INTRODUCTION — Carcinoma of the head and neck can be treated and potentially cured by surgery, radiation therapy (RT), or a combined modality approach, which may also incorporate chemotherapy. The defects caused by surgical excision can cause significant problems in airway management, mastication, deglutition, speech, and cosmesis. In addition, RT has significant adverse effects upon wound healing that can complicate surgical management. (See "Management of late complications of head and neck cancer and its treatment".)
The goal of surgical reconstruction is to restore presurgical function and cosmesis. Optimization of the outcome of surgical reconstruction requires a team approach and should include speech pathology, physical therapy, and psychosocial support as appropriate.
The basic elements of mandibular reconstruction and palatal reconstruction will be reviewed here. The management of maxillary defects is discussed separately, as is rehabilitation for speech and swallowing defects. (See "Management of acquired maxillary and hard palate defects" and "Speech and swallowing rehabilitation of the patient with head and neck cancer".)
TIMING OF RECONSTRUCTION — Reconstruction may be primary (performed at the time of resection of the tumor) or secondary (performed as a separate procedure after resection or to repair a defect left by an ulcerative tumor treated by primary radiation). Primary reconstruction has become the standard of care for most patients [1].
●Primary reconstruction can rapidly restore anatomy and function and decrease the number of operations and duration of hospitalization [2]. Because the head and neck patient may have a limited life span and significant premorbid conditions, rapid recovery and decreased hospital stay are important considerations. However, the possibility of infection with intraoral contamination of the graft is always of concern.
●The delay in reconstruction with a secondary procedure may lead to significant muscle atrophy and fibrosis with contracture of soft tissues, functional difficulties, and cosmetic deformities that may be hard to correct at a later stage, although secondary reconstruction may avoid some risk of intraoral contamination [2].
The timing of reconstruction relative to radiation therapy (RT) is controversial [3]. Radiation causes a decrease in the vascular supply to the affected tissues, which can lead to reduced oxygenation and nutrient supply and impaired wound healing. The tissue response to radiation is bimodal with an acute and a chronic phase [4]. The acute phase occurs during radiation and lasts a few weeks postradiation; the chronic phase causes long-term damage to the tissue.
There is no evidence from randomized trials addressing the timing relative to RT. A study of 140 patients who received a fibular free flap found no difference in the rate of complications among patients receiving preoperative radiotherapy with immediate reconstruction, preoperative radiotherapy with delayed reconstruction, or postoperative radiotherapy [4].
MANDIBULAR RECONSTRUCTION — The goals of mandibular reconstruction include restoration of deglutition, speech, airway support, oral sphincter competence, and cosmesis. In addition, reconstruction must provide adequate strength to support masticatory force and the possibility of future dental implants in some cases [5,6]. Reconstruction has positive effects on the quality of life in these patients [7].
Mandibular defects may range from minimal bony loss to composite loss of both soft tissue and hard tissue. Defects of the posterolateral aspect of the mandible have significant associated mucosa loss and minimal bone requirements, while anterior defects require good bone stock for implants and less bulky tissues for normal facial contour. Restoration of bony continuity is recommended to optimize mastication and speech and to maintain symmetry of the lower third of the face [8].
The type of reconstruction required depends upon the defect and the quality and quantity of the remaining soft and hard tissue bed [5]. The choice of reconstruction is also affected by patient factors, including preoperative morbidity, ability to withstand long operations, mental status, and motivation. Rehabilitation and patient motivation play a large role in the success of reconstruction.
There are a variety of options for mandibular reconstruction, and each has inherent advantages and disadvantages [6,9-11]. Free flaps that transfer blocks of vascularized tissue from a distant site represent the state of the art in head and neck reconstruction and offer a much greater range of tissue options [9,12].
Although free tissue transfer techniques require increased operative time, donor site morbidity, and the need for a surgeon trained in microvascular anastomoses, these drawbacks are outweighed by the improved healing and function that can be achieved. Computerized virtual surgery applications exist for planning purposes and for increasing accuracy of shaping of the graft intraoperatively [13].
Other approaches include pedicled, vascularized regional grafts; nonvascularized autogenous bone grafts; and alloplasts of foreign material.
Free tissue transfer — Free tissue transfer has become the treatment of choice, when feasible, and its use is increasing, with success rates approximating 96 percent [2,14-18]. Free flaps have the following advantages:
●Improved vascularity compared with pedicled grafts and an expanded range of bony options [5].
●Flaps can be transferred with a sensory nerve, which can aid in oral sphincter competence, improved deglutition, and decreased aspiration [5].
●Free flaps can accept endosteal dental implants that function as tooth root analogs, thereby permitting improved denture stability and retention. This results in superior function and restoration of mastication compared with patients who have not received reconstruction [19].
The advantages of free flaps were illustrated in a study that compared the outcomes with vascularized bone flaps to those with nonvascularized bone grafts in 75 consecutive mandibular reconstructions [20]. Patients receiving vascularized bone flaps had a significantly higher incidence of bony union and implant success compared with those with nonvascularized bone grafts (96 versus 69 percent and 99 versus 82 percent, respectively). Based upon these data, nonvascularized bone grafts should be used primarily for short bone defects in nonirradiated tissue and/or in patients who are too medically compromised to tolerate the additional operative time required for a free flap procedure.
Pedicled vascularized grafts — Pedicled, vascularized regional grafts transfer healthy tissue and bone to the defect; however, these grafts are restricted by limited bone and soft tissue mobility [6]. Examples include pectoralis major and deltopectoral flaps.
Nonvascularized autogenous bone grafts — Nonvascularized autogenous bone grafts use the patient's own cancellous bone to reform the mandible and stimulate new bone formation. Although theoretically ideal, autogenous bone grafts do have potential complications, including resorption, inadequate soft tissue coverage, infection, and loss of stabilization [21].
Alloplasts — Alloplasts are implants made of foreign material and include pins, trays, bars, and plates. The ideal material is made of an inert biocompatible material that can withstand force. Options include vitallium, stainless steel, and titanium [22]. The alloplasts are readily available, allow for immediate reconstruction, do not affect later radiation or delayed reconstruction, and obviate the problem of donor site morbidity [6]. Complications include extrusion, fracture of the material, and plate exposure. Alloplasts play an important role for patients unable to tolerate long procedures or for those with lateral mandibular defects but are not recommended for otherwise healthy patients [6,23].
Donor sites — The major donor sites for mandibular reconstruction include the fibula, iliac crest, scapula, medial femoral condyle, and radius [2,14,24,25].
●The fibula osteocutaneous flap is the most versatile bone flap. This approach allows two teams to operate at the same time, thereby limiting time in the operating room. It also allows longer lengths of bone to be used in patients undergoing wide surgical resections. The bone flap can be harvested with a skin paddle for intraoral or skin defects. The segmental blood supply allows excellent shaping with multiple osteotomies [26]. After osseous free flap mandible reconstruction, bone mass, particularly with fibular free flaps, appears to be well preserved over time, and loss of height is not a major problem [27].
●The iliac crest offers good bone stock and allows superior mandibular height. This procedure requires release of the abdominal musculature to access the properitoneal space [28]. As a result of the flap harvest, patients may complain of acute pain, ventral (abdominal wall) hernia formation, and long-term sensory disturbances [6,28]. The native shape of the iliac crest is similar to a mandible, and osteotomies are not required. The iliac crest also offers the best bone stock for osseointegration of dental implants.
●The scapular flap system is useful because a variety of free flaps can be incorporated with a high degree of mobility relative to the bone. The major drawback to this donor site is the limited length and width of bone, which may be unsuitable for dental implants [29].
●The medial femoral condylar flap can be advantageous when thin monocortical bone is required as a patch, such as in a nonunion. Its advantages include sacrifice of a noncritical artery, ease of dissection, and inclusion of a skin paddle for monitoring [30,31].
●The radial forearm flap is the most useful flap for thin soft tissue replacement required for mucosal loss. The flap can be innervated for excellent sensory function. Bone stock, however, is limited, and radial fracture is a known complication, especially in older women [32].
Several techniques have been used to secure the grafts to the remaining mandibular segment. Rigid fixation with reconstruction plates allows more rapid resumption of oral function. As an example, one study compared stainless steel, titanium, and titanium hollow screw reconstruction plates [33]. The titanium reconstruction plates were preferred because of their potential for osseointegration and because fewer screws are necessary to attain adequate fixation. Stainless steel had the highest rate of complications.
Reconstruction plates — Reconstruction plates have been used to bridge mandibular defects alone or with vascularized soft tissue coverage at the time of primary surgery. Lateral oromandibular reconstruction with soft tissue free flaps combined with plates maintains dental occlusion and facial contour while avoiding the morbidity associated with harvesting a bone-containing free flap [34,35]. Bridging plates have also been used successfully with irradiation. In one study, the plate failure rate was approximately 20 percent and was similar in patients receiving preoperative and postoperative irradiation [36].
Currently, main centers are using computer-aided design (CAD)/virtual design of plates based off imaging that can be used as guides for osteotomies and exact shaping intraoperatively. In the future, plates may be fabricated on site with laser printing [37].
Early complications are minor. However, some series of patients followed for a minimum of one year report a significant overall rate of delayed reconstructive failure in 25 to 40 percent of patients, which is often due to external plate exposure [38,39].
SOFT PALATE RECONSTRUCTION — Postsurgical defects may interfere with the physiologic function of the soft and hard palate and result in problems with deglutition and speech; these include nasal regurgitation and rhinolalia (hypernasal speech).
Function of the palate — The hard palate functions as a barrier between the oral and nasal cavities, aids in articulation, and assists in food processing. The function of the soft palate can be divided by anatomic region [40]:
●The anterior soft palate is relatively fixed and slung from the posterior edge of the hard palate.
●The middle soft palate containing the muscular bulk of the palate is where the levator action is most marked and is involved mostly in speech.
●The posterior soft palate is involved in deglutition.
The soft palate and base of tongue come together while chewing to hold food in the oral cavity. Depression of the soft palate prevents food from prematurely entering the oropharynx and may even increase the size of the nasal airway to help in breathing during oral intake of food [41]. If the patient loses the ability to apply the palate to the base of the tongue, inefficient transport of food may occur. This may result in problems with coordination and timing of relaxation of the upper esophageal sphincter and failure of laryngeal closure, leading to pooling of food contents and aspiration [42].
Closure of the velopharynx, as the soft palate reaches the posterior pharyngeal wall, prevents nasal regurgitation by ensuring that food or liquid does not enter the nasal cavity. Velopharyngeal closure is accomplished by elevation of the soft palate, anterior motion of the posterior pharyngeal wall, and medial movement of the lateral pharyngeal wall [43]. The action of the posterior pharyngeal wall, in an effort to maintain palatopharyngeal closure, is exaggerated in patients with palatal insufficiency [44].
Speech may also be adversely affected by a palatal defect. Without a partition between the oropharynx and nasopharynx, vocalization may be transmitted through the nasal cavity as opposed to the oral cavity, which leads to rhinolalia. Articulation of the sounds "k" and "g" and the sibilant sounds "s" and "z" requires a functional soft and hard palate, respectively [44,45].
Treatment of palatal defects — There are two types of palatal defects [46]:
●Palatal insufficiency, which occurs when there is an inadequate length of soft palate to obtain palatopharyngeal closure. Movement of the remaining tissues is normal.
●Palatal incompetence refers to an inability to obtain palatopharyngeal closure due to the absence of palatal movement. The palatal structure is normal.
Surgical or prosthetic methods, or a combination of both, can be used to remedy palatal defects. The type of reconstruction or rehabilitation depends upon the size and placement of the defect, the baseline medical condition of the patient, and the goals of the patient. The prosthodontist and the surgeon must work together as a team.
The patient should undergo complete preoperative counseling and discussion of options, as well as formation of dental impressions [46]. Not only may the patient be more likely to adjust to the emotional changes caused by the postsurgical defect, but immediately after surgery, they may be fitted for a prosthesis that would aid in speech and swallowing and offer structural support [46]. This is especially important in the patient undergoing delayed reconstruction or choosing prosthetic rehabilitation.
Obturators — An obturator can be used to close a palatal defect [44]. A soft palate obturator is a removable dental appliance attached to the remaining teeth and soft tissue structures. The goal is to provide a barrier from the nasal cavity and posterior pharynx when appropriate. The obturator must leave space posteriorly for nasal breathing at rest and must be abutted by the posterior pharynx and lateral pharyngeal walls to close the defect [46].
The dentate status of the patient and the decision to use a prosthesis may affect the surgical resection [46]:
●If more than one-half of the soft palate needs to be resected for tumor-free margins in a dentate patient, the entire soft palate should be removed since the small amount of retained soft palate may interfere with obturator function.
●If the patient is edentulous, the goal is to save as much soft palate as possible because it may aid in stabilization of the obturator. Edentulous mouths are more difficult to treat with a prosthesis due to limited tissue for prosthetic stability.
Obturators are more successfully used in defects of the hard palate. Because the defect is bound by the soft palate and remaining hard palate, there is little movement of the boundaries and the obturator is more easily stabilized. As much hard palate tissue must be preserved as is oncologically safe in an effort to save the premaxilla and key teeth, including the canine. These structures give the obturator improved support [47]. (See "Management of acquired maxillary and hard palate defects".)
Reconstructive flaps — Surgical reconstruction of palatal defects is accomplished with flaps that may be local, regional, or distant.
Local flaps move adjacent tissue to fill in the defect. These include the advancement rotation palatoplasty and lateral pharyngeal wall flap, the superiorly based pharyngeal flap, the lateral-based tongue flap, and the uvulopalatal flap [40-42,48].
●The uvulopalatal flap is most appropriate for small to moderate defects of the lateral soft palate. In one study of five patients undergoing partial ipsilateral excision of the soft palate, postoperative rhinolalia and regurgitation were unremarkable, and an obturator was seldom needed [40].
●The superior-constrictor advancement-rotation flap (SCARF) achieves circumferential closure of the velopharynx and reestablishes its valvular sphincteric function. In one study of 10 patients who underwent a SCARF reconstruction of the velopharynx after 35 to 65 percent resection, normal velopharyngeal function was reestablished in all without significant phonatory or deglutitive disability [49].
Other local or regional flaps include the superior-based pharyngeal flap, the facial artery musculomucosal (FAMM) flap, the pectoralis flap, and the temporalis flap [41,48,50].
●The superior-based pharyngeal flap offers good reliability and allows the donor site to heal by secondary intention [48]. Complications may include airway obstruction, which can be prevented by a prophylactic tracheostomy, and hyponasality [48].
●The FAMM flap has excellent vascularity based on the facial artery and supplies mucosal replacement for palatal defects [51].
●The pectoralis flap is the workhorse for most reconstructive surgeons for many defects of the head and neck. This flap can be used for oropharyngeal defects, including the palate. Bulk, hair-bearing tissue and breast asymmetry are potential problems that may be decreased by raising only the muscle of the flap, not the overlying skin [42,52].
●The temporalis flap permits local availability; however, loss of the temporal branch of the facial nerve occurs 20 percent of the time [53].
Distant flaps or free tissue transfers have been performed with the radial forearm flap, the anterior lateral thigh (ALT) flap, the fibula flap, and the scapular flap [32,42]. These flaps differ in tissue bulk, tissue viability, ease of manipulation, strength, sensation, and donor site morbidity.
●The radial forearm free flap is a popular tissue for reconstruction for the reasons mentioned above (see 'Donor sites' above). The thinness of the tissues of the flap is perhaps the best replacement for missing palate. Bone may be carried for maxillary support or reconstruction [42].
●The ALT flap is the most versatile of reconstructive flaps. It is used for its ample supply of thin skin and muscle and the possibility of chimeric flaps, where secondary flaps such as the rectus femoris or gracilis can be carried on the same vascular pedicle. Like the radial forearm free flap, the ALT flap facilitates a two-team approach as it is far removed from the head and neck area [54].
●The fibula flap has the advantages mentioned above and is especially valuable when a small skin paddle is needed with a bone segment for maxillary support [55]. (See 'Donor sites' above.)
●The scapular flap provides the largest available amount of skin with the possibility of bone for maxillary support. Its use has been largely supplanted by the ALT flap for ease of a two-team approach, but its place in the reconstructive armamentarium remains, especially when other choices are not available [56].
●Computerized virtual surgery applications exist for planning purposes and for increasing accuracy of shaping of the graft intraoperatively [37,57-59].
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
●Surgical reconstruction after resection of head and neck cancer – The goal of surgical reconstruction is to restore presurgical function and cosmesis. Optimization of the outcome of surgical reconstruction requires a team approach and should include speech pathology, physical therapy, and psychosocial support as appropriate. Primary reconstruction, rather than a secondary procedure, has become the standard of care for most patients. (See 'Timing of reconstruction' above.)
•Mandibular reconstruction – Optimal mandibular reconstruction is important to restore for deglutition, speech, airway support, oral sphincter competence, and cosmesis. Free-flap transfer blocks of vascularized tissue from a distant site represent the state of the art in head and neck reconstruction and offer a much greater range of tissue options. Although free tissue transfer techniques require increased operative time, donor site morbidity, and the need for a surgeon trained in microvascular anastomoses, these drawbacks are outweighed by the improved healing and function that can be achieved. (See 'Mandibular reconstruction' above.)
•Palatal reconstruction – Postsurgical defects may interfere with the physiologic function of the palate and result in problems with deglutition and speech. The associated physiologic defects vary depending upon the particular region of the hard or soft palate involved, and the treatment must be directed accordingly. (See 'Soft palate reconstruction' above.)
ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Michael R Zenn, MD, FACS, who contributed to earlier versions of this topic review.
