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Biomedical subjects

A Sepehrnia

Publications and source records attributed to A Sepehrnia.

At least 19 recordsLinked to original sources
PubMed2005

A new collagen biomatrix of equine origin versus a cadaveric dura graft for the repair of dural defects--a comparative animal experimental study.

OBJECT: Numerous types of materials have been evaluated over the past decades in the quest for the ideal dural replacement, but no product fully meets all the applicable criteria. This paper presents the long-term results of an animal trial of a collagen biomatrix (TISSUDURA, Baxter AG, Vienna/Austria) for the repair and regeneration of dural defects. This product provides a matrix with a special layer structure and consists of pure naturally cross-linked collagen of equine origin. The comparable material is Tutoplast Dura, a human cadaveric-derived dural graft preserved in a multiple stage chemical process. METHODS: Bihemispheric parietotoccipital dural defects of a defined size were induced in 25 sheep and subsequently closed with the collagen graft or Tutoplast Dura, respectively. RESULTS: Postoperative neurological abnormalities did not occur in any animal. There were no signs of graft rejection or formation of cerebrospinal fluid fistulae. The collagen graft site displayed histological signs as early as 2 weeks postoperatively consistent with a moderate Iymphocytic inflammatory response and infiltration with fibroblasts and macrophages. The graft subsequently developed a neodura-like connective tissue architecture. The Tutoplast Dura showed only minimal cellular infiltration, and again the surrounding structures displayed a mild inflammatory response. 24 weeks postoperatively, the dura and neomembrane were barely distinguishable at the collagen biomatrix site, but the Tutoplast Dura displayed inadequate fusion with the dural border and was encapsulated in a connective tissue layer. CONCLUSION: The outcomes demonstrate that the collagen graft can be used for dura reconstruction as a temporary dural replacement and at the same time as a biomatrix for dural regeneration.

Animals↗
PubMed2005

Taylored implants for alloplastic cranioplasty--clinical and surgical considerations.

Traumatic loss of bone substance or post - decompression defects require the reconstruction of the skull. In cases of simple geometry there are handy, secure and cost effective procedures such as using autologuous cryopreserved bone flaps or polymerized Methylmethacrylat. For large sized defects CAD - taylored implants developed to provide a comfortable procedure to ensure high biocompatibility and perfect anatomical results by one - stage surgery. Furthermore cranioplasty does not only imply anatomical reconstruction but also functional recovery of awareness, cognition and motoric functions as shown in several studies according to changes in cerebral hemodynamics and metabolism. In our series of 286 patients who underwent cranioplasty during the past 10 years (1993-2003) we used taylored implants in 15 cases starting in 1999. All the patients included showed large sized defects > 64 cm2, complications did not occur neither during surgery nor the postoperative course, cosmetical results were excellent in all the patients. Neurological findings and the functional state improved in 11/15 patients, 4/15 patients showed no change, nevertheless these patients had reached a good recovery before surgery. Application of this technique is limited by cost, nonetheless it is recommended for extensive reconstruction of the skull.

Adult↗
PubMed2005

[Preservation of olfaction in bifrontal craniotomies for lesions of the anterior and middle cranial fossa].

OBJECTIVE: The preservation of the olfactory tract during bifrontal approach for lesions located in the frontal skull base and the supra- and parasellar region has not previously been investigated. METHODS: In our study 12 patients underwent surgery for various lesions via the basal subfrontal route. All patients were observed prospectively, olfaction testing was performed pre- and postoperatively by an independent otorhinolaryngologist. RESULTS: We obtained complete preservation of the olfactory tracts and normal postoperative olfaction in all 12 cases. CONCLUSION: The bifrontal approach allowed a bilateral, wide operative field with excellent orientation and views of important structures. The shortcoming of this method, damage of the olfactory tracts and postoperative anosmia can be overcome.

Adolescent↗
PubMed2002

A new instrument facilitates the needle trephination procedure: technical note.

INTRODUCTION: Percutaneous needle trephination is a well known neurosurgical procedure. The aim of this study was to develop a new instrument, which allows a stable fixation of an 18-G spinal needle in order to improve handling and precision of percutaneous needle trephinations. METHODS AND INSTRUMENTATION: The needle stabilizer was designed in a T-shape fashion morphologically similar to a corkscrew. The length of the uncovered needle tip is adjustable for individual requirements. RESULTS: Using the new needle stabilizing device a total number of 18 percutaneous needle trephinations were performed for the following indications: subdural hematoma, epidural hygroma, bifrontal air accumulation, superficial tumor cyst, superficial brain abscess. No complications have been observed. DISCUSSION: Our experience using this device shows that the modified technique fulfils criteria for clinical acceptance such as simplicity, low risk, reliability and cost effectiveness.

Brain Diseases↗
PubMed2002

The combined subtemporal-suboccipital approach: a modified surgical access to the clivus and petrous apex.

OBJECTIVE: The surgical access to the clivus and the petrous apex is still a challenge. A combined approach is best fitted to lesions located in the middle and posterior cranial fossa. The approach described is centered on the petrous bone and requires an extensive bone resection; nevertheless, no osteoplastic bone flap is necessary. METHODS: In contrast to approaches described before, the petrous bone is drilled away anterior to the sigmoid sinus more extensively, the sinus is unroofed. For exposure of the middle cranial fossa the petrous bone should be resected down to the roof of the external meatus, the total extent of the craniotomy is significantly smaller. RESULTS AND CONCLUSION: The surgical access as described above provides a wide operative field under preservation of important intracranial structures. This modified approach minimizes the cerebellar and temporal lobe retraction. The neural and vascular structures can be preserved under direct vision to the tumor. The blood supply is interrupted at the beginning of the operation.

Cranial Fossa, Posterior↗
PubMed2001

Osteoplastic lateral suboccipital approach for acoustic neuroma surgery.

OBJECTIVE: Persistent headache remains a significant problem in a small group of patients after acoustic neuroma surgery via the lateral suboccipital approach. We describe a modified technique of osteoplastic lateral suboccipital craniotomy for surgery of the cerebellopontine angle. This simple and elegant technique provides a superior cosmetic result and a significant reduction in patients' symptoms. METHODS: We report on our series of 75 patients who underwent surgery for acoustic neuroma. The maximal follow-up period was 4 years. RESULTS: No patients reported headache postoperatively. Cerebrospinal fluid fistulae were not observed. CONCLUSION: This modified approach minimizes cerebellar retraction, and the neural and vascular structures can be preserved under direct visualization of the tumor. This lateral suboccipital approach is a useful modification of previous approaches in acoustic neuroma surgery. It provides successful tumor resection and excellent functional results.

Cerebellopontine Angle↗
PubMed2000

Cavernous angioma as a rare neuroradiologic finding in the cavernous sinus.

We report the case of a 56-year-old female with a pathologically confirmed cavernous angioma of the cavernous sinus. There are only a few reports on cavernous sinus angiomas in the literature. In contrast to typical intracerebral cavernous angiomas, these lesions are characterized by strong contrast enhancement on computed tomography and magnetic resonance imaging. In spite of the problematic location within the cavernous sinus, these angiomas can be completely resected without additional neurologic deficits. The clinical course of the patient and the unusual neuroradiologic imaging findings, as well as the cases from the literature are discussed.

Cavernous Sinus↗
PubMed2000

A cavernous hemangioma simulating an intracanalicular acoustic neurinoma--a case report.

A case of an intrameatal cavernous hemangioma is reported. The 53-year-old patient presented with decreased hearing and a slight 7th nerve palsy on the left. Clinical features and preoperative radiological appearances were indistinguishable from those of an acoustic neurinoma. Though, DD the involvement of all three nerves (N. facialis, N. cochlearis, N. vestibularis) should have lead to another entity. The tumour showed intraoperatively no relationship to the 8th cranial nerve, but was very adherent to the facial nerve. The macroscopic appearance differed to the usual aspect of an acoustic neurinoma. The final diagnosis was made after the operation with histopathological methods. The clinical features and pathology of this type of tumour are discussed.

Diagnosis, Differential↗
PubMed1999

Preservation of the olfactory tract in bifrontal craniotomy for various lesions of the anterior cranial fossa.

OBJECTIVE: Preservation of the olfactory tract during use of the bifrontal approach for the treatment of lesions located in the frontal cranial base and the supra- and parasellar regions has not been previously investigated. METHODS: In our study, 12 patients underwent surgery, via the basal subfrontal route, for treatment of various lesions. All patients were observed prospectively, and olfactometry was performed pre- and postoperatively by an independent otorhinolaryngologist. RESULTS: We obtained complete preservation of the olfactory tracts and normal postoperative olfaction in all 12 cases. CONCLUSION: The bifrontal approach yields a bilateral wide operative field with excellent orientation and views of important structures. The shortcomings of this method, i.e., damage to the olfactory tracts and postoperative anosmia, can be overcome.

Adolescent↗
PubMed1998

A craniospinal enterogenous cyst: case report.

An enterogenous cyst of the craniospinal region producing medullary compression is reported in a 4.5-year-old boy. The patient presented with stiffness of the neck and headache, but otherwise without neurological deficits. Magnetic resonance imaging (MRI) demonstrated a high-intensity mass extending from the cerebellomedullary cisterna to the second cervical vertebra flattening the medulla and the upper cervical cord. Complete recovery ensued following total excision of the cyst. Histologically, the cyst was lined by a single layer of PAS-positive columnar epithelium. Presentation of this unusual case is discussed together with a review of the literature.

Child, Preschool↗
PubMed1996

Analgesic effect of epidural morphine in lumbar disc surgery.

In patients operated on for herniated lumbar disc, epidural morphine was administered intraoperatively at the end of the procedure. A 10 milligram dose of morphine provided significant pain relief expressed by less requirement for strong analgesics on the day of operation and the day following, as well as for sedatives during the postoperative observation period of four days in comparison to a control group of patients. The only side effect observed was urinary retention.

Adolescent↗
PubMed1995

Syringomyelia in association with tumours of the posterior fossa. Pathophysiological considerations, based on observations on three related cases.

In this report we describe 3 patients with syringomyelia in association with tumours of the posterior fossa. In each patient the syrinx was demonstrated on pre-operative magnetic resonance imaging (MRI). After total or partial removal of the tumour the syrinx collapsed. It is concluded that the pathogenesis of syrinx formation in this entity requires interference with normal cerebrospinal fluid (CSF) flow at the foramen magnum. We suggest that the obstruction to the flow of CSF causes alterations in the passage of extracellular fluid (ECF) in the spinal cord which lead to syringomyelia.

Adolescent↗
PubMed1995

Neuromuscular choristoma.

Neuromuscular choristomas are rare, with only 13 cases having been previously reported. They usually arise in association with large nerves, and most often occur in the first decade of life. A few have been congenital. Although resection is typically curative, in two instances partial resection alone appears to have been followed by spontaneous regression. The authors report an unusual example of an otherwise classic neuromuscular choristoma where the lesion appeared to grow after incomplete initial resection. Re-excision disclosed a fibromatosis unassociated with choristoma. Despite its wide excision, a recurrence of the fibromatosis required a forequarter amputation. Theories of histogenesis and the clinicopathologic features of the neuromuscular choristomas reported to date are reviewed. The term "benign Triton tumor," although incorrectly applied to this lesion, should be reserved for benign, true nerve sheath neoplasms exhibiting myogenic differentiation.

Axilla↗
PubMed1995

Surgical treatment of jugular foramen schwannomas.

Sixteen patients with schwannomas of the jugular foramen were operated on in the Department of Neurosurgery of the Nordstadt Hospital in Hannover, Germany, between 1986 and 1992. Patients with neurofibromatosis were excluded. The records of the 16 patients were retrospectively reviewed. There were five women and 11 men (mean age 43 years) with a symptom duration ranging from 6 months to 20 years (mean 5 years). The predominant symptoms were hearing loss, hoarseness, and cerebellar symptoms. Computerized tomography (CT), magnetic resonance (MR) imaging, and angiography were performed in all 16 patients. Depending on the radiological and surgical features, the tumors were classified into four types: Type A, a tumor primarily at the cerebellopontine angle with minimal enlargement of the jugular foramen (eight cases); Type B, a tumor primarily at the jugular foramen with intracranial extension (two cases); Type C, a primarily extracranial tumor with extension into the jugular foramen (one case); and Type D, a dumbbell-shaped tumor with both intra- and extracranial components (five cases). A retromastoid suboccipital craniectomy was performed for Type A tumors, and a combined cervical-mastoidectomy for Types B, C, and D. Total tumor removal was achieved in all cases. There was no operative mortality. Postoperative complications were cerebrospinal fluid leakage in one patient and mastoiditis in two patients. The follow-up period ranged from 12 to 42 months (mean 22 months). All patients were alive at the last follow-up review, and CT and/or MR imaging showed no tumor recurrence.

Adult↗
PubMed1994

Involvement of spinal nerves in neurofibromatosis.

Spinal tumors are a frequent form of manifestation of neurofibromatosis. Out of 171 patients, who have been operated on over a ten years period on spinal tumors, 7 patients had neurofibromatosis (4.1%). A total of 9 operations were performed, removing 20 spinal tumors. Three patients had multiple neurofibromas. Half of the neurofibromas had a dumbbell configuration with a larger extraspinal extension. In three patients a family history of neurofibromatosis and typical dermatological signs were evident. Two cases will be selected and the basic concept regarding treatment and the risks involved will be discussed.

Adolescent↗
PubMed1991

Management of intracavernous tumours: an 11-year experience.

Seventy-one patients with tumours involving the cavernous sinus (CS) were operated upon between 1979 and 1989. Fifty-four patients underwent a direct approach to the CS. The average age of these latter patients was 47 (9-69) years. The lesions included 51 benign tumours (26 meningiomas, 16 [7 invasive] pituitary adenomas, 3 trigeminal neurinomas, one chordoma, one chondroma, one craniopharyngioma, one epidermoid tumour, and one cavernous haemangioma), and 3 malignant tumours (one chondrosarcoma, one adenoid cystic carcinoma and one metastatic adenocarcinoma). Dissecting tumour away from the carotid artery was the management of choice for intracavernous tumours which involved the internal carotid artery, except when the carotid artery had already pre-operatively presented with advanced narrowing or occlusion by encasing tumour. Microsurgical technique facilitated dissection and preservation of the cranial nerves. Patients treated radically by direct CS surgery had improvement of their symptoms and signs more frequently than those patients treated by subtotal tumour removal. However, operative complications in direct CS surgery were higher than in subtotal tumour removal without CS entry.

Adenoma↗