During laparoscopy, methylene blue was injected into the cystic mass using a 6F urethral catheter through the heterotopic sinus. The dissection was difficult because of severe adhesions between the cystic mass and the bladder; hence, we removed the cystic mass and part of the anterior wall of urinary bladder. We also closed the heterotopic sinus. Histopathological examination confirmed that this mass was urachal tissue (Fig. 2B). After the patient was discharged from the hospital, we conducted a 6-month follow-up to him by telephone and the recent results showed that the patient was discharged without any complications. We will follow-up by telephone every 6 months until 5 years after surgery.
The urachus is located in the center of a pyramid-shaped space outside the peritoneum. This space has its base on the anterior dome of urinary bladder, and the tip is directed toward the umbilicus. The length of the urachus ranges from 3 to 10 cm, and the diameter ranges from 8 to 10 mm. It is connected by 1 or 2 closed umbilical arteries. The urachus is surrounded by the umbilicovesical fascia, which means that a disease of the urachus usually occurs inside the pyramid-shaped space. If the urachus remains either open or partially obliterated, different urachal anomalies are seen.
The Fox's classification, which identifies 4 types of urachal anomalies, is most commonly used; patent urachus (50%): it might be caused by retubularization, rather than as a primary patency. This type is more common in newborn babies and presents with continuous or intermittent drainage of fluid from the umbilicus. Umbilical-urachus sinus (15%): In this type, the urachus remains open at the umbilical site and closed at the bladder level. It has a similar manifestation to the patent urachus. It can occur at any age and presents with a purulent secretion. Urachal cyst (30%): The cyst has no communication with the bladder or umbilicus. If there are no complications, there will be no symptoms for life. Once infected, it can manifest as lower abdominal pain, voiding symptoms, or a painful and palpable mass. Vesicourachal diverticulum (3–5%): Except at the level of the bladder apex, the urachus obliterates completely. This type usually has no symptoms because the diverticulum communicates with the bladder and drains into the bladder well. If the neck is narrow, it may cause stone formation and urinary tract infections. Rich adds another type of urachal anomalies, which is named as the alternating sinus: it is a cyst-like structure that can drain to either the bladder or the umbilicus. There are only 2 cases reporting the urachal remnant with heterotopic sinus on the dorsum penis. Based on the observations during surgery and the histopathological results, we diagnosed of our case as the alternating sinus.
Diagnosing an urachal anomaly can be complicated. A careful history and physical examination is important. Using the ultrasound, CT scan, retrograde urethrography, and voiding cystourethrogram can be helpful.[4,5] In our case, the CT scan demonstrated a 4 cm cystic mass next to the anterior wall of the urinary bladder. The retrograde urethrography demonstrated that this mass communicated with the heterotopic sinus on the dorsal side of the normal external urethral orifice, which led us to consider the possibility of an urachal anomaly. The pathology results confirmed our assumption. It is worth mentioning that the possibility of associated genitourinary defects must be considered because they can be more harmful than the urachal anomaly itself. In our case, the patient had undergone a surgery for the congenital malformations of the 2 feet more than 20 years ago. Further examination did not reveal any associated genitourinary defects.
Once the diagnosis of urachal anomaly is confirmed, the urachus and other tissues must be removed immediately because the remnants can be cancerous.[6–8] If there are some complications such as infection, the surgery should be performed after the infection is controlled. During the surgery, we can inject methylene blue to identify the direction of the drainage. However, the diseased tissue must be completely removed.[7,8] The superficial arteriovenous vein and dorsal nerve should be well protected when dissociating and resecting the fistula.
Urachal remnant with heterotopic sinus is rare, and we recommend that urachal remnant should be considered when a patient presents with a mass in the retropubic space.
Data curation: Zhao-Hui Sun, Xiang-Hui Kong, Wen-Jie Huang, Gang Chen.
Writing – original draft: Zhao-Hui Sun, Xiang-Hui Kong, Wen-Jie Huang.
Writing – review & editing: Xiao-Jun Huang.
Zhao-Hui Sun orcid: 0000-0003-2294-7476.
. Zhu XW, Shen Y, Zhang BH, Yan JJ. Diagnosis and treatment of urachal remnants with heterotopia sinus: a report of 2 cases. Zhonghua Nan Ke Xue 2005;11:142–4.
. Berman SM, Tolia BM, Laor E, et al. Urachal remnants in adults. Urology 1998;31:17–21.
. Rich RH, Hardy BE, Filler RM. Surgery for anomalies of the urachus. J Pediatr Surg 1983;18:370–2.
. Catanzaro D, Mirk P, Carbone A, et al. Amebic abscess of urachal remnants. Eur J Radiol 2001;38:219–24.
. Yu JS, Kim KW, Lee HJ, et al. Urachal remnant
diseases: spectrum of CT and US findings. Radiographics 2001;21:451–61.
. Gleason JM, Bowlin PR, Bagli DJ, et al. A comprehensive review of pediatric urachal anomalies and predictive analysis for adult urachal adenocarcinoma. J Urol 2015;193:632–6.
. Risher WH, Sardi A, Bolton J. Urachal abnormalities in adults: the Ochsner experience. South Med J 1990;83:1036–9.
. Jeong HJ, Han DY, Kwon WA. Laparoscopic management of complicated urachal remnants. Chonnam Med J 2013;49:43–7.
. Potisek N, Weihe J. Infected urachal cyst. N Engl J Med 2016;375:2582.
Keywords:Copyright © 2019 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.
heterotopic sinus; urachal anomaly; urachal remnant