Gill E. Sviri

Long-term outcome of superficial temporal artery-middle cerebral artery bypass for patients with moyamoya disease in the US

OBJECT The authors report the long-term results of a series of direct superficial temporal artery-middle cerebral artery (STA-MCA) bypass procedures in patients with moyamoya disease from the western US. METHODS All patients with moyamoya disease treated at the University of Washington from 1990 through 2004 (39 patients) were included in this study. Patients underwent pre- and postoperative evaluation of cerebral perfusion dynamics. Surgical revascularization procedures were performed in all patients with impaired cerebral blood flow (CBF) findings. RESULTS The mean age of patients at diagnosis was 34 years (range 10-55 years). All 39 patients had impaired CBF and/or vasomotor reserve and underwent revascularization procedures: 26 patients underwent bilateral operations, 13 unilateral (65 total procedures). An STA-MCA bypass was technically possible in 56 procedures (86.2%); saphenous vein interposition grafts were required in 3 procedures (4.6%); encephaloduroarteriosynangiosis was performed in 6 procedures (9.2%). Three patients died due to postoperative complications, yielding a procedure-related mortality rate of 4.61%, and 8 experienced non-life threatening complications (for a procedure-related rate of 12.3%). Long-term follow-up appeared to indicate a reduction in further ischemic events in surviving patients compared with the natural history. Cerebral perfusion dynamics improved postoperatively in all 36 surviving patients. CONCLUSIONS Moyamoya disease may differ in the US and Asia, and STA-MCA bypass procedures may prevent future ischemic events in patients with this condition.

Transcranial doppler grading criteria for basilar artery vasospasm

OBJECTIVE:Transcranial Doppler (TCD) criteria for basilar artery (BA) vasospasm are poorly defined, and grading criteria for vertebrobasilar vasospasm are unavailable. The purpose of the present study was to define TCD grading criteria for BA vasospasm on the basis of the absolute flow velocities and the intracranial to extracranial flow velocity ratios for the posterior circulation, and to improve the sensitivity and specificity of TCD for diagnosis of BA vasospasm. METHODS:One hundred twenty-three patients with aneurysmal subarachnoid hemorrhage underwent 144 cerebral arteriograms with views of the BA during the acute phase of vasospasm (Days 3–14 after hemorrhage). BA diameters were measured and compared with diameters obtained from baseline arteriograms. Both BA and extracranial vertebral artery flow velocities were measured by TCD within 4 hours before the arteriogram. RESULTS:The velocity ratio between the BA and the extracranial vertebral arteries (VA) strongly correlated with the degree of BA narrowing (r2 = 0.648; P < 0.0001). A ratio higher than 2.0 was associated with 73% sensitivity and 80% specificity for BA vasospasm. A ratio higher than 2.5 with BA velocity greater than 85 cm/s was associated with 86% sensitivity and 97% specificity for BA narrowing of more than 25%. A BA/VA ratio higher than 3.0 with BA velocities higher than 85 cm/s was associated with 92% sensitivity and 97% specificity for BA narrowing of more than 50%. CONCLUSION:The BA/VA ratio improves the sensitivity and specificity of TCD detection of BA vasospasm. On the basis of the BA/VA ratio and BA mean velocities, we suggest new TCD grading criteria for BA vasospasm.

Time course for autoregulation recovery following severe traumatic brain injury

OBJECT The aim of the present study was to evaluate the time course for cerebral autoregulation (AR) recovery following severe traumatic brain injury (TBI). METHODS Thirty-six patients (27 males and 9 females, mean +/- SEM age 33 +/- 15.1 years) with severe TBI underwent serial dynamic AR studies with leg cuff deflation as a stimulus, until recovery of the AR responses was measured. RESULTS The AR was impaired (AR index < 2.8) in 30 (83%) of 36 patients on Days 3-5 after injury, and in 19 individuals (53%) impairments were found on Days 9-11 after the injury. Nine (25%) of 36 patients exhibited a poor AR response (AR index < 1) on postinjury Days 12-14, which eventually recovered on Days 15-23. Fifty-eight percent of the patients with a Glasgow Coma Scale score of 3-5, 50% of those with diffuse brain injury, 54% of those with elevated intracranial pressure, and 40% of those with poor outcome had no AR recovery in the first 11 days after injury. CONCLUSIONS Autoregulation recovery after severe TBI can be delayed, and failure to recover during the 2nd week after injury occurs mainly in patients with a lower Glasgow Coma Scale score, diffuse brain injury, elevated ICP, or unfavorable outcome. The finding suggests that perfusion pressure management should be considered in some of the patients for a period of at least 2 weeks.

DYNAMIC PERFUSION COMPUTED TOMOGRAPHY IN THE DIAGNOSIS OF CEREBRAL VASOSPASM

OBJECTIVE:The aim of the study was to correlate absolute cerebral blood flow (CBF) and mean transient time (MTT) measured by dynamic perfusion computed tomographic (PCT) scanning with the clinical course, vasospasm severity, and perfusion abnormality in patients with cerebral vasospasm after aneurysmal subarachnoid hemorrhage. METHODS:Forty-six patients with vasospasm after aneurysmal subarachnoid hemorrhage had 63 PCT images obtained during the course of vasospasm. All patients had transcranial Doppler measurements, 28 had an angiography study, and 38 had 99mTc single-photon emission computed tomographic imaging performed in conjunction with the PCT scan. RESULTS:The average minimal regional CBF (rCBF) and maximal regional MTT in patients with delayed ischemic deficit were significantly different in comparison with patients without delayed ischemic deficit (22.6 ± 11.2 cm3/100 g/min versus 45.2 ± 21.3 cm3/100 g/min, P < 0.001; 7.3 ± 2.5 s versus 3.3 ± 1.7 s, P < 0.05). The average minimal rCBF and maximal regional MTT in middle cerebral vascular territories in which severe middle cerebral artery vasospasm was measured by transcranial Doppler were significantly different in comparison with middle cerebral vascular territories in which no vasospasm was measured by transcranial Doppler (29.3 ± 1.7 cm3/100 g/min versus 54.1 ± 25.4 cm3/100 g/min, P < 0.01; 4.5 ± 2.4 s versus 2.8 ± 1.1 P < 0.001). The average minimal rCBF and maximal rMTT in vascular territories with estimated severe hypoperfusion on single-photon emission computed tomographic imaging were significantly different in comparison with values in vascular territories with unimpaired perfusion as estimated by single-photon emission computed tomographic imaging (18.9 ± 6.9 cm3/100 g/min versus 54.2 ± 23.4 cm3/100 g/min, P < 0.001, 0.001; 8.1 ± 1.9 s versus 2.5 ± 0.39 s, P < 0.001). CONCLUSION:The present study suggests that, in general, quantitative measurements of rCBF and regional MTT by PCT show high concordance rates with the clinical course, vasospasm severity, and hemodynamic impairments in patients with cerebral vasospasm aneurysmal subarachnoid hemorrhage.

Monitoring of cerebral metabolism: non-ischemic impairment of oxidative metabolism following severe traumatic brain injury.

Abstract Objective: To investigate and compare the respective dynamics of cerebral blood flow (CBF) and metabolism in response to changes in neurological condition and intracranial pressure (ICP) in severe traumatic brain injury (TBI). Methods: Eight-four patients with severe TBI were prospectively enrolled in this study. CBF was measured daily and global cerebral metabolic rates of oxygen (CMRO2), glucose (CMRGlc) and lactate (CMRLct) were calculated using arterial jugular differences. In addition, 33 patients had a second evaluation shortly after a significant change (>5 mmHg) in their ICP. Results: Eight hundred and ninety-four evaluations were collected during a period ranging between 1 and 12 days (mean: 5.1 ± 2.6 days). CBF was moderately but significantly decreased. Oppositely, CMRO2 was profoundly reduced with evidence for critical metabolic failure (<1.2 ml/100 g/min) in 30.5% whereas only 8.5% of CBF measurements were lower than 20 ml/100 g/min. Furthermore, in 78 instances of a dynamic assessment performed following ICP increase (n = 20) or decrease (n = 58), CMRO2 but not CBF proved to be significantly and inversely affected by ICP fluctuations. Finally, CMRO2 and CMRLct correlated with GCS score in contrast with CBF. Both CBF and metabolic indices, however, correlated with neurological outcome. Conclusion: This study shows that cerebral metabolic failure following TBI is a common finding that is not of ischemic origin in most instances. Unlike frequently assumed, cerebral metabolism is not constrained within the narrow range of a static depression sustained for weeks but rather subject to significant variations in response to changes in ICP or neurological condition.

Impact of Basilar Artery Vasospasm on Outcome in Patients With Severe Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage

Background and Purpose— The purpose of the present study was to evaluate the impact of basilar artery (BA) vasospasm on outcome in patients with severe vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). Methods— Sixty-five patients with clinically suspect severe cerebral vasospasm after aSAH underwent cerebral angiography before endovascular treatment. Vasospasm severity was assessed for each patient by transcranial Doppler measurements, angiography, and 99mTc-ethylcysteinate dimer single-photon emission computed tomography (ECD-SPECT) imaging. Percentage of BA narrowing was calculated in reference to the baseline angiogram. Results— BA narrowing ≥25% was found in 23 of 65 patients, and delayed brain stem (BS) hypoperfusion, as estimated by ECD-SPECT, was found in 16. Fourteen of 23 patients with BA narrowing ≥25% experienced BS hypoperfusion, whereas only 2 of 42 patients with ≥25% BA narrowing experienced BS ischemia (P<0.001). Stepwise logistic regression after adjusting for age with Hunt and Hess grade, Fisher grade, hydrocephalus, and aneurysmal location as covariables revealed BA narrowing ≥25% and delayed BS hypoperfusion to be significantly and independently associated with unfavorable 3-month outcome (P=0.0001; odds ratio, 10.1; 95% CI, 2.5 to 40.8; and P=0.007; odds ratio, 13.8, 95% CI, 2.18 to 91.9, respectively). Conclusions— These findings suggest for the first time that BA vasospasm after aSAH is an independent and significant prognostic factor associated with poor outcome in patients with severe cerebral vasospasm requiring endovascular therapy. Further study should be done to evaluate the role of interventional therapy on outcome in patients with posterior circulation vasospasm.

Brainstem hypoperfusion in severe symptomatic vasospasm following aneurysmal subarachnoid hemorrhage: role of basilar artery vasospasm.

SummaryBackground. The hemodynamic effects of vertebrobasilar vasospasm are ill defined. The purpose of this study was to determine the effects of basilar artery (BA) vasospasm on brainstem (BS) perfusion. Methods. Forty-five patients with delayed ischemic neurological deficits (DIND) following aneurysmal subarachnoid hemorrhage (SAH) underwent cerebral angiography prior to decision-making concerning endovascular treatment. BA diameter was compared with baseline angiogram. Regional brainstem (BS) cerebral blood flow (CBF) was qualitatively estimated by 99mTc ethyl cysteinate dimer single photon emission computed tomography (ECD-SPECT). Findings. Delayed BS hypoperfusion was found in 22 (48.9%) of 45 patients and BA narrowing of more than 20% was found in 23 (51.1%). Seventeen of 23 (73.9%) patients with BA narrowing of more than 20% experienced BS hypoperfusion compared to 6 of 22 (27.3%) patients with minimal or no narrowing (p = 0.0072). Patients with severe and moderate BS hypoperfusion had higher degree of BA narrowing compared to patients with normal BS perfusion and mild BS hypoperfusion (p < 0.001). The three-month outcome of patients n-22) with BS hypoperfusion was significantly worse compared to patients (n-23) with unimpaired (p = 0.0377, odd ratio for poor outcome 4, 1.15–13.9 95% confidence interval). Interpretation. These findings suggest that the incidence of BA vasospasm in patients with severe symptomatic vasospasm is high and patients with significant BA vasospasm are at higher risk to experience BS ischemia. Further studies should be done to evaluate the effects of endovascular therapy on BS perfusion and the impact of BS ischemia on morbidity and mortality of patients with severe symptomatic vasospasm.

Smart(phone) medicine

A ttending: ‘‘I can’t log inI The image is not loadingI Just tell me what you see.’’ Resident: ‘‘I see a depressed skull fracture, and there is some midline shiftI’’ We have all experienced this situation beforeVit is the middle of the night, an emergent patient arrives, and you, the young resident, need guidance from the attending on call to decide the best course of action and fast. Not only do you need to discuss the case with the senior staff member, but also they must see the relevant imaging to make a critical decision. In the best-case scenario, they are able to access the imaging via the hospital’s home access system within minutes and can tell you how to expeditiously treat the patient, but far worse scenarios can quickly develop. What if there is a technical problem, and the attending cannot access the imaging? What if the expert consultant is abroad and does not have access to the hospital’s network? The possible causes of delays in patient care are endless. Both residents and senior physicians have recognized that communication is both the crux of the problem and the solution. Communication between all levels of hospital staff as well as patients is essential in providing optimal patient care and is a well-recognized challenge. There has been much work focused on improving physician-patient communication, but intrahospital and interhospital communication remains underdeveloped. Communication between health care professionals is a complex issue, where significant advancements in the dialogue can be found in the timely access to imaging. We have seen the progression from physicians requiring actual physical films to intrahospital and later extrahospital digital viewing. One of the benefits of this progression is the reduction in patient complications arising from delays in an access to imaging. It is projected that more than one quarter of the global population will use ‘‘smartphones’’ in 2015, and by 2016, approximately two billion people worldwide will be using smartphones for personal or professional use. Many hospitals are now supplying their staff with smartphones, which can send media via multimedia messaging service (MMS). MMS is an easy and user-friendly mode of instantaneously delivering multimedia among people or groups. For example, the resident can immediately share relevant media with an attending and, if further consultation is needed, can quickly share it with others in any location. The feature of group communication expands the conversation to allow for multiple experts to share their insight and experience and ultimately form a rich and wellconceived treatment plan. Furthermore, group conversation can be forums for brainstorming. For residents, exposure to this didactic dialogue is invaluable for their training. Group communication can also be tailored so that conversations can be among attendings, residents, nursing staff, or any combination of relevant health care providers. The benefits to health care providers from using MMS capabilities to enhance communication are endless, and they all result in dramatically improved quality of care. MMS can act as a source of quick expert backup in one’s pocket enabling real-time multidirectional flow of communication, resulting in effective decision making regarding patient care. The development of an application that could allow health care providers to securely share relevant patient information in the form of images, videos, or even laboratory data all via a smartphone could revolutionize health care. Multidisciplinary group collaboration through these communication channels maintains unprecedented consistency in patient care. Moreover, nightlong group discussions can make morning rounds more purposeful. In addition to the benefits of multiple expert insights in patient diagnosis and treatment, MMS can cut down on many errors that are made because of a delay in communication. Peripherally affiliated hospitals, smaller departments, and facilities with older technology can also benefit from this kind of multimedia communication. Organizing communication as such also ensures that pertinent information can follow a patient transferred between hospitalsVthis information could otherwise be potentially lost because of software incompatibility or other gaps in communication. All of the shared information and decisions developed via MMS can be downloaded and could be embedded in the patient medical record. The benefits discussed here only exhibit a limited scope of how MMS can dramatically improve patient care as well as hospital personnel communication and education. We encourage its consideration as a dramatically improved form of medical communication. Improvement in patient care exists when communication is open, and when communication is open, fewer mistakes are made. Fewer mistakes caused by communication errors or unintentional suboptimal initial treatment plans by incorporating MMS will hopefully result in fewer admission days, which would result in fewer avoidable patient complications and the harsh reality of losing a patient. There is no worse CURRENT OPINION

Why Mortality Is Still High with Modern Care of 613 Evacuated Mass Lesions Presented as Severe Head Injuries 1999–2009

Of 1,949 successive acute severe head injuries (SHI) over a period of 11 years 1999-2009, 613 (31.5%) underwent evacuation of mass lesions. Mortality at 3 months of evacuated mass (EM) lesions was higher over 10 years compared with that of non-EM lesions (it was overall 22%). The reduction of mortality was significantly less in EM compared with that for non-surgical cases (14.4-9.4% recently) and for the cases that were operated but not for mass evacuation (18.1-12.1%). A few explanations are: first, more SDH (60.5% of the EM recently compared with 45.9% in the first few years); second, more severe cases and older patients with co-morbidities were treated surgically; third, advances in prehospital care brought more severe patients to operative care - the rate of referrals decreased from 61.5% to 52.8% recently; fourth, part of the significant shortening of the injury to NT admission time (163-141 min) vanished owing to the parallel elongation of admission to operation time (95-100 min), thus, the threshold recommendation of 4 h to mass evacuation was achieved in only 52%; fifth, introducing decompressive craniectomy was not associated with outcome improvement.

Basilar artery vasospasm: impact on outcome

The aim of the present study was to define the influence of basilar artery (BA) vasospasm on the outcome of patients with delayed ischemic deterioration after aneurysmal subarachnoid hemorrhage (aSAH).