Deyond Y.W. Siu

Development of a Scoring System From Noncontrast Computerized Tomography Measurements to Improve the Selection of Upper Ureteral Stone for Extracorporeal Shock Wave Lithotripsy

PURPOSE We investigated the role of noncontrast computerized tomography in predicting the treatment outcome of shock wave lithotripsy on upper ureteral stones to formulate a clinical algorithm to facilitate clinical management. MATERIALS AND METHODS Adult patients with upper ureteral stones confirmed by noncontrast computerized tomography and scheduled for primary in situ shock wave lithotripsy were prospectively recruited. Standardized treatment was performed on each patient. The primary end point was stone-free status at 3 months. Pretreatment noncontrast computerized tomography was assessed by a single radiologist blinded to the clinical parameters. Predictive values of computerized tomography measurements on the treatment outcome were then assessed. RESULTS Between October 2004 and July 2007 a total of 94 patients (60 male and 34 female) were recruited for the study. Logistic regression showed that stone volume, mean stone density and skin-to-stone distance were potential predictors of successful treatment. From ROC curves the optimum cutoff for predicting treatment outcomes for stone volume, mean stone density and skin-to-stone distance was 0.2 cc, 593 HU and 9.2 cm, respectively. A simple scoring system was constructed based on the 3 factors of stone volume less than 0.2 cc, mean stone density less than 593 HU or skin-to-stone distance less than 9.2 cm. The stone-free rate for patients having 0, 1, 2 and 3 factors was 17.9%, 48.4%, 73.3% and 100%, respectively (linear-by-linear association test 22.83, p <0.001). CONCLUSIONS Stone volume, mean stone density and skin-to-stone distance were potential predictors of the successful treatment of upper ureteral stones with shock wave lithotripsy. A scoring system based on these 3 factors helps separate patients into outcome groups and facilitates treatment planning.

High-Dose Simvastatin for Aneurysmal Subarachnoid Hemorrhage: Multicenter Randomized Controlled Double-Blinded Clinical Trial

Background and Purpose— Experimental evidence has indicated the benefits of simvastatin for the treatment of subarachnoid hemorrhage. Two randomized placebo-controlled pilot trials that used the highest clinically approved dose of simvastatin (80 mg daily) gave positive results despite the fact that a lower dose of simvastatin (40 mg daily) did not improve clinical outcomes. We hypothesized that a high dose of 80 mg of simvastatin daily for 3 weeks would reduce the incidence of delayed ischemic deficits after subarachnoid hemorrhage compared with a lower dose (40 mg of simvastatin daily) and lead to improved clinical outcomes. Methods— The study design was a randomized controlled double-blinded clinical trial. Patients with aneurysmal subarachnoid hemorrhage (presenting within 96 hours of the ictus) from 6 neurosurgical centers were recruited for 3 years. The primary outcome measure was the presence of delayed ischemic deficits, and secondary outcome measures included a modified Rankin disability score at 3 months and an analysis of cost-effectiveness. Results— No difference was observed between the groups treated with the higher dose or the lower dose of simvastatin in the incidence of delayed ischemic deficits (27% versus 24%; odds ratio, 1.2; 95% confidence interval, 0.7–2.0; P=0.586) or in the rate of favorable outcomes (modified Rankin Scale score, 0–2) at 3 months (73% versus 72%; odds ratio, 1.1; 95% confidence interval, 0.6–1.9; P=0.770). Conclusions— High-dose simvastatin treatment should not be prescribed routinely for aneurysmal subarachnoid hemorrhage. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01077206.

Computed Tomographic Angiography and Venography for Young or Nonhypertensive Patients With Acute Spontaneous Intracerebral Hemorrhage

Background and Purpose— We compared the effectiveness of using computed tomographic angiography and venography (CTAV) with digital subtraction angiography (DSA) in young or nonhypertensive patients with acute spontaneous intracerebral hemorrhage. Methods— We prospectively recruited 109 young (age between 18 and 45 years) or nonhypertensive patients with acute spontaneous intracerebral hemorrhage for this comparative study. All patients had CTAV using multidetector CT with 64 detectors. They were then scheduled to have catheter angiography the next day. Radiological data were collected for blinded analysis. Results— DSA-positive pathologies causing hemorrhage were identified in 37 (33%) patients, which included cerebral arteriovenous malformation in 22 cases. The positive and negative predictive values of CTAV for DSA-positive pathologies causing hemorrhage were 97.3% (95% CI, 88.3%–99.9%) and 100% (95% CI, 95.9%–100%), respectively. Conclusions— CTAV was able to detect DSA-positive pathologies causing acute spontaneous intracerebral hemorrhage in young (age between 18 and 45 years) or nonhypertensive patients with high positive and negative predictive values.

Cognitive domain deficits in patients with aneurysmal subarachnoid haemorrhage at 1 year

Background Cognitive domain deficits can occur after aneurysmal subarachnoid haemorrhage (aSAH) though few studies systemically evaluate its impact on 1-year outcomes. Objective We aimed to evaluate the pattern and functional outcome impact of cognitive domain deficits in aSAH patients at 1 year. Methods We carried out a prospective observational study in Hong Kong, during which, 168 aSAH patients (aged 21–75 years and had been admitted within 96 h of ictus) were recruited over a 26-month period. The cognitive function was assessed by a domain-specific neuropsychological assessment battery at 1 year after ictus. The current study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193). Results Prevalence of individual domain deficits varied between 7% to 15%, and 13% had two or more domain deficits. After adjusting for abbreviated National Institute of Health Stroke Scale and Geriatric Depressive Scale scores, unfavourable outcome (Modified Rankin Scale 3–5) and dependent instrumental activity of daily living (Lawton Instrumental Activity of Daily Living<15) were significantly associated with two or more domain deficits and number of cognitive domain deficits at 1 year. Two or more domain deficits was independently associated with age (OR, 1.1; 95% CI 1.1 to 1.2; p<0.001) and delayed cerebral infarction (OR, 6.1; 95% CI 1.1 to 33.5; p=0.036), after adjustment for years of school education. Interpretation In patients with aSAH, cognitive domain deficits worsened functional outcomes at 1 year. Delayed cerebral infarction was an independent risk factor for two or more domain deficits at 1 year.

MoCA-assessed cognitive function and excellent outcome after aneurysmal subarachnoid hemorrhage at 1 year.

After aneurysmal subarachnoid hemorrhage (aSAH), cognitive impairment, even mild and relatively isolated, can be devastating, especially in working‐age persons. The Montreal Cognitive Assessment (MoCA) is accepted as a valid screening tool for mild cognitive impairment due to cerebral ischaemia. Whether MoCA is independently associated with excellent outcome [a score of 0 on the modified Rankin Scale (mRS) or 18/18 on the Lawton Instrumental Activities of Daily Living (IADL) scale] 1 year after aSAH was assessed.

Computed tomographic angiography for patients with acute spontaneous intracerebral hemorrhage

With the advanced technology of multi-slice CT scans, we explored the effectiveness of CT angiography (CTA) in place of digital subtraction angiography (DSA) in patients with acute spontaneous intracerebral hemorrhage (ICH). We performed a computerized PubMed search of the literature from inception to 27 July 2011 to find reports of similar comparative studies and performed a meta-analysis of diagnostic accuracy. The pooled sensitivity was 97.0% (95% confidence interval [CI]: 93.2-99.1%), specificity was 98.9% (95% CI: 97.0-99.7%), accuracy was 98.2% (95% CI: 96.6-99.2%), positive predictive value was 97.8% (95% CI: 94.2-99.5%) and negative predictive value was 98.5% (95% CI: 96.6-99.5%). The false negative rate was 1% (95% CI: 0.4-2.6%). We concluded that CTA with venography could replace DSA as the initial vascular investigation in patients presenting with spontaneous ICH during the acute phase. Future studies should focus on whether refinement of the techniques could preclude the false negative results.

Risk of Intracerebral Hemorrhage in Patients With Cerebral Microbleeds Undergoing Endovascular Intervention

Background and Purpose— Cerebral microbleeds (CMBs) on MRI gradient echo images are hemosiderin deposits, which may predict intracerebral hemorrhage (ICH). The risk of ICH in patients with CMBs could be exacerbated by the use of antithrombotics. The purpose of our study is to prospectively evaluate the risk of ICH in patients with ischemic stroke who receive dual antiplatelet therapy for endovascular intervention. Methods— We analyzed MRI of 133 patients admitted consecutively for intra- and extracranial stenting for symptomatic large artery atherosclerosis who received aspirin and clopidogrel. Quantity and location of CMBs were recorded by neuroradiologists independent from the angioplasty team. The primary end point was symptomatic ICH as evident in CT of the brain within 12 weeks of procedure. Results— CMBs were identified in 23 patients. Mean number of CMBs was 2.3±1.6. Four patients had >5 CMBs. Forty-seven patients had intracranial stents, 84 patients had extracranial stents, and 2 patients had both intracranial and extracranial stents. There was no difference in risk of symptomatic ICH between those with (4.3%) and without CMBs (5.5%) patient with CMBs (P=1.000). Conclusions— The presence of a small number of CMBs does not cause a large increase in the short-term risk of symptomatic ICH in patients with ischemic stroke who undergo endovascular intervention with dual antiplatelet therapy. The risk of ICH in patients with ≥5 CMBs, however, remains unclear. Further studies with a larger sample size of patients with multiple CMBs are needed.

Comparisons of DSA and MR angiography with digital subtraction angiography in 151 patients with subacute spontaneous intracerebral hemorrhage

To exclude underlying vascular abnormalities in patients with spontaneous intracerebral hemorrhage, the traditional paradigm requires investigation using digital subtraction angiography (DSA) in both the acute and subacute phases. We investigated whether MRI and magnetic resonance angiography (MRA), in the subacute stage of intracerebral hematoma, had high positive predictive values (PPV) and negative predictive values (NPV) in screening for vascular abnormality in the routine clinical setting. In a regional neurosurgical center in Hong Kong, we retrospectively reviewed 151 patients investigated with both MRI and DSA for underlying structural vascular abnormalities during the subacute phase. Sensitivity, specificity, and intermodality agreement were assessed. A total of 70/151 (46%) vascular lesions accountable for the hemorrhage were found. Patients with vascular abnormalities tended to be younger (mean age+/-standard deviation [SD], 33+/-15years), less likely to be hypertensive (6.3%), and the lesion was more likely to be accompanied by intraventricular hemorrhage (22%). In terms of cerebral arteriovenous malformation and dural arteriovenous fistulas, MRI/MRA had a PPV of 0.98 and a NPV of 1.00. We concluded that MRI/MRA was able to detect most structural vascular abnormalities in the subacute phase in most patients and, thus, its use is recommended as the screening test.

Performance of serum α-fetoprotein levels in the diagnosis of hepatocellular carcinoma in patients with a hepatic mass

OBJECTIVES The role of serum α-fetoprotein (AFP) measurements in the diagnosis of hepatocellular carcinoma (HCC) remains controversial. Some guidelines have advised against the use of AFP in the diagnosis of HCC. This study was conducted to evaluate the performance of AFP in the diagnosis of HCC, and to identify the optimal cut-off value of serum AFP in the diagnosis of HCC in patients with a hepatic mass. METHODS Patients who presented during the period from May 1997 to March 2003 with hepatic lesions, for whom paired data on serum AFP values at baseline and lesion histology were available, were reviewed. The performance of AFP in the diagnosis of HCC was determined using receiver operating characteristic curve analysis. RESULTS Data for a total of 805 patients were evaluated. The mean AFP value was 26,900 ng/ml (range: 0-1,965,461 ng/ml). The histological diagnosis was HCC in 557 patients. The optimal AFP cut-off value was 10 ng/ml (for sensitivity of 82.6% and specificity of 70.4%). At a cut-off level of 200 ng/ml, sensitivity, specificity, and positive and negative predictive values were 47.7%, 97.1%, 97.5% and 44.4%, respectively. The diagnostic performance of AFP remains similar in patients with chronic hepatitis B virus infection, despite a lower negative predictive value. Common aetiologies of liver lesions associated with elevated AFP include cholangiocarcinoma and neuroendocrine tumours. CONCLUSIONS In Asian patients with suspicious liver lesions, the cut-off AFP level of 200 ng/ml is useful to achieve a diagnosis of HCC with high specificity and reasonable sensitivity. The measurement of serum AFP should not be excluded from guidelines for the diagnosis of HCC.

Angiographic Features, Collaterals, and Infarct Topography of Symptomatic Occlusive Radiation Vasculopathy A Case-Referent Study

Background and Purpose— Occlusive radiation vasculopathy (ORV) predisposes head-and-neck cancer survivors to ischemic strokes. Methods— We analyzed the digital subtraction angiography acquired in 96 patients who had first-ever transient ischemic attack or ischemic strokes attributed to ORV. Another age-matched 115 patients who had no radiotherapy but symptomatic high-grade (>70%) carotid stenoses were enrolled as referent subjects. Digital subtraction angiography was performed within 2 months from stroke onset and delineated carotid and vertebrobasilar circulations from aortic arch up to intracranial branches. Two reviewers blinded to group assignment recorded all vascular lesions, collateral status, and infarct pattern. Results— ORV patients had less atherosclerotic risk factors at presentation. In referent patients, high-grade stenoses were mostly focal at the proximal internal carotid artery. In contrast, high-grade ORV lesions diffusely involved the common carotid artery and internal carotid artery and were more frequently bilateral (54% versus 22%), tandem (23% versus 10%), associated with complete occlusion in one or both carotid arteries (30% versus 9%), vertebral artery (VA) steno-occlusions (28% versus 16%), and external carotid artery stenosis (19% versus 5%) (all P<0.05). With comparable rates of vascular anomaly, ORV patients showed more established collateral circulations through leptomeningeal arteries, anterior communicating artery, posterior communicating artery, suboccipital/costocervical artery, and retrograde flow in ophthalmic artery. In terms of infarct topography, the frequencies of cortical or subcortical watershed infarcts were similar in both groups. Conclusions— ORV angiographic features and corresponding collaterals are distinct from atherosclerotic patterns at initial stroke presentation. Clinical decompensation, despite more extensive collateralization, may precipitate stroke in ORV.