Infusion Of Recombinant Tissue Plasminogen Activator Research Articles

Transcatheter closure of patent foramen ovale using the Cocoon occluder: A multicenter retrospective study

BackgroundThe Cocoon patent foramen ovale (PFO) occluder is a new device especially designed for transcatheter closure of PFO. This occluder has some distinctive structural modifications aimed at reducing the risk of major complications of transcatheter PFO closure. In this report we present our initial experience to evaluate the efficacy and safety of the Cocoon PFO occluder in 253 patients who underwent transcatheter PFO closure. MethodsThe study cohort included 253 patients (median age 45 years) with embolic stroke of undetermined source who underwent attempted transcatheter closure of PFO for secondary prevention of paradoxical embolism. Patients were enrolled retrospectively from five sites in Greece and one in Romania between December 2016 and January 2021, and the median follow-up period was 28 months (range 12–48 months). Clinical and laboratory data from each participating center were sent to an electronic registry for evaluation and statistical analysis. ResultsThe Cocoon PFO occluder was permanently implanted in all patients. At 6 months, complete occlusion of PFO was observed in 251/253 (99.2%) patients. Three (1.2%) patients had a trivial residual shunt. Thrombus formation on the device, which was successfully treated with recombinant tissue plasminogen activator infusion, was observed in one (0.4%) patient. No other complications occurred. During a median follow-up period of 28 months, 3 (1.2%) patients, aged 64–67 years, developed new onset paroxysmal atrial fibrillation. No neurologic events, cardiac erosions, allergic reactions to nickel, or thrombus formation occurred. ConclusionThe Cocoon PFO occluder is an effective and safe device that adds to our armamentarium for transcatheter closure of PFO.

The Japan Neurosurgical Database: Statistics Update 2018 and 2019.

Each year, the Japan Neurosurgical Society (JNS) reports up-to-date statistics from the Japan Neurosurgical Database regarding case volume, patient demographics, and in-hospital outcomes of the overall cohort and neurosurgical subgroup according to the major classifications of main diagnosis. We hereby report patient demographics, in-hospital mortality, length of hospital stay, purpose of admission, number of medical management, direct surgery, endovascular treatment, and radiosurgery of the patients based on the major classifications and/or main diagnosis registered in 2018 and 2019 in the overall cohort (523283 and 571143 patients, respectively) and neurosurgical subgroup (177184 and 191595 patients, respectively). The patient demographics, disease severity, proportion of purpose of admission (e.g., operation, 33.9–33.5%) and emergent admission (68.4–67.8%), and in-hospital mortality (e.g., cerebrovascular diseases, 6.3–6.5%; brain tumor, 3.1–3%; and neurotrauma, 4.3%) in the overall cohort were comparable between 2018 and 2019. In total, 207783 and 225217 neurosurgical procedures were performed in the neurosurgical subgroup in 2018 and 2019, respectively, of which endovascular treatment comprised 19.1% and 20.3%, respectively. Neurosurgical management of chronic subdural hematoma (19.4–18.9%) and cerebral aneurysm (15.4–14.8%) was most common. Notably, the proportion of management of ischemic stroke/transient ischemic attack, including recombinant tissue plasminogen activator infusion and endovascular acute reperfusion therapy, increased from 7.5% in 2018 to 8.8% in 2019. The JNS statistical update represents a critical resource for the lay public, policy makers, media professionals, neurosurgeons, healthcare administrators, researchers, health advocates, and others seeking the best available data on neurosurgical practice.

Effects of Early Changes in Blood Pressure During Intravenous Thrombolysis on the Prognosis of Acute Ischemic Stroke Patients.

Background: Intravenous thrombolysis (IVT) therapy is currently one of the best medical treatments available for patients with acute ischemic stroke. Studies have shown that blood pressure (BP) changes in patients treated with IVT are significantly correlated with prognosis.Objective: Our study aimed to determine the relationship between BP changes during recombinant tissue plasminogen activator (rt-PA) infusion and the 3-month prognosis evaluated using the modified Rankin Scale (mRS) and determine the factors influencing BP changes during rt-PA infusion.Methods: Consecutive patients who were treated with IVT and admitted to our stroke center between May 2015 and October 2017 were analyzed retrospectively. Patients were divided into two groups according to their 3-month prognosis status: patients with mRS ≤ 2 were defined as “favorable outcome group” and those with mRS ≥ 3 as “unfavorable outcome group”. First, the factors affecting prognosis after thrombolysis were analyzed. Second, we analyzed the relationship between BP and the prognosis. BP was taken before and at regular intervals of 15 min during the rt-PA infusion (1 h). The average value of BP during thrombolysis was calculated and compared to the baseline BP. BP decrease was defined as the difference between the baseline BP and the average BP, provided it was greater than 0 mmHg. Third, univariate and multivariate analyses were performed to identify factors that may contribute to BP decrease.Results: In total, 458 patients were included. Patients with a lower baseline National Institute of Health Stroke Scale (NIHSS) score (8.25 ± 5.57 vs. 13.51 ± 7.42, P < 0.001), a higher Alberta Stroke Program Early CT Score (ASPECTS; 8.65 ± 1.82 vs. 8.13 ± 2.00, P = 0.005), decreased BP during thrombolysis (69.4% vs. 59.8%, P = 0.037), and steady BP (SD < 10 mmHg) were more likely to have a favorable outcome (73.9% vs. 60.6%, P = 0.019). High baseline BP (OR > 1), hypertension history (OR < 1), and baseline ASPECTS (OR > 1) were independent factors of BP change during thrombolysis.Conclusion: Patients with decreased or steady BP during thrombolysis were more likely to have a favorable outcome. Baseline ASPECTS, baseline NIHSS score, and hypertension history influenced BP changes during thrombolysis.

Rheumatoid meningitis presenting with a stroke-like attack treated with recombinant tissue plasminogen activator: a case presentation

BackgroundRheumatoid meningitis presenting with a stroke-like attack (RMSA) is a rare manifestation of rheumatoid arthritis (RA). When the patients arrive within the time-window for recombinant tissue plasminogen activator (rt-PA) infusion therapy, no diagnostic protocol has been established.Case presentationA 55-year-old woman was brought by ambulance to our hospital with complaints of sudden-onset dysarthria and left arm numbness. The National Institutes of Health Stroke Scale (NIHSS) score was 5, and the Alberta Stroke Program Early CT Score was 8. She was diagnosed with acute embolic stroke. At 4 h, 6 min after onset, intravenous administration of rt-PA (alteplase, 0.6 mg/kg) was started. Her neurological deficits improved rapidly, and her NIHSS score was 1. Brain MRI was then performed. There was no hemorrhagic transformation, but the MRI findings were not compatible with ischemic stroke. She had a past history of RA diagnosed 6 months earlier, and she had been treated with methotrexate (10 mg daily). She was diagnosed with RMSA, and continuous infusion of methylprednisolone 1000 mg daily was started for 3 days. The high signal intensity on the FLAIR image disappeared.ConclusionCT-based decision-making for rt-PA injection is reasonable, but MRI is needed for the early diagnosis of RMSA. In this case, it is particularly important that neither adverse events nor bleeding complications were observed, suggesting the safety of CT-based thrombolytic therapy in RMSA.

Prolonged Microcatheter-Based Local Thrombolytic Infusion as a Salvage Treatment After Failed Endovascular Treatment for Cerebral Venous Thrombosis: A Multicenter Experience.

To determine the effectiveness of prolonged microcatheter-based local thrombolytic infusion in treatment of patients with cerebral venous thrombosis who achieved no or suboptimal recanalization with transvenous endovascular treatment. Data collection: Prospectively registries supplemented by retrospective review. Three hospitals with tertiary referral base. Patients who underwent transvenous endovascular treatment for cerebral venous thrombosis. Prolonged microcatheter-based local thrombolytic infusion of alteplase at the rate of 0.5-1mg/h in patients in whom initial angiographic outcome was deemed suboptimal, either due to incomplete or no recanalization. Serial angiograms were performed to assess treatment response as follows: grade I, partial recanalization of one or more occluded dural sinuses with improved flow or visualization of branches; grade II, complete recanalization of one sinus but persistent occlusion of the other sinuses (A-no residual flow, B-nonocclusive flow); grade III, complete recanalization. Clinical outcome was determined at 1-3 months using modified Rankin scale. A total of 14 patients underwent 15 transvenous endovascular treatments. Initial treatment was considered suboptimal in 12/15 procedures due to no recanalization in five (grade 0), partial recanalization (grade I) in four, complete recanalization of one sinus but persistent occlusion of the other sinuses (grade 2A in two and 2B in one). A prolonged microcatheter-based local recombinant tissue plasminogen activator infusion was used following ten of the 15 procedures for a median duration of 18h (range 13-22 h). Follow-up angiography demonstrated complete recanalization in four procedures and improvement in grades of partial recanalization in six procedures (final grades 2A in three and 2B in three procedures). None of the patients developed new symptomatic intracranial hemorrhage associated with local thrombolytic infusion. At follow-up, patients in five of ten procedures had achieved a modified Rankin scale of 0 and one patient had achieved a score of 1 (no neurological deficits but had residual headaches). Prolonged microcatheter-based local thrombolytic infusion appeared to be effective treatment in patients who have suboptimal response to acute transvenous endovascular treatment without any additional adverse events.

Abstract WP10: Prolonged Microcatheter-based Local Thrombolytic Infusion as a Salvage Treatment for Failed Endovascular Treatment for Cerebral Venous Thrombosis: A Multicenter Registry

Background: Transvenous endovascular treatment including combination pharmacological and mechanical modalities is reserved for patients with cerebral venous thrombosis (CVT) not responsive to standard anticoagulation. However, transvenous endovascular treatment may not always be successful in achieving recanalization. Objective: To determine the effectiveness of prolonged microcatheter based local thrombolytic infusion in treatment of patients with CVT who achieved no or suboptimal recanalization with endovascular treatment. Methods: Patients who underwent transvenous endovascular treatment for cerebral venous thrombosis at three hospitals were identified through local registries. The final response to treatment was assessed and prolonged microcatheter based local thrombolytic infusion was instituted in selected patients as second line treatment. Serial angiograms were performed to assess treatment response and determine the duration of infusion. Results: Of the 85 patients admitted with CVT, 13 patients underwent 14 transvenous endovascular treatments. Initial treatment was considered suboptimal in 10/14 procedures due to no recanalization in 6, partial recanalization in 3, and re-occlusion in 1 patient. A prolonged microcatheter-based local recombinant tissue plasminogen activator (rt-PA) infusion was used in 9 of the 10 procedures for a median duration of 16 hours (range 15-22 hours). Follow up angiography demonstrated complete recanalization in 4 procedures and improvement of the partial recanalization in 5 additional procedures. One patient died before the follow up imaging could be acquired. None of the patients developed intracranial hemorrhage associated with local thrombolytic infusion. The microcatheter position had shifted during the infusion in one procedure. Conclusion: Prolonged microcatheter based local thrombolytic infusion appears to effective treatment in patients who have suboptimal response to acute transvenous endovascular treatment without any additional adverse events.

Helicopter transportation in the era of thrombectomy: The next frontier for acute stroke treatment and research.

Many patients suffer a stroke at a significant distance from a specialized center capable of delivering endovascular therapy. As a result, they require rapid transport by helicopter emergency medical services, sometimes while receiving a recombinant tissue plasminogen activator infusion (drip and ship). Despite its critical role in the new era of reperfusion, helicopter emergency medical services remains a poorly evaluated aspect of stroke care. Comprehensive narrative review of all published articles of helicopter emergency medical services related to acute stroke care in the inter-hospital and pre-hospital settings, including technical aspects and physical environment implications. Helicopter emergency medical services transports are conducted during a critical early time period when specific interventions and ancillary care practices may have a significant influence on outcomes. We have limited knowledge of the potential impact of the unusual physical factors generated by the helicopter on the ischemic brain, which affects our ability to establish rational guidelines for ancillary care and the delivery of specific interventions. Unlike the pre-hospital and hospital settings where stroke interventions are delivered, the inter-hospital helicopter emergency medical services transfer setting remains a "black box" for acute stroke care and research. This gap is particularly relevant for many patients living in rural areas, or in congested urban areas, that depend on helicopter emergency medical services for rapid access to a tertiary stroke center. Addressing the helicopter emergency medical services stroke gap in clinical trials and acute care delivery would homogenize capabilities through all care settings, thus minimizing potential disparities in research access and outcomes based on geographical location.

Effect of helicopter transport on neurological outcomes in a mouse model of embolic stroke with reperfusion: AIR-MICE pilot study.

Patients often suffer a stroke at a significant distance from a center capable of delivering endovascular therapy, thus requiring rapid transport by helicopter emergency medical services while receiving a recombinant tissue plasminogen activator infusion that was initiated locally. But little is known about how a helicopter flight may impact the safety and efficacy of recombinant tissue plasminogen activator-induced reperfusion and patient outcomes. To establish a new animal method to address with fidelity the safety and overall effect of helicopter emergency medical services during thrombolysis. Prospective randomized open blinded end-point study of an actual helicopter flight exposure. Adult C57BL/6 male mice were treated with a 10 mg/kg recombinant tissue plasminogen activator infusion two-hours after an embolic middle cerebral artery occlusion. Mice were randomized in pairs to simultaneously receive the infusion during a local helicopter flight or in a ground hangar. Eighteen mice (nine pairs) were analyzed. The paired t-test analysis showed nonsignificant smaller infarction volumes in the helicopter-assigned animals (mean pair difference 33 mm(3) , P = 0·33). The amount of hemorrhagic transformation between the helicopter and ground groups was 4·08 vs. 4·56 μl, respectively (paired t-test, P = 0·45). This study shows that helicopter emergency medical services do not have an inherent adverse effect on outcome in a mouse model of ischemic stroke with reperfusion. These results endorse the safety of the practice of using helicopter emergency medical services in stroke patients. The observed potential synergistic effect of helicopter-induced factors, such as vibration and changes in altitude, with reperfusion merits further exploration in animal experimental models and in stroke patients.

Massive Pulmonary Embolism after Overdose of Oral Benzodiazepine

Overdose of benzodiazepines rarely causes morbidity or mortality. A 58-year-old woman presented to the emergency department in coma after ingestion of 30 tablets of 0.5 mg alprazolam. She recovered after flumazenil was administered. However, massive pulmonary embolism developed during observation in the emergency department. Endotracheal intubation and recombinant tissue plasminogen activator infusion were initiated. This case report highlights that benzodiazepine overdose can contribute to pulmonary embolism which is a life-threatening condition.

Emergency department companions of stroke patients: implications on quality of care.

Acute care of stroke victims largely relies on the rapid identification and timely clinical and radiological assessment. We evaluated the effect of the number of patient companions on the efficiency of the diagnostic process in the emergency department (ED).Consecutive stroke patients admitted to the ED between August 2011 and October 2012 were evaluated. Clinical, epidemiological, and timeline data (symptoms onset, ED arrival, computed tomography [CT] scanning, and recombinant tissue plasminogen activator infusion), as well as the number of accompanying persons in the ED were prospectively recorded. We used multivariate Poisson log linear models to analyze the association of number of companions adjusted and door-to-CT times and logistic regression for the analysis of the successful identification of stroke patient by ED triage nurse.Out of a total of 724 stroke patients admitted, data regarding number of ED companions were available for 610 (84.3%) patients. Number of companions was associated with higher National Institute of Health Stroke Scale and speech disturbances. It was found to be independently associated with shorter time to CT scanning adjusted for the stroke severity, sex, and speech disturbances (no companions as a reference group, relative risks 0.82, 0.73, and 0.70 for 1, 2, and ≥3 companions, respectively, all P < 0.001). Similarly, number of companions was associated with higher rates of stroke recognition by the triage nurse adjusted for covariates (odds ratios 2.11, 2.62, and 4.11, respectively, all P < 0.05).Our findings suggest that the family members and other companions could serve as facilitators of faster and more effective ED management of stroke patients, possibly improving their outcome.

Early neurological improvement after intravenous tissue plasminogen activator infusion in patients with ischemic stroke aged 80 years or older

BackgroundEarly neurological improvement has been observed in patients with stroke receiving treatment with standard intravenous recombinant tissue plasminogen activator. However, the effectiveness of thrombolytic treatment and the risk of hemorrhagic transformation are not well understood in patients aged ≥80 years. In this study, we investigated the influence of age on early neurological improvement and hemorrhagic transformation rates in patients with stroke aged ≥80 years and receiving recombinant tissue plasminogen activator. MethodsThe study included 157 patients who received recombinant tissue plasminogen activator infusion at a teaching hospital. The National Institutes of Health Stroke Scale was used to evaluate stroke severity. Early neurological improvement was defined as an improvement of 8 or more points on this scale (compared with baseline) 24 hours after thrombolytic treatment. Neurological improvement was defined as an improvement of 8 or more points (compared with baseline) at discharge. Neurological deterioration was defined as an increase of 4 or more points (compared with baseline). Multivariate analysis was used to evaluate the associations among age, neurological improvement, and hemorrhagic transformation. ResultsThe rate of early neurological improvement was 36.9% (58/157 patients) and the rate of hemorrhagic transformation was 22.3% (35/157 patients). At discharge, the rate of neurological improvement was 50.9% (80/157 patients) and the rate of neurological deterioration was 13.4% (21/157 patients). There was no statistically significant difference between patients aged ≥80 years and those <80 years of age with respect to rates of early neurological improvement, neurological deterioration, or hemorrhagic transformation. Among patients ≥80 years, the rate of neurological improvement in those receiving thrombolytic treatment was higher than the rate in those patients not receiving thrombolytic treatment (58.8% vs. 14.1%, p < 0.01). We concluded that thrombolysis increases the rate of neurological improvement in patients aged ≥80 years. ConclusionIn older patients, thrombolytic treatment increased the rate of neurological improvement compared with patients not receiving the treatment. The study showed that thrombolytic treatment may be beneficial for patients ≥80 years, but should be performed with extreme care.

Intravenous Thrombolysis for Acute Ischemic Stroke Occurring during Hospitalization for Transient Ischemic Attack

There are limited data regarding the use of intravenous thrombolysis in patients who experienced acute ischemic symptoms during their hospitalization for prior transient ischemic attack. We sought to prospectively evaluate the safety and efficacy of intravenous thrombolysis for the treatment of acute ischemic stroke occurring during hospitalization for transient ischemic attack in an international, multicenter study. Consecutive patients with acute ischemic stroke that occurred during hospitalization for prior transient ischemic attack were treated with intravenous thrombolysis in five tertiary-care stroke centers. Early arterial recanalization was determined by transcranial Doppler at the end of recombinant tissue plasminogen activator infusion using previously validated criteria. Symptomatic intracranial hemorrhage complicating intravenous thrombolysis was evaluated using the National Institute of Neurological Disorders and Stroke Recombinant Tissue Plasminogen Activator Stroke Study definition. Functional independence at three-months was defined as Modified Rankin Scale score of 0-2. Systemic recombinant tissue plasminogen activator infusion (median onset-to-treatment time 70 mins, interquartile range 50-150) was given in 25 consecutive patients (mean age 66 ± 10 years) who developed acute ischemic stroke symptoms (median National Institutes of Health Stroke Scale score 10 points; interquartile range 8-14) during hospitalization for prior transient ischemic attack (median ABCD(2) score 5 points; median time-to-symptom recurrence 24 h, interquartile range 24-48). No symptomatic intracranial hemorrhage (0%; 95% confidence interval 0-12%) was documented. Early complete recanalization occurred in 64% of patients (95% confidence interval 44-80%), and 84% (95% confidence interval 65-94%) achieved three-month functional independence. The rate of three-month functional independence was higher in patients treated with intravenous tissue plasminogen activator within 90 mins from symptom onset compared with those with onset-to-treatment time>90 mins (81% vs. 33%; P = 0.031). Intravenous thrombolysis for symptoms of acute ischemic stroke occurring after hospitalization for transient ischemic attack appears to be safe. These pilot data support resetting the clock if new symptoms recur shortly after transient ischemic attack.

Hand-Held Echocardiography in the Management of Cardiac Arrest

November 2012 • Volume 115 • Number 5 A 65-year-old diabetic man underwent toe amputations. The patient collapsed on postoperative day 3 due to cardiac arrest with pulseless electrical activity (PEA). During Advanced Cardiac Life Support (ACLS) protocol, an intensivist-physician with extensive echocardiographic experience performed a point-of-care transthoracic echocardiogram (TTE) using a hand-held ultrasound device (VscanTM; GE Healthcare, Wauwatosa, WI ; see Fig. 3). A subcostal view was used to record images both during resuscitation and after return of spontaneous circulation. The echocardiographic examination did not interfere with cardiopulmonary resuscitation (CPR) or the ACLS protocol. The images demonstrated a large echo-dense mass in the right atrium moving through the tricuspid valve into the right ventricle (RV), suggestive of a clot in transit (Fig. 1) (Video 1, mobile mass in RV; see Supplemental Digital Content 1, http://links.lww. com/AA/A428). In this postoperative patient, pulmonary embolism (PE) was the most likely etiology of hemodynamic collapse. Shortly thereafter, a repeated focused examination by the intensivist with a conventional echocardiography machine confirmed the findings seen on the hand-held device (Fig. 2) (Video 2, mobile mass in RV; see Supplemental Digital Content 2, http://links.lww.com/ AA/A429). Based on these results, heparin and recombinant tissue plasminogen activator were administered IV during the code. A follow-up TTE 40 minutes later demonstrated absence of the mass in the RV (Video 2, http://links.lww.com/AA/A429), indicating that the mass either dissolved or moved forward into the pulmonary artery. Because of refractory shock, the patient was transferred to the catheterization lab for embolectomy or local recombinant tissue plasminogen activator infusion. Unfortunately, a right heart catheterization demonstrated diffuse clot burden in the entire left lung not amendable to therapy. The patient experienced repeated episodes of PEA arrest and ultimately died.

Intravenous thrombolysis on early recurrent cardioembolic stroke

Early recurrent cardioembolic stroke on the previously unaffected side has very rarely been reported during or after intravenous recombinant tissue plasminogen activator for acute ischemic stroke. For these cases, thrombolysis guidelines lack any clear recommendation. We report two cases of thrombolysed stroke patients, with paroxysmal atrial fibrillation but normal sinus rhythm on admission, who respectively developed recurrent ischemic stroke within few hours after complete improvement and during intravenous recombinant tissue plasminogen activator infusion. Intravenous thrombolysis was successfully repeated after echocardiographic evidence of left appendage thrombus in the first case and discontinued before complete administration in the second.

A Case of Spontaneous Spinal Epidural Hematoma Mimicking a Stroke

For intravenous (IV) thrombolytic therapies to be effective, a correct diagnosis of acute ischemic stroke must be made within 3 hours from the onset of symptoms, a relatively short window period. However, obtaining a diagnosis in the time frame is not easy; a wide variety of conditions mimic a stroke, including seizures, migraine, and even a spinal mass, and often these are diagnosed as acute ischemic stroke and receive thrombolytic therapy. A patient presented suffering progressive and fluctuating painful triparesis coupled with acute onset dissociated sensory loss. The patient complained of dysarthria and transient altered mentality at the onset of symptoms; therefore, we suspected an ischemic infarction of the brainstem and spinal cord accompanied by vertebral artery dissection. As the time at diagnosis was 2 hours 30 minutes after symptom onset, we started IV thrombolytic treatment using recombinant tissue plasminogen activator. Magnetic resonance imaging during the recombinant tissue plasminogen activator infusion revealed a spontaneous spinal epidural hematoma (SSEH) of the cervical and thoracic spine, leading the patient to undergo an emergency surgery. SSEH is an uncommon clinical condition, and a manifestation of SSEH with anterior spinal artery syndrome is also rare. Furthermore, an emergency operation after IV thrombolytic treatment is an extraordinary situation.

Systemic Thrombolysis in Ischemic Stroke After Recent Oral Surgery and Management of Oral Cavity Bleeding

Thrombolysis with recombinant tissue plasminogen activator in the treatment of acute ischemic stroke carries a long list of contraindications. One of these is recent surgery, but the extent of complications after minor surgeries such as dental extraction or oral surgical procedures is unclear. Here, we report the management of 2 cases with accidental bleeding from the oral cavity during systemic thrombolysis in ischemic stroke because of recent unreported oral surgery. Bleeding at the operation site occurred early and was stopped by prompt discontinuation of the recombinant tissue plasminogen activator infusion and local compressive therapy. Patients and relatives may not be aware that surgical procedures within the oral cavity are regarded as minor surgery and should be explicitly asked during the evaluation of ischemic stroke within the period for thrombolysis.

Successful treatment of pacemaker-induced stricture and thrombosis of the cranial vena cava in two dogs by use of anticoagulants and balloon venoplasty

2 castrated male Labrador Retrievers (dogs 1 and 2) were evaluated 3 to 4 years after placement of a permanent pacemaker. Dog 1 was evaluated because of a large volume of chylous pleural effusion. Dog 2 was admitted for elective replacement of a pacemaker. Dog 1 had mild facial swelling and a rapidly recurring pleural effusion. Previously detected third-degree atrioventricular block had resolved. Cranial vena cava (CVC) syndrome secondary to pacemaker-induced thrombosis and stricture of the CVC was diagnosed on the basis of results of ultrasonography, computed tomography, and venous angiography. Dog 2 had persistent third-degree atrioventricular block. Intraluminal caval stricture and thrombosis were diagnosed at the time of pacemaker replacement. Radiographic evidence of pleural effusion consistent with CVC syndrome also was detected at that time. Dog 1 improved after treatment with unfractionated heparin and a local infusion of recombinant tissue-plasminogen activator. Balloon venoplasty was performed subsequently to relieve the persistent caval stricture. In dog 2, balloon dilatation of the caval stricture was necessary to allow for placement of a new pacing lead. Long-term anticoagulant treatment was initiated in both dogs. Long-term (> 6 months) resolution of clinical signs was achieved in both dogs. Thrombosis and stricture of the CVC are possible complications of a permanent pacemaker in dogs. Findings suggested that balloon venoplasty and anticoagulation administration with or without thrombolytic treatment can be effective in the treatment of dogs with pacemaker-induced CVC syndrome.

Right Internal Carotid Artery Occlusion during Intravenous Thrombolysis for Left Middle Cerebral Artery Occlusion

Thrombolysis with recombinant tissue plasminogen activator is the only established treatment for acute ischemic stroke. Recurrent ischemic stroke involving an initially unaffected arterial territory during the course of thrombolysis has been reported but remains exceptionally rare. Here we report a 75-year-old woman with acute left middle cerebral artery occlusion who developed right internal carotid artery occlusion during the last minutes of recombinant tissue plasminogen activator infusion. Although the transthoracic echocardiography did not reveal an intra-atrial thrombus, cardioembolism due to disintegration of a pre-existing thrombus was thought to be the underlying mechanism because the patient had atrial fibrillation. Arterial occlusion due to intraplaque hemorrhage and de novo thrombosis caused by thrombin-mediated platelet aggregation are also discussed as potential mechanisms of arterial occlusion.

Neonatal white leg: a case of anatomical misjudgment

A baby girl of 28 weeks' gestation was delivered by emergency caesarean section because of fetal distress. At delivery her heart rate was &gt;100 beats per minute, she cried and gasped, and was initially given bag and mask ventilation. She was subsequently intubated. An umbilical artery catheter was sited with aseptic technique for continuous blood pressure monitoring and arterial blood gas sampling. A second cannula was inserted into an umbilical vessel thought to be an umbilical vein. However, X-ray showed it to be malpositioned and probably arterial, and so it was removed immediately. Three hours later her left leg had turned white (Figure 1). She was consequently transferred to the neonatal unit where recombinant tissue plasminogen activator infusion was commenced. The whiteness did not disappear and no pulse reappeared below the femoral artery. However, the dusky red area above the knee resolved and, after a few days, an obvious area of demarcation of the ischaemia was seen at knee level. The patient subsequently underwent a through-knee amputation and has been fitted with a prosthesis.

Hemodialysis Catheter-associated Fibrin Sheaths: Treatment with a Low-Dose rt-PA Infusion

To prospectively evaluate the efficacy of a low-dose, 3-hour recombinant tissue plasminogen activator (rt-PA) infusion for the treatment of hemodialysis catheter (HDC)-associated fibrin sheaths. Seventeen patients with end-stage renal disease (female, n = 11; male, n = 6), who were undergoing catheter-directed hemodialysis, were evaluated for 28 episodes of HDC dysfunction. This patient group ranged in age from 25 to 92 years (mean, 57 years). Radiographic contrast and/or clinical evaluation were consistent with the presence of a fibrin sheath on either the arterial and/or venous port in all cases. Patients subsequently underwent a thrombolytic infusion consisting of 2.5 mg rt-PA in 50 mL normal saline at a rate of 17 mL/h (3-hour infusion) per port. All infusions were performed in the interventional radiology recovery room, on an outpatient basis. Patients were followed-up prospectively for technical success, complications, catheter patency, and long-term outcome. The immediate technical success rate, defined as return of manual aspiration and infusion capabilities to both ports, was 100%. No potential patients required exclusion from thrombolytic therapy secondary to contraindications, and no procedure-related complications occurred. The arithmetic mean and median catheter patency at the end of the study was 41 and 25 days, respectively (range, 1-116 days). A Kaplan-Meier survival analysis yielded a 30-, 60-, and 90-day probability of patency of 0.67, 0.61, and 0.51, respectively. At the end of the study period, all 17 patients remained on catheter-directed hemodialysis and 13 (76%) were utilizing the same catheter present at the time of entrance into the study. Thrombolytic therapy utilizing a 2.5-mg rt-PA infusion through each port during a 3-hour period would appear to be a safe, efficient method for treating HDC-associated fibrin sheaths. Three-month patency rates are comparable to those reported for other methods of restoring function to HDC catheters, including new catheter placement, catheter exchange over a guide wire, thrombolytic infusions with urokinase, and percutaneous fibrin sheath stripping.