The ABCs of Accurate Volumetric Measurement of Cerebral Hematoma

Background and Purpose—

Both initial hematoma volume and hematoma growth are independent predictors of clinical outcomes and mortality among intracerebral hemorrhage patients. The purpose of this study was to evaluate the accuracy of different computed tomography image acquisition protocols and hematoma volume measurement techniques.

Methods—

We used plastic and cadaveric phantoms to determine the accuracy of different volumetric measurement techniques. We performed both axial and spiral computed tomography scans with 0.75-, 1.5-, 3.0-, and 4.5-mm-thick transverse sections (with no gap). Different measurement techniques (planimetry, ABC/2, and 3D rendering) and different window width/level settings (I, 150/50 versus II, 587/−321) were used to assess generated errors in volumetric calculations.

Results—

Both axial and spiral computed tomography scans yielded similar percent errors for different slice thicknesses and different measurement techniques. Comparison of different measurement techniques revealed a significant difference in measurement error only from the ABC/2 method as compared with 3D-rendering measurements ( P <0.0001). The overall measurement error according to the ABC/2 method was further increased by ≈8% for irregularly shaped hematomas ( P =0.0004). A significant percent difference in measurement error was observed between window width/levels I and II for both planimetry (mean difference across all thicknesses, 1.91±3.78, P =0.004) and Analyze software (mean difference across all thicknesses, 6.92±7.29, P <0.0001) methods.

Conclusions—

A better understanding of the limitations that may affect measurement of hematoma volume is crucial in the assessment of hematoma volume, which is considered an independent marker of clinical outcome.

Predictors and Timing of Neurological Complications Following Intracranial Angioplasty and/or Stent Placement

BACKGROUND:

Transient or permanent neurological complications can occur in the periprocedural period following intracranial angioplasty and/or stent placement. Which patients are at risk and the time period for maximum vulnerability among those who undergo intracranial angioplasty and/or stent placement have not been formally studied.

OBJECTIVE:

To assess the predictors and timing of neurological complications following intracranial angioplasty and/or stent placement in the periprocedural period in a consecutive series of patients.

METHODS:

We reviewed medical records and angiograms of consecutive patients treated with intracranial angioplasty and/or stent placement in 3 academic institutions. We evaluated the effect of demographic, clinical, intraprocedural, and angiographic risk factors on subsequent development of periprocedural neurological complications. Periprocedural neurological complications were defined as new or worsening transient or permanent neurological complications that occurred during or within 1 month of the procedure. We also recorded the timing and nature of neurological complications in the periprocedural period.

RESULTS:

A total of 92 patients were included in the study (mean age ± standard deviation: 59 ± 14 years; 59 were men). The overall rate of in-hospital neurological complications was 9.8% (9 of 92 patients). Eight out of 9 neurological complications occurred either during the procedure or within 6 hours thereafter. Presence of diabetes mellitus (P = .003) and use of balloon-expandable stent (P = .09) were associated with periprocedural neurological complications. The degree of pre- and post-procedure stenosis, morphological appearance, and length of lesion were unrelated to periprocedural complications.

CONCLUSION:

Patients with diabetes mellitus and those treated with balloon expandable stents are at high risk for periprocedural neurological complications. The first 6 hours following intracranial angioplasty and stent placement represent the period of highest risk.

Intracranial angioplasty and/or stent placement in octogenarians is associated with a threefold greater risk of periprocedural stroke or death

PURPOSE

To compare the clinical and angiographic outcomes of endovascular treatment of symptomatic intracranial stenosis between octogenarian and younger patients.

METHODS

Data for 244 consecutive patients (173 men; mean age 61.6 years) who underwent angioplasty and/or stenting for intracranial atherosclerotic disease at 5 specialized centers were pooled. Baseline, 30-day, and follow-up clinical and angiographic information were collected. Rates of clinical and angiographic endpoints were compared between patients >or=80 years old versus those <80 years.

RESULTS

Patients >or=80 years (n = 15) were more likely to be hypertensive (87% versus 69%) and have underlying coronary artery disease (73% versus 36%, p<0.05) compared to younger patients (n = 229). The rate of periprocedural stroke and/or death was 3-fold higher among patients aged >or=80 years compared with those <80 years (20% versus 7%, p = 0.11). No recurrent stroke or death (excluding periprocedural events) was observed during follow-up in the octogenarian group. In patients who had follow-up angiography, a similar rate of >or=50% restenosis was observed among patients aged >or=80 years and those aged <80 years (25% versus 29%, p>0.1).

CONCLUSION

The 3-fold higher periprocedural death and/or stroke rate suggests cautious use of intracranial angioplasty and/or stent placement in octogenarians.

A Comparison of Computed Tomography Perfusion-Guided and Time-Guided Endovascular Treatments for Patients With Acute Ischemic Stroke

Background and Purpose— The role of CT perfusion (CT-P) imaging for the selection of patients with acute ischemic stroke who may benefit from endovascular treatment is not defined. The objective of this study was to determine whether CT-P-guided endovascular treatment improves clinical outcomes compared with standard endovascular treatment based on the time interval between symptom onset and presentation and noncontrast cranial CT imaging.

Methods— A retrospective study was performed comparing the clinical characteristics, complications, and clinical outcomes of patients with acute ischemic stroke who were treated using endovascular modalities based on either CT-P imaging (CT-P-guided) or time interval between symptom onset and presentation and absence of intracerebral hemorrhage or extensive ischemic changes on noncontrast cranial CT scan (time-guided).

Results— The rates of partial and complete recanalization were similar between the CT-P- and time-guided treatment groups (n=61 [88%] versus n=103 [81%]; P =0.52) regardless of whether they received intravenous recombinant tissue plasminogen activator before endovascular treatment. Comparing the CT-P-guided with the time-guided patients, favorable discharge outcome (modified Rankin Scale 0 to 2) was observed in 23 (32%) versus 41 (33%) of the patients, respectively ( P =0.9). In-hospital mortality was observed in 15 (21%) of CT-P- and 29 (23%) of time-guided patients ( P =0.74).

Conclusion— CT-P-guided endovascular treatment did not increase the rate of short-term favorable outcomes among patients with acute ischemic stroke. Prospective studies are required to validate the CT-P criteria and protocols currently in use before incorporating CT-P as a routine modality for patient selection for endovascular treatment.

Carotid artery stenting under flow arrest for the management of intraluminal thrombus: technical case report

OBJECTIVE

The management of intraluminal carotid thrombus is not well defined. Medical and surgical management carry a relatively high risk of thromboembolism. Although endovascular options also carry the risk of thromboembolism from manipulation of the lesion, successful carotid stent placement using various methods of flow restriction has been reported anecdotally. We describe a technique to arrest antegrade flow before placement of carotid stents in the setting of symptomatic intraluminal thrombus.

CLINICAL PRESENTATION

A 49-year-old woman presented with expressive dysphasia, right-upper extremity weakness, and an episode of left monocular blindness. Angiography confirmed the presence of a large intraluminal thrombus in a chronic dissection of the left internal carotid artery.

RESULTS

We devised a configuration to arrest antegrade flow in the internal carotid artery before crossing the thrombus with a distal embolic protection device by inflating balloons in the common carotid artery and external carotid artery before crossing the lesion. After inflation of a balloon in the internal carotid artery, we completed overlapping stent placement to completely exclude the thrombus from the lumen.

CONCLUSION

The patient remained neurologically unchanged during and immediately after the procedure. She had mild neurological deficits at the 1 month follow-up evaluation. Follow-up ultrasonography at 1 and 3 months and computed tomographic angiography at 3 months after the procedure showed patency of the stented carotid artery, with no evidence of restenosis or thrombus. Although the risks of carotid stent placement for intraluminal thrombus remain unclear, the technique of flow arrest seems to provide a safe endovascular treatment option.

Use of the 8 French Simmons-2 guide catheter for carotid artery stent placement in patients with difficult aortic arch anatomy

Inability to achieve vascular access is a common reason for failure to perform carotid artery angioplasty and stent placement. The authors report their experience with the use of an 8 Fr Simmons-2 catheter to gain carotid artery access in the setting of complex aortic arch anatomy. This guide catheter was used successfully to perform carotid artery angioplasty and stent placement in 10 patients with markedly tortuous aortic arches or supra-aortic branches. As the authors gained experience with this catheter, they used it as a first option in patients with the appropriate aortic arch anatomy.

Combined surgical and endovascular approach to treat symptomatic in-stent occlusion of the left common carotid artery origin

Symptomatic occlusive lesions at the origins of the supra-aortic vessels pose challenges for treatment. Endovascular angioplasty and stent placement via the transfemoral approach is possible, but obtaining a stable position for the guide catheter via this approach is technically difficult. The authors describe the case of a 56-year-old man presenting with symptomatic occlusion of a previously placed stent at the origin of the left common carotid artery (CCA). An endovascular revascularization of the left CCA was planned. However, the absence of a lumen proximal to the stent prevented stable placement of a guide catheter via the transfemoral route. Consequently, the authors used a combined surgical and endovascular approach to gain access to the lesion. The left CCA was exposed surgically distal to the occlusion and clamped just proximal to its bifurcation to preserve flow from the external to the internal carotid artery (ICA) and to prevent embolism into the ICA. A wire was passed retrograde through the occlusive lesion and then was subsequently advanced proximally into the femoral sheath. This allowed transfemoral advancement of the appropriate endovascular devices to perform an angioplasty and placement of a stent. The patient remained neurologically stable, and postoperative studies showed improvement in cerebral perfusion. This case demonstrates the feasibility of distal-to-proximal stent delivery with a combined endovascular and surgical approach.

Variant of subclavian steal in the setting of ipsilateral common carotid artery occlusion: case report

Subclavian steal is a well-described angiographic finding and clinical syndrome that rarely results in vertebrobasilar ischemic symptoms. In classic subclavian steal, left subclavian artery (SA) stenosis occurs proximal to the left vertebral artery (VA) origin. We report a symptomatic variant of this syndrome that occurred in the setting of left common carotid artery occlusion and anomalous origin of the left VA directly from the aortic arch. The steal and symptoms resolved after stenting of the left SA stenosis.

Carotid Artery Stenting under Flow Arrest for the Management of Intraluminal Thrombus: Technical Case Report

Objective

The management of intraluminal carotid thrombus is not well defined. Medical and surgical management carry a relatively high risk of thromboembolism. Although endovascular options also carry the risk of thromboembolism from manipulation of the lesion, successful carotid stent placement using various methods of flow restriction has been reported anecdotally. We describe a technique to arrest antegrade flow before placement of carotid stents in the setting of symptomatic intraluminal thrombus.

Clinical Presentation

A 49-year-old woman presented with expressive dysphasia, right-upper extremity weakness, and an episode of left monocular blindness. Angiography confirmed the presence of a large intraluminal thrombus in a chronic dissection of the left internal carotid artery.

Results

We devised a configuration to arrest antegrade flow in the internal carotid artery before crossing the thrombus with a distal embolic protection device by inflating balloons in the common carotid artery and external carotid artery before crossing the lesion. After inflation of a balloon in the internal carotid artery, we completed overlapping stent placement to completely exclude the thrombus from the lumen.

Conclusion

The patient remained neurologically unchanged during and immediately after the procedure. She had mild neurological deficits at the 1 month follow-up evaluation. Follow-up ultrasonography at 1 and 3 months and computed tomographic angiography at 3 months after the procedure showed patency of the stented carotid artery, with no evidence of restenosis or thrombus. Although the risks of carotid stent placement for intraluminal thrombus remain unclear, the technique of flow arrest seems to provide a safe endovascular treatment option.

MRI assessment followed by successful mechanical recanalization of a complete tandem (internal carotid/middle cerebral artery) occlusion and reversal of a 10-hour fixed deficit

BACKGROUND

Mechanical clot extraction up to 8 hours after stroke onset is an alternative strategy for opening large vessels, especially for patients ineligible for intravenous thrombolysis. Safety beyond this therapeutic window is untested.

METHODS

An 81-year-old woman presented 8 hours after she developed left-sided weakness and dysarthria with a National Institutes of Health Stroke Scale (NIHSS) score fluctuating between 6 and 13. Neuroimaging revealed a large perfusion deficit with no diffusion abnormalities. An emergent cerebral angiogram revealed a complete internal carotid artery terminus occlusion.

RESULTS

Successful mechanical thrombectomy was performed without complication and resulted in almost complete reversal of the patient's deficit to an NIHSS score of 1, 10 hours after stroke onset.

CONCLUSION

Patients with large hypoperfused areas and minimal diffusion abnormalities on the MRI may benefit from mechanical thrombectomy beyond an 8-hour window.

"Internal cross-clamping" for symptomatic internal carotid artery thrombus. Report of two cases

Both carotid endarterectomy and carotid artery stent placement with filter embolic protection present a higher risk for patients with internal carotid artery (ICA) lesions containing intraluminal thrombus. Despite the risk associated with intervention, patients with symptomatic intraluminal thrombus who were enrolled in the North American Symptomatic Endarterectomy Trial did better with surgical than medical treatment. We describe the novel use of an endovascular "internal cross-clamping" technique in two patients with symptomatic intraluminal thrombus in the ICA. A 57-year-old woman presented with a history of multiple episodes of left upper-extremity numbness, mild dysarthria, and agraphia occurring over the previous 24 hours. Cranial magnetic resonance imaging revealed a scattered watershed infarction of the right hemisphere and a critical stenosis of the right ICA. An 81-year-old man awoke with hemiplegia and inability to follow commands after undergoing a complicated carotid endarterectomy. Computed tomographic perfusion imaging demonstrated an increased time to peak in the left middle cerebral territory, and emergent angiography demonstrated both intimal flaps and thrombus in the endarterectomy bed. The lesions in both patients were treated with endovascular stent placement using both proximal and distal flow occlusion--a functional "internal cross-clamping"--for embolic protection. To our knowledge, this is the first report of internal trapping and stent placement for symptomatic carotid stenosis containing intraluminal thrombus. This treatment strategy should be added to the armamentarium of endovascular surgeons in selected patients with symptomatic carotid intraluminal thrombus.

Neuroprotection in brain and spinal cord trauma

PURPOSE OF REVIEW

Traumatic brain and spinal cord injuries continue to be a public health problem. These types of injuries often occur in early adulthood and have a major impact for society. This review discusses strategies and therapeutic agents for perioperative neuroprotection in the management of brain and spinal cord trauma.

RECENT FINDINGS

There are no definitive drugs or strategies that can be utilized to provide perioperative neuroprotection in brain and spinal cord trauma patients. Phase III trials of several pharmacologic agents, including inhibitors of oxidative and excitotoxic injury, have been unable to demonstrate clinical efficacy. Although experimental animal data for hypothermia have been promising over the years, clinical application of therapeutic hypothermia cannot be recommended for routine use in neurotrauma patients. Administration of methylprednisolone, which has become common practice in acute spinal cord injury, has come under close scrutiny. Various experimental animal investigations suggest that potential therapeutic agents include estrogen, progesterone, minocycline, erythropoietin, and magnesium.

SUMMARY

The main priority in the initial treatment of brain and spinal cord trauma is to maintain oxygenation and perfusion in order to avoid aggravating secondary injury. Future progress will depend on the translation of neuroprotective strategies into well designed clinical trials with promising outcomes.

Cerebral revascularization in skull base tumors

Skull base tumors involving the carotid artery pose a difficult surgical challenge. The potential for bypass grafting for cerebral revascularization carries inherent risks but may aid in tumor resection and control in those who warrant carotid sacrifice but have inappropriate natural cerebrovascular reserve. We include a review of the literature discussing the indications for carotid resection as part of skull base tumor surgery, indications for cerebral revascularization, balloon test occlusion, graft types and operative technique, complications, and results.

Transpetrosal approaches to the posterior fossa

Resection of the petrous temporal bone to various degrees provides different levels of access to lesions of the posterior fossa. Although their nomenclature can be confusing, the numerous variants of the transpetrosal approaches can be classified broadly into anterior and posterior groups. The posterior transpetrosal approaches include the retro-labyrinthine, translabyrinthine, and transcochlear, whereas the ones in the anterior group are extensions of the basic middle fossa approach. Both the anterior and posterior approaches have the potential of exposing the cerebellopontine angle and the petroclival region.

The posterior approaches are based on the standard mastoidectomy and involve resection of the petrous bone to various degrees. This results in progressively increased exposure anteriorly, but comes at the expense of hearing in the translabyrinthine approach and of hearing and facial strength in the transcochlear approach.

In contrast, the middle fossa approaches spare the lateral petrous bone and involve resection of the medial petrous bone to various degrees. All of the middle fossa approaches are designed to preserve hearing. Extensions of the middle fossa approaches involve resection of bone within the Kawase rhomboid and division of the tentorium to provide exposure of the posterior fossa.