Introduction and Acknowledgements
Prabha Yadav is the head of the department of reconstructive surgery at the Tata cancer hospital in Mumbai India and together with her two junior consultants Vinay Shankdhar and Dushyat Jaiswal perform on an average six hundred reconstructions in one year a majority of which follow excisions for cancers in the head and neck region. She has kindly consented to share their experience as well as the vast clinical material in their collection without which this chapter could not have been written.
Once their material was sifted through the compiler of these notes met with Dr. Yadav’s senior fellow Amit Patil and her two senior residents, Rajendra Dhondge, Saumya Mathews, on several occasions to ascertain how a flap or flaps were chosen for a particular defect as well as to arrive at a cogent bibliography as to how we have arrived at the present stage of our reconstructive choices. What surprised the compiler of these notes was that the Tata group was relying on only three flaps for almost ninety percent of their reconstructive work namely the radial artery forearm flap, the free micro vascular fibular transfer and the lateral thigh flap. They are shown below in the sequence that they have been mentioned.
Radial artery forearm flap
Fibula osteocutaneous flap
Anterio lateral thigh flap
One obvious advantage of this or these choices is that the operative areas are wide apart allowing two teams to operate simultaneously. The flap can be developed once the approximate size of the defect is known and the vessels at the recipient site can be made ready after the tumor is excised saving considerable amount of time so crucial for patients rendered weak by their disease. To a question as to what they would fall back upon in case of a major loss of one or more flaps in a given case the answer was equally surprising. The team invariably would use these same flaps from the opposite side of the body after debridement of the dead tissue in the recipient area, suitable antibiotics and a waiting period. Salvage flaps such as a pectoralis major flap would only be a last choice. As to whether reconstruction with flaps hides early recurrences, the oncologist in the team said that all flaps might hinder recognition of recurrences but immediate reconstruction allows for ancillary radio-therapy to begin immediately and therefore recurrences have fallen in general.
Pectoralis major flap
This discussion is narrated here to indicate that free micro vascular flaps are now as far as possible the first choice even in difficult situations. This certainly is a revolution particularly in India which continues to be a developing country. The days when tissue was moved in stages to the defect during which patients were unable to swallow properly or covered their faces for long durations and many times continued to stay in the ward till the reconstruction was complete are now history.
Another point that emerged during the discussion was the nature of cancers that were seen at the Tata cancer hospital and the infrequency of cancers of the skin including melanomas. Their work load consisted mainly of cancers of the buccal mucosa as well as that of the tongue and the gingiva or the mandible and many of them were aggressive. The title of this chapter was therefore modified to call it the Indian experience. Examples of some infrequent tumors of the skin are presented below:
A brief history of pedicle flaps
It is on this background that we launched a search for a comprehensive history of pedicle flaps when we came across the introduction to the Encyclopedia of flaps; editors Strauch Vasconez and Hall Findlay, Lippincot Raven 1998 by R.A. Chace to realise that the thirty years beginning with 1968 were for plastic surgery what the first thirty years of the same century was for physics. The introduction begins with Sushruta’s forehead flap from the pre-Christian era and lauds it because it is still used today.
Though it is certain that Sushruta described the cheek flap for reconstruction of the nose historians have not found a description of the forehead flap in his treatise; However a fragment survives of a conversation between a student and Sushruta in which the student wonders as to how such a flap survives Sushruta answers by saying that the flap survives by way of its continuity with the skin from which it is fashioned. The original terse aphorism is in Sanskrit: सानुबंधेन जीवित:
Sushruta’s verse does not however comment on the nature of the continuity; or the bridge. Be that as it may the sudden appearance of this flap in 18th century in India almost certainly is not an accident. The technique probably lay hidden but was carried by way of an oral tradition from ancient times. Curiously this bridge or the base; or the continuity that Sushrut alluded to remained unexplored for almost two thousand years until Milton in 1968 showed the fallacy of the length breadth ratio in the planning of flaps. The one to one ratio between the base and the length therefore was no longer sacrosanct if a sizable vessel ran along the length of the flap from its base. Milton proved this in an experiment on pigs by cutting flaps of various dimensions on the back of the animal and demonstrated that disproportionately long flaps which had survived in the experiment had a segmental vessel running within them.
This discovery was preceded by a prescient observation nearly hundred years earlier in 1863 by John Wood that the inclusion of the superficial inferior epigastric artery in a flap in the lower abdomen leads to a better survival of the flap. Strangely he called this flap a groin flap. Incidentally a flap based the superficial external pudendal artery (s.e.p.a.) from the lower abdomen was described by Dias and Dias and Patil in 1984 and 1987.
To pick up the link again In 1920 Sir Harold Gillies had stated that in general a flap should not be larger than the width of the flap but later added a rider that a longer flap could be raised if the flap contained in its base a larger vascular pedicle such as the superficial temporal artery. In 1931 Jacques Joseph using illustrations from Manchos Atlas of Cutaneous Vessels (1889) described the delto-pectoral-flap later imaginatively used for reconstruction in the head face and the neck by Bakamjian in 1965.The flap is shown in the figure below.
Almost certainly as a consequence of Milton’s work mentioned earlier Macgregor and Jackson described the groin flap in 1972 and in the same year Macgregor and Morgan coined the term axial pattern flap the word axial denoting the presence of a vessel along the longer axis of the flap.
In 1973 Daniel and Taylor reported the first free micro vascular flap transfer of an axial pattern flap which incidentally was the groin flap. The groin flap as shown in the above drawing is a flap supplied by a direct cutaneous vessel the superficial circumflex iliac artery a branch of the femoral artery and runs in the subcutaneous tissue almost from its beginning unlike a majority of other vessels which perforate deeper structures such as deep fascia and muscle to supply the skin (please see note in a later paragraph about the vascularity of faciocutaneous flaps). Incidentally a free flap was attempted earlier by Antia and Buch in 1970 where adipo-fascial tissue from the lower abdomen was transferred for a soft tissue defect of the face but the attempt failed.
The role of fascia in cutaneous flaps
Ponten in 1981 included the fascia in a flap in the leg below the knee to demonstrate that the standard one to one ratio can be exceeded up to one as to three and longer flaps can be successfully designed and rotated for local use. Barclay and others in 1983 reported twelve cases of cross leg fasciocutaneous flaps. In 1984 Thatte and Laud showed that fascia alone can be moved based superiorly as a transposition flap, to be covered by a split skin graft to heal wounds on the anterior surface of the lower leg.
Thatte et al, in two papers in 1986 showed that fasciocutaneous cross leg flaps can be detached in ten days by incorporating a distal fascial extension to the main flap which was buried in the normal tissue beyond the defect for faster revascularization.
Thatte et al also used the anterior rectus sheath to cover a wound on the volar surface of the palm which in turn was covered by a skin graft to avoid too much bulk that a conventional flap carried. In the case reported in that paper in 1986 the wound on the dorsum of the hand was covered by the S.E.P.A. flap described earlier in this chapter (superfial external pudendal artery flap).
Around this time a series of papers were published underlying the importance of the deep fascia together with its rich vascularity because of a main vessel which ran underneath it and which in turn pierced it to form a rich plexus on the outer surface of this fascia This fascia could be in the form of an intermuscular septum in which case the vessel that arose from the main underlining vessel and which penetrated the fascial septum was called a septocutaneous vessel and its branches that supplied the subcutaneous tissue and skin came to be called as perforators. Occasionally these septocutaneous vessels penetrated the adjoining muscle to appear on its surface by penetrating the fascia of the muscle; or the epimyceum to supply the skin.
The blood supply to the skin and subcutaneous tissue that resulted from this vascular architecture was not random but had a certain territorial arrangement. Several papers were published on these vascular territories in various parts of the body and to name only one Whetzel et al in 1997 mapped the areas of blood supplying the lower leg which corresponded with specific septocutaneous vessels.
Taylor in 2003 in his seminal work called these territories angiosomes and showed that they were connected by way of what he called choke vessels which otherwise lie dormant but can be activated by a delaying procedure in which two adjoining angiosomes can be possibly raised as a single flap.
Taylor most notably demonstrated the presence of approximately four hundred perforators in the human body on which flaps can be based. The most commonly used fasciocutaneous flap as of today is the lateral thigh flap originally described by Baek (1984) and later became popular though the work of Song et al and Koshima et al (1984/1989).
Unlike the comparatively short and a somewhat nuanced history of fasciocutaneous flaps over the last twenty years the history of muscle flaps is longer and more robust and direct. Ombredanne in 1906 folded the pectoralis minor muscle on itself by cutting its humeral attachment to create a breast mound after a mastectomy. In the same year Tanzini used the latissimus dorsi muscle for the same purpose as a transposition flap after a mastectomy. Six years later in 1912 Stephano d Estes used the same muscle this time together with its overlying skin to create a new breast. It is not quite clear as to whether these surgeons were aware of the exact axial nature of the blood supply of the muscle and and\or in what manner the overlying skin was supplied by blood vessels that emerged from the muscle. In 1955 Neal Owens used a composite flap of the sterno mastoid muscle together with the platysma and the overlying skin based superiorly to cover defects in the face. However the muscle flap technique gathered pace after Ger used muscle flaps for compound defects in the lower leg a notoriously difficult area for reconstructive surgery. Orticochea ventured even further by raising a superiorly based gracilis muscle flap together with its overlying skin and used it as a cross leg flap in 1972. All these efforts were somewhat empirical in that the exact blood supply of various muscles as well as the territories of skin that got supplied through the muscles was not known.
McCraw and Dibell put the whole story together by publishing their work on musculocutaneous territories in 1977. One of the more high profile musculocutaneous flaps was the one in which soft tissue and skin in the lower abdomen based on its blood supply emerging from the rectus abdominus was transferred together with the muscle to create the breast mound the rectus being supplied by the superior epigastric artery (1983 Bunkis et al. and Elliot and Hamtrampf). The same soft tissue in the lower abdomen is now being transferred to the area of the breast as a free microvascular flap because it is supplied by a perforator which arises from the inferior epigastric artery. This avoids sacrificing a muscle. Generally speaking the role of muscle and musculocutaneous flaps in closing defects has diminished considerably and muscle flaps are now used mainly as a pedicled local flap or as a free flap with its nerve kept intact as a dynamic transfer. For example, the gracilis muscle is used locally to reconstruct a dynamic anal sphincter or the same muscle is moved by way of a free micro vascular transfer and later neurotised at the new site for restoring animation in the face following a facial palsy. Such a procedure can also be done to restore motion across a joint in cases such as a palsy of the brachial plexus. Here too the most frequently used muscle is the Gracilis muscle.
Flaps of an entirely different genre namely the pedicled venous flaps and the neurocutaneous flaps are included here only to complete this review though they are not amenable to a free vascular transfer. The pedicled fasciocutaeous venous flap has only a large vein in the base of the flap without any known artery or a perforator. Two such fairly large flaps based on the cephalic and the saphenous vein in the hand and the leg have been successfully employed for adjacent defects (Thatte and Thatte et al (1992-1994, 1998-2000). Their circulatory physiology is somewhat obscure though three possible explanations have been offered by experimental work done mainly by Mukund Thatte.
The neurocutaneous flap described by Masquelet et al 1992 and Bertelli et al 1992 has a far better explanation in that vessels are laid pari pasu with the nerve as it leads with its ingrained genetic developmental impulse during the embryological stages of the deposition of tissue and consequently the nerve has a profuse blood supply both within itself and in its surroundings to enable it to carry out its high metabolic functions in a chain linked fashion and therefore can support a flap of the surrounding tissue. This kind of transfer has the added advantage of the flap being a sensate flap because most neurocutaneous flaps are based on subcutaneous sensory nerves.
Neither the pedicled venous nor the neurocutaneous flap can be transferred as free flaps. Since this discussion began with Sushruta’s forehead flap a technique is presented below in which two flaps have been fashioned from this area.
While plastic surgeons have dramatically improved their expertise in reconstructing flat surfaces both for cover and lining as for example of the oral cavity or in filling a dead space or infected cavities as well as reimplanting and transplanting of composite tissue such as limbs toes or fingers they have not had such success in creating functioning tubes. Hypospadias is a prime example. In the more proximal variety of that condition for example in penoscrotal hypospadias a locally constructed skin tube is frequently bolstered by a flap of the dartos fascia from under the median raphe of the scrotum to prevent disruption leading to formation of fistulae. Reconstruction of the oesophagus in the neck is a far more formidable proposition ideally requiring immediate reconstruction. More often than not the local tissue might be short or scarred and the patient might also need post-operative radiation. All methods in the past which invariably used some form of a skin tube either created locally or transported from a distance and then covered by a flap have had indifferent results and were time consuming as well as cumbersome. One of the more dramatic improvements in this regard has been the free microvascular transfer of a jejunal loop with almost zero morbidity in digestive function. Also this is a composite tissue in many ways resembling the excised oesophagus. Whether the isoperistatically placed jejunal tube does actually participates in the act of swallowing is somewhat doubtful because it has lost its nerves in the process of its transfer but the transplanted living jejunal tube probably compensates by being an open and passive conduit and allows the forward motion generated in the proximal segment.
A few examples of reconstructive procedures following excisions of malignant tumors around the oral cavity are presented below.
A small chapter following this will include some alternative methods of reconstruction in the region of the head and neck and a possible systematic nomenclature of fasciocutaneous flaps.