Month: October 2018

Posted on

Advances in intraoperative brain mapping

Neurosurg Focus 45 (Suppl2):Intro, 2018

In the last decade, there has been significant interest among neurosurgeons in intraoperative brain mapping in cases of lesions in eloquent cortex and subcortical regions. This has occurred because foundational studies have provided strong evidence for the value of maximal safe resection of glioma.

Further evidence of the important role of cortical and subcortical stimulation mapping in achieving a safe, maximal resection has come forth.

Clinicians are also becoming aware of the limitations of preoperative imaging studies for definitive intraoperative decision-making.
Preoperative mapping techniques are commonly used, but the extent to which they are relied upon is quite variable.

In some centers, preoperative imaging techniques are used to guide the decision to choose cortical stimulation mapping, in other centers, it directs where the mapping may start, and in others, it is used in case the intraoperative mapping is ambiguous. It should be noted that there is significant variability in techniques in obtaining and processing this functional imaging data. Surgeons should become familiar both with this variability in general and with the protocols at their own center before relying on functional imaging for crucial decision-making.

In this issue of Neurosurgical Focus, we are pleased to show some of the recent advances and new applications of intraoperative brain mapping.
A variety of techniques and protocols are discussed in this issue. A variety of pathologies, including glioma, metastatic tumor, vascular lesions, and epileptic foci, are addressed through transcortical, trans-sylvian, transventricular, and intrahemispheric routes. The common theme in each of these cases is to apply cortical and subcortical stimulation in at-risk areas in order to minimize risk and maximize resection.

Readers should take note of stimulation parameters in each video and understand that there is practice variability that has evolved in each center. Whether a center is using monopolar or bipolar stimulation (or both), electrocorticography or not, common themes include careful observation and recording of stimulation response after escalation of intensity in a well-organized operative plan. Resection of the lesion is then performed, with the patient awake, or monitored, until the lesion is out or until the early onset of a new deficit. This careful monitoring is essential for safety and avoiding anything more than a temporary deficit.

Important tips for comfortable and safe awake surgical techniques are also a common theme in the video cases in this issue.
Finally, emerging technologies and older technologies, such as transcranial magnetic stimulation and subdural grid mapping, are discussed, along with advantages and disadvantages.
This month’s issue shows an excellent cross-section of the variety of contemporary applications of cortical stimulation mapping. We would like to thank the authors for their outstanding contributions to the field.

Posted on

Glaucoma in patients with shunt-treated normal pressure hydrocephalus

J Neurosurg 129:1078–1084, 2018

Changes in the pressure gradient between intraocular and intracranial compartments at the lamina cribrosa level are a possible explanation of normal tension glaucoma (NTG). Shunt-treated normal pressure hydrocephalus (NPH) is a model for testing whether the increase (time from disease onset to CSF shunt placement, i.e., “protection period”) and decrease (time from shunt placement to observation, i.e., “exposure period”) in intracranial pressure (ICP) are glaucoma protective or risk factors, respectively. The authors estimated the prevalence of NTG in patients with shunt-treated NPH and calculated the extent of optic nerve exposure to changes in the trans–lamina cribosa gradient.

METHODS Data obtained in patients with NPH who had undergone ventriculoperitoneal (VP) shunt placement were analyzed. Patients with more than 6 months’ follow-up, no pathologies associated with ICP changes or CSF dynamics disturbances, and no surgical or valve-related complications were scheduled for ophthalmic evaluation.

RESULTS Nine of 22 patients had NTG, which is about a 40-fold increase in rate compared with the rate in the general elderly population without hydrocephalus (p < 0.001). The median protection period was 12.0 months in patients with NTG and 18.0 months in those without NTG (p = 0.033). The median ICP decrease multiplied by duration of exposure in months was 76.0 mm Hg × months in the NTG group and 24.1 mm Hg × months in the no-NTG group (p = 0.048). The patients’ median adjusted age (adjusted for “protection” and “exposure” times) was 85.1 years in the NTG group and 78.8 years in the no-NTG group (p = 0.001).

CONCLUSIONS A crucial risk factor for development of NTG in patients with shunt-treated NPH is the duration of optic nerve exposure to the lowering of ICP. Patients with NPH who are candidates for CSF shunting should be informed of the risk of incurring glaucoma. Longitudinal studies could provide estimates of tolerated times for a given ICP decrease.

Posted on

Simple presurgical method of predicting C5 palsy after cervical laminoplasty using C5 nerve root ultrasonography

J Neurosurg Spine 29:365–370, 2018

The incidence of C5 palsy after cervical laminoplasty is approximately 5%. Because C5 palsy is related to cervical foraminal stenosis at the C4–5 level, the authors hypothesized that cervical foraminal stenosis can be diagnosed by examining the C5 nerve root (NR) using ultrasonography. The purpose of this study was to investigate whether postoperative C5 palsy could be predicted using ultrasonography.
METHODS This study used a prospective diagnosis design. In total, 140 patients undergoing cervical laminoplasty were examined with ultrasound. The cross-sectional area (CSA) of the C5 NR was measured on both sides before surgery, and the incidence of postoperative C5 palsy was examined. The difference between the CSA of the patients with and without C5 palsy and the lateral differences in the C5 palsy group were determined.
RESULTS The incidence of C5 palsy was 5% (7 cases). Symptoms manifested at a median of 5 days after surgery (range 1–29 days). The CSA of the C5 NR on the affected side was significantly enlarged in the C5 palsy group compared with that in the no–C5 palsy group (p = 0.001). In addition, in the patients who had C5 palsy, the CSA of the C5 NR was significantly enlarged on the affected side compared with that on the unaffected side (p = 0.02). Receiver operating characteristic analysis indicated that the best threshold value for the CSA of the C5 NR was 10.4 mm2 , which provided 91% sensitivity and 71% specificity.
CONCLUSIONS C5 palsy may be predicted preoperatively using ultrasound. The authors recommend the ultrasonographic measurement of the CSA of the C5 NR prior to cervical laminoplasty.

Posted on

Pulsatile versus non-pulsatile tinnitus in idiopathic intracranial hypertension

Acta Neurochirurgica (2018) 160:2025–2029

Tinnitus is a symptom commonly associated with idiopathic intracranial hypertension (IIH) that can have a profound effect on quality of life. We aim to determine tinnitus symptom response after dural venous sinus stenting (DVSS) or CSF diversion with a shunt, in patients with both pulsatile (PT) and non-pulsatile tinnitus (NPT).

Methods: Single-centre cohort of IIH patients (2006–2016) who underwent 24-h ICP monitoring (ICPM). An un-paired t test compared ICP and pulse amplitude (PA) values in IIH patients with PT vs. NPT.

Results: We identified 59 patients with IIH (56 F:3 M), mean age 32.5 ± 9.49 years, 14 of whom suffered from tinnitus. Of these 14, seven reported PT and seven reported NPT. Patients with tinnitus had a mean 24-h ICP and PA of 9.09 ± 5.25 mmHg and 6.05 ± 1.07 mmHg respectively. All 7 patients with PT showed symptom improvement or resolution after DVSS (n = 4), secondary DVSS (n=2) or shunting (n = 1). In contrast, of the 7 with NPT, only 1 improved post intervention (DVSS), despite 2 patients having shunts and 5 having DVSS.

Conclusions: NPT and PT were equally as common in our group of IIH patients. DVSS appears to be an effective management option for IIH patients with a clear history of pulsatile tinnitus. However, non-pulsatile tinnitus was more persistent and did not respond well to either DVSS or CSF diversion.

Posted on

Minimally Invasive Trigeminal Ablation: Novel Transoral Technique for Targeted Treatment of V3

World Neurosurg. (2018) 118:193-196

Trigeminal neuralgia (TN) is a chronic orofacial pain syndrome that presents with debilitating shooting pains in the V3 nerve distribution. The condition is traditionally responsive to anticonvulsant therapy; however, cases that become refractory to medications often require surgical intervention.

CASE DESCRIPTION: We present a case of TN that was treated with minimally invasive trigeminal ablation. The patient presented with a 6-year history of TN that had been resistant to medical management. The patient opted for minimally invasive management, refused stereotactic radiosurgery, and was treated using the minimally invasive trigeminal ablation approach. At 16 weeks postoperatively, the patient reported complete alleviation of pain with minimal sensorineural numbness.

CONCLUSIONS: The endoscopic approach allows for precise targeting through visual guidance, which is ideal in patients undergoing neuroablation for pain within specific nerve distributions. This is the first documented case of an endoscopic minimally invasive transoral approach toward ablative TN management.

Posted on

Prognosis of Symptoms and Complications After Microvascular Decompression for Hemifacial Spasm

World Neurosurg. (2018) 118:e557-e561

The aim of this study was to identify potential prognostic factors of hemifacial spasm (HFS) after microvascular decompression (MVD), to establish the appropriate way to tackle postprocedure symptoms and complications (PPSCs), and to find the incidence and duration of PPSCs.

METHODS: Two hundred and forty-eight patients with HFS were monitored between December 2009 and December 2014. The mean follow-up duration was 24 months (range, 6e67 months). We divided patients based on their PPSC status and investigated the following factors: age, sex, spasm side, facial nerve block before MVD (botulinum toxin treatment), acupuncture before MVD, duration of HFS, hypertension, diabetes, hepatitis B virus (HBV) infection status, herpes simplex virus infection status, smoking status and alcohol use, offending vessels, Chiari malformation, electrophysiologic monitoring results, and postoperative HFS. Univariable analysis and multivariate logistic regression were used to find potential risk factors. Kaplan-Meier analysis was used to show the duration of postprocedure facial palsy.

RESULTS: Age (odds ratio [OR], 1.037; 95% confidence interval [CI], 1.004e1.072; P [ 0.03) and HBV status (OR, 18.256; 95% CI, 2.723e122.415; P [ 0.03) were positive predictors of PPSCs. Postoperative HFS (OR, 0.249; 95% CI, 0.084e0.0739; P [ 0.012) may be a protective factor for postprocedure facial palsy. Most PPSCs related to cranial nerves recovered spontaneously in 3 months. Infections and cerebrospinal fluid leakages were controlled by medical intervention in 1e2 weeks. The permanent complication rate was only 4.8%.

CONCLUSIONS: Although the incidence of PPSCs after MVD is very high, most PPSCs related to cranial nerves recovered spontaneously in several days. Permanent complications after MVD for HFS are rare. Age may relate to the occurrence of PPSCs, and postoperative HFS may be a protective factor for patients with facial palsy after MVD.

Posted on

Patient-Reported Outcome Measures in Neurosurgery

Neurosurgery 83:622–630, 2018

Patient-reported outcome measures (PROMs) play an important role in the evaluation of health outcomes, quality of life, and satisfaction, and have been successfully utilized in many areas of clinical medicine and surgical practice. The prevalence of PROMs in neurosurgery is not known.

OBJECTIVE: To review the PROMs that have been utilized in the published neurosurgery literature to date.

METHODS: Articles were searched in MEDLINE, EMBASE, HMIC HealthManagement Information Consortium, PsycARTICLES, and PsycINFO using search terms related to neurosurgery and PROMs, published from 1806 to August 2016. A total of 268 articles were identified that were stratified by the inclusion and exclusion criteria leading to a total of 137 articles. Twenty-six PROMs, involving both adult and pediatric populations,were identified.

RESULTS: A large number of generic and disease-specific PROMs are used in the neurosurgical literature. Generic PROMs are usually nonspecific measures of health status. Disease specific PROMs may not address issues relevant to neurosurgical procedures. There are very few neurosurgery-specific PROMs that take into account the impact of a neurosurgical procedure on a specific condition.

CONCLUSION: PROMs that currently feature in the neurosurgical literature may not address the specific outcomes relevant to neurosurgical practice. There is an emergent need for generic and disease-specific PROMs to be validated in neurosurgical patients and neurosurgery-specific PROMs developed to address unmet needs of patients undergoing neurosurgical procedures.

 

Posted on

Autonomic Function in Insular Glioma

World Neurosurg. (2018) 118:e951-e955

Autonomic nervous system dysfunction is a known entity in strokes involving insula. It causes significant morbidity and mortality. No study to date has demonstrated autonomic nervous system dysfunction in patients with insular glioma. This is an exploratory study to identify the
subclinical autonomic dysfunctions in insular glioma.

METHODS: A total 50 patients with newly diagnosed insular glioma in the age group of 18e60 years were evaluated with heart rate variability (HRV). All the HRV parameters in patients with insular glioma were compared with normal healthy age- and sex-matched control patients.

RESULTS: There was a significant difference (P < 0.05) in most of the HRV parameters between patients and control patients. Patients with left insular glioma showed significantly increased heart rate (P [ 0.027), low-frequency normalized units (P [ 0.048), and also increased low-frequency/highfrequency ratio (P [ 0.015), which indicates sympathetic
dominance. Patients with seizures had significantly lower values of total power (P [ 0.042). No significant difference was found in terms of the extent and size of the tumor or histopathologic grades of gliomas.

CONCLUSIONS: Patients with insular gliomas have significant impairment of autonomic functions, with left insular glioma showing sympathetic dominance. Suppression of autonomic function is greater in those presenting with seizures.

Posted on

Use of the Airo mobile intraoperative CT system versus the O-arm for transpedicular screw fixation in the thoracic and lumbar spine

J Neurosurg Spine 29:397–406, 2018

Navigation-enabling technology such as 3D-platform (O-arm) or intraoperative mobile CT (iCT-Airo) systems for use in spinal surgery has considerably improved accuracy over that of traditional fluoroscopy-guided techniques during pedicular screw positioning. In this study, the authors compared 2 intraoperative imaging systems with navigation, available in their neurosurgical unit, in terms of the accuracy they provided for transpedicular screw fixation in the thoracic and lumbar spine.

METHODS The authors performed a retrospective analysis of clinical and surgical data of 263 consecutive patients who underwent thoracic and lumbar spine screw placement in the same center. Data on 97 patients who underwent surgery with iCT-Airo navigation (iCT-Airo group) and 166 with O-arm navigation (O-arm group) were analyzed. Most patients underwent surgery for a degenerative or traumatic condition that involved thoracic and lumbar pedicle screw fixation using an open or percutaneous technique. The primary endpoint was the proportion of patients with at least 1 screw not correctly positioned according to the last intraoperative image. Secondary endpoints were the proportion of screws that were repositioned during surgery, the proportion of patients with a postoperative complication related to screw malposition, surgical time, and radiation exposure. A blinded radiologist graded screw positions in the last intraoperative image according to the Heary classification (grade 1–3 screws were considered correctly placed).

RESULTS A total of 1361 screws placed in 97 patients in the iCT-Airo group (503 screws) and in 166 in the O-arm group (858 screws) were graded. Of those screws, 3 (0.6%) in the iCT-Airo group and 4 (0.5%) in the O-arm group were misplaced. No statistically significant difference in final accuracy between these 2 groups or in the subpopulation of patients who underwent percutaneous surgery was found. Three patients in the iCT-Airo group (3.1%, 95% CI 0%–6.9%) and 3 in the O-arm group (1.8%, 95% CI 0%–4.0%) had a misplaced screw (Heary grade 4 or 5). Seven (1.4%) screws in the iCT-Airo group and 37 (4.3%) in the O-arm group were repositioned intraoperatively (p = 0.003). One patient in the iCT-Airo group and 2 in the O-arm group experienced postoperative neurological deficits related to hardware malposition. The mean surgical times in both groups were similar (276 [iCT-Airo] and 279 [O-arm] minutes). The mean exposure to radiation in the iCT-Airo group was significantly lower than that in the O-arm group (15.82 vs 19.12 mSv, respectively; p = 0.02).

CONCLUSIONS Introduction of a mobile CT scanner reduced the rate of screw repositioning, which enhanced patient safety and diminished radiation exposure for patients, but it did not improve overall accuracy compared to that of a mobile 3D platform.

 

Posted on

Resection of primary motor cortex tumors

J Neurosurg 129:961–972, 2018

Brain tumors involving the primary motor cortex are often deemed unresectable due to the potential neurological consequences that result from injury to this region. Nevertheless, we have challenged this dogma for many years and used asleep, as well as awake, intraoperative stimulation mapping to maximize extent of resection. It remains unclear whether these tumors can be resected with acceptable morbidity, whether performing the surgery with the patient awake or asleep impacts extent of resection, and how stimulation mapping influences outcomes.

METHODS A retrospective chart review was performed on the senior author’s cohort to identify patients treated between 1998 and 2016 who underwent resection of tumors that were located within the primary motor cortex. Clinical notes, operative reports, and radiographic images were reviewed to identify intraoperative stimulation mapping findings and functional outcomes following tumor resection. Extent of resection was quantified volumetrically. Characteristics of patients were analyzed to identify factors associated with postoperative motor deficits.

RESULTS Forty-nine patients underwent 53 resections of tumors located primarily within the motor cortex. Stimulation mapping was performed in all cases. Positive cortical sites for motor response were identified in 91% of cases, and subcortical sites in 74%. Awake craniotomy was performed in 65% of cases, while 35% were done under general anesthesia. The mean extent of resection was 91%. There was no statistically significant difference in extent of resection in cases done awake compared with those done under general anesthesia. New or worsened postoperative motor deficits occurred in 32 patients (60%), and 20 patients (38%) had a permanent deficit. Of the permanent deficits, 14 were mild, 4 were moderate, and 2 were severe (3.8% of cases). Decreased intraoperative motor response and diffusion restriction on postoperative MRI were associated with permanent deficit. Awake motor mapping surgery was associated with increased diffusion signal on postoperative MRI.

CONCLUSIONS Resection of tumors from the primary motor cortex is associated with an increased risk of motor deficit, but most of these deficits are transient or mild and have little functional impact. Excellent extent of resection can be achieved with intraoperative stimulation mapping, suggesting that these tumors are indeed amenable to resection and should not be labeled unresectable. Injury to small perforating or en passage blood vessels was the most common cause of infarction that led to moderate or severe deficits. Awake motor mapping was not superior to mapping done under general anesthesia with regard to long-term functional outcome.

 

Posted on

Double-barrel STA to proximal MCA bypass and proximal parent artery occlusion for a fusiform superior clinoidal ICA aneurysm

Acta Neurochirurgica (2018) 160:1939–1943

Blood flow replacement and parent artery occlusion are alternative treatments of complex fusiform superior clinoidal ICA aneurysms. While double-barrel STA to proximal MCA bypass is a conventional approach among these reported bypass algorithms, its technical details remain underexplored.

Method We have applied the double-barrel STA to proximal MCA bypass and parent artery occlusion to treat a 45-year-old female patient with a right fusiform superior clinoidal ICA aneurysm. The technical nuances of this approach are reported.

Conclusion We show that double-barrel STA to proximal MCA bypass and proximal parent artery occlusion can be alternative treatments of complex fusiform superior clinoidal ICA aneurysms.

Posted on

The value of sitting radiographs: analysis of spine flexibility and its utility in preoperative planning for adult spinal deformity surgery

J Neurosurg Spine 29:414–421, 2018

Preoperative planning of thoracolumbar deformity (TLD) surgery has been shown to improve radiographic and clinical outcomes. One of the confounders in attaining optimal postoperative alignment is the reciprocal hyperkyphosis of unfused thoracic segments. Traditional planning utilizes standing radiographs, but the value of sitting radiographs to predict thoracic flexibility has not been investigated. Authors of the present study propose that alignment changes from a sitting to a standing position will predict changes in unfused thoracic segments after TLD correction.

METHODS Patients with degenerative spine pathology underwent preoperative sitting and standing full-spine stereotactic radiography. A subset of TLD patients who had undergone corrections with minimum T10-pelvis fusions was analyzed in terms of pre- to postoperative alignment. Radiographic parameters were analyzed, including the T1 pelvic angle (TPA), T1–L1 pelvic angle (TLPA), lumbar pelvic angle (LPA), pelvic tilt (PT), mismatch between pelvic incidence and lumbar lordosis (PI-LL mismatch), and T2–12 kyphosis (TK). Thoracic compensation was calculated as the expected TK minus actual TK (i.e., [2/3 × PI] – actual TK). Statistical analysis consisted of paired and unpaired t-tests and linear regression analysis.

RESULTS The authors retrospectively identified 137 patients with full-body standing and sitting radiographs. The mean age of the patients was 60.9 years old, 60.0% were female, and the mean BMI was 27.8 kg/m2. The patients demonstrated significantly different radiographic alignments in baseline spinopelvic and global parameters from the preoperative sitting versus the standing positions: LL (-34.20° vs -47.87°, p < 0.001), PT (28.31° vs 17.50°, p < 0.001), TPA (27.85° vs 16.89°, p < 0.001), TLPA (10.63° vs 5.17°, p < 0.001), and LPA (15.86° vs 9.67°, p < 0.001). Twenty patients (65.0% female) with a mean age of 65.3 years and mean BMI of 30.2 kg/m2 had TLD and underwent surgical correction (pre- to postoperative standing change in TPA: 33.90° to 24.50°, p = 0.001). Preoperative sitting radiographs demonstrated significant differences in alignment compared to postoperative standing radiographs: larger TPA (39.10° vs 24.50°, p < 0.001), PT (35.40° vs 28.10°, p < 0.001), LL (-11.20° vs -44.80°, p < 0.001), LPA (22.80° vs 14.20°, p < 0.001), and unfused Cobb (T2 to upper instrumented vertebra [UIV] Cobb angle: 19.95° vs 27.50°, p = 0.039). Also in the TLD group, mean thoracic compensation was 6.75°. In the linear regression analysis, the change from sitting to standing predicted pre- to postoperative changes for TK and the unfused thoracic component of TPA (5° change in preoperative sitting to preoperative standing corresponded to a pre- to postoperative change in standing TK of 6.35° and in standing TPA of 7.23°, R2 = 0.30 and 0.38, respectively).

CONCLUSIONS Sitting radiographs were useful in demonstrating spine flexibility. Among the TLD surgery group, relaxation of the unfused thoracic spine in the sitting position predicted the postoperative increase in kyphosis of the unfused thoracic segments. Sitting radiographs are a useful tool to anticipate reciprocal changes in thoracic alignment that diminish global corrections.

 

Posted on

Cost-Effectiveness in Adult Spinal Deformity Surgery

Neurosurgery 83:597–601, 2018

The complexity and heterogeneity of adult spinal deformity (ASD) creates significant difficulties in performing high-quality, complete economic analyses. For the same reasons, however, such studies are immensely valuable to clinicians and health policy experts. There has been a paradigm shift towards value-based healthcare provision and as such, there is an increasing focus on demonstrating not just the value ASD surgery, but the provision of care at large. Health-related quality of life measures are an important tool for assessing value of an intervention and its effect on a quality-adjusted life year (QALY). Currently, there are no definitive criteria in regard to assigning the appropriate value to a QALY. A general accepted threshold discussed in literature is $100 000 per QALY gained. However, this figure may be variable across populations, and may not necessarily be applicable in today’s economy, or in all healthcare economies. Fundamentally, an effective treatment method may be associated with a high upfront cost, however, if durable, will be costeffective over time. The emphasis on carotid endarterectomy and CUA in the field of adult spine deformity is relatively recent; therefore, there is a limited amount of data on cost-effectiveness analyses. Continued efforts with emphasis on value-based outcomes are needed with long-term follow-up studies.

Posted on

The influence of spinopelvic parameters on adjacent-segment degeneration after short spinal fusion for degenerative spondylolisthesis

J Neurosurg Spine 29:407–413, 2018

Spinopelvic parameters, such as the pelvic incidence (PI) angle, sacral slope angle, and pelvic tilt angle, are important anatomical indices for determining the sagittal curvature of the spine and the individual variability of the lumbar lordosis (LL) curve. The aim of this study was to investigate the influence of spinopelvic parameters and LL on adjacent-segment degeneration (ASD) after short lumbar and lumbosacral fusion for single-level degenerative spondylolisthesis.

METHODS The authors retrospectively reviewed the records of all short lumbar and lumbosacral fusion surgeries performed between August 2003 and July 2010 for single-level degenerative spondylolisthesis in their orthopedic department.

RESULTS A total of 30 patients (21 women and 9 men, mean age 64 years) with ASD after lower lumbar or lumbosacral fusion surgery comprised the study group. Thirty matched patients (21 women and 9 men, mean age 63 years) without ASD comprised the control group, according to the following matching criteria: same diagnosis on admission, similar pathologic level (≤ 1 level difference), similar sex, and age. The average follow-up was 6.8 years (range 5–8 years). The spinopelvic parameters had no significant influence on ASD after short spinal fusion.

CONCLUSIONS Neither the spinopelvic parameters nor a mismatch of PI and LL were significant factors responsible for ASD after short spinal fusion due to single-level degenerative spondylolisthesis.

Posted on

Robot-assisted multi-level anterior lumbar interbody fusion: an anatomical study

Acta Neurochirurgica (2018) 160:1891–189

Minimally invasive surgical approaches still provide limited exposure. Access to the L2–L5 intervertebral discs during a single procedure is challenging and often requires repositioning of the patient and adopting an alternative approach.

Objectives Investigate the windows to the L2–L5 intervertebral discs to assess the dimensions of the interbody implants suitable for the procedure and evaluate the feasibility of multi-level lumbar intervertebral disc surgery in robot-assisted surgery (RAS)

Methods Sixteen fresh-frozen cadaveric specimens underwent a retroperitoneal approach to access the L2–L5 intervertebral discs. The L2–L3 to L4–L5 windows were defined as the distance between the left lateral border of the aorta (or nearest common iliac vessel) and the medial border of the psoas, measured in a static state and after gentle medial retraction of the vascular structures. Two living porcine specimens and one cadaveric specimen underwent da Vinci robot-assisted transperitoneal approach to expose the L2–L3 to L4–L5 intervertebral discs and perform multi-level discectomy and interbody implant placement.

Results The L2–L3 to L4–L5 intervertebral disc windows significantly increased from a static to a retracted state (p < 0.05). The mean L2–L3, L3–L4, and L4–L5 windows measured respectively 20.1, 21.6, and 19.6 mm in the static state, and 27.2, 30.9, and 30.3 mm after gentle vascular retraction. The intervertebral windows from L2–L3 to L4–L5 were successfully exposed through an anterior transperitoneal approach with the da Vinci robot on the cadaveric and living porcine specimens, and interbody implants were inserted.

Conclusion RAS appears to be feasible for a mini-invasive multi-level lumbar intervertebral disc surgery. The RAS procedure, longer and more expensive than conventional MIS approaches, should be reserved for elective patients.

 

Posted on

Reduced Acute Care Costs With the ERAS ® Minimally Invasive Transforaminal Lumbar Interbody Fusion Compared With Conventional Minimally Invasive Transforaminal Lumbar Interbody Fusion

Neurosurgery 83:827–834, 2018

Enhancing Recovery After Surgery (ERAS (R)  ) programs have been widely adopted throughout the world, but not in spinal surgery. In this report, we review the implementation of a “fast track”surgery for lumbar fusion and its effect on acute care hospitalization costs.

OBJECTIVE: To determine if a “fast track” surgery methodology results in acute care cost savings.

METHODS: Thirty-eight consecutive ERAS patients were compared with patients undergoing conventional minimally invasive transforaminal lumbar interbody fusion. Differences between these groups included the use of endoscopic decompression, injections of liposomal bupivacaine, and performing the surgery under sedation in the ERAS R  group.

RESULTS: Patients had similar medical comorbidities (2.02 vs 2 for ERAS R  and comparator groups, respectively; P = .458). Body mass index was similar (26.5 vs 27.0; P = .329). ERAS R  patients were older (65 vs 59 yr, P= .031). Both groups had excellent clinical results with an improvement of 23% and 24%, respectively. Intraoperative blood loss was less (68±31 cc vs 231±73, P<0.001). Length of staywas also less with ERAS R  surgery, at ameanof 1.23±0.8 d vs 3.9 ± 1.1 d (P = 0.009). When comparing ERAS R  surgery to standard minimally invasive transforaminal lumbar interbody fusion, the total cost for the acute care hospitalization was $19212vs $22656, respectively(P<0.001). This reflected an average of $3444 in savings, which was a 15.2% reduction.

CONCLUSION: ERAS (R)  programs for spinal fusion surgery have the potential to reduce the costs of acute care. This is made possible by leveraging less invasive interventions to minimize soft tissue damage.

Posted on

Randomized controlled study comparing 2 surgical techniques for decompressive craniectomy: with watertight duraplasty and without watertight duraplasty

J Neurosurg 129:1017–1023, 2018

Decompressive craniectomy (DC) is a widely used procedure in neurosurgery; however, few studies focus on the best surgical technique for the procedure. The authors’ objective was to conduct a prospective randomized controlled trial comparing 2 techniques for performing DC: with watertight duraplasty and without watertight duraplasty (rapid-closure DC).

METHODS The study population comprised patients ranging in age from 18 to 60 years who were admitted to the Neurotrauma Service of the Hospital da Restauração with a clinical indication for unilateral decompressive craniectomy. Patients were randomized by numbered envelopes into 2 groups: with watertight duraplasty (control group) and without watertight duraplasty (test group). After unilateral DC was completed, watertight duraplasty was performed in the control group, while in the test group, no watertight duraplasty was performed and the exposed parenchyma was covered with Surgicel and the remaining dura mater. Patients were then monitored daily from the date of surgery until hospital discharge or death. The primary end point was the incidence of surgical complications (CSF leak, wound infection, brain abscess, or subgaleal fluid collections). The following were analyzed as secondary end points: clinical outcome (analyzed using the Glasgow Outcome Scale [GOS]), surgical time, and hospital costs.

RESULTS Fifty-eight patients were enrolled, 29 in each group. Three patients were excluded, leaving 27 in the test group and 28 in the control group. There were no significant differences between groups regarding age, Glasgow Coma Scale score at the time of surgery, GOS score, and number of postoperative follow-up days. There were 9 surgical complications (5 in the control group and 4 in the test group), with no significant differences between the groups. The mean surgical time in the control group was 132 minutes, while in the test group the average surgical time was 101 minutes, a difference of 31 minutes (p = 0.001). The mean reduction in total cost was $420.00 USD (a 23.4% reduction) per procedure in the test group.

CONCLUSIONS Rapid-closure DC without watertight duraplasty is a safe procedure. It is not associated with a higher incidence of surgical complications (CSF leak, wound infection, brain abscess, or subgaleal fluid collections), and it decreased surgical time by 31 minutes on average. There was also a hospital cost reduction of $420.00 USD (23.4% reduction) per procedure. Clinical trial registration no.: NCT02594137 (clinicaltrials.gov)

 

Posted on

Robotic Stereotaxy in Cranial Neurosurgery

Neurosurgery 83:642–650, 2018

Modern-day stereotactic techniques have evolved to tackle the neurosurgical challenge of accurately and reproducibly accessing specific brain targets. Neurosurgical advances have beenmadein synergywith sophisticated technological developments and engineering innovations such as automated robotic platforms. Robotic systems offer a unique combination of dexterity, durability, indefatigability, and precision.

OBJECTIVE: To perform a systematic review of robotic integration for cranial stereotactic guidance in neurosurgery. Specifically, we comprehensively analyze the strengths and weaknesses of a spectrum of robotic technologies, past and present, including details pertaining to each system’s kinematic specifications and targeting accuracy profiles.

METHODS: Eligible articles on human clinical applications of cranial robotic-guided stereotactic systems between 1985 and 2017 were extracted from several electronic databases, with a focus on stereotactic biopsy procedures, stereoelectroencephalography, and deep brain stimulation electrode insertion.

RESULTS: Cranial robotic stereotactic systems feature serial or parallel architectures with 4 to 7 degrees of freedom, and frame-based or frameless registration. Indications for robotic assistance are diversifying, and include stereotactic biopsy, deep brain stimulation and stereoelectroencephalography electrode placement, ventriculostomy, and ablation procedures. Complication rates are low, and mainly consist of hemorrhage. Newer systems benefit fromincreasing targeting accuracy, intraoperative imaging ability, improved safety profiles, and reduced operating times.

CONCLUSION: We highlight emerging future directions pertaining to the integration of robotic technologies into future neurosurgical procedures. Notably, a trend toward miniaturization, cost-effectiveness, frameless registration, and increasing safety and accuracy characterize successful stereotactic robotic technologies.

Posted on

Head-up display may facilitate safe keyhole surgery for cerebral aneurysm clipping

J Neurosurg 129:883–889, 2018

The head-up display (HUD) is a modern technology that projects images or numeric information directly into the observer’s sight line. Surgeons will no longer need to look away from the surgical view using the HUD system to confirm the preoperative or navigation image. The present study investigated the usefulness of the HUD system for performing cerebral aneurysm clipping surgeries.

METHODS Thirty-five patients underwent clipping surgery, including 20 keyhole surgeries for unruptured cerebral aneurysm, using the HUD system. Image information of structures such as the skull, cerebral vasculature, and aneurysm was integrated by the navigation software and linked with the positional coordinates of the microscope field of view. “Image injection” allowed visualization of the main structures that were concurrently tracked by the navigation image, and “closed shutter” switched the microscope field of view and the pointer image of the 3D brain image.

RESULTS The HUD system was effective for estimating the location and 3D anatomy of the aneurysm before craniotomy or dural opening in most patients. Scheduled keyhole minicraniotomy and opening of the sylvian fissure or partial rectal gyrus resection were performed on the optimized location with a minimum size in 20 patients.

CONCLUSIONS The HUD images superimposed on the microscope field of view were remarkably useful for less invasive and more safe aneurysm clipping and, in particular, keyhole clipping.

 

Posted on

Topical Vancomycin Reduces Surgical-Site Infections After Craniotomy: A Prospective, Controlled Study

Neurosurgery 83:761–767, 2018

Surgical-site infections (SSIs) are an important cause of morbidity and mortality in neurosurgical patients. Topical antibiotics are one potential method to reduce the incidence of these infections.

OBJECTIVE: To examine the efficacy of topical vancomycin applied within the wound during craniotomy in a large prospective cohort study at a major academic center.

METHODS: Three hundred fifty-five patients were studied prospectively in this cohort study; 205 patients received 1 g of topical vancomycin powder in the subgaleal space while 150 matched control patients did not. Patients otherwise received identical care. The primary outcome variable was SSI rate factored by cohort. Secondary analysis examined cost savings from vancomycin usage estimated from hospital costs associated with SSI in craniotomy patients.

RESULTS: The addition of topical vancomycinwas associated with a significantly lower rate of SSI than standard of care alone (0.49% [1/205] vs 6% [9/150], P=.002). Based on the costs of revision surgery for infections, topical vancomycin usage was estimated to save $1367 446 per 1000 craniotomy patients. No adverse reactions occurred.

CONCLUSION: Topical vancomycin is a safe, effective, and cost-saving measure to prevent SSIs following craniotomy. These results have broad implications for standard of care in craniotomy.

Proudly powered by WordPress