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Biomedical subjects

W Lees

Publications and source records attributed to W Lees.

At least 19 recordsLinked to original sources
PubMed2006

Radiofrequency ablation (RFA) as a cytoreductive strategy for hepatic metastasis from breast cancer.

INTRODUCTION: Patients with liver metastasis from breast cancer have a poor prognosis, although this may be improved by hepatectomy in a selected group with disease confined to the liver. We evaluate the effectiveness of radiofrequency ablation (RFA) as a cytoreductive strategy in the management of liver metastasis from primary breast cancer. PATIENTS AND METHODS: Nineteen patients with hepatic metastasis from primary breast cancer underwent RFA of their liver lesions between April 1998 and August 2004. RESULTS: The median age of the patients was 52 years (range, 32-69 years), 8 had disease confined to the liver, with 11 having stable extrahepatic disease in addition. Seven patients with disease confined to the liver at presentation are alive, as are 6 with extrahepatic disease, median follow-up after RFA was 15 months (range, 0-77 months). Survival at 30 months was 41.6%. In addition, 7 patients followed up for a median of 14 months (range, 2-29 months) remain alive and disease-free. RFA failed to control hepatic disease in 3 patients. RFA was not associated with any mortality or major morbidity. CONCLUSIONS: Control of hepatic metastasis from breast cancer is possible using RFA and may lead to a survival benefit, particularly in those patients with disease confined to the liver.

Adult↗
PubMed2002

The clinical utility of nuclear medicine imaging for the detection of occult gastrointestinal haemorrhage.

Acute gastrointestinal bleeding is often intermittent and the bleeding source may be difficult to locate, resulting in delay of potentially life-saving treatment. The aim of this study was to determine the clinical utility of 99mTc labelled red blood cell imaging and [99mTc]pertechnetate (Meckel's scan) imaging in a series of 137 patients admitted over a 5 year period to hospital for management of acute gastrointestinal bleeding. Of the 137 patients, 70 had positive 99mTc red blood cell studies. Eleven of 24 patients who had imaging performed beyond 3 h had positive scans that would otherwise have been missed. Only 47 patients had a definite final diagnosis at the time of hospital discharge, of which six were negative on 99mTc red blood cell imaging. The correct site of bleeding was localized in seven of 21 patients with foregut bleeding, and 15 of 20 patients with colonic bleeding. Endoscopy yielded a diagnosis in 13 of the 47 patients (28%). Eleven patients had Meckel's scans but all were negative. Angiography was diagnostic in one of 17 patients studied. 99mTc red blood cell imaging is a useful test in the management of acute gastrointestinal bleeding. Imaging beyond 3 h may further improve the bleeding detection rate. This test, however, may be an unreliable means of localization of bleeding, particularly in the foregut.

Adolescent↗
PubMed2001

Ultrasound imaging in three and four dimensions.

Three-dimensional (3D) reconstruction of ultrasound images was first demonstrated nearly 15 years ago, but only now is becoming a clinical reality. In the meantime, methods for 3D reconstruction of CT and MRI images have achieved an advanced state of development, and 3D imaging with these modalities has been applied widely in clinical practice. 3D applications in ultrasound have lagged behind CT and MRI, because ultrasound data is much more difficult to render in 3D, for a variety of technical reasons, than either CT or MRI data. Only in the past few years has the computing power of ultrasound equipment reached a level adequate enough for the complex signal processing tasks needed to render ultrasound data in three dimensions. At this point in time, the clinical application of 3D ultrasound is likely to advance rapidly, as improved 3D rendering technology becomes more widely available. This article is a review of the present status of 3D ultrasound imaging. It begins by comparing the characteristics of CT, MRI, and ultrasound image data that either make these data amenable or not amenable to 3D reconstruction. The article then considers the technical features involved with acquiring an ultrasound 3D data set and the mechanisms for reconstructing the images. Finally, the article reviews the literature that is available regarding clinical application of 3D ultrasound in obstetrics, ultrasound, the abdomen, and blood vessels.

Echocardiography, Four-Dimensional↗
PubMed2000

A prospective study of changes in aneurysm and graft length after endovascular exclusion of AAA using balloon and self-expanding endograft systems.

PURPOSE: Longitudinal shrinkage of aneurysms post-endovascular repair, employing unvalidated measurement techniques has been held to account for endograft disruption. In this study we record changes in aneurysm length, diameter and volume using the gold standard of calibrated spiral CT angiography (SCTA). METHOD: From 179 patients with AAA scanned by SCTA, 68 were selected for endografting. Twenty-seven had PTFE home-made prostheses while 41 patients had Talent endografts. SCTA was performed on the fifth postoperative day and 6-monthly intervals thereafter. The distance between the lowest renal artery and the aortic bifurcation (VBL - vertical body length) and the luminal centre line length (LCL) were measured. Maximal sac diameters and volumes were recorded using 3DCT reconstruction. RESULTS: Significant increase was noted in VBL (3.2) mm for PTFE-treated patients accompanied by an increase in sac volume at day 5 (12.5 ml). No changes in LCL or maximal diameters were evident. At 1.5 years further lengthening of both VBL (6.4 mm) and LCL (9.3 mm) was unaccompanied by sac diameter/volume changes. Talent patients - no changes in VBL or LCL were evident. Volumes and maximal AP and transverse diameters showed marked shrinkage: AP -11. 2 mm; transverse -2.6 mm; volumes by -35.5 ml at 6 months. CONCLUSION: With PTFE increase in VBL but not graft length, without concurrent changes in maximal diameters at day 5, is commensurate with increase in sac volume; after 1.5 years graft lengthening overtakes aortic lengthening. In Talent patients VBL/graft length remained unchanged. There is no evidence for longitudinal aneurysmal contracture. Volumes and maximal diameters for the Talent endograft but not for PTFE show shrinkage.

Aged↗
PubMed2000

The abdominal aortic aneurysm sac after endoluminal exclusion: a medium-term morphologic follow-up based on volumetric technology.

PURPOSE: The purpose of this study was to evaluate the role of three-dimensional spiral computed tomographic angiography (SCTA) for the assessment of the feasibility and results of endoluminal repair of infrarenal abdominal aortic aneurysm. METHODS: Laboratory studies: Phantom glass aneurysms, filled with contrast, underwent SCTA. The correlation between SCTA and laboratory measurements of linear dimensions and volumes was highly accurate (r(2) = 1.0). CLINICAL STUDIES: From the first 7 patients that were suitable for endoluminal repair, the correlation between SCTA and angiocatheter measurements was 0.85 to 0.99 (P <.04), but there was poor agreement between individual values. As determined from the measurements by 2 experienced investigators, intraobserver and interobserver errors for volume calculation in 12 randomly chosen scans from a total of 120 scans were 5.7 and 4.4 mL, respectively (range of volumes, 100-403 mL). The conditions of 53 patients were judged suitable for endoluminal repair of which 30 patients reached 1 year or more follow-up. The median aneurysm neck length and diameter were 24.5 mm (range, 11.5-60.8 mm) and 23.4 mm (18.3-31.5 mm), respectively. The fate of the sac after endografting by two techniques (pre-expanded polytetrafluoroethylene [PTFE] fixed with Palmaz stents and endografts) was defined with three-dimensional SCTA. RESULTS: The sac volume after endografting by pre-expanded PTFE (n = 12 patients) showed a significant median increase (P =.02) from 129 mL before surgery to 141 mL at 5 days after the operation with no change at 6 (139 mL), 12 (137 mL), and 18 (159 mL) months later. With the endografts (n = 18), there was an initial increase in median volume at 5 days (179-194 mL; P =.02) and then a significant shrinkage at 6 (148 mL; P =.012) and 12 (94.9 mL; P =.02) months. CONCLUSION: Three-dimensional SCTA has been validated and is both precise and reliable. Interobserver and intraobserver errors are within acceptable ranges. Angiocatheter measurements are less accurate and may give misleading information when used for patient selection and endograft construction. The sac volume increased after endografting and later shrank in patients who were treated with endografts, but not in those patients treated with pre-expanded PTFE. We propose that three-dimensional SCTA should be regarded as the gold standard for linear and volumetric measurement for infrarenal abdominal aortic aneurysm.

Aortic Aneurysm, Abdominal↗
PubMed1999

Contrast-enhanced colour Doppler ultrasonography in suspected breast cancer recurrence.

BACKGROUND: Postoperative scarring and radiotherapy changes in the conservatively treated breast often mimic breast cancer recurrence, resulting in many unnecessary biopsies. Local breast cancer recurrence may be detected more accurately with contrast-enhanced colour Doppler imaging. METHODS: Fifty-eight women with suspected local breast cancer recurrence were evaluated prospectively by means of conventional and contrast-enhanced colour Doppler imaging before surgical biopsy. RESULTS: Sensitivity for the detection of breast cancer recurrence using contrast enhancement was 94 per cent (specificity 67 per cent). Contrast enhancement significantly increased overall diagnostic accuracy, from 80 to 90 per cent (P < 0. 04). CONCLUSION: Contrast-enhanced colour Doppler imaging is a highly accurate method for detecting local breast cancer recurrence. Its adoption may substantially reduce biopsy rates.

Adult↗
PubMed1996

Experimental studies on Brucella abortus in moose (Alces alces).

Four moose (Alces alces) were inoculated conjunctivally with B. abortus biovar 1 to determine their susceptibility to brucellosis, and to describe the serology, bacteriology, hematology, clinical chemistry, and pathology associated with infection. All moose became infected. Two moose were killed at day 70 post-exposure, one (83F) died acutely at day 85, and one was killed at day 166. None of the moose had clinical signs, except for 83F immediately before death. Infected moose were readily detected serologically by the buffered antigen plate test, Brewer card test, standard tube agglutination test, and complement fixation test as used for brucellosis in cattle. With the exception of samples from 83F taken 24 hours before death, clinical chemistry, and hematology results were stable for all moose, and similar to normal values seen in cattle. Lesions seen in all moose were indicative of endotoxemia, and moose 83F died of acute endotoxic shock. Brucella abortus biovar 1 was isolated from several tissues in all moose, most notably from lymph nodes where counts often exceeded 4 x 10(4) colony forming units per g of tissue. Thus infection with B. abortus will kill moose, and progression of the disease is likely rapid under field conditions. Moose appear to be a dead-end host for brucellosis.

Agglutination Tests↗
PubMed1992

Technical considerations in 113 percutaneous cholecystolithotomies.

Percutaneous cholecystolithotomy (PCCL) was considered appropriate on the basis of clinical and ultrasound criteria in 220 of 283 patients referred with symptomatic cholecystolithiasis. Contraindications to PCCL were a small, shrunken, thick-walled gallbladder or an intrahepatic gallbladder. PCCL was performed in 113 patients (80 women, 33 men; mean age, 56 years). Local anesthesia was used in 10 patients; general anesthesia, in 103 patients. The average procedure time was 1 hour. Complete stone clearance was achieved in 100 patients. PCCL was successful in 107 patients; in 77 of these, it was completed in a single stage. Six technical failures occurred, and seven patients had persistent cystic duct stones. Acute, nonfatal complications occurred in 15 patients and were managed conservatively. In 12 of 13 patients with stones impacted in the Hartmann pouch, patency of the cystic duct was restored. It is concluded that PCCL is a safe, effective procedure for clearing the gallbladder of calculi regardless of their size, composition, or number. It preserves the gallbladder, enables possible restoration of contractility, and can be performed without general anesthesia.

Cholangiography↗
PubMed1987

Role of immunoblotting in the diagnosis of culture negative and enterococcal endocarditis.

Serum samples from patients with endocarditis and septicaemia due to Enterococcus faecalis, Enterococcus faecium, Streptococcus bovis, and Streptococcus sanguis were immunoblotted against antigenic extracts from all four species. In E faecalis endocarditis there was a strong IgM response to E faecalis antigenic bands of 112, 88-90, and 45-47 Kd and a strong IgG response to 88-90 and 45-47 Kd bands. In E faecium endocarditis there was a pronounced IgG response to an E faecium band of 82-90 Kd. For S bovis endocarditis, there was a strong IgG response to several components of S bovis including bands of 66, 58, 52 and 4 Kd. For S sanguis, there was a strong IgG response to bands of 80-82, 76, 60 and 45 Kd. These patterns of antibody production were absent in patients with uncomplicated septicaemia and in controls. The delineation of these patterns enabled confirmation of the final diagnosis in seven patients initially suspected of having culture negative endocarditis.

Antibodies, Bacterial↗
PubMed1978

Comparative clinical impact of endoscopic pancreatography, grey-scale ultrasonography, and computed tomography (EMI scanning) in pancreatic disease: preliminary report.

Grey-scale ultrasound scanning (US), computed tomography (CT), and endoscopic retrograde cholangiopancreatography (ERCP) were performed in a series of 50 patients with known or suspected pancreatic disease. The impact of the individual tests were assessed in the relevant clinical context. With a maximum of 100, the overall clinical impact score of ERCP (75) exceeded that of CT(63) and US (36). In patients with obscure pain, and in those with relapsing pancreatitis, a combination of US and ERCP provides good clinical guidance. Computed tomography scanning can currently be reserved for documentation of patients with a major mass lesion. None of the techniques can detect early pancreatic cancer, except of the papilla of Vater, where ERCP is diagnostic. Recommendations for future diagnostic strategies may alter as grey-scale ultrasonography and computed tomography develop, and, in any case, depend on many factors including local expertise, availability, and cost.

Adolescent↗