Delayed Infrarenal Aortic Pseudoaneurysm Treated by Endovascular Stent Graft in Pyogenic Spondylitis
A 61-year-old male patient presented with severe back pain for 15 days, which occurred even during rest. A physical examination showed tenderness in the back are, and difficulty changing positions due to pain. Motor and sensory functions were normal. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were elevated to 88 mm/hr and 88.2 mg/L (normal, <8.0 mg/L) respectively. Lumbar spine magnetic resonance imaging (L-MRI) findings showed disk space narrowing and an endplate irregularity with a hyperintense signal on T2-weighted images at the L1-2 and L3-4 disk levels, as well as diffuse swelling in prevertebral and paraspinal soft tissue at the lumbar spine level, which suggested early findings of infective spondylodiscitis (). The patient underwent conservative treatment with teicoplanin antibiotic for 6 weeks.\nHowever symptoms did not improve, and motor power of both low extremities was weakened to grade IV with persistent radiating pain. Laboratory results showed an increased ESR to 130 mm/hr and CRP of 111 mg/L. A blood culture was positive for methicillin-resistant Staphylococcus aureus (MRSA), and a follow-up L-MRI demonstrated progression of the pyogenic spondylitis (). The patient underwent a staged operation. Posterior decompressive laminectomy at the abscess level (L1-3), drainage of the epidural abscess, and posterior instrumented fusion (T11-L5) were performed initially (). The psoas abscess was partially drained posteriorly by approaching posteriorly through the intertransverse membrane, followed by longitudinal splitting of the psoas muscle, which was targeted on MRI images. The intraoperative specimen culture result was positive for MRSA. Debridement of the infected tissue and reconstruction with an autogenous iliac strut bone graft was performed 2 weeks after the initial surgery using an anterior retroperitoneal approach (). ESR and CRP were 81 mm/hr and 9.43 mg/dL at 4 weeks postoperatively. The patient developed relative sudden discomfort on the left flank area over a 3 day period at 7 weeks postoperatively. ESR and CRP were 71 mm/hr, and 37.9 mg/dL, respectively. A contrast L-MRI showed the lesion as a hematoma-like dilatation (). Diagnostic angiography demonstrated a weakly enhanced, pulsating dilatation without definite arterial wall involvement, which was 6.4 cm×4.5 cm in size. We radiographically diagnosed the lesion as a pseudoaneurysm located in the infrarenal aortic area (). An endovascular stent graft (SEAL stent graft type I; 2.4 mm×6 cm; S & G Biotech Inc., Seoul, Korea) was applied. The celiac trunk, the superior mesenteric artery, and both renal arteries were preserved, whereas the inferior mesenteric artery was blocked (). The flank pain disappeared immediately after applying the graft. However, Klebsiella pneumoniae was detected in blood and urine cultures, so we administered intravenous meropenem according to the sensitivity test, which controlled the infection. The antibiotic was continued for 4 weeks until the CRP value normalized. Thereafter, infection control was uneventful. Laboratory findings remained stable at the 6 month follow-up (ESR, 64 mm/hr; CRP, 3.70 mg/dL), and at the 3 and one-half year follow-up (ESR, 35 mm/hr; CRP, 2.08 mg/dL). The patient has maintained normal daily life without medication ().