Long-term angiographic and histopathologic findings in experimental aneurysms of the carotid bifurcation embolized with platinum and tungsten coils.

PURPOSETo evaluate the long-term outcome of endovascular occlusion of arterial aneurysms effected with metal coils.METHODSMicrosurgical methods were used to produce carotid bifurcation aneurysms in 20 rabbits and the radiologic and histologic changes were examined. Eight of these aneurysms were occluded with electrically detachable platinum coils (Guglielmi detachable coils [GDCs] and nine were treated with mechanically detachable tungsten coils (mechanical detachable system [MDS]). Three aneurysms remained untreated and served as controls. One animal died of embolic complications 12 hours after endovascular treatment. After observation periods of 3 to 6 months, the remaining animals were examined by intraarterial digital subtraction angiography and subsequent fixation and light and electron microscopy.RESULTSLarge open spaces without signs of thrombosis were found between the loops of the coil baskets in 12 aneurysms (six treated with GDCs and six treated with MDS) regardless of the observation period. In very densely packed aneurysms (four cases with complete occlusion as determined by angiographic criteria), the coil surfaces were for the most part covered by thin cell layers; however, complete endothelialization was never seen. In aneurysms with an initial partial occlusion of 70% to 90%, coil compaction and/or recanalization was a consistent finding. A comparison of the radiologic findings with the histologic aspect revealed that the degree of occlusion was often overrated on the radiographs (in eight of 17 cases). In general, the fibrous tissue reaction appeared to be slightly more pronounced in aneurysms occluded with tungsten coils.CONCLUSIONSPlatinum and tungsten coils were not always effective in causing endoluminal thrombosis leading to long-term occlusion by organized thrombus.     

Rescue Treatment of Thromboembolic Complications during Endovascular Treatment of Cerebral Aneurysms: A Meta-Analysis

BACKGROUND AND PURPOSE:Intraprocedural thrombus formation during endovascular treatment of intracranial aneurysms is often treated with glycoprotein IIb/IIIa inhibitors and, in some instances, fibrinolytic therapy. We performed a meta-analysis evaluating the safety and efficacy of GP IIb/IIIa inhibitors compared with fibrinolysis. We also evaluated the safety and efficacy of abciximab, an irreversible inhibitor, compared with tirofiban and eptifibatide, reversible inhibitors of platelet function.MATERIALS AND METHODS:We performed a comprehensive literature search for studies on rescue therapy for intraprocedural thromboembolic complications with glycoprotein IIb/IIIa inhibitors or fibrinolysis during endovascular treatment of intracranial aneurysms. We studied rates of periprocedural stroke/hemorrhage, procedure-related morbidity and mortality, immediate arterial recanalization, and long-term good clinical outcome. Event rates were pooled across studies by using random-effects meta-analysis.RESULTS:Twenty-three studies with 516 patients were included. Patients receiving GP IIb/IIIa inhibitors had significantly lower perioperative morbidity from stroke/hemorrhage compared with those treated with fibrinolytics (11.0%; 95% CI, 7.0%–16.0% versus 29.0%; 95% CI, 13.0%–55.0%; P = .04) and were significantly less likely to have long-term morbidity (16.0%; 95% CI, 11.0%–21.0% versus 35.0%; 95% CI, 17.0%–58.0%; P = .04). There was a trend toward higher recanalization rates among patients treated with glycoprotein IIb/IIIa inhibitors compared with those treated with fibrinolytics (72.0%; 95% CI, 64.0%–78.0% versus 50.0%; 95% CI, 28.0%–73.0%; P = .08). Patients receiving tirofiban or eptifibatide had significantly higher recanalization rates compared with those treated with abciximab (83.0%; 95% CI, 68.0%–91.0% versus 66.0%; 95% CI, 58.0%–74.0%; P = .05). No difference in recanalization was seen in patients receiving intra-arterial (77.0%; 95% CI, 66.0%–85.0%) or intravenous GP IIb/IIIa inhibitors (70.0%; 95% CI, 57.0%–80.0%, P = .36).CONCLUSIONS:Rescue therapy with thrombolytic agents resulted in significantly more morbidity than rescue therapy with glycoprotein IIb/IIIa inhibitors. Tirofiban/eptifibatide resulted in significantly higher recanalization rates compared with abciximab.

Periprocedural thromboembolic complications from endovascular treatment of intracranial aneurysms occur in 2%–15% of patients.¹ Intraprocedural thrombus formation is often treated with pharmacologic rescue, by using intra-arterial or intravenous administration of glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitors or fibrinolytics. The primary goal of rescue therapy is to recanalize the artery to avoid permanent neurologic deficits. Many studies have described intraprocedural administration of GP IIb/IIIa inhibitors and thrombolytic agents during endovascular treatment of intracranial aneurysms. Some studies have suggested that patients receiving GP IIb/IIIa inhibitors have better outcomes than those treated with fibrinolytic therapy. Studies have also examined the comparative efficacy of irreversible GP IIb/IIIa inhibitor agents (abciximab) and reversible agents (tirofiban/eptifibatide) and the comparative efficacy of intra-arterial and intravenous administration of GP IIb/IIIa inhibitors, but they have not demonstrated any significant differences in recanalization rates and outcomes.^2,3 Overall however, the evidence is limited to small case series. We performed a meta-analysis of the literature examining angiographic and clinical outcomes in patients treated with GP IIb/IIIa inhibitors and fibrinolytic therapy for intraprocedural thrombus formation during intracranial aneurysm treatment.⁴ We also performed subgroup analyses to compare outcomes of patients treated with abciximab versus tirofiban/eptifibatide and those treated with intra-arterial (IA) and intravenous GP IIb/IIIa rescue therapy.     

Endovascular treatment of pseudoaneurysms with electrolytically detachable coils.

PURPOSEWe describe the clinical presentation, angiographic findings, and clinical outcome in a group of patients with pseudoaneurysms treated by a new endovascular technique using Guglielmi electrolytically detachable platinum coils (GDCs).METHODSWe retrospectively reviewed the angiographic and clinical findings in a series of 11 patients with pseudoaneurysms occurring in a variety of locations: seven in the cavernous carotid artery, one in the petrous carotid artery, two in the anterior cerebral artery, and one in the cervical vertebral artery.RESULTSAll aneurysms were cured with GDC embolization. The only complication was a branch occlusion, which resolved with heparinization and produced no clinical sequelae.CONCLUSIONPseudoaneurysms can be safely and effectively treated by embolization with GDCs. Consideration needs to be given to the anatomic location of the pseudoaneurysm and the acuity of onset. Treatment efficacy may by improved if there are bony confines around the aneurysm or if therapy takes place in the subacute period, when the wall of the pseudoaneurysm has matured and stabilized.     

Risk of Thrombus Fragmentation during Endovascular Stroke Treatment

BACKGROUND AND PURPOSE:Periprocedural thrombus fragmentation is a relevant risk in endovascular stroke treatment. Because factors influencing its occurrence are largely unknown, this study addresses a potential relationship between thrombus histology and clot stability.MATERIALS AND METHODS:Eighty-five patients with anterior circulation stroke treated with thrombectomy were included in this retrospective study. The number and location of emboli after retrieving the primary thrombus, the number of maneuvers, and TICI scores were evaluated. H&E and neutrophil elastase staining of retrieved clots was performed, and semiquantitative measurements of thrombus components were correlated with procedural parameters.RESULTS:An inverse correlation between maneuvers required for thrombus retrieval and the number of distal and intermediate emboli was observed (Spearman r, −0.23; P = .032). Younger patients were at higher risk for periprocedural thrombus fragmentation (Spearman r, −0.23; P = .032). Bridging thrombolysis tended to be associated with fewer maneuvers (2 vs 3, P = .054) but more emboli (1 vs 0, P = .067). While no consistent correlation between procedural parameters and red/white blood cells and fibrin-/platelet fractions could be found, higher amounts of neutrophil elastase–positive cells within the thrombus were independently associated with the occurrence of multiple emboli (adjusted OR, 4.6; 95% CI, 1.1–19.7; P = .041) and lower rates of complete recanalization (adjusted OR, 0.3; 95% CI, 0.1–0.9; P = .050).CONCLUSIONS:Younger age, easy-to-retrieve thrombi, and bridging thrombolysis may be risk factors for periprocedural thrombus fragmentation. Findings from standard histologic stains did not provide insight into thrombectomy-relevant thrombus stability. However, higher neutrophil levels in the thrombus tissue were related to an increased risk of periprocedural thrombus fragmentation. This observation aligns with the proposed thrombolytic capacity of neutrophil elastase and points to its potential clinical relevance in the context of stroke thrombectomy.

Mechanical thrombectomy (MT) of large-vessel occlusion has evolved as a safe and effective procedure that plays an indispensable role in modern therapeutic management of acute ischemic stroke.^1–5 In recent randomized trials, high rates of successful recanalization (range, 59%–88%) were considered a key element in achieving excellent rates of good functional outcome (range, 33%–71%).⁶ However, not all successfully treated patients showed complete (TICI 3) recanalization; this outcome potentially limits therapeutic benefit.In general, all endovascular MT techniques are accompanied by the risk of periprocedural thrombus fragmentation (PTF) and subsequent downstream embolism,^7–9 preventing complete recanalization. Because the neurologic outcome of patients with complete (TICI 3) recanalization is significantly better compared with patients with “almost complete” (TICI 2b)¹⁰ or incomplete recanalization (TICI 1–2a),¹¹ understanding the factors contributing to PTF may prove beneficial in achieving maximal therapeutic benefit. Previous reports demonstrated that thrombus stability¹² may influence the incidence of PTF, and analyses of cellular thrombus composition have revealed a possible association between thrombus histology and thrombus etiology^13,14 as well as clinical outcome.^15,16 Discrepant results in previous studies¹⁷ might be primarily explained by low patient numbers and the risk of clot fragmentation. The latter may bias the representative character of the analyzed fragment.While the main cellular components of a thrombus are known to be fibrin-/platelet accumulations (F/P) as well as red (RBC) and white blood cells (WBC),^15,17 a higher fraction of RBC has been associated with increased rates of successful endovascular recanalization as noninvasively measured by whole-thrombus density (CT)^13,18 and corresponding blooming artifacts (MR imaging).^16,18–21 Besides common thrombus characteristics obtained from H&E staining, new evidence has emerged that the degree of inflammatory cell invasion, particularly by neutrophils, may alter the stability and degradation of a thrombus.^22,23 This finding is of particular interest because neutrophils exhibit fibrinolytic activity, which may weaken clot stability.²⁴ Nevertheless, the impact of inflammatory cells on the mechanical properties of a thrombus remains uncertain, especially in the context of stroke thrombectomy. Potential knowledge of the clot composition before MT may be a further valuable tool to aid in the selection of the most appropriate devices and techniques to avoid PTF.To this end, this is the first study investigating the dependency of procedural thrombectomy characteristics on anatomic and immune-histochemical thrombus histology, to our knowledge.     

Internal carotid artery stent implantation in 25 patients with acute stroke: preliminary results

PURPOSE: To evaluate retrospectively the outcome for patients with acute ischemic stroke in the territory of the middle cerebral artery (MCA) who had undergone stent implantation in the proximal segment of the internal carotid artery (ICA) in addition to intraarterial thrombolysis (IAT). MATERIALS AND METHODS: Stent implantation and retrospective analysis of clinical and radiologic data were approved by the institutional ethical committee. Endovascular treatment was performed after obtaining informed consent from patients or their closest relatives. Informed consent for retrospective review was not required. After pharmacologic and/or mechanical IAT, 25 consecutive patients (seven women, 18 men; mean age, 59 years +/- 14 [standard deviation]) underwent stent implantation in the proximal segment of the ICA (endovascular group). The clinical and radiologic characteristics (ie, interval from symptom onset to arrival at the emergency department, prevalence of vascular risk factors, causes of stroke, stroke severity, early signs of cerebral ischemia, duration of endovascular intervention, type of occlusion, and prevalence of leptomeningeal collateral vessels), recanalization rates, and clinical outcomes for patients in the endovascular group were compared with those for patients in the medical group (10 women, 21 men; mean age, 62 years +/- 12) who experienced ischemic stroke in the territory of the MCA as a result of ICA occlusion and who received antithrombotic treatment only. Differences between groups were assessed by using the chi2 test. A logistic regression analysis was performed to assess the effect of clinical and radiologic factors on recanalization rates and outcome. RESULTS: ICA recanalization was successful in 21 patients. Good recanalization of the MCA was achieved in 11 patients. In nine of these patients, recanalization of the MCA was achieved by using mechanical IAT only. In the remaining 12 patients, administration of intraarterial urokinase was performed in addition to mechanical thrombolysis. Two patients from the endovascular group experienced symptomatic intracerebral hemorrhage. At 3 months, 56% of the endovascular group and 26% of the medical group had a favorable outcome. Mortality was 20% in the endovascular and 16% in the medical group. CONCLUSION: IAT and stent implantation in the proximal segment of the ICA seem to improve the outcome for patients with ischemic stroke caused by occlusion of the cervical portion of the ICA.     

Frequency of cerebral vasospasm in patients treated with endovascular occlusion of intracranial aneurysms.

UNLABELLEDThe purpose of this study was to retrospectively compare a group of 19 patients treated with craniotomy and aneurysmal clipping with a group of 18 patients who were treated via endovascular occlusion with Guglielmi detachable coils in regard to frequency and severity of cerebral vasospasm.METHODSAll patients were treated within 48 hours of ictus. In the endovascular group, nine patients had Hunt and Hess grade I subarachnoid hemorrhage, five patients had grade II aneurysms, and four patients had grade III. According to the Fisher classification, one aneurysm was grade I, nine were grade II, and eight were grade III. Twelve of the aneurysms were on the anterior circulation and seven were on the posterior circulation. In the surgical group, 10 patients had Hunt and Hess grade I hemorrhage, seven had grade II aneurysms, and two had grade III. Nine of these were Fisher grade II and 10 were grade III. Eighteen aneurysms were on the anterior circulation and one was on the posterior circulation. Endovascularly treated patients were medically treated identically to those in the surgical group, with prophylactic volume expansion and hemodilution immediately after endovascular occlusion, except that they also received 48 hours of full heparinization followed by 24 hours of dextran infusion after endovascular occlusion.RESULTSAll four patients in the endovascular group in whom delayed neurologic deficits developed as a result of vasospasm responded to elevation of blood pressure and did not require either mechanical or chemical angioplasty to reverse their symptomatology. In the surgical group, 14 of 19 developed clinical vasospasm, with elevation of their transcranial Doppler velocities, and required maximum triple-H (hypertensive, hypervolemic, hemodilutional) therapy. Three of these patients required mechanical and pharmacologic angioplasty. No surgical complications were incurred as a direct result of the craniotomy. One patient in the endovascular group developed a femoral pseudoaneurysm as a complication of the procedure and postocclusion anticoagulation. No thromboembolic events were noted in this group.CONCLUSIONIn patients with similar Hunt and Hess grades and Fisher grades, preliminary data suggest that the frequency and severity of cerebral vasospasm may be reduced in those treated by endovascular occlusion of their aneurysm as compared with those treated by direct surgical clipping.     

Massive Pulmonary Embolism: Treatment with Thrombus Fragmentation and Local Fibrinolysis with Recombinant Human-Tissue Plasminogen Activator

Purpose: To report the results of thrombus fragmentation in combination with local fibrinolysis using recombinant human-tissue plasminogen activator (rtPA) in patients with massive pulmonary embolism. Methods: Five patients with massive pulmonary embolism were treated with thrombus fragmentation followed by intrapulmonary injection of rtPA. Clot fragmentation was performed with a guidewire, angiographic catheter, and balloon catheter. Three patients had undergone recent surgery; one of them received a reduced dosage of rtPA. Results: All patients survived and showed clinical improvement with a resultant significant (p < 0.05) decrease in the pulmonary blood pressure (mean systolic pulmonary blood pressure before treatment, 49 mmHg; 4 hr after treatment, 28 mmHg). Angiographic follow-up in three patients revealed a decrease in thrombus material and an increase in pulmonary perfusion. Two patients developed retroperitoneal hematomas requiring transfusion. Conclusion: Clot fragmentation and local fibrinolysis with rtPA was an effective therapy for massive pulmonary embolism. Bleeding at the puncture site was a frequent complication. Received: 0/00/00/Accepted: 0/00/00     

Selective endovascular treatment of intracranial aneurysms with a liquid embolic: a single-center experience in 39 patients with 41 aneurysms

BACKGROUND AND PURPOSE: Although embolization with detachable coils is an accepted alternative to surgical clipping, a major long-term problem is aneurysm recanalization due to coil compaction. Liquid embolic agents are a possible alternative as filling material that might decrease the recanalization rate. We evaluated the use of a liquid embolic for endovascular treatment of intracranial aneurysms. METHODS: During 1999-2003, 10 patients with 11 small aneurysms (group 1) and 29 patients with 30 large or giant aneurysms (group 2) were treated with a liquid embolic. Of 32 female and seven male patients, 20 had mass effect and two had subarachnoid hemorrhage; 17 were asymptomatic. All aneurysms were judged unsuitable for regular treatment; selective embolization was performed with a liquid embolic alone or with coils and liquid embolic. Stent placement was performed in 15 cases. Clinical and anatomic outcomes were assessed with the Modified Glasgow Outcome Scale and with angiography at 3, 12, and 24 months. RESULTS: In group 1, good or excellent outcome and complete occlusion were observed in all patients. In group 2, clinical outcome was good or excellent in 26 patients and fair in one, and death occurred in two patients (one procedure related and one disease related). Technical complications occurred in four patients in group 1 (one permanent neurologic deficit) and in four patients in group 2 (one patient died, two remain hemiparetic, one remains asymptomatic). Follow-up images showed two recanalizations in group 1 and nine in group 2. CONCLUSION: Selective embolization with a liquid embolic is useful to treat aneurysms unsuitable for coiling or for patients in whom previous treatment failed. This mostly applies to large and giant aneurysms in which morbidity and mortality rates are better than those associated with surgery, and the recanalization rate is lower than that previously described with coiling.     

Acute intracranial hemorrhage secondary to thrombocytopenia: CT appearances unaffected by absence of clot retraction.

PURPOSETo describe the in vivo CT appearance of acute intracerebral blood clots formed from anemic platelet-depleted blood.METHODSThree patients with intracerebral hemorrhage secondary only to thrombocytopenia were examined with CT within 2 1/2 hours after the onset of clinical symptoms.RESULTSThere were no unusual CT features found in the intracerebral hemorrhages of patients with only thrombocytopenia. Specifically, a hyperdense zone(s) surrounded by areas of decreased density was identified.CONCLUSIONClot retraction (which cannot occur in patients with severe thrombocytopenia) is not necessary for the CT appearance of acute intracerebral hemorrhage.     

Recanalization of Chronic Total Occlusions of the Superior Mesenteric Artery in Patients with Chronic Mesenteric Ischemia: Technical and Clinical Outcomes

PurposeTo evaluate the safety and outcomes of endovascular recanalization of chronic total occlusions (CTOs) of the superior mesenteric artery (SMA) in patients with chronic mesenteric ischemia (CMI).Materials and MethodsA single-institution retrospective review was performed of 47 consecutive patients (18 male, 29 female) who underwent endovascular stent placement for CTOs of the SMA between February 2006 and November 2012. All patients had symptoms of CMI. Procedural and follow-up data were collected for assessment of technical success, safety, and outcome.ResultsTechnical success was achieved in 41 of 47 patients (87%). Forty-two of the 47 procedures were performed from a femoral approach. Fifteen patients underwent concurrent revascularization of the celiac artery. All patients who underwent successful recanalization reported symptomatic improvement. Kaplan–Meier analysis revealed primary freedom from symptomatic recurrence of 95% at 12 months and 78% at 24 months. Symptomatic recurrence was observed in seven patients, all of whom underwent successful assisted or secondary endovascular procedures. Secondary freedom from symptomatic recurrence rates were 100% at 12 months and 88% 24 months. There were three (7%) minor access-related complications and no major complications.ConclusionsEndovascular stent-assisted recanalization of chronic SMA occlusions is safe and effective, with an acceptable rate of technical success and excellent midterm clinical outcomes.     

Endovascular Procedures versus Intravenous Thrombolysis in Stroke with Tandem Occlusion of the Anterior Circulation

PurposeStroke with tandem occlusion within the anterior circulation presents a lower probability of recanalization and good clinical outcome after intravenous (IV) thrombolysis than stroke with single occlusion. The present study describes the impact of endovascular procedures (EPs) compared with IV thrombolysis alone on recanalization and clinical outcome.Materials and MethodsThirty patients with symptom onset less than 4.5 hours and tandem occlusion within the anterior circulation were analyzed retrospectively. Recanalization was assessed per Thrombolysis In Cerebral Infarction (TICI) classification on computed tomography, magnetic resonance imaging, or digital subtraction angiography within 24 hours. Infarct size was detected on follow-up imaging as a dichotomized variable, ie, more than one third of the territory of the middle cerebral artery. Clinical outcomes were major neurologic improvement, independent outcome (90-d modified Rankin Scale [mRS] score), symptomatic intracerebral hemorrhage (sICH; per European Cooperative Acute Stroke Study criteria), and death within 7 days.ResultsPatients treated with EPs (n = 14) were significantly younger and had a history of arterial hypertension more frequently than patients treated with IV thrombolysis alone (n = 16). Recanalization (ie, TICI score 2b/3; EP, 64%; IV, 19%; P = .01), major neurologic improvement (EP, 64%; IV, 19%; P = .01), and independent outcome (mRS score ≤ 2; EP, 54% IV, 13%; P = .02) occurred more often in the EP group, whereas infarct sizes greater than one third of the MCA territory (EP, 43%; IV, 81%; P = .03) were observed less often. Rates of sICH (P = .12) and death within 7 days (P = .74) did not differ significantly.ConclusionsHigher recanalization rate, smaller infarct volume, and better clinical outcome in the EP group should encourage researchers to include this subgroup of patients in prospective randomized trials comparing IV thrombolysis versus EP in stroke.     

Interlocking detachable coil occlusion in the endovascular treatment of intracranial aneurysms: preliminary results.

PURPOSETo present our preliminary experience with the recently developed interlocking detachable coils in the treatment of intracranial aneurysms.METHODSTwo aneurysms of the basilar tip, two of the internal carotid artery, and one of the posterior inferior cerebellar artery were treated by an endovascular technique using interlocking detachable coils. Three of the patients had undergone unsuccessful surgical clipping. Three-month and 1-year control angiograms were obtained.RESULTSIn all patients but one, who had an aneurysm of the internal carotid artery, the aneurysmal sac was occluded with preservation of the parent artery and did not show recanalization on the follow-up control angiograms. In the other patient who had a wide-necked aneurysm of the internal carotid artery, the sac could not be totally obliterated and showed contrast filling in the neck remnant at 3-month angiography. None of the patients experienced neurologic deficit after treatment.CONCLUSIONBecause they are soft and retrievable, interlocking detachable coils, with their immediate coil release design, may provide an alternative to surgery in the future treatment of endovascular aneurysms.     

Complete recanalization via fibrinolytic therapy can reduce the number of ischemic territories that progress to infarction.

PURPOSETo clarify the clinical significance of fibrinolytic therapy for acute ischemic stroke.METHODSWe analyzed findings in 18 patients with occlusion of a major artery in respect to cerebral blood flow thresholds for infarction. Nine of these patients had shown complete recanalization just after the treatment, between 3.5 and 7.25 hours after symptom onset, and the other nine had shown no change. Cerebral blood flow was measured by single-photon emission CT using 99mTC-labeled hemamethylpropyleneamine oxime and assessed semiquantitatively: multiple regions of interest were placed on the section images and two parameters, the R/CL ratio and the R/CE ratio, were calculated (where R represents a mean count of the region of interest in the affected hemisphere, CL on the opposite side, and CE in the cerebellar hemisphere on the affected ischemic side).RESULTSReperfusion significantly reduced the development of infarction in the regions of interest with an R/CL ratio between 0.65 and 0.85 or an R/CE ratio between 0.55 and 0.75. No correlation was observed between the development of infarction and the duration of ischemia. The cerebral blood flow threshold in patients without recanalization was higher than that in patients with recanalization.CONCLUSIONReperfusion achieved by fibrinolytic therapy in the acute stage can save ischemic brain within a limited cerebral blood flow value.     

Novel Percutaneous Radiofrequency Ablation of Portal Vein Tumor Thrombus: Safety and Feasibility

Purpose

We report our experience of the safety of partial recanalization of the portal vein using a novel endovascular radiofrequency (RF) catheter for portal vein tumor thrombosis.

Methods

Six patients with liver cancer and tumor thrombus in the portal vein underwent percutaneous intravascular radiofrequency ablation (RFA) using an endovascular bipolar RF device. A 0.035-inch guidewire was introduced into a tributary of the portal vein and through which a 5G guide catheter was introduced into the main portal vein. After manipulation of the guide catheter over the thrombus under digital subtraction angiography, the endovascular RF device was inserted and activated around the thrombus.

Results

There were no observed technique specific complications, such as hemorrhage, vessel perforation, or infection. Post-RFA portography showed partial recanalization of portal vein.

Conclusions

RFA of portal vein tumor thrombus in patients with hepatocellular carcinoma is technically feasible and warrants further investigation to assess efficacy compared with current recanalization techniques.     

Acute Combined Revascularization in Acute Ischemic Stroke with Intracranial Arterial Occlusion: Self-expanding Solitaire Stent during Intravenous Thrombolysis

PurposeTo investigate the safety and efficacy of the self-expanding Solitaire stent used during intravenous thrombolysis (IVT) for intracranial arterial occlusion (IAO) in acute ischemic stroke (AIS).Materials and MethodsConsecutive nonselected patients with AIS with IAO documented on computed tomographic angiography or magnetic resonance angiography and treated with IVT were included in this prospective study. Stent intervention was initiated and performed during administration of IVT without waiting for any clinical or radiologic signs of potential recanalization. Stroke severity was assessed by National Institutes of Health Stroke Scale (NIHSS), and 90-day clinical outcome was assessed by modified Rankin scale (mRS), with a good outcome defined as an mRS score of 0–2. Recanalization was rated by thrombolysis in cerebral infarction (TICI) scale.ResultsFifty patients (mean age, 66.8 y ± 14.6) had a baseline median NIHSS score of 18.0. Overall recanalization was achieved in 94% of patients, and complete recanalization (ie, TICI 3 flow) was achieved in 72% of patients. The mean time from stroke onset to maximal recanalization was 244.2 minutes ± 87.9, with a median of 232.5 minutes. The average number of device passes was 1.5, with a mean procedure time to maximal recanalization of 49.5 minutes ± 13.0. Symptomatic intracerebral hemorrhage occurred in 6% of patients. The median mRS score at 90 days was 1, and 60% of patients had a good outcome (ie, mRS score 0–2). The overall 3-month mortality rate was 14%.ConclusionsCombined revascularization with the Solitaire stent during IVT appears to be safe and effective in the treatment of acute IAO.     

Correlation of Thrombectomy Maneuver Count with Recanalization Success and Clinical Outcome in Patients with Ischemic Stroke

BACKGROUND AND PURPOSE:In the treatment of acute thromboembolic stroke, the effectiveness and success of thrombus removal when using stent retrievers is variable. In this study, we analyzed the correlation of thrombectomy maneuver count with a good clinical outcome and recanalization success.MATERIALS AND METHODS:One hundred and four patients with acute occlusion of the middle cerebral artery or the terminal internal carotid artery who were treated with thrombectomy were included in this retrospective study. A good clinical outcome was defined as a 90-day mRS of ≤2, and successful recanalization was defined as TICI 2b–3.RESULTS:The maneuver count ranged between 1–10, with a median of 2. Multivariate logistic regression analyses identified an increasing number of thrombectomy maneuvers as an independent predictor of poor outcome (adjusted OR, 0.59; 95% CI, 0.38–0.87; P = .011) and unsuccessful recanalization (adjusted OR, 0.48; 95% CI, 0.32–0.66; P < .001). A good outcome was significantly more likely if finished within 2 maneuvers compared with 3 or 4 maneuvers, or even more than 4 maneuvers (P < .001).CONCLUSIONS:An increasing maneuver count correlates strongly with a decreasing probability of both good outcome and recanalization. The probability of successful recanalization decreases below 50% if not achieved within 5 thrombectomy maneuvers. Patients who are recanalized within 2 maneuvers have the best chance of achieving a good clinical outcome.

Recent trials showed that mechanical thrombectomy is effective in acute ischemic stroke caused by large vessel occlusion.^1–7 The speed and success of thrombus removal is variable.^8–12 Often, several thrombectomy maneuvers are necessary to restore antegrade flow and cerebral perfusion. However, it is uncertain whether flow restoration after multiple thrombectomy maneuvers is still followed by a good clinical outcome. Currently, there is no consensus on a maximum number of maneuver attempts in cases where the thrombus cannot be removed promptly. Hence, the decision to abort the procedure for technical futility is mostly at the discretion of the individual operator. To address this question, we retrospectively analyzed the impact of thrombectomy maneuver count on recanalization and clinical outcome.     

Risk Factors for Early Hemorrhagic Complications after Endovascular Coiling of Ruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE:The risk factors of early hemorrhagic complications after endovascular coiling are not well-known. We identified the factors affecting early hemorrhagic complications, defined as any expansion or appearance of hemorrhage shown by head CT in the initial 48 hours after coiling.MATERIALS AND METHODS:We retrospectively reviewed a series of 93 patients who underwent coiling for a ruptured saccular aneurysm between 2006 and 2012 at our hospital.RESULTS:Five patients showed early hemorrhagic complications, and all involved an expansion of the existing intracerebral hematoma immediately after coiling. The associated risk factors were accompanying intracerebral hemorrhage at onset (P < .001), postoperative antiplatelet therapy (P < .001), and thromboembolic complications (P = .044). In the accompanying intracerebral hemorrhage group, the associated risk factors were postoperative antiplatelet therapy (P = .044) and earlier initiation of coiling (9.8 ± 6.5 versus 28.1 ± 24.0 hours, P = .023). Early hemorrhagic complications were significant risk factors for worse clinical outcome (modified Rankin Scale, 2.02 ± 2.21 versus 4.4 ± 2.30, P = .022). None of the 93 patients showed further hemorrhage after the initial 48 hours after coiling.CONCLUSIONS:The accompanying intracerebral hemorrhage at onset, thromboembolic complications, postoperative antiplatelet therapy, and earlier initiation of coiling were the risk factors for early hemorrhagic complications.

A recent guideline stated that endovascular coiling should be considered if ruptured aneurysms were judged to be technically amenable to both endovascular coiling and neurosurgical clipping.¹ Consequently, the use of coiling for ruptured saccular cerebral aneurysms has been increasing. One problem is that the incidence of periprocedural hemorrhagic complications within 30 days was reportedly high in the endovascular arm of a study,² and they were reported to be associated with high mortality and morbidity.³ The risk factors for such early hemorrhagic complications are not well-known. Although the word “rebleeding” is often used for perioperative hemorrhagic complications, it is also unclear whether “rebleeding” is really caused by a rerupture of the aneurysm or is due to other mechanisms. Therefore, we analyzed cases of coiling for ruptured saccular aneurysms in which early hemorrhagic complications had occurred within 48 hours after coiling, to identify factors affecting these complications.     

Endovascular treatment of intracranial aneurysms with matrix detachable coils: midterm anatomic follow-up from a prospective multicenter registry

BACKGROUND AND PURPOSE: Polyglycolic/polylactic acid–covered platinum coils have been proposed to reduce the rate of aneurysm recanalization after endovascular treatment. A prospective and multicenter registry was conducted in France to evaluate the safety and short-term and midterm efficacy of Matrix coils. This analysis focused on anatomic midterm results.MATERIALS AND METHODS: Two hundred thirty-six patients harboring 244 ruptured or unruptured aneurysms treated via endovascular approach by using Matrix coils were included in this registry. Treatment was totally or partially performed by using Matrix coils. Anatomic results were evaluated on postoperative and last-follow-up digital subtraction angiography (DSA) by using the Raymond scale. “Recanalization” was defined as worsening, and “progressive thrombosis” was defined as improvement on the Raymond scale.RESULTS: Anatomic midterm follow-up was obtained in 165 of 236 patients (70%) harboring 171 aneurysms (range, 6–27 months; mean, 14 ± 4 months). At midterm follow-up angiography, 79 aneurysms were completely occluded (46.2%), 43 had a neck remnant (25.1%), and 49 had an aneurysm remnant (28.7%). Of 171 aneurysms, recanalization was observed in 44 patients (25.7%), including major recanalization in 18 patients (10.5%). Recanalization was more frequent if the embolized volume of aneurysm was ≤25%. Progressive thrombosis was observed in 52 aneurysms (30%). No bleeding or rebleeding was observed during the period of follow-up.CONCLUSION: The efficacy of Matrix coils in preventing recanalization was not demonstrated in our series. In agreement with previous studies using bare platinum coils, volumic occlusion was an important feature for the prediction of aneurysm recanalization. A high percentage of progressive thrombosis in incompletely treated aneurysms was observed in our series, suggesting a biologic activity of Matrix coils.

Endovascular treatment by using bare platinum coils is currently used in patients worldwide as an alternative to surgery to occlude ruptured and unruptured cerebral aneurysms.¹ The most significant limitation of the technique is aneurysm recanalization that may occur in 15%–30%^2–5 and may potentially lead to aneurysm rebleeding. The modification of the surface of bare platinum coils was proposed in the late 1990s to accelerate the biologic response to coils and subsequently reduce the rate of recanalization.^6–7The first coated coil available for clinical use was covered with a bioactive copolymer consisting of polyglycolic/polylactic acid (PGLA).⁷ Several monocentric series have been recently published regarding the short- and midterm clinical and anatomic results of Matrix detachable coils (Boston Scientific, Natick, Mass) in the treatment of cerebral aneurysms.^8–12 A small number of patients were included in most series (25–112 patients), and midterm clinical and anatomic results were not always available.We recently published the immediate clinical and anatomic posttreatment results of a large prospective multicenter registry conducted in France in 2004.¹³ In this series, the overall morbidity and mortality rates of patients with intracranial aneurysms treated with Matrix detachable coils were within the ranges of previously published series using bare platinum coils. Similar results were reported by other teams.^8–12The potential influence of PGLA platinum coils on anatomic results in the time course after endovascular treatment of intracranial aneurysms remains debated. In a preliminary study, Kang et al⁸ found that the recanalization rate by the use of PGLA-coated coils was similar to that previously reported with the use of bare platinum coils. More recently, Niimi et al¹² found a higher recanalization rate with Matrix coils, whereas Murayama et al,¹¹ in the largest series published, to our knowledge, showed that anatomic results at midterm follow-up were better with Matrix coils compared with the Guglielmi detachable coil (GDC, Boston Scientific) system.The objective of the present study was to evaluate the midterm anatomic results in 165 patients harboring 171 intracranial aneurysms treated by Matrix coils and included in a prospective multicenter French registry.     

Frequency and Relevance of Anterior Cerebral Artery Embolism Caused by Mechanical Thrombectomy of Middle Cerebral Artery Occlusion

BACKGROUND AND PURPOSE:Spread of thrombus material in previously unaffected vessels is a potential hazard of mechanical thrombectomy, but it has not yet been investigated in detail, to our knowledge. Our purpose was to evaluate the frequency and relevance of these events in mTE of M1 occlusions.MATERIALS AND METHODS:We retrospectively reviewed all patients treated for isolated M1 occlusion between January 2008 and July 2012. Angiographic images were analyzed to assess emboli in anterior cerebral artery branches induced by mTE and associated devices. Recanalization attempts in the ACA were reported as well as technical success and adverse events of rescue therapies. ACA infarcts on follow-up imaging served as a surrogate for clinical relevance. ACA infarcts were quantified volumetrically and assessed visually for involvement of motor or supplementary motor areas.RESULTS:New ACA emboli occurred in 12 of 105 (11.4%) M1 recanalization procedures and were caused by a stent-retriever in 11 intances. Attempts to recanalize the ACA were made in 6 patients and were deemed technically successful in 5 with no adverse events. We detected 6 (5.7%) new infarcts on follow-up imaging with an average volume of 26.9 cm³. Involvement of motor or supplementary motor areas was seen in 4 (3.8%) cases. Three patients developed ACA infarcts despite successful endovascular ACA recanalization.CONCLUSIONS:The frequency of ACA emboli in mTE of M1 occlusions is relevant, causing ACA infarcts in 5.7% of patients; 3.8% of emboli were likely to hamper motor-function recovery. Endovascular recanalization of major ACA branches reduced the incidence of infarcts with no adverse events.

Mechanical thrombectomy is an effective tool for recanalization of occluded cerebral vessels in acute stroke treatment. This is especially true because stentlike retrievers were added to the already-existing armamentarium of devices, allowing even higher success rates.¹ Recently this observation was proved in a randomized trial comparing the Solitaire FR stent-retriever (Covidien Neurovascular, Irvine, California) and the Merci thrombectomy device (Merci retriever; Concentric Medical, Mountain View, California).² The improved morphologic results translated into a significantly better clinical outcome 3 months after the ischemic event. Similar results were shown in the Thrombectomy Revascularization of Large Vessel Occlusions in Acute Ischemic Stroke Trial comparing the Trevo Pro Retriever (Stryker, Kalamazoo, Michigan) and the Merci thrombectomy device.³Even though angiographic and, in part, clinical results of mTE are promising, adverse events might occur. The main interest is in intracranial hemorrhage, but embolism to previously unaffected vessels is another adverse event of catheter-directed treatment that might hamper patient recovery. Although this also happens in IVT when thrombus material resolves and fragments are carried into peripheral vessels, the phenomenon of thrombus loss can be observed directly in endovascular treatment and therefore attracts attention. Due to improper embedding of the thrombus into the device, fragments may embolize not only into the downstream arterial territory but also into side branches proximal to the primary occlusion site. The aim of our study was to determine the frequency of thrombus loss into proximal vessels and to assess the relevance of this phenomenon in mTE of middle cerebral artery occlusion.     

Effects of Antecedent Intravenous Thrombolysis on Endovascular Treatment of Acute Stroke Using Tirofiban

PurposeTo investigate whether preceding intravenous thrombolysis combined with tirofiban in patients with acute ischemic stroke undergoing endovascular treatment is safe and effective.Materials and MethodsConsecutive data were identified for patients who experienced acute ischemic stroke and were admitted to 2 comprehensive stroke centers from January 2015 to August 2021. All patients were divided into 2 groups—a thrombolytic with tirofiban group and a tirofiban-alone group—on the basis of whether intravenous thrombolysis before emergency endovascular angioplasty was used. Multivariate regression and propensity adjustment analyses were performed to characterize differences in safety and clinical outcomes between the 2 groups.ResultsOf 373 eligible patients, 111 (29.7%) were treated with thrombolysis with tirofiban. There was a significant difference in the rate of any intracerebral hemorrhage (35.1% vs 24.8%; P = .04) but not in the rates of symptomatic intracerebral hemorrhage (16.2% vs 11.5%; P = .23) and reocclusion at 24 hours (5.4% vs 7.6%; P = .51) between the 2 groups. Multivariate regression analysis revealed that intravenous thrombolysis was not associated with any or symptomatic intracerebral hemorrhage, artery occlusion, functional outcome, or death at the 3-month follow-up (all adjusted P > .05). After propensity adjustment, the thrombolytic with tirofiban group showed nonsignificant rates of clinical and safety outcomes compared with those of the tirofiban-alone group (all P > .05).ConclusionsTirofiban may be used without increasing the risk of adverse events in selected patients who experienced ischemic stroke and were treated with intravenous thrombolysis and endovascular therapy.