Incidental Finding of a Popliteal Artery Aneurysm while performing an iPACK block (local anesthetic infiltration of the interspace between the popliteal artery and the posterior knee capsule): A Case Report 

The popliteal artery is the most common peripheral site for aneurysm formation. Complication rates are 61%, with the most feared complication being acute limb ischemia secondary to thromboemboli. Poplital artery aneurysm (PAA) is also a risk factor in the development of arterial complications during total knee arthroplasty (TKA), with reports of arterial occlusion and other thromboembolic events occurring in the operative period. 

Several studies show the superiority of an iPACK block integrated with an adductor canal block (ACB) in both postoperative pain control and hospital length of stay with no significant difference in postoperative motor function versus an ACBalone in patients undergoing TKA. Discovery of a PAA in this setting has not been described before. This case may highlight the role of ultrasound-guided nerve blocks as an opportunity to screen for PAA in high-risk patients before TKA and other surgeries in this anatomical region.