Free Tissue Transfer to Head and Neck

This article provides a lesson-learned approach per site and anatomic structure to head and neck reconstruction. It addresses the most common unfavorable results following successful free flap transfer shedding light on why they happen and how to prevent them. It draws from hundreds of advanced and complicated microsurgical head and neck reconstruction cases, aiming to achieve excellence in the reconstructive endeavor and to enhance the patient’s quality of life.

Key points

  • Unfavorable microsurgical head and neck reconstruction refers to complicated wound healing and suboptimal form and function despite free flap survival.

  • The unique characteristics of some of the anatomic subsites and the unavailability of optimal techniques contribute to the unfavorable result.

  • Knowing when to offer a priority reconstruction and when to do total reconstruction per site can reduce unfavorable outcomes.

  • The reconstructive surgeon should foresee the effect of surgical scar contracture, radiotherapy, and the extent of tissue atrophy on the reconstruction and take necessary countermeasures.

Introduction

Free tissue transfer after ablation of head and neck cancer has become the gold standard of reconstruction. In order for the microsurgical reconstruction to achieve its ultimate goal of good patient quality of life, successfully transferred free flaps should aim at restoring optimal form and function.

Good quality of life after head and neck reconstruction depends on uncomplicated wound healing to allow timely administration of chemotherapy and radiotherapy; adequate mouth opening, good deglutition, and intelligible speech; minimal donor site morbidity; minimal revision surgeries; and good cosmesis. Fulfilling these goals demands thorough planning, wise and proper selection of techniques, and flawless execution of the surgery to ensure successful reconstruction beyond free flap survival.

Failure in achieving one or more of these goals despite successful free flap transfer results in unfavorable reconstruction marked with downgraded quality of life. Avoidance and treatment of the unfavorable results thus should be at the core of contemporary head and neck surgery.

The authors of this article, based on their extensive experience, identify potential challenges and pitfalls by region or anatomic structure in the head and neck and share their refined approach in a lesson-learned manner.

Introduction

Free tissue transfer after ablation of head and neck cancer has become the gold standard of reconstruction. In order for the microsurgical reconstruction to achieve its ultimate goal of good patient quality of life, successfully transferred free flaps should aim at restoring optimal form and function.

Good quality of life after head and neck reconstruction depends on uncomplicated wound healing to allow timely administration of chemotherapy and radiotherapy; adequate mouth opening, good deglutition, and intelligible speech; minimal donor site morbidity; minimal revision surgeries; and good cosmesis. Fulfilling these goals demands thorough planning, wise and proper selection of techniques, and flawless execution of the surgery to ensure successful reconstruction beyond free flap survival.

Failure in achieving one or more of these goals despite successful free flap transfer results in unfavorable reconstruction marked with downgraded quality of life. Avoidance and treatment of the unfavorable results thus should be at the core of contemporary head and neck surgery.

The authors of this article, based on their extensive experience, identify potential challenges and pitfalls by region or anatomic structure in the head and neck and share their refined approach in a lesson-learned manner.

Unfavorable results after microsurgical reconstruction of tongue and mouth floor defects

Unfavorable Results

Untoward outcomes after microsurgical reconstruction of the tongue and mouth floor involve inadequate volume reconstruction of the neotongue; strictures and tethering of the tongue; orocutaneous fistula; and/or suboptimal management of associating bony and/or soft tissue defect involving the mandible, palate, and lateral pharyngeal wall.

Radiotherapy negatively affects the reconstruction, and the effect of radiotherapy on the flap and surrounding tissue is unpredictable and hard to control. Therefore, it seems logical to foresee the aftermath of radiotherapy to minimize related shortcomings and complications.

Classification of Tongue Defects

To avoid confusion, the authors refer to 50% loss of the tongue in anterior-to-posterior direction as hemiglossectomy and to more than 90% loss of the tongue with preservation of less than 10% of tongue base as near-total glossectomy. Total tongue defect refers to total resection of the tongue with/without the hyoid bone.

Other forms of tongue defects or defects not limited to the tongue, extending to mouth floor and adjacent structures, represent a largely diverse group that lacks uniformity and is better addressed individually.

Revisited Approach

On hemiglossectomy

Tethering-free reconstruction and water-tight closure at mouth floor are the goals. The authors prefer thin anterolateral thigh cutaneous flap to ensure pliable, soft neohemitongue. The flap is harvested above the deep fascia or the scarpa fascia depending on patient’s thigh thickness. During inset, the flap is sutured from posterior to anterior starting with the lateral side of the lower gum, then the tongue side leaving the anterior ventral tongue and anterior side of the lower gum toward the end. This allows the redundant part of the flap to be de-epithelialized to augment the neotongue with tension-free closure. Before closure and with care not to injure skin vessels, the inner side of the flap is sutured to the intrinsic muscles of the tongue to separate between mouth floor and oral tongue creating oral gutter ( Fig. 1 ).

Fig. 1
Adequate gutter between tongue and lower gum after reconstruction of hemiglossectomy defect with thin anterolateral thigh flap.

On near-total and total glossectomies

The key goals are to achieve long-lasting bulky neotongue with protective sensation, allow decanulation of the tracheostomy, and reasonable swallowing. The flap of choice is the combined anterolateral thigh flap with vastus lateralis muscle. Any flap with similar characteristics and tissue component can also be used.

The anterolateral thigh flap allows stocky neotongue given that the flap is not stretched too thin to reconstruct every soft tissue defect in the oral cavity, such as the palatine tonsillar fossa or the soft palate. The vastus lateralis muscle is designed along the distal runoff of the descending branch to allow versatile obliteration of the dead space between the mandible and the hyoid bone.

Flap inset starts with the epiglottis all the way up along the lateral pharyngeal wall, then the flap is folded on itself anteriorly to create bulky tongue and finally sutured to the mandible/plate to seal the mouth floor. The next important step is hyoid bone suspension to the mandible/reconstruction plate, which opens up the epiglottis and lifts up the hyoid bone and the bottom of the flap minimizing sagging and flap sinking caused by gravity and bottoming out. The lateral cutaneous femoral nerve is coapted to the lingual nerve to provide protective sensation.

The presence of associating segmental mandibulectomy further complicates the reconstruction. The authors recommend another free flap to address these defects. This is discussed further in the section on mandible reconstruction ( Fig. 2 ).

Fig. 2
( A ) Total glossectomy defect. ( B ) The combined anterolateral thigh with vastus lateralis muscle flap including the motor nerve and the sensory nerve. ( C ) Inset of the flap for total tongue reconstruction with hyoid bone suspension ( arrow ). ( D ) Appearance after reconstruction with good shape and function at 1-year follow-up.

Unfavorable results after microsurgical reconstruction of the mandible

Unfavorable Results

The untoward outcomes are soft tissue–related and bone- and hardware-related. In the first category, sunken appearance and orocutaneous fistula are the main unfavorable results. In the second category, malocclusion, plate exposure, trismus, and asymmetric appearance are the main problems.

The untoward outcomes following the reconstruction of the mandible arise largely from poor decision making; in particular, whether or not to reconstruct the bone and failing to appreciate the importance of adequate volume replacement and soft tissue coverage. Other aspects of poor decision making include whether or not to plate and failure to prioritize reconstruction goals in the setting of an extensive defect, building on a deceiving concept: “One flap can do many things.”

Revisited Approach

To avoid poor decision making leading to inadequate or overzealous reconstruction, a refined multifactorial approach, that of the patient, the disease, and the defect elements, has been adopted into our practice. Based on this approach, the suitable reconstructive plan consists of vascularized bone alone, soft tissue flap with or without reconstruction plate, and double free flap (vascularized bone plus soft tissue flap). The reconstruction is done in either one-stage when a full-scope reconstructive effort is desired based on favorable general and oncologic conditions, proper defect type, and good mouth opening; or in multistage starting with soft tissue first, then bone reconstruction later when a full-scope endeavor is deemed unsuitable, in contract to that of one-stage reconstruction ( Fig. 3 ).

Fig. 3
One-stage reconstruction of a compound mandibular defect. ( A ) The compound mandibular defect after excision of ameloblastoma with preformed reconstruction plate. ( B ) Appearance at 1-year follow-up after one-stage reconstruction with the fibula osteoseptocutaneous free flap.

Special Considerations

Defect classification

Defect type based on Jewer’s and Wei’s classification does not necessarily preclude the bony reconstruction; instead, these classifications are used as a guideline for potential compromise in the reconstruction plan when other factors, such as prognosis and mouth opening, are unfavorable; for example, an L compound defect in poor prognosis tumors may be best reconstructed with soft tissue flap with or without plate depending on the severity of trismus. However, the same defect following ameloblastoma resection is best reconstructed with vascularized bone.

The reconstruction plate

Although the reconstruction plate maintains the continuity of the mandible, it could be a double-edge sword leading to complications; exposure is not uncommon, not to mention malocclusion, trismus, and asymmetry. To minimize plate-related complications, the authors advocate plate-free reconstruction in the case of long-standing severe trismus with a history of radiotherapy or osteoradionecrosis, because the mandible is less likely to drift after resection and plate-free reconstruction.

The recently available preformed plate (MatrixMandible, Synthes CMF, West Chester, PA) allows anatomic and symmetric restoration of the shape of the mandible with ease and minimal or no bending. The plate is suitable for a wide array of mandibular defects except central (C type) and bilateral defects (LCL type).

High osteotomies and condyle head

The main concern following high mandibulectomy is condyle head malposition after fixation. Malpositioned condyle head leads to locked jaw and pain. To avoid that, intraoperative navigation to register the location of the condyle head before resection and then to use the registered location as a landmark for plate fixation can be used, or a miniplate can be fixed to the condyle head and to the zygoma/maxilla before segmental resection, so that when plating is done, the condyle is already in the anatomic location ( Fig. 4 ). When none of these techniques is feasible, the condyle head could be pushed upward and backward to ensure its proper position in the glenoid fossa.

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