E. Sander Connolly

Pseudoaneurysms of the superficial temporal artery secondary to placement of external ventricular drainage catheters.

BACKGROUNDnPseudoaneurysms of the superficial temporal artery have been described following trauma and various surgical procedures. There are no reports in the literature of these lesions following the placement of external ventricular drainage catheters. This article describes two patients and their successful treatment, and reviews diagnostic and treatment strategies.nnnCASE DESCRIPTIONnTwo patients developed tender, nonpulsatile masses in the scalp along the former subcutaneous tract of an EVD catheter. Both lesions were successfully excised in the operating room and found to be thrombosed pseudoaneurysms of the superficial temporal artery.nnnCONCLUSIONnPseudoaneurysms of the parietal branch of the STA may occur secondary to incision of the skin for twist drill hole placement or the use of a sharp trocar for subcutaneous tunneling of catheters. Use of a blunt-tipped trocar may reduce the risk of developing pseudoaneurysms secondary to EVD placement. Knowledge of the possibility of developing these lesions from catheter placement may aid the neurosurgeon in proper diagnosis and treatment.

The role of vascular remodeling and inflammation in the pathogenesis of intracranial aneurysms.

While the mechanisms triggering pathogenesis of intracranial aneurysms have not been fully elucidated, different mechanisms have been proposed ranging from hemodynamic mechanisms to genetic predispositions. One mechanism that has been thoroughly explored is the physiological and pathological vascular remodeling that occurs in conjunction with inflammatory reactions resulting in the initiation and progression of these lesions. Both hemodynamic stimuli and vascular inflammation can trigger a series of biochemical reactions resulting in vascular smooth muscle cell apoptosis and migration causing thinned, dilated areas of the cerebral vasculature. In addition, an imbalance between extracellular matrix remodeling proteins, such as matrix metalloproteinases and their inhibitors, can result in accelerated degradation of the internal elastic lamina and the adventitial layers, further weakening the vessel. While these processes occur under normal physiological conditions, situations that alter their balance such as inflammation caused by cigarette smoking or cocaine usage or hypoxia induced under chronic hypertensive conditions can alter the delicate balance of these reactions potentiating pathological remodeling and aneurysm development. The present study represents a thorough literature review of the vascular remodeling and inflammatory components to aneurysmal pathogenesis.

Giant posterior fossa cystic craniopharyngiomas presenting with hearing loss: Report of three cases and review of the literature

BACKGROUNDnAutopsy studies and recent reviews report that 4% of craniopharyngiomas have posterior fossa extension at initial operation, and 12% subsequently develop this extension during their course. However, only two patients in the literature have been shown to present with deafness, which preceded the more typical suprasellar signs and symptoms of increased intracranial pressure, endocrine disturbance, altered mentation, and visual deterioration.nnnMETHODSnThe authors report three cases of giant cystic posterior fossa craniopharyngioma initially presenting in childhood with either unilateral or bilateral deafness. These cases are presented, the literature on posterior fossa craniopharyngioma is reviewed, and staged operative management is discussed.nnnRESULTSnDespite being rarely reported, 10% to 20% of giant cystic craniopharyngiomas with posterior fossa extension at presentation may have unilateral or bilateral deafness as their first symptom. Deafness as a presenting symptom is much less common in patients presenting with recurrent tumors in this location than with primary tumors. Pterional or bifrontal craniotomy is appropriate for management of the parasellar component and should be undertaken first when visual symptoms are present. Suboccipital craniectomy is appropriate for management of the posterior fossa component and should be undertaken first when brain stem compressive symptoms make it necessary. Skull-base techniques may have value in certain settings, but patients morbidity when using these techniques must be carefully considered.nnnCONCLUSIONSnOur results indicate that staged operations with the goal of achieving gross total resection can yield excellent results. Adjuvant radiation is indicated for those with residual tumor seen on magnetic resonance imaging (MRI), but in young children without residual tumors by MRI, we prefer to follow carefully with serial scans. Since the loss of hearing in children can compromise language development, we suggest referral of these children to a specialist in language rehabilitation.

Transdermal nicotine replacement therapy in cigarette smokers with acute subarachnoid hemorrhage.

BackgroundWe evaluated the safety of nicotine replacement therapy (NRT) in active smokers with acute (aneurysmal) subarachnoid hemorrhage (SAH).MethodsA retrospective observational cohort study was conducted in a prospectively collected database including all SAH patients admitted to an 18-bed neuro-ICU between January 1, 2001 and October 1, 2007. Univariate and multivariable models were constructed, employing stepwise logistic regression. The primary endpoint was 3-month mortality. Delayed cerebral ischemia (DCI) due to vasospasm, angiographic and TCD evidence of vasospasm, and delirium were secondary endpoints.ResultsActive cigarette smokers admitted with SAH included 128 that received NRT and 106 that did not. Patients were well-matched for age, admission Hunt-Hess Grade, radiographic findings, and APACHE II scores, but those who received NRT were more likely to be heavy smokers (>10 cigarettes daily), diabetic, heavy alcohol users, and to have cerebral edema on admission. NRT was associated in multivariate analysis with a lower risk of death at 3xa0months (OR 0.12, 95% CI 0.04–0.37, Pxa0<xa00.001). There were no differences in the frequency of DCI and most other medical complications, but delirium (19 vs. 9%, Pxa0=xa00.006) and seizures (9 vs. 2%, Pxa0=xa00.024) were more common in patients who received NRT.ConclusionsDespite vasoactive properties, administration of NRT among active smokers with acute SAH appeared to be safe, with similar rates of vasospasm and DCI, and a slightly higher rate of seizures. The association of NRT with lower mortality could be due to chance, to uncontrolled factors, or to a neuroprotective effect of nicotine in active smokers hospitalized with SAH, and should be tested prospectively.

MMP-9 levels in elderly patients with cognitive dysfunction after carotid surgery

Approximately 25% of elderly patients scheduled for carotid endarterectomy (CEA) develop post-operative cognitive dysfunction (CD). We tested the hypothesis that the plasma levels of matrix metalloproteinase 9 (MMP-9) are predictive of moderate to severe CD after CEA. A total of 73 patients were prospectively enrolled in this Institutional Review Board-approved study. Plasma samples were obtained at baseline and day 1 post-surgery. We measured the plasma concentrations of both MMP-9 and its inhibitor, tissue inhibitor of metalloproteinases 1 (TIMP-1). We estimated the MMP-9 activity by calculating the MMP-9:TIMP-1 ratio. The cognitive performance day 1 post-surgery was quantified with z-scores, using a control group who were undergoing spinal surgery. The criteria used to define CD was performance of >or=1.5 standard deviations worse than the control group; approximately 19% of eligible patients developed CD. Compared to patients without CD, this group had both higher total (81.66+/-12.25 ng/mL versus [vs.] 43.18+/-4.44 ng/mL, p=0.005) and activity (0.88+/-0.24 ng/mL vs. 0.54+/-0.06 ng/mL, p=0.003) MMP-9 levels at baseline. All of the results were adjusted for age, diabetes and neurovascular symptoms.

Pathological mechanisms underlying aneurysmal subarachnoid haemorrhage and vasospasmElsevier Ltd

Aneurysmal subarachnoid haemorrhage is a cerebrovascular disease associated with an overall mortality as high as 50%. Delayed ischaemic neurologic deficits are a major contributor to this statistic, as well as the significant morbidity associated with the disease. Studies examining the pathophysiologic events causing these devastating changes in cerebral blood flow have identified several mechanisms which are thought to contribute to the development of delayed ischaemic neurological deficits, perhaps the most damaging of which are increased intracranial pressure and cerebral vasospasm. In addition, the presence of blood in the subarachnoid space can trigger a myriad of reactions resulting in increased capillary permeability, breakdown of the blood-brain barrier, and inflammation in surrounding neural tissue that adds to the devastating effects of haemorrhage. A detailed understanding of the post-haemorrhagic cellular and molecular changes that contribute to the development of cerebral ischaemia and vasospasm is imperative to the formulation of treatment and prevention options for subarachnoid haemorrhage patients. Despite a large body of research within this field, a complete understanding of rupture and vasospasm remains elusive. This study reviews the role of vasoactive substances, such as endothelin-1, as well as the histochemistry and molecular pathology of post-haemorrhage inflammation in the development of vasospasm and cerebral ischaemia.

Significant Reductions in Length of Stay After Carotid Endarterectomy Can Be Safely Accomplished Without Modifying Either Anesthetic Technique or Postoperative ICU Monitoring

BACKGROUND AND PURPOSEnWe sought to determine whether postoperative length of stay (LOS) and resource utilization could be safely reduced without changing our uniform protocol of performing carotid endarterectomy (CEA) under general anesthesia with postoperative intensive care unit monitoring.nnnMETHODSnWe retrospectively reviewed the hospital records of 421 consecutive CEA operations performed during a 3-year period of transition in discharge policy to determine LOS, complications, and resource utilization. We divided operated patients into 3 cohorts: cohort I patients were operated on before a stay reduction policy was instituted (1995, n=171); cohort II patients were operated on after the institution of a single-day-stay policy for selected patients (January to August 1996, n=95); and cohort III patients were operated on after the institution of a universal single-day-stay policy (September 1996 to December 1997, n=155).nnnRESULTSnWhile significant in-hospital complications leading to increased LOS remained essentially unchanged over time (cohort I: 4.0%; II: 6.3%; III: 3.9%; P=NS), the mean postoperative LOS decreased from 2.6+/-0.3 days in cohort I to 1.6+/-0.1 days in cohort III (P<0.0001). The median postoperative LOS also decreased from 2 days to 1 day from cohort I to III, with 70% of patients discharged after 1 day in cohort III compared with only 32% for cohort I (P<0.0001). In addition, the total number of laboratory studies ordered decreased from 8.0+/-0.8 per patient in cohort I to 6.4+/-0.5 in cohort III (P<0.01).nnnCONCLUSIONSnA uniform policy of discharge home from the intensive care unit on postoperative day 1 following CEA under general anesthesia can reduce LOS and decrease resource utilization without compromising care.