RECONSIDERATION OF THE ROLES OF URINARY-INFECTION AND VESICOURETERAL REFLUX IN THE PATHOGENESIS OF RENAL SCARRING

In an experimental study of female piglets with surgically created uni lateral vesicoureteric reflux, Escherichia coli were inoculated into t he bladder and, at later sacrifice, bacterial culture was undertaken o f renal parenchyma from the refluxing and non-refluxing kidneys. Posit ive cultures of the same E. coli were obtained from 33% of refluxing k idneys with pyelonephritic renal scars, 23% of refluxing kidneys witho ut scars and 21% of non-refluxing kidneys. Although other aspects of t he experiments confirmed that a combination of urinary infection, vesi coureteric reflux and intra-renal reflux is a necessary precondition f or renal scarring, these findings indicate that reflux plays a role in the pathogenesis of renal scarring over and above a means whereby pat hogens gain access from the lower urinary tract to the renal substance . Possible mechanisms are discussed.