Spontaneous rupture of the urinary bladder (SRUB) is rare and is often a life-threatening condition usually caused by abdominal or pelvic trauma (1). Unfortunately, the diagnosis and treatment of SRUB are often delayed and missed; most cases are discovered during laparotomy. Surgical management is the recommended treatment for SRUB (2). However, the literature proved that conservative treatment by indwelling catheterization could also achieve good results for specific cases (3). Only a small case series of SRUB were found in the literature. Herein, we report two cases and review the literature to illustrate the clinical features, diagnosis, and treatment of SRUB.

The most common causes for SRUB were alcohol intoxication (39.27%), lower urinary tract obstruction (18.37%), bladder tumor or inflammation (12.76%), pregnancy-related causes (7.57%), bladder dysfunction (5.89%), pelvic radiotherapy (3.51%), history of bladder surgery or bladder diverticulum (3.37%), neurological or psychiatric diseases (1.4%), strenuous activity (0.56%), pelvic disease invasion (0.42%), long-term maintenance hemodialysis (0.28%), and idiopathic rupture (6.59%).

Most of the reported cases were diagnosed by exploratory laparotomy (51.89%), cystography (22.64%), computed tomography (14.15%), cystoscopy (8.02%), and Meilan tests (3.3%).

Patients with extraperitoneal rupture presented with abdominal pain, abdominal distention, dysuria, oliguria or anuria, and fever. While the main symptoms of intraperitoneal rupture patients could be various and non-specific. The patients' main symptoms are shown in Table 2.

A total of 154 patients were reported to be misdiagnosed, as summarized in Table 3. The patients were misdiagnosed with acute abdomen, inflammatory digestive disease, bladder tumor or inflammation, and renal failure in a ratio of 78.57, 11.69, 5.84, and 4.55%, respectively.

Overall, 84.57% of patients were treated by open surgery, and most of them were intraperitoneal rupture patients. In total, 1.12% of patients were treated by laparoscopic surgery, and all of them were intraperitoneal rupture patients. Besides, 17 intraperitoneal rupture patients and 6 extraperitoneal rupture patients were treated by indwelling catheterization and antibiotic therapy. Nine patients died due to delayed diagnosis and treatment. The treatment plan is summarized in Table 4. Usually, an indwelling catheterization duration lasted from 1 to 3 weeks.

Spontaneous rupture of the bladder is rare (<1%); the incidence is around 1 in every 126,000 people. The most common cause of bladder rupture is trauma (96%). And the bladder is most vulnerable when distended and can rupture from the weakest point. Extraperitoneal rupture of the bladder occurs in ~60–65% of cases, and intraperitoneal rupture in 25% (1). SRUB (intraperitoneal or extraperitoneal rupture) reported in the literature is a rare and life-threatening event (4). An accurate diagnosis followed by surgical intervention is the key for a successful outcome. Only 319 literature papers of 713 cases were included in our study; most of them were middle-aged men.

By analyzing the 713 cases, we concluded that the primary etiology of SRUB is the weakness of the bladder wall. Therefore, the bladder would rupture at the weak area during urination and increasing abdominal pressure (5). Alcohol intoxication is considered the most common predisposing factor to SRUB, can involve increased urine volume, causing bladder distention, decreasing perception of desire to void, and blunt trauma (6–8). Urinary bladder ruptures are attributed to a variety of predisposing factors, including but not limited to bladder surgery, such as TURBT, bladder repair or partial cystectomy, renal transplantation, bladder artery embolization, causing bladder wall weakness such as in bladder diverticulum (5), tumor infiltration, and inflammation which can also cause bladder local ulceration and necrosis (9, 10). Chronic urinary retention and recurrent urinary tract infections due to bladder dysfunction like neurogenic bladder also predispose a patient to bladder wall weakness and bladder rupture (11). Chronic urinary retention due to benign prostatic hyperplasia (BPH), bladder or urethral calculi, urethral stricture, female bladder outlet obstruction, and female pelvic organ prolapse can also lead to weakness of the bladder wall. Pelvic tumor radiotherapy is a possible cause of bladder complications, including inflammatory infiltrates, fibrosis, necrosis, and cellular atypia (12–14). Chronic urine retention during the prenatal period might also cause SRUB (15).

Other causes of excessive bladder filling can be responsible for rupture of the bladder.

Extraperitoneal bladder rupture most commonly presents with abdominal pain and dysuria. In contrast, intraperitoneal rupture has a classic triad consisting of macroscopic hematuria, abdominal pain, difficulty, or inability to void. Other presentations of bladder ruptures could be various and non-specific, ranging from anuria with free fluid to abdominal distention and oliguria. The diagnosis of SRUB is challenging; therefore, most patients were misdiagnosed with acute abdomen and inflammation of the digestive system.

Case 2 of our report was misdiagnosed as renal failure. This is because when urine comes in contact with the peritoneum, the higher concentrations of creatinine and urea nitrogen in the urine allows for concentration gradient diffusion, thus resulting in continuous reabsorption of creatinine, urea nitrogen, and potassium in the urine via the peritoneum into the systemic circulation. Therefore, the diagnosis will be delayed and missed for several days (5, 6, 16).

Early diagnosis and treatment of SRUB are closely linked to better prognosis (11, 12). Exploratory laparotomy is considered to be the gold standard of diagnosis as almost all the reported cases were diagnosed intraoperatively during a laparotomy for acute peritonitis. After literature review, we found that CT cystography can be the best recommended preoperative evaluation for suspected bladder rupture, and it can allow simultaneous assessment of multiple abdominal organs (17–19).

There are no specific guidelines for the treatment of SRUB. The European Association of Urology guidelines recommend that an intraperitoneal bladder rupture should always be managed by standard surgical repair because it might lead to a life-threatening condition due to the risk of abdominal sepsis and peritonitis. In contrast, conservative management can be considered for extraperitoneal bladder rupture (1, 4). However, after literature review, we found that conservative management proved to be a successful treatment for both intraperitoneal and extraperitoneal bladder rupture under particular situations (3) without severe infection, bleeding, or major injuries. The principles of conservative treatment are adequate urine drainage and antibiotic therapy. For urine drainage, an indwelling catheter or puncture drainage catheter may be used. Laparoscopic surgery can be performed for patients with definite intraperitoneal rupture without severe abdominal infection and other organ injury (5).

SRUB often presents with non-specific symptoms, which results in missed or delayed diagnosis. When patients present with urinary symptoms and abdominal pain suggestive of peritonitis, the possibility of bladder rupture should be taken into consideration, especially those with a history of bladder disease. CT cystography is considered the best accurate non-invasive diagnostic and evaluation tool for suspected bladder rupture. Conservative management is recommended for patients without severe infection, bleeding, or major injuries. The principles of conservative treatment are adequate urine drainage and antibiotic therapy. Early diagnosis and management of SRUB are crucial for an uneventful recovery.

The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author/s.

The studies involving human participants were reviewed and approved by the Second Hospital of Dalian Medical University. The patients/participants provided their written informed consent to participate in this study. Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.

BY, YY, and RA: protocol/project development. YZ, SY, WL, and YH: data collection and management. YZ, SY, WL, CS, and HL: data analysis. YZ, SY, and RA: manuscript writing and editing. All authors contributed to the article and approved the submitted version.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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