Prospective Multicenter International Registry of Ultrasound-Facilitated Catheter-Directed Thrombolysis in Intermediate-High and High-Risk Pulmonary Embolism (KNOCOUT PE)

BACKGROUND

Prior clinical trials have demonstrated the efficacy of ultrasound-facilitated catheter-directed thrombolysis (USCDT) for the treatment of acute intermediate-risk pulmonary embolism (PE) using reduced thrombolytic doses and shorter infusion durations. However, utilization and safety of such strategies in broader PE populations remain unclear. The KNOCOUT PE (The EKoSoNic Registry of the Treatment and Clinical Outcomes of Patients With Pulmonary Embolism) registry is a multicenter international registry designed to study the treatment of acute PE with USCDT, with focus on safety outcomes.

METHODS

The KNOCOUT PE prospective cohort included 489 patients (64 sites internationally) with acute intermediate-high or high-risk PE treated with USCDT between March 2018 and June 2020. Principal safety outcomes were independently adjudicated International Society on Thrombosis and Haemostasis major bleeding at 72 hours post-treatment and mortality within 12 months of treatment. Additional outcomes included change in right ventricular/left ventricular ratio and quality of life measures over 12 months.

RESULTS

Mean alteplase (r-tPA [recombinant tissue-type plasminogen activator]) infusion duration was 10.5 hours. Mean total r-tPA dose was 18.1 mg, with 31.0% of patients receiving ≤12 mg. Major bleeding events within 72 hours occurred in 1.6% (8/489) of patients. One patient experienced worsening of a preexisting subdural hematoma after USCDT and therapeutic anticoagulation, which ultimately required surgery. All-cause mortality at 30 days was 1.0% (5/489). Improvement in PE quality of life score was observed with a 41.1% (243/489, 49.7%) and 44.2% (153/489, 31.3%) mean relative reduction by 3 and 12 months, respectively.

CONCLUSIONS

In a prospective observational cohort study of patients with intermediate-high and high-risk PE undergoing USCDT, mean r-tPA dose was 18 mg, and the rates of major bleeding and mortality were low.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03426124.

Ultrasound-facilitated, catheter-directed thrombolysis vs anticoagulation alone for acute intermediate-high-risk pulmonary embolism: Rationale and design of the HI-PEITHO study

BACKGROUND

Due to the bleeding risk of full-dose systemic thrombolysis and the lack of major trials focusing on the clinical benefits of catheter-directed treatment, heparin antiocoagulation remains the standard of care for patients with intermediate-high-risk pulmonary embolism (PE).

METHODS AND RESULTS

The Higher-Risk Pulmonary Embolism Thrombolysis (HI-PEITHO) study (ClinicalTrials.gov Identifier: NCT04790370) is a multinational multicenter randomized controlled parallel-group comparison trial. Patients with: (1) confirmed acute PE; (2) evidence of right ventricular (RV) dysfunction on imaging; (3) a positive cardiac troponin test; and (4) clinical criteria indicating an elevated risk of early death or imminent hemodynamic collapse, will be randomized 1:1 to treatment with a standardized protocol of ultrasound-facilitated catheter-directed thrombolysis plus anticoagulation, vs anticoagulation alone. The primary outcome is a composite of PE-related mortality, cardiorespiratory decompensation or collapse, or non-fatal symptomatic and objectively confirmed PE recurrence, within 7 days of randomization. Further assessments cover, apart from bleeding complications, a broad spectrum of functional and patient-reported outcomes including quality of life indicators, functional status and the utilization of health care resources over a 12-month follow-up period. The trial plans to include 406 patients, but the adaptive design permits a sample size increase depending on the results of the predefined interim analysis. As of May 11, 2022, 27 subjects have been enrolled. The trial is funded by Boston Scientific Corporation and through collaborative research agreements with University of Mainz and The PERT Consortium.

CONCLUSIONS

Regardless of the outcome, HI-PEITHO will establish the first-line treatment in intermediate-high risk PE patients with imminent hemodynamic collapse. The trial is expected to inform international guidelines and set the standard for evaluation of catheter-directed reperfusion options in the future.

One-Year Echocardiographic, Functional, and Quality of Life Outcomes After Ultrasound-Facilitated Catheter-Based Fibrinolysis for Pulmonary Embolism

Accelerated tPA (tissue-type plasminogen activator) dosing regimens for ultrasound-facilitated, catheter-directed fibrinolysis improve short-term computed tomographic-measured right ventricular (RV)-to-left ventricular diameter ratio in massive and submassive pulmonary embolism. The impact on RV remodeling, functional status, and quality of life over the long-term remains unclear.

Ultrasound-Accelerated Thrombolysis and Venoplasty for the Treatment of the Postthrombotic Syndrome: Results of the ACCESS PTS Study

Background Postthrombotic syndrome is a common complication of deep vein thrombosis, with limited treatment options. Methods and Results ACCESS PTS (Accelerated Thrombolysis for Post-Thrombotic Syndrome Using the Acoustic Pulse Thrombolysis Ekosonic Endovascular System) is a multicenter, single-arm, prospective study evaluating patients with chronic deep vein thrombosis and postthrombotic syndrome (Villalta score ≥8) who received minimum 3 months of anticoagulation. Patients underwent percutaneous transluminal venoplasty and ultrasound-accelerated thrombolysis, with data collected on clinical characteristics, postthrombotic syndrome, imaging, and quality of life to 1 year. The primary efficacy outcome was a reduction of ≥4 points in the Villalta score 30 days after procedure. The primary safety outcomes were major bleeding episodes within 72 hours and symptomatic pulmonary embolism during the index hospitalization. A total of 82 limbs (78 patients) were treated (age, 54.6±12.7 years; 32.1% women; mean Villalta score, 15.5±5.2). The primary end point was met in 64.6% (51/79). At 1 year, 77.3% (51/66) of limbs continued with a Villalta reduction ≥4. At 365 days, >90% of segments had patency with ultrasound flow present. Baseline to 1-year Physical Component Summary mean score of the Short Form-36 increased from 38.9±9.5 to 45.2±9.8 (P≤0.0001), and mean VEINES-QOL (Venous Insufficiency Epidemiological and Economic Study-Quality of Life) increased from 61.9±19.7 to 82.6±20.8 at 1 year (P<0.0001). Iliofemoral venous stenting was performed in 42 patients, with similar improvements seen in all outcomes, regardless of stenting status. One patient developed severe bleeding within 72 hours of the intervention and died at 32 days after procedure (1.3% mortality rate). Conclusions Percutaneous transluminal venoplasty and ultrasound-accelerated thrombolysis resulted in successful recanalization of chronic venous obstruction with improved postthrombotic syndrome severity and quality of life. Results were sustained at 1-year after procedure. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02159521.

A Prospective, Single-Arm, Multicenter Trial of Ultrasound-Facilitated, Catheter-Directed, Low-Dose Fibrinolysis for Acute Massive and Submassive Pulmonary Embolism: The SEATTLE II Study

OBJECTIVES

This study conducted a prospective, single-arm, multicenter trial to evaluate the safety and efficacy of ultrasound-facilitated, catheter-directed, low-dose fibrinolysis, using the EkoSonic Endovascular System (EKOS, Bothell, Washington).

BACKGROUND

Systemic fibrinolysis for acute pulmonary embolism (PE) reduces cardiovascular collapse but causes hemorrhagic stroke at a rate exceeding 2%.

METHODS

Eligible patients had a proximal PE and a right ventricular (RV)-to-left ventricular (LV) diameter ratio ≥0.9 on chest computed tomography (CT). We included 150 patients with acute massive (n = 31) or submassive (n = 119) PE. We used 24 mg of tissue-plasminogen activator (t-PA) administered either as 1 mg/h for 24 h with a unilateral catheter or 1 mg/h/catheter for 12 h with bilateral catheters. The primary safety outcome was major bleeding within 72 h of procedure initiation. The primary efficacy outcome was the change in the chest CT-measured RV/LV diameter ratio within 48 h of procedure initiation.

RESULTS

Mean RV/LV diameter ratio decreased from baseline to 48 h post-procedure (1.55 vs. 1.13; mean difference, -0.42; p < 0.0001). Mean pulmonary artery systolic pressure (51.4 mm Hg vs. 36.9 mm Hg; p < 0.0001) and modified Miller Index score (22.5 vs. 15.8; p < 0.0001) also decreased post-procedure. One GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries)-defined severe bleed (groin hematoma with transient hypotension) and 16 GUSTO-defined moderate bleeding events occurred in 15 patients (10%). No patient experienced intracranial hemorrhage.

CONCLUSIONS

Ultrasound-facilitated, catheter-directed, low-dose fibrinolysis decreased RV dilation, reduced pulmonary hypertension, decreased anatomic thrombus burden, and minimized intracranial hemorrhage in patients with acute massive and submassive PE. (A Prospective, Single-arm, Multi-center Trial of EkoSonic® Endovascular System and Activase for Treatment of Acute Pulmonary Embolism (PE) [SEATTLE II]; NCT01513759).

A Prospective, Single-Arm, Multicenter Trial of Ultrasound-Facilitated, Catheter-Directed, Low-Dose Fibrinolysis for Acute Massive and Submassive Pulmonary Embolism: The SEATTLE II Study

OBJECTIVES

This study conducted a prospective, single-arm, multicenter trial to evaluate the safety and efficacy of ultrasound-facilitated, catheter-directed, low-dose fibrinolysis, using the EkoSonic Endovascular System (EKOS, Bothell, Washington).

BACKGROUND

Systemic fibrinolysis for acute pulmonary embolism (PE) reduces cardiovascular collapse but causes hemorrhagic stroke at a rate exceeding 2%.

METHODS

Eligible patients had a proximal PE and a right ventricular (RV)-to-left ventricular (LV) diameter ratio ≥0.9 on chest computed tomography (CT). We included 150 patients with acute massive (n = 31) or submassive (n = 119) PE. We used 24 mg of tissue-plasminogen activator (t-PA) administered either as 1 mg/h for 24 h with a unilateral catheter or 1 mg/h/catheter for 12 h with bilateral catheters. The primary safety outcome was major bleeding within 72 h of procedure initiation. The primary efficacy outcome was the change in the chest CT-measured RV/LV diameter ratio within 48 h of procedure initiation.

RESULTS

Mean RV/LV diameter ratio decreased from baseline to 48 h post-procedure (1.55 vs. 1.13; mean difference, -0.42; p < 0.0001). Mean pulmonary artery systolic pressure (51.4 mm Hg vs. 36.9 mm Hg; p < 0.0001) and modified Miller Index score (22.5 vs. 15.8; p < 0.0001) also decreased post-procedure. One GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries)-defined severe bleed (groin hematoma with transient hypotension) and 16 GUSTO-defined moderate bleeding events occurred in 15 patients (10%). No patient experienced intracranial hemorrhage.

CONCLUSIONS

Ultrasound-facilitated, catheter-directed, low-dose fibrinolysis decreased RV dilation, reduced pulmonary hypertension, decreased anatomic thrombus burden, and minimized intracranial hemorrhage in patients with acute massive and submassive PE. (A Prospective, Single-arm, Multi-center Trial of EkoSonic® Endovascular System and Activase for Treatment of Acute Pulmonary Embolism (PE) [SEATTLE II]; NCT01513759).

Geniculate artery embolization in the management of spontaneous recurrent hemarthrosis of the knee: case series

Spontaneous recurrent hemarthrosis after knee arthroplasty is reported to occur in 0.3%-1% of patients, likely secondary to hypertrophic vascular synovium. Five patients who underwent previous arthroplasty presented with spontaneous hemarthrosis. Selective arterial embolization was performed with spherical embolic particles (diameter range, 100-700 μm). Angiography demonstrated synovial hypervascularity with geniculate artery "tumor blush" appearance in all patients. Average time to resolution of effusion was 2.6 weeks, with no recurrences reported during follow-up (mean, 25.4 mo; range, 16-48 mo). Two patients experienced transient cutaneous ischemia. Selective geniculate artery embolization with spherical embolic particles is an effective treatment for spontaneous recurrent hemarthrosis of the knee.

Uterine artery embolization versus myomectomy: a multicenter comparative study

OBJECTIVE

To determine whether there is significant quality of life score improvement after uterine artery embolization (UAE) and to compare UAE and myomectomy outcomes.

DESIGN

Prospective cohort controlled study.

SETTING

Sixteen medical centers in the United States.

PATIENT(S)

One hundred forty-nine UAE patients and 60 myomectomy patients. Patients were assigned to myomectomy or UAE on the basis of a best treatment decision made by the patient and her physician. All patients were observed for 6 months. The UAE patients also had follow-up examinations at 1 year.

INTERVENTION(S)

Myomectomy or UAE.

MAIN OUTCOME MEASURE(S)

Quality of life score changes, menstrual bleeding score changes, uterine size differences, time off, and adverse events.

RESULT(S)

Both groups experienced statistically significant improvements in the uterine fibroid quality of life score, menstrual bleeding, uterine volume, and overall postoperative quality of life. The mean hospital stay was 1 day for the UAE patients, compared with 2.5 days for the myomectomy patients. The UAE and myomectomy patients returned to their normal activities in 15 days and 44 days, respectively, and returned to work in 10 days and 37 days, respectively. At least one adverse event occurred in 40.1% of the myomectomy patients, compared with 22.1% in the UAE group.

CONCLUSION(S)

The uterine fibroid quality of life score was significantly improved in both groups. No significant differences were observed in bleeding improvement, uterine volume reduction, uterine fibroid quality of life score improvement, and overall quality of life score improvement between groups. Patients receiving UAE required fewer days off work, fewer hospital days, and experienced fewer adverse events.

I. Uterine fibroid embolization: preprocedure assessment

Increasing clinical experience with uterine fibroid embolization (UFE) has improved the ability of interventionalist radiologists to discern who is and who is not an appropriate candidate for this procedure. Initial evaluation should be directed at obtaining answers to the following key questions: (1) Does the patient have uterine fibroids that account for her symptoms and are they severe enough to require invasive treatment? (2) Does she desire future childbearing? (3) Are there any clinical indications or imaging signs of uterine malignancy? (4) Are there any medical or anatomic features that would favor a particular therapeutic modality? (5) What are her own preferences regarding treatment? Ultrasound and magnetic resonance imaging are vital elements to the assessment and planning of the appropriate course of action. Given the lack of prospective comparative trials between UFE and surgical treatment, recommendations are often highly influenced by patient preference.

VI. Uterine fibroid embolization: developing a clinical service

Building a uterine fibroid embolization (UFE) practice can be a complex process. Choices must be made regarding whether to align oneself with a gynecologist or to accept direct referrals. For the interventional radiologist, the responsibilities of evaluation and patient care pose unique and time-consuming administrative and clinical challenges. Physician extenders, either nurse practitioners or physician's assistants, play key roles as clinical coordinators by guiding the patient through the medical system and making certain that she is cleared for the procedure medically and logistically. In some settings, they may also assist in many of the technical aspects of the procedure and postoperative care. Interventional radiologists must be prepared for battles with insurance companies and be willing to go through the appeals process. Business officers must also be trained to properly code for the procedures to insure optimal reimbursement. The success of building a UFE practice may also be bolstered by directly marketing to patients and by providing them with access via the Internet.

V. Uterine fibroid embolization: management of complications

Fortunately, the number of complications reported after uterine fibroid embolization (UFE) is extremely low. Angiographic mishap or drug reaction are probably more common than purely UFE-related complications. However, the possibility of infection or necrosis of the uterus, with their significant attendant morbidity, is a sobering reminder that embolotherapy can have a powerful impact on the target organ(s). Knowledge of the expected time course for symptom resolution and the often confusing imaging findings shortly after UFE are critical for avoiding unnecessary delay in surgical intervention or, perhaps more important, an inappropriate rush to surgery when antibiotics alone will suffice. Other complications include alteration of uterine physiology, which may disrupt sexual function, and menstrual irregularity and even premature menopause.

Cellular and biophysical evidence for interactions between adenosine triphosphate and P-glycoprotein substrates: functional implications for adenosine triphosphate/drug cotransport in P-glycoprotein overexpressing tumor cells and in P-glycoprotein low-level expressing erythrocytes

P-glycoprotein is involved with the removal of drugs, most of them cations, from the plasma membrane and cytoplasm. Pgp is also associated with movement of ATP, an anion, from the cytoplasm to the extracellular space. The central question of this study is whether drug and ATP transport associated with the expression of Pgp are in any way coupled. We have measured the stoichiometry of transport coupling between drug and ATP release. The drug and ATP transport that is inhibitable by the sulfonylurea compound, glyburide (P. E. Golstein, A. Boom, J. van Geffel, P. Jacobs, B. Masereel, and R. Beauwens, Pfluger's Arch. 437, 652, 1999), permits determination of the transport coupling ratio, which is close to 1:1. In view of this result, we asked whether ATP interacts directly with Pgp substrates. We show by measuring the movement of Pgp substrates in electric fields that ATP and drug movement are coupled. The results are compatible with the view that substrates for Pgp efflux are driven by the movement of ATP through electrostatic interaction and effective ATP-drug complex formation with net anionic character. This mechanism not only pertains to drug efflux from tumor cells overexpressing Pgp, but also provides a framework for understanding the role of erythrocytes in drug resistance. The erythrocyte consists of a membrane surrounding a millimolar pool of ATP. Mammalian RBCs have no nucleus or DNA drug/toxin targets. From the perspective of drug/ATP complex formation, the RBC serves as an important electrochemical sink for toxins. The presence in the erythrocyte membrane of approximately 100 Pgp copies per RBC provides a mechanism for eventual toxin clearance. The RBC transport of toxins permits their removal from sensitive structures and ultimate clearance from the organism via the liver and/or kidneys.

Erythrocyte membrane ATP binding cassette (ABC) proteins: MRP1 and CFTR as well as CD39 (ecto-apyrase) involved in RBC ATP transport and elevated blood plasma ATP of cystic fibrosis

In addition to the better-known roles of the erythrocyte in the transport of oxygen and carbon dioxide, the concept that the red blood cell is involved in the transport and release of ATP has been evolving (J. Luthje, Blut 59, 367, 1989; G. R. Bergfeld and T. Forrester, Cardiovasc. Res. 26, 40, 1992; M. L. Ellsworth et al., Am. J. Physiol. 269, H2155, 1995; R. S. Sprague et al., Am. J. Physiol. 275, H1726, 1998). Membrane proteins involved in the release of ATP from erythrocytes now appear to include members of the ATP binding cassette (ABC) family (C. F. Higgins, Annu. Rev. Cell Biol. 8, 67, 1992; C. F. Higgins, Cell 82, 693, 1995). In addition to defining physiologically the presence of ABC proteins in RBCs, accumulating gel electrophoretic evidence suggests that the cystic fibrosis transmembrane conductance regulator (CFTR) and the multidrug resistance-associated protein (MRP1), respectively, constitute significant proteins in the red blood cell membrane. As such, this finding makes the mature erythrocyte compartment a major mammalian repository of these important ABC proteins. Because of its relative structural simplicity and ready accessibility, the erythrocyte offers an ideal system to explore details of the physiological functions of ABC proteins. Moreover, the presence of different ABC proteins in a single membrane implies that interaction among these proteins and with other membrane proteins may be the norm and not the exception in terms of modulation of their functions.

Doppler sonography findings associated with transjugular intrahepatic portosystemic shunt malfunction

OBJECTIVE

Our purpose was to determine the overall accuracy of Doppler sonography and the accuracy of specific Doppler parameters associated with a compromised transjugular intrahepatic portosystemic shunt (TIPS).

MATERIALS AND METHODS

For 43 patients who had undergone TIPS, 64 correlated sonogram-venogram paired examinations were analyzed. Sonographic parameters assessed included absolute velocities plus absolute and percentage changes in velocities measured in the main portal vein (MPV) and in several intrashunt locations (including peak and minimum velocity). Direction of flow and change in direction of flow in the left and right portal veins were also examined. TIPS malfunction was defined as any shunt with greater than or equal to 50% stenosis or any stenosis with a portosystemic gradient greater than 15 mm Hg.

RESULTS

The prospective interpretation of the sonograms using all available parameters resulted in a sensitivity of 92% and a specificity of 72% for detecting TIPS malfunction. Peak shunt velocity (absolute velocity and velocity change), distal shunt velocity, MPV velocity (absolute velocity and percentage change in velocity), change in minimum shunt velocity, and direction of flow in branch portal veins were found to have statistically significant differences between normal and abnormal shunts. Sensitivities for these individual parameters ranged from 64% to 84%, and specificities ranged from 70% to 100%. When either the MPV velocity or the distal shunt velocity was abnormal, the sensitivity was 94%. When both parameters were abnormal, the specificity for detecting TIPS malfunction was 100%.

CONCLUSION

Doppler sonography is a sensitive and relatively specific means of revealing TIPS malfunction. Accuracy depends on analysis of multiple sonographic parameters.

Stenosis of transjugular intrahepatic portosystemic shunts: presentation and management

OBJECTIVE

The purpose of this study was to define the incidence, nature, and presentation of stenoses that develop in patients with transjugular intrahepatic portosystemic shunts (TIPS) and to assess the efficacy of treatment that prolongs shunt patency.

MATERIALS AND METHODS

TIPS were successfully created in 108 patients over a 43-month period. Of the 93 patients with adequate radiologic or pathologic follow-up, 60 had no shunt problems and 33 developed shunt stenoses or occlusions. Follow-up of these 93 patients included sonography, venography, and/or pathologic confirmation. Presentations of stenoses, types of therapy, and patency after treatment were evaluated in all patients.

RESULTS

In the cohort group, 35% of the patients had shunt problems (mean time to presentation, 7.4 months after TIPS). Forty stenoses and eight occlusions occurred in the 33 patients. Of the 48 shunt problems, 35 (73%) were detected with routine radiologic screening, 12 (25%) presented with recurrent symptoms, and one (2%) was confirmed by pathologic evaluation. Of the 33 patients with stenoses and occlusions, 21 had one reintervention, six had two reinterventions, three had three reinterventions, one had four reinterventions, and two received no therapy. These reinterventions included 30 restentings, 11 angioplasties, four new shunts, and one thrombolysis alone. Of the 31 primary reinterventions, 23 (74%) were restentings, six (19%) were angioplasties, and two patients received a new TIPS. Of the 10 secondary reinterventions, six were restentings, three were angioplasties, and one was a new TIPS. Of the four tertiary reinterventions, one was a restenting, two were angioplasties, and one was thrombolysis. Kaplan-Meier survival analysis revealed the primary patency of the shunt to be 67% at 6 months, 48% at 1 year, and 26% at 2 years. The primary-assisted patency of the shunt was 96% at 6 months and 87% at 3 years. The secondary patency was 99% at 1 year and 89% at 3 years.

CONCLUSION

Stenoses are common after TIPS procedures and frequently can be detected on routine screening studies. Shunt revision can effectively extend the patency of TIPS. Restenting is generally required for hepatic vein stenoses. Angioplasty should be the first line of therapy for intrashunt stenoses, as only 44% of patients will require restenting.

Comparison of portal vein anatomy and bony anatomic landmarks

PURPOSE

To determine if a relationship exists between the right portal trunk (RPT) and bony structures that might aid guidance of needle passes into the RPT during transjugular intrahepatic portosystemic shunt (TIPS) placement.

MATERIALS AND METHODS

Sixty-two TIPS portal venograms were reviewed. The distance of the mid-RPT from the lateral margin of the vertebral column was measured and calculated as a fraction of the adjacent vertebral body width. The cephalocaudal height of the RPT was compared with that of the posterior ribs and rib spaces. The cephalocaudal height was evaluated with frequency distribution, and scattergram plots were used to determine the most common location of the mid-RPT relative to bony structures. The height and lateral position were analyzed in relation to clinical parameters to determine the effect of these parameters on RPT position.

RESULTS

The mean distance of the mid-RPT from the lateral vertebral margin was 0.9 vertebral widths (range, 0.1-1.5). Fifty-six of 62 (90%) mid-RPTs were between 0.5 and 1.5 vertebral widths to the right of the lateral margin of the vertebrae. Fifty-four of 62 (87%) mid-RPTs were below the 10th and above the 12th ribs. Clinical factors did not affect RPT position.

CONCLUSION

Bony landmarks provide an approximation of the mid-RPT location and may aid in TIPS placement.

Systemic venous enhancement patterns during dynamic abdominal CT

In 25 patients we assessed the enhancement of abdominal venous structures during dynamic computed tomography (CT). The degree of venous enhancement demonstrated great variation. In six instances (out of 250 observations) a vessel was visually perceived as not enhancing and potentially thrombosed, including three gonadal veins. CT measurements were helpful in identifying enhancement, but were occasionally low enough that thrombosis remained a radiological consideration. The great variation in venous enhancement makes the diagnosis of thrombosis suspect, based on CT alone. Corroboration of this finding is suggested, when clinically relevant.

Safety of pulmonary angiography in the 1990s

PURPOSE

To examine the safety of pulmonary angiography with low-osmolar contrast material and modern angiographic techniques and to analyze periprocedural complications with respect to potential predictors.

PATIENTS AND METHODS

A retrospective review was conducted of data from 547 consecutive patients who underwent pulmonary angiography. Minor and major complications were analyzed by using several clinical parameters.

RESULTS

There were five major (0.9%) and 26 minor complications (4.8%). Eleven of the 26 minor complications were contrast-induced nephrotoxicity. There were no periprocedural deaths. Patients with complications had an increased incidence of coexistent pulmonary morbidities and were of a poorer physical status according to the American Society of Anesthesiology criteria. Moderate to severe pulmonary hypertension was correlated with major complications. Age, volume of contrast material used, and presence of pulmonary embolism were not correlated with complications.

CONCLUSION

Pulmonary angiography is a safe procedure with an acceptable complication rate. These findings should be considered in the selection of an imaging method for the diagnosis of pulmonary embolism.

Nuclear transcription factor Oct-1 binds to the 5'-upstream region of CYP1A1 and negatively regulates its expression

The cytochrome P450-dependent monooxygenases, which represent an extended superfamily, catalyze the biotransformation of many endogenous and exogenous substances. One of these hemoproteins, cytochrome P4501A1, is most closely associated with the bioactivation of polycyclic aromatic hydrocarbons such as benzo[a]pyrene, which may play a role in environmental carcinogenesis. A negative regulatory element (NRE) has been localized in the 5'-upstream region of the cytochrome P4501A1 gene (CYP1A1) at -843 to -746 base pairs from the site of transcription. The purpose of this research was to define any interactions of trans-acting proteins with this cis element. Rat liver nuclei were used as the source of trans-acting proteins and a biotinylated NRE-bearing fragment (-782 to -843 bp) from a plasmid which contained the CYP1A1 was prepared by the polymerase chain reaction technique. Gel mobility shift assays were used to demonstrate interactions between this NRE fragment and nuclear proteins. The specific binding to an octamer-containing motif in the 5'-upstream region of CYP1A1 was demonstrated; this was used as a step in the partial purification from rat liver of the transcription factor, Oct-1. Conventional chromatographic procedures and DNA recognition site affinity chromatography were also used. HepG2 human hepatoma cells were transfected with both pMCoLUC+ which contains the luciferase gene as a reporter gene driven by the CYP1A1 promoter (including the NRE), and an Oct-1 expression vector. Luciferase activity/mg protein in the doubly-transfected cells was significantly lower than in cells containing only pMCoLUC+. A nuclear transcription factor Oct-1 interacts with a portion of the NRE of the rat CYP1A1, suppressing the expression of this gene. These findings may help to explain the low level of basal expression of CYP1A1 in mammalian systems.

Obstetric hemorrhage: prophylactic and emergency arterial catheterization and embolotherapy

The role of arterial catheterization and embolotherapy was evaluated in 18 patients with postpartum hemorrhage or a risk of hemorrhage. Nine patients underwent emergency arterial catheterization for unanticipated postpartum hemorrhage due to uterine and vaginal tears and/or placental abnormalities. Bleeding was controlled with embolization with gelatin sponge in eight patients, while bleeding in one patient stopped spontaneously during angiography. Nine patients underwent prophylactic arterial catheterization before cesarean section or for abnormalities associated with risk of hemorrhage. Two subsequently underwent embolization before surgery, and embolization in two others was performed intraoperatively in response to serious bleeding. Bleeding in the other five was controlled by the usual surgical means. Arterial embolotherapy in these patients was an effective means of controlling postpartum hemorrhage. Prophylactic arterial catheterization has a role in patients with an increased risk for obstetric hemorrhage.

Color Doppler sonography of vascular malformations of the liver

Nine cases of intrahepatic vascular malformations diagnosed using color Doppler sonography are described. These consisted of six cases of intrahepatic portal-hepatic venous shunts and three cases of arteriovenous fistulas. Among these is a case of multiple intrahepatic portal-systemic shunts. The sonographic findings and theories explaining the formation of vascular malformations in the liver are discussed.

Ossifying fibroma of sphenoid bone with coexistent mucocele: CT and MRI

A case of a 26-year-old woman with decreasing vision in her right eye, diplopia, headache, and galactorrhea is presented. Both CT and MR studies showed a large sphenoid fibroosseous lesion that had a ground glass appearance on CT and low-to-intermediate proton density and low T2-weighted and low T1-weighted signal intensities on MR. After contrast medium administration, this process diffusely enhanced on CT and MR. There was also an expansile mass in the sphenoid sinus that had intermediate proton density, high T2-weighted and low T1-weighted signal intensities compared with brain. This mass did not enhance but had an intensely enhancing, uniformly thin rim. The pathologic diagnosis was ossifying fibroma with a sphenoid sinus mucocele. There are only isolated reports in the literature of benign fibrosseous lesions causing mucoceles. This association is reviewed as are the findings in this case.

CT findings after percutaneous biliary procedures

A prospective study was performed to determine the frequency, type, and extent of abnormalities depicted with computed tomography (CT) after percutaneous biliary procedures (PBPs). Abdominal CT scans were obtained 24-72 hours after the PBP in 31 consecutive cases in 29 patients. Fifteen abnormalities were proved with CT in 14 patients (45%), as follows: subcapsular hematoma (two patients), subcapsular or perihepatic fluid collection (three patients), intrahepatic hematoma (three patients), nonspecific intrahepatic fluid collection (three patients), subcutaneous hematoma at the puncture site (one patient), free intraperitoneal air (one patient), intraperitoneal collection of contrast material (one patient), and inadvertent transxiphoid catheter tract (one patient). Only five of these patients had clinically apparent post-PBP complications that could be explained with CT findings. The 14 patients with positive CT findings required more needle passes (mean, 8.3 vs 4.6) during the PBP, had a difficult PBP more often (five patients [36%] vs four patients [27%]), and had more frequent placement of an internal-external drain (nine patients [64%]) than those with negative findings (eight patients [53%]). Positive findings on CT scans are common after a PBP and often are not associated with clinical symptoms.

Regulation of types I, III, and IV procollagen mRNA synthesis in glucocorticoid-mediated intestinal development

Administration of dexamethasone (0.8 mg/kg) to 9-day-old rats once daily for 3 consecutive days caused precocious induction of adult specific disaccharidase activity in the small intestine. Maturation-specific disaccharidase activity was accompanied by decreased amounts of types I and III collagen and decreased procollagen type I and III mRNA levels. Conversely, type IV procollagen, fibronectin, and laminin amounts and their respective mRNA levels were increased. In vitro transcription of nuclei isolated from small intestine and colon of suckling rats indicated a decreased rate of synthesis of procollagen types I and III mRNAs and an increased rate of synthesis of procollagen type IV mRNAs and laminin mRNAs after dexamethasone treatment. The data suggest that glucocorticoids mediate a differential regulation of interstitial and basement membrane collagen gene expression in the developing rat intestine.

Glucocorticoids decrease the synthesis of type I procollagen mRNAs

Glucocorticoids selectively decrease procollagen synthesis in animal and human skin fibroblasts. beta-Actin content and beta-actin mRNA are not affected by glucocorticoid treatment of chick skin fibroblasts. The inhibitory effect of glucocorticoids on procollagen synthesis is associated with a decrease in total cellular type I procollagen mRNAs in chick skin fibroblasts. These effects of dexamethasone are receptor mediated as determined by pretreatment with the glucocorticoid antagonists progesterone and RU-486 and with the agonist beta-dihydrocortisol. Dexamethasone has a small but significant inhibitory effect on cell growth of chick skin fibroblasts. The ability of this corticosteroid to decrease the steady-state levels of type I procollagen mRNAs in nuclei, cytoplasm, and polysomes varies. The largest decrease of type I procollagen mRNAs is observed in the nuclear and cytoplasmic subcellular fractions 24 h after dexamethasone treatment. Type I procollagen hnRNAs are also decreased as determined by Northern blot analysis of total nuclear RNA. The synthesis of total cellular type I procollagen mRNAs is reversibly decreased by dexamethasone treatment. In addition the synthesis of total nuclear type I procollagen mRNA sequences is decreased at 2, 4, and 24 h following the addition of radioactive nucleoside and dexamethasone to cell cultures. Although the synthesis of pro alpha 1(I) and pro alpha 2(I) mRNAs is decreased in dexamethasone-treated chick skin fibroblasts, the degradation of the total cellular procollagen mRNAs is not altered while the degradation of total cellular RNA is stabilized. These data indicate that the dexamethasone-mediated decrease of procollagen synthesis in embryonic chick skin fibroblasts results from the regulation of procollagen gene expression.

Bleomycin treatment of chick fibroblasts causes an increase of polysomal type I procollagen mRNAs. Reversal of the bleomycin effect by dexamethasone

Bleomycin treatment of primary chick skin fibroblasts and chick lung fibroblasts resulted in a selective dose-dependent increase of cell layer procollagen synthesis. Solid support hybridization of total cellular RNA to 32P-labeled pro-alpha 1(I) and pro-alpha 2(I) cDNAs did not indicate an increase of total cellular procollagen type I mRNAs in bleomycin-treated cells. However, bleomycin treatment of chick skin fibroblasts causes a redistribution of procollagen type I mRNAs within the nuclear, cytoplasmic, and polysomal subcellular fractions. Both the nuclear and cytoplasmic procollagen type I mRNAs are significantly decreased in concentration after bleomycin administration. In contrast, the polysomal procollagen type I mRNAs are significantly increased in both chick skin and lung fibroblasts treated with bleomycin. Administration of dexamethasone to bleomycin-treated fibroblasts resulted in a reversal of the bleomycin-induced increase in cell layer procollagen synthesis. The increased amounts of polysomal procollagen type I mRNAs in bleomycin-treated cells were also reduced by subsequent administration of dexamethasone. These data indicate that bleomycin treatment of chick skin and chick lung fibroblasts results in a specific increase in procollagen synthesis in the cell layer which is mediated by elevated levels of polysomal type I procollagen mRNAs via a repartitioning of these mRNAs within the fibroblast. Furthermore, dexamethasone reverses the bleomycin-induced elevations of both cell layer procollagen synthesis and polysomal type I procollagen mRNAs.

Dexamethasone decreases the amounts of type I procollagen mRNAs in vivo and in fibroblast cell cultures

Dexamethasone treatment of neonatal chicks resulted in a time- and dose-dependent selective decrease of skin collagen synthesis. Total RNA of chick skin was isolated and hybridized to the cloned cDNAs pCg54 for pro-alpha 1 (I) mRNA and pCg45 for pro-alpha 2(I) mRNA. RNA isolated from the total skin of chicks receiving various doses of dexamethasone had dose-related decreases of pro-alpha 1 (I) and pro-alpha 2(I) mRNAs. The decrease of type I procollagen mRNAs for various doses of dexamethasone were similar to the decreases observed for collagen synthesis in vivo. Dexamethasone treatment of chick skin and chick lung fibroblasts resulted in a selective decrease of procollagen synthesis. A dose-related decrease of procollagen synthesis was observed with chick skin fibroblasts. Dexamethasone-treated chick skin and chick lung fibroblasts had decreased levels of pro-alpha 1 (I) and pro-alpha 2(I) mRNAs as determined by solid support hybridization with pCg54 and pCg45. The dexamethasone-mediated decreases of type I procollagen mRNAs in skin fibroblasts and lung fibroblasts were similar to the decreases observed in procollagen synthesis.

Bleomycin-induced increase of collagen turnover in IMR-90 fibroblasts: an in vitro model of connective tissue restructuring during lung fibrosis

Late-log-phase IMR-90 human fetal lung fibroblasts were incubated with bleomycin sulfate for 48 hr. The culture medium was removed and replaced with serum-free medium and [5-3H]proline. The cells were then incubated for increasing time intervals. The cells and culture medium were collected, and radioactive proline incorporated into collagen and noncollagen protein was determined. Intracellular collagen synthesis was selectively increased. Furthermore, polysomes isolated from bleomycin-treated cells synthesized significantly more collagen in the wheat germ lysate than did control polysomes. Prolyl hydroxylase activity was also increased significantly in the bleomycin-treated cells. Free and peptide-bound radioactive hydroxyproline in the cells and medium was greatly increased in bleomycin-treated cells, which indicates increased collagen degradation. The results demonstrate that, although collagen synthesis in lung fibroblasts is increased by bleomycin, the newly synthesized collagen is rapidly degraded in both the cell layer and the medium. This increased collagen degradation may be responsible for the remodeling which takes place during lung fibrosis.

Inhibition of collagen accumulation by glucocorticoids in rat lung after intratracheal bleomycin instillation

Male Fischer 344 rats were given a single lung instillation of bleomycin sulfate (0.6 units/100 g). some animals were treated 24 hr after bleomycin administration with triamcinolone diacetate. Steroid treatment was continued on alternate days for 4 weeks. At the end of 4 weeks, the lungs of rats receiving bleomycin alone had two-fold increases of both prolyl hydroxylase activity and proteinaceous hydroxyproline as compared to control values. The lungs of bleomycin-treated rats which received 4 mg of triamcinolone diacetate per kg on alternate days had a 33% increase of prolyl hydroxylase activity and proteinaceous hydroxyproline content of bleomycin-treated animals receiving glucocorticoid (8 mg/kg) on alternate days were the same as control values. The results indicate that alternate day administration of the synthetic glucocorticoid triamcinolone diacetate blocks lung collagen accumulation following a single intratracheal dose of bleomycin to rats.

Collagen lysyl oxidase activity in the lung increases during bleomycin-induced lung fibrosis

Intratracheal administration of bleomycin caused pulmonary fibrosis in rats. Bleomycin sulfate (640 micro grams/165 g b.wt. in 0.5 ml of sterile saline) was instilled Intratracheally into male Fisher 344 rats (169 +/- 5 g), whereas control animals received 0.5 ml of sterile saline by the same route. One, 3, 7, 14, 28 and 322 days after instillation, the animals were killed, the lungs were homogenized in 6 M urea, 0.01 M NaCl, 0.001 M potassium phosphate (pH 8.3) and the homogenates were subjected to ultracentrifugation. The 106,000 x g supernate was assayed for lysyl oxidase activity. Total lung hydroxyproline and desmosine content was determined at each time point. Lysyl oxidase specific activity in the lung was elevated significantly 3 days after bleomycin treatment, peaked 14 days after bleomycin treatment at 230% above the control value and was returned toward normal 28 days after treatment. The increase of lysyl oxidase activity preceded the maximal increase of total lung hydroxyproline and desmosine which occurred 28 days after bleomycin instillation.