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Biomedical subjects

Ketan R Bulsara

Publications and source records attributed to Ketan R Bulsara.

At least 19 recordsLinked to original sources
PubMed2006

Effect of combined simvastatin and cyclosporine compared with simvastatin alone on cerebral vasospasm after subarachnoid hemorrhage in a canine model.

OBJECT: The object of this study was to determine whether the combination of cyclosporine and simvastatin could ameliorate cerebral vasospasm after subarachnoid hemorrhage (SAH) in a canine model to a greater extent than simvastatin alone. METHODS: Animals were assigned to one of three groups: control (five dogs), simvastatin alone (four), or simvastatin and cyclosporine (four). A double SAH model was used. Baseline basilar artery (BA) angiograms were obtained. These were repeated at Days 3, 7, and 10. Measurement of the BA diameter was performed. Decreased BA diameter was seen on Day 3 in the control and simvastatin/cyclosporine group. A return to baseline diameters was seen by Day 7. An increase from baseline diameter was seen in the simvastatin group at Day 10. CONCLUSIONS: Cyclosporine may interfere with the vasodilatory effects of simvastatin. Vasodilation greater than baseline is seen at Day 10 in the simvastatin group. The combination of simvastatin and cyclosporine does not ameliorate cerebral vasospasm in a canine model to a greater extent than simvastatin alone.

Analysis of Variance↗
PubMed2006

Review of the literature on de novo formation of cavernous malformations of the central nervous system after radiation therapy .

In this paper the authors review the literature concerning de novo cavernoma formation after radiation treatment. PubMed and MEDLINE database searches were performed. Data were compiled on all patients in whom de novo cavernomas formed after radiation treatment and whose cases were reported in the literature. The authors found reports in the literature of 76 patients in whom cavernomas formed de novo after radiation treatment. The mean age of the patients was 11.7 years, and the majority of these lesions occurred in males. The patients received a mean radiation dose of 60.45 Gy. The mean latency period before detection of the cavernoma was 8.9 years, and most of these lesions were detected incidentally. In symptomatic patients, the most common presenting symptoms were seizures. Thirty-seven of the patients had evidence of hemorrhage, and 54% of these required surgical intervention. De novo formation of cavernomas after radiation treatment is a relatively rare phenomenon. Patients in whom these cavernomas develop need to be followed closely because there is a propensity for the lesions to hemorrhage. Surgical intervention to treat symptomatic lesions has a favorable outcome.

Age of Onset↗
PubMed2006

History of bipolar coagulation.

Bipolar coagulation heralded an age of improved hemostasis for microneurosurgery. This, coupled with an improved understanding of microsurgical anatomy, has allowed access to areas of the brain once considered inaccessible. In this review, we trace the history of bipolar coagulation.

Electrocoagulation↗
PubMed2006

Rotational vertebral artery insufficiency resulting from cervical spondylosis: case report and review of the literature.

BACKGROUND: Four cases of vertebrobasilar insufficiency secondary to osteophyte formation at C5-C6 have been reported in the literature. In this article, we report the fifth such case and discuss the utility of dynamic computed tomographic angiography (CTA) in the management of this disorder. CASE DESCRIPTION: A 55-year-old right-handed man presented for evaluation after syncopal episodes associated with right-head turning. Workup revealed cervical spondylosis with stenosis. The C5-C6 level was significantly affected. Dynamic angiography revealed obstruction of vertebral artery flow with right-head turning secondary to an osteophyte at the foramen transversarium at C5-C6. This patient underwent a C5-C6 anterior cervical discectomy and fusion. He also underwent unroofing of the vertebral artery and drilling of the osteophyte at the foramen transversarium. Postoperative CTAs reveal reconstitution of flow in the vertebral artery with head turning. CONCLUSION: The utility of dynamic 3-dimensional CTA in the management of this disorder avoids the risk of invasive studies.

Cervical Vertebrae↗
PubMed2006

Perioperative complications in transforaminal lumbar interbody fusion versus anterior-posterior reconstruction for lumbar disc degeneration and instability.

OBJECTIVES: Multiple different approaches are used to treat lumbar degenerative disc disease and spinal instability. Both anterior-posterior (AP) reconstructive surgery and transforaminal lumbar interbody fusion (TLIF) provide a circumferential fusion and are considered reasonable surgical options. The purpose of this study was to quantitatively assess clinical parameters such as surgical blood loss, duration of the procedure, length of hospitalization, and complications for TLIF and AP reconstructive surgery for lumbar fusion. METHODS: A retrospective analysis was completed on 167 consecutive cases performed between January 2002 and March 2004. TLIF surgical procedure was performed on 124 patients, including 73 minimally invasive and 51 open cases. AP surgery was performed on 43 patients. Patients were treated for painful degenerative disc disease, facet arthropathy, degenerative instability, and spinal stenosis. RESULTS: The mean operative time for AP reconstruction was 455 minutes, for minimally invasive TLIF 255 minutes, and open TLIF 222 minutes. The mean blood loss for AP fusion surgery was 550 mL, for minimally invasive TLIF 231 mL, and open TLIF 424 mL. The mean hospitalization time for AP reconstruction was 7.2 days, for minimally invasive TLIF 3.1 days, and open TLIF 4.1 days. The total rate of complications was 76.7% for AP reconstruction, including 62.8% major and 13.9% minor complications. The minimally invasive TLIF patients group had the total 30.1% rate of complications, 21.9% of which were minor and 8.2% major complications. There were no major complications in the open TLIF patients group, with 35.3% minor complications. CONCLUSIONS: AP lumbar interbody fusion surgery is associated with a more than two times higher complication rate, significantly increased blood loss, and longer operative and hospitalization times than both percutaneous and open TLIF for lumbar disc degeneration and instability.

Adult↗
PubMed2006

Three-dimensional computed tomographic analysis of the relationship between the arcuate eminence and the superior semicircular canal.

OBJECTIVE: The location of the superior semicircular canal (SSC) is often determined intraoperatively based on its topographic association with the arcuate eminence (AE). This determination is not always possible because of the potential variability in the relationship between these two structures. The goal of this study was to describe the three-dimensional (3-D) relationship between the AE and SSC using 3-D computed tomography (CT) and to evaluate the utility of 3-D CT for preoperative planning for surgical approaches to the middle cranial fossa. METHODS: We studied 11 patients (22 sides) radiographically using 0.8- to 1-mm thick reconstructed CT images. A standard set of structural relationships was measured between the AE, SSC, and other regional landmarks. RESULTS: 3-D CT clearly demonstrated the relationships between traditional landmarks along the petrous ridge and middle cranial fossa. The relationship between the arcuate eminence and SSC was found to be highly variable. The average distance between the tips of the two structures was found to be 5.7 mm (range, 2.7-10.4 mm). CONCLUSIONS: There is significant variability in the relationship between the AE and the SSC. The AE is not a consistent or reliable landmark for identifying the precise position of the SSC. Detailed preoperative information regarding the relationship between the AE, SSC, and other bony landmarks can be easily and quickly assessed using 3-D CT.

Adolescent↗
PubMed2006

Jugular tubercle: Morphometric analysis and surgical significance.

OBJECT: Maximizing intradural exposure via the extreme lateral infrajugular transcondylar-transtubercular exposure (ELITE) approach depends on understanding the fundamental anatomy of the jugular tubercle (JT). Drilling the JT can maximize the extent of exposure achieved with the ELITE approach. Removing the JT is critical for optimizing access to the inferior and midclival areas, vertebrobasilar artery junction, and ventral pons and medulla. METHODS: In this cadaveric study, the individual structural variations in the JT were evaluated in 100 split occipital bones. The mean length of the JT was 1.65 +/- 0.36 cm (range 1.2-3 cm); its mean width was 1.15 +/- 0.16 cm (range 0.7-1.7 cm); and its mean thickness was 0.61 +/- 0.15 cm (range 0.2-1 cm). The authors analyzed the difference in morphometric data with regard to right and left sides and found no statistically significant difference between the two sides. Furthermore, data from the morphometric study were compared with the results of 20 measurements obtained from three-dimensional computed tomography (3D CT) scans. Accordingly, the mean length of the JT was 1.35 +/- 0.15 cm (range 1-2.8 cm); the mean width, 1.10 +/- 0.12 cm (range 0.8-1.3 cm); and the mean thickness, 0.51 +/- 0.18 cm (range 0.2-1 cm). CONCLUSIONS: Morphometric data on the JT contribute significantly to the neurosurgeon's task of skull base drilling. The 3D CT scans were useful in the preoperative planning.

Body Weights and Measures↗
PubMed2005

Intraoperative three-dimensional fluoroscopy-based computerized tomography guidance for percutaneous kyphoplasty.

OBJECT: Percutaneous kyphoplasty is an established method for the treatment of pathological vertebral compression fractures (VCFs). This procedure is usually performed with the aid of biplanar fluoroscopic image guidance. There are currently no published clinical studies in which the use of three-dimensional (3D) image guidance to facilitate this technique has been evaluated. The purpose of this study was to evaluate the efficacy of isocentric fluoroscopy-based navigation for the kyphoplasty procedure, with special reference to operating time and the amount of radiation exposure. METHODS: A prospective clinical study was performed in which 11 consecutive patients with painful pathological VCFs that did not respond to conservative treatment underwent the kyphoplasty procedure. During this procedure, cannulation of the pedicle and vertebral body was performed with the aid of isocentric 3D fluoroscopy visualization. Total operating time and intraoperative fluoroscopy time for this group was compared with a cohort of nine patients who underwent the procedure prior to the availability of isocentric fluoroscopy (only biplanar fluoroscopy was used). Possible complications such as cement extravasations were evaluated during the procedure and on postoperative computerized tomography scans. The mean duration of surgery for the 3D isocentric fluoroscopic guidance group was 60 minutes (range 36-89 minutes) for one-level and 68.5 minutes (range 65-75 minutes) for two-level cases. Because of a learning curve with the equipment, the operating time for the initial cases was significantly longer than with the later ones. Even with the initial cases included, the mean operating time was shorter compared with the biplanar fluoroscopy-assisted procedures, which averaged 69.2 minutes (range 44-113 minutes) for one-level procedures. This difference was not statistically significant. The mean fluoroscopy exposure time was 41.3 seconds (range 25-62 seconds) in the isocentric fluoroscopy-assisted procedures, with an additional 40 seconds of fluoroscopy time used for the 3D fluoroscopy "spin," compared with 293.2 seconds (range 180-400 seconds) in the biplanar fluoroscopy-assisted procedures. The difference was statistically significant (p = 0.02). All pedicles were accessed without difficulty and no complications were encountered in either group of patients. CONCLUSIONS: The main advantage of isocentric fluoroscopy is the significant reduction in radiation exposure for the patient and surgical staff without an increase in the mean operating time. This technique is a significant advancement over biplanar fluoroscopy in this setting.

Adult↗
PubMed2005

Superior ophthalmic vein approach to carotid-cavernous fistulas. Technical note.

Endovascular procedures have revolutionized the treatment of carotid-cavernous fistulas through transarterial and transvenous routes. In some circumstances, however, traditional endovascular approaches may fail. Direct access to the superior ophthalmic vein (SOV) can be used to treat fistulas in this circumstance. The authors discuss the technical aspects of direct exposure of the SOV for access to the cavernous sinus.

Carotid-Cavernous Sinus Fistula↗
PubMed2005

Utility of computerized isocentric fluoroscopy for minimally invasive spinal surgical techniques.

OBJECTIVE: The purpose of this study was to prospectively evaluate the clinical utility and accuracy of intraoperative three-dimensional fluoroscopy as an adjunct for the placement of a complex spinal instrumentation. METHODS: The Siemens Iso-C three-dimensional fluoroscopy unit in the combination with the Stealth Treon computer volumetric navigational system was used. A total of 279 spinal instrumentation screws or transpedicular cannulations were performed in 69 patients. Accuracy, operative time, and amount of fluoroscopy utilization time were assessed for transforaminal lumbar interbody fusion (TLIF) and kyphoplasty cases. RESULTS: Only 4 percutaneous transpedicular lumbar screws out of 265 total (1.5%) were malpositioned. Average operative time for TLIF cases was 185 minutes (range 114-311 minutes) for one-level and 292.6 minutes (range 173-390 minutes) for two-level procedures. Biplanar fluoroscopy utilization time was 93 seconds (range 27-280 seconds) for one-level procedures and 216 seconds (range 80-388 seconds) for two-level procedures. Average surgery duration for kyphoplasty was 60 minutes (range 36-79 minutes) for one-level procedures and 68.5 minutes (range 65-75 minutes) for two-level cases. Biplanar fluoroscopy utilization time was 41.3 seconds per case (range 25-62 seconds). CONCLUSIONS: Use of intraoperative three-dimensional fluoroscopy for image guidance in minimally invasive complex spinal instrumentation procedures is feasible and safe. This technique provides excellent visualization of three-dimensional relationships. This potentially results in improved accuracy of screw positioning and the ability to detect misplaced screws prior to wound closure. This technique also potentially results in a significant reduction in radiation exposure for both the patient and the staff.

Adult↗
PubMed2005

Correlation of cerebrospinal fluid flow dynamics and headache in Chiari I malformation.

OBJECTIVE: The management of patients with a Chiari I malformation who present with headaches alone remains unclear. We studied the cerebrospinal fluid (CSF) flow dynamics of Chiari I malformation patients presenting with headaches alone so as to identify headache types that are associated with CSF flow obstruction versus those that may be unrelated to Chiari I malformations. METHODS: Preoperative cine phase-contrast magnetic resonance imaging of the craniocervical junction was prospectively performed in 33 patients presenting with headaches alone and a Chiari I malformation (tonsillar ectopia >5 mm below the foramen magnum). Headaches were classified as frontal, occipital, or generalized. CSF flow dynamics were then prospectively compared with presenting symptomatology. A subgroup of 17 patients underwent surgical decompression of the Chiari I malformations. RESULTS: Patients with frontal or generalized headaches were 10-fold less likely to demonstrate obstructed CSF flow (odds ratio, 0.10; 95% confidence interval, 0.02-0.52) and 8-fold less likely to have tonsillar descent greater than 7 mm (odds ratio, 0.12; 95% confidence interval, 0.03-0.62) compared with patients with occipital headaches. Adjusting for degree of tonsillar herniation in multivariate analysis, frontal and generalized headaches remained independently associated with nonobstructed CSF flow pathological findings, whereas occipital headaches remained associated with obstructed CSF flow independent of tonsil location (odds ratio, 5.84; 95% confidence interval, 1.01-34.28). In the surgical group, all patients with obstructed CSF flow did well compared with the group with normal flow, regardless of headache location. CONCLUSION: Regardless of the degree of tonsillar ectopia, occipital headaches were strongly associated with hindbrain CSF flow abnormalities, whereas frontal and generalized headaches were not. Normal magnetic resonance imaging-cine CSF flow in the setting of a Chiari I malformation and frontal headaches alone suggests that frontal headaches are not pathologically or causatively associated with the Chiari I malformation in the vast majority of patients. Frontal headaches with obstructed flow may respond to surgery.

Adolescent↗
PubMed2005

Safety of transforaminal lumbar interbody fusion and intervertebral recombinant human bone morphogenetic protein-2.

OBJECT: Recombinant human bone morphogenetic protein-2 (rhBMP-2) is being increasingly used for spinal fusion. There are few data regarding its clinical safety, effectiveness, and clinical outcome when applied on an absorbable collagen sponge (ACS) in conjunction with allograft for transforaminal lumbar interbody fusion (TLIF). METHODS: Seventy-four consecutive patients undergoing TLIF for degenerative disc disease were divided into five groups depending on whether the patient underwent a minimally invasive or open approach, as well as the number of spinal levels surgically treated. Surgery-related data, fusion results, complications, and clinical outcome were evaluated. The mean follow-up duration was 20.6 months (range 14-28 months). The radiographic fusion rate was 100% at 12 and 24 months after the surgery. No bone overgrowth or other complications related to BMP use were demonstrated. CONCLUSIONS: Analysis of the results demonstrated that TLIF combined with a BMP-2-soaked ACS is a feasible, effective, and safe method to promote lumbar fusion. There were no significant intergroup differences in clinical outcome between patients who underwent open compared with minimally invasive procedures. Patient satisfaction rates, however, were higher in the minimally invasive procedure group. The efficacy of BMP-2 was not dependent on which approach was used or the number of spinal levels that were treated.

Absorbable Implants↗
PubMed2004

HIV and cerebral aneurysms.

Patients infected with the human immunodeficiency virus (HIV) or suffering from acquired immunodeficiency syndrome (AIDS) are now surviving for longer periods of time secondary to improvements in medical management. As the classical causes of morbidity and mortality in this patient population have come under better control, new complications are becoming more prevalent. In our clinical practice, there appears to have been a rise in the number of patients with HIV infection and AIDS who have experienced aneurysmal subarachnoid hemorrhage (SAH). In this paper, we review the available literature regarding cerebral aneurysms in patients infected with HIV and/or suffering from AIDS.

Adolescent↗
PubMed2004

The value of magnetic resonance imaging in the evaluation of fatty filum terminale.

OBJECTIVE: To determine whether there are magnetic resonance imaging (MRI) characteristics of fatty fila that are correlated with neurological deficits, especially in the presence of a normal-level conus medullaris. METHODS: Lumbosacral MRI scans were reviewed for patients with fatty fila who were treated at Duke University Medical Center during a 5-year period. The patients were divided into three groups. Group I patients (n = 5) had fatty fila that were incidentally detected during evaluations for metastases or infections. Group II patients (n = 16) exhibited isolated low back pain but were in neurologically intact condition. Group III patients (n = 15) exhibited neurological impairments consistent with distal spinal cord dysfunction. Several characteristics were measured on the MRI scans, including the location of the conus medullaris, the filum thickness, and the distance of fat from the conus. These results were assessed for statistically significant correlation with the presence of clinical symptoms. RESULTS: The majority of patients in all three groups demonstrated the normal conus position (L2 or above) and thickened fila. The distance of fat from the conus was the only parameter that demonstrated a statistically significant difference among the groups. CONCLUSION: The following findings were noted: 1) patients were likely to exhibit neurological deficits at a younger age (<22 yr in Group III versus 47 yr in Groups I and II); 2) a conus level below L2 was associated with neurological deficits (Group III); 3) filum thickness was not correlated with clinical presentation; 4) fat in the filum within 13 mm of the conus medullaris was most predictive of neurological deficits (Group III).

Adipose Tissue↗
PubMed2003

Successful aqueductal plasty and stenting for tectal plate tumor after failed third ventriculostomy: a case report.

BACKGROUND: Tectal region tumors can lead to hydrocephalus secondary to aqueductal compression. Surgical options for these patients include extracranial cerebrospinal fluid (CSF) shunts, third ventriculostomy, and/or aqueductal plasty. In cases of third ventriculostomy failure, the accepted alternative is an extracranial CSF shunt. We report a patient in whom a repeat third ventriculostomy with aqueductal plasty and stenting was successful after a failed initial third ventriculostomy. CASE PRESENTATION: A 12-year-old patient with hydrocephalus secondary to a tectal tumor presented with headaches and blurry vision. She had no focal neurologic findings. She underwent a third ventriculostomy. Five months after the procedure she had recurrence of her symptoms. Therefore, she underwent a secondary third ventriculostomy with aqueductal plasty and stenting. She has been symptom-free for 1 year. CONCLUSION: Aqueductal plasty with stenting may be an alternative to CSF shunts in some patients with hydrocephalus because of aqueductal compression resulting from tectal tumors.

Brain Neoplasms↗
PubMed2003

MRI-guided stereotactic biopsy in the diagnosis of glioma: comparison of biopsy and surgical resection specimen.

BACKGROUND: Although there has been a dramatic increase in the accessibility and utilization of high-resolution MRI techniques for the evaluation of brain tumors, there is currently only a single report comparing stereotactic brain biopsy specimen to subsequent resection specimen exclusively in the management of gliomas. METHODS: The diagnoses in 43 cases of astrocytic brain tumors were derived using MRI-guided stereotactic biopsy followed by open resection of the lesion. The histologic diagnoses yielded by biopsy were compared with subsequent histologic diagnosis after open tumor resection. All biopsies and histologic diagnoses were made by the same surgeon and pathologist, respectively. RESULTS: In 23 patients undergoing resection <60 days after biopsy, the biopsy diagnosis was consistent with resection diagnosis in 18 cases (79%) and led to the correct treatment in 22 cases (96%). Recurrent glioblastoma multiforme (GBM) was undergraded as anaplastic astrocytoma in 4 patients. GBM was misdiagnosed as radiation necrosis in 1 patient. MR-nonenhancing lesions [10/10 (100%)] yielded histology that correlated with subsequent craniotomy, while only 8/13 (61%) MR-enhancing lesions yielded histology that was consistent with that at craniotomy (p < 0.05). In 20 patients undergoing resection because of radiologic tumor progression (mean 7 months after biopsy), 6/6 (100%) biopsy diagnoses of a specific glioma grade correlated with resection diagnosis, while only 6/14 (43%) biopsy diagnoses of radiation effect correlated with resection diagnosis (p < 0.01). CONCLUSION: MRI-guided stereotactic brain biopsy specimen accurately represents the grade of the larger glioma mass sufficiently to guide subsequent therapy. Enhancement on MR may be a negative prognostic indicator of biopsy accuracy.

Biopsy↗