Timing of surgery for a melioidosis-associated abdominal aortic pseudoaneurysm: a case report

Melioidosis is a tropical infectious disease caused by Burkholderia pseudomallei. Although vascular involvement is rare, melioidosis-associated abdominal aortic pseudoaneurysm can rapidly progress and carries a high risk of rupture and mortality. Due to nonspecific early symptoms and the lack of specific guidelines, the optimal timing of surgery remains unclear.

A 62-year-old female farmer from Hainan Province, China, presented with persistent lower abdominal pain for over 10 days, followed by low back pain and fever (maximum 38.0 °C). She was diagnosed with type 2 diabetes mellitus based on persistent hyperglycemia and an HbA1c level of 14.8%. Emergency CTA revealed a focal pseudoaneurysmal lesion of the abdominal aorta at the L3 level, with periaortic inflammatory changes and suspected contained rupture, but no active contrast extravasation. As the patient was hemodynamically stable, empirical piperacillin/tazobactam therapy was initiated with close monitoring. Blood cultures on hospital day 5 suggested gram-negative bacilli, prompting a switch to imipenem/cilastatin. On day 6, cultures confirmed B. pseudomallei, susceptible to imipenem, ceftazidime, and TMP-SMX. Targeted antimicrobial therapy was continued with addition of TMP-SMX. The patient's fever, pain, and inflammatory markers improved significantly. Follow-up CTA on day 21 showed marked resolution of periaortic inflammation, and blood cultures became negative on day 28. Antimicrobial therapy was switched to ceftazidime on day 30, and open vascular reconstruction was performed on day 38.

In melioidosis-endemic regions, aortic infection should be considered in diabetic patients with fever and abdominal or back pain. For carefully selected patients with suspected contained rupture, hemodynamic stability, and good response to targeted antimicrobial therapy, delayed elective open reconstruction under strict surveillance and with emergency intervention capability may be a feasible strategy. However, this single case cannot establish the superiority of delayed surgery or define the optimal timing of intervention.