삼킨 생선 뼈에 의해 발생한 요막관 농양

대한요로생식기감염학회지: 제2권 제2호 2007년 10월

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238

•교신저자：이길호, 단국대학교 의과대학 비뇨기과학교실 충남 천안시 안서동 산 29

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E-mail: [email protected]

삼킨 생선 뼈에 의해 발생한 요막관 농양

단국대학교 의과대학 비뇨기과학교실

[Abstract]

Urachal Abscess Caused by a Swallowed Fish Bone

Inho Sohng, Gilho Lee

From the Department of Urology, College of Medicine, Dankook University, Cheonan, Korea

A 64-year-old man visited our hospital with a 2 weeks history of lower abdominal pain and palpable mass. Physical examination revealed a tender mass in the suprapubic area. Abdominal ultrasonography and abdominal computerized tomography of the patient showed a cystic mass and adhesion of the bowel with a foreign body which fortunately found out to be a fish bone. An urachal abscess was suspected, and we first drained the cystic mass and debrided the necrotic tissues. We then performed a complete resection of the urachal remnant, a fistulectomy, a partial resection of adhesive ileum and a partial resection of the bladder. Urachal abscess by a swallowed fish bone is rare, and it was only reported in Japan. A preoperative diagnosis with ultrasonography or CT scan may be helpful to evaluate patients and make a treatment plan. (Korean J UTII 2007;2:238-241)

Key Words: Urachus, Abscess

Urachal abscess is rare disease and related to urachal anomalies.

Clinically, urachal anomalies can be simplified into 3 categories based on presentation.

The first and most common presentation is periumbilical inflammation. This is most frequently associated with an infected urachal cyst. The second is umbilical drainage, which can be related to an urachal sinus, patent urachus, or an alternating urachal sinus.

The third is the incidental finding of an asymptomatic

urachal diverticulum during cystoscopy, or an asymptomatic urachal cyst found on screening ultrasound scan. An infected urachal cyst can present with abdominal pain and tenderness as well as fever, nausea, vomiting and leukocytosis, closely mimicking acute abdomen. Misdiagnosis of anurachal anomaly may lead to significant delays in treatment. Here we present a case of an infected urachal cyst caused by a swallowed fish bone.

CASE REPORT

A 64-year-old man was visiting our hospital with a

송인호 외: 삼킨 생선 뼈에 의해 발생한 요막관 농양 239

Fig. 3. The foreign body is a fish bone (Lophiomus setigerus) in the infected urachal cyst.

Fig. 2. CT scan shows a irregular shaped mass near anterior abdominal wall contained heterogenous low density lesions. The white line arrow indicates a needle shaped foreign body.

Fig. 1. Ultrasound image shows round cystic mass with asymmetric wall thickening. The white line arrow indicates high echogenic linear foreign body.

2 weeks history of lower abdominal pain and a palpable mass. There was no associated vomiting or diarrhea. On initial physical examination the patient had a mild fever 37.5℃ and a 12×10cm tender mass.

Reddish discoloration was observed on the skin covering the mass. He had no diabetes mellitus, hypertension or other chronic conditions on medical history review. Remarkably however, he reported eaten bony fish meat two months ago. Initial laboratory test

are as follows: white blood cell count 22480/mm,

hemoglobin 11.5g/dl, hematocrit 34.0%, and platelets

485×10/mm,

CRP test 14.20mg/dl, Electrolytes-sodium

138, potassium 4.3, chloride 105mEq/L, and creatinine

0.63mg/dl, BUN 8.5mg/dl, AST 25U/L, ALT 18U/L,

total bilirubin 0.40mg/dl, glucose 91mg/dl. On

radiologic evaluation, an abdominal ultrasonography

demonstrated a 10×5.1×5.3cm sized, focal high

echogenic mass, located just below the umbilicus with

asymmetric wall thickening and a needle shaped foreign

body (2.7cm length) in the central portion of the mass

(Fig. 1). And an abdominal computerized tomography

demonstrated 9×6×7.4cm sized mass with multiple

septations. The mass contained several heterogenous low

density lesions and was connected to the bladder. In

addition, the foreign body which was noted on the

previous ultrasonography was also observed in the mass

on the computerized tomography (Fig. 2). There was no

lymph node enlargement. Based on above all findings

although we were not able to completely rule out a

sarcoma, a urachal abscess was suspected. We

planned a 2-stage operation that first was emergent

240 대한요로생식기감염학회지: 제2권 제2호 2007년 10월

operation for drainage with decompensation of the abscess followed by resection of the urachal remnant with partial cystectomy for patient. A vertical lower midline incision was made. On the surgical findings, we found severe adhesions of the subcutaneous tissues, rectus muscle, rectus fascia and peritoneum. A multiple septated abscess pocket, suspected to be a urachal cyst, was found just beneath the adhesive tissues. There were multiple necrotic tissues around the abscess. The infected cyst was drained (pus, about 20cc), and the necrotic tissue was debrided. Culture was sent to laboratory and cytology to department of pathology. The foreign body that presented on previous radiologic studies was found in the cyst and then removed. It appeared to be a fish bone (Fig. 3).

We finished the first operation, and apenrose drain was left in place. After the operation, the symptoms of the patient was much improved and all laboratory findings were normalized. After antibiotic therapy for 3days, the 2nd operation was done. The same incision was used from the previous operation. We found adhesion and a fistula of the cyst with ileum. So, we performed a fistulectomy, a partial resection of the ileum, a complete resection of the urachal remnant with partial cystectomy. Organism from culture studies was Streptococcus Salivarius. The cytology showed negative finding. On pathologic findings, the urachal remnant was lined by metaplastic columnar epithelium associated with extensive inflammation with many foreign body gaint cells. The patient was discharged after 7days and followed up for 9 months without complications.

COMMENT

lesions of the genitourinary tract that often come to the attention of the pediatric general surgeon due to their frequent abdominal manifestations and the young age at presentation. However, symptomatic urachal remnant occasionally presents in adults. Urachal

remnants are an end results of incomplete regression of the intra-embryonic connection between the allantois and the cloaca.

Especially urchal cyst may form in the isolated urachal canal if the lumen is enlarged with epithelial desquamation and degeneration. Urachal cysts are found in 1 in 5,000~8,000 and 30% of all urachal anomalies.

A non-infected urachal cyst has no significant general symptoms, but an infected urachal cyst can cause lower abdominal pain, tenderness, mass, fever and voiding difficulty. Possible causative conditions of infected urachal remnant are urinary tract infection, secondary infection through vascular or lymphatic systems, even by trauma.

But infection of urachal remnant by an ingested foreign body (fish bone) is extremely rare with only 3cases in Japan.

We presume the mechanism of development of the abscess is that the swallowed fish bone was indigested and caused a perforation of the bowel. The species of the fish was Lophiomus setigerus (Vahl).

Urachal anomalies must be at least considered in the

differential of every patient with abdominal pain or

an abdominal mass, especially in the pediatric

population. However, this presents a problem to the

clinician as these disorders may mimic any one of a

large number of conditions. Since the diagnosis may

prove difficult due to a nonspecific presentation, it is

important to consider that a urachal abscess,

especially when perforated, may closely mimic the

symptoms of other etiologies of acute abdomen. An

incorrect preoperative diagnosis was made in 55% the

cases of urachal abscess in Minevich’s series, equal

to an incorrect diagnosis rate of 35%.

Nagasaki et

al

reported a 75% success rate for the ultrasound

diagnosis of nurachal remnants, including urachal

cysts. Ultrasound is an ideal modality for diagnosing

urachal cysts, since these entities are cystic,

extraperitioneal and directly related bladder. In our

case, an abdominal ultrasonography was used to

diagnose a urachal cyst as well as an intra-urachal

송인호 외: 삼킨 생선 뼈에 의해 발생한 요막관 농양 241

foreign body. But a complete radiological evaluation, including cross-sectional CT or MRI should be performed in each patient presenting with an acute abdomen and suspected urachal abscess to ensure the correct preoperative diagnosis and appropriate management unless ultrasound was definitive.

We utilized CT image to confirm the urachal cyst and identify adhesions, and the foreign body, these were used to help determine the course of treatment.

Blichert-Toft et al

reported that the persistence of epithelium leads to a recurrence rate of 30% if excision does not follow. MacNeily et al noted a high rate of complications after primary excision of urachal abscesses, although they were mostly wound infections.

Minevich et al reported that median postoperative hospital stay for the urachal abscess group was 14 and 11.5 days for single and 2-stage procedures and after immediate excision postoperative complications developed in each cases, although none occurred with a 2-stage approach.

We performed aprimary drainage of the abscess and debridment of necrotic tissue. And then definitive surgical correction (resection of the urachal remnant, fistulectomy, resection of adhesive ileum, and partial cystectomy) was done after sufficient antibiotic therapy for several days. It was successful treatment for our patient without complication.

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