Megacystis--microcolon--intestinal hypoperistalsis syndrome--case report and review of literature.
CASE REPORT-A 30-year-old [G.sub.2][P.sub.1] woman presented to our hospital with a routine ultrasound examination at 22 weeks. The ultrasonographic examination [fig. 1] revealed a single male fetus with a markedly distended bladder and normal to increased amniotic fluid volume. There was minimal distension of the renal pelvis, no other abnormalities were detected. The most likely diagnosis of these ultrasonographic findings was megacystis-microcolon-hypoperistalsis syndrome.
The patient was referred for genetic counseling and the examination was repeated in two weeks to assess the progression of the syndrome. The second examination performed at 24 weeks again demonstrated increased amniotic fluid. The bladder was further distended and extended into the left upper quadrant of the fetus filling the pelvis and maximum part of the abdomen.
Even after advice to terminate the pregnancy patient decided to continue it and delivered prematurely at 32 weeks. Baby was 1.5kg male presented with perforation peritonitis after 24 hours. Baby-gram showed gas under right dome of diaphragm [fig.2].Exploratory laparotomy was planned & on exploration a markedly distended bladder filling the abdominal cavity with no urethral stricture or gross evidence of mechanical outlet obstruction. Mild hydronephrosis was noted bilaterally without hydroureter along with small ileal perforation near ileo-ceacal junction and complete micro colon [fig.3]. Ileostomy was done & abdomen was closed. The baby died 24 hours after surgery due to cardiopulmonary dysfunction.
DISCUSSION- Megacystis-microcolon hypoperistalsis syndrome is rare and lethal in most cases. It was first described in 1974 by Berdon in 5 female infants, 2 of whom were sisters. The first reported ultrasound diagnosis was made by Vezina et al. in 1979. In all cases, the enlarged bladder and absence of oligohydramnios typical of this syndrome were easy to define by ultrasound. Polyhydramnios is present in approximately 25% of the cases . The length of gestation and birth weight are within normal limits. Megacystis-microcolon-intestinal hypoperistalsis syndrome is more common in females perhaps due to under diagnosis in males who are labeled instead as "prune belly". Most cases are sporadic. An autosomal recessive inheritance has been supported by reports of affected siblings.
A transient anatomical and/or functional urinary tract obstruction has been considered. Srikanth  suggested that an intramural inflammatory process affecting the gastrointestinal and urinary tracts could lead to extensive fibrosis. The fibrosis would destroy the intestinal neural network, producing hypo peristalsis and causes neuromuscular in coordination of the bladder. The resulting bladder distension could interfere with the rotation of the intestine causing malrotation. Another theory suggests the urinary tract obstruction in this condition is secondary to the intestinal defect. It is not clear whether this is a primary neuropathy or myopathy . At pathology, vacuolar degeneration of smooth muscle is observed. The ganglion cell distribution is normal but axonal dystrophy of the central, peripheral, and autonomic nervous systems  and dysplastic changes associated with increased laminin and fibronectin have been observed suggesting a primary myocellular defect of contractile fiber synthesis. This suggests a defect of glycogen-energy utilization but a deficiency of fiber synthesis could also be responsible for the disorder. In mice a deficiency in alpha3 subunit of the neuronal nicotinic acetylcholine receptor (a mediator of normal function of the autonomic nervous system) results in similar symptoms to those of megacystismicrocolon-intestinal hypoperistalsis .
On USG megacystis-microcolon-intestinal hypoperistalsis syndrome should be considered in the presence of an abnormally distended bladder with a normal or increased amount of amniotic fluid. Dilatation of the urinary bladder in conjunction with the absence of oligohydramnios should raise the suspicion of the diagnosis, particularly in a patient at risk. It should be noted though, that the dilatation of the bladder may not be visible in some case at the 18-20 weeks exam, and that the earliest sign maybe mild hydronephrosis .
The main differential diagnosis is obstructive uropathy. In a female fetus, a low urinary tract obstruction can be due to urethral agenesis, variants of caudal regression syndrome, or to the rare detrusor hypertrophy . All of these cases are associated with severe oligohydramnios. Megacystis-microcolon-intestinal hypoperistalsis syndrome must be distinguished from isolated "prune belly" caused by urethral obstruction. Prune belly occurs predominantly in males, is commonly due to posterior urethral valves and has a low recurrence risk.
Megacystis-microcolon-intestinal hypoperistalsis syndrome is lethal in most cases, with only about 6% survivors at one year . An intrauterine death has been described. Intestinal dysfunction is the cause of death despite hyperalimentation. Septicemia has been reported as the cause of death in several infants . There are no reported cases of long term survivors. The prognosis is poor and treatment has been shown to be ineffective. Trans uterine- trans fetal bladder taps have been used to relieve bladder pressure in utero . Recommendations for surgical management include palliative surgery. Hyper alimentation is required. Parasympathomimetics, synthetic gastrointestinal stimulants, adrenergic blockers, and multiple gastrointestinal hormones have not been effective in inducting adequate bowel function. Obstetrical management should include a careful search for associated anomalies. Considering the poor prognosis, termination of pregnancy may be offered to the patient.
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Gunjan Mehrotra (1), Rajesh Sharma (2), Manoj Kela (3), Avinash Vishwani (4), Sangram Singh (5).
(1.) Senior Resident, Department Of Paediatrics, Saims Medical College, Indore
(2.) Associate Professor, Department Of Surgery, Saims Medical College, Indore
(3.) Associate Professor, Department Of Surgery, Saims Medical College, Indore
(4.) Assistant Professor, Department Of Surgery, Saims Medical College, Indore
(5.) Professor And Head ,Department Of Paediatric Surgery, Saims Medical College, Indore
Dr Gunjan Mehrotra, C/o Flat 201, A Block, Omgurudev Complex Sch , No 54 Vijay Nagar, Indore 452010,
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|Title Annotation:||CASE REPORT|
|Author:||Mehrotra, Gunjan; Sharma, Rajesh; Kela, Manoj; Vishwani, Avinash; Singh, Sangram|
|Publication:||Journal of Evolution of Medical and Dental Sciences|
|Article Type:||Clinical report|
|Date:||Jun 10, 2013|
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