Vascular extracellular matrix remodeling in cerebral aneurysms.

OBJECT: The occurrence of cerebral aneurysms has been linked to alterations in the extracellular matrix and to matrix-degrading proteases. The purpose of the present study was to determine whether active extracellular matrix remodeling occurs within cerebral aneurysms. METHODS: Aneurysm tissue was collected from 23 patients (two of whom had a ruptured aneurysm and 21 of whom had an unruptured aneurysm) and compared with 11 control basilar arteries harvested at autopsy. Active proteinases capable of gelatin lysis were identified by performing in situ zymography in the presence and absence of a metalloproteinase inhibitor (ethylenediamine tetraacetic acid) and a serine proteinase inhibitor (phenylmethylsulfonyl fluoride). Immunohistochemical analysis was used to localize plasmin, tissue-type (t)-plasminogen activator (PA), urokinase-type (u)-PA, membranetype (MT1)-matrix metalloproteinase (MMP), MMP-2, MMP-9, and tenascin. Focal areas of gelatin lysis occurred in most cerebral aneurysm tissue samples (17 of 21), but rarely in control arteries (two of 11) (p = 0.002). Both serine proteinases and MMPs contributed to gelatin lysis; however, the MMPs were the predominant enzyme family. Plasmin (p = 0.04) and MT1-MMP (p = 0.04) were expressed in the aneurysm tissue but were unusual in control tissue. The MMP-2 was also expressed more commonly in aneurysm than in control tissue (p = 0.07). The MMP-9 and t-PA were expressed in both groups; however, different staining patterns were observed between aneurysm and control tissue. Tenascin staining was commonly present in both groups, whereas u-PA staining was rarely present. CONCLUSIONS: Aneurysm tissue demonstrates increased proteolytic activity capable of lysing gelatin and increased expression of plasmin, MT1-MMP, and MMP-2 when compared with normal cerebral arteries. This activity may contribute to focal degradation of the vascular extracellular matrix and may be related to aneurysm formation and growth.

Misdiagnosis of symptomatic cerebral aneurysm. Prevalence and correlation with outcome at four institutions.

BACKGROUND AND PURPOSE: It is not known what fraction of patients with symptomatic cerebral aneurysms are misdiagnosed at initial medical presentation. It is also not clear whether misdiagnosed patients more frequently deteriorate before definitive aneurysm diagnosis and therapy or achieve a poorer outcome than correctly diagnosed patients. METHODS: We reviewed records of consecutive patients with symptomatic cerebral aneurysms managed by four tertiary-care neurosurgical services during a recent 19-month period. Clinical course and outcome were analyzed according to misdiagnosis or correct diagnosis at initial medical evaluation. RESULTS: Fifty-four of 217 patients (25%) were misdiagnosed at initial medical evaluation, including 46 of 121 patients (38%) initially in good clinical condition (clinical grade 1 or 2). Forty-six of 54 patients (85%) in the misdiagnosis group were initially grade 1 or 2 compared with 75 of 163 patients (46%) with correct initial diagnosis (P < .01). Twenty-six of 54 misdiagnosed patients (48%) deteriorated or rebled before definitive aneurysm treatment compared with 4 of 165 correctly diagnosed patients (2%) (P < .001). Among patients initially presenting as clinical grade 1 or 2, overall good or excellent outcome was achieved in 91% of those with correct initial diagnosis and 53% of patients with initial misdiagnosis (P < .001). Deterioration before correct diagnosis accounted for 16 of 67 patients (24%) with poor or worse final outcome in this series. CONCLUSIONS: Patients in good clinical condition with symptomatic cerebral aneurysms were commonly misdiagnosed. Misdiagnosed patients were more likely than correctly diagnosed patients to deteriorate clinically and had a worse overall outcome. Misdiagnosed cases accounted for a significant fraction of overall poor outcomes among consecutive cases of symptomatic aneurysms.

Pott's puffy tumor: the forgotten entity. Case report.

Pott's puffy tumor is a subperiosteal abscess of the frontal bone associated with underlying frontal osteomyelitis. The introduction of antibiotic medications has diminished the incidence of complications of frontal sinusitis. As a result, Pott's puffy tumor has become a rarity. In this communication a case of Pott's puffy tumor secondary to antecedent frontal sinusitis in an otherwise healthy adult man is described.

Continuous arteriovenous hemofiltration countercurrent dialysis (CAVH-D) in acute respiratory failure (ARDS).

The balance between intravascular volume, oxygen transport, and arterial oxygenation is delicate in patients with adult respiratory distress syndrome (ARDS). Recently, we used continuous arteriovenous countercurrent hemodialysis (CAVH-D) in 14 nonoliguric patients who had severe ARDS. The cause of the ARDS was pancreatitis in 1 patient, trauma in 10 patients, and postoperative in 4 patients. All patients were edematous, in marked positive fluid balance but not intravascularly overloaded before institution of CAVH-D. Transfemoral CAVH-D was instituted and managed by the SICU staff. Patients underwent CAVH-D for a mean of 65.2 hours (range, 12-140 hours) and cleared a mean of 480 mL/h of filtrate. The only complication was one patient who bled from a loose tubing connection. Three patients were grossly unstable when CAVH-D was begun. Their mean cardiac index (CI) was 2.3 L/min/m2 despite maximal inotropes. Their CAVH-D filters cleared a mean of 600 mL/h, but they required constant fluid resuscitation and died of cardiogenic shock and ARDS within 3 days. The other 11 patients had significant improvement in their respiratory function. Mean FI02 was weaned from 0.73 to 0.45 (p less than 0.005) and PEEP from 14.3 cm to 8.9 cm (p less than 0.005). Peak airway pressures fell from a mean of 60 mm Hg to 45 mm Hg (p less than 0.01). There was no significant change in CI or wedge pressure, but oxygen consumption rose from a mean of 279 to 409 mL/m (p less than 0.05). The technique of CAVH-D offers an alternative to patients with ARDS who do not have large on-going fluid requirements. It is safe, can be managed by the surgical staff, and is associated with a significant improvement in respiratory variables without requiring a drop in filling pressures that might potentially compromise oxygen transport.