Every 15-Min Delay in Recanalization by Intra-Arterial Therapy in Acute Ischemic Stroke Increases Risk of Poor Outcome

Background

Intra-arterial therapy has improved recanalization rates compared with intravenous thrombolysis for acute ischemic stroke; however, superior clinical efficacy has not been convincingly demonstrated. Time to recanalization is postulated as a mechanism hindering the efficacy of intra-arterial therapy.

Aim

To investigate the effects of time to recanalization on clinical outcome postintra-arterial therapy for acute ischemic stroke.

Methods

Clinical data were collected prospectively for consecutive patients undergoing intra-arterial therapy for acute ischemic stroke at a single center between 2009 and 2013. Ninety-day functional outcome was assessed by the modified Rankin scale. Univariate analyses identified candidate clinical variables for inclusion in the multivariable model; multivariable logistic regression analyses identified variables independently associated with good outcome, defined as modified Rankin scale 0–2.

Results

One hundred and seven patients were included in the analysis. Median (interquartile range) age was 67 (54–77) years, 41 (38%) were female, and median (interquartile range) baseline National Institute of Health Stroke Severity score was 18 (13–22). Median time from symptom onset to recanalization was 330 min (interquartile range 277–397). Fifty-four (50%) patients achieved a favorable modified Rankin scale at 90 days. Age, successful recanalization, and time to recanalization were independently associated with good outcome at 90 days in multivariable logistic regression analysis. For every 15 min delay in recanalization, the odds of good outcome decreased by 10%.

Conclusions

Longer time to recanalization was associated with poorer functional outcome post intra-arterial therapy. We recommend that a systematic approach to minimize time delay to treatment is warranted in intra-arterial therapy for acute ischemic stroke.

Endovascular therapy for ischemic stroke with perfusion-imaging selection

BACKGROUND

Trials of endovascular therapy for ischemic stroke have produced variable results. We conducted this study to test whether more advanced imaging selection, recently developed devices, and earlier intervention improve outcomes.

METHODS

We randomly assigned patients with ischemic stroke who were receiving 0.9 mg of alteplase per kilogram of body weight less than 4.5 hours after the onset of ischemic stroke either to undergo endovascular thrombectomy with the Solitaire FR (Flow Restoration) stent retriever or to continue receiving alteplase alone. All the patients had occlusion of the internal carotid or middle cerebral artery and evidence of salvageable brain tissue and ischemic core of less than 70 ml on computed tomographic (CT) perfusion imaging. The coprimary outcomes were reperfusion at 24 hours and early neurologic improvement (≥8-point reduction on the National Institutes of Health Stroke Scale or a score of 0 or 1 at day 3). Secondary outcomes included the functional score on the modified Rankin scale at 90 days.

RESULTS

The trial was stopped early because of efficacy after 70 patients had undergone randomization (35 patients in each group). The percentage of ischemic territory that had undergone reperfusion at 24 hours was greater in the endovascular-therapy group than in the alteplase-only group (median, 100% vs. 37%; P<0.001). Endovascular therapy, initiated at a median of 210 minutes after the onset of stroke, increased early neurologic improvement at 3 days (80% vs. 37%, P=0.002) and improved the functional outcome at 90 days, with more patients achieving functional independence (score of 0 to 2 on the modified Rankin scale, 71% vs. 40%; P=0.01). There were no significant differences in rates of death or symptomatic intracerebral hemorrhage.

CONCLUSIONS

In patients with ischemic stroke with a proximal cerebral arterial occlusion and salvageable tissue on CT perfusion imaging, early thrombectomy with the Solitaire FR stent retriever, as compared with alteplase alone, improved reperfusion, early neurologic recovery, and functional outcome. (Funded by the Australian National Health and Medical Research Council and others; EXTEND-IA ClinicalTrials.gov number, NCT01492725, and Australian New Zealand Clinical Trials Registry number, ACTRN12611000969965.).

A Multicenter, Randomized, Controlled Study to Investigate Extending the Time for Thrombolysis in Emergency Neurological Deficits with Intra-Arterial Therapy (EXTEND-IA)

Background and Hypothesis

Thrombolysis with tissue plasminogen activator is proven to reduce disability when given within 4.5 h of ischemic stroke onset. However, tissue plasminogen activator only succeeds in recanalizing large vessel arterial occlusion in a minority of patients. We hypothesized that anterior circulation ischemic stroke patients, selected with ‘dual target’ vessel occlusion and evidence of salvageable brain using computed tomography or magnetic resonance imaging ‘mismatch’ within 4.5 h of onset, would have improved reperfusion and early neurological improvement when treated with intra-arterial clot retrieval after intravenous tissue plasminogen activator compared with intravenous tissue plasminogen activator alone.

Study Design

EXTEND-IA is an investigator-initiated, phase II, multicenter prospective, randomized, open-label, blinded-endpoint study. Ischemic stroke patients receiving standard 0.9 mg/kg intravenous tissue plasminogen activator within 4.5 h of stroke onset who have good prestroke functional status (modified Rankin Scale <2, no upper age limit) will undergo multimodal computed tomography or magnetic resonance imaging. Patients who also meet dual target imaging criteria: vessel occlusion (internal carotid or middle cerebral artery) and mismatch (perfusion lesion: ischemic core mismatch ratio >1.2, absolute mismatch >10 ml, ischemic core volume <70 ml) will be randomized to either clot retrieval with the Solitaire FR device after full dose intravenous tissue plasminogen activator, or tissue plasminogen activator alone.

Study Outcomes

The coprimary outcome measure will be reperfusion at 24 h and favorable clinical response (reduction in National Institutes of Health Stroke Scale by ≥8 points or reaching 0–1) at day 3. Secondary outcomes include modified Rankin Scale at day 90, death, and symptomatic intracranial hemorrhage.

Current status of pipeline embolization device in the treatment of intracranial aneurysms: a review

OBJECTIVE

Pipeline embolization device (PED) implantation is a novel endovascular treatment option for the treatment of intracranial aneurysms. It is emerging as a useful alternative to coiling and to open surgery, and its use is increasing worldwide. We performed a literature review to examine its efficacy, technical challenges, and safety.

METHODS

PubMed database was used to identify all articles relating to PED.

RESULTS

The review outlines the indications for PED, its technical aspects, complications, and clinical outcomes.

CONCLUSIONS

PED offers an alternative to endovascular coiling for aneurysms with complex morphology. The indication for its use has evolved from the limited scope of treatment of giant aneurysms with wide necks to the inclusion of smaller aneurysms. The procedural safety profile of PED is comparable with or possibly superior to balloon-remodeling or stent-assisted coil embolization in specific circumstances. However, questions remain regarding the incidence of post-procedural subarachnoid hemorrhage. Ongoing monitoring and meticulous documentation of PED postimplantation safety is strongly recommended.

Imaging predictors of clinical deterioration in cerebral venous thrombosis

Cerebral venous thrombosis (CVT) is a rare stroke subtype with a highly variable clinical course. There is limited information on clinical deterioration in these patients, and imaging predictors of deterioration have not been studied adequately. Therefore, we aimed to investigate the radiological predictors of clinical deterioration in patients with CVT. We conducted a retrospective study of 106 consecutive patients from 1997 to 2010. All patients were confirmed as having CVT using imaging techniques. The following clinical data were collected: patient demographics, clinical presentation, radiological findings, treatment and clinical deterioration. Of the 106 patients, there were 77 females and 29 males, with a mean age of 43 years (range 19-79 years). The common symptoms of clinical presentation included headache (72%), seizure (29%) and severe motor impairment (20%). Overall, 34% of the patients with CVT developed clinical deterioration during hospital admission. Univariate analysis showed venous infarcts and hyperintensity on diffusion-weighted imaging (DWI) as predictors of clinical deterioration. Parenchymal haemorrhage, vasogenic oedema, midline shift and thrombosis location were not predictive of clinical deterioration. In conclusion, our study showed that venous infarcts and hyperintensity on DWI were associated with clinical deterioration in patients with CVT. These findings suggest that close monitoring is necessary in these groups of patients as they may require more aggressive therapy.

Antiplatelet resistance and thromboembolic complications in neurointerventional procedures

Antiplatelet resistance is emerging as a significant factor in effective secondary stroke prevention. Prevalence of aspirin and clopidogrel resistance is dependent upon laboratory test and remains contentious. Large studies in cardiovascular disease populations have demonstrated worse ischemic outcomes in patients with antiplatelet resistance, particularly in patients with coronary stents. Thromboembolism is a complication of neurointerventional procedures that leads to stroke. Stroke rates related to aneurysm coiling range from 2 to 10% and may be higher when considering silent ischemia. Stroke associated with carotid stenting is a major cause of morbidity. Antiplatelet use in the periprocedure setting varies among different centers. No guidelines exist for use of antiplatelet regimens in neurointerventional procedures. Incidence of stroke in patients post procedure may be partly explained by resistance to antiplatelet agents. Further research is required to establish the incidence of stroke in patients with antiplatelet resistance undergoing neurointerventional procedures.

Does Treatment of Ruptured Intracranial Aneurysms Within 24 Hours Improve Clinical Outcome?

Background and Purpose—

The purpose of this study was to analyze whether treating ruptured intracranial aneurysms within 24 hours of subarachnoid hemorrhage improves clinical outcome.

Methods—

An 11-year database of consecutive ruptured intracranial aneurysms treated with endovascular coiling or craniotomy and clipping was analyzed. Outcome was measured by the modified Rankin Scale at 6 months. Our policy is to treat all cases within 24 hours of subarachnoid hemorrhage. Treatment delays are due to nonclinical logistical factors.

Results—

Two hundred thirty cases were coiled or clipped within 24 hours of subarachnoid hemorrhage and 229 at >24 hours. No difference in age, gender, smoking, family history of subarachnoid hemorrhage, aneurysm size, or aneurysm location was found between the groups. Poor World Federation of Neurological Surgeons clinical grade patients were overrepresented in the ultra-early group. Increasing age and higher World Federation of Neurological Surgeons clinical grade were predictors of poor outcome. Eight point zero percent of cases treated within 24 hours of subarachnoid hemorrhage (ultra-early) were dependent or dead at 6 months compared with 14.4% of those treated at >24 hours (delayed), a 44.0% relative risk reduction and a 6.4% absolute risk reduction (χ 2 , P =0.044). A total of 3.5% of cases coiled within 24 hours were dependent or dead at 6 months compared with 12.5% of cases coiled at 1 to 3 days, an 82% relative risk reduction and a 10.2% absolute risk reduction (χ 2 , P =0.040). These groups did not differ in age, World Federation of Neurological Surgeons clinical grade, aneurysm size, or aneurysm location.

Conclusions—

Treatment of ruptured aneurysms within 24 hours is associated with improved clinical outcomes compared with treatment at >24 hours. The benefit is more pronounced for coiling than clipping.

Glasgow coma scale does not predict outcome post-intra-arterial treatment for basilar artery thrombosis

BACKGROUND AND PURPOSE

Evidence to guide patient selection for IA therapy in acute basilar artery thrombosis is lacking. The GCS is frequently used as a selection criterion, based on the view that higher GCS correlates with better neurologic outcome. This view has not been systematically studied. We hypothesize that low GCS does not correlate with poor outcome and that it should not preclude IA therapy.

MATERIALS AND METHODS

We included 40 consecutive patients with basilar artery thrombosis treated with IA therapy. Clinical characteristics, GCS, time to intervention, and postprocedural TIMI scores were collected. Recanalization was defined as TIMI grade 2 or 3; clinical outcome was measured by 90-day mRS.

RESULTS

Median patient age was 63.5 years. Most presented with gaze palsies (67.5%) or hemiparesis (45%). Median GCS was 9, the median time to intervention was 7.2 hours, and recanalization rate was 82.5%. Good neurologic outcome (mRS ≤ 1) occurred in 30%. There was no correlation between GCS and 90-day mRS (Spearman ρ - 0.174, P = .283). Equal numbers of patients with good neurologic outcome of mRS ≤ 1 (n = 12) had a GCS of ≤6 or >6. In those with GCS ≤ 6 for >3 hours, 33.3% had good neurologic outcome-a similar rate to that of the overall cohort. Statistical significance was demonstrated between time to IA therapy within 6 hours and mRS ≤ 2.

CONCLUSIONS

Low GCS score did not correlate with poor neurologic outcome in patients with acute basilar artery thrombosis managed with IA therapy. It is not appropriate to exclude patients from IA therapy on the basis of low GCS.

Rational approach to diagnosis and management of blunt scrotal trauma

OBJECTIVES

To provide a rational approach to the diagnosis and management of blunt scrotal trauma to aid clinicians in the selection of patients for surgical exploration.

METHODS

We performed a retrospective evaluation of the medical records of 44 patients from two metropolitan tertiary referral hospitals. A total of 29 patients were recruited from July 1, 1993 to June 30, 2003 at one institution and an additional 15 patients from February 1, 1991 to January 31, 1999 at the second. Scrotal ultrasound scans were retrieved and reviewed by a uroradiologist unaware of the treatment regimen and outcome.

RESULTS

The presence of both testicular swelling and tenderness suggested more significant testicular injury; however, testicular rupture was present in the absence of tenderness. Three patients with operatively confirmed testicular rupture had only swelling on clinical examination. Five patients with intratesticular hematoma were successfully treated conservatively with interval ultrasound scans recommended to assess for resolution. All patients with operatively confirmed testicular rupture had a combination of the following ultrasound features: the presence of hematocele, disruption of the tunica albuginea, and/or extrusion of the seminiferous tubules.

CONCLUSIONS

Patients presenting after blunt scrotal trauma with clinical hematocele should progress directly to exploration. The remainder should undergo scrotal ultrasonography. Those with large hematoceles or suspected rupture on ultrasonography should also proceed to exploration. Those without hematocele, a clearly distinct tunica albuginea, and a lack of fracture planes within the testes are a subgroup that can be successfully treated conservatively.

Iliocaval arteriovenous fistula presenting with multiple organ failure

Iliac arteriovenous fistulas are an uncommon condition, which may be spontaneous or traumatic in nature. Such fistulas classically present with a triad of high-output cardiac failure, pulsatile abdominal mass with a bruit and unilateral leg ischaemia or venous congestion. We describe a case of an iliocaval fistula secondary to rupture of a common iliac artery aneurysm, with an unusual presentation of multiple organ failure, masquerading as sepsis. We describe the CT findings of iliocaval fistula, which was the means of diagnosis in this study.

Unusual presentation of perirenal lung metastases

Lung cancer is not commonly known to metastasize to the perirenal space, with only five such cases previously published. We present an unusual case of perirenal lung metastases manifesting as diffuse perinephric stranding which to our knowledge has not been described before.

Endovascular treatment of arterial mesenteric ischaemia: a retrospective review

Mesenteric ischaemia is a condition that has traditionally been managed surgically. It poses a challenging diagnostic and therapeutic problem, particularly in the acute setting. We review a small series of eight patients managed with endovascular techniques for either acute or chronic mesenteric ischaemia at The Royal Melbourne Hospital, from 1997 to 2002. We describe our results and relate these to the recent published literature regarding endovascular and surgical management of mesenteric ischaemia. Our experience confirms the valuable contribution of angioplasty and stenting in chronic mesenteric ischaemia, which compares favourably with surgery with regards to complication rates and mortality. We suggest the need for further studies to compare the long-term efficacy of endovascular techniques compared with surgery in the management of chronic mesenteric ischaemia. Furthermore, we demonstrate a role for endovascular management in acute mesenteric ischaemia, in the appropriate clinical setting.

Acute presentations of renal artery stenosis in three patients with a solitary functioning kidney

Renal artery stenosis can present uncommonly in the acute state as flash pulmonary oedema and hypertensive encephalopathy. We present three such cases in patients with a solitary functioning kidney, with successful management via renal artery angioplasty and stent insertion.

Angioplasty and stenting of the superior mesenteric artery in acute mesenteric ischaemia

Acute mesenteric ischaemia is a challenging diagnostic problem with a very high mortality. Traditionally, laparotomy is required for definitive management. We describe a successful case of angioplasty and stenting of the superior mesenteric artery in a surgically unfit patient. We recommend that stenting be considered only in situations where the diagnosis has been made prior to bowel infarction, and if the patient poses a poor operative risk.

Doppler ultrasound (pre- and post-contrast enhancement) for detection of recurrent stenosis in stented renal arteries: preliminary results

The purpose of the present paper was to assess whether conventional renal Doppler ultrasound and the commonly used parameters of peak systolic velocity and renal aortic ratio may be an appropriate modality for the follow-up of renal artery stents. A total of 19 arteries in 15 patients was examined with both renal Doppler ultrasound and angiography for the presence or absence of recurrent renal artery stenosis. Disease was considered present on angiography if the arterial diameter was more than 60% stenotic. Doppler criteria for stenosis were either a peak systolic velocity of > 180 cm/s or a renal aortic ratio of > 3.0. Echo enhancement with Levovist (Schering, Berlin, Germany) was used if studies were technically unsuccessful or to improve diagnostic confidence. Renal Doppler ultrasound detected 100% of renal artery stenoses. The specificity was 75%, the positive predictive value was 67% and the negative predictive value was 100%. Echo enhancement improved the technical success rate from 89 to 95% and also increased diagnostic confidence in six examinations. The present limited study suggests that similar renal Doppler parameters as used for the study of unstented renal arteries may be applied to the examination of renal arteries with renal stents in situ. It therefore suggests that Doppler ultrasound may provide an adequate non-invasive means of renal artery stent follow-up, particularly when combined with echo-enhancing agents. Further study is warranted to confirm these initial conclusions.

Using Doppler sonography to reveal renal artery stenosis: an evaluation of optimal imaging parameters

OBJECTIVE

The aim of this study was to determine the accuracy of direct and indirect parameters for the diagnosis of renal artery stenosis and to determine the most useful thresholds for these parameters.

SUBJECTS AND METHODS

One hundred twenty-five arteries in 63 patients were examined with renal Doppler sonography and angiography for the presence or absence of renal artery stenosis. Arteries were considered stenosed on angiography if there was a diameter reduction of greater than 60%. Renal Doppler sonographic measures of peak systolic velocity, renal aortic ratio, acceleration time, and acceleration were recorded and compared with the angiographically determined presence or absence of disease.

RESULTS

Doppler examination was technically successful in 87% of kidneys and 76% of patients. Receiver operating characteristic analysis showed the optimal peak systolic velocity threshold to be 180 cm/sec and the optimal renal aortic ratio threshold to be 3.0. An acceleration time greater than 70 msec and an acceleration less than 300 cm/sec2 yielded sensitivities of 41% and 56%, respectively, and specificities of 85% and 62%, respectively. Combining a renal aortic ratio of greater than 3.0 or peak systolic velocity greater than 180 cm/sec provided the best combination of parameters with a sensitivity and sensitivity at 85% and 76%, respectively.

CONCLUSION

The most accurate use of parameters was found to be a combination of either peak systolic velocity greater than 180 cm/sec or renal aortic ratio greater than 3.0. Indirect parameters were not found to be useful in predicting the presence or absence of renal artery stenosis.

Contrast-enhanced Doppler ultrasound for renal artery stenosis

The use of renal artery Doppler ultrasound for the diagnosis of renal artery stenosis is a well-established technique in selected populations, but the technical failure rate of the examination leading to incomplete studies is a major drawback. The results of ultrasound contrast-enhanced renal artery Doppler for renal artery stenosis, using the echo-enhancing agent, Levovist, are reported here. Sixteen patients (22 arteries) were examined with Levovist. The technical success rate of these examinations was 91%, and all four renal artery stenoses were correctly identified. It is concluded that the use of ultrasound contrast (Levovist) increases the technical success rate of renal artery Doppler ultrasound in this setting, with similar accuracy to unenhanced Doppler examinations.

Imaging and stenting for renal artery stenosis

Renal artery stenosis is a potentially correctable cause of hypertension and renal failure, using endoluminal or, less commonly, surgical techniques. A number of imaging techniques can be used to diagnose renal artery stenosis, all with similar accuracy.

Patellar tendinosis (jumper's knee): findings at histopathologic examination, US, and MR imaging. Victorian Institute of Sport Tendon Study Group

PURPOSE

To determine the histopathologic findings of patellar tendinosis ("jumper's knee") demonstrated with ultrasonography (US) and magnetic resonance (MR) imaging.

MATERIALS AND METHODS

Twenty-four athletes (28 knees) with jumper's knee (23 men, one women; mean age, 30.9 years) scheduled to undergo open tenotomy underwent US patellar tendon examination. Seventeen patients (19 knees) also underwent MR imaging. Tissue was obtained for histopathologic examination in all 28 cases. Eleven age-, height-, and weight-matched athletes (22 knees) without previous knee symptoms served as control subjects for the US examination. Control material for histopathologic examination was obtained in 20 cadavers (39 knees). Data were analyzed with standard statistical methods.

RESULTS

MR imaging and US both revealed an abnormal zone at the proximal patellar tendon attachment. Histopathologic examination revealed mucoid degeneration in all tendons in patients and in 8% (three of 39) of tendons in cadavers (P < .01).

CONCLUSION

Jumper's knee is characterized by consistent changes at MR imaging, US, and histopathologic examination and is appropriately described as patellar tendinosis.

Efficient optical elements to generate intensity weighted spot arrays: design and fabrication

We report on the design and fabrication of fully 2-D surface relief diffraction elements that can split a single collimated beam into many beams in an arbitrary intensity distribution. These splitters were designed by computer using simulated annealing, and made into phase gratings by electron-beam lithography followed by plasma etching into quartz glass. Both two and four phase level gratings have been fabricated, allowing a wide range of uniform and weighted spot patterns to be generated. These grating elements have a measured diffraction efficiency of over 74%, with the beam intensity ratios accurate to within 1% of their target values.