While there have been over 130 cases of EC documented in the literature [1
], there has only ever been, up to now, one published case report of EC presenting with subcutaneous emphysema [2
]. Using plain radiographs and a cystogram, this earlier case report from 1978 described luminal and possible intramural gas within the bladder and the presence of subcutaneous emphysema in the absence of a possible vesicoenteric fistula. We report the first case of subcutaneous emphysema due to EC based on a clinical diagnosis confirmed using CT.
Emphysematous cystitis, per se, was first described in 1671 when a patient was said to have passed wind (i.e., intraluminal gas) through his urethra [3
]. A little later in the 1800s intramural gas was discovered on autopsy [4
]. And in 1961 a review [5
] of multiple cases concluded that the two conditions (i.e. intraluminal and intramural gas) were manifestations of a single disease. The clinical presentation of EC is variable; approximately 53% of cases present with classical symptoms of urinary tract infection [6
], whilst others may present with an acute abdomen [7
]. Up to 7% of cases are asymptomatic and are diagnosed on the basis of an incidental finding on abdominal/pelvic imaging [6
In spite of the variation in clinical presentation of EC, type 2 diabetes mellitus has been shown to be present in 2/3 of all cases, and of these 64% were women [1
]. These figures may well be even higher as a 1/3 of all cases of diabetes mellitus are undiagnosed [8
]. Moreover, with the predicted doubling of the prevalence of type 2 diabetes from 1995 to 2025 [9
], clinicians need to be aware of its role as possible pathological basis for a complicated or un-resolving UTI.
It is postulated that the presence of gas-producing organisms in conjunction with high glucose or albumin concentrations (both bacterial substrates) favours the development of emphysematous infections within the urinary tract [10
]. In 90% of cases of EC a urinary tract pathogen was isolated [6
], and E. coli
was the most prevalent pathogen (57%). It may very well be that the remaining 10% of cases where a urinary tract pathogen was not isolated may be attributable to detection failure. Indeed, it was only on the second urine culture that E. coli
was isolated in our case.
It is tempting to speculate the anatomical route taken by the perivesicular gas to produce the radiological imaging observed in this case study. It is probable that the carbon dioxide bubbles produced as a result of urinary glucose fermentation collect and pass into the submucosa of the bladder and out into the infra-peritoneal space around the bladder base. Once here these bubbles may move across and diffuse into and through abdominal musculature. Similarly they may move down into the ischiorectal fossa or up through the retroperitoneal paravertebral tissues into the posterior mediastinum [2
The management of EC has remained unchanged over the last 30 years [2
], with broad-cover intravenous antibiotics being used until urinary pathogen sensitivities are known. Concurrently, the bladder should be drained and blood glucose levels should be controlled. Between 10-20% of documented patients with EC underwent surgical debridement [1
]. As carbon dioxide is absorbed readily in human tissue, eventual resolution should occur following antibiotic elimination of the infecting pathogen; hence, the precise role of surgical intervention is not clear. By itself, EC usually runs a benign course with an overall death rate of 7% [1
]; this however rises to almost 50% when perivesicular gas migrates up the urinary tract or when gas-producing organisms infect the kidneys [11
]. It is likely that patients with EC with extensive emphysematous changes will have a worse prognosis because of the greater distribution of perivesicular gas.