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Page 2 of 9 Swendseid et al. Plast Aesthet Res 2021;8:41 https://dx.doi.org/10.20517/2347-9264.2021.47

challenging. The range of available treatment options, from primary chemotherapy with radiation to
multispecialty radical open surgery, all risk significant patient morbidity is given the critical importance of
the adjacent central nervous system (CNS) structures, leaving little room for error. When surgical
approaches are selected, the reconstructive team must work to convert the complex 3-dimensional defect
into a safe, functional, and cosmetically acceptable wound. Thankfully, there has been significant recent
growth in the knowledge regarding successful skull base reconstruction, with the expanded use of free tissue
transfer (FTT) leading to improvements in patient outcomes. This review highlights some of the
considerations and challenges of using FTT in skull base reconstruction.

PRINCIPLES OF SKULL BASE RECONSTRUCTION
The reconstructive surgeon faces many daunting decisions with serious consequences following extirpative
surgery for advanced skull base pathology. Accessing the tumor may mean violating the bony partitions that
normally separate the CNS from extracranial spaces, including the nasal, orbital, and oral cavities, and dura
and/or brain tissue may be resected. These approaches, therefore, create avenues by which bacteria and air
[1,2]
can spread into the normally protected CNS, leading to meningitis, brain abscess, or pneumocephalus .
Thus, a critically important concept for preventing cerebrovascular complications is reestablishing the
separation of the intracranial and extracranial cavities. Additionally, when dura has been resected or
violated, providing a water-tight dural closure is critical to minimize the risk of cerebrospinal fluid (CSF)
leak . Non-vascularized grafting is often sufficient, although vascularized tissue can also be inset into the
[3,4]
dural repair and integrates well [Figure 1].
[5]
Many options exist for reestablishing CNS separation, including local flaps, regional flaps, and FTT. Having
a diverse array of tools allows the surgeon to best select the optimal reconstructive for a given patient and
defect. Before the rise in popularity of FTT, regional flaps such as the temporoparietal fascia flap (TPFF) and
the pericranial flap were commonly employed. With the increasing availability of microvascular expertise,
many centers now consider FTT for many of these patients. Head-to-head comparisons have shown
improved wound healing and prevention of intracranial complications with FTT compared to regional
flaps. This may be due in part to the distal portion of the regional flaps having the most precarious blood
supply, which is often also by necessity placed at the most critical portion of the reconstruction .
[4]
Additional important principles include obliteration of dead space to prevent seroma and hematoma
formation, which can become infected and spread intracranially. Any exposed major vessels, such as the
carotid artery should be covered with healthy tissue to prevent hemorrhage and blowout. When possible,
resected soft tissue and bony structures, should be reconstructed in a way that preserves functionality and is
cosmetically acceptable .
[3,4]

Skull base reconstruction with FTT often requires atypical or creative management of the vascular pedicle.
The long distance between the inset site and the cervical vessels that are traditional recipients for
anastomosis in head and neck FTT can be addressed with various strategies. One is selecting free flaps such
as the radial forearm or fibula free flap, which have long vascular pedicles often capable of reaching the
neck. Another is using venous and/or arterial grafting when the pedicle length is insufficient to reach the
[6,7]
cervical vessels. However, grafting may be associated with higher failure rates . Alternative recipient
vessels can be used with demonstrated success. For example, the superficial temporal vessels are often easily
reachable and have high success rates when there is minimal size mismatch. Unfortunately, prior surgeries
such as craniotomies may damage them, making them non-viable recipient vessels . The angular vessels are
[8]
another recipient vessel option that has a high success rate and does not require as long a pedicle as cervical
vessels . The distal facial vessels can also be accessed with a separate incision near the facial notch of the
[9]