Percutaneous drainage in emphysematous pyelonephritis

Clinical Radiology (1989) 40, 434-437

Correspondence Letters are published at the discretion of the Editor. @&ions expressed by correspondents are not necessarily those of the Editor. Unduly long letters may be returned to the authors for shortening. Letters in response to a paper may be sent to the author of the paper so that the reply can be published in the same issue. Letters should be typed double spaced and should be signed by all authors personally. References should be given in the style specified in the Instruction to Authors at the front of the Journal.

P E R C U T A N E O U S DRAINAGE IN E M P H Y S E M A T O U S PYELONEPHRITIS Sm - We were very interested to read the paper by Hall et al. (1988), 'Percutaneous Drainage in E m p h y s e m a t o u s Pyelonephritis - A n Alternative to Major Surgery'. We have just been involved in the management of a case of emphysematous pyelonephritis in a transplant kidney. Our patient was a 66-year-old diabetic w o m a n with an Eschericia coli infection who presented with deteriorating renal function. An ultrasound examination demonstrated a fluid and gas collection within the parenchyma of the transplant kidney together with a psoas abscess on the opposite side. She was treated with antibiotics and ultrasound-guided percutaneous drainage of both the psoas and intra-renal abscesses. There has subsequently been improvement in her renal function. The literature suggests that the best management is combined antibiotics and prompt surgery (nephrectomy) with a mortality of 7% (Michaeli et al. 1984). Emphysematous pyelonephritis is however a rare condition and almost all the cases from the literature pre-date the wide availability of ultrasound and CT. We would agree with the present authors that the modern management o f e m p h y s e m a t o u s pyelonephritis is tending towards conservation and should be by percutaneous drainage and antibiotics. In our patient surgery was not considered initially as every effort had to be made to conserve the transplanted kidney. D. G L E N A. P. BAYLISS E. M. R O B E R T S O N

Department of Diagnostic Radiology Aberdeen Royal Infirmary Foresterhill Aberdeen AB9 2ZB

Reference Michaeli, P, Mogle, P, Perlberg, S, Heiman, S & Caine, M (1984). Emphysematous pyelonephritis. Journal of Urology, I31, 203.

SXR We were most interested to learn of the experience of the Aberdeen group relating to emphysematous pyelonephritis in a transplant kidney. The mortality figure of 7% to which they refer is at the lowest end of published mortality figures, with other workers suggesting figures approaching 40%. Their case reinforces the need to consider percutaneous drainage in this condition both to produce clinical cure and preserve renal function even in the transplanted kidney. J. R. W. H A L L R. G. C H O A I. P. W E L L S

Bradford Royal Infirmary Duckworth Lane Bradford, West Yorkshire BD9 6RJ

strated at urography in 59% of children with acute non-obstructive pyelonephritis, and dilatation was noted also in the absence of reflux (Hellstrom et al., 1985; Hellstrom et al., 1987). This effect is probably mediated by the action of bacteria or bacterial products on the smooth musculature of the ureter (King and Cox, 1972), with consequent impaired peristalsis and ureteral widening. This possibility should be kept in mind in the differential diagnosis of upper urinary tract dilatation, especially if the imaging study is performed in close association to the urinary infection. M. H E L L S T R O M B. JACOBSSON

Department of Radiology King Faisal Specialist Hospital and Research Center Riyadh, Saudi Arabia

References Hellstrom, M, Hjalmas, K, Jacobsson, B, Jodal, U & Oden, A (1985). Normal ureteral diameter in infancy and childhood. Acta Radiologica (Diagnosis), 26, 433-439. Hellstrom, M, Jodal, U, Marild, S & Wettergren, B (1987). Ureteral dilatation in children with febrile urinary tract infection or screening bacteriuria. American Journal of Roentgenology, 148, 483 486. King, W & Cox, CE (1972). Bacterial inhibition of ureteral smooth muscle contractility. I. The effect of c o m m o n urinary pathogens and endotoxins in an in vitro system. Journal of Urology, 108, 700 705. Saxton, H (1988). Myths and misconceptions in uroradiology. Clinical Radiology, 39, 361-362.

S m - I am grateful for the comments by Dr Hellstrom and Dr Jacobsson adding the possibility of infection as a cause of upper urinary tract dilatation. I have always had a certain difficulty with this concept because I have not seen any cases personally and have not come across a series of cases in w h o m the calibre of the ureter was demonstrated to return completely to normal after effective treatment of infection. In addition the failure to demonstrate vesico ureteric reflux on one study does not mean that it has not been present nor even that it is not occurring currently. These factors have made me hesitate in accepting the suggestion that infection per se causes as distinct from aggravates ureteric dilatation. This kept me from including infection as a cause in my list, which is by no means exclusive. However, the point made by Drs Hellstrom and Jacobsson is a fair one - that in children with unexplained ureteric dilatation one should look for infection. H. M. S A X T O N

Department of Diagnostic Radiology Guy's Hospital St Thomas Street London SE1 9RT

C A U S E S OF URINARY T R A C T D I L A T A T I O N

A P R O T O C O L F O R T H E I N V E S T I G A T I O N OF I N F A N T S AND CHILDREN WITH URINARY TRACT INFECTION

Sm The excellent editorial entitled 'Myths and Misconceptions in Uroradiology' by H u g h Saxton (1988) includes aspects on upper urinary tract dilatation. Under the heading 'Dilatation of the upper tracts with slow excretion of contrast medium indicates the presence of obstruction or gross reflux', a number of causes, other than obstruction or reflux, for upper urinary tract dilatation are mentioned. These include postobstructive dilatation, post-reflux dilatation, persistent pregnancy hypotonia, prune belly syndrome, flow uropathy including diabetes insipidus, nephrogenic diabetes insipidus, psychogenic water drinking and Bartter's syndrome. However, mention of an additional important and c o m m o n cause of upper urinary tract dilatation is not made, namely infection. In a recent prospective study, ureteral dilatation was demon-

S m - Further to the very relevant letter of Dr G. M. Steiner (1988), with which I fully agree, and the reply of Dr T. M. J. Maling (1988) relating to 'A Protocol for the Investigation of Infants and Children with Urinary Tract Infection' (Whyte et al., 1988), I would like to stress that in 1988 89 it is not enough for Dr Maling to justify their protocol by suggesting that standards of ultrasound examinations vary greatly as they depend upon the operator and also the co-operation of the child. Paediatric renal ultrasound is very actively practised in most centres and considerable experience and expertise is now available generally to provide a reliable good quality service. At the Birmingham Children's Hospital renal ultrasound forms over 50% of the ultrasound work-load and it is the first investigation of choice for infants and children with urinary