Perforator Flap versus Conventional Flap ... Perforator Flap versus Conventional Flap The introduction

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  • © 2015 The Korean Academy of Medical Sciences. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

    pISSN 1011-8934 eISSN 1598-6357

    Perforator Flap versus Conventional Flap

    The introduction of perforator flaps represented a significant advance in microsurgical reconstruction. However, confusion has developed due to the erroneous belief that perforator flaps are different from conventional flaps. The concept of the perforator is not new, but is an idea that evolved from the conventional flap. In fact, some of the flaps used by microsurgeons were perforator flaps. The only difference is the anatomical level of the blood vessels involved; the perforator concept is focused on the distal circulation, so- called ‘perforator’. Therefore, thinner sections of tissue can be taken from the conventional donor sites of myocutaneous flaps. With the use of perforators, there are no longer “flap of choice” for specific reconstructions, because conventional donor sites have become universal donor sites, enabling the harvesting of a variety of flaps. Moreover, depending on the surgeon’s ability, any flap can be utilized as a perforator-based island flap whose source vessel has been completely preserved. Therefore, tissues can be efficiently customized and tailored into any configuration required for reconstruction. The application of perforator flap technique enables more precise dissection, and allows more selective harvesting of thinner flaps, which will expand options in reconstructive surgery. No doubt the technique will continue to evolve.

    Keywords: Surgical Flaps; Perforator Flap; Microsurgery; Reconstruction

    Jeong Tae Kim1 and Sang Wha Kim2

    1Department of Plastic and Reconstructive Surgery, College of Medicine, Hanyang University, Seoul; 2Department of Plastic and Reconstructive Surgery, College of Medicine, Seoul National University, Seoul National University Hospital, Seoul, Korea

    Received: 31 March 2014 Accepted: 26 June 2014

    Address for Correspondence: Sang Wha Kim, MD Department of Plastic and Reconstructive Surgery, College of Medicine, Seoul National University, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea Tel: +82.2-2072-2374, Fax: +82.2-36757792 E-mail: sw1215@snu.ac.kr

    http://dx.doi.org/10.3346/jkms.2015.30.5.514 • J Korean Med Sci 2015; 30: 514-522

    INTRODUCTION

    The use of perforator flaps in reconstructive surgery is a superi- or surgical technique when compared to the use of convention- al flaps. Initially, the concept of the flap based on a perforating vessel, or ‘perforator’ was viewed as being new and distinct from the older concept of the conventional flap (1, 2). However, the perforator technique has in fact evolved directly from, and is not very different from, the conventional approach. The lack of experience of surgeons with the techniques involved in perfo- rator flap surgery, and confusion about the nature of the tech- nique, led to the misconception that perforator flap surgery was difficult to perform. This misconception has extended to confu- sion about the distinction between perforator flaps and earlier classical flaps. In fact, many of the flaps that surgeons have used for years were actually perforator flaps according to the current definition, although they were described by many different names at the time (1-3). The development of the perforator flap technique has result- ed in an improved understanding of how flaps receive their blood supply (3, 4). Major source vessels supply nutritional blood flow to all tissues they traverse. These major vessels and their main branches send other smaller branches to supply the surround- ing muscles, connective tissue, and skin (5). Axial pattern flaps were designed to include axial vessels at the flap base, to pro-

    vide blood supply (2). It was therefore important to know the precise vascular anatomy to design the flap, which was a branch- based concept. However, as the flap concept developed, flap design evolved from being based on a source vessel or branch concept, to being based on a specific perforating vessel. The successful harvest of a perforator flap requires the identifica- tion of a perforating vessel, and dissection in a retrograde fash- ion (from distal to proximal) (6). Therefore, the route of access to the pedicle is changed: a direct approach to the source vessel is essential in the harvest of a conventional flap, but when har- vesting a perforator flap, the approach starts from the distal part of circulation at the subcutaneous tissue layer, and proceeds to the source vessel. As a matter of fact, the flap harvest is frequent- ly free-style depending on the anatomical variations of the ped- icle (3, 6, 7). The source and path of a perforating vessel are not the essential considerations of the operation although it is obvi- ous that a perforator always comes from a source vessel (6). Some- times, a perforator alone can be selectively used as a pedicle (4), so eliminating the proximal dissection (3). Here, we review historical aspects of the development of the flap technique and provide an overview of perforator flaps. The application of the perforator flap technique enables more pre- cise dissection, and allows more selective harvesting of thinner flaps, which has expanded options in reconstructive surgery. There is no doubt that the technique will continue to develop.

    REVIEW ARTICLE Surgery

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  • Kim JT, et al. • Perforator Flap versus Conventional Flap

    http://jkms.org 515http://dx.doi.org/10.3346/jkms.2015.30.5.514

    CONCEPT AND CLASSIFICATION OF PERFORATOR FLAPS

    Overall, the vasculature of the skin and subcutaneous tissue is arranged in five vascular plexuses: the subepidermal plexus, dermal plexus, subdermal plexus, subcutaneous plexus, and fascial plexus (subfascial and suprafascial). Conventional mus- culocutaneous or fasciocutaneous flaps are connected to a source vessel under the muscle, or to vessels at the fascial level (5). On the other hand, a perforator flap is connected to vessels of the subdermal or subcutaneous plexus, which therefore involve a connection to more distal vascularity than a conventional flap (8, 9). Based on the path taken by the perforating vessel, perforators can be categorized as direct cutaneous, septocutaneous, and musculocutaneous perforators (10). The exact definition of per- forator is still controversial. When the concept of the perforator was first introduced, Wei el al. (11) defined perforating vessels as those of which the source artery is deep and the branch that carries blood directly to the fasciocutaneous tissues, in its course to reach the skin, passes through the overhanging muscular tis- sue without exclusively following the intermuscular septum. By this definition, only musculocutaneous perforators are consid- ered true perforators, and flaps based on other types of perfora- tor are not regarded as perforator flaps. However, this rigid defi- nition has caused confusion about the concept of the perfora- tor. The anterolateral thigh (ALT) flap, one of the most popular perforator flaps, is a representative example that demonstrates the differences between perforator flaps and conventional flaps. The anterolateral thigh flap is based on a perforator connected to the descending branch of the lateral circumflex femoral sys- tem (6, 12, 13). Most of the time, the perforator comes through the vastus lateralis muscle (82%) and is therefore musculocuta- neous, or it is a septocutaneous perforator, which is easier to harvest and use than the musculocutaneous perforator (14). According to strict definitions, the flap based on the musculo- cutaneous perforator is a perforator flap and the flap based on the septocutaneous perforator is not a perforator flap. These flaps differ from each other in terms of the ease of pedicle dis- section - tedious transmuscular dissection in musculocutane- ous flaps, as opposed to easy and rapid dissection between mus- cles in septocutaneous flaps (6, 14). Most microsurgeons tried to select septocutaneous perforators to save operating time be- fore the development of the perforator concept, but now trans- muscular dissection is more popular due to the reliability of the perforator. Moreover, when the perforator is reliable and the length is sufficient, pedicle dissection stops at the level of the perforator without requiring transmuscular dissection (6). There- fore, the ALT flap has evolved from a myocutaneous flap, to a range of flaps based on either septocutaneous or musculocuta- neous perforators. As it is important to distinguish between these

    flaps, workers have named the different flaps ‘ALT myocutane- ous flaps,’ ‘lateral circumflex femoral perforator flaps,’ ‘vastus lateralis perforator flaps,’ and ‘ALT perforator based flaps,’ de- pending on the perforators involved (10). The former two pat- terns are conventional flaps while the latter three are perforator flaps. The lateral circumflex femoral flap can be included in both groups: it was initially designated an ALT (conventional) flap but is now considered a perforator flap, which illustrates the confusion surrounding the perforator concept. That is the reason why we insist that the concept of the perforator flap is not completely distinct from that of the conventional flap con- cept (Fig. 1). We therefore conclude tha