Primary and Neck Resection

Throughout the extirpation, there must be good communication between the extirpative and reconstructive surgeons. Frequently, both are working concurrently to minimize anesthesia time. Continuous monitoring of the patient status intraopera-tively is also crucial, as any decline in the medical status of a patient, requires an immediate change in the operative plan. Unlike the aesthetic resection of a complete nasal unit, in the oral cavity, any native tissue in the oral cavity that can be spared will generally provide improved post-operative function. During the resection, unanticipated areas of resection or tissue sparing and areas of potential re-resection after frozen-section margin analysis should be accurately communicated to the reconstructive surgeon to allow for intraoperative adjustments. This information not only can affect flap cutaneous paddle size but also its shape and orientation. Having the surgeon to mark transected nerve stumps that require subsequent reanastomosis or cable grafting can be advantageous because of the inherent difficulties in finding these areas at the end of the case. This is also pertinent when innervated free flaps are going to be inset later in the case.

In cases involving mandibulotomy, best occlusal results are obtained when the internal fixation or reconstruction plate (compressive or locking) is modeled on the buccal and labial contour spanning the anticipated mandibulotomy site. In the instance of compression- and tension-band plate placement, the two medial holes of each plate should be drilled appropriately eccentrically and neutrally positioned, respectively. Subsequent plate holes can be drilled at the time of mandibulotomy repair, because this will assure good compression across the mandibulotomy site. Similarly, in cases of segmental mandibulectomy, pre-contouring the reconstruction plate is crucial for maintaining the best occlusal relationships and temporomandib-ular function. Even in edentulous cases, this planning and early effort can maintain a more natural contour and good joint function. If there is involvement and/or distortion of the buccal or labial cortex of the mandible, direct plate contouring to the bone is not possible. Placement of the patient into maxillo-mandibular fixation or use of a mandibular fix bridge system (Synthes CMF, Paoli, Pennsylvania) can help maintain preoperative occlusal and joint relationships. Post-resection freehand plate contouring and fixation is difficult and often yields suboptimal symmetry and joint function. With the currently available low-profile locking reconstruction plates, the contoured plate can closely approximate the natural mandibular projection and contour without sacrificing durability and strength when used in conjunction with bone grafts (26,27). These thinner reconstruction plates are usually not visible or palpable through the external skin flap, even after some subcutaneous tissue resection. In the atrophic edentulous mandible, the older, more stout reconstruction plates (i.e., THORP; titanium hollow screw reconstruction plate) must often be set back distally one to two holes to avoid mentum over-projection and minimize tension on the overlying skin paddle. This is usually not necessary with the slimmer and lower profile reconstruction plates (2.0 mm and 2.4 mm). In addition, with the locking-plate design, less accurate contouring of the native mandible contour is necessary prior to screw fixation since it acts as an internal external-fixator device. Accurate measurement of bicortical locking screw length is paramount to minimizing readily palpable, and often bothersome, sharp lingual screw tips. This is also true for lin-gually placed bone grafts placed in the segmental defect. The plate should be screw-fixated at the appropriate location along the native mandibular height such that the bone graft and overlying alveolar soft tissue paddle lie even with the remaining native occlussal surface. Adequate neo-mandibular height will also facilitate maintenance of gingivo-buccal, gingivo-labial and floor of mouth sulci to preserve tongue mobility, oral competence, and adhesive surface area for dentures. Use of reconstruction plates to span segmental mandibular defects without the concomitant use of bone grafts can affect the long-term complication rate and functional effect of the reconstruction, depending upon the mandibular defect location and size and the type of plate used (28-30). Depending upon the size and location of the soft-tissue defect, removal of the reconstruction plate prior to flap inset by the surgeon may be necessary for adequate exposure to perform the inset or microvas-cular anastomosis.

Communication among surgeons during the neck dissection is also important. For anticipated microvascular cases, gentle dissection and sparing of arterial and venous vessels and lengthy stumps is important for maintaining anastomosis options. Although this requires extra effort and time, sparing extra vessels such as the transverse cervical pedicle and external jugular vein should usually not compromise oncologic resection. The appropriate recipient vessel size needed can be estimated from the anticipated donor site. In addition, inter-surgeon communication of anticipated defect location and microvascular pedicle length, can guide the extirpative surgeon to save potential recipient vessels in a given area of the neck, while allowing faster dissection in non-essential areas. Similarly, anticipated resection of the proximal external carotid arterial system due to neck disease should be communicated to the reconstructive surgeon so alternative recipient arterial supplies can be prepared (31). This frequently requires vein grafting and can compromise anastomotic patency (17,32). Sacrifice of the ipsilateral sternocleidomastoid muscle should also be strongly considered for cases requiring pedicled myofascial or myocutaneous flap reconstruction, as the pedicle muscle bulk is significant and can serve as carotid sheath coverage. Partial removal of the anterior sternocleidomastoid muscle can allow improved microvascular pedicle geometry and/or decrease venous pedicle compression. In cases of across-midline resections or previous ipsilateral radical neck dissections, vessels from the contralateral neck may need to be isolated and prepared. This need may prompt the extirpative surgeon to perform a full-neck dissection for oncologic reasons in a borderline indication case.

Suction drain placement at the completion of the procedure is also crucial. The best type of post-operative neck drainage remains controversial, but a balance between adequate drainage of all potential dead spaces and minimal interruption of any reconstructive flap pedicle must be maintained. A tight neck closure can apply significant pressure to a drain tube if it overlies a vascular pedicle, especially with routine post-operative swelling. Compression dressings can also compromise pedicled and free-flap pedicles. Drains should typically be placed parallel to flap pedicles and carotid sheath contents. Drain tips should be placed away from mucosal or skin suture lines to avoid salivary or air leakage. Maintenance of internal drain position with post-operative head and neck movement can be assured by loose suturing with absorbable sutures.

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