The authors report dural sinus thrombosis diagnosed in 2 patients based on noninvasive imaging results, which were revealed to be dural arteriovenous fistulas (DAVFs) diagnosed using digital subtraction (DS) angiography. The first patient was a 63-year-old man who presented with headaches. Magnetic resonance venography was performed and suggested dural sinus thrombosis of the left transverse sinus and jugular vein. He was administered warfarin anticoagulation therapy but then suffered multiple intracranial hemorrhages. A DS angiogram was requested for a possible dural sinus thrombectomy, but the DS angiogram revealed a DAVF. The patient underwent serial liquid embolization with complete obliteration of the DAVF. The second patient, an 11-year-old boy, also presented with headaches and was diagnosed with dural sinus thrombosis on MR imaging. A DS angiogram was also requested for a possible thrombectomy and revealed a DAVF. This patient underwent serial liquid embolization and eventual operative resection. These reports emphasize that different venous flow abnormalities can appear similar on noninvasive imaging and that proper diagnosis is critical to avoid contraindicated therapies.
Report of 2 cases
Scott Simon, Tom Yao, Arthur J. Ulm, Benjamin P. Rosenbaum and Robert A. Mericle
Varun R. Kshettry, Michael L. Kelly, Benjamin P. Rosenbaum, Andreea Seicean, Lee Hwang and Robert J. Weil
Myelomeningocele repair is an uncommonly performed surgical procedure. The volume of operations has been decreasing in the past 2 decades, probably as the result of public health initiatives for folate supplementation. Because of the rarity of myelomeningocele, data on patient or hospital factors that may be associated with outcome are scarce. To determine these factors, the authors investigated the trends in myelomeningocele surgical repair in the United States over a 23-year period and examined patient and hospital characteristics that were associated with outcome.
The Nationwide Inpatient Sample database for 1988–2010 was queried for hospital admissions for myelomeningocele repair. This database reports patient, hospital, and admission characteristics and surgical trends. The authors used univariate and multivariate logistic regression to assess associations between patient and hospital characteristics and in-hospital deaths, nonroutine discharge, long hospital stay, and shunt placement.
There were 4034 hospitalizations for surgical repair of myelomeningocele. The annual volume decreased since 1988 but plateaued in the last 4 years of the study. The percentages of myelomeningocele patients with low income (30.8%) and Medicaid insurance (48.2%) were disproportionately lower than those for the overall live-born population (p < 0.0001). More operations per 10,000 live births were performed for Hispanic patients (3.2) than for white (2.0) or black (1.5) patients (p < 0.0001). Overall, 56.6% of patients required shunt placement during the same hospital stay as for surgical repair; 95.0% of patients were routinely discharged; and the in-hospital mortality rate was 1.4%. Nonwhite race was associated with increased in-hospital risk for death (OR 2.8, 95% CI 1.2–6.3) independent of socioeconomic or insurance status.
Overall, the annual surgical volume of myelomeningocele repairs decreased after public health initiatives were introduced but has more recently plateaued. The most disproportionately represented populations are Hispanic, low-income, and Medicaid patients. Among nonwhite patients, increased risk for in-hospital death may represent a disparity in care or a difference in disease severity.
Michael F. Shriver, Jack J. Xie, Erik Y. Tye, Benjamin P. Rosenbaum, Varun R. Kshettry, Edward C. Benzel and Thomas E. Mroz
Lumbar microdiscectomy and its various minimally invasive surgical techniques are seeing increasing popularity, but a systematic review of their associated complications has yet to be performed. The authors sought to identify all prospective clinical studies reporting complications associated with lumbar open microdiscectomy, microendoscopic discectomy (MED), and percutaneous microdiscectomy.
The authors conducted MEDLINE, Scopus, Web of Science, and Embase database searches for randomized controlled trials and prospective cohort studies reporting complications associated with open, microendoscopic, or percutaneous lumbar microdiscectomy. Studies with fewer than 10 patients and published before 1990 were excluded. Overall and interstudy median complication rates were calculated for each surgical technique. The authors also performed a meta-analysis of the reported complications to assess statistical significance across the various surgical techniques.
Of 9504 articles retrieved from the databases, 42 met inclusion criteria. Most studies screened were retrospective case series, limiting the number of studies that could be included. A total of 9 complication types were identified in the included studies, and these were analyzed across each of the surgical techniques. The rates of any complication across the included studies were 12.5%, 13.3%, and 10.8% for open, MED, and percutaneous microdiscectomy, respectively. New or worsening neurological deficit arose in 1.3%, 3.0%, and 1.6% of patients, while direct nerve root injury occurred at rates of 2.6%, 0.9%, and 1.1%, respectively. Hematoma was reported at rates of 0.5%, 1.2%, and 0.6%, respectively. Wound complications (infection, dehiscence, orseroma) occurred at rates of 2.1%, 1.2%, and 0.5%, respectively. The rates of recurrent disc complications were 4.4%, 3.1%, and 3.9%, while reoperation was indicated in 7.1%, 3.7%, and 10.2% of operations, respectively. Meta-analysis calculations revealed a statistically significant higher rate of intraoperative nerve root injury following percutaneous procedures relative to MED. No other significant differences were found.
This review highlights complication rates among various microdiscectomy techniques, which likely reflect real-world practice and conceptualization of complications among physicians. This investigation sets the framework for further discussions regarding microdiscectomy options and their associated complications during the informed consent process.
Andrew T. Healy, Prasath Mageswaran, Daniel Lubelski, Benjamin P. Rosenbaum, Virgilio Matheus, Edward C. Benzel and Thomas E. Mroz
The degenerative process of the spinal column results in instability followed by a progressive loss of segmental motion. Segmental degeneration is associated with intervertebral disc and facet changes, which can be quantified. Correlating this degeneration with clinical segmental motion has not been investigated in the thoracic spine. The authors sought to determine if imaging-determined degeneration would correlate with native range of motion (ROM) or the change in ROM after decompressive procedures, potentially guiding clinical decision making in the setting of spine trauma or following decompressive procedures in the thoracic spine.
Multidirectional flexibility tests with image analysis were performed on thoracic cadaveric spines with intact ib cage. Specimens consisted of 19 fresh frozen human cadaveric spines, spanning C-7 to L-1. ROM was obtained for each specimen in axial rotation (AR), flexion-extension (FE), and lateral bending (LB) in the intact state and following laminectomy, unilateral facetectomy, and unilateral costotransversectomy performed at either T4–5 (in 9 specimens) or T8–9 (in 10 specimens). Image grading of segmental degeneration was performed utilizing 3D CT reconstructions. Imaging scores were obtained for disc space degeneration, which quantified osteophytes, narrowing, and endplate sclerosis, all contributing to the Lane disc summary score. Facet degeneration was quantified using the Weishaupt facet summary score, which included the scoring of facet osteophytes, narrowing, hypertrophy, subchondral erosions, and cysts.
The native ROM of specimens from T-1 to T-12 (n = 19) negatively correlated with age in AR (Pearson’s r coefficient = -0.42, p = 0.070) and FE (r = -0.42, p = 0.076). When regional ROM (across 4 adjacent segments) was considered, the presence of disc osteophytes negatively correlated with FE (r = −0.69, p = 0.012), LB (r = −0.82, p = 0.001), and disc narrowing trended toward significance in AR (r = −0.49, p = 0.107). Facet characteristics, scored using multiple variables, showed minimal correlation to native ROM (r range from −0.45 to +0.19); however, facet degeneration scores at the surgical level revealed strong negative correlations with regional thoracic stability following decompressive procedures in AR and LB (Weishaupt facet summary score: r = −0.52 and r = −0.71; p = 0.084 and p = 0.010, respectively). Disc degeneration was not correlated (Lane disc summary score: r = −0.06, p = 0.861).
Advanced age was the most important determinant of decreasing native thoracic ROM, whereas imaging characteristics (T1–12) did not correlate with the native ROM of thoracic specimens with intact rib cages. Advanced facet degeneration at the surgical level did correlate to specimen stability following decompressive procedures, and is likely indicative of the terminal stages of segmental degeneration.
Matthew D. Alvin, Jacob A. Miller, Daniel Lubelski, Benjamin P. Rosenbaum, Kalil G. Abdullah, Robert G. Whitmore, Edward C. Benzel and Thomas E. Mroz
Cost-effectiveness research in spine surgery has been a prominent focus over the last decade. However, there has yet to be a standardized method developed for calculation of costs in such studies. This lack of a standardized costing methodology may lead to conflicting conclusions on the cost-effectiveness of an intervention for a specific diagnosis. The primary objective of this study was to systematically review all cost-effectiveness studies published on spine surgery and compare and contrast various costing methodologies used.
The authors performed a systematic review of the cost-effectiveness literature related to spine surgery. All cost-effectiveness analyses pertaining to spine surgery were identified using the cost-effectiveness analysis registry database of the Tufts Medical Center Institute for Clinical Research and Health Policy, and the MEDLINE database. Each article was reviewed to determine the study subject, methodology, and results. Data were collected from each study, including costs, interventions, cost calculation method, perspective of cost calculation, and definitions of direct and indirect costs if available.
Thirty-seven cost-effectiveness studies on spine surgery were included in the present study. Twenty-seven (73%) of the studies involved the lumbar spine and the remaining 10 (27%) involved the cervical spine. Of the 37 studies, 13 (35%) used Medicare reimbursements, 12 (32%) used a case-costing database, 3 (8%) used cost-to-charge ratios (CCRs), 2 (5%) used a combination of Medicare reimbursements and CCRs, 3 (8%) used the United Kingdom National Health Service reimbursement system, 2 (5%) used a Dutch reimbursement system, 1 (3%) used the United Kingdom Department of Health data, and 1 (3%) used the Tricare Military Reimbursement system. Nineteen (51%) studies completed their cost analysis from the societal perspective, 11 (30%) from the hospital perspective, and 7 (19%) from the payer perspective. Of those studies with a societal perspective, 14 (38%) reported actual indirect costs.
Changes in cost have a direct impact on the value equation for concluding whether an intervention is cost-effective. It is essential to develop a standardized, accurate means of calculating costs. Comparability and transparency are essential, such that studies can be compared properly and policy makers can be appropriately informed when making decisions for our health care system based on the results of these studies.