Umbilical Cord Hernia Associated with a Patent Urachus: A Case Report

An umbilical cord hernia (UCH) is a form of abdominal wall defect, affecting 6 out of every 10,000 newborns. The persistence of urachus is an embryonic remnant that connects the bladder to the abdominal wall at the level of the umbilicus, being yet more uncommon. We reviewed the literature, searching in PubMed, under the terms “Hernia of umbilical cord”, “Congenital hernia of cord” and “Persistent Urachus”. Only a few similar cases of both pathologies associated described were found. Our main objective is to highlight the distinct clinical features, embryogenesis, prognosis and associated anomalies of two infrequent embryopathies. And to describe a infrequent case of both abnormalities presenting simultaneously.

UCH are often misdiagnosed with other abdominal wall deffects, such as omphalocele, umbilical hernias, gastroschisis and umbilical cord cysts. The normal cord insertion, adequate muscle development of the abdominal wall and a wall defect less than 5cm is what differentiates it from an omphalocele. UCH has a low morbidity overall, as it is not associated with other anomalies. The most frequently observed urachal malformations are the persistence of a urachus and urachal cyst. The prenatal diagnosis of patent urachus is made by ultrasound or magnetic resonance, being easily mistaken with abdominal wall defects, confirming the diagnosis with an ultrasound at birth. The persistence of urachus may resolve spontaneously, if not, surgical resolution is recommended. Similar to a UCH, a patent urachus shows little association with other malformations.

It is important to know the clinical presentation and the diagnostic perinatal methods employed for appropriate management and favorable results for both pathologies. This relies on knowing when to suspect possible associated anomalies and when complementary studies might be needed. It is also important to be aware that there is the possibility of a UCH and a patent urachus existing simultaneously.


Introduction
An umbilical cord hernia (UCH) is a form of abdominal wall defect, affecting 6 out of every 10,000 newborns [1]. In a UCH the bowel herniates into the base of a normally inserted umbilical cord through a patent umbilical ring. Diagnosis is based on physical examination, making it crucial to differentiate from other similar abdominal wall defects such as omphalocele, gastroschisis, umbilical hernia or umbilical cyst, all of which are different in anatomy, presentation, management and prognosis. Although difficult at times, the key to making an accurate diagnosis is assessing the position of the cord, its contents and the relation of the wall defect to the cord's insertion. The first impression on physical examination is crucial to guide the physician in making an accurate diagnosis and performing further investigations.
Yet more uncommon is the presence of a concomitant patent urachus. Localized in the preperitoneal space, this is an embryonic remnant derived from the involution of the allantois that connects the bladder to the abdominal wall at the level of the umbilicus. The persistence of the urachus is easily misdiagnosed as cord abnormalities and other urachal abnormalities such as urachal cyst, umbilicalurachal sinus and vesico-urachal diverticulum.
Cases of UCH associated with extracelomic colonic atresia, short gut and patent omphalomesenteric duct have been reported in the literature. But only a few similar cases that describe swelling of the umbilical cord or cord cyst associated with a patent urachus have been described.
Our aim is to present the case of a newborn with both UCH and patent urachus malformations and highlight the distinct clinical features, embryology and associated anomalies thereof. We also discuss the importance of an adequate management plan to avoid further complications.

Case Report
A full-term male baby was delivered by emergency C-section due to oligohydramnios (amniotic fluid index 2.7), intrauterine growth retardation and was severely small for gestational age (2.260kg). During routine prenatal care, the ultrasound showed an umbilical cord cyst of 10 to 12cm in length. On physical examination at birth, a cyst at the base of the umbilical cord was noted with no other gross congenital anomalies. (Fig-1) Over the following days the umbilical cord remained moist and increased in size.
A postnatal ultrasound was performed, showing extension of the bladder vertex, consistent with a persistent urachus, no other anatomic malformations or signs of urinary tract obstruction were observed. (Fig-2) Surgery was carried out eight days after delivery. A supra-and infra-umbilical midline laparotomy was performed followed by sectioning and ligation of the umbilical vessels. A wide, permeable urachal defect of 2cm was identified communicating with the bladder. A Foley catheter was installed filling the bladder with saline solution confirming permeability from the bladder to the umbilical defect. Sectioning of the patent urachus at the base of the bladder dome was performed followed by closure of the bladder with sutures in two planes. To complete the operation, closure of the abdominal wall and an umbilicoplasty was performed. The Foley catheter was left for seven days. There were no intraoperative complications and postoperative recovery was uneventful. The patient was discharged nine days later in a good clinical condition. One month after surgery, the umbilical scar looked acceptable and there was no evidence of recurrence or complications on ultrasound examination.

Discussion
UCHs arise due to a failure of closure of the abdominal wall. This occurs following return of the physiologically eviscerated abdominal contents to the umbilical coelom during the fetal period. It is commonly misdiagnosed as a small omphalocele which differentiates itself by having a normal cord insertion, adequate muscle development of the abdominal wall and a wall defect less than 5cm. Omphaloceles also present with healthy skin surrounding the base of the cord. We present a table with the main differential diagnoses of UCH comparing embryological origin, clinical features, associated anomalies and prognosis. (Table-1) The management of UCH begins at the point of delivery, as inadequate clamping of the umbilical cord may cause damage to its contents. UCH represents a defect at a more advanced stage of embryological development than the other aforementioned abnormalities'. UCH has a lower morbidity overall, as it is not associated with other anomalies, has fewer complications and is relatively straightforward to resolve with an excellent prognosis. Furthermore, the surgical procedure to manage a UCH carries a lower morbidity in comparison to that for gastroschisis and omphalocele.
As mentioned previously, the urachus is an embryologic remnant derived from the lack of obliteration of the allantois lumen. It carries arteries on either side, which undergo fibrosis forming the medial umbilical ligaments. The most frequently observed urachal malformations are the persistence of a urachus and urachal cyst. Due to their anatomical  The urachal remnants in patients less than six months old normally resolve spontaneously, being supported with urethral catheterization to facilitate their closure. If it fails to resolve spontaneously, surgical resolution is recommended via laparoscopy or open surgery through an umbilical incision. The primary goal for a satisfactory management is to prevent urinary tract infections and, to a lesser extent, avoid neoplastic urachal changes. The risk of malignancy of the umbilical remnant is rare and uncertain [10]. Some authors suggest that the absence of epithelial elements would make it unlikely to undergo malignant degeneration; therefore waiting for spontaneous resolution is a reasonable alternative [11]. Similar to a UCH, a patent urachus shows little association with other malformations and its early, accurate diagnosis is crucial to avoid further complications.
There are few case reports of umbilical cord cysts described in the literature [7,11,12,13], and as mentioned previously it is one of the main differential diagnosis of UCH and commonly related with persistent urachus. The case described has evisceration of abdominal contents into the cord, not considered as a cyst, but still a cord anomaly which derives from the same embryologic origin. Therefore, we think it is important to rule out the presence of urinary anomaly when a pathologic swelling of the cord is found.
Due to the low incidence of both UCHs and a patent urachus as well as its broad range of differential diagnoses, it is important to know their clinical presentation and the diagnostic perinatal methods employed for appropriate management and favorable results. This relies on knowing when to suspect possible associated anomalies and when complementary studies might be needed, as in the case of a gastroschisis or omphalocele. Furthermore, it is important to note that trivial umbilical pathologies may be misdiagnosed as UCHs and other abdominal defects indicating surgery. It is also important to be aware that despite being a rare occurrence, there is the rather interesting possibility of a UCH and a patent urachus existing simultaneously.
Depends on the associated anomaly and karyotype.