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Biomedical subjects

C Cope

Publications and source records attributed to C Cope.

At least 37 records · Page 2Linked to original sources
PubMed1995

Intentional reversible thrombosis of transjugular intrahepatic portosystemic shunts.

PURPOSE: To assess whether balloon occlusion of a transjugular intrahepatic portosystemic shunt (TIPS) will allow permanent yet reversible shunt thrombosis. MATERIALS AND METHODS: A balloon catheter was inflated in the midportion of the TIPS in two women with severe, uncontrollable encephalopathy or liver failure (aged 42 and 65 years, respectively) to allow occlusive thrombus to develop below the balloon. RESULTS: Balloon occlusion led to rapid TIPS thrombosis, which was readily reversible. CONCLUSION: Balloon thrombosis is a simple technique for complete occlusion of a TIPS. This technique may also be useful for occlusion of surgical mesocaval H-graft shunts or dialysis access shunts.

Adult↗
PubMed1995

Thrombosed hemodialysis grafts: percutaneous mechanical balloon declotting versus thrombolysis.

PURPOSE: To compare a technique of mechanical balloon declotting of thrombosed hemodialysis grafts with conventional pulsed-spray thrombolysis. MATERIALS AND METHODS: Forty patients had 53 episodes of graft thrombosis over a 19-month period. Twenty-nine grafts were randomly treated with thrombolysis with urokinase and 24 grafts with mechanical declotting by placement of crossed balloon catheters within the graft. Patency was determined by retrospective review of hemodialysis records. RESULTS: Successful hemodialysis for 1 week after the procedure was achieved in 21 (88%) of the 24 grafts treated mechanically and 26 (90%) of 29 grafts treated with thrombolysis. Continuous pulse oximetry showed no change in oxygen saturation in either group, and no clinical signs or symptoms of pulmonary embolism were noted. Average total procedure times were 2.2 hours for mechanical declotting and 3.5 hours for thrombolysis (P < .05). Probability of patency (mechanical vs thrombolysis) was 42% vs 45% at 3 months, 36% vs 25% at 6 months, and 8% vs 4% at 12 months. One major complication of ulnar artery embolization occurred in the thrombolysis group. CONCLUSION: Mechanical declotting of hemodialysis grafts is faster and as effective as thrombolysis.

Adult↗
PubMed1995

Transjugular intrahepatic portosystemic shunting: decreased survival for patients with high APACHE II scores.

OBJECTIVES: To determine which clinical characteristics are associated with decreased survival after transjugular intrahepatic portosystemic shunting (TIPS). METHODS: Forty-nine consecutive patients were treated with TIPS; 46 of them had refractory variceal bleeding. Univariate statistics and logistic regression analyses were used to determine the relationship between clinical, biochemical, and hemodynamic variables and 30-day) survival. RESULTS: Shunt insertion was successful in 48 (98.0%) of 49 cases. Median portal-systemic gradient was reduced from 22.5 (range 9-36) [median (5th-95th percentile)] to 12 (range 4-20) mm Hg. Thirty (61.2%) of 49 patients survived more than 30 days; four patients died more than 30 days after TIPS in mean follow-up of 8.4 months. Significant differences (p < 0.05) were found between those who survived more than 30 days and those who did not, with respect to preprocedural prothrombin time, bilirubin, albumin, alanine aminotransferase, and treatment with vasopressin and nitrates, balloon tamponade, or mechanical ventilation. Whereas there were no significant differences between the pre- and post-TIPS portal vein pressures and portal-systemic gradients in survivors and non-survivors, the pre- and post-TIPS hepatic vein pressures were significantly lower in survivors. Survival was inversely proportional to Child-Pugh class (p < 0.01) and to APACHE II score (p < 0.01). The single determinant most closely associated with decreased survival in the month after TIPS was the APACHE II score, a score of 18 stratifying patients into those at low and high risk of mortality [odds ratio 21.7 (CI 3.6-131.7)]. Only 1 (7.7%) of 13 patients with Child-Pugh C cirrhosis and an APACHE II score exceeding 18 survived more than 30 days. CONCLUSIONS: Patients with advanced cirrhosis, especially those with high pre-TIPS APACHE II scores, are at high risk for reduced survival after TIPS, despite adequate portal decompression.

APACHE↗
PubMed1994

Double-blind study of the safety, tolerance, and diagnostic efficacy of iopromide as compared with iopamidol and iohexol in patients requiring aortography and visceral angiography.

RATIONALE AND OBJECTIVES: Nonionic contrast media have been shown to be more effective, better tolerated, and safer than standard high-osmolality contrast media when given intravascularly. The aim of this study was to assess the diagnostic efficacy, tolerance, and safety of a new nonionic contrast agent, iopromide (370 mg I/mL), in comparison with two available similar agents, iopamidol (370 mg I/mL) and iohexol (350 mg I/mL), in two randomized, double-blind clinical studies of patients undergoing abdominal aortography and visceral angiography. METHODS: The iopromide group included 80 patients, and the comparator group consisted of 36 iopamidol and 45 iohexol patients. The quality and diagnostic efficacy of all three contrast agents was rated equally as either good or excellent. RESULTS: On a scale of 0 (none) to 3 (severe) for heat and pain, respectively, the mean scores were 1.08 and 0.43 for iopromide in comparison with 1.15 and 0.35 for the comparator media. Minor adverse clinical experiences were noted in 23% of the iopromide group versus 20% of the comparator group. Nausea and vomiting were more common in the comparator group (7% versus 3%), and headache was noted only in the iopromide group (4%). There were no clinically significant changes in laboratory values in any group. Three severe adverse experiences occurred, but all were deemed unrelated to the contrast agents. CONCLUSION: Based on the results of this study, iopromide appears to be efficacious, safe, well tolerated, and comparable with iohexol and iopamidol for use in abdominal aortography and visceral angiography.

Angiography↗
PubMed1994

MR imaging with spatial modulation of magnetization in the evaluation of chronic central pulmonary thromboemboli.

PURPOSE: To assess the diagnostic value of magnetic resonance (MR) imaging with SPAMM (spatial modulation of magnetization) in the identification of chronic central pulmonary thromboemboli. MATERIALS AND METHODS: Twelve patients with pulmonary hypertension and five healthy volunteers were prospectively studied with a 1.5-T MR imaging system. The SPAMM technique was integrated into a conventional cardiac-synchronized spin-echo (SE) sequence. Six of the 12 patients had central thromboemboli. RESULTS: In the healthy subjects, intravascular stripes in the central pulmonary arteries disappeared as a result of flow within 100 msec after the R wave. Areas of persistent stripes were identified in seven of eight central pulmonary arteries with thromboemboli. Conversely, in the 16 central pulmonary arteries without clot, intraluminal stripes disappeared despite the presence of flow-related signal (sensitivity = 88%, specificity = 100%, accuracy = 96%). CONCLUSION: SPAMM appears to be a simple and effective technique for differentiating central pulmonary arterial thromboemboli from flow-related signal frequently observed with pulmonary hypertension.

Adult↗
PubMed1994

Intestinal varices: treatment with the transjugular intrahepatic portosystemic shunt.

PURPOSE: To perform a retrospective evaluation of transjugular intrahepatic portosystemic shunt (TIPS) placement for treatment of intestinal varices. MATERIALS AND METHODS: TIPS were placed in nine patients (six women and three men, aged 36-85 years [mean, 64 years]) with small- (n = 6) and large- (n = 3) intestinal varices. Six patients were actively bleeding at the time of shunt placement. One patient with colon cancer underwent prophylactic TIPS placement for variceal decompression before colectomy. RESULTS: The mean preprocedure portosystemic gradient of 26.8 mm Hg +/- 5.1 was reduced to 8.8 mm Hg +/- 2.9. Bleeding was controlled in all but one case, in which supplemental variceal embolization was required. Two patients died within 5 days of TIPS placement of preexisting multisystem failure. Three patients died of unrelated causes at 2, 6, and 7 months. The remaining patients were alive an average of 15 months after TIPS placement. There was no recurrent bleeding in any case. CONCLUSION: TIPS placement is an effective method of decompressing intestinal varices.

Adult↗
PubMed1994

Life-threatening pulmonary emboli and cor pulmonale: treatment with percutaneous pulmonary artery stent placement.

Large, central bilateral pulmonary emboli led to cor pulmonale and severe hypoxemia in a patient who had recently undergone cardiac surgery. After percutaneous catheter fragmentation and thrombolysis of the emboli failed, the left and right interlobal pulmonary arteries were recanalized by placement of self-expanding Wallstent endoprostheses through the clots. Pulmonary perfusion was restored to the lower lobes, and the patient demonstrated rapid clinical improvement.

Coronary Artery Bypass↗
PubMed1994

Transjugular intrahepatic portosystemic shunt stenosis and revision: early and midterm results.

OBJECTIVE: The purpose of this study was to define the pattern, rate, and interval during which stenosis develops in transjugular intrahepatic portosystemic shunts (TIPS) and to assess the effect of revision in prolonging shunt patency. MATERIALS AND METHODS: TIPS were created in 100 patients during a 34-month period. Sixty-one shunt venograms were obtained in 38 consecutive patients between 1 and 24 months after TIPS placement. Eighteen patients were examined because of recurrent symptoms, and all 38 had routine follow-up. RESULTS: Stenoses attributed to neointimal hyperplasia developed within both the TIPS stent and the outflow hepatic veins. Stenoses of greater than 50% developed in 12 patients within 6 months of TIPS placement. In addition to focal stenoses, the outflow hepatic veins diffusely shrank an average of 51% in diameter. Thirty-six shunt interventions were required: eleven balloon dilatations and 25 placements of an additional stent. Life-table analysis showed that patency of the primary shunt was 75% at 6 months, 50% at 1 year, and 32% at 2 years. The primary-assisted patency of the shunt was 85% at 12 months after shunt creation. CONCLUSION: The results indicate that TIPS are prone to significant and frequent early stenosis, warranting follow-up within 3-6 months in all cases. Stenosis of the outflow hepatic vein is the most common cause of shunt malfunction. Revision of a shunt significantly prolongs shunt patency.

Catheterization↗
PubMed1994

Magnetic resonance angiography of the aorta, iliac, and femoral arteries.

BACKGROUND: Successful management of patients with peripheral vascular disease requires detailed vascular imaging, usually performed by contrast arteriography. Recently, magnetic resonance angiography (MRA) has been shown to be a noninvasive technique with greater sensitivity than contrast arteriography for detecting distal runoff vessels in patients with peripheral arterial occlusive disease. However, to supplant the need for contrast arteriography and provide a completely noninvasive evaluation of patients with occlusive disease, accurate imaging of the inflow vessels and the runoff vessels is necessary. METHODS: We used both conventional arteriography and MRA in preoperative studies of the aorta, iliac, and femoral vessels of 47 patients. Conventional arteriography and MRA studies were compared for their ability to detect vessel patency and the presence of hemodynamically significant stenoses. Independent interventional plans were developed based on the information provided by each technique. The findings of conventional and MRA studies were verified by intraoperative arteriography or direct operative exploration. RESULTS: Results of the two studies were identical in 41 (87%) of 47 patients or 600 (98%) of 614 segments imaged. MRA accurately detected patent and occluded arterial segments (sensitivity 99.6%, specificity 100%, positive predictive value 100%, negative predictive value 98.6%) and hemodynamically significant stenoses. Therapeutic plans based on either MRA or conventional arteriography were identical for each patient. CONCLUSIONS: MRA provides comparable results to contrast arteriography in the proximal arterial system and superior results for imaging the distal vasculature. This noninvasive technique may replace contrast arteriography in a large number of patients in the future.

Adult↗
PubMed1993

Lymphangiography as a staging tool for cervix cancer: limited value after hip arthroplasty.

Lymphangiography (LAG) is often used in the work-up of cervical carcinoma. A patient with a history of bilateral hip arthroplasty, who presented with Stage IIIB squamous cell carcinoma of the cervix, was sent for lymphangiography. The LAG was deemed suboptimal, most likely because of altered lymphatic drainage engendered by the previous orthopaedic procedures. As the American population ages and hip arthroplasty becomes more common, the value of LAG in such patients will need to be reconsidered.

Aged↗
PubMed1993

Magnetic resonance venography for the detection of deep venous thrombosis: comparison with contrast venography and duplex Doppler ultrasonography.

PURPOSE: Contrast venography is the gold standard for diagnosis in deep venous thrombosis (DVT); however, this technique is invasive and requires the use of potentially hazardous contrast agents. Although duplex Doppler ultrasonography is accurate in the evaluation of lower extremity DVT, it is less accurate in the assessment of the pelvic and intraabdominal veins. Magnetic resonance venography (MRV) has recently been developed, and our purpose was to determine whether MRV could accurately demonstrated DVT when compared with duplex scanning and contrast venography. METHODS: Eighty-five patients underwent contrast venography and MRV from the inferior vena cava to the popliteal veins to rule out DVT. Thirty-three of these patients also underwent duplex scanning. Blinded readings of these studies were compared for the presence or absence and extent of venous thrombosis. RESULTS: DVT was documented by contrast venography in 27 (27%) venous systems. Results of MRV and contrast venography were identical in 98 (97%) of 101 venous systems, whereas results of duplex scanning and contrast venography were identical in 40 (98%) of 41 venous systems. All DVTs identified by contrast venography were detected by MRV and duplex scanning. The discrepancies were due to false-positive MRV (3) and duplex scanning (1) results. When compared with contrast venography, MRV had a sensitivity of 100%, specificity of 96%, positive predictive value of 90%, and negative predictive value of 100%. For duplex scanning the sensitivity was 100%, specificity was 96%, positive predictive value was 94%, and negative predictive value was 100%. CONCLUSIONS: It is concluded that MRV is an accurate noninvasive venographic technique for the detection of DVT.

Humans↗
PubMed1993

Symptomatic peripheral vascular disease: selection of imaging parameters and clinical evaluation with MR angiography.

In the first phase of this study, seven healthy subjects underwent examination with two-dimensional time-of-flight (TOF) magnetic resonance (MR) angiography to develop a protocol for evaluation of peripheral arterial vasculature from the infrarenal aorta to the foot. In the second phase, 73 patients with symptomatic peripheral vascular disease underwent examination with both conventional contrast material-enhanced arteriography and two-dimensional TOF MR angiography to evaluate the clinical usefulness of MR angiography. Postinterventional and intraoperative angiography or direct surgical exploration was the standard of reference. In 32 patients, discrepancies occurred between findings on arteriograms and those on MR angiograms; most of these discrepancies were caused by improved depiction of runoff vessels on MR angiograms. The demonstration with MR angiography of blood vessels not seen on conventional arteriograms, unidentified stenoses, or misidentified blood vessels altered surgical management in 12 patients (16%). Metal-clip artifacts obscured clinically important disease on MR angiograms in two patients. It is concluded that two-dimensional TOF MR angiography is very useful in preoperative assessment of patients with severe peripheral vascular disease.

Adult↗
PubMed1993

Recurrent bleeding from anorectal varices: successful treatment with a transjugular intrahepatic portosystemic shunt.

Anorectal varices are portal-systemic collaterals commonly found in patients with portal hypertension. Although these varices rarely bleed, when bleeding does occur it may be massive and life threatening. Anorectal varices may be mistaken for hemorrhoids and there is no agreed upon method for their definitive diagnosis. Additionally, there is no standard therapy for bleeding anorectal varices, and when techniques designed for the control of hemorrhoidal bleeding are employed the results can be disastrous. We report here the first use of a transjugular intrahepatic portosystemic shunt (TIPS) for the permanent control of bleeding anorectal varices. Magnetic resonance imaging/magnetic resonance venography (MRI/V) was used as a non-invasive method for the identification of anorectal varices and to confirm the successful decompression of these varices with TIPS placement. MRI/V and TIPS may provide significant advances in the diagnosis and treatment of rectal variceal bleeding.

Female↗
PubMed1993

Magnetic resonance arteriography of the pelvis and lower extremities.

Reconstructive vascular surgery is the last resort for limb salvage in patients with vascular insufficiency. Planning the sites of arterial bypass grafts depends on an exact knowledge of the angiographic anatomy. Currently, conventional contrast angiography is the primary preoperative study for surgical planning. Recently, magnetic resonance (MR) arteriography has been shown to be an accurate technique for the evaluation of slow arterial flow in the lower extremities. The purpose of this review will be to show how MR arteriography can be used as both an adjunct to and in some cases instead of conventional angiography for the preoperative assessment of lower-extremity vascular reconstruction. The derivation of common artifacts, the many pitfalls of interpretation, and the evaluation of peripheral arterial occlusion and percentage stenosis will be discussed. MR arteriography of the lower extremities is an important advance for the noninvasive evaluation of disease of the peripheral vasculature.

Algorithms↗
PubMed1992

Magnetic resonance imaging of angiographically occult runoff vessels in peripheral arterial occlusive disease.

BACKGROUND: Bypass grafting to arteries of the lower leg has become standard surgical management of advanced peripheral vascular disease. Its success depends on identifying suitable distal vessels. Preoperative preparation includes imaging of the arteries of the lower leg, usually by conventional contrast arteriography. An alternative procedure, magnetic resonance (MR) angiography, has been successfully employed in patients with various cardiovascular diseases, but its possible value in patients with peripheral vascular disease has received little attention. METHODS: We used both conventional and MR angiography in preoperative studies of the lower-leg vessels of 23 patients (25 legs) with peripheral arteriosclerosis and arterial insufficiency, and developed independent therapeutic plans based on the information provided by each technique. When the plans differed, the interventional procedure judged more likely to save the limb was performed. The findings of conventional and MR angiography were verified by intraoperative arteriography, postinterventional arteriography, or direct operative exploration. RESULTS: MR angiography detected all vessels identified by conventional angiography, whereas conventional arteriography failed to detect 22 percent of the runoff vessels identified by MR angiography. The detection by MR angiography of vessels not identified by conventional angiography altered the surgical management of the disorders of four patients (17 percent) and guided successful bypass procedures. CONCLUSIONS: MR angiography is a noninvasive technique with greater sensitivity than conventional contrast arteriography for detecting distal runoff vessels in patients with peripheral arterial occlusive disease.

Aged↗