Holding Water: Congenital Anomalies of the Kidney and Urinary Tract, CKD, and the Ongoing Role of Excellence in Plumbing

Congenital anomalies of the kidneys and urinary tracts can result in diminished natal kidney function, possibly through common embryologic pathway disruption or as a result of development taking place in the face of disordered 'post-renal' drainage. Impaired conduit and reservoir function present potential for an ongoing assault leading to further deterioration and progression of chronic kidney disease, a risk that extends to adults with these conditions, even after “correction”. The drainage and storage aspects of the urinary system that can impact kidney function are reviewed with attention to correctable or manageable problems including: Bladder dysfunction wherein the low pressure storage of urine is compromised requiring the kidney to work against a pressure gradient, the classic post renal failure problem. The kidney in the aftermath of obstruction which may have lost concentrating capacity leading to a tendency to dehydration ('pre-renal' failure) and through polyuria which exacerbates bladder pressure problems. Further there is an added challenge in evaluation for ongoing or reemergent obstruction in a significantly dilated system where the capacious system leads to slow turnover of urine often requiring a ureteral stent or nephrostomy to clearly establish clinical significance of delayed drainage. Stasis where slow urine flow leads to buildup of debris (stone) or potentiates infection. Vessicoureteral reflux which allows for introduction of lower urinary tract bacteria to the kidney and can lead to pyelonephritis. Conditions which combine problems such as posterior urethral valves where the bladder outlet obstruction compromises kidney function potentially impairing concentrating ability, creates bladder compromise often reducing emptying efficiency or elevating bladder storage pressures, as well as dilating the system potentially promoting stasis. Cognizance of the potential for plumbing problems to further kidney deterioration as patients with congenital urinary tract anomalies, even after they have been repaired is incumbent on those caring for these patients as they age. Thoughtful evaluation of those patients in whom kidney compromise maybe aggravated by drainage and storage disorder will optimize native renal function.