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Graeme F Woodworth

Publications and source records attributed to Graeme F Woodworth.

13 recordsLinked to original sources
PubMed2006

Adjustable vs set-pressure valves decrease the risk of proximal shunt obstruction in the treatment of pediatric hydrocephalus.

INTRODUCTION: The use of programmable shunt valves has increased dramatically in the practice of pediatric hydrocephalus. Despite theoretical advantages, it remains unclear if the use of programmable vs set-pressure valves affects shunt outcome. MATERIALS AND METHODS: The clinical and radiological records of all pediatric patients undergoing ventriculoperitoneal (VP), ventriculopleural (VPl), and ventriculoatrial (VA) shunt surgery from 2001 to 2004 at an academic institution were reviewed. The association of programmable vs set-pressure valves with subsequent shunt revision was assessed by Kaplan-Meier shunt survival plots and log-rank analysis. RESULTS: A total of 279 VP, VPl, and VA shunt surgeries were performed on patients with median (interquartile range) age of 4 (1-14) years (161 male, 118 female; 158 communicating, 122 obstructive hydrocephalus). Programmable valves were used in 76 (27%) cases and set-pressure valves in 203 (73%). At mean+/-SD follow-up of 17 +/- 13 months, programmable vs set-pressure valves were associated with reduced risk of both overall shunt revision [26 (35%) vs 109 (54%); relative risk (RR) (95% CI); 0.61 (0.41-0.91), p = 0.016] and proximal obstruction [9 (12%) vs 58 (28%); RR (95% CI); 0.39 (0.27-0.80), p = 0.006]. There was no difference in distal obstruction [3 (4%) vs 11 (5%) cases], infection [6 (8%) vs 12 (6%) cases], valve obstruction [0 (0%) vs 4 (2%)], or shunt disconnection [2 (3%) vs 1 (1%)] between adjustable and set-pressure valves, respectively. CONCLUSION: In our experience, the use of programmable vales was associated with a decreased risk of proximal shunt obstruction and shunt revision. Programmable valves may be preferred in patients frequently experiencing proximal shunt failure. A prospective, controlled study is warranted to evaluate the potential value of adjustable vs set-pressure valve systems.

Adolescent↗
PubMed2006

Hyperglycemia independently increases the risk of perioperative stroke, myocardial infarction, and death after carotid endarterectomy.

OBJECTIVE: Clinical and experimental evidence suggests that hyperglycemia lowers the neuronal ischemic threshold, potentiates stroke volume in focal ischemia, and is associated with morbidity and mortality in the surgical critical care setting. It remains unknown whether hyperglycemia during carotid endarterectomy (CEA) predisposes patients to perioperative stroke and operative related morbidity and mortality. METHODS: The clinical and radiological records of all patients undergoing CEA and operative day glucose measurement from 1994 to 2004 at an academic institution were reviewed and 30-day outcomes were assessed. The independent association of operative day glucose before CEA and perioperative morbidity and mortality were assessed via multivariate logistic regression analysis. RESULTS: One thousand two hundred and one patients with a mean age of 72 +/- 10 years (748 men, 453 women) underwent CEA (676 asymptomatic, 525 symptomatic). Overall, stroke occurred in 46 (3.8%) patients, transient ischemic attack occurred in 19 (1.6%), myocardial infarction occurred in 19 (1.6%), and death occurred in 17 (1.4%). Increasing operative day glucose was independently associated with perioperative stroke or transient ischemic attack (Odds ratio [OR], 1.005; 95% confidence interval [CI], 1.00-1.01; P = 0.03), myocardial infarction (OR, 1.01; 95% CI, 1.004-1.016; P = 0.017), and death (OR, 1.007; 95% CI, 1.00-1.015; P = 0.04). Patients with operative day glucose greater than 200 mg/dl were 2.8-fold, 4.3-fold, and 3.3-fold more likely to experience perioperative stroke or transient ischemic attack (OR, 2.78; 95% CI, 1.37-5.67; P = 0.005), myocardial infarction (OR, 4.29; 95% CI, 1.28-14.4; P = 0.018), or death (OR, 3.29; 95% CI, 1.07-10.1; P = 0.037), respectively. Median and interquartile range length of hospitalization was greater for patients with operative day glucose greater than 200 mg/dl (4 d [interquartile range, 2-15 d] versus 3 d [interquartile range, 2-7 d]; P < 0.05). CONCLUSION: Independent of previous cardiac disease, diabetes, or other comorbidities, hyperglycemia at the time of CEA was associated with an increased risk of perioperative stroke or transient ischemic attack, myocardial infarction, and death. Strict glucose control should be attempted before surgery to minimize the risk of morbidity and mortality after CEA.

Aged↗
PubMed2006

Frameless image-guided stereotactic brain biopsy procedure: diagnostic yield, surgical morbidity, and comparison with the frame-based technique.

OBJECT: The gold standard for stereotactic brain biopsy target localization has been frame-based stereotaxy. Recently, frameless stereotactic techniques have become increasingly utilized. Few authors have evaluated this procedure, analyzed preoperative predictors of diagnostic yield, or explored the differences in diagnostic yield and morbidity rate between the frameless and frame-based techniques. METHODS: A consecutive series of 110 frameless and 160 frame-based image-guided stereotactic biopsy procedures was reviewed. Associated variables for both techniques were reviewed and compared. All stereotactic biopsy procedures were included in a risk factor analysis of nondiagnostic biopsy sampling. Frameless stereotaxy led to a diagnostic yield of 89%, with a total permanent morbidity rate of 6% and a mortality rate of 1%. Larger lesions were fivefold more likely to yield diagnostic tissues. Deep-seated lesions were 2.7-fold less likely to yield diagnostic tissues compared with cortical lesions. Frameless compared with frame-based stereotactic biopsy procedures showed no significant differences in diagnostic yield or transient or permanent morbidity. For cortical lesions, more than one needle trajectory was required more frequently to obtain diagnostic tissues with frame-based as opposed to frameless stereotaxy, although this factor was not associated with morbidity. CONCLUSIONS: With regard to diagnostic yield and complication rate, the frameless stereotactic biopsy procedure was found to be comparable to or better than the frame-based method. Smaller and deep-seated lesions together were risk factors for a nondiagnostic tissue yield. Frameless stereotaxy may represent a more efficient means of obtaining biopsy specimens of cortical lesions but is otherwise similar to the frame-based technique.

Adult↗
PubMed2006

Risk of cerebral vasopasm after subarachnoid hemorrhage reduced by statin therapy: A multivariate analysis of an institutional experience.

OBJECT: Impairment of endothelial nitric oxide synthase (eNOS), endothelium-dependent relaxation, and cerebrovascular autoregulation all occur in vasospastic cerebral arteries following subarachnoid hemorrhage (SAH). The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, both improve endothelial function and increase eNOS messenger RNA, protein, and enzymatic activity threefold. Increasing experimental evidence in animal models of SAH suggests that statins may ameliorate cerebral vasospasm. The authors hypothesized that patients chronically treated with statins would have a decreased risk of symptomatic vasospasm after SAH. METHODS: The authors retrospectively reviewed the charts of 115 patients with SAH who were consecutively admitted to the Neuroscience Intensive Care Unit of Duke University between 1998 and 2001. The independent association of statin therapy to symptomatic vasospasm was assessed using multivariate logistic regression analysis. Fifteen patients (13%) admitted with SAH were receiving statin therapy for at least 1 month before admission. Forty-nine patients (43%) experienced symptomatic vasospasm a mean of 5.8 +/- 3 days after onset of SAH. Current statin therapy on admission (odds ratio [OR] 0.09, 95% confidence interval [CI] 0.01-0.77) was independently associated with an 11-fold reduction in the risk of symptomatic vasospasm. Fisher Grade 3 SAH (OR 2.82, 95% CI 1.50-5.71) and rupture of anterior cerebral or internal carotid artery aneurysm (OR 3.77, 95% CI 1.29-10.91) were independently associated with an increased risk of symptomatic vasospasm. CONCLUSIONS: In this retrospective case series, patients who received statin therapy for at least 1 month demonstrated an 11-fold decrease in the risk of developing symptomatic vasospasm after SAH.

Adult↗
PubMed2006

Preoperative imaging of cervical spine hemangioblastomas using three-dimensional fusion digital subtraction angiography. Report of two cases.

Angiography is often performed to identify the vascular supply of hemangioblastomas prior to resection. Conventional two-dimensional (2D) digital subtraction (DS) angiography and three-dimensional (3D) DS angiography provides high-resolution images of the vascular structures associated with these lesions. However, such 3D DS angiography often does not provide reliable anatomical information about nearby osseous structures, or when it does, resolution of vascular anatomy in the immediate vicinity of bone is sacrificed. A novel angiographic reconstruction algorithm was recently developed at The Johns Hopkins University to overcome these inadequacies. By combining two separate sequences of images of bone and blood vessels in a single 3D representation, 3D fusion DS (FDS) angiography provides precise topographic information about vascular lesions in relation to the osseous environment, without a loss of resolution. In this paper, the authors present the cases of two patients with cervical spine hemangioblastomas who underwent preoperative evaluation with FDS angiography and then successful gross-total resection of their tumors. In both cases, FDS angiography provided high-resolution 3D images of the hemangioblastoma anatomy, including each tumor's topographic relationship with adjacent osseous structures and the location and size of feeding arteries and draining veins. These cases provide evidence that FDS angiography represents a useful adjunct to magnetic resonance imaging and 2D DS angiography in the preoperative evaluation and surgical planning of patients with vascular lesions in an osseous environment, such as hemangioblastomas in the spinal cord.

Adult↗
PubMed2005

Frameless stereotactic ventricular shunt placement for idiopathic intracranial hypertension.

INTRODUCTION: Cerebrospinal fluid (CSF) shunting effectively reverses symptoms of idiopathic intracranial hypertension (IIH). Lumboperitoneal (LP) shunts have traditionally been used in patients with IIH due to a frequently undersized ventricular system. However, the advent of image-guided stereotaxis has enabled effective ventricular catheter placement in patients with IIH. We describe the first large series of frameless stereotactic ventriculoperitoneal (VP) shunting for patients with slit ventricles and IIH. METHODS: We describe the frameless stereotactic VP shunting technique for IIH in 32 procedures. Outcomes following shunt placement, time to shunt failure, and etiology of shunt failure are reported. RESULTS: A total of 21 patients underwent 32 ventricular shunting procedures (20 VP, 10 ventriculoatrial, 2 ventriculopleural). One hundred percent of shunts were successfully placed into slit ventricles, all requiring only one pass of the catheter under stereotactic guidance to achieve the desired location and CSF flow. There were no procedure-related complications and each ventricular catheter showed rapid egress of CSF. All (100%) patients experienced significant improvement of headache immediately after shunting. Ten percent of ventricular shunts failed at 3 months after insertion, 20% failed by 6 months, 50% failed by 12 months, and 60% failed by 24 months. Shunt revision was due to distal obstruction in 67%, overdrainage in 20%, and distal catheter migration or CSF leak in 6.5%. There were no shunt revisions due to proximal catheter obstruction or shunt infection. CONCLUSIONS: In our experience treating patients with IIH, frameless stereotactic ventricular CSF shunts were extremely effective at treating IIH-associated intractable headache, and continued to provide relief in nearly half of patients 2 years after shunting without many of the shunt-related complications that are seen with LP shunts. Placing ventricular shunts using image-guided stereotaxis in patients with IIH despite the absence of ventriculomegaly is an effective, safe treatment option.

Adult↗
PubMed2005

3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors reduce the risk of perioperative stroke and mortality after carotid endarterectomy.

OBJECTIVE: There is increasing evidence that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) reduce cardiovascular and cerebrovascular events through anti-inflammatory, plaque stabilization, and neuroprotective effects independent of lipid lowering. This study was designed to investigate whether statin use reduces the incidence of perioperative stroke and mortality among patients undergoing carotid endarterectomy (CEA). METHODS: All patients undergoing CEA from 1994 to 2004 at a large academic medical center were retrospectively reviewed. The independent association of statin use and perioperative morbidity was assessed via multivariate logistic regression analysis. RESULTS: CEA was performed by 13 surgeons on 1566 patients (987 men and 579 women; mean age, 72 +/- 10 years), including 1440 (92%) isolated and 126 (8%) combined CEA/coronary artery bypass grafting procedures. The indication for CEA was symptomatic disease in 660 (42%) cases. Six hundred fifty-seven (42%) patients received a statin medication for at least 1 week before surgery. Statin use was associated with a reduction in perioperative strokes (1.2% vs 4.5%; P < .01), transient ischemic attacks (1.5% vs 3.6%; P < .01), all-cause mortality (0.3% vs 2.1%; P < .01), and median (interquartile range) length of hospitalization (2 days [2-5 days] vs 3 days [2-7 days]; P < .05). Adjusting for all demographics and comorbidities in multivariate analysis, statin use independently reduced the odds of stroke threefold (odds ratio [95% confidence interval], 0.35 [0.15-0.85]; P < .05) and death fivefold (odds ratio [95% confidence interval], 0.20 [0.04-0.99]; P < .05). CONCLUSIONS: These data suggest that perioperative statin use may reduce the incidence of cerebrovascular events and mortality among patients undergoing CEA.

Aged↗
PubMed2005

The use of ventriculoperitoneal shunts for uncontrollable intracranial hypertension without ventriculomegally secondary to HIV-associated cryptococcal meningitis.

BACKGROUND: The risks associated with implanting a cerebrospinal fluid (CSF) shunt in immunocompromised patients with ongoing CSF infection have historically discouraged surgeons from implanting CSF shunts in patients with HIV and cryptococcal meningitis. However, this patient population often requires frequent lumbar punctures to manage elevated intracranial pressure (ICP) secondary to cryptococcal infection. To date, only 7 cases of ventriculoperitoneal (VP) shunting for the treatment of intracranial hypertension in patients with HIV-associated cryptococcal meningitis have been reported. Few of these reports have included outcomes more than 3 months postsurgery. It remains unclear if VP shunts are an effective long-term treatment of intracranial hypertension in this patient population. CASE DESCRIPTIONS: Two patients with HIV/AIDS (CD4 counts of 8 and 81 cells/mm(3)) presented with altered mental status, visual changes, florid cryptococcal meningitis, and elevated ICP (>500 mm CSF) without evidence of hydrocephalus on computed tomography scan. Both patients experienced rapid reversal of symptoms with external lumbar CSF drainage, and remained lumbar drain-dependent after 2 weeks of amphotericin B and flucytosine therapy. Despite evidence of unresolved cryptococcal meningitis, each patient underwent implantation of a VP shunt without complication and was discharged on lifetime fluconazole therapy. They remained asymptomatic at 12 and 16 months after surgery without evidence of shunt infection or malfunction. CONCLUSION: Patients with intracranial hypertension and HIV-associated cryptococcal meningitis who cannot tolerate cessation of external lumbar CSF drainage or frequent lumbar punctures may be considered for VP shunt placement despite severe immunosuppression and persistent CSF cryptococcal infection.

AIDS-Related Opportunistic Infections↗
PubMed2005

Evaluation of a distal pericallosal aneurysm visualized with 3-dimensional digital subtraction angiography: case report and treatment implications.

BACKGROUND: Digital subtraction angiography (DSA) is considered the gold standard in the evaluation of cerebrovascular structures. Recently, 3-dimensional DSA (3D-DSA) has been increasingly used to obtain detailed information about the morphology and dimensions of intracranial aneurysms. We report the case of a patient who presented with a distal pericallosal artery aneurysm, which appeared by 2D imaging to be a fusiform, possible mycotic aneurysm. This was then revealed to be a saccular bifurcation aneurysm by 3D-DSA. This additional information changed the treatment plan for this patient from medical management to a surgical approach. CASE DESCRIPTION: The patient is a 56-year-old man with a history of hypertension and alcohol abuse with withdrawal seizures, who presented with a large intracranial hemorrhage on initial computed tomography scan. After stabilization with intracranial pressure management, the patient underwent magnetic resonance angiography and 4-vessel DSA. These initial studies showed a distal, fusiform pericallosal aneurysm consistent with a mycotic aneurysm. Rotational DSA was then used to generate 3D images of the structure that revealed a saccular bifurcation aneurysm. This enabled the decision to offer operative treatment rather than conservative medical management. DISCUSSION: This report highlights the value of 3D-DSA in establishing the appropriate treatment plan for patients with unique cerebral aneurysms. The higher resolution images used in this case provided information that was crucial in shifting the treatment focus from medical management, for what appeared to be a mycotic aneurysm by traditional DSA, to surgical intervention, for a clear hemodynamic aneurysm at a vessel bifurcation seen with 3D-DSA. Accurate pre-interventional evaluation and differential diagnosis are critical to designing the most effective lowest risk treatment plan. The standard method in the diagnosis of cerebral aneurysms has been DSA. Yet, higher resolution images of unclear or high-risk aneurysms are often required to guide clinical decision making. The emergence of new, less invasive endovascular techniques for securing intracranial aneurysms has placed greater emphasis on precisely defining the shape and dimensions of an aneurysm. Three-dimensional DSA is currently the highest resolution imaging modality available for the evaluation of intracranial aneurysms. CONCLUSION: 3D-DSA was used to evaluate a small, distal pericallosal artery aneurysm and revealed a saccular bifurcation aneurysm not visualized with magnetic resonance angiography and conventional DSA. This additional resolution permitted the team to consider a surgical approach for a patient who would otherwise have been treated medically. This high-resolution technique is particularly useful in guiding clinical decision making in the context of aneurysms that carry a relatively broad differential diagnosis, potentially high interventional risk, and unclear morphology.

Alcohol Withdrawal Seizures↗
PubMed2005

Independent predictors of morbidity after image-guided stereotactic brain biopsy: a risk assessment of 270 cases.

OBJECT: Image-guided stereotactic brain biopsy is associated with transient and permanent incidences of morbidity in 9 and 4.5% of patients, respectively. The goal of this study was to perform a critical analysis of risk factors predictive of an enhanced operative risk in frame-based and frameless stereotactic brain biopsy. METHODS: The authors reviewed the clinical and neuroimaging records of 270 patients who underwent consecutive frame-based and frameless image-guided stereotactic brain biopsies. The association between preoperative variables and biopsy-related morbidity was assessed by performing a multivariate logistic regression analysis. Transient and permanent stereotactic biopsy-related morbidity was observed in 23 (9%) and 13 (5%) patients, respectively. A hematoma occurred at the biopsy site in 25 patients (9%); 10 patients (4%) were symptomatic. Diabetes mellitus (odds ratio [OR] 3.73, 95% confidence interval [CI] 1.37-10.17, p = 0.01), thalamic lesions (OR 4.06, 95% CI 1.63-10.11, p = 0.002), and basal ganglia lesions (OR 3.29, 95% CI 1.05-10.25, p = 0.04) were in'dependent risk factors for morbidity. In diabetic patients, a serum level of glucose that was greater than 200 mg/dl on the day of biopsy had a 100% positive predictive value and a glucose level lower than 200 mg/dl on the same day had a 95% negative predictive value for biopsy-related morbidity. Pontine biopsy was not a risk factor for morbidity. Only two (4%) of 45 patients who had epilepsy before the biopsy experienced seizures postoperatively. The creation of more than one needle trajectory increased the incidence of neurological deficits from 17 to 44% when associated with the treatment of deep lesions (those in the basal ganglia or thalamus; p = 0.05), but was not associated with morbidity when associated with the treatment of cortex lesions. CONCLUSIONS: Basal ganglia lesions, thalamic lesions, and patients with diabetes were independent risk factors for biopsy-associated morbidity. Hyperglycemia on the day of biopsy predicted morbidity in the diabetic population. Epilepsy did not predispose to biopsy-associated seizure. For deep-seated lesions, increasing the number of biopsy samples along an established track rather than performing a second trajectory may minimize the incidence of morbidity. Close perioperative observation of glucose levels may be warranted.

Basal Ganglia Diseases↗
PubMed2005

Effect of antibiotic-impregnated shunt catheters in decreasing the incidence of shunt infection in the treatment of hydrocephalus.

OBJECT: The majority of shunt infections occur within 6 months of shunt placement and chiefly result from perioperative colonization of shunt components by skin flora. Antibiotic-impregnated shunt (AIS) systems have been designed to prevent such colonization. In this study, the authors evaluate the incidence of shunt infection after introduction of an AIS system in a population of children with hydrocephalus. METHODS: The authors retrospectively reviewed all pediatric patients who had undergone cerebrospinal fluid (CSF) shunt insertion at their institution over a 3-year period between April 2001 and March 2004. During the 18 months prior to October 2002, all CSF shunts included standard, nonimpregnated catheters. During the 18 months after October 2002, all CSF shunts included antibiotic-impregnated catheters. All patients were followed up for 6 months after shunt surgery, and all shunt-related complications, including shunt infection, were evaluated. The independent association of AIS catheter use with subsequent shunt infection was assessed via multivariate proportional hazards regression analysis. A total of 211 pediatric patients underwent 353 shunt placement procedures. In the 18 months prior to October 2002, 208 (59%) shunts were placed with nonimpregnated catheters; 145 (41%) shunts were placed with AIS catheters in the 18 months after October 2002. Of patients with nonimpregnated catheters, 25 (12%) experienced shunt infection, whereas only two patients (1.4%) with antibiotic-impregnated catheters experienced shunt infection within the 6-month follow-up period (p < 0.01). Adjusting for intercohort differences via multivariate analysis, AIS catheters were independently associated with a 2.4-fold decreased likelihood of shunt infection. CONCLUSIONS: The AIS catheter significantly reduced incidence of CSF shunt infection in children with hydrocephalus during the early postoperative period (< 6 months). The AIS system used is an effective instrument to prevent perioperative colonization of CSF shunt components.

Adolescent↗