Master Techniques in Otolaryngology - Head and Neck Surgery: Reconstructive Surgery, 1ed.

5. Management of the Partial Glossectomy Defect: Split Thickness Skin Graft

D. Gregory Farwell

INTRODUCTION

Cancer of the oral tongue is typically treated by surgical resection. Optimal reconstruction of the partial glossectomy defect recreates a functional tongue that allows for oral diet and normal articulation. Several techniques are available to reconstruct the tongue including healing by secondary intention, skin grafting, allografting, pedicled local and regional flaps, and free tissue transfer.

Split-thickness skin grafting is a time-honored technique that allows for the rapid reconstruction of select defects. This technique is straightforward and does not require additional specialized surgical techniques but is not appropriate for every defect. Smaller defects in a healthy, well-vascularized wound bed are best for this technique. Larger defects and hostile wounds are less appropriate for this technique and are typically better reconstructed with vascularized free flaps.

The typical patient in need of split-thickness skin graft (STSG) reconstruction of the oral tongue has been diagnosed with cancer of the tongue (Fig. 5.1). With improvements in dental education, many patients may be referred from a dentist for an asymptomatic lesion noted on routine dental evaluation.

FIGURE 5.1 Squamous cell cancer of the tongue appropriate for STSG reconstruction.

Other patients may present with a lesion on the tongue that is often painful locally or has referred pain to the ear or is bleeding. The patient may complain of being “tongue-tied” (dysarthria). If the cancer has impeded their diet, they may complain of either dysphagia or frank weight loss. Because of the robust lymphatics of the ventral tongue and floor of the mouth, even small cancers may have already metastasized. In these cases, the patient may notice a mass in the neck.

A careful history should be elicited, documenting known risk factors such as the use of tobacco and alcohol, recurring trauma from a dental or prosthetic source, and preexisting lesions such as erosive lichen planus. Questions should be asked about other symptoms such as dysgeusia or paresthesias of the tongue, lips, or cheek. Other symptoms to look for include dental issues with pain in the teeth or loose teeth. Additionally, a history that evaluated the patient’s comorbidities is important.

A careful diagnostic evaluation including a staging examination is critical before embarking on aggressive surgical therapy. Any suggestion of cervical lymphadenopathy should be carefully noted and evaluated. As many of these patients have been smokers, a systematic evaluation should include a careful history of pulmonary disease or other coexisting medical conditions that might complicate treatment.

A comprehensive examination of the head and neck is performed with special attention to the tongue including the size of the lesion, the thickness of the lesion, deviation of the tongue on protrusion, tethering of the tongue or reduced mobility, and the cranial nerve examination. Fixation of the cancer to the mandible may imply bone invasion that may influence the reconstructive choices other than the skin graft. Any suggestion of hypoglossal nerve weakness or lingual nerve involvement suggests a larger and more extensive tumor and may imply a more extensive resection, less appropriate for an STSG. A careful assessment of the rest of the aerodigestive tract is indicated to rule out a second primary cancer in patients with a smoking history. The submental, submandibular, and jugulodigastric chains are most commonly involved with cervical metastasis; therefore, a complete examination of the neck is also critical to document lymphatic metastasis. The donor site must be inspected to rule out infection, cutaneous lesions, or indications of previous surgery or radiation.

Indications for the STSG include small- or moderate-sized defects with limited involvement of the floor of the mouth. Large defects managed with a skin graft will scar and tether the tongue, which leads to an impairment of speech and swallowing.

Contraindications to split-thickness skin grafting include tumor-specific and patient-specific factors. Larger tumors are best treated with other techniques such as free tissue transfer with an anterolateral thigh or radial forearm free flap. The complication rate is higher with STSG reconstruction of large oral defects. Specifically, large skin graft reconstructions are prone to wound breakdown, fistula, wound contracture, and poorer functional outcomes such as dysarthria and dysphagia. STSG reconstruction is contraindicated in previously radiated patients. Patient-specific factors such as diffuse skin disease, significant sun exposure, and lack of an appropriate donor site may be rare contraindications to the use of a skin graft.

Imaging Studies

Computed tomography (CT) and/or magnetic resonance imaging (MRI) scans may be used to evaluate the extent of the primary cancer and the regional lymphatics. Historically, the contrast-enhanced CT is the most frequently used form of imaging for evaluating the oral cavity due to its resolution and ability to evaluate for bone invasion. However, dental artifact from metal fillings or prosthesis may compromise its quality in the area of interest. MRI scanning may provide excellent soft tissue resolution of the tongue when there is unacceptable artifact found on the CT scan.

For cancers with advanced T and N stages, examination of the chest and abdomen is important. Historically, CT of the chest and abdomen were frequently used. Currently, PET–CT is increasingly used to stage cancers of the head and neck. This modality is especially useful in lesions with multiple metastatic lymph nodes or inferior level IV lymph nodes where the likelihood of distant metastasis is increased.

Staging Endoscopy

Preoperative endoscopy and examination under anesthesia is important in determining the extent of the lesion and the resectability of the cancer. The extent of the cancer is mapped, and the extension into the mandible or adjacent structures is analyzed. The expected size of the defect is determined to guide the choice of the optimal reconstruction technique. Unexpected second primary cancers may be discovered, which will probably influence the timing of additional procedures.

Preoperative Testing

No additional testing is required for split-thickness skin grafting beyond the tumor assessment as listed above.

An STSG is typically harvested from the thigh or abdomen depending upon the quality of the skin and the patient preference. Selecting a donor site that can be easily hidden with clothing is ideal. Using a dermatome with settings of approximately 0.015 inch, the skin is stretched flat with a tongue blade, malleable, or other flat instrument to minimize the redundancy of the skin and maximize the chance of an optimal graft. Often a skin lubricant such as mineral oil is applied to allow the dermatome to advance smoothly. The dermatome is then advanced against the skin and the appropriate-sized graft is harvested. My preferred technique is to have the dermatome at full speed and then engage the skin at an acute angle. The graft is harvested with the dermatome flat against the skin with the tongue blade advancing just ahead of the dermatome to flatten the skin and then lifting the dermatome off of the skin at the angle. This approach has been likened to an airplane doing a “touch and go” where it lands, rolls along the runway, and then takes off again.

The graft is then placed in a moist sponge until ready to be inset. Once the glossectomy defect is created and the margins are confirmed as free of cancer, the graft may be inset. Typically, an absorbable suture such as a 4-0 chromic is used to inset the graft circumferentially. Care should be taken to stretch out the defect (Fig. 5.2) and use a graft that is at least as large as the defect. The graft will often contract with healing, and in order to maximize the mobility of the tissues, the graft is often slightly oversized before inset. Another technique is to perform small fenestrations through the graft. These holes allow the serum and exudate to escape from under the graft and not lift up the graft like a bulla (Fig. 5.3). If these bulla form, the graft is less likely to achieve a blood supply and adhere to the wound bed leading to failure of the graft. The graft is then bolstered to the wound with a dressing made from petroleum-based gauze, cotton balls, or other dressing material (Fig. 5.4). Sutures from the periphery of the tongue are then tied over the graft to apply gentle downward pressure on the graft, increasing the chances of adherence to the underlying muscle and good healing. Approximately a week later, the bolster is removed and the graft is inspected. Minimization of tissue trauma is ideal on the new graft. Therefore, a soft diet is typically recommended for a short period of time to allow for healing. Careful oral hygiene with saline rinses or chlorhexidine gluconate rinses are often used.

FIGURE 5.2 Defect after tumor resection with healthy, well-vascularized surgical bed.

FIGURE 5.3 A. STSG of appropriate size is sutured into place. B. Illustration of graft placement. Small fenestrations are made to avoid bulla formation.

FIGURE 5.4 Bolster in place.

Care of the split-thickness graft site centers on an occlusive dressing and monitoring for signs of infection. There are several commercial dressings that have been used from petroleum-based products to newer products that are gel based. Surgeon preference will determine the optimal choice of dressing material. The wound is often painful, and appropriate analgesics are required.

Postoperatively, the patient is followed for wound healing and signs of infection. In defects where there is continuity with the neck, such as after a neck dissection, the wound is watched closely for signs of a fistula. Once the bolster is removed on approximately the 7th postoperative day, the skin graft is inspected for its viability. Any blebs are opened to allow the graft to adhere to the wound and prevent additional accumulation that might lift off adjacent portions of the graft. Oral hygiene is continued as the patient’s diet is advanced. The skin graft donor site is also monitored during the healing period. Typically, an occlusive dressing is applied while the donor site reepithelializes.

Fortunately, complications from skin graft reconstruction of partial glossectomy defects happen infrequently. While complete necrosis of the graft is rare, partial necrosis of a portion of the graft may happen if the graft does not adhere to the underlying vascularized tissue. Nonadherence of the graft can be minimized by fenestration of the graft and bolster placement, but due to the convexities and concavities of the three-dimensional tongue, it can be difficult to get complete adaptation of the graft to the graft bed. The necrotic portion of the skin graft should be debrided, and the tissue beneath the graft will typically heal by second intention. Rarely, patients cannot tolerate the bolster due to discomfort, globus sensation, or airway concerns. In these patients, the graft can usually be successfully adapted to the bed with quilting sutures throughout the graft to the underlying soft tissue. Infections of the donor site are rare and can be managed with local wound care and antibiotics as necessary.

More commonly, complications are related to contracture. Depending upon the location of the graft, the wound may contract and restrict the mobility of the oral tissues. Attempting to control for this by stretching the wound bed and sizing the graft to the maximum size of the defect can help minimize this problem. Similarly, trying to use the skin graft technique for larger and more complex defects will be associated with more failures including fistulas. Utilizing alternative techniques such as microvascular tissue transfer will minimize these complications.

Surgical reconstruction of partial glossectomy defects with STSGs is a time-tested technique that when applied to appropriate defects can successfully achieve the goals of wound closure and return to function (Fig. 5.5). McConnel et al. in 1982 evaluated the functional results of STSG compared to tongue flaps and regional myocutaneous flaps and found that STSG reconstructions had superior results compared to the alternatives studied. Since that time, microvascular reconstruction has revolutionized oral cavity reconstruction and improved our ability to reliably close larger defects with superior functional results.

FIGURE 5.5 Healed split-thickness skin graft.

Steiner and others have demonstrated excellent functional results with limited complications using transoral laser resection with healing by secondary intention with the potential advantage of not “burying” residual tumor thereby allowing for earlier detection of recurrences. However, for small defects, an STSG offers a straightforward technique for rapid closure of partial glossectomy defects and is an appropriate and reasonable choice in these defects.

• Appropriate tumor sizing and staging of the cancer is critical to choosing the appropriate reconstructive technique. Small cancers and smaller defects are most appropriately treated with an STSG.

• Stretching the defect to its maximum dimension will allow the appropriate sizing of the skin graft. The skin graft should be the maximum size of the defect to avoid contracture and maximize mobility of the residual tongue.

• Fenestration and bolstering of the graft to its underlying vascularized bed will maximize skin graft take and successful reconstruction.

• Choosing the skin graft technique for larger defects will give a suboptimal result compared to other techniques such as microvascular reconstruction.

• Undersizing STSGs can result in wound contracture and limited mobility.

• Standard head and neck surgery set

• Dermatome

SUGGESTED READING

Schramm VL, Myers EN. Skin grafts in oral cavity reconstruction. Arch Otolaryngol 1980;106:528–532.

McConnel FMS, Teichgraeber JF, Adler RK. A comparison of three methods of oral reconstruction. Arch Otolaryngol Head Neck Surg 1987;113:496–500.

Zuydam AC, Lowe D, Brown JS, et al. Predictors of speech and swallowing function following primary surgery for oral and oropharyngeal cancer. Clin Otolaryngol 2005;30(5):428–437.

Ellies M, Steiner W. Peri- and postoperative complications after laser surgery of tumors of the upper aerodigestive tract. Am J Otolaryngol 2007;28(3):168–172.