II. Physiology

  1. Urachus develops from Urogenital sinus
    1. Superior portion develops into Bladder and Urachus
    2. Inferior portion develops into Urethra
  2. Urachus obliterates during month 4-5 of gestation
    1. Urachus left as fibrous cord remnant
    2. Cord stretches from Bladder to Umbilicus

III. Signs

  1. Persistent drainage from newborn Umbilicus
  2. Delayed separation of Umbilical Cord
  3. Omphalitis

IV. Causes: Urachal Anomaly (Urachus not fully obliterated)

  1. Patent Urachus (50%)
    1. Results from complete lack of urachal involution
    2. Free communication from Bladder to Umbilicus
  2. Urachal Cyst (30%)
    1. Cyst of desquamated epithelial cells
    2. Small and undetected in two thirds of cases
    3. Risk of urachal abscess with secondary peritonitis
  3. Urachal Sinus
    1. Communication with Umbilicus
  4. Vesicourachal Diverticulum (Bladder Diverticulum)

V. Radiology: Urachal Anomaly Detection

  1. CT Abdomen (best evaluation)
  2. Abdominal Ultrasound
  3. Voiding Cystourethrogram (if umbilical discharge)

VI. References

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Ontology: Urachus (C0041916)

Definition (NCI_NCI-GLOSS) A fibrous cord that connects the urinary bladder to the umbilicus (navel). The urachus is formed as the allantoic stalk during fetal development and lasts through life.
Definition (NCI) The urinary canal of the fetus; postnatally it is usually a fibrous cord but occasionally persists as a vesicoumbilical fistula. (MeSH)
Definition (MSH) An embryonic structure originating from the ALLANTOIS. It is a canal connecting the fetal URINARY BLADDER and the UMBILICUS. It is normally converted into a fibrous cord postnatally. When the canal fails to be filled and remains open (patent urachus), urine leaks through the umbilicus.
Concepts Embryonic Structure (T018)
MSH D014497
SnomedCT 14105008
English Urachus, urachus, median umbilical ligament, Structure of urachus (body structure), Structure of urachus
Swedish Fostrets urinkanal
Czech urachus
Finnish Urakus
Russian URAKHUS, MOCHEVOI KHOD, МОЧЕВОЙ ХОД, УРАХУС
Portuguese Úraco
Polish Przewód omoczniowy, Moczownik
Norwegian Urachus, Fosterets urinkanal
Spanish estructura del uraco (estructura corporal), estructura del uraco, uraco, Uraco
French Ouraque
German Urachus
Italian Uraco
Dutch Urachus, Urinekanaal

Ontology: Persistent umbilical sinus (C0266357)

Definition (NCI) A congenital abnormality that results from the failure of the lumen of urachus to be obliterated. It presents with leakage of urine from the bladder through the umbilicus.
Concepts Congenital Abnormality (T019)
ICD10 Q64.4
SnomedCT 123282008, 34351008, 205018004, 253898008, 398316009
English Persistent umbilical sinus, patent urachus (diagnosis), patent urachus, urachus patent, Patent Urachus, Urachus: [patent] or [persistent] (disorder), Persistent umbilical sinus (disorder), Urachus: [patent] or [persistent], Persistent urachus, Patent urachus, Patent urachus (disorder), Patent urachal duct, persistent; urachus, urachus; patent or persistent, urachus; persistent, Patent urachus -RETIRED-, Patent of urachus
Spanish uraco patente, uraco patente - RETIRADO -, uraco patente - RETIRADO - (concepto no activo), uraco patente (trastorno), uraco persistente, seno umbilical persistente, uraco permeable (trastorno), uraco permeable
Dutch persisterend; urachus, urachus; open of persisterend, urachus; persisteren