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Obstructive sleep apnea (OSA) has been associated with negative cardiovascular effects and negative outcomes following cardiovascular surgery in the adult population. Our objective was to evaluate if there is a similar association in children. Single center retrospective matched cohort study, we collected data on patients aged 1-18 who were admitted to the cardiac intensive care unit (CICU) between Jan 2012 and Dec 2021. We used a 3:1 propensity score matching for cases not diagnosed with OSA. Primary outcome was a composite variable: "adverse outcome," consisting of prolonged hospital and CICU stay, prolonged duration of mechanical ventilation, need for extracorporeal membrane oxygenation, and death. The study comprised 80 patients diagnosed with OSA and 240 patients without a diagnosis of OSA before cardiac surgery. The median age was 5.3 years (IQR 2.7-11.2). There were 184 (57.5%) males, and 102 (31.9%) had chromosomal and genetic abnormalities. There was a difference in "adverse outcome" between the OSA and non-OSA groups [34 (42.50%) vs 68 (28.33%), p = 0.027]. Moreover, bivariate analysis revealed that CICU length of stay, and chromosomal anomalies were statistically different between the groups. By logistic regression the composite variable "adverse outcome" remained associated to the OSA group (p = 0.009) with an adjusted odds ratio (OR) of 4.09 (1.83-9.18), p < 0.001. Children diagnosed with OSA had a higher risk of "adverse outcome" following cardiac surgery. The risk disappeared if the patient had Tonsillectomy and Adenoidectomy before cardiac surgery. Further studies should explore a proactive treatment for OSA in pediatric patients who need cardiac surgery.
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Medical malpractice suits within the military have historically been limited by the Feres Doctrine, a legal precedent arising from a Supreme Court decision in 1950, which stated that active-duty personnel cannot bring suit for malpractice against either the United States government or military healthcare providers. This precedent has increasingly become a focus of discussion and reform as multiple cases claiming malpractice have been dismissed. Recently, however, the National Defense Authorization Act of 2020 initiated the first change to this precedent by creating an administrative body with the sole purpose of evaluating and settling claims of medical malpractice within the military's $50 billion healthcare system. This article seeks to present the legal history related to military malpractice and the Feres Doctrine as well as discuss the potential future implications that may arise as the Feres Doctrine is modified for the first time in 70 years.
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Imperícia , Militares , Humanos , Responsabilidade Legal , Estados UnidosRESUMO
INTRODUCTION: Craniotomy and craniectomy are common neurosurgical procedures with wide applications in both civilian and military practice. Skill maintenance for these procedures is required for military providers in the event they are called to support forward deployed service members suffering from combat and non-combat injuries. The presents investigation details the performance of such procedures at a small, overseas military treatment facility (MTF). MATERIALS AND METHODS: A retrospective review of craniotomy procedures performed at an overseas military treatment facility (MTF) over a 2-year period (2019-2021) was performed. Patient and procedural data were collected for all elective and emergent craniotomies including surgical indications, outcomes, complications, military rank, and impact on duty status and tour curtailment. RESULTS: A total of 11 patients underwent a craniotomy or craniectomy procedure with an average follow-up of 496.8 days (range 103-797). Seven of the 11 patients were able to undergo surgery, recovery, and convalesce without transfer to a larger hospital network or MTF. Of the 6 patients that were active duty (AD), one returned to full duty while three separated and two remain in partial duty status at latest follow-up. There were four complications in four patients with one death. CONCLUSIONS: In this series, we demonstrate that cranial neurosurgical procedures can be performed safely and effectively while at an overseas MTF. There are potential benefits to the AD service members, their unit, and family as well as to the hospital treatment team and surgeon as this represents a clinical capability requisite to maintain trauma readiness for future conflicts.
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Militares , Cirurgiões , Humanos , Craniotomia , Procedimentos Neurocirúrgicos/métodos , Estudos RetrospectivosRESUMO
Background: There is increasing recognition of connective tissue disorders and their influence on disease in the general population. A conserved clinical phenotype involving connective tissue disorders and idiopathic intracranial hypertension (IIH) and associated cerebral venous outflow disorders (CVD) has not been previously described. Methods: A single-institution retrospective review of a prospectively maintained database of patients with connective tissue disorders and CVD was performed. Results: A total of 86 patients were identified. The majority of these patients carried a diagnosis of Ehlers-Danlos syndrome (55%) and most were non-obese (mean body mass index 29.7 kg/m2), Caucasian (90%) females (87%). Most prevalent presenting symptoms included pressure headache (98%), dizziness (90%), tinnitus (92%), and cognitive dysfunction (69%). Aside from CVD and IIH, the most common associated conditions were postural orthostatic tachycardia syndrome (POTS; 55.8%), cerebrospinal fluid (CSF) leaks (51.2%), dysautonomia (45.3%), cranio-cervical instability (37.2%), mast cell activation syndrome (25.6%), and tethered cord syndrome (23.3%). Allergies to medications (87.2%) and surgical tape (19.8%) were also frequent. Despite significantly lower opening pressures on lumbar puncture, headache severity and quality of life scores were reported with the same severity of classic IIH patients, suggesting an underlying hypersensitivity to intracranial pressures and cerebral venous congestion. Conclusion: There is a rare but conserved clinical phenotype that has not been described previously that presents with severe IIH symptoms in predominantly young, non-obese Caucasian women with a high associated incidence of dysautonomia, POTS, craniocervical instability, and CSF leaks, among others.
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BACKGROUND: Mechanical thrombectomy (MT) is the standard-of-care treatment for stroke patients with emergent large vessel occlusions. Despite this, little is known about physician decision making regarding MT and prognostic accuracy. METHODS: A prospective multicenter cohort study of patients undergoing MT was performed at 11 comprehensive stroke centers. The attending neurointerventionalist completed a preprocedure survey prior to arterial access and identified key decision factors and the most likely radiographic and clinical outcome at 90 days. Post hoc review was subsequently performed to document hospital course and outcome. RESULTS: 299 patients were enrolled. Good clinical outcome (modified Rankin Scale (mRS) score of 0-2) was obtained in 38% of patients. The most frequently identified factors influencing the decision to proceed with thrombectomy were site of occlusion (81%), National Institutes of Health Stroke Scale score (74%), and perfusion imaging mismatch (43%). Premorbid mRS score determination in the hyperacute setting accurately matched retrospectively collected data from the hospital admission in only 140 patients (46.8%). Physicians correctly predicted the patient's 90 day mRS tertile (0-2, 3-4, or 5-6) and final modified Thrombolysis in Ischemic Cerebral Infarction score preprocedure in only 44.2% and 44.3% of patients, respectively. Clinicians tended to overestimate the influence of occlusion site and perfusion imaging on outcomes, while underestimating the importance of pre-morbid mRS. CONCLUSIONS: This is the first prospective study to evaluate neurointerventionalists' ability to accurately predict clinical outcome after MT. Overall, neurointerventionalists performed poorly in prognosticating patient 90 day outcomes, raising ethical questions regarding whether MT should be withheld in patients with emergent large vessel occlusions thought to have a poor prognosis.
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Isquemia Encefálica , Acidente Vascular Cerebral , Humanos , Estudos Prospectivos , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/cirurgia , Estudos de Coortes , Estudos Retrospectivos , Resultado do Tratamento , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/cirurgia , Trombectomia/métodos , Tomada de DecisõesRESUMO
BACKGROUND: Fulminant idiopathic intracranial hypertension (IIH) can cause rapid vision loss. Transverse sinus stenosis is a finding commonly associated with IIH, and transverse sinus stenting has been used to rapidly reduce intracranial pressure and improve visual symptoms. Our objective was to describe a case of immediate alteration in reversed superior ophthalmic vein (SOV) flow in a fulminant IIH patient who underwent venous sinus stenting. METHODS: All charts, imaging, and notes spanning from the initial presentation to the post-intervention follow-up were reviewed and summarized for inclusion. RESULTS: A 24-year-old woman presented with several weeks of severe headaches and progressive vision loss. She was found to have severe papilledema and the opening pressure on lumbar puncture (LP) was 70 mm Hg. Computed tomography (CT) and magnetic resonance imaging demonstrated findings consistent with elevated intracranial pressure, and CT venography revealed stenosis of the right transverse sinus. She underwent an uncomplicated diagnostic cerebral angiogram, right venous sinus manometry, and right transverse to sigmoid sinus stenting procedure. Prior to deployment of the stent, a trans-stenotic pressure gradient of 12 mm Hg was observed within the right transverse-sigmoid junction, and flow through the bilateral SOVs was retrograde. Following stent placement, the pressure gradient normalized, and SOV flow was bidirectional. She subjectively reported improved vision, and there was improving papilledema. Repeat LP yielded an opening pressure of 21.6 mm Hg. CONCLUSIONS: This case demonstrates reversed SOV flow should be considered an indicator of severe venous sinus stenosis, and restoration to normal or near normal state following stenting for IIH is likely indicative of procedural success.
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Hipertensão , Hipertensão Intracraniana , Papiledema , Pseudotumor Cerebral , Adulto , Constrição Patológica/complicações , Constrição Patológica/diagnóstico por imagem , Constrição Patológica/cirurgia , Cavidades Cranianas/diagnóstico por imagem , Cavidades Cranianas/cirurgia , Feminino , Humanos , Hipertensão/complicações , Hipertensão Intracraniana/complicações , Hipertensão Intracraniana/cirurgia , Papiledema/etiologia , Pseudotumor Cerebral/complicações , Pseudotumor Cerebral/diagnóstico por imagem , Pseudotumor Cerebral/cirurgia , Stents/efeitos adversos , Adulto JovemRESUMO
BACKGROUND: Retroperitoneal nerve sheath tumors present a surgical challenge. Despite potential advantages, robotic surgery for these tumors has been limited. Identifying and sparing functional nerve fascicles during resection can be difficult, increasing the risk of neurological morbidity. OBJECTIVE: To review the literature regarding robotic resection of retroperitoneal nerve sheath tumors and retrospectively analyze our experience with robotic resection of these tumors using a manual electromyographic probe to identify and preserve functional nerve fascicles. METHODS: We retrospectively analyzed the clinical courses of 3 patients with retroperitoneal tumors treated at the National Institutes of Health by a multidisciplinary team using the da Vinci Xi system. Parent motor nerve fascicles were identified intraoperatively with a bipolar neurostimulation probe inserted through a manual port, permitting tumor resection with motor fascicle preservation. RESULTS: Two patients with neurofibromatosis type 1 underwent surgery for retroperitoneal neurofibromas located within the iliopsoas muscle, and 1 patient underwent surgery for a pelvic sporadic schwannoma. All tumors were successfully resected, with no complications or postoperative neurological deficits. Preoperative symptoms were improved or resolved in all patients. CONCLUSION: Resection of retroperitoneal nerve sheath tumors confers an excellent prognosis, although their deep location and proximity to vital structures present unique challenges. Robotic surgery with intraoperative neurostimulation mapping is safe and effective for marginal resection of histologically benign or atypical retroperitoneal nerve sheath tumors, providing excellent visibility, increased dexterity and precision, and reduced risk of neurological morbidity.
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Neoplasias de Bainha Neural , Neurilemoma , Procedimentos Cirúrgicos Robóticos , Humanos , Neoplasias de Bainha Neural/patologia , Neoplasias de Bainha Neural/cirurgia , Neurilemoma/cirurgia , Procedimentos Neurocirúrgicos , Estudos Retrospectivos , Estados UnidosRESUMO
BACKGROUND: Rheumatoid arthritis (RA) frequently features degeneration and instability of the cervical spine. Rarely, this degeneration manifests as symptoms of bow hunter syndrome (BHS), a dynamic cause of vertebrobasilar insufficiency. OBSERVATIONS: The authors reviewed the literature for cases of RA associated with BHS and present a case of a man with erosive RA with intermittent syncopal episodes attributable to BHS as a result of severe extrinsic left atlantooccipital vertebral artery compression from RA-associated cranial settling. A 72-year-old man with RA-associated cervical spine disease who experienced gradual, progressive functional decline was referred to a neurosurgery clinic for evaluation. He also experienced intermittent syncopal events and vertiginous symptoms with position changes and head turning. Vascular imaging demonstrated severe left vertebral artery compression between the posterior arch of C1 and the occiput as a result of RA-associated cranial settling. He underwent left C1 hemilaminectomy and C1-4 posterior cervical fusion with subsequent resolution of his syncope and vertiginous symptoms. LESSONS: This is an unusual case of BHS caused by cranial settling as a result of RA. RA-associated cervical spine disease may rarely present as symptoms of vascular insufficiency. Clinicians should consider the possibility, though rare, of cervical spine involvement in patients with RA experiencing symptoms consistent with vertebral basilar insufficiency.
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Traumatic brain injury is a rapidly increasing source of morbidity and mortality across the world. As such, the evaluation and management of traumatic brain injuries ranging from mild to severe are under active investigation. Over the last two decades, quantitative pupillometry has been increasingly found to be useful in both the immediate evaluation and ongoing management of traumatic brain injured patients. Given these findings and the portability and ease of use of modern pupillometers, further adoption and deployment of quantitative pupillometers into the preclinical and hospital settings of both resource rich and medically austere environments.
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This report describes the case of a 5-year-old male with intractable hydrocephalus secondary to neonatal intraventricular hemorrhage who was ultimately managed with the placement of a ventriculo-ureteral (VU) shunt. He had previously failed numerous attempts at cerebrospinal fluid shunting, choroid plexus cauterization, and endoscopic third ventriculostomy. The patient had a history of end stage renal disease, and had previously undergone renal transplant. In an operation that involved Neurosurgeons, Pediatric Urologists, and Transplant surgeons, a Gibson incision was used to avoid the patient's multiple intra-abdominal adhesions, and his nonfunctioning renal unit was used to implant a VU shunt without early or late complications.
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Derivações do Líquido Cefalorraquidiano , Hidrocefalia/cirurgia , Derivações do Líquido Cefalorraquidiano/métodos , Pré-Escolar , Humanos , Hidrocefalia/complicações , Falência Renal Crônica/complicações , Falência Renal Crônica/cirurgia , Transplante de Rim , Masculino , Reoperação , UreterRESUMO
The COVID-19 pandemic has altered preexisting patient treatment algorithms and referral patterns, which has affected neurosurgical care worldwide. Brain arteriovenous malformations are complex vascular lesions that frequently present with intracerebral hemorrhage. Care for these patients is best performed at large medical centers by specialists with high volumes. The authors describe the care of a patient who presented in extremis to a resource-limited, community-sized military treatment facility (MTF) in Southeast Asia. In the MTF, the patient underwent emergent neurosurgical therapy. However, given newly implemented restrictions enacted to mitigate COVID-19 spread, local transfer for definitive care to a tertiary care facility was not possible. In order to attain definitive care for the patient, a transpacific aeromedical evacuation augmented with a critical care air transport team was utilized for transfer to a tertiary care, teaching hospital. This case demonstrates the safe treatment of a patient with hemorrhagic arteriovenous malformations and postoperative management under limited conditions in an MTF outside the CONUS. Given the unique circumstances and challenges the pandemic presented, the authors feel that this patient's outcome was only possible by leveraging all the capability military medicine has to offer.
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Resgate Aéreo , Malformações Arteriovenosas , COVID-19 , Encéfalo , Humanos , Pandemias , SARS-CoV-2RESUMO
Duplicated origin of the vertebral artery (VA) is an extremely rare normal anatomic variant. While most often considered non-pathological, duplicated origin carries an increased risk of dissection. An association with vascular pathologies such as aneurysms, arteriovenous malformations, and AV fistulas has been suggested. The objective is to describe this unusual anatomic variant with is concomitant vascular pathology and review current literature. The authors report a case of incidentally-discovered duplicated origin of the left VA in patients with a spinal dural arteriovenous fistula (dAVF). A 61-year-old man with a history significant for sarcoidosis presented with progressive lower extremity weakness and paresthesias. MRI of the thoracic spine demonstrated significant confluent edema and patchy contrast enhancement in the caudal spinal cord and conus medullaris which did not appear related to the patient's neurosarcoidosis. A diagnostic spinal angiogram incidentally demonstrated that the left V1 segment had a duplicated origin, one branch arising from the aortic arch and the other branch arising from the left subclavian artery, with union at the C5 transverse foramen. This finding represented an incidental anomaly discovery was noted to be incidental and was not believed to be related to the patients underlying pathology. Subsequently, a dAVF was discovered, originating from the right T7 spinal artery. Location of this vascular malformation directly correlated with the patient's symptoms. The patient then underwent embolization of the spinal dAVF and recovered uneventfully. Duplicated origin of the VA is an extremely rare but well-described variant, most commonly involving the left VA. To our knowledge, this is the only reported spinal dAVF associated with duplicated origin of the left VA. An association with other pathological entities has been suggested, and thus this case adds to a growing body of cases characterizing these relationships.
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BACKGROUND: The opioid epidemic continues to worsen with a concomitant increase in opioid-related mortality. In response, the Department of Defense and Veterans Health Agency recommended against the use of long-acting opioids (LAOs) and concurrent use of opioids with benzodiazepines. Subsequently, we eliminated benzodiazepines and LAOs from our postoperative pain control regimen. OBJECTIVE: To evaluate the impact of removing benzodiazepines and LAOs on postoperative pain in single-level transforaminal lumbar interbody fusion (TLIF) patients. METHODS: A retrospective cohort study of single-level TLIF patients from February 2016-March 2018 was performed. Postoperative pain control in the + benzodiazepine cohort included scheduled diazepam with or without LAOs. These medications were replaced with nonbenzodiazepine, opioid-sparing adjuncts in the -benzodiazepine cohort. Pain scores, length of hospitalization, trigger medication use, and opioid use and duration were compared. RESULTS: Among 77 patients, there was no difference between inpatient pain scores, but the -benzodiazepine cohort experienced a faster rate of morphine equivalent reduction (-18.7%, 95% CI [-1.22%, -36.10%]), used less trigger medications (-1.55, 95% CI [-0.43, -2.67]), and discharged earlier (0.6 d; 95% CI [0.01, 1.11 d]). As outpatients, the -benzodiazepine cohort was less likely to receive opioid refills at 2 wk (29.2% vs 55.8%, P = .021) and 6 mo postoperatively (0% vs 13.2%, P = .039), and was less likely to be using opioids by 3 mo postoperatively (13.3% vs 34.2%, P = .048). CONCLUSION: Replacement of benzodiazepines and LAOs in the pain control regimen for single-level TLIFs did not affect pain scores and was associated with decreased opioid use, a reduction in trigger medications, and shorter hospitalizations.
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Analgésicos não Narcóticos/uso terapêutico , Analgésicos Opioides , Benzodiazepinas , Manejo da Dor/métodos , Dor Pós-Operatória/tratamento farmacológico , Adulto , Estudos de Coortes , Feminino , Humanos , Dor Lombar/tratamento farmacológico , Dor Lombar/etiologia , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fusão Vertebral/efeitos adversosRESUMO
Within the text we elaborate on the relationship between war and medicine, particularly as it pertains to neurosurgery and the management of brain trauma, and emphasize neurosurgical advancements in the treatment of brain trauma gleaned from U.S.-involved conflicts of the 21st century.
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Lesões Encefálicas Traumáticas , Lesões Encefálicas Traumáticas/cirurgia , Humanos , Medicina Militar , Neurocirurgia , Procedimentos Neurocirúrgicos , Envio de Mensagens de TextoRESUMO
INTRODUCTION: The advancement of interventional neuroradiology has drastically altered the treatment of stroke and trauma patients. These advancements in first-world hospitals, however, have rarely reached far forward military hospitals due to limitations in expertise and equipment. In an established role III military hospital though, these life-saving procedures can become an important tool in trauma care. MATERIALS AND METHODS: We report a retrospective series of far-forward endovascular cases performed by 2 deployed dual-trained neurosurgeons at the role III hospital in Kandahar, Afghanistan during 2013 and 2017 as part of Operations Resolute Support and Enduring Freedom. RESULTS: A total of 15 patients were identified with ages ranging from 5 to 42 years old. Cases included 13 diagnostic cerebral angiograms, 2 extremity angiograms and interventions, 1 aortogram and pelvic angiogram, 1 bilateral embolization of internal iliac arteries, 1 lingual artery embolization, 1 administration of intra-arterial thrombolytic, and 2 mechanical thrombectomies for acute ischemic stroke. There were no complications from the procedures. Both embolizations resulted in hemorrhage control, and 1 of 2 stroke interventions resulted in the improvement of the NIH stroke scale. CONCLUSIONS: Interventional neuroradiology can fill an important role in military far forward care as these providers can treat both traumatic and atraumatic cerebral and extracranial vascular injuries. In addition, knowledge and skill with vascular access and general interventional radiology principles can be used to aid in other lifesaving interventions. As interventional equipment becomes more available and portable, this relatively young specialty can alter the treatment for servicemen and women who are injured downrange.
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Hospitais Militares , Militares , Adolescente , Adulto , Afeganistão , Isquemia Encefálica , Criança , Pré-Escolar , Atenção à Saúde , Feminino , Humanos , Estudos Retrospectivos , Acidente Vascular Cerebral/cirurgia , Estados Unidos , Adulto JovemRESUMO
Although decompressive surgery following traumatic spinal cord injury (TSCI) is recommended, adequate surgical decompression is rarely verified via imaging. We utilized magnetic resonance imaging (MRI) to analyze the rate of spinal cord decompression after surgery. Pre-operative (within 8 h of injury) and post-operative (within 48 h of injury) MRI images of 184 motor complete patients (American Spinal Injury Association Impairment Scale [AIS] grade A = 119, AIS grade B = 65) were reviewed to verify spinal cord decompression. Decompression was defined as the presence of a patent subarachnoid space around a swollen spinal cord. Of the 184 patients, 100 (54.3%) underwent anterior cervical discectomy and fusion (ACDF), and 53 of them also underwent laminectomy. Of the 184 patients, 55 (29.9%) underwent anterior cervical corpectomy and fusion (ACCF), with (26 patients) or without (29 patients) laminectomy. Twenty-nine patients (16%) underwent stand-alone laminectomy. Decompression was verified in 121 patients (66%). The rates of decompression in patients who underwent ACDF and ACCF without laminectomy were 46.8% and 58.6%, respectively. Among these patients, performing a laminectomy increased the rate of decompression (72% and 73.1% of patients, respectively). Twenty-five of 29 (86.2%) patients who underwent a stand-alone laminectomy were found to be successfully decompressed. The rates of decompression among patients who underwent laminectomy at one, two, three, four, or five levels were 58.3%, 68%, 78%, 80%, and 100%, respectively (p < 0.001). In multi-variate logistic regression analysis, only laminectomy was significantly associated with successful decompression (odds ratio 4.85; 95% confidence interval 2.2-10.6; p < 0.001). In motor complete TSCI patients, performing a laminectomy significantly increased the rate of successful spinal cord decompression, independent of whether anterior surgery was performed.
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Descompressão Cirúrgica/métodos , Discotomia/métodos , Laminectomia/métodos , Traumatismos da Medula Espinal/diagnóstico por imagem , Traumatismos da Medula Espinal/cirurgia , Fusão Vertebral/métodos , Adulto , Medula Cervical/lesões , Medula Cervical/cirurgia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Anatomical variations in the musculature surrounding the thyroid gland have the potential to cause iatrogenic injuries during neck and thyroid surgical procedures. Herein is presented a unilateral case found in an 83-year-old Caucasian female cadaver during a surgical mock thyroidectomy. The thyroid gland had a small pyramidal lobe with three muscular slips of levator glandulae thryroideae (LGT) muscle and a large tributary of the inferior thyroid vein descending posteriorly along the muscular slips. The nerve and arterial supply of the LGT was a twig of the ansa cervicalis and muscular branches from the superior thyroid artery, respectively. Clinicians who interpret imaging of the neck or surgeons who operate in the neck and especially on or near the thyroid gland should be aware of such a variation.
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Músculos do Pescoço/anormalidades , Glândula Tireoide/anatomia & histologia , Idoso de 80 Anos ou mais , Feminino , Humanos , Músculos do Pescoço/irrigação sanguínea , Músculos do Pescoço/inervação , TireoidectomiaRESUMO
The crista terminalis (CT) is an important anatomic landmark due its close association with the sinoatrial node artery and the origin of the pectinate muscles (PM). However, the gross anatomy of the PM in relation to the CT has not been well described. The aim of our study has been to investigate the location and the morphology of PM in relation to the CT. We examined 300 adult formalin-fixed human hearts. All PM originated from the CT and extended along the wall of the appendage toward the vestibule of the tricuspid valve. It was observed that the PM varied significantly with respect to arrangement and course of its fibers. We were able to classify the course of the PM, including the most prominent PM called the tenia sagittalis (TS), into 6 different patterns with 3 different TS types. In Type A (15%), the TS was absent. Type B (65%) demonstrated a single TS and Type C (20%) was characterized by the presence of multiple TS. Furthermore, the course of the PM was classified into 6 patterns: Type I (40%), the PM was oriented perpendicular to the CT with uniform spacing and lack of crossover (trabeculation); Type II (20%), non-uniform PM was organized in a haphazard, trabecular fashion with numerous crossovers; Type III (15%), the PM had uniform spacing with no trabeculation with fibers oriented parallel to the CT; Type IV (10%), had arborizing PM originating from a common muscular trunk (solitary trunk); Type V (10%), fibers were oriented both perpendicular and parallel to the CT, similar in architecture to Type III, but with more than one common muscular trunk; Type VI (5%), prominent muscular column with velamentous PM with potential implications in cardiac catheterization procedures. The exact morphology of PM and TS may be clinically important in right atrial catheterization procedures, as well as in the development of arrhythmias but further investigations are now necessary to prove this theory.
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Átrios do Coração/anatomia & histologia , Adulto , Idoso , Cadáver , Circulação Coronária , Feminino , Humanos , Masculino , Nó Sinoatrial/anatomia & histologiaRESUMO
The effects of single 4-hr bouts of continuous 30, 60, 120, and 800 Hz tail vibration (49 m/sec2, root mean squared) were compared to assess frequency-amplitude-related structural damage of the ventral caudal artery. Amplitudes were 3.9, 0.98, 0.24, and 0.0055 mm, respectively. Vibrated, sham-vibrated, and normal arteries were processed for light and electron microscopy. The Curry rat tail model of hand-arm vibration (Curry et al. Muscle Nerve 2002;25:527-534) proved well-suited for testing multiple frequencies. NFATc3 immunostaining, an early marker of cell damage, increased in smooth muscle and endothelial cells after 30, 60, and 120 Hz but not 800 Hz. Increased vacuolization, which is indicative of smooth muscle contraction, occurred for all frequencies except 800 Hz. Vacuoles increased in both endothelial and smooth muscle cells after 60 and 120 Hz. Only 30 Hz showed pronounced smooth muscle cell vacuolization along the internal and external elastic membranes, suggesting stretch-mediated contraction from the large amplitude shear stress. Discontinuities in toluidine blue staining of the internal elastic membrane (IEM) increased for all frequencies, indicating vibration-induced structural weakening of this structure. Patches of missing IEM and overlying endothelium occurred in approximately 5% of arteries after 60, 120, and 800 Hz. The pattern of damage after 800 Hz suggests that the IEM is disrupted because it resonates at this frequency. Vibration acceleration stress and smooth muscle contraction appear to be the major contributors to arterial damage. The pattern of vibration-induced arterial damage of smooth muscle and endothelial cells is frequency-amplitude-dependent.