Megacystis

Duodenal Obstruction 170 Jejunal and Ileal Obstruction 172 Meconium Peritonitis 173 Meconium Ileus 173 Megacystis-Microcolon-Malrotation-Intestinal-Hypoperistalsis Syndrome (MMMIHS) 174... 

Megacystis-Microcolon-Malrotation-Intestinal-Hypoperistalsis Syndrome (MMA/llHS)... 

Chronic intestinal pseudo-obstruction is a rare clinical condition also known as chronic adynamic ileus, pseudo-Hirschsprung s disease, and adynamic bowel syndrome. Megacystis-microcolon-intestinal hypoperistalsis syndrome is the most severe form of chronic intestinal pseudo-obstruction. 

Transient megacystis may he a sign of obstruction and/or vesicoureteric reflux. In boys, it could be the consequence of transient bladder outlet obstruction and the starting point of a series of abnormalities. Notably, it could explain the male predominance in neonatal vesicoureteric reflux. This hypothesis was... 

Fig. 6.2a,b. Prenatal sonography in a 22-week gestational age male fetus, a Megacystis with dilated posterior urethra. Moderately dilated left kidney (not shown), b Huge dilatation of the right kidney with perirenal urinoma (courtesy of D. Eurin)... 

Megacystis-megaureter association (high-grade reflux)... 

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS)... 

Fig. 6.5. VCU in a neonate with prenatal diagnosis of megacystis and bilateral ureterohydronephrosis. Absence of posterior urethral valves. Megacystis megaureter association by aberrant micturition phenomenon...

The clinical presentation is completely different in older children. The main complaint is usually dys-uria or infection (Fig. 6.6). Megacystis and thickening of the bladder wall are less frequent. Kidneys are usually normal, as is renal function. The differential diagnosis should include the other causes of bladder outlet obstruction (see below) and functional disorders such as dysfunctional voiding with severe bladder-sphincter dyscoordination. Both VCU and urodynamic studies can be diagnostic (Fig. 6.7). In case of valves, there is reduced urinary flow with no reinforcement of the perineal electric activity. 

Ectopic ureterocele develops at the lower end of the upper pole ureter of a duplicated kidney. It is a cyst-like thin-walled structure that is known to be mobile and variable in shape. During fetal life, the ureterocele can prolapse into the posterior urethra and create obstruction (Fig. 6.9). Bilateral hydronephrosis and megacystis can subsequently develop. Clinical diagnosis can be made at birth in girls with a perineal soft tissue mass, megacystis and bilateral urinary tract obstruction. Sonographic diagnosis can be difficult when the ectopic ureterocele has... 

Fig. 6.9. VCU in a female neonate with prenatal diagnosis of megacystis and hydronephrosis. Vesicoureteric reflux into the lower pole of a left duplicated kidney. Left upper pole ureter is obstructed by an ectopic ureterocele that is prolapsed in the urethra during micturition...

Willi UV, Lebowitz RL (1979) The so-called megaureter-megacystis syndrome. AJR 133 409-416... 

In the megacystis-megaureter association, massive bilateral grade IV or V VUR is present. During micturition, the bladder empties normally through the urethra, but also through reflux into the ureters (Fig. 11.23a-d). At the end of micturition, the bladder is completely empty, but only for a very short time. It refills immediately with the refluxed urine ... 

Mandell J, Lebowitz RL, Peters CA et al (1992) Prenatal diagnosis of the megacystis-megaureter association. JUrol 148 1487-1489... 

Since megacystis can be expected in patients with prune belly syndrome, the investigator should be prepared for a large bladder volume (Fig. 17.4). A persistent urachus may be seen, and the bladder typically empties slowly and incompletely. Bilateral vesicoure-teric reflux is commonly observed. The prostatic urethra is often dilated, presents in a V-shaped manner, and the prostatic utricle maybe opacified. 

Preservation of bladder function (e.g., megacystis-megaureter syndrome)... 

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