Axial Magnetic Resonance Angiography in Evaluating Revascularization after Indirect Bypass Surgery for Moyamoya Axial Magnetic Resonance Angiography after Indirect Bypass.

INTRODUCTION: At our institution, revascularization after indirect moyamoya surgery is routinely evaluated using magnetic resonance angiography (MRA) rather than catheter angiography. In this paper, we review how revascularization can be visualized on axial MRA and compare its visualization on MRA to that on catheter angiography. We also compare clinical outcomes of patients followed with routine postoperative MRA with outcomes of patients followed with routine catheter angiography. METHODS: We retrospectively reviewed the records of all patients treated at our institution who underwent unilateral encephaloduroarteriosynangiosis (EDAS) and/or pial synangiosis between the ages of 1 and 21 years and between December 31, 2003, and May 1, 2021. We included patients who underwent EDAS/pial synangiosis at other hospitals as long as they met all inclusion criteria. Inclusion criteria included having a preoperative MRA within 18 months of surgery and a postoperative MRA 3-30 months after surgery. Clinical outcomes included development of postoperative stroke and transient ischemic attacks (TIAs) and changes in symptoms (improved, unchanged, or worsened), including seizures, balance issues, and headaches. Clinical outcomes were compared between patients who had routine postoperative MRA only versus those who had routine postoperative angiograms, with or without routine MRA. For each surgery, we determined the ratios of the diameters and areas of the donor vessel and the contralateral corresponding vessel, as well as the relative signal intensities of these two vessels, on preoperative and 3- to 30-month postoperative MRA. We did the same for the middle meningeal artery (MMA) ipsilateral to the donor artery and the contralateral MMA. We assessed changes from pre- to post-operation in diameter ratios, area ratios, relative signal intensity, ivy sign, and in brain perfusion on arterial spin labeled (ASL) imaging. MRI and MRA measures of revascularization and flow were compared to Matsushima grades in patients who had postoperative catheter angiograms. RESULTS: Fifty-one operations for 42 unique patients were included. There were no significant differences in the rates of postoperative strokes, postoperative TIAs, changes in symptoms, or new symptoms after surgeries evaluated by routine postoperative MRA versus catheter angiogram (p = 0.282, 1, 0.664, and 0.727, respectively). There were significant associations between greater collateralization on postoperative MRA and greater median increases in preoperative-to-postoperative ratios of donor-vessel-over-contralateral-vessel diameter (p = 0.0461), ipsilateral-MMA-over-contralateral-MMA diameter (p = 0.0135), and the summed donor and ipsilateral MMA diameters over the summed contralateral vessel diameters (p < 0.001). The median increase in the ratio of the donor vessel and contralateral corresponding vessel diameters was significantly higher for Matsushima grade A versus B (p = 0.036). The median increase in the ratio of the sum of donor and ipsilateral MMA diameters over the sum of the contralateral vessel diameters was significantly higher for improved-versus-unchanged perfusion on ASL imaging (p = 0.0074). There was a nonsignificant association between greater postoperative collateralization on MRA and Matsushima grade (p = 0.1160). CONCLUSION: Cerebral revascularization after EDAS and pial synangiosis can be evaluated on axial MRA by comparing the diameter and/or signal intensity of the donor vessel and corresponding contralateral vessel, as well as the ipsilateral and contralateral MMA, on postoperative-versus-preoperative MRA. The use of routine postoperative MRA rather than catheter angiography does not appear to negatively affect outcomes.

Magnetic resonance imaging-guided stereotactic laser ablation therapy for the treatment of pediatric epilepsy: a retrospective multiinstitutional study.

OBJECTIVE: The authors of this study evaluated the safety and efficacy of stereotactic laser ablation (SLA) for the treatment of drug-resistant epilepsy (DRE) in children. METHODS: Seventeen North American centers were enrolled in the study. Data for pediatric patients with DRE who had been treated with SLA between 2008 and 2018 were retrospectively reviewed. RESULTS: A total of 225 patients, mean age 12.8 ± 5.8 years, were identified. Target-of-interest (TOI) locations included extratemporal (44.4%), temporal neocortical (8.4%), mesiotemporal (23.1%), hypothalamic (14.2%), and callosal (9.8%). Visualase and NeuroBlate SLA systems were used in 199 and 26 cases, respectively. Procedure goals included ablation (149 cases), disconnection (63), or both (13). The mean follow-up was 27 ± 20.4 months. Improvement in targeted seizure type (TST) was seen in 179 (84.0%) patients. Engel classification was reported for 167 (74.2%) patients; excluding the palliative cases, 74 (49.7%), 35 (23.5%), 10 (6.7%), and 30 (20.1%) patients had Engel class I, II, III, and IV outcomes, respectively. For patients with a follow-up ≥ 12 months, 25 (51.0%), 18 (36.7%), 3 (6.1%), and 3 (6.1%) had Engel class I, II, III, and IV outcomes, respectively. Patients with a history of pre-SLA surgery related to the TOI, a pathology of malformation of cortical development, and 2+ trajectories per TOI were more likely to experience no improvement in seizure frequency and/or to have an unfavorable outcome. A greater number of smaller thermal lesions was associated with greater improvement in TST. Thirty (13.3%) patients experienced 51 short-term complications including malpositioned catheter (3 cases), intracranial hemorrhage (2), transient neurological deficit (19), permanent neurological deficit (3), symptomatic perilesional edema (6), hydrocephalus (1), CSF leakage (1), wound infection (2), unplanned ICU stay (5), and unplanned 30-day readmission (9). The relative incidence of complications was higher in the hypothalamic target location. Target volume, number of laser trajectories, number or size of thermal lesions, or use of perioperative steroids did not have a significant effect on short-term complications. CONCLUSIONS: SLA appears to be an effective and well-tolerated treatment option for children with DRE. Large-volume prospective studies are needed to better understand the indications for treatment and demonstrate the long-term efficacy of SLA in this population.

Fusion of Lateral Calvarial Sutures on Volume-Rendered Computed Tomography Reconstructions in Patients With Known Craniosynostosis.

INTRODUCTION: After treating a child with familial sagittal craniosynostosis, clinocephaly, and bilateral parietomastoid/posterior squamosal suture fusion, the authors wondered if major-suture synostosis and clinocephaly were associated with abnormal fusion of minor lateral calvarial sutures. METHODS: The authors reviewed all preoperative volume-rendered head computed tomography reconstructions performed for craniosynostosis at their institution from 2010 through 2014 and determined whether the sphenoparietal, squamosal, and parietomastoid sutures were open, partially fused, or fused. The authors determined whether any sutures were abnormally fused based upon a previous study from their center, in which abnormal fusion was defined as either 1 of 3 abnormal fusion patterns or abnormally-early fusion. The authors then determined the rate of abnormal fusion of these sutures and whether abnormal fusion was associated with (1) major-suture craniosynostosis, (2) type of craniosynostosis (sutures involved; single-suture versus multisuture; syndromic versus nonsyndromic), and (3) clinocephaly. RESULTS: In 97 included children, minor lateral sutures were abnormally fused in 8, or 8.2%, which was significantly higher than in children without craniosynostosis from our earlier study. Abnormal minor lateral suture fusion was not associated with the type of single-suture synostosis or with multisuture synostosis but was associated with syndromic synostosis. Four of 8 children with abnormal minor lateral suture fusion had multisuture synostosis and 6 had syndromic synostosis. Lateral sutures were abnormally fused in 1 of 4 subjects with clinocephaly, which was not significant. CONCLUSION: Abnormal minor lateral calvarial suture fusion is significantly associated with major-suture craniosynostosis, especially syndromic synostosis.

Use of the Posterior Auricular Artery for Indirect Bypass in Moyamoya: A Pediatric Case Series.

INTRODUCTION: Encephaloduroarteriosynangiosis (EDAS) for moyamoya is predominantly performed using a branch of the superficial temporal artery (STA) as the donor artery. At times, other branches of the external carotid artery are better suited for EDAS than is the STA. There is little information in the literature concerning using the posterior auricular artery (PAA) for EDAS in the pediatric age-group. In this case series, we review our experience using the PAA for EDAS in children and adolescents. CASE PRESENTATIONS: We describe the presentations, imaging, and outcomes of 3 patients in whom the PAA was used for EDAS, as well our surgical technique. There were no complications. All 3 patients were confirmed to have radiologic revascularization from their surgeries. All patients also had improvement of their preoperative symptoms, and no patient has had a stroke postoperatively. CONCLUSION: The PAA is a viable option for use as a donor artery in EDAS for the treatment of moyamoya in children and adolescents.

Pediatric pineal region masses: a single-center experience over 25 years.

PURPOSE: Pineal region tumors (PRT) represent less than 1% of brain neoplasms. The rare and heterogeneous nature of these tumors is reflected in the variety of treatment modalities employed. METHODS: A single-center retrospective review of all pediatric patients with pineal region tumors between November 1996 and June 2021 was performed. Fifty-six cases of pineal tumors were reviewed for age and symptoms upon presentation, diagnostic methods, imaging characteristics, histological classification, treatment modalities, recurrence, and mortality rates. RESULTS: The average age at diagnosis was 11.3 years. The majority of patients were male (82.1%) and Caucasian (73.2%). The most common presenting symptoms were headache (n = 38, 67.9%) and visual problems (n = 34, 60.7%). Hydrocephalus was present in 49 patients (87.5%). Germinoma (n = 20, 35.7%) and non-germinomatous germ cell tumor (NGGCT) (n = 17, 30.4%) were the most common tumors. Chemotherapy was employed for 54 patients (96.4%), radiation for 49 (87.5%), and surgical resection for 14 (25.0%). The average duration of treatment was 5.9 months. Progression-free survival was 74.4% at 5 years and 72.0% at 10 years. Overall survival was 85.7% at 5 years and 77.1% at 10 years. CONCLUSION: Treatment of pineal region tumors must be targeted to each patient based on presentation, subtype, presence of hydrocephalus, and extent of disease. Upfront surgical resection is usually not indicated. As advances in oncological care proceed, treatment modalities may continue to improve in efficacy.

Postoperative general medical ward admission following Chiari malformation decompression.

OBJECTIVE: Prior to 2019, the majority of patients at Children's Hospital Colorado were admitted to the pediatric intensive care unit (PICU) following Chiari malformation (CM) decompression surgery. This study sought to identify the safety and efficacy of postoperative general ward management for these patients. METHODS: After a retrospective baseline assessment of 150 patients, a quality improvement (QI) initiative was implemented, admitting medically noncomplex patients to the general ward postoperatively following CM decompression. Twenty-one medically noncomplex patients were treated during the QI intervention period. All patients were assessed for length of stay, narcotic use, time to ambulation, and postoperative complications. RESULTS: PICU admission rates postoperatively decreased from 92.6% to 9.5% after implementation of the QI initiative. The average hospital length of stay decreased from 3.4 to 2.6 days, total doses of narcotic administration decreased from 12.3 to 8.7, and time to ambulation decreased from 1.8 to 0.9 days. There were no major postoperative complications identified that were unsuitable for management on a conventional pediatric medical/surgical nursing unit. CONCLUSIONS: Medically noncomplex patients were safely admitted to the general ward postoperatively at Children's Hospital Colorado after decompression of CM. This approach afforded decreased length of stay, decreased narcotic use, and decreased time to ambulation, with no major postoperative complications.

Spinal cord tethering after selective dorsal rhizotomy below the conus medullaris.

BACKGROUND: Two techniques for selective dorsal rhizotomy (SDR) involve stimulating and sectioning nerve rootlets either below the conus medullaris or above the entrances to their respective dural root sleeves. In general, both techniques lead to sustained improvements in lower extremity spasticity with low complication rates. To our knowledge, spinal cord tethering has not been previously reported as a complication of SDR using either technique. METHODS: We review the presentation, treatment, and outcome of two patients who developed symptomatic spinal cord tethering after SDR below the conus. RESULTS: A 4-year-old male and a 6-year-old female each with a history of spastic diparetic cerebral palsy underwent L1-L2 osteoplastic laminectomy and SDR below the conus. Both surgeries went well with no known complications. Both patients initially did well, with marked improvement in their tone and gait. There were no significant immediate postoperative bowel or bladder problems. The male patient presented 10 months after surgery with new-onset urinary incontinence. A urological evaluation was performed but no imaging was performed. He re-presented 8 months later with worsened urinary incontinence, new fecal incontinence, and worsened gait. An MRI showed signs of tethering, including a holocord syrinx. He underwent two untethering surgeries as well syrinx fenestration, and although his gait improved, it remained worse than it had been several months after surgery. The incontinence did not improve. The second patient also developed urinary incontinence a year after SDR. Due to our experience with the first patient, we obtained an MRI immediately and found evidence of tethering. She underwent untethering and her incontinence improved. CONCLUSION: We report two cases of spinal cord tethering after SDR below the conus, a previously unreported complication. It is important to realize that this complication can occur after SDR.

International survey on the management of lumbosacral cutaneous stigmata in infants with suspected occult spinal dysraphism.

OBJECTIVE: Occult spinal dysraphism (OSD) is a common pediatric neurosurgical diagnosis rife with controversy surrounding both the screening of asymptomatic infants and the threshold to offer a prophylactic detethering operation. The authors sought to clarify international practice patterns with a survey of pediatric neurosurgeons. METHODS: A survey asked pediatric neurosurgeons whether they would perform imaging in patients with a variety of cutaneous stigmata associated with OSD and whether they would offer prophylactic detethering surgery for asymptomatic patients with a variety of imaging findings on the OSD spectrum. RESULTS: Completed surveys were received from 141 pediatric neurosurgeons. Broad consensus was demonstrated on the need for obtaining images in sample patients with more severe stigmata ranging from large lipoma with a skin appendage to focal dysplastic skin in the lumbar midline. Ninety percent of respondents would perform MRI for these patients. In contrast, for patients with a low-sacral dimple, flat hemangioma, and symmetric (Y-shaped) splaying of the intergluteal cleft, opinion on the need for imaging varied considerably (between 57% and 89% recommended imaging). Respondents differed on the type of imaging that they would perform, with 31% to 38% recommending ultrasound screening. The responses reflected less consensus on when to offer surgery to patients with simple spinal tethering (low-lying conus medullaris and fatty filum terminale). Both a lower level of the conus and increased thickness of the filum terminale affected decision-making. CONCLUSIONS: The results of this survey showed significant consensus on the recommendation for screening imaging in patients with more dramatic cutaneous stigmata, although these stigmata are the rarest. A significant variance in opinions was reflected in the recommendation for imaging of the most common cutaneous stigmata. Consensus was also lacking on which lesions deserve prophylactic detethering surgery. Significant equipoise exists for future study of screening imaging and of surgical decision-making in patients with asymptomatic OSD and associated cutaneous stigmata.

Vascularized Pericranial Flap as a Method to Prevent Persistent Skull Defects After Craniectomy for Sagittal Synostosis.

ABSTRACT: Some cranial defects resulting from sagittal craniectomy for craniosynostosis never completely close and require cranioplasty. This study evaluates the results of 2 methods to minimize such defects: (1) trapezoidal craniectomy that is narrower posteriorly (2) vascularized pericranial flap that is sewn to the dura under a rectangular craniectomy.Children who underwent primary open sagittal craniectomy with biparietal morcellation (with/without frontal cranioplasty) for single-suture nonsyndromic sagittal synostosis from 2013 through 2018 were included. Children were excluded if there was a dural tear, if they had no 1-year follow-up, or if they had unmeasured and/or uncounted skull defects. Surgeries were divided into (1) standard craniectomy, (2) trapezoidal craniectomy, or (3) craniectomy with pericranial flap. Differences in percentage of children with defects and mean total defect area 1 year postsurgery were compared between the 3 groups.We reviewed 148 cases. After exclusions, 34 of 53 children (64%) who underwent standard craniectomy, 6 of 17 children (35%) who had pericranial flaps, and 5 of 11 children (46%) who underwent trapezoidal craniectomy had defects 1 year postsurgery. The percentage of children with defects (P = 0.0364) but not the defect area was significantly higher in the standard craniectomy than in the pericranial flap group. The percentage of subjects with defects was not significantly different between the standard and the trapezoidal craniectomy groups.Sewing a vascularized pericranial flap to the dura at the craniectomy site may protect against persistent bony defects after sagittal craniectomy for craniosynostosis. Longer follow-up is needed to determine if this technique leads to lower rates of cranioplasty.

Placement of leads for stereotactic electroencephalography without the use of anchor bolts: technical note.

OBJECTIVE: Stereotactic electroencephalography (SEEG) is an increasingly common technique that neurosurgeons use to help identify the epileptogenic zone. The anchor bolt, which typically secures the electrode to the skull, can be problematic in very thin bone or in electrodes placed in the occiput. METHODS: A technique is described to place electrodes without the use of an anchor bolt. Accuracy data for entry point, target point, and depth were collected and compared between electrodes placed with and those placed without an anchor bolt. RESULTS: A total of 58 patients underwent placement of 793 electrodes, of which 25 were boltless. The mean entry and depth errors at target were equivalent, although there was a trend toward greater depth error with boltless electrodes (3.4 mm vs 2.01 mm and 2.59 mm in the bolted groups, respectively). The mean lateral target error was slightly but significantly smaller for boltless electrodes. The majority (60%) of boltless leads were placed into thin temporal squamous bone. The average skull thickness at the entry point for all boltless leads was 1.85 mm. CONCLUSIONS: Boltless SEEG electrodes can be placed through thin bone, adjacent to a cranial defect, or in the occiput with equivalent accuracy to electrodes placed with anchor bolts.

Magnetic resonance-guided stereotactic laser ablation therapy for the treatment of pediatric brain tumors: a multiinstitutional retrospective study.

OBJECTIVE: This study aimed to assess the safety and efficacy of MR-guided stereotactic laser ablation (SLA) therapy in the treatment of pediatric brain tumors. METHODS: Data from 17 North American centers were retrospectively reviewed. Clinical, technical, and radiographic data for pediatric patients treated with SLA for a diagnosis of brain tumor from 2008 to 2016 were collected and analyzed. RESULTS: A total of 86 patients (mean age 12.2 ± 4.5 years) with 76 low-grade (I or II) and 10 high-grade (III or IV) tumors were included. Tumor location included lobar (38.4%), deep (45.3%), and cerebellar (16.3%) compartments. The mean follow-up time was 24 months (median 18 months, range 3-72 months). At the last follow-up, the volume of SLA-treated tumors had decreased in 80.6% of patients with follow-up data. Patients with high-grade tumors were more likely to have an unchanged or larger tumor size after SLA treatment than those with low-grade tumors (OR 7.49, p = 0.0364). Subsequent surgery and adjuvant treatment were not required after SLA treatment in 90.4% and 86.7% of patients, respectively. Patients with high-grade tumors were more likely to receive subsequent surgery (OR 2.25, p = 0.4957) and adjuvant treatment (OR 3.77, p = 0.1711) after SLA therapy, without reaching significance. A total of 29 acute complications in 23 patients were reported and included malpositioned catheters (n = 3), intracranial hemorrhages (n = 2), transient neurological deficits (n = 11), permanent neurological deficits (n = 5), symptomatic perilesional edema (n = 2), hydrocephalus (n = 4), and death (n = 2). On long-term follow-up, 3 patients were reported to have worsened neuropsychological test results. Pre-SLA tumor volume, tumor location, number of laser trajectories, and number of lesions created did not result in a significantly increased risk of complications; however, the odds of complications increased by 14% (OR 1.14, p = 0.0159) with every 1-cm3 increase in the volume of the lesion created. CONCLUSIONS: SLA is an effective, minimally invasive treatment option for pediatric brain tumors, although it is not without risks. Limiting the volume of the generated thermal lesion may help decrease the incidence of complications.

Fusion patterns of major calvarial sutures on volume-rendered CT reconstructions.

OBJECTIVE: Recently, the authors investigated the normal course of fusion of minor lateral calvarial sutures on "3D" volume-rendered head CT reconstructions in pediatric trauma patients. While evaluating these reconstructions, they found many more fused sagittal sutures than expected given the currently accepted prevalence of sagittal craniosynostosis. In the present study, using the same set of head CT reconstructions, they investigated the course of fusion of the sagittal as well as the lambdoid, coronal, and metopic sutures. METHODS: They reviewed all volume-rendered head CT reconstructions performed in the period from 2010 through mid-2012 at Children's Hospital Colorado for trauma patients aged 0-21 years. Each sagittal, lambdoid, coronal, or metopic suture was graded as open, partially fused, or fused. The cephalic index (CI) was calculated for subjects with fused and partially fused sagittal sutures. RESULTS: After exclusions, 331 scans were reviewed. Twenty-one subjects (6%) had fusion or partial fusion of the sagittal suture. Four of the 21 also had fusion of the medial lambdoid and/or coronal sutures. In the 17 subjects (5%) with sagittal suture fusion and no medial fusion of adjacent sutures, the mean CI was 77.6. None of the 21 subjects had been previously diagnosed with craniosynostosis. Other than in the 21 subjects already mentioned, no other sagittal or lambdoid sutures were fused at all. Nor were other coronal sutures fused medially. Coronal sutures were commonly fused inferiorly early during the 2nd decade of life, and fusion progressed superiorly and medially as subjects became older; none were completely fused by 18 years of age. Fusion of the metopic suture was first seen at 3 months of life; fusion was often not complete until after 2 years. CONCLUSIONS: The sagittal and lambdoid sutures do not usually begin to fuse before 18 years of age. However, more sagittal sutures are fused before age 18 than expected given the currently accepted prevalence of craniosynostosis. This finding is of unknown significance, but likely many of them do not need surgery. The coronal suture often begins to fuse inferiorly early in the 2nd decade of life but does not usually complete fusion before 18 years of age. The metopic suture often starts to fuse by 3 months of age, but it may not completely fuse until after 2 years of age.

The utility of magnetic resonance imaging in pediatric trauma patients suspected of having cervical spine injuries.

BACKGROUND: Pediatric cervical spine injuries (CSI) are rare but potentially devastating sequelae of blunt trauma. Existing protocols to evaluate children at risk for CSI frequently incorporate computed topography (CT) and magnetic resonance imaging (MRI); however, the clinical value of performing both remains unclear. METHODS: Single-center retrospective review of pediatric trauma patients who underwent both CT and MRI of the cervical spine between 2001 and 2015. Based on radiographic findings, CT and MRI results were grouped into one of three categories: no injury, stable injury, or unstable injury. Radiographic instability was defined by disruption of two or more contiguous spinal columns while radiographic stability was defined by any other acute cervical spine abnormality on imaging. Clinical instability was defined by the need for surgical intervention (halo or spinal fusion), with the remaining patients, including children discharged in a cervical collar, considered clinically stable. RESULTS: In total, 221 children met inclusion criteria, with a median age of 9 (interquartile range, 3-14). The Glasgow Coma Scale (GCS) score of the cohort was 9 (interquartile range, 4-15). Thirty-three (14.9%) children had clinically unstable injuries, requiring surgical intervention. Among the 160 (72.4%) children with no injury on CT, MRI identified no injury in 84 (52.5%) cases, a stable injury in 76 (47.5%) cases, and an unstable injury in none. Among the 21 children with stable injuries on CT, MRI findings were concordant in 17 (81.0%) cases. In four (19.0%) cases, a spinal column injury was identified on CT and appeared to be stable, but later deemed unstable on MRI. Forty (18.1%) patients had an unstable injury on CT with 100% MRI concordance. CONCLUSION: In pediatric trauma patients suspected of having a CSI, a normal cervical spine CT is sufficient to rule out a clinically significant CSI as no child with a normal cervical CT was found to be radiographically or clinically unstable. LEVEL OF EVIDENCE: Diagnostic Test, level III.

Outcome of hospital discharge on postoperative Day 1 following uncomplicated tethered spinal cord release.

OBJECTIVE Postoperative management following the release of simple spinal cord-tethering lesions is highly variable. As a quality improvement initiative, the authors aimed to determine whether an institutional protocol of discharging patients on postoperative day (POD) 1 was associated with a higher rate of postoperative CSF leaks than the prior protocol of discharge on POD 2. METHODS This was a single-center retrospective review of all children who underwent release of a spinal cord-tethering lesion that was not associated with a substantial fascial or dural defect (i.e., simple spinal cord detethering) during 2 epochs: prior to and following the institution of a protocol for discharge on POD 1. Outcomes included the need for and timing of nonroutine care of the surgical site, including return to the operating room, wound suturing, and nonsurgical evaluation and management. RESULTS Of 169 patients identified, none presented with CSF-related complications prior to discharge. In the preintervention group (n = 113), the postoperative CSF leak rate was 4.4% (5/113). The mean length of stay was 2.3 days. In the postintervention group, the postoperative CSF leak rate was 1.9% (1/53) in the patients with postdischarge follow-up. The mean length of stay in that group was 1.3 days. CONCLUSIONS At a single academic children's hospital, a protocol of discharging patients on POD 1 following uncomplicated release of a simple spinal cord-tethering lesion was not associated with an increased rate of postoperative CSF leaks, relative to the previous protocol. The rates identified are consistent with the existing literature. The authors' practice has changed to discharge on POD 1 in most cases.