Whether resulting from oncologic resection, trauma, or congenital malformations, defects in the head and neck region create a reconstructive challenge. Each case is unique and may require restoration of both form and function across multiple tissue layers that can include mucosa, muscle, nerve, bone, and skin. The head and neck region contains a high density of structures essential for sight, speech, swallowing, breathing, and facial expression.

Historically, reconstruction in the head and neck was limited to local, regional, and pedicled flaps, such as the supraclavicular, deltopectoral, and pectoralis major flaps. These options ultimately had limited reach and tissue availability. These flaps remain appropriate in some cases; however, in larger, more complex reconstructions, a resultant suboptimal esthetic and functional outcome can occur. ^, The 1970s marked a significant turning point with the emergence of microsurgery, which expanded the reconstructive options available to surgeons. This advancement enabled the ideal donor site to be utilized, addressing the anatomic and functional demands of each defect for optimal outcomes.

The introduction of vascularized free bone flaps, such as the fibula and scapular flaps, revolutionized bony reconstruction, especially for mandibular and maxillary defects. Early freehand shaping techniques have since evolved into digitally planned reconstructions with computer-aided design and 3 dimensional (3D) printing, improving accuracy and reducing operative time. ^,

Head and neck microsurgical reconstruction has become essential in managing a wide range of defects. These techniques have been established as safe and reliable, and the field continues to evolve to deliver the best possible outcomes and the highest quality of life (QOL) for patients. New innovations are constantly being integrated, including advances in robot-assisted microsurgery, virtual planning, intraoperative imaging, and artificial intelligence (AI).

Given the complexity of head and neck defects, a multidisciplinary approach is essential to address the reconstructive, functional, esthetic, and oncologic needs of each patient. The primary goals of head and neck reconstruction are to restore both function and esthetics efficiently, while minimizing surgical morbidity.

Some specific site considerations:

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  Cutaneous defects : Optimal functional and esthetic outcomes depend on preserving similar skin color, texture, and thickness. For larger defects, reconstructing entire anatomic subunits typically yields the best cosmetic results.

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  Tongue : Reconstructing the tongue presents unique challenges due to its critical role in articulation, swallowing, and airway protection. Defects involving up to 50% of the tongue can often be closed primarily. Larger defects, however, require additional bulk, which is best provided using thin fasciocutaneous or muscle-free flaps in the appropriate indications. ^,

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  Oral cavity : Precise measurement of the defect is crucial to ensure the harvest of an adequately sized flap. The skin paddle should be contoured to allow accurate 3D reconstruction of intraoral structures. Recreating a redundant gingivobuccal sulcus below the alveolar ridge is important to prevent tethering of any tongue remnant, which can impair speech and swallowing.

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  Scalp : While smaller scalp defects may be addressed with local flaps, larger defects often require free flap reconstruction, potentially in conjunction with cranial reconstruction. Currently, no flap exists that fully replicates the hair-bearing characteristics of the native scalp.

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  Skull base : For larger defects that cannot be served with a local pericranial flap or a temporalis flap, especially where there is the need to obliterate significant dead space and separate the meninges from the aerodigestive tract, a free flap is the safest and most effective form of reconstruction. It has more flexibility and can be paired with endoscopic approaches for inset. ^,

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  Maxilla : 3D midface reconstruction is crucial for restoring speech, swallowing, and velopharyngeal function, maintaining facial symmetry, supporting orbital contents, separating the oral and nasal cavities, preserving nasal patency and lip competency, and providing a stable foundation for dental rehabilitation. Reconstruction may include bony and soft tissue components.

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  Mandible : Reconstruction must consider the biomechanical demands of each mandibular subunit:

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    Anterior mandible: Subject to high masticatory loads and is best reconstructed using a bone-containing free flap.

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    Posterior mandible (including ascending ramus and condyle): Can often be reconstructed successfully with or without bone-containing flaps. Autologous tissue should always be the first choice for reconstructing oncologic defects of the posterior mandible, as prosthetic devices have a high rate of complications.

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    Lateral mandible: Experiences lower stress; segmental defects may be managed with a reconstruction plate in select cases, but younger patients with a long-life expectancy may benefit from a more robust and vascularized bony reconstruction, such as a fibula or scapular free flap.

Indications for reconstruction in the head and neck can be variable, and may include defects due to oncologic resection, traumatic injuries, congenital anomalies, sequelae of osteoradionecrosis, or additional salvage surgeries.

A key consideration when presented with a defect in the head and neck is to determine the goals of reconstruction. A helpful method to guide decision-making and surgical planning is to determine the need for restoration of integrity, function, and form. Depending on their diagnosis, prognosis, and overall health, some patients may not be candidates for major reconstructive surgery. A reconstructive surgeon’s priority should be restoration of the integrity of the face, neck, and alimentary tract. Complications such as life-threatening infection or fistula resulting in loss of ability to feed can lead to devastating results. Next, the restoration of function—speech, mastication, swallowing, and facial expression—should be evaluated and considered. Examples include placement of vascular bone for mandible reconstruction, allowing mastication, restoration of speech following total laryngectomy via free ileocolon flap, or reconstruction of the tongue through free tissue transfer following resection. And finally, when appropriate, restoration of form or the esthetic appearance of the defect, should be considered.

Patient assessment is critical when assessing the goals of reconstruction. Patient-specific factors, including comorbidities, smoking status, nutrition and functional status, body mass index, donor site evaluation, psychosocial considerations, social support, and rehabilitation potential, should be considered. The patient’s wishes and goals of care should be discussed and taken into consideration. Disease-specific factors, such as diagnosis, prognosis, prior surgical intervention, and adjuvant therapies (eg, chemotherapy or radiation), should be evaluated. The defect, or anticipated defect, should be analyzed and determined if skin, soft tissue, cartilage, muscle, tendon, bone, or some combination will be involved. Head and neck defects can be subclassified into 6 anatomic areas: intraoral, mandibular, midfacial, cranial, cutaneous, and scalp.

A comprehensive and extensive medical workup should be performed in these patients, requiring a multidisciplinary approach to optimize both esthetics and function. A thorough history and physical examination, along with laboratory testing and detailed imaging, are obtained. Imaging studies may vary based on diagnosis and reconstructive needs. Many patients undergo computed tomography, MRI, and/or PET scans to characterize their pathology further. Patients with head and neck cancer may also undergo biopsies, evaluation with direct laryngoscopy, bronchoscopy, or esophagoscopy to evaluate the extent of disease. These patients will typically be presented at a multidisciplinary meeting to confirm the diagnosis, stage the disease, and recommend a treatment plan. The management of patients with head and neck cancer is complex, and the treatment is optimized with a team-focused approach consisting of head and neck surgeons, plastic and reconstructive surgeons, radiation oncologists, medical oncologists, pathologists, radiologists, dentists, orthodontists, oral and maxillofacial surgeons, speech pathologists, nutritionists and dieticians, psychiatrists, and clinical support nurse navigators. Factors such as neoadjuvant therapy can impact the resection burden and ultimately change the reconstructive plan and may allow the patient to undergo a less invasive surgery. Optimizing nutrition is essential, especially in patients with head and neck cancer, whose disease burden may affect their ability to tolerate adequate oral intake. Inadequate nutrition can lead to wound healing difficulties and affect patient morbidity. Considerations such as preoperative feeding tubes or nasogastric tubes at the time of surgery to optimize caloric intake should be discussed among the multidisciplinary team, particularly in patients whose feeding abilities are expected to be impacted by disease or surgical intervention. Patients with comorbidities will require additional disease-specific workup. Individuals with cardiac disease may require additional testing, such as an electrocardiogram, echocardiogram, or stress test, and clearance from a cardiologist. Those with pulmonary disease require pulmonary function tests or further evaluation by a pulmonologist. Endocrinology evaluation may be required in patients with uncontrolled diabetes to optimize blood glucose control for wound healing. Additionally, smoking cessation should be emphasized and strongly encouraged for all patients.

Surgical preparation has evolved with the development of imaging, angiography, and virtual surgical planning (VSP). Increasingly, preoperative studies are used to better prepare and plan the surgeries. Advanced imaging with new technological modalities has drastically influenced preoperative planning, 3D reconstruction, and patient-specific tools. In addition, angiography has enabled the assessment of vessel anatomy and facilitated the selection and design of flaps. ^,, Intraoperative use of fluorescence angiography is also helpful in evaluating tissue perfusion and identifying perforator locations.

Optimizing patient-specific comorbidities, understanding disease burden and reconstructive defects, utilizing advances in imaging, and collaborating via a multidisciplinary team approach are essential when considering any head and neck reconstructive patient. Thorough preoperative evaluation and planning are essential to the success of reconstruction.

Successful microsurgical reconstruction in head and neck defects has been well established, with reports of up to 90% to 99% free flap survival in many microsurgical centers. ^,,,, Acceptable speech and swallowing outcomes are reported in the literature, with up to 80% of patients achieving “normal to nearly normal intelligibility” with unrestricted diets, as well as acceptable esthetic outcomes. Achieving these final functional and esthetic outcomes may require additional secondary surgeries, and patient education on the need for multi-stage reconstruction is important in preoperative discussions. Examples of this include flap debulking for improved contour, revisions for symmetry, scar revisions, and tracheoesophageal puncture for voice rehabilitation.

Despite advances in microsurgical success of head and neck free flaps, flap failures are inevitable in every surgeon’s career. When first presented with a failing flap, early detection and identification of the causative factor are of utmost importance to swiftly attempt flap salvage. Venous thrombosis has been noted to account for up to 58% of compromised flaps. Non-thrombotic vascular events, including vasospasm, mechanical problems related to flap inset, compression of the pedicle by hardware or clips, or pedicle injury, should be identified and corrected in the take-back surgery. Use of interposition vein grafts and performing a second venous anastomosis if not performed in the initial surgery may help relieve flap congestion or arterial compromise.

Aggressive and early debridement of infected and necrotic tissue should be performed when there is concern for infection. This is particularly important in head and neck flaps to prevent potential erosion into neck vessels, which may ultimately lead to carotid blowout. A common cause of infection in head and neck flap reconstruction is a salivary fistula, resulting in saliva pooling in the neck. This should be addressed by aggressive debridement and reclosure with a watertight seal of the oral cavity.

When faced with an unsalvageable flap, early coverage with a second free flap is the preferred option in the head and neck. A second free tissue transfer is more reliable and effective when compared to a local flap or conservative treatment. ^, In a review of 1235 flaps in the head and neck with 42 failures (3.4%), 40% of patients underwent a second free flap, 36% underwent a local flap, and 24% were treated conservatively. Around 47% of those regional flaps failed, and 40% of those treated conservatively required additional interventions, often with free tissue transfer. The mean time between primary flap failure and second free tissue transfer was 12 days. A study of 502 free flaps with 19 failures (3.8%) reached similar conclusions, preferring a second free flap for reconstruction salvage. This study cited that those who underwent pedicled flaps for secondary esophageal reconstruction had worse outcomes compared to those who were reconstructed with free jejunal flaps, notably in postoperative intake abilities. Additional factors to consider when considering further secondary reconstruction include the patient’s overall health to undergo additional free tissue transfer, exposed vital structures such as exposed dura or the carotid artery, as well as donor site morbidity and functional loss. Furthermore, in patients with head and neck cancer, additional oncologic treatments such as chemotherapy and radiation are often dependent on healed surgical wounds; any delayed healing may adversely affect oncologic outcomes in these patients. Medical complications, including postoperative deep venous thrombosis, pulmonary embolism, pneumonia, atrial fibrillation, and renal failure, may also be encountered and affect overall surgical outcomes. This emphasizes the importance of preoperative optimization and collaboration with medical colleagues, as well as enhanced recovery after surgery (ERAS) protocols. These factors will all impact the timing of surgical intervention and the decision-making process.

Late complications following microsurgical reconstruction in the head and neck can also occur. Ectropion can affect up to 50% of patients, most often those undergoing maxillectomies. Fistulas (nasocutaneous, orocutaneous, or oronasal) are also common, and likely due to the difficulty in obliterating dead space, insufficient flap volume, or gravity causing the flap to descend from its original location. Wound healing complications can also occur, particularly in the setting of radiation, due to its effect on tissues.

Unfortunately, many patients undergoing head and neck reconstruction are patients with cancer, and disease recurrence is common. In recurrent head and neck cancer, re-excision with secondary salvage reconstruction is often the only curative option. Patients with recurrent T1 and T2 tumors often have the best outcomes. In these patients, tissue is often scarred due to prior surgery and radiation. Recipient vessels, particularly in the neck, are often scarred and difficult to identify, making them poor choices for recipient vessels in additional free flap reconstructions. Exploration of the contralateral neck vessels may be needed for recipient vessels, as well as the use of interpositional vein grafts. ^, The use of vein grafts, however, has been associated with a higher incidence of thrombosis. Utilization of additional vessels outside the field of radiation and the surgical site, such as the transverse cervical vessels, the thoracoacromial artery, and the cephalic vein, should be considered, particularly in the setting of a vessel-depleted neck.