Rapid thrombectomy with a hydrodynamic catheter: results from a prospective, multicenter trial

Neurosurgical Breakthroughs of the Last 50 Years: A Historical Journey Through the Past and Present

This article presented the author's historical perspective on 25 of the most significant neurosurgical breakthrough events of the last 50 years. These breakthroughs have advanced neurosurgical patient care and management. They have improved the management of aneurysms, arteriovenous malformations, tumors, stroke, traumatic brain injury, movement disorders, epilepsy, hydrocephalus, and spine pathologies. Neurosurgery has evolved through research, innovation, and technology. Several neurosurgical breakthroughs were achieved using neuroendoscopy, neuronavigation, radiosurgery, endovascular techniques, and refinements in computer technology. With these breakthroughs, neurosurgery did not change; it just progressed. Neurosurgery should continue its progress through research to obtain new knowledge for the benefit of our patients.

Contraindications to tissue plasminogen activator thrombolysis for acute lower extremity ischemia

OBJECTIVE

Previous randomized prospective trials have demonstrated the effectiveness of transcatheter tissue plasminogen activator (tPA) thrombolysis in treating acute limb ischemia (ALI) compared to conventional surgery. These pivotal trials have also highlighted contraindications for these procedures. Given recent advancements in techniques and technology, our aim is to reassess the relevance of these contraindications in contemporary practice.

METHODS

A retrospective chart analysis was performed utilizing the inpatient medical records of consecutive individuals who underwent tPA treatment for acute limb ischemia (ALI) from September 2016 to April 2022. Inclusion criteria encompassed patients aged 18 and above displaying clinical symptoms and imaging evidence of ALI within 14 days. All patients received tPA with suction thrombectomy following the fast-track thrombolysis protocol. In cases where a persistent thrombus or stenosis was detected, catheter-directed thrombolysis was considered overnight, and patients underwent angiography and reassessment in the operating room subsequently.

RESULTS

Patients were classified into two groups based on the STILE trial's established contraindications for endovascular treatment in acute limb ischemia (ALI). If a patient had any of these contraindications, they were placed in the contraindicated group. This resulted in 24 patients (32%) in the contraindicated group and 52 patients (68%) in the non-contraindicated group. No statistically significant demographic variations were observed between these groups. Contraindications in our study included uncontrolled hypertension (12/24, 50%), recent invasive procedures (7/27, 29%), history of cerebrovascular accident (CVA) within 6 months (3/24, 12%), and intracranial malformation/neoplasms (2/24, 8%). Three patients within the non-contraindicated group experienced bleeding complications: two with puncture site bleeds and one with nasal bleeding. In contrast, one patient in the contraindicated group had transient postoperative hematuria. There were no significant differences in bleeding complications observed between the two groups (p = .771). Additionally, no amputations were observed within our population.

CONCLUSIONS

In light of our study results and advancements in endovascular therapies, we can now safely and efficiently treat patients who were previously considered contraindicated for such treatments. It is essential to individualize treatments and carefully balance the risks and benefits of endovascular versus open surgical revascularization for these patients. Additionally, we believe that the nearly 30-year-old guidelines for endovascular therapies need to be revisited and updated to align with modern technology.

Acute ischemia of the upper and lower limbs: Tailoring the treatment to the underlying etiology

Acute limb ischemia (ALI) can be a devastating clinical emergency with potentially limb- or life-threatening consequences. It is defined as a quickly developing or sudden decrease in limb perfusion producing new or worsening symptoms and signs, often threatening limb viability. ALI is commonly related to an acute arterial occlusion. Rarely, extensive venous occlusion can lead to upper and lower extremities ischemia (ie, phlegmasia). The incidence of acute peripheral arterial occlusion causing ALI is approximately 1.5 cases per 10,000 people per year. The clinical presentation depends on the etiology and whether the patient has underlying peripheral artery disease. Except for traumas, the most common etiologies are embolic or thrombotic events. Peripheral embolism, likely related to embolic heart disease, is the most common cause of acute upper extremity ischemia. However, an acute thrombotic event may occur in native arteries, at the site of a pre-existing atherosclerotic plaque, or as a failure of previous vascular interventions. The presence of an aneurysm may predispose to ALI for both embolic and thrombotic mechanisms. Immediate diagnosis, accurate assessment of limb viability, and prompt intervention, when needed, play important roles in salvaging the affected limb and preventing major amputation. Severity of symptoms is usually dependent on the amount of surrounding arterial collateralization, which may often reflect a pre-existing chronic vascular disease. For this reason, early recognition of the underlying etiology is crucial for choice of best management and definitely for treatment success. Any error in the initial evaluation may negatively affect the functional prognosis of the limb and endanger the patient's life. The aim of this article was to discuss diagnosis, etiology, pathophysiology, and treatment of patients with acute ischemia of the upper and lower limbs.

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.

Comparison of Direct Iliofemoral Stenting Following AngioJet Rheolytic Thrombectomy vs Staged Stenting After AngioJet Rheolytic Thrombectomy Plus Catheter-Directed Thrombolysis in Patients With Acute Deep Vein Thrombosis

Purpose: To compare the treatment outcomes in patients with acute proximal deep vein thrombosis (DVT) and iliofemoral stenosis who underwent either direct stenting after AngioJet rheolytic thrombectomy or staged stenting after AngioJet thrombectomy plus catheter-directed thrombolysis with urokinase. Methods: From June 2014 to February 2016, 91 DVT patients underwent 2 treatments for duplex-verified iliofemoral stenosis: direct stenting (n = 46; mean age 54.8 years; 32 men) or staged stenting (n = 45; mean age 56.5 years; 27 men). The degree of patency after thrombectomy or thrombolysis was evaluated using the Venous Registry Index (VRI), while the risk of postthrombotic syndrome (PTS) was evaluated according to the Villalta scale. Patients were followed with periodic duplex ultrasound scans up to 1 year. Results: The technical success rates were 100% in both groups; there was no 30-day mortality. Immediate (24-hour) clinical improvement was achieved in 42 (91%) of 46 direct group patients vs 33 (73%) of 45 staged group patients (p<0.001). A significant reduction (p<0.001) in the length of hospital stay was noted in the direct group (4.59±0.91) compared with that in the staged group (5.8±1.6). The stents used in the direct group were longer but with similar diameter compared with the staged group. The thrombolysis rates were 81.50%±5.76% in the direct group and 85.67%±3.84% in the staged group (p<0.001). The VRIs declined (improved) significantly in both groups (11.68±1.92 to 3.21±1.44 in the direct group and 12.17±2.29 to 2.36±1.19 in the staged group, both p<0.001). The Villalta scores were significantly better in the staged group (p<0.001). Recurrent DVT occurred in 2 patients in the direct group. The primary patency rates at 1 year were 93.5% in the direct group and 97.8% in the staged group (p=0.323). Conclusion: Both direct and staged stenting are effective treatment modalities for patients with acute proximal DVT. Compared with staged stenting, direct stenting provides similar treatment success and a significant reduction in the length of hospital stay; however, it has lower thrombolysis efficacy, and the risk of PTS at 1 year is greater with direct stenting.

Early Thrombosuction and Tirofiban Use in Knee and Below-Knee Arterial Thrombosis

BACKGROUND Acute limb ischemia (ALI) is a clinical entity with a high rate of morbidity and mortality. Despite advances and variety of its management, there is still no criterion standard treatment. The goal of this study was to evaluate the effect of tirofiban use on the early and 6-month prognosis of patients with knee and below-knee arterial thrombosis who were treated with percutaneous thrombosuction (PT) within 24 h. MATERIAL AND METHODS Data of consecutive ALI patients who were diagnosed with popliteal and infra-popliteal arterial thrombosis and underwent PT procedure within 24 h between January 2010 and September 2015 were evaluated retrospectively. Patients were separated into 2 groups according to tirofiban usage. RESULTS A total of 105 patients (mean age 67±16; 53% men) were included in the study. Atrial fibrillation (n 64, 61%) and hypertension (n 60, 57%) were the most frequent comorbidities in patients with thromboembolic events. A significantly higher rate of distal embolization (6% vs. 16%; p=0.01) and slow-flow (17% vs. 30%; p<0.01) developed in patients who were not treated with tirofiban after the PT procedure. Although major and minor bleeding were more frequent in the tirofiban group, only the rate minor bleeding was statistically significant (29% vs. 9%, p=0.001). Reverse embolic event ratio was similar in both groups. Although there was a higher rate of amputation in patients not treated with tirofiban, the difference was not significant. CONCLUSIONS Adding tirofiban to PT reduces angiographic thromboembolic complications. Usage of tirofiban in patients prone to thromboembolic events may be useful for improving success of the PT procedure, with a reasonable bleeding ratio.

Acute Iliac and Femoral Arterial Thrombosis Secondary to Total Hip Arthroplasty

In the presented case report, we evaluated the mechanism of the external iliac, the common femoral and the superficial femoral arterial thrombosis secondary to total hip arthroplasty. A 75-year-old female sufferd from 5.5 cm shorter left lower limb and same sade coxarthritis. Next day after arthroplasty and eqalisation of the lower limbs, an acute ishemia of the treated leg was presented. Multyscan CT angiography revealed the presence of the external iliac, the common femoral and the superficial femoral arterial thrombosis. From the best of our knowledge, it seems to be the only case of this arterial segment thrombosis after total hip arthroplasty and equalistaion of the lower limbs reported.

Axillary Arterial Thrombosis Secondary to Re-Fracture of the Humerus

In the presented case report, we evaluated mechanism of axillary artery thrombosis in cases of repeated fracture of the shoulder. A 73-year-old female fell down on an outstretched hand. Radiographs demonstrated a Neer’s 2-part displaced fracture of the proximal humerus and open fracture of the acromion. Forty years ago, in a car accident, fractures of the same proximal humerus and clavicle occurred and were surgically treated. Two hours after fixation with Kirschner wires, thrombosis of the axillary artery was quickly diagnosed and rapid treatment allowed revascularisation of the arm without any consequences.

Acute Limb Ischemia

Acute limb ischemia is a vascular event presenting with sudden decrease in limb perfusion (of <14 days' duration) that threatens limb viability. Acute thrombosis of the native artery or graft makes up the bulk of etiopathogenesis. Prompt revascularization is the cornerstone of management of acute limb ischemia in limbs that have not undergone irreversible tissue and nerve damage. Amputation is performed in patients with irreversible tissue and nerve damage.

One of the most urgent vascular circumstances: Acute limb ischemia

Acute limb ischemia is a sudden decrease in limb perfusion that threatens limb viability and requires urgent evaluation and management. Most of the causes of acute limb ischemia are thrombosis of a limb artery or bypass graft, embolism from the heart or a disease artery, dissection, and trauma. Assessment determines whether the limb is viable or irreversibly damaged. Prompt diagnosis and revascularization by means of catheter-based thrombolysis or thrombectomy and by surgery reduce the risk of limb loss and mortality. Amputation is performed in patients with irreversible damage. Despite urgent revascularization, amputation rate is 10%–15% in patients during hospitalization, mostly above the knee, and mortality within 1 year is 10%–15% due to the coexisting conditions.

Treatment of infrainguinal thromboembolic complications during peripheral endovascular procedures with AngioJet rheolytic thrombectomy, intraoperative thrombolysis, and selective stenting

OBJECTIVE

This study investigated the safety and effectiveness of the infrainguinal use of the AngioJet rheolytic mechanical thrombectomy system (Possis Medical, Minneapolis, Minn) for the treatment of acute infrainguinal thromboembolism occurring during lower limb revascularization procedures.

METHODS

For the interval between January 2000 and January 2011, our hospital's database was meticulously searched for all patients with acute thromboembolism that occurred during lower limb angioplasty, with or without stenting procedures, who were treated with infrainguinal AngioJet thrombectomy. Baseline patient demographics and procedural details were analyzed. Primary end points included technical success, defined as the complete revascularization of the acutely occluded vessel; clinical success, defined as the absence of death or amputation ≤ 60 days; and procedure-related complication. Secondary end points included embolized vessel primary patency and overall patient survival.

RESULTS

During this 12-year period, 3147 peripheral percutaneous procedures of angioplasty, with or without stenting, were performed in our department. Intraoperative, clinically, and angiographically evident thromboembolism occurred in 18 of 3147 procedures (0.57%), and 14 (77.7%) were managed using the AngioJet thrombectomy system. In total, 22 arteries were treated (13 infrapopliteal, 3 femoropopliteal, and 6 popliteal arteries). All patients had a completion angiogram for the assessment of the runoff vessels' status. Technical and clinical success occurred in 13 of 14 (92.8%). Adjunctive local thrombolysis or clot trapping, or both, with stenting was used in 64.3% and 42.8% of the procedures, respectively. Mean time follow-up was 38.1 ± 49.0 months. The 1-year embolized vessel primary patency rate was 50.9%, and the survival rate was 53.5% up to 11.5 years of follow-up, as estimated by Kaplan-Meier analysis. The 1-year limb salvage rate was 92.3%. There were no procedure-related minor amputations and one (7.1%) procedure-related major above-knee amputation.

CONCLUSIONS

The use of AngioJet rheolytic thrombectomy and adjunctive local thrombolysis or stenting, or both, under filter protection, is safe and effective for the management of severe thromboembolic complications occurring in the femoropopliteal and infrapopliteal arteries during peripheral endovascular procedures.

Quality improvement guidelines for percutaneous catheter-directed intra-arterial thrombolysis and mechanical thrombectomy for acute lower-limb ischemia

Percutaneous catheter-directed intra-arterial thrombolysis is a safe and effective method of treating acute and subacute lower limb ischemia, as long as accurate patient selection and procedural monitoring are ensured. Although larger, controlled trials are needed to establish the role of PTDs in ALI, mechanical thrombectomy could currently be applied combined with lytic infusion in selected cases where rapid recanalization is required or as a stand-alone therapy when the administration of thrombolytic agents is contraindicated.

Acute limb ischemia

Acute limb ischemia is a medical emergency with management options ranging from urgent revascularization to limb amputation. The best patient outcome requires tailoring the treatment to the individual patient. This article describes a step-by-step approach for diagnosis and management of patients presenting with acute limb ischemia.

Endovascular treatment of peripheral vascular disease

Peripheral arterial disease (PAD) affects about 27 million people in North America and Europe, accounting for up to 413,000 hospitalizations per year with 88,000 hospitalizations involving the lower extremities and 28,000 involving embolectomy or thrombectomy of lower limb arteries. Many patients are asymptomatic and, among symptomatic patients, atypical symptoms are more common than classic claudication. Peripheral arterial disease also correlates strongly with risk of major cardiovascular events, and patients with PAD have a high prevalence of coexistent coronary and cerebrovascular disease. Because the prevalence of PAD increases progressively with age, PAD is a growing clinical problem due to the increasingly aged population in the United States and other developed countries. Until recently, vascular surgical procedures were the only alternative to medical therapy in such patients. Today, endovascular practice, percutaneous transluminal angioplasty with or without stenting, is used far more frequently for all types of lower extremity occlusive lesions, reflecting the continuing advances in imaging techniques, angioplasty equipment, and endovascular expertise. The role of endovascular intervention in the treatment of limb-threatening ischemia is also expanding, and its promise of limb salvage and symptom relief with reduced morbidity and mortality makes percutaneous transluminal angioplasty/stenting an attractive alternative to surgery and, as most endovascular interventions are performed on an outpatient basis, hospital costs are cut considerably. In this monograph we discuss current endovascular intervention for treatment of occlusive PAD, aneurysmal arterial disease, and venous occlusive disease.

Acute kidney injury caused by intravascular hemolysis after mechanical thrombectomy

BACKGROUND

A 43-year-old African-American female (gravida 5 para 0) with an 8-week intrauterine pregnancy presented to the emergency room with crampy abdominal pain, shortness of breath, and shoulder pain. She had normal renal function on admission. CT angiography of the chest revealed bilateral pulmonary emboli; therefore, the AngioJet (Possis Medical, Inc., Minneapolis, MN) device was used to perform mechanical thrombolysis. The patient subsequently developed hyperkalemia, red urine and anuria.

INVESTIGATIONS

Physical examination, measurement of serum creatinine level and electrolytes, dipstick urinalysis and centrifugation of urine and blood.

DIAGNOSIS

Acute kidney injury due to hemoglobinuria as a result of non-immune-mediated intravascular hemolysis following the use of a percutaneous mechanical thrombectomy device (AngioJet).

MANAGEMENT

Hydration, alkalinization of urine and initiation of hemodialysis (temporarily switched to continuous venovenous hemodiafiltration). Urine output improved after the 20th day of hospitalization, at which point dialysis was discontinued. The patient's renal function completely recovered by day 25.

[Peripheral arterial obstruction and acute lower limb ischemia]

In this article, current evidence-based treatment recommendations for acute and chronic lower limb ischemia will be presented considering the varied possibilities of endovascular techniques and open surgical vascular strategies. Beside presentation of the different therapeutic possibilities, advantages of the combination of both techniques will be described. Despite the BASIL trial, there are no prospective randomised controlled trials comparing endovascular and open surgical interventions. Different therapeutic rules along the different vascular segments will be discussed for both acute and chronic peripheral arterial disease. Generally it can be stated that aortoiliac revascularization for chronic obstructions is increasingly being carried out by endovascular means or hybrid procedures using a minimally invasive femoral approach, whereas acute occlusions in this vascular segment are still treated with open surgical techniques (Fogarty balloon thrombectomy). In the infrainguinal region, endovascular therapeutic strategies are gaining favor. However, multilevel occlusions and long-segment obstructions in the femoral and popliteal segment are still treated by bypass procedures. Acute ischemia in the infrainguinal segment is increasingly treated with endovascular methods (local thrombolysis and percutaneous thrombectomy).

Successful complex bifurcation stenting of a native SFA after failed femoropopliteal bypass grafting

Endovascular treatments are becoming more beneficial in the treatment of complex peripheral arterial disease. We report a novel case of using a y-stenting technique at 2 bifurcation sites in the femoropopliteal region, to revascularize a long native SFA occlusion after failed femoropopliteal bypass grafting.

Comparison of AngioJet Rheolytic Pharmacomechanical Thrombectomy versus AngioJet Rheolytic Thrombectomy in a Porcine Peripheral Arterial Model

INTRODUCTION

Rheolytic thrombectomy using the AngioJet catheter for arterial thrombosis has been shown to be effective in restoring blood flow. Additional infusion of thrombolytic agents via the AngioJet catheter results in combined rheolytic pharmacomechanical thrombolysis (PMT), which further enhances thrombectomy efficacy. However, the histologic response to rheolytic PMT therapy remains unclear. This study compares the acute and chronic vessel wall response and hemolysis due to conventional AngioJet rheolytic thrombectomy (RT) and AngioJet PMT in the porcine peripheral arterial model.

METHODS

A total of 19 juvenile pigs were divided into acute and chronic groups. In the acute group (n = 6), bilateral common carotid, femoral, and iliac arteries ranging from 3 to 6 mm in diameter were randomized to the control RT group or to PMT therapy. Vessels were analyzed 4 days following interventions. In the chronic group (n = 5), bilateral common carotid, femoral, and iliac arteries ranging from 3 to 6 mm in diameter were randomized to the control RT group or to PMT therapy. Vessels were analyzed at 30 days following interventions. Hemolytic evaluation was performed in additional eight pigs, which were randomized to either RT or PMT intervention.

RESULTS

In the acute group, similar histologic injury grades were noted between the RT- and PMT-treated femoral and iliac vessels. Endothelial denudation in the RT and PMT vessels were 43% and 39% (NS), respectively. Vessels with intact internal elastic lamina (IEL) in the RT and PMT groups were 54% and 57% (NS), respectively. In vessels < 4 mm in diameter, fractured IEL in the AT and PMT groups occurred in 23% and 27% (NS), respectively. The degrees of smooth muscle cell (SMC) loss were similar for the RT- and PMT-treated vessels (45% and 40%, respectively; NS). In the chronic group, no differences were seen between the RT and PMT groups with respect to endothelial denudation, IEL fracture rate, or SMC loss. Similar degrees of medial thickening or intimal hyperplasia were noted in the RT and PMT groups (49% and 43%, respectively; NS). No difference in hemolytic effect was noted in the treatment groups.

CONCLUSIONS

AngioJet rheolytic pharmacomechanical thrombectomy treatment incurs an equivalent safety profile in medium-caliber peripheral arteries when compared to rheolytic thrombectomy treatment. No difference in hemolytic reaction occurred in either group. The observed clinical efficacy of rheolytic pharmacomechanical thrombectomy does not result in untoward vessel injury compared to conventional rheolytic thrombectomy therapy.

Endovascular Treatment of Peripheral Vascular Disease

An estimated 10 million people in the U.S. have symptomatic peripheral arterial disease (PAD); 20 to 30 million have asymptomatic PAD. The prevalence of intermittent claudication increases with age, affecting >5% of patients over 70. The incidence of claudication doubles or triples in patients with diabetes. As people grow older, symptoms from peripheral vascular disease increasingly limit daily activity. Until recently, vascular surgical procedures were the only alternative to medical therapy in such patients. Today, advances in minimally invasive percutaneous interventions have made endovascular procedures the primary modality for revascularization in most patients. Compared with open surgical procedures, endovascular interventions offer comparable or superior long-term rates of success with very low rates for morbidity and mortality. Furthermore, most of these interventions are performed on an outpatient basis, reducing hospital stays considerably. In this monograph we discuss current endovascular interventions for treating occlusive PAD, aneurysmal arterial disease, and increasingly common venous occlusive diseases.

Recanalization of acute and subacute femoropopliteal artery occlusions with the rotarex catheter: one year follow-up, single center experience

PURPOSE

To assess the efficacy and safety of a new rotational catheter for percutaneous removal of fresh and organized thrombi in the femoropopliteal artery.

METHODS

Forty-one limbs in 38 patients (age 56--90 years, mean 75.6 years) with acute, subacute or chronic femoropopliteal occlusions of 1--180 days' duration (mean 31.6 days) were treated with the Rotarex device. The Fontaine stage was mainly IIB (Rutherford 2--3, 22 patients) or III (Rutherford 4, 14 patients). The length of occlusion varied from 2 to 35 cm (mean 13.1 cm). After recanalization percutaneous transluminal angioplasty (PTA) was performed if there was a residual stenosis of >25%. Patients were followed up with color Doppler ultrasound at 48 hr and clinically with Doppler pressures and oscillometry at 3, 6, and 12 months.

RESULTS

After an average of two passages with the Rotarex catheter all but two limbs required PTA for residual stenosis >25%. Five patients needed additional stenting. Major complications were one groin hematoma requiring blood transfusion and one arteriovenous fistula spontaneously thrombosing after unsuccessful primary prolonged balloon dilation. Distal embolizations occurred in 10 patients; 6 clinically relevant emboli were aspirated. All occlusions were technically successfully recanalised there were 2 early reocclusions after 1 day and two at 2 weeks. Brachial-ankle indices improved from an average of 0.41 before to 0.93 after recanalization. Primary and secondary patency rates were 62% / 84% after 6 months and 39% / 68% after 1 year. The amputation-free survival at 12 months was 100%.

CONCLUSION

The Rotarex mechanical thrombectomy device is an efficient, quick, easy to handle, and safe tool for the treatment of acute, subacute or even chronic peripheral arterial thromboembolic occlusions. It can be used for short or long occlusions with equal success, provided the obstruction is not heavily calcified and has been safely passed with a guidewire first.

Percutaneous endovascular treatment of acute sequential systemic emboli

A 65-year-old woman was evaluated for acute right lower-extremity ischemia secondary to embolization from atrial fibrillation and subtherapeutic anticoagulation. Her symptoms quickly evolved in a dynamic fashion to involve multiple vascular beds, including a transient ischemic attack, abdominal pain secondary to mesenteric ischemia, and contralateral lower-extremity ischemia. Synchronous emboli were treated by using mechanical and pharmacologic thrombolysis via an endovascular approach under local anesthesia. This intervention allows prompt evaluation of multiple vascular beds with good short-term outcomes and minimal morbidity.

Hemolysis during percutaneous mechanical thrombectomy can mimic a hemolytic transfusion reaction

BACKGROUND

Interventional radiologists have developed percutaneous mechanical thrombectomy (PMT) devices to remove intravascular thrombi. Hemolysis, secondary to thrombus destruction from these devices, has been described in radiology journals, but similar reports appear to be lacking in the transfusion medicine literature. Two cases of hemolysis after PMT are described that involved the transfusion service, one of which was reported as a hemolytic transfusion reaction.

CASE REPORTS

The first patient received 4 units of red cells (RBCs) during a thrombectomy and subsequent placement of a transjugular intrahepatic portosystemic shunt. The patient developed hemoglobinuria, and it was reported to the blood bank as a possible hemolytic transfusion reaction. After RBC mismatch and bacterial contamination were excluded, the hemolysis was attributed to thrombectomy-related mechanical hemolysis. In the second case, a hemolyzed sample was sent to the blood bank for a type and cross-match. Upon requesting that the sample be redrawn, it was learned that the sample was obtained after PMT.

CONCLUSION

Patients who have undergone PMT can have clinical and laboratory findings suggestive of hemolytic transfusion reactions. Although interventional radiologists are familiar with these side effects, the blood bank profession needs to be aware that these procedures cause nonimmune hemolysis and must consider this possibility when evaluating transfusion reactions in these patients.

Characterization of alteplase (tPA) following delivery through the AngioJet rheolytic catheter

PURPOSE

To analyze alteplase solutions following delivery through the AngioJet Xpeedior rheolytic thrombectomy device to characterize the viability of proteins exposed to high shear stress.

METHODS

Alteplase solutions were prepared by reconstitution in sterile water to obtain a targeted concentration of 1.0 mg/mL. A baseline control sample was obtained. The AngioJet system was modified by occluding the return line to allow collection of the dispersed fluid volume. Alteplase solutions (n=5) were delivered through the 6-F, 120-cm Xpeedior catheter and collected. All samples were assayed and compared to baseline using qualitative visual inspection, ultraviolet spectrophotometry, size exclusion chromatography, and in vitro clot lysis assays.

RESULTS

Analysis of the test solutions demonstrated a mean protein recovery of 98.0%+/-3.5% of targeted concentration; the collected protein was fully active, as determined by clot lysis assays (specific activity > or =100%). All samples were clear and colorless. No significant fragmentation or aggregation of protein was observed.

CONCLUSIONS

Alteplase solutions, when delivered through the AngioJet Xpeedior rheolytic thrombectomy device, remain stable and biologically active in vitro. Further clinical investigation is warranted using this method as a novel approach for pharmacomechanical thrombolysis.

How thrombus model impacts the in vitro study of interventional thrombectomy procedures

RATIONALE AND OBJECTIVES

Numerous experimental models are used to investigate the effectiveness of thrombectomy devices. We aimed to study the systematic effects of different in vitro thrombus models on the results of experimental thrombectomy and examined how thrombi formed in vitro and ex vivo differ.

METHODS

Three variables involved in human in vitro thrombogenesis were investigated: spontaneous or thrombin-induced clotting, age (1 or 5 days old), and storage temperature (4 degrees C or 21 degrees C). The fibrin content of in vitro and fresh or old ex vivo thrombi was measured by histologic studies. Ten experiments were performed with each of 8 different in vitro thrombus types using (1) ultrasound thrombolysis, (2) Oasis thrombectomy, (3) Amplatz thrombectomy, and (4) Straub-Rotarex catheters. Thrombus weight was measured after standardized treatment.

RESULTS

The fibrin content was markedly lower in all in vitro than in fresh and old ex vivo thrombi. In vitro thrombus type had no impact on the effectiveness of ultrasound thrombolysis and Amplatz thrombectomy. Thrombogenesis type affected Oasis and Straub-Rotarex catheter use. Storage temperature had a systematic impact on the outcome of Oasis thrombectomies.

CONCLUSION

The fibrin content of in vitro thrombi differs substantially from that of fresh and old ex vivo human thrombi. Experimental conditions may systematically impact experimental evaluation of thrombectomy procedures. In vitro thrombi with thrombin-induced thrombogenesis should be favored for use in thrombectomy experiments.

Percutaneous rheolytic thrombectomy for treatment of acute renal-artery thrombosis

PURPOSE

We present our experience with percutaneous rheolytic treatment with the AngioJet thrombectomy catheter for acute renal-artery thrombosis.

CASE REPORT

A 63-year-old male patient with renal-artery thrombosis presented 48 hours after the onset of acute nonradiating flank pain. Thrombosis was documented by CT angiography, 99mTc-DTPA, and digital subtraction angiography. A percutaneous thrombectomy was performed with the AngioJet catheter. At the end of the procedure, the arterial lumen was patent, and no underlying stenosis or other deformity of the arterial wall was found. Thus, the cause of the obstruction was considered to be an embolus. After the procedure, urokinase was given to prevent distal occlusions from emboli that could have escaped mechanical thrombectomy. Heparin was also administered. The patient was released from the hospital with a patent renal unit and ameliorated serum creatinine concentration.

CONCLUSION

We propose the use of the AngioJet thrombectomy catheter for the percutaneous treatment of acute renal-artery thrombosis.

Novel simultaneous combination chemical thrombolysis/rheolytic thrombectomy therapy for acute critical limb ischemia: The power-pulse spray technique

The novel power-pulse spray (P-PS) technique maximizes and combines the advantages and minimizes the disadvantages of both chemical thrombolysis (CT) and rheolytic thrombectomy (RT). Forty-nine consecutive patients with iliofemoral thrombotic occlusion were treated via P-PS technique. Using a 6 Fr RT catheter, saline prime was exchanged for thrombolytic solution [group 1, 10-20 mg tenecteplase (TNK)/50 cc saline, n = 25; group 2, 1,000,000 urokinase (UK)/50 cc saline, n = 24]. The outflow port was closed, then the catheter was advanced at 1 mm increments while pulsing lytic agent. After 30-min lysis time, RT and definitive treatment of the underlying stenosis were performed. Procedure success was 23/25 (92%) and 22/24 (91.6%) for group 1 and 2, respectively. The mean total procedure time was 72 and 75 min in group 1 and 2, respectively. Thirty-day limb salvage was 91% in both groups. There were no major surgical complications. The P-PS technique is safe and effective using either UK or TNK, offering several potential advantages over monotherapy, including more rapid revascularization, decreases systemic lytic exposure and bleeding complications while facilitating both CT and RT capacity and efficacy.

[Radiological diagnosis and treatment of acute limb ischemia]

Acute limb ischemia is associated with significant morbidity and mortality, despite diagnostic and therapeutic advances. Threatened limbs require immediate imaging in order to determine the subsequent therapeutic procedures. Conventional angiography in the DSA technique still has advantages over CT and MR angiography. In acute arterial occlusions below the femoral bifurcation, endovascular treatment with intra-arterial local thrombolysis or percutaneous thrombectomy is an alternative to open vascular surgical procedures. The following article describes diagnostic and therapeutic strategies for acute limb threat induced by arterial occlusion.

Small peripheral pulmonary carcinomas evaluated with dynamic MR imaging: correlation with tumor vascularity and prognosis

PURPOSE

To correlate the findings at contrast material-enhanced dynamic magnetic resonance (MR) imaging of small peripheral pulmonary carcinomas with tumor vascularity and prognosis.

MATERIALS AND METHODS

Ninety-four patients with small peripheral pulmonary carcinomas who underwent surgical resection were examined retrospectively. Pathologic specimens were stained with hematoxylin-eosin and elastin-van Gieson. CD34 and vascular endothelial growth factor (VEGF) were assessed immunohistochemically. Delineated CD34-positive cells were counted as microvessels. Dynamic MR imaging was performed prior to and at 1, 2, 3, 4, 5, 6, and 8 minutes after injection of a bolus of gadopentetate dimeglumine. The two observers reviewed all images, and two pathologists performed all histologic analyses; a decision was determined with consensus. The maximum enhancement ratio (MER), the time lapse between the completion of the injection and the point of maximum signal intensity (Tmax), the washout ratio, and the slope value of the time-signal intensity curve were correlated with the microvessel density. VEGF-positive and VEGF-negative tumors were compared. All statistical analyses were performed by using nonparametric methods.

RESULTS

The MER and the slope value were positively correlated, and the Tmax was negatively correlated (Spearman rank test, P <.0001, all comparisons) with the microvessel counts. The distribution of elastic and collagen fibers correlated with the washout ratio (Kruskal-Wallis test, P <.001). There was a statistically significant difference between the slope value of VEGF-positive tumors and that of VEGF-negative tumors (Mann-Whitney U test, P <.0001). Patients with VEGF-positive tumors had a significantly shorter overall survival than did those with VEGF-negative tumors (log-rank test, P <.0001).

CONCLUSION

Dynamic MR imaging findings correlate with tumor vascularity and may be helpful in the prediction of prognosis.

Peripheral arterial applications of percutaneous mechanical thrombectomy

Various devices have been introduced for the purpose of percutaneous mechanical thrombectomy (PMT). These devices show promise as a valuable treatment option in acute arterial thrombotic occlusions, in addition to the gold-standard surgical method, the Fogarty balloon embolectomy, and local fibrinolysis therapy. Local fibrinolytic therapy cannot be used in the presence of contraindications, and can be time-consuming in limb threatening situations. Surgical intervention can also result in intimal vessel wall injury and is of limited value in infrageniculate occlusions. In this review, currently available PMT devices for peripheral arterial applications will be introduced, and their advantages, drawbacks and finally the reported clinical experience with these devices will be presented.

Adjunctive techniques in percutaneous mechanical thrombectomy

Percutaneous mechanical thrombectomy is an established method in interventional radiology and refers to the removal of acute embolic or thrombotic occlusive material in arteries, veins, or vascular grafts using percutaneous transluminal methods. However, initial complete removal of occlusive material can be achieved only in a minority of patients. The amount of removed material varies with the age and composition of the occlusive material. To achieve sufficient revascularization, adjunctive use of a variety of percutaneous endovascular recanalization techniques is necessitated. Additional treatment with local intra-arterial fibrinolysis, balloon angioplasty, stent implantation, endoluminal atherectomy, and other measures results in primary technical success rates of 70% to 100% for revascularization of acutely occluded vessels. The above-mentioned different techniques should not be viewed as competitive treatment modalities, rather a synergistic approach should be offered. The aim of this report is to review different adjunctive techniques in percutaneous mechanical thrombectomy with emphasis on techniques, mechanisms of action, experimental and clinical results, potential complications, and their potential role in view of clinical pathways to treat acute limb ischemia.

Successful treatment of aortic endograft thrombosis with rheolytic thrombectomy

PURPOSE

To report the benefits of rheolytic thrombectomy for treating aortic endograft thrombosis.

METHODS

Of 40 patients who received the Ancure bifurcated endograft to treat abdominal aortic aneurysm (AAA) during a 9-month period, 6 (15%) patients (6 men; mean age 62.6 years, range 53-77) developed thrombosis of the endograft at an average of 9 weeks (range 1-20 months). Five patients were taking aspirin, and 3 were on warfarin therapy for atrial fibrillation. Immediately after angiography, rheolytic thrombectomy was used to remove the thrombus, followed by adjunctive procedures to treat the underlying pathology.

RESULTS

Causes were kinking or extrinsic compression of the graft limb in 5 cases and thrombosis of the surgical closure site in a common femoral artery. Mechanical thrombectomy was successful in restoring circulation in all cases; thrombolysis was used in 1. All 6 patients had additional stents placed in the graft limbs, re-establishing patency. There was no mortality or recurrent thrombosis in a follow-up that has extended to 26 months, but 1 patient required additional stenting for subsequent focal kinking of a graft limb above the previously implanted stent.

CONCLUSIONS

Rheolytic thrombectomy can safely and effectively treat endograft thrombosis after endovascular AAA repair. Additional thrombolytic agents, angioplasty, and stenting may be needed to correct the underlying causes of the thrombosis. Prophylactic stenting of iliac limbs at the time of implantation in patients with complex anatomy may prevent thrombosis of unsupported bifurcated endografts.

Comparison and modification of two cerebral protection devices used for carotid angioplasty: in vitro experiment

The effectiveness of two basic cerebral protection devices designed for carotid angioplasty with and without additional aspiration techniques was compared in an in vitro model. During carotid angioplasty, embolization was simulated by injecting polyvinyl alcohol particles of different sizes into the model system. None of the tested devices, all of which were positioned in the internal carotid artery, was able to completely prevent embolization. In the internal carotid artery, the rate of particle capture did not vary among protection devices. However, embolization into the external carotid artery was more frequent with use of the GuideWire, as compared with that with use of the Angioguard.

Neuroendovascular Rescue: Interventional Treatment of Acute Ischemic Stroke

Stroke continues to be a major health problem for our society. Despite the proven effectiveness of intravenous tissue plasminogen activator (t-PA) for the treatment of acute ischemic stroke, only a minority of patients qualify for this type of therapy. Furthermore, the existing literature has demonstrated that t-PA is not as effective in the treatment of occlusion of large cerebral arteries. The benefit-to-risk assessment of this subpopulation of stroke patients makes them the best candidates for neuroendovascular rescue. This term refers to the intra-arterial application of techniques designed to promote arterial recanalization, and includes intra-arterial thrombolysis and antithrombotic agents, direct mechanical disruption, angioplasty, stenting, embolectomy, and vasoactive pharmacologic intervention. The timing and choice of these procedures, as well as the care of the patient prior to, during, and after the intervention, requires a highly focused and expert approach.

Rheolytic Thrombectomy of Acute Stent Thrombosis of Cervical Vertebral Artery

A new Xpeedior rheolytic thrombectomy catheter has been successfully used to extract thrombus from an acutely thrombosed vertebral artery stent without apparent distal embolism. The ease of use and the speed of thrombectomy suggest that this system may be useful for the treatment of acute ischemic stroke.