Long-Term Outcomes of Catheter-Directed Thrombolysis for Acute Lower Extremity Occlusions of Native Arteries and Prosthetic Bypass Grafts

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.

Sex-related differences in the effect of rotational thrombectomy for thrombus-containing lower limbs ischemic lesions

BACKGROUND

To assess the immediate effect and factors affecting the efficacy of rotational thrombectomy (RT) in patients with thrombus-containing lower-limb ischaemic lesions.

METHODS

Patients were retrospectively divided into two groups: RT and RT+ CDT (Catheter-directed thrombolysis). The RT group included patients in whom intraoperative thrombus aspiration was successful, while the RT + CDT group included patients in whom intraoperative thrombus aspiration was less effective and remedial CDT treatment was used. The primary outcome was the immediate effect of RT on thrombus-containing lower-limb ischaemic lesions.

RESULTS

From May 2015 to July 2021, 170 patients (113 men, 57 women; mean age, 74.0 years) with thrombus-containing lower-limb ischaemic lesions were treated in our centre. Of these patients, 113 received RT only, while 57 received RT + CDT. There were no significant intergroup differences in terms of age, disease duration, or comorbidities, but a higher proportion of male patients and higher preoperative plasma D-dimer levels (1.23 vs. 0.84; p = .017) was observed in the RT + CDT group. There were no significant intergroup differences in terms of diagnosis, lesion characteristics, lesion location, or lesion length. Multivariate logistic regression analysis revealed that male sex (odds ratio [OR], 2.65; 95% confidence interval [CI], 1.098-6.410; p = .030) and poor distal runoff (OR, 2.94; 95% CI, 1.439-5.988; p = .003) were associated with higher rates of additional CDT. Male patients also had a significantly longer onset time, more thrombotic occlusions, and a greater frequency of in-stent restenosis.

CONCLUSIONS

RT alone or with CDT is a feasible primary treatment option for thrombus debulking. Sex significantly influences the effect of RT on thrombus-containing lower-limb ischaemic lesions.

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.

In-Hospital Outcomes after Endovascular Therapy for Acute Limb Ischemia: A Report from a Japanese Nationwide Registry [J-EVT Registry]

Aim: The aim of the current study was to describe the clinical profile, frequency of in-hospital complications, and predictors of adverse events in patients undergoing endovascular therapy (EVT) for acute limb ischemia (ALI), and to compare them with those of patients undergoing EVT for chronic symptomatic peripheral artery disease (PAD).

Methods: The current study compared 2,398 cases of EVT for ALI with 74,171 cases of EVT for chronic symptomatic PAD performed between January 2015 and December 2018 in Japan. We first compared the clinical profiles of ALI patients with those of PAD patients. We then evaluated the proportion of in-hospital complications and investigated their risk factors in the ALI patients. The association of clinical characteristics with the risk of in-hospital complications was analyzed via logistic regression modeling.

Results: Patients with ALI were older and had a higher prevalence of female sex, impaired mobility, and history of cerebrovascular disease, but a lower prevalence of cardiovascular risk factors and history of coronary artery disease. The proportion of in-hospital EVT-related complications in ALI was 6.1% and was significantly higher compared with those in chronic symptomatic PAD patients (2.0%, P ＜0.001). Bedridden status (adjusted odds ratio [aOR], 1.74 [1.14 to 2.66]; P =0.010), history of coronary artery disease (aOR, 1.80 [1.21 to 2.68]; P =0.004), and a suprapopliteal lesion (aOR, 1.70 [1.05 to 2.74]; P =0.030) were identified as independent risk factors for in-hospital complications.

Conclusion: The current study demonstrated that ALI patients with significant comorbidities show a higher proportion of in-hospital complications after EVT.

Safety aspect of intraoperative, local urokinase lysis in patients with acute lower limb ischemia

BACKGROUND

Acute lower limb ischemia (ALI) is associated with a high risk of limb loss and death.

OBJECTIVE

The present study evaluates the safety of intraoperative, local urokinase lysis in patients with ALI and crural artery occlusion.

METHODS

A total of 107 patients (115 legs) were treated surgically for ALI with additional intraoperative urokinase lysis to improve the outflow tract. Minor and major bleeding as well as efficacy of treatment and amputation-free survival were investigated.

RESULTS

Complete restoration of at least one run-off vessel was achieved in 64%. Collateralization was improved in 34%. Lysis failed in 2%. Major amputation rate was 27% overall (12% within 30 days) and depended on Rutherford class of ALI (overall/30 day: IIa 11%/6%; IIb 20%/17%; III 37%/15%). Amputation-free survival turned out to be 82% after 30 days, 58% after one, and 41% after five years. Minor bleeding occurred in 21% (24/115) and major bleeding in 3.5% (4/115). One of these patients died of haemorrhage. No patient experienced intracranial bleeding.

CONCLUSION

Intraoperative urokinase lysis improves limb perfusion and causes low major and intracranial bleeding. It can be safely applied to patients with severe ischaemia when surgical restoration of the outflow tract fails.

Acute kidney injury following percutaneous mechanical thrombectomy of subclavian artery stent graft thrombosis: a case report

BACKGROUND

Percutaneous mechanical thrombectomy (PMT) is a well-established technique for treatment of acute arterial and venous thrombosis which inevitably leads to intravascular erythrocyte hemolysis, resulting in hemoglobinuria.

CASE PRESENTATION

We present a case of 66-year-old Caucasian female with subclavian artery aneurysm causing distal embolization and hand ischemia. The aneurysm was treated with stent graft, but with a subsequent graft thrombosis 3 months later. After graft recanalisation, AngioJet PMT was performed which resulted in dialysis-requiring acute kidney injury.

CONSLUSION

Only several cases of acute kidney injury following AngioJet PMT have been published in literature. To our knowledge, this is the first reported case of dialysis-requiring AKI after PMT for peripheral arterial thrombosis. Until there is sufficient evidence and recommendation on preventing AKI in this setting, we believe that by being aware of the risk and by monitoring of patient, one might minimize the damage in case it occurs.

Acute Limb Ischemia Interventions

Acute limb ischemia (ALI) is a sudden decrease in limb perfusion that threatens limb viability. Using the Rutherford classification, limbs can be categorized as threatened but viable, or irreversibly damaged, which aids clinicians in selecting appropriate therapy. Treatment options for threatened limbs include catheter-directed thrombolysis, percutaneous mechanical thrombectomy, and surgical revascularization. Potential complications from ALI and treatment include ischemia-reperfusion injury, compartment syndrome, systemic inflammatory response syndrome, multiple organ dysfunction syndrome, hyperkalemia, and bleeding.

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.

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.

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%.

Limb Salvage After Percutaneous Mechanical Thrombectomy in Patients with Acute Lower Limb Ischemia: A Retrospective Analysis from Two Institutions

BACKGROUND

To evaluate the short-term outcomes of percutaneous mechanical thrombectomy (PMT) in patients with acute lower limb ischemia (ALI) and to analyze the effect of ALI of different etiologies on the limb salvage.

MATERIALS AND METHODS

From January 2015 to December 2017, a retrospective analysis was performed on 112 patients (mean age: 66.5 years; 117 limbs in total; 66 limbs in 61 males) with ALI treated with PMT at 2 vascular institutions. Of the 117 limbs, 44 (41 patients) had acute arterial embolism, 36 (34 patients) had acute arterial thrombosis, and 37 (37 patients) had acute stent (31 limbs in 31 patients) or graft (6 limbs in 6 patients) thrombosis. The primary end point was limb salvage rate, and subgroups were analyzed by etiological factors. The secondary end points included patency rates, major bleeding complications, 30-day mortality, and reintervention rates.

RESULTS

The 30-day mortality rate was 3.6%. The incidence of major bleeding complications was 2.7%. During the follow-up, the limb salvage rates at 1 year and 2 years were 83.8% and 74.7%, respectively. Subgroup analysis showed that the limb salvage rate in patients with acute arterial embolism was 92.9% at 2 years after PMT, which was higher than that in patients with acute arterial thrombosis (73.3%, P = 0.04, hazard ratio [HR]: 3.6, 95% confidence interval [CI]: 1.1-11.7) and acute stent/graft thrombosis (62.5%, P = 0.01, HR: 4.7, 95% CI: 1.5-13.6).

CONCLUSIONS

PMT in patients with ALI is effective in preventing amputations over the 3-year study period with a reasonable safety profile, especially in patients with acute arterial embolism.

Patient Assessment: Clinical Presentation, Imaging Diagnosis, Risk Stratification, and the Role of Pulmonary Embolism Response Team

Pulmonary embolism (PE) is currently the third leading cause of death and moreover is likely underdiagnosed. PE remains the most common preventable cause of hospital deaths in the United States, which may be attributable to its diagnostic challenges. Although difficult to diagnose, patient mortality rates are time-dependent, and thus, the suspicion and diagnosis of PE in a timely manner is imperative. Diagnosis based on several criteria which may dictate imaging workup as well as laboratory tests and clinical parameters are discussed. The evolution of treatment guidelines via various clinical trials and recommendations is outlined, setting the stage for the use of fibrinolytics, whether systemic or catheter directed. Treatment, including fibrinolytics, is predicated on patient triage into three large categories-massive, submassive, or low-risk PE. Additionally, a relatively new concept of a multidisciplinary team composed of several subspecialty experts known as the PE response team (PERT) is discussed. PERT's timely and unified recommendations have been shown to optimize care and decrease mortality while tailoring treatment to each individual afflicted by PE.

Intraprocedural Distal Embolization After Femoropopliteal Angioplasty: Is There a Role for Below-the-Knee Stents?

PURPOSE

Intraprocedural distal embolization is an accepted complication of femoropopliteal angioplasty. The purpose of this study is to assess the use of below-the-knee stents in the "bail-out" of conventional methods.

MATERIALS AND METHODS

We retrospectively reviewed 1485 of femoropopliteal angioplasties that were performed in our centre in a 4-year period and analysed 12 cases (<1%) where distal embolization that required further intervention occurred. In all cases lesions were chronic and 75% suffered from critical limb ischaemia. The target vessel was the SFA in all of the cases with a long (>10 cm) occlusion in 50%. A three-vessel run-off was present in only 25%. Patients that received a stent as a limb salvage attempt were analysed. Outcome measures were technical success, clinical success and procedure-related complications. Multivariate regression analysis of the factors related to stenting was also performed.

RESULTS

In 41% of the cases with distal embolization, recanalization with aspiration, thrombolysis or angioplasty offered a satisfactory result. In 59%, conventional methods were ineffective; a stent was deployed in 85%, whereas in 15% surgical embolectomy was required. Technical and clinical success of the stent cases was 100% without any procedure-related complications. There was significance (p < 0.05) between critical limb ischaemia and stenting; single-vessel run-off has also shown a positive trend (p = 0.88).

CONCLUSION

Stents appear as a valid salvage option for infragenicular distal embolization when conventional methods fail; the likelihood of having to use a stent is higher for patients with critical limb ischaemia and a single-vessel run-off.