Thrombolysis for acute arterial occlusion

Nomogram for predicting amputation-free survival in acute lower limb ischemia patients treated by endovascular therapy

Objectives

To develop a novel and accurate nomogram to predict survival without amputation in patients with acute lower limb ischemia (ALLI) during the first year following endovascular therapy.

Methods

Patients with ALLI who underwent endovascular therapy in our department between January 2012 and September 2020 were screened and included in the research. The included patients were randomly divided into a training and validation cohorts, respectively. Univariate and multivariate analyses were used in the training cohort to identify independent risk factors for amputation-free survival (AFS). A nomogram was then developed according to the identified independent risk factors. The nomogram was then validated in the validation cohort.

Results

415 Chinese patients with 417 affected limbs were included in this study. Among these patients, 311 patients were classified into the training cohort and 104 patients were assigned to the validation cohort. Most patients were men (n = 240) and the average age of patients was 71.43 (standard deviation 8.86) years old. After the univariate and multivariate analyses, advanced age (p < 0.001), history of smoking (p < 0.001), atrial fibrillation (p < 0.001), and insufficient outflow (p = 0.001) were revealed as independent risk factors for AFS during the first year. The nomogram yielded AUROC values of 0.912 (95 % confidence interval [CI]: 0.873-0.950) and 0.889 (95 % CI: 0.812-0.967) in the training and validation cohorts, respectively.

Conclusion

Advanced age, history of smoking, atrial fibrillation, and insufficient outflow were independent negative predictors for AFS in ALLI patients treated by endovascular therapy. The novel nomogram offered an accurate prediction of AFS in ALLI patients.

Feasibility of Microbubble-Accelerated Low-Dose Thrombolysis of Peripheral Arterial Occlusions Using an Ultrasound Catheter

PURPOSE

Intra-arterial administration of microbubbles (MBs) through an ultrasound (US) catheter increases the local concentration of MBs into the thrombus and may further enhance outcomes of contrast-enhanced sonothrombolysis (CEST). The objective of this study was to evaluate the feasibility and lytic efficacy of intra-arterial infusion of MBs during US-enhanced thrombolysis in both in vitro and in vivo peripheral arterial occluded models.

MATERIALS AND METHODS

SonoVue and Luminity MBs were infused at a flow rate of 20 mL/h through either the drug delivery lumen of the US catheter (DDC, n=20) or through the tube lumen of the vascular phantom (systematic infusion, n=20) during thrombolysis with a low-dose urokinase (UK) protocol (50 000 IU/h) with(out) US application to assess MB survivability and size by pre-treatment and post-treatment measurements. A human thrombus was placed into a vascular phantom of the flow system to examine the lytic effects of CEST by post-treatment D-dimer concentrations measurements of 5 treatment conditions (saline, UK, UK+US, UK+US+SonoVue, and UK+US+Luminity). Thrombolytic efficacy of localized MBs and US delivery was then investigated in vivo in 5 porcine models by arterial blood flow, microcirculation, and postmortem determined thrombus weight and remaining length.

RESULTS

US exposure significantly decreased SonoVue (p=0.000) and Luminity (p=0.000) survivability by 37% and 62%, respectively. In vitro CEST treatment resulted in higher median D-dimer concentrations for the SonoVue (0.94 [0.07-7.59] mg/mL, p=0.025) and Luminity (0.83 [0.09-2.53] mg/mL, p=0.048) subgroups when compared with thrombolysis alone (0.36 [0.02-1.00] mg/mL). The lytic efficacy of CEST examined in the porcine model showed an improved median arterial blood flow of 21% (7%-79%), and a median thrombus weight and length of 1.02 (0.96-1.43) g and 2.25 (1.5-4.0) cm, respectively. One allergic reaction and 2 arrhythmias were observed due to the known allergic reaction on lipids in the porcine model.

CONCLUSION

SonoVue and Luminity can be combined with an US catheter and could potentially accelerate thrombolytic treatment of peripheral arterial occlusions.

CLINICAL IMPACT

Catheter-directed thrombolysis showed to be an effective alternative to surgery for acute peripheral arterial occlusions, but this technique is still associated with several limb and life-threatening complications. The effects of thrombolysis on clot dissolution may be further enhanced by intra-arterial administration of microbubbles through an ultrasound catheter. This study demonstrates the feasibility and lytic efficacy of intra-arterial infusion of microbubbles during US-enhanced thrombolysis in both in vitro and in vivo peripheral arterial occluded models.

Safety and efficacy of interventional treatment of acute limb ischemia in Germany 2021

PURPOSE

Interventional procedures have become a mainstay in the therapy of acute limb ischemia caused by embolism or arterial thrombosis. Treatment options include pharmacological thrombolysis (PT) and mechanical thrombectomy (MT). The aim of this study was to evaluate success and major complication rates of interventional radiological treatments of arterial embolism and thrombosis in Germany in 2021 and to compare their results with accepted international quality standards.

MATERIALS AND METHODS

Data for PT and MT for 2021 was obtained from the quality management system of the German interventional radiological society (DeGIR). 2431 PT and 1582 MT procedures were documented for 2021, with 459 combinations of PT and MT. Data was analysed for technical and clinical success rates, as well as major complication rates such as intracranial bleeding, major bleeding, distal embolization, aneurysm formation, organ-failure and cardiac-decompensation.

RESULTS

PT alone had technical and clinical success rate of 90.21% and 81.08%, respectively. MT alone had technical and clinical success rates of 97.41% and 95.39%, respectively. MT&PT had technical and clinical success rates of 91.07% and 84.75%, respectively. Major complications were: distal embolization (PT:2.02%; MT:1.74%; PT&MT:2.61%), major bleeding (PT:0.94%; MT:1.14%; PT&MT:0.87%), aneurysm formation (PT:0.33%;MT: 1.14%;PT&MT: 0%), intracranial bleeding (PT:0.16%;MT:0%;PT&MT:0.22%), cardiac-decompensation (PT:0.21%;MT: 0.06%;PT&MT:0%) and organ-failure (PT:0%;MT:0.06%;PT&MT:0.22%). Technical and clinical success rates were higher, while complication rates were lower than the corresponding threshold recommended by the Society of Interventional Radiology for percutaneous management of acute lower-extremity ischemia.

CONCLUSION

Treatment of arterial embolism and thrombosis performed by interventional radiologists in Germany is effective and safe with outcomes exceeding internationally accepted standards.

Solitaire™ Stent Thrombectomy System in the Treatment of Acute Lower-Limb Ischemia: Comparisons in Safety and Effectiveness with Conventional Catheter-Directed Thrombolysis Therapy

Objective

The study aimed to investigate the safety and efficacy of the Solitaire™ AB Stent System (ev3 Inc., Plymouth, MN, USA) for the treatment of acute lower extremity ischemia (ALLI) compared with conventional catheter-directed thrombolytic therapy.

Methods

Retrospective analysis of patients with ALLI treated in the Department of Interventional Radiology at the First Hospital of Nanjing from January 2017 to April 2020 divided into a conventional (CDT) group (n = 106) and a percutaneous mechanical thrombectomy (PMT) group (n = 55) according to the procedure. PMT was performed using the Solitaire™ AB stent system. The combined clinical outcomes of mortality, major amputation, recurrent ischemia, and major morbidity were compared between the two groups.

Results

Of the 161 patients, 128 (79.5%) did not have a composite clinical outcome after 12 months of follow-up, namely, 78 CDT patients and 50 PMT patients, with significant differences in composite clinical outcome (26.4% vs. 9.1%, P = 0.010) and mortality (19.8% vs. 7.3%, P = 0.037) between them. Thrombolytic drug dose (19.34 ± 5.93 vs. 13.55 ± 6.54 mg, P < 0.001) and length of hospital stay (8.29 ± 3.91 vs. 5.49 ± 1.18 days, P = 0.003) were significantly lower in the PMT group.

Conclusion

PMT with the Solitaire™ AB Stent System is safer and more effective in treating patients with Rutherford stage I-IIB ALLI, with the advantage of rapid opening of obstructed vessels, shorter thrombolysis time, reduced thrombolytic dose, and improved blood flow to the infrapopliteal vessels.

Safety and Efficacy of Vacuum Assisted Thrombo-Aspiration in Patients with Acute Lower Limb Ischaemia: The INDIAN Trial

OBJECTIVE

The aim was to evaluate the short term safety and effectiveness of the Penumbra/Indigo aspiration thrombectomy Systems (Penumbra Inc.) in patients with acute lower limb ischaemia. (ALLI). Recently, endovascular vacuum assisted thrombectomy devices, similar to those used in the management of acute ischaemic stroke, have become available for peripheral arteries, but data are still scarce.

METHODS

To assess vessel patency, a modified Thrombolysis in Myocardial Infarction (TIMI) classification, called TIPI (Thrombo-aspiration In Peripheral Ischaemia), is proposed. The TIPI flow is assessed at presentation, immediately after treatment with the study device, and after all adjuvant procedures. The primary outcome is the technical success of the thrombo-aspiration with the investigative system, defined as near complete or complete revascularisation TIPI 2 - 3. Safety and clinical success rate were collected at one month.

RESULTS

One hundred and fifty patients were enrolled. The mean age was 72.4 years and 73.3% were male. Rutherford grade on enrolment was I in 16%, IIa in 40.7%, and IIb in 43.3% with a mean ankle brachial index of 0.19. Primary technical success (TIPI 2 - 3 flow) was achieved in 88.7% of patients. Adjunctive procedures included angioplasty/stenting of chronic atherosclerotic lesions (n = 39), thrombolysis (n = 31), covered stenting (n = 15), and supplementary Fogarty embolectomy (n = 6). After all interventions, assisted primary technical success was 95.3% (TIPI 2 - 3 in 143/150). No systemic bleeding complications or device related serious adverse events were reported. At one month follow up, one death, and one below the knee amputation were recorded. Primary patency was 92% (138/150), and the re-intervention rate was 7.33%, resulting in an assisted primary and secondary patency of 94% and 99.33%, respectively.

CONCLUSION

Results from the INDIAN registry reveal that mechanical thrombectomy using the Indigo system is safe and effective for revascularisation of ALLI as a primary therapy.

Endovascular approach for acute limb ischemia without thrombolytic therapy

Background:

Endovascular therapy for acute lower limb ischemia (ALLI) has developed and demonstrated safety and efficacy. The purpose of this study was to assess clinical outcomes in patients treated for ALLI with conventional endovascular or surgical revascularization.

Method:

This study was a retrospective single-center review. Consecutive patients with ALLI treated with conventional endovascular revascularization (ER) without thrombolytic agent or surgical revascularization (SR) between 2008 and 2014 were investigated. The 1 year and 3 year amputation rate and mortality rate were assessed by time-to-event methods, including Kaplan–Meier estimation.

Result:

A total of 64 limbs in 62 patients with ALLI due to thromboembolism or thrombosis of a native artery, bypass graft, or previous stented vessel were included. The majority of limbs (90.9%) presented with Rutherford clinical categories 1 to 2 ischemia. Technical success rate was 95.5% in ER and 92.9% in SR group (p = 0.547). Overall amputation rates were 9.1% in ER versus 9.5% in SR after 1 year (p = 0.971) and 9.1% in ER versus 11.9% in SR after 3 year (p = 0.742). Overall mortality rates were 15% in ER versus 7.1% in SR after 1 year (p = 0.491) and 15% in ER versus 11.2% in SR after 3 year (p = 0.878).

Conclusion:

Endovascular or surgical revascularization of ALLI resulted in comparable outcomes in limb salvage and mortality rate at 1 year and 3 year. Conventional endovascular therapy without thrombolytic agent such as stenting, balloon angioplasty, or catheter-directed thrombosuction may be considered as a treatment option for ALLI.

Intra-arterial thrombolysis in acute popliteal artery occlusion is a safe and effective technique reducing the rate of open surgery

BACKGROUND

Acute popliteal artery occlusion is a frequent clinical entity with a risk of major amputation. Several attitudes are possible and treatment is not standardized. The purpose of this study is to demonstrate safety and effectiveness of intra-arterial thrombolysis in acute popliteal artery occlusion.

METHODS

This is a retrospective analysis of a prospective database of patients treated by intra-arterial thrombolysis for acute lower-limb ischemia due to popliteal artery occlusion between 2001 and 2014.The primary endpoint was technical and clinical success. Etiologies and etiologic treatment, amputation-free survival, in-hospital mortality and bleeding complications rates were secondary endpoints.

RESULTS

Seventy-one patients, with a mean 6-day-old ischemic time before thrombolysis, were analyzed. Technical and clinical success was 90% and 87% respectively. Etiology was embolic in 33 patients (cardiac N.=14, aortic=6, unknown=13) and thrombotic in 38 (atheromatous N.=19, entrapment N.= 4, popliteal aneurysm N.=11, Buerger N.=2, thrombophilia N.=1, hyperhomocysteinemia N.=1). Survival and amputation-free survival at 30 days were 97% and 94% respectively. There were no major bleeding complications.

CONCLUSIONS

Intra-arterial thrombolysis of acute popliteal artery occlusion is an effective technique which reduces the rate of open surgery. The risk of bleeding complications is very low.

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

OBJECTIVE

The objective of this study was to assess factors predisposing patients to recurrent acute lower limb ischemia (RALLI).

METHODS

Acute 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.

RESULTS

Altogether, 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).

CONCLUSIONS

Appropriate 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.

Acute Limb Ischemia: An Update on Diagnosis and Management

This review presents an update on the diagnosis and management of acute limb ischemia (ALI), a severe condition associated with high mortality and amputation rates. A comprehensive spectrum of ALI etiology is presented, with highlights on embolism and in situ thrombosis. The steps for emergency diagnosis are described, emphasizing the role of clinical data and imaging, mainly duplex ultrasound, CT angiography and digital substraction angiography. The different therapeutic techniques are presented, ranging from pharmacological (thrombolysis) to interventional (thromboaspiration, mechanical thrombectomy, and stent implantation) techniques to established surgical revascularization (Fogarty thrombembolectomy, by-pass, endarterectomy, patch angioplasty or combinations) and minor or major amputation of necessity. Postprocedural management, reperfusion injury, compartment syndrome and long-term treatment are also updated.

A comprehensive report of long-term outcomes after catheter-directed thrombolysis for occluded infrainguinal bypass grafts

OBJECTIVE

The objective of this study was to assess the technical and short- and long-term clinical outcomes of catheter-directed thrombolysis (CDT) with urokinase for occluded infrainguinal bypass grafts. In addition, factors associated with technical success and amputation-free survival were assessed.

METHODS

A retrospective analysis of a cohort of patients treated with catheter-directed urokinase-based thrombolysis for occluded infrainguinal bypass grafts was conducted between January 2000 and December 2015. Demographics, procedural data, and short- and long-term outcome data, including patency rates of the bypasses, limb salvage, and overall survival, were collected. Statistical models for clustered data were applied to assess predictive factors.

RESULTS

In 177 patients, 251 CDTs were performed on 204 bypasses. In 209 procedures (83.3%), the occluded bypass was reopened; clinical disappearance of ischemic symptoms occurred after 157 procedures (62.6%). Premature cessation of thrombolysis occurred in 33 procedures (13.2%), and periprocedural and postprocedural complications were noted in 91 patients (36.3%). Factors associated with long-term limb salvage are fewer vascular interventions before CDT (P = .0003), higher number of patent outflow vessels before start of CDT (P < .0001), and higher number of patent outflow vessels after CDT (P < .0001). The 1- and 5-year patency rates of bypasses after successful CDT were 64.6% and 48.9%; amputation-free survival after 1 year, 5 years, and 7 years was 81.5%, 71.3%, and 70.5%, respectively.

CONCLUSIONS

Clinical success after CDT was observed in 62% of procedures with an associated complication rate of 36%. Patent outflow vessels before and after CDT are factors associated with long-term limb salvage. Amputation-free survival after 5 years is 71.3%.

Contemporary trends and outcomes of thrombolytic therapy for acute lower extremity ischemia

Objective

Acute limb ischemia is a common vascular emergency requiring immediate intervention. Thrombolysis has been widely utilized for acute limb ischemia; the purpose of this study is to analyze contemporary trends, outcomes and complications of thrombolysis for acute limb ischemia.

Methods

Patients were identified from the Nationwide Inpatient Sample (2003–2013) using ICD-9. Patients undergoing emergency thrombolysis for acute limb ischemia were evaluated. Three groups were analyzed: thrombolysis alone, thrombolysis and endovascular procedure (T+ENDO), and failed thrombolysis requiring open surgery (T+OPEN).

Results

A total of 162,240 patients with acute limb ischemia were estimated: 33,615 patients (20.7%) underwent thrombolysis as the initial treatment. Mean age was 66.2 ± 34.9 years with 54% male. The utilization of thrombolysis increased significantly during the study period (16.8–24.2%, p < 0.0001). The most common group was thrombolysis and endovascular procedure (40.7%), followed by thrombolysis alone (34.1%), and T+OPEN (25.2%). Thrombolysis and endovascular procedure increased significantly over time (31.6–47.8%, p < 0.0001) whereas thrombolysis alone and T+OPEN significantly decreased (39.6–28.6% and 28.7–23.6%, respectively, p < 0.0001). Overall mortality was 4.9%; thrombolysis and endovascular procedure compared to thrombolysis alone and T-OPEN had a lower mortality rate (3.2% vs. 6.1% and 5.9%, p < 0001). The overall stroke rate was 1.9%; thrombolysis alone had the highest stroke rate (3.0%, p < 0.0001) with thrombolysis and endovascular procedure the lowest (1.2%) and T+OPEN 1.7%. The highest amputation rate was T+OPEN (11.6%, p < 0.001) compared to thrombolysis and endovascular procedure (5.1%) and thrombolysis alone (5.3%). T+OPEN had the highest incidence of cardiac (5.5%), respiratory (7.3%) and renal complications (12.5%), pneumonia (4.0%), and fasciotomy (16.8%) (all p < 0.0001).

Conclusion

Thrombolysis remains an effective treatment for acute limb ischemia with increased utilization over time. There was a significant increase in thrombolysis and endovascular procedure leading to improved outcomes. Thrombolysis alone carried the highest mortality and stroke rate, with T+OPEN associated with the highest amputation and complications. Although thrombolysis is effective, 25% of patients required an open procedure suggesting that patient selection for thrombolysis first instead of open surgery continues to be a clinical challenge.

Open or endovascular revascularization in the treatment of acute lower limb ischaemia

Background

Consensus is lacking regarding intervention for patients with acute lower limb ischaemia (ALI). The aim was to study amputation‐free survival in patients treated for ALI by either primary open or endovascular revascularization.

Methods

The Swedish Vascular Registry (Swedvasc) was combined with the Population Registry and National Patient Registry to determine follow‐up on mortality and amputation rates. Revascularization techniques were compared by propensity score matching 1 : 1.

Results

Of 9736 patients who underwent open surgery and 6493 who had endovascular treatment between 1994 and 2014, 3365 remained in each group after propensity score matching. Results are from the matched cohort only. Mean age of the patients was 74·7 years; 47·5 per cent were women and mean follow‐up was 4·3 years. At 30‐day follow‐up, the endovascular group had better patency (83·0 versus 78·6 per cent; P < 0·001). Amputation rates were similar at 30 days (7·0 per cent in the endovascular group versus 8·2 per cent in the open group; P = 0·113) and at 1 year (13·8 versus 14·8 per cent; P = 0·320). The mortality rate was lower after endovascular treatment, at 30 days (6·7 versus 11·1 per cent; P < 0·001) and after 1 year (20·2 versus 28·6 per cent; P < 0·001). Accordingly, endovascular treatment had better amputation‐free survival at 30 days (87·5 versus 82·1 per cent; P < 0·001) and 1 year (69·9 versus 61·1 per cent; P < 0·001). The number needed to treat to prevent one death within the first year was 12 with an endovascular compared with an open approach. Five years after surgery, endovascular treatment still had improved survival (HR 0·78, 99 per cent c.i. 0·70 to 0·86) but the difference between the treatment groups occurred mainly in the first year.

Conclusion

Primary endovascular treatment for ALI appeared to reduce mortality compared with open surgery, without any difference in the risk of amputation.

Endovascular may save lives

Thrombectomy Using Myocardial Biopsy Forceps in Acute Limb Ischemia Patients

PURPOSE

To evaluate the efficacy and safety of thrombectomy using myocardial biopsy forceps for the treatment of acute limb ischemia (ALI).

MATERIALS AND METHODS

A retrospective review of 11 ALI patients (12 affected limbs, 18 affected vessels) who underwent thrombectomy using biopsy forceps between November 2011 and April 2016 was performed. Of the 12 affected limbs, 2 limbs had stent thrombosis, 1 limb had thrombotic occlusion at a de novo stenosis site, and 9 limbs had embolic ALI. Biopsy forceps were used for angiographically limited arterial flow that persisted after the use of an aspiration catheter and conventional balloon angioplasty. The general technique for use of the biopsy forceps included advancement in parallel to a guidewire to the thrombus site, grasping of the thrombus with the forceps, and confirmation of grasping the thrombus with injection of a contrast medium prior to thrombus extraction.

RESULTS

Partial or total retrieval of the thrombus was angiographically confirmed in 12 of the 18 affected vessels, with restoration of normal blood flow in 11 vessels. Unsuccessful results in the remaining 6 affected vessels appeared to be due to friction at the aortoiliac bifurcation caused by the contralateral approach, small vessel size, or curvature of the anterior tibial artery. None of the 18 treated vessels had any complications such as dissection or perforation of the target vessel wall and distal emboli. None of the surviving patients required major or minor amputation.

CONCLUSIONS

Thrombectomy using biopsy forceps is a feasible technique for removal of an arterial thrombus in patients with ALI.

Practice Trends of Fibrinogen Monitoring in Thrombolysis

There is a lack of evidence or societal guidelines regarding the utility of fibrinogen monitoring during thrombolysis. The purpose of our study was to investigate the current use of monitoring fibrinogen levels during thrombolysis. A voluntary, anonymous online survey was sent to all physician members of the Society of Interventional Radiology, consisting of 23 questions related to practitioner demographics, thrombolysis protocol, and fibrinogen monitoring. There were 455 physician responses; 82% of respondents monitored fibrinogen levels during thrombolysis, of which 97% decreased or stopped tissue plasminogen activator based on the level. Self-reported estimates of significant bleeding events during thrombolysis were 1.86% in those who monitored fibrinogen and 1.93% in those who did not. Only 34% of all respondents report, in their clinical experience, having found low fibrinogen level to be correlated with bleeding events. There was no significant difference in self-reported major bleeding rates between practitioners who monitor and those who do not monitor fibrinogen. This high variability of clinical use of fibrinogen monitoring during catheter-directed thrombolysis is secondary to the paucity of scientific studies demonstrating its utility; further scientific investigation is needed to define the true utility of fibrinogen monitoring.

Intra-arterial fibrinolysis for the management of acute ischemia on a below-knee amputation stump. Case report

Preservation of the knee joint has enormous advantages in terms of mobility and rehabilitation of an amputee. Any cause of breakdown requiring revision to an above-knee amputation is a major setback because it reduces the patient’s rehabilitative potential. We report a case of intra-arterial thrombolysis use to save a below-knee amputation stump with acute ischemia. A 56-year-old man who sought the emergency department with 1-day history of acute pain on his right below-knee stump. The angiography confirmed popliteal artery occlusion. Pharmacomechanical thrombectomy, with Aspirex (rotational catheter to restore blood flow in occluded vessel, by removing occlusion material from the vessel) and recombinant tissue plasminogen activator, was performed. After 9 years of follow-up the patient remained asymptomatic, capable of independent ambulation with prosthetic limb. Intra-arterial fibrinolysis seems to be a safe and effective treatment for cases of acutely ischemic amputation stump.

Microbubbles and UltraSound-accelerated Thrombolysis (MUST) for peripheral arterial occlusions: protocol for a phase II single-arm trial

INTRODUCTION

Acute peripheral arterial occlusions can be treated with intra-arterial catheter-directed thrombolysis as an alternative to surgical thromboembolectomy. Although less invasive, this treatment is time-consuming and carries a significant risk of haemorrhagic complications. Contrast-enhanced ultrasound using microbubbles could accelerate dissolution of thrombi by thrombolytic medications due to mechanical effects caused by oscillation; this could allow for lower dosages of thrombolytics and faster thrombolysis, thereby reducing the risk of haemorrhagic complications. In this study, the safety and practical applicability of this treatment will be investigated.

METHODS AND ANALYSIS

A single-arm phase II trial will be performed in 20 patients with acute peripheral arterial occlusions eligible for thrombolytic treatment. Low-dose catheter-directed thrombolysis with urokinase will be used. The investigated treatment will be performed during the first hour of thrombolysis, consisting of intravenous infusion of 4 Luminity phials (6 mL in total, diluted with saline 0.9% to 40 mL total) of microbubbles with the use of local ultrasound at the site of occlusion. Primary end points are the incidence of complications and technical feasibility. Secondary end points are angiographic and clinical success, duration of thrombolytic infusion, treatment-related mortality, amputations, additional interventions and quality of life.

ETHICS AND DISSEMINATION

Ethical approval for this study was obtained in 2015 from the Medical Ethics Committee of the VU University Medical Center, Amsterdam, the Netherlands. A statement of consent for this study was given by the Dutch national competent authority. Data will be presented at national and international conferences and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBERS

Dutch National Trial Registry: NTR4731; European Clinical Trials Database of the European Medicines Agency: 2014-003469-10; Pre-results.

Direct Stenting in Patients with Acute Lower Limb Arterial Occlusions: Immediate and Long-Term Results

PURPOSE

The purpose of this study is to accentuate the efficacy of direct stenting (stent placement without predilatation of the lesion) in patients with acute lower limb arterial ischemia (ALLI).

MATERIALS AND METHODS

Between January 2010 and September 2015, 16 patients (11 men and 5 women) underwent direct stenting of acute arterial occlusions. All patients had contraindication for surgical revascularization or catheter-directed thrombolysis. According to SVS/ISCVS Classification, six patients had IIa and ten patients IIb ALLI. The occlusions were located in CIA, EIA, SFA, or popliteal artery. Mean follow-up time with clinical examination and color Duplex ultrasonography was 37.6 months (range 1-72). We analyzed the technical and clinical outcomes of the procedures, as well the complications and patency rates.

RESULTS

Technical success was achieved in all patients (16/16) and there was significant clinical improvement in 15 patients. There was neither distal embolization nor procedure-related complications. During the 6 years of follow-up, four patients died due to non-procedure-related causes and there were two minor and one major amputations. The primary patency rates and the amputation-free survival rates were 93.7 and 87% at 1 year, 75.2 and 71.2% at 3 years, and 75.2 and 62.3%, respectively, at 6 years.

CONCLUSIONS

Direct stenting may be a valuable alternative procedure for acute arterial occlusions in selected cases with high technical success and significant clinical improvement.

LEVEL OF EVIDENCE

Level 4, Case Series.

A unique case of acute embolus in a renal transplant with salvage by catheter-directed thrombolysis

INTRODUCTION

Acute renal transplant emboli can be disastrous and result in loss of the renal transplant. This case was successfully treated with thrombolysis.

CASE PRESENTATION

A 66-year-old female underwent a right-sided deceased heart-beating donor renal transplant. She had excellent transplant function but presented acutely three years later with pain in the transplanted kidney, an acute rise in serum creatinine and new onset atrial fibrillation. Bedside ultrasound scan demonstrated absent transplant perfusion. Emergency angiogram confirmed acute emboli in the transplant renal artery with some kidney perfusion. Thrombolysis with alteplase and anticoagulation with heparin was commenced. Serial imaging at 24 and 36 h demonstrated significant improvement in transplant perfusion. Following a period of supportive therapy, her transplant function recovered, although not to pre-morbid baseline levels.

CONCLUSION

Consider acute embolus in a renal transplant patient with acute kidney injury, transplant tenderness and cardiac arrhythmia. Early thrombolysis may salvage renal transplants and good transplant function may be regained.

Pharmacological protection of mitochondrial function mitigates acute limb ischemia/reperfusion injury

We describe several novel curcumin analogues that possess both anti-inflammatory antioxidant properties and thrombolytic activities. The therapeutic efficacy of these curcumin analogues was verified in a mouse ear edema model, a rat arterial thrombosis assay, a free radical scavenging assay performed in PC12 cells, and in both in vitro and in vivo ischemia/reperfusion models. Our findings suggest that their protective effects partially reside in maintenance of optimal mitochondrial function.

Risk Factors for Long-Term Mortality and Amputation after Open and Endovascular Treatment of Acute Limb Ischemia

BACKGROUND

Acute limb ischemia (ALI) is a highly morbid and fatal vascular emergency with little known about contemporary, long-term patient outcomes. The goal was to determine predictors of long-term mortality and amputation after open and endovascular treatment of ALI.

METHODS

A retrospective review of ALI patients at a single institution from 2005 to 2011 was performed to determine the impact of revascularization technique on 5-year mortality and amputation. For each main outcome 2 multivariable models were developed; the first adjusted for preoperative clinical presentation and procedure type, the second also adjusted for postoperative adverse events (AEs).

RESULTS

A total of 445 limbs in 411 patients were treated for ALI. Interventions included surgical thrombectomy (48%), emergent bypass (18%), and endovascular revascularization (34%). Mean age was 68 ± 15 years, 54% were male, and 23% had cancer. Most patients presented with Rutherford classification IIa (54%) or IIb (39%). The etiology of ALI included embolism (27%), in situ thrombosis (28%), thrombosed bypass grafts (32%), and thrombosed stents (13%). Patients treated with open procedures had significantly more advanced ischemia and higher rates of postoperative respiratory failure, whereas patients undergoing endovascular interventions had higher rates of technical failure. Rates of postprocedural bleeding and cardiac events were similar between both treatments. Excluding Rutherford class III patients (n = 12), overall 5-year mortality was 54% (stratified by treatment, 65% for thrombectomy, 63% for bypass, and 36% for endovascular, P < 0.001); 5-year amputation was 28% (stratified by treatment, 18% for thrombectomy, 27% for bypass, and 17% for endovascular, P = 0.042). Adjusting for comorbidities, patient presentation, AEs, and treatment method, the risk of mortality increased with age (hazard ratio [HR] = 1.04, P < 0.001), female gender (HR = 1.50, P = 0.031), cancer (HR = 2.19, P < 0.001), fasciotomy (HR = 1.69, P = 0.204) in situ thrombosis or embolic etiology (HR = 1.73, P = 0.007), cardiac AEs (HR = 2.25, P < 0.001), respiratory failure (HR = 2.72, P < 0.001), renal failure (HR = 4.70, P < 0.001), and hemorrhagic events (HR = 2.25, P = 0.003). Risk of amputation increased with advanced ischemia (Rutherford IIb compared with IIa, HR = 2.57, P < 0.001), thrombosed bypass etiology (HR = 3.53, P = 0.002), open revascularization (OR; HR = 1.95, P = 0.022), and technical failure of primary intervention (HR = 6.01, P < 0.001).

CONCLUSIONS

After the treatment of ALI, long-term mortality and amputation rates were greater in patients treated with open techniques; OR patients presented with a higher number of comorbidities and advanced ischemia, while also experiencing a higher rate of major postoperative complications. Overall, mortality rates remained high and were most strongly associated with baseline comorbidities, acuity of presentation, and perioperative AEs, particularly respiratory failure. Comparatively, amputation risk was most highly associated with advanced ischemia, thrombosed bypass, and failure of the initial revascularization procedure.

Perioperative management of lower extremity revascularization

Patients presenting for lower extremity revascularization often have multiple systemic comorbidities, making them high-risk surgical candidates. Neuraxial anesthesia and general anesthesia are equivocal in their effect on perioperative cardiac morbidity and improved graft patency. Postoperative epidural analgesia may improve perioperative cardiac morbidity. Systemic antithrombotic and anticoagulation therapy is common among this patient population and may affect anesthetic techniques.

Thrombolysis for acute limb-threatening ischemia: a practical approach

Lower extremity arterial thrombolysis is a safe and effective means of treating acute limb ischemia due to in situ thrombosis or embolic occlusion. It is optimally used in occlusions of <7 days duration. Proper patient selection is critical to successful outcome. In all patients undergoing successful thrombolysis, it is mandatory to ascertain the etiology of the thrombosis and correct the underlying problem to facilitate a durable outcome.

Use of duplex guided stent graft placement to prevent bleeding from previously thrombosed pseudo-aneurysms during thrombolytic therapy for acute popliteal artery occlusion

We present a 68-year-old female who developed multiple pseudo-aneurysms (PSAs) following cardiac catheterization via the right groin. During subsequent thrombin injection of PSAs, the patient developed acute occlusion of the popliteal artery. A covered stent was placed to obliterate the PSAs and allow for successful endovascular treatment of the occlusion without hemorrhage from the previous arteriotomy sites. This report demonstrates a safe and successful method to treating high surgical risk patients with recent PSA's and a necessity for thrombolysis.

Intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) in acute lower limb ischaemia

For various reasons some patients are unable to undergo intra-arterial thrombolysis for acute limb ischaemia. This interventional case series study prospectively evaluated the effect of thrombolytic treatment with 100 mg recombinant tissue plasminogen activator (rt-PA), administered intravenously, in patients with acute thrombosis of the lower limb arteries and onset of symptoms within 12 h prior to treatment. During a 3-year period (2007-2009), 18 of 86 patients satisfied the inclusion criteria and were included in the study (age range 65-80 years; 11 women). Complete and partial thrombolysis was observed in eight (44.4%) and six (33.3%) patients, respectively. All patients experienced clinical improvement. There were no amputations during the 36-month follow-up period and no haemorrhagic complications in the first 30 days post-treatment. Five patients died (27.8%) during follow-up from unrelated causes. This small study demonstrated that thrombolytic treatment with intravenous rt-PA in selected patients with acute limb ischaemia is feasible.

Dutch randomized trial comparing standard catheter-directed thrombolysis versus ultrasound-accelerated thrombolysis for thromboembolic infrainguinal disease (DUET): design and rationale

BACKGROUND

The use of thrombolytic therapy in the treatment of thrombosed infrainguinal native arteries and bypass grafts has increased over the years. Main limitation of this treatment modality, however, is the occurrence of bleeding complications. Low intensity ultrasound (US) has been shown to accelerate enzymatic thrombolysis, thereby reducing therapy time. So far, no randomized trials have investigated the application of US-accelerated thrombolysis in the treatment of thrombosed infra-inguinal native arteries or bypass grafts. The DUET study (Dutch randomized trial comparing standard catheter-directed thrombolysis versus Ultrasound-accElerated Thrombolysis for thrombo-embolic infrainguinal disease) is designed to assess whether US-accelerated thrombolysis will reduce therapy time significantly compared with standard catheter-directed thrombolysis.

METHODS/DESIGN

Sixty adult patients with recently (between 1 and 7 weeks) thrombosed infrainguinal native arteries or bypass grafts with acute limb ischemia class I or IIa, according to the Rutherford classification for acute ischemia, will be randomly allocated to either standard thrombolysis (group A) or US-accelerated thrombolysis (group B). Patients will be recruited from 5 teaching hospitals in the Netherlands during a 2-year period. The primary endpoint is the duration of catheter-directed thrombolysis needed for uninterrupted flow in the thrombosed infrainguinal native artery or bypass graft, with outflow through at least 1 crural artery.

DISCUSSION

The DUET study is a randomized controlled trial that will provide evidence of whether US-accelerated thrombolysis will significantly reduce therapy time in patients with recently thrombosed infrainguinal native arteries or bypass grafts, without an increase in complications.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN72676102.