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Chen et al. Plast Aesthet Res 2023;10:24 https://dx.doi.org/10.20517/2347-9264.2022.136 Page 15 of 26

success rates, but given the limited number of studies and their small sample sizes, they are highly likely to
be subject to publication bias.

Postoperative management of venous insufficiency
Delayed venous thrombosis in the postoperative period is most likely to occur within 3 days of the initial
operation . As previously discussed, early detection of a possible venous thrombosis allows for the best
[125]
chance of ensuring flap survival. Since prolonged venous congestion is often a precursor to venous
thrombosis, flap monitoring and timely detection of signs of venous congestion is essential to the
[104]
prevention of this complication .
If clinical signs of venous congestion are present, initial management involves addressing sources of
extrinsic compression that may be contributing to poor venous outflow. Common troubleshooting
techniques include loosening of surgical bra, removing tight dressings, or removing compressive
sutures [113,126-128] . Topical nitroglycerin paste causes both arterial and venous dilation; it may be used as an
adjunct to remove extrinsic compression [127,129,130] . If conservative methods fail to relieve congestion, or if
venous thrombosis is suspected, reoperation offers the best potential for flap salvage.

The strategy for addressing postoperative venous compromise in the operating room follows a pattern
similar to that seen with intraoperative venous insufficiency. One notable exception is the presence of a
hematoma that may be compressing the pedicle. Hematoma may be seen in the presence or absence of
[131]
venous congestion . However, it is more often seen concurrently with venous congestion. When
hematoma is suspected as the cause of venous compromise, the hematoma should be evacuated on an
emergent basis to avoid further compression of the pedicle [103,131] . In cases of delayed venous insufficiency
(i.e., greater than 3 postoperative days) and/or when re-exploration of anastomosis and surgical revision
[128]
may be impossible, venous insufficiency may be managed medically .

While the majority of venous thrombosis events occur within the immediate postoperative period, delayed
venous insufficiency and/or thrombosis have been documented up to 5 weeks after initial operation [125,128] . In
these later presentations, successful salvage without re-exploration of anastomosis is more common .
[128]
Yoon and Jones suggest a critical time period for flap survival whereby flaps with delayed thrombosis have a
[132]
higher rate of survival due to neovascularization and angiogenesis that has already taken place .

Systemic anticoagulation in conjunction with reoperation
Heparin prevents clot formation by activating antithrombin III, which ultimately prevents the formation of
fibrin . While some have utilized antiplatelet therapy in addition to systemic anticoagulation, there is
[133]
well-documented evidence to show that heparin is favorable to antiplatelet therapy in cases of microvascular
thrombosis . Several methods have been reported on the use of systemic heparin in cases of venous
[134]
thrombosis or congestion, but timing, dosage, and routes of administration vary depending on the
institution. Most authors report using the same protocol for systemic anticoagulation in both venous and
arterial thrombotic complications. There is currently no standardized recommendation, and no single
protocol has been proven to be superior. At our institution, we typically recommend a continuous weight-
based heparin infusion titrated with a PTT of 60-80. This can be transitioned to weight-based low molecular
weight heparin injections once the patient is deemed to have a sufficiently low bleeding risk. The duration
of the treatment may range from 1 week to 4 weeks, depending on our level of concern for thrombosis.