Advantages of perforator flaps in reconstruction of complex defects of the head and neck.

Abstract

Microsurgical transfer of vascularized tissue during the past three decades has allowed highly complicated postoncologic defects in the head and neck region to be reconstructed. Recently, perforator taps have been used to reduce postoperative pain, shorten hospital stay, and lessen donor-site complications. These flaps are offsprings of previously known musculocutaneous and fasciocutaneous flaps and are harvested with preservation of the underlying muscular and fascial structures. The vascularized skin and soft-tissue envelope is supplied by perforating branches from the parent vessel. Less is known about the performance of these flaps in the head and neck region. During a 4-year period, 22 patients at our institution underwent reconstruction of the head and neck region with deep inferior epigastric perforator (DIEP) or thoracodorsal artery perforator (TDAP) flaps. All but one of the flaps survived. Advantages noted include. (1) longer vascular pedicles, (2) less postoperative pain, (3) less donor-site deformity, (4) improvedaesthetic outcome, (5) potential for a neurosensory flap, (6) potential for an osteocutaneous flap, and (7) ease of postoperative radiologic follow-up. The DIEP flap can be harvested concurrent with oncologic resection, with the patient in the supine position. The TDAP flap is dissected with the patient in the decubitus position, creating an additional step to change operative position, and separates extirpative and reconstructive stages.

Introduction

Since its inception, free tissue transfer has revolutionized the field of head and neck reconstruction by allowing surgeons to rebuild defects of increasing complexity. During the first decade of microvascular surgery, the focus was on developing techniques that would increase the survival of free flaps. Many donor sites were developed at that time to match the specific needs of the defect. As techniques improved, free tissue transfer became more reliable. (1-3) Perforator flaps were conceived to decrease morbidity at the donor site. These flaps include skin and subcutaneous tissue only, preserving muscle, fascia, nerves, and other vital structures at the donor site. (4-6) The additional surgical complexity and increased operating time for harvest of perforator flaps was compensated for by decreased pain and improved functional outcome at the donor site. (7,8)

In the head and neck region, the anterolateral thigh flap has been used most often, with good results and excellent reliability. (9) However, the donor site on the thigh may be a disadvantage for many individuals. (10) The abdominal and thoracic regions have ample tissue that can be used in head and neck reconstruction while placing the scar in a more cosmetic location. The deep inferior epigastric perforator (DIEP) flap can potentially reestablish sensory innervation in oral cavity reconstruction, and the thoracodorsal artery perforator (TDAP) flap can be combined with vascularized scapular bone to create a composite osteocutaneous flap. (11,12)

Perforator flaps from the abdominal and thoracic regions were applied at Louisiana State University Health Sciences Center to 22 defects in the head and neck area of 22 patients (21 postoncologic surgical cases and 1 traumatic infectious complication). Defects were located at the anterior skull base (2), lateral skull base (4), scalp (4), maxilla (6), oropharynx (4), and mandible (2). As our experience increased, we discovered advantages and disadvantages with each procedure. We detail our successful experience with perforator flaps from the abdomen and thoracic region in the reconstruction of complex head and neck defects.

Materials and methods

The charts of 22 patients who underwent reconstruction from March 1998 to March 2002 by means of DIEP or TDAP flaps were retrospectively reviewed. The charts were analyzed for demographic information, hospital stay, operative technique, and early and late complications. Early complications included vessel thrombosis, return to the operating suite, flap loss, early debridement, seromas, and wound infections. Late complications included delayed wound healing, fat necrosis, and unexpected revision surgery. Elective debulking procedures were not considered complications.

Technique. The DIEP flap. Preoperative markings (figure 1) are performed with the patient in the standing position. The superior margin of the flap is shifted slightly above the umbilicus to include periumbilical perforators. Vertical dimensions of the flap rarely exceed 12 cm, allowing for closure under minimal tension. Skin paddles can be up to 12 cm wide and 30 to 45 cm long when a transverse design is used. A hemiabdominal skin paddle design will yield a flap up to 12 cm wide by 15 to 20 cm long. Perforators are identified with a Doppler probe (Koven Technology, Inc., St. Louis).

[FIGURE 1 OMITTED]

Using a two-team approach, the DIEP flap is harvested concurrent with oncologic resection and exposure of recipient vessels. The DIEP flap is elevated from lateral to medial in a suprafascial plane. (5) The superficial inferior epigastric vein is preserved. The lateral row of perforators is identified and evaluated. These vessels are usually capable of nourishing the flap; otherwise, medial-row perforators are chosen. The largest perforators are selected. The anterior rectus sheath is opened around the perforating vascular bundle, allowing the perforators to be traced to the deep inferior epigastric vessels. Intercostal motor nerves should be left intact to avoid denervating the muscles medially. Intercostal sensory nerves can be dissected for flap innervation. (8) The rectus sheath and muscle are separated to allow isolation of the pedicle.

After division of the pedicle, the flap is brought to the neck for anastomosis. Vessel anastomosis is performed with 9-0 nylon for the artery and with a vessel coupler (Medical Companies Alliance, Inc., Bessemer, Ala.) for the vein. A neurorraphy can be performed between the flap sensory nerve and the lingual nerve in oropharynx reconstruction. An implantable Doppler (Cook Vascular, Inc., Leechburg, Pa.) is placed around the vein for postoperative monitoring. The flap is tailored and inset into the defect. Each opening in the rectus sheath is closed without tension. The abdominal apron is advanced and closed in routine fashion.

The TDAP flap. With the patient in the sitting position (figure 2), an area 2 cm behind the anterior border of the latissimus dorsi muscle and 4 cm inferior to the tip of the scapula is marked in an attempt to locate the hilus of the vessel. (13) A point 8 cm below the posterior axillary fold and centering 2 cm behind the anterior edge of the latissimus dorsi muscle is mapped out with a handheld Doppler device (Huntleigh Healthcare, Eatontown, N.J.). A skin paddle of 10 x 25 cm is reliably achieved with this flap. (14,15)

[FIGURE 2 OMITTED]

Surgery is performed with the patient in the lateral decubitus position. The inferior portion of the flap is raised first. The neurovascular bundle is identified. Subsequently, the posterior-dorsal edge of the flap is elevated (figure 3). We begin dissection above the dorsal thoracic fascia and descend below the fascia when we get within 2 cm of the perforating row of vessels. Visibility is maximized in this plane. Dissection should be done carefully as one approaches the meridian of the flap. As dissection continues, the perimysium is peeled off the muscle bundles until the perforator cleavage line is identified on the muscle. This line appears white because of the presence of the lateral thoracodorsal nerve and vascular bundle. The perforating vessels will be found along this line as dissection proceeds proximally.

[FIGURE 3 OMITTED]

Once a perforator vessel is visible, the anterolateral edge of the flap can then be elevated in a similar fashion toward the meridian. Dissection proceeds until all the perforators are identified. The space between two large muscle bundles where the perforator vessels ascend toward the skin flap is dissected until the underlying structures are identified. The thoracodorsal nerve can be separated from the vessels and preserved. The distal ends of the thoracodorsal vessels, close to the origin of the muscle, are ligated and dissected toward the axilla, being careful not to damage the delicate venae comitantes that accompany the perforating artery. Once the perforator is released, retractors are placed on the proximal latissimus dorsi muscle. Dissection continues below the muscle. Dissection proceeds more rapidly at this point to include ligation of major branches until one reaches the axillary artery and vein.

The TDAP-osteocutaneous flap. When bony stock is desired for the reconstruction, dissection should include the angular artery. (16,17) This vessel most commonly arises from the thoracodorsal artery (16) and may originate from the serratus anterior muscular branch. The latissimus dorsi muscle is retracted to expose the vessel heading toward the angle of the scapula. The angular vessel is dissected out and preserved from under the teres major, which is divided. The muscular bundles on the dorsal surface of the scapula are dissected to expose the desired segment of scapular bone. By carefully preserving the angular vessel and its periosteal blood supply to the scapula, a 14 x 3-cm bone segment is obtained (figure 4). Once the skin and bone flaps are released, dissection continues proximally to the axilla in preparation for flap harvest.

[FIGURE 4 OMITTED]

Results

Demographics. The average age of the 22 patients was 57 years (range, 16 to 74). Twelve (55%) were active smokers up to the time of surgery. Eighteen (82%) had consumed alcohol within the 12 months before surgery. One case was a repair of a traumatic infectious complication of the anterior skull base, and 21 cases were postoncologic reconstructions. Most lesions were squamous or basal cell carcinomas (figure 5, A and B). Twelve DIEP and 10 TDAP flap procedures were performed (table 1). The average operating time was 12.3 hours (range, 10.5 to 23). The average hospital stay was 11.5 days (range, 8 to 42). Ten patients (45%) experienced 18 complications. One patient had 5 separate complications. Of the patients with complications, most had 2. There were 6 flap- or donor-site-related complications and 12 systemic complications (table 2).

Early complications. Twenty-one of 22 flaps survived. No perioperative mortality occurred. One DIEP flap used for floor-of-mouth reconstruction was lost to venous thrombosis within the first 24 hours after surgery. Examination of the flap 16 hours after surgery demonstrated increased bluish discoloration. Despite normal Doppler pulses, the patient was returned to surgery. The venous anastomosis was found to be filled with old clot. Attempts were made to reestablish flow, without success. A DIEP flap from the opposite hemiabdomen was subsequently completed on this patient.

Two partial flap losses occurred. One patient with a TDAP-osteocutaneous flap experienced ischemia in the distal portion of the flap and required debridement and a nasolabial flap to close a palatal defect. A patient with a double-skin-paddle-osteocutaneous flap (TDAP and scapular fasciocutaneous flaps), which was used for a massive defect of the lower face, also sustained distal ischemia. This patient returned to surgery for debridement. A postoperative fistula developed but healed, and he began postoperative radiation therapy without delay. Approximately 10% of each flap was lost.

A DIEP flap used for oropharyngeal reconstruction underwent 5% fat necrosis. The skin remained viable without fistula formation. Two abdominal donor sites sustained postoperative infection. One of those wounds was opened on postoperative day 5 and was packed, with secondary healing; the other resolved with intravenous antibiotic therapy. No donor seromas or wound healing problems occurred at the thoracic donor site. Early systemic complications included delirium tremens (3), pneumonia (3), meningitis (1), deep vein thrombosis (1), and congestive heart failure (1).

Late complications. No postoperative hernias or bulges were seen at abdominal donor sites in this series. Tumors recurred in three patients in the follow-up period; two of these patients subsequently died of their disease.

Four elective debulking procedures were carried out on the flaps, most using suction lipectomy to reduce the bulk of the flap.

Discussion

Patients with head and neck carcinoma usually have many comorbidities. After many years of alcohol and cigarette consumption, they become poor candidates for surgery, and both donor and recipient reconstructive sites have difficulty healing. Additionally, these patients have multiple systemic complications in the postoperative period. (2) In this series, 12 systemic complications occurred in 7 of 22 (32%) patients and accounted for 67% of the overall complications.

No mortality occurred within the immediate postoperative period. Two patients died from their disease: one at 10 months and the other at 28 months postsurgery. Six flap- and donor-site related complications occurred in 5 of 22 (23%) patients and accounted for 33% of the overall complications. One-half of these complications were minor and required little intervention. One flap was lost, and 3 patients (14%) were returned to the surgical suite. One patient developed a fistula after the reconstruction of a massive lower facial defect and required multiple debridements (4), flap advancements (2), and a pectoralis flap to eventually heal his wound. Another patient was debrided twice, at two separate times, and required a nasolabial flap to close a palatal defect.

Despite these complications, aesthetic results were superior to those that can be achieved with muscle flaps. Perforator flaps are noteworthy for their ability to resurface defects in an elegant manner with tissues of similar composition and color match (14) (figure 5, C and D). These flaps do not undergo atrophy like their muscular counterparts, insetting and shaping are more straightforward, and the final volume is more predictable. (18)

[FIGURE 5 OMITTED]

We have found that perforator flaps can also facilitate postoperative oncologic follow-up. These flaps are composed of vascularized fat under the skin that enhances brightly on MRI T1-weighted images (figure 6). Bone, dura, and other neurologic components do not enhance in this setting. The contrast between fat and underlying tissues is impressive and makes identification of early recurrence a simpler matter in skull-base surgery.

[FIGURE 6 OMITTED]

The harvesting of both DIEP and TDAP flaps involves a muscle-splitting approach that is advantageous for several reasons. Dissection through the muscle results in longer pedicles. The pedicle length for the DIEP is 8 to 12 cm, and the TDAP pedicle averages 20 cm long. (5,13) Long pedicles are of great advantage in head and neck reconstruction because they allow for anastomosis to any vessel in the neck without need of vein grafts. (18) Vein grafts were completely avoided in this series. Vein grafts increase operative times and can be associated with higher rates of thrombosis, failure, and complications. (19,20)

In other reconstructive disciplines, perforator-based flaps have allowed surgeons to provide vascularized tissue transfers while minimizing donor-site morbidity. (7,8) Patients in our series required less postoperative pain medication than patients in whom rectus or latissimus dorsi muscle flaps were used for the same purpose. Seroma formation, a frequent complication of the latissimus dorsi muscle flap, was avoided in our series. (15,21) The latissimus dorsi muscle is left largely undisturbed, and its innervation is spared. Because no dead space is created and the muscle remains functional, the chance of seroma formation is minimal with use of the TDAP flap.

In the abdomen, the muscular and fascial structures are maximally preserved. A recent series involving 758 DIEP flaps reported an incidence of hernia formation in 0.6% of the patients. (22) In our series, we did not encounter hernia or bulge formation during the follow-up period. Two wound infections occurred but were resolved with appropriate treatment.

The disadvantages for both DIEP and TDAP flaps are related to the techniques used in perforator flap dissection. In general, the learning curve is steep for both procedures. Selecting the perforator to carry the DIEP flap can be a challenge. Perforating vessels will undergo vasospasm as they are dissected from the musculature. In smokers, the vasospasm can be profound and may seriously affect the surgeon's ability to select the appropriate perforator. Patience is needed to allow vasospasm to resolve. The flap must be handled with extreme care in order not to avulse the perforating vessels as they enter the flap. Dissection of the flap through the muscle requires great patience and care to avoid damaging the delicate venae comitantes that accompany the perforating vessels. Initially, this will increase operative times.

With experience and coordination, flap dissection can be accomplished in times comparable to those for muscle and musculocutaneous flaps. A recently reported series of DIEP flaps reported total operative times of 7.3 hours for bilateral breast reconstruction. (22) This indicates that even in cases in which two flaps are harvested concurrently, dissection of perforator flaps was accomplished within reasonable times.

The DIEP flap is harvested with the patient in the supine position, and in all our cases it was dissected simultaneously with oncologic extirpation. The TDAP flap, on the other hand, requires intraoperative position changes and separate extirpative and reconstructive stages, which is a disadvantage. (23) Despite this, we successfully performed two composite palatal reconstructions with TDAP-osteocutaneous flaps. The TDAP flap is an extension of the subscapular vasculature and can be safely combined with tissues from the same vascular tree to create a variety of composite flaps. (24) Deraemaecker et al (16) identified the angular artery that independently nourished the scapular tip. This vessel is easily identified during routine TDAP harvest.

Alternative donor sites may offer tissue with similar characteristics that can be harvested with the patient in the supine position. (9) Both the radial forearm and anterolateral thigh flap are useful in head and neck reconstruction, but these donor sites are in areas of high visibility. (10) Tendon exposure with the radial forearm flap increases the morbidity of the donor site and offsets many of the benefits of this flap. (25) Additionally, use of this flap is contraindicated in patients with radially dominant blood supply to the hand. In one series, the radial donor site was aesthetically unsatisfactory for 17% of patients, and 33% experienced tendon-exposure morbidity. (26)

The incisions for both DIEP and TDAP flaps are located in better cosmetic locations than both anterolateral thigh and radial forearm flaps. The lower abdominal incision for the DIEP flap resembles the abdominoplasty incision when the flap is designed transversely across the abdomen. The donor site for the TDAP flap remains well hidden in the posterior axillary fold. (23) We have used DIEP flaps designed vertically and transversely, using only the hemiabdomen in 6 patients. This method is advantageous because the undisturbed hemiabdomen will yield a second free flap if the first flap fails. One patient in our series required a second DIEP flap from the opposite hemiabdomen. The skin area of each hemiabdominal flap was 12 x 15 cm (figure 1). With the rest of the patients, a transversely designed flap was used.

Microvascular surgery in reconstruction of head and neck defects can be rewarding when appropriately planned and executed. Perforator flaps offer several distinct advantages over muscle and musculocutaneous flaps that were noted in this series. Reconstruction of complicated head and neck defects can be accomplished in a highly aesthetic, reproducible, and safe manner.

Table 1. Tumor histology and flap location

Tumor type            No.  Flap             TDAP *   DIEP ([dagger])
                           location        (n = 10)     (n = 12)

Squamous cell              Anterior skull
  carcinoma           13     base             1             1
Basal cell                 Lateral skull
  carcinoma            5     base             2             2
Adenoid cystic             Scalp defect       1             3
  carcinoma            1
Dermatofibrosarcoma        Maxilla            3             3
  protuberans          1
Epithelioid sarcoma    1   Oropharynx         1             3
                           Mandible           2             0

Note: One other patient in our series had traumatic infection,
not tumor.

* TDAP = thoracodorsal artery perforator

([dagger]) DIEP = deep inferior epigastric perforator:

Table 2. Flap-related and systemic complications

           Flap-related                          Systemic

Type                            Number   Type                 Number

Flap loss                         1      Pneumonia              3
Infections (donor site)           2      Neurologic             4
Flap ischemia w/partial loss      1        Delirium             3
Flap ischemia w/fistula                    Meningitis           1
  that required debridement       1      Deep vein
                                           thrombosis           1
                                         Congestive heart
                                           failure              1
                                         Patient alive
                                           w/recurrence         1
                                         Recurrence-related
                                           deaths               2

References

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(2.) Teknos TN, Smith JC, Day TA, et al. Microvascular free tissue transfer in reconstructing skull base defects: Lessons learned. Laryngoscope 2002;112:1871-6.

(3.) Califano J, Cordeiro PG, Disa JJ, et al. Anterior cranial base reconstruction using free tissue transfer: Changing trends. Head Neck 2003;25:89-96.

(4.) Koshima I, Soeda S. Inferior epigastric artery skin flaps without rectus abdominis muscle. Br J Plast Surg 1989;42:645-8. (5.) Allen RJ, Treece P. Deep inferior epigastric perforator flap for breast reconstruction. Ann Plast Surg 1994:32:32-8.

(6.) Angrigiani C, Grilli D, Siebert JW. Latissimusdorsi musculocutaneous flap without muscle. Plast Reconstr Surg 1995:96:1608-14.

(7.) Kroll SS, Sharma S, Koutz C, et al. Postoperative morphine requirement of free TRAM and DIEP flaps. Plast Reconstr Surg 2001;107:338-41.

(8.) Blondeel N, Vanderstraeten GG, Monstrey SJ, et al. The donor site morbidity of free DIEP flaps and tree TRAM flaps for breast reconstruction. Br J Plast Surg 1997;53:322-30.

(9.) Wei FC, Jain V, Celik N, et al. Have we found an ideal soft-tissue flap? An experience with 672 anterolateral thigh flaps. Plast Reconstr Surg 2002;109:2219-30.

(10.) Kimata Y, Uchiyama K, Ebihara S, et al. Anterolateral thigh flap donor-site complications and morbidity. Plast Reconstr Surg 2000;106:584-9.

(11.) Blondeel PN, Demuynck M, Mete D, et al., Sensory nerve repair in perforator flaps for autologous breast reconstruction: Sensational or senseless? Br J Plast Surg 1999;52:37-44.

(12.) Bidros R, Metzinger SE, Guerra AB. The thoracodorsal artery perforator-scapular osteocutaneous (TDAP-SOC) flap for reconstruction of palatal and maxillary detects. Ann Plast Surg 2005;54:59-65.

(13.) Heitmann C, Guerra A, Metzinger SW, et al. The thoracodorsal artery perforator flap: Anatomical basis and clinical application. Ann Plast Surg 2003;51:23-9.

(14.) Kim JT, Koo BS, Kim SK. The thin latissimus dorsi perforator-based free flap for resurfacing. Plast Reconstr Surg 2001;107:374-82.

(15.) Schwabegger A, Ninkovic M, Brenner E, Anderl H. Seroma as a common donor site morbidity after harvesting the latissimus dorsi flap: Observations on cause and prevention. Ann Plast Surg 1997;38:594-7.

(16.) Deraemaecker R, Thienen CV, Lejour M, Dor P. The serratus anterior-scapular free flap: A new osteomuscular unit for reconstruction after radical head and neck surgery (abstract). In: Proceedings of the Second International Conference on Head and Neck Cancer, 1988.

(17.) Seneviratne S, Duong C, Taylor GI. The angular branch of the thoracodorsal artery and its blood supply to the inferior angle of the scapula: An anatomical study. Plast Reconstr Surg 1999;104: 85-8.

(18.) Marchetti C, Gessaroli M, Cipriani R, et al. Use of "perforator flaps" in skull base reconstruction alter tumor resection. Plast Reconstr Surg 2002;110:1303-9.

(19.) Khouri RK, Cooley BC, Kunselman AR, et al. A prospective study of microvascular free-flap surgery and outcome. Plast Reconstr Surg 1998;102:711-21.

(20.) Schusterman MA, Miller MJ, Reece GP, et al. A single center's experience with 308 free flaps for repair of head and neck cancer defects. Plast Reconstr Surg 1994;93:472-80.

(21.) Titley OG, Spyrou GE, Fatah MF. Preventing seroma in the latissimus dorsi flap donor site. Br J Plast Surg 1997;50:106-8.

(22.) Gill PS, Hunt JP, Guerra AB, et al. A 10-year retrospective review of 758 DIEP flaps for breast reconstruction. Plast Reconstr Surg 2004;113:1153-60.

(23.) Schwabegger AH, Bodner G, Ninkovic M, Piza-Katzer H. Thoracodorsal artery perforator (TAP) flap: Report of our experience and review of the literature. Br J Plast Surg 2002;55:390-5.

(24.) Germann G, Bickert B, Steinau HU, et al. Versatility and reliability of combined flaps of the subscapular system. Plast Reconstr Surg 1999;103:1386-99.

(25.) Kolker AR, Coombs CJ, Meara JG. A method for minimizing donor site complications of the radial forearm flap. Ann Plast Surg 2000;45:329-31.

(26.) Swanson E, Boyd JB, Manktelow RT. The radial forearm flap: Reconstructive applications and donor-site defects in 35 consecutive patients. Plast Reconstr Surg 1990;85:258-66.

From the Department of Surgery, Division of Plastic and Reconstructive Surgery (Dr. Guerra, Dr. Dupin, and Dr. Metzinger), and the Department of Otolaryngology--Head and Neck Surgery (Dr. Lyons), Louisiana State University Health Sciences Center, New Orleans.

Reprint requests: Stephen Eric Metzinger, MD, Aesthetic Surgical Associates, 3601 Houma Blvd., Suite 300, Metairie, LA 70006. Phone: [phone]; fax: [phone]: e-mail: [e-mail]