Emphysematous cystitis in a patient with type-2 diabetes mellitus.

Emphysematous cystitis is a relatively rare clinical entity caused by gas-fermenting bacteria or fungus. Presentation is often nonspecific and imaging is the best diagnostic modality. We report a case of a 45-year-old male who presented with fever, dysuria, and pneumaturia, and was found to have emphysematous cystitis.

INTRODUCTION

Emphysematous cystitis is a distinct complicated lower urinary tract infection (UTI) characterized by air within the bladder wall and lumen. The disease is most common in middle-aged diabetic women. Patients with chronic UTIs, indwelling urethral catheters, urinary tract outlet obstruction, or neurogenic bladders are predisposed to complicated UTIs such as emphysematous cystitis. Air within the urinary tract can also occur due to instrumentation, fistula to a hollow viscus, tissue infarction with necrosis. Patients might have varied presentations, ranging from incidental diagnosis on abdominal imaging to severe sepsis. Gas-forming infections or emphysematous conditions of the urinary tract are potentially life-threatening, and require prompt evaluation and management. We describe a case of emphysematous cystitis that was managed successfully with bladder drainage, intravenous antibiotics, and strict glycemic control.

CASE REPORT

A 45-year-old male who was a known case of type-2 diabetes mellitus for last 16 years, complained of on and off fever, dysuria and turbid colored urine for last 3 months. He was treated with parenteral antibiotics and improved. However, he was lost to follow up. He was admitted with recurrence of symptoms associated with pneumaturia. He had past history of suprapubic catheterization for obstructive uropathy due to meatal stenosis 15 years back. Clinical examination revealed pallor, penile hypospadias, meatal stenosis, bilateral nonproliferative diabetic retinopathy and evidence of sensory neuropathy. Investigations showed anemia (Hb7.7 gm/dl), neutrophilic leukocytosis (total leukocyte count 19800 cells/cmm (N, 4000–11000 cells/cmm) with 90% neutrophils. Serum creatinine was 3.5 mg/dl (N, 0.6-1.2 mg/dl) and HbA1c was 8.5%. Urine culture grew Escherichia coli sensitive to piperacillin/tazobactum. CT abdomen revealed intraluminal and intramural gas in the bladder with thickening of bladder wall [Figure 1a–c]. Kidneys were normal in size and shape and there was no perinephric stranding or gas in renal parenchyma or renal pelvis. Patient was managed with piperacillin/tazobactum for 6 weeks along with bladder catheterization. Good glycemic control was established with insulin therapy. Patient improved clinically, became afebrile and repeat urine culture was sterile. Figure 1d shows disappearance of intramural and intraluminal gas on follow up CT imaging after 8 weeks. Serum creatinine was decreased to 2 mg/dl, but not normalized probably because of underlying diabetic nephropathy.

Figure 1

(a) Skiagram showing air in the bladder region. (b) Sagittal CT image through pelvis showing pneumobladder and intramural air. (c) Axial CT image through lower pelvis showing pneumobladder, intramural air and circumferential mural thickening. (d) Axial CT image through lower pelvis after treatment showing disappearance of air; however, mural thickening is persisting

DISCUSSION

Emphysematous cystitis was first reported by Hueper in 1926.[1] It is a rare condition, often occurring in diabetic and immunocompromised patients. The organism most commonly responsible is E.coli (58%). Other organisms reported include Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Candida albicans, and Candida tropicalis, Aspergillus fumigatus, Staphylococcus aureus, Group D Streptococcus, Enterococcus faecalis, Enterobacter aerogenes, and Clostridium perfringens and Cl. welchii. The clinical presentation of emphysematous cystitis is varied; patients can be asymptomatic, describe pnematuria, or irritative voiding symptoms, or present with an acute abdomen with severe sepsis.[2] Of reported patients with emphysematous cystitis, 7% were asymptomatic and were diagnosed incidentally on abdominal imaging for other concurrent illnesses. Predisposing factors for emphysematous cystitis include diabetes mellitus, neurogenic bladder, lower urinary tract obstruction, urethral catheter placement, vesicourethral reflex, and end stage renal disease. The effects of diabetes mellitus on the urinary tract include diabetic nephropathy, renal papillary necrosis, renal artery stenosis, and bladder dysfunction secondary to neuropathy. These factors combined with glycosuria and impaired leukocyte function place diabetic patients at greater risk of complicated UTIs such as emphysematous cystitis.[3] Overall, two-thirds of reported cases of emphysematous cystitis were diabetic and 64% were women.

The symptoms of emphysematous cystitis are similar to those of uncomplicated cystitis, consisting of frequency, urgency, and dysuria. Patients may be asymptomatic or have nonspecific complaints. Pneumaturia is an infrequent presentation. Therefore, a high index of suspicion is required for diagnosis especially in patients with risk factors.

Diagnosis of emphysematous cystitis is established by radiological means. Plain radiographs of the abdomen reveal radiolucency within the lumen of the bladder as a ring of radiolucency outlining the bladder wall. Computed tomography of the abdomen is superior to plain radiographs as a diagnostic tool because it clarifies the extent and location of the gas collection as observed in our case. A pathological assessment of involved bladder tissue might show bladder wall thickening with vesicles of varying size, and microscopically there are multiple gas filled vesicles predominantly within the bladder mucosa, lined by flattened fibrocytes and multinucleated giant cells.[24]

It is thought that the high glucose concentration within the tissues acts as a favourable substrate for organisms to produce carbon dioxide through facultative anaerobic glycolysis. However, this does not account for the significant number of non-diabetic patients with emphysematous infections. In such patients, urinary albumin might act as the substrate for gas production by urinary pathogens. Another theory suggests that an impaired host response, involving vascular compromise and impaired catabolism within the tissues, predisposes patients to gas production within these tissues.[5] The pathogenesis is not yet fully understood, but a multifactorial aetiology of impaired host responses with sugar or protein fermentation seems to be a plausible explanation for the production of gas within the affected tissues.

Management consists of adequate urinary drainage, appropriate antibiotic treatment, and good blood glucose control. Surgical debridement or cystectomy may rarely be needed. However, delayed diagnosis may lead to extension to the ureters and renal parenchyma, bladder rupture, and death.[6] The overall death rate of emphysematous cystitis is 7%. The gas is reabsorbed once the infection is eliminated as was seen in our patient [Figure 1d].

CONCLUSION

History of pneumaturia and evidence of intraluminal and intramural gas along with bladder thickening on imaging clinches the diagnosis of emphysematous cystitis.