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Biomedical subjects

T K Egglin

Publications and source records attributed to T K Egglin.

At least 19 recordsLinked to original sources
PubMed2000

Fibrin sheath stripping versus catheter exchange for the treatment of failed tunneled hemodialysis catheters: randomized clinical trial.

PURPOSE: To compare the effectiveness of two treatments for tunneled hemodialysis catheter malfunction: percutaneous fibrin sheath stripping (PFSS) and over-the-wire catheter exchange (EX). MATERIALS AND METHODS: Adult patients with poorly functioning tunneled hemodialysis catheters (flow rates < 200 mL/min) were randomly assigned to receive either PFSS or EX. Over the course of 20 months, 30 patients (37 encounters) referred to a single institution met the inclusion criteria and consented to participate. PFSS employed transcatheter snares via femoral vein puncture, whereas EX was performed over a guide wire with use of fluoroscopic guidance. Patients were followed up to determine the duration of continued adequate hemodialysis via manipulated catheters for up to 4 months (primary outcome measure). RESULTS: Overall technical success rate was 97%. Mean catheter patency for the PFSS group was 24.5 +/- 29.3 days, and 52.2 +/- 43 days for the EX group (P < .0001). After EX, patency rates at 1, 2, 3, and 4 months were 71%, 33%, 27%, and 27%, compared to 31%, 16%, 7%, and 0% after PFSS (P = .04, logrank test). Exchanged catheters were significantly more likely to be patent for as long as 4 months (23% versus 0%; P < .05, chi2 test). CONCLUSIONS: Malfunctioning tunneled hemodialysis catheters treated by means of EX are significantly more likely to remain patent for up to 4 months than are those treated by means of PFSS. According to the results of this trial, PFSS should not be performed as a routine therapy for catheter malfunction.

Adult↗
PubMed1997

Embolotherapy of large pulmonary arteriovenous malformations: long-term results.

BACKGROUND: The purpose of this study was to document the long-term results of transcatheter embolotherapy of large pulmonary arteriovenous malformations (PAVMs). METHODS: From a data base of 221 consecutive patients with PAVMs treated by embolotherapy between 1978 and 1995, 45 patients with 52 PAVMs, supplied by feeding arteries 8 mm in diameter or larger, were selected for a retrospective investigation. RESULTS: Of 45 patients with 52 large PAVMs, 38 patients (84%) with 44 PAVMs (85%) were cured by the first embolotherapy (mean follow-up, 4.7 years). Acute periprocedural complications included self-limited pleurisy (31%), angina secondary to air embolus (2%), and paradoxical embolization of a device during deployment (4%). None of these events led to short- or long-term sequelae. Seven patients (16%) had persistence of the PAVM attributable to either recanalization (n = 4) or interim accessory artery growth (n = 3). Two of these patients presented with ischemic stroke several years after the initial treatment. Persistent PAVMs (n = 8) were retreated successfully by a second procedure (n = 7), or a third procedure (n = 1) (mean follow-up, 5.9 and 5.3 years, respectively). CONCLUSIONS: Embolotherapy of large PAVMs results in permanent occlusion in an overwhelming majority of patients. Continued patency due to recanalization or accessory artery growth is easily detected and treated.

Adolescent↗
PubMed1997

Cost-effectiveness of stereotactic core needle biopsy: analysis by means of mammographic findings.

PURPOSE: To determine the cost savings of stereotactic core needle biopsy over open surgical biopsy in patient subgroups defined according to mammographic findings. MATERIALS AND METHODS: From July 1992 through February 1995, stereotactic core needle biopsy was performed in 356 women with 405 nonpalpable breast lesions (254 were masses and 151 were calcification). Lesions were classified according to mammographic finding, size, and level of suspicion. Two hundred three lesions were classified as indeterminate, 166 as suspicious, and 36 as highly suspicious. Medicare reimbursements for 1995 were used to determine costs and cost savings. RESULTS: Overall cost savings for stereotactic core biopsy over open surgical biopsy was $741 per case. Average cost savings per case was $807 for masses and $630 for calcifications. The greatest savings occurred in the cases of indeterminate masses, with an average of $856 saved per case. The least savings occurred in the cases of highly suspicious calcifications, with $446 saved per case. CONCLUSION: Cost savings of stereotactic core needle biopsy vary in subgroups of patients defined according to mammographic findings. Over-all savings will depend on the distribution of patients among these groups. In this series, cost savings were realized with stereotactic core biopsy over open surgical biopsy for all mammographic subgroups.

Biopsy↗
PubMed1996

Context bias. A problem in diagnostic radiology.

OBJECTIVE: To determine whether radiologists' interpretations of images are biased by their context and by prevalence of disease in other recently observed cases. METHODS: A test set of 24 right pulmonary arteriograms with a 33% prevalence of pulmonary emboli (PE) was assembled and embedded in 2 larger groups of films. Group A contained 16 additional arteriograms, all showing PE involving the right lung, so that total prevalence was 60%. Group B contained 16 additional arteriograms without PE so that total prevalence was 20%. Six radiologists were randomly assigned to see either group first and then "cross over" to review the other group after a hiatus of at least 8 weeks. The direction of changes in a 5-point rating scale for the 2 readings of each film in the test set was compared with the sign test; mean sensitivity, specificity, and areas under receiver operating characteristic (ROC) curves were compared with the paired t test. RESULTS: In the context of group A's higher disease prevalence, radiologists shifted more of their diagnoses toward higher suspicion than expected by chance (P=.03, sign test). In group A, mean sensitivity for diagnosing PE was significantly higher (75% vs 60%; P=.04), and area under the ROC curve was significantly larger (0.88 vs 0.82; P=.02). CONCLUSIONS: Radiologists' diagnoses are significantly influenced by the context of interpretation, even when spectrum and verification bias are avoided. This "context bias" effect is unique to the evaluation of subjectively interpreted tests, and illustrates the difficulty of obtaining unbiased estimates of diagnostic accuracy for both new and existing technologies.

Angiography↗
PubMed1996

The case for better research standards in peripheral thrombolysis: poor quality of randomized trials during the past decade.

RATIONALE AND OBJECTIVES: We assessed how well published randomized controlled trials (RCTs) of peripheral thrombolysis have been designed and how they adjusted for patient characteristics that may influence responses to therapy. METHODS: RCT studies published between 1984 and 1994 were reviewed to determine whether they included nine crucial elements: sample size calculations, description of unenrolled eligible participants, homogeneous samples, balanced experimental groups, equal potency therapies, equal follow-up of outcomes, appropriate statistical inference, multivariable or subgroup analyses, and anonymous review of subjective endpoints. RESULTS: The nine RCTs complied with a median of three of nine standards (range = 2-6). Each report exhibited serious flaws that may affect generalizability and external validity. None adequately adjusted for sample heterogeneity or sought to identify characteristics that may affect responses to therapy. CONCLUSION: Failure to address prognostic or confounding variables restricts the utility of peripheral thrombolysis RCTs and helps explain why contentious debates about this therapy persist. A model for future thrombolysis trials is proposed.

Arterial Occlusive Diseases↗
PubMed1995

Complications of peripheral arteriography: a new system to identify patients at increased risk.

PURPOSE: The most quoted literature on arteriographic complications is based on self-reports collected during the mid 1970s. We sought to determine whether those results remain valid despite changes in arteriographic practice and whether patient subgroups at increased risk could be identified. METHODS: Five hundred forty-nine consecutive patients were examined after arteriography and twice over 72 hours. Patients were telephoned at least 2 weeks later to identify delayed complications. The sample was divided into two groups to allow independent validation of suspected prognostic factors. RESULTS: The rate of major complications was 2.9% (16/549), but varied from 0.7% to 9.1% among three strata of relative risk. Rates were highest in patients studied for suspected aortic dissection, mesenteric ischemia, gastrointestinal bleeding, or symptomatic carotid artery stenosis and lowest in patients with trauma or aneurysmal disease. Patients studied for claudication or limb-threatening ischemia had intermediate risk (2.0%). Within these strata, congestive heart failure and furosemide use were the only variables independently associated with a significantly increased complication rate. CONCLUSIONS: Previous reports have overestimated the risk of arteriography for trauma or aneurysm but substantially underestimate the risk for patients with other common conditions. Such stratified complication rates are essential to understand relative costs and benefits of arteriography and other vascular imaging modalities in specific clinical situations.

Acute Kidney Injury↗
PubMed1995

Retrieval of intravascular foreign bodies: experience in 32 cases.

OBJECTIVE: Recent reports suggest that both the nature of intravascular foreign bodies and the tools available to retrieve them have changed substantially in the past decade. We reviewed our recent experience with percutaneous retrieval of intravascular foreign bodies to determine the efficacy and safety of the procedure using currently available devices. MATERIALS AND METHODS: Between 1990 and 1994, we attempted retrieval of 35 intravascular foreign bodies in 32 patients. Twelve patients (38%), including all five with intraarterial foreign bodies, were treated for complications of transcatheter interventional procedures that resulted in embolization of seven coils, four intravascular stents, an inferior vena cava filter, and a valvuloplasty balloon fragment. From procedure records, we reviewed the types of retrieval devices and methods used; the medical record was studied to determine the occurrence and treatment of any procedure-related complications. RESULTS: Retrieval was successful in 31 (97%) of 32 patients. All five intraarterial and 29 of 30 IV objects were removed. Nitinol goose-neck snares were used in 28 of 32 cases, but more than one retrieval system was required in eight cases (25%), often using grasping forceps, tip-deflecting wires, or stone baskets to move the foreign body into a more favorable position for snaring. In the single failure, the tip of a largely extravascular catheter fragment lay in a venous valve and could not be snared in a patient who refused surgery. Two of five patients with arterial foreign bodies suffered occlusive arterial spasm, reversible with local administration of nitroglycerine. Two large objects were repositioned to the femoral vein and removed by surgical cutdown. No other procedural complications occurred, and none of the patients required additional compression, transfusion, or surgical intervention. CONCLUSION: We conclude that use of preformed nitinol goose-neck snares facilitates retrieval of intravascular foreign bodies in most cases, although interventional radiologists must be familiar with a variety of techniques to deal with the expanding spectrum of foreign bodies currently encountered.

Adolescent↗
PubMed1994

Clinical results of transvenous systemic embolotherapy with a neuroradiologic detachable balloon.

PURPOSE: To evaluate the efficacy of transvenous systemic embolotherapy with a neuroradiologic detachable balloon. MATERIALS AND METHODS: As part of a clinical trial, a detachable silicone balloon was used to occlude pulmonary arteriovenous malformations (PAVMs) in 35 patients and varicocele in 14 patients. In patients with PAVM, the indications for embolotherapy were prophylaxis against paradoxic embolization (n = 35) and dyspnea, fatigue, or both (n = 26); in patients with varicocele, they were pain or a discomforting lesion (n = 8) or infertility (n = 6). RESULTS: Balloon embolotherapy was successful in 79 (98%) of the 81 lesions in which it was attempted; 29 (37%) of these 79 balloons were used in conjunction with coils. Ninety-six (97%) of 99 balloons were successfully placed; the three technical failures had no substantial clinical sequelae, and in all three, occlusion was eventually achieved with either detachable balloons or coils. Of six late deflations, five occurred in balloons placed adjacent to coils; only one, which occurred between 1 day and 21 days after placement, resulted in recanalization. CONCLUSION: Transvenous embolization with this detachable balloon was relatively simple and provided cross-sectional occlusion of PAVMs and varicocele.

Angiography, Digital Subtraction↗
PubMed1994

Peripheral vascular occlusive disease: accuracy and reliability of time-of-flight MR angiography.

PURPOSE: To determine the accuracy and reliability of magnetic resonance (MR) angiography for identification of stenosis and patent distal vessels in patients with peripheral vascular disease. MATERIALS AND METHODS: Two-dimensional time-of-flight MR angiography and conventional arteriography were performed in 22 patients. Four blinded radiologists independently graded multiple anatomic segments. RESULTS: MR angiography allowed detection of more patent vessel segments than did conventional arteriography. For detection of significant stenosis (> 75%), MR angiography had 43%-67% sensitivity and 74%-89% specificity. Discrepancies in detection of significant stenosis occurred in 39 segments for the most accurate reviewer; 27 of these discrepancies were avoidable. CONCLUSION: For detection of significant stenosis, MR angiography has low to moderate sensitivity and specificity; however, observer variability appears to be a major contributing factor to the discrepancies. Greater reviewer experience or techniques for improving reliability may improve the accuracy of MR angiography in peripheral vascular disease.

Adult↗
PubMed1992

Variance of the position of the cerebellar tonsils with age: preliminary report.

The position of the cerebellar tonsils relative to the foramen magnum was measured with sagittal magnetic resonance (MR) images in 221 patients aged 5 months to 89 years who were considered not to have disorders that would affect tonsillar position. All patients were grouped according to age. All measurements of the tonsils were obtained directly from the video console. Statistically significant (P less than .05) differences in tonsillar position were found between the 1st and 9th decades (P less than .001) and the 3rd and 9th decades (P less than .003) of life. An obvious trend existed: tonsillar ascent with increasing age. Therefore, the authors believe that a single reference standard that indicates the normal distance of the cerebellar tonsils from the foramen magnum is inappropriate unless age is considered. They suggest that the following distances below the foramen magnum (more than 2 standard deviations out of the normal range) be used as criteria for ectopia of the cerebellar tonsils: 1st decade of life, 6 mm; 2nd and 3rd decades, 5 mm; 4th to 8th decades, 4 mm; and 9th decade, 3 mm.

Adolescent↗
PubMed1992

Extension of saphenous thrombophlebitis into the femoral vein: demonstration by color flow compression sonography.

Five cases are presented in which compression and color flow sonography were used to diagnose extension of superficial saphenous thrombophlebitis into the deep system at the saphenofemoral junction. In one case thrombus originated in the calf, demonstrating an unusual mode of propagation into the deep venous system above the knee. Color Doppler imaging is especially helpful in diagnosing this complication of superficial thrombophlebitis.

Aged↗
PubMed1991

Ewing's sarcoma. Radiographic pattern of healing and bony complications in patients with long-term survival.

The radiographic appearance of Ewing's sarcoma was studied retrospectively in 22 patients who survived 5 years or longer after diagnosis and treatment. Expected changes from treatment, including regression of the extraosseous soft tissue mass, periostitis, and reconstitution of the cortex, occurred in all patients. Local recurrence occurred in one patient 10 years after complete remission whereas secondary osteosarcoma occurred more than 5 years after complete remission in two other cases. Both recurrent and secondary tumors presented as new lytic foci at the site of the original primary lesion. Lytic changes from radiation (radiation osteitis) may develop more than 2 years after treatment and in this sample; such findings were widely distributed in the radiation port. The authors conclude that bone remodeling and postradiation changes occur slowly over 2 years after treatment, and that any localized lysis at the primary site is suspicious for recurrence or secondary neoplasm. Knowledge of the expected changes and patterns of local recurrence and secondary neoplasms helps one to detect any significant change in its early phase.

Adolescent↗
PubMed1991

Determination of prostate volume with transrectal US for cancer screening. Part I. Comparison with prostate-specific antigen assays.

To investigate whether radiologists can objectively define a high-risk group for prostate cancer, the researchers measured gland volume and compared it with results of a screening blood test, prostate-specific antigen (PSA) assay. A total of 768 men, aged 55-71 years, were self-referred to two prostate cancer screening programs using transrectal ultrasound (US) and digital rectal examination. In patients with no evidence of cancer, statistically significant increases in mean PSA values were noted with increasing gland volume ranges (P less than .05). PSA values in patients with cancer were more likely to exceed the volume-adjusted 95th percentile (mean + [1.65.standard deviation]) than those in patients with negative biopsy results (P less than .005). Patients with PSA values above the volume-adjusted 95th percentile have an estimated risk for prostate cancer up to nine times that of the general screening population. The researchers conclude that knowledge of transrectal US gland volume and prostate-specific antigen assay type are important objective variables for future prostate cancer screening programs. The volume-adjusted 95th percentiles presented may help guide cost-effective management of current early detection efforts.

Aged↗
PubMed1991

Determination of prostate volume with transrectal US for cancer screening. Part II. Accuracy of in vitro and in vivo techniques.

Improved diagnostic information is obtained when prostate volume is correlated with results of prostate-specific antigen assays for early detection of prostate cancer. Three commonly used prostate volume measurement techniques were analyzed: planimetry, prolate ellipse volume calculation (HWL), and an ellipsoid volume measurement technique. For in vitro volume measurement, the declining order of accuracy was planimetry, HWL, and ellipsoid techniques. At the 95% confidence level, inverse prediction produced full-range values for a 40-cm3 model of 5.7, 16.0, 28.8, and 32.8 cm3 for planimetry, HWL, and the two ellipsoid techniques, respectively. Despite its superior accuracy, planimetry is not available on most ultrasound units, increases estimated clinical scanning time, requires additional equipment, and is difficult for a sole operator to perform. Although less accurate than planimetry, HWL is a rapid volume measurement technique that appears to be more accurate than ellipsoid software packages; its universal availability makes it practical for routine clinical use.

Humans↗
PubMed1991

Benign and malignant adrenal masses: CT distinction with attenuation coefficients, size, and observer analysis.

In a retrospective study of adrenal masses evaluated with computed tomography (CT), lesion x-ray attenuation was compared with size and radiologists' interpretations in discriminating benign lesions from malignant ones. Unenhanced CT attenuation coefficient and size were analyzed electronically in 55 patients with 66 adrenal masses. There were 38 nonhyperfunctioning adenomas in 33 patients and 28 malignant masses in 22 patients. Primary extraadrenal malignancies were present in 45 of the 55 patients. Three blinded readers characterized the adrenal masses using a seven-point scale of certainty. Results were subjected to receiver operating characteristic (ROC) analysis. The mean CT attenuation coefficient for benign adrenal masses was -2.2 HU +/- 16.0 and was significantly different from the mean for malignant lesions (28.9 HU +/- 10.6). The area under the ROC curve for CT attenuation coefficients (0.91 +/- 0.04) was significantly larger than that for lesion size (0.84 +/- 0.05) or best observer interpretation (0.84 +/- 0.05). A threshold CT attenuation value of 0 HU had a sensitivity-to-specificity ratio of 47%:100% for characterizing benign adrenal masses, whereas a threshold attenuation of 10 HU had a ratio of 79%:96%.

Adrenal Gland Neoplasms↗
PubMed1991

Isolated calf venous thrombosis: diagnosis with compression US.

Compression ultrasound (US) is an excellent means of evaluating the femoral and popliteal veins but is generally regarded as inadequate for the diagnosis of calf vein thrombosis. This prospective study evaluated compression sonography of the calf veins in 45 symptomatic patients with normal femoral and popliteal veins. All patients underwent correlative venography. Compression US enabled identification of 15 of 17 patients with calf vein thrombosis (sensitivity, 88%). The two false-negative results were in patients with small isolated thrombi. Compression US results were true-negative in 26 of 27 patients with normal venograms (specificity, 96%). If these results can be duplicated by other investigators in larger series of patients, compression US will be an adequate screening modality for calf vein thrombosis.

Acute Disease↗
PubMed1991

Epiphyseal marrow in infancy: MR imaging.

Hypointense epiphyseal marrow on T1-weighted magnetic resonance images often suggests disease. To determine whether hypointense marrow sometimes represents normal red marrow in a recently ossified epiphyseal center, the authors studied 38 infants without known marrow disease. Patients with hypointense epiphyseal marrow on T1-weighted images were younger (3.9 months +/- 3.2) than those with hyperintense marrow (9.6 months +/- 3.9) (P less than .001). T1-weighted imaging and histologic correlation were also performed in animals. The signal was hypointense and the marrow was red in the epiphyseal centers of all newborn animals, while all 6-week-old animals had hyperintense signal and yellow marrow. The authors conclude that hypointense marrow on T1-weighted images represents normal red marrow in a recently formed ossification center in newborn rabbits and lambs, and the same is probably true in humans. Epiphyseal marrow becomes hyperintense within a few months of development of the secondary center of ossification.

Animals↗