PEDIATRICS Vol. 108 No. 2 August 2001, pp. 493-494

EXPERIENCE AND REASON:
Delayed Separation of the Umbilical Cord Attributable to Urachal Anomalies

The umbilical cord of the newborn usually separates and sloughs by the end of the second postnatal week.¹ However, a wide variation exists in the age at which cord separation occurs in healthy infants with regard to ethnicity, geographical location, and methods of cord care. A marked delay in cord separation raises the suspicion of leukocyte adhesion deficiency (LAD), a rare disorder leading to defective neutrophil function.² Patients with LAD type I have been found to have a history of delayed umbilical cord separation and omphalitis in infancy.³ As this immunologic disorder has a high morbidity and mortality, screening and early detection are recommended. This has prompted increased referrals for screening for immune defects. Two infants in whom an alternate diagnosis for the delayed cord separation was made are described.

	CASE REPORTS

Case 1

The first case was a healthy male infant born at 41 weeks' gestation by cesarean section, weighing 8 lbs, 2 oz. He had no history of local or systemic infections at 3 months of age. His growth and development were appropriate for age. Physical examination revealed an active, well-appearing infant with mild eczema of the cheeks and a firmly attached, dry umbilical cord (Fig 1). There was no erythema, induration, or discoloration of the umbilicus or abdominal wall. On investigation, total and differential blood counts were normal, with normal T and B cell subpopulations. Evaluation for leukocyte adhesion markers revealed normal expression of CD18 and CD 11 a, b, and c molecules on leukocyte cell surfaces, excluding an adhesion defect. Ultrasound showed a well-demarcated, extraperitoneal, subumbilical cyst. There were no other genitourinary abnormalities. Complete surgical excision of a urachal cyst was done. The postoperative period was uneventful, with good healing on follow-up.

View larger version (110K): [in this window] [in a new window]   Fig. 1.   The still attached umbilical cord of infant 1 at 90 days of age, before surgery.

Case 2

The second case was a healthy, male infant born at 40 weeks' gestation by normal vaginal delivery. His birth weight was 8 lbs, 10 oz. At 4 weeks of age, because of the persistently attached umbilical cord he was referred for screening for congenital immune defects. Results of the immunologic screening tests (as detailed above for infant 1) were normal. As he was healthy and growing normally he was followed-up as an outpatient. At 6 weeks of age the umbilical cord was still firmly attached. No other abnormalities were seen on physical examination. At 8 weeks of age, he developed a mild discharge at the umbilicus with an erythematous, periumbilical rash. Bacteriologic culture of the discharge was negative for pathogens. An umbilical granuloma was diagnosed and local cauterization with silver nitrate was done. As the discharge persisted, a diagnostic ultrasound of the abdomen was done which showed a subumbilical cyst just below the abdominal wall. The genitourinary tracts were normal. Complete excision of the urachal cyst was done. On follow-up, there were no complications with good healing.

	DISCUSSION

Top Introduction Discussion Conclusion References

The time at which the umbilical cord separates is often a cause of concern to parents. Several studies in both developing and developed countries have followed healthy newborns to determine the effect of perinatal factors such as birth weight, gestational age, type of delivery, and neonatal complications on umbilical cord separation. A study of 911 neonates by Oudesluys-Murphy et al⁴ determined the mean time of cord separation as 7.4 days (standard deviation: 3.3; range: 1-29 days). In 1993, a follow-up of 293 consecutive healthy term newborns by Rais-Bahrami et al⁵ estimated the mean age at cord separation to be 10.9 days. Other studies^6,7 have reported the mean age at cord separation to range between 5.8 and 10.9 days. Overall, cord separation may be said to be delayed when it occurs after 2 weeks and is considered well beyond the normal limit when it occurs after 3 weeks of age.

Although the precise mechanism of cord separation is not known, drying, infarction, collagenase activity, necrosis, and granulocyte influx may all influence the time at which it occurs. Superimposed bacterial infection of the umbilicus may delay this process. Perinatal factors influencing the histology of the umbilical area have been studied in neonates who had died when cord separation was occurring or had just been completed.⁸ Histopathologic results showed that the older the infant was at death, the greater was the degree of infiltration of polymorphonuclear cells into the area of separation of the umbilical cord. Granulocyte influx and phagocytosis play a role in the resorption of the umbilical cord base leading to involution, cord separation, and healing.

The movement of neutrophils toward sites of inflammation and emigration from the bloodstream is mediated by various families of adhesion molecules including integrins and selectins. A genetic defect in the -subunit of the integrin molecule (gene symbol ITGB2) has been described as LAD I in >150 children, with profound impairment of leukocyte mobilization into extravascular sites.² The pathologic hallmark of LAD I is the complete absence of neutrophils in sites of infection and consequently necrotic areas that are devoid of pus. These patients have recurrent bacterial infections, primarily localized to skin and mucosal surfaces that are often apparent from birth onward. Because of the lack of neutrophils at sites of inflammation, a common presentation in infancy is omphalitis with delayed separation of the umbilical cord. Recurrent infections and sepsis beginning in infancy and failure to thrive are usually present. Stem cell or bone marrow transplantation from histocompatible relatives are the best means of treatment.

When cord separation is delayed in healthy infants with no local or systemic infections, an important diagnostic consideration is a urachal anomaly, as reported in the 2 infants described here. Obliteration of the urachus normally occurs during the fourth and fifth gestational month resulting in a fibrous cord extending from the dome of the bladder to the umbilicus.⁹ Variable persistence of the urachal tract results in 4 anatomically distinct anomalies which are: 1) a patent urachus (as a result of total lack of involution) with free communication between the bladder and the umbilicus in 50% of cases; 2) a urachal cyst consisting of a portion of the urachus containing desquamated epithelial cells (30% of cases); 3) a urachal sinus communicating with the umbilicus; and 4) a vesicourachal diverticulum communicating with the bladder. A review of 45 pediatric patients with urachal anomalies during the period 1970 to 1997 by Cilento et al¹⁰ included 24 boys and 21 girls with an average age of 4 years. The presenting complaint was periumbilical discharge in 42% of the patients. A urachal cyst was diagnosed in 16 (36%) of these patients. Urachal cysts are noncommunicating urachal duct remnants that occur anywhere along a line between the bladder and the umbilicus. In a completely walled off urachal cyst, there may be no discharge at the umbilicus, as was the case with infant 1. These cysts are small and remain undetected, being discovered in infancy in only a third of cases. If left untreated, a urachal abscess can develop, which may rupture either through the umbilicus or into the peritoneal cavity causing peritonitis.

In neonates, a delay in umbilical cord separation may indicate an underlying urachal anomaly. A knowledge of anatomy and embryology as well as a high index of suspicion are required to establish the correct diagnosis. The optimal diagnostic modality for urachal anomalies depends on the clinical presentation.¹⁰ The anatomic extent of the anomaly is best delineated by a computed tomography scan, but is limited by its cost. An ultrasound of the abdomen serves as well and the appearance of a fixed midline, extraperitoneal cystic swelling between the umbilicus, and the bladder suggests the diagnosis of a urachal cyst. However, if the cystic component is absent, this diagnosis may be missed. In cases where there is an accompanying umbilical discharge, a sinogram or a voiding cystourethrogram are diagnostic for a urachal sinus or a patent urachus.

	CONCLUSION

Top Introduction Discussion Conclusion References

Pediatricians need to keep in mind the possibility of a urachal anomaly when faced with delayed separation of the umbilical cord. In otherwise healthy infants, this diagnosis should be considered before testing for leukocyte adhesion defects. Complete surgical excision is the treatment of choice.

Samiya Razvi, MD^*
Ramon Murphy, MD
Edward Shlasko, MD^{, §}
Charlotte Cunningham-Rundles, MD, PhD^*,
* Division of Clinical Immunology, Departments of  Pediatrics and ^§ Surgery
Mount Sinai Medical Center
New York, NY 10029

	FOOTNOTES

Received for publication Nov 9, 2000; accepted Feb 16, 2001.

Address correspondence to Charlotte Cunningham-Rundles, MD, PhD, Mount Sinai Medical Center, Box 1089, 1425 Madison Ave, New York, NY 10029. E-mail: chalotte.cunningham-rundles{at}mssm.edu

	ABBREVIATIONS

LAD, leukocyte adhesion deficiency; CD, cluster of differentiation.

	REFERENCES

Top Introduction Discussion Conclusion References

1. Kliegman RM, Stoll BJ. The fetus and the neonatal infant. In: Behrman RE, Kliegman RM, Jenson HB, eds. Nelson Textbook of Pediatrics. 16th ed. Philadelphia, PA: WB Saunders; 2000:527
2. Hayward AR, Leonard J, Wood CBS, Harvey BAM, Greenwood MC, Soothill JF Delayed separation of the umbilical cord, widespread infections and defective neutrophil mobility. Lancet 1979; 1:1099-1101 [CrossRef][Medline]
3. Etzioni A, Harlan JM. Cell adhesion and leukocyte adhesion defects. In: Ochs HD, Smith CIE, Puck JM, eds. Primary Immunodeficiency Diseases: A Molecular and Genetic Approach. New York, NY: Oxford University Press; 1999:375-387
4. Oudesluys-Murphy AM, Eilers GAM, de Groot CJ The time of separation of the umbilical cord. Eur J Pediatr 1987; 146:387-389 [CrossRef][Medline]
5. Rais-Bahrami K, Schulte EB, Naqvi M Postnatal timing of spontaneous umbilical cord separation. Am J Perinatol 1993; 10:453-454 [Medline]
6. Sarwono E, Disse WS, Ousdesluys-Murphy AM, Oosting H, de Groot CJ Paediatr Indones 1991; 31:179-184 [Medline]
7. Bhalla JN, Nafis N, Rohtagi P, Singh J Some observations on the separation of the umbilical stump in the newborn. Indian J Pediatr 1975; 42:329-334 [Medline]
8. Oudesluys-Murphy AM, den Hollander JC, Hop WC Umbilical cord separation: histological findings and perinatal factors. Biol Neonate 1990; 58:236-240 [Medline]
9. Bauer SB, Retik AB Urachal anomalies and related umbilical disorders. Urol Clin North Am 1978; 5:195-202 [Medline]
10. Cilento BG Jr, Bauer SB, Retik AB, Peters CA, Atala A Urachal anomalies: defining the best diagnostic modality. Urology 1998; 52:120-122 [CrossRef][Medline]