PMC6159109_01
CT scan immediately after conclusion of surgery in prone position. Non-contrast-enhanced (a) and contrast-enhanced (b) scans show the dislodged transforaminal lumbar interbody fusion spacer in the prevertebral space (arrows). Significant vascular trauma has led to the formation of a pseudoaneurysm with incorporation of the spacer. Early arterial contrast phase documents extensive contrast within the inferior vena cava (c, d) up to the diaphragm indicating an arteriovenous fistula. Please note that the right renal artery (star) is merely located in close proximity to the inferior vena cava (d) without further vessel anomaly.
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The scan revealed only minor retroperitoneal haematoma [Figure 1].
CT scans on the 2nd postoperative day. (a, b) show coronal and transversal non-contrast-enhanced CT images of the chest. The transforaminal lumbar interbody fusion spacer (arrows) has embolized to the left pulmonary artery, partly extending into the lower lobe artery. Contrast-enhanced image (c) of the prior transforaminal lumbar interbody fusion location proves its embolization. The arteriovenous fistula originating from the right common iliac artery is now more clearly identifiable.
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A follow-up CT scan on the second postoperative day revealed that the spacer had not only been incorporated into the venous system but had embolized in the left pulmonary artery, partly extending into the lower lobe artery [Figure 2].
Angiographic images of the transforaminal lumbar interbody fusion (TLIF) retrieval procedure: (a) The wedged TLIF spacer (arrow) is embolized to the left pulmonary artery. (b) Arteriovenous fistula (star) originating from the right common iliac artery. (c) Occlusion of the arterial shunt feeder by application of overlapping covered stents due to residual arteriovenous fistula after initial stenting (10/20 mm Advanta stent and 11/38 mm Advanta stent). The right internal iliac artery is consecutively occluded. (d) Retrieval of the TLIF spacer and retraction thereof into the right femoral vein utilizing an Amplatz GooseNeck  Snare Kit. Re-migration of the spacer during venotomy was prevented by introducing a venous balloon catheter via the contralateral groin in order to temporarily occlude the right iliac vein.
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The TLIF spacer, which continued to be located within the left pulmonary artery [Figure 3a], was grasped by means of a snare catheter (Amplatz GooseNeck  Snare Kit, Medtronic Minimally Invasive Therapies Group, Mineapolis, Minnesota, USA), mobilized and retrieved through the inferior vena cava. AV fistula originating from the right common iliac artery [Figure 3b] was temporarily occluded with an inflated balloon. Almost immediately, blood pressure levels increased significantly, spiking to as much as 300 mm Consecutive angiographic visualization revealed a persisting AV shunt, so another covered stent was placed in overlapping technique (11/38 mm Advanta  stent, Maquet, Rastatt, Germany), resulting in occlusion of the arterial side of the shunt and covering of the right internal iliac artery [Figure 3c]. Re-migration of the spacer during venotomy was prevented by introducing a venous balloon catheter via the contralateral groin in order to occlude the right iliac vein [Figure 3d].