John R. Gaughen

Early postmarket results after treatment of intracranial aneurysms with the pipeline embolization device: A US multicenter experience

BACKGROUND The pipeline embolization device (PED) is the latest technology available for intracranial aneurysm treatment. OBJECTIVE To report early postmarket results with the PED. METHODS This study was a prospective registry of patients treated with PEDs at 7 American neurosurgical centers subsequent to Food and Drug Administration approval of this device. Data collected included clinical presentation, aneurysm characteristics, treatment details, and periprocedural events. Follow-up data included degree of aneurysm occlusion and delayed (> 30 days after the procedure) complications. RESULTS Sixty-two PED procedures were performed to treat 58 aneurysms in 56 patients. Thirty-seven of the aneurysms (64%) treated were located from the cavernous to the superior hypophyseal artery segment of the internal carotid artery; 22% were distal to that segment, and 14% were in the vertebrobasilar system. A total of 123 PEDs were deployed with an average of 2 implanted per aneurysm treated. Six devices were incompletely deployed; in these cases, rescue balloon angioplasty was required. Six periprocedural (during the procedure/within 30 days after the procedure) thromboembolic events occurred, of which 5 were in patients with vertebrobasilar aneurysms. There were 4 fatal postprocedural hemorrhages (from 2 giant basilar trunk and 2 large ophthalmic artery aneurysms). The major complication rate (permanent disability/death resulting from perioperative/delayed complication) was 8.5%. Among 19 patients with 3-month follow-up angiography, 68% (13 patients) had complete aneurysm occlusion. Two patients presented with delayed flow-limiting in-stent stenosis that was successfully treated with angioplasty. CONCLUSION Unlike conventional coil embolization, aneurysm occlusion with PED is not immediate. Early complications include both thromboembolic and hemorrhagic events and appear to be significantly more frequent in association with treatment of vertebrobasilar aneurysms.

Reduced neutrophil infiltration protects against lung reperfusion injury after transplantation

BACKGROUND There is evidence that lung ischemia reperfusion injury is a result of the activation of components of the inflammatory cascade. However, the role of neutrophils in lung reperfusion injury continues to be a source of controversy. METHODS Using an isolated, whole blood-perfused, ventilated rabbit lung model, we sought to characterize the pattern of reperfusion injury and investigate the contribution of neutrophils to this injury. Donor rabbits underwent lung harvest after pulmonary arterial prostaglandin E1 injection and Euro-Collins preservation solution flush. Group I lungs (n = 8) were immediately reperfused without ischemic storage. Group II lungs (n = 8) were stored for 18 h at 4 degrees C before reperfusion. Group III lungs (n = 10) underwent 18 h of ischemic storage and were reperfused with whole blood that was first passed through a leukocyte-depleting filter. All lungs were reperfused for 2 h. RESULTS Arterial oxygenation in group III progressively improved, and was significantly higher than that of group II after 2 h of reperfusion (272.58+/-58.97 vs 53.58+/-5.34 mm Hg, p = 0.01). Both pulmonary artery pressure and pulmonary vascular resistance were significantly reduced in group III when compared with group II (27.85+/-1.45 vs 44.15+/-4.77 mm Hg, p = 0.002; and 30,867+/-2,323 vs 52,775+/-6,386 dynes x sec x cm(-5), p = 0.003, respectively). Microvascular permeability in group III lungs was reduced to 73.98+/-6.15 compared with 117.16+/-12.78 ng Evans blue dye/g tissue in group II (p = 0.005). Group III myeloperoxidase activity was 56.92+/-6.31 deltaOD/g/min compared with 102.84+/-10.41 delta0d/g/min in group II (p = 0.002). CONCLUSIONS Leukocyte depletion of the blood reperfusate protects against microvascular permeability and significantly improves pulmonary graft function. The neutrophil plays a major role in amplifying lung injury later during reperfusion, and this lung ischemia reperfusion injury may be reversed through the interruption of the inflammatory cascade and the interference with neutrophil infiltration.

The Efficacy of Endovascular Stenting in the Treatment of Supraclinoid Internal Carotid Artery Blister Aneurysms Using a Stent-in-Stent Technique

BACKGROUND AND PURPOSE: Blister aneurysms of the supraclinoid ICA represent a rare but well-documented cause of subarachnoid hemorrhage. These aneurysms are difficult to detect, and their surgical treatment is challenging, with high morbidity and mortality rates. The reports currently in the literature that describe the surgical and endovascular treatment of these aneurysms offer no clear consensus on the optimal treatment. We describe a staged endovascular treatment entailing stenting using a stent-in-stent technique, as well as planned but delayed embolization as the aneurysm increases in size to allow the introduction of coils. MATERIALS AND METHODS: We performed a retrospective review of all cerebral angiograms performed at our institution over an 8-month period for evaluation of subarachnoid hemorrhage, identifying 6 ICA blister aneurysms. RESULTS: All 6 blister aneurysms were located in the supraclinoid ICA. The stent-in-stent technique was used for the initial treatment of all patients. Three patients had no residual or recurrent aneurysm following initial treatment. Three patients required retreatment with coils after continued growth of the aneurysm, identified on follow-up angiography. Five patients had good recovery (average mRS score of 1), and 1 patient had poor neurologic recovery (mRS score of 3) due to a large hemorrhagic infarction. CONCLUSIONS: Our case series suggests that staged endovascular treatment entailing the use of a stent-in-stent technique, augmented with subsequent coil embolization as necessary for progressive disease, is a viable endovascular option for treating ruptured supraclinoid blister aneurysms, allowing for parent artery preservation.

Solitaire flow restoration thrombectomy for acute ischemic stroke: Retrospective multicenter analysis of early postmarket experience after FDA approval

BACKGROUND The promising results of the Solitaire Flow Restoration (FR) With the Intention for Thrombectomy (SWIFT) trial recently led to Food and Drug Administration (FDA) approval of the Solitaire FR stent retriever device for recanalization of cerebral vessels in patients with acute ischemic stroke. OBJECTIVE To report the early postmarket experience with this device since its FDA approval in the United States, which has not been previously described. METHODS We conducted a retrospective analysis of consecutive acute ischemic strokes cases treated between March 2012 and July 2012 at 10 United States centers where the Solitaire FR was used as a single device or in conjunction with other intraarterial endovascular approaches. RESULTS A total of 101 patients were identified (mean age, 64.7 years; mean admission National Institutes of Health Stroke Scale [NIHSS] score, 17.6). Intravenous thrombolysis was administered in 39% of cases; other endovascular techniques were utilized in conjunction with the Solitaire FR in 52%. Successful recanalization (Thrombolysis in Myocardial Infarction 2/3) was achieved in 88%. The rate of symptomatic intracranial hemorrhage within the first 24 hours was 15%. In-hospital mortality was 26%. At 30 days, 38% of patients had favorable functional outcome (modified Rankin scale score ≤2). Severity of NIHSS score on admission was a strong predictor of poor outcome. CONCLUSION Our study shows that a variety of other endovascular approaches are used in conjunction with Solitaire FR in actual practice in the United States. Early postmarket results suggest that Solitaire FR is an effective tool for endovascular treatment of acute ischemic stroke.

Lack of Preoperative Spinous Process Tenderness Does Not Affect Clinical Success of Percutaneous Vertebroplasty

PURPOSE Some operators use the lack of point tenderness over compression fractures to exclude patients from undergoing percutaneous vertebroplasty procedures. The purpose of this study was to determine whether this lack of tenderness portends a poorer clinical outcome after vertebroplasty than is achieved in patients with such tenderness. MATERIALS AND METHODS The authors conducted a retrospective review of consecutive percutaneous vertebroplasty procedures performed at their institution to define two populations. Group 1 included 90 patients with tenderness to palpation over the spinous process of the fractured vertebra, whereas group 2 included 10 patients without such tenderness. This second group presented with back pain and demonstrated tenderness distant from the fracture (n = 5), tenderness lateral to the fracture (n = 4), or no focal tenderness at all (n = 1). All were treated because of edema seen on magnetic resonance (MR) imaging and/or increased activity on bone scan. Clinical outcomes were assessed by quantitative measurements of pre- and postoperative levels of pain (11-point scale) and mobility (five-point scale). RESULTS Pain improvement of three points or greater occurred in 77 of the 85 patients (91%) in group 1 who complied with follow-up and nine of nine such patients (100%) in group 2, with mean postoperative pain levels of 1.82 and 0.33 points, respectively (P =.14). Forty of 45 patients (89%) in group 1 with impaired preoperative mobility reported improvement postoperatively, as did two of three such patients (67%) in group 2. Mean levels of postoperative impaired mobility for groups 1 and 2 were 0.27 and 0.67 points, respectively (P =.27). CONCLUSION Pain on palpation over the fractured vertebra is not a necessary requirement in selecting patients who will benefit from percutaneous vertebroplasty. Other factors, such as MR evidence of edema or increased uptake on bone scan, should be weighed considerably in the decision to treat a patient.

Spinal cord protection during aortic cross-clamping using retrograde venous perfusion

BACKGROUND Paraplegia remains a devastating complication following thoracic aortic operation. We hypothesized that retrograde perfusion of the spinal cord with a hypothermic, adenosine-enhanced solution would provide protection during periods of ischemia due to temporary aortic occlusion. METHODS In a rabbit model, a 45-minute period of spinal cord ischemia was produced by clamping the abdominal aorta and vena cava just below the left renal vessels and at their bifurcations. Four groups (n = 8/group) were studied: control, warm saline, cold saline, and cold saline with adenosine infusion. In the experimental groups, saline or saline plus adenosine was infused into the isolated cavae throughout the ischemic period. Clamps were removed and the animals to recovered for 24 hours before blinded neurological evaluation. RESULTS Tarlov scores (0 = paraplegia, 1 = slight movement, 2 = sits with assistance, 3 = sits alone, 4 = weak hop, 5 = normal hop) were (mean +/- standard error of the mean): control, 0.50 +/- 0.50; warm saline, 1.63 +/- 0.56; cold saline, 3.38 +/- 0.26; and cold saline plus adenosine, 4.25 +/- 0.16 (analysis of variance for all four groups, p < 0.00001). Post-hoc contrast analysis showed that cold saline plus adenosine was superior to the other three groups (p < 0.0001). CONCLUSION Retrograde venous perfusion of the spinal cord with hypothermic saline and adenosine provides functional protection against surgical ischemia and reperfusion.

Inhibition of Inducible Nitric Oxide Synthase After Myocardial Ischemia Increases Coronary Flow

BACKGROUND The role of nitric oxide synthase in myocardial ischemia-reperfusion injury is complex. Our hypothesis was that inducible nitric oxide synthase has a role in the regulation of coronary flow after ischemia. METHODS Four groups of isolated blood-perfused rabbit hearts underwent sequential periods of perfusion, ischemia, and reperfusion (20, 30, and 20 minutes). Two groups underwent 40 minutes of perfusion. Ischemic groups received saline vehicle, N omega-nitro-L-arginine methyl ester (L-NAME) or the highly specific inducible nitric oxide synthase inhibitor 1400W in low or high doses during reperfusion. Two nonischemic groups were treated with saline vehicle or 1400W during the last 20 minutes of perfusion. Left ventricular developed pressure and coronary flow were measured after each perfusion period. Ventricular levels of myeloperoxidase and cyclic guanosine monophosphate were measured at the end of the second perfusion period. RESULTS Coronary flow was significantly increased in both 1400W groups versus L-NAME (p < 0.001) and in high-dose 1400W versus control (p < 0.001). Coronary flow was not significantly different between the nonischemic groups. Left ventricular developed pressure was not significantly different among the ischemic groups or between the two nonischemic groups. There were no differences in cyclic guanosine monophosphate levels in any of the ischemic hearts. Myeloperoxidase levels were significantly elevated in L-NAME versus high-dose 1400W, nonischemic 1400W, and nonischemic saline groups (p < 0.02). CONCLUSIONS Highly selective inhibition of inducible nitric oxide synthase results in increased coronary flow after ischemia but not after continuous perfusion. This occurs with decreased neutrophil accumulation and a trend toward increased contractility without elevation of cyclic guanosine monophosphate levels.

Endovascular treatment of ophthalmic artery aneurysms: ophthalmic artery patency following flow diversion versus coil embolization

Background and purpose The Pipeline Embolization Device (PED) has been shown to effectively treat complex internal carotid artery aneurysms while maintaining patency of covered side branches. The purpose of this retrospective matched cohort study is to evaluate the effect of flow diversion on the patency of the ophthalmic artery when treating ophthalmic artery aneurysms. Methods A retrospective review of our prospectively collected institutional database identified 19 ophthalmic artery aneurysms treated with a PED. These were matched according to aneurysm diameter in a 1:2 fashion to ophthalmic artery aneurysms treated via coil embolization, although it is important to note that there was a statistically significance difference in the neck diameter between the two groups (p=0.045). Clinical and angiographic outcomes were recorded and analyzed. Results On follow-up angiography, decreased flow through the ophthalmic artery was observed in 26% of the PED cohort and 0% of the coil embolization cohort (p=0.003). No ophthalmologic complications were noted in either cohort. Complete occlusion at 12 months was more common following PED treatment than coil embolization (74% vs 47%; p=0.089), although lower than reported in previous trials. This may be due to inflow into the ophthalmic artery keeping the aneurysm patent. Retreatments were more common following coil embolization than PED (24% vs 11%), but this was not significant (p=0.304). Permanent morbidity rates were not significantly different between the PED (11%) and coil embolization (3%) cohorts (p=0.255). Conclusions Our results suggest that ophthalmic artery aneurysms may be adequately and safely treated with either the PED or coil embolization. However, treatment with the PED carries a higher risk of impeding flow to the ophthalmic artery, although this did not result in clinical sequelae in the current study.

Utility of CT Angiography in the Identification and Characterization of Supraclinoid Internal Carotid Artery Blister Aneurysms

BACKGROUND AND PURPOSE: Blister aneurysms of the supraclinoid ICA represent a rare but potentially catastrophic cause of SAH, often presenting both diagnostic and therapeutic dilemmas. We explore the utility of CTA in the identification and characterization of ICA blister aneurysms. MATERIALS AND METHODS: We performed a retrospective review of catheter cerebral angiograms obtained at our institution over a 12-month period for evaluation of SAH, identifying 6 cases of ICA blister aneurysms. All patients underwent CTA and DSA for evaluation of SAH. The reports from the CTA and DSA studies were reviewed to identify aneurysms correctly diagnosed prospectively. Retrospective review of the CTA and DSA images was also performed. Review of the interpretations and images was performed for any follow-up studies. RESULTS: All 6 patients presented with SAH, diagnosed by head CT. All patients subsequently underwent CTA prior to DSA evaluation. All 6 aneurysms were identified prospectively on initial DSA imaging. Of the 6 blister aneurysms, 4 (67%) were identified prospectively; and 5 (83%), retrospectively on CTA. All 6 patients underwent endovascular treatment with stent placement. Four of the 6 aneurysms underwent follow-up CTA (range, 9–22 days), including the 2 aneurysms that had been unidentifiable preprocedurally. All 4 blister aneurysms were seen postprocedurally by DSA. Three of these 4 (75%) residual aneurysms were detected by CTA (both prospectively and retrospectively). CONCLUSIONS: In the presence of SAH and otherwise negative findings on CTA, a catheter cerebral angiogram should be performed to absolutely exclude an ICA blister aneurysm.

Magnetic resonance angiography of the extracranial carotid system.

Objectives: To discuss the role of magnetic resonance angiography (MRA) in the evaluation of the extracranial carotid system with an emphasis on atherosclerosis and to briefly address the role of magnetic resonance imaging in imaging of carotid atherosclerotic plaque. Methods: Literature and institutional review. Discussion: The North American Symptomatic Carotid Endarterectomy Trial and European Carotid Surgery Trial studies have emphasized the importance of recognition and treatment of carotid stenosis in the prevention of ischemic stroke. Magnetic resonance angiography is a viable tool in the screening and quantification of this entity. Both time of flight and contrast-enhanced MRA techniques are available for clinical use, each with distinct advantages and limitations. A thorough understanding of these is vital for correct performance and interpretation of these studies. Plaque imaging with magnetic resonance imaging offers new insights into the pathophysiology of the atherosclerotic process and may be used in the future to monitor response to lipid-lowering drug therapy. Conclusion: Magnetic resonance angiography is a robust imaging technique for evaluation of the extracranial carotid circulation. The radiologist must be aware of the advantages and limitations of the different techniques available. Contrast-enhanced MRA is now the most widely performed technique. It can be used to replace digital subtraction angiography in the evaluation of carotid stenosis in most clinical settings.