Re: treatment of acute aortorenal bypass graft thrombosis by means of primary stent placement and adjunctive thrombolysis.
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Acute Disease↗
Biomedical subjects
S M Rivitz
Publications and source records attributed to S M Rivitz.
Acute pulmonary embolism: assessment of helical CT for diagnosis.
PURPOSE: To determine the sensitivity and specificity of helical computed tomography (CT) for the diagnosis of acute pulmonary embolism. MATERIALS AND METHODS: This prospective study included 47 patients who underwent pulmonary arteriography for evaluation for possible acute pulmonary embolism. Tailored helical CT and pulmonary arteriography were performed within 24 hours of each other. Each CT scan was interpreted by two chest radiologists, blinded to arteriographic results, at two institutions. CT scan interpretations were compared with findings on bilateral selective pulmonary arteriograms interpreted by two vascular radiologists at one institution. RESULTS: Fifteen (32%) of 47 patients had angiographically proved pulmonary embolism. For the readers at the first institution, helical CT had 60% sensitivity, 81% specificity, 60% positive predictive value, 81% negative predictive value, and 75% overall accuracy. For the readers at the second institution, helical CT had 53% sensitivity, 97% specificity, 89% positive predictive value, 82% negative predictive value, and 83% accuracy. CONCLUSION: Detection of pulmonary embolism with helical CT may be less accurate than previously reported. Given its high specificity but relatively low sensitivity, helical CT may not have the ideal attributes of a first-line imaging study for the diagnosis of pulmonary embolism.
Acute Disease↗
Guide-wire entrapment by inferior vena caval filters: in vitro evaluation.
PURPOSE: To study guide-wire engagement and entrapment by inferior vena caval (IVC) filters. MATERIALS AND METHODS: Patterns of engagement were determined in six IVC filters with four commonly used guide wires in a simulated IVC. Force required to disengage guide wires from filters was measured. RESULTS: Eleven engagement patterns were identified with J-tipped guide wires; straight guide wires never engaged. The Simon-Nitinol filter engaged guide wires with the highest frequency (P < .05). The 15-J wire was engaged most frequently overall (P < .0005) but disengaged with forces not significantly different (P > .05) from those required to open the J. Entrapment occurred with only the Vena-Tech (VT) and 12-F stainless steel Greenfield (12SSG) filters and the 1.5-J and 3-J guide wires. The former guide wire became entrapped regardless of engagement pattern; the latter became entrapped only when engaged in the hole in the apex of the 12SSG and VT filters. CONCLUSION: Guide wires with a J tip 3 mm or less in radius are at risk for entrapment by the 12SSG and VT filters.
Catheterization, Central Venous↗
Long-term outcomes of radiologically placed arm ports.
PURPOSE: To evaluate long-term outcomes of an initial experience with radiologic placement of arm ports. MATERIALS AND METHODS: The follow-up of 46 consecutive arm port placements (44 patients) was reviewed by means of chart review (hospital, office, and clinic) in 41 patients, telephone interview in 20, physical, examination in 15, and venous ultrasound in 14. Data on port complications and function were recorded. Statistical methods were the Fisher Exact Test and Cochran-Mantel-Haenszel Test. RESULTS: Technical success for placement was 100%. Follow-up was obtained in 41 (93%) of the 44 patients (43 ports); mean days of catheter use was 344 days (total, 14,797 days; range, 10-1,104 days; median, 278 days). Rate (per 100 catheter days) of symptomatic central venous thrombosis was 0.054; arm phlebitis, 0.007; confirmed infection, 0.034; and catheter dysfunction, 0.095. Prophylactic anti-coagulants did not affect symptomatic central venous thrombosis (P > .05, Fisher Exact Test). Catheter tip high in the right atrium was marginally associated with better catheter function (P = .041, Fischer Exact Test). CONCLUSION: Good long-term results can be anticipated with radiologic placement of arm ports.
Adult↗
Embolization of pulmonary catheter-induced pulmonary artery pseudoaneurysms.
STUDY OBJECTIVES: To determine the outcome of patients with pulmonary catheter-induced pulmonary artery pseudoansurysms (PSAs) treated with embolization. DESIGN: Retrospective outcomes review. SETTING: Large urban tertiary-care hospital. PATIENTS: All patients who presented to diagnostic angiography for ruptured pulmonary artery PSA caused by pulmonary artery catheters (PACs) from November 1990 to September 1995. A total of six patients were examined. INTERVENTIONS: Transcatheter embolotherapy with coils, absorbable gelatin sponges (Gelfoam), and suture material. RESULTS: These procedures were technically successful in all patients, and none had recurrent hemoptysis. Four of the six patients were discharged from the hospital. CONCLUSION: Embolotherapy is a useful alternative to surgery for some patients with PAC-induced pulmonary PSA.
Aged↗
MR angiography of tibial runoff vessels: imaging with the head coil compared with conventional arteriography.
OBJECTIVE: We compared peripheral vascular MR angiography done with a standard transmit-receive head coil with conventional arteriography for identifying and evaluating runoff vessels below the knee. MATERIALS AND METHODS: We examined 55 legs in 31 symptomatic patients with both conventional contrast angiography and gradient-echo two-dimensional time-of-flight MR angiography. Both legs of patients were placed in a standard transmit-receive head coil for MR angiography and were imaged simultaneously. For evaluation of stenoses, images of vessels were divided into 10 segments, and each segment was graded on a four-point scale. RESULTS: In the 393 native vascular segments evaluated, the sensitivity of MR angiography in identifying normal vessels was 95% and the specificity was 98%. In detecting segmental occlusion, MR angiography was 98% sensitive and 97% specific. Sensitivity and specificity for stenoses greater than 75% were 98% and 96%, respectively, and for stenoses greater than 50%, they were 98% and 95%, respectively. Interpretative discrepancies were found in 35 vessel segments in 18 legs; none was of clinical relevance. Of all vessel segments shown as occluded by conventional angiography, 1% appeared patent on MR angiograms. No vessel segments shown as normal on MR angiograms were found to be occluded on conventional angiograms. CONCLUSION: When performed simultaneously on both legs of symptomatic patients, 2D time-of-flight MR angiography with a standard transmit-receive head coil provides a time-efficient and highly sensitive and specific means of evaluating below-knee runoff.
Adult↗
Long-term central venous catheterization in patients with limited access.
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Adult↗
Percutaneous aspiration thrombectomy of an acutely occluded aortorenal bypass graft.
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Acute Disease↗
Operator errors during percutaneous placement of vena cava filters.
Operator errors during percutaneous insertion of inferior vena cava (IVC) filters are procedural complications specific to filter placement that cannot be attributed to defects in the device itself. These errors can occur during preplacement imaging of the IVC, selection of the filter, or deployment of the filter. Although technical problems are reported to occur in 5-20% [1] of filter insertions, the precise frequency of operator errors is not known. This pictorial essay reviews the different types of operator errors that can occur during percutaneous insertion of IVC filters.
Humans↗
Perfusion imaging in ischemic heart disease.
Myocardial perfusion imaging with thallium-201 has been used extensively for many years in the evaluation of ischemic heart disease. It is a valuable adjunct to exercise treadmill testing and is especially helpful in evaluating cardiac perfusion in patients who have abnormal resting electrocardiograms, who are unable to exercise, and whose clinical history and exercise test results are discordant. Perfusion imaging is useful for both diagnosis and prognosis in patients with coronary artery disease. In patients unable to exercise, the coronary vasodilators dipyridamole and adenosine may be used in conjunction with thallium imaging. Two recently approved technetium agents, sestamibi and teboroxime, may be used in place of thallium.
Adenosine↗
Predictive value of dipyridamole thallium imaging in a patient with myocardial bridging but without fixed obstructive coronary artery disease.
Both dipyridamole and exercise-201Tl imaging are sensitive, specific and of prognostic value in patients with suspected coronary artery disease, following myocardial infarction, and undergoing major noncardiac surgery. Though reported sensitivities and specificities vary widely from 60% to 100%, the consensus is that both are between 80% and 90% for both dipyridamole and exercise studies (23). Moreover, when compared directly in the same study populations, the two have equal sensitivities and specificities (9,11,13,23). Transient thallium perfusion abnormalities are the most consistent predictors of adverse cardiac events and have more predictive power than clinical and angiographic parameters. Thallium reversibility may be a better predictor of adverse cardiac events than angiography since it represents more of a physiologic rather than a purely anatomic evaluation of the heart. It is difficult to make an exact comparison of some of the studies in the literature because they use different patient populations, sometimes define coronary stenosis in different ways, may have different cardiac endpoints and may not differentiate between reversible and fixed thallium perfusion defects. Exercise has the advantage of a graded examination and more experience historically and is of importance in a detailed study of cardiopulmonary hemodynamics, as in cardiac transplantation. Dipyridamole is more useful in patients who cannot achieve symptom-limited, submaximal exercise. It may also be more useful for patients who are bedridden or have peripheral vascular disease. Angina occurs less frequently with dipyridamole.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Posterior mediastinal masses in children: ganglioneuroblastoma.
Ganglioneuroblastoma, although a rare neoplasm, is one of the most common causes of posterior mediastinal masses in children. This tumor occurs in children from one to 10 years of age. With intrathoracic involvement, the tumor may remain asymptomatic until it is large. The case reported illustrates a typical presentation of intrathoracic ganglioneuroblastoma.
Child, Preschool↗
Stenotic anomalous circumflex artery causing myocardial infarction following angioplasty of a right coronary artery stenosis.
A 68 yr-old male with evidence of persistent inferior wall ischemia after successful PTCA of a solitary right coronary artery (RCA) lesion was found to have an anomalous left circumflex artery (LCX) arising from the ostium of the RCA. The LCX harbored an atherosclerotic subtotal obstruction, which was then successfully dilated with resolution of the myocardial ischemia. Although not known to have a statistical predisposition to atherosclerotic disease, diseased anomalous coronary arteries can be responsible for myocardial ischemia and infarction. A thorough search for such vessels is warranted in patients with abnormal diagnostic tests and no apparent obstructive lesions in the normally positioned arteries. Similarly, when ischemia does not resolve after successful treatment of a coronary stenosis, anomalous coronary arteries should be sought.
Aged↗
Fractionated endocardial electrograms are associated with slow conduction in humans: evidence from pace-mapping.
Fractionated ventricular electrograms recorded during catheter mapping may arise from areas of asynchronous depolarization associated with slow conduction, the substrate for reentrant ventricular tachycardia, but can also be a nonspecific abnormality or even artifact. To determine whether fractionated sinus rhythm electrograms are associated with slow conduction in humans, the results of endocardial catheter mapping and pacing at 133 endocardial sites in 13 patients were analyzed. Eleven patients had sustained monomorphic ventricular tachycardia and two patients had old myocardial infarction without ventricular tachycardia. Functional evidence of slow conduction at the recording site was assessed by pacing at that site and measuring the interval between the stimulus artifact (S) and the onset of the QRS complex in the 12 lead electrocardiogram (ECG). During pacing at 89 of 90 sites without fractionated sinus rhythm electrograms, the S-QRS interval was less than 40 ms, a value consistent with rapid propagation of the stimulated wave front away from the pacing site. During pacing at 21 (49%) of 43 sites with fractionated sinus rhythm electrograms, the S-QRS interval was greater than 40 ms (range 40 to 140), consistent with slow conduction at the pacing site (p less than 0.001 versus nonfractionated sites). In 9 of the 11 patients with ventricular tachycardia analysis of the paced QRS configuration, electrograms during induced ventricular tachycardia or programmed stimulation during tachycardia suggested that a site with a long S-QRS interval during pacing was located at or near a ventricular tachycardia circuit. Therefore, fractionated sinus rhythm electrograms are often associated with slow conduction, which may be the substrate for reentrant ventricular tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Anatomical observations on the renal veins and inferior vena cava at magnetic resonance angiography.
PURPOSE: To describe the renal vein and inferior vena cava (IVC) anatomy found at abdominal magnetic resonance (MR) angiography. METHODS: Gadolinium-enhanced, three-dimensional, time-of-flight MR angiograms of 150 patients were evaluated for the number and configuration of the renal veins, and the number, configuration, and dimensions of the IVC. Data were analyzed with the Student's t-test. RESULTS: Retroaortic left renal veins were found in 7% of patients, circumaortic left renal veins in 5%, multiple right renal veins in 8%, and duplicated IVCs in 0.7%. The length of the infrarenal IVC averaged 94 mm in females and 110 mm in males (p < 0.00001). The length of the infrarenal IVC in patients with circumaortic and retroaortic left renal veins averaged 76 mm and 46 mm, respectively. The mean maximal caval diameter was 23.5 +/- 4 mm. No megacavae (diameter if the mid-IVC > 28 mm) were identified. CONCLUSION: Variant renal vein and IVC anatomy can be identified at MR angiography.
Adult↗
Embolization of an hepatic artery pseudoaneurysm following laparoscopic cholecystectomy.
Vascular injuries during laparoscopic cholecystectomy can occur in an analogous fashion to biliary injuries, with potential laceration, transection, and occlusion of blood vessels. A patient presented with symptomatic hemobilia 1 month following laparoscopic cholecystectomy and was found to have a right hepatic artery pseudoaneurysm which communicated with the common bile duct. This was successfully embolized with several embolic agents, resulting in rapid resolution of all signs and symptoms. The patient has been free of symptoms during a follow-up period of 1 year. A brief discussion of hepatic artery pseudoaneurysms is presented.
Adult↗