Newborn With Wrinkled Abdomen and Other Anomalies

September 20, 2009

Prune belly syndrome is a rare condition, classically referred to as a triad of abdominal wall musculature deficiency, bilateral cryptorchidism, and other urological abnormalities, although the clinical presentation can vary. A case history here.

HISTORY
A 1909-g (4.3-lb) boy born at 29 weeks' gestation to a 14-year-old gravida 1, para 0 mother via cesarean delivery because of fetal bradycardia. Results of antenatal screening were negative. Mother denied substance abuse. Prenatal ultrasonography showed bilateral hydronephrosis, dilated fetal bladder, bilateral clubbed feet, and polyhydramnios.

Apgar scores were 1, 4, and 5 at 1, 5, and 10 minutes, respectively. The infant was intubated in the delivery room, given a dose of surfactant, and then transferred to the neonatal ICU for further treatment. Umbilical artery blood gas analysis revealed a pH of 6.99 and a Po2 of 45 mm Hg.

PHYSICAL EXAMINATION
The following anomalies noted at birth: underdeveloped chest wall with moderate subcostal retractions, respiratory rate of 70 breaths per minute, rales, cyanosis, heart rate of 160 beats per minute, distended abdomen with wrinkled appearance, a 10-mm patent urachus at the 7 o'clock position adjacent to the umbilicus that constantly drained urine, undescended testes bilaterally, 1 x 2-cm aplasia cutis congenita of the right groin, and club feet with hypoplastic toenails.

WHAT’S YOUR DIAGNOSIS?

(answer on next page)

ANSWER: PRUNE BELLY SYNDROMEPrune belly syndrome (PBS), also known as triad syndrome, Eagle-Barrett syndrome, and abdominal muscle deficiency syndrome, is a rare condition with a reported incidence of 1 in 35,000 to 50,000 births.1 About 95% of affected neonates are boys. The syndrome was first described in 1839 by Frlich and later defined in 1895 by Parker. It is classically referred to as a triad of abdominal wall musculature deficiency, bilateral cryptorchidism, and other urological abnormalities, although the clinical presentation can vary.2 Abdominal wall musculature defects, when associated with fetal ascites, cause the wrinkled appearance of the neonatal abdominal wall.2

In addition to bilateral cryptorchidism, dilated, tortuous distal ureters are commonly present; obstruction is a potential complication.3 Renal involvement can include asymmetrical renal dysplasia and hydronephrosis.4 The bladder is frequently enlarged and accompanied by a pseudodiverticulum at the urachal attachment, which is often patent.4 Vesicoureteral reflux occurs in about two-thirds of infants.3 The exact cause of PBS is unknown; however, one possible explanation is a deficiency of mesenchyme destined to develop into abdominal wall and urinary tract musculature.2 There may be genetic factors.

PRENATAL ULTRASONOGRAPHIC FINDINGS
Often the diagnosis can be suspected on the basis of prenatal ultrasonographic findings that show a severely distended abdomen and dilated urinary tract.5 Traditionally, the diagnosis of PBS has been supported by the presence of oligohydramnios on prenatal ultrasonography. The prenatal course is often complicated by oligohydramnios secondary to renal dysplasia and urinary outlet obstruction.4 This case is unique because of the finding of polyhydramnios, which typically is not associated with PBS.

Polyhydramnios is associated with CNS, GI, respiratory, genitourinary, and genetic disorders.5 Genitourinary abnormalities, such as urethral stricture and ureteral obstruction, although most commonly associated with oligohydramnios, can present with polyhydramnios.5 Similarly, pulmonary hypoplasia, which occurs in PBS, is often induced by oligohydramnios; however, if subsequent absorption of lung fluid is impeded, polyhydramnios can result.5 Any irregularity that affects swallowing or otherwise impedes the passage of fluid might also explain the polyhydramnios.5 In this case, the constant urine leakage from the fetal bladder through the patent urachus may have contributed to the development of polyhydramnios (Figure 1).

ASSOCIATED ANOMALIES
PBS may be defined by abdominal and genitourinary defects; however, its associated extragenitourinary defects often determine patient outcome. Cardiac anomalies occur in 10% of patients.4 GI defects are common and include malrotation, gastroschisis, and imperforate anus.4 Pulmonary hypoplasia, which can result from the oligohydramnios commonly seen in PBS, is a frequent cause of death. Various musculoskeletal abnormalities, such as clubbing (Figure 2), occur as a result of fetal compression.4

TREATMENT AND OUTCOME
Initially, the infant required total parenteral nutrition. Once physiologically stable, enteral nutrition was introduced; he progressed to full feedings with a 22 cal/oz formula that provided 120 kcal/kg/d.

A chest radiograph showed bibasilar infiltrates and pulmonary hypoplasia. An echocardiogram showed a patent ductus arteriosus, mild tricuspid regurgitation, and aortic regurgitation. Radiographs revealed marked distention of the abdomen without obstruction, and abdominal ultrasonograms showed marked bilateral hydronephrosis with hydroureter and right upper quadrant ascites. Fluid was present in all parts of the peritoneum but most notably in the right upper quadrant. A voiding cystourethrogram showed a bladder pseudodiverticulum.

Blood and urine cultures were ordered (results of which were normal); however, urinary tract infection prophylaxis with ampicillin was initiated because of the urological abnormalities. The infant had normal renal function; the bladder drained through the urachal remnant without urinary retention or reflux.

When the infant was 2 weeks old, blood was obtained for another culture because of temperature instability and desaturation, and a combination of nafcillin and gentamicin was prescribed empirically. These blood cultures grew Pseudomonas aeruginosa, and the nafcillin was discontinued and ceftazidime was added to the gentamicin. Repeated blood cultures were negative after 48 hours of treatment; the gentamicin and ceftazidime were continued for 10 days and then stopped. The baby continued to be cared for in the neonatal ICU, receiving 21% oxygen and ampicillin prophylaxis. At about 5 months of age, he died of severe chronic acidosis secondary to pulmonary hypoplasia. Renal function had remained intact throughout the ICU course.

References:

HISTORY
A 1909-g (4.3-lb) boy born at 29 weeks' gestation to a 14-year-old gravida 1, para 0 mother via cesarean delivery because of fetal bradycardia. Results of antenatal screening were negative. Mother denied substance abuse. Prenatal ultrasonography showed bilateral hydronephrosis, dilated fetal bladder, bilateral clubbed feet, and polyhydramnios.

Apgar scores were 1, 4, and 5 at 1, 5, and 10 minutes, respectively. The infant was intubated in the delivery room, given a dose of surfactant, and then transferred to the neonatal ICU for further treatment. Umbilical artery blood gas analysis revealed a pH of 6.99 and a Po2 of 45 mm Hg.

PHYSICAL EXAMINATION
The following anomalies noted at birth: underdeveloped chest wall with moderate subcostal retractions, respiratory rate of 70 breaths per minute, rales, cyanosis, heart rate of 160 beats per minute, distended abdomen with wrinkled appearance, a 10-mm patent urachus at the 7 o'clock position adjacent to the umbilicus that constantly drained urine, undescended testes bilaterally, 1 x 2-cm aplasia cutis congenita of the right groin, and club feet with hypoplastic toenails.

WHAT’S YOUR DIAGNOSIS?

(answer on next page)

@page_break@

ANSWER: PRUNE BELLY SYNDROMEPrune belly syndrome (PBS), also known as triad syndrome, Eagle-Barrett syndrome, and abdominal muscle deficiency syndrome, is a rare condition with a reported incidence of 1 in 35,000 to 50,000 births.1 About 95% of affected neonates are boys. The syndrome was first described in 1839 by Frölich and later defined in 1895 by Parker. It is classically referred to as a triad of abdominal wall musculature deficiency, bilateral cryptorchidism, and other urological abnormalities, although the clinical presentation can vary.2 Abdominal wall musculature defects, when associated with fetal ascites, cause the wrinkled appearance of the neonatal abdominal wall.2

In addition to bilateral cryptorchidism, dilated, tortuous distal ureters are commonly present; obstruction is a potential complication.3 Renal involvement can include asymmetrical renal dysplasia and hydronephrosis.4 The bladder is frequently enlarged and accompanied by a pseudodiverticulum at the urachal attachment, which is often patent.4 Vesicoureteral reflux occurs in about two-thirds of infants.3 The exact cause of PBS is unknown; however, one possible explanation is a deficiency of mesenchyme destined to develop into abdominal wall and urinary tract musculature.2 There may be genetic factors.

PRENATAL ULTRASONOGRAPHIC FINDINGS
Often the diagnosis can be suspected on the basis of prenatal ultrasonographic findings that show a severely distended abdomen and dilated urinary tract.5 Traditionally, the diagnosis of PBS has been supported by the presence of oligohydramnios on prenatal ultrasonography. The prenatal course is often complicated by oligohydramnios secondary to renal dysplasia and urinary outlet obstruction.4 This case is unique because of the finding of polyhydramnios, which typically is not associated with PBS.

Polyhydramnios is associated with CNS, GI, respiratory, genitourinary, and genetic disorders.5 Genitourinary abnormalities, such as urethral stricture and ureteral obstruction, although most commonly associated with oligohydramnios, can present with polyhydramnios.5 Similarly, pulmonary hypoplasia, which occurs in PBS, is often induced by oligohydramnios; however, if subsequent absorption of lung fluid is impeded, polyhydramnios can result.5 Any irregularity that affects swallowing or otherwise impedes the passage of fluid might also explain the polyhydramnios.5 In this case, the constant urine leakage from the fetal bladder through the patent urachus may have contributed to the development of polyhydramnios (Figure 1 ).

ASSOCIATED ANOMALIES
PBS may be defined by abdominal and genitourinary defects; however, its associated extragenitourinary defects often determine patient outcome. Cardiac anomalies occur in 10% of patients.4 GI defects are common and include malrotation, gastroschisis, and imperforate anus.4 Pulmonary hypoplasia, which can result from the oligohydramnios commonly seen in PBS, is a frequent cause of death. Various musculoskeletal abnormalities, such as clubbing (Figure 2 ), occur as a result of fetal compression.4

TREATMENT AND OUTCOME
Initially, the infant required total parenteral nutrition. Once physiologically stable, enteral nutrition was introduced; he progressed to full feedings with a 22 cal/oz formula that provided 120 kcal/kg/d.

A chest radiograph showed bibasilar infiltrates and pulmonary hypoplasia. An echocardiogram showed a patent ductus arteriosus, mild tricuspid regurgitation, and aortic regurgitation. Radiographs revealed marked distention of the abdomen without obstruction, and abdominal ultrasonograms showed marked bilateral hydronephrosis with hydroureter and right upper quadrant ascites. Fluid was present in all parts of the peritoneum but most notably in the right upper quadrant. A voiding cystourethrogram showed a bladder pseudodiverticulum.

Blood and urine cultures were ordered (results of which were normal); however, urinary tract infection prophylaxis with ampicillin was initiated because of the urological abnormalities. The infant had normal renal function; the bladder drained through the urachal remnant without urinary retention or reflux.

When the infant was 2 weeks old, blood was obtained for another culture because of temperature instability and desaturation, and a combination of nafcillin and gentamicin was prescribed empirically. These blood cultures grew Pseudomonas aeruginosa, and the nafcillin was discontinued and ceftazidime was added to the gentamicin. Repeated blood cultures were negative after 48 hours of treatment; the gentamicin and ceftazidime were continued for 10 days and then stopped. The baby continued to be cared for in the neonatal ICU, receiving 21% oxygen and ampicillin prophylaxis. At about 5 months of age, he died of severe chronic acidosis secondary to pulmonary hypoplasia. Renal function had remained intact throughout the ICU course.

REFERENCES:1. Dénes FT, Arap MA, Giron AM, et al. Comprehensive surgical treatment of prune belly syndrome: 17 years’ experience with 32 patients. Urology. 2004;64: 789-794.

2. Jennings RW. Prune belly syndrome. Semin Pediatr Surg. 2000;9:115-120.

3. Strand WR. Initial management of complex pediatric disorders: prune belly syndrome, posterior urethral valves. Urol Clin North Am. 2004;31:399-415.

4. Smith EA, Woodard JR. Prune belly syndrome. In: Campbell MF, Walsh PC, Retik AB, eds. Campbell’s Urology. 8th ed. Philadelphia: Saunders; 2002:2117-2135.

5. Phelan JP, Martin GI. Polyhydramnios: fetal and neonatal implications. Clin Perinatol. 1989;16:987-994.