Perforator flaps in the hand

The need for an appropriate flap cover to protect vital structures, restore and preserve function and aesthetics of the hand following tissue loss remains a challenge to the reconstructive hand surgeon. Following the description of the angiosome concept by Taylor and Palmer and the pioneering work of authors such as Koshima & Soeda, Kroll, and Rosenfield, in the late 1980s, the perforator flap technique has moved to the centre stage in reconstructive flap surgery.


Introduction
The need for an appropriate flap cover to protect vital structures, restore and preserve function and aesthetics of the hand following tissue loss remains a challenge to the reconstructive hand surgeon. Following the description of the angiosome concept by Taylor and Palmer and the pioneering work of authors such as Koshima & Soeda, Kroll, and Rosenfield, in the late 1980s, the perforator flap technique has moved to the centre stage in reconstructive flap surgery.

Materials and methods
A literature review of the 'named' perforator flaps which have been used in the hand and published in peer reviewed English literature using keywords in the title and abstract (perforator flap, hand, palm, dorsum of hand, digits fingers) in MEDLINE served as the framework for this presentation. A further review of the references in the core articles for other perforator based flaps was also done. Clinical examples of the indications, pedicle peculiarities, ideal recipient sites and specific donor site problems of some of the workhorse perforator flaps from my personal experience are also presented.

Results
There were fifty core articles with 'named' perforator flaps. Despite the attempts to achieve a standardized nomenclature for these flaps (Blondeel 2002(Blondeel , 2003, it is clear that the terminology is lacking in universal applicability or acceptance making communication and comparison of literature on 'perforator' flaps difficult. Pre-operative planning involves mostly a good knowledge of the anatomy and the use of the Doppler probe and occasionally imaging investigations such as duplex ultrasound, MRI and other modalities. Once the perforator is identified, the flap design and movement is based on traditional principles of plastic surgery such as rotation, transposition, V-Y flaps, pedicled, free, ad hoc or freestyle. But the conventional flap design rules of length and width ratios do not apply (Lee et al 2009).
The 'named' perforator flaps can be grouped into local (harvested from the hand itself), regional (from the upper limb excluding the hand) and distant (from the rest of the body); in other words, based on the distance of the donor site from the recipient site (the hand being the reference point). Examples (with glabrous and non glabrous subgroups) are as follows:  Donor site closure ranged from direct closure to skin grafting and occasionally closure by means of another flap.
There were very contrasting views of donor site morbidity with most authors subjectively judging the morbidity of the donor site for their chosen flap to be minor or acceptable as opposed to the donor sites of other flaps.

Discussion
The increased appreciation of the perforator concept in reconstructive hand surgery has enabled surgeons to harvest flaps of sufficient size or 'tailor made size' that are much thinner and pliable than would have been feasible with reduced donor site morbidity and very importantly avoiding the sacrifice of major blood vessels. A grater precision of insetting of the flaps is possible, further reducing the need for secondary procedures.
For regional and distant perforator flaps, the ability to isolate and define the 'final pathway' of blood supply to the skin has enabled accurate placement of expanders and recruitment of more skin safely with less donor site morbidity (Hocaoglu et al  The local perforator flaps have added advantage that they provide 'like for like' tissue in colour, texture and resilience, one site operation, early and one site rehabilitation of the hand but suffer from limited availability.
Excellent microsurgical skills are necessary for surgery of free perforator flaps especially the smaller ones utilised on the digits.

Conclusion
As the functional donor site morbidity has been reduced by this technique, hand surgeons have to be more conscious of the aesthetic morbidity of using certain donor sites in the long term. The versatility and the gains with this concept have made perforator flaps a welcome addition to the reconstructive armory of the hand surgeon.