- Email: [email protected]
Introducing the ‘walk-up’ flap
oral surgery oral medicine oral pathology with se~~i~~s
on
oral and maxillofacial radiology and endodontics
oral surgery Editor: ROBERT
8. SHIRA,
DDS
School of Dental Medicine, Tufts University 1 Kneeland Street Boston, Massachusetts 021 I1
Introducing
the ‘walk-up’ flap
Robert E. Marx, DDS,a Robert P. Johnson, DDS,b and Pairot Tayapongsak, DDS,c Miami, Fla., and San Antonio, Texas UNIVERSITY
OF MIAMI
SCHOOL OF MEDICINE
Reconstructive oral and maxillofacial surgeons often find the need for additional soft tissue even when a myocutaneous flap has been previously placed. This article introduces the principles. technique, and results of 32 “walk-up” muscle flaps derived from existing myocutaneous flaps. The anastomotic vascular ingrowth at the original myocutaneous flap’s distal end permits its proximal detachment and axial vessel ligation to rotate the proximal two thirds to a tissue-deficient site. In our experience at the University of Miami, these flaps have been predictable (97% viable transfer rate), have provided vascular soft tissue in deficient areas, and have been skin grafted at their surface to increase oral lining or skin cover, among several other uses. (ORAL SURC ORAL MED ORAL PATHOL
1990;70:545-51)
M
yocutaneous flaps have been an important addition to the reconstructive armamentarium for oral and maxillofacial cancer- and trauma-related deformities. The basic concept of a muscle with a dominant axial vessel and vascular territory of overlying skin has been proven to be valid by both cadaver angiograms and a decade of clinical experience.lM3Pertinent to partial and full thickness soft tissue loss in the oral and maxillofacial region, these flaps can provide aDirector of Graduate Training and Research, Division of Oral and Maxillofacial Surgery; Director of the University Center for Maxillofacial Reconstruction, University of Miami School of Medicine; consultant to Miami Veterans Administration Hospital. bin private practice, oral and maxillofacial surgery, Methodist Hospital Medical Center, San Antonio. =Former Research Fellow, Division of Oral and Maxillofacial Surgery, University of Miami School of Medicine; Oral and Maxillofacial Surgeon. 7/12/15712
mucosal lining, skin cover, and tissue bulk, as well as positioning vascular nonirradiated tissue into an irradiated neck.3*4 In our experience and that of others, the pectoralis major myocutaneous flap is the most useful and most commonly employed soft tissue transfer.3. 5 However, similar myocutaneous flaps from the latissimus dorsi,(j trapezius,7 temporalis,* and sternocleidomastoid muscles739 can also be used with predictable results. Even with the use of these flaps, residual soft tissue deficiencies and scar retractions often remain that may preclude bone graft placement and continue to compromise both function and cosmesis.In our experience residual soft tissue deficiencies remain mostly becausethe skin paddle and distal end of the muscle have beenplaced too low in the neck. Other causesare from an inadequate dissection and mobilization of tissue in the recipient tissue bed, an inadequate size of skin paddle or muscle for the size of the defect, and 545
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ORAL. SURG ORAL MED ORAL PATHOI. November 1990
Fig. 1. Patient with significant soft tissue defect in body, angle, and ramus area. A healed pectoralis major myocutaneous flap is seen outlined in the neck.
Fig. 2. Muscle is dissected from its surrounding tissues in mid-neck and separated from its proximal attachments about clavicle. Here submandibular and clavicular horizontal incisions were used.
radiotherapy. In particular, myocutaneous flaps placed at the time of extirpative cancer surgery for the purpose of gaining closure of a gaping wound often leave the tissue bed with thin areas and areas where tissue becomescontracted so that bony reconstruction is impossible without further soft tissue augmentation. These situations have placed reconstructive oral and maxillofacial surgeons in the dilemma of committing their patients to another myocutaneous flap, forcing a bone graft into a deficient tissue volume, or abandoning reconstruction altogether. The purpose of this article is to describe the principles and methods of “walking up” an existing myocutaneous flap to further augment facial soft tissue without sacrificing the additional tissue inherent in a second soft tissue myocutaneous flap.
supply is from the dominant artery and the drainage is usually from a corresponding dominant vein. These vesselstravel on the undersurface of the muscle within the fascia and in a general sensecourse along the long axis of the muscle’s length. These flaps are therefore referred to as axial pattern flaps. The dominant axial arteries of the more commonly used myocutaneous flaps are as follows: pectoralis major, the pectoral branches of the thoracoacromial artery, which arises from the junction of the subclavian and axillary artery L**, latissimus dorsi, the thoracodorsal artery, which arises in the axilla from the third division of the axillary artery$ trapezius, the transverse cervical artery, which arises from the thyrocervical trunk’; and sternocleidomastoid, the occipital artery from the external carotid artery.9 As these flaps heal into the recipient tissues, capillaries, arterioles, and venules from the surrounding tissue grow into and anastomose with the arteriolecapillary network of the flap. Within 4 to 8 weeks, a secondary blood supply to the flap has developedfrom
postflap
PRINCIPLES
OF THE ‘WALK-UP’
FLAP
When the initial myocutaneous flap is placed into its recipient area in the neck or oral cavity, its blood
Introducing
Volume 70 Number 5
Fig. 3. Vertical not necessary but a different patient, romial artery and is evident.
neck incision may also be used, which is provides wide-open access. Seen here in the proximal segments of the thoracoacvein are being ligated and a wider access
this random ingrowth and vessel anastomosis.These vesselsare located in the area of the skin paddle and its associated subcutaneous tissues in addition to the distal one third of the muscle. The proximal two thirds of the muscle does not develop anastomotic channels to the deep tissues of the neck. The anastomotic vessels of the distal one third are sufficient to perfuse the entire muscle even if the axial vesselsare sacrificed. Therefore the proximal two thirds may be repositioned from the lower portion of the neck to a more advantageous position about the upper portion of the neck, the mandible, or into the oral cavity by keeping the distal one third anastomotic vesselsintact and rotating the proximal muscle bulk on the distal one third healed into its original position. The flap is therefore converted from an axial pattern flap into a random pattern flap. This walked-up flap has a long length to width ratio but remains a viable one-stagerotation. Its viability is predictable and is due to the rich capillary network, which develops in the distal one third of the
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547
Fig. 4. Pectoralis major flap is now separated completely from its proximal vessels and attachments, as well as from surrounding tissues of the neck. Its only tissue attachment is the distal one third.
healed myocutaneous flap. This rich capillary network is in turn related to two unique features of myocutaneous flaps. The first is simply the naturally abundant blood supply of muscle itself. The secondis the muscle fascia of the proximal two thirds. This fascial envelope prevents the same anastomotic vessels from developing into the muscle along its length as develop in the distal one third. This vessel inhibition servesthe same purpose as a delay used in twostage flaps by directing perfusion demands to come from one specific portion of the flap, in this case the distal one third of the original myocutaneous flap. The intact muscle fascia, therefore, can also be conceptualized as being similar in purpose to the tubing of an external cutaneous flap. The distal one third of myocutaneous flaps used in oral and maxillofacial reconstruction is separatedfrom bony origins and insertions at the donor site and is therefore absent of enveloping fascia. Their proximal two thirds, however, is not separated from bone but is enveloped by fascia to es-
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ORAL SURG ORAL MED ORAL PATHOL November 1990
Fig. 5. Fluorescein dye photo taken with the room darkened and illumination with a Wood’s ultraviolet light at 5460 Au. Retrofilling of thoracoacromial vessel and capillary perfusion to flap’s edge are evident by blue-green fluorescence.
tablish this delaylike characteristic and thus ensure the predictable viability of the walk-up flap. SURGICAL
TECHNIQUE
Although the walk-up principle is applicable to all myocutaneous flaps, the basic techniques will be outlined here in reference to the most commonly employed flap, the pectoralis major flap. The healed pectoralis major myocutaneous flap will course over the clavicle at its lateral one third and obliquely across the neck deep to the platysma and superficial to all other muscles including the sternocleidomastoid, if present (Fig. 1). The skin paddle will either be present externally at about the level of the mandible, or within the oral mucosa. The initial incision should be for the purpose of access to the proximal muscle as it courses over the clavicle. An incision over the clavicle is most often used becauseit can then also be used to develop the subplatysmal neck tunnel (Fig. 2). One may also use the upper portion of the chest incision used to develop the original myocutaneous flap. The muscle is transected from each edge toward the palpable and visible axial vessels.Each vessel is clamped, transected, and ligated (Fig. 3). Residual motor innervation is also transected. The neck tunnel is usually developed between the clavicular incision and a submandibular incision. As an alternative, the neck may be fully opened through a vertical incision between the submandibular and clavicular incisions, but it is not necessary (Fig. 3). Such a vertical incision will provide a more direct visualization of the muscle in the neck (Fig. 3) and may
Fig. 6. Walk-up of flap’s proximal two thirds with distal one third attachments as its base.
be preferred initially until the surgeon gains more experience with this flap. We will usually use the parallel submandibular and clavicular horizontal incisions and reserve the vertical incision when the neck shows excessivescarring from previous operations or the original flap was placed over a very thin and superficial carotid sheath. The flap is walked up by separating the flap’s muscle fascia from the tissuesin the neck (Fig. 4). Since the proximal two thirds of the flap is enveloped by remaining muscle fascia, this can be accomplished with blunt dissection. A traction suture through the proximal cut end aids the separation of the muscle from the surrounding neck tissues. This type of dissection is carried superiorly in the neck toward the area of the skin paddle. Once the distal one third of the original myocutaneous flap is reached, the muscle will be found to be more tenaciously healed into the neck tissues. This is where the anastomotic vesselsrandomly enter the muscle, which will perfuse the proximal two thirds of the muscle separated from its original blood supply. Further dissection of this distal one third is done only to gain a final extension, or rotation for flap placement, and is done with the
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Fig. 7. Walk-up flap transposed to provide soft tissue contour about posterior body and angle region.
knowledge that it decreasesthe number of anastomotic vesselsperfusing the flap. At this point the flap’s perfusion may be assessedby fluorescein. Two ampules (1000 mg) of sodium fluoroscein is given intravenously and the room completely darkened. After 1 minute of circulation time, the flap can be fluoresced with a Wood’s light (5460 Au wavelength ultraviolet light). Fluorescenceis usually observedin patches and streaks in the muscle fascia (Fig. 5), at the proximal cut end, and often in the axial vessel by retrofilling (Fig. 5). The walked-up flap is placed in the prepared tissue-deficient site and sutured with numerous individual sutures that engagelittle of the muscle inasmuch as deep bites of suture may tie off small vesselscoursing through the flap and may necroseflap edges(Figs. 6 and 7). The walked-up flap will add tissue bulk, contour, and vascularized tissue substance to the recipient site, as seen in Fig. 8. The case illustrated in Fig. 8 specifically emphasizes the contour gained in the body and angle region as compared to the presurgical view of Fig. 1 and contrasts sharply with the unaugmented preauricular area that this flap did not extend to. The limitations of this flap are also, therefore, seen to be a limitation of flap reach, which can be an area only within the radius of two thirds a pectoral muscle length from the center point of the healed-in skin paddle, which in our experience has averaged 14.2 cm and ranged from 12.1 to 17.4 cm. Therefore the most common walk-up flaps from the pectoralis major and the latissimus dorsi cannot be expected to augment areas above the ala-tragal line. However, trapezius flaps that are initially placed in a more superior position can be walked up above the ala-tragal line. Another skin paddle cannot be brought up with a
8. Two-year follow-up showing added contour in posterior body and angle region contrasted against residual hollowed appearancein preauricular area where flap did not extend. Fig.
walk-up flap. The overlying skin at the proximal cut end over the clavicle and lower portion of the neck is not dependent on the muscle for perfusion. Such skin will therefore not transfer with the walked-up muscle. However, when the recipient site is deficient in mucosal lining or skin cover as well as bulk, the muscle surface may be skin grafted. We have frequently employed split-thickness skin grafts to expand the epithelialized surface area of a defect in conjunction with a walk-up flap. Such split-thickness skin grafts readily heal to the richly vascular muscular surface. RESULTS
To date, we have walked up 32 myocutaneous flaps; 30 from the pectoralis major and one each from the latissimus dorsi and trapezius (Table I). Thirty-one of the 32 flaps transferred fully. One flap from the pectoralis major was lost becauseof a persistent infection from true methicillin-resistant Staphylococcus aurem.
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Table
I. Walk-up flap use
Table
ORAL SURG ORAL MED ORAL PATHOL November 1990
Muscle
No.
No. failed
Pectoralis major Latissimus dorsi Trapezius
30 1 1
1 (3%) 0 0
II. Reasons for walk-up flap No.
Original flap positioned too low Original flap too small Original recipient site dissection inadequate Postflap radiotherapy
18 (56%) 7 (22%) 4 (12.5%) 3 (9.5%) 32 (100%)
Ten flaps were skin grafted on its surface to increase the epithelialized surface area of either skin or mucosa. Four were skin grafted for skin cover only, four for mucosal lining only, and two were skin grafted for both. The one failed flap was not in the group that was skin grafted. The remaining 22 flaps were transferred to add a vascularized tissue bulk for contour and tissue volume for bone grafting. All 31 successful walk-up flaps were bone grafted for complete reconstruction without complications. Seven bone grafts were placed at the time the flap was walked up, and 24 were placed after the flap was walked up. The primary requirement for additional soft tissue augmentation necessitating a walk-up flap was as follows: the original myocutanous flap placed too low in the neck, 18 (56%); inadequate dissection of the recipient site, 4 (12.5%); inadequate size of original flap, 7 (22%); and postflap radiotherapy, 3 (9.5%) (Table II). DISCUSSION
Walking up tissue from a distant site is certainly not a new concept. Cutaneous flaps from the chest, back, and even abdomen have been serially advanced in a tubed fashion for many years.‘0-‘3 Such flaps brought skin and subcutaneous tissue to the area of the upper neck and face but were mostly multistaged. These flaps also developed a collateral blood flow from their recipient tissue bed, perfusing the entire tube length within 6 weeks, and thus allowed their detachment and walk-up to another area. These flaps were, however, cutaneous flaps of a random pattern nature, or had multiple axial feeder vessels, as did the deltopectoral flap. These vascular patterns and the tubing of such
Surface skin grafted
IO (33%) 0 0
Bone grafted
29 I I
flaps gave great assurance to the development of collateral blood flow from recipient tissue bed. Walking up a muscle flap has not been widely used. One reason for this has been the concern of muscle necrosisif the original axial vesselsare sacrificed. The dye studies discussed in this article and our related experience with muscle walk-up flaps should document the random pattern peripheral reperfusion of these flaps in a similar fashion to the older cutaneous tubed flaps. The muscle not only continues to survive on the basis of these random peripheral anastomotic vessels, but can also undergo rotation for use elsewhere in the area of the upper neck and face in a consistent and predictable fashion. The muscle’sviability also maintains its size so that overcontouring in an attempt to predict shrinkage is not necessary. The walk-up muscle flap principle thereby gives the surgeon and patient more options and flexibility in reconstructive planning. In many instances it will conservea patient’s tissue by providing additional soft tissue bulk, mucosal lining, or skin cover if skin grafted, or correct a soft tissue contour deficiency while at the same time sparing the patient additional donor tissue loss from another myocutaneous or free flap. Since only the distal muscle and skin paddle (10% of the total tissue) are used in most myocutaneous flaps, the remaining 90% is usually wasted. It is left to atrophy in the neck, or debrided at a later operation. The walk-up flap permits the maximum gain from a single flap. The walk-up flap additionally gives the surgeon the option of adding soft tissue contour at the time of bony reconstruction, or to obliterate the dead space areas often encountered during bony reconstruction. It is hoped that the knowledge of this one-staged walk-up flap will add yet another tool to the armamentarium of the reconstructive oral and maxillofacial surgeon-a tool that is based on the sound principle of random pattern peripheral vascular ingrowth and is made possible by the tubing effect of the muscle fascia. CONCLUSIONS
1. The proximal two thirds of myocutaneous flaps may be detached from their axial vesselswith continued survival.
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2. The proximal two thirds of the muscle may be rotated into another position about the upper neck, oral cavity, or face, with a predictable and lasting outcome. 3. Such walk-up flaps may be employed for the requirements of (a) additional vascularized soft tissue before or during bony reconstruction of the jaws, (b) obliterating dead space during bony reconstruction of the jaws, (c) adding soft tissue contour to deficient areas, and (d) adding epithelialized surface areas to oral mucosa or external skin when the muscle’s surface is skin grafted. REFERENCES
1. Wei WI, Lam KH, Wong J. The true pectoralis major myocutaneous island flap: an anatomic study. Br J Plast Surg 1984;37:568-73. 2. Ariyan S. The pectoralis major myocutaneous flap: a versatile flap for reconstruction in the head and neck. Plast Reconstr Surg 1979;63:73-81. 3. Wilson JSP, Yiacoumettis AM, O’Neill T. Some observations on 112 pectoralis major myocutaneous flaps. Am J Surg 1984;147:273-9. 4. Schuller DE. Limitations of the pectoralis major myocutaneous flap in head and neck cancer reconstruction. Arch Otolaryngol 1980;106:709-11. 5. Ariyan S. Further experiences with the pectoralis major myocutaneous flap for the immediate repair of defects from ex-
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cisions of head and neck cancers. Plast Reconstr Surg 1979;64:605-12. 6. Sabatier RE, Bakamjian VY. Transaxillary latissimus dorsi flap reconstruction in head and neck cancer-limitations and refinements in 56 cases.Am J Surg 1985;150:427-34. 7. McGraw JB, Magee WP, Kalwaic H. Usesof the trapezius and sternomastoid myocutaneous flaps in head and neck reconstruction. Plast Reconstr Surg 1979;63:49-57. 8. Bakamjian VY, Souther SG. Use of temporal muscle flap for reconstruction after orbito-maxillary resection for cancer. Plast Reconstr Surg 1975;56:171-7. 9. Marx RE, McDonald DK. The sternocleidomastoid muscle as a muscular and myocutaneous flap. J Oral Maxillofac Surg 1985;42:251-63. 10. Bakamjian VY. A two-staged method for pharyngoesophageal reconstruction with a primary pectoral skin flap. Plast Reconstr Surg 1965;36:173-84. Il. Lichtveld PLM, Snow AB. Reconstruction by means of pedicled skin flaps in the head and neck region. Arch Chu Nether 1973;25:379-91. 12. Krizek TJ, Robinson MC. The deltopectoral flap for reconstruction of irradiated cancer of the head and neck. Surg Gynecol Obstet 1972;135:87-94. 13. Banks P. Gunshot wounds. In: Rowe NL, Williams JLI, eds. Maxillofacial injuries; vol. 2. London: Churchill Livingstone, 1985:619-30. Reprint requests to:
Dr. Robert E. Marx Department of Surgery Division of Oral and Maxillofacial Surgery Jackson Memorial Hospital 1611 N.W. 12th Ave. Miami, FL 33136
on
oral and maxillofacial radiology and endodontics
oral surgery Editor: ROBERT
8. SHIRA,
DDS
School of Dental Medicine, Tufts University 1 Kneeland Street Boston, Massachusetts 021 I1
Introducing
the ‘walk-up’ flap
Robert E. Marx, DDS,a Robert P. Johnson, DDS,b and Pairot Tayapongsak, DDS,c Miami, Fla., and San Antonio, Texas UNIVERSITY
OF MIAMI
SCHOOL OF MEDICINE
Reconstructive oral and maxillofacial surgeons often find the need for additional soft tissue even when a myocutaneous flap has been previously placed. This article introduces the principles. technique, and results of 32 “walk-up” muscle flaps derived from existing myocutaneous flaps. The anastomotic vascular ingrowth at the original myocutaneous flap’s distal end permits its proximal detachment and axial vessel ligation to rotate the proximal two thirds to a tissue-deficient site. In our experience at the University of Miami, these flaps have been predictable (97% viable transfer rate), have provided vascular soft tissue in deficient areas, and have been skin grafted at their surface to increase oral lining or skin cover, among several other uses. (ORAL SURC ORAL MED ORAL PATHOL
1990;70:545-51)
M
yocutaneous flaps have been an important addition to the reconstructive armamentarium for oral and maxillofacial cancer- and trauma-related deformities. The basic concept of a muscle with a dominant axial vessel and vascular territory of overlying skin has been proven to be valid by both cadaver angiograms and a decade of clinical experience.lM3Pertinent to partial and full thickness soft tissue loss in the oral and maxillofacial region, these flaps can provide aDirector of Graduate Training and Research, Division of Oral and Maxillofacial Surgery; Director of the University Center for Maxillofacial Reconstruction, University of Miami School of Medicine; consultant to Miami Veterans Administration Hospital. bin private practice, oral and maxillofacial surgery, Methodist Hospital Medical Center, San Antonio. =Former Research Fellow, Division of Oral and Maxillofacial Surgery, University of Miami School of Medicine; Oral and Maxillofacial Surgeon. 7/12/15712
mucosal lining, skin cover, and tissue bulk, as well as positioning vascular nonirradiated tissue into an irradiated neck.3*4 In our experience and that of others, the pectoralis major myocutaneous flap is the most useful and most commonly employed soft tissue transfer.3. 5 However, similar myocutaneous flaps from the latissimus dorsi,(j trapezius,7 temporalis,* and sternocleidomastoid muscles739 can also be used with predictable results. Even with the use of these flaps, residual soft tissue deficiencies and scar retractions often remain that may preclude bone graft placement and continue to compromise both function and cosmesis.In our experience residual soft tissue deficiencies remain mostly becausethe skin paddle and distal end of the muscle have beenplaced too low in the neck. Other causesare from an inadequate dissection and mobilization of tissue in the recipient tissue bed, an inadequate size of skin paddle or muscle for the size of the defect, and 545
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ORAL. SURG ORAL MED ORAL PATHOI. November 1990
Fig. 1. Patient with significant soft tissue defect in body, angle, and ramus area. A healed pectoralis major myocutaneous flap is seen outlined in the neck.
Fig. 2. Muscle is dissected from its surrounding tissues in mid-neck and separated from its proximal attachments about clavicle. Here submandibular and clavicular horizontal incisions were used.
radiotherapy. In particular, myocutaneous flaps placed at the time of extirpative cancer surgery for the purpose of gaining closure of a gaping wound often leave the tissue bed with thin areas and areas where tissue becomescontracted so that bony reconstruction is impossible without further soft tissue augmentation. These situations have placed reconstructive oral and maxillofacial surgeons in the dilemma of committing their patients to another myocutaneous flap, forcing a bone graft into a deficient tissue volume, or abandoning reconstruction altogether. The purpose of this article is to describe the principles and methods of “walking up” an existing myocutaneous flap to further augment facial soft tissue without sacrificing the additional tissue inherent in a second soft tissue myocutaneous flap.
supply is from the dominant artery and the drainage is usually from a corresponding dominant vein. These vesselstravel on the undersurface of the muscle within the fascia and in a general sensecourse along the long axis of the muscle’s length. These flaps are therefore referred to as axial pattern flaps. The dominant axial arteries of the more commonly used myocutaneous flaps are as follows: pectoralis major, the pectoral branches of the thoracoacromial artery, which arises from the junction of the subclavian and axillary artery L**, latissimus dorsi, the thoracodorsal artery, which arises in the axilla from the third division of the axillary artery$ trapezius, the transverse cervical artery, which arises from the thyrocervical trunk’; and sternocleidomastoid, the occipital artery from the external carotid artery.9 As these flaps heal into the recipient tissues, capillaries, arterioles, and venules from the surrounding tissue grow into and anastomose with the arteriolecapillary network of the flap. Within 4 to 8 weeks, a secondary blood supply to the flap has developedfrom
postflap
PRINCIPLES
OF THE ‘WALK-UP’
FLAP
When the initial myocutaneous flap is placed into its recipient area in the neck or oral cavity, its blood
Introducing
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Fig. 3. Vertical not necessary but a different patient, romial artery and is evident.
neck incision may also be used, which is provides wide-open access. Seen here in the proximal segments of the thoracoacvein are being ligated and a wider access
this random ingrowth and vessel anastomosis.These vesselsare located in the area of the skin paddle and its associated subcutaneous tissues in addition to the distal one third of the muscle. The proximal two thirds of the muscle does not develop anastomotic channels to the deep tissues of the neck. The anastomotic vessels of the distal one third are sufficient to perfuse the entire muscle even if the axial vesselsare sacrificed. Therefore the proximal two thirds may be repositioned from the lower portion of the neck to a more advantageous position about the upper portion of the neck, the mandible, or into the oral cavity by keeping the distal one third anastomotic vesselsintact and rotating the proximal muscle bulk on the distal one third healed into its original position. The flap is therefore converted from an axial pattern flap into a random pattern flap. This walked-up flap has a long length to width ratio but remains a viable one-stagerotation. Its viability is predictable and is due to the rich capillary network, which develops in the distal one third of the
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547
Fig. 4. Pectoralis major flap is now separated completely from its proximal vessels and attachments, as well as from surrounding tissues of the neck. Its only tissue attachment is the distal one third.
healed myocutaneous flap. This rich capillary network is in turn related to two unique features of myocutaneous flaps. The first is simply the naturally abundant blood supply of muscle itself. The secondis the muscle fascia of the proximal two thirds. This fascial envelope prevents the same anastomotic vessels from developing into the muscle along its length as develop in the distal one third. This vessel inhibition servesthe same purpose as a delay used in twostage flaps by directing perfusion demands to come from one specific portion of the flap, in this case the distal one third of the original myocutaneous flap. The intact muscle fascia, therefore, can also be conceptualized as being similar in purpose to the tubing of an external cutaneous flap. The distal one third of myocutaneous flaps used in oral and maxillofacial reconstruction is separatedfrom bony origins and insertions at the donor site and is therefore absent of enveloping fascia. Their proximal two thirds, however, is not separated from bone but is enveloped by fascia to es-
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ORAL SURG ORAL MED ORAL PATHOL November 1990
Fig. 5. Fluorescein dye photo taken with the room darkened and illumination with a Wood’s ultraviolet light at 5460 Au. Retrofilling of thoracoacromial vessel and capillary perfusion to flap’s edge are evident by blue-green fluorescence.
tablish this delaylike characteristic and thus ensure the predictable viability of the walk-up flap. SURGICAL
TECHNIQUE
Although the walk-up principle is applicable to all myocutaneous flaps, the basic techniques will be outlined here in reference to the most commonly employed flap, the pectoralis major flap. The healed pectoralis major myocutaneous flap will course over the clavicle at its lateral one third and obliquely across the neck deep to the platysma and superficial to all other muscles including the sternocleidomastoid, if present (Fig. 1). The skin paddle will either be present externally at about the level of the mandible, or within the oral mucosa. The initial incision should be for the purpose of access to the proximal muscle as it courses over the clavicle. An incision over the clavicle is most often used becauseit can then also be used to develop the subplatysmal neck tunnel (Fig. 2). One may also use the upper portion of the chest incision used to develop the original myocutaneous flap. The muscle is transected from each edge toward the palpable and visible axial vessels.Each vessel is clamped, transected, and ligated (Fig. 3). Residual motor innervation is also transected. The neck tunnel is usually developed between the clavicular incision and a submandibular incision. As an alternative, the neck may be fully opened through a vertical incision between the submandibular and clavicular incisions, but it is not necessary (Fig. 3). Such a vertical incision will provide a more direct visualization of the muscle in the neck (Fig. 3) and may
Fig. 6. Walk-up of flap’s proximal two thirds with distal one third attachments as its base.
be preferred initially until the surgeon gains more experience with this flap. We will usually use the parallel submandibular and clavicular horizontal incisions and reserve the vertical incision when the neck shows excessivescarring from previous operations or the original flap was placed over a very thin and superficial carotid sheath. The flap is walked up by separating the flap’s muscle fascia from the tissuesin the neck (Fig. 4). Since the proximal two thirds of the flap is enveloped by remaining muscle fascia, this can be accomplished with blunt dissection. A traction suture through the proximal cut end aids the separation of the muscle from the surrounding neck tissues. This type of dissection is carried superiorly in the neck toward the area of the skin paddle. Once the distal one third of the original myocutaneous flap is reached, the muscle will be found to be more tenaciously healed into the neck tissues. This is where the anastomotic vesselsrandomly enter the muscle, which will perfuse the proximal two thirds of the muscle separated from its original blood supply. Further dissection of this distal one third is done only to gain a final extension, or rotation for flap placement, and is done with the
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Fig. 7. Walk-up flap transposed to provide soft tissue contour about posterior body and angle region.
knowledge that it decreasesthe number of anastomotic vesselsperfusing the flap. At this point the flap’s perfusion may be assessedby fluorescein. Two ampules (1000 mg) of sodium fluoroscein is given intravenously and the room completely darkened. After 1 minute of circulation time, the flap can be fluoresced with a Wood’s light (5460 Au wavelength ultraviolet light). Fluorescenceis usually observedin patches and streaks in the muscle fascia (Fig. 5), at the proximal cut end, and often in the axial vessel by retrofilling (Fig. 5). The walked-up flap is placed in the prepared tissue-deficient site and sutured with numerous individual sutures that engagelittle of the muscle inasmuch as deep bites of suture may tie off small vesselscoursing through the flap and may necroseflap edges(Figs. 6 and 7). The walked-up flap will add tissue bulk, contour, and vascularized tissue substance to the recipient site, as seen in Fig. 8. The case illustrated in Fig. 8 specifically emphasizes the contour gained in the body and angle region as compared to the presurgical view of Fig. 1 and contrasts sharply with the unaugmented preauricular area that this flap did not extend to. The limitations of this flap are also, therefore, seen to be a limitation of flap reach, which can be an area only within the radius of two thirds a pectoral muscle length from the center point of the healed-in skin paddle, which in our experience has averaged 14.2 cm and ranged from 12.1 to 17.4 cm. Therefore the most common walk-up flaps from the pectoralis major and the latissimus dorsi cannot be expected to augment areas above the ala-tragal line. However, trapezius flaps that are initially placed in a more superior position can be walked up above the ala-tragal line. Another skin paddle cannot be brought up with a
8. Two-year follow-up showing added contour in posterior body and angle region contrasted against residual hollowed appearancein preauricular area where flap did not extend. Fig.
walk-up flap. The overlying skin at the proximal cut end over the clavicle and lower portion of the neck is not dependent on the muscle for perfusion. Such skin will therefore not transfer with the walked-up muscle. However, when the recipient site is deficient in mucosal lining or skin cover as well as bulk, the muscle surface may be skin grafted. We have frequently employed split-thickness skin grafts to expand the epithelialized surface area of a defect in conjunction with a walk-up flap. Such split-thickness skin grafts readily heal to the richly vascular muscular surface. RESULTS
To date, we have walked up 32 myocutaneous flaps; 30 from the pectoralis major and one each from the latissimus dorsi and trapezius (Table I). Thirty-one of the 32 flaps transferred fully. One flap from the pectoralis major was lost becauseof a persistent infection from true methicillin-resistant Staphylococcus aurem.
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Marx, ,Johnson, and Tayapongsak
Table
I. Walk-up flap use
Table
ORAL SURG ORAL MED ORAL PATHOL November 1990
Muscle
No.
No. failed
Pectoralis major Latissimus dorsi Trapezius
30 1 1
1 (3%) 0 0
II. Reasons for walk-up flap No.
Original flap positioned too low Original flap too small Original recipient site dissection inadequate Postflap radiotherapy
18 (56%) 7 (22%) 4 (12.5%) 3 (9.5%) 32 (100%)
Ten flaps were skin grafted on its surface to increase the epithelialized surface area of either skin or mucosa. Four were skin grafted for skin cover only, four for mucosal lining only, and two were skin grafted for both. The one failed flap was not in the group that was skin grafted. The remaining 22 flaps were transferred to add a vascularized tissue bulk for contour and tissue volume for bone grafting. All 31 successful walk-up flaps were bone grafted for complete reconstruction without complications. Seven bone grafts were placed at the time the flap was walked up, and 24 were placed after the flap was walked up. The primary requirement for additional soft tissue augmentation necessitating a walk-up flap was as follows: the original myocutanous flap placed too low in the neck, 18 (56%); inadequate dissection of the recipient site, 4 (12.5%); inadequate size of original flap, 7 (22%); and postflap radiotherapy, 3 (9.5%) (Table II). DISCUSSION
Walking up tissue from a distant site is certainly not a new concept. Cutaneous flaps from the chest, back, and even abdomen have been serially advanced in a tubed fashion for many years.‘0-‘3 Such flaps brought skin and subcutaneous tissue to the area of the upper neck and face but were mostly multistaged. These flaps also developed a collateral blood flow from their recipient tissue bed, perfusing the entire tube length within 6 weeks, and thus allowed their detachment and walk-up to another area. These flaps were, however, cutaneous flaps of a random pattern nature, or had multiple axial feeder vessels, as did the deltopectoral flap. These vascular patterns and the tubing of such
Surface skin grafted
IO (33%) 0 0
Bone grafted
29 I I
flaps gave great assurance to the development of collateral blood flow from recipient tissue bed. Walking up a muscle flap has not been widely used. One reason for this has been the concern of muscle necrosisif the original axial vesselsare sacrificed. The dye studies discussed in this article and our related experience with muscle walk-up flaps should document the random pattern peripheral reperfusion of these flaps in a similar fashion to the older cutaneous tubed flaps. The muscle not only continues to survive on the basis of these random peripheral anastomotic vessels, but can also undergo rotation for use elsewhere in the area of the upper neck and face in a consistent and predictable fashion. The muscle’sviability also maintains its size so that overcontouring in an attempt to predict shrinkage is not necessary. The walk-up muscle flap principle thereby gives the surgeon and patient more options and flexibility in reconstructive planning. In many instances it will conservea patient’s tissue by providing additional soft tissue bulk, mucosal lining, or skin cover if skin grafted, or correct a soft tissue contour deficiency while at the same time sparing the patient additional donor tissue loss from another myocutaneous or free flap. Since only the distal muscle and skin paddle (10% of the total tissue) are used in most myocutaneous flaps, the remaining 90% is usually wasted. It is left to atrophy in the neck, or debrided at a later operation. The walk-up flap permits the maximum gain from a single flap. The walk-up flap additionally gives the surgeon the option of adding soft tissue contour at the time of bony reconstruction, or to obliterate the dead space areas often encountered during bony reconstruction. It is hoped that the knowledge of this one-staged walk-up flap will add yet another tool to the armamentarium of the reconstructive oral and maxillofacial surgeon-a tool that is based on the sound principle of random pattern peripheral vascular ingrowth and is made possible by the tubing effect of the muscle fascia. CONCLUSIONS
1. The proximal two thirds of myocutaneous flaps may be detached from their axial vesselswith continued survival.
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2. The proximal two thirds of the muscle may be rotated into another position about the upper neck, oral cavity, or face, with a predictable and lasting outcome. 3. Such walk-up flaps may be employed for the requirements of (a) additional vascularized soft tissue before or during bony reconstruction of the jaws, (b) obliterating dead space during bony reconstruction of the jaws, (c) adding soft tissue contour to deficient areas, and (d) adding epithelialized surface areas to oral mucosa or external skin when the muscle’s surface is skin grafted. REFERENCES
1. Wei WI, Lam KH, Wong J. The true pectoralis major myocutaneous island flap: an anatomic study. Br J Plast Surg 1984;37:568-73. 2. Ariyan S. The pectoralis major myocutaneous flap: a versatile flap for reconstruction in the head and neck. Plast Reconstr Surg 1979;63:73-81. 3. Wilson JSP, Yiacoumettis AM, O’Neill T. Some observations on 112 pectoralis major myocutaneous flaps. Am J Surg 1984;147:273-9. 4. Schuller DE. Limitations of the pectoralis major myocutaneous flap in head and neck cancer reconstruction. Arch Otolaryngol 1980;106:709-11. 5. Ariyan S. Further experiences with the pectoralis major myocutaneous flap for the immediate repair of defects from ex-
Introducing
the “walk-up”Jlap
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cisions of head and neck cancers. Plast Reconstr Surg 1979;64:605-12. 6. Sabatier RE, Bakamjian VY. Transaxillary latissimus dorsi flap reconstruction in head and neck cancer-limitations and refinements in 56 cases.Am J Surg 1985;150:427-34. 7. McGraw JB, Magee WP, Kalwaic H. Usesof the trapezius and sternomastoid myocutaneous flaps in head and neck reconstruction. Plast Reconstr Surg 1979;63:49-57. 8. Bakamjian VY, Souther SG. Use of temporal muscle flap for reconstruction after orbito-maxillary resection for cancer. Plast Reconstr Surg 1975;56:171-7. 9. Marx RE, McDonald DK. The sternocleidomastoid muscle as a muscular and myocutaneous flap. J Oral Maxillofac Surg 1985;42:251-63. 10. Bakamjian VY. A two-staged method for pharyngoesophageal reconstruction with a primary pectoral skin flap. Plast Reconstr Surg 1965;36:173-84. Il. Lichtveld PLM, Snow AB. Reconstruction by means of pedicled skin flaps in the head and neck region. Arch Chu Nether 1973;25:379-91. 12. Krizek TJ, Robinson MC. The deltopectoral flap for reconstruction of irradiated cancer of the head and neck. Surg Gynecol Obstet 1972;135:87-94. 13. Banks P. Gunshot wounds. In: Rowe NL, Williams JLI, eds. Maxillofacial injuries; vol. 2. London: Churchill Livingstone, 1985:619-30. Reprint requests to:
Dr. Robert E. Marx Department of Surgery Division of Oral and Maxillofacial Surgery Jackson Memorial Hospital 1611 N.W. 12th Ave. Miami, FL 33136