What Is Transoral Surgery and Who Qualifies for It?

Transoral surgery refers to any procedure performed through the mouth rather than through external incisions in the skin. What began decades ago as simple biopsies and laser treatments of throat lesions has expanded into a family of techniques that now treat everything from throat and laryngeal cancers to acid reflux, thyroid tumors, and spinal deformities. The shared principle is access through a natural opening, which often means no visible scars, shorter hospital stays, and a faster return to eating and speaking. But the specific technique, the tools involved, and what the evidence shows vary widely depending on what is being treated.

Transoral Robotic Surgery for Oropharyngeal Cancer

The highest-profile use of transoral surgery today is transoral robotic surgery, or TORS, for cancers of the oropharynx, the region that includes the base of the tongue, the tonsils, and the soft palate. A surgeon sits at a console and controls miniaturized robotic instruments and a high-definition camera threaded through the patient’s open mouth. The robot’s wristed instruments can articulate in ways a human hand cannot within such a confined space, allowing tumor removal with precise margins while preserving surrounding tissue. This approach grew rapidly after the mid-2000s, driven largely by the rise of HPV-associated oropharyngeal cancers, which tend to occur in younger, otherwise healthy patients who stand to benefit from treatments that minimize long-term side effects.

A recent systematic review and meta-analysis pooling data from multiple TORS cohorts found five-year overall survival of about 90% in patients with HPV-positive oropharyngeal cancer, compared with roughly 73% in HPV-negative patients. Local recurrence rates were low in the HPV-positive group, around 2%, with distant metastasis at about 5.6%.¹ Individual center reports are consistent with those numbers. One Australian cohort reported five-year disease-specific survival of about 94% and overall survival around 93%.² A separate series found five-year overall survival of 91%, with all patients who died of their disease having developed distant metastasis rather than local failure.³ The consistent theme across studies is that TORS achieves strong local control, meaning the tumor rarely comes back at the original site, but distant spread remains the main mode of failure when the disease does recur.

Swallowing, Feeding Tubes, and Quality of Life After TORS

Survival numbers only tell part of the story. For patients with throat cancer, the ability to eat, drink, and speak normally after treatment matters enormously. One of the primary arguments for TORS over radiation-based treatment is that it may preserve swallowing function better in the long run, though the picture is not as simple as one approach being universally superior.

A meta-analysis comparing TORS with radiation or chemoradiation found that TORS patients were less likely to still have a feeding tube at six and twelve months after treatment. However, on a validated swallowing questionnaire at twelve months, the TORS group actually scored somewhat worse than the radiation group.⁴ That seeming contradiction likely reflects the fact that many TORS patients also receive adjuvant radiation afterward, meaning they get surgery plus some radiation, while radiation-only patients may have different patterns of tissue damage. A study comparing TORS with primary radiation found that at one year, swallowing function scores were better maintained in the TORS group, and feeding tube dependence was higher in the radiation group.⁵ The takeaway for patients is that TORS generally leads to lower rates of long-term tube feeding, but swallowing outcomes depend heavily on whether additional treatment is needed after surgery and on the size and location of the original tumor.

Using Surgery to Reduce Radiation Doses

Perhaps the most compelling argument for TORS in HPV-positive oropharyngeal cancer is not that surgery replaces radiation but that it allows doctors to safely reduce how much radiation a patient gets afterward. This concept is called treatment de-escalation. The idea is straightforward: by removing the tumor surgically, a pathologist can examine the specimen under a microscope and determine exactly how aggressive the cancer was. Patients whose pathology looks favorable can receive lower doses of radiation, or in some cases skip radiation entirely, reducing the risk of long-term side effects like chronic dry mouth, difficulty swallowing, and jawbone damage.

The Sinai Robotic Surgery (SIRS) trial tested exactly this. Patients with early-stage HPV-positive oropharyngeal cancer underwent TORS, then were sorted into risk groups based on what the pathologist found. The lowest-risk group received no additional treatment at all. An intermediate group received reduced-dose radiation. A higher-risk group received reduced-dose chemoradiation. Long-term follow-up showed that this de-escalation strategy maintained survival while reducing the harmful side effects of full-dose treatment.⁶ The trial’s investigators emphasized that obtaining actual pathologic information, rather than relying on imaging alone, was central to safely tailoring each patient’s post-surgical plan.⁷ This is a meaningful advantage that radiation-first approaches cannot easily replicate, because without a surgical specimen there is no pathology to guide de-escalation.

Transoral Laser Microsurgery for Laryngeal Cancer

A related but distinct technique is transoral laser microsurgery, or TLM, which uses a CO₂ laser threaded through a laryngoscope to vaporize or excise early-stage cancers of the vocal cords. TLM has been used for decades and remains a first-line option for early glottic (voice box) cancers, particularly small tumors confined to one vocal cord. A review of over 400 patients with the earliest-stage glottic cancer treated by TLM reported five-year local control of about 87%, disease-specific survival of 98%, and larynx preservation of over 97%.⁸ Smaller series have reported disease-free survival as high as 97% and overall survival of 100% in selected patients.⁹ Recurrence rates tend to be higher when tumors involve the anterior commissure, the point where the two vocal cords meet at the front of the larynx.¹⁰

The major appeal of TLM over radiation for early glottic cancer is that it can be performed as a same-day procedure, avoids weeks of daily radiation treatments, and can be repeated if a small recurrence develops. The trade-off, especially for patients, is what it does to the voice.

Voice Quality After Laser Cordectomy

How much voice change a patient experiences after TLM depends almost entirely on how much tissue is removed. Cordectomies are graded by type: the smallest (type I and II) shave only the surface layers of the vocal cord, while larger ones (type IV through VI) remove deeper muscle and sometimes extend beyond one cord. A systematic review of voice outcomes found that patients who underwent type I or II cordectomy had significantly better voice quality than those who had type III, IV, or V procedures, across both self-reported questionnaires and objective acoustic measurements.¹¹

A prospective study tracking patients over twelve months confirmed this pattern. Those with type I to III cordectomies showed progressive improvement in voice quality scores and acoustic parameters over the first year. By twelve months, breathiness, roughness, and overall voice handicap scores had all improved from their pre-treatment baseline. Patients with type IV to VI cordectomies, on the other hand, experienced some subjective improvement in their self-reported voice handicap but had persistent worsening of maximum phonation time, meaning they could not sustain a note as long as before surgery.¹² A comparative study of type I versus type II cordectomies specifically found that type I patients improved more quickly and more completely, with measurable voice gains at three months that took six months to appear in type II patients.¹³ For patients weighing TLM against radiation, this means the expected voice outcome is closely tied to the depth and extent of the resection the surgeon plans.

Transoral Thyroidectomy

Transoral surgery has also reached the thyroid gland. The transoral endoscopic thyroidectomy vestibular approach, or TOETVA, accesses the thyroid through three small incisions hidden inside the lower lip. The surgeon inflates a working space under the skin of the neck using carbon dioxide gas and removes the thyroid or thyroid nodules with endoscopic instruments. The primary advantage is cosmetic: there is no visible neck scar, which matters considerably to patients who would otherwise have a prominent incision across the lower neck.

A meta-analysis comparing TOETVA with another scarless approach that uses incisions around the areola found that the transoral route had slightly less blood loss and produced higher patient satisfaction with cosmetic results, though it took about 17 minutes longer on average.¹⁴ The transoral approach also yielded a higher number of lymph nodes removed during central neck dissection, which is relevant for cancer staging.

The unique complication of TOETVA involves the mental nerve, which runs along the jawbone and provides sensation to the lower lip and chin. Because the surgical instruments pass right over this nerve, temporary numbness of the lower lip is common. In a large two-center study of nearly 300 procedures, transient numbness was reported in about 81% of patients, though permanent numbness occurred in only about 2.4%.¹⁵ A smaller series from a center early in its experience reported permanent mental nerve damage in 15% of patients, underscoring the importance of surgeon volume and training.¹⁶ Other complications familiar from conventional thyroidectomy, such as hoarseness from recurrent laryngeal nerve injury and low calcium from parathyroid damage, occur at rates similar to traditional surgery. One experienced center reported temporary hoarseness in 4% and temporary low calcium in about 18%, with no permanent cases of either.¹⁷

Transoral Treatment for Acid Reflux

On the gastrointestinal side, transoral incisionless fundoplication, or TIF, offers a middle ground between medications and traditional anti-reflux surgery for people with gastroesophageal reflux disease. A flexible device is passed through the mouth and down into the stomach, where it creates a partial wrap of the stomach around the lower esophagus, reinforcing the valve that is supposed to prevent acid from flowing upward. The entire procedure happens through the mouth with no abdominal incisions.

In a randomized trial, TIF eliminated troublesome regurgitation in 97% of patients at six months, compared with 50% of those who stayed on proton pump inhibitors (PPIs). About 90% of TIF patients were off PPIs entirely at that point.¹⁸ Another randomized trial confirmed that GERD symptoms improved more after TIF than with continued PPI therapy, with quality-of-life benefits persisting at twelve months.¹⁹ An earlier study found that six months after TIF, over half of patients had stopped PPIs completely and another 22% had reduced their dose.²⁰

One comparison found that symptom resolution rates were similar among TIF, Nissen fundoplication, and Toupet fundoplication, with over 80% of patients in all three groups reporting symptoms less than once per month. TIF had shorter operative times and shorter hospital stays.²¹ However, a network meta-analysis found that while TIF had the highest probability of improving quality of life, Nissen fundoplication was more effective at normalizing esophageal acid exposure and had a lower probability of persistent esophagitis.²² A separate network meta-analysis found no significant differences between endoscopic and surgical approaches for esophagitis or PPI cessation, but noted that lower esophageal sphincter pressure was comparable between TIF and standard surgical fundoplication.²³ In practical terms, TIF works best for patients with moderate GERD who want to get off daily medications but do not have severe anatomic disruption like a large hiatal hernia, which usually still requires a conventional surgical repair.

Transoral Spine Surgery

At the far end of complexity, transoral approaches have long been used by neurosurgeons and spine surgeons to reach the craniovertebral junction, the area where the skull meets the uppermost vertebrae. Conditions like basilar invagination, where the top of the second cervical vertebra pushes upward into the skull base, cause compression of the brainstem and spinal cord. The transoral route provides the most direct path to the front of this junction, allowing surgeons to remove the offending bony process (an odontoidectomy) without navigating around the spinal cord from behind.²⁴

A recently described technique goes further, using a transoral approach not just to remove bone but to release and reposition the odontoid process, pushing it forward and out of the way. Patients who underwent this procedure showed significant improvements in neurological function scores and imaging measurements of brainstem compression.²⁵ The main concern with transoral spine surgery is wound healing and infection, because the surgical field sits in the mouth, which is inherently colonized by bacteria. In one cohort, superficial wound complications from the transoral approach occurred in about 18% of patients, though none became infected. Deep wound infections were rare and appeared primarily after the subsequent posterior stabilization stage.²⁶

Who Qualifies for Transoral Surgery

Not every patient can undergo a transoral procedure, even if their disease is otherwise appropriate. The fundamental constraint is access: the surgeon has to be able to see and reach the target through the mouth. For TORS and TLM, this means getting adequate exposure of the throat using rigid mouth retractors while the patient is under general anesthesia. Patients with limited mouth opening, a large tongue base, cervical spine stiffness, or a thick neck may have difficult or impossible exposure. One study found that restricted cervical extension (as measured on a simple lateral X-ray), prior radiation to the head and neck, and a high Mallampati class (the standard anesthesia assessment of how visible the back of the throat is) were all significant predictors of inadequate exposure.²⁷ A separate group developed a scoring system called the Pharyngoscore, incorporating Mallampati class, the distance between the upper and lower teeth, and neck circumference, to predict which patients would have difficult exposure during TORS.²⁸

Airway management adds another layer of complexity. Because the surgical instruments and the breathing tube both pass through the mouth, anesthesiologists and surgeons must coordinate carefully. In high-risk cases, such as patients with prior radiation or those undergoing large resections, a preventive tracheostomy may be performed to protect the airway from post-operative swelling or bleeding.²⁹

New Robotic Platforms and Technology

The original TORS procedures were performed with the multi-arm da Vinci Si and Xi systems, which were designed primarily for abdominal and pelvic surgery and adapted for head and neck use. A newer platform, the da Vinci single-port (SP) system, was designed with a single cannula through which a flexible camera and three articulating instruments are deployed. This is a better anatomic fit for the narrow confines of the mouth and throat. Early clinical experience showed that the SP system provides sufficient access and visualization for procedures including supraglottic laryngectomy, base-of-tongue surgery for sleep apnea, and removal of parapharyngeal space tumors.³⁰ One series of 63 patients who underwent robotic head and neck surgery using the SP system, through either a transoral or retroauricular approach, reported that all operations were completed successfully without significant complications. The system’s “cobra” endoscope configuration, where the camera can navigate independently of the instruments, was specifically noted as helpful for identifying nerves and blood vessels.³¹

Image guidance is another frontier. Researchers have developed systems that overlay preoperative CT or MRI data onto the live robotic video feed during surgery, highlighting tumor boundaries and critical structures like the carotid artery. In animal models, this augmented-reality approach significantly improved the accuracy of target localization compared with standard unguided surgery.³² Early clinical experience in human patients achieved registration accuracy of about 1 mm within the pharynx and larynx.³³

The Learning Curve and Training

Transoral robotic surgery requires a distinct skill set from open surgery or even conventional endoscopic work, and the learning curve is real. An analysis of multiple surgeons’ early TORS cases, using positive margin rates and operative time as benchmarks, found that the learning curve ranged from 15 to 40 cases depending on the individual surgeon, with most hitting an inflection point around 20 to 30 cases.³⁴ A scoping review found that estimates remain somewhat uncertain due to varying definitions of proficiency across studies, but generally placed the number at 20 to 50 cases for operative outcomes, with mastery of long-term oncologic results requiring higher volumes.³⁵

Access to the robot for training purposes is itself a barrier. Unlike open surgery, where trainees can gradually take on more of the operation under supervision, only one surgeon operates the robotic console at a time. Simulation-based training is emerging as a partial solution. A 3D-printed TORS simulator using artificial tissue showed construct validity, meaning it could distinguish experienced robotic surgeons from novices based on performance scores.³⁶ Virtual reality training modules for head and neck TORS have been slow to develop compared with modules for abdominal procedures, leaving most training still dependent on cadaver labs and proctored live cases.

Cost and Hospital Stay

Robotic equipment is expensive, and TORS has higher operating room costs than open surgery. But the total picture often favors TORS because of what happens after the operation. A systematic review of cost-effectiveness found that TORS was associated with fewer tracheotomies, less tube feeding, shorter hospital stays, and lower total costs than open surgical approaches. One included study found TORS patients stayed about 1.5 days less than open surgery patients and cost roughly $4,285 less per case. Another found that while the operating room cost was higher for TORS, the total cost was significantly lower because the hospital stay was about eight days shorter.³⁷ A narrative review of financial outcomes across multiple studies reached the same conclusion: TORS is broadly cost-effective for both treatment and diagnostic procedures in head and neck cancer.³⁸ The cost equation is less clear-cut when comparing TORS to radiation alone, because radiation costs are spread over weeks and vary enormously by region, insurance structure, and whether chemotherapy is added.