Transoral Robotic Surgery (TORS)
Fig.1.Tumour of base of tongue.
Fig.2. Carcinoma of tonsil.
Tumours in the throat, base of the tongue (Fig1), and tonsils (Fig.2) are difficult to reach through the mouth. Therefore, these have traditionally been removed through surgeries requiring a large neck incision and cutting of the lower jaw (Fig.3). These types of surgeries often require tracheostomy, long hospital stay, and may result in difficulty in swallowing and speaking. Therefore, chemoradiation had been the treatment of choice for throat cancer. However, the side effects of chemoradiation may permanently affect the long-term ability to speak, and eat normally. Open surgery was reserved for residual or recurrent tumours.
Fig.3. In open surgery, the lip is split in midline and the lower jaw (mandible) is divided to expose the tumour.
Fig.4. Surgeon's console.
Advances in surgical equipment have made it possible to reach these tumours through the mouth by using robotic technology. During transoral robotic surgery, surgeon sits at a remote control console (Fig.4) a short distance from the operating table. The mouth is kept open with special retractor. Three arms of the robot go through the open mouth armed with camera and two instruments (Fig.5). Using two special joystick-like instruments known as endowrist instruments, the surgeon guides very small tools at the ends of the robot arms to remove the cancer (Fig.6). Robot allows more-precise tremor-free movements in tiny spaces. The surgeon’s console displays a magnified, 3-D view of the surgical area that enables the surgeon to visualize the procedure in much greater detail. Tumours can be dissected free from surrounding tissue safely. The machine is not a true robot (it does not operate or move by itself), but is a “master slave” unit. This means the surgeon is in complete control throughout the procedure, and controls the instruments at all times.
Fig.5. Three arms of the robot go through the open mouth armed with camera and two instruments.
Fig.6. Using two special joystick-like instruments known as endowrist instruments, the surgeon guides very small tools at the ends of the robot arms to remove the cancer.
Patients with early stage tumours (T1 or T2) with limited lymph node involvement in the neck are suitable candidates for TORS. Approximately 20 to 30 percent of patients with oropharygeal (tonsils and tongue base) tumours may be considered ideal candidates for the procedure. Patients with certain tumours of the larynx and throat may also be candidates. Patients who smoke tobacco or have Human Papillomavirus (HPV) negative tumours are especially encouraged to receive surgical treatment for their cancer, as these cancers often do not respond as well to radiation and chemotherapy.
Compared with open surgical approaches, TORS offers the patient numerous potential benefits that include:
Avoidance of a jaw split approach.
Avoidance of tracheotomy.
Quicker return to normal speech and swallowing.
Significantly less pain.
Less blood loss.
Shorter hospital stay.
Minimization or elimination of need for chemoradiation therapy.
Contraindications for TORS:Jaw bone invasion.
Anticipated tongue base involvement requiring removal of more than 50%.
Presence of trismus (inability to open jaw easily).
Carotid artery involvement.
Fixation of tumour to prevertebral fascia (layer in front of spine).