Dutch randomized trial comparing standard catheter-directed thrombolysis and ultrasound-accelerated thrombolysis for arterial thromboembolic infrainguinal disease (DUET)

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

Ultrasound-Accelerated Catheter-Directed Thrombolysis

Venous thromboembolism is a very common presentation in the hospital setting. In patients with high-risk pulmonary embolism (PE) or PE and hemodynamic instability, systemic thrombolytic treatment is generally indicated. In those with contraindications to systemic thrombolysis, catheter-directed local thrombolytic therapy and surgical embolectomy are currently considered. In particular, catheter-directed thrombolysis (CDT) is a drug delivery system coupling the endovascular drug administration nearby in the thrombus and the local facilitating effect of ultrasounds. The applications of CDT are currently debated. Here we provide a systematic review of the clinical utilization of CDT.

A single-centre protocol using low-dose urokinase for catheter-directed thrombolysis in the treatment of acute lower limb ischaemia

OBJECTIVES

Catheter-directed thrombolysis is one of the main treatments for acute limb ischaemia. Urokinase is still a widely used thrombolytic drug in some regions. However, there needs to be a clear consensus on the protocol of continuous catheter-directed thrombolysis using urokinase for acute lower limb ischaemia.

METHODS

A single-centre protocol of continuous catheter-directed thrombolysis with low-dose urokinase (20,000 IU/hour) lasting 48-72 h for acute lower limb ischaemia was proposed based on our previous experiences. A retrospective study from June 2016 to December 2020 was conducted to evaluate the efficacy and safety of this protocol. The target lesion revascularisation, amputation and death were also monitored during follow-up. The Kaplan-Meier estimator was used for the subgroup analysis, and univariate and multivariate Cox regression analysis was applied to identify risk factors for reinterventions and death.

RESULTS

90 lower limbs were involved, including 51 Rutherford Grade I, 35 Grade IIa and four Grade IIb. During a 60.8-h thrombolysis, 86 cases (95.5%) were considered effective according to the angiogram. No major bleeding complication occurred during thrombolysis, and one amputation occurred after. Freedom from target lesion revascularisation, amputation and death were 75.6%, 94.4% and 91.1% during a mean 27.5-month follow-up, respectively. According to the Kaplan-Meier estimator, aortoiliac lesions had lower reintervention rates than femoropopliteal lesions (Log-rank p = 0.010), and cases without narrowing atheromatous plaque had a lower reintervention rate (Log-rank p = 0.049). Age was an independent risk factor for death (p = 0.038, hazard ratio 1.076, 95% confidence interval 1.004-1.153).

CONCLUSIONS

The single-centre protocol of catheter-directed thrombolysis we proposed for acute lower limb ischaemia was effective and safe. Strict blood pressure control during catheter-directed thrombolysis ensured safety. Aortoiliac lesions and cases without narrowing atheromatous plaque had lower reintervention rates during follow-up.

Percutaneous thrombectomy or ultrasound-accelerated thrombolysis for initial management of acute limb ischaemia

BACKGROUND

Acute limb ischaemia (ALI), the sudden and significant reduction of blood flow to the limb, is considered a vascular emergency. In the general population, the incidence is estimated as 14 per 100,000. Prognosis depends on the time it takes to diagnose the condition and begin appropriate treatment. Standard initial interventional treatments include conventional open surgery and endovascular interventions such as catheter-directed thrombolysis (CDT). Percutaneous interventions, such as percutaneous thrombectomy (PT, including mechanical thrombectomy or pharmomechanical thrombectomy) and ultrasound-accelerated thrombolysis (USAT), are also performed as alternative endovascular techniques. The proposed advantages of PT and USAT include reduced time to revascularisation and when combined with catheter-directed thrombolysis, a reduction in dose of thrombolytic agents and infusion time. The benefits of PT or USAT versus open surgery or thrombolysis alone are still uncertain. In this review, we compared PT or USAT against standard treatment for ALI, in an attempt to determine if any technique is comparatively safer and more effective.

OBJECTIVES

To assess the safety and effectiveness of percutaneous thrombectomy or ultrasound-accelerated thrombolysis for the initial management of acute limb ischaemia in adults.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, the World Health Organization (WHO) International Clinical Trials Registry Platform, and ClinicalTrials.gov to 3 March 2021. We searched reference lists of relevant studies and papers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared PT (any modality, including mechanical thrombectomy (aspiration, rheolysis, rotation) or pharmomechanical thrombectomy) or USAT with open surgery, thrombolysis alone, no treatment, or another PT modality for the treatment of ALI.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies, assessed risk of bias, extracted data, performed data analysis, and assessed the certainty of evidence according to GRADE. Outcomes of interest were primary patency, amputation rate, major bleeding, clinical success, secondary patency, and adverse effects.

MAIN RESULTS

We included one RCT in this review. This study had a total of 60 participants and compared USAT with standard treatment (CDT). The study included 32 participants in the CDT group and 28 participants in the USAT group. We found no evidence of a difference between USAT and CDT alone for the following evaluated outcomes: amputation rate (risk ratio (RR) 1.14, 95% confidence interval (CI) 0.17 to 7.59); major bleeding (RR 1.71, 95% CI 0.31 to 9.53); clinical success (RR 1.00, 95% CI 0.94 to 1.07); and adverse effects (RR 5.69, 95% CI 0.28 to 113.72). We rated the certainty of the evidence as very low for these outcomes. We downgraded the certainty of the evidence for amputation rate, major bleeding, clinical success, and adverse effects by two levels due to serious limitations in the design (there was a high risk of bias in critical domains) and by two further levels due to imprecision (a small number of participants and only one study included). The study authors reported 30-day patency, but did not report primary and secondary patency separately. The patency rate in the successfully lysed participants was 71% (15/21) in the USAT group and 82% (22/27) in the CDT group. The study authors did not directly report secondary patency, which is patency after secondary procedures, but they did report on secondary procedures. Secondary procedures were subdivided into embolectomy and bypass grafting. Embolectomy was performed on 14% (4/28) of participants in the USAT group versus 3% (1/32) of participants in the CDT group. Bypass grafting was performed on 4% (1/28) of participants in the USAT group versus 0% in the CDT group. As we did not have access to the specific participant data, it was not possible to assess these outcomes further. We did not identify studies comparing the other planned interventions.

AUTHORS' CONCLUSIONS

There is insufficient evidence to assess the safety and effectiveness of USAT versus CDT alone for ALI for our evaluated outcomes: amputation rate, major bleeding, clinical success, and adverse effects. Primary and secondary patency were not reported separately. There was no RCT evidence for PT. Limitations of this systematic review derive from the single included study, small sample size, short clinical follow-up period, and high risk of bias in critical domains. For this reason, the applicability of the results is limited. There is a need for high-quality studies to compare PT or USAT against open surgery, thrombolysis alone, no treatment, or other PT modalities for ALI. Future trials should assess outcomes, such as primary patency, amputation rate, major bleeding, clinical success, secondary patency, and adverse effects.

Efficacy of ultrasound assisted catheter-directed thrombolysis compared to catheter-directed thrombolysis in vitro

BACKGROUND

Catheter-directed thrombolysis (CDT) is an effective and safe endovascular method used in critical limb ischemia and many other thromboembolic events. Ultrasound-assisted catheter-directed thrombolysis (US-CDT) is an emerging technique considered to accelerate thrombolysis and therefore is supposed to improve outcome.

PURPOSE

To evaluate the efficacy of US-CDT in comparison to standard CDT in vitro.

MATERIAL AND METHODS

A total of 69 sets of human venous blood were evaluated, each comprising a tube just treated with CDT, a tube treated with US-CDT, and a control tube. All tubes were kept under physiological conditions. Except for the controls, in all tubes 5 mg of tissue-type plasminogen activator was administered over the predetermined treatment interval. Thrombus mass was weighted at the end of the lysis intervals at 6 h or 24 h, respectively.

RESULTS

CDT led to a mean thrombus reduction of 32% and ultrasound-assisted lysis led to a mean thrombus reduction of 41% (P < 0.001 for both). Thrombus reduction was significantly higher after US-CDT compared to CDT (P = 0.001). The better efficacy of US-CDT was mostly already apparent at early phases during thrombolysis and did further mildly increase over time (r = 0.24; P = 0.047).

CONCLUSION

In vitro US-CDT is significantly superior to standard CDT; this effect is apparent at an early timepoint of lysis and slightly further increases over time.

Microbubbles and Ultrasound Accelerated Thrombolysis for Peripheral Arterial Occlusions: The Outcomes of a Single Arm Phase II Trial

OBJECTIVE

Acute peripheral arterial occlusions can be treated by catheter directed thrombolysis (CDT). However, CDT is time consuming and accompanied by the risk of bleeding complications. The addition of contrast enhanced ultrasound and microbubbles could improve thrombus susceptibility to thrombolytic agents and potentially shorten treatment time with a lowered risk of bleeding complications. This article reports the outcomes of the safety and feasibility of this novel technique.

METHODS

In this single arm phase II trial, 20 patients with acute lower limb ischaemia received CDT combined with an intravenous infusion of microbubbles and locally applied ultrasound during the first hour of standard intra-arterial thrombolytic therapy. The primary endpoint was safety, i.e., occurrence of serious adverse events (haemorrhagic complications and/or amputation) and death within one year. Secondary endpoints included angiographic and clinical success, thrombolysis duration, additional interventions, conversion, and quality of life.

RESULTS

The study included 20 patients (16 men; median age 68.0 years; range, 50.0 - 83.0; and 40% native artery and 60% bypass graft). In all patients, the use of microbubble contrast enhanced sonothrombolysis could be applied successfully. There were no serious adverse events related to the experimental treatment. Duplex examination showed flow distal from the occlusion after 23.1 hours (range 3.1 - 46.5) with a median thrombolysis time of 47.5 hours (range 6.0 - 81.0). The short term ABI and pain scores significantly improved; however, no changes were observed before or after thrombolysis in the microcirculation. Overall mortality and amputation rates were both 2% within one year. The one year patency rate was 55%.

CONCLUSION

Treatment of patients with acute peripheral arterial occlusions with contrast enhanced sonothrombolysis is feasible and safe to perform in patients. Further research is necessary to investigate the superiority of this new treatment over standard treatment.

The plasma D-dimer trends and their value in acute lower limb ischemia patients treated by catheter directed thrombolysis

To investigate the change trends of plasma D-dimer during catheter-directed thrombolysis (CDT) in acute lower limb ischemia (ALI) patients and their clinical value. A retrospective review of patients with ALI who received CDT was carried out. The repeated measurements of plasma D-dimer were analyzed by generalized estimating equations (GEEs) and the change trends of D-dimer were analyzed by spline regression approach. A total of 150 patients were included. Among them, 3 days of CDT was ineffective in 41 cases, effective in 33 cases and markedly effective in 76 cases. The results of GEEs analysis showed that serum D-dimer changed significantly with time (time effect, P < 0.001). Serum D-dimer levels of patients with different treatment outcomes were different after treatment (group effect, P < 0.001), and serum D-dimer levels in these three groups showed different trends over time (group*time effect, P < 0.001). The different trends in serum D-dimer level with time after treatment in the three groups could be directly seen in the spline regression curve (P < 0.001). The plasma D-dimer changes regularly during CDT for ALI. We can predict the efficacy of CDT and guide adjustments of the therapeutic regimen according to the trend of D-dimer changes during thrombolysis.

Asia-Pacific Consensus Statement on the Management of Peripheral Artery Disease: A Report from the Asian Pacific Society of Atherosclerosis and Vascular Disease Asia-Pacific Peripheral Artery Disease Consensus Statement Project Committee

BACKGROUND

Peripheral artery disease (PAD) is the most underdiagnosed, underestimated and undertreated of the atherosclerotic vascular diseases despite its poor prognosis. There may be racial or contextual differences in the Asia-Pacific region as to epidemiology, availability of diagnostic and therapeutic modalities, and even patient treatment response. The Asian Pacific Society of Atherosclerosis and Vascular Diseases (APSAVD) thus coordinated the development of an Asia-Pacific Consensus Statement (APCS) on the Management of PAD.

OBJECTIVES

The APSAVD aimed to accomplish the following: 1) determine the applicability of the 2016 AHA/ACC guidelines on the Management of Patients with Lower Extremity Peripheral Artery Disease to the Asia-Pacific region; 2) review Asia-Pacific literature; and 3) increase the awareness of PAD.

METHODOLOGY

A Steering Committee was organized to oversee development of the APCS, appoint a Technical Working Group (TWG) and Consensus Panel (CP). The TWG appraised the relevance of the 2016 AHA/ACC PAD Guideline and proposed recommendations which were reviewed by the CP using a modified Delphi technique.

RESULTS

A total of 91 recommendations were generated covering history and physical examination, diagnosis, and treatment of PAD-3 new recommendations, 31 adaptations and 57 adopted statements. This Asia-Pacific Consensus Statement on the Management of PAD constitutes the first for the Asia-Pacific Region. It is intended for use by health practitioners involved in preventing, diagnosing and treating patients with PAD and ultimately the patients and their families themselves.

Acute Lower Limb Ischemia-Etiology, Pathology, and Management

Acute limb ischemia (ALI) is a vascular emergency associated with a high risk for limb loss and death. Most cases result from in situ thrombosis in patients with preexisting peripheral arterial disease or those who have undergone vascular procedures including stenting and bypass grafts. The other common source is cardioembolic. The incidence has decreased in recent times due to better anticoagulation strategies. Patients with suspected ALI should be evaluated promptly by a vascular specialist and consideration should be given for transfer to a higher level of care if such expertise is not available locally. Initial assessment should focus on staging severity of ischemic injury and potential for limb salvage. Neurological deficits can occur early and are an important poor prognostic sign. Duplex ultrasound and computed tomography angiography help plan intervention in patients with a still-viable limb and prompt catheter-based angiography is mandated in patients with an immediately threatened limb. Further investigations need to be pursued to differentiate embolic from thrombotic cause for acute occlusion as this can change management. Options include intravascular interventions, surgical bypass, or a hybrid approach. In this article, the authors discuss the common etiologies, clinical evaluation, and management of patients presenting with acute limb ischemia.

Real-World Outcomes of EKOS Ultrasound-Enhanced Catheter-Directed Thrombolysis for Acute Limb Ischemia

BACKGROUND

Ultrasound-enhanced catheter-directed thrombolysis (UET) using the Ekosonic® Endovascular System device for acute, peripheral arterial ischemia has been purported in clinical trials to accelerate the fibrinolytic process to reduce treatment time and lytic dosage. We aim to describe outcomes of UET in a real-world clinical setting.

METHODS

We performed a retrospective review of all patients undergoing UET for acute limb ischemia at a single institution. Data collected included patient demographics, procedural details, and 30-day and 1-year outcomes. The primary endpoints for analysis were major adverse limb events (MALEs; reintervention and/or amputation) and mortality within 30-days and 1-year. Secondary endpoints included technical success, use of adjunctive therapies, and postoperative complications.

RESULTS

A total of 32 patients (mean age 67.4 ± 14.9 years; 25% women) underwent UET for acute limb ischemia between 2014 and 2018. The Rutherford Acute Limb Ischemia Classification was Rutherford (R) 1 in 56.3%, R2a in 31.3%, and R2b in 12.5%. Etiology was thrombosis of native artery in 12.5% of patients, prosthetic bypass in 31.3%, autogenous bypass in 6.3%, and stented native vessel in 50.0%. Mean duration of thrombolytic therapy was 22.2 ± 11.3 hr, and mean tissue plasminogen activator dose was 24.5 ± 15.3 mg. MALEs occurred in 16.7% of patients within the first 30 days and 38.9% experienced a MALE by 1 year. Limb salvage at 30 days and 1 year was 93.8% and 87.5%, respectively. Ipsilateral reintervention was required in 12.5% of patients within 30 days and 37.5% of patients within 1 year. Overall mortality was 6.2% at 30 days and 13.5% at 1 year. In-line flow to the foot was re-established in 90.6% of patients, with a significant improvement in preoperative to postoperative ankle-brachial index (0.31 ± 0.29 vs. 0.78 ± 0.34, P < 0.001) and number of patent tibial runoff vessels (1.31 ± 1.20 vs. 1.96 ± 0.86, P < 0.001). There was no significant difference in revascularization success between occluded vessel types. All but one patient required adjunctive therapy such as further thromboaspiration, stenting, or balloon angioplasty. Major bleeding complications occurred in 3 patients (9.4%), including 1 intracranial hemorrhage (3.1%).

CONCLUSIONS

UET with the EKOS device demonstrates acceptable real-world outcomes in the treatment of acute limb ischemia. UET is generally safe and effective at re-establishing in-line flow to yield high limb salvage rates. However, UET is associated with a high rate of reintervention. Further investigation is needed into specific predictors of limb salvage and need for reintervention, as well as cost-efficacy of this technology compared with that of traditional methods.

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 systematic review and meta-analysis of endovascular and surgical revascularization techniques in acute limb ischemia

BACKGROUND

The initial treatment of patients with acute limb ischemia (ALI) remains undefined. The aim of this article was to compare the safety and effectiveness of catheter-driven thrombolysis (CDT) with surgical revascularization and evaluate the various fibrinolytic agents, endovascular, and pharmacochemical approaches that aim for thrombectomy.

METHODS

PubMed, Embase, and the Cochrane Library were searched for studies on the management of ALI by means of surgical or endovascular recanalization, returning 520 studies. All randomized, controlled trials, nonrandomized prospective, and retrospective studies were included comparing treatment of ALI.

RESULTS

Twenty-five studies, investigating a total of 4689 patients, were included for meta-analysis spread across nine different comparisons. No differences were found in limb salvage between thrombectomy and thrombolysis. More major vascular events were seen in the thrombolysis group (6.5% compared with 4.4% in the surgically treated group; odds ratio [OR], 0.33; 95% confidence interval [CI], 0.13-0.87; P = .02; I² = 20%). Comparable limb salvage was found for high- and low-dose recombinant tissue plasminogen activator (r-tPA). No significant differences were found in major vascular event between low r-tPA (14%) and high r-tPA (10.5%; P = .13). The 30-day limb salvage rate was 79.7% for r-tPA treatment and 60.4% for streptokinase (OR, 3.14; 95% CI, 1.26-7.85; P = .01; I² = 0%). AngioJet showed more limb salvage at 6 months compared with r-tPa (OR, 2.21; 95% CI, 1.17-4.18; P = .01; I² = 0%).

CONCLUSIONS

Both CDT and surgery have comparable limb salvage rates in patients with ALI; however, CDT is associated with a higher risk of hemorrhagic complications. No conclusions can be drawn regarding the risk of hemorrhagic complications regarding thrombolytic therapy by means of r-tPA, streptokinase, or urokinase. Insufficient data are available to conclude the preference of using a hybrid approach, ultrasound-accelerated CDT, heated r-tPA. or novel endovascular (rheolytical) thrombectomy systems. Future trials regarding ALI need to be constructed carefully, ensuring comparable study groups, and should follow standardized practices of outcome reporting.

Comparison of Ultrasound-Accelerated Versus Multi-Hole Infusion Catheter-Directed Thrombolysis for the Treatment of Acute Limb Ischemia

Objective:

Thrombolytic therapy is widely used in the treatment of arterial occlusions causing acute limb ischemia (ALI); however, knowledge regarding the efficacy of the different catheter systems available is scarce. The objective of this study was to compare the safety and efficacy of 2 catheter-directed infusion systems for intra-arterial thrombolysis in the setting of ALI.

Methods:

A retrospective analysis was conducted to study all catheter-directed thrombolysis procedures performed over 32 months in patients diagnosed with ALI. Patients with thrombosis in both native arteries and bypass grafts were included. Patients with contraindications to thrombolysis, or those receiving thrombolysis for deep venous thrombosis, were excluded. The duration of thrombolysis, amount of thrombolytic agent, and technical success rate were recorded. Technical success was defined as complete or near-complete resolution of thrombus burden, allowing for further intervention. Data were stratified to include location of thrombus, procedural complications, mortality, and rates of limb loss.

Results:

Ninety-one patients met inclusion criteria. Among them, Uni-Fuse and EKOS catheters were used in 69 and 22 patients, respectively. The mean age of the population was 71 (standard deviation [SD]: ±1.5) for patients treated with the EKOS catheter and 70 years (SD: ±2.6) for patients receiving thrombolysis with Uni-Fuse. There was no significant difference in the mean infusion duration (1.65 vs 1.9 days), volume of tissue plasminogen activator (44.6 vs 48.2 mg), or technical success rate (72% vs 86%) between the Uni-Fuse and EKOS cohorts ( P > .3). Furthermore, there was no difference in major limb loss or compartment syndrome between each group ( P > .4). The overall complication rate was 14% in both groups, with a 30-day mortality rate of 4% when treated with either catheter system.

Conclusion:

This study suggests that a standard multi-hole infusion catheter demonstrates similar clinical safety and efficacy as the ultrasound-accelerated EKOS system in the treatment of ALI.

Acute on chronic limb ischemia: From surgical embolectomy and thrombolysis to endovascular options

After the invention of the balloon catheter by Fogarty in 1963, surgical thromboembolectomy was considered the gold standard treatment for many years in patients with acute lower limb ischemia (ALLI). ALLI is a dramatic event, carrying a high risk of amputation and perioperative morbidity and mortality. The evolution of endovascular technologies has resulted in a variety of therapeutic options to establish arterial patency. In the 1970s, Dotter first introduced the idea of clot lysis in the treatment of ALLI, which was modified to catheter-directed thrombolysis, and now clot aspiration techniques. Currently, the majority of ALLI (about 70%) is arterial thrombosis, which generally occurs in the setting of preexisting vascular lesion. This condition is very common in patients with diabetes. Clinical presentation in case of thrombosis on atherosclerotic stenosis (so called "acute on chronic ischemia") may be less severe, but treatment is generally more challenging than ALLI due to embolism, considering the complexity in device trackability through the diseased vessels, potential vessel injury, incomplete revascularization, and need of correction of underlying vascular lesions. Although surgery is still a treatment option, especially for ALLI, endovascular interventions have assumed a prominent role in restoring limb perfusion. In this review, the treatment options for ALLI are detailed from surgical thromboembolectomy to thrombolysis and current endovascular techniques, including mechanical fragmentation, rheolytic thrombectomy, and aspiration thrombectomy. The evolution to endovascular therapies has resulted in improved clinical outcomes and lower rates of morbidity.

Could mechanical thrombectomy replace thrombolysis in the treatment of acute and subacute limb ischemia?

Acute limb ischemia is a vascular emergency defined as a sudden decrease in limb perfusion associated with a risk of loss of viability of the affected extremity. Surgical treatment (Fogarty thromboembolectomy) is indicated only in suprainguinal occlusions. Other cases of acute and subacute limb ischemia should be managed percutaneously. Catheter-based treatment involves local thrombolysis and percutaneous mechanical thrombectomy (PMT). There are several devices in use for PMT; of them, the Rotarex system appears to be the most useful. There are no randomized studies comparing thrombolysis and PMT. Only indirect comparison is possible. The immediate and long-term results of PMT using the Rotarex device are probably more favorable than those following thrombolysis. Particularly for older and polymorbid patients, it may be significant that PMT, in comparison with thrombolysis, can restore blood flow faster and in one session; no contraindications for PMT in contrast to potentially life-threatening complications in thrombolysis exist, and there is also no need for observation in intensive care unit after PMT. Hospital stay after PMT is shorter. There is only one exception when thrombolysis cannot be replaced by Rotarex PMT - in the case of crural arteries involvement - due to the catheter size. In our opinion, PMT is superior to thrombolysis in the treatment of acute and subacute limb ischemia. Thrombolysis should be considered only in special cases, e.g. in crural arteries occlusions or in failure of mechanical thrombectomy.

Surgery versus thrombolysis for initial management of acute limb ischaemia

BACKGROUND

Both peripheral arterial thrombolysis and surgery can be used in the management of peripheral arterial ischaemia. Much is known about the indications, risks, and benefits of thrombolysis. However, whether thrombolysis works better than surgery for initial management of acute limb ischaemia remains unknown. This is the second update of the review first published in 2002.

OBJECTIVES

To determine whether thrombolysis or surgery is the more effective technique in the initial management of acute limb ischaemia due to thromboembolism.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist (CIS) searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE Ovid, Embase Ovid, CINAHL, AMED, and clinical trials registries up to 7 May 2018.

SELECTION CRITERIA

All randomised controlled studies comparing thrombolysis and surgery for initial treatment of acute limb ischaemia.

DATA COLLECTION AND ANALYSIS

We independently assessed trial quality and extracted data. Agreement was reached by consensus. We performed analyses using odds ratios (ORs) and 95% confidence intervals (CIs).

MAIN RESULTS

We identified no new studies for this update. We included five trials with a total of 1292 participants; agents used for thrombolysis were recombinant tissue plasminogen activator and urokinase. Trials were generally of moderate methodological quality. The quality of evidence according to GRADE was generally low owing to risk of bias (lack of blinding), imprecision in estimates, and heterogeneity.Trial results showed no clear differences in limb salvage, amputation, or death at 30 days (odds ratio (OR) 1.02, 95% confidence interval (CI) 0.41 to 2.55, 4 studies, 636 participants; OR 0.97, 95% CI 0.51 to 1.85, 3 studies, 616 participants; OR 0.59, 95% CI 0.31 to 1.14, 4 studies, 636 participants, respectively), and we rated the evidence as low, low, and moderate quality, respectively. Trial results show no clear differences for any of the three outcomes at six months or one year between initial surgery and initial thrombolysis. A single study evaluated vessel patency, so no overall association could be determined (OR 0.46, 95% CI 0.08 to 2.76, 20 participants; very low-quality evidence). Evidence of increased risk of major haemorrhage (OR 3.22, 95% CI 1.79 to 5.78, 4 studies, 1070 participants; low-quality evidence) and distal embolisation (OR 31.68, 95% CI 6.23 to 161.07, 3 studies, 678 participants; very low-quality evidence) was associated with thrombolysis treatment at 30 days, and there was no clear difference in stroke (OR 5.33, 95% CI 0.95 to 30.11, 5 studies, 1180 participants; low-quality evidence). Participants treated by initial thrombolysis had a greater reduction in the level of intervention required, compared with a pre-intervention prediction, at 30 days (OR 9.06, 95% CI 4.95 to 16.56, 2 studies, 502 participants). None of the included studies evaluated time to thrombolysis as an outcome.

AUTHORS' CONCLUSIONS

There is currently no evidence in favour of either initial thrombolysis or initial surgery as the preferred option in terms of limb salvage, amputation, or death at 30 days, six months, or one year. Low-quality evidence suggests that thrombolysis may be associated with higher risk of haemorrhagic complications and ongoing limb ischaemia (distal embolisation). The higher risk of complications must be balanced against risks of surgery in each individual case. Trial results show no statistical difference in stroke, but the confidence interval is very wide, making it difficult to interpret whether this finding is clinically important. We used GRADE criteria to assess the quality of the evidence as generally low. We downgraded quality owing to risk of bias, imprecision, and heterogeneity between included studies.

Current Status of Distal Embolization in Femoropopliteal Endovascular Interventions

The application of advanced endovascular techniques in very complex femoropopliteal atherosclerotic lesions has shown to expose patients to a higher risk of distal embolization (DE). This complication can affect both the short- and long-term outcomes, leading to worsening ischemia, early minor/major amputation, and longer hospital stay. Recently, there has been an increasing body of evidence on pathophysiology and clinical–radiological management of DE that however has not been systematically addressed by guidelines. The aim of this review was to analyze the current evidence outlining definition and classification, risk assessment, prevention, and management strategies of DE in femoropopliteal endovascular interventions.

Efficacy versus Complications in Arterial Thrombolysis

BACKGROUND

Acute peripheral arterial occlusions threaten life and limb. Thrombolysis is an established, minimally invasive alternative treatment for surgical thromboembolectomy. Yet, there is no consensus regarding an optimal thrombolysis protocol, and current knowledge is largely based on studies from the 1990s. This study reviews a contemporary cohort of patients treated with thrombolysis and aims to evaluate the treatment results and to identify possible predictors for outcome and (bleeding) complications.

METHODS

The electronic health record data of all consecutive patients who underwent thrombolysis for acute limb ischemia due to thromboembolic lower extremity arterial occlusions between April 2006 and June 2012 were analyzed. End points were change in clinical stage of ischemia, incidence of bleeding complications, duration of thrombolysis, predictors of outcome and complications, and mortality and amputation-free rates after 30-day and 6-months follow-up.

RESULTS

In total, 109 cases were included. Clinical improvement was observed in 79%. Amputation-free rates at 30 days and 6 months were 94% and 90%, respectively. The incidence of major bleeding complications was 13%. Median duration of thrombolysis was 27 (4-68) hr. Mortality rates at 30 days and 6 months were 7% and 16%, respectively; none bleeding related. In addition to age, popliteal artery occlusions and a progressed chronic vascular stage are predictive for a worse outcome. Age, female sex, and cardiac history were risk factors for bleeding.

CONCLUSIONS

Treatment of peripheral arterial occlusions with high-dose thrombolysis on an intensive-care unit yields high clinical success rates, but major bleeding complications are often observed. Strict clinical observation remains essential since intensive monitoring of hemostatic parameters during thrombolysis does not predict bleeding complications.

Ultrasound-assisted thrombolysis of an occluded transjugular portosystemic shunt

Transjugular intrahepatic portosystemic shunt (TIPS) insertion is commonly performed for refractory ascites or variceal bleeding. However, TIPS dysfunction can be seen in both early and late settings, with shunt thrombosis a particular problem. Treatment of shunt dysfunction commonly involves angioplasty and re-lining, with or without embolectomy, mechanical thrombectomy, or thrombolysis. Ultrasound-assisted thrombolysis has been shown to be successful for treatment of pulmonary embolism, deep vein thrombosis, and peripheral arterial thromboembolism, but has not been described before for TIPS occlusion. Ultrasound is theorized to lead to a shortened duration of thrombolysis due to thinning of the fibrin clot and exposing plasminogen receptor sites. In this technical report, we describe the first published use of ultrasound-assisted thrombolysis in the declotting of an occluded TIPS. We found that the use of ultrasound-assisted thrombolysis allowed a relatively short duration of thrombolytic therapy, with removal of thrombus extending into the portal vein, facilitating stent re-lining. No complications were observed, in particular no bleeding complications. The TIPS remains patent at 8 months postprocedure.

Single-center retrospective review of ultrasound-accelerated versus traditional catheter-directed thrombolysis for acute lower extremity deep venous thrombosis

Objective

Systemic anticoagulation remains the standard for acute lower extremity (LE) deep venous thrombosis (DVT), but growing interest in catheter-directed thrombolysis (CDT) and its potential to reduce the incidence of post-thrombotic syndrome (PTS) has led to advent of ultrasound-accelerated CDT (US-CDT). Few studies to date have examined the outcomes of US-CDT against traditional CDT (T-CDT).

Methods

This is a retrospective, single-center review of all patients treated for acute LE DVT over a five-year period with either US- and T-CDT. Patients were stratified based on demographics, presentation, co-morbidities, risk factors, and peri-procedural data.

Results

Seventy-six limbs in 67 patients were treated; 51 limbs in 42 patients were treated with US-CDT, and 25 limbs in 25 patients were treated with T-CDT. Adjuncts include: pharmacomechanical thrombolysis ( n = 28 vs. 20, p = 0.04), angioplasty ( n = 22 vs. 18, p = 0.11), stenting ( n = 30 vs. 6, p ≤ 0.001), and IVC filter insertion ( n = 5 vs. 0, p = 0.07). Mean lysis times were 21 ± 1.7 and 24 ± 1.8 h for US- and T-CDT, respectively ( p = 0.26). Thirty (25 ultrasound, 5 traditional) limbs had complete lysis. Thirty-one (22 ultrasound, 9 traditional) limbs had incomplete lysis. Fifteen (4 ultrasound, 11 traditional) limbs had ineffective lysis ( p = 0.002 in favor of ultrasound). Four patients (3 US-CDT, 1 T-CDT) had recurrent ipsilateral thrombosis within 30 days ( p = 0.60). By Kaplan-Meier analysis, there were no significant difference between primary patency, primary-assisted patency, secondary patency, re-thrombosis, and recurrent symptoms at 6, 12, and 24 months.

Conclusion

US-CDT does not significantly improve mid-term patencies but results in greater acute clot burden reduction in patients with acute LE DVTs compared to T-CDT, which may be beneficial in reducing the long-term incidence of PTS.

Thrombolysis in peripheral artery disease

Peripheral artery disease (PAD) has been associated with severe morbidity and mortality worldwide, affecting the quality of life for millions of patients. Acute thrombosis has been identified as a major complication of PAD, with proper management including both open as well as endovascular techniques. Thrombolysis has emerged as a reasonable option in the last decades to treat such patients although data produced by randomized trials have been limited. This review aims to present major aspects of thrombolysis in PAD regarding its indications and contraindications, technique tips as well as to review literature data in order to produce useful conclusions for everyday clinical practice.

Comparative Outcomes of Ultrasound-Assisted Thrombolysis and Standard Catheter-Directed Thrombolysis in the Treatment of Acute Pulmonary Embolism

OBJECTIVES

The objective of this study was to compare the outcomes of patients undergoing ultrasound-accelerated thrombolysis (USAT) and standard catheter-directed thrombolysis (CDT) for the treatment of acute pulmonary embolism (PE).

METHODS

The records of all patients in our institution having undergone CDT or USAT for massive or submassive PE from 2009 to 2014 were retrospectively reviewed. Standard statistical methods were used to compare characteristics and to assess for longitudinal change in outcomes.

RESULTS

Sixty-three patients, 27 CDT and 36 USAT, were treated for massive (12.7%) or submassive (87.3%) PE. Of which, 96.8% were treated for bilateral PE. Baseline patient characteristics did not differ between the 2 treatment groups. There was no difference in total dose of lytic administered (CDT: 23.2 ± 13.7 mg; USAT: 27.5 ± 12.9 mg; P = .2). Two patients in the CDT and 1 in the USAT groups required conversion to surgical thrombectomy (CDT: 7.4%; USAT: 2.8%; P = .6). Rates of major and minor bleeding complications (CDT: 11.0%; USAT: 13.9%; P = .8) did not differ significantly between the CDT and USAT groups. Estimated survival at 90 days was 92% for CDT and 93% for USAT and 82% at 1 year for both groups (P = .8). All echocardiographic parameters improved significantly from baseline to 1-year follow-up, but quantitative improvement did not differ between groups.

CONCLUSION

This study suggests no statistical differences in clinical and hemodynamic outcomes or procedural complication rates between USAT and standard CDT for the treatment of acute PE. Prospective studies are needed to further evaluate comparative and cost-effectiveness of different interventions for acute massive and submassive PE.

Current Endovascular Management of Acute Limb Ischemia

Acute limb ischemia is a vascular emergency, threatening the viability of the affected limb and requiring immediate recognition and treatment. Even with revascularization of the affected extremity, acute limb ischemia is associated with significant morbidity and mortality resulting in up to a 15% risk of amputation during the initial hospitalization and a 1 in 5 risk of mortality within 1 year of the index event. This review summarizes the current management of acute limb ischemia. Understanding the diagnosis and therapeutic options will aid clinicians in treating these critically ill patients.