Aortic complications after treatment with bacillus Calmette-Guérin: a tertiary hospital experience and an update of the literature

Background: Intravesical instillation of bacillus Calmette-Guérin (BCG) is currently the gold standard for treating non-muscle-invasive bladder cancer (NMIBC). Vascular complications following bladder instillations, including the development of mycotic aneurysms, are extremely rare. This study aims to report six cases of mycotic aneurysm following intravesical BCG instillations and to review the relevant literature. Methods: We present a case series of six patients with mycobacterial aortic infections related to BCG treatment, managed at our hospital between 2017 and 2023, following the PROCESS (Preferred Reporting of Case Series in Surgery) guidelines. Additionally, a literature review was conducted using major international databases (PubMed, Scopus, and EMBASE). Results: A total of 74 patients with aortic lesions following intravesical BCG instillation have been reported in the literature. All patients were male (74/74), with a mean age of 72±7 years. The demographic characteristics in our series were similar. In five of our six cases (83.3%), the infection involved the thoracic or thoracoabdominal aorta. The mean time from the first BCG instillation to the development of a mycotic aneurysm was 15±2 months in the literature, whereas in our experience it was 26 months. Overall, open surgical repair was the definitive treatment in 71.6% of patients, whereas in our series the rate was 83.3%. Major postoperative complications included bleeding (2.7%), multi-organ failure (4%), and reinfection (4%). The overall 30-day mortality rate was 9.4%, in our series was 16.6% (one case). All surviving patients initiated multidrug antitubercular therapy. Conclusions: Although extremely rare, mycotic aneurysms related to intravesical BCG instillation can develop months to years after treatment. Diagnosis requires a high index of suspicion due to nonspecific symptoms. Both prosthetic and biological grafts yielded favorable outcomes regarding early mortality and morbidity. Postoperative multidrug antitubercular therapy appears essential following surgical repair.