Mandibulectomy Periprocedural Care

Management of patient expectations is important in any medical or surgical undertaking. This holds also true for patients undergoing mandibulectomy.

The potential sequela and postoperative symptoms vary by mandibular resection approach. Patients who undergo full-thickness segmental mandibulectomy will have permanent anesthesia of the affected lower lip postoperatively owing to the position of the inferior alveolar nerve in the core of the medullary cavity of the mandible. Some surgeons have attempted to reconstruct this with a segmental nerve graft using a donor nerve (eg, sural nerve or lateral femoral cutaneous nerve), with variable success. ^[5] In addition, in the setting of benign disease, some surgeons have attempted to mobilize the nerve out of the bone and to preserve it during mandibulectomy and reconstruction. ^[6]

The patient must be aware that, in all likelihood, the sensory defect will be long term. The author usually explains to mandibulectomy candidates that this sensation is similar to what they would experience after they have been to the dentist and local anesthetic has been infiltrated into the mandible. A temporary numbness of the lower lip is common when one leaves the dentist. This is an example nearly everyone can understand.

The patients need to be informed that, depending on the approach and the degree of reconstruction, the contour of the lower third to the face may be altered. In almost every situation today, some type of mandibular reconstruction is attempted, even in the patients with modest comorbidities.

In most cases of malignant disease, mandibulectomy is only one component of a more significant operative procedure. In many cases, as part of the oncologic resection, other surrounding tissue (eg, the floor of mouth, tongue, overlying facial skin, innervation to the lower lip) must be removed to obtain clear oncologic margins. Removal of these subsites has individual functional and cosmetic consequences. When the defect has been mapped out preoperatively, the surgeon should be able to anticipate the probable functional implications of the procedure. These need to be carefully explained to the patient and their family members so that appropriate expectations are established preoperatively. Most patients who undergo mandibulectomy will also undergo some form of neck dissection.

Typically, incisions need to be made on the lower face, particularly in the area of the chin and submandibular areas. Families need to be aware of this.

Airway management is a key component of the treatment of mandibular processes that will require mandibulectomy. Some patients may require tracheotomy, which is detailed below. Others may require nasotracheal tube intubation and overnight ventilatory support. The patients need to be adequately prepared for this possibility.

Preprocedure planning consists of several key elements. In the setting of mandibulectomy, the most important determination is how the airway will be managed.

Patients with limited disease that may involve only the mandible and does not extend into the adjacent floor of mouth who have an airway that can be easily visualized and managed by the anesthesia staff may undergo mandibulectomy with nasotracheal intubation and not require a temporary tracheotomy. This includes some patients who undergo immediate mandibular reconstruction with free-tissue transfers. These patients can usually be treated overnight with a nasotracheal tube in the ICU, with extubation the following day. In patients who will undergo significant floor-of-mouth resection with tongue and perhaps other adjacent areas in the oral cavity and oropharynx, tracheotomy is best advised and is the safest methodology to manage the airway.

Among patients who have large mandibular tumors that have destroyed the outer cortex of the mandible, thereby making it unusable as a template on which to bend a preresection bony mandibular internal fixation plate, a prebent plate using a computer generated model of the affected mandible may need to be obtained. In this setting, a plastic model is created that can then be used as a base onto which to create a template for the mandibular plate postresection. Typically, such models have an internal fixation system that allows stabilization of the fragments once the affected portion of the mandibular model is resected. These models are made to exact scale of the patient so the reconstruction bar can be bent to the perfect contour on the patient’s mandibular model and the plate can be sterilized and ready to use in the patient postresection (see image below).

A model of the patient's mandible generated from the preoperative CT scan. This model will assist in postoperative reconstruction.

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This requires a few weeks of preoperative planning, with time allowing for the turnaround of the model in preform plates. ^[7]

Mandibulectomy entails an adequate mandibular reconstruction plating system, a sagittal or reciprocating saw, and a standard head and neck tray.

Anesthesia

Mandibulectomy is performed under general endotracheal anesthesia. The endotracheal tube must be positioned so as not to obstruct access to the anatomical components. Thus, in patients with a lesion limited to the mandible without adjacent floor-of-mouth or tongue involvement, who will not require tracheotomy, the endotracheal tube can be placed nasotracheally in nearly all cases. If the lesion is well lateralized, the tube can be placed transorally and secured to the contralateral side of the oral cavity, but only in patients who will not require intermaxillary mandibular fixation, which could be used to help maintain perfect occlusion throughout the course of the resection and postoperatively. in patients who require a large transoral resection with adjacent soft tissue, tracheotomy is appropriate.

Positioning

Generally, the authors position the patient supine and rotated 180° away from anesthesia so that the patient’s feet are adjacent to the anesthesiologist. This requires long ventilator tubing and allows the surgeon to take command of 280° of the patient’s operative field around the head and neck and potential free-flap donor sites. The patient’s head should be placed in a “donut” and a shoulder roll placed under the shoulders in a moderate degree of extension.

During mandibular resection and reconstruction, the patients are under general anesthetic and standard anesthetic monitoring. Special exceptions for free-flap cases include the necessity for an arterial line. In addition, the surgical team must communicate with the anesthesia team about location of line placement and judicious use of vasopressors, which negatively affect free-flap survival.

After the surgery and reconstruction is complete, if a free flap was used, a Doppler signal is detected and a single suture placed to ensure that both the medical and nursing team can properly assess the free-flap viability. In most cases, the patients are then transferred to the ICU, where they under frequent free-flap checks (Doppler, capillary refill, color, turgor). Once the patient is deemed stable and the free flap shows consistent viability, the patient is often transferred to a regular surgical ward until discharge.

The short-term follow-up regimen is surgeon-specific, but most patients are seen between 7 and 14 days after discharge for suture removal and dressing changes. Afterward, consistent follow-up plans are made every 1-2 months for the first year, mostly for oncologic surveillance and functional status inquiry.