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Biomedical subjects

V J Harris

Publications and source records attributed to V J Harris.

At least 19 recordsLinked to original sources
PubMed1998

Possible pulmonary embolus: evaluation with digital subtraction versus cut-film angiography--prospective study in 80 patients.

PURPOSE: To determine whether intraarterial digital subtraction angiography (DSA) is as accurate as cut-film (film hard-copy) angiography (CFA) in the evaluation of suspected pulmonary embolus. MATERIALS AND METHODS: Under a protocol approved by the institutional review board, CFA and DSA images were obtained in identical posteroanterior and oblique projections in one lung of each patient undergoing pulmonary angiography (n = 80). Diagnoses based on results of blinded review of each study (CFA vs DSA) by three separate reviewers (80 patients x three reviewers = 240 diagnoses for each modality) were compared with the diagnoses made by the physician who performed the procedure on the basis of CFA, DSA, and clinical data and with the consensus diagnoses obtained by means of group review of both studies together if necessary. The reviewers' confidence in their diagnoses was graded from 1 (certain) to 10 (uncertain). RESULTS: Pulmonary emboli were present in 13 (16%) of 80 patients. Two hundred thirty-six (98.3%) of 240 DSA diagnoses and 231 (96.3%) of 240 CFA diagnoses were correct. The sensitivity (correct identification of emboli by all three reviewers) of DSA was 92% and of CFA was 69% (P = .083). The specificities of the modalities were not statistically significantly different. The reviewers' confidence was significantly better in their DSA diagnoses than in their CFA diagnoses (P < .004). CONCLUSION: DSA allows more confident detection of pulmonary embolus than does CFA, with no loss in diagnostic accuracy.

Adult↗
PubMed1998

Tunneled hemodialysis catheters: use of a silver-coated catheter for prevention of infection--a randomized study.

PURPOSE: To determine whether silver-coated tunneled hemodialysis catheters reduce infection and to determine the frequency of central venous thrombosis and stenosis with percutaneous placement of right internal jugular vein dialysis catheters by interventional radiologists. MATERIALS AND METHODS: Ninety-one patients were randomly assigned to a treatment (silver-coated catheter; n = 47) or control (identical catheter without silver coating; n = 44) arm. Baseline venography was performed. Catheter tips were cultured and venography was repeated at catheter removal. RESULTS: Mean duration of catheter placement was 92 days. Infection occurred in 11 patients (five in the treatment group, six in the control group). Tip cultures in 15 patients (eight treatment, seven control) were positive without clinical infection. Infection and colonization rates were slightly but not significantly higher in the treatment group than in the control group. Silver-coated catheters in two (4%) patients were removed due to reaction to the coating. Completion venograms (n = 72) showed new minor abnormalities in four (6%) patients and major abnormalities (stenosis, thrombosis) in three (4%) patients. Permanent venous abnormalities occurred in two (3%) patients. CONCLUSION: Silver coating does not confer a benefit against clinical infection or colonization. Interventional radiologic placement of tunneled dialysis catheters yields a low frequency of permanent central venous thrombosis and stenosis.

Bacteria↗
PubMed1997

Outcome of tunneled hemodialysis catheters placed via the right internal jugular vein by interventional radiologists.

PURPOSE: To assess the outcome of interventional radiologic placement of tunneled hemodialysis catheters via the right internal jugular vein. MATERIALS AND METHODS: In 194 patients, the catheter was placed via the right internal jugular vein unless thrombosis was present. Real-time ultrasound-guided puncture and fluoroscopic guidance were used. Patients were followed up until catheter removal or death. Outcomes evaluated included infection, thrombosis, and catheter malfunction. RESULTS: In 175 patients, 250 consecutive catheters were placed via the right internal jugular vein with 100% success. All catheters functioned immediately after placement. Procedural complications were limited to clinically unimportant air embolus (n = 2). No instances of pneumothorax, hemothorax, or substantial bleeding complications occurred. Follow-up was available in 173 (99%) patients. Mean and median "catheter duration" were 87 and 56 days, respectively. Catheter-related symptomatic venous thrombosis or stenosis was not observed. The rate of infection was 0.08 per 100 catheter days, and the rate of malfunction that necessitated removal was 0.22 per 100 catheter days. Definite or possible catheter thrombosis that necessitated removal occurred at a rate of 0.16 per 100 catheter days. CONCLUSION: Interventional radiologic placement of tunneled hemodialysis catheters via the right internal jugular vein showed equal or better long-term results than those reported for surgical placement. Interventional radiologic placement should be the method of choice.

Catheterization↗
PubMed1996

Comparison of spiral CT scan and arteriography for evaluation of renal and visceral arteries.

Renal and visceral artery images obtained concurrently with spiral CT and conventional arteriography were compared for 32 patients. Indications for imaging were occlusive disease (n = 12), aneurysmal disease (n = 9), and renal or visceral artery disease (n = 11). Conventional arteriography enabled visualization of 64 renal arteries and 15 accessory renal arteries. Lateral aortograms obtained in 15 patients enabled visualization of 14 superior mesenteric (SMA) and 14 celiac arteries. Spiral CT enabled visualization of 60 renal arteries, 12 accessory renal arteries, 27 SMAs, and 22 celiac arteries. Calcification or a disparity in timing of contrast material injection and scanning prevented visualization of the celiac artery in 10 patients and the SMA in four patients. With conventional arteriography as the standard for comparison, spiral CT had a sensitivity of 67% and a specificity of 95% for depiction of at least 75% stenosis in the main renal artery. By means of the Pearson correlation coefficient, significant correlation (p < 0.001) was confirmed between spiral CT and arteriography for evaluation of stenosis of the main renal artery, SMA, and celiac artery. This early experience suggests that spiral CT may be useful in evaluation of renal and visceral arteries and their relationship to aortic disease.

Adult↗
PubMed1996

Three-dimensional gadolinium-enhanced MR angiography for aortoiliac inflow assessment plus renal artery screening in a single breath hold.

PURPOSE: To develop a magnetic resonance (MR) angiography protocol, with use of breath-hold techniques, for simultaneous aortoiliac inflow assessment and renal artery screening in patients with lower extremity ischemia or aortic aneurysm. MATERIALS AND METHODS: Breath-hold three dimensional gadolinium-enhanced MR angiography was performed in 50 patients (conventional arteriography in 47 was the standard of reference). After multiple strategies were tested in the first 18 patients, a final protocol was formulated and tested in the subsequent 32 patients. RESULTS: The final protocol comprised a single-slab (28 3-mm-thick partitions) coronal acquisition (repetition time, 7 msec; echo time, 2.8 msec; flip angle, 60 degrees) during a single breath hold, enhanced with 30 mL gadoteridol. In the final 32 patients, sensitivity and specificity, respectively, for obstructive lesions were 100% and 100% for the aorta, 100% and 98% for common iliac arteries, 100% and 89% for external iliac arteries, 100% and 89% for main renal arteries, and 100% and 62% for accessory renal arteries. CONCLUSION: This breath-hold protocol improves the accuracy of aortoiliac inflow assessment, but low resolution limits evaluation of small renal arteries.

Adult↗
PubMed1996

Complex biliary stones: treatment with a small choledochoscope and laser lithotripsy.

PURPOSE: To evaluate the use of a small choledochoscope and laser lithotripsy in the treatment of complex biliary stone disease. MATERIALS AND METHODS: Twenty-five consecutive patients with complex biliary stone disease not amenable to surgical therapy, peroral endoscopic removal, or simple percutaneous retrieval techniques underwent 35 stone-removal procedures. A 3.4-mm endoscope and a pulsed dye coumarin green laser were used to pulverize and remove stones through preexisting, mature transhepatic biliary drain tracts (n = 18), t-tube tracts (n = 3), cholecystostomy tube tracts (n = 3), and a hepaticocutaneous enterostomy (n = 1). Procedures in 14 of the 25 patients (56%) were performed on an outpatient basis. RESULTS: Twenty-four of the 25 patients (96%) were cleared of their stone burden and underwent subsequent catheter therapy of strictures or abscesses as necessary. Complications of the stone removal included fever and chills in six patients (24%) and mild bleeding from a bile duct wall during removal of an adherent stone in one patient. CONCLUSION: Use of a small choledochoscope and a coumarin green pulsed dye laser is safe and effective in the management of complex biliary stone disease.

Bile Duct Diseases↗
PubMed1996

Transjugular intrahepatic portosystemic shunt procedure: efficacy of 10-mm versus 12-mm Wallstents.

PURPOSE: To compare results of transjugular intrahepatic portosystemic shunt (TIPS) placement with 10- and 12-mm Wallstents. MATERIALS AND METHODS: Forty-six TIPS procedures in 47 patients were retrospectively reviewed. Wallstents that were 10 mm in diameter were used in 23 patients, and those that were 12 mm in diameter were used in 23 patients. Immediate results were compared, which included initial portosystemic gradient and Doppler measurements of blood flow velocity through the shunt at 1 day. Long-term patency and velocities were also assessed. RESULTS: TIPS were successfully created in 46 of 47 patients (98%). In one patient in the 10-mm group, the portal vein could not be accessed. When compared with TIPS in the 10-mm group, TIPS placed in the 12-mm group required dilation to larger diameters (mean, 11.1 vs 9.2 mm; P < .0001) to achieve an identical target gradient of 10 mm Hg and exhibited lower 1-day velocities (mean, 1.3 m/sec vs 1.7 m/sec; P < .03). The 1-day occlusion rate was 17% (four of 23 patients) in the 12-mm group versus 0% in the 10-mm group (P < .02). Patient survival was statistically significantly less in the 12-mm group (P < .03). CONCLUSION: Twelve-millimeter Wallstents yield statistically significantly poorer short- and long-term results in TIPS procedures. This is most likely due to the decreased radial strength of the larger stent, which is 50% less than that of the 10-mm stent.

Adolescent↗
PubMed1995

Long-term follow-up of the Palmaz stent for iliac occlusive disease.

BACKGROUND: Thirty-eight limbs with iliac occlusive disease were treated with Palmaz stents from 1987 through 1991. METHODS: Indications for stent utilization included dissection induced by percutaneous transluminal balloon angioplasty (PTA) (10), restenosis after PTA (nine), post-PTA residual stenosis (nine), multiple stenoses or occlusion (five), and unfavorable location (five). RESULTS: The ankle/brachial pressure index increased from 0.53 +/- 0.27 to 0.8 +/- 0.26 after stent deployment. The intraluminal pressure gradient decreased from 31.9 +/- 16.3 to 0.9 +/- 2.2 mm Hg after stent deployment. Complications included pseudoaneurysm (one), arteriovenous fistula (one), iliac perforation (one), groin hematoma (two), and occlusion (two). Follow-up arteriogram showed stenosis proximal or distal (n = 4) or within the stents (n = 4). These were treated with PTA or stents. Two patients required an aortobifemoral graft. Nine patients have died. Life table analysis showed a 1-, 3-, and 5-year primary and secondary cumulative patency of 87% +/- 5.9%, 74% +/- 8.2%, and 63% +/- 10% and 91% +/- 5.1%, 91% +/- 5.6%, and 86% +/- 7.6%, respectively. CONCLUSIONS: Palmaz stents, often required to salvage a PTA failure, appear to maintain overall patency at a high level. However, intimal hyperplasia and the progression of atherosclerotic disease may result in a need for additional procedures to obtain this favorable outcome.

Adult↗
PubMed1995

Iliac artery MR angiography: comparison of three-dimensional gadolinium-enhanced and two-dimensional time-of-flight techniques.

PURPOSE: To determine if a three-dimensional (3D) gadolinium-enhanced technique is useful for improving the accuracy of magnetic resonance (MR) angiography. MATERIALS AND METHODS: Prospectively, two-dimensional (2D) time-of-flight (TOF) and 3D gadolinium-enhanced MR angiography was performed in 23 patients. Conventional arteriography, the reference standard, was performed in all but five patients. Images from each examination were interpreted blindly by two observers. RESULTS: For common and external iliac arteries, interpretations of dynamic 3D gadolinium-enhanced MR angiograms matched those of conventional arteriograms in 12 of 18 patients (67%) for both observers. Interpretations of 2D TOF images matched those of conventional arteriograms in six (33%) and seven (39%) patients for the two observers respectively. CONCLUSION: Preliminary results suggest that iliac artery MR angiography can be improved by complementing standard 2D TOF acquisitions with 3D gadolinium-enhanced acquisitions.

Angiography↗
PubMed1992

Localization of the portal vein for transjugular catheterization: percutaneous placement of a metallic marker with real-time US guidance.

Transjugular catheterization of the portal vein can be used to form a portosystemic shunt. Conventionally, the passage of a needle from the hepatic vein into the portal vein is performed with fluoroscopic monitoring only. Several methods to target the portal vein have been previously reported, including transhepatic venous catheterization, indirect portography (arterial catheterization), or skin marking based on ultrasound (US) mapping of portal landmarks. The authors used realtime US guidance to percutaneously place a small marking wire in the parenchyma next to the portal bifurcation. A 0.018-inch-diameter, 5-mm-long platinum wire is delivered through a 22-gauge echo-tipped needle placed adjacent to the right portal vein. This marking wire enabled rapid entry into the portal vein, helped avoid extrahepatic puncture, and was useful during stent deployment and positioning.

Adolescent↗
PubMed1989

Indications for breast imaging in women under age 35 years.

To determine appropriate indications for breast imaging in young women, the authors correlated patient histories with mammographic and/or sonographic findings and biopsy or follow-up results for 625 patients aged 13-34 years. The only important indications were a palpable mass and suspicion of an abscess. Of the 335 studies performed for evaluation of a palpable mass, 184 (55%) were normal, 28 (8%) were compatible with benign disease, and 123 (37%) were suggestive of malignancy. Biopsies were performed in 73 patients; the findings were benign in 67 cases, and carcinoma was found in six. Imaging studies were considered helpful in four of the 15 cases of suspected abscess, in that the studies established the presence and extent of an abscess. Studies in 275 women were performed for a variety of other indications. The findings were normal in 239 (87%) studies, benign in 21 (8%), and suggestive of malignancy in 15 (5%); there were no known carcinomas in any of the patients. Women with the "low-yield" indications identified in this study should be followed up clinically rather than referred for imaging studies.

Adolescent↗
PubMed1988

Facial bone infarcts in sickle cell syndromes.

Bone infarction in the sickle cell syndromes (sickle cell anemia, sickle beta thalassemia, and sickle C disease) is common in the long bones, but the facial bones, particularly the orbits, are infrequently involved. In a review of the literature, only 13 cases of facial bone infarcts in sickle cell syndromes were found. Seven episodes of facial bone infarcts--four orbital, two mandibular, and one in the zygomatic arch--in six patients encountered at the authors' institution are reported. Five patients had hemoglobin SS, and one had hemoglobin SC. Bone marrow scans were positive for infarction in five of the six episodes during which they were obtained, which highlights the usefulness of this technique in the diagnosis of facial bone infarction.

Adolescent↗
PubMed1983

Cervical pregnancy diagnosed by ultrasound.

The preoperative diagnosis of cervical pregnancy by ultrasound is described. To the authors' knowledge, this is the third such diagnosis that has been reported in the literature. Ultrasound examination showed a gestational sac with smooth margins occupying the entire cervix in a 23-year-old woman. It is suggested that this diagnosis be considered in the appropriate clinical setting of painless first trimester vaginal bleeding in a patient who has had an abortion or other gynecologic surgery.

Adult↗
PubMed1983

Unilateral absence of a pulmonary artery.

Congenital absence of a main pulmonary artery is a rare anomaly. Most patients without associated congenital cardiac abnormalities are asymptomatic, and the diagnosis is first suggested by the appearance of the involved lung on a routine chest roentgenogram. The ipsilateral lung will be smaller than normal, and the contralateral lung will be overinflated and may herniate across the midline. We describe eight children with unilateral pulmonary arterial atresia (seven on the right side, four of whom were without associated cardiac anomalies).

Adolescent↗
PubMed1981

Upper airways obstruction. Presentation with systemic hypertension.

Of 14 patients whose final diagnosis was upper airways obstruction associated with heart failure, 3 presented with systemic hypertension (up to 200/100 mmHg). In 2 the hypertension was so severe that at first it had to be considered as a possible cause of the presenting symptoms. The subsequent history indicated that it was an effect of the upper airways obstruction with heart failure.

Airway Obstruction↗
PubMed1980

The thymic mass as a mediastinal dilemma.

Five patients with normal thymus glands whose radiographs were mimicking mediastinal masses are presented; one in an infant with a compressed right upper lobe bronchus and two in adolescents with normal large lobes of the thymus. There were also two patients with regrowth of the thymus, one after severe infection and one after irradiation for secondary malignancies. We discuss the use of various techniques utilised to confirm the diagnosis and avert surgical procedures.

Bronchography↗