Thrombotic superior vena cava syndrome: a national emergency department database study.

Literature regarding etiology and trends of incidence of major thoracic vein thrombosis in the United States is limited. To study the causes, complications, in-hospital mortality rate, and trend in the incidence of major thoracic vein thrombosis which could have led to superior vena cava syndrome (SVCS) between 2010 and 2018. Data from the nationwide emergency department sample (NEDS) that constitutes 20% sample of hospital-owned emergency departments (ED) and in-patient sample in the United States were analyzed using diagnostic codes. A linear p-trend was used to assess the trends. Of the total 1082 million ED visits, 37,807 (3.5/100,000) (mean age 53.81 ± 18.07 years, 55% females) patients were recorded with major thoracic vein thrombosis in the ED encounters. Among these patients, 4070 (10.6%) patients had one or more cancers associated with thrombosis. Pacemaker/defibrillator-related thrombosis was recorded in 2820 (7.5%) patients, while intravascular catheter-induced thrombosis was recorded in 1755 (4.55%) patients. Half of the patients had associated complication of pulmonary embolism. A total of 59 (0.15%) patients died during these hospital encounters. The yearly trend for the thrombosis for every 100,000 ED encounters in the United States increased from 2.17/100,000 in 2010 to 5.98/100,000 in 2018 (liner p-trend < 0.001). Yearly trend for catheter/lead associated thrombosis was also up-trending (p-trend 0.015). SVCS is an uncommon medical emergency related to malignancy and indwelling venous devices. The increasing trend in SVCS incidence, predominantly catheter/lead induced, and the high rate of associated pulmonary embolism should prompt physicians to remain vigilant for appropriate evaluation.

Increased frequency of obstructive sleep apnea syndrome in Behçet's syndrome patients with superior vena cava syndrome.

OBJECTIVES: Superior vena cava syndrome (SVCS) is a medical emergency which can also be seen in Behçet's syndrome (BS). Having noted that BS patients with SVCS frequently complained of sleep disturbances, snoring and sleep apnea, suggesting obstructive sleep apnea (OSA), we formally surveyed the risk for OSA among BS patients. METHODS: We studied 28 patients, all male, with SVCS (Group 1), 129 with vascular involvement without a SVCS (Group 2) and 151 with no vascular involvement (Group 3). In addition, 100 apparently healthy individuals (Group 4) were studied. The Berlin questionnaire (BQ), a validated screening tool with a high sensitivity and modest specificity that identifies individuals with high-risk for OSA, was administered to all study participants. RESULTS: The study groups were similar with regard to age (Group 1, mean age: 44.3±9.7; Group 2, mean age: 41.5±8.7, Group 3, mean age: 40.4±9.4 and Group 4, mean age: 42.1±9.4) mean body mass index and the frequency of hypertension and other comorbidities. The frequency of those patients at high-risk for OSA according to the BQ was 57%, 17%, 17% and 11% in Groups 1, 2, 3 and 4, respectively (p<0.05). Age-adjusted ORs of OSA compared to healthy controls (Group 4) was 11.00 (95%CI: 4.01-30.07) for Group 1, 1.78 (95%CI: 0.81-3.94) for Group 2, 1.92 (95%CI: 0.90-4.14) for Group 3. CONCLUSIONS: BS patients with SVCS are at high risk for OSA. This is probably due to the external pressure of the significant presence of venous collaterals that surround the upper airways. Our results should be further confirmed by polysomnography, and future research should be carried out to clarify the causes of this association.

Pediatric superior vena cava syndrome: An evidence-based systematic review of the literature.

Superior vena cava syndrome (SVCS) results in vascular, respiratory, and neurologic compromise. A systematic search was conducted to determine the prevalence of pediatric SVCS subtypes and identify clinical characteristics/treatment strategies that may influence overall outcomes. Data from 101 case reports/case series (142 patients) were analyzed. Morbidity (30%), mortality (18%), and acute complications (55%) were assessed as outcomes. Thrombosis was present in 36%, with multi-modal anticoagulation showing improved outcome by >50% (P = 0.004). Infant age (P = 0.04), lack of collaterals (P = 0.007), acute complications (P = 0.005), and clinical presentation may have prognostic utility that could influence clinical decisions and surveillance practices in pediatric SVCS.

Endovascular stent-based revascularization of malignant superior vena cava syndrome with concomitant implantation of a port device using a dual venous approach.

PURPOSE: The aim of this paper is to evaluate the safety and efficacy of endovascular revascularization of malignant superior vena cava syndrome (SVCS) and simultaneous implantation of a totally implantable venous access port (TIVAP) using a dual venous approach. MATERIALS AND METHODS: Retrospectively, 31 patients (mean age 67 ± 8 years) with malignant CVO who had undergone revascularization by implantation of a self-expanding stent into the superior vena cava (SVC) (Sinus XL®, OptiMed, Germany; n = 11 [Group1] and Protégé ™ EverFlex, Covidien, Ireland; n = 20 [Group 2]) via a transfemoral access were identified. Simultaneously, percutaneous access via a subclavian vein was used to (a) probe the lesion from above, (b) facilitate a through-and-through maneuver, and (c) implant a TIVAP. Primary endpoints with regard to the SVC syndrome were technical (residual stenosis < 30%) and clinical (relief of symptoms) success; with regard to TIVAP implantation technical success was defined as positioning of the functional catheter within the SVC. Secondary endpoints were complications as well as stent and TIVAP patency. RESULTS: Technical and clinical success rate were 100% for revascularization of the SVS and 100% for implantation of the TIVAP. One access site hematoma (minor complication, day 2) and one port-catheter-associated sepsis (major complication, day 18) were identified. Mean catheter days were 313 ± 370 days. Mean imaging follow-up was 184 ± 172 days. Estimated patency rates at 3, 6, and 12 months were 100% in Group 1 and 84, 84, and 56% in Group 2 (p = 0.338). CONCLUSION: Stent-based revascularization of malignant SVCS with concomitant implantation of a port device using a dual venous approach appears to be safe and effective.

The Extended Dwell Peripheral Intravenous Catheter Is an Alternative Method of NICU Intravenous Access.

BACKGROUND: Establishing vascular access is a common neonatal intensive care unit procedure. The extended dwell peripheral intravenous (EPIV) catheter is a 6-cm and 8-cm silicone catheter for peripheral vein insertion, which is a newer vascular access device than peripherally inserted central catheters (PICCs) and peripheral intravenous (PIV) catheter. Extended dwell peripheral intravenous catheters have been widely used in adults but evidence in neonates is lacking. PURPOSE: To explore indwell time, success rate, catheter-associated complications, and cost among EPIV catheters, PICCs, and PIV catheters in neonates. METHODS: We retrospectively compare patient demographics, indwell time, success rate, and catheter-associated complications, and analyze the rate of hyaluronidase-treated intravenous (IV) fluid extravasation on neonates who had an EPIV catheter, a PICC, or a PIV catheter in a level III neonatal intensive care unit. We also estimate the insertion cost of these 3 vascular access devices on the basis of our hospital charges. RESULTS: Extended dwell peripheral intravenous catheters were inserted in 432 neonates with an indwell time of 4.0 ± 2.3 (mean ± SD) days. Peripherally inserted central catheters were inserted in 202 neonates with an average indwell time of 7.3 ± 4.4 (mean ± SD) days, which was longer than EPIV catheters (P < .001). Peripherally inserted central catheters had a higher success rate of 83.6% than 71.7% of EPIV catheters, meaning succeeded in lasting through the completion of therapy (P = .001). Peripherally inserted central catheters were associated with 4 cases of life-threatening complications; none was seen in the EPIV catheter group. The incidence of hyaluronidase-treated IV fluid extravasation was less in EPIV catheter recipients (1.2%) than in the PIV catheter recipients (3.9%) (P = .004); none was in the PICC group. Cost savings were noted with using an EPIV catheter. IMPLICATIONS FOR PRACTICE: Extended dwell peripheral intravenous catheter is a feasible option for neonatal vascular access. IMPLICATIONS FOR RESEARCH: These data provide a baseline for future studies to explore the efficacy and effectiveness of EPIV catheter in the neonates.

A Review of Open and Endovascular Treatment of Superior Vena Cava Syndrome of Benign Aetiology.

BACKGROUND: The widespread use of central venous catheters, ports, pacemakers, and defibrillators has increased the incidence of benign superior vena cava syndrome (SVCS). This study aimed at reviewing the results of open and endovascular treatment of SVCS. METHOD: Medical literature databases were searched for relevant studies. Studies with more than five adult patients, reporting separate results for the SVC were included. Nine studies reported the results of endovascular treatment of SVCS including 136 patients followed up for a mean of 11-48 months. Causes of SVCS were central venous catheters and pacemakers (80.6%), mediastinal fibrosis (13.7%), and other (5.6%). Percutaneous transluminal angioplasty (PTA) and stenting was performed in 73.6%, PTA only in 17.3%, and thrombolysis, PTA, and stenting in 9%. Four studies reported the results of open repair of SVCS including 87 patients followed up between 30 months and 10.9 years. The causes were mediastinal fibrosis (58.4%), catheters and pacemakers (28.5%), and other (13%). Operations performed included a spiral saphenous interposition graft, other vein graft, PTFE graft, and human allograft. Thirteen patients required re-operations (15%) before discharge mainly for graft thrombosis. RESULTS: In the endovascular group technical success was 95.6%. Thirty day mortality was 0%. Regression of symptoms was reported in 97.3%. Thirty-two patients (26.9%) underwent 58 secondary procedures. In the open group the 30 day mortality was 0%. Symptom regression was reported in 93.5%. Twenty-four patients (28.4%) underwent a total of 33 secondary procedures. CONCLUSIONS: Endovascular is the first line treatment for SVCS caused by intravenous devices, whereas surgery is most often performed for mediastinal fibrosis. Both treatments show good results regarding regression of the symptoms and mid-term primary patency, with a significant incidence of secondary interventions.

Prevalence and etiology of focal liver opacification in patients with superior vena cava obstruction.

OBJECTIVE: This study aimed to assess the prevalence and etiologies of focal liver opacification (FLO) in the setting of superior vena cava (SVC) obstruction. METHODS: An archival search using key words to identify patients with SVC obstruction or severe narrowing and who had computed tomographic scans with intravenous contrast was performed at our institution. RESULTS: Thirty-one patients were included. Focal liver opacification was identified in 9 (29%). The most common direct causes of FLO and SVC obstruction were benign. CONCLUSIONS: Focal liver opacification caused by SVC obstruction is relatively common. Focal liver opacification is more commonly associated with benign causes of obstruction such as end-stage renal disease. Identifying FLO is important not only as an indirect sign of SVC obstruction but also must be distinguished from avidly enhancing liver masses. This study also reflects the overall recent increase in benign causes of SVC obstruction.

[Non-infectious respiratory emergencies in patients with cancer]. / Urgences respiratoires (non infectieuses) du patient d'onco-hématologie.

Patients with a solid tumor or hematologic malignancy are often addressed to emergency units for an acute respiratory complication associated with the underlying cancer or secondary to treatments. The current article is part of a thematic series: "Intensive care and emergencies in solid tumours and blood cancer patients" and will develop the following points: (1) malignant proximal airway obstruction and, more specifically, the role of therapeutic bronchoscopy; (2) superior vena cava syndrome by tumor compression and/or secondary to thrombosis (diagnosis, local and systemic treatments); (3) cancer-related pulmonary embolism (incidence, indications for low-molecular weight heparins and direct oral anticoagulants). Other respiratory emergencies will be dealt in the other articles of this series.

Blood loss during flexible bronchoscopy: a prospective observational study.

BACKGROUND: Haemorrhage remains a complication of flexible bronchoscopy. OBJECTIVES: We aimed to measure the actual blood loss in patients at low risk of bleeding and to assess its association with the underlying pulmonary pathology, superior vena cava (SVC) syndrome, procedure(s) performed and laboratory values. METHODS: We screened all patients scheduled for flexible bronchoscopy and enrolled 234 subjects over 18 months. Subjects with a history of haemorrhagic tendency, platelets <20 × 10(3)/µl, a history of anti-coagulation or anti-platelet therapy and a history or clinical evidence of liver failure were excluded. Blood loss during the procedure was measured from aspirated secretions with a haemoglobin detector and categorised into minimal (<5 ml), mild (5-20 ml), moderate (20-100 ml) and severe bleeding (>100 ml). RESULTS: Overall, 210 subjects had minimal, 19 had mild and 5 had moderate bleeding. No subject experienced severe blood loss. Patients with SVC syndrome had the highest mean blood loss (6.0 ml) when compared to bronchogenic carcinoma without SVC syndrome (p = 0.033) and other diagnosis (p = 0.026). The blood loss with trans-bronchial needle aspiration (TBNA, mean 3.4 ml) was significantly less than with TBNA combined with endobronchial or transbronchial biopsy (mean 5.0 ml, p < 0.001). Anaemia, a platelet count of 25-155 × 10(3)/µl and an international normalized ratio of >1.3 were not associated with an increased risk of bleeding. CONCLUSIONS: We found no severe bleeding in this cohort preselected to have a low clinical risk of bleeding. Moreover, our data suggest that clinical screening and a platelet count ≥20 × 10(3)/µl alone may be sufficient to identify low-risk patients.

Superior vena cava syndrome in thoracic malignancies.

The superior vena cava syndrome (SVCS) comprises various symptoms due to occlusion of the SVC, which can be easily obstructed by pathological conditions (eg, lung cancer, due to the low internal venous pressure within rigid structures of the thorax [trachea, right bronchus, aorta]). The resulting increased venous pressure in the upper body may cause edema of the head, neck, and upper extremities, often associated with cyanosis, plethora, and distended subcutaneous vessels. Despite the often striking clinical presentation, SVCS itself is usually not a life-threatening condition. Currently, randomized controlled trials on many clinically important aspects of SVCS are lacking. This review gives an interdisciplinary overview of the pathophysiology, etiology, clinical manifestations, diagnosis, and treatment of malignant SVCS.

Managing superior vena cava syndrome as a complication of pacemaker implantation: a pooled analysis of clinical practice.

BACKGROUND: Superior vena cava syndrome (SVCS) is a rare complication of pacemaker implantation. Numerous methods have been employed to treat this condition, ranging from anticoagulation and thrombolysis to surgical interventions and stenting. However, thus far only small case series have been reported and there is no currently accepted standard of care. METHODS: Our group preformed a PubMed literature search to identify cases of symptomatic SVCS that developed following implantation of permanent pacemakers or implanatable cardioverter defibrillators and were treated with one of five different modalities: anticoagulation, thrombolysis, venoplasty, stenting, and surgical reconstuction. Duration of follow-up and incidence of recurrence of symptoms were the main end-points. RESULTS: One hundred and four eligible cases from 74 different publications were identified, in which SVCS presented at a median of 48 (range 0-396) months after device implantation. We found that over the last 40 years, conservative treatments have been replaced by surgical reconstruction, and most recently by stenting, as the most common therapeutic modality employed. Anticoagulation, thrombolysis, and venoplasty alone were all associated with high recurrence rates. Surgery and stenting were more successful: recurrence rates were 12% and 5% over a median follow-up of 16 (range: 2-179) and 9.5 (range: 2-60) months, respectively. CONCLUSIONS: Currently, transvenous stenting is the most common treatment used for pacemaker-related SVCS, usually with conservation of the implanted leads. Both surgery and stenting appear to be effective treatments, with low incidences of recurrent SVCS over the first 12 months, but there is unfortunately a paucity of data on long-term outcomes. (PACE 2010; 420-425).

Thromboembolic risk with IVIg: Incidence and risk factors in patients with inflammatory neuropathy.

Our objective was to evaluate whether IV immunoglobulin (IVIg) increases the risk of thromboembolic events in neurology outpatients with inflammatory neuropathies, as there is conflicting evidence supporting this hypothesis, mainly from non-neurologic cohorts. We investigated this question over 30 months in our cohort of patients with inflammatory neuropathies receiving regular IVIg and found a greater incidence of arterial and venous thromboembolic events than population-based rates determined by hospital admissions data. Vascular risk factors were more common in the event group but there were no IVIg administration factors that contributed to the risk. This study suggests that IVIg may have a small but contributory role in determining thromboembolic risk in the inflammatory neuropathy cohort and more evidence is required before it is clear whether the current primary prevention guidelines are appropriate in this group of patients.

Chemoradiation-induced superior vena cava syndrome: a case report.

A case of a 54-year-old man who developed superior vena cava syndrome secondary to vascular fibrosis, 30 months after radical chemoradiation for stage III non-small cell lung cancer, is presented. The literature regarding the etiology, diagnosis and treatment of this rare entity is discussed.

Superior vena cava obstruction: diagnosis, management and outcome.

OBJECTIVE: To document our experience with superior vena cava obstruction in a black African population. DESIGN: A retrospective study of clinical data collected from cancer registry, patients case noted, cardiothoracic surgical unit's and operating records between June 1975 and May 1999. SETTING: University College Hospital, Ibadan, Nigeria which hosts a major cancer centre in the West African sub-region and also serves community clinics. PATIENTS: All patients with superior vena cava (SVC) obstruction referred for evaluation and treatment. MAIN OUTCOME MEASURES: Patients who had clinical features related to SVC obstruction and full investigation including tissue diagnosis were collated. Methods of treatment of acute episodes, definitive treatment and outcome of SVC obstruction were studied. RESULTS: One hundred and twenty nine consecutive patients with SVC obstruction were treated. There were 100 males and 29 females. Mean age was 36 +/- 15 years. The annual incidence increased from 2.3 patients per year during the first 12 years to 8.4 patients per year during the second 12 years. The most common symptoms were swelling of face, arms and chest-wall (87.6%) with associated venous congestion over these areas. Majority of the patients (73.8%) presented within 1 to 12 months of onsets of symptoms. Patients with benign diseases had longer duration of symptoms before presentation (mean 3 months) than those with malignant disease (mean 6 months). Majority of the patients (82.2%) had malignancy as the underlying cause of the SVC obstruction and 47.2% of the malignancy was bronchogenic carcinoma. Symptomatic relief and outcome was best in benign disease (7 out of 8 patients, 87.5%). Lymphomas had better outcome than bronchogenic carcinoma among the patients with malignant diseases. CONCLUSION: Patients with SVC obstruction should be carefully evaluated before treatment. This will enhance application of specific therapy.

Endovascular Therapy for Central Venous Thrombosis.

Central vein thrombosis is defined as thrombosis of the major vessels draining either the upper or lower extremities. It presents most commonly in the upper limb, where it affects the subclavian veins and the superior vena cava; in the lower limb, it affects the common iliac veins and the inferior vena cava. These different anatomical segments pose unique challenges in both acute and chronic settings, and this article will summarize the current best practice treatment options.

Disease-specific survival for limited-stage small-cell lung cancer affected by statistical method of assessment.

BACKGROUND: In general, prognosis and impact of prognostic/predictive factors are assessed with Kaplan-Meier plots and/or the Cox proportional hazard model. There might be substantive differences from the results using these models for the same patients, if different statistical methods were used, for example, Boag log-normal (cure-rate model), or log-normal survival analysis. METHODS: Cohort of 244 limited-stage small-cell lung cancer patients, were accrued between 1981 and 1998, and followed to the end of 2005. The endpoint was death with or from lung cancer, for disease-specific survival (DSS). DSS at 1-, 3- and 5-years, with 95% confidence limits, are reported for all patients using the Boag, Kaplan-Meier, Cox, and log-normal survival analysis methods. Factors with significant effects on DSS were identified with step-wise forward multivariate Cox and log-normal survival analyses. Then, DSS was ascertained for patients with specific characteristics defined by these factors. RESULTS: The median follow-up of those alive was 9.5 years. The lack of events after 1966 days precluded comparison after 5 years. DSS assessed by the four methods in the full cohort differed by 0-2% at 1 year, 0-12% at 3 years, and 0-1% at 5 years. Log-normal survival analysis indicated DSS of 38% at 3 years, 10-12% higher than with other methods; univariate 95% confidence limits were non-overlapping. Surgical resection, hemoglobin level, lymph node involvement, and superior vena cava (SVC) obstruction significantly impacted DSS. DSS assessed by the Cox and log-normal survival analysis methods for four clinical risk groups differed by 1-6% at 1 year, 15-26% at 3 years, and 0-12% at 5 years; multivariate 95% confidence limits were overlapping in all instances. CONCLUSION: Surgical resection, hemoglobin level, lymph node involvement, and superior vena cava (SVC) obstruction all significantly impacted DSS. Apparent DSS for patients was influenced by the statistical methods of assessment. This would be clinically relevant in the development or improvement of clinical management strategies.

Home parenteral nutrition-associated thromboembolic and bleeding events: results of a cohort study of 236 individuals.

UNLABELLED: Essentials Sparse or outdated studies focus on thrombotic and bleeding risk in home parenteral nutrition (HPN). 236 HPN patients followed at a single center for a total of 684 patient-years were evaluated. Rates of venous thrombosis and major bleeding, and prevalence of vena cava syndrome are provided. Anticoagulants might reduce thrombosis risk, but population-specific safety concerns remain. SUMMARY: Background Home parenteral nutrition (HPN) is necessary for patients with intestinal failure. Recurrent catheter-related thrombosis (CRT) is common, leading to infectious complications, pulmonary embolism, vascular access loss and intestinal transplantation. The efficacy and safety of anticoagulants are unknown in this setting and based on sparse and low-quality observational data. Objectives Our aim was to estimate the incidence of thromboembolic, bleeding and anticoagulant-related complications in HPN patients, and evaluate risk factors for first venous thrombosis (VT). Methods This retrospective cohort study included all adult patients followed for long-term HPN at our center between 1986 and 2014. Primary outcomes were symptomatic objectively diagnosed VT, encompassing CRT and venous thromboembolism, and major bleeding. Secondary outcomes were vena cava syndrome and heparin-induced thrombocytopenia or hypersensitivity. Results A total of 236 patients were included (median HPN duration, 17 months) and 136 received anticoagulants at HPN onset (57.6%). Overall, the annual incidence of first VT was 11.4% (95% confidence interval [95% CI], 8.6-14.7%); VT was associated with a personal history of thrombosis (adjusted hazard ratio, 2.22; 95% CI, 1.06-4.64), whereas anticoagulation seemed to account only for a mild protection (adjusted hazard ratio, 0.72; 95% CI, 0.36-1.44). The annual incidence of major bleeding was 4.3% for patients on anticoagulants vs. 1.8% for those off anticoagulants. Vena cava syndrome developed in 20.7% of patients with VT. One patient had isolated heparin-induced thrombocytopenia (0.6%) and four had heparin hypersensitivity (2.5%). Conclusions Patients on HPN have a significant risk of venous thrombosis, major bleeding and vena cava syndrome. Anticoagulants might reduce thrombosis risk, but population-specific safety concerns remain.

Superior vena cava syndrome in small-cell lung cancer.

BACKGROUND: The aim of this study was to analyze the features of the superior vena cava syndrome (SVCS) as initial characteristics in small-cell lung cancer: incidence, dissemination of disease, diagnostic procedures, efficacy and toxic effects of chemotherapy, and median survival in patients with SVCS. METHODS: In a prospective series of 724 patients with biopsy-proved small-cell lung cancer seen during a 6-year period, we reviewed data from patients who also had SVCS. RESULTS: The incidence of SVCS was 87 of 724 at the time of diagnosis. Initial emergency radiation therapy was not used in these patients. Diagnostic procedures in these patients were not associated with mortality. Rapid initiation of intensive chemotherapy, often with heparin therapy, resulted in complete or partial responses in 81% and no response in 12%; data were not evaluable in 7%. Two of these 87 patients died of aplasia within 4 weeks of chemotherapy. Median survival was not significantly different in the patients with SVCS (median, 42 weeks) and without SVCS (median, 40 weeks). A significant increase in initial brain metastases at the time of diagnosis was observed in patients with SVCS (22% vs 11%). CONCLUSIONS: Intensive chemotherapy is the first line of therapy in small-cell lung cancer. Histologic diagnostic procedures must be performed in patients with SVCS to adapt the treatment to the underlying cause. Initial emergency radiotherapy, before diagnosis or chemotherapy, does not seem to be useful in these patients. Computed tomography of the brain should be performed routinely in patients with SVCS, and prophylactic brain irradiation could be helpful in such patients. Apparently SVCS is not a poor prognostic factor in treated small-cell lung cancer.

Frequency of superior vena cava syndrome following radiofrequency modification of the sinus node and its management.

In a series of 35 consecutive patients, the presence of a permanent pacemaker appears to be a strong risk factor for developing superior vena cava syndrome after radiofrequency modification of the sinus node. Treatment of this complication with balloon venoplasty is as effective as surgical repair.

Safety and efficacy of thrombolytic therapy for superior vena cava syndrome.

The experience at the Cleveland Clinic from 1982 to 1990 using thrombolytic therapy for superior vena cava (SVC) syndrome was retrospectively reviewed. Sixteen patients, 11 of whom had indwelling central venous catheters, were treated with either urokinase (n = 11) or streptokinase (n = 5). Either urokinase (4,400 U/kg bolus followed by 4,400 U/kg/h) or streptokinase (250,000 U bolus followed by 100,000 U/h) was used, and venograms were performed before and after. Overall, 56 percent of patients had complete clot lysis and relief of symptoms. Thrombolytic therapy was effective in eight (73 percent) of 11 patients receiving urokinase and one (20 percent) of five patients receiving streptokinase. Of those with a central venous catheter, eight (73 percent) of 11 patients were successfully lysed, whereas only one (20 percent) of five patients was successfully lysed if no catheter was present. If thrombolytic therapy was performed less than or equal to five days of symptom onset, seven (88 percent) of eight patients were successful, if thrombolytic therapy was performed greater than five days after symptom onset, two (25 percent) of eight patients were successful. Symptoms were relieved and the catheter was preserved in patients in whom thrombolytic therapy was effective. Factors predicting success were as follows: (1) the use of urokinase compared with streptokinase; (2) the presence of a central venous catheter; and (3) a duration of symptoms less than or equal to five days.