Rupture of urachal diverticulum in radiation cystitis and neurogenic bladder dysfunction after radical hysterectomy

Authors


Masako Kawakami md, Department of Urology, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto 390-8621, Japan. Email: kawakamimasako@hotmail.com

Abstract

Abstract  We experienced a rare case of the rupture of the urachal diverticulum in radiation cystitis and neurogenic bladder after radical hysterectomy. A 61-year-old woman presented with severe lower abdominal pain and urinary retention. Abdominal computed tomography revealed that the urachal remnant contained a large volume of urine that leaked to subcutaneous tissue. We excised the urachal diverticulum and bladder together and created a continent urinary diversion using transverse colon. Nine months after the operation, the patient could manage clean intermittent self-catheterization 6 times a day through her umbilical stoma without any urinary complications.

Introduction

Urachal remnants are categorized into five major groups: patent urachal, urachal sinus, urachal diverticulum, urachal cyst and alternating sinus.1 They are rarely observed clinically and most cases do not require any treatment. We report a rare case of the rupture of the urachal diverticulum due to voiding dysfunction and the low compliance bladder. We also discuss the treatment of this patient.

Case report

A 61-year-old woman presented to emergency room (ER) of the Maruko Central Hospital, Japan, with severe lower abdominal pain and urinary retention. The patient had felt abdominal pain for four days before she visited the hospital and took antibiotic medicine and pain killers without any result. The patient felt that her total urine volume was decreasing after the pain started and experienced urinary retention the day she went to the hospital. The patient had had difficulties with voiding for 20 years after she underwent a radical hysterectomy for uterus carcinoma stage IIb and had received postoperative irradiation of 40 Gry. However, she did not consult an urologist regarding her urinary difficulties. Her physical examination showed red skin extending from the suprapubic area to the bilateral dorsal skin and a distended lower abdomen. The serum blood urea nitrogen (BUN) level was 86.4 mg/dL and creatinine level was 7.44 mg/dL. Computed tomography (CT) showed an urinoma in the abdominal wall connected to the urinary bladder. The venous-injected contrast medium flowed inside the urinoma and leaked into the abdominal muscle and subcutaneous space. The large subcutaneous area of the lower abdomen showed edematous change caused by inflammation (Fig. 1). Bilateral hydronephrosis and hydroureter was shown. There was no fluid discharge from the umbilicus. The patient still felt suprapubic tenderness after the evacuation of 700 mL of urine by transurethral catheterization. The ER doctor suspected an abscess of urachal remnant and consulted the Department of Urology, Shinshu University School of Medicine, Asahi, Matsumoto, Japan. Indwelling catheterization in the bladder did not remove enough urine from the urinoma to the bladder. Percutaneous drainage of the urinoma resulted in the gradual disappearance of the reddish skin. Urinalysis of the fluid from the urinoma showed a red blood cell count of 100/high power field (HPF) and a white blood cell count of 45/HPF with no bacterial growth. We placed four open drains in the urinoma space. The serum BUN level and creatinine improved to normal range after four days of drainage. We suspected that the patient had asymptomatic urachal remnant before radical hysterectomy and irradiation. The patient's bladder then changed to a thick wall and low compliance bladder as the CT showed and she had voiding dysfunction after the treatment. Voiding pressure would dilate the urachal remnant, making the urachal remnant grow as a large urinoma and finally, the urine seeped into the subcutaneous tissue. The patient underwent retrograde cystography that confirmed the urinoma on CT was equal to the dilated urachal remnant that is categorized as an urachal diverticulum (Fig. 2). The cystogram also suggested a contracted bladder with a capacity of less than 100 mL. The urachal diverticulum was excised together with the bladder and, using the transverse colon, a continent urinary diversion was created.2 A part of the rectus sheath and the parietal peritoneum removed with the urachal diverticulum because they were one clump (Fig. 3). The pelvic space looked like a ‘frozen pelvis’ due to the irradiation of 40 Gry and, therefore, it was very difficult to resect the bladder. Pathological examination of the specimen showed that the diverticulum was thick–walled with acute and chronic inflammation and the bladder wall consisted of fibroblastic tissues. Three months after the operation, the patient could manage clean intermitted self-catheterization six times a day through her umbilical stoma without any urinary complications.

Figure 1.

Computed tomography scans of abdomen. a) An urinoma is shown in the abdominal wall connected to the urinary bladder. b) The contrast medium has leaked from bladder (arrow) to the urinoma. The bladder wall is very thick.

Figure 2.

Retrograde cystography shows a contracted bladder and urachal diverticulum that is drained by open drain.

Figure 3.

a) The photo of the excised specimen. Arrows enclose the inner surfaces of urachal remnant. b) Illustrative diagram of the photo. The stars show a canal between the bladder and urachal remnant. The white space at the right side of the canal is the inner surface of the bladder.

Discussion

The majority of urachal diverticulum are asymptomatic, are usually detected during cystography and do not require treatment. However, it appears that a large urachal diverticulum associated with neurogenic bladder may require resection. Berman et al.3 reported a similar urachal diverticulum case. In the present case, we could not successfully demonstrate that the urinoma was an urachal remnant in histopathological study, because most of tissue had changed to fibroblastic tissue. However, we became convinced that it was an urachal diverticulum from CT and operative findings, as the ventral border of the urinoma was rectus sheath and the dorsal border was parietal peritoneum. The reason for removing the bladder with the urachal remnant was that we believed clean intermittent self-catheterization would not work well in such a low compliance bladder. Computed tomography showed the bladder wall was very thick and the bladder capacity was less than 100 mL on retrograde cystograpy. The operative findings showed that the decision was correct as the bladder was contracted and the muscle had changed to fibroblastic tissue. In the present case, the bladder function of the patient was impaired by radical hysterectomy and radiation therapy, after which the urachal diverticulum would have gradually distended and finally ruptured into the subcutaneous space. From the present case, we have to recognize that the potential risk of the rupture of a urachal remnant or the bladder itself in neurogenic bladders caused by pelvic irradiation or pelvic operation. Therefore, these patients need urological follow-up at least once a year.

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