|Home | About | Journals | Submit | Contact Us | Français|
In the March JRSM, Mr Richard Krysztopik presented a diagnostic dilemma. Here he records the outcome. The names of those who offered the correct diagnosis, and the prizewinner drawn from a hat, will be announced in the next issue
The patient, a man aged 61 with type 2 diabetes, had been referred with hesitancy of micturition, poor stream, haematuria and dysuria. Pneumaturia was not reported. On examination his abdomen was distended and tympanitic; the prostate was mildly enlarged and smooth. The urine contained 1% glucose and Gram-negative bacteria were seen on microscopy. Antibiotics were prescribed.
Abdominal radiography revealed a massive gas-filled structure, seemingly arising from the pelvis, and a diagnosis of caecal volvulus was suggested. Colonoscopically, the distal colon appeared normal. On barium enema, contrast flowed freely as far as the ascending colon but none reached the caecum (Figure 1).
Caecostomy was undertaken through a right gridiron incision. On entry into the peritoneal cavity a large smooth viscus was encountered, into which a balloon catheter was inserted and secured with a purse-string suture. Gas was released and the viscus deflated; subsequently pus and then urine drained from it. When contrast solution was instilled down the tube, radiographs disclosed an irregular cavity in the pelvis anterior to the rectum. Intravenous urography showed bilateral pelvicalyceal dilatation, with a high-capacity bladder filling easily and corresponding topographically to the gas-filled structure seen on the original radiographs. On cystoscopy the bladder was oedematous and there was moderate enlargement of the median and lateral lobes of the prostate.
The prostate was resected transurethrally and histological examination of the material showed benign prostatic hypertrophy with foci of chronic infection, and chronic cystitis with prominent lymphoid follicles in the lamina propria. On culture the urine grew Escherichia coli. The abdominal tube was removed and the patient recovered without incident.
Emphysematous cystitis (intramural gas) and primary pneumaturia (intraluminal gas) are caused by infection with gas-forming organisms within the bladder lumen or wall. Over half the cases are in middle-aged diabetic patients1, the incidence in women being twice that in men. Autonomic neuropathy or, in men, outflow obstruction results in a stagnant pool of urine where facultative anaerobes produce gas by fermenting urinary glucose. In non-diabetic patients, alcohol is another possible substrate for gas formation2. The commonest pathogen is E. coli, others being Enterobacter aerogenes, Klebsiella, Staphylococcus aureus, streptococci, Proteus and Candida albicans3; infection with the true anaerobe Clostridium perfringens has been described4.
For diagnosis of emphysematous cystitis, several imaging techniques can be used. Plain X-ray images often show thin lines or streaks of radiolucent gas in the bladder wall. Coalescence of gas into bubbles within the bladder wall can give a beaded necklace appearance. When gas is present in the bladder lumen, a fluid level may be seen on erect films. Intravenous urography can reveal filling defects within the bladder, if the bladder wall is involved. Computed tomography (CT)5 and ultrasound6 have been used in the detection of intramural and intraluminal bladder gas. A CT scan is particularly sensitive in detecting air in the upper urinary tract if extension of infection is suspected. Cystoscopy is also diagnostic; tiny bubbles in an inflamed bladder wall are seen.
If emphysematous cystitis is left untreated, infection can extend upward to the kidneys and adrenals with a high mortality3. Prompt treatment by antibiotics, glucose control and bladder drainage leads to resolution of the infection and reabsorption of the gas.