PubMed Health⌕ Search

Biomedical subjects

Amin B Kassam

Publications and source records attributed to Amin B Kassam.

18 recordsLinked to original sources
PubMed2007

Corridor surgery: the current paradigm for skull base surgery.

INTRODUCTION: Clival chordomas are rare tumors, especially in the pediatric population. In this report, we present the case of a 3-year-old boy who was found to have a large posterior pharyngeal, clival, and posterior fossa tumor detected on a CT scan after a closed head injury. DISCUSSION: Further questioning revealed a history of ataxia and dysphagia. Imaging confirmed severe extrinsic brain stem compression. The tumor was resected in multiple stages utilizing a minimally invasive endoscopic endonasal technique along with open transfacetal, transcondylar approach through the carotid-vertebral window. The child suffered no permanent complications as a result of our treatment and his dysphagia significantly improved. Although a complete resection was not feasible due to vascular encasement by the tumor, extensive decompression was obtained with minimal morbidity. CONCLUSION: We present this case to illustrate a new paradigm of skull base surgical approaches for large clival lesions in pediatric patients that allows aggressive resection with minimal morbidity.

Child, Preschool↗
PubMed2007

Expanded endonasal approach: a fully endoscopic completely transnasal resection of a skull base arteriovenous malformation.

OBJECTIVE AND IMPORTANCE: Vascular lesions with an intraosseus nidus involving the skull base are uncommon and challenging [Gianoli GJ, Amedee RG Vascular malformation of the sphenoid sinus. Ear Nose Throat J. 70:373-375;(1991), Malik GM, Mahmood A, Mehta BA Dural arteriovenous malformation of the skull base with intraosseous vascular nidus. Report of two cases. J. Neurosurg 81:620-623;(1994)]. We present a pediatric patient, with a life-threatening arteriovenous malformation (AVM) of the sphenoid sinus, clivus, and ventral skull base, who failed routine multimodality management of AVMs. An entirely transsphenoidal fully endoscopic resection was used to resect this ventral cranial base AVM with an intraosseus nidus located in the clivus. CLINICAL PRESENTATION: A 4-year-old female presented with recurrent, life-threatening hemorrhages from a clival and ventral skull base AVM of the entire clivus and ventral skull base. The patient had been temporized from the age of 2-4 years with multiple internal and external carotid arterial particulate and alcohol embolizations, including both external and internal carotid artery embolizations, intracranial ligation of the right internal carotid artery, and gamma knife irradiation. Despite these multiple interventions, the patient had persistent, life-threatening hemorrhages from arterial recanalization and recruitment requiring intubation, tracheostomy, and nasopharyngeal packing. INTERVENTION: The patient underwent a three-stage surgical intervention to resect the AVM. An open subfrontal approach, as the first procedure, provided minimal access to the feeding vessels and was therefore aborted. A two-stage image-guided fully endoscopic approach via a sublabial midface approach without external incisions was performed. Postoperative angiography revealed minimal residual shunting in the pharynx and cavernous sinus. The patient has been free of significant hemorrhages over the past three years. CONCLUSION: Technological advances in endoscopic surgery and image guidance are now allowing for purely endoscopic surgical treatment of previously unresectable lesions with acceptable morbidity. We report the successful and safe resection of a ventral cranial base AVM via a fully endoscopic approach. This paper reports the first AVM with a purely intraosseus nidus of the ventral skull base and demonstrates the ability to deal with complex ventral skull base lesions using a fully endoscopic transsphenoidal technique.

Cerebral Angiography↗
PubMed2006

The expanded endonasal approach for an endoscopic transnasal clipping and aneurysmorrhaphy of a large vertebral artery aneurysm: technical case report.

OBJECTIVE: Aneurysms of the vertebral artery are rare, comprising less than 5% of all aneurysms. They can present with subarachnoid hemorrhage, medullary compression, and cranial neuropathies. In consideration of their surrounding regional anatomy, they present a formidable surgical challenge to the neurosurgeon using traditional techniques. Recent advances in endoscopic transnasal surgery have provided an additional approach for the treatment of these difficult lesions. CLINICAL PRESENTATION: We present a case of a large vertebral artery aneurysm causing mass effect on the medulla. Initial treatment consisted of endovascular trapping of the aneurysm; however, because of concerns that the remaining aneurysm and intraluminal thrombus was causing mass effect and continued brainstem compression, a decompressive procedure was required. INTERVENTION: After the endovascular trapping, the patient underwent a completely endoscopic transnasal surgical clipping and aneurysmorrhaphy. After exposure of the aneurysm, distal and proximal clips were applied transnasal, and the aneurysmorrhaphy completed using suction and ultrasonic aspiration. CONCLUSION: In consideration of their surrounding regional anatomy, aneurysms of the vertebral artery present a formidable surgical challenge to the neurosurgeon. Although endovascular techniques have proven to be extremely valuable for the treatment of these lesions, they are limited when patients have significant mass effect with brainstem compression or cranial neuropathy. Advances in endoscopic transnasal surgery have provided an additional approach for the treatment of these difficult lesions. This case report represents, to our knowledge, the first literature report of a transnasal endoscopic aneurysm clipping and thrombectomy.

Atlanto-Occipital Joint↗
PubMed2005

Extended endoscopic endonasal approach to the pterygopalatine fossa: anatomical study and clinical considerations.

OBJECT: The pterygopalatine fossa is an area located deep in the skull base. The microsurgical transmaxillary-transantral route is usually chosen to remove lesions in this region. The increasing use of the endoscope in sinonasal functional surgery has more recently led to the advent of the endoscope for the treatment of tumors located in the pterygopalatine fossa as well. METHODS: An anatomical dissection of three fresh cadaveric heads (six pterygopalatine fossas) and three dried skull base specimens was performed to evaluate the feasibility of the approach and to illustrate the surgical landmarks that are useful for operations in this complex region. The endoscopic endonasal approach allows a wide exposure of the pterygopalatine fossa. Furthermore, with the same access (that is, through the nostril) it is possible to expose regions contiguous with the pterygopalatine fossa, either to visualize more surgical landmarks or to accomplish a better lesion removal. CONCLUSIONS: In this anatomical study the endoscopic endonasal approach to the pterygopalatine fossa has been found to be a safe approach for the removal of lesions in this region. The approach could be proposed as an alternative to the standard microsurgical transmaxillary-transantral route.

Cranial Fossa, Anterior↗
PubMed2005

Expanded endonasal approach: fully endoscopic, completely transnasal approach to the middle third of the clivus, petrous bone, middle cranial fossa, and infratemporal fossa.

OBJECT: The middle third of the clivus and the region around the petrous internal carotid artery (ICA) is a difficult area of the skull base in terms of access. This is a deep area rich with critical neurovascular structures, which is often host to typical skull base diseases. Expanded endoscopic endonasal approaches offer a potential option for accessing this difficult region. The objective of this paper was to establish the clinical feasibility of gaining access to the paraclival space in the region of the middle third of the clivus, to provide a practical modular and clinically applicable classification, and to describe the relevant critical surgical anatomy for each module. METHODS: The anatomical organization of the region around the petrous ICA, cavernous sinus, and middle clivus is presented, with approaches divided into zones. In an accompanying paper in this issue by Cavallo, et al., the anatomy of the pterygopalatine fossa is presented; this was observed through cadaveric dissection for which an expanded endonasal approach was used. In the current paper the authors translate the aforementioned anatomical study to provide a clinically applicable categorization of the endonasal approach to the region around the petrous ICA. A series of zones inferior and superior to the petrous ICA are described, with an illustrative case presented for each region. CONCLUSIONS: The expanded endonasal approach is a feasible approach to the middle third of the clivus, petrous ICA, cavernous sinus, and medial infratemporal fossa in cases in which the lesion is located centrally, with neurovascular structures displaced laterally.

Cavernous Sinus↗
PubMed2005

A DNA sequence polymorphism in the endoglin gene is not associated with intracranial aneurysm or aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Endoglin is a member of the transforming growth factor beta family of proteins and plays a central role in vascular growth and development. There have been conflicting reports that polymorphic variation in the endoglin gene is a risk factor for intracranial aneurysms (IAs). We sought to further investigate the intron 7 5'-TCCCCC-3' endoglin polymorphism as a risk factor for IA and subarachnoid hemorrhage (SAH) in a population of patients from western Pennsylvania. METHODS: We genotyped 98 IA patients and 191 unaffected controls for a length polymorphism in intron 7 using PCR-based methods. RESULTS: The endoglin polymorphism was not associated with IA or the incidence of aneurysm rupture and SAH. No association was found when data were stratified by smoking and hypertension. CONCLUSION: These data, from a population recruited in western Pennsylvania, support recent findings in Japanese and German populations that, despite earlier observation to the contrary, endoglin is not associated with IA. Furthermore, our study extends previous observations by demonstrating no association between endoglin and either IA or SAH regardless of whether data were stratified for modifiable risk factors such as smoking and hypertension.

Adult↗
PubMed2005

The management of cerebrospinal fluid leaks in patients at risk for high-pressure hydrocephalus.

OBJECTIVES/HYPOTHESIS: The transnasal endoscopic approach has become the preferred technique for the surgical management of patients with cerebrospinal fluid (CSF) leaks of the anterior, sellar, and parasellar skull base. The literature has reported an 85% to 100% success rate for the endoscopic repair of CSF leaks, which compares favorably with that reported after transcranial repair. Despite an adequate repair, a subpopulation of patients remain at high risk for recurrence of the CSF leak attributable to undiagnosed high-pressure hydrocephalus. Patients at high risk for high-pressure hydrocephalus include those who have had a subarachnoid hemorrhage as a result of trauma (accidental or surgical) or stroke and those with spontaneous CSF leaks. STUDY DESIGN: With the goal of reducing the risk of recurrence, the authors developed a protocol for the identification and management of patients with CSF leaks who are at risk for high-pressure hydrocephalus. METHODS: The protocol includes endoscopic repair, temporary CSF diversion, measurement of CSF pressure after the repair, and immediate ventriculoperitoneal shunting if necessary. RESULTS: During the period of September 1999 to April 2002, the authors repaired 25 CSF leaks through an endonasal endoscopic approach. Nineteen patients were considered at high risk for high-pressure hydrocephalus. Using the protocol described, the authors identified six patients (31%) with CSF leaks that could be associated with undiagnosed high-pressure hydrocephalus. All CSF leaks were successfully repaired using a transnasal endoscopic repair. Six patients with high-pressure hydrocephalus underwent ventriculoperitoneal shunting after repair of the CSF Leak. No recurrence has been observed at a follow-up ranging from 24 to 84 months (median period, 30 mo). CONCLUSION: Patients with high-pressure hydrocephalus may be identified in a prospective fashion to prevent recurrence or persistence of the CSF leaks. The presence or absence of high-pressure CSF may be established by means of direct CSF pressure measurement through lumbar puncture postoperatively. This allows early intervention and prevention of recurrence.

Adolescent↗
PubMed2005

Microsurgical removal of intraventricular lesions using endoscopic visualization and stereotactic guidance.

OBJECTIVE: To demonstrate the technique of stereotactic microsurgical endoscopic removal of intraventricular tumors or colloid cysts assisted by intraoperative computed tomography. METHODS: We adapted a tubular "ventriculoport" for stereotactic insertion of an endoscope into the ventricle. This facilitated microsurgical resection of 14 intraventricular tumors or colloid cysts by use of intraoperative stereotactic microsurgical endoscopic removal of intraventricular tumors or colloid cysts assisted by intraoperative computed tomography. RESULTS: Gross total resection was achieved in 12 patients and confirmed by intraoperative computed tomographic scanning and postoperative magnetic resonance imaging. Patients with preoperative hydrocephalus had relief of their symptoms. Perioperative morbidity was limited to mild headache associated with postoperative pneumocephalus. The average length of stay was 3.6 days. Twelve patients had significant improvement in their symptoms. CONCLUSION: The combination of intraoperative computed tomography-guided stereotactic technique and rigid endoscopy facilitated an accurate, minimally invasive, microsurgical removal of these intraventricular masses. This approach minimized retraction and provided satisfactory visualization.

Adult↗
PubMed2005

The expanded endonasal approach: a fully endoscopic transnasal approach and resection of the odontoid process: technical case report.

The transoral approach to the odontoid process is considered the "gold standard" for resection of extradural lesions at this location. A completely transnasal endoscopic approach is feasible based on anatomic studies and our experience with the expanded endonasal approach for neoplasms of the cranial base. An illustrative case is presented to demonstrate the technical details of a fully transnasal completely endoscopic approach for the resection of the odontoid process. A 73-year-old woman with a long-standing history of rheumatoid arthritis presented with progressive cervicomedullary compression. Complete resection of the odontoid was achieved with no significant morbidity. This is the first reported case of a completely endoscopic resection of the odontoid using a fully transnasal route. The report demonstrates the feasibility of this approach and larger clinical series with long-term follow-up will be needed to determine the reproducibility and validation of any potential benefits.

Aged↗
PubMed2005

The short form-12 and the measurement of health status in patients with cerebral aneurysms: performance, validity, and reliability.

OBJECT: Cerebral aneurysms can affect a patient's health status by rupture and stroke, impingement on neural structures, treatment side effects, or psychological stress. The authors assessed the performance, validity, and reliability of the Short Form-12 (SF-12), a self-administered written survey instrument, to assess health status in patients with cerebral aneurysms. METHODS: A cohort of 170 patients with cerebral aneurysms who were seen at a neurosurgery clinic underwent structured interviews including measurement of their health statuses (SF-12 physical component summary [PCS] and mental component summary [MCS]), functional status (Glasgow Outcome Scale score, modified Rankin Scale score, and Barthel Index), and mental health (Hospital Anxiety and Depression Scale score). The SF-12 scores were compared with US population norms by performing t-tests with unequal variances. The validity of the SF-12 was assessed by comparing the PCS and MCS scores with each patient's functional status and mental health scores by using rank-order methods. Inter-item reliability was assessed using the Cronbach alpha statistic. Patients with cerebral aneurysms had decreased health status PCS and MCS scores when compared with population norms (p < 0.001 for all). A history of subarachnoid hemorrhage (SAH) (p = 0.006) and previous surgical or endovascular treatment (p = 0.047) was associated with worse PCS scores. The validity of the SF-12 was supported by the relationship between the PCS and MCS scores and the patient's functional status and mental health (p < 0.001 for all). The reliability of the SF-12 was documented by the Cronbach alpha statistic (alpha = 0.76). CONCLUSIONS: Patients with cerebral aneurysms have a diminished physical and mental health status as measured using the SF-12. The presence of SAH and aneurysm treatment are associated with a worse physical health status. The SF-12 is a valid and reliable instrument for measuring health status in patients with cerebral aneurysms.

Adult↗
PubMed2005

Mental health, anxiety, and depression in patients with cerebral aneurysms.

OBJECT: Aneurysm disease and its treatment can have an adverse impact on mental health, yet the affects of cerebral aneurysms on general mental health, anxiety, and depression are poorly understood. METHODS: Patients with cerebral aneurysms who were seen at a neurosurgery clinic underwent a structured interview, completed the Hospital Anxiety and Depression Scale and the Medical Outcomes Study 12-item Short Form Health Survey (providing a mental component summary [MCS] score for general mental health), and were assigned functional status scores based on the Glasgow Outcome Scale (GOS), Rankin Scale, and Barthel Index. Rank-order methods were used to assess the relationship between mental health, aneurysm characteristics and history, and functional status. Data were collected in 166 patients (71% women) with a mean age of 53.7 years. Depression was present in 8% of the study population and an anxiety disorder in 17%. Patients with both an unsecured aneurysm and a history of subarachnoid hemorrhage (SAH) tended toward higher anxiety scores (p = 0.086). Higher depression scores were associated with a decreased functional status on the GOS (p = 0.015) and Rankin Scale (p = 0.010). The mean +/- standard deviation adjusted MCS score (37.9 +/- 7.1) was significantly less than that of the US population (p < 0.001). Lower MCS scores were associated with a decreased functional status on the GOS (p = 0.052), Rankin Scale (p < 0.001), and Barthel Index (p = 0.002). CONCLUSIONS: Patients with cerebral aneurysms have increased levels of anxiety and depression and poor general mental health. Those who have experienced an SAH and harbor an unsecured cerebral aneurysm demonstrate increased levels of anxiety. A lower functional status in patients with aneurysms is associated with depression and decreased general mental health.

Adult↗
PubMed2005

The carotid-vertebral space: an 'extended' lateral window to the ventromedial cranial base and lower craniocervical junction.

We describe a unique method of accessing the ventromedial skull base and lower craniocervical junction. Our method employs a trajectory between that of the more anterior transoral or retropharyngeal approaches and the various posterior or posterolateral skull base approaches. This "extended" lateral approach allows surgeons to resect very large tumors of the skull base through a single incision. The operative field is more extensive than that achieved with other approaches; it extends from the cerebellar hemisphere to the extradural ventral upper cervical spine, and it provides access to tissue outside the spinal canal, such as the ventral strap muscles. We describe our use of this approach during a single-stage resection of a large hemangiopericytoma in a 37-year-old man.

Acyclovir↗
PubMed2004

Preauricular infratemporal fossa surgical approach: modifications of the technique and surgical indications.

A retrospective clinical analysis was performed to evaluate the effectiveness of the preauricular infratemporal fossa (ITF) surgical approach using modifications based on tumor pathology and extension, without compromising outcomes. Patients were surgically treated for tumors involving the ITF via a preauricular surgical approach during 1990 to 2000. Their clinical charts were reviewed to determine the association among pathological variables, details of the surgical procedure, and outcomes. Tumors in 65 patients were categorized as "malignant" and "benign." The malignant group included 44 patients (mean age, 49.5 years). Squamous cell carcinoma was the most common pathology followed by sarcomas. To achieve complete tumor resection, the ITF approach and dissection were combined with other procedures in 74% of these patients. No surgical complications were encountered in 74.4%, and a clinical cure was obtained in 55% of patients (follow-up, 2 years). The benign group included 21 patients (mean age, 36.7 years). Juvenile angiofibromas and meningiomas constituted most of the tumors in this group. An ITF approach alone was sufficient to achieve complete tumor excision in 66.7% of these patients. A clinical cure was achieved in 85% of patients (follow-up, 2 years), and 76.2% had no surgical complications. Chi-square tests revealed significant correlations between tumor extensions and surgical treatment variables. These were more evident in the malignant group, indicating the use of wider surgical exposures and more aggressive, extirpative surgery. The preauricular surgical approach to the ITF can be used to achieve a complete resection of a variety of tumors arising from or extending into the ITF. This approach can be tailored to the nature of the tumor and its extensions.

Journal Article↗
PubMed2004

Altered arterial homeostasis and cerebral aneurysms: a molecular epidemiology study.

OBJECTIVE: We hypothesized that patients with intracranial cerebral aneurysms (IAs) harbor a molecular defect in the process responsible for maintaining arterial integrity (arterial homeostasis). In this study, we undertook a preliminary assessment of differential expression of key molecules involved with each phase of homeostasis: arterial flow modulation, arterial tear and repair, and the ensuing extracellular matrix. METHODS: Key molecules from each phase of the arterial homeostatic process were selected: prostacyclin-stimulating factor, implicated with arterial flow modulation; PNUT and RAI, involved with tissue repair and arterial remodeling; and Type III collagen and fibronectin, which are key constituents of the extracellular matrix. A small sample of the IA dome was harvested at the time of surgical repair from both ruptured and unruptured domes. Pericranial vascular tissue was harvested from a sample of the superficial temporal artery (STA) or occipital artery from aneurysmal and nonaneurysmal patients undergoing craniotomy for unrelated conditions. Statistical analysis examining expression of each marker was performed initially using dichotomous analysis (presence or absence of expression), followed by an assessment of quantitative differences in expression. Initial analysis was restricted to the pair consisting of dome and STA harvested from each individual patient. This was followed by a pooled analysis in which all domes and STAs were respectively pooled. RESULTS: A total of 86 tissue samples were studied, including 24 IA domes, STA samples from 43 aneurysmal patients, and STA samples from 19 nonaneurysmal patients. We found that the degree of prostacyclin-stimulating factor and RAI expression was reduced in ruptured aneurysm domes when compared with STAs from IA patients (odds ratio, 0.26; 95% confidence interval [CI], 0.08-0.89; and odds ratio, 0.18; 95% CI, 0.03-0.94, respectively). Type III collagen expression also was reduced among ruptured domes when compared with STA (P = 0.042). These differences were found to be independent of the effects of smoking with adjusted odds ratios of 0.25 (95% CI, 0.08-0.77) and 0.18 (95% CI, 0.04-0.79), respectively, for prostacyclin-stimulating factor and RAI. No statistically significant differences were noted among the unruptured domes. CONCLUSION: These preliminary data suggest an impaired ability to express proteins responsible for flow modulation and arterial repair within the ruptured domes when compared with control pericranial tissue. The study generates a hypothesis of impaired arterial homeostasis with a reduced ability to modulate hemodynamic flow with perhaps increased microinjury. This is exacerbated further by an impaired molecular ability to repair the vessel wall, culminating in aneurysm rupture. The study has limitations based on the use of pericranial tissue as the control and the relatively small sample size. Nevertheless, this study suggests that altered arterial homeostasis warrants further investigation in hopes of better understanding IA pathogenesis.

Adult↗
PubMed2002

Giant parapharyngeal space lipoma: case report and surgical approach.

Large parapharyngeal space tumors near critical neurovascular structures pose challenging management problems. Only eight cases of a lipoma in the parapharyngeal space have been reported. We present a surgical approach that permits safe resection of such unusual tumors.A 49-year-old man had a 2-year history of progressive pain in the left neck radiating from the shoulder to the occiput. Contrast-enhanced computed tomography (CT) of the neck demonstrated a fat-attenuation mass located in the poststyloid parapharyngeal space. The mass extended into the foramen transversarium at the level of the second cervical vertebra and encased the vertebral artery. The tumor was removed through an extended transcervical approach that included transection of the attachments of the sternocleidomastoid, trapezius, splenius capitus, and the longissimus capitus muscles. The approach provided access to the first cervical vertebra, allowing dissection of the tumor from the vertebral artery in the foramen transversarium. An extended transcervical approach provides exposure from the carotid artery to the vertebral artery and facilitates the complete excision of large parapharyngeal space masses.

Case Reports↗
PubMed2002

Predictors of outcome in surgically managed patients with typical and atypical trigeminal neuralgia: comparison of results following microvascular decompression.

OBJECT: Microvascular decompression (MVD) has become one of the primary treatments for typical trigeminal neuralgia (TN). Not all patients with facial pain, however, suffer from the typical form of this disease; many patients who present for surgical intervention actually have atypical TN. The authors compare the results of MVD performed for typical and atypical TN at their institution. METHODS: The results of 2675 MVDs in 2264 patients were reviewed using information obtained from the department database. The authors examined immediate postoperative relief in 2003 patients with typical and 672 with atypical TN, and long-term follow-up results in patients for whom more than 5 years of follow-up data were available (969 with typical and 219 with atypical TN). Outcomes were divided into three categories: excellent, pain relief without medication; good, mild or intermittent pain controlled with low-dose medication; and poor, no or poor pain relief with large amounts of medication. The results for typical and atypical TN were compared and patient history and pain characteristics were evaluated for possible predictive factors. CONCLUSIONS: In this study, MVD for typical TN resulted in complete postoperative pain relief in 80% of patients, compared with 47% with complete relief in those with atypical TN. Significant pain relief was achieved after 97% of MVDs in patients with typical TN and after 87% of these procedures for atypical TN. When patients were followed for more than 5 years, the long-term pain relief after MVD for those with typical TN was excellent in 73% and good in an additional 7%, for an overall significant pain relief in 80% of patients. In contrast, following MVD for atypical TN, the long-term results were excellent in only 35% of cases and good in an additional 16%, for overall significant pain relief in only 51%. Memorable onset and trigger points were predictive of better postoperative pain relief in both atypical and typical TN. Preoperative sensory loss was a negative predictor for good long-term results following MVD for atypical TN.

Adolescent↗