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Biomedical subjects

J J Snidow

Publications and source records attributed to J J Snidow.

15 recordsLinked to original sources
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↗
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↗
PubMed1990

New guide wire for high-flow infusion.

A new open-ended guide wire with a large internal diameter was compared with two other open-ended guide-wire and catheter infusion systems. Simple experiments were performed to compare flow rates and ability to track. The larger internal diameter of the new wire allowed higher flow rates and accepted an 0.025-inch (0.64-mm) guide wire. The flexibility of the new infusion wire was shown to be equivalent to that of the catheter system. The authors conclude that the new wire has advantages in terms of flow rates and ability to track, compared with presently available infusion systems.

Catheterization↗
PubMedDate not supplied

Percutaneous radiologic, surgical endoscopic, and percutaneous endoscopic gastrostomy/gastrojejunostomy: comparative study and cost analysis.

PURPOSE: To compare the results and costs of three different means of achieving direct percutaneous gastroenteric access. METHODS: Three groups of patients received the following procedures: fluoroscopically guided percutaneous gastrostomy/gastrojejunostomy (FPG, n = 42); percutaneous endoscopic gastrostomy/gastrojejunostomy (PEG, n = 45); and surgical endoscopic gastrostomy/gastrojejunostomy (SEG, n = 34). Retrospective review of the medical records was performed to evaluate indications for the procedure, procedure technical success, and outcome. Estimated costs were compared for each of the three procedures, using a combination of charges and materials costs. RESULTS: Technical success was greater for FPG and SEG (100% each) than for PEG (84%, p = 0.008 vs FPG and p = 0.02 vs SEG). All patients (n = 7) who failed PEG subsequently underwent successful FPG. Success in placing a gastrojejunostomy was 91% for FPG, and estimated at 43% for PEG and 0 for SEG. Complications did not differ in frequency among groups. For gastrostomy, the average cost per successful tube was lowest in the PEG group ($1862, p = 0.02); FPG averaged $1985, and SEG $3694. SEG costs significantly more than FPG or PEG (p = 0.0001). For gastrojejunostomy, FPG averaged $2201, PEG $3158, and SEG $3045. CONCLUSION: Technical success for gastrostomy is higher for FPG and SEG than PEG. Though PEG is the least costly procedure, the difference is modest compared with FPG. For gastrojejunostomy, FPG offers the highest technical success rate and lowest cost. Due to high costs associated with the operating room, SEG should be reserved for those patients undergoing a concurrent surgical procedure.

Adult↗
PubMedDate not supplied

Interpretations and treatment decisions based on MR angiography versus conventional arteriography in symptomatic lower extremity ischemia.

PURPOSE: To determine the frequency with which treatment plans based on findings at magnetic resonance angiography (MRA) match those based on findings at conventional x-ray arteriography (XRA) in the evaluation of symptomatic lower extremity ischemia. PATIENTS AND METHODS: Two-dimensional time-of-flight (TOF) MRA was performed in 42 patients undergoing XRA for evaluation of symptomatic lower extremity ischemia. The blind interpretations and treatment plans based on MRA findings were compared with those based on XRA findings, with use of XRA as the standard of reference. RESULTS: For identification of hemodynamically significant stenosis or occlusion, the sensitivity and specificity of MRA was 100% and 23% for iliac segments, 100% and 82% for common femoral segments, 89% and 67% for superficial femoral segments, 100% and 88% for popliteal segments, and 92% and 91% for tibioperoneal segments, respectively. The treatment plan based on MRA findings matched that based on XRA findings in 41% of patients. CONCLUSION: For evaluation of symptomatic lower extremity ischemia, two-dimensional TOF MRA cannot be considered a reliable substitute for XRA in patients who lack contraindications to XRA.

Angiography↗
PubMedDate not supplied

Iliac artery evaluation with two-dimensional time-of-flight MR angiography: update.

PURPOSE: To determine the accuracy of two-dimensional (2D) time-of-flight (TOF) magnetic resonance (MR) angiography, performed with state-of-the-art equipment, in the evaluation of the iliac arteries. MATERIALS AND METHODS: The iliac arteries of 50 patients undergoing conventional arteriography for evaluation of lower-extremity ischemia or abdominal aortic aneurysm were also imaged with axial 2D TOF MR angiography. Blinded interpretations of conventional arteriograms and MR angiograms were compared. MR angiography was performed with a 1.5-T system with 2-mm contiguous axial sections, 60 degrees flip angle, 28-msec repetition time, and 7.4-msec echo time. RESULTS: Blinded interpretations of 2D TOF MR angiograms matched those of conventional arteriograms in 26 of 50 patients (52%). For the diagnosis of obstructive iliac artery lesions, sensitivity and specificity with MR angiography were 85% and 59%, respectively. Two of three saccular iliac artery aneurysms escaped detection with MR angiography. CONCLUSION: Iliac artery evaluation with axial 2D TOF MR angiography is not sufficiently accurate to warrant its use as a replacement for conventional arteriography in patients who lack contraindications to the latter.

Angiography↗
PubMedDate not supplied

Comparison of digital subtraction and cut film arteriography in the evaluation of suspected thoracic aortic injury.

PURPOSE: To determine whether intraarterial digital subtraction arteriography (DSA) is as sensitive and specific as cut film arteriography (CFA) in the evaluation of suspected aortic injury resulting from blunt chest trauma. MATERIALS AND METHODS: Both CFA and DSA images of the thoracic aorta were obtained in the right posterior oblique (RPO) projection in 100 of 103 consecutive patients undergoing arteriography after blunt chest trauma. Diagnoses based on blinded separate review of both studies (CFA vs DSA) by four independent reviewers were compared. Reviewers graded their confidence in their diagnoses from 1 (certain) to 10 (uncertain). RESULTS: Eleven of 100 patients had aortic or great vessel injuries confirmed by operation (n = 10) or transesophageal echocardiography (n = 1). Three hundred eighty-eight of 400 diagnoses based on RPO CFA and 390 of 400 diagnoses based on RPO DSA agreed with the correct diagnoses. The sensitivity, specificity, and diagnostic accuracy of CFA versus DSA were not significantly different. The reviewers' confidence in their diagnoses was equivalent between CFA (average confidence score, 1.373) and DSA (average confidence score, 1.375). CONCLUSION: DSA and CFA yield equivalent sensitivity, specificity, and diagnostic accuracy in the evaluation of blunt chest trauma.

Adolescent↗