PP-12 Fetal Patent Uracus Coexistence of recurrent megacystis, umbilical cord cyst and impaired kidney functions

Objective

The urachus is a thin fibromuscular tubular structure that connects the apex of the bladder and the umbilicus. Its lumen normally obliterates at the 6th week of pregnancy and remains as a dysfunctional remnant called the median umbilical ligament in adult life.[1] Patent urachus refers to an anomaly that occurs with failure of obliteration of the urachus. It is a rare anomaly with a frequency of 1 to 2.5 per 100000 live births.[2] While it can be detected sonographically with findings such as megacystis and umbilical cord cyst in the first trimester, no sonographic finding may be detected in cases with partial failure in obliteration of the urachus. Cases that are not detected in the prenatal period may become symptomatic in the neonatal period and usually present with edematous umbilical cord, wetness in the umbilical region, or recurrent umbilical infections.[3] We aimed to share the follow-up and management of our case with patent urachus and progressively increasing megacystis since the first trimester.

Methods

Computer-based and ultrasonography records of a patent urachus case with megacystis and umbilical cord cyst, who applied to the Perinatology outpatient clinic of Prof. Dr. Cemil Taşçıoğlu City Hospital at the 12th week of pregnancy, were scanned retrospectively from the hospital software and the history of the ultrasonography device. Fetal ultrasonography examination was performed using Mindray Resona 7 device and its 1.2-6 MHz convex abdominal probe. Ultrasonography findings and patient history were noted.

Case

A 24-year-old gravida 1 pregnant woman referred to our clinic due to megacystitis was admitted to our clinic at 12 weeks of gestation. On examination, the superior-inferior diameter of the bladder was 12.9 mm and it was evaluated as megacystitis. Left renal anteroposterior diameter was measured as 3.6 mm. Chorionic villus sampling was done to the patient at this gestational week and it was concluded as normal karyotype. In the examination performed at the 15th gestational week, the bladder superior-inferior diameter was 72 mm, and an umbilical cord cyst and a single umbilical artery were observed. Vesicocentesis was performed on the patient and 85 cc of urine was drained from the fetal bladder (Figure 1-2). After the procedure, the bladder diameter was measured as 11 mm, and fetal kidneys were observed as hyperechoic in the sonographic examination (Figure 3). Results of urine sampling: Na 104 mEq/L, Cl 82 mEq/L, urine osmolarity 275 mOsm/L, beta-2 microglobulin 16.1 mg/L, Ca 9.6 mEq/L, total protein 0.7 mg/dl. At the patient’s admission 72 hours later, the vesicocentesis procedure was repeated and approximately 40 cc of urine sample was taken. Results were reported as Na 136 mEq/L, Cl 107 mEq/L, urine osmolarity 216 mOsm/L, beta-2 microglobulin 11.9 mg/L, Ca 9.6 mEq/L, total protein 3.1mg/dl. The patient and her husband were informed about the possible prognosis and termination option at the 17th gestational week due to high Na, Cl, Ca, beta-2 microglobulin and urine osmolarity as a result of vesicocentesis, recurrence of megacystis in the ultrasound examination after vesicocentesis, bilateral echogenic monitoring of the kidneys and anhydramnios (Figure 3). At the request of the family, the fetus was terminated. No additional findings were observed in the terminated fetus, except for the pathologies detected during inspection. Since the family did not want an autopsy, it was not possible to comment on interal.

Results

First trimester sonography is becoming increasingly important in evaluating fetal anatomy and detecting major anomalies. Detection of megacystis in the first trimester is almost always simple and is among the first noticeable findings in sonographic examination. The incidence of megacystis in the first trimester is 1 in 1800, and in almost half of these cases, it is observed that the megacystis resolves within 2 weeks.[4] The prognosis usually depends on the width of the megacystis. Megacystis larger than 15 mm has been associated with a poor prognosis. Megacystis smaller than 15 mm usually resolves spontaneously in approximately 90% of cases without aneuploidy, and this is attributed to a temporary functional neurogenic bladder secondary to a delay in the development of autonomic innervation.[1,4] In the case we presented, the fact that megacystis is close to the border associated with poor prognosis in the literature, recurrence of megacystis after vesicocentesis, hyperechoic appearance in bilateral kidneys, and subsequent anhydramnios were warnings about poor prognosis.

Conclusion

In such cases, performing ultrasonography in expert hands, sharing the current findings and possible prognosis in detail with the family, and making a joint decision by interviewing the family will be decisive in the management of the cases.

Keywords

Megacystis, patent urachus, vesicocentesis, umbilical cord cyst

1. Sepulveda W, Rompel SM, Cafici D, Carstens E, Dezerega V. Megacystis Associated With an Umbilical Cord Cyst. Journal of Ultrasound in Medicine. 2010 Feb;29(2):295–300. 
2. Kwon JY, Pyeon SY. Prenatally Ruptured Patent Urachus: A Case Report and Review of Literature. Medicina. 2022 Nov 10;58(11):1621.
3. Briggs KB, Rentea RM. Patent Urachus. In: StatPearls. StatPearls Publishing, Treasure Island (FL); 2022.
4. Liao AW, Sebire NJ, Geerts L, Cicero S, Nicolaides KH. Megacystis at 10-14 weeks of gestation: chromosomal defects and outcome according to bladder length. Ultrasound in Obstetrics and Gynecology. 2003 Apr;21(4):338–41. 

	File/Dsecription
	Fig.1 Vesicocentesis procedure
	Fig.2 Fetal bladder after vesicocentesis procedure
	Fig.3 Ultrasonographic view of echogenic kidneys