Clinical stroke penumbra: use of National Institutes of Health stroke scale as a surrogate for CT perfusion in patient triage for intra-arterial middle cerebral artery stroke therapy.

BACKGROUND AND PURPOSE: CTP may help triage acute stroke patients for IAT, but requires additional contrast agent, radiation, and imaging time. Our aim was to determine whether clinical examination (NIHSS) with NCCT and CTA can substitute for CTP without significantly affecting IAT triage of patients with acute MCA stroke. MATERIALS AND METHODS: We reviewed NCCT, CTA, and CTP imaging performed within 8 hours of symptom onset in 36 patients presenting with MCA territory stroke (September 2007-October 2009). Two neuroradiologists reviewed, independently and by consensus, NCCT, CTA, and CTP (CTP group), and 2 different neuroradiologists blinded to CTP reviewed NCCT, CTA, and NIHSS (stroke scale group) to determine IAT eligibility: M1 or proximal M2 occlusion; infarct core <1/3 MCA territory; and ischemic penumbra >20% infarct core. The stroke scale group estimated infarct core from NCCT and CTA source images and ischemic penumbra from core size relative to NIHSS score and re-evaluated patients after unblinding to CTP. We computed intragroup and intergroup κ scores for IAT treatment recommendation and used the McNemar test to determine whether CTP significantly affected the stroke scale group's decisions. RESULTS: IAT was recommended in 16/36 (44%) and 17/36 (47%) patients by the CTP and stroke scale groups, respectively, with intragroup κ scores of 0.78 ± 0.11 versus 0.83 ± 0.09. The intergroup κ score was 0.83 ± 0.09. When unblinded to CTP, the stroke scale group revised 2/36 (5.6%) decisions, which was insignificant (P = .48, McNemar test). CONCLUSIONS: NIHSS interpreted with NCCT and CTA may be an effective substitute for CTP-derived measures in the IAT triage of patients with acute MCA stroke. Replacing CTP may potentially reduce radiation and contrast dose and time to treatment.

Incidence of extrinsic compression of the internal jugular vein in unselected patients undergoing CT angiography.

BACKGROUND AND PURPOSE: Little is known about how commonly the internal jugular vein is compressed by extrinsic structures in the upper neck. The purpose of this paper was to identify the frequency and cause of external compression of the superior segment of the internal jugular vein. MATERIALS AND METHODS: Retrospective review of CT angiograms of the neck was performed in 108 consecutive patients. Axial source images were evaluated for moderate (>50%) or severe (>80%) stenosis of the internal jugular vein on the basis of external compression. The cause of extrinsic compression was also recorded. In cases with stenosis, the presence of ipsilateral isoattenuated collateral veins was recorded and considered representative of collateral flow. RESULTS: Moderate stenosis was seen in 33.3% of right and 25.9% of left internal jugular veins. Severe stenosis was seen in 24.1% of right and 18.5% of left internal jugular veins. The most common causes of extrinsic compression included the styloid process and the posterior belly of the digastric muscle. In patients with severe internal jugular vein stenosis, 53.8% of right sides and 55% of left sides had associated condylar collaterals. CONCLUSIONS: Extrinsic compression of the superior segment of the internal jugular vein is a common finding in unselected patients, often caused by the styloid process or the posterior belly of the digastric muscle. Presence of severe stenosis is not universally associated with collateral formation.

StarClose vascular closure device: safety and efficacy of deployment and reaccess in a neurointerventional radiology service.

BACKGROUND AND PURPOSE: Obtaining safe and effective closure of the femoral access site following neurointerventional procedures can sometimes be challenging, especially in patients on anti-coagulation or anti-platelet therapy. The purpose of this study was to evaluate the safety and efficacy of a novel percutaneous closure device that employs a nitinol clip-mediated extravascular closure strategy following neurointerventional procedures. MATERIALS AND METHODS: We performed a retrospective review of all patients who underwent neurointerventional procedures at our institution between January 1, 2006 and December 31, 2008. We evaluated the safety and efficacy of the StarClose device in patients undergoing first and repeat procedures. Groin complications were classified as self-limited hematoma, hematoma requiring transfusion, other/minor (pseudoaneurysm, infection), and other/major (vascular complication). RESULTS: StarClose device use was attempted in 281 of 352 cases (79.8%) with success reported in 269 cases (95.7%). Minor and major complications occurred in 0.7% and 0.4% of patients, respectively. There was one major vascular complication. Repeat use was performed in 84 patients with 100% success and a 2.3% minor complication rate. Time to reaccess ranged from 1 to 1036 days (mean, 105 days). CONCLUSIONS: The StarClose device achieves rapid and safe femoral arterial closure in patients, both for primary closure and after reaccess.

Safety of intravenous heparin administration after endovascular treatment for ruptured intracranial aneurysms.

INTRODUCTION: Thromboembolic events are the primary complications encountered during endovascular treatment (EVT) of intracranial aneurysms. Intraprocedural heparinization is common during EVT but is less common post-procedure. The safety of heparinization following EVT is unknown, especially for ruptured aneurysms. MATERIALS AND METHODS: The records of 138 consecutive patients at our institution from 1 January 2000 to 30 June 2007 who were treated with EVT for 140 ruptured intracranial aneurysms were reviewed. All patients were treated with low dose intravenous heparin post-procedure for 24 h as per the departmental protocol. Cases of worsening hemorrhage requiring surgical evacuation were considered significant hemorrhages. Prior surgical exploration and external ventricular drain (EVD) placement were also noted. RESULTS: There were two cases (1.4%) of significant worsening hemorrhage during post-procedure heparin administration. Among 13 patients who underwent craniotomy (for hematoma evacuation or attempted surgical clipping) prior to EVT, there was one (7.7%) case of significant hemorrhage. Among the 60 patients who underwent EVD placement prior to EVT, there was one (1.7%) case of significant hemorrhage. CONCLUSION: Administration of systemic heparinization may be safe during the first 24 h post-EVT of a ruptured intracranial aneurysm in patients without recent craniotomy. Further study in determining the benefit of this protocol in reducing post-embolization thromboembolic complications may be warranted.

Acute vertebrobasilar occlusion: treatment with high-dose intraarterial urokinase.

OBJECTIVE: The purpose of this study was to describe our successful experience with high-dose intraarterial urokinase therapy in treating acute, life-threatening vertebrobasilar occlusion. CONCLUSION: We successfully treated five patients with acute vertebrobasilar occlusion who presented up to 24 hr after the onset of symptoms. Higher doses of urokinase than are commonly reported in the literature were used in this series at a rapid infusion rate with a "pulse-spray" technique. The result was prompt thrombolysis and good clinical outcome.

Assessment of the value of MR imaging for examining patients with angiographically negative subarachnoid hemorrhage.

OBJECTIVE: Our goal was to assess the value of MR imaging to patient care in the setting of angiographically negative subarachnoid hemorrhage and to evaluate the potential of MR imaging for revealing the mechanism for idiopathic perimesencephalic subarachnoid hemorrhage. MATERIALS AND METHODS: We retrospectively reviewed 71 patients who presented with subarachnoid hemorrhage and in whom the results of a four-vessel cerebral arteriogram were negative, a CT scan showed no evidence of intraaxial hemorrhage, and MR imaging had been performed within 72 hr of presentation. MR imaging of the brain included sagittal spin-echo T1-weighted, turbo spin-echo proton density-weighted, T2-weighted, and axial T2-weighted gradient-echo sequences. MR imaging of the cervical spine, which was performed in 41 of the 71 patients, included sagittal spin-echo T1-weighted, turbo spin-echo proton density-weighted, T2-weighted, and axial T2-weighted gradient-echo sequences. RESULTS: Perimesencephalic subarachnoid hemorrhage was seen on CT in 25 patients; in four of these patients (16%), MR imaging revealed acute perforator territory infarction involving the caudate, putamen, or thalamus. In 26 other patients, nonperimesencephalic subarachnoid hemorrhage was revealed on CT; in two of these patients (8%), MR imaging showed the cause of the subarachnoid hemorrhage. By contrast, 20 patients had negative findings on CT scans but xanthochromic CSF on lumbar puncture; in two of these patients (10%), MR findings were interpreted as responsible for subarachnoid hemorrhage. CONCLUSION: MR imaging showed diagnostic value in patients with angiographically negative subarachnoid hemorrhage, revealing abnormalities in 14% of the 71 patients, and resulted in a significant change in patient treatment in 6% of the patients. MR imaging also revealed an association between perimesencephalic subarachnoid hemorrhage and infarcts involving the territory of perforating arteries at the base of the brain. This finding may provide insight into the pathogenesis of perimesencephalic subarachnoid hemorrhage.

Percutaneous revascularization of complex iliac artery stenoses and occlusions with use of Wallstents: three-year experience.

PURPOSE: To assess the outcome of percutaneous placement of Wallstents for treatment of hemodynamically significant diffuse stenoses (> 3 cm in length), chronic occlusions, failed angioplasty procedures, and flow-limiting dissection in the iliac arteries. MATERIALS AND METHODS: Lesions in 94 iliac limbs were treated in 66 patients. Indications for stent placement included claudication in 49 limbs and limb-threatening ischemia in 45. Forty-two limbs were treated for diffuse disease, 39 for chronic occlusion, nine for failed angioplasty, and four for flow-limiting dissection. RESULTS: Technical success was achieved in 86 of 94 limbs (91%), with major complications in 9% of patients. One death occurred within 30 days (not procedure-related). Ankle-brachial indexes improved from 0.51 +/- 0.24 to 0.76 +/- 0.22 (P < .001). Eighty-five percent demonstrated improvement under Rutherford criteria. Follow-up was obtained up to 38 months (mean, 14 months +/- 8). Cumulative primary patency rates were 78% at 1 year and 53% at 2 and 3 years (standard error 10%). Secondary patency rates were 86% at 1 year and 82% up to 32 months (standard error > 10% after 32 months). No significant decrease in mean ankle-brachial index was observed during follow up. No difference in primary patency was observed based on lesion type, symptom severity, lesion location, or runoff status. The limb salvage rate for patients with limb-threatening ischemia was 98% at a mean follow-up of 14 months +/- 7. CONCLUSIONS: Technical success and complication rates for percutaneous iliac artery revascularization with use of Wallstents are favorable, symptoms improved in the majority of patients, and excellent secondary patency can be achieved. With use of Wallstents, most patients with iliac artery insufficiency as a result of long-segment disease or chronic occlusions can be treated percutaneously.

Association of PAH-DNA adducts in peripheral white blood cells with dietary exposure to polyaromatic hydrocarbons.

Previous investigations suggest that dietary sources of polycyclic aromatic hydrocarbons (PAHs) contribute to the PAH-DNA adduct load in peripheral white blood cells (WBCs). In the current study, we measured PAH-DNA adducts by enzyme-linked immunosorbent assay in WBCs obtained from 47 California wildland (forest) firefighters at two time points (early and late) during an active forest fire season. PAH-DNA adduct levels were not associated with recent firefighting activity, but were positively associated with frequency of charbroiled food consumption in the previous 2 weeks. In addition, adduct levels declined with time since last ingestion of charbroiled food. These studies indicate that recent consumption of charbroiled food contributes to the PAH-DNA adduct load in peripheral WBCs.

Prebiopsy wire localization of a small peripheral lung nodule.

The authors report a case in which metallic microcoils were placed under computed tomographic guidance as wire localization devices prior to an excisional lung biopsy. The technique and advantages are somewhat analogous to those of pre-excisional biopsy of a breast mass with use of wire localization performed under mammographic guidance. This technique was useful for localizing the mass as well as limiting the amount of surgically excised tissue in this case. Additionally, the postexcision specimen radiograph helped confirm that the lung lesion in question had been removed. This may be a useful preoperative technique prior to excisional biopsies of small lung lesions that may not be accessible with percutaneous biopsy techniques and in selected cases such as in patients with diseased lung parenchyma surrounding a lesion or in patients in whom the lesion to be excised is adjacent to the pulmonary root.

Immunochemical techniques in biological monitoring.

Immunoassays are analytical methods that detect interactions between antibodies and antigens. Immunoassays were used originally to detect large biological molecules. The new generation of these antibody-based assays can detect small synthetic compounds. As a result, immunoassays are being developed specifically for biomarkers of exposure and effect to environmentally prevalent chemicals. Immunochemical detection of parent compounds in blood and tissues, metabolites in excreta, and adducts with DNA and protein have been successfully performed by several investigators. Although there is great potential for use of immunoassays in biological monitoring studies, the limitations of these analyses must be fully understood to prevent improper evaluation of the acquired data. This review will cover some of the background material necessary to understand how an antibody-based assay is developed. The differences between polyclonal and monoclonal antibody-based assays and the importance of antibody class, affinity, specificity, and cross-reactivity must be considered in both study design and data analysis.

Extensive thromboembolic disease of the hand and forearm: treatment with thrombolytic therapy.

Six patients with extensive hand and forearm thromboembolic disease were treated by means of intraarterial infusion of urokinase, with good clinical results. Four significant complications occurred, including a possible stroke. Embolization of pericatheter thrombus was a possible etiologic factor in this case. Antegrade brachial artery puncture should be used in the setting of prolonged upper extremity thrombolytic therapy to avoid the cerebral vasculature. Thrombolysis is an effective technique for tissue salvage in cases of inoperable hand thrombosis.

Iatrogenic changes at the venotomy site after percutaneous placement of the Greenfield filter.

To determine the prevalence of iatrogenic abnormalities associated with percutaneous delivery of Greenfield filters, the authors prospectively evaluated 69 peripheral veins used for filter placement in 68 patients. Of the 69 venotomy sites, 63 were not associated with preexisting thrombosis and were evaluated with compression and Doppler ultrasound within 1 week of placement and over 13-541 days. New thrombosis developed at the puncture site in nine of 63 sites (14.3%), although clinical suspicion of clot was raised in only one patient. Fifty-four sites (85.7%) showed no evidence of acute deep venous thrombosis, even though three patients had signs and symptoms suggestive of thrombosis. During the follow-up, most new thromboses resolved, yielding a 96.3% long-term patency rate. The authors conclude that postplacement increase in symptoms of venous stasis and occlusion may not correlate with placement site thrombosis. New filters should be evaluated for their ability to capture potential pulmonary emboli while maintaining caval patency and for mechanical and biologic stability because placement site complications occur at low rates and resolve in most cases.

Antibiotics and nephrostomy tube care: preliminary observations. Part II. Bacteremia.

Bacteriuria occurs after long-term drainage of the kidney. This study was designed to determine if the risk of bacteremia increases at the time of tube or stent change, whether bacteremia correlates with clinical infection, and if prophylactic antibiotics are effective in the prevention of bacteremia. One hundred four tube changes in 74 patients with percutaneous nephrostomy tubes and documented positive urine cultures were studied. Patients were arbitrarily divided into groups receiving and not receiving antibiotics before nephrostomy tube change. Asymptomatic bacteremia was documented in 11 of 104 tube changes (11%). Results of five blood cultures were positive in the group receiving antibiotics, and six cases of bacteremia occurred in the group not receiving antibiotics (P = .96). Routine nephrostomy/stent change can cause frequent, asymptomatic bacteremia in patients with colonization of bacteria in the urinary tract. Antibiotic prophylaxis was unsuccessful in preventing transient bacteremia, a factor that may have implications in patients with underlying valvular heart disease and other patients at risk for bacteremia.

Postoperative abscesses with enteric communication: percutaneous treatment.

Patients with abscesses that have enteric communication in the absence of underlying inflammatory bowel disease require modification of the usual percutaneous treatment techniques. An ongoing source of output (gastrointestinal secretions) is a complicating factor in treatment. The results of percutaneous treatment of 17 abscesses with enteric communication in 16 patients without a history of inflammatory bowel disease were reviewed. The long-term cure rate was 71%. Pancreatic involvement in abscess-bowel communication diminished the cure rate to 50% (two of four) and lengthened the duration of drainage required. The results suggest that percutaneous treatment of abscesses with enteric communication is a viable alternative to surgical intervention. Minimal morbidity and no mortality were directly attributable to percutaneous therapy in this series. When the pancreas is involved in the establishment or persistence of the abscess-bowel communication, or when the underlying bowel is diseased, the rate of success decreases.