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Biomedical subjects

T Farrell

Publications and source records attributed to T Farrell.

At least 37 records · Page 2Linked to original sources
PubMed2000

Percutaneous treatment of portal venous stenosis in children and adolescents with segmental hepatic transplants: long-term results.

PURPOSE: To evaluate the long-term effectiveness of the percutaneous treatment of portal venous stenoses in children and adolescents with reduced-size hepatic transplants. MATERIALS AND METHODS: During the past 5 years, percutaneous transhepatic balloon venoplasty was attempted in 25 children and adolescents with anastomotic portal venous stenoses that occurred after reduced-size hepatic transplantation. All procedures were performed with direct puncture of the intrahepatic portal vein and with subsequent balloon dilation. Intravascular stents were deployed in patients with suboptimal results after dilation or with recurrent stenoses. RESULTS: Percutaneous venoplasty was technically successful in 19 of 25 patients. In the remaining six patients, portal venous occlusion precluded access to the extrahepatic portal vein. Intravascular stents were deployed in 12 patients for "elastic" (n = 5) or recurrent (n = 7) stenoses. Seven patients who underwent successful venoplasty without stent placement have required no further intervention. All stents have remained patent without further intervention. Portal venous patency has been maintained for 5-61 months (mean time, 46 months) in all 19 patients. CONCLUSION: Percutaneous treatment of portal venous stenoses is effective and long lasting in children with reduced-size hepatic transplants. In patients with elastic or recurrent lesions, portal venous stents have excellent long-term primary patency despite continued patient growth. Successful, percutaneous transhepatic venoplasty eliminates the need for surgical revision, portacaval shunting, or repeat transplantation.

Adolescent↗
PubMed1999

Sharp recanalization of central venous occlusions.

PURPOSE: To describe a sharp puncture technique for recanalization of chronic central venous occlusions that could not be traversed by a guide wire. MATERIALS AND METHODS: Five patients presented with six longstanding central venous occlusions that could not be traversed with a guide wire after thrombolysis. The occlusions occurred following radiation for lung carcinoma (n = 2) and indwelling venous catheters (n = 4). The length of venous occlusion was determined by simultaneously advancing transbrachial and transfemoral catheters to the site of occlusion. Initially, a curved guiding catheter with a Rosch-Uchida needle and, in subsequent patients, a coaxial sheathed needle with a 21-gauge stylet were used for recanalization. The recanalized veins were then balloon dilated and stents were placed. RESULTS: With use of this technique, recanalization was successful in five of the six occlusions. One occlusion was too long to traverse safely in one patient. Two patients were asymptomatic 16-18 months after the recanalization. CONCLUSION: This new technique offers an effective alternative to surgery in the treatment of central venous occlusion.

Aged↗
PubMed1999

Immunocytochemical characterization of catecholaminergic neurons in the rat striatum following dopamine-depleting lesions.

It is possible either permanently or transiently to deplete the rat striatum of dopamine. Following such depletions, striatal neurons immunoreactive for tyrosine hydroxylase (TH), aromatic L-amino acid decarboxylase (AADC) or dopamine appear. The presence of dopamine-producing neurons in the striatum has relevance for the treatment of Parkinson's disease, but whether these catecholaminergic phenotypes all produce dopamine is unclear. In the present study we establish that after unilateral 6-hydroxydopamine lesions or methamphetamine administration, striatal TH-immunoreactive neurons differ in size, morphology and location from those that are immunopositive for AADC or dopamine. The TH-positive cells which were localized either to ventral parts of the striatum or to the central and dorsal areas of the caudate-putamen generally have the morphological features of projection neurons, whereas those containing AADC or dopamine were confined to subcallosal positions in the dorsal medial quadrant of the caudate-putamen and resemble small, local-circuit neurons. The fact that AADC-immunoreactive neurons overlap in size, morphology and location with the cells that produce dopamine suggests strongly that this population is dopaminergic. However, the simultaneous appearance of neurons that contain the TH enzyme but clearly do not make dopamine raises questions about the functional role of these cells and the cellular mechanisms responsible for their induction following striatal dopamine loss.

Animals↗
PubMed1999

Intrapartum umbilical artery Doppler velocimetry as a predictor of adverse perinatal outcome: a systematic review.

OBJECTIVE: To evaluate the diagnostic prediction of intrapartum umbilical artery Doppler velocimetry for adverse perinatal outcomes using systematic quantitative overview of the available literature. DESIGN: Online searching of MEDLINE database (January 1966-September 1997), scanning of bibliography of known primary and review articles, review of recent journal issues and that from personal files. Study selection, assessment of study quality and data extraction were all performed in duplicate under masked conditions. PARTICIPANTS: 2700 women (unselected, low, high, and combined low and high obstetric risk populations) included in eight studies selected for meta-analyses. MAIN OUTCOME MEASURES: Likelihood ratios (LRs) for positive and negative test results were generated for the following outcome measures: Apgar scores < 7 at 1 and 5 minute following delivery, small for gestational age fetus; intrapartum fetal heart rate abnormality, umbilical arterial acidosis at delivery; and caesarean section for fetal distress. RESULTS: For Apgar score < 7 at 1 minute following delivery, the pooled LR was 2.5 (95% CI 1.7-3.7) for a positive test and 1.0 (95% CI 0.9-1.1) for a negative test result. A positive test predicted an Apgar score < 7 at 5 minute following delivery with a pooled LR of 1.3 (95% CI 0.4-4.1) while a negative test had a pooled LR of 1.0 (95% CI 0.8-1.2). For the prediction of a small for gestational age fetus, the pooled LR was 3.4 (95% CI 2.3-5.1) for a positive test and 0.9 (95% CI 0.8-1.0) for a negative test. The prediction for fetal heart rate abnormality during labour was similarly disappointing: the pooled LR for a positive test result was 1.4 (95% CI 0.9-1.2) whereas a negative test result generated a pooled LR of 0.9 (95% CI 0.9-1.0). With umbilical acidosis at delivery, the pooled LR was 1.6 (95% CI 1.1-2.5) for a positive test and 1.1 (95% CI 1.0-1.2) for a negative test. The LRs for the prediction of caesarean section for fetal distress were 4.1 (95% CI 2.7-6.2) for a positive test result and 0.9 (95% CI 0.8-1.0) for a negative test result. CONCLUSION: Intrapartum umbilical artery Doppler velocimetry is a poor predictor of adverse perinatal outcomes.

Blood Flow Velocity↗
PubMed1999

Treatment of venous outflow stenoses in thigh grafts with Wallstents.

OBJECTIVE: We studied the effectiveness of Wallstent deployment to treat elastic femoral and iliac vein stenoses in patients with lower extremity hemodialysis grafts. MATERIALS AND METHODS: Between August 31, 1992, and October 13, 1997, 44 metallic stents were deployed in 20 patients to treat stenoses exhibiting immediate, significant elastic recoil after angioplasty. Twenty-four stents were placed in the femoral and saphenous veins, and the remaining 20 stents were placed in the iliac veins. Follow-up was provided by the nephrology and surgical service at our institution and by electronic review of patients' charts. The follow-up period was from August 31, 1992, until October 1, 1998. RESULTS: Stents were successfully inserted and stenotic lesions dilated in 100% of procedures. Each patient successfully completed at least one session of dialysis after the procedure. The primary patency rate of stents was 87% 60 days after the procedure, 51% 180 days after, 39% 1 year after, and 20% 2 years after. The secondary patency rate was 95% 60 days after the procedure, 92% 180 days after, 81% 1 year after, and 62% 2 years after. Complications were limited to two graft infections that developed 5 and 7 days after stent placement. CONCLUSION: Treatment of elastic venous stenoses is effective in patients with lower extremity dialysis grafts using metallic stents. The patency rates of these devices placed in the iliac and femoral veins are comparable with those of metallic stents placed in upper extremity and central veins.

Adolescent↗
PubMed1999

The significance of an 'insufficient' Pipelle sample in the investigation of post-menopausal bleeding.

BACKGROUND: Out-patient endometrial sampling is a commonly performed procedure in the investigation of post-menopausal bleeding. We hypothesized that an 'insufficient' Pipelle sample reliably reflected the absence of serious endometrial pathology. METHODS AND RESULTS: A review of 141 consecutive cases reported as 'insufficient' for diagnostic purposes revealed 29 (20%) cases to have uterine pathology after secondary investigation. These included two cases of endometrial carcinoma and two other cases of uterine malignancy. CONCLUSION: These results do not support the initial hypothesis and suggest that in women presenting with post-menopausal bleeding, an 'insufficient' sample is an indication for further investigation.

Biopsy↗
PubMed1998

Randomised trial of management of hypertensive pregnancies by Korotkoff phase IV or phase V.

BACKGROUND: There is debate about whether diastolic blood pressure should be recorded as the fourth (muffling, K4) or fifth (disappearance, K5) Korotkoff sound in pregnancy. We compared maternal and fetal outcomes and the likelihood that episodes of severe hypertension would be recorded when hypertensive pregnancies were managed according to either K4 or K5. METHODS: 220 pregnant women with diastolic hypertension (K4 > or =90 mm Hg) after the 20th week of gestation were enrolled in a prospective randomised study at two obstetric units in Australia; they were randomly assigned management with K4 (n=103) or K5 (n=117) for the remainder of the pregnancy. Clinical management was according to a uniform department protocol. Analysis was by intention to treat. All the women completed the trial. FINDINGS: An episode of severe hypertension (systolic > or =170 mm Hg, diastolic > or =110 mm Hg, or both) was more likely to be recorded with use of K4 than with use of K5 (39 [38%] vs 30 [26%] women, p=0.051), mainly because of a greater likelihood that severe diastolic hypertension would be recorded (34 [33%] vs 20 [17%], p=0.006). The frequency of severe systolic hypertension and simultaneous severe systolic and diastolic hypertension did not differ between groups. Pregnancy was prolonged by an average of 2 weeks in both groups, and there were no significant differences between the groups in laboratory data, requirements for antihypertensive treatment, birthweight, fetal growth retardation, or perinatal mortality. There was no eclampsia or significant maternal morbidity in either group. INTERPRETATION: A change from use of K4 to K5 would mean that one fewer case of severe diastolic hypertension would be recorded for every six hypertensive pregnancies, but all other episodes of severe hypertension would be recorded with similar frequency. Since the K4/K5 difference is smaller in hypertensive than in normotensive pregnant women and since K5 is closer to the actual intra-arterial pressure and more reliably detected, universal adoption of K5 to record diastolic blood pressure in hypertensive pregnancy should be considered.

Blood Pressure Determination↗
PubMed1998

The reliability of the detection of an early diastolic notch with uterine artery Doppler velocimetry.

This study evaluates the ability of two reviewers to detect independently an early diastolic notch in 1371 uterine artery Doppler velocity waveform recordings. Agreement between the two reviewers for the detection of uterine artery notching was assessed by using the Kappa statistic. The inter-rater reliability for the detection of unilateral notching was 0.75 (95% CI 0.70-0.80), whereas that for the presence or absence of bilateral notching was 0.66 (95% CI 0.60-0.71). The results suggest that there was good reviewer agreement for the presence or absence of a notch on uterine artery Doppler velocimetry.

Arteries↗
PubMed1998

Evaluation of fetal movements as an early labour admission test in low-risk pregnancies.

Fetal movements were quantified in 182 low-risk women in early labour using the Hewlett-Packard M1350A (Boblingen, Germany) fetal heart rate monitor. There were no statistically significant differences in adverse intrapartum or neonatal outcomes detected by the fetal heart rate pattern or fetal movement profile. This study confirms the feasibility of obtaining, a measure of fetal movement in early labour but does not support its use as an admission test in low-risk pregnancies.

Cardiotocography↗
PubMed1997

A prospective evaluation of the value of intrapartum biophysical and Doppler parameters in identifying the potentially compromised fetus.

This study was designed to evaluate the use of the biophysical profile and umbilical arterial Doppler in early labour in identifying the potentially compromised fetus. Two hundred and forty-two women attending the labour suite in early labour were studied. One hundred and fifty-one were in spontaneous labour and the remaining 91 had labour induced. All women had intrapartum biophysical profile assessment and umbilical arterial Doppler performed. Umbilical arterial Doppler and fetal movements were variously identified as being independently and significantly associated with adverse perinatal outcomes. Positive predictive values for adverse outcomes were however poor. Umbilical arterial Doppler used individually or in combination with clinical risk, gave no advantage over the use of clinically assigned risk alone in identifying fetuses at risk of subsequent adverse outcome. The assignment of clinical risk on admission in labour remains the most predictive 'test' for identifying the fetus at risk of subsequent adverse outcome. The routine addition of intrapartum biophysical parameters and umbilical arterial Doppler as methods of assessment is not justified.

Journal Article↗
PubMed1997

Improved methods of assessing proteinuria in hypertensive pregnancy.

OBJECTIVE: To determine whether use of an automated urinalysis device will improve the accuracy of detecting proteinuria, and whether spot urine protein to creatinine ratio will provide accurate quantitation of proteinuria in hypertensive pregnant women. DESIGN: Prospective studies assessing the accuracy of both detection and quantitation of proteinuria. SETTING: Antenatal ward and pregnancy day assessment unit of St George Hospital, a teaching hospital in Sydney, Australia. POPULATION: Hypertensive pregnant women admitted to hospital or day assessment unit for management of their hypertensive disorders. METHODS: 1. Routine dipstick urinalysis and 2. urinalysis by an automated device (Clinitek 100 Ames) on a midstream urine sample were compared with measurement of protein concentration on that sample (n = 103). In a third study, the protein:creatinine ratio on a midstream (spot) urine sample was compared with protein excretion over the subsequent 24 hours (n = 100). MAIN OUTCOME MEASURES: Relations between urine protein concentrations and 1. dipstick urinalysis and 2. automated urinalysis; 3. Positive and negative predictive values of spot protein:creatinine ratio for true proteinuria (> or = 300 mg/day). RESULTS: Automated urinalysis improved the percentage of true positive urinalyses from 48% with visual urinalysis to 74% (P = 0.02). True negatives were 98% to 100% for both methods. Spot urine protein:creatinine ratio correlated well with subsequent 24-hour urine proteinuria (r = 0.93, P < 0.001). A protein:creatinine ratio > 30 mg protein/mmol creatinine was the optimum discriminant value for true proteinuria, with sensitivity 93%, specificity 92%, positive predictive value 95% and negative predictive value 90%. CONCLUSIONS: Use of an automated urinalysis device improved accurate detection of proteinuria, particularly reducing false positive tests. A random urine protein:creatinine ratio provides an accurate and rapid quantitation of proteinuria in hypertensive pregnant women. This should improve clinical care, especially when managing hypertensive pregnant women as outpatients.

Creatinine↗
PubMed1997

Fetal size and growth velocity in the prediction of intrapartum caesarean section for fetal distress.

OBJECTIVE: To evaluate and compare third trimester ultrasound measurements of fetal size and growth velocity in the prediction of intrapartum operative delivery for fetal distress and admission to the special care baby unit in a low risk antenatal population undergoing labour at term. DESIGN: Retrospective analysis of prospectively collected ultrasound data. SETTING: Ninewells Hospital, Dundee, Scotland. POPULATION: Three hundred and ninety-eight women previously enrolled in a longitudinal study of intrauterine volume undergoing labour at a gestational age of > 37 weeks. METHOD: Fetal abdominal area (FAA) standard deviation scores (Z scores) were calculated for size at 32 and 36 weeks of gestation together with the growth velocity Z scores between these two gestational ages. Receiver-operator characteristics were calculated for fetal abdominal area Z scores at 32, 36 weeks and velocity Z scores in the prediction of caesarean section for fetal distress and/or admission to the special care baby unit. MAIN OUTCOME MEASURES: Intrapartum caesarean section for fetal distress and admission to the special care baby unit with a diagnosis of perinatal hypoxia. RESULTS: Pregnancies ending in caesarean section for fetal distress or admission to the special care baby unit (n = 17) had significantly lower fetal abdominal area Z scores at 36 weeks of gestation (mean Z score -0.71 vs -0.18) and lower fetal abdominal area growth velocity (mean Z score - 1.31 vs -0.01). Taking a cutoff Z score of -1.2 derived from the receiver-operator characteristic curve, fetal abdominal area velocity has a sensitivity of 65% and specificity 75% for caesarean section for fetal distress and/or admission to the special care baby unit. CONCLUSION: Growth velocity of the fetal abdominal area in the third trimester is superior to a single measurement of the fetal abdominal area at either a mean of 32 or 36 weeks of gestation in the prediction of caesarean section for fetal distress and admission to the special care baby unit in low-risk women labouring at term. These results support the hypothesis that in the third trimester at least, growth rate in utero is more relevant to intrapartum performance and immediate perinatal outcome than estimates of fetal size alone.

Adult↗
PubMed1996

Improved intrapartum surveillance with PR interval analysis of the fetal electrocardiogram: a randomized trial showing a reduction in fetal blood sampling.

OBJECTIVE: Our goal was to test the hypothesis that the addition of fetal electrocardiogram time-interval analysis to conventional electronic fetal monitoring would significantly reduce the number of cases requiring fetal scalp blood sampling without an increase in adverse outcome. STUDY DESIGN: A randomized prospective trial was performed in 214 women with high-risk labor. RESULTS: There was a significant reduction in the number of cases that had fetal blood sampling performed in the fetal electrocardiogram plus electronic fetal monitoring group (risk ratio for electronic fetal monitoring alone 3.53; p < 0.01, 95% confidence interval 1.39 to 8.95). The fetal blood samplings performed in the electronic fetal monitoring alone group were less likely to be abnormal (pH < 7.25, base excess < -8.0) than those performed in the fetal electrocardiogram plus electronic fetal monitoring group (risk ratio for electronic fetal monitoring alone 0.62, p = 0.05, 95% confidence interval 0.35 to 1.10). There was a trend of more infants with an arterial umbilical pH < 7.15 and a base excess less than -8.0 mmol/L at birth being unsuspected and more instrumental deliveries for presumed fetal distress being performed in the electronic fetal monitoring alone than in the fetal electrocardiogram plus electronic fetal monitoring group. CONCLUSION: The addition of fetal electrocardiogram analysis to conventional electronic fetal monitoring during labor can reduce significantly the number of parturients undergoing fetal scalp blood sampling and can simultaneously increase its efficiency without an increase in adverse outcome.

Acidosis↗
PubMed1996

Fetal movements following intrapartum maternal opiate administration.

Fetal movements were quantified prior to and after administration of intramuscular Diamorphine in thirteen labouring women. A significant reduction in the number of fetal heart rate accelerations was observed following Diamorphine. Thirty minutes after Diamorphine, all fetal movement parameters had returned to pre-Diamorphine values. If fetal movement detection is to be incorporated into an assessment of intrapartum fetal well being, the transient influence of narcotic analgesia must be allowed for.

Analgesia, Obstetrical↗