INVITED DISCUSSION

Dr. Sarukawa and his colleagues are to be congratulated for bringing objectivity to our subjective clinical impressions in the area of skull-base surgery. They also articulate what many of us have been thinking, that our reconstructions are often not very good. The authors give us documented justification, for a change, in the way we approach complex craniofacial defects. Microvascular surgery has, to a large extent, been responsible for the advances that have taken place in skull-base surgery, allowing more extensive resections in the knowledge that the defect can be safely covered.[1] However, we have tended to concentrate on wound closure without paying much attention to facial aesthetics in these complex cases. The rectus abdominis myocutaneous flap has been the workhorse for these reconstructions, and we are all aware of the variable atrophy that occurs with this and other muscle flaps. We have all had patients who looked great after the initial surgery, only to witness the subsequent loss of bulk with consequent deterioration in aesthetics associated with flap atrophy.

This paper attempts (and I think succeeds) to define the problem but, more important, gives us a method of objectively measuring our results. The concept of PSA and POA was, at first, difficult to grasp but it is an elegant one. The perfect reconstruction is when PSA and POA are 100 percent. That is our goal. While it is intuitive that reconstructing the bony defect will result in a better outcome, we can clearly see that in this series, the two patients who had bony reconstruction maintained their PSA and POA numbers with much less variation that those reconstructed with soft tissue alone (see Fig. 5). It is also intuitive that flaps supported by underlying bone are less likely to droop or at the very least, will droop less than those that are unsupported. Many of us have already started to move away from soft-tissue-only reconstructions for complex defects such as the maxillectomy defect,[2] and the results are gratifying. This paper shows us objectively that our clinical impressions are correct.

There are still many challenges. The complication rate cited in this paper is in keeping with other reported series and underlines the complexity of these cases. This, at least in part, is why we have opted for flaps such as the rectus abdominis. It is a safe flap, relatively simple to harvest, with a large and reasonably long pedicle. While safety is important in everything we do, in this region it is particularly important because the consequences of failure are so serious. Furthermore, the region is one of the most anatomically complex, so that the defects that result from surgical ablation are three-dimensional and frequently incorporate multiple skin and mucosal surfaces, together with the varying convexities and concavities of the facial skeleton. Reconstructing all elements of this defect tests our reconstructive ingenuity.

This paper shows us, in an objective way, what needs to be done. The challenge is now to devise ways of incorporating bony reconstruction in our treatment paradigm in the context of high stakes surgery, in which the clinical risks of exposure to the aerodigestive system, dural patches, and adjuvant treatment with chemotherapy and/or radiation all come into play. Any or all of these associated risks can have an adverse effect on ultimate outcome. Once again, the authors are to be commended for their objectivity.

REFERENCES

• 1 Neligan P C, Mulholland S, Irish J et al.. Flap selection in cranial base reconstruction.  Plast Reconstr Surg. 1996;  98 1159-1166
• 2 Brown J S. Deep circumflex iliac artery free flap with internal oblique muscle as a new method of immediate reconstruction of maxillectomy defect.  Head Neck. 1996;  18 412-421