Library

Notes: SUMMARY: Renovascular hypertension may be caused by atherosclerotic disease or less commonly by fibromuscular dysplasia (FMD) of the renal arteries. Fibromuscular dysplasia is the commonest cause of renal artery stenosis in the younger age group and affects women predominantly. A review of our clinical database identified all patients with renovascular hypertension. All relevant clinical, biochemical and radiological findings on those with FMD were noted. the outcome of percutaneous transluminal renal angioplasty (PTRA) or reconstructive surgery was evaluated. Eight out of 62 (13%) patients with hypertension secondary to renovascular disease had FMD (all female; bilateral in four; mean age at diagnosis 37.6 years; age range 12–70 years). the mean duration of hypertension before the diagnosis of FMD was 3.3 years (range 3 months-10 years). A renal artery bruit was detected in five, hypertensive retinopathy in three and one had mild renal insufficiency. Twelve PTRAs were attempted on 10 stenotic lesions in six women. This cured the hypertension in three, while the other three have required less antihypertensive therapy. Percutaneous transluminal renal angioplasty was complicated by a trivial renal artery dissection in one, and a small upper pole infarction in another. One patient required a repeat PTRA. the other two women presented before the availability of PTRA and had successful reconstructive surgery. Fibromuscular dysplasia was the cause of hypertension in eight out of 62 (13%) patients with renovascular hypertension. Percutaneous transluminal renal angioplasty has shown encouraging results with a low complication rate. If technically feasible, PTRA should be attempted on all patients with FMD of the renal artery.

Notes: Summary: Percutaneous renal biopsy, an essential procedure for the evaluation of a patient with renal disease, has been improved by the use of semi-automated, spring-loaded renal biopsy guns. We have carried out a prospective, randomized study comparing the safety and tissue adequacy for histopathological diagnosis of renal biopsies performed under real-time ultrasound guidance using the Biopty gun (Bard, Covington, GA, USA) and a 14 or 18 gauge needle on 103 native and 30 transplant kidneys. Repeat biopsy was necessary for only one renal transplant (0.75%) because of inadequate tissue. the biopsy procedure was well tolerated and complications (〈5%) were uncommon in both groups. Biopsies of native kidneys with the 14 gauge needle required fewer attempts (3.23 vs 3.98; P= 0.005) and the cores obtained contained more glomeruli for light (24.8 in 2.78 cores vs 16.0 in 3.03 cores; P=0.0001) and immunofluorescence microscopy (9.5 vs 7.4; P= 0.01) than with the 18 gauge needle. Similarly, more glomeruli were obtained from transplant kidneys with the 14 gauge needle (19.5 in 1.19 cores vs 12.9 in 1.57 cores; P=0.004).

Notes: Summary: It is widely believed that symptomatic urinary tract infections (UTI) are very uncommon in males, except in infancy and the ‘prostatic’ age group. Most men with a UTI have been considered to have a functional or anatomical abnormality of the urinary tract. Recent reports have suggested that there is an increasing number of otherwise healthy young men presenting with uncomplicated acute pyelonephritis with similar clinical features as those affecting sexually active young women. From 1 January 1988 to 31 July 1995 a total of 42 men were admitted with acute pyelonephritis (fever 〉37.8°C, loin pain or tenderness and infected urine). of the total of 42 men, 23 (55%) were under the age of 40 years. Five of these 23 young men were known to have a serious underlying urinary tract abnormality and had required frequent admission for a symptomatic UTI. of the other 18 young men with an isolated episode of acute pyelonephritis, 14 were infected with Escherichia coli, 2 with Proteus mirabilis and 1 each with Enterococcus faecadis and Staphylococcus saprophyticus. All 18 had normal imaging of the urinary tract, and all were cured (sterile urine 7–10 days later) with a 5-day course of treatment. In summary, more than half of the males admitted with acute pyelonephritis were under the age of 40 years. Men with an isolated episode of acute pyelonephritis should be treated in the same way as for women in a similar age group. Not all require extensive urinary tract investigations.

Notes: Summary: We report a 29-year-old man with renal failure due to focal and segmental glomerulosclerosis (FSGS) who received a well-matched cadaveric renal allograft and had the early appearance of the nephrotic syndrome and renal insufficiency. His condition responded dramatically to plasmapheresis. the pathogenesis of FSGS recurring in a renal allograft may involve a recently identified circulating factor. the possible efficacy of plasmapheresis in the treatment of recurrent FSGS may be attributable to the removal of this factor.

Notes: Summary: Avascular necrosis (AVN) of bone is the most debilitating musculoskeletal complication that can follow renal transplantation, and has been reported in 3-41% of patients. In this unit 351 renal transplants have been done on 285 recipients. Five (1.8%) of these patients (mean age 41.6 years; range 22-57 years; four female; all cadaveric kidneys) developed AVN which affected both hip joints. the mean duration of renal failure before dialysis was 18.2 months (range 5-36). All five were on dialysis for a mean of 16.2 months (range 4-29) pre-transplant. No patient had radiological evidence of renal osteodystrophy prior to transplantation. the first 116 patients were immunosuppressed with prednisone/azathioprine and four (3.5%) developed AVN. the subsequent 169 patients were treated with prednisone/azathioprine/ cyclosporine and one (0.6%) developed AVN. Only two of the five patients needed treatment for acute rejection (methylprednisolone 3 g and 6 g). the mean time from transplantation to onset of joint pain was 45.4 months (range 6-108). Total hip replacement (THR) was undertaken on all 10 joints with the first side being operated on after a mean of 73.2 months (range 23-124) from transplantation and the contralateral side after 88.4 months (range 24–144). Total hip replacement resulted in relief of pain in all joints: three surgical revisions were required, two for dislocation and one for a fractured prosthesis. This study has shown a low prevalence of AVN after renal transplantation. Possible explanations include careful control of renal osteodystrophy while on dialysis and the use of low dose prednisone in the immunosuppressive regimen.

Notes: Summary: Hypertension in the presence of renal artery stenosis may not necessarily be renovascular hypertension. the two conditions may simply co-exist. Some features of renovascular hypertension include: a worse prognosis than essential hypertension, less amenable to drug treatment, a greater risk of dose-dependent side effects, a higher risk of progression to accelerated hypertension and it may result in irreversible ischaemic failure of the affected kidney. Renovascular hypertension is usually symptomless, while hypertension that is difficult to control with antihypertensive therapy is probably the best indication as to whether further diagnostic evaluation is indicated. A clue is a rise in the plasma creatinine concentration following the introduction of an angiotensin converting enzyme inhibitor (ACEI). Renal artery stenosis may be present in up to 30% of drug resistant hypertensive patients. Arteriosclerotic renovascular disease is an increasingly important cause of renal failure. In this institution from 1 January 1988 to 31 December 1993,491 patients were referred with a plasma creatinine of ≥0.30 mmol/L. Hypertension/nephrosclerosis/renal artery stenosis was the diagnosis in 75 of 372 (20%) of those patients who had chronic renal failure. of the last 427 patients entering our renal replacement programme, 23 were due to hypertensive nephrosclerosis and an additional five due to renal artery stenosis (6.6% of the total). Functional diagnostic tests for renovascular hypertension such as rapid sequence intravenous urography have now been superseded by the captopril challenge test and in particular scintigraphy following captopril provocation. Tests of prediction as to whether correction of a demonstrated renal artery stenosis will lead to an improvement in the blood pressure include renal vein renin estimations and scintigraphy. the key diagnostic procedure is renal angiography. the approaches to management primarily include appropriate antihypertensive therapy, while there is an increasing place for percutaneous transluminal angioplasty, with or without stenting of an occluding lesion. There is still a small place for corrective surgery. Renal ischaemia due to atherosclerotic renovascular disease is becoming an increasing problem in nephrology. Treatment should be directed at preserving or even restoring renal function.

Notes: Summary: Prosthetic devices are commonly used in nephrological and urological practice for the management of urinary and peritoneal dialysis flow, haemodialysis and drainage of renal calculi after laser or lithotripsy treatment. Many different types of materials are used and a number of complications arise, yet the fundamental interactions which occur at these biomaterial surfaces have been little studied. Recent information has shown that host conditioning films are deposited onto materials upon implantation, and that dense bacterial biofllms can form and resist conventional therapy. In order to better manage patients with prostheses, it will be imperative to understand the processes arising in the host and, using scientific data, to select the optimal interventions.