Case report: Emphysematous cystitis due to Escherichia coli infection with the extension of gas into multiple locations in two non-diabetic dogs: a computed tomographic diagnosis and successful management

Emphysematous cystitis is an extremely rare, complicated urinary tract infection with the presence of gas in the bladder wall and lumen caused by gas-producing bacterial infections. A 7-year-old spayed female pomeranian dog was presented with a 3-day history of hematuria and pollakiuria (case 1), and a 9-year-old spayed female jindo dog was presented with a 4-day history of intermittent hematuria (case 2). Imaging modalities, including radiography, ultrasonography, and computed tomography, and bacterial culture tests were used for the diagnosis. Emphysematous cystitis due to Escherichia coli infection with the extension of gas into multiple locations was identified in both cases. Based on the results of antibiotic susceptibility testing, systemic antibiotics were initiated. Both animals had an excellent response to antibiotic treatment, and the clinical signs of the gas collection were completely resolved within ~1 month after treatment initiation. This response was sustained without recurrence in the follow-up period. This case report describes clinical details of extremely rare canine cases of emphysematous cystitis with the extension of gas into multiple locations and evaluates the clinical efficacy of antibiotic therapy.

Anatomic Variations of the Perineal Arteries and Nerves in the Male and Female Dog and Its Clinical Implications

The anatomic variations of the perineal arteries and nerves are studied in the dog. The aim of the study is to provide a more detailed understanding of the blood supply and innervation of the perineal region, providing detailed information on the perineal arteries and nerve distribution and their variability in male and female dogs. The study used 232 pelvic halves from 116 adult dogs and analysed the differences using the chi-squared test. The results showed that the presumptive model for perineal artery distribution described in N.A.V. was observed in 46% of the specimens. Additionally, a dorsal perineal artery "long type" was found in 13% of the dogs, and a perineal trunk was present in 41% of the dogs. In the study, there was no variation in perineal nerve distribution, and it was found that the perineal nerve did not run together with the dorsal perineal artery when it was the "short type" as described in the presumptive model for perineal artery distribution. Instead, it always followed the route of the dorsal perineal artery "long type" and the perineal trunk when they were present. The findings of the study may be useful for veterinary surgeons when approaching the perineal region in dogs.

A New Anatomical Pathway of Spread of Pus/Sepsis in Anal Fistulas Discovered on MRI and Its Clinical Implications

BACKGROUND

In the anal sphincter complex, the intersphincteric space between the internal and external sphincters is the only conventionally recognized pathway for the spread of sepsis. However, there is another unrecognized space discovered on MRI, the "outer-sphincteric space", between the external anal sphincter and its lateral fascia along which pus can spread. An abscess in the intersphincteric space is easily drained into the rectum via the transanal route and is more likely to spread into the supralevator space. Conversely, an abscess in the outer-sphincteric space is difficult to drain transanally into the rectum and is more likely to become a transsphincteric abscess/fistula.

METHODS

The MRIs of anal fistula patients operated over four years on intersphincteric abscesses were analyzed. The pattern of spread into the ischiorectal fossa and/or supralevator space and ease of drainage into the rectum through the transanal route were studied.

RESULTS

Thirty-six patients were operated on to drain their intersphincteric abscesses through the anal canal. Two distinct patterns were noted. Twenty patients had abscesses in the intersphincteric space, which were easily drained into the rectum. Of them, 6/20 had supralevator extension, while only 1/20 had spread to the ischiorectal fossa. In 16/36 patients, the abscess was in the outer-sphincteric space and could not be drained into the rectum. In 9/16 of these patients, pus spread into the ischiorectal fossa but supralevator spread did not happen in any patient.

CONCLUSION

Apart from the intersphincteric space, there is perhaps another unrecognized anatomical space - the outer-sphincteric space - discovered on MRI, through which pus can spread in anal fistulas or abscesses.

Metastatic prostate cancer to an ischiorectal fossa lymph node identified on multiparametric magnetic resonance imaging

Prostate cancer is the most common noncutaneous malignancy in American men. Its lymphatic drainage is very well established throughout literature. We report the case of a 72-year-old Caucasian male with elevated serum prostate-specific antigen and biopsy-confirmed high-risk prostate cancer who underwent multiparametric magnetic resonance imaging (MRI) for staging and treatment planning. The imaging revealed suspicious lymph nodes in the left ischiorectal and right obturator fossae that were biopsy confirmed as metastatic prostate adenocarcinoma. Herein, we present the divergence from the well-established lymphatic drainage of prostate cancer and the role of MRI in detecting this prostate cancer site of spread.