Overview of head and neck reconstruction

INTRODUCTION — Modern reconstruction techniques have greatly improved the function and quality of life of patients undergoing major head and neck surgery.

While small defects can be reconstructed with basic techniques such as primary closure or skin graft, many larger or complex defects in the head and neck require free flap reconstruction. Free flap reconstruction, also referred to as free tissue transfer, refers to the transfer of autogenous tissue that is disconnected from its native blood supply and reimplanted into another area of the body with anastomosis of the vascular pedicle. (See "Overview of flaps for soft tissue reconstruction", section on 'Free tissue transfer'.)

The optimal reconstructive approach is determined by a multitude of factors, including but not limited to the tumor stage, subsite, previous treatment such as radiation therapy, patient body habitus and comorbidities, as well as available local resources.

This topic provides a defect-based approach to head and neck reconstruction. Because contemporary head and neck reconstruction commonly employs free flap reconstruction, we describe the most commonly utilized free flap donor sites. Techniques specific to certain defects are discussed in detail in other topics:

●(See "Mandibular and palatal reconstruction in patients with head and neck cancer".)

●(See "Management of acquired maxillary and hard palate defects".)

●(See "Speech and swallowing rehabilitation of the patient with head and neck cancer".)

The treatment of head and neck cancer is reviewed elsewhere. (See "Overview of treatment for head and neck cancer".)

ORAL CAVITY RECONSTRUCTION — Reconstruction of the oral cavity is aimed at maintaining oral competence and optimizing speech and swallowing outcomes [1]. Oral cavity defects can be classified into tongue defects, mandible defects, and floor of mouth/mandibular alveolus defects.

Tongue reconstruction — The primary goals of tongue reconstruction are [1]:

●Obliteration of oral cavity volume

●Maintenance of premaxillary contact with the tip of the tongue

●Maintenance of anterior-to-posterior movement of secretions

●Maintenance of "finger function" of the tongue

●Optimization of sensation of the native tongue and the reconstruction

Reconstructive approaches should be chosen with these principles in mind. Reconstructive options are dictated by the volume and location of the defect as well as the size of the native tongue relative to the volume of the oral cavity contained by the lingual surfaces of the mandible. Free tissue transfers are frequently utilized in tongue reconstruction for hemiglossectomy and total glossectomy defects.

●Small defects – Small defects of the tongue can be closed primarily if the remaining native tongue is sufficient to fill and obliterate the oral cavity without significant tethering [2].

●Superficial defects – Split-thickness skin grafts can also be utilized in superficial defects that do not require volume in the reconstruction [3]. Skin grafts can help reduce contraction of the defect, which is expected to a substantial extent.

●Hemiglossectomy defects – Hemiglossectomy defects refer to defects involving 50 percent of the oral tongue. These patients require volume reconstruction of the defect while maintaining mobility of the remaining native tongue. The hemiglossectomy defect is traditionally reconstructed with the radial forearm free flap, which offers pliability; a long vascular pedicle; and the appropriate tissue volume for most partial and hemiglossectomy defects (figure 1). The radial forearm flap can also be harvested with a beavertail modification to provide additional volume [4]. If the patient's body mass index (BMI) is low, the radial forearm donor site may not offer enough volume. In these cases, the anterolateral thigh [5], lateral arm [6], and rectus abdominis [7] donor sites can be used (table 1).

●Total glossectomy defects – Total oral glossectomy defects result from resection of 100 percent of the oral tongue and can include parts of the base of the tongue. These defects require a significant amount of volume reconstruction in order to achieve premaxillary contact and oral cavity obliteration [8]. Reconstruction of these defects may depend on patient BMI. Frequent donor sites used in total glossectomy reconstruction include the anterolateral thigh [5], rectus abdominis, and latissimus dorsi (table 1). Due to muscle atrophy that naturally occurs over time, limiting the amount of muscle on the flap achieves the best long-term result [7].

Mandible reconstruction — Reconstruction of the mandible aims to restore bite force, maintain oral competence, and optimize mastication after complete or partial resection of the mandible [9]. Reconstruction of the mandible depends on whether a segmental or marginal mandibulectomy is performed. (See "Mandibular and palatal reconstruction in patients with head and neck cancer".)

Segmental defects — Segmental mandibulectomy refers to the segmental resection of the mandible, resulting in disruption of the continuity from condyle to condyle. Reconstruction of segmental defects of the mandible depends on whether the patient is dentulous or edentulous (which portends the level of load the mandibular reconstruction plate will receive) and whether the defect is anterior or lateral (which dictates whether an osseous free flap is necessary to reconstruct the defect).

●Anterior defects – Anterior mandible defects require an osseous free flap and reconstruction plate to reconstruct the defect to prevent an "Andy Gump" deformity and plate extrusion.

●Lateral defects in dentulous patients – Lateral defects should be reconstructed with an osseous free flap and reconstruction plate if the patient is dentulous in order to prevent plate exposure fracture [9].

●Lateral defects in edentulous patients – Lateral defects in edentulous patients may be reconstructed with either an osseous flap and mandibular reconstruction plate or a soft tissue free flap and mandibular reconstruction plate.

The primary donor sites considered for reconstruction of segmental defects are the fibula, scapula, and osseocutaneous radial forearm (table 2) [10,11].

●The fibula donor site is perhaps the most frequently utilized donor site due to ease of harvest, outstanding bone stock amenable to dental implantation [12], ability to make wedge ostectomies to fit the mandible defect, and excellent pedicle length. The fibula can be customized to mandible defects by cutting out wedge ostectomies (figure 2) [13].

●The scapular donor site also permits excellent contour and reconstruction of anterior and lateral mandibular defects [14]. With the popularization of the scapular tip flap based on the angular artery, this donor site may be harvested in the supine position and no longer requires intraoperative repositioning of the patient [15-17]. The scapular tip donor site also permits a long pedicle and the ability to include a soft tissue latissimus dorsi component on the thoracodorsal pedicle that permits a freely mobile soft tissue component [18].

●The osseocutaneous radial forearm flap can incorporate 40 percent of the cross section of the radius and a segment of bone up to 10 cm long and can be a useful donor site for short-segment lateral mandibular defects.

Marginal defects — Marginal mandibulectomy refers to the partial resection of the mandible, where the mandible is left in continuity. Because the mandible is left in continuity, marginal mandibulectomy defects typically only require reconstruction of the soft tissue defect resulting from removal of the mandibular alveolus and surrounding tissue.  

Because bone reconstruction is not necessary in these defects, a multitude of options exist, including primary closure, local flaps such as the facial artery musculomucosal flap, and radial forearm free tissue transfer.

Some consideration should be given to the need for a mandibular reconstruction plate to prevent postoperative mandible fracture, particularly in dentulous patients. At least 1 cm of inferior mandible should be preserved during marginal mandibulectomy [19].

MIDFACE RECONSTRUCTION — The goals of midface reconstruction are to [20]:

●Restore anterior projection of the premaxilla

●Reconstruct the malar eminence

●Maintain position of the inferior orbital rim and the orbital contents

●Separate the oral cavity from the sinonasal cavity

The maxilla is a three-dimensional structure comprised of three buttresses: nasomaxillary, zygomaticomaxillary, and pterygomaxillary buttresses (figure 3) [21]. Restoration of the buttresses involved with oncologic resection are paramount to optimal functional and cosmetic outcome. Multiple classifications have been developed to consistently report reconstructive defects (figure 4) [21-23]. Midface defects can be successfully reconstructed with osseous and soft tissue free tissue transfers or obturators in select patients. (See "Management of acquired maxillary and hard palate defects".)

Osseous reconstruction of the midface — Osseous free tissue transfer is often needed for midface reconstruction of the inferior orbital rim, the malar eminence, or the anterior maxillary alveolus. When these structures are involved, soft tissue flaps cannot restore contour to the midface as well as osseous flaps. The two most commonly utilized osseous donor sites are the fibula and scapula (table 2).

Fibula osseocutaneous — The fibula donor site provides a straight segment of bone that can be osteotomized and contoured to reconstruct the maxillary alveolar arch, similar to mandibular defects.

●For smaller infrastructure defects, the fibula can be used as a straight segment, depending on the contour of the defect. The segments can be plated with the use of multiple miniplates or a customized reconstruction plate. The skin paddle can be used to resurface the palatal defect.

●For larger defects, a layered approach can be utilized. In this technique, the fibula can be osteotomized into three to six segments to reconstruct the malar eminence, inferior orbital rim, vertical buttress, and maxillary alveolus [24].

Lateral border scapula and scapular tip — The scapula donor site can be utilized for midface reconstruction with two approaches: the lateral border of the scapula based upon the circumflex scapular artery or the scapular tip based upon the angular branch of the thoracodorsal artery [15,18].

The lateral border scapula typically provides a longer segment of bone that comes with a fasciocutaneous skin paddle, but with a shorter pedicle. The scapular tip, on the other hand, can be harvested with the latissimus dorsi flap and provides a longer pedicle [18]. The scapular tip can also be used to contour the anterior maxilla as well as the orbital rim.

The scapula can be inset in multiple orientations, including a vertical and horizontal inset as well as utilization of a Greenstick osteotomy [25,26]. For smaller infrastructure defects involving the palate and inferior maxilla, the scapular tip flap without an additional soft tissue component can be inset directly into the palatal defect to separate the oronasal cavity and provide bone restoration of the maxillary alveolus.

Soft tissue reconstruction of the midface — Soft tissue reconstruction of the midface is ideal for palatomaxillary infrastructure defects, where bone is not necessary to reconstruct the projection of the midface [20].

The radial forearm donor site provides a thin fasciocutaneous flap with a long pedicle that can easily reach the recipient vessels from the midface and is ideal for posterior infrastructure maxillary defects. Other alternatives for palate reconstruction include the anterolateral thigh donor site, although pedicle length can vary (table 1).

For high-volume midface defects where soft tissue is desired in lieu of a bone flap, the rectus and latissimus dorsi are common donor sites where large volumes of soft tissue can be utilized for volume restoration of large maxilla defects where bone flaps are not available for use. They can provide excellent pedicle length and additional adipose tissue not available at the radial forearm donor site.

Obturator — For select patients with infrastructure maxillectomy defects, obturators may be an excellent rehabilitative option. Successful use of an obturator provides oronasal separation and prosthetic dental rehabilitation without the need for free tissue transfer.

The ideal defect for obturation is the infrastructure maxillectomy defect where the remaining palate and teeth can support and retain the obturator while providing a complete seal between the oral cavity and sinonasal cavities. A triangular-shaped fulcrum line is formed, and preservation of the canines are ideal to support the obturator. As more dentition and palate is removed, the obturator becomes more unstable and less likely to prevent air and fluid leakage into the nasal cavity [21].

The advantages of the obturator include shorter operative time due to simpler reconstructive technique and, in most cases, dental restoration with the obturator. Tumor surveillance is also somewhat simplified because the resection margin is easily accessible. The major downside to obturation is the need to manage the obturator on a daily basis as opposed to autogenous free tissue transfer. (See "Management of acquired maxillary and hard palate defects", section on 'Obturators'.)

PHARYNGOESOPHAGEAL RECONSTRUCTION — The goals of pharyngoesophageal reconstruction are to restore continuity from the oral cavity to the hypopharynx and esophagus (figure 5). This is typically achieved by performing a tension-free closure along the suture line, which is critical to prevent pharyngocutaneous fistula formation [27]. When a primary closure is not feasible or tenuous, free flap or regional flap reconstruction is required.

●Total laryngectomy without pharyngectomy – Total laryngectomy without pharyngectomy often allows for primary closure of the pharynx without the need for vascularized tissue augmentation as long as there has not been prior irradiation. Patients who have undergone previous radiation or chemoradiation treatment benefit from either free flap or regional flap reconstruction, utilized with either a cutaneous paddle inset or muscle overlay, to prevent major complications such as pharyngocutaneous fistula formation [28-30]. Commonly utilized donor sites include the anterolateral thigh and radial forearm for free flap reconstruction, and the pectoralis myocutaneous flap is the commonly utilized regional flap.

●Total laryngectomy with partial pharyngectomy – Total laryngectomy with partial pharyngectomy often requires "patch" augmentation with cutaneous pharyngeal inset of vascularized tissue because there is not enough remnant pharyngeal mucosa to close primarily. The primary donor sites for reconstructing partial hypopharyngeal defects are the radial forearm and anterolateral thigh (table 1) [5,31]. Both donor sites allow incorporation of a cutaneous paddle into the hypopharyngeal defect. Another non-free-tissue transfer option for these defects is the pectoralis myocutaneous rotational flap [32].

●Total laryngopharyngectomy – Total laryngopharyngectomy requires complete circumferential reconstruction of the hypopharynx with creation of a tubed conduit connecting the oropharynx at the level of the tongue base to the upper cervical esophagus. This can be accomplished by creating a tubed soft tissue flap, often from the radial forearm or anterolateral thigh donor sites as these donor sites permit the harvest of a long and wide cutaneous paddle necessary for these defects (table 1) [33]. An alternative option to a tubed soft tissue flap is the free jejunum transfer, which can successfully reconstruct circumferential hypopharyngeal and esophageal defects [34].

●Salvage laryngectomy – In salvage laryngectomy, vascularized tissue augmentation via a free or regional flap prevents fistula formation, major complications, and reoperation due to fistula [28-30,35]. Use of vascularized tissue in this setting can either be in the form of a cutaneous paddle inset or an onlay flap, where vascularized tissue (typically muscle) is placed over primary closure of the pharyngeal mucosa [29]. Both cutaneous paddle inset and onlay flaps prevent fistula formation and major complications after salvage laryngectomy. Commonly utilized donor sites for onlay flaps are the vastus lateralis (anterolateral thigh), radial forearm fasciocutaneous, serratus, latissimus, and gracilis.

PAROTID RECONSTRUCTION — Advanced parotid malignancies can often result in the need to reconstruct not only the volume of the parotid defect but also the overlying facial skin. If the facial nerve is invaded, it may also need to be resected with simultaneous facial nerve rehabilitation [36]. The primary goal of complex parotid reconstruction is to restore the volume of the parotidectomy defect with tissue that provides ideal cutaneous color match with minimal ptosis and to provide facial nerve rehabilitation [37]. (See "Parotidectomy", section on 'Reconstruction of surgical defects'.)

Several important factors should be considered when choosing a donor site for parotid reconstruction. Because the defect is readily visible, contour and color match for these defects are of very high priority. Additionally, the flap should be created with a minimal amount of muscle to avoid subsequent muscle atrophy as well as ptosis.

Two commonly used donor sites for parotid reconstruction are the lateral arm and anterolateral thigh because the thickness of adipose tissue in these two sites is typically ideal for parotid reconstruction (table 1) [37-39].

●The lateral arm donor site is an ideal donor site for parotid reconstruction because it provides a fasciocutaneous flap that typically provides excellent facial color match [39] and compartmentalized fat that resists ptosis and can provide vascularized nerve for facial nerve rehabilitation [37,40]. Additionally, the donor site can be closed primarily without the need for a skin graft [39].

●For larger defects that result from extensive skin resection, the anterolateral thigh is a very common donor site as it permits the harvest of a larger flap than the lateral arm donor site (figure 6). While the skin color match of the anterolateral thigh is typically less ideal than that of the lateral arm, the thigh donor site also allows the use of the nerve to the vastus lateralis for facial nerve rehabilitation, if needed.

SKULL BASE RECONSTRUCTION — The primary goal of skull base reconstruction is to separate the sinonasal cavity from the intracranial cavity [41]. Successful reconstruction of the skull base is critical to prevent cerebrospinal fluid (CSF) leak, pneumocephalus, and meningitis and to provide coverage for critical structures such as the internal carotid artery.

As the indications for endoscopic skull base surgery continue to expand, more resections are performed via an expanded endonasal approach [42-44]. Reconstruction of skull base defects has evolved accordingly. Many endoscopic skull base defects can be reconstructed with nonvascularized free grafts and locoregional flaps or a combination [45]. Free tissue transfer is rarely required and may be challenging given the limited access to the defect.

Free grafts — Free grafts are a highly effective method for reconstructing small-volume skull base defects. Common donor sites for autologous grafts include the middle turbinate mucosa, tensor fascia lata, and temporalis fascia, which can be placed as an "inlay" graft and supported with adipose fat graft. This is an excellent choice for small anterior defects with low risk of CSF leak and a well-vascularized tissue bed.

Locoregional flaps — Because vascularized locoregional flaps result in fewer postoperative CSF leaks compared with free graft reconstruction, they are typically preferred as the ideal reconstructive approach for most endoscopic skull base defects [43].

●The nasoseptal flap [46], based on the posterior septal branch of the sphenopalatine artery, is the workhorse flap for endoscopic skull base reconstruction. This well-described flap has been utilized to reconstruct defects from the frontal sinus to the clivus. Many useful technical variations have also been described.

●The pericranial flap, based on the supratrochlear artery, is another reconstructive option if the sphenopalatine has been sacrificed or the nasal septum is resected, and it can be harvested via an open or endoscopic approach [44].

●Finally, though less common, the temporoparietal fascial flap, based on the superficial temporal artery, can also be transposed through a temporal-infratemporal tunnel via an endoscopic endonasal transpterygoid approach [47].

Free tissue reconstruction — Endoscopic skull base defects requiring free tissue transfer are rare and present unique reconstructive challenges. Most defects are relatively small-volume defects within a tight corridor and are difficult to access. The use of free flaps for these defects is typically reserved for previously irradiated defects in which no locoregional option exists and dural exposure or CSF leak is present. Prompt reconstruction using free tissue transfer is critical in these situations in order to prevent meningitis.

In the setting where no adequate locoregional options exist, use of the free vastus lateralis flap has been described in the reconstruction of endoscopic endonasal skull base defects. This donor site provides vascularized muscle that can be inset through an endoscopic approach [48].

Another option for free tissue reconstruction of endoscopic defects is the adipofascial radial forearm flap, which provides vascularized fascia with a long pedicle to reach recipient vessels [49].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Head and neck cancer".)

SUMMARY AND RECOMMENDATIONS

●Tongue – The goals of tongue reconstruction include obliteration of oral cavity volume, among others. Options mostly depend on defect volume (see 'Tongue reconstruction' above):

•Small defects can be primarily closed.

•Superficial defects can be split-thickness skin grafted.

•Hemiglossectomy defects require free flaps, most commonly from the radial forearm, but can also be from the anterolateral thigh, lateral arm, and rectus abdominis in patients with a low body mass index.

•Total glossectomy defects also require free flaps from the anterolateral thigh, rectus abdominis, or latissimus dorsi.

●Mandible – The goals of mandible reconstruction are to restore bite force, maintain oral competence, and optimize mastication. Options mostly depend on whether the patient is dentulous or edentulous, whether the defect is segmental or marginal, and whether a segmental defect is anterior or lateral. (See 'Mandible reconstruction' above.)

•Anterior segmental defects and lateral segmental defects in dentulous patients require an osseous free flap, most commonly from the fibula or scapula, but it can also be from the osseocutaneous radial forearm.

•Lateral segmental defects in edentulous patients and marginal defects can have soft tissue reconstruction.

●Midface – The goals of midface reconstruction are to restore anterior projection of the premaxilla and the malar eminence, among others. Options mostly depend on the location of the defect. (See 'Midface reconstruction' above.)

•Inferior orbital rim, malar eminence, and anterior maxillary alveolus defects require osseous free flap reconstruction, most commonly from the fibula, but they can also be from the lateral border or tip of the scapula.

•Soft tissue reconstruction of the midface is ideal for palatomaxillary infrastructure defects. The flap is most commonly from the radial forearm but can also be from the rectus or latissimus dorsi for high-volume defects.

•For select patients with infrastructure maxillectomy defects where the remaining palate and teeth can support and retain the obturator while providing a complete seal between the oral cavity and sinonasal cavities, obturators may be an excellent rehabilitative option.

●Pharyngoesophagus – The goals of pharyngoesophageal reconstruction are to restore continuity from the oral cavity to the hypopharynx and esophagus. Options mostly depend on the size of the pharyngeal defect. (See 'Pharyngoesophageal reconstruction' above.)

•Total laryngectomy without pharyngectomy – Primary closure in nonirradiated patients; primary closure with muscle overlay or cutaneous inset of vascularized tissue (free or regional flap) in previously irradiated patients.

•Total laryngectomy with partial pharyngectomy – "Patch" augmentation with cutaneous pharyngeal inset of vascularized tissue from the radial forearm or anterolateral thigh.

•Total laryngopharyngectomy – Requires a tubed conduit connecting the oropharynx at the level of the tongue base to the upper cervical esophagus created from the radial forearm or anterolateral thigh free flaps.

•Salvage laryngectomy – Vascularized tissue from the vastus lateralis (anterolateral thigh), radial forearm fasciocutaneous, serratus, latissimus, or gracilis to be used in the form of a cutaneous paddle inset or an onlay flap.

●Parotid – The goals of complex parotid reconstruction are to restore the volume of the parotidectomy defect with tissue that provides ideal skin color match with minimal ptosis and to provide facial nerve rehabilitation if needed. Free flaps are usually taken from the lateral arm or anterolateral thigh, depending on defect size. (See 'Parotid reconstruction' above.)

●Skull base – The goals of skull base reconstruction are to separate the sinonasal cavity from the intracranial cavity; prevent cerebrospinal fluid (CSF) leak, pneumocephalus, and meningitis; and provide coverage for critical structures such as the internal carotid artery. Options mostly depend on defect size. (See 'Skull base reconstruction' above.)

•Small-volume skull base defects can be repaired with free grafts taken from the middle turbinate mucosa, tensor fascia lata, or temporalis fascia, which can be placed as an "inlay" graft and supported with adipose fat graft.

•Most endoscopic skull base defects are reconstructed with vascularized locoregional flaps such as the nasoseptal flap, the pericranial flap, and the temporoparietal fascial flap.

•Endoscopic skull base defects requiring free flap reconstruction are rare and typically reserved for previously irradiated defects in which no locoregional option exists and dural exposure or CSF leak is present. Donor sites include the vastus lateralis and adipofascial radial forearm.

●Free flaps – Free flap reconstruction, also referred to as free tissue transfer, refers to the transfer of autogenous tissue that is disconnected from its native blood supply and reimplanted into another area of the body with anastomosis of the vascular pedicle. Free flaps commonly used in head and neck reconstruction are summarized in these tables (table 1 and table 2). (See 'Introduction' above.)