Extra-anatomic stent (EAS) as a salvage procedure for transplant ureteric stricture.

Ureteric stricture is the most common urological complication following renal transplantation. Management often involves endo-urological interventions and open surgery. The definitive treatment is surgical reconstruction to restore continuity. Where this is not possible or contra-indicated and a stent cannot be placed in the ureter, an extra-anatomic stent (EAS) could be used to bypass a complete ureteric obstruction. Using an existing nephrostomy tract, a percutaneous stent is placed in the kidney and is tunneled under the skin into the bladder establishing extra-anatomical urinary drainage. We report the use of a novel EAS system in a patient with transplant ureteric stricture when antegrade stent placement or surgical reconstruction was not possible.

Emergency department imaging protocol for suspected acute renal colic: re-evaluating our service.

OBJECTIVES: The objective of our study is to determine the positive rate for urolithiasis in male and female patients, and evaluate whether there has been any change at our institution in the use and outcome of unenhanced multidetector CT (CT KUB) performed in the emergency department (ER) for patients presenting with suspected acute renal colic. METHODS: A retrospective review of all 1357 consecutive cases between August 2007 and August 2009 admitted to the ER and investigated with CT KUB. RESULTS: The positive rate for urolithiasis was 47.5% and the rate of other significant findings was 10%. Female patients had a significantly lower positive rate than male patients (26.8% vs 61.6%, p<0.001). Urological intervention was required in 37% and these patients had a larger average stone size. In young female patients with a significantly sized ureteric calculus (>4 mm), the presence of hydronephrosis vs no hydronephrosis was 83% vs 17%, respectively. Among them, only three patients required ureteroscopy for stone removal. CONCLUSION: Contrary to other studies there has been no "indication creep" in the use of CT KUB at our institution. However, the young female patient presenting with suspected urolithiasis presents a particular diagnostic problem, and the significant percentage of negative examinations in females implies that an improvement in current practice is needed. The indiscriminate use of CT KUB in all female patients with flank pain should be avoided, and it is suggested that they should be initially evaluated with ultrasound to detect the presence of hydronephrosis.

Is the KUB radiograph redundant for investigating acute ureteric colic in the non-contrast enhanced computed tomography era?

AIM: To establish whether non-contrast enhanced computed tomography (NCCT) renders the kidneys-ureters-bladder (KUB) radiograph redundant as the initial imaging investigation for suspected acute ureteric colic. MATERIALS AND METHODS: The imaging investigations for 120 patients consecutively admitted to an emergency department-led clinical decisions unit (CDU) with suspected acute ureteric colic were retrospectively reviewed. A multidisciplinary meeting reviewed the findings and recommended that KUB radiographs should not be routinely performed prior to NCCT. Prospective assessment of 116 consecutive patients admitted over a comparable period was then undertaken. RESULTS: In the retrospective group, 61 (50.8%) patients had calculi to account for symptoms (positive NCCT) and 59 (49.2%) patients did not have stone disease (negative NCCT). Ninety (75%) patients had a KUB radiograph prior to NCCT. However, in 46 (38% of total) of these patients the NCCT was negative for stones, and therefore, they had been subjected to an unnecessary radiographic examination. These results prompted a change in practice. In the subsequent and prospectively studied group, preliminary KUB radiographs were performed in only 6% of the patients, with no significant change in the positive NCCT rate (50.8 versus 51.7%) or the total number of examinations performed (120 versus 116). CONCLUSION: NCCT should be the initial imaging examination for acute ureteric colic. Up to 50% of patients with clinical suspicion do not have stone disease, and therefore, preliminary KUB radiographs with attendant radiation and cost implications are unjustified. Preliminary KUB radiographs can be omitted from the imaging pathway with no resultant indication creep or increase in demand for NCCT examinations.

Unenhanced multidetector CT (CT KUB) in the initial imaging of suspected acute renal colic: evaluating a new service.

AIM: To evaluate a new imaging pathway for the investigation of patients presenting with suspected acute renal colic. MATERIALS AND METHODS: A retrospective review of 500 consecutive cases of suspected acute renal colic was undertaken to evaluate the initial results of a new imaging pathway introduced at our institution, which completely replaced the intravenous urogram (IVU) with unenhanced multidetector CT (CT KUB). RESULTS: The positive rate for urolithiasis was 44% (221/500), the negative rate 46% (229/500) and the rate of other significant findings was 12% (59/500). Female patients had a low positive rate compared with male patients (27.5 versus 57.5%; p<0.001). Urological intervention was required in 28% (61/221) and these patients had a larger average stone size (6.6 versus 3.7 mm; p<0.001) and the stone was located more proximally. Out-of-hours imaging was performed in 37% (186/500), and these patients had a higher positive rate (52 versus 40%; p<0.001). Other findings included a wide range of acute non-urological conditions. CONCLUSION: The feasibility of replacing the acute IVU with CT KUB in the initial assessment of suspected acute renal colic was demonstrated in the present study. The technique enables rapid diagnosis of urolithiasis, stratification of patients likely to proceed to urological intervention, and prompt diagnosis of a variety of other acute pathological conditions.

Ureteric complications of renal transplantation: the impact of the double J stent and the anterior extravesical ureteroneocystostomy.

The urological complications of renal transplantation are well documented. In 1990, our experience of 507 consecutive renal transplants using the Leadbetter-Politano technique, which was unsplinted in the vast majority of patients, had a ureteric complication rate of 7.7%. Here, we report the long-term incidence and management of our ureteric complications in 1186 consecutive renal transplants done over the following 11 years using an extravesical onlay stented ureteroneocystostomy. We report a considerable reduction in the urological complications of renal transplantation to 3.8%. Furthermore, we were able to use percutaneous radiological techniques to salvage the majority (84.7%) of ureteric complications. Recourse to surgery was required rarely but enabled salvage of all treatment failures.

Percutaneous nephrostomy insertion: outcome data from a prospective multi-operator study at a UK training centre.

AIM: To determine the success and complication rates of percutaneous nephrostomies (PCNs) performed at a UK training centre over a one-year period by different groups of operators. MATERIALS AND METHODS: During 2002, a total of 276 PCNs were performed in 190 patients by operators of varying experience. We employed two different techniques: (1) a "Seldinger" technique (ultrasound-guided puncture with a 19G sheathed needle followed by guide-wire insertion and track dilatation to accommodate 8-12F nephrostomy catheters), with or without fluoroscopic guidance, and (2) an ultrasound-guided "one-stab" technique using a 6F Bonanno catheter. Selection of technique was according to configuration of the collecting system and whether the procedure was performed out of hours. RESULTS: There were 218 procedures using the Seldinger technique and 62 using the one-stab technique. The Seldinger technique and one-stab technique were compared: primary technical success rate was 98 versus 93%, the major complication rate was 4.1 versus 3.2%, the minor complication rate was 5 versus 13%, and tube complications, such as drainage catheter dislodgement and blockage, were 29.5 versus 17.7%, respectively. The 30-day mortality was 4.3%, none of which were procedure related. CONCLUSION: Based on data from the USA, proposed targets for primary technical success rates are 88-99%, major complications 4-8%, and minor complications 3-15%, and the results were within these target ranges. The ultrasound-guided one-stab technique is a quick and safe procedure in selected cases, and we recommend this method for temporary urinary diversion in cases with moderate to severe degrees of pelvicalyceal system dilatation. These data may help to form a baseline for outcome targets in the UK.

Lower moiety pelvic-ureteric junction obstruction (PUJO) of the duplex kidney presenting with pyonephrosis in adults.

The most common congenital abnormality of the urinary tract is a duplex kidney. Pelvic-ureteric junction obstruction (PUJO) is a rare association that can affect the lower moiety of incomplete duplex kidneys. We report two adult cases of PUJO of the lower moiety in a duplex kidney that both presented with pyonephrosis. This late presentation of lower moiety PUJO with pyonephrosis has not been described previously. We describe the imaging appearances of this rare association and highlight this important diagnostic consideration in lower moiety hydronephrosis of the adult patient.

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.

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.

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.

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.

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.

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.

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.

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.

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.