Milrinone does not improve free flap survival in microvascular surgery

Free flap microvascular surgery involves the transfer of a mobilised tissue flap with complete vascular re-anastomosis at the new site. Ischaemia frequently threatens flap survival and may require a return to the operating theatre for anastomotic revision. Arterial spasm and hypoperfusion are recognised as factors in flap ischaemia. Phosphodiesterase inhibitors such as milrinone may improve flap blood flow and possibly flap survival by arterial dilation and increasing cardiac output. To investigate the role of milrinone in this type of surgery, a double-blinded randomised controlled trial was conducted with 88 patients receiving either a milrinone bolus and infusion throughout surgery or placebo (normal saline). We found that milrinone did not improve graft survival, return to theatre rate, or surgically graded arterial spasm, but did require more vasopressor support. We conclude that intraoperative milrinone did not improve flap outcomes in microvascular surgery.