An 81-year-old man, with a 3-day history of loss of appetite and abdominal pain, presented to the emergency department of our hospital with fever and tachypnoea. His hemodynamic status was stable; however, chills, shivering, and mild tenderness in the upper abdomen were observed at presentation. The patient had a history of hypertension, hyperlipidaemia, insulin usage for type 2 diabetes mellitus, percutaneous coronary intervention for unstable angina pectoris, and postoperative lobectomy for right lung cancer. The patient had also undergone pancreaticoduodenectomy for a duodenal papillary carcinoma, and had experienced recurrent cholangitis since then. Blood tests revealed a white blood cell count and C-reactive protein level of 12,100/µL and 10.87 mg/dL, respectively. While chest radiography revealed no abnormalities, contrast-enhanced computed tomography (CT) revealed a pseudoaneurysm in the descending thoracic aorta (at the level of Th10) surrounded by fluid accumulation (Fig. 1A, B). Based on the fever, inflammatory response, and the aneurysm shape, we diagnosed the patient with as having an ITAA.
We performed a minimally invasive TEVAR as an emergency procedure even though the patient presented with a pseudoaneurysm and localized rupture, owing to his advanced age, medical histories (especially insulin usage for type 2 diabetes mellitus), and fears of progression to a free rupture. Meropenem and vancomycin were administered intravenously before the TEVAR procedure, and a 28 × 100 mm GORE TAG device (W. L. Gore and Associates, Flagstaff, Ariz) was implanted during the procedure. One week after TEVAR, a blood culture yielded Escherichia coli, and the antibiotic therapy was switched to cefotaxime. The inflammatory response decreased, and the patient remained afebrile; however, CT performed 17 days after TEVAR revealed that the abscess cavity had extended beyond the proximal end of the implanted stent-graft, i.e., into an area uncovered by the graft. Considering the possibility that the patient was refractory to cefotaxime, the antibiotic therapy was switched to meropenem. However, the abscess cavity continued to enlarge (Fig. 1C, D), and we decided to perform a surgical intervention. The patient was re-evaluated for his eligibility for a prosthetic graft replacement; however, the procedure was deemed too invasive due to the initial preoperative risk as well as the patient's worsening frailty. Instead, abscess drainage and autologous tissue filling were performed simultaneously for further infection control. The use of the omentum for the filing procedure was deemed difficult owing to the patient’s history of pancreatoduodenectomy; thus, LDM flaps were selected instead. Eighteen days after the second TEVAR, a thoracoscopic abscess debridement was performed to prevent damage to the LDMs intended for use in the autologous tissue filling procedure. This operation was performed through a small incision made 10 cm away from the left fifth intercostal space. The abscess was detected using ultrasound, and a 5 cm long-axis incision was made through the aortic adventitia. The abscess was debrided and the abscess cavity was cleaned; following this, drains were placed. Similar to the blood culture, a pus culture also yielded Escherichia coli. Seven days after abscess debridement, stent-graft wrapping was performed using LDM flaps constructed with the thoracodorsal artery as the feeding vessel. The surgery was performed through thoracotomy at the left fifth intercostal space. We widened the previously debrided aortic exenteration site in a cephalocaudal direction and completely unroofed the abscess cavity. The stent graft was partially exposed (Fig. 2A), and the abscess cavity was thoroughly flushed. The LDM flaps were guided into the thoracic cavity from the second intercostal space and wrapped around the stent-graft (Fig. 2B). Two weeks after the stent-graft wrapping procedure, the antibiotic therapy was switched from meropenem to cefotiam based on pus culture results; it was administered intravenously for 6 weeks after abscess debridement. The patient was then switched to oral levofloxacin, and a lifelong oral antibiotics policy was adopted.
Postoperatively, debridement and wound closure were performed using a rectus abdominis musculocutaneous flap. The patient made an excellent recovery and was discharged home on day 77. No recurrent infection was observed at the 8-month outpatient follow-up.