Biomedical subjects

Henry E Aryan

Publications and source records attributed to Henry E Aryan.

At least 37 records · Page 2Linked to original sources

PubMed2005

Thymoma metastatic to the extradural spine.

BACKGROUND: Spinal epidural metastases are the most common spinal tumor, occurring in 10% of cancer patients. Malignant thymoma is a mediastinal tumor, with extrathoracic metastases occurring in 15% of patients to liver, kidney, and bone. Spinal metastasis is exceptionally rare. We present a case of thymoma with extradural metastasis and discuss the relevant literature. CASE REPORT: We describe a 45-year old man presenting with back pain and hypoesthesia twelve years after a diagnosis of thymoma. A review of the literature reveals few cases of thymoma metastatic to the extradural spine. We describe a novel surgical approach allowing ventral spinal cord decompression through a posterior incision. CONCLUSION: Spinal epidural metastases should be suspected in all cancer patients with back pain. Early detection of epidural metastases may enable improved pain control and preservation of spinal stability, ambulation and sphincter control.

Epidural Neoplasms↗

PubMed2005

Microsurgical keyhole middle fossa arachnoid cyst fenestration.

Microsurgical keyhole fenestration is a safe and effective surgical procedure for the treatment of middle fossa arachnoid cysts. This procedure can be performed with minimal morbidity through a keyhole craniotomy. Patient selection is crucial, as is knowledge of the surgical anatomy. We provide a detailed description of the technique, with Illustrations of the key aspects of the procedure.

Arachnoid Cysts↗

PubMed2005

Retinal hemorrhage and pediatric brain injury: etiology and review of the literature.

Retinal hemorrhages have long been linked with child abuse and, in particular, the "shaken baby/shaking-impact" syndrome. However, the presence of retinal hemorrhages is neither necessary nor sufficient for the diagnosis of child abuse. Additionally, retinal hemorrhages are also associated with an ever-expanding list of conditions, each of which carries important implications for patients and their families. To correctly interpret a patient's retinal hemorrhages, the physician requires a broad knowledge base, including of child abuse, the "shaken baby/shaking-impact" syndrome, the differential diagnosis of retinal hemorrhages and the types of retinal hemorrhage and their diagnostic implications. We review the literature regarding types of retinal hemorrhage and their associated etiologies.

Accidents, Traffic↗

PubMed2005

The Charité Artificial Disc: insertion technique.

The Charité Artificial Disc is the first commercially available motion-preserving technology for the lumbar spine. The Charité is the first US Food and Drug Administration-approved artificial disc for the treatment of single-level lumbar degenerative disc disease from L4 to S1. With thousands of implantations worldwide since 1987, it has the longest clinical experience of any artificial disc. No other artificial disc has the substantial preclinical and clinical history that validates its use.

Arthroplasty, Replacement↗

PubMed2005

Emerging directions in motion preservation spinal surgery.

In this review, we focus on novel surgical techniques and spinal arthroplasty systems inactive development. First, we discuss systems that allow for minimally invasive approaches to the lumbar disc space: (1) lateral approaches, (2) posterior approaches,and (3) oblique approaches. These techniques offer the potential for a minimally invasive lumbar arthroplasty system. Second, we discuss novel facet replacement technology. The facet joints, with the intervertebral disc, comprise the three-joint complex of the spinal unit. Facet joint health is thus crucial to proper disc biomechanics and function. Finally,we discuss dynamic neutralization of the lumbar spine with an artificial posterior tension band device. This allows for a certain degree of immobilization without fusion. Minimally invasive surgical approaches, facet arthroplasty, and posterior tension band devices may be the future of motion preservation spinal surgery.

Arthroplasty↗

PubMed2005

The ProDisc artificial disc: insertion technique.

The ProDisc artificial lumbar disc was designed for use in treatment of degenerative lumbar disease. The disc is implanted using an anterior approach to the lumbar spine with the assistance of intraoperative fluoroscopy. A variety of insertion instruments guide the surgeon through this process. The disc is implanted via an anterior approach, generally retroperitoneally but on occasion transperitoneally. The different approaches and insertion technique are described in this article.

Arthroplasty, Replacement↗

PubMed2005

Gunshot wounds to the spine in adolescents.

OBJECTIVE: The incidence of spinal instability after penetrating gunshot wounds to the spine in adolescents is unknown. We describe our experience over a 15-year period. METHODS: Hospital records were reviewed retrospectively. After injury and emergency care, patients were transferred to a rehabilitation facility. Examinations were completed using the American Spinal Injury Association and Frankel scales on admission, discharge, and 6 and 12 months after injury. Severity of injury was described by: 1) degree of neurological damage, 2) degree of preserved neurological function, and 3) presence of instability. RESULTS: Sixty patients were identified with a mean age 15.6 years (+/- 2.7 yr). Twelve patients had cervical, 31 thoracic, and 17 lumbosacral injuries. No operative treatments were used in their care. Thirty-four patients had complete neurological deficits. Mean acute hospitalization was 21.1 days (+/- 22.8 d), and mean rehabilitation stay was 86.3 days (+/- 48.9 d), for a total hospitalization of 107.4 days (+/- 65.9 d). At 1 year, 19 patients were ambulatory and 53 were autonomous. Despite the presence of bony involvement in all, no evidence of spinal instability was noted on follow-up dynamic imaging. Even in two patients with apparent two-column disruption, no instability was noted. At 1-year follow-up, significant (nonfunctional) improvement was noted in the neurological examination (P < 0.0001). Improvements were most notable in those patients with cervical injuries, followed by thoracic and lumbar injuries. CONCLUSION: After penetrating gunshot wounds to the spine, patients at 1-year follow-up examinations have evidence of significant, but nonfunctional, improvement. No evidence of spinal instability was noted in this study, and no surgical intervention was required.

Adolescent↗

PubMed2005

Gel-based surgical preparation resulting in an operating room fire during a neurosurgical procedure: case report.

Despite general reports of fires in the operating room, those during neurosurgical procedures are rare. The most significant contributor to perioperative fires is excess oxygenation. The consideration of novel gel-based surgical preparation solutions as potential fuel sources should be included in the literature. Given the significant patient risk and legal ramifications of surgical fires, education regarding operating room fires and the potential for prevention and treatment is requisite. The authors describe the case of an 18-month-old girl who, while undergoing a resection of a right retroauricular scalp mass, suffered partial thickness bums as a result of the ignition of surgical preparation solution following the use of monopolar electrocautery.

Administration, Topical↗

PubMed2004

Initial experience with antibiotic-impregnated silicone catheters for shunting of cerebrospinal fluid in children.

INTRODUCTION: Infection is a major complication of cerebrospinal fluid (CSF) shunting procedures. Recently, rifampin-impregnated and clindamycin-impregnated silicone catheters have been developed in an attempt to prevent and/or reduce the incidence of shunt infections. In vitro and in vivo animal studies have shown their efficacy in reducing bacterial colonization of catheters. However, these shunts are yet to be evaluated in clinical trials and their safety and efficacy in preventing shunt infections is unknown. METHODS: Between April 2002 and April 2003, 31 children (age range 6 months to 17 years, mean 4.5 years) underwent implantation of an antibiotic-impregnated silicone catheter for CSF diversion. All surgeries were performed by a single neurosurgeon (HSM) at a single medical center. The Codman Hakim Bactiseal silicone catheter was used in all children. Thirty-two catheters were implanted in 31 children. All children have been followed since surgery (for an average of 19 months). For comparison, the previous 46 standard implanted shunts over a similar period of time were reviewed (average follow-up 31 months). RESULTS: Of the 32 implanted catheters, 11 involved placement of a new complete shunt system, 8 were distal revisions, and 13 were proximal/ventricular revisions. There were fewer early and late complications than in the standard shunt group (12.5 and 18.8% vs. 23.9 and 34.8%). There was no local reaction from implantation of the catheters. One child contaminated his distal catheter by disrupting his abdominal incision. None of the other patients have developed any evidence of shunt infection to date. CONCLUSION: Rifampin-impregnated and clindamycin-impregnated silicone catheters appear to be safe and well tolerated in children. Preliminary results suggest a low incidence of shunt infection. Longer follow-up and a larger number of patients are needed to more accurately assess the efficacy of these catheters compared with traditional silicone catheters.

Adolescent↗

PubMed2004

Management of pilocytic astrocytoma with diffuse leptomeningeal spread: two cases and review of the literature.

INTRODUCTION: Leptomeningeal dissemination of juvenile pilocytic astrocytoma (JPA) is a rare event. We report two children with disseminated JPAs treated with a chemotherapeutic agent, temozolomide, after progression of the disease despite surgery, traditional chemotherapy, and/or radiation therapy. CASE REPORTS: Patient 1 presented with hydrocephalus and progressive lower extremity weakness, and was found to have a suprasellar mass as well as extensive spinal disease. Ventriculoperitoneal shunting, decompressive laminectomy with spinal tumor debulking, and chemotherapy with carboplatin and vincristine were initially employed. However, disease progressed and craniospinal irradiation and temozolomide were used. Patient 1 remains in a fair condition today, 2 years later. Patient 2 presented at 8 months of age with failure to thrive. Imaging revealed a cystic lesion in the hypothalamic region with extensive subarachnoid metastatic disease to the spine. Biopsy was performed followed by chemotherapy with vincristine, cyclohexylchloroethylnitrosourea (CCNU), 6-TG, and procarbazine. Due to the continued progression of the disease, cytoreductive surgery was performed and her chemotherapeutic regimen was switched to temozolomide. Two years after initial presentation patient 2 is clinically much improved with stable residual disease. DISCUSSION: We review the literature and discuss treatment strategies for this challenging disease.

Antineoplastic Agents, Alkylating↗

PubMed2004

Primary anaplastic glio-neuronal tumor of the pineal gland: a new type of pineal neoplasm?

BACKGROUND: Tumors of the pineal gland are relatively rare. Most are solid, infiltrative lesions characterized by either germ cell, glial, or pineal parenchymal origin. To our knowledge, none have been described that contain an admixture of both anaplastic glial and neuronal elements. CASE REPORT: The authors present a case of a primary anaplastic glio-neuronal tumor of the pineal gland in a 78-year-old gentleman who presented with hydrocephalus. The patient underwent an endoscopic third ventriculostomy for treatment of his hydrocephalus as well as tumor biopsy under endoscopic visualization. RESULTS: Sections of the tumor displayed a modestly to moderately cellular neoplasm infiltrating the residual pineal gland. The majority of the nuclei appeared hyperchromatic, spindle-shaped, and pleomorphic, with fibrillary cytoplasmic processes. Rare nuclei were round with vesicular chromatin and red nucleoli. Mitotic figures were easily identified, despite small sample size. GFAP immunostaining highlighted the fibrillar background and cytoplasmic processes while synaptophysin immunostains revealed intense, dot-like positivity in the rounder nuclei with vesicular chromatin. Although the different nuclear morphologies seen on the hematoxylin-eosin stained slides suggested both glial and neuronal origin, immunostains were required to confirm the presence of dual differentiation. CONCLUSION: We present the first case of a primary anaplastic glio-neuronal neoplasm of the pineal gland. Increased use of immunostaining may unveil additional cases in the future. Furthermore, additional research will be required to determine whether the dual differentiation has prognostic significance.

Aged↗

PubMed2004

Cerebello-Pontine angle (CPA) lymphoma with perineural extension into the middle fossa: case report.

BACKGROUND: Tumors of the cerebello-pontine angle are most commonly schwannoma and meningioma. Primary central nervous system (CNS) lymphoma usually presents deep within the cerebral hemispheres, occasionally is found in the cerebellum, and rarely occurs in the cerebello-pontine angle. We report a rare case of primary CNS lymphoma involving the right cerebello-pontine angle and the middle cranial fossa mimicking a tentorial meningioma. METHODS: A 21-year-old woman presented with right sided hearing loss and a facial droop. Computed tomography (CT) and magnetic resonance imaging (MRI) were performed, followed by cerebral angiography to assess vascularity. RESULTS: Imaging revealed a bilobed mass involving the right cerebello-pontine angle and middle fossa. The labyrinthine segment of the facial nerve canal was enlarged, and some bony erosion was seen along the petrous bone anteriorly. The mass was hypointense on both T1 and T2-weighted MRI and exhibited heterogenous enhancement. It was distinctly hypovascular on angiography. At surgery, a B-cell lymphoblastic lymphona was found that infiltrated along the 7(th) and 8(th) nerve complexes into the internal auditory canal. CONCLUSION: Imaging and surgery disclosed a cerebello-pontine lymphoma with perineural extension along the 7(th) nerve to reach the middle cranial fossa. Because of the unusual imaging characteristics of this tumor, as well as special considerations with respect to treatment, preoperative consideration of this entity is important in planning direct surgical biopsy rather than an extensive resection.

Adult↗

PubMed2004

Intramedullary spinal cord metastasis of lung adenocarcinoma presenting as Brown-Sequard syndrome.

BACKGROUND: It is extremely rare for cancer to present first as an intramedullary spinal cord metastasis. Furthermore, because it is unlikely for spinal cord neoplasm to present acutely, an acute presentation may signify metastatic disease and should be considered in the initial differential diagnosis. METHODS: The authors present a case of a 59-year-old man presenting with Brown-Sequard syndrome and in whom metastatic lung adenocarcinoma to the spinal cord was subsequently discovered. Review of the literature reveals this case to be one of only a very few where intramedullary tumor was the first manifestation of metastatic disease. RESULTS: The mainstay of treatment for intramedullary spinal metastases remains steroids, radiation, and chemotherapy, though no well-designed study compares these modalities by long-term survival and functional results. This patient underwent local radiation and systemic chemotherapy following surgical resection. CONCLUSIONS: This patient had no preoperative signs suggesting disease in other organs, making the diagnosis of lung adenocarcinoma metastatic to the intramedullary cord surprising, especially given the extremely rare incidence of spinal intramedullary metastatic disease. However, the patient had an acute presentation, uncommon for primary neoplasm, which may be an indication of metastatic disease.

Adenocarcinoma↗

PubMed2004

Syringocephaly.

Syringomyelia is associated with Arnold-Chiari Type I malformations. Syringobulbia describes the phenomenon of syrinx extension into the brain stem. Syringocephaly is the further dissection of the fluid-filled cavity into the cerebral peduncles and cerebrum. In this case report, we describe a patient who presented with bulbar, sensory, motor, and coordination deficits both ipsilateral and contralateral to the lesion. This is most likely attributable to the wandering course the syrinx takes as it dissects through the spinal cord and into the internal capsule. This ill-defined syrinx disrupts various nuclei and fasciculi, both pre- and post-decussation, thus explaining the multiple deficits on each side. We initially treated this patient with a suboccipital craniectomy, C1 laminectomy, and duraplasty, which mildly improved his deficits. During follow-up, the patient was then found to have an exacerbation of his symptoms, at which time we performed a VP shunt revision (the patient had a history of hydrocephalus treated by a functioning VP shunt). Approximately 2 weeks after revision of the VP shunt, the patient had worsening of his symptoms, which we treated with a syringopleural shunt. This proved to be the most effective treatment with the greatest clinical improvement. Several months later, however, the patient died secondary to pulmonary disease exacerbated by VP shunt infection. In this paper, we also review the literature regarding the formation and treatment of syringocephaly, a rare and poorly understood entity.

Cerebellum↗

PubMed2004

Stabilization of anterior cervical spine with bioabsorbable polymer in one- and two-level fusions.

OBJECTIVE: We present our experience using a bioabsorbable polymer in the surgical management of one- and two-level degenerative disc disease of the cervical spine with anterior cervical discectomy and fusion. Twenty-six patients were treated at the University of California, San Diego Medical Center or the Veterans Affairs Medical Center in San Diego, CA. All cases were performed under the direction of a single neurosurgeon (WRT). METHODS: A retrospective review of patients' charts and imaging was performed to determine outcomes after anterior cervical spine operations. Specifically, we looked at the need for additional surgery, local reaction to the bioabsorbable polymer, fusion rate, and complications. Procedures involved the C3-C4, C4-C5, C5-C6, and/or C6-C7 levels, and fibular allograft was used in all but one case. The anterior cervical discectomy and fusion procedures with internal fixation were performed in 26 patients between March 2000 and November 2001. The patients were followed for up to 2 years after surgery (average, 14 mo). RESULTS: Radiographic fusion was achieved in 25 (96.2%) of 26 patients. Only one instance of treatment failure was encountered that required additional surgery and the placement of a titanium plate. There were no clinical signs or symptoms of reaction to the bioabsorbable material. CONCLUSION: The rates of fusion after single-level anterior cervical discectomy and fusion with internal fixation using bioabsorbable polymer and screws in this study match those using metallic implants, as previously reported in the literature, and are superior to those achieved with noninstrumented fusions. Preliminary results suggest that this newly available technology for anterior fusion is as effective in single-level disease as traditional titanium plating systems. The bioabsorbable material seems to be tolerated well by patients. A larger, randomized, controlled study is necessary to bring the results to statistical significance.

Absorbable Implants↗

PubMed2004

Leptomeningeal cyst development after endoscopic craniosynostosis repair: case report.

OBJECTIVE AND IMPORTANCE: Endoscopically assisted (minimally invasive) craniosynostosis repair has been suggested as an alternative to traditional open craniosynostosis repair. Advocates of this approach assert advantages, including decreased blood loss, operative time, and hospital stay, while providing esthetic results and safety comparable with traditional open craniosynostosis repair. The difficulties inherent in endoscopic visualization may result in complications, however, that could temper enthusiasm for this procedure. The authors report a child in whom a leptomeningeal cyst developed after performance of endoscopic craniosynostosis repair, presumably from an iatrogenic dural laceration. CLINICAL PRESENTATION: A 5-month-old girl with sagittal synostosis underwent endoscopically assisted craniosynostosis repair. By report, the procedure was uneventful and the initial results were acceptable. The authors performed a chart review of their own experience with both endoscopically assisted craniosynostosis repair and traditional open repair. INTERVENTION: Five months after surgery, a pulsating forehead mass developed. Neuroimaging confirmed the diagnosis of a leptomeningeal cyst. The child was referred to our pediatric neurosurgery practice for operative repair. At the time of surgery, a dural defect lying directly under a previous osteotomy site was identified. After uneventful repair and follow-up of more than 1 year, the child is well and is without the development of a clinical seizure disorder or recurrence of her leptomeningeal cyst. CONCLUSION: Unrecognized dural injury combined with an overlying osteotomy in an infant can result in the development of a leptomeningeal cyst. Care must be taken at the time of endoscopic extradural surgery to recognize any inadvertent dural tears and to perform a direct repair at the time of the initial occurrence. Facility with and use of an appropriate endoscope is essential to the safe performance of minimally invasive craniosynostosis surgery.

Arachnoid Cysts↗

PubMed2004

Effect of vagus nerve stimulator magnet on programmable shunt settings.

OBJECTIVE: Vagus nerve stimulators and programmable shunt valves are used in the operative care of epilepsy and hydrocephalus, respectively. Both devices use magnetic fields to activate and program their various settings and functions. The authors conducted several ex vivo trials to better elucidate any interplay between the two systems. METHODS: A pulse generator controller (Cyberonics Corp., Houston, TX) was brought to within 4 cm of Strata programmable shunt valves (Medtronic Neurosurgery, Goleta, CA). Each of five valves was preset to either a low- or high-pressure setting and then challenged with the vagus nerve stimulator generator. Each valve was challenged 20 times, for a total of 100 trials. RESULTS: In 100 trials, 78 inadvertent pressure setting adjustments were recorded. In 46 attempts, the valve pressure was increased, and in 34 attempts, the pressure was decreased. CONCLUSION: This study provides some support to the anecdotal reports of inadvertent adjustments of programmable shunt valves by the external magnetic field created by vagus nerve stimulator pulse generator controllers. Further trials and a double-blind study are necessary to illustrate more clearly the possible relationship of these magnetically controlled neurosurgical devices.

Cerebrospinal Fluid Pressure↗

PubMed2004

Analysis and evolution of head injury in football.

OBJECTIVE: To review head injury in football through historical, anatomic, and physiological analysis. METHODS: We obtained data from a thorough review of the literature. RESULTS: The reported incidence of concussion among high school football players dropped from 19% in 1983 to 4% in 1999. During the 1997 Canadian Football League season, players with a previous loss of consciousness in football were 6.15 times more likely to experience a concussion than players without a previous loss of consciousness (P < 0.05). Players with a previous concussion in football were 5.10 times more likely to experience a concussion than players without a previous concussion (P = 0.0001). With the implementation of National Operating Committee on Standards for Athletic Equipment standards, fatalities decreased by 74% and serious head injuries decreased from 4.25 per 100,000 to 0.68 per 100,000. CONCLUSION: Significant declines in both the incidence and severity of head injury have been observed. The enhanced safety records in football can be attributed to the application of more stringent tackling regulations as well as the evolving football helmet. The role of a neurosurgeon is critical in further head injury prevention and guidelines in sport.

Adolescent↗