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Biomedical subjects

T M Vesely

Publications and source records attributed to T M Vesely.

At least 19 recordsLinked to original sources
PubMed2001

Air embolism during insertion of central venous catheters.

PURPOSE: To determine the clinical consequences of air embolism occurring during insertion of central venous catheters. MATERIALS AND METHODS: A computer search of our interventional radiology database revealed that 11,583 central venous catheters were inserted between January 1, 1995 and August 1, 2000: 7,178 were nontunneled and 4,404 were tunneled. Air embolism was reported to have occurred in 15 patients. Air embolization was recognized by audible air aspiration during catheter insertion or by fluoroscopic visualization of air within the right atrium or pulmonary artery. The radiology reports and medical records of these 15 patients were reviewed. RESULTS: All 15 patients had an air embolism occur during insertion of a tunneled central venous catheter. These included eight Ash catheters, five chest wall ports, one Tesio catheter, and one Pheres-Flow catheter. Four patients remained asymptomatic. Six patients had mild symptoms that quickly resolved with supplemental oxygen. Four had moderate symptoms that also resolved with supplemental oxygen. One patient died acutely as a result of the air embolism. CONCLUSION: Air embolism is a rare but potentially fatal complication of central venous catheter procedures. In our series, all occurred during insertion of a tunneled catheter through a peel-away sheath. The administration of supplemental oxygen was an effective treatment in the majority of patients.

Adult↗
PubMed2001

Flow in hemodialysis grafts after angioplasty: Do radiologic criteria predict success?

BACKGROUND: The anatomic success of percutaneous angioplasty of venous stenosis is determined by the improvement in cross-sectional diameter of the vessel. A successful outcome is defined as a residual stenosis of <30%. The purpose of this study was to determine whether the angiographic assessment of a venous stenosis correlates with the change in graft blood flow following angioplasty. METHODS: Twenty-two hemodialysis patients with decreased intragraft blood flow (<700 mL/min) underwent diagnostic fistulography and angioplasty. All grafts were patent at the time of the procedure. Intragraft blood flow was measured before and after angioplasty using the ultrasonic dilution technique. Change in graft blood flow after angioplasty was correlated to the morphologic changes of the treated stenosis. RESULTS: The mean preangioplasty and postangioplasty graft blood flows were 457 +/- 136 and 818 +/- 202 mL/min, respectively. The mean degree of stenosis before angioplasty was 74 +/- 15% and 18 +/- 14% after dilation (P < 0.001). The only variable that significantly correlated with postangioplasty blood flow was preangioplasty flow (r2 = 0.22, P < 0.001). The postangioplasty blood flow was not significantly different than the highest recorded blood flow measured in that graft (798 +/- 213 mL/min, P = NS). There was no significant correlation between the change in blood flow and the change in percentage of stenosis. CONCLUSION: Following angioplasty of a venous stenosis, the graft blood flow is most closely predicted by the preprocedural blood flow and is similar to the highest recorded blood flow ever measured in that graft. Angiographic criteria to assess the success of angioplasty are not predictive of changes in blood flow.

Aged↗
PubMed2001

Angioscopy.

Angioscopy provides a magnified, real-time, 360-degree view of the endoluminal surface of blood vessels, yielding unique information that is often complementary to conventional angiography. This unique perspective can significantly enhance one's perception and appreciation of endovascular disease. Although angioscopy is primarily used as a research tool, its ability to characterize accurately the morphology and color of atherosclerotic lesions may lead to improved treatment and better clinical outcomes.

Angioscopy↗
PubMed2000

Angioscopic observations after percutaneous thrombectomy of thrombosed hemodialysis grafts.

PURPOSE: To use angioscopy to evaluate and compare the amount of residual thrombus and endoluminal wall damage in hemodialysis grafts after percutaneous thrombectomy procedures. MATERIALS AND METHODS: Thirty-nine thrombectomy and angioscopy procedures were performed in 35 patients. Percutaneous thrombectomy methods included eight different mechanical thrombectomy devices and the "lyse and wait" technique. Videotaped images of 33 angioscopic examinations were independently reviewed by three radiologists. Two parameters-the amount of residual thrombus and degree of endoluminal wall damage-were scored on a scale of 1 to 5. Data were initially analyzed to validate the grading system and then further studied to compare the different thrombectomy techniques. RESULTS: The Spearman rank order analysis validated the data pertaining to the amount of residual thrombus (r = 0.71, P < .0001), but there was poor correlation between reviewers regarding the degree of endoluminal wall damage. Combined scores from three reviewers revealed that the Cragg brush and Percutaneous Thrombectomy Device (PTD) left the smallest amounts of residual thrombus. The other methods tested, listed by increasing amount of residual thrombus, were the Endovac, Hydrolyser, Amplatz Thrombectomy Device, AngioJet, Oasis, and the lyse and wait technique. There were two complications related to angioscopy procedures. CONCLUSION: Subjective observations reveal that wall-contact thrombectomy devices leave less residual thrombus than hydrodynamic devices, aspiration devices, or the lyse and wait technique.

Angioscopy↗
PubMed1999

Initial performance of Tesio hemodialysis catheters.

PURPOSE: This retrospective study was performed to investigate the authors' clinical observations that suggest that Tesio hemodialysis catheters may initially have suboptimal blood flow rates, which improve spontaneously after several hemodialysis treatment sessions. MATERIALS AND METHODS: Sixty Tesio twin hemodialysis catheters were placed in 49 patients during a 2-year period. Thirty twin catheters were placed by radiologists, and 30 were placed by surgeons. The catheter blood flow rates and catheter line pressures, which were recorded during each of the first five hemodialysis treatment sessions, were reviewed and analyzed to determine the performance of each catheter during the first five hemodialysis treatments. In addition, the authors compared the site of catheter placement and responsible service (surgery or radiology) using this catheter performance data. RESULTS: Twenty-six catheters (43%) provided adequate blood flow (250 mL/min) throughout the first five hemodialysis sessions. Twenty-six catheters (43%) had inadequate or variable blood flow rates, some of which improved without intervention. Eight catheters (13%) required an intervention before the first five hemodialysis sessions had been completed. Right-sided catheters performed better than left-sided catheters. There was no difference in performance between catheters placed by surgeons and those placed by radiologists. CONCLUSION: This investigation supports the authors' suspicion that some Tesio catheters may have inadequate initial performance but the blood flows can improve, without intervention, during the first five hemodialysis sessions/2 weeks of use.

Catheterization, Central Venous↗
PubMed1999

Comparison of the angiojet rheolytic catheter to surgical thrombectomy for the treatment of thrombosed hemodialysis grafts. Peripheral AngioJet Clinical Trial.

PURPOSE: To compare the clinical effectiveness of the AngioJet F105 rheolytic catheter to that of surgical thrombectomy for the treatment of thrombosed hemodialysis grafts. MATERIALS AND METHODS: This was a multicenter, prospective, randomized trial comparing technical success, primary patency, and complication rates. A total of 153 patients were enrolled: 82 patients in the AngioJet group and 71 patients in the surgical thrombectomy group. Patient follow-up was performed 24-48 hours, 1 month, and 6 months after the procedures. RESULTS: Technical success, as defined by the patient's ability to undergo hemodialysis treatment, was 73.2% for the AngioJet group and 78.8% for the surgical thrombectomy group (P = .41). The primary patency rates of the AngioJet group were 32%, 21%, and 15% at 1, 2, and 3 months, respectively. The primary patency rates for the surgical group were 41%, 32%, and 26% at 1, 2, and 3 months, respectively. This difference approached statistical significance (P = .053). The groups had similar complication rates-14.6% in the AngioJet group and 14.1% in the surgery group-although the surgery group had more major complications (11.3%). In the AngioJet group, there was a transient increase in plasma-free hemoglobin, which normalized within 24-48 hours. CONCLUSIONS: The AngioJet F105 catheter provides similar clinical results when compared to surgical thrombectomy for the treatment of thrombosed hemodialysis grafts. The difference in patency rates between these two techniques approached statistical significance. In addition, results of both thrombectomy methods were inferior to those suggested by the Dialysis Outcomes Quality Initiative guidelines.

Adult↗
PubMed1998

Treatment of thrombosed hemodialysis access grafts: Arrow-Trerotola percutaneous thrombolytic device versus pulse-spray thrombolysis. Arrow-Trerotola Percutaneous Thrombolytic Device Clinical Trial.

PURPOSE: To evaluate a percutaneous thrombolytic device (PTD) designed for treating thrombosed hemodialysis access grafts. MATERIALS AND METHODS: To compare the PTD with pulse-spray pharmacomechanical thrombolysis (PSPMT) by using urokinase, 122 randomly chosen patients with synthetic, thrombosed hemodialysis access grafts from multiple centers prospectively underwent thrombolysis with the PTD (5-F, low-speed rotational mechanical device) or PSPMT. Major outcome variables included the procedure time, the immediate technical patency rate, the complication rate, and the 3-month patency rate. RESULTS: Sixty-four PTD and 58 PSPMT procedures were performed with intent to treat. The immediate technical patency rate was 95% (61 of 64 [PTD] and 55 of 58 [PSPMT]) in both procedures. Median procedure times were 75 minutes in the PTD group (range, 25-209 minutes) and 85 minutes in the PSPMT group (range, 50-273 minutes; P < .04). Major complications occurred in 8% (five of 64) of PTD procedures (none related to the PTD) and 9% (five of 58) PSPMT procedures (not significant). Two devices broke (one during training) with no clinical sequela. The 3-month primary patency rate was 39% (25 of 64) in the PTD group and 40% (23 of 58) in the PSPMT group (not significant). CONCLUSION: The PTD is safe and effective for treating thrombosed hemodialysis access grafts. The technical and long-term success rates are similar to those of PSPMT; procedure times are shorter.

Procedural Sedation↗
PubMed1998

Percutaneous drainage of fluid collections in the extremities.

PURPOSE: To analyze the results of percutaneous drainage of fluid collections in the extremities. MATERIALS AND METHODS: From 1990-1997, 28 patients aged 14-90 years underwent percutaneous drainage of 33 fluid collections in the extremities; two patients underwent multiple drainages. Fluid collections were in the hip-groin area (n = 16), thighs (n = 6), buttocks (n = 6), knees (n = 3), calf (n = 1), and axilla (n = 1). Three intraarticular collections were included. The patients who had undergone prior procedures were eight who had undergone surgical drainage, 10 who had undergone needle aspiration, and one who had undergone surgical débridement. The two most common guidance methods of catheter placement were ultrasound localization and fluoroscopy. RESULTS: The average drainage duration was 18.2 days (range, 1-93 days). The estimated cavity sizes were 4-733 cm3. Purulent fluid was drained in 13 patients. Staphylococcus aureus was the most commonly identified organism (n = 9). Nine patients had postoperative lymphoceles; five of these patients underwent sclerotherapy. Two (7%) patients had two complications, one of which was major. Failure occurred in four (16%) of 25 patients; two needed repeat drainage for recurrence, and two needed subsequent surgery. Success could not be determined in three patients who were lost to follow-up. CONCLUSION: Percutaneous drainage of fluid collections in the extremities is an effective alternative to open-incision drainage in inpatients and outpatients.

Adolescent↗
PubMed1997

Upper extremity central venous obstruction in hemodialysis patients: treatment with Wallstents.

PURPOSE: To determine the effectiveness of using Wallstents to treat subclavian or brachiocephalic venous obstruction after unsuccessful angioplasty, in patients undergoing hemodialysis. MATERIALS AND METHODS: Dialysis records, radiology reports, and procedural images of 20 hemodialysis patients who underwent Wallstent insertion into a subclavian (n = 11) or brachiocephalic (n = 9) vein were reviewed. Technical success and primary, assisted primary, and cumulative patency rates were calculated. RESULTS: Twenty-three Wallstents were inserted for stenosis (n = 18) or occlusion (n = 2). Technical success was 100%. Eight patients underwent 11 reinterventions to maintain patency of the Wallstent during the follow-up period. Patency rates of the Wallstent were (a) primary at 1 month, 3 months, 6 months, and 1 year: 90%, 67%, 42%, and 25%; (b) assisted primary at 3 months, 6 months, and 1 year: 88%, 62%, and 47%; and (c) cumulative at 3 months, 6 months, 1 year, and 2 years: 89%, 64%, 56%, and 22%. Considerable shortening of the stent occurred in five patients. One occurred immediately during the deployment procedure, but four were discovered weeks to months later. No other complications occurred. CONCLUSION: After suboptimal angioplasty, treatment of subclavian and brachiocephalic vein stenoses with a Wallstent can provide continued use of a hemodialysis access. Close clinical surveillance and multiple reinterventions are necessary to maintain Wallstent patency.

Angioplasty↗
PubMed1996

Evaluation of coagulation tests as predictors of angiographic bleeding complications.

PURPOSE: To determine whether prothrombin time (PT), partial thromboplastin time (PTT), and platelet count are useful predictors of postangiographic hematoma. MATERIALS AND METHODS: The authors prospectively studied 1,000 consecutive patients who underwent femoral arterial puncture for a diagnostic or therapeutic vascular procedure. Demographic and procedural variables were recorded, including patient age and sex, history of medications and bleeding, procedure type and length, catheter size, and experience level of radiologist applying compression for hemostasis. RESULTS: Abnormal results of coagulation tests were not correlated with an increased occurrence of hemorrhagic complications, but bleeding complications did occur more often in patients with thrombocytopenia. Hematomas occurred in 8.1% (10 of 123) of patients with any abnormal coagulation test results and 9.7% (85 of 877) of patients with normal test results. A platelet count of less than 100 X 10(9)/L was correlated with a higher occurrence of hematoma (P = .002). CONCLUSION: Abnormal PT and PTTs do not correlate with an increased risk of postangiographic hematoma, but a low platelet count is associated with more bleeding complications.

Adolescent↗
PubMed1995

Laparoscopic detection of hepatic metastases in patients with residual or recurrent medullary thyroid cancer.

BACKGROUND: After initial operations for medullary thyroid cancer (MTC), reoperation with removal of metastatic disease confined to the neck may benefit some patients. The identification of distant metastases precludes the possibility of curative reoperation. METHODS: Forty-one patients with hypercalcitoninemia after initial surgical treatment for MTC underwent laparoscopic (n = 36) or open (n = 5) examination and biopsy of the liver. Thirty-seven of these patients underwent imaging by computed tomography (CT), magnetic resonance imaging (MRI) of the liver, or both, and 17 underwent selective venous catheterization (SVC) with measurement of hepatic and peripheral vein stimulated calcitonin levels. RESULTS: Liver metastases were found in eight patients, seven by laparoscopy and one by open examination. Seven of these patients had normal CT or MRI scans of the liver. Laparoscopy or open liver examination revealed metastases in 2 of 11 patients with elevated hepatic vein-peripheral vein stimulated calcitonin ratios (greater than 1.3). Metastases appeared as small (less than 5 mm), bright white nodules on the surface of the liver. CONCLUSIONS: Direct examination and biopsy of the liver by laparoscopy may show small deposits of metastatic MTC in patients with normal CT and MRI scanning.

Adolescent↗
PubMed1995

Dialysis access grafts: anatomic location of venous stenosis and results of angioplasty.

PURPOSE: To determine the distribution of stenoses and results of angioplasty in patients with similar forearm dialysis grafts made of polytetrafluoroethylene (PTFE). MATERIALS AND METHODS: Diagnostic radiographs of the fistula obtained in 215 patients were reviewed; 90 patients had similar, unrevised forearm PTFE loop dialysis grafts. The location, morphology, and results of angioplasty were reviewed for each measurable stenosis. Surgical, radiologic, and dialysis records were reviewed to document the subsequent patency rate of each patient's dialysis access. RESULTS: On the initial diagnostic fistulogram, 93 stenoses were identified. The anatomic distribution included 47% at the venous anastomosis and 11% within 1 cm of the anastomosis. Life table analysis revealed a 6-month patency rate of 63% and a 1-year patency rate of 41% for the first angioplasty in a given graft, and a 6-month patency rate of 44% and a 1-year patency rate of 22% [corrected] for the second angioplasty. CONCLUSION: Performance of serial venous angioplasty procedures may help prolong the life of a graft, but the patency rates diminish with subsequent interventions.

Aged↗
PubMed1995

Renal arteries: clinical comparison of three-dimensional time-of-flight MR angiographic sequences and radiographic angiography.

PURPOSE: To prospectively compare three magnetic resonance (MR) angiographic techniques in the renal arteries. MATERIALS AND METHODS: Twenty-five adult patients underwent three-dimensional time-of-flight MR angiography with three different sequences: conventional, tilted optimized nonsaturating excitation (TONE), and selective inversion-recovery rapid gradient-echo (SIR-RAGE). Fifteen also underwent radiographic angiography. Stenosis grade measured with each MR angiographic technique was compared with that measured with radiographic angiography by using correlation coefficients. Visible artery lengths with each MR angiographic technique were compared by using the Turkey method. RESULTS: Correlation between stenosis grades with each MR angiographic technique and with radiographic angiography was good (P < .01). Stenosis was correctly excluded with SIR-RAGE findings in six patients. Mean visible artery length was greatest with SIR-RAGE (P < .01). CONCLUSION: SIR-RAGE depicts a greater length of renal artery than does conventional MR angiography. TONE also improved depiction of distal arteries. Normal SIR-RAGE findings were highly predictive of normal arteries.

Adult↗
PubMed1994

Peripheral vascular disease: evaluation with stepping DSA and conventional screen-film angiography.

PURPOSE: To prospectively evaluate stepping digital subtraction angiography (S-DSA), which enables peripheral digital subtraction angiography (DSA) of both lower extremities after one injection of contrast material, in comparison with conventional screen-film angiography (SFA) for evaluation of lower-extremity vascular disease. MATERIALS AND METHODS: Fifty consecutive patients were prospectively examined. Each study was performed without knowledge of the findings in the other. Additional stationary DSA images were obtained whenever necessary. All studies were individually evaluated for diagnostic adequacy and then side by side for vascular opacification, timing of contrast enhancement, ease of reading, and overall superiority. RESULTS: The diagnostic adequacy of S-DSA was not statistically different from that of SFA (P > .30). SFA was subjectively considered superior in opacification (P < .003), ease of reading (P < .003), and subjective overall superiority (P < .005). S-DSA was superior in timing of contrast enhancement (P < .001). CONCLUSION: The advantages of S-DSA can be achieved while the diagnostic adequacy of SFA is maintained. However, SFA was considered superior in three of four subjective characteristics.

Aged↗