Complex reconstructions in head and neck cancer surgery: decision making

Local pedicled flaps

The deltopectoral flap came up in the 70ies, first described in 1971 by Bakamjian [1, 2]. The reconstruction can be performed in a single-stage operation, but a second operation is required to divide the pedicle after the skin island has regained its vascularisation from local tissue. The pedicle for this flap arises from the internal mammary artery, the application for intraoral or pharyngeal reconstruction is limited because of the pedicle length.

The pectoralis maior musculocutaneous flap is sourced by the pectoral branch of the acromiothoracic branch and became a workhorse for head and neck reconstruction. Aryian was first to describe this flap in 1979 [3]. The limitation of the flap is the bulkiness-especially in female patients. The pedicle length reaches up to 7 cm.

The pedicled latissimus dorsi musculocutaneous flap was first described to cover defects in head and neck in 1978 by Quillen [4], the flap came up in 1896 (Tansini) [5]. As a free flap the latissimus was first described in 1979 by Watson [6]. Based on the thoracadorsal artery the harvesting of the flap requires an intraoperative change of the patient's positioning, the flap is bulky and implies relatively high donor site morbidity such as seroma. To avoid bulkiness, the flap can be harvested as a muscle flap covered with skin graft. A perforator flap with the same pedicle excluding the muscle was described by Cavadas in 2002: the TAP flap (thoracodorsal artery perforator flap) [7].

The internal mammary artery perforator flap (IMAP) is a new flap, which can be harvested from the ventral thorax either horizontally or vertically orientated. Rotation arc allows defect closure at the neck and lower head. However, its application has to be defined yet [8].

Free microvascular flaps

The radial forearm flap (Table 1) is the workhorse in intraoral and hypopharyngeal reconstruction. First described by Yang [9] this flap is based on the radial artery, shows a constant anatomy with a high-caliber and long pedicle. This flap is thin and provides a good pliability. Intraoperative view of the harvested flap, the skin island and the reverse view including the pedicle are demonstrated in figures 1 and 2 (the fascia over the tendon is not removed to improve postoperative range of motion). It covers defects in the oral cavity, as shown in figure 3, the tongue, trachea, oesophagus and the hypopharyngeal region. By including a radius bony segment an osteocutaneous flap can be raised to reconstruct small mandible defects [10]. Nevertheless the donor site shows aesthetic and functional problems: if primary closure is not possible, skin graft is necessary. Planning the radial forearm flap, the Allen test must be performed to ensure sufficient blood supply of the hand by the ulnar artery and palmar arch.

Flap size	Pedicle length	Pedicle diameter	Donor site morbidity	Patient's position	Special considerations
-Length: 12 cm (4-30 cm) -Width: 5 cm (4-15 cm) -Thickness: 1 cm -Bone: Length: 10 cm (6-14 cm), Width: 1 cm (0,7-1,5 cm)	-18 cm (15-22 cm)	-3 mm (2,5-3,5 mm)	-Cosmetic impairment -Diminishing blood supply of hand -Injury of superficial sensory branch of the radial nerve (neuroma)	-Back, arm on hand table, extended to 90 degrees	-Constant anatomy -Allen test

In patients with arteriosclerosis a reversed Allen test or an angiogram is advised.

Flap raising

Flap raising

Flap raising

Flap raising

Flap raising

Flap raising

The rectus abdominis muscle can also be taken on the same pedicle with or without a skin island to fill up dead space after soft tissue or bone removal, and if necessary covered with skin graft. If the skin is orientated vertically, the flap is named VRAM flap (vertical rectus abdominis musculocutaneous flap).

Flap raising

In 1989 Hildago performed the first fibula osteocutaneous flap (Table 8) for reconstruction of the mandible [26]. This flap allows to reconstruct defects exceeding the length of 75% mandible as the fibula is the longest bone flap with up to 25 cm [27]. An intraoperative situs with the inset fibula after mandible resection due to cancer is shown in figure 4. Figure 5 shows the postoperative intraoral mucosa. The same patient is shown in the x-ray 3 months after operation and in the CT 4 months after transplantation in figures 6 and 7. It is necessary to save the proximal and distal end to avoid instability of ankle and knee. Meticulous dissection preserves the peroneal nerve. The vascular pedicle is the peroneal artery. This flap can be harvested with one or two skin paddles, based on perforators from the peroneal artery, which travel through the soleus muscle or the posterior intermuscular septum [28]. The donor site often requires a split-thickness skin graft.

Flap size	Pedicle length	Pedicle diameter	Donor site morbidity	Patient's position	Special considerations
Skin: -Length: 12 cm (10-32 cm) -Width: 6 cm (4-14 cm) Muscle: (lateral hemi-soleus): -Length: 16 cm (18-30 cm) -Width: 8 cm (6-15 cm) Bone: -Length: 16 cm (6-26 cm) -Thickness: 2 cm (1-3 cm)	- Up to 10 cm, depending on bone length and location of donor site (proximal or distal)	-1,5 mm (1-2,5 mm)	-Cosmetic deformity -Limitations and discomfort in ankle function -Peroneal nerve palsy	-Supine position, knee flexed 90°, pelvic girdle internally rotated -Prone position	-Preoperative vascular study could be useful (angiogram)

Flap raising

Flap raising

Flap raising

1. Soft tissue defects

The radial forearm flap requires the integrity and patency of the palmar arch. Disadvantages are possible cold intolerance and an unsightly scar at the donor site with limitation in motion. The large diameter of the vessels and the long pedicle are very helpful when planning and performing the anastomoses. The radial forearm flap can be harvested in parallel to tumor resection which helps to keep operation time low. To minimize problems with skin graft healing due to underlying tendons it is suggested to harvest the flap without fascia and to use a collagen matrix (such as Matriderm^®) underneath the skin graft. In this way the aesthetic outcome and the range of motion are improved.

The lateral arm flap can be used the restore intraoral defects. Koapting the posterior cutaneous nerve with the lingual nerve was described to feature a high success rate of neurocutaneous reinnervation [32]. In comparison to the radial forearm flap the harvesting of the upper arm flap is more demanding because of the vessel's smaller diameter, the deeper location of the pedicle and the close relationship to the radial nerve. The subcutaneous fat layer is thinner in the radial forearm flap, especially in adipose patients [33]. The average length of the pedicle is 7 cm [34]. The pedicle of the radial forearm flap is described with up to 47 cm [35]. In case of reconstruction after radical neck dissection a longer pedicle is often necessary. The lateral arm flap mostly cannot be harvested simultaneously to the tumor resection because of the nearby localisation to the head and neck area.

The ALT flap shows difficulties in obese patients because of the thickness of the subcutaneous fat tissue. In these cases it can be derogatory to cover defects in the oral cavity and the hypopharyngeal region due to its thickness. The course of the pedicle shows enormous variation: the pedicle can run through the vastus lateralis instead of going through the intermuscular septum [36]. One advantage of the ALT over the radial forearm flap is the donor site closure: most of donor sites of ALT can be closed primarily, skin graft was only necessary in 2 of 39 flaps for restorage of the upper aerodigestive tract [37]. Donor site can be closed primarily when the width does not exceed approx. 8 cm. Even when harvesting a large portion of the vastus lateralis muscle there is no significant functional or aesthetic impairment [38]. The ALT can be tubulized to reconstruct hypopharyngeal structures. Depending on the different perforators (up to 3 or 4) the ALT can be designed to cover defects with two linings e.g. intraoral or extraoral by dividing the skin paddles based on the respective perforator as shown in figures 8, 9, 10 and 11.

The latissimus dorsi flap shows constant anatomy with a reliable pedicle and an enormous length and width. A simultaneous harvesting of the flap to head and neck cancer surgery is nearly impossible, which prolongs operation time and demands intraoperative position change of the patient. The donor site morbidity of the latissimus dorsi is quite high: seroma can occur, and shoulder function can be impaired [39]. The latissimus dorsi muscle is mostly too bulky for reconstruction in the intraoral cavity because of the subcutaneous fat layer. To avoid bulkiness using the same donor site the perforator version of this flap (TAP flap) is recommended.

As in the latissimus dorsi flap scapular/parascapular flaps cannot be raised at the same time as tumor ablation. The donor site of the scapular/parascapular flap has fewer complications compared to the latissimus donor site, as it creates no hole.

TRAM/DIEP and isolated rectus abdominis muscle flaps can be harvested parallel to tumor resection, no intraoperative patient change is necessary. These flaps show a save and certain blood supply with a long pedicle. The thickness of these flaps depends on the patient's general size. If possible, DIEP flap should be chosen rather than TRAM flap to avoid abdominal wall weakness and herniation [24].

Muscle flaps provide good tissue bulk, but in the long run they begin to shrink and sag, which makes long-term results inconstant to the postoperative situation.

The free jejunal graft and its complications were described by Coleman [30]. Despite the advantage of the tubed nature of the jejunum and its natural lubrication there are many disadvantages: Coleman described a failure rate of 13,5% with a mortality of 5%. Pharyngo-cutaneous fistula occurred in 33 of 101 patients. 18 of 101 patients suffered from stricture or stenosis at the bowel anastomoses, 4 patients suffered from abdominal wall dehiscences. To harvest the flap, laparotomy or laparoscopy-assisted approaches to the abdomen are required which carry their own risk. Besides the jejunal flap shows very low tolerance to ischemia. To minimize the risks and complications we try to avoid free jejunal graft, because the donor site morbidities of radial forearm flap or ALT flap diminishes to those of the free jejunal graft. A tube with a sufficient diameter (up to 3 cm in ALT flap) can be formed by most of the fasciocutaneous flaps.

2. Bony defects

For restoration of bony defects the fibula osteocutaneous flap is convenient because of the possibility to raise the flap parallel to tumor resection in a two team approach. The quality of the skin paddle is comparable to the radial forearm flap but the hairiness of the skin paddle can incommode the patient, especially in intraoral situations. The vascular pedicle can reach up to 15 cm with a large diameter which allows performing anastomoses easily [40]. The high frequency of arteriosclerosis in the lower leg vessels especially in these patients suffering of oral cancer must be included in the flap choice. We recommend to perform an angiography before planning a fibula flap to uncover arteriosclerosis or the absence of the peroneal artery. The donor site morbidity of the fibula flap shows hypoesthesia at the lateral malleolus, pain and oedema and a reduction of the motor range of ankle when the superficial peroneal nerve is injured [1]. In special cases it can become necessary to use an iliac crest flap for bone reconstruction (if possible with the defect's size).

The iliac crest flap has a reliable pedicle and offers a wide variation of combinations of bone, muscle and skin flap. This flap is highly suited to reconstruct mandible. The skin paddle is often bulky; especially in obese patients it is difficult to harvest this flap. If the flap is too bulky for the recipient site it can be harvested as crest bone with oblique abdominis muscle and a skin graft without a skin paddle. In many times herniation occurs, even long lasting pain, neuropathy, gait disturbance and impotence were described [41]. The natural contour of the iliac crest is ideal to reconstruct lateral mandibular defects, by contrast to the free fibular flap osteotomies are rarely needed in smaller defects. This flap can be harvested parallel to tumor resection, which spares operating time. Alternatively, especially for smaller defects a radial forearm flap with a part of radial bone can be performed.

3. Flap choice

Disa found that most defects can be reconstructed with jejunum, rectus, forearm and fibula flap [42]. Neligan postulated that 2 flaps are sufficient for most intraoral reconstructions: radial forearm flap for restoration of the intraoral lining [34], and the fibula osteocutaneous flap for mandible reconstruction, as it provides a good quality and quantity bone stock with a reliable skin paddle [43].

Reconstruction of hypopharynx is a challenge for the plastic surgeon. A watertight conduit is needed, that can be punctated tracheoesophageal for speech. This is rarely successful in free jejunal transfers due to the mucus that leads to a wet-sounded voice and a loss of stability [44].

In our experience procedures should be performed in a single stage procedure to reduce hospitalisation and complications which in many cases can be attributed to secondary wound infections, radiation depending problems and strictures due to secondary healing. ENT surgeons and Plastic surgeons have to establish an attentive multi disciplinary approach to provide optimal oncologic and reconstructive procedures for their patients.