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Chen et al. Plast Aesthet Res 2023;10:24 https://dx.doi.org/10.20517/2347-9264.2022.136 Page 11 of 26

balloon. The catheter may be introduced via the proximal lumen or a distal side branch if one of sufficient
size is available for cannulation. The catheter should be carefully passed until it reaches the perforating
vessels entering the flap to ensure that the entire vessel is cleared. Prior to withdrawal, the balloon is
typically inflated to half its total capacity to minimize damage to the perforator. Multiple passes may be
needed to completely eliminate the propagated thrombus . Once the mechanical thrombectomy is
[101]
complete, heparinized saline flushes can be used to assess the flap’s resistance to flow. If the pedicle can be
flushed easily and venous return of the saline is confirmed, a revision of the anastomosis should be
attempted. Nevertheless, if resistance to flow is detected, chemical thrombolysis may be needed. At our
center, a catheter clearing dose of 1-2 mg of tissue plasminogen activator (tPA) is used. To avoid systemic
thrombolysis, we ensure that the flap is isolated from the systemic circulation during the injection of the
tPA. After the thrombolytic is allowed to dwell within the flap for several minutes, the flap is again flushed
with 300-500 milliliters of heparinized saline to minimize the introduction of systemic tPA after
reanastomosis. Furthermore, should an arterial thrombus not be identified after opening the anastomosis,
the venous anastomosis should be further explored per the Intraoperative Management of Venous
Insufficiency guidelines.

Although the above algorithm is used for complete loss of inflow, it is also possible to have partial loss of
arterial flow. If the clinical examination or ICG angiography demonstrates inadequate flow to only a portion
of the flap, the presence of partial flap thrombosis should be considered. Partial flap thrombosis, especially if
it is thought to be intra-flap thrombosis, is often treated with medical management. At our center, we
typically attempt to treat partial intra-flap thrombosis with a combination of chemical thrombolysis (e.g.,
tPA), anticoagulation and/or simple debridement of the thrombosed portion of the flap.

Postoperative management of arterial insufficiency
Reoperation
If arterial thrombosis is suspected in the postoperative period, expeditious return to the operating room to
expose the anastomosis is the most appropriate next step . Time to reoperation is consistently shown to be
[90]
associated with salvage rates after arterial and venous thrombosis [71,72,102] . Likely secondary to delays in
management, the rate of flap salvage in postoperative compromise is less than that of intraoperative
[90]
compromise . It has been shown that the use of careful continuous postoperative monitoring is associated
with a decreased time to diagnosis and operative management of flap thrombosis, and thus an increase in
[81]
the rate of salvage . The approach to anastomotic assessment and revision is discussed in the
intraoperative management section above. Our novel algorithm for the approach to postoperative
management of thrombotic complications is available in [Figure 4].

Systemic anticoagulation
In the setting of postoperative arterial thrombosis, the use of systemic anticoagulation varies by surgeon and
institution. Many authors report urgent administration of a 5,000-unit bolus of intravenous heparin at the
time of reoperation [71,103] . Others report the use of weight-based dosing to achieve an institution-determined
therapeutic PTT level [58,103] . Given higher rates of hematoma with systemic heparin use in free tissue transfer,
we typically recommend weight-based dosing of intravenous heparin without the use of a bolus . Once the
[87]
risk of postoperative hemorrhage is deemed sufficiently low, the patient may be transitioned to a low
molecular weight heparin injection (eg., enoxaparin). The duration of anticoagulation after flap thrombosis
is often driven by surgeon experience. Although there is no definitive data on the optimal duration of
therapeutic anticoagulation in this cohort, Khansa et al maintain systemic anticoagulation for at least 4-7
days after reoperation, which is consistent with what other authors report [58,71,90] .