Persistent Urachal Patency Presenting as Umbilical Discharge: A Surgical Case Report

Abstract

Patent urachus is a very rare congenital anomaly caused by failure of obliteration of the allantois, which generally reduces during fetal development to form the urachus. In humans, the urachus typically closes by the end of the first trimester and persists as the median umbilical ligament; failure of this process results in a persistent communication between the bladder and the umbilicus. This anomaly most commonly presents in the neonatal period with urinary leakage from the umbilicus and presentation beyond infancy is uncommon, often leading to diagnostic challenges. Urachal anomalies are classified into patent urachus, urachal sinus, urachal cyst and bladder diverticulum and early recognition with surgical excision is recommended to prevent recurrent infection and other complications.

We report a significant case of patent urachus in a 15-year-old female who presented with a one-year history of intermittent discharge from the umbilicus and mild pain in the periumbilical region. Imaging, including USG and contrast-enhanced computed tomography, confirmed the presence of a patent urachus extending from the umbilicus to the dome of the urinary bladder. The patient underwent laparoscopic excision of the urachus, with absolute resolution of all postoperative symptoms. This case signifies the importance of considering patent urachus as a differential diagnosis of chronic umbilical discharge in older children and focuses the value of proper imaging and timely surgical intervention for achieving favourable outcomes.

Introduction

The urachus is a fibrous remnant of the allantois, an embryonic canal that drains the fetal bladder and passes through the umbilical cord. It lies in the space of Retzius, between the transversalis fascia anteriorly and the peritoneum posteriorly.^[1] The allantois extends from the body stalk to the cloaca, giving rise to the bladder and becoming evident by the eighth week of gestation. By the fourth to fifth month, it normally obliterates to form the urachus, a fibrous cord from the bladder to the umbilicus. As the fetus grows, the urachus typically loses its lumen and detaches from the umbilicus before birth, remaining as a fibrous vestige.^[2]

In humans, the urachus usually closes by 12 weeks’ gestation, later forming the median umbilical ligament, though it may rarely remain patent. Congenital patent urachus was first described in the 16th century, with more than 100 neonatal cases reported. It occurs in about 0.02 per 1,000 live births and can be detected prenatally by ultrasonography. Diagnosis often follows umbilical stump separation, when urine leaks from the navel.^[3] Urachal anomalies are rare and present in four forms: Patent urachus (a complete bladder-umbilicus connection); urachal sinus (open only at the umbilicus); urachal cyst (fluid-filled mid-portion remnant); and bladder diverticulum (patency at the bladder end).^[4]

This case report describes a rare patent urachus in a 15-year-old female with recurrent umbilical discharge. Its presentation beyond infancy highlights diagnostic challenges in older children, where such anomalies are often missed. We detail the clinical features, diagnostic evaluation and surgical management, underscoring the need to consider patent urachus in paediatric patients with chronic umbilical discharge. This case emphasises the importance of heightened clinical suspicion for urachal anomalies in older children to enable early diagnosis and timely treatment.

Case Presentation

A 15-year-old female patient came to the surgical OPD and presented with a history of persistent and intermittent umbilical discharge for the past one-year, occasionally associated with mild pain in the periumbilical region for the same year. There was no significant history of fever, urinary symptoms such as haematuria, anuria or dysuria, abdominal distension or bowel habit abnormalities. The patient had no significant past medical or surgical history and developmental milestones were appropriate for the age. General physical examination revealed normal physiological parameters and vitals were found to be normal. Local abdominal examination revealed a small amount of serous discharge released from the umbilicus with moderate tenderness on deep palpation, but there was no presence of surrounding erythema, swelling or signs of acute infection. Other systemic examinations were found to be normal.

As the symptoms were chronic, imaging was done and initial ultrasonography suggested the presence of a tubular tract extending from the umbilicus toward the dome of the urinary bladder. Contrast-enhanced computed tomography of the abdomen gave clear and detailed anatomical delineation, confirming a patent urachal tract from the umbilicus to the urinary bladder dome, without any associated abscess, intraperitoneal collection or calcification. Routine laboratory investigations, including CBC, LFT and RFT, were well within the normal ranges. These findings supported the diagnosis of patent urachus, requiring surgical intervention as a treatment modality to relieve symptoms and prevent any further complications such as recurrent infection or malignant transformation.

The patient underwent laparoscopic excisional surgery under general anaesthesia. Intraoperatively, a well-defined tubular structure, anatomically delineated, was identified and meticulously dissected from the umbilicus to its attachment at the urinary bladder dome, ensuring complete resection while avoiding injury to adjacent structures. The residual defect was safely closed with absorbable polydioxanone sutures, proper clotting was confirmed and the procedure was concluded without any complications. The postoperative period was smooth and uneventful, with proper early restart of oral feeds and minimal movement after the required time for essential rest and healing was given. The complaint of umbilical discharge was completely resolved and at follow-up, the patient remained asymptomatic with excellent wound healing and no recurrence.

Discussion

Patent urachus is a congenital anomaly that can present either in infancy due to a widely patent tract or posterior urethral valve or in elderly individuals secondary to lower urinary tract obstruction, such as benign prostatic hyperplasia.^[5] Occasionally, a young patient may present with pus discharge from the umbilicus or urine discharge secondary to a urethral stricture or a lower urinary tract calculus. History plays an important role in the evaluation of patent urachus. Patent urachus may develop shortly after birth or later within the first 7–14 days of life.^[6] Foals with patent urachus may appear otherwise healthy, may show early signs of infection or may have prolonged recumbency due to another primary disease condition. The average umbilical cord measures about 1.5 cm in diameter and 3.6 cm in circumference and an abnormally thick umbilical cord should raise suspicion of an underlying urachal anomaly.^[7] In the absence of obvious abnormalities at birth, some infants and older children may later present with persistent umbilical discharge, often described as a urinous discharge.^[8] Umbilical polyps can also result in umbilical discharge and are characterised by the presence of abnormal tissue at the umbilicus that fails to resolve with silver nitrate treatment. In contrast, urachal cysts usually present at a later age, most commonly with infection and may manifest as periumbilical cellulitis, abdominal or suprapubic pain and, in some cases, a palpable mass.^[9] Ultrasonography serves as a valuable diagnostic and follow-up modality in cases of patent urachus and detailed evaluation of the umbilical remnant has been thoroughly reviewed and documented in previous literature. In neonatal foals, patent urachus may arise due to simple mechanical causes, infectious processes, systemic illness or a combination of these factors.^[10]

Simple patency generally resolves on its own, while a few mechanical factors, such as increased abdominal pressure or improper voiding posture, may contribute to persistence. Failure of the normal embryological obliteration of the urachus leads to a persistent communication passage between the bladder and the umbilicus. Depending on the varying extent of persistence along the bladder-umbilical tract, urachal anomalies can be classified as patent urachus (47%), umbilical-urachal sinus (18%), urachal cyst (30%) and vesico-urachal diverticulum (3%).^[11] In critically ill people, specifically those with sepsis or prematurity, a long period of immobilisation and continuous presence of moisture around the umbilical region increase the risk of maceration and late umbilical closure. Identification of these predisposing factors is key to early diagnosis and proper management, helping to avoid secondary complications. Urachal abnormalities can be broadly classified into congenital and acquired forms.^[12]

A study conducted by Doari described a relevant case of bladder evagination, referring to it as umbilical evagination of the bladder, that was associated with a small omphalocele.^[13] Patent urachus is most probably a congenital anomaly, commonly identified at birth and treated during the period of infancy; thus, its presentation in patients older than 20 years is extremely rare. Suspicion of patent urachus is often raised through a detailed clinical history focusing on umbilical symptoms, with diagnostic confirmation obtained using indigocarmine dye testing and fistulography.^[14] Complete patent urachus is usually easy to diagnose in the first few days of life because urine can be seen leaking from the umbilicus. In contrast, other urachal abnormalities are often missed during this period, as they are generally symptom-free unless an infection occurs. Infants with these conditions may initially be thought to have persistent omphalitis until the correct diagnosis is identified. Although a patent urachus is not life-threatening, failure to treat it can lead to long-term urinary infections and the formation of stones.^[5] In addition, malignant tumour changes arising from urachal remnants have been reported later in life. Because of these possible complications, early identification of urachal abnormalities allows the infant to be monitored closely [Figures 1–4].^[2]

Figure 1.

Contrast-enhanced CT imaging demonstrating a patent urachus extending from the umbilicus to the bladder

Figure 2.

Patent urachus traced superiorly to its attachment at the bladder dome

Figure 3.

Intraoperative delineation of a patent urachus

Figure 4.

Division of the urachus at the bladder with primary bladder repair using PDS sutures

Grinda reported a case of a female infant born with complete eversion of the bladder through the umbilicus. They suggested that this abnormality represented a variant of patent urachus, complicated by herniation of the bladder.^[15] Graßl reported a prevalence of patent urachus of 4.5% in foals examined up to 10 days of age. In contrast, the present study found a higher rate of 7.8% in foals assessed up to 14 days of age, which may be explained by the wider age range included. In this group, patent urachus most commonly appeared as a secondary urachal fistula, accounting for 91.1% of cases, while persistent urachus present at birth represented only 8.9%. By comparison, a study conducted by Codina reported an unusual pattern, with patent urachus more commonly detected at birth, occurring in 27.5% of children. These differences among studies are likely related to variations in the study design, inclusion and exclusion criteria and the timing of the clinical trial.^[7] Imaging is key in both the diagnosis and management of major urachal abnormalities. USG is commonly used as the first-line investigation, as it provides a non-invasive method for visualising and analysing a patent urachus and any relevant anomalies.^[16] Fluoroscopic and cystoscopic methods using contrast agents are useful in tracing the umbilico-vesical tract. Advanced imaging techniques, including CT and MRI, provide a very detailed anatomical resolution and can help detect the presence of fluid, air or calculi mass within the urachus, as well as assess for further complications such as malignancy or infection. In the following study, the fluoroscopy method was used to confirm the diagnosis and define the umbilico-vesical tract, while ultrasonography was employed to guide the removal of the umbilical cord.^[17]

Conclusion

Patent urachus is a very rare congenital anomaly that typically presents in the neonatal period of life and is very rarely encountered after infancy. This case highlights an abnormal presentation of patent urachus in a 15-year-old girl child with chronic discharge from the umbilicus, emphasising the diagnostic challenges associated with delayed presentation in older patients of the paediatric age group. Accurate imaging played a pivotal role in establishing the diagnosis and complete surgical excision resulted in an excellent clinical result with absolute resolution of all the symptoms. This case is remarkably significant due to its rarity apart from the neonatal period, in the older paediatric age group and highlights the importance of maintaining a high index of consideration and suspicion for urachal anomalies in the non-neonatal age group presenting with persistent umbilical discharge, thereby assisting in timely diagnosis and definitive management.