also possible, depending on its exact grade and location. CONCLUSIONS Shunt obstructions can be assessed using the pumping test. The reservoir construction presented here provides a clear enhancement of that diagnostic test.

Timing of surgical treatment for idiopathic normal pressure hydrocephalus: association between treatment delay and reduced short-term benefit.

OBJECTIVE A growing body of evidence suggests that longer durations of preoperative symptoms may correlate with worse postoperative outcomes following cerebrospinal fluid (CSF) diversion for treatment of idiopathic normal pressure hydrocephalus (iNPH). The aim of this study is to determine whether the duration of preoperative symptoms alters postoperative outcomes in patients treated for iNPH. METHODS The authors conducted a retrospective review of 393 cases of iNPH involving patients treated with ventriculoperitoneal (VP) shunting. The duration of symptoms prior to the operative intervention was recorded. The following outcome variables were assessed at baseline, 6 months postoperatively, and at last follow-up: gait performance, urinary continence, and cognition. RESULTS The patients' median age at shunt placement was 74 years. Increased symptom duration was significantly associated with worse gait outcomes (relative risk (RR) 1.055 per year of symptoms, p = 0.037), and an overall absence of improvement in any of the classic triad symptomology (RR 1.053 per year of symptoms, p = 0.033) at 6 months postoperatively. Additionally, there were trends toward significance for symptom duration increasing the risk of having no 6-month postoperative improvement in urinary incontinence (RR 1.049 per year of symptoms, p = 0.069) or cognitive symptoms (RR 1.051 per year of symptoms, p = 0.069). However, no statistically significant differences were noted in these outcomes at last follow-up (median 31 months). Age stratification by decade revealed that prolonging symptom duration was significantly associated with lower Mini-Mental Status Examination scores in patients aged 60-70 years, and lack of cognitive improvement in patients aged 70-80 years. CONCLUSIONS Patients with iNPH with longer duration of preoperative symptoms may not receive the same short-term benefits of surgical intervention as patients with shorter duration of preoperative symptoms. However, with longer follow-up, the patients generally reached the same end point. Therefore, when managing patients with iNPH, it may take longer to see the benefits of CSF shunting when patients present with a longer duration of preoperative symptoms.

Endoscopic third ventriculostomy for treatment of adult hydrocephalus: long-term follow-up of 163 patients.

OBJECTIVE The efficacy of endoscopic third ventriculostomy (ETV) for the treatment of pediatric hydrocephalus has been extensively reported in the literature. However, ETV-related long-term outcome data are lacking for the adult hydrocephalus population. The objective of the present study was to assess the role of ETV as a primary or secondary treatment for hydrocephalus in adults. METHODS The authors performed a retrospective chart review of all adult patients (age ≥ 18 years) with symptomatic hydrocephalus treated with ETV in Calgary, Canada, over a span of 20 years (1994-2014). Patients were dichotomized into a primary or secondary ETV cohort based on whether ETV was the initial treatment modality for the hydrocephalus or if other CSF diversion procedures had been previously attempted respectively. Primary outcomes were subjective patient-reported clinical improvement within 12 weeks of surgery and the need for any CSF diversion procedures after the initial ETV during the span of the study. Categorical and actuarial data analysis was done to compare the outcomes of the primary versus secondary ETV cohorts. RESULTS A total of 163 adult patients with symptomatic hydrocephalus treated with ETV were identified and followed over an average of 98.6 months (range 0.1-230.4 months). All patients presented with signs of intracranial hypertension or other neurological symptoms. The primary ETV group consisted of 112 patients, and the secondary ETV consisted of 51 patients who presented with failed ventriculoperitoneal (VP) shunts. After the initial ETV procedure, clinical improvement was reported more frequently by patients in the primary cohort (87%) relative to those in the secondary ETV cohort (65%, p = 0.001). Additionally, patients in the primary ETV group required fewer reoperations (p < 0.001), with cumulative ETV survival time favoring this primary ETV cohort over the course of the follow-up period (p < 0.001). Fifteen patients required repeat ETV, with all but one experiencing successful relief of symptoms. Patients in the secondary ETV cohort also had a higher incidence of complications, with one occurring in 8 patients (16%) compared with 2 in the primary ETV group (2%; p = 0.010), although most complications were minor. CONCLUSIONS ETV is an effective long-term treatment for selected adult patients with hydrocephalus. The overall ETV success rate when it was the primary treatment modality for adult hydrocephalus was approximately 87%, and 99% of patients experience symptomatic improvement after 2 ETVs. Patients in whom VP shunt surgery fails prior to an ETV have a 22% relative risk of ETV failure and an almost eightfold complication rate, although mostly minor, when compared with patients who undergo a primary ETV. Most ETV failures occur within the first 7 months of surgery in patients treated with primary ETV, but the time to failure is more prolonged in patients who present with failed previous shunts.

Revisiting secondary normal pressure hydrocephalus: does it exist? A review.

OBJECTIVE There are several etiologies that can lead to the development of secondary normal pressure hydrocephalus (sNPH). The aim of this study was to evaluate the etiology, diagnosis, treatment, and outcome in patients with sNPH and to highlight important differences between the separate etiologies. METHODS A comprehensive review of the literature was performed to identify studies conducted between 1965 and 2015 that included data regarding the etiology, treatment, diagnosis, and outcome in patients with sNPH. Sixty-four studies with a total of 1309 patients were included. The inclusion criteria of this study were articles that were written in English, included more than 2 patients with the diagnosis of sNPH, and contained data regarding the etiology, diagnosis, treatment, or outcome of NPH. The most common assessment of clinical improvement was based on the Stein and Langfitt grading scale or equivalent improvement on other alternative ordinal grading scales. RESULTS The main etiologies of sNPH were subarachnoid hemorrhage (SAH) in 46.5%, head trauma in 29%, intracranial malignancies in 6.2%, meningoencephalitis in 5%, and cerebrovascular disease in 4.5% of patients. In 71.9% of patients the sNPH was treated with ventriculoperitoneal shunt placement, and 24.4% had placement of a ventriculoatrial shunt. Clinical improvement after shunt placement was reported in 74.4% and excellent clinical improvement in 58% of patients with sNPH. The mean follow-up period after shunt placement was 13 months. Improvement was seen in 84.2% of patients with SAH, 83% of patients with head trauma, 86.4% of patients with brain tumors, 75% of patients with meningoencephalitis, and 64.7% of patients with NPH secondary to stroke. CONCLUSIONS Secondary NPH encompasses a diverse group of clinical manifestations associated with a subset of patients with acquired hydrocephalus. The most common etiologies of sNPH include SAH and traumatic brain injury. Secondary NPH does indeed exist, and should be differentiated from idiopathic NPH based on outcome and on clinical, pathophysiological, and epidemiological characteristics, but should not be considered as a separate entity.

Role of radiological parameters in predicting overall shunt outcome after ventriculoperitoneal shunt insertion in pediatric patients with obstructive hydrocephalus.

OBJECTIVE Despite significant advances in the medical field and shunt technology, shunt malfunction remains a nightmare of pediatric neurosurgeons. In this setting, the ability to preoperatively predict the probability of shunt malfunction is quite compelling. The authors have compared the preoperative radiological findings in obstructive hydrocephalus and the subsequent clinical course of the patient to determine any association with overall shunt outcome. METHODS This retrospective study included all pediatric patients (age < 18 years) who had undergone ventriculoperitoneal shunt insertion for obstructive hydrocephalus. Linear measurements were taken from pre- and postoperative CT or MRI studies to calculate different indices and ratios including Evans' index, frontal horn index (FHI), occipital horn index (OHI), frontooccipital horn ratio (FOHR), and frontooccipital horn index ratio (FOIR). Other morphological features such as bi- or triventriculomegaly, right-left ventricular symmetry, and periventricular lucency (PVL) were also noted. The primary clinical outcomes that were reviewed included the need for shunt revision, time interval to first shunt revision, frequency of shunt revisions, and revision-free survival. RESULTS A total of 121 patients were eligible for the analysis. Nearly half of the patients (47.9%) required shunt revision. The presence of PVL was associated with lower revision rates than those in others (39.4% vs 58.2%, p = 0.03). None of the preoperative radiological indices or ratios showed any correlation with shunt revision. Nearly half of the patients with shunt revision required early revision (< 90 days of primary surgery). The reduction in the FOHR was high in patients who required early shunt revision (20.16% in patients with early shunt revision vs 6.4% in patients with late shunt revision, p = 0.009). Nearly half of the patients (48.3%) requiring shunt revision ultimately needed more than one revision procedure. Greater occipital horn dilation on preoperative images was associated with a lower frequency of shunt revision, as dictated by a high OHI and a low FOIR in patients with a single shunt revision as compared with those in patients who required multiple shunt revisions (p = 0.029 and 0.009, respectively). The mean follow-up was 49.9 months. Age was a significant factor affecting shunt revision-free survival. Patients younger than 6 months of age had significantly less revision-free survival than the patients older than 6 months (median survival of 10.1 vs 94.1 months, p = 0.004). CONCLUSIONS Preoperative radiological linear indices and ratios do not predict the likelihood of subsequent shunt malfunction. However, patients who required early shunt revision tended to have greater reductions in ventricular volumes on postoperative images. Therefore a greater reduction in ventricular volume is not actually desirable, and a ventricular volume high enough to reduce intracranial pressure is instead to be aimed at for long-term shunt compliance.

Low-dose acetylsalicylic acid and bleeding risks with ventriculoperitoneal shunt placement.

OBJECTIVE Ventriculoperitoneal (VP) shunt placement is a common procedure for the treatment of hydrocephalus following diverse neurosurgical conditions. Most of the patients present with other comorbidities and receive antiplatelet therapy, usually acetylsalicylic acid (ASA). Despite its clinical relevance, the perioperative management of these patients has not been sufficiently investigated. The aim of this study was to compare the peri- and postoperative bleeding complication rates associated with ASA intake in patients undergoing VP shunt placement. METHODS Of 172 consecutive patients undergoing VP shunt placement between June 2009 and December 2015, 40 (23.3%) patients were receiving low-dose ASA treatment. The primary outcome measure was bleeding events in ASA users versus nonusers, whereas secondary outcome measures were postoperative cardiovascular events, hematological findings, morbidity, and mortality. A subgroup analysis was conducted in patients who discontinued ASA treatment for < 7 days (n = 4, ASA Group 1) and for ≥ 7 days (n = 36, ASA Group 2). RESULTS No statistically significant difference for bleeding events was observed between ASA users and nonusers (p = 0.30). Cardiovascular complications, surgical morbidity, and mortality did not differ significantly between the groups either. Moreover, there was no association between ASA discontinuation regimens (< 7 days and ≥ 7 days) and hemorrhagic events. CONCLUSIONS Given the lack of guidelines regarding perioperative management of neurosurgical patients with antiplatelet therapy, these findings elucidate one issue, showing comparable bleeding rates in ASA users and nonusers undergoing VP shunt placement.

A quantitative analysis of craniopharyngioma cyst expansion during and after radiation therapy and surgical implications.

OBJECTIVE When complete resection of craniopharyngioma is not achievable or the sequelae are prohibitive, limited surgery and radiation therapy have demonstrated excellent local disease control while minimizing treatment-related sequelae. When residual tissue exists, there is a propensity for further cyst development and expansion during and after radiation therapy. This can result in obstructive hydrocephalus, visual changes, and/or clinical decline. The authors present a quantitative analysis of cyst expansion during and after radiotherapy and examine how it affected subsequent management. METHODS The authors performed an institutional review board-approved retrospective study of patients with histologically confirmed craniopharyngioma treated between 2000 and 2015 with surgery and intensity-modulated radiation therapy (IMRT) at a single institution. Volumetric measurements of cyst contours were generated by radiation oncology treatment planning software postoperatively, during IMRT, and up to 12 months after IMRT. Patient, tumor, and treatment-related variables were collected until the last known follow-up and were analyzed. RESULTS Twenty-seven patients underwent surgery and IMRT. The median total radiation dose was 54 Gy. Of the 27 patients, 11 patients (40.7%) demonstrated cyst expansions within 1 year of IMRT. Of note, all tumors with cyst expansion were radiographically Puget Grade 2. Maximal cyst expansion peaked at 4.27 months following radiation therapy, with a median volume growth of 4.1 cm3 (mean 9.61 cm3) above the postoperative cyst volume. Eight patients experienced spontaneous cyst regression without therapeutic intervention. Three patients experienced MRI-confirmed cyst enlargement during IMRT, all of whom required adaptive planning to ensure adequate coverage of the entire tumor volume. Two of these 3 patients required ventriculoperitoneal shunt placement and additional intervention. One underwent additional resection, and the other had placement of an intracystic catheter for aspiration and delivery of intracystic interferon within 12 months of completing IMRT. All 3 patients now have stable disease. CONCLUSIONS Craniopharyngioma cyst expansion occurred in approximately 40% of the patients during or after radiotherapy. In the majority of patients, cyst expansion was a self-limiting process and did not confer a worse outcome. During radiotherapy, cyst expansion may be apparent on image-guided radiation therapy. Adaptive IMRT planning may be required to ensure that the intended IMRT dose covers the entire tumor and cyst volume. The sequelae of cyst expansion include progressive hydrocephalus, which may be treated with a shunt. For patients with solitary cyst expansion, cyst aspiration and/or intracystic interferon may result in disease control.