The essence of plastic surgery is the flap. After a century of human development, the perforator flap, as a hot research and application flap in international plastic surgery, has many special advantages compared with the myocutaneous flap and free axial flap: it preserves muscle tissue, reduces complications and diminished function in the donor area; its versatility solves many clinical problems; it is the ideal flap for three-dimensional tissue reconstruction. For example, thin flaps can be obtained for breast reconstruction or to reshape trauma.
Each epochal development in plastic surgery was first based on the efforts of pioneering researchers, clinical trials, and then the development of refined surgical techniques until eventually this surgical skill entered the world and became a standard surgical approach. The musculocutaneous artery perforator flap is just now entering this final phase, and there are currently 5-6 perforator flaps being used by surgeons worldwide.
The essence of plastic surgery is the flap, which is required for repair and reconstruction, and tissue and organ reconstruction. For the past century flaps have been divided into arbitrary and axial types according to the type of flap blood circulation. As knowledge of human anatomy and microscopic techniques continued to evolve, the thru-branching flap evolved from the traditional myocutaneous and fasciocutaneous flaps.
Studies have shown that instead of a vascularized muscle carrying flap and a fascial vascular network beneath the flap, a carefully dissected out myocutaneous perforator vessel is all that is needed to ensure flap viability. By selectively obtaining a flap over the underlying muscle, complications in the donor area are reduced. The myocutaneous perforator flap represents a novel advancement in plastic microsurgery. It is quite reasonable and logical to repair a skin soft tissue defect with a skin flap alone, while preserving the muscle integrity of the donor area.
I. History of skin flaps
Initially, random flaps were obtained adjacent to the defect without specialized knowledge to obtain a reliable blood supply, and these random flaps sometimes survived and sometimes necrosed. Therefore, based on Milton’s work and Daniel’s study, the length-to-width ratio of the random flap at acquisition was defined. The subsequent discovery of axial flaps such as the pectoral deltoid flap [1] and the inguinal flap led to the rapid development of axial flaps throughout the body with a reliable blood supply, and therefore the rapid development of free apparent microvascular tissue transfer, allowing for distant tissue grafts.
These free flaps include muscle. In the late 1970s and 1980s, the repair of large soft tissue defects with a tipped myocutaneous flap became a popular procedure. The viability of the myocutaneous flap is dependent on the blood supply to the muscle. The advantage of the myocutaneous flap is that it has a reliable blood supply and sufficient tissue volume to repair large defects and is widely used to solve many different clinical challenges. However, large tissue volumes of myocutaneous flaps (e.g., latissimus dorsi flap) not only affect the function and shape of the recipient area, but also cause functional deficits in the donor area. a survey by Mizgala et al. of 150 patients 5-7.5 years after undergoing TRAM flap grafting showed: decreased abdominal strength; asymmetric abdominal bulge, flaccidity and back pain.
II. Development of the penetrating flap
In the late 1980s and 1990s, pioneers Koshima, Soeda, Kroll, and Rosenfield introduced a flap based on the musculocutaneous penetrating artery, which consists only of skin and subcutaneous fat, as long as the small artery penetrating from the underlying muscle is protected and obtained. This discovery and subsequent clinical application of the perforator flap is considered to be a new era in reconstructive plastic surgery.
Its advantages include fewer complications in the donor area; preservation of muscle; flexible design and versatility; aesthetic appearance of the recipient area; and reduced recovery time. The muscle is preserved in the perforator flap, and a functional and aesthetic postoperative result is obtained. This is illustrated in many publications comparing the Diep through-branch flap with the Tram myocutaneous flap.Futter and Cowworks [2] tested 50 patients with breast reconstruction after breast cancer surgery, 23 with Diep and 27 with Tram,the latter group showed a significant reduction in muscle strength when extending the abdomen and back, respectively.
In the frontal region, can nasal reconstruction be performed without carrying the frontal muscle? In 2004, Li Qingfeng [3], a Chinese scholar, reported a group of 9 cases of nasal reconstruction with a stepped flap carrying only the muscle at the tip and a double flap of muscle and skin, based on the anatomical basis that the supraorbital artery has the same direction of the skin branch, and all the flaps survived and the reconstructed nose was satisfactory. However, there was one case of exposed nasal pedicle prosthesis.
In a similar report by Ullman, Y, et al. in Israel in 2005, 17 patients underwent paramedian flap nasal reconstruction without frontalis muscle, and branches of suprascapular vessels were visible on the deep subcutaneous surface of the flap. There was necrosis at the distal edge of the flap in one case, but it did not affect the postoperative results. In 2006, we completed a case of paramedian flap nasal reconstruction with only the tip carrying muscle, and also observed that the flap was well hemorrhaged, and when the tip was severed, an arterial skin branch with a diameter of about 1 mm was found just under the skin, and its vascular perfusion pressure was high, and the blood spray reached nearly 50 cm away.
None of the aforementioned scholars have described in detail the travel pattern of the cutaneous branch of the superior talofibular artery. Previous anatomic studies have reported very few detailed reports involving the prefrontal architecture associated with the supraglottic vessels, and even fewer have mentioned that the supraglottic artery issues a percutaneous branch shortly after its main trunk ascends and enters the subcutis. The long history of nasal reconstruction, and the corresponding paucity of anatomical studies, creates an interesting phenomenon. This has led to certain perceived ambiguities in clinical understanding.
What is currently referred to as the paramedian flap should be referred to as the paramedian muscle flap, which is actually a perforator muscle flap with the main trunk of the suprascapular vessels as the tip. In today’s flap research field, the search for a muscle-free carrying perforator flap has become a hot topic. It is in line with the modern trend of minimally invasive or noninvasive repair in surgery, and is the essence of plastic surgery.
In 1984, Song YG and colleagues first described and named a perforator flap supplied by the descending branch of the lateral rotor femoral artery as an intermuscular perforator femoral flap. Subsequently, from 1987 to 1993, Koshima, Kroll, and Rosenfield developed this flap based on extensive basic anatomy and clinical applications, naming it the anterolateral femoral perforator flap. Since then, this flap has been widely used in Taiwan, Japan, Europe and the United States for soft tissue skin defects, especially in the head, neck, and extremity regions. A large number of cases have been reported, some of them reaching 200 to hundreds of cases.
The majority of the reported statistics are muscle-derived flaps, about 85-95% of which are muscle-derived; only 5-15% are interstitial muscle-derived flaps. Based on the widespread use of the perforator flap worldwide, in 1998 Koshima discovered and named a new, widely used perforator flap, whose source vessel is the inferior abdominal wall artery system, named the paramedian perforator flap, which is now the most advanced inferior abdominal wall artery perforator (DIEP) flap for breast reconstruction.
Advantages and clinical applications of the perforator flap
From the late 1990s to the present, based on anatomical studies and clinical applications since the 1980s, new perforator flaps have been discovered and used in clinical practice. According to Taler and Palmar, there are 40 potential penetrating flaps in the human body that are supplied by well-known blood vessels and are distributed in various parts of the body. However, the clinical selection of a perforator flap should have the following characteristics [8]: (1) a continuous and stable blood supply; (2) adequate hematophore length; (3) at least one perforator vessel with a caliber greater than or equal to 0.5 mm; and (4) the donor area can be directly sutured. Of course, there are many other factors: the aesthetic effect of the donor area after surgery, the size of the flap that can be taken, the acceptability of the patient, and the experience of the surgeon.
Fourth, the most commonly used penetrating flap
Currently, there are six most commonly used penetrating flaps internationally [9-16]. By name, the blood supplying artery and the muscle they cross are.
(i) inferior abdominal wall artery perforator flap (DIEP), inferior abdominal wall artery, and rectus abdominis;
(ii) Superior gluteal artery perforator flap (SGAP), superior gluteal artery, and gluteus maximus muscle;
(iii) thoracodorsal artery perforator flap (TAP), thoracodorsal artery, latissimus dorsi muscle;
(iv) lateral lateral artery descending branch flap (ALT), lateral lateral artery descending branch, and lateral femoral muscle;
⑤ transverse femoral artery flap (TFL), transverse branch of the lateral rotor femoral artery, and vastus lateralis muscle;
(6) Medial peroneal artery perforator flap (MASP), medial peroneal artery, and gastrocnemius muscle.
In the past two years, the superior abdominal wall artery perforator flap (seap) and inferior gluteal artery perforator flap (igap) have also been used to some extent.
V. Naming of perforator flaps
With its many advantages and wide human distribution, the musculocutaneous perforator flap is a hot topic for research and application in the international plastic surgery community in recent years, and it is also a project that is being explored continuously.
At present, the scientific and comprehensive naming of the perforator flap has not been fully unified internationally, and Hallock [18] in the United States, Neligan [19] in Canada, Koshima and Nakjima in Japan, and Wei FC [20] in Taiwan all have their own constructive naming features. This includes naming the blood supplying vessels, the muscle through which the penetrating branch passes, and the site where the flap is located to prevent confusion and facilitate differentiation of what is indeed a particular flap for surgical clinical application.
VI. Conclusion
The myocutaneous perforator flap represents the most important advance in restorative and reconstructive surgery. Faced with the complexity of very similar self-replacing tissues; minimal cost to the donor area and the most efficient repair. The perforator flap allows plastic surgery to better accomplish this goal. Given the many advantages of the musculocutaneous perforator flap, the development of newer and more desirable flaps is currently not possible. To advance this development, continuous research, practice, and exploration of currently unused international perforator flaps will be required on the various perforator flaps themselves.