Multidisciplinary surgical considerations for en bloc resection of sacral chordoma: review of recent advances and a contemporary single-center series.

OBJECTIVE: Contemporary management of sacral chordomas requires maximizing the potential for recurrence-free and overall survival while minimizing treatment morbidity. En bloc resection can be performed at various levels of the sacrum, with tumor location and volume ultimately dictating the necessary extent of resection and subsequent tissue reconstruction. Because tumor resection involving the upper sacrum may be quite destabilizing, other pertinent considerations relate to instrumentation and subsequent tissue reconstruction. The primary aim of this study was to survey the surgical approaches used for managing primary sacral chordoma according to location of lumbosacral spine involvement, including a narrative review of the literature and examination of the authors' institutional case series. METHODS: The authors performed a narrative review of pertinent literature regarding reconstruction and complication avoidance techniques following en bloc resection of primary sacral tumors, supplemented by a contemporary series of 11 cases from their cohort. Relevant surgical anatomy, advances in instrumentation and reconstruction techniques, intraoperative imaging and navigation, soft-tissue reconstruction, and wound complication avoidance are also discussed. RESULTS: The review of the literature identified several surgical approaches used for management of primary sacral chordoma localized to low sacral levels (mid-S2 and below), high sacral levels (involving upper S2 and above), and high sacral levels with lumbar involvement. In the contemporary case series, the majority of cases (8/11) presented as low sacral tumors that did not require instrumentation. A minority required more extensive instrumentation and reconstruction, with 2 tumors involving upper S2 and/or S1 levels and 1 tumor extending into the lower lumbar spine. En bloc resection was successfully achieved in 10 of 11 cases, with a colostomy required in 2 cases due to rectal involvement. All 11 cases underwent musculocutaneous flap wound closure by plastic surgery, with none experiencing wound complications requiring revision. CONCLUSIONS: The modern management of sacral chordoma involves a multidisciplinary team of surgeons and intraoperative technologies to minimize surgical morbidity while optimizing oncological outcomes through en bloc resection. Most cases present with lower sacral tumors not requiring instrumentation, but stabilizing instrumentation and lumbosacral reconstruction are often required in upper sacral and lumbosacral cases. Among efforts to minimize wound-related complications, musculocutaneous flap closure stands out as an evidence-based measure that may mitigate risk.

Prenatal Neurosurgical Counseling for Myelomeningocele and Treatment-Determining Factors for Fetal Repair.

INTRODUCTION: Spina bifida guidelines recommend neurosurgical involvement in prenatal counseling to inform decision-making between prenatal and postnatal myelomeningocele (MMC) repair. This study examines whether families with MMC presenting to one fetal center had timely neurosurgical prenatal counseling (nPNC) encounters and assesses modifiable and non-modifiable treatment-determining factors. METHODS: History and timing of nPNC were quantified among infants undergoing postnatal and prenatal MMC repair, pregnant patients referred, and MMC studies in a fetal MRI database (2015-2023). Fetal repair exclusions, presentation timing, social determinants, and reported rationale for not selecting offered fetal therapy were assessed. RESULTS: Nearly all patients (34/35; 97%) engaged in nPNC, 82% prior to 24 weeks GA. Fourteen patients were excluded from fetal repair for lack of hindbrain herniation (43%), obstetric exclusions (21%), fetal exclusions (21%), suspected closed defect (7%), and delayed presentation (7%). These patients ultimately underwent postnatal repair (71%), and pregnancy termination (14%). The 20 fetal-repair-eligible patients selected fetal repair (50%), postnatal repair (45%), and pregnancy termination (5%). Reasons for declining fetal repair included risk (55%) and cost (22%). CONCLUSIONS: Among MMC families presenting to a regional fetal therapy center, nPNC was widely extended, in a mostly timely fashion. Very few were deterred from fetal repair by potentially modifiable barriers.

Cooperativity of silanol defect chemistry in zeolites.

Deboronation treatment of zeolite B-SSZ-55 can generate vacancy defects consisting of four silanol groups (silanol nests). However, 1H solid-state NMR spectroscopy indicates the prevalence of two silanol groups (silanol dyads) instead of four silanol groups. Such silanol dyads must be formed by the silanol condensation of two silanol groups at the silanol nests. Yet, the exact mechanism of this condensation and detailed structure of the silanol defect are not known. Here, the structure and formation mechanism of silanol dyads in the SSZ-55 zeolite have been investigated by both cluster and periodic density functional theory calculations. The calculated 1H NMR chemical shifts agree with the experimental values, showing that the silanol dyads are indeed commonly present at the vacancies and the vacancy density plays a role in the relaxation of the zeolite framework. The nature (size) of the silanol clusters influences their acidity.

Hydrogen Bonds Dominate Brønsted Acid Sites in Zeolite SSZ-42: A Classification of Their Diversity.

The zeolite catalyst SSZ-42 shows a remarkable high abundance (≈80 %) of hydrogen-bonded Brønsted acid sites (BAS), which are deshielded from the 1 H chemical shift of unperturbed BAS at typically 4 ppm. This is due to their interaction with neighboring oxygen atoms in the zeolite framework when oxygen alignments are suitable. The classification and diversity of hydrogen bonding is assessed by DFT calculations, showing that oval-shaped 6-rings and 5-rings allow for a stronger hydrogen bond to oxygen atoms on the opposite ring side, yielding higher experimental chemical shifts (δ (1 H)=6.4 ppm), than circular 6-rings (δ(1 H)=5.2 ppm). Cage-like structures and intra-tetrahedral interactions can also form hydrogen bonds. The alignment of oxygen atoms is expected to impact their role in the stabilization of intermediates in catalytic reactions, such as surface alkoxy groups and possibly transition states.

Characterization of a Molecule Partially Confined at the Pore Mouth of a Zeotype.

We investigate the interaction between a molecule and a pore mouth-a critical step in adsorption processes-by characterizing the conformation of a macrocyclic calix[4]arene-TiIV complex, which is grafted on the external surface of a zeotype (*-SVY). X-ray absorption and 13 C{1 H} CPMAS NMR spectroscopies independently detect a unique conformation of this complex when it is grafted at crystallographically equivalent locations that lie at the interface of 7 Šhemispherical microporous cavities and the external surface. Electronic structure calculations support the presence of this unique conformation, and suggest that it is brought about by a specific orientation of the macrocycle that maximizes non-covalent interactions between calix[4]arene upper-rim tert-butyl substituents and the microporous-cavity walls. Our comparative study provides a rare "snapshot" of a molecule partially confined at a pore mouth, an essential intermediate for adsorption into micropores, and demonstrates how surrounding environment controls this confinement in a sensitive fashion.

A Stable Silanol Triad in the Zeolite Catalyst SSZ-70.

Nests of three silanol groups are located on the internal pore surface of calcined zeolite SSZ-70. 2D 1 H double/triple-quantum single-quantum correlation NMR experiments enable a rigorous identification of these silanol triad nests. They reveal a close proximity to the structure directing agent (SDA), that is, N,N'-diisobutyl imidazolium cations, in the as-synthesized material, in which the defects are negatively charged (silanol dyad plus one charged SiO- siloxy group) for charge balance. It is inferred that ring strain prevents the condensation of silanol groups upon calcination and removal of the SDA to avoid energetically unfavorable three-rings. In contrast, tetrad nests, created by boron extraction from B-SSZ-70 at various other locations, are not stable and silanol condensation occurs. Infrared spectroscopic investigations of adsorbed pyridine indicate an enhanced acidity of the silanol triads, suggesting important implications in catalysis.

Outer-Sphere Control of Catalysis on Surfaces: A Comparative Study of Ti(IV) Single-Sites Grafted on Amorphous versus Crystalline Silicates for Alkene Epoxidation.

The effect of outer-sphere environment on alkene epoxidation catalysis using an organic hydroperoxide oxidant is demonstrated for calix[4]arene-TiIV single-sites grafted on amorphous vs crystalline delaminated zeotype (UCB-4) silicates as supports. A chelating calix[4]arene macrocyclic ligand helps enforce a constant TiIV inner-sphere, as characterized by UV-visible and X-ray absorption spectroscopies, thus enabling the rigorous comparison of outer-sphere environments across different siliceous supports. These outer-sphere environments are characterized by solid-state 1H NMR spectroscopy to comprise proximally organized silanols confined within 12 membered-ring cups in crystalline UCB-4, and are responsible for up to 5-fold enhancements in rates of epoxidation by TiIV centers.

Ultrastabilization of Zeolite†Y Transforms Brønsted-Brønsted Acid Pairs into Brønsted-Lewis Acid Pairs.

Two pairs of Brønsted acid sites have been identified in H,Na-Y zeolite, located in the supercage and in the sodalite cage, which upon ultrastabilization (dealumination) are transformed into pairs of Brønsted and Lewis acid sites. This mild postsynthetic modification step is an important process for converting this material into an active catalyst for large-scale commercial reactions. Pairing structures and their transformations have been investigated using 1 H double-quantum NMR spectroscopy experiments for dehydrated zeolite, H,Na-Y, and its ultrastabilized form, H,Na-USY. This approach enables the detection of pairs of Brønsted and Lewis acid sites with unprecedented 1 H resolution and distinguishing them from isolated acid sites. The dealumination is also detected by static 27 Al solid-state NMR experiments.

Efficacy of Child Abuse Evaluations for Infants With Possible Subdural Hemorrhage Identified on Cranial Ultrasound Completed for Macrocephaly.

Abusive head trauma (AHT) is a significant cause of morbidity and mortality for infants. Determining when to pursue a complete physical abuse evaluation can be difficult, especially for nonspecific findings or when a child appears clinically well. This retrospective study of 7 cases sought to describe the presentation, evaluation, and diagnoses for infants with abnormal subdural collections identified on cranial ultrasound for macrocephaly, and to determine how frequently AHT is diagnosed. The results of this study showed that while each patient presented due to asymptomatic macrocephaly, the extent of the workup varied greatly. In addition, no infants had suspicious injuries for abuse during the initial evaluation or the year following. In summary, among the 7 patients seen for asymptomatic macrocephaly with possible subdural hemorrhage, there were very inconsistent child abuse workups. There needs to be a standardized clinical guideline for this specific patient population involving a child abuse pediatric evaluation.

Animal model considerations for chordoma research: reproducing the tumor microenvironment in vivo with humanized mice.

Animal models have been commonly used in immunotherapy research to study the cell response to external agents and to assess the effectiveness and safety of new therapies. Over the past few decades, immunocompromised (also called immunodeficient) mice allowed researchers to grow human tumor cells without the impact of the host's immune system. However, while this model is very valuable to understand the tumor biology and to understand the underlying mechanism of immunotherapy, the results may not always directly translate to humans. The tumor microenvironment has significant implications for tumor engraftment, growth, invasion, etc., and the immune system plays a critical role in shaping the tumor microenvironment. Human immunocompetent mice, also named humanized mice, are engineered mice that possess functional human immune cells. This in vivo model can be used to effectively study the effect of the human immune system to a human implanted tumor. Moreover, this can effectively mimic the response to treatment. This section is an overview of the current understanding of the different humanized mice that could be utilized to mimic the tumor microenvironment in chordoma.

Endoscopic Lateral Lumbar Interbody Fusion: Technical Note and Case Series.

BACKGROUND: Our objective is to describe a minimally invasive endoscopic surgical technique for performing lateral lumbar interbody fusion (LLIF). LLIF is a common approach to lumbar fusion in cases of degenerative lumbar disease; however, complications associated with psoas and lumbar plexus injury sometimes arise. The endoscopic modification presented here diminishes the requirement for sustained muscle retraction, minimizing complication risk while allowing for adequate decompression in select cases. METHODS: Endoscopic LLIF (ELLIF) was performed in 3 patients from 2019 to 2021. Surgeries were performed in the lateral position under general anesthesia with neurophysiological monitoring. Discectomy, endplate preparation, and harvesting of iliac crest bone were performed through a working channel endoscope. The introduction of an interbody cage (Joimax EndoLIF) was performed over a nitinol blunt-tip wire (Joimax). No expandable blade retractors were required. RESULTS: At 2-year follow-up of these 3 patients, the mean visual analog scale (VAS) score for leg pain improved from 9.3 to 1.7, and the mean Oswestry Disability Index (ODI) score improved from 40 to 8.3. There were no complications, readmissions, or recurrence of symptoms during the 2-year follow-up period. Patients spent an average of 36 hours in the hospital postoperatively and returned to normal daily activities after an average of 48 days. CONCLUSIONS: A minimally invasive modification to the LLIF procedure is presented that offers several potential advantages due to the application of endoscopic techniques: reduced muscle retraction, smaller incision, and the opportunity to perform both indirect decompression and endoscopically visualized discectomy in the same fusion procedure. CLINICAL RELEVANCE: The proposed endoscopic lateral lumbar interbody fusion and decompression is a minimally invasive technique that may provide patients with minimal complications, quick recovery, and good functional recovery.

Therapeutic Opportunities for Biomarkers in Metastatic Spine Tumors.

For many spine surgeons, patients with metastatic cancer are often present in an emergent situation with rapidly progressive neurological dysfunction. Since the Patchell trial, scoring systems such as NOMS and SINS have emerged to guide the extent of surgical excision and fusion in the context of chemotherapy and radiation therapy. Yet, while multidisciplinary decision-making is the gold standard of cancer care, in the middle of the night, when a patient needs spinal surgery, the wealth of chemotherapy data, clinical trials, and other medical advances can feel overwhelming. The goal of this review is to provide an overview of the relevant molecular biomarkers and therapies driving patient survival in lung, breast, prostate, and renal cell cancer. We highlight the molecular differences between primary tumors (i.e., the patient's original lung cancer) and the subsequent spinal metastasis. This distinction is crucial, as there are limited data investigating how metastases respond to their primary tumor's targeted molecular therapies. Integrating information from primary and metastatic markers allows for a more comprehensive and personalized approach to cancer treatment.

Excision of a supergiant spinal schwannoma: illustrative case.

BACKGROUND: The authors report on a patient who presented with an extremely large presacral schwannoma and subsequent mass effect-induced hydronephrosis and kidney failure. To the authors' knowledge, this case represents the largest radiographically verified spinal schwannoma in the medical literature. The tumor presented here was more than three times as large as a typical giant schwannoma. While smaller presacral schwannomas are usually uncomplicated surgical cases, the supergiant schwannomas described here create significant surgical challenges. OBSERVATIONS: The extremely large size of this nerve sheath tumor introduced a level of surgical complexity not seen in most spinal schwannoma cases. The authors hope that this case informs surgeons regarding the approach to excision of giant spinal schwannomas. LESSONS: The resection of giant spinal schwannomas is likely to involve one or more lengthy surgeries, and the resection volume can be limited by excessive bleeding. Physicians approaching these large, benign spinal tumors should be aware of the challenges of surgery duration and hemostasis before approaching a tumor of this kind. https://thejns.org/doi/10.3171/CASE24224.

The influence of third-body particles on wear rate in unicondylar knee arthroplasty: a wear simulator study with bone and cement debris.

The reduced intraoperative visibility of minimally invasive implanted unicondylar knee arthroplasty makes it difficult to remove bone and cement debris, which have been reported on the surface of damaged and retrieved bearings. Therefore, the aim of this study was to analyze the influence of bone and cement particles on the wear rate of unicompartmental knee prostheses in vitro. Fixed bearing unicompartmental knee prostheses were tested using a knee-wear-simulator according to the ISO standard 14243-1:2002(E) for 5.0 million cycles. Afterwards bone debris (particle size 671 ± 262 µm) were added to the test fluid in a concentration of 5 g/l for 1.5 million cycles, followed by 1.5 million cycles blended with cement debris (particle size 644 ± 186 µm) in the same concentration. Wear rate, knee-kinematics and wear-pattern were analyzed. The wear rate reached 12.5 ± 1.0 mm³/million cycles in the running-in and decreased during the steady state phase to 4.4 ± 0.91 mm³/million cycles. Bone particles resulted in a wear rate of 3.0 ± 1.27 mm³/million cycles with no influence on the wear rate compared to the steady state phase. Cement particles, however, lead to a significantly higher wear rate (25.0 ± 16.93 mm³/million cycles) compared to the steady state phase. The careful removal of extruded cement debris during implantation may help in reducing wear rate. Bone debris are suggested to have less critical influence on the prostheses wear rate.

Medical Evaluations in Rhode Island for Suspected Child Abuse and Neglect Prior to and During the COVID-19 Pandemic.

During the COVID-19 pandemic, there was an increase in several risk factors for child maltreatment. There was also a sudden decrease in the systems available to identify and support at risk children and families. This study aims to describe the number of children presenting to specialized medical care for suspected child abuse and neglect during the first seven months of the COVID-19 pandemic compared to the three previous years. This was a retrospective chart review of all cases evaluated by the child abuse team in Rhode Island from March 1st until September 30th of 2017, 2018, 2019 and 2020. During the first seven months of the COVID-19 pandemic, there were 10% fewer children evaluated by the child abuse team with the most significant decrease (35%) in the number of children evaluated for physical abuse. With the known increased risk factors for physical abuse due to COVID-19, the decrease in the number of children evaluated for physical abuse is unlikely due to a decrease in the incidence of physical abuse. This decrease is most likely due to physical abuse not being identified or children not being referred to specialized medical care. Without the ability to see and interact with children in person, professionals' ability to identify child victims of abuse is limited. Professionals working with children and families at risk should develop strategies to be able to continue to provide in-person services in the future if another pandemic or natural disaster occurs.

Shedding light on emerging therapeutic targets for chordoma.

INTRODUCTION: Despite encouraging advances in radiation and surgical treatment, chordomas remain resistant to chemotherapy and local recurrence is common. Although the primary mechanism of recurrence is local, metastatic disease occurs in a small subset of patients. Recurrence may also occur along the surgical trajectory if care is not taken to fully excise the open biopsy pathway. There is increasing morbidity with reoperation upon disease recurrence, and radiation is an option for cytoreduction in primary disease or for recurrent disease, although toxicity may be observed with high-dose therapies. Given these challenges, targeted chemotherapeutic agents for postoperative adjuvant treatment are needed. AREAS COVERED: In this review, we summarize the genetic drivers of chordoma and the state of the current research in chordoma immunotherapy and epigenetics. EXPERT OPINION: Chordoma is a heterogenous tumor that should be targeted from different angles and the study of its characteristics, from molecular to immunological to epigenetic, is necessary. Combining different approaches, such as studying noninvasive patient methylation patterns with tissue-based molecular and drug screening, can transform patient care by guiding treatment decisions based on prognostic mechanisms from different sources, while helping individualize surgical planning and treatment.

Anogenital HSV in Children: Should Providers Be Concerned for Sexual Abuse?

OBJECTIVE: Anogenital herpes simplex virus (HSV) is most commonly acquired via sexual transmission, although other nonsexual modes of transmission have been proposed. When a child presents with a first-time outbreak of anogenital HSV, providers must consider sexual abuse. There are currently no evidence-based consensus guidelines to inform management of these patients. The purpose of this study was to describe how child abuse pediatricians (CAPs) evaluate children with anogenital HSV infection and determine whether any consistent practice patterns are followed. PARTICIPANTS AND SETTING: The patients included in this study were children between the ages of 0 and 12 years with a first-time outbreak of anogenital HSV who were medically evaluated by a CAP. METHODS: Patient charts were retroactively reviewed for the period of January 1 2004 to May 1 2020. RESULTS: Twenty-two cases were referred for evaluation by a CAP in the chosen time frame. Fifteen were seen in person. Ten of these patients were interviewed, 15 had an anogenital exam with colposcopy, and 14 were tested for at least one other sexually transmitted infection. A diagnosis of sexual abuse was made for 1 patient. CONCLUSION: This study demonstrates that although nonsexual transmission of anogenital HSV may be possible, providers must still consider sexual abuse. Children with a first-time outbreak of anogenital HSV should have a comprehensive evaluation for sexual abuse, including interview, physical exam, and testing for sexually transmitted infections. Evidence-based concerns for sexual abuse should be reported to child protective services.

Climate and human mortality in Virginia, 2005-2020.

Using an extensive database of every resident death in Virginia from 2005 to 2020, climate-mortality relationships are examined for 12 climatically homogeneous regions within the Commonwealth. Each region is represented by a first-order weather station from which archived temperature and humidity data are used to generate a variety of biometeorologically relevant indices. Using these indices and other variables (such as air quality and heat and cold waves), daily mortality and climate relationships are modeled for each region over a 21-day lag period utilizing generalized additive models and distributed lag non-linear models. Optimal models are identified for each region, and a consensus model was also run based on maximum temperature to facilitate inter-regional comparisons. The relative risk of mortality varies markedly as a function of climate between regions, with U-shaped, J-shaped, and inverse linear relationships evident. Cold mortality exceeds heat mortality across most of Virginia (typical relative risks are 1.10 for cold and 1.03 for heat), with cold risks strongest at lags 3 to 10. Low temperatures (or low humidity) are protective at lags 0-2 days except in the colder, western parts of state. Heat mortality occurs at short lags (0-2 days) for three-fourths of the stations, but the spatial pattern is random. Mortality displacement is evident for most regions for several days following the heat-related spike. Although the use of region-specific models is justified, the simple consensus model based on a consistent set of predictors provides similar results.

Serial T2-Weighted Thoracic and Abdominal Lymphatic Imaging in Fontan Patients-New Insights into Dynamics of Lymphatic Abnormalities after Total Cavopulmonary Connection.

Lymphatic congestion in single-ventricle patients has been associated with increased morbidity and poor outcomes. Little is known about the dynamics of lymphatic abnormalities over time, on their association with clinical presentation or response to catheter interventions. This retrospective, single-center study describes Fontan patients who underwent at least two magnetic resonance imaging (MRI) studies. T2-weighted lymphatic imaging was used to classify thoracic and abdominal (para-aortic and portal-venous) lymphatic abnormalities. The relationship between lymphatic congestion and hemodynamic changes after cardiac catheter interventions, clinical presentation and MRI data was analyzed. A total of 33 Fontan patients underwent at least two cardiac MRI studies. Twenty-two patients had two, eight had three and three had four lymphatic imaging studies (total of 80 MRIs studies). No significant changes in lymphatic classification between MRI 1 and 2 were observed for thoracic (p = 0.400), para-aortic (0.670) and portal-venous (p = 0.822) abnormalities. No significant correlation between lymphatic classification and hemodynamic changes after intervention or MRI parameters was found. This study illustrates thoracic and abdominal lymphatic abnormalities in serial T2-weighted imaging after Fontan. Fontan patients did not demonstrate significant changes in their lymphatic perfusion, despite clinical or hemodynamic changes. We assume that lymphatic congestion might develop after total cavopulmonary connection (TCPC) and remain relatively stable, despite further intervention targeting hemodynamic parameters.

A classification of abdominal lymphatic perfusion patterns after Fontan surgery.

OBJECTIVES: Complications after Fontan surgery have been associated with arise and classification of abnormal thoracic lymphatic perfusion pattern. This study compiles abnormal abdominal lymphatic perfusion patterns and investigates their impact on serum protein readings. METHODS: We performed a retrospective analysis of patients who underwent magnetic resonance imaging with T2-weighted lymphatic imaging and serum protein measurements 6 months after having Fontan surgery. The abdominal lymphatic images were classified according to the anatomical lymphatic drainage patterns into 2 categories: (1) para-aortic (types 1-4); (2) portal-venous (types 1-3). Thoracic lymphatic images were classified (types 1-4) as described earlier. RESULTS: A total of 71 patients were included in the study. Para-aortic lymphatic perfusion patterns were classified as type 1 in 4, type 2 in 13, type 3 in 37 and type 4 in16 out of 71 patients. Portal-venous lymphatic perfusion patterns were classified as type 1 in 20, type 2 in 10 and type 3 in 41 patients. Thoracic lymphatic perfusion patterns were classified as type 1 in 8, type 2 in 11, type 3 in 39 and type 4 in 13 patients. The serum protein level was 66 (interquartile range: 7.5) g/l (< standard value in 37%). Higher-grade para-aortic (p = 0.0062), portal-venous (p = 0.022) and thoracic (p = 0.011) lymphatic abnormalities were correlated with lower total serum protein levels. Higher ratings of para-aortic lymphatic abnormalities were significantly associated with higher ratings of portal-venous abnormalities (p < 0.0001). Ratings of para-aortic and portal-venous classifications were correlated with the thoracic classification (p < 0.001). CONCLUSIONS: Abnormal abdominal lymphatic perfusion patterns can be classified according to anatomical structures with increasing severity. Higher grade abdominal and thoracic lymphatic perfusion patterns are associated with lower serum protein values.