Unfavorable Results After Free Tissue Transfer to Head and Neck

The purpose of the current article is to provide an overview of the functional and aesthetic unfavorable results of head and neck reconstruction, and provide suggestions on how to address these issues. Understanding the consequences of an unsuccessful reconstruction provides the foundation for proper planning and personalized approach to reconstruction of lost structures.

Key points

  • When performing head and neck reconstructions precise knowledge of function and aesthetic requirements of each specific area is mandatory. Careful assessment of what is missing and replacing like with like is essential.

  • Development of microsurgical techniques has enabled reconstruction of more complex defects with better functional and aesthetic results.

  • Microsurgical techniques have not been able to prevent unfavorable outcomes as they have allowed ablative surgery that was previously not possible due to the lack in reconstructive abilities.

  • Functional as well as aesthetic suboptimal results can lead to major impairment of quality of life. The awareness of all possible adverse effects characteristic to each anatomic site is the key to avoiding and managing them.

Introduction

Head and neck surgery has improved through significant changes and development over the past decades. Factors contributing to this favorable progress include better understanding of anatomy, improved preoperative imaging, more precise delivery of radiation, and advances in surgical technique. Development of microsurgery has enabled reconstruction of virtually any defect after ablative surgery. The foundation for success in head and neck surgery is the restoration of function and aesthetics for which microsurgical reconstruction is often the method of choice. With free tissue transfer, it is possible to replace ablated tissues with similar well-perfused tissues and reconstructions can be individually planned to fulfill the tissue requirements of the defect. Microvascular reconstruction has become a reliable way to recreate ablated tissues, as microvascular success rate is approximately 97% in most high-volume centers.

The definition of an acceptable result in head neck surgery has evolved over time. From the earlier simple need to fill the hole, we have advanced to a fuller understanding of the need to exactly specify the defect and missing components. In reconstructing the form and function of the ablated tissues, failure to appreciate the unique features of individual tissues will most likely lead to suboptimal outcome. Unfavorable results in head and neck free flap surgery are more than just a failed flap but also include cases in which reasonable restoration or acceptable aesthetics have not been achieved. In addition, an unfavorable result has been obtained if unacceptable donor site morbidity or patient dissatisfaction is present.

The purpose of the current article is to provide an overview of the functional and aesthetic unfavorable results of head and neck reconstruction, and provide suggestions on how to address these issues. Understanding the consequences of an unsuccessful reconstruction provides the foundation for proper planning and personalized approach to reconstruction of lost structures.

Introduction

Head and neck surgery has improved through significant changes and development over the past decades. Factors contributing to this favorable progress include better understanding of anatomy, improved preoperative imaging, more precise delivery of radiation, and advances in surgical technique. Development of microsurgery has enabled reconstruction of virtually any defect after ablative surgery. The foundation for success in head and neck surgery is the restoration of function and aesthetics for which microsurgical reconstruction is often the method of choice. With free tissue transfer, it is possible to replace ablated tissues with similar well-perfused tissues and reconstructions can be individually planned to fulfill the tissue requirements of the defect. Microvascular reconstruction has become a reliable way to recreate ablated tissues, as microvascular success rate is approximately 97% in most high-volume centers.

The definition of an acceptable result in head neck surgery has evolved over time. From the earlier simple need to fill the hole, we have advanced to a fuller understanding of the need to exactly specify the defect and missing components. In reconstructing the form and function of the ablated tissues, failure to appreciate the unique features of individual tissues will most likely lead to suboptimal outcome. Unfavorable results in head and neck free flap surgery are more than just a failed flap but also include cases in which reasonable restoration or acceptable aesthetics have not been achieved. In addition, an unfavorable result has been obtained if unacceptable donor site morbidity or patient dissatisfaction is present.

The purpose of the current article is to provide an overview of the functional and aesthetic unfavorable results of head and neck reconstruction, and provide suggestions on how to address these issues. Understanding the consequences of an unsuccessful reconstruction provides the foundation for proper planning and personalized approach to reconstruction of lost structures.

Unfavorable results in oral cavity reconstruction

The oral cavity is composed of the floor of the mouth, the anterior two-thirds of the tongue, buccal mucosa, hard palate, mandibular and maxillary alveolar ridges, and retromolar trigones. The oral cavity is bordered by the lips anteriorly, and the base of the tongue and soft palate posteriorly. All these different structures have unique properties that will be affected by ablative surgery. These properties include important roles in speech, taste, and mastication. The structures of the oral cavity are also used for breathing, facial expressions, and social interactions. Partial resection of many of these functional structures is frequently required to achieve disease control. An unfavorable result in oral cavity reconstruction is more often a problem of function than aesthetics. Speech can become unintelligible and impair social life. Also, ability to chew and swallow food can be severely affected. Suboptimal results can have serious effects on the patient’s quality of life.

Floor of Mouth

When planning a reconstruction of the floor of the mouth, it is important to acknowledge that no one part can be reconstructed without it having an effect on the other parts. The main issues in designing the reconstruction are restoring the buccogingival and/or labiogingival sulcus of adequate depth, avoiding excessive height of the floor of the mouth, and allowing optimal tongue mobility by restoring exactly what has been removed. Major indications for floor of the mouth flap reconstruction are to close defects that communicate with the neck to prevent vascular blow out caused by salivary contamination of the major vessels, and to achieve coverage of exposed mandibular bone which may not remucosalize spontaneously especially in the setting of radiation therapy.

The precise planning and careful analysis of what is missing will prevent the reconstruction with a flap that is either too small or too large. In either condition, with excessive bulk or too much tension, the mobility of the tongue is affected, having a significant impact on both the speech and swallowing. This emphasizes the importance of using a flap of adequate thickness. The radial forearm flap is still the most popular flap when a thin reconstruction of the floor of the mouth is needed, although the anterolateral thigh flap has gained increasing popularity. One option is to reconstruct a floor of the mouth defect with a fascial or muscle flap and let it reepithelialize by the surrounding mucosal surface. These non–skin bearing flaps can be subject to considerable contraction as a result of wound-healing forces. In the presence of radiation, remucosalization may not occur. Xerostomia following radiation is a common problem and jejunal patches and colon patches have been used for floor of the mouth reconstruction in an attempt to address this debilitating condition. Although these flaps are thin and have the ability to produce mucus, the risk of donor site morbidity and limited ability to endure radiation have prevented them from being widely used.

In the case of an unsatisfactory result after reconstruction, revision may become necessary. The second procedure is typically required to reduce bulkiness or add tissue to gain mobility or depth. When performing de-bulking, one must beware of creating too much tension on tissues or exposing intraoral bone. If the sulcus is too shallow or the tongue movement is limited, additional tissue needs to be brought in. This can range from a full-thickness skin graft to local flaps or even a new free flap ( Fig. 1 ). Sometimes simple release of scar tissue will improve movement of the tongue, but careful patient selection is critical, as in some cases this release will diminish the function of the tongue, as remaining tongue function can be dependent on the fixed less-mobile position ( Box 1 ).

Fig. 1
( A ) Patient with bulky floor of mouth reconstruction obliterating the labiogingival sulcus complicated by external skin loss that was reconstructed with a split-thickness skin graft at the time of ablative surgery. The split-thickness skin graft causes additional contraction resulting in downward pull of the lip. The outcome of this initial reconstruction can be scored as 100% flap survival with complete functional and aesthetic failure. ( B ) Revision surgery is directed at removal of the split-thickness skin graft that caused contraction and full release of the scarred tissues to restore lower lip position and thus addressing complete oral incontinence. Reconstructive requirement is for a free flap, as the radiated tissue bed requires well-vascularized tissue transfer to allow healing. ( C ) An anterolateral thigh free flap was used to provide well-vascularized tissue for permanent restoration of lip position. The labiogingival sulcus was debulked at the same operation. A permanent result with normal oral continence was maintained at follow-up after 1 year.

Box 1

  • Goal:

    • Watertight closure of oral cavity from neck

  • Salient points:

    • Avoid excessive bulk or tightness to preserve tongue mobility

    • Preserve bucco/labiogingival sulcus to prevent oral incontinence

  • In case of an unfavorable result:

    • Excision of excess bulk

    • Addition of new tissue to resolve tightness

  • Cave:

    • Radiated local tissues can give poor healing and revision can give bigger problems

Floor of mouth reconstruction

Tongue

The tongue has a highly specialized function and reconstruction can be challenging. The aim of the reconstruction is to restore and/or maintain the important roles in speech, swallowing, and airway protection. Tongue reconstruction is focused on preservation of optimal mobility. After tongue reconstruction, the tongue should be able to contact the hard palate for speech articulation, and to clear the oral cavity and move food and secretions from anterior to posterior.

Smaller defects can be closed primarily. Tongue tissue should not be used to close adjacent defects as this will significantly impair mobility. Larger defects that involve around half of the tongue will mostly require a free flap for reconstruction. Mostly a thin pliable flap, such as a radial forearm or thin anterolateral thigh flap, will preserve the mobility of the tongue ( Fig. 2 ). It is important to ensure that sufficient bulk remains to obliterate the oral cavity space when the mouth is closed, and to prevent secretions from directly draining to the larynx. The approach for reconstruction of total or near-total glossectomy defects is slightly different. Bulkier flaps are needed to replace the resected volume. Larger flaps can provide better bulk so as to assist in swallowing. Still, patients with total glossectomy are at high risk of remaining dependent on parenteral nutrition and may suffer from frequent episodes of aspiration. When considering the location of the defect on the tongue, it can be generally stated that anterior and lateral tongue defects often have limited requirement for bulk and can be reconstructed with thinner flaps, whereas more posterior defects require more bulk.

Fig. 2
( A ) A thin anterolateral thigh flap can be used for lateral tongue defects. In this flap elevation, a small segment of vastus lateralis muscle is included to add bulk to the base of tongue that has partially been resected. The main perforator can be seen with a small block of muscle on a side branch of the perforator. ( B ) The intraoperative view shows a tidy inset restoring proper volume of the tongue. ( C ) At 1 year after operation, the anterolateral thigh flap has incorporated well into the native tongue. The tongue has maintained excellent mobility.

Revision surgery following tongue reconstruction may be required to improve functional outcome. As mentioned previously, there are 2 goals of these secondary procedures: to improve movement or reduce bulkiness. In the pursuit of better mobility skin grafts, local flaps or even free flaps might be needed. The reduction of bulkiness is more straightforward, but the improvement of function is often less than expected or desired ( Box 2 ).

Box 2

  • Goal:

    • Maintain or restore maximal mobility

  • Salient points:

    • Mobile tongue defects require less bulk

    • Loss of base of tongue will in general require bulk to allow swallowing

  • In case of an unfavorable result:

    • Bulk reduction or release of tethering may improve mobility

  • Cave:

    • Revision for limited mobility gives often only very modest improvement at best

Tongue reconstruction

Palate

The palate forms the roof of the mouth and it separates the oral cavity from the nasal cavity. The palate is divided into anterior bony hard palate and posterior muscular soft palate. The functional importance of the hard palate lies in speech. The mobile soft palate is involved in swallowing, breathing, and speech. During swallowing and speech, the soft palate separates the oral from the nasal cavity. After resection, reconstructive challenges arise from these functional requirements. An open connection between the nasal and oral cavities will result in open nasal speech and oral intake escaping through the nose.

Midpalatal resections that spare all the teeth, premaxillary resections that include only the incisors, and unilateral posterior defects that involve only the teeth posterior to the canine may be suitable to be treated by an obturator prosthetic. Smaller defects also can be reconstructed with local flaps from adjacent palatal mucosa or tongue. However, in ablative cancer surgery, a free flap often will be required. Defects involving 50% or more of the palate usually require free flap reconstruction, partly due to the lack of supporting tissues to stabilize the prosthesis. There are studies supporting the opinion that even in small or medium-size defects, a free flap reconstruction provides superior results compared with a prosthetic device by improving patients’ daily quality of life. For free flaps, the reconstruction with soft tissue flaps will generally give a good result.

When reconstructing soft palate, there are 2 main considerations. First, oral and nasal cavities need to be kept separate, and second, there needs to be sufficient bulk in the back of the oral cavity for the tongue to push against for swallowing. For smaller defects, a radial forearm flap is sufficient. It should be folded so that both the nasal and oral surfaces are reconstructed. If the nasal surface is left raw, the flap will shrink significantly due to wound-healing forces, and the shrinkage is even more pronounced in the presence of radiation therapy. For larger defects, a bulkier flap, such as an anterolateral thigh flap, is indicated to provide sufficient volume for adequate postoperative swallowing ( Fig. 3 ). All flaps used to reconstruct the soft palate should be planned so that they reach close to or touch the posterior pharyngeal wall, because they will experience considerable postoperative shrinkage due to the lack of surrounding support, which is normally present in the hard palate but not the soft palate.

Fig. 3
( A ) A large combined hard and soft palate defect is visible through a mandibular split approach. Reconstruction of the defect is with a soft tissue flap, as the remaining hard palate provides sufficient support. The large soft palate resection requires a bulky reconstruction to provide sufficient tissue to enable separation of the oral and nasal cavities. ( B ) A very large anterolateral thigh flap is inset into the defect. Inset is challenging due to the bulk during surgery. Bulk will decrease in the postoperative period as part of general decrease of swelling. The anterolateral thigh flap will retain significant bulk, as it is a skin and subcutaneous tissue flap as opposed to a muscle flap that loses a large amount of the volume not only as a result of postoperative decrease of swelling but also as a result of muscle atrophy. ( C ) At 18 months after surgery, the anterolateral has fully integrated into the surrounding palate tissues. Permanent separation of oral and nasal cavity has been achieved. The patient had mild nasal speech after this reconstruction.

In the event of a suboptimal result after the primary reconstruction of hard palate there are usually 2 complaints: leakage of oral intake through the nose or unintelligible open nasal speech. If after soft palate reconstruction the patient suffers from the open nasal speech, this condition may be improved with a cranially or caudally based pharyngoplasty ( Box 3 ).

Box 3

  • Goal:

    • Keep the nasal and oral cavities separated

  • Salient points:

    • Hard palate defects may be treated by an obturator or small soft tissue flap

    • Soft palate defects need to have sufficient bulk to touch the posterior pharyngeal wall and prevent air leakage.

  • In case of an unfavorable result:

    • A pharyngeal flap can be added to improve function after soft palate reconstruction

    • Nasal side lining should be provided to prevent excessive shrinking of a soft tissue flap without any other support

  • Cave:

    • The soft palate is muscular, which usually cannot be reconstructed adequately in a cancer-ablative reconstruction followed by radiation

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Nov 21, 2017 | Posted by in Dental Materials | Comments Off on Unfavorable Results After Free Tissue Transfer to Head and Neck
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