Acute Reocclusion Research Articles

Outcomes of Catheter Directed Thrombolysis for Early and Late Re-occlusions in Acute Lower Limb Ischemia.

Acute lower limb ischemia (ALI) is a sudden decrease in arterial limb perfusion due to an arterial blockage, threatening limb and life. Catheter-directed thrombolysis (CDT) is a minimally invasive procedure to remove such obstructions. However, approximately one-third of patients endure a re-occlusion after successful CDT. This study aimed to investigate the short- and long-term outcomes of CDT for early (<1 year) and late (>1 year) re-occlusions. This retrospective multicenter study reviewed patients from 2 medical centers with an acute arterial re-occlusion of the lower limb after successful CDT between December 1996 and April 2021. The primary endpoints were angiographic success, defined as thrombus dissolution over 95% with outflow to at least 1 crural artery, and clinical success, defined as a score of ≥1 on the Rutherford scale for assessing changes in clinical status. Secondary endpoints included bleeding complications, patency, amputation, and mortality. Kaplan-Meier analyses were used to estimate patency, survival, and freedom from amputation. Seventy-seven cases were included, with 52 early re-occlusions (<1 year) and 25 late re-occlusions (>1 year). The median time to re-occlusion since the last CDT treatment was 4 months in the early re-occlusion group and 24 months in the late re-occlusion group. Angiographic success was achieved in 73% of early and 64% of late re-occlusions. Clinical success rates were 80.8% for the early and 80.0% of the late re-occlusion cases. Major bleeding occurred in 2% of the early and 8% of the late re-occlusion group. Patients were followed up until symptoms or signs of limb ischemia were resolved, with a median follow-up time of 15 months for the early and 22 months for the late re-occlusion group. During follow-up, secondary re-occlusions were observed in 59.6% of the early and 44% in the late group. Cumulative amputation rates at 1, 5, and 8 years were 36%, 36%, and 52% for early and 18%, 30%, and 30% for the late re-occlusions, respectively. In our experience, CDT is an effective short-term revascularization strategy for the majority of patients with both early and late re-occlusions. Long-term results are limited by secondary re-occlusions and limb loss. Catheter-directed thrombolysis (CDT) is a well-established treatment for acute lower limb ischemia (ALI). Re-occlusions after successful treatment are, however, observed in almost a third of the patients. Yet, the outcomes of CDT for re-occlusions for patients who were previously treated with CDT are not well known. This study showed that CDT is effective in achieving revascularization in cases of early and late re-occlusion after treatment for ALI, but the risk for further re-occlusions is high. Future studies should focus on maintaining patency after successful CDT for ALI.

Early neurological changes following endovascular therapy for acute stroke due to intracranial atherosclerotic disease

BackgroundEndovascular therapy (EVT) reduces functional disability in patients with acute large vessel occlusion (LVO). However, the early neurological change after EVT may be limited in patients with intracranial atherosclerotic disease (ICAD). MethodsWe analyzed the Japanese Registry of NeuroEndovascular Therapy (JR-NET) 4 which was a retrospective, nationwide, multicenter registry of patients with LVO between 2015 and 2019. We compared the early neurological change, efficacy and safety of EVT for acute LVO in ICAD and other etiologies. The primary outcome was NIHSS improvement ≥10 points, and secondary outcome were NIHSS worsening ≥4 points 7 days after EVT, effective reperfusion rate, 30-day functional outcomes, and safety outcomes. ResultsAmong the 6710 enrolled patients, 610 (9.1%) had ICAD. The ICAD group was younger (mean 72.0 vs. 75.8 years) and predominantly male (63.4% vs. 56.0%), had lower NIHSS scores before EVT (median 16 vs. 18), and underwent percutaneous transluminal angioplasty and stenting more frequently (43.0% vs. 4.4%, 12.3% vs. 4.4%). In the ICAD group, NIHSS improvement was significantly lower (adjusted odds ratio (aOR) [95% confidence interval (95%CI)] 0.52 [0.41–0.65]), NIHSS worsening was significantly higher (aOR [95%CI] 1.76 [1.31–2.34]), and effective reperfusion was significantly lower (aOR [95%CI] 0.47 [0.36–0.60]). Fewer patients with ICAD had modified Rankin scale 0–2 at 30 days (aOR [95%CI] 0.60 [0.47–0.77]). The risk of acute reocclusion was more prominent in the ICAD group (aOR [95%CI] 4.03 [1.98–8.21]). ConclusionsImprovement in neurological severity after EVT was lower in patients with LVO and ICAD.

Effect of Standardized Perioperative Management on EEG Indexes and Nerve and Limb Functions of Patients with Acute Cerebral Infarction Undergoing Mechanical Thrombectomy.

Objective To explore the application value of standardized perioperative management in mechanical thrombectomy for acute cerebral infarction. Methods 98 patients with acute cerebral infarction admitted to our hospital from January 2019 to January 2022 were selected as the study sample in this study, and all patients were given the standardized perioperative management. According to the interventional methods, they were divided into the thrombolytic treatment group (arteriovenous combined thrombolysis, n = 49) and mechanical thrombectomy group (mechanical thrombectomy, n = 49) to compare the nerve function, limb function, thrombolysis in myocardial infarction (TIMI) flow grade, symptomatic intracranial hemorrhage within 24 hours, acute vascular reocclusion, and the death status within 1 year and incidence of adverse events in 90 days of the two groups after treatment. Results After treatment, the values of brain symmetry index (BSI) and power ratio indices (DTABR) in the two groups were obviously lower than those before treatment (P < 0.05), and the values of BSI and DTABR in the mechanical thrombectomy group were lower than those in the thrombolytic treatment group (P < 0.05). According to the statistical data of National Institutes of Health Stroke Scale (NIHSS) score in patients, the NIHSS scores of the two groups after treatment were visibly decreased (P < 0.05), while the NIHSS score in the mechanical thrombectomy group after treatment was lower than that in the thrombolytic treatment group (P < 0.05). The proportion of modified Rankin scale (mRS) score < 3 in the mechanical thrombectomy group was distinctly higher than that in the thrombolytic treatment group (P < 0.05). The proportion of TIMI flow grade ≥ 2 in the mechanical thrombectomy group was significantly higher than that in the thrombolytic treatment group (P < 0.05). The rate of symptomatic intracranial hemorrhage within 24 hours in the mechanical thrombectomy group was lower than that in the thrombolytic treatment group (P < 0.05), with the indistinctive difference between the two groups (P > 0.05). The incidence of acute vascular reocclusion in the mechanical thrombectomy group was markedly lower than that in the thrombolytic treatment group (P < 0.05). There was no significant difference in 1-year mortality between the two groups (P > 0.05). In the mechanical thrombectomy group, there were 1 case of gingiva bleeding, 1 case of hemorrhinia, and 2 cases of recurrent cerebral infarction in 90 days, with a total of 4 cases (8.16%), while in the thrombolytic treatment group, there were 4 cases of gingiva bleeding, 4 cases of hemorrhinia, and 15 cases of recurrent cerebral infarction in 90 days, with a total of 23 cases (46.94%), indicating that the incidence of adverse events in 90 days in the mechanical thrombectomy group was significantly lower than that in the thrombolytic treatment group (P < 0.05). Conclusion The standardized perioperative management is effective in patients with acute cerebral infarction who were treated with arteriovenous combined thrombolysis or mechanical thrombectomy, which can improve the neurological function and physical function of patients. However, the mechanical thrombectomy has a better improvement effect on the neurological function and physical function of patients, with the relatively better safety, thrombolytic effect, and long-term prognosis.

Endovascular Treatment of ICAS Patients: Targeting Reperfusion Rather than Residual Stenosis.

Background and Purpose: Previous studies showed that acute reocclusion after endovascular therapy is related to residual stenosis. However, we observed that reperfusion status but not residual stenosis severity is related to acute reocclusion. This study aimed to assess which factor mention above is more likely to be associated with artery reocclusion after endovascular treatment. Methods: This study included 86 acute ischemic stroke patients who had middle cerebral artery (MCA) atherosclerotic occlusions and received endovascular treatment within 24 h of a stroke. The primary outcomes included intraprocedural reocclusion assessed during endovascular treatment and delayed reocclusion assessed through follow-up angiography. Results: Of the 86 patients, the intraprocedural reocclusion rate was 7.0% (6/86) and the delayed reocclusion rate was 2.3% (2/86). Regarding intraprocedural occlusion, for patients with severe residual stenosis, patients with successful thrombectomy reperfusion showed a significantly lower rate than unsuccessful thrombectomy reperfusion (0/30 vs. 6/31, p = 0.003); on the other hand, for patients with successful thrombectomy reperfusion, patients with severe residual stenosis showed no difference from those with mild to moderate residual stenosis in terms of intraprocedural occlusion (0/30 vs. 0/25, p = 1.00). In addition, after endovascular treatment, all patients achieved successful reperfusion. There was no significant difference in the delayed reocclusion rate between patients with severe residual stenosis and those with mild to moderate residual stenosis (2/25 vs. 0/61, p = 0.085). Conclusion: Reperfusion status rather than residual stenosis severity is associated with artery reocclusion after endovascular treatment. Once successful reperfusion was achieved, the reocclusion occurrence was fairly low in MCA atherosclerosis stroke patients, even with severe residual stenosis.

Dual antiplatelet use in the management of COVID-19 associated acute ischemic stroke reocclusion.

SARS-CoV-2 (COVID-19) infection is associated with acute ischemic stroke (AIS), which may be due to a prothrombotic state. Early reports have suggested high rates of reocclusion following mechanical thrombectomy (MT) with poor radiographic and clinical outcomes. We report our early experience using intra-procedural antithrombotics to address SARS-CoV-2 reocclusion. We identified 6 patients that experienced early reocclusion after MT for COVID-19-associated AIS through retrospective chart review abstracting their basic demographics, COVID-19 status, and stroke management. All these patients were treated after reocclusion with aspirin and cangrelor intra-procedurally, the latter of which was converted to ticagrelor post-procedurally. Some patients additionally received argatroban infusion intraprocedurally. Mean age was 54. There were 3 post-procedural and 3 intra-procedural re-occlusions. After repeat thrombectomy and treatment with aspirin and cangrelor, those with post-procedure reocclusion did not show further reocclusion, while those with intra-procedural reocclusion showed radiographic improvement with intraprocedural cangrelor administration. Outcomes for these patients were poor, with a median mRS of 4. Two patients developed petechial hemorrhage of their stroke which was managed conservatively, and one developed a retroperitoneal hemorrhage from femoral access requiring transfusion. There were no patients who developed new parenchymal hematomas. COVID-19 AIS may be associated with a hypercoagulable state which risks malignant reocclusion complicating MT. We found antithrombotic treatment periprocedural cangrelor with or without argatroban transitioned to oral aspirin with ticagrelor to be a viable method for management of these patients.

Efficacy of intravenous thrombolysis combined with mechanical stent interventional thrombectomy on acute ischemic stroke.

To investigate the efficacy and safety of intravenous thrombolysis combined with mechanical stent interventional thrombectomy in the treatment of acute ischemic stroke. A retrospective analysis was carried out for clinical data of 118 patients with acute ischemic stroke. The patients enrolled were divided into control group (recombinant tissue plasminogen activator (rt-PA) intravenous thrombolysis) and thrombectomy group (mechanical stent interventional thrombectomy based on rt-PA intravenous thrombolysis). The vascular recanalization rate and clinical efficacy after treatment were compared between the two groups. National Institutes of Health Stroke Scale (NIHSS) was used to identify the degree of neurological impairment in all patients before and after treatment, and Barthel Index was used to assess their activity of daily living. Moreover, the changes in the levels of T-lymphocyte subpopulation in peripheral blood and immuno-inflammatory factors before and after treatment were compared, and prognosis of patients and incidence of adverse reactions were recorded. The response rate inthrombectomy group (93.2%) was significantly better than that in control group (76.3%). The NIHSS sore and modified Rankin scale (mRS) score after treatment were significantly lower than those before treatment, while the Barthel Index after treatment was distinctly higher than that before treatment. The NIHSS score and mRS score in thrombectomy group obviously declined compared with those in control group at 1 month after treatment. The Barthel Index in thrombectomy group was obviously higher than that in control group at 1 month and 2 months after treatment. Levels of cluster of differentiation 3 (CD3)+, CD3+CD4+, CD4+/CD8+ and natural killer (NK) cells in peripheral blood at 6 months after treatment evidently rose compared with those before treatment, while level of CD3+CD8+ evidently declined compared with that before treatment. In thrombectomy group, levels of CD3+, CD3+CD4+, CD4+/CD8+ and NK cells were markedly higher than those in control group, while the level of CD3+CD8+ was markedly lower than that in control group. Besides, in thrombectomy group, levels of serum osteopontin (OPN), malondialdehyde (MDA) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were evidently lower than those in control group at 1 month after treatment, while the level of serum superoxide dismutase (SOD) was evidently higher than that in control group. Compared with that in control group, the acute vascular reocclusion rate in thrombectomy group was significantly decreased at 3 months after treatment (10.2% vs. 22.0%). Intravenous thrombolysis combined with mechanical stent interventional thrombectomy can effectively promote the vascular recanalization, improve the neurological function and activity of daily living of patients, reinforce the immunological function, inhibit the oxidative stress response and improve the prognosis of patients.

Antiplatelet Therapy During Emergent Extracranial Internal Carotid Artery Stenting: Comparison of Three Intravenous Antiplatelet Perioperative Strategies

IntroductionGuidelines for antiplatelet therapy administration, during emergent stenting for extra-cranial internal carotid artery (EC-ICA) occlusion in the setting of acute ischemic stroke (AIS) are lacking. Different antiplatelet regimen are used in association to endovascular therapy (EVT) for the treatment of EC-ICA lesions. We aimed to compare the clinical and radiological effects of three intravenous antiplatelet agents used during emergent EC-ICA stenting. Material and MethodsClinical data were collected from January 2015 to December 2019 in a monocentric prospective registry of AIS patients treated by EVT. All patients who underwent emergent EC-ICA stenting were sorted regarding the intravenous antiplatelet agent used during the procedure. ResultsAmong 218 patients treated by EVT for an EC-ICA occlusion of the anterior circulation during the study period, 70 underwent an emergent stenting of the EC-ICA. 60 were included in the present study, 9 received intravenous (IV) Cangrelor, 8 IV abciximab and 43 Aspirin. The rate of favorable neurological outcome, defined as modified Rankin Scale (mRS) ≤ 2 at three months were better in the Cangrelor and Aspirin groups (66,7% and 58,1%, respectively) than in the Abciximab group (37,5%), as well as, the rate of any intracranial ICH (22,2% and 37,2% vs 62,5%). The rate of acute stent reocclusion was similar between groups. ConclusionWhen used as a rescue treatment during emergent stenting of EC-ICA, Cangrelor and Aspirin present a better safety profile than Abciximab, with less intracranial hemorrhages and a higher rate of good clinical outcome. Additional studies are needed to confirm these findings.

Preliminary study of treatment for chronic symptomatic internal carotid artery long-segmental occlusion

Objective To evaluate the feasibility, safety and efficacy of the treatment of chronic symptomatic internal carotid artery long-segmental occlusion. Methods Fifty-one cases of chronic symptomatic internal carotid artery long-segmental occlusion (arterial occlusion more than 2 anatomical segments) who were treated with hybrid surgery (plaque located at the carotid sinus) or endovascular revascularization (plaque located at the distal end of the internal carotid artery occlusion) from May 2015 to May 2018 were reviewed. Recanalization, perioperative complications, stroke events, and reocclusion events during the follow-up period were recorded. Results The occlusion was recanalized successfully in 45 of 51 patients (88.2%, 45/51), 6 patients failed because the guidewire could not cross the distal arterial occlusion. And the technical success rate was 96.0% (24/25) in hybrid surgery and 80.8% (21/26) in endovascular revascularization. Perioperative complications occurred in 2 patients who underwent combined endovascular treatment. One patient had a small branch embolism due to intraoperative thrombus shift, and 1 patient had large area cerebral infarction. The complications occurred in 2 patients who underwent thybrid surgery, including 1 case of internal carotid cavernous fistula and 1 case of acute reocclusion of internal carotid artery. Forty-four patients with successful operation received clinical follow-up, with the median follow-up time of 24 months (7-43 months). No recurrent stroke and death occurred during the follow-up period. Clinical symptoms were improved in 34 cases. Totally 44 patients received imaging follow-up, and during the median imaging follow-up time of 8 month (4-28 months), 6 cases had reocclusion, and 2 cases had restenosis. Conclusion The treatment of chronic symptomatic internal carotid artery long-segmental occlusion is technically feasible and safety with good short-term efficacy. However, its exact efficacy remains to be confirmed by long-term follow-up studies with large samples. Key words: Carotid artery, internal; Arterial occlusive diseases; Radiology, interventional; Endovascular procedures

Prognostic risk factors for recurrent acute lower limb ischemia in patients treated with intra-arterial thrombolysis

ObjectiveThe objective of this study was to assess factors predisposing patients to recurrent acute lower limb ischemia (RALLI). MethodsAcute lower limb ischemia patients treated with catheter-directed thrombolysis (CDT) at Tampere University Hospital and Turku University Hospital between March 2002 and December 2015 were included. The patients' baseline demographics, comorbidities, and other characteristics were assessed retrospectively. Significant factors revealed by univariable analysis were tested in a multivariable model for associations with RALLI. A patency analysis was performed, and the risks of reocclusion were identified. The limb salvage rates after reocclusion were evaluated. ResultsAltogether, 303 consecutive patients with a mean age of 71 years (standard deviation, 11.8 years) were included. Of them, 159 (52.5%) were men. A total of 164 (54.1%) native arterial and 139 (45.9%) bypass graft occlusions were initially treated with CDT. On completion of CDT, 204 additional endovascular or conventional surgical procedures on 203 patients were performed to obtain adequate distal perfusion. During a median follow-up of 40 months (interquartile range, 69 months), 40 (24.4%) cases of RALLI occurred in native arteries and 90 (64.7%) in bypass graft patients (P < .001). In native arteries, the absence of appropriate anticoagulant and antiplatelet medication was independently associated with the development of acute reocclusions (hazard ratio, 6.51) in the Cox multivariable regression analysis. The patency rates were 86.6%, 72.2%, and 68.0% at 1 year, 5 years, and 9 years, respectively. In bypass grafts, worsened tibial runoff (crural index III: hazard ratio, 2.40) was independently associated with RALLI. The respective patency rates were 60.5%, 34.0%, and 29.2% for synthetic conduits and 30.8%, 20.5%, and 13.7% for autologous vein grafts at 1 year, 5 years, and 9 years. Altogether, 38 (29.2%) major amputations were performed on patients with reocclusions. Patients with synthetic conduits demonstrated superior limb salvage rates after reocclusion in comparison to native arteries or vein grafts (P = .025). ConclusionsAppropriate post-thrombolytic antiplatelet or anticoagulant treatment after native arterial events is of great importance, but additional data are needed to improve treatment algorithms. Adequate outflow in bypass graft patients is crucial. Patients with prosthetic bypass grafts have superior limb salvage rates after reocclusion.

Rescue Intracranial Stenting After Failed Mechanical Thrombectomy for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Up to 20% of patients fail to achieve reperfusion with modified Thrombolysis in Cerebral Infarction (mTICI) scores of 0-1 after mechanical thrombectomy (MT). Furthermore, underlying intracranial atherosclerotic disease, particularly when associated with >70% residual or flow limiting stenosis, is associated with higher rates of failed MT and high failure risk MT. The aim of this study was to systematically review the procedural and clinical outcomes in patients with failed MT and high failure risk MT. We also explored differences between patients receiving acute rescue stenting compared with medical management alone. A systematic literature search was conducted in Ovid MEDLINE, PubMed, Embase, andCochrane online scientific publication databases for English language publications from their date of inception until October 2018. Studies including adult patients with acute ischemic stroke because of emergent large vessel occlusion with failed (mTICI score 0-1) or high failure risk MT within the anterior circulation who underwent rescue stenting were included. A systematic review and meta-analysis of proportions was performed. Rescue intracranial stenting after failed MT or high failure risk MT results in improved clinical outcomes compared with patients without stenting (48.5% vs. 19.7%, respectively; P < 0.001), without an increase in the rate of symptomatic intracranial hemorrhage, despite additional use of antiplatelet agents (9.7% vs. 14.1%, respectively; P= 0.04). In patients who fail initial attempts at MT or are high risk for acute reocclusion, rescue intracranial stenting could be considered with the aim to improve functional outcomes. Antiplatelet agents do not increase the risk of hemorrhage in these patients.

Endovascular recanalization of symptomatic non-acute intracranial artery occlusion: Procedural and mid-term clinical outcomes in the anterior circulation.

Symptomatic non-acute intracranial arterial occlusion (NAICO) is not uncommon. We report a single-center experience of the feasibility and safety of endovascular treatment of anterior circulation NAICO and summarize the outcomes of patient groups with successful or failed recanalization. Patients who underwent endovascular therapy for intracranial arterial stenosis between January 2010 and May 2017 were retrospectively reviewed. Thirty-eight patients with symptomatic NAICO (symptom onset > 24 hours) in the anterior circulation were identified. Successful recanalization was achieved in 76.3% of patients (29/38). Intraprocedural events occurred in 10.5% (4/38), including intima dissection (n = 1), parent artery rupture (n = 1) and acute in-stent thrombosis (n = 2). Mean follow-up duration after successful recanalization was 36.5 months. One patient died 68 days after the procedure because of a newly developed posterior circulation stroke. Acute reocclusion was observed in two patients (6.7%); subacute or delayed reocclusion was observed in three patients (10%). Good final outcome (modified Rankin Scale score ≤ 2) was achieved in 25 of 28 patients (89.3%) at three months. Mean follow-up duration of the nine patients with failed recanalization was 41.4 months. Three patients underwent extra-intracranial bypass for worsening symptoms. The other six patients showed stable or improved neurological status with antiplatelet medications. Good final outcome was achieved in eight of nine patients (88.9%) at three months. Endovascular revascularization can be a viable option with an acceptable safety profile in selected patients with symptomatic NAICO in the anterior circulation. Further characterization of aborted cases would facilitate proper patient selection for endovascular treatment.

Deferred versus conventional stent implantation in patients with acute ST-segment elevation myocardial infarction: An updated meta-analysis of 10 studies

BackgroundWe sought to evaluate safety and efficacy of the deferred stenting versus immediate stent implantation of infarct-related arteries in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). MethodsA meta-analysis using random-effects models were conducted. The primary outcome, major adverse cardiac events (MACE), was a composite of all-cause mortality, myocardial infarction (MI), any unplanned target vessel revascularization (TVR), and hospitalization due to cardiac cause. Periprocedural composite events were composed of acute re-occlusion, no-reflow/slow flow, or distal embolization. ResultsSeven non-randomized registries and three randomized trials comparing outcomes of deferred versus immediate stenting in infarct-related arteries of 2281 STEMI patients were selected. Risk of MACE between deferred or immediate stenting did not differ significantly (rates, 12.8% vs 15.0%; pooled RR=0.68, 95% CI: 0.43–1.06; p=0.087; I2=26.8%). Deferred stenting was associated with significantly reduced risk of periprocedural composite events (rates, 5.3% vs 10.2%; pooled RR=0.36, 95% CI: 0.18–0.69; p=0.002; I2=68.0%) and flow abnormality in infarct-related arteries (rates, 3.8% vs 8.4%; pooled RR=0.29, 95% CI: 0.14–0.61; p=0.001; I2=58.1%). However, clinical outcomes including all-cause mortality, MI, or any unplanned TVR, were unaffected. Meta-regression indicated a significant relationship between prolonged total ischemic and reduced risk of MACE after deferred stenting (OR=0.994, 95% CI: 0.990–0.998; p=0.027; I2 residual 0.0%, adjusted R2=100.0%). ConclusionsAlthough deferred stenting carried significantly lower risk of periprocedural composite events and abnormal flow in patients undergoing primary PCI for STEMI, such benefits had no impact on MACE, which did not differ significantly by timing of stent placement.

Incidence and Clinical Significance of Acute Reocclusion after Emergent Angioplasty or Stenting for Underlying Intracranial Stenosis in Patients with Acute Stroke.

A major concern after emergent intracranial angioplasty in cases of acute stroke with underlying intracranial stenosis is the acute reocclusion of the treated arteries. This study reports the incidence and clinical outcomes of acute reocclusion of arteries following emergent intracranial angioplasty with or without stent placement for the management of patients with acute stroke with underlying intracranial atherosclerotic stenosis. Forty-six patients with acute stroke received emergent intracranial angioplasty with or without stent placement for intracranial atherosclerotic stenosis and underwent follow-up head CTA. Acute reocclusion was defined as "hypoattenuation" within an arterial segment with discrete discontinuation of the arterial contrast column, both proximal and distal to the hypoattenuated lesion, on CTA performed before discharge. Angioplasty was defined as "suboptimal" if a residual stenosis of ≥50% was detected on the postprocedural angiography. Clinical and radiologic data of patients with and without reocclusion were compared. Of the 46 patients, 29 and 17 underwent angioplasty with and without stent placement, respectively. Acute reocclusion was observed in 6 patients (13%) and was more frequent among those with suboptimal angioplasty than among those without it (71.4% versus 2.6%, P < .001). The relative risk of acute reocclusion in patients with suboptimal angioplasty was 27.857 (95% confidence interval, 3.806-203.911). Furthermore, a good outcome was significantly less frequent in patients with acute reocclusion than in those without it (16.7% versus 67.5%, P = .028). Acute reocclusion of treated arteries was common after emergent intracranial angioplasty with or without stent placement in patients with acute stroke with intracranial atherosclerotic stenosis and was associated with a poor outcome. Suboptimal results of angioplasty appear to be associated with acute reocclusion, irrespective of whether stent placement was performed.

Chapter 55 - Vascular imaging: ultrasound

The complexity of current stroke treatments requires detailed vascular imaging information. Vascular imaging using ultrasound is a safe, inexpensive, and portable technique that provides continuous real-time hemodynamic information, which allows flow changes to be monitored over prolonged time. Ultrasound imaging is in continuous development, which has led to a growing number of situations where ultrasound can be helpful, foremost in dynamic and rapidly changing clinical scenarios like acute stroke. The aim of this chapter is to review the main indications of vascular ultrasound in acute stroke, including extracranial steno-occlusive lesions diagnosis and its consequences on distal vasculature, intracranial stenosis diagnosis, acute intracranial occlusion, recanalization, and reocclusion diagnosis and monitoring, therapeutic sonothrombolysis, and vasospasm after subarachnoid hemorrhage.

Delayed Stenting for ST-Elevation Acute Myocardial Infarction in Daily Practice: A Single-Centre Experience

BackgroundThe minimalist immediate mechanical intervention (MIMI) strategy aims to restore normal anterograde flow in the culprit artery (by using manual thrombectomy or small-sized balloon predilation) and to defer potential stent implantation. This study evaluated the applicability and midterm clinical results of the MIMI strategy for ST-elevation myocardial infarction (STEMI) management. MethodsThis observational study included consecutive patients admitted for ongoing STEMI (<24 hours' evolution) at 1 institution between June 2010 and June 2013. Revascularization was performed at the physician's discretion. We compared retrospectively “intentional immediate stenting” (standard technique) and “intentional delayed stenting” (MIMI technique). ResultsTwenty percent of the 279 included patients were treated with the MIMI strategy. These patients were significantly younger and were more frequently men and smokers compared with patients who underwent the standard procedure. The rate of acute reocclusion of the culprit artery related to STEMI in the MIMI group was 1.8%. Drug-eluting stents were used more frequently in the MIMI group (52% vs 27% in the standard group; P < 0.001). The culprit lesion was stented less frequently in the patients treated with MIMI compared with patients in the other group (28.5% vs 9%; P < 0.001). The 1-year actuarial survival free from major adverse cardiovascular events was higher in the MIMI group than in the standard group (96.3% ± 1.8% vs 83.8% ± 2.5%; P = 0.01). ConclusionsThe MIMI strategy can be applied in selected patients with STEMI. In our centre, this strategy is associated with less systematic culprit lesion stenting and more implantation of drug-eluting stents. However, this needs to be evaluated further in a randomized trial.

THIRTY-YEARS OF STANDALONE PCI: EXPERIENCE FROM A HIGH VOLUME CANADIAN CENTRE

The safety of PCI without on-site cardiac surgery has been an ongoing debate since the early 1980’s. However, success rate has improved and acute reocclusion rate reduced since the introduction of stents and new antiplatelet therapy in the 1990s. PCI is now the predominant revascularization modality for coronary disease(CAD) worldwide and where available, primary PCI has become the standard of care for STEMI. In Ontario, 5 new standalone PCI centres have been established in the past 14 years. However, elective standalone PCI remained a Class IIb indication in the 2011 ACCF/AHA/SCAI guidelines. Nonetheless, the recent C-PORT and MASS COM trials in the US concluded that in non-emergency patients, standalone PCI is non-inferior to that performed in centres with on-site cardiac surgery. The Royal Alexandra Hospital performed the first standalone PCI in Canada in 1981 and has provided PCI services to a full spectrum of CAD patients ranging from elective, in-hospital to emergency cases with STEMI and cardiogenic shock. Surgical backup is located at the University of Alberta Hospital 6 km away. Joint case conference is conducted weekly with the cardiac surgery program. In the first 30 years, 23,261 PCIs were performed. We report our 30-year standalone experience, which we believe is the largest single centre experience in literature to date. PCI volumes, clinical and procedural characteristics, lesion success, emergency coronary bypass and mortality rates were collected and reported for the 30-year period. Results for 2006-2011, a period most relevant to current practice were compared with the most recent US PCI data. PCI volumes, CCS Class 4 patients, ad hoc, rescue and primary PCIs all increased significantly over the 30-year period. Success and emergency coronary bypass rates also improved (see Table). For 2006-11, our success, emergency CABG and 30-day mortality rates (96.5, 0.04, 1.1%) compared favorably with National Cardiovascular Data Registry (93-94, 0.3-0.4, 1.2-1.7 %*), C-PORT (93.4-94.1, 0.2, 0.8-0.9 %**) & MASS COM(95.6-97.1, 0.1-0.3, 0.3-0.7 %). PCIs can be performed safely in an experienced, high volume standalone centre with excellent success and very low complication rates. These results support the safety of establishing new standalone PCI centres to meet the growing population demand for percutaneous revascularization for coronary disease.

Transpopliteal balloon-assisted excimer-laser atherectomy for the treatment of chronic femoropopliteal occlusions: feasibility and initial results.

PURPOSERecanalization of chronic total occlusions (CTOs) of the femoropopliteal arteries depends on a successful lesion crossing with the guide wire. The aim of this retrospective study was to evaluate the safety, feasibility, and the primary results of retrograde recanalization of CTOs with balloon-assisted excimer–laser atherectomy (ELA) via a transpopliteal approach after failed antegrade attempts.METHODSA total number of 15 patients (10 male, 5 female) with a mean age of 68.5 years (range: 43–91 years) treated with retrograde transpopliteal ELA in the years 2009–2012 were included retrospectively. After unsuccessful antegrade recanalization attempts with conventional guide wires and catheters, patients were treated with a retrograde recanalization attempt via a transpopliteal access using an excimer laser, followed by pressure-only balloon angioplasty (POBA). The mean length of the CTOs in the femoropopliteal arteries was 17.8 ± 5.4 cm (range: 9–29 cm).RESULTSTechnically successful recanalization was achieved in 14 of 15 patients. Provisional stenting was done in two cases. There were no major adverse events regarding the laser atherectomy or popliteal access site. One acute reocclusion was observed in the first 48 hours after intervention. The ankle-brachial Index increased from preinterventional 0.45 ± 0.07 to 0.77 ± 0.29 (P < 0.05) in the follow-up period (1.5 months), resulting in a primary patency of 80%.CONCLUSIONThe retrograde ELA for recanalization of chronic femoropopliteal occlusions via a popliteal access turned out to be a safe and effective procedure with promising primary results. Thus it may be an endovascular treatment option for long chronic occlusions after failed antegrade recanalization or in patients who are not suitable for surgery.

Perioperative Complications of Recanalization and Stenting for Symptomatic Nonacute Vertebrobasilar Artery Occlusion

Endovascular recanalization and stenting has been used to treat patients with symptomatic nonacute intracranial vertebrobasilar artery occlusion (VBAO) refractory to aggressive medical treatment. This study was performed to analyze the perioperative complications of the procedures. Between February 2010 and March 2012, 27 consecutive patients (24 men, 3 women; age: 57 ± 10 years) with symptomatic, nonacute intracranial VBAO including 12 basilar artery occlusions and 15 vertebral artery occlusions were collected and retrospectively analyzed. The median time between symptom onset and recanalization was 1.5 months (interquartile range [IQR]: 0.7-3.4) and between imaging-documented occlusion and recanalization was 9.5 days (IQR: 6-18 days). Recanalization was achieved in 96% of patients (26/27). Five (5/27; 19%) perioperative complications occurred. Two patients had dissections: 1 dissection resulted in termination of the procedure without successful recanalization, and the other was handled by the placement of 2 stents. There was 1 intraprocedural acute thrombosis that was successfully treated with balloon angioplasty. One patient experienced thrombus disruption and translocation during the procedure: thrombus was dislodged after disruption by the guidewire. There was 1 acute reocclusion after procedure: while recanalization was achieved again, there was no improvement in clinical outcome. This study revealed that recanalization and stenting for nonacute VBAO may be technically feasible but that it is accompanied by a high risk of complication. The causative factors for perioperative complications need future study.

Safety and Efficacy of Periprocedural Anticoagulation With Enoxaparin in Patients Undergoing Peripheral Endovascular Revascularization

Periprocedural anticoagulation is primarily used in endovascular procedures to prevent acute reocclusion of the target vessel, but periprocedural anticoagulation might also have an impact on long-term outcome. Consecutive bleeding events are feared complications. Despite changes in peripheral endovascular revascularizations (EVRs), the periprocedural management has remained unchanged for years. Unfractionated heparin is still the treatment of choice during and immediately after EVR. We performed a prospective, single-center, open-label phase III study comparing 2 different regimes of enoxaparin peri-interventional to peripheral EVR stratified into low- and high-risk groups according to the acute and long-term reocclusion risk due to their vessel morphology. In both groups, 0.5 mg/kg of enoxaparin as a bolus was administered intravenously 10 to 15 minutes before the start of the procedure. In the low-risk group, 40 mg of enoxaparin were administered once daily for 7 days; whereas in the high-risk group, 1 mg/kg of enoxaparin was administered subcutaneously (sc) 2 times a day for 48 hours after the procedure and afterward 40 mg of enoxaparin was administered sc once daily for 5 days. For the analysis of the per protocol population, 44 patients remained in the low-risk group and 140 in the high-risk group. Concerning the primary safety end point, a total of 25 (13.59%) bleeding events occurred until day 30; 5 (11.36%) of them in the low-risk group and 20 (14.29%) in the high-risk group (P = .809 for low vs high risk). None of the bleeding events observed were major according to Thrombolysis In Myocardial Infarction criteria. Concerning our primary efficacy end point, none of the patients showed an acute reocclusion classified as a significant decrease in ankle-brachial index (ABI) or elevated peak systolic velocity ratio confirmed by duplex sonography until day 30. Concerning the second end point of prevention of chronic reobstruction, at day 180 ABI has decreased in the low-risk group from mean 0.94 at day 30 to mean 0.89 and from 1.28 at day 30 to 0.85 after 6 months in the high-risk group. No significant reobstruction was found in the low-risk group, whereas 5 significant reobstruction events were objectified in the high-risk group, all of them in the femoropopliteal arterial segment at day 180. We conclude that low-molecular-weight heparin either in a low-dose or high-dose regime during a peripheral EVR is safe concerning bleeding complications and acute reobstructions. The long-term follow-up showed no significant difference between our high- and low-risk groups concerning reobstruction. The periprocedural anticoagulation seems to have no influence on the long-term patency rate after peripheral EVR.

Re-endovascular recanalization for acute middle cerebral artery reocclusion after surgical embolectomy

A 62-year-old woman with atrial fibrillation underwent burr hole trephination for a chronic subdural hematoma. Two days later the patient suddenly presented with motor dysphasia and slightly decreased motor power....