Misinterpretations about CT numbers, material decomposition, and elemental quantification.

BACKGROUND: Quantitative CT imaging, particularly iodine and calcium quantification, is an important CT-based biomarker. PURPOSE: This study quantifies sources of errors in quantitative CT imaging in both single-energy and spectral CT. MATERIALS AND METHODS: This work examines the theoretical relationship between CT numbers, linear attenuation coefficient, and material quantification. We derive four understandings: (1) CT numbers are not proportional with element mass in vivo, (2) CT numbers are proportional with element mass only when contained in a voxel of pure water, (3) iodine-water material decomposition is never accurate in vivo, and (4) for error-free material decomposition a voxel must only consist of the basis decomposition vectors. Misinterpretation-based errors are calculated using the National Institute of Standards and Technology (NIST) XCOM database for: tissue chemical compositions, clinical concentrations of hydroxyapatite (HAP), and iodine. Quantification errors are also demonstrated experimentally using phantoms. RESULTS: In single-energy CT, misinterpretation-induced errors for HAP density in adipose, muscle, lung, soft tissue, and blood ranged from 0-132%, i.e., a mass error of 0-749 mg/cm3. In spectral CT, errors with iodine in the same tissues resulted in a range of < 0.1-33% error, resulting in a mass error of < 0.1-1.2 mg/mL. CONCLUSION: Our work demonstrates material quantification is fundamentally limited when measured in vivo due to measurement conditions differing from assumed and the errors are at or above detection limits for bone mineral density (BMD) and spectral iodine quantification. To define CT-derived biomarkers, the errors we demonstrate should either be avoided or built into uncertainty bounds. CLINICAL RELEVANCE STATEMENT: Improving error bounds in quantitative CT biomarkers, specifically in iodine and BMD quantification, could lead to improvements in clinical care aspects based on quantitative CT. KEY POINTS: CT numbers are only proportional with element mass only when contained in a voxel of pure water, therefore iodine-water material decomposition is never accurate in vivo. Misinterpretation-induced errors ranged from 0-132% for HAP density and < 0.1-33% in spectral CT with iodine. For error-free material decomposition, a voxel must only consist of the basis decomposition vectors.

Structure-sparing resection for the management of cervical chordomas: a retrospective institutional series.

OBJECTIVE: Chordomas are a rare and relatively slow-growing malignancy of notochordal origin with a nearly 50% recurrence rate. Chordomas of the cervical spine are particularly challenging tumors given surrounding vital anatomical structures. Although standard in other areas of the spine, en bloc resection of cervical chordomas is exceedingly difficult and carries the risk of significant postoperative morbidity. Here, the authors present their institutional experience with 13 patients treated with a structure-sparing radical resection and adjuvant radiation for cervical chordomas. METHODS: Records of the standing senior author and institutional database of spinal surgeries were retrospectively reviewed for surgically managed cervical and high thoracic chordomas between 1997 and 2022. Chordomas whose epicenter was cervical but touched the clivus or had extension to the thoracic spine were included in this series. Clinical and operative data were gathered and analyzed for the index surgery and any revisions needed. Outcome metrics such as recurrence rates, complication rates, functional status, progression-free interval (PFI) and overall survival (OS) were evaluated. RESULTS: The median patient age at diagnosis was 57 (range 32-80) years. The median modified Rankin Scale (mRS) score at the time of presentation was 1 (range 0-4). Approximately 40% of tumors were located in the upper cervical spine (occiput-C2). The median time from diagnosis to surgery was 74.5 (range 10-483) days. Gross-total resection was achieved in just under 40% of patients. All patients received adjuvant radiotherapy. The mean duration of follow-up was 4.09 years, with a mean PFI of 3.80 (range 1.16-13.1) years. Five patients experienced recurrence (38.5%). The mean OS was 3.44 years. Three patients died during the follow-up period; 2 due to disease progression and 1 died in the immediate postoperative period. One patient was lost to follow-up. A significant positive relationship was identified between high cervical tumor location and disease recurrence (p = 0.021). CONCLUSIONS: While en bloc resection is appropriate and feasible for tumors in the sacral spine, the cervical region poses a significant technical challenge and is associated with increased postoperative morbidity. Radical resection may allow for achievement of negative operative margins and, along with sparing postoperative morbidity following resection of cervical chordomas, maintaining a similar rate of recurrence when compared with en bloc resection while preserving quality of life.

Work-Related Fatigue Among Indonesian Offshore Oil and Gas Workers.

BACKGROUND: Work-related fatigue, combined with shift work and prolonged work hours, has a significant effect, contributing to increasing accident rate by 50-100%. AIMS: To assess the level of work-related fatigue over a 4-week work period among offshore rig oil and gas workers in Indonesia. METHODS: This cohort study evaluated acute fatigue, chronic fatigue, and intershift recovery scores among offshore oil and gas rig workers using the Occupational Fatigue Exhaustion Recovery 15 (OFER15) questionnaire. Fatigue levels were assessed weekly throughout the study duration, which was 4-week work period. Additionally, at the fourth week, participants were asked about psychosocial factors that could be potentially related to fatigue. RESULTS: Of 67 participants, the average scores of acute and chronic fatigue were 30.0 and 33.3, and the scores had significantly increased over 4 weeks (P < 0.001). The intershift recovery scores statistically significantly decreased over 4 weeks (P < 0.001), and the differences between weeks (Week 1 versus 2, Week 1 versus 3 and Week 1 versus 4) were also statistically significant (P < 0.001). Acute and chronic fatigue scores had a significant positive correlation with psychological job demands and negatively correlated with influence at work and job satisfaction. Over 4 weeks, acute fatigue augmented chronic fatigue, while acute and chronic fatigue demanded a longer recovery. CONCLUSIONS: Workers at the offshore rig experienced work fatigue during their on-duty periods, with the level of fatigue significantly increasing over the 4 weeks. Comprehensive fatigue management at offshore rigs is vital to mitigate work fatigue and minimize the risk of work-related accidents.

CT Number Accuracy and Association With Object Size: A Phantom Study Comparing Energy-Integrating Detector CT and Deep Silicon Photon-Counting Detector CT.

BACKGROUND. Variable beam hardening based on patient size causes variation in CT numbers for energy-integrating detector (EID) CT. Photon-counting detector (PCD) CT more accurately determines effective beam energy, potentially improving CT number reliability. OBJECTIVE. The purpose of the present study was to compare EID CT and deep silicon PCD CT in terms of both the effect of changes in object size on CT number and the overall accuracy of CT numbers. METHODS. A phantom with polyethylene rings of varying sizes (mimicking patient sizes) as well as inserts of different materials was scanned on an EID CT scanner in single-energy (SE) mode (120-kV images) and in rapid-kilovoltage-switching dual-energy (DE) mode (70-keV images) and on a prototype deep silicon PCD CT scanner (70-keV images). ROIs were placed to measure the CT numbers of the materials. Slopes of CT number as a function of object size were computed. Materials' ideal CT number at 70 keV was computed using the National Institute of Standards and Technology XCOM Photon Cross Sections Database. The root mean square error (RMSE) between measured and ideal numbers was calculated across object sizes. RESULTS. Slope (expressed as Hounsfield units per centimeter) was significantly closer to zero (i.e., less variation in CT number as a function of size) for PCD CT than for SE EID CT for air (1.2 vs 2.4 HU/cm), water (-0.3 vs -1.0 HU/cm), iodine (-1.1 vs -4.5 HU/cm), and bone (-2.5 vs -10.1 HU/cm) and for PCD CT than for DE EID CT for air (1.2 vs 2.8 HU/cm), water (-0.3 vs -1.0 HU/cm), polystyrene (-0.2 vs -0.9 HU/cm), iodine (-1.1 vs -1.9 HU/cm), and bone (-2.5 vs -6.2 HU/cm) (p < .05). For all tested materials, PCD CT had the smallest RMSE, indicating CT numbers closest to ideal numbers; specifically, RMSE (expressed as Hounsfield units) for SE EID CT, DE EID CT, and PCD CT was 32, 44, and 17 HU for air; 7, 8, and 3 HU for water; 9, 10, and 4 HU for polystyrene; 31, 37, and 13 HU for iodine; and 69, 81, and 20 HU for bone, respectively. CONCLUSION. For numerous materials, deep silicon PCD CT, in comparison with SE EID CT and DE EID CT, showed lower CT number variability as a function of size and CT numbers closer to ideal numbers. CLINICAL IMPACT. Greater reliability of CT numbers for PCD CT is important given the dependence of diagnostic pathways on CT numbers.

Vertebral multiple myeloma with pathological fracture: the most common etiology for emergency spine surgery in patients with no cancer diagnosis on admission.

OBJECTIVE: Vertebral compression fractures are common in multiple myeloma (MM). Modern treatment paradigms place emphasis on treatment with radiation, with surgery reserved for cases involving frank instability or severe neural compression. However, experience at the authors' institution has led them to suspect a more prominent role for surgical intervention in some settings. The authors undertook the present study to better understand the incidence of MM in undiagnosed patients who require urgent surgery for pathological vertebral fracture. METHODS: The authors reviewed a prospectively collected database of all patients who underwent surgery with the senior author at their main hospital between June 1, 1998, and June 30, 2020. Patients admitted from the emergency room or after transfer from another hospital who then underwent surgery for pathological fracture during the same admission were included in the final analysis. Patients scheduled for elective surgery and those with previous cancer diagnoses were excluded. RESULTS: Forty-three patients were identified as having undergone urgent surgical decompression and/or stabilization for pathological fracture. Histopathology confirmed diagnosis of MM in 22 (51%) patients, lung metastasis in 5 (12%) patients, and breast metastasis in 4 (9%) patients. Twelve (28%) patients were diagnosed with other types of metastatic carcinoma or undifferentiated disease. Sixteen of 29 (55%) men and 6 of 14 (42%) women were diagnosed with MM (p = 0.02). Seventeen of 34 (50%) patients who underwent surgery for neurological deficit, 5 of 6 (83%) patients who underwent surgery for spinal instability, and 0 (0%) patients who underwent surgery for pain with impending spinal cord injury were diagnosed with MM (p = 0.12). CONCLUSIONS: A majority of patients presenting to the authors' hospital with no history of malignancy who required urgent surgery for pathological compression fracture were found to have MM or plasmacytoma. This disease process may affect a significant portion of patients requiring decompressive or stabilizing surgery for compression fracture in academic medical centers.

Incidence of high grade gliomas presenting as radiographically non-enhancing lesions: experience in 111 surgically treated non-enhancing gliomas with tissue diagnosis.

PURPOSE: Although non-enhancing lesions suspicious for glioma are usually assumed to be low grade glioma (LGG), some high grade glioma (HGG) do not enhance, which may lead to a delay in biopsy and/or resection, diagnosis, and treatment initiation. Thus, there is a clear need for a large-sample study that quantifies the rate of malignant, non-enhancing gliomas. METHODS: We retrospectively reviewed our series of 561 consecutive surgically treated gliomas with tissue diagnosis, 111 of which were non-enhancing, to determine the prevalence of high-grade histology in radiographically presumed LGG. Relative expression of tumor markers were also reported for non-enhancing lesions to investigate genetic correlates. RESULTS: We identified 561 surgically treated gliomas with tissue diagnosis from August 2012 to July 2018 and found that 111 patients (19.8%) demonstrated non-enhancing lesions suspicious for glioma on preoperative MRI. Thirty-one (27.9%) of the non-enhancing lesions were classified as HGGs (WHO Grade III or IV). Non-enhancing lesions were four times more likely to be HGG in patients older than 60 years than patients younger than 35 years (41.2% vs. 11.4%, Pearson Chi2 p < 0.001). Binomial logistic regression showed a significant inverse effect of age on the presence of IDH mutation in non-enhancing HGGs (p = 0.007). CONCLUSION: A clinically significant proportion (27.9%) of non-enhancing lesions were found to be HGG on final pathologic diagnosis. Thus, in patients with good functional and health status, especially those older than 60 years, we recommend obtaining tissue diagnosis of all lesions suspected to be glioma, even those that are non-enhancing, to guide diagnosis as well as early initiation of chemotherapy and radiation therapy.

The association between burning mouth syndrome and sleep disturbance: A case-control multicentre study.

OBJECTIVES: To investigate the quality of sleep and the psychological profiles of a large cohort of Italian patients with burning mouth syndrome (BMS) and to clarify the relationships between these variables and pain. METHODS: In this case-control study, 200 patients with BMS vs an equal number of age- and sex-matched healthy controls, recruited in 10 universities, were enrolled. The Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Hamilton Rating Scale for Depression (HAM-D), Hamilton Rating Scale for Anxiety (HAM-A), Numeric Pain Intensity Scale (NRS) and Total Pain Rating Index (T-PRI) were administered. Descriptive statistics, including the Mann-Whitney U test and hierarchical multiple linear regression analysis, were used. RESULTS: Poor sleep quality (PSQI ≥ 5) was present in 78.8% (160) patients with BMS. BMS patients had statistically higher scores in all items of the PSQI and ESS than the healthy controls (p < .001). A depressed mood and anxiety correlated positively with sleep disturbance. The Pearson correlations were 0.570 for the PSQI vs HAM-D (p < .001) and 0.549 for the PSQI vs HAM-A (p < .001). Pain intensity (NRS) poorly correlated to sleep quality; the Pearson correlation was 0.162 for the PSQI vs NRS (p = .021). CONCLUSIONS: The BMS patients showed a poor sleep quality, anxiety and depression, as compared with the controls, highlighting the relationships between oral burning, sleep and mood.

Sleep disturbances, anxiety and depression in patients with oral lichen planus: a case-control study.

BACKGROUND: The psychological factors and their association with chronic inflammatory disease, aren't well recognized, yet their importance in oral lichen planus is still debated. AIMS: The aim of this study was to investigate the prevalence of sleep disturbances, anxiety, depression and their association in patient with oral lichen planus. MATERIALS AND METHODS: 50 patients with oral lichen planus vs. equal number of age and sex-matched healthy controls were enrolled. Questionnaires examining insomnia symptoms, excessive daytime sleepiness (Pittsburgh sleep quality index and Epworth aleepiness scale) depression and anxiety (The Hamilton rating scale for Depression and Anxiety) were used. RESULTS: The patients with oral lichen planus had statistically higher scores in all items of the Pittsburgh sleep quality index, the Hamilton rating scale for depression and anxiety and Epworth sleepiness scale than the healthy controls. The median and inter-quartile range of the Pittsburgh sleep quality index was 5-2 and for the oral lichen planus patients and 4-2 for the healthy controls (P < 0.011). In the study group, a depressed mood and anxiety correlated positively with sleep disturbances. The Pearson correlations were 0.76 for Pittsburgh sleep quality Index vs. Hamilton rating scale for depression (P < 0.001) and 0.77 for Pittsburgh sleep quality Index vs. Hamilton rating scale for anxiety (P < 0.001). DISCUSSION: Oral lichen planus patients report a greater degree of sleep problems, depressed mood and anxiety as compared with controls. CONCLUSION: We suggest to screen sleep disturbances in patients with oral lichen planus because they could be considered a prodromal symptoms of mood disorders.

Predictors of clinical and structural outcomes after surgery for spinal nerve sheath tumor resection: a retrospective analysis.

OBJECTIVE: Resection of spinal nerve sheath tumors (SNSTs) typically necessitates laminectomy, often with facetectomy, for adequate exposure of tumor. While removal of bone affords a greater operative window and extent of resection, it places the patient at greater risk for spinal instability. Although studies have identified risk factors for fusion at the time of tumor resection, there has yet to be a study assessing long-term stability following SNST resection. In this study, the authors sought to identify preoperative and operative risk factors that predispose to long-term spinal instability and investigate clinical variables associated with greater risk for subsequent fusion in the time following initial SNST resection. METHODS: An institutional registry of spinal surgeries was queried at a single institution over a 20-year period. Demographic, clinical, and operative variables were recorded retrospectively and investigated for predictive value of several postoperative sequelae. RESULTS: A total of 122 SNST cases among 112 patients were included. At a mean follow-up time of 27.7 months, patients with a history of neurofibromatosis type 2 (NF2) (p = 0.014) and those who had undergone a laminectomy of ≥ 4 levels at the time of initial SNST resection (p = 0.028) were more likely to present with some degree of structural abnormality or neurological deficit following their initial surgery. The presence of facetectomy, degree of laminectomy, and level of spinal surgery were not found to be predictors of future instability. Ultimately, there was no significant predictor for true spinal instability following index surgery without fusion. A secondary analysis showed that an entirely extradural location (p = 0.044) and facetectomy at index surgery (p = 0.012) were predictive of fusion being performed at the time of tumor resection. Four of the 112 patients required fusion after their index SNST resection, 3 of whom underwent fusion for instability at the level of the index surgery. No variables were identified as predictive for future instrumentation. CONCLUSIONS: Ultimately, the authors conclude that resection of SNSTs does not always necessitate fusion, and good outcomes can be obtained with motion-preserving techniques and minimizing facetectomy when possible. Patients with a history of NF2 and those with SNSTs that required ≥ 4-level laminectomy were more likely to exhibit some degree of structural abnormality and/or neurological deficit localized to the index level defined as either new or worsening spinal instability and/or new or worsening neurological deficit at last follow-up; however, no variable was found to be predictive of true spinal instability. Furthermore, a complete facetectomy at initial SNST resection and entirely extradural tumor location were noted to be associated with fusion at index surgery. Lastly, the authors were unable to identify a clinical predictor for future instrumentation.

Surgical Management of Thoracolumbar Adjacent Segment Disease: Techniques and Outcomes in 107 Patients Undergoing Surgical Intervention.

BACKGROUND: Adjacent segment disease (ASD) is a known sequela of thoracolumbar instrumented fusions. Various surgical options are available to address ASD in patients with intractable symptoms who have failed conservative measures. However, the optimal treatment strategy for symptomatic ASD has not been established. We examined several clinical outcomes utilizing different surgical interventions for symptomatic ASD. METHODS: A retrospective review was performed for a consecutive series of patients undergoing revision surgery for thoracolumbar ASD between October 2011 and February 2022. Patients were treated with endoscopic decompression (N = 17), microdiscectomy (N = 9), lateral lumbar interbody fusion (LLIF; N = 26), or open laminectomy and fusion (LF; N = 55). The primary outcomes compared between groups were re-operation rates and numeric pain scores for leg and back at 2 weeks, 10 weeks, 6 months, and 12 months postoperation. Secondary outcomes included time to re-operation, estimated blood loss, and length of stay. RESULTS: Of the 257 patients who underwent revision surgery for symptomatic ASD, 107 patients met inclusion criteria with a minimum of 1-year follow-up. The mean age of all patients was 67.90 ± 10.51 years. There was no statistically significant difference between groups in age, gender, preoperative American Society of Anesthesiologists scoring, number of previously fused levels, or preoperative numeric leg and back pain scores. The re-operation rates were significantly lower in LF (12.7%) and LLIF cohorts (19.2%) compared with microdiscectomy (33%) and endoscopic decompression (52.9%; P = 0.005). Only LF and LLIF cohorts experienced significantly decreased pain scores at all 4 follow-up visits (2 weeks, 10 weeks, 6 months, and 12 months; P < 0.001 and P < 0.05, respectively) relative to preoperative scores. CONCLUSION: Symptomatic ASD often requires treatment with revision surgery. Fusion surgeries (either stand-alone lateral interbody or posterolateral with instrumentation) were most effective and durable with respect to alleviating pain and avoiding additional revisions within the first 12 months following revision surgery. CLINICAL RELEVANCE: This study emphasizes the importance of risk-stratifying patients to identify the least invasive approach that treats their symptoms and reduces the risk of future surgeries.

Exogenous lipid vesicles induce endocytosis-mediated cellular aggregation in a close unicellular relative of animals.

Capsaspora owczarzaki is a protozoan that may both reveal aspects of animal evolution and also curtail the spread of schistosomiasis, a neglected tropical disease. Capsaspora exhibits a chemically regulated aggregative behavior that resembles cellular aggregation in some animals. This behavior may have played a key role in the evolution of animal multicellularity. Additionally, this aggregative behavior may be important for Capsaspora 's ability to colonize the intermediate host of parasitic schistosomes and potentially prevent the spread of schistosomiasis. Both applications demand elucidation of the molecular mechanism of Capsaspora aggregation. Toward this goal, we first determined the necessary chemical properties of lipid cues that activate aggregation. We found that a wide range of abundant zwitterionic lipids induced aggregation, revealing that the aggregative behavior could be activated by diverse lipid-rich conditions. Furthermore, we demonstrated that aggregation in Capsaspora requires clathrin-mediated endocytosis, highlighting the potential significance of endocytosis-linked cellular signaling in recent animal ancestors. Finally, we found that aggregation was initiated by post-translational activation of cell-cell adhesion-not transcriptional regulation of cellular adhesion machinery. Our findings illuminate the chemical, molecular and cellular mechanisms that regulate Capsaspora aggregative behavior-with implications for the evolution of animal multicellularity and the transmission of parasites.

Spatial Resolution Fidelity Comparison Between Energy Integrating and Deep Silicon Photon Counting CT: Implications for Pulmonary Imaging.

PURPOSE: We investigated spatial resolution loss away from isocenter for a prototype deep silicon photon-counting detector (PCD) CT scanner and compare with a clinical energy-integrating detector (EID) CT scanner. MATERIALS AND METHODS: We performed three scans on a wire phantom at four positions (isocenter, 6.7, 11.8, and 17.1 cm off isocenter). The acquisition modes were 120 kV EID CT, 120 kV high-definition (HD) EID CT, and 120 kV PCD CT. HD mode used double the projection view angles per rotation as the "regular" EID scan mode. The diameter of the wire was calculated by taking the full width of half max (FWHM) of a profile drawn over the radial and azimuthal directions of the wire. Change in wire diameter appearance was assessed by calculating the ratio of the radial and azimuthal diameter relative to isocenter. t tests were used to make pairwise comparisons of the wire diameter ratio with each acquisition and mean ratios' difference from unity. RESULTS: Deep silicon PCD CT had statistically smaller (P<0.05) changes in diameter ratio for both radial and azimuthal directions compared with both regular and HD EID modes and was not statistically different from unity (P<0.05). Maximum increases in FWMH relative to isocenter were 36%, 12%, and 1% for regular EID, HD EID, and deep silicon PCD, respectively. CONCLUSION: Deep silicon PCD CT exhibits less change in spatial resolution in both the radial and azimuthal directions compared with EID CT.

Delayed subdural fluid collections after Ommaya reservoir placement.

BACKGROUND: Delayed subdural fluid collections can occur after Ommaya reservoir placement and can cause neurological symptoms and interfere with treatment. We performed a retrospective chart review to study risk factors for delayed subdural fluid collections and clinical outcomes. METHODS: Retrospective chart review was performed for patients undergoing Ommaya reservoir placement between 2010-2019 at our institution. RESULTS: Out of 53 patients who had Ommaya reservoir placement during the study period, 11 developed delayed subdural fluid collections (21%). HIV infection was the only statistically significant risk factor (P=0.001, Fisher's Exact Test). Thrombocytopenia, ventricle size, use of the reservoir, and suboptimal catheter placement were not associated with development of delayed subdural fluid collections. 2 patients, both HIV positive, required surgical evacuation. CONCLUSIONS: Delayed subdural fluid collections occur in a significant minority of patients after Ommaya reservoir placement, and some patients require surgical intervention. HIV infection is associated with a higher risk of development of delayed subdural fluid collections. This patient subpopulation may benefit from closer monitoring or adjustment of management protocols.

Transdural Approach for Resection of Craniovertebral Junction Cysts: Case Series.

BACKGROUND: Craniovertebral junction (CVJ) cysts, including retro-odontoid pseudotumors, are challenging pathologies to treat and manage effectively. Surgical intervention is indicated when these lesions result in progressive myelopathy, intractable pain, or instability. OBJECTIVE: To present a case series of older patients who underwent successful resection retro-odontoid lesions using transdural approach. METHODS: A single-center, retrospective observation study of older patients who underwent transdural resection of CVJ cysts at a single institution was performed. Summary demographic information, clinical presentation, perioperative and intraoperative imaging, and Nurick scores were collected and analyzed. RESULTS: Eight patients were included (mean age [±SD] 75.88 ± 9.09 years). All patients presented with retro-odontoid lesions resulting in severe cervical stenosis, cord compression, and myelopathy. The mean duration of surgery was 226 ± 83.7 minutes. The average intraoperative blood loss was 181.2 cc. The average hospital stay was 4.5 days ± 1.3 (range, 3-7 days). The average follow-up time was 12.5 ± 9.5 months. No intraoperative complications were encountered. The Nurick classification score for myelopathy improved at the final postoperative examination (2.38 ± 1.06 vs 1 ± 1.07). Three patients demonstrated a pre-existing deformity prompting an instrumented fusion. Both computed tomography and MRI evidence of complete regression of retro-odontoid cyst were noted in all patients on the final follow-up. CONCLUSION: Posterior cervical transdural approach for ventral lesions at the CVJ is a safe and effective means of treating older patients with progressive myelopathy. This technique provides immediate spinal cord decompression while limiting neurological complications commonly associated with open or endoscopic anterior transpharyngeal approaches.

Percutaneous Direct Pars Repair in Young Athletes.

BACKGROUND: Lumbar pars defects are common in adolescent athletes and are often due to recurrent axial loading and traumatic stressors. OBJECTIVE: To present an updated case series of young athletes who underwent percutaneous direct pars repair after failure of conservative management. METHODS: A single-center, nonrandomized, retrospective observation study of athletes who were referred for minimally invasive direct pars repair after failure of at least 6 months of conservative management was performed. Summary demographic information, clinical features of presentation, perioperative and intraoperative radiographic imaging, and visual analog scale back pain scores were collected and analyzed. RESULTS: A total of 21 patients were included (mean age [± SD] 17.47 ± 3.02 years, range 14-25 years), 6 of whom were female (29%). All patients presented with bilateral pars fractures, with L5 being the most frequent level involved (n = 13). The average follow-up time was 31.52 ± 9.38 months (range 3-110 months). The visual analog scale score for back pain was significantly reduced from 7.62 ± 1.83 preoperatively to 0.28 ± 0.56 at the final postoperative examination (P < .01). Fusion was noted in 20 of the 21 patients on final follow-up (95%). CONCLUSION: Percutaneous direct pars repair is a safe and effective means in treating young adolescents who have failed conservative management. The advantages included minimized muscle and soft tissue dissection, reduced blood loss, and early mobilization and recovery. In young athletes who desire return to high-level physical activity, this surgical technique is of particular benefit and should be considered in this patient population.

Use of intraoperative topical antibiotics to reduce intrathecal baclofen pump surgical site infections: a single institution's experience over 24 years.

OBJECTIVE: Patients requiring intrathecal baclofen (ITB) therapy are at high risk for surgical site infections (SSIs) given their poor functional status. After years of a nominal infection rate, there was an inexplicable increase in ITB pump infections at the authors' institution and multiple investigations offered no solution. Use of intraoperative topical antibiotics is well-documented in the orthopedic literature and was considered for ITB pump insertion. In this study, the authors investigated whether intraoperative vancomycin and tobramycin powder at the ITB pump site could reduce SSIs. METHODS: Operative and infection data were collected and analyzed retrospectively to determine the efficacy of this change. Patients were stratified into three cohorts (1998-2009, 2010-2012, and 2013-2021) to better understand the trends before and after implementation of intraoperative topical antibiotics. Each cohort had similar demographics. RESULTS: One hundred fifty-four patients underwent 272 ITB pump procedures between 1998 and 2021 (131 in 1998-2009, 49 in 2010-2012, and 92 in 2013-2021) for cerebral palsy (69.5%), spastic quadriparesis due to traumatic brain injury (7.1%), anoxic brain injury (6.5%), and other causes (16.9%). Infection rates were reduced from a high of 32% in 2010-2011 to 3.8% over the last 2.5 years (p = 0.0094). There were no adverse effects from the use of topical antibiotics. CONCLUSIONS: In the setting of an intractable rise in ITB pump infections, the addition of intraoperative topical antibiotics significantly reduced postoperative infections in a high-risk population. One could appreciate a significant drop each year in the rate of infections after the institution of intraoperative topical antibiotics. The reduction in SSIs significantly improved the long-term outcomes for these patients.

Efficacy of Reverse and Modified Bohlman Technique for Lumbar Spondylolisthesis: A Systematic Review of the Literature.

OBJECTIVE: High-grade lumbar spondylolisthesis (HGLS) remains a challenging surgical entity, and there is no current consensus regarding optimal surgical approach. The purpose of this study was to systematically review the literature for studies utilizing the reverse or modified Bohlman technique for the treatment of HGLS to assess their safety and efficacy. METHODS: The authors performed a literature search of PubMed/MEDLINE electronic databases from their inception according to the PRISMA guidelines. RESULTS: A total of 8 studies were included. The studies comprised a total of 43 patients, with mean age of 41.4 ± 19.8 (range: 9-83) years. The mean follow-up was 38.2 ± 41.7 (range: 3-137) months. Most patients (81.4%) were classified as having grade III or higher spondylolisthesis. The most common presenting symptom was back pain (93%), followed by radiculopathy in roughly half of patients (41.9%). The majority of patients (93%) experienced complete resolution of symptoms as well as successful fusion (90.7%) on follow-up. Complications included cage/graft failure (7%), nerve injury (7%), wound infection (7%), pseudoarthrosis (2.3%), epidural hematoma (2.3%), and deep vein thrombosis (2.3%). Revision surgery was required in 4 (9.3%) patients. Slip percentage (60.2% vs. 43.2%, P < 0.0001) and slip angle (17.1° vs. 6.4°, P < 0.001) both decreased significantly following surgery. CONCLUSIONS: Our data demonstrate that reverse and modified Bohlman techniques appear to be effective in both improving slip angle/percentage and relieving symptoms with low risk of complications. These findings are limited by the small sample size of patients. The authors recommend larger series before formal recommendations can be made.

Conservative Management of Post-Operative Cerebrospinal Fluid Leak following Skull Base Surgery: A Pilot Study.

BACKGROUND/AIMS: Iatrogenic CSF leaks after endoscopic endonasal transsphenoidal surgery remain a challenging entity to manage, typically treated with CSF diversion via lumbar drainage. OBJECTIVE: To assess the safety and efficacy of high-volume lumbar puncture (LP) and acetazolamide therapy to manage iatrogenic CSF leaks. METHODS: We performed a prospective pilot study of four patients who developed iatrogenic postoperative CSF leaks after transsphenoidal surgery and analyzed their response to treatment with concomitant high-volume lumbar puncture followed by acetazolamide therapy for 10 days. Data collected included demographics, intra-operative findings, including methodology of skull base repair and type of CSF leak, time to presentation with CSF leak, complications associated with high-volume LP and acetazolamide treatment, and length of follow-up. RESULTS: Mean patient age was 44.28 years, with an average BMI of 27.4. Mean time from surgery to onset of CSF leak was 7.71 days. All four patients had resolution of their CSF leak at two- and four-week follow-up. Mean overall follow-up time was 179 days, with a 100% CSF leak cure rate at the last clinic visit. No patient suffered perioperative complications or complications secondary to treatment. CONCLUSION: Although our pilot case series is small, we demonstrate that a high-volume LP, followed by acetazolamide therapy for 10 days, can be considered in the management of post-operative CSF leaks.

Diaphragmatic Hernia With Incarcerated Spleen as a Complication After Lateral Anterior Column Realignment.

BACKGROUND: The creation of sagittal balance of the spine is critical in the treatment adult spinal deformity. Anterior column release (ACR) has gained traction as a minimally invasive alternative to pedicle subtraction osteotomy. By releasing the anterior longitudinal ligament, the anterior column can be lengthened and physiologic lordosis restored. Risks such as transient psoas weakness and thigh numbness have been well documented in the literature; however, diaphragmatic hernia has never been reported. OBJECTIVE: To highlight the difficulties encountered in diagnosing, managing, and treating iatrogenic diaphragmatic hernia in the setting of ACR and stress the relevant retropleural, retroperitoneal, and diaphragmatic structures during the surgical approach. METHODS: In this technical note, we discuss the relevant anatomy in a direct lateral approach to the thoracolumbar junction and the management of an iatrogenic diaphragmatic hernia, which occurred in a patient who underwent a L1 ACR. RESULTS: Three months after surgery, our patient was assessed in clinic and endorsed significant improvements in her pain and mobility. Her 3-month postoperative scoliosis x-rays demonstrated a significant improvement in her sagittal alignment, and she experienced no further negative sequelae from the iatrogenic hernia. CONCLUSION: Iatrogenic diaphragmatic hernia with an intrathoracic spleen after direct lateral ACR is a risk spine surgeons should be aware of and address promptly.

Fusiform Dilatation of the Internal Carotid Artery in Childhood-Onset Craniopharyngioma: A Systematic Review.

OBJECTIVE: Patients with fusiform dilatation of the carotid artery (FDCA) following pediatric craniopharyngioma resection typically have a benign clinical course. We reviewed the neurosurgical literature for FDCA outcomes after resection of these tumors. METHODS: Using PubMed, Web of Science, and Cochrane databases, we identified surgical series or case reports reporting incidences of FDCA following craniopharyngioma resection. Inclusion criteria included FDCA outcomes reported specifically after craniopharyngioma resection, with at least 6 months of follow-up data. RESULTS: Our literature search yielded 15 full-text articles comprising 799 patients (376 [52.3%] males). The weighted mean follow-up was 74.8 months (range, 9-140 months). Most tumors were suprasellar (62.1%), with traditional microsurgery being more commonly employed than endoscopic endonasal surgery (80.9% vs. 19.1%). Gross total resection was achieved in 42.6% of cases. There were 55 aneurysms reported, most commonly occurring at the terminal internal carotid artery (66.7%). Aneurysmal progression on follow-up occurred in 10 (18.5%) cases, with no reports of rupture. Ten (18.2%) aneurysms were treated with clipping, endovascular, or bypass techniques. CONCLUSIONS: FDCA is a rare complication following pediatric craniopharyngioma resection. The exact cause is unclear, and factors related to tumor invasiveness, size, location, and differences in surgical approach may contribute to FDCA development. Most patients who go on to develop FDCA have an innocuous course on follow-up, with no reports of rupture in the present literature. For this reason, patients rarely require surgical or endovascular intervention for these lesions, and conservative management is favored.