Research and publications
Hundreds of studies have been published on transoral thyroid and parathyroid surgery. These are the ones that best answer the questions patients ask, each with a one-line summary. Where a free full copy exists, we link to it.
1. Is it safe?
Pooling 15 studies with nearly 3,000 patients, transoral surgery took about an hour longer and had a higher chance of wound infection than standard neck-incision surgery, but temporary voice-nerve problems were not more common.
Zhou S, et al. Endocrine, 2023.
Combining 12 studies with about 3,000 patients, transoral and standard surgery had similar complication rates; the transoral operation took longer and the hospital stay was slightly longer.
Huo J, et al. Surg Laparosc Endosc Percutan Tech, 2023.
Across nine European hospitals, 391 transoral operations had low rates of lasting problems (0.5% permanent voice-nerve injury and no permanent low-calcium cases), and 3.3% were switched to standard surgery.
Arikan M, et al. World J Surg, 2023.
In 152 transoral operations at five hospitals in several countries, 2% were switched to open surgery and 2% had a lasting voice-nerve injury; the authors concluded it can be as safe as standard surgery in selected patients.
Fernandez Ranvier G, et al. J Laparoendosc Adv Surg Tech A, 2020.
In the first large North American report, 200 transoral operations at one U.S. academic center had about the same rate of major complications as 333 standard operations (1.5% vs 2.1%).
Russell JO, et al. World J Surg, 2021.
In 425 transoral operations in Thailand, compared with matched standard operations, complication rates were similar and first-day pain was lower, but the operation took about 20 minutes longer.
Anuwong A, et al. JAMA Surg, 2018.
2. Does it work as well, including for cancer?
Combining 28 studies with more than 8,000 patients with papillary thyroid cancer, transoral and open surgery removed similar numbers of lymph nodes and had similar cancer-return rates, though open surgery was shorter and had a shorter hospital stay.
Li P, Li K. Front Oncol, 2026.
In 177 matched patients with small (2 cm or less) papillary cancers, cancer outcomes were similar, but the transoral group had fewer central lymph nodes removed, longer surgery and hospital stays, and more injuries to the nerve that gives feeling to the chin.
Zhang X, et al. Ann Surg Oncol, 2025.
In 115 patients with early thyroid cancer followed for about 3 years after transoral endoscopic or robotic surgery, all were alive and 98% had an acceptable response to treatment.
Chen YH, et al. Surg Endosc, 2023.
In 78 matched pairs of patients with papillary cancers 1 to 3.5 cm, transoral and open surgery removed similar numbers of lymph nodes and were equally complete; transoral surgery took longer but gave better cosmetic results.
Liu Z, et al. Surgery, 2021.
3. What is recovery like, and how does it look afterward?
Pooling 57 studies with more than 9,000 patients, thyroid operations that avoid a front-of-neck incision gave better cosmetic results than standard surgery, with the transoral approach ranked near the top; quality-of-life results also favored them, but that evidence is limited.
Nguyen VC, et al. Head Neck, 2025.
Combining 11 studies with 1,291 patients, transoral surgery caused less pain on the first day after surgery, but overall pain during recovery was not clearly different from standard surgery.
Mirghani H, et al. Cureus, 2024.
About 3 years after surgery, 108 transoral patients and 129 standard-surgery patients in the U.S. reported similar quality of life, voice and swallowing, but transoral patients felt less self-conscious about their skin.
Nagururu NV, et al. Otolaryngol Head Neck Surg, 2024.
In 81 U.S. patients, scar and appearance scores were much better after transoral surgery than after surgery through a neck incision.
Chen LW, et al. Head Neck, 2020.
In a survey of more than 1,200 people in the U.S. and Israel, about 3 in 4 who had never had thyroid surgery said they would choose a scarless approach if its risks matched standard surgery.
Chen LW, et al. Head Neck, 2021.
In 70 patients, those who had transoral surgery reported better cosmetic results and satisfaction at every follow-up and better quality of life in several areas, though the operation took longer.
Kasemsiri P, et al. BMC Surg, 2020.
4. Who is a candidate?
Experts from six international thyroid and surgery societies agreed on 23 statements about choosing patients for scarless-in-the-neck thyroid and parathyroid surgery and doing it safely; they found results similar to open surgery with better cosmetic satisfaction, but longer operations.
Russell JO, et al. Thyroid, 2025.
Among 1,000 U.S. patients who had thyroid or parathyroid surgery, about 56% would have qualified for transoral surgery (76% of those with uncertain nodules, 29% of those with cancer); prior neck surgery was the most common reason someone did not qualify.
Grogan RH, et al. JAMA Netw Open, 2019.
This review describes who is usually a good candidate (for example, a thyroid 10 cm or smaller, a nodule 6 cm or smaller, or a small cancer 2 cm or less) and who usually is not (for example, prior neck surgery or radiation, or cancer in the lymph nodes or growing outside the thyroid).
Razavi CR, Russell JO. Ann Thyroid, 2017.
5. Parathyroid surgery
In 101 transoral parathyroid operations at hospitals around the world, 98% of patients had normal parathyroid hormone levels right after surgery, with one temporary voice-nerve injury and no permanent low-calcium cases.
Grogan RH, et al. Surg Endosc, 2022.
A review of 78 reported transoral parathyroid operations found a 96% success rate and complications in about 4%, but the authors noted that the evidence is still limited.
Entezami P, et al. Am J Otolaryngol, 2021.
At 11 hospitals in Turkey, 32 of 35 planned transoral parathyroid operations were finished this way; complications occurred in 19%, mostly minor, and there were no voice-nerve injuries.
Makay Ö, et al. Surg Endosc, 2022.
At one hospital, 20 transoral parathyroid operations took longer than 37 focused open operations, and neither group had voice-nerve or chin-nerve injuries.
Sabuncuoglu MZ, et al. Med Sci Monit, 2024.
In the first report of transoral parathyroid surgery, calcium levels returned to normal in all 12 patients, and one temporary voice-nerve injury healed within a month.
Sasanakietkul T, et al. Surg Endosc, 2017.
Want to see every study? Search all published research on transoral thyroid surgery on PubMed.