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Biomedical subjects

H C Irving

Publications and source records attributed to H C Irving.

At least 19 recordsLinked to original sources

Extra-anatomic stents in ureteric obstruction: experience and complications.

OBJECTIVE: To assess the role of extra-anatomic stents (EAS) as a means of urinary diversion in patients with ureteric obstruction secondary to malignancy. PATIENTS AND METHODS: The technique for inserting EAS in patients with ureteric obstruction was described previously; to date, 13 patients (seven women and six men, mean age 45.3 years, range 22-78) have been treated. All patients had ultrasonographic evidence of hydronephrosis and/or significant biochemical evidence of renal impairment. Patients had advanced malignancy and one patient an abdominal aortic aneurysm. RESULTS: Urinary diversion was successful in all patients; two survived for more than 1 year, with stent changes at 6-monthly intervals. In three patients the stents were replaced by percutaneous nephrostomies because of problems with leakage or infection. The remaining patients died with functioning EAS in situ. CONCLUSIONS: In patients with ureteric obstruction secondary to malignancy or medical conditions excluding them from more invasive surgery, EAS provide a further therapeutic option instead of a permanent nephrostomy, which has associated inherent problems. This technique is not without potential problems and careful selection of patients remains vital in this difficult area.

Adult↗

Assessment of ultrasound guided percutaneous ethanol injection and parathyroidectomy in patients with tertiary hyperparathyroidism.

BACKGROUND: Tertiary hyperparathyroidism continues to cause significant morbidity in patients with chronic renal failure. This is frequently resistant to medical management and may ultimately require a surgical parathyroidectomy. Recent studies have reported upon the technique of percutaneous ethanol ablation for both primary and tertiary hyperparathyroidism. In this study we report on a 5 year experience using ethanol injection and compare the results with surgical parathyroidectomy. METHODS: A prospective study in 39 patients with tertiary hyperparathyroidism, 25 were dialysis dependent and 14 had a functioning renal allograft. Twenty-two patients underwent percutaneous fine needle ethanol injection (PFNEI) and 17 underwent surgical parathyroidectomy. RESULTS: A > 30% reduction in intact parathyroid hormone (iPTH) was achieved in 11 of 22 patients undergoing PFNEI after a mean of 1.8 +/- 1.4 injections per gland. In four patients, symptomatic hyperparathyroidism recurred and they required further PFNEI or surgical parathyroidectomy at 17, 28, 46, and 48 months later. There was no significant reduction in iPTH in 11 patients following PFNEI after a mean of 2.5 +/- 1.3 injections per gland. They all required a subsequent surgical parathyroidectomy for symptomatic hyperparathyroidism. Four patients developed a laryngeal nerve palsy following PFNEI, two of which were permanent. Seventeen patients underwent successful surgical parathyroidectomy as a primary procedure. CONCLUSION: Whilst PFNEI is successful in primary hyperparathyroidism, when typically only one adenoma is present, the effectiveness of PFNEI is unpredictable and the long term results are poor compared with those of surgical parathyroidectomy in tertiary hyperparathyroidism. The procedure is not without complications and makes subsequent surgery more difficult. Therefore it can only be recommended for patients with a known single parathyroid gland such as patients in whom hyperparathyroidism has recurred following a previous surgical subtotal parathyroidectomy and who are unsuitable for further surgery.

Administration, Cutaneous↗

Comparison of dynamic contrast enhanced MRI and Doppler ultrasound in the pre-operative assessment of the portal venous system.

The purpose of this study was to compare dynamic contrast enhanced MRI (DCEMR) with Doppler ultrasound (US) in the assessment of portal venous anatomy and to analyse the causes of discrepancy. Over a 1 year period, 97 patients undergoing assessment prior to hepatic surgery underwent imaging of the liver and portal venous system using US with colour and spectral Doppler and MRI with axial T2 weighted spin echo (SE) and coronal oblique T1 weighted rapid gradient echo (GRE) imaging before and immediately after bolus injection of Gd-DTPA (0.1 mmol kg-1). When the US and MRI findings were discrepant, the images were reviewed by two observers and compared with surgical findings. US and DCEMR were concordant in 90 patients (portal vein patent in 80, occluded in 10). In three patients with cirrhosis and gross ascites the portal vein was reported as occluded on US and patent on MRI; surgery confirmed the MRI findings. In one patient the portal vein was patient on US but not on MRI, but there was a 3 week interval between the examinations. In three patients the portal vein was patent on US, but MRI detected occlusion of intrahepatic portal vein branches in two, and encasement of an intrahepatic branch in the third case. Spontaneous splenorenal shunts were seen in 15 patients only on MRI; varices were seen in 39 patients on MRI and in 22 patients on US. Both US and DCEMR contribute to the pre-operative assessment of the portal venous system. MRI provides additional information over US in assessing intrahepatic portal branches and detecting varices and splenorenal shunts, and is recommended for all surgical candidates and in patients with abnormal portal venous anatomy and equivocal US findings.

Adolescent↗

The role of hepatobiliary scintigraphy in cystic fibrosis.

This was a prospective open study that examined the quantitative and qualitative analysis of hepatobiliary scintigraphy (DISIDA) in detecting liver involvement in cystic fibrosis (CF). Forty-four adult and pediatric patients (median age, 12.1 years; range, 1.1-36.3 years) were divided into three groups: group 1, no evidence of liver involvement (n = 8); group 2, biochemical evidence of liver involvement on two or more occasions (n = 26); and group 3, clinical evidence of liver disease (n = 10). In groups 1 and 2, the most common qualitative scintigraphic finding was focal intrahepatic retention of tracer (26/34 patients, 12 of whom had normal findings on ultrasonography). This finding corresponds to focal cholestasis and may warrant treatment with the choleretic agent ursodeoxycholic acid (UDCA). In the group 3 patients, the abnormal qualitative scintigraphic appearances (heterogeneous uptake of tracer and nodular liver outline) added little to the findings on ultrasonography; however, these patients had a prolonged mean hepatic clearance time compared with those in groups 1 and 2 (one-way ANOVA; P < .015). It is proposed that scintigraphy with DISIDA has a role in the detection of early liver involvement in cystic fibrosis.

Adolescent↗

Clinical significance of fetal choroid plexus cysts.

Choroid plexus (CP) cysts are commonly detected on routine mid-trimester ultrasound scan. When associated anomalies are detected, the risk is sufficient to justify an invasive diagnostic test such as amniocentesis. However, the risk when no associated anomalies are detected is much less well defined. This information is required to determine the appropriate management in cases of apparently isolated CP cysts. We thought the only way to resolve the difficulties in counselling prospective parents was to conduct a prospective study in a large unselected population. A registry of fetal CP cysts detected over 3 years in the Yorkshire Region was compiled and we identified 524 CP cysts. These cases were then amalgamated and analysed with 1361 cases from prospective studies reported in the world English literature and a further 71 unpublished cases identified from a 2 year prospective series from Ninewells Hospital, Dundee. The risk of chromosomal abnormalities was 1 in 150 (95% CI 1 in 85, 1 in 261) when no fetal anatomic abnormalities, apart from the CP cysts themselves, were detected antenatally. The risk increased to approximately 1 in 3 if any other associated ultrasound abnormalities were detected antenatally. The risk did not appear to be related to whether or not cyst size diminished as gestation progresses, whether they were unilateral or bilateral, and whether they were small or large in size (60-80% < 10 mm). 76% of aneuploidic cases were trisomy 18 and 17% were trisomy 21. The risk of Down's syndrome in fetuses with CP cysts but no other anomalies detected antenatally is 1 in 880. The probability of a chromosomal abnormality is high when CP cysts are associated with any other antenatally detected anomaly, indicating a clear need to offering amniocentesis. The predictive value is much lower when no other anomalies are detected. In such cases, it is probably advisable to regard CP cysts as an indication for detailed ultrasound assessment, rather than invasive testing.

Brain Diseases↗

Fetal pelvi-ureteric junction obstruction: predictors of outcome.

OBJECTIVE: To examine the relationship between pre-natal ultrasonographic findings typical of pelvi-ureteric junction (PUJ) obstruction and post-natal renal function in the affected kidney. PATIENTS AND METHODS: This retrospective study comprised 35 infants in whom pre-natal ultrasonography had identified a unilateral pattern of dilatation of the renal pelvis and calices typical of PUJ obstruction. In each case, the presence of unilateral hydronephrosis had been confirmed post-natally by ultrasonography, and differential function and drainage evaluated by isotope renography. The results of isotope renography were compared with the severity and timing of onset of the fetal hydronephrosis. RESULTS: Eleven kidneys (31%) appeared normal in the second trimester and dilatation only became apparent during the third trimester. Mean differential function in these kidneys was 48%. However, mean differential function was reduced (mean 38%) in those kidneys noted to be dilated between 16 and 24 weeks gestation. Differential function was loosely correlated with the severity of dilatation in early onset cases, i.e. the mean differential function was 42% for mild, 37% for moderate and 27% for severe dilatation. A considerable variation in differential function values was present in each group except for those with severe dilatation, which was a significant predictor of poor functional outcome when compared with mild and moderate dilatation combined (P < 0.01). CONCLUSION: Fetal PUJ obstruction is a heterogeneous condition permitting only broad predictions of functional outcome. Severe dilatation detected on second trimester imaging predicted significant loss of function. Mild and moderate degrees of dilatation were associated with a one in three risk of functional impairment in the obstructed kidney.

Dilatation, Pathologic↗

An audit of the role of the sonographer in non-obstetric ultrasound.

In order to investigate the role of the sonographer in non-obstetric ultrasound, 1046 consecutive non-obstetric ultrasound scans performed by sonographers were audited. In 94% of cases, the report prepared by the sonographer gave an accurate account of the findings. In 6.3% of reports the radiologist provided additional comments, whilst in only 0.7% of cases was the sonographer's report significantly altered. In the 630 patients in whom adequate follow-up data was available, there was a single instance of a false positive ultrasound finding but no other significant ultrasound inaccuracy. This audit indicates that the local arrangements for involving sonographers in a non-obstetric ultrasound service has resulted in agreed standards being met. It is suggested that sonographers can and should be involved more widely in the provision of non-obstetric ultrasound services.

England↗

Prenatally detected posterior urethral valves: is gestational age at detection a predictor of outcome?

Between 1982 and 1992, 67 boys with posterior urethral valves were managed at our hospital, including 32 (48%) in whom the condition was detected prenatally. We examined the relationship between gestational age at detection and outcome at a median followup of 3.9 years (range 4 months to 10 years). Detection at or before 24 weeks of gestation predicted a poor outcome with 9 of 17 patients (53%) dead or in chronic renal failure at followup. Of the cases detected later in pregnancy only 1 had a poor outcome (p = 0.01). All of the cases detected after 24 weeks of gestation had had normal second trimester scans. Growth parameters for boys in the early and late detection groups were not statistically different. However, there was a significant association between renal failure and growth with 67% versus 14% having heights less than the 3rd percentile (p = 0.05). Respiratory distress at birth predicted a poor outcome, while the presence of palpable abdominal abnormalities or vesicoureteral reflux failed to predict outcome.

Female↗

Ureteric rupture in an elderly patient following minor trauma: case report.

A 75-year-old woman arrived at our hospital 2 weeks after falling from a bus. She was shown to have a ruptured left ureter. After drainage of a urine collection and decompression of her obstructed kidney she recovered. To our knowledge ureteric rupture has not before been reported as a consequence of such minor trauma.

Accidental Falls↗

Mild dilatation of the fetal kidney: a follow-up study.

OBJECTIVE: To assess morbidity in children with mild prenatally detected pelvicalyceal dilatation and to document the natural history of this ultrasound finding in post-natal life. PATIENTS AND METHODS: A retrospective (on-going) study was carried out in 29 children (39 kidneys) with mild dilatation confined to the pelvis and/or calices confirmed on initial post-natal ultrasound scan. Re-evaluation was carried out at a mean age of 4.2 years (range 1.5-7.8). Clinically, each patient's history, height, weight and blood pressure were recorded. On ultrasound examination the renal length, collecting system appearances and dimensions were recorded. RESULTS: Vesico-ureteric reflux was demonstrated in 1 of 14 infants who underwent neonatal micturating cystourethrography. During cumulative follow-up totaling 122 years, there were only two documented episodes of urological morbidity, i.e. one episode of unexplained haematuria and one of urinary tract infection. By a mean age of 4.2 years the ultrasound appearances had reverted to normal in 69% of kidneys. In 31% dilatation persisted and was unchanged or diminished in severity. No case of increasing dilatation was seen. Renal growth was normal in 97% of kidneys. CONCLUSIONS: Mild dilatation of the fetal urinary tract is a common prenatal ultrasound finding. When confined to the renal pelvis and/or calices it is of doubtful clinical significance and is associated with a low level of morbidity in infancy and early childhood. Invasive investigation in post-natal life is not justified.

Child↗

Specificity of antenatal ultrasound in the Yorkshire Region: a prospective study of 2261 ultrasound detected anomalies.

OBJECTIVE: To evaluate the specificity of the ultrasound diagnosis of fetal anomalies. Pregnancies which proceeded to termination and ultrasound-diagnosed fetal anomalies which were not offered termination were considered. DESIGN: Prospective, region-wide study over three and a half years. SETTING: Cases were identified through 25 ultrasound departments representing the 15 districts in the Yorkshire Region. SUBJECTS: Pregnant women with an ultrasound-diagnosed fetal anomaly. MAIN OUTCOME MEASURES: Information obtained from the ultrasound report was compared with the outcomes determined by cytogenetics, postmortem or paediatric examination. RESULTS: Of 2261 pregnancies with an ultrasound-diagnosed fetal anomaly 369, (16%) were terminated and 357 (97%) were followed by postmortem examination. Ultrasound findings exactly matched those of the postmortem or were accompanied by additional anomalies in 325 cases (91%). In 32 cases ultrasound findings were not confirmed by postmortem, but in 30 of these the decision to offer termination remained justified because the correct diagnosis was judged equally or more serious. Two (0.5%) were terminated for an anomaly which subsequently proved less severe than predicted on ultrasound. Ultrasound significantly over- or under-diagnosed a major fetal anomaly in 27 of the 1139 (2.4%) cases in which an anomaly was detected, but the pregnancy was not terminated. CONCLUSION: Termination of pregnancy was based on the correct prognosis in over 99.5% of cases. This does not obviate the need for pathological examination of the fetus which changed or refined the diagnosis in 35% of cases.

Abortion, Induced↗

Reproducibility of Doppler ultrasound measurement of resistance index in renal allografts.

In recent years measurements of arterial blood flow in the renal allograft have been studied in an attempt to provide a non-invasive method of diagnosing and monitoring post-transplant renal dysfunction. Many studies have involved measurement of the resistance index (RI) of arterial blood flow. Although the reproducibility of the technique has been studied in other areas of application, no such studies have been performed on the renal allograft. In this study we attempted to evaluate the reproducibility of the measurement of the RI of the interlobar artery in the renal allograft. 18 renal allograft recipients with stable functioning grafts were studied twice by each of two experienced sonographers using a colour-coded duplex Doppler ultrasound scanner, in order to determine the intraobserver and interobserver variability in the measurement of RI of the interlobar arteries in the allograft. Variability was small and although interobserver variability exceeded intraobserver variability, both were within repeatability limits adopted by the British Standards Institution. The results suggest that measurement of the RI of the interlobar artery of renal allografts is repeatable and reproducible when performed by experienced operators.

Adult↗

Does the Whitaker test add to antegrade pyelography in the investigation of collecting system dilatation in renal allografts?

Significant pelvicalyceal dilatation in renal allografts is currently investigated by antegrade pyelography. However, the clinical significance of a radiologically demonstrated narrowing of the ureter is unclear. Over a 21-month period 26 of 155 renal allografts with pelvicalyceal dilatation were investigated by antegrade pyelography. In eight allografts no ureteric stenosis could be identified. Two grafts were shown to have ureteric necrosis and required surgical intervention and 16 of the other grafts appeared to have a ureteric stenosis. 15 of the 16 allografts with radiological ureteric stenosis underwent a concurrent pressure flow study to assess the functional relevance of the ureteric narrowing. As shown by a pressure rise of > 7 mmHg at a perfusion rate of 10 ml min-1, 11 of the 15 grafts were functionally obstructed and were treated by a nephrostomy catheter followed by antegrade insertion of a ureteric stent. The four grafts with a negative pressure flow study were subsequently shown on biopsy to have rejection. The diagnosis of allograft rejection was also confirmed by biopsy in seven of the eight allografts without a radiological ureteric stenosis. The last of the eight allografts was found to be cyclosporin toxic. Pelvicalyceal dilatation of renal allografts is appropriately investigated by antegrade pyelography in combination with a pressure flow study which identifies those grafts with mechanical obstruction.

Adult↗

Improving the evaluation of renal transplant collecting system dilatation by computerized ultrasound image digitization.

43% of the renal allografts transplanted at our centre demonstrate pelvicalyceal dilatation on ultrasonography. However, only 6% of grafts are ultimately shown to be obstructed by antegrade pyelography. We have attempted to improve the specificity of ultrasonography by a quantitative analysis of 394 serial ultrasound studies from 150 renal transplant recipients. Representative images in the longitudinal and transverse axes were selected by a single observer for each of the studies and the outline of the kidney and its pelvicalyceal system was traced out. The images were then digitized using a Summagraphics tablet so that the length, width and area of the kidney and its pelvicalyceal system were calculated for each image. A step-wise discriminant analysis was performed which showed that the ratio of the area of the kidney to its pelvicalyceal area in both axes discriminated between normal, dilated but non-obstructed, and obstructed grafts. The median ratio of kidney to collecting system area in the obstructed grafts was 5.2 in the longitudinal and 4.4 in the transverse scan planes (vs median ratios of 32.8 and 22.0 for non-dilated grafts). Using canonical discriminant function, an index was derived which combines these ratios for the longitudinal and transverse images of the same kidney and this has further improved the diagnostic accuracy (median index of 2.45 in obstructed group vs -0.85 in non-dilated kidneys). This method improves upon the radiologist's report and identifies those grafts which require intervention.

Adolescent↗

Complications of renal transplantation and the role of interventional radiology.

As rejection therapy has improved, the interventional complications of renal transplantation have increased in relative importance as potentially reversible causes of graft malfunction and failure. Ultrasonically guided aspiration and drainage techniques are essential for the characterization and subsequent management of perinephric fluid collections that occur in as many as 51% of cases, of which up to 18% may be clinically significant. In a series of 507 consecutive renal transplants, urological complications were seen in 9% of patients, consisting of ureteric obstruction in 6% and urinary leaks in 3%. Detection via ultrasound scanning, evaluation via antegrade pyelography and pressure-flow tests, and management via percutaneous nephrostomy and ureteric stenting all contribute to rapid diagnosis and subsequent treatment. Serial ultrasound scanning of renal transplants and the aggressive use of interventional radiological techniques are vital to the early detection and management of complications, and can lead to preservation of graft function and continued improvement in graft survival figures.

Graft Rejection↗