Minimally Invasive Surgery for Intracerebral Hemorrhage.

PURPOSE OF REVIEW: Recent success in preliminary clinical studies evaluating various forms of minimally invasive surgery for spontaneous intracerebral hemorrhage (ICH) has renewed interest in the surgical treatment of this disease process. RECENT FINDINGS: In December of 2016, phase 2 of the Minimally Invasive Surgery Plus Rt-PA for ICH Evacuation (MISTIE) study demonstrated that this form of stereotactic thrombolysis safely reduces clot burden and may improve functional outcome 6 months after injury. A smaller arm of this study, the Intraoperative Stereotactic Computer Tomography-Guided Endoscopic Surgery (ICES) study, also demonstrated feasibility and good functional outcome for endoscopic minimally invasive evacuation. Early-phase clinical studies evaluating various forms of minimally invasive surgery for intracerebral hemorrhage evacuation have shown safety and feasibility with a preliminary signal towards improved functional long-term outcome. Results from phase 3 studies addressing various minimally invasive techniques are imminent and will shape how intracerebral hemorrhage is treated.

Improving discharge data fidelity for use in large administrative databases.

OBJECT: Large administrative databases have assumed a major role in population-based studies examining health care delivery. Lumbar fusion surgeries specifically have been scrutinized for rising rates coupled with ill-defined indications for fusion such as stenosis and spondylosis. Administrative databases classify cases with the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). The ICD-9-CM discharge codes are not designated by surgeons, but rather are assigned by trained hospital medical coders. It is unclear how accurately they capture the surgeon's indication for fusion. The authors first sought to compare the ICD-9-CM code(s) assigned by the medical coder according to the surgeon's indication based on a review of the medical chart, and then to elucidate barriers to data fidelity. METHODS: A retrospective review was undertaken of all lumbar fusions performed in the Department of Neurosurgery at the authors' institution between August 1, 2011, and August 31, 2013. Based on this review, the indication for fusion in each case was categorized as follows: spondylolisthesis, deformity, tumor, infection, nonpathological fracture, pseudarthrosis, adjacent-level degeneration, stenosis, degenerative disc disease, or disc herniation. These surgeon diagnoses were compared with the primary ICD-9-CM codes that were generated by the medical coders and submitted to administrative databases. A follow-up interview with the hospital's coders and coding manager was undertaken to review causes of error and suggestions for future improvement in data fidelity. RESULTS: There were 178 lumbar fusion operations performed in the course of 170 hospital admissions. There were 44 hospitalizations in which fusion was performed for tumor, infection, or nonpathological fracture. Of these, the primary diagnosis matched the surgical indication for fusion in 98% of cases. The remaining 126 hospitalizations were for degenerative diseases, and of these, the primary ICD-9-CM diagnosis matched the surgeon's diagnosis in only 61 (48%) of 126 cases of degenerative disease. When both the primary and all secondary ICD-9-CM diagnoses were considered, the indication for fusion was identified in 100 (79%) of 126 cases. Still, in 21% of hospitalizations, the coder did not identify the surgical diagnosis, which was in fact present in the chart. There are many different causes of coding inaccuracy and data corruption. They include factors related to the quality of documentation by the physicians, coder training and experience, and ICD code ambiguity. CONCLUSIONS: Researchers, policymakers, payers, and physicians should note these limitations when reviewing studies in which hospital claims data are used. Advanced domain-specific coder training, increased attention to detail and utilization of ICD-9-CM diagnoses by the surgeon, and improved direction from the surgeon to the coder may augment data fidelity and minimize coding errors. By understanding sources of error, users of these large databases can evaluate their limitations and make more useful decisions based on them.

Spinal deformity surgery in patients for whom blood transfusion is not an option: a single-center experience.

OBJECTIVE: Spinal deformity surgery is associated with significant blood loss, often requiring the transfusion of blood and/or blood products. For patients declining blood or blood products, even in the face of life-threatening blood loss, spinal deformity surgery has been associated with high rates of morbidity and mortality. For these reasons, patients for whom blood transfusion is not an option have historically been denied spinal deformity surgery. METHODS: The authors retrospectively reviewed a prospectively collected data set. All patients declining blood transfusion who underwent spinal deformity surgery at a single institution between January 2002 and September 2021 were identified. Demographics collected included age, sex, diagnosis, details of any prior surgery, and medical comorbidities. Perioperative variables included levels decompressed and instrumented, estimated blood loss, blood conservation techniques used, length of surgery, length of hospital stay, and complications from surgery. Radiographic measurements included, where appropriate, sagittal vertical axis correction, Cobb angle correction, and regional angular correction. RESULTS: Spinal deformity surgery was performed in 31 patients (18 male, 13 female) over 37 admissions. The median age at surgery was 41.2 years (range 10.9-70.1 years), and 64.5% had significant medical comorbidities. A median of 9 levels (range 5-16 levels) were instrumented per surgery, and the median estimated blood loss was 800 mL (range 200-3000 mL). Posterior column osteotomies were performed in all surgeries, and pedicle subtraction osteotomies in 6 cases. Multiple blood conservation techniques were used in all patients. Preoperative erythropoietin was administered prior to 23 surgeries, intraoperative cell salvage was used in all, acute normovolemic hemodilution was performed in 20, and perioperative administration of antifibrinolytic agents was performed in 28 surgeries. No allogenic blood transfusions were administered. Surgery was staged intentionally in 5 cases, and there was 1 unintended staging due to intraoperative blood loss from a vascular injury. There was 1 readmission for a pulmonary embolus. There were 2 minor postoperative complications. The median length of stay was 6 days (range 3-28 days). Deformity correction and the goals of surgery were achieved in all patients. Two patients underwent revision surgery during the follow-up period: one for pseudarthrosis and the other for proximal junctional kyphosis. CONCLUSIONS: With proper preoperative planning and judicious use of blood conservation techniques, spinal deformity surgery may be performed safely in patients for whom blood transfusion is not an option. The same techniques can be applied widely to the general population in order to minimize blood loss and the need for allogeneic blood transfusion.

Pallidal deep brain stimulation for DYT6 dystonia.

BACKGROUND: Mutations of the THAP1 gene were recently shown to underlie DYT6 torsion dystonia. Little is known about the response of this dystonia subtype to deep brain stimulation (DBS) at the internal globus pallidus (GPi). METHODS: Retrospective analysis of the medical records of three DYT6 patients who underwent pallidal DBS by one surgical team. The Burke-Fahn-Marsden Dystonia Rating scale served as the primary outcome measure. Comparison is made to 23 patients with DYT1 dystonia also treated with GPi-DBS by the same team. RESULTS: In contrast with the DYT1 patients who exhibited a robust and sustained clinical response to DBS, the DYT6 patients exhibited more modest gains during the first 2 years of therapy, and some symptom regression between years 2 and 3 despite adjustments to the stimulation parameters and repositioning of one stimulating lead. Microelectrode recordings made during the DBS procedures demonstrated no differences in the firing patterns of GPi neurons from DYT1 and DYT6 patients. DISCUSSION: Discovery of the genetic mutations responsible for the DYT6 phenotype allows for screening and analysis of a new homogeneous group of dystonia patients. DYT6 patients appear to respond less robustly to GPi-DBS than their DYT1 counterparts, most likely reflecting differences in the underlying pathophysiology of these distinct genetic disorders. CONCLUSIONS: While early results of pallidal DBS for DYT6 dystonia are encouraging, further research and additional subjects are needed both to optimise stimulation parameters for this population and to elucidate more accurately their response to surgical treatment.

Utility of intraoperative electromyography in placing C7 pedicle screws.

OBJECTIVE: The C7 vertebral body is morphometrically unique; it represents the transition from the subaxial cervical spine to the upper thoracic spine. It has larger pedicles but relatively small lateral masses compared to other levels of the subaxial cervical spine. Although the biomechanical properties of C7 pedicle screws are superior to those of lateral mass screws, they are rarely placed due to increased risk of neurological injury. Although pedicle screw stimulation has been shown to be safe and effective in determining satisfactory screw placement in the thoracolumbar spine, there are few studies determining its utility in the cervical spine. Thus, the purpose of this study was to determine the feasibility, clinical reliability, and threshold characteristics of intraoperative evoked electromyographic (EMG) stimulation in determining satisfactory pedicle screw placement at C7. METHODS: The authors retrospectively reviewed a prospectively collected data set. All adult patients who underwent posterior cervical decompression and fusion with placement of C7 pedicle screws at the authors' institution between January 2015 and March 2019 were identified. Demographic, clinical, neurophysiological, operative, and radiographic data were gathered. All patients underwent postoperative CT scanning, and the position of C7 pedicle screws was compared to intraoperative neurophysiological data. RESULTS: Fifty-one consecutive C7 pedicle screws were stimulated and recorded intraoperatively in 25 consecutive patients. Based on EMG findings, 1 patient underwent intraoperative repositioning of a C7 pedicle screw, and 1 underwent removal of a C7 pedicle screw. CT scans demonstrated ideal placement of the C7 pedicle screw in 40 of 43 instances in which EMG stimulation thresholds were > 15 mA. In the remaining 3 cases the trajectories were suboptimal but safe. When the screw stimulation thresholds were between 11 and 15 mA, 5 of 6 screws were suboptimal but safe, and in 1 instance was potentially dangerous. In instances in which the screw stimulated at thresholds ≤ 10 mA, all trajectories were potentially dangerous with neural compression. CONCLUSIONS: Ideal C7 pedicle screw position strongly correlated with EMG stimulation thresholds > 15 mA. In instances, in which the screw stimulates at values between 11 and 15 mA, screw trajectory exploration is recommended. Screws with thresholds ≤ 10 mA should always be explored, and possibly repositioned or removed. In conjunction with other techniques, EMG threshold testing is a useful and safe modality in determining appropriate C7 pedicle screw placement.

Minimally Invasive Evacuation of Spontaneous Cerebellar Intracerebral Hemorrhage.

OBJECTIVE: Spontaneous cerebellar intracerebral hemorrhage (scICH) constitutes ∼10% of all cases of spontaneous ICH, with a mortality of 20%-50%. Suboccipital craniectomy (SOC) is commonly performed for scICH causing brainstem compression or hydrocephalus. However, SOC requires long anesthesia times and results in a high complication rate. We present a series of patients who minimally invasive scICH evacuation as an alternative to traditional SOC. METHODS: We retrospectively reviewed the operative records for patients presenting to a single center from January 1, 2009 to March 1, 2017. All patients who had undergone evacuation of scICH were included in the present study. Clinical and radiographic variables were collected, including admission and postoperative Glasgow coma scale (GCS) scores, preoperative and postoperative hematoma volumes, and modified Rankin scale (mRS) scores at long-term follow-up. RESULTS: We identified 10 patients who had presented with scICH requiring surgery. All scICH evacuations were performed through a minicraniectomy positioned in the suboccipital area as close to the hematoma as possible. The mean patient age was 64.1 years. The mean presenting GCS score was 8.6, the mean initial hematoma volume was 25.4 mL, the mean procedure time was 57 minutes, and the mean postoperative hematoma volume was 2.8 mL. The mortality rate was 10% and mean long-term follow-up mRS score was 2. CONCLUSIONS: Minimally invasive scICH hematoma evacuation is a feasible alternative to SOC with numerous advantages that could lead to improved radiographic and clinical results.

Complications of Poor Cervical Alignment in Patients Undergoing Posterior Cervicothoracic Laminectomy and Fusion.

OBJECTIVE: This study sought to determine whether a relationship exists between caudal instrumented level and revision rates, neck disability index scores, and cervical alignment in patients undergoing multilevel posterior cervical fusion. METHODS: This study examined a dataset of all patients undergoing posterior cervical decompression and fusion at ≥3 levels, terminating between C4 and T4, between January 2010 and December 2015, with at least 12 months of clinical follow-up. Patients were separated into cohorts based on caudal level of the fusion: C6 (or more cranial), C7, T1, or T2 (or more caudal). Revision rate, neck disability index score, sagittal vertical axis, T1 slope, and cervical lordosis were recorded. Linear regression and multivariate analysis were performed to identify independent predictors of patient outcomes and disparities between ending constructs in the cervical and the thoracic spine. RESULTS: The overall revision rate was 10.8% (n = 24). No statistically significant difference in the revision rate was identified between fusions terminating at C6 or cranial, C7, T1, or T2 and caudal (P = 0.74). Revision correlated strongly with increased sagittal vertical axis (P = 0.002) and T1 slope (P = 0.04). Increased neck disability index score correlated with revision rate (P = 0.01), cervical kyphosis (P < 0.001), and increased sagittal vertical axis (P = 0.04). CONCLUSIONS: This study suggests that constructs terminating in the proximal thoracic spine have similar revision rates, postoperative neck disability index scores, and radiographic measurements as those terminating in the cervical spine. Poor cervical alignment, as evidenced by increased sagittal vertical axis, cervical kyphosis and T1 slope, predicts need for revision and of poorer clinical outcomes.

The case for T2 pedicle subtraction osteotomy in the surgical treatment of rigid cervicothoracic deformity.

OBJECTIVE: Rigid cervicothoracic kyphotic deformity (CTKD) remains a difficult pathology to treat, especially in the setting of prior cervical instrumentation and fusion. CTKD may result in chronic neck pain, difficulty maintaining horizontal gaze, and myelopathy. Prior studies have advocated for the use of C7 or T1 pedicle subtraction osteotomies (PSOs). However, these surgeries are fraught with danger and, most significantly, place the C7, C8, and/or T1 nerve roots at risk. METHODS: The authors retrospectively reviewed their experience with performing T2 PSO for the correction of rigid CTKD. Demographics collected included age, sex, details of prior cervical surgery, and coexisting conditions. Perioperative variables included levels decompressed, levels instrumented, estimated blood loss, length of surgery, length of stay, complications from surgery, and length of follow-up. Radiographic measurements included C2-7 sagittal vertical axis (SVA) correction, and changes in the cervicothoracic Cobb angle, lumbar lordosis, and C2-S1 SVA. RESULTS: Four male patients were identified (age range 55-72 years). Three patients had undergone prior posterior cervical laminectomy and instrumented fusion and developed postsurgical kyphosis. All patients underwent T2 PSO: 2 patients received instrumentation at C2-T4, and 2 patients received instrumentation at C2-T5. The median C2-7 SVA correction was 3.85 cm (range 2.9-5.3 cm). The sagittal Cobb angle correction ranged from 27.8° to 37.6°. Notably, there were no neurological complications. CONCLUSIONS: T2 PSO is a powerful correction technique for the treatment of rigid CTKD. Compared with C7 or T1 PSO, there is decreased risk of injury to intrinsic hand muscle innervators, and there is virtually no risk of vertebral artery injury. Laminectomy may also be safer, as there is less (or no) scar tissue from prior surgeries. Correction at this distal level may allow for a greater sagittal correction. The authors are optimistic that these findings will be corroborated in larger cohorts examining this challenging clinical entity.

Ethylenevinylalcohol copolymer (Onyx-18) used in endovascular treatment of vein of Galen malformation.

BACKGROUND: Vein of Galen malformations (VGM) are rare congenital arteriovenous fistulas that usually present with heart failure in the neonate. Endovascular treatment options in the past have utilized coils, balloons, and acrylics. CASE REPORT: We present, for the first time in the literature, a case of an infant with VGM treated initially with staged coil embolizations followed 1 year later by the transarterial and transvenous catheter based injection of Onyx-18 (ethylenevinylalcohol copolymer) in a single treatment session. The fistula was eliminated, and the infant's cardiopulmonary symptoms were improved.

Cerebellar cryptococcoma in an immunocompetent child. Case report.

This is the first report of a cerebellar cryptococcoma in a previously healthy, HIV-negative child. Cryptococcus neoformans is an opportunistic fungus that typically affects patients who are HIV-positive and other patients with compromised immune systems. Isolated cryptococcomas of the central nervous system (CNS) have been previously described in immunocompetent adults; however, this is the first report of a cryptococcoma in a child. The patient presented with progressive headaches and nausea and was found to have a large cerebellar hemispheric mass. The patient underwent excision of the mass, and analysis of frozen sections suggested the presence of an astrocytic tumor with pilocytic features; therefore gross-total resection was performed. Once the definitive diagnosis of a cryptococcal abscess was obtained, medical treatment with antifungal medications led to the resolution of all symptoms and the normalization of serum titers. Cryptococcoma is a rare cause of ring enhancing lesions in the cerebellum, even in apparently immunocompetent patients. The authors' experience with this case and the patient's postoperative care lead them to advocate resection of large isolated cryptococcomas of the CNS, especially those situated in the posterior fossa.

Familial multiple lipomatosis: report of a new family.

Familial multiple lipomatosis (FML) is a rare entity. We report a family with this disease. Karyotypic analysis was performed on tissue isolated from excised lipomas and peripheral blood. No chromosomal abnormalities were found. This is the first report of karyotypic analysis of lipomas removed from a patient with FML. The finding of a normal karyotype is important because approximately 25% of spontaneous lipomas will have abnormal karyotypes; therefore, we felt there was a significant probability that familial lipomas in FML would have abnormal karyotypes.

Clinical and anatomic outcomes after endovascular coiling of middle cerebral artery aneurysms: report on 30 treated aneurysms and review of the literature.

BACKGROUND: Endovascular treatment of middle cerebral artery (MCA) aneurysms has not been extensively studied. We report our experience on a select group of patients that underwent coil embolization of an MCA bifurcation aneurysm. METHODS: From August 1999 to January 2005, 29 patients harboring 30 MCA aneurysms were treated with coil embolization. These patients were felt to have favorable characteristics for endovascular therapy including absence of thrombus in the aneurysm, absence of an efferent artery off of the aneurysm, and ability to reconstruct the wide neck with stent reconstruction. We retrospectively reviewed their records and angiographic images to evaluate for technical result and complications. RESULTS: The mean age of our cohort was 59 +/- 13 years with 19 patients presenting with a ruptured aneurysm. Complete obliteration was achieved in 24 (80%) of 30 of aneurysms on postprocedural angiography and no patient showed aneurysm regrowth at 6-month follow-up. Twenty-seven (93%) of 29 patients had no change in baseline neurological function post-embolization. There were two procedural-related complications: one intraprocedural rupture of an aneurysm and one thromboembolic stroke in the ipsilateral MCA territory. CONCLUSIONS: Coil embolization of MCA bifurcation aneurysms has a high rate of complete obliteration with acceptable morbidity in our selected group of patients.