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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

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

Use of 99mtechnetium-dimercaptosuccinic acid to study patterns of renal damage associated with prenatally detected vesicoureteral reflux.

Static isotope imaging with 99mtechnetium-dimercaptosuccinic acid was performed at a mean age of 34 days in 32 children (50 kidneys) whose vesicoureteral reflux had been identified as a result of prenatal ultrasound scanning. Three patterns of isotope uptake were observed: 1) noninfected primary vesicoureteral reflux (15 children, 24 kidneys), 2) noninfected secondary (obstructed) vesicoureteral reflux (9 patients, 11 kidneys) and 3) infected primary reflux (8 infants, 15 kidneys). In 20 pattern 1 kidneys (83%) renal morphology and differential isotope were normal. In the 4 kidneys (17%) that showed evidence of impaired function this took the form of global parenchymal loss, that is small kidneys rather than focal scarring. In pattern 2 the combination of fetal vesicoureteral reflux and obstruction was a potent cause of renal damage with total or near total loss of function in 7 of 9 refluxing units associated with posterior urethral valves and in 2 kidneys with secondary ureteropelvic junction obstruction. Appearances of focal scarring were confined in pattern 3 and were found in 4 kidneys (27%). This overall incidence of detectable renal damage was lower than expected. Even when infection occurs, prenatal diagnosis may lessen the risk of scarring by enabling treatment to be instituted promptly. The findings suggest that uncomplicated primary vesicoureteral reflux is a relatively benign insult to the fetal kidney and that reflux nephropathy found in children presenting clinically is the result of infected vesicoureteral reflux in postnatal life. Any comparison of published studies will prove difficult until there is a more standardized approach to imaging technique and patient selection.

Female

Ureteric complications of renal transplantation.

Of 507 consecutive recipients of renal allografts, 45 developed a urological complication. In 39 patients (7.7%) ureteric problems were implicated and these comprised 30 cases of obstruction and 9 cases of ureteric necrosis presenting as urinary leakage. In 7 patients ureteric obstruction resolved following a period of nephrostomy decompression; 10 patients were reconstructed surgically and this was successful in 8, with 2 patients requiring further surgical procedures. Ten patients were successfully treated by percutaneous stenting after dilatation of the stricture. Stenting failed in 4 patients and in 1 patient caused rupture of a calix. All 10 stents have now been removed and there is no recurrence of stricture (follow-up 32.0 +/- 8.6 months). Of the remaining 3 grafts, 2 were removed and the other graft had percutaneous removal of a ureteric calculus. The 1-year survival rate of allografts in the ureteric complication group was 84.6%; in the recipients without a urological complication it was 81%. It was concluded that an active approach to ureteric problems following renal transplantation results in the rescue of the majority of allografts.

Adolescent

A tale of two prior probabilities--avoiding the false positive antenatal diagnosis of autosomal recessive polycystic kidney disease.

We describe a case in which the typical ultrasound diagnosis of infantile polycystic kidney in a woman with no family history of renal disease was not confirmed by histology following termination of the pregnancy. This is contrasted with the situation in another couple who were known carriers of autosomal recessive polycystic kidney disease and where the prenatal ultrasound diagnosis was confirmed histologically. When prior genetic risk is low, the possibility of a normal or less severe outcome must be discussed with parents when fetal ultrasound shows large, echogenic kidneys but normal amniotic fluid volume.

Diagnostic Errors

Intrarenal Doppler ultrasound studies in normal and acutely obstructed kidneys.

Renal ultrasound examinations and intrarenal arterial Doppler studies were performed on 48 patients with normal renal tracts and 20 patients presenting with acute renal colic resulting from ureteric calculus, 14 of whom had urographic evidence of renal obstruction. The mean resistance index (RI) of the Doppler waveforms obtained on the 14 obstructed kidneys (70.4 +/- 6.22) was significantly higher than the mean RI of the 96 normal kidneys (62.4 +/- 6.43). The mean difference between the RIs of the obstructed kidneys and their contralateral non-obstructed kidneys (8.37 +/- 4.43) was also significantly higher than the differences in RI seen between pairs of normal kidneys (2.70 +/- 1.71). Five out of 14 obstructed kidneys showed no pelvicalyceal dilatation and could not have been shown to be obstructed on conventional sonography. Four of these five had RI changes suggestive of obstruction and thus 13 of 14 obstructed kidneys would have been identified as obstructed by a combination of Doppler and conventional sonographic findings. 10 of the 14 obstructed kidneys were re-examined after passage of a urinary calculus and nine showed a reduction in the RI of the previously obstructed kidneys. The 10th subsequently required ureterolithotomy.

Acute Disease

Inability of color and spectral Doppler to identify fetal renal obstruction.

Color flow Doppler imaging was used to obtain fetal renal artery flow velocity waveforms in 130 normal fetuses at various gestational ages to build a database for the establishment of normal ranges for the Pulsatility Index in the fetal renal arteries throughout pregnancy. Twenty-nine cases of fetal renal tract dilation (greater than 5 mm anteroposterior diameter of the renal pelvis) of various causes were investigated. We found that measurements of the pulsatility index were not significantly altered from the normal range, so that color flow Doppler does not appear to be helpful in the differential diagnosis of fetal renal dilation.

Blood Flow Velocity

Early computed colour echo Doppler imaging following renal transplantation.

Thirty patients with renal allografts were monitored for 15 postoperative days by colour-coded Doppler imaging and categorized as stable, rejection, acute tubular necrosis and cyclosporine toxicity. All forms of graft dysfunction showed significantly raised resistance (P less than 0.01) and pulsatility (P less than 0.01) indices (RI and PI, respectively). It was not possible to use Doppler imaging to differentiate the cause of graft dysfunction, but stable grafts in patients with high cyclosporin levels had significantly higher RI (P less than 0.04) and PI (P less than 0.04) than similar grafts in patients with cyclosporine levels in the therapeutic range.

Adolescent

Ultrasonography of renal allografts: collecting system dilatation and its clinical significance.

Reports and ultrasound scans (658 studies) of 135 renal allografts, transplanted in the years 1987 and 1988, have been reviewed. Records of the recipients were also studied in order to determine the clinical status of the kidney at the time of each ultrasound examination and to obtain long-term follow-up of allograft function. Seventy-seven allografts (57%) never showed pelvicalyceal dilatation on 342 serial examinations. Forty-two kidneys (31%) had mild dilatation reported on at least one scan, which did not progress. However, 11 mildly dilated allografts developed moderate to severe dilatation on later examinations and these, together with 5 allografts reported as exhibiting moderate to severe hydronephrosis on their first dilated scan, were classed as moderate to severe (n = 16 = 12%). Thirty-eight patients (90%) with mild dilatation of the collecting system had no evidence of obstruction. However, in allografts with moderate to severe dilatation and poor or deteriorating function, ten patients (70%) were found to have ureteric obstruction. There was no significant difference in 1-year graft survival (87% versus 81.8%) and the median serum creatinine at 3 and 12 months after transplantation between non obstructed 'dilated' and non-dilated allografts (149 mumol/l versus 153.7 mumol/l; 139 mumol/l versus 147.3 mumol/l). All 14 obstructed allografts were salvaged with a graft survival of 85.7% at 1 year. Median serum creatine in these patients was significantly elevated at 200 mumol/l and 189 mumol/l at 3 and 12 months; P = 0.05 and 0.01 compared to dilated non-obstructed allografts. Our results indicate that grafts with moderate to severe dilatation should be urgently investigated to minimise further allograft damage.

Adult

Antenatally detected pelviureteric junction obstruction. Is non-operation safe?

We report follow-up data (minimum of 1 year) on 63 kidneys with antenatally detected pelviureteric junction obstruction, as defined by renographic criteria. The condition was bilateral in 10 patients (i.e. 20 kidneys), 2 patients had unilateral obstruction with contralateral multicystic dysplastic kidneys, and 41 patients had unilateral obstruction with a normal contralateral kidney. In the latter group, 29 (71%) had good function (greater than 40%) at initial assessment. Of the 63 kidneys, 24 (38%) were operated upon following initial assessment, mainly for impaired function. Of 39 patients, initially managed non-operatively, 8 (21%) were operated upon subsequently: 3 for deteriorating function (2 of whom have been reassessed and both have regained their lost function) and 5 for other renographic or ultrasonic indications). Of the original 63 kidneys, 31 (49%) continue to be managed non-operatively; 16 of these (52%) show improving ultrasound appearances, 8 of 17 studied show improved drainage, and all unilateral cases have stable good function. It is concluded that non-operative management of selected cases of antenatally detected pelviureteric junction obstruction is safe.

Female

Prenatally diagnosed reflux: a follow-up study.

This report analyses the characteristics and outcome of 25 infants with vesicoureteric reflux detected prenatally on the basis of dilatation of the fetal urinary tract. Sixteen infants had bilateral reflux--a total of 41 refluxing units. The high proportion of males (84%) contrasts with clinically presenting reflux, which is dominated by females. Prenatally diagnosed reflux is generally of a higher grade--usually grade IV. Eight children (32%) had coexistent congenital abnormalities. Chemoprophylaxis was completely effective in 17 children (68%), who remained infection-free; 3 children (12%) had a single urinary infection and were managed conservatively whilst 5 (20%) experienced 2 or more infections and required reimplantation or vesicostomy. Spontaneous cessation of reflux was observed in 6 (35%) of 17 refluxing ureters reassessed after a mean interval of 2.1 years. The significance of isotope findings was sometimes difficult to assess but results in 30 refluxing units support the concept that focal renal scarring is usually a consequence of infected reflux in postnatal life.

Female

Fetal choroid plexus cysts: a report of 100 cases.

A prospective study was undertaken to evaluate the prevalence and significance of fetal choroid plexus cysts detected on screening ultrasound (US) scans. One hundred cases of fetal choroid plexus cysts were detected from 11,700 examinations: There were 95 healthy newborns, three newborns with trisomy 18, one newborn with syndactyly of the toes, and one intrauterine death. In the three neonates with trisomy 18 the cysts were large (greater than 1 cm in diameter), and additional abnormalities were detected. Although there is a clear association between fetal choroid plexus cysts and trisomy 18, amniocentesis or chorionic villus sampling should be reserved for high-risk patients with either large cysts or US evidence of other abnormalities.

Brain Diseases

Bilateral fetal uropathy: what is the outlook?

OBJECTIVE: To assess the morbidity and mortality associated with a prenatal diagnosis of bilateral fetal uropathy. DESIGN: Retrospective study. SETTING: Departments of radiology, paediatric surgery, obstetrics, and pathology in two teaching hospitals that serve as referral centres for the Yorkshire region. PATIENTS: 126 Cases of fetal uropathy were referred either prenatally or postnatally from hospitals in Yorkshire between August 1982 and December 1987. The disease was bilateral in 54 cases and unilateral in 72 cases. In 14 cases bilateral fetal uropathy was associated with coexistent disease. INTERVENTIONS: All cases were managed individually by an obstetrician after discussion with the radiologists and paediatric surgeons. Babies who survived were treated prophylactically with antibiotics after delivery and were operated on if appropriate. END POINT: Assessment of prognosis for long term renal function for each baby referred between August 1982 and December 1987: follow up ranged from six months to five years. MEASUREMENTS AND MAIN RESULTS: Of the 54 fetuses with bilateral fetal uropathy, 13 were terminated as the prenatal findings of ultrasonography were considered to be incompatible with long term survival. Ten of the liveborn babies died, five of renal or pulmonary insufficiency, or both, and five of associated congenital anomalies. Thirty one infants survived to follow up; four of these had serious coexistent disease and two had impaired renal function. Thus the overall mortality was 43% and the morbidity rate 19%. The renal anomaly was associated with other serious disease in 14 cases (26%) compared with two (3%) of the 72 cases of unilateral fetal uropathy. All but two of the 27 infants with isolated bilateral urinary tract disease had excellent prospects for survival. CONCLUSION: Although bilateral fetal uropathy is associated with a high morbidity rate and mortality, careful prenatal assessment can help to identify fetuses with a poor prognosis. The outlook for a fetus with isolated renal disease if treated promptly after delivery is excellent and compares favourably with that reported after prenatal surgical intervention.

Abnormalities, Multiple

A prospective study of the incidence and significance of fetal choroid plexus cysts.

Cysts of the choroid plexus of the lateral ventricle can be detected in the fetus during routine scanning at 16-18 weeks' gestation with an approximate incident of one in every 120 pregnancies. It is likely that in a high percentage of cases cysts are bilateral and that their recent discovery is mainly due to improvements in imaging technology. Although the great majority of cases resolve and do not result in any morbidity, five cases of trisomy 18 and one case of trisomy 21 associated with fetal choroid plexus cysts have been reported. In this prospective study, choroid plexus cysts were detected in 42 fetuses, resulting in 40 normal infants and 2 cases of trisomy 18. It is concluded that there may be a relationship between fetal choroid plexus cysts and trisomy 18. In order to obtain a more precise and accurate result, a multi-centre prospective study is being organized.

Brain Diseases

Multicystic dysplastic kidney: is nephrectomy still appropriate?

We analyzed 25 cases of multicystic kidney to assess the impact of prenatal diagnosis on the management of this condition. The incidence of unilateral multicystic kidney was 1 in 4,300 live births. Of the 23 children with unilateral multicystic kidneys only 3 (13 per cent) had a readily palpable lesion. These findings suggest that multicystic kidney is a more common renal anomaly than was previously recognized and that the majority of cases remained undiagnosed before the advent of prenatal diagnosis. Ultrasound re-evaluation in 11 children suggests that the natural history of multicystic kidneys is towards spontaneous involution. Two kidneys were not identifiable by followup ultrasound. Hypertension and malignancy complicating multicystic kidney are reported infrequently. The literature on hypertension does not generally support the view that multicystic kidney poses a significant risk of hypertension in later childhood or adult life. We believe that the routine removal of multicystic kidneys in infancy is no longer appropriate.

Evaluation Studies as Topic