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Inchauste. Plast Aesthet Res 2023;10:27 https://dx.doi.org/10.20517/2347-9264.2022.139 Page 11 of 15

The first step is to evaluate the arterial and venous anastomosis for adequate flow. This can be assessed with
[61]
a strip test, intraoperative Doppler, or angiography with the use of indocyanine green . If arterial or
venous thrombosis is identified, maneuvers to remove the thrombus, correct the problem and reestablish
perfusion are performed.

Direct thrombectomy:

When a thrombus within the vessel is suspected, the first step is to open or cut out the anastomosis. The
vessels should be inspected for intimal injury or technical errors, such as a suture catching the vessel
backwall that may be the source of thrombus. Direct thrombectomy can be performed at the anastomosis.
Jewler’s forceps can be used to gently milk the clot out of the vessel in an atraumatic fashion. The vessel is
then copiously irrigated with heparinized saline irrigation. The vessel lumen is inspected again for any
intimal injury and cut back to healthy tissue. Adequate flow of the recipient artery is evaluated to ensure
complete removal of a possible proximal thrombus. The anastomosis is then revised, and the flap reassessed
for perfusion.

Fogarty:

If the thrombus cannot be directly removed from the vessel using Jewler’s forceps, then a Fogarty catheter
can be used to perform the thrombectomy in free flap salvage . The Fogarty catheter is passed distal to the
[62]
thrombus, gently inflated the balloon to fill the lumen of the vessel without overexpansion, then slowly and
gently pulled back to remove the clot. Fogarty catheters can damage the vessel lumen; therefore, it is
imperative to limit the number of passes and not overexpand the balloon. Improper technique can denude
the endothelium and cause intimal dissection, vessel rupture, or balloon rupture inside the vessel, leaving
foreign material within the vessel lumen [63,64] . Once the thrombus has been removed, it is critically important
to carefully inspect for any intimal injury before proceeding with anastomotic revision.

Thrombolysis:

If thrombectomy cannot be accomplished or distal thrombosis in the microvascular circulation is suspected,
then targeted thrombolytic therapy is a crucial next step. Tissue plasminogen activator (TPA) is an enzyme
that catalyzes the conversion of plasminogen to plasmin and breaks down fibrin in thrombus. TPA is a
thrombolytic that can be used in flap salvage. Thrombolytics are often given when there is extensive clot
burden, incomplete thrombectomy and evidence of microvascular thrombosis in the capillary system seen
with no-reflow phenomenon. No reflow phenomenon occurs when arterial inflow has been reestablished
and adequate venous thrombectomy has been performed, but there is inadequate venous flow from the flap
vein.

Thrombosis at the level of anastomosis is adequately treated with thrombectomy and does not require
thrombolytic intervention. However, distal arteriolar and capillary thrombus cannot be manually or
mechanically evacuated but instead require chemical thrombolysis [65,66] . TPA is typically injected into the
flap arterial system and allowed to marinate within the flap, then drain out the flap venous system. The goal
is to target thrombolytic therapy within the flap without introduction into the systemic circulation. This
allows higher doses of TPA to be administered without systemic complications. The typical dilution dose of
TPA given during flap salvage is 1 mg/mL. A slow injection of 2-10 mg of dilute TPA is performed over a
one-to-two-minute period [46,48,66,67] , followed by a 10-15 min rest in the flap microcirculation. TPA
administration can be repeated immediately thereafter until adequate venous flow has been