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Page 4 of 10 García Nores et al. Plast Aesthet Res 2023;10:33 https://dx.doi.org/10.20517/2347-9264.2022.146

the number of harvested perforators potentially risks higher donor site morbidity. Taking all the
aforementioned into consideration, surgeons must carefully balance these factors in the decision making of
[25]
flap harvest and perforator selection to maximize flap perfusion and minimize donor site morbidity .

Maximize perfusion (APEX/supercharging)
A novel option to maximize perfusion by incorporating both medial and lateral row perforators yet
minimizing the donor site morbidity was described by Dr. Allen et al. The abdominal perforator exchange
(APEX) flap allows harvest of two perforators while sparing the intervening rectus fibers by adding an
additional anastomosis to reconnect the medial and lateral division prior to division of the primary pedicle.
DellaCroce et al. reported his 6-year experience with 364 flaps and nearly eliminated abdominal bulge/
hernia. The operative time was 34 min longer on average. Only one patient presented with diffuse fat
necrosis . Other surgeons have also advocated supercharging by harvesting a second or third pedicle
[26]
(SIEA, SCIA, and/or DCIA) to improve the perfusion of the flap. Both these options require increased
technical difficulty and complexity, but in experienced hands, they can optimize flap perfusion without an
increase in donor site morbidity. Further studies are needed to better understand appropriate patient
selection and long-term evidence on these refinements.

Additional venous outflow
Some incidences of fat necrosis may not be due entirely to ischemia but are rather a result of progressive
venous congestion. For example, superficially dominant venous drainage may not be apparent during the
index operation. We strongly recommend dissecting the superficial inferior epigastric vein (SIEV) routinely
during DIEP flap harvest to serve as an indicator of risks of venous congestion and a secondary outflow as
needed. Engorgement of the SIEV during DIEP harvest is an early indicator of possible superficial
dominance. ICG angiography can often confirm this anatomical variant with delayed drainage of the dye
until the SIEV is vented. Ming-Huei Cheng often routinely augments his venous outflow using the SIEV
through a variety of configurations to connect to the DIEV or a secondary recipient vein. He elects to
routinely dissect a length of at least 7-10 cm of SIEV. He reported 32 episodes of venous congestion in 162
patients undergoing unilateral DIEP flap reconstruction. Salvage consisted of either venous augmentation
or SIEV substitution with no statistical difference in flap salvage. This was mostly done by anastomosis of
the SIEV to either the 2nd vena comitantes or the internal mammary vein with the use of a vein graft or
DIEV .
[27]

Minimize ischemia time
The easiest and quickest way to prevent partial flap necrosis is to minimize flap ischemia time. High-volume
surgical centers with dedicated surgical teams and experienced surgeons have demonstrated remarkable
efficiency with DIEP flaps, and there are anecdotal reports of DIEP flaps being routinely performed now in
under 2 h. Lee et al. reported 86 patients with a mean ischemia time of 89 min and an incidence of fat
necrosis at 17.4%. Ischemia time was found to be significant in both univariate and multivariate analyses.
[28]
The authors report the threshold of 99.5 min as a cutoff for higher rates of fat necrosis . Ideally, a
microsurgical operative team would include dedicated and experienced nurses, surgical technicians,
anesthesiologists, and surgeons. In other surgical subspecialties (i.e., transplant, bariatrics, hepatobiliary),
designated centers of excellence have lower complication rates and patients are occasionally funneled by
their insurance to these facilities to receive their care. There are already several large private groups in the
USA dedicated solely to breast reconstruction with good outcomes. Whether this model or designation of
excellence is applicable to microsurgical breast reconstruction remains to be seen.