Pelviureteric junction obstruction and megaureter in children

Mapping Intimacies ◽

10.1093/med/9780199592548.003.0353 ◽

2015 ◽

Author(s):

Michiel F. Schreuder

Keyword(s):

Urinary Tract ◽

Upper Urinary Tract ◽

Urine Flow ◽

Ultrasound Screening ◽

Antenatal Ultrasound ◽

Antenatal Hydronephrosis ◽

Pelviureteric Junction Obstruction ◽

Good Marker ◽

Urinary Tract Dilatation ◽

Vesicoureteric Junction

Two main sites of urine flow obstruction in the upper urinary tract are located at the pelviureteric and vesicoureteric junctions, both of which result in urinary tract dilatation. With current antenatal ultrasound screening, most patients are identified before birth, and 10–30% of infants with antenatal hydronephrosis are found to have pelviureteric junction obstruction, and 5–10% vesicoureteric junction obstruction/megaureter. In addition, a megaureter can also be based on urine reflux, even in combination with obstruction, or be a non-refluxing non-obstructed megaureter. In case of obstruction, surgery may be indicated, but identifying cases that need to be operated on is challenging and no good marker to assist in this differentiation is available yet.

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Anatomical types of congenital anomalies

10.1093/med/9780199592548.003.0345 ◽

2015 ◽

Author(s):

Michiel F. Schreuder

Keyword(s):

Urinary Tract ◽

Lower Urinary Tract ◽

Urinary Tract Obstruction ◽

Daily Practice ◽

Posterior Urethral Valves ◽

Ultrasound Screening ◽

Antenatal Ultrasound ◽

Antenatal Hydronephrosis ◽

Vesicoureteric Junction ◽

Lower Urinary

Antenatal hydronephrosis is the most common abnormality detected during antenatal ultrasound screening (1 in 100–500 pregnancies). Depending on the degree of dilatation, postnatal evaluation with ultrasound and/or renography is indicated to detect urinary tract obstruction. Obstruction can be found at various levels of the urinary tract such as the pyeloureteric junction, vesicoureteric junction (resulting in a megaureter), and lower urinary tract (most commonly posterior urethral valves). The decision to surgically correct obstruction can be challenging to make, and additional markers (both radiological as urinary) are needed but are not yet available in daily practice.

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Pyeloureteral dynamics in the intact and chronically obstructed multicalyceal kidney

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1981.241.5.r398 ◽

1981 ◽

Vol 241 (5) ◽

pp. R398-R411 ◽

Cited By ~ 1

Author(s):

C. E. Constantinou ◽

J. C. Djurhuus

Keyword(s):

Urinary Tract ◽

Ureteral Obstruction ◽

Intravenous Infusion ◽

Upper Urinary Tract ◽

Urine Flow ◽

Hierarchical Organization ◽

Bolus Volume ◽

Pelvic Contractions ◽

The Mean ◽

Pelvic Pressure

The transport of urine in the upper urinary tract of the multicalyceal kidney was studied in healthy and chronically obstructed pigs in terms of renal pelvic pressure, rate of and coordination of ureteral contractions, and bolus volume. The variations of these parameters to diuresis was examined by incremental elevation of urine output effected by intravenous infusion of mannitol. In 16 healthy animals the mean variation in urine flow was 0.01-3.20 ml/min, the change in peristaltic rate ranged from 0.763 to 5.125 min-1, and bolus volume from 0.003 to 2.083 ml.. In 14 chronically obstructed kidneys, for a mean variation in urine flow of 0.006-5.4 ml/min, peristaltic rate ranged from 0.237 to 6.095 min-1 and bolus volume from 0.00 to 1.80 ml. Discoordinated contractions, bursts of peristalsis, and incompletely transmitted pelvic contractions were characteristic of a chronically obstructed system. These observations are compared with the unobstructed unicalyceal and multicalyceal kidney. The disrupting impact of chronic ureteral obstruction on the hierarchical organization of the pyeloureteral pacemaker system is discussed.

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