Vesico-uretero-renal reflux and the kidney

Abstract

The most frequent complications of non-obstructive vesico-uretero-renal reflux (VUR) are segmental renal scars. These scars are confined to segments with intrarenal reflux which are, in addition, exposed to bacterial infection. Primarily, only gaping collecting duct orifices, confined to compound papillae and mainly situated at the kidney poles, allow intrarenal reflux. Scar contraction and obstruction seem to be able to transform closed collecting duct orifices into gaping ones, thereby enlarging the parenchymal area prone to intrarenal reflux and to renal scarring. Contrary to earlier reports, a recent survey has documented that new scars in children develop with significant frequency beyond 5 years of age. There is a greater tendency for scarring to develop with more severe VUR, but new renal scars can develop with all grades of VUR. Early and adequate antibiotic treatment decreases the extent of scarring. The results of experimental studies in which renal scarring developed in piglets with bladder decompensation resulting from intravesical obstruction but without bacterial infection may be relevant to the few children with proximal urethral valves and hypertonic neurogenic bladders but not to the large number with non-neurogenic detrusor instability or detrusor sphincter dyssynergia. Prospective studies have not shown different recurrence rates of urinary tract infections in medically managed compared with surgically managed children. The frequency of acute pyelonephritic attacks decreased significantly after operation.

Long-Term Follow-Up of Children with Surgically Treated Yesicorenal Reflux: Postoperative Incidence of Urinary Tract Infections, Renal Scars and Arterial Hypertension

“…Recent prospective studies have shown that parenchy mal damage can be prevented by long-term chemopro phylaxis or a reflux operation [1][2][3]. The outcome of conservative therapy, however, depends on strict chemo prophylaxis until the disappearance of VUR is con firmed radiologically.…”

Vesicoureteral Reflux, Reflux Nephropathy, and End-Stage Renal Disease

“…In animals, when the flow of urine is obstructed in the developing kidney a series of abnormalities occur including (1) arrest of glomerular maturation, (2) glomerulosclerosis, (3) ischemia and necrosis of some tubular cells, (4) apoptosis of other tubular and collecting duct cells, (5) interstitial inflammation, proliferation, and fibrosis, and (6) tubular dilatation and atrophy [4–6]. In addition, in animals and humans there is evidence that scarring occurs in compound papillae where intrarenal reflux is present [7]. In humans, RN is usually identified as renal scarring as defined on dimercaptosuccinic acid (DMSA) scan in a patient known to have VUR.…”

Urinary beta2-microglobulin as a marker for vesicoureteral reflux

“…The renal scarring associated with vesicoureteral reflux (VUR) and urinary tract infection in childhood is one of the [1,2]. Some of the renal changes associated with reflux are developmental and are present from birth, but a proportion are acquired after urinary infection and, therefore, are preventable [3][4][5].…”

“…Reflux nephropathy has been shown to be associated with significant renal tubular dysfunction [1,6]. Renal tubular damage mediated by VUR may be manifested by increased levels of renal tubular enzymes.…”