66 - The Lactobacillus Strikes Back: Peroneal Mycotic Pseudoaneurysm
E. T. Lim, K. Hamdulay, A. J. Heath, P. G. Bridgman, S. C. Dalton, O. T. Lyons, P. E. Laws
Purpose: Peroneal artery pseudoaneurysms are a rare clinical entity, typically due to trauma or iatrogenic injury. There are currently no guidelines describing the optimal management of peripheral mycotic pseudoaneurysms. We present a man presenting with leg pain due to an expanding peroneal artery pseudoaneurysm, as the presentation of infective endocarditis caused by Lactobacillus rhamnosus (typically found in probiotic drinks). To our knowledge, this is the first report on Lactobacillus rhamnosus causing a peripheral mycotic pseudoaneurysm.
Material and Methods: A 71 year-old man presented with a one week history of right calf pain and swelling. He felt generally unwell with fevers and chills. He denied any recent history of trauma or precipitating factors. An ultrasound scan was performed to exclude venous thrombosis, but identified a pseudoaneurysm of the peroneal artery. Dedicated vascular ultrasound demonstrated a pseudoaneurysm neck 3.6mm wide and 3.5mm in length. This was confirmed by computed tomographic angiography. Peripheral blood cultures subsequently grew Lactobacillus rhamosus. Echocardiography demonstrated vegetations on his aortic valve with moderate to severe aortic regurgitation. The pseudoaneurysm was accessed using a Progreat catheter and a 6.5x12mm microvascular plug was deployed across the neck of the pseudoaneurysm, with a good result on completion angiogram. Follow-up ultrasound scan 6 weeks post procedure demonstrated successful occlusion of the pseudoaneurysm.
Results: Peroneal pseudoaneurysms are rare and uncommonly due to infection, but should raise suspicion for a proximal embolic source. Multiple endovascular interventions have been described in the management of crural pseudoaneurysms such as coil embolisation, covered stent insertion or a combination of techniques. These risk endograft infection but appear to be a durable option with comparable outcomes to open surgical repair. We opted for a microvascular plug rather than coil embolisation due to the short section of the peroneal artery feeding the pseudoaneurysm, and the associated risk of occluding the posterior tibial artery.
Conclusions: Lactobacillus rhamnosus may cause peripheral mycotic pseudoaneurysms. Vascular surgeons should be aware of infective endocarditis presenting with peripheral embolisation and infection, which may initially present similarly to deep vein thrombosis. There is no consensus on the best approach to peripheral mycotic pseudoaneurysms, but microvascular plug embolisation may be a durable approach.