Patient selection

Patient selection

As outlined previously , patients’ comorbidities and functional status as well as their social circumstances play a significant role - in their ability to tolerate surgery and rehabilitation. The early involvement of an MDT including physicians, anaesthetists, physiotherapists and dieticians is important particularly in high-risk patients in order to optimise their performance status - preoperatively . The ‘operability’ of a tumour is determined largely by its size and relationship to important anatomical structures of the head and neck. In the AJCC eighth edition TNM staging sys - tem T4b tumour s are those that may be unresectable owing to involvement of or proximity to the skull base, masticator space, ptery goid plates and/or the internal carotid artery . Once the decision has been made that surgery is appropriate, a few key decisions are to be made. These are as follows: /uni25CF airway management; /uni25CF access to the tumour; /uni25CF tumour resection; /uni25CF management of the neck; /uni25CF reconstruction. Airway management Airway management in patients undergoing surgery for OCSCC is largely centred on protecting the airway against acute embarrassment in the perioperative period. The available options are immediate postoperative extubation, overnight intubation/delayed extubation, submental intubation and tracheostomy . The choice of airway is a joint decision made between the anaesthetist and surgeon, and is influenced heavily by the ability to re-establish a patient’s airway quickly should a life-threatening event occur. Immediate postoperative extuba tion is generally reserved for smaller well-lateralised tumours in uncomplicated patients who may not require reconstruction. In selected patients, overnight intubation is considered when tracheostomy is unlikely yet can still be sited on postopera day 1 if warranted; this approach is burdensome on resources given the higher level of care for the first night, but it reduces length of stay via a quicker restoration of speech and swallow . A low threshold for placing a tracheostomy is appropriate in patients having a bilateral neck dissection or previous neck dissection; large resection with reconstruction; and in patients with a di ffi cult airway . Consideration should also be given to placing a tracheostomy in patients having a segmental mandibular resection; lateralised resections involving the floor of mouth and reconstruction; as well as previously irradiated patients. Access surgery The goal in surgical management of OCSCC is to remove the tumour with an adequate margin circumferentially . While most tumours can be removed via a transoral approach, some cannot be resected safely without an access procedure. These might include large maxillary tumours, posteriorly located tumours and tongue base tumours, or patients who have previ ously had surgery and/or radiotherapy . The most commonly used access procedures include the lip-split mandibulotomy (LSM) ( Figure 53.5 ), the mandibular lingual release, the visor flap and the Weber–Fergusson approach ( Figure 53.6 ), w provides excellent access to the maxilla and, if extended infra orbitally , to the periorbital area. Lip-split mandibulotomy This is the most commonly used access procedure and provides excellent access to the posterior oral cavity , tongue base and oropharynx. It involves making an osteotomy in the mandible in order to ‘swing’ it laterally , thereby facilitating access. Care must be taken to ensure that the lingual mucosa does not tear in an uncontrolled fashion towards the tumour resection margin. Sir William Fergusson , 1808–1877, Scottish surgeon, described and published a modification of the original Weber incision to access the midface. The gold standard in OCSCC is resection with a 1-cm clinical margin circumferentially , vital structures permitting. Mandibular resection Decisions regarding management of the mandible when tumour lies close to, abuts or invades the bone are critical. If there is evidence of infiltrative bone invasion, either segmental or rim resection of the involved mandible is required. Segmental resection involves removing the full height of the invaded section of the mandible such that there is loss of continuity of the lower border. Rim resection or ‘marginal mandibulectomy’ inv olves removing a partial thickness of mandible such that continuity of the lower border remains. A rim resection is sometimes performed when a tumour lies close to but does not definitively invade the mandible, in order to achieve a satisfactory soft-tissue margin. Maxillary resection - Owing to anatomical di ff erences such as thinner bone, the presence of sinuses, tightly adherent palatal mucosa and prox - imity to the orbit and skull base, maxillary resection consid - erations di ff er from those in the mandible. Small tumours of tive the maxillary alveolus can be managed by transoral partial maxillectomy . More extensive tumours involving the floor of the maxillary sinus require wider access by a Weber–Fer gusson incision ( Figure 53.6 ). If the preoperative investigations demonstrate extension of the disease into the pterygoid space or the infratemporal fossa, the prognosis is poor as surgical clearance is di ffi cult or not possible. Tumour extending into the orbit requires simultaneous orbital exenteration or, in some instances, a combined neurosurgical resection. The various methods of maxillary reconstruction can be guided by the extent of resection and tissues involved. Reconstruction seeks to provide an oral seal and restore facial profile and tissue loss, while facilitating a means to achieve dental rehabilitation. Management of the neck In surgical terms, ‘management of the neck’ refers to a neck dissection – elective or therapeutic. In patients with clinical and/or radiographic evidence of cervical metastases, treat - ment of the neck in the form of a therapeutic neck dissection - is indicated (primary radiotherapy is less common). In patients with early-stage disease and in whom there is no clinical or radiographic evidence for cervical metastases, there is now strong evidence showing that patients w ho have an up-front or hich elective neck dissection have better overall and disease-specific - survival relative to patients who have a ‘watch-and-wait’ policy and a therapeutic neck dissection only when a metastasis 5 becomes apparent. SLNB can be utilised as a staging investi - gation to better guide the indications for a neck dissection in the setting of a small tumour where occult metastases may still be present. Over the last 100 years, neck dissections have evolved to achiev e a less radical extent as evidence emerged for the onco - 6 logical safety of more selective or nuanced procedures. For elective neck dissections, a selective neck dissection involving levels I–III of the neck is indicated for the management of 7 OCSCC. A neck dissection is performed not only to stage a disease and aid prognosis, but also for therapeutic purposes as well as informing the need for adjuvant therapy . Additionally , it pro - vides access to recipient vessels within the neck, which may be used in microvascular free tissue reconstruction.

Figure 53.5 Lip-split mandibulotomy. Figure 53.6 Weber–Fergusson approach.

Patient selection

As outlined previously , patients’ comorbidities and functional status as well as their social circumstances play a significant role - in their ability to tolerate surgery and rehabilitation. The early involvement of an MDT including physicians, anaesthetists, physiotherapists and dieticians is important particularly in high-risk patients in order to optimise their performance status - preoperatively . The ‘operability’ of a tumour is determined largely by its size and relationship to important anatomical structures of the head and neck. In the AJCC eighth edition TNM staging sys - tem T4b tumour s are those that may be unresectable owing to involvement of or proximity to the skull base, masticator space, ptery goid plates and/or the internal carotid artery . Once the decision has been made that surgery is appropriate, a few key decisions are to be made. These are as follows: /uni25CF airway management; /uni25CF access to the tumour; /uni25CF tumour resection; /uni25CF management of the neck; /uni25CF reconstruction. Airway management Airway management in patients undergoing surgery for OCSCC is largely centred on protecting the airway against acute embarrassment in the perioperative period. The available options are immediate postoperative extubation, overnight intubation/delayed extubation, submental intubation and tracheostomy . The choice of airway is a joint decision made between the anaesthetist and surgeon, and is influenced heavily by the ability to re-establish a patient’s airway quickly should a life-threatening event occur. Immediate postoperative extuba tion is generally reserved for smaller well-lateralised tumours in uncomplicated patients who may not require reconstruction. In selected patients, overnight intubation is considered when tracheostomy is unlikely yet can still be sited on postopera day 1 if warranted; this approach is burdensome on resources given the higher level of care for the first night, but it reduces length of stay via a quicker restoration of speech and swallow . A low threshold for placing a tracheostomy is appropriate in patients having a bilateral neck dissection or previous neck dissection; large resection with reconstruction; and in patients with a di ffi cult airway . Consideration should also be given to placing a tracheostomy in patients having a segmental mandibular resection; lateralised resections involving the floor of mouth and reconstruction; as well as previously irradiated patients. Access surgery The goal in surgical management of OCSCC is to remove the tumour with an adequate margin circumferentially . While most tumours can be removed via a transoral approach, some cannot be resected safely without an access procedure. These might include large maxillary tumours, posteriorly located tumours and tongue base tumours, or patients who have previ ously had surgery and/or radiotherapy . The most commonly used access procedures include the lip-split mandibulotomy (LSM) ( Figure 53.5 ), the mandibular lingual release, the visor flap and the Weber–Fergusson approach ( Figure 53.6 ), w provides excellent access to the maxilla and, if extended infra orbitally , to the periorbital area. Lip-split mandibulotomy This is the most commonly used access procedure and provides excellent access to the posterior oral cavity , tongue base and oropharynx. It involves making an osteotomy in the mandible in order to ‘swing’ it laterally , thereby facilitating access. Care must be taken to ensure that the lingual mucosa does not tear in an uncontrolled fashion towards the tumour resection margin. Sir William Fergusson , 1808–1877, Scottish surgeon, described and published a modification of the original Weber incision to access the midface. The gold standard in OCSCC is resection with a 1-cm clinical margin circumferentially , vital structures permitting. Mandibular resection Decisions regarding management of the mandible when tumour lies close to, abuts or invades the bone are critical. If there is evidence of infiltrative bone invasion, either segmental or rim resection of the involved mandible is required. Segmental resection involves removing the full height of the invaded section of the mandible such that there is loss of continuity of the lower border. Rim resection or ‘marginal mandibulectomy’ inv olves removing a partial thickness of mandible such that continuity of the lower border remains. A rim resection is sometimes performed when a tumour lies close to but does not definitively invade the mandible, in order to achieve a satisfactory soft-tissue margin. Maxillary resection - Owing to anatomical di ff erences such as thinner bone, the presence of sinuses, tightly adherent palatal mucosa and prox - imity to the orbit and skull base, maxillary resection consid - erations di ff er from those in the mandible. Small tumours of tive the maxillary alveolus can be managed by transoral partial maxillectomy . More extensive tumours involving the floor of the maxillary sinus require wider access by a Weber–Fer gusson incision ( Figure 53.6 ). If the preoperative investigations demonstrate extension of the disease into the pterygoid space or the infratemporal fossa, the prognosis is poor as surgical clearance is di ffi cult or not possible. Tumour extending into the orbit requires simultaneous orbital exenteration or, in some instances, a combined neurosurgical resection. The various methods of maxillary reconstruction can be guided by the extent of resection and tissues involved. Reconstruction seeks to provide an oral seal and restore facial profile and tissue loss, while facilitating a means to achieve dental rehabilitation. Management of the neck In surgical terms, ‘management of the neck’ refers to a neck dissection – elective or therapeutic. In patients with clinical and/or radiographic evidence of cervical metastases, treat - ment of the neck in the form of a therapeutic neck dissection - is indicated (primary radiotherapy is less common). In patients with early-stage disease and in whom there is no clinical or radiographic evidence for cervical metastases, there is now strong evidence showing that patients w ho have an up-front or hich elective neck dissection have better overall and disease-specific - survival relative to patients who have a ‘watch-and-wait’ policy and a therapeutic neck dissection only when a metastasis 5 becomes apparent. SLNB can be utilised as a staging investi - gation to better guide the indications for a neck dissection in the setting of a small tumour where occult metastases may still be present. Over the last 100 years, neck dissections have evolved to achiev e a less radical extent as evidence emerged for the onco - 6 logical safety of more selective or nuanced procedures. For elective neck dissections, a selective neck dissection involving levels I–III of the neck is indicated for the management of 7 OCSCC. A neck dissection is performed not only to stage a disease and aid prognosis, but also for therapeutic purposes as well as informing the need for adjuvant therapy . Additionally , it pro - vides access to recipient vessels within the neck, which may be used in microvascular free tissue reconstruction.

Figure 53.5 Lip-split mandibulotomy. Figure 53.6 Weber–Fergusson approach.