The indications for video-assisted thyroidectomy with SLND generally included unilateral PTC with a primary tumor <4cm, no extrathyroidal extension, LNM <2 cm, no prior neck surgery or radiation, and no evidence of thyroiditis. Contraindications included distant metastases, LNM at level I or Va, or preoperative invasion of major neurovascular structures, trachea, or esophagus (32, 35). Xu et al. also excluded patients who had previous neck surgery or radiation and bilateral cervical LNM (37).

Among studies, the mean LN yield was 25-41, except in two studies that had a much lower yield of 8.3 (range 3-21) and 8.5 (range 8-9) (30–38). Mean operative time for VASLND alone was 46-60 minutes, but when included with thyroidectomy and CND, mean operative times were 198-220 minutes (30–34, 37). In Zhang et al, hospital length of stay (LOS) were similar between groups but the operative times were longer in the VASLND, 198.8±19.6 min vs 172.3±28.0 min (35). In 2 other studies, LOS was shorter in the VASLND by 2 days (33, 34).

Among studies with at least 12 months of follow-up, there were no reported recurrences, sTg levels were low or undetectable, and there were no differences in postoperative complications between groups, including transient hypocalcemia or hoarseness, Horner’s, seroma, hematoma, wound infections, or chyle leak (32–36). There were no cases of permanent RLN injury or hypocalcemia in the studies. Zhang et al’s group reported one serious complication comprising an injury to the trapezius branch of the spinal accessory nerve that resolved after 18 months (33).

All patients in the VASLND groups were satisfied with their cosmetic results (32, 34, 35). In a study by Zhang et al, the cosmetic outcomes were evaluated by a numerical and verbal response scales, evaluated in both the VASLND group (n=54) and transcervical group (n=38) at 1 year after surgery. Both scale scores were better in the minimally invasive group, which was statistically significant (35). In another study by Zhang et al, these results remained significant (33).

The biggest advantage to this approach is avoidance of a long collar or L-shaped incision with a better cosmetic outcome and less tissue trauma. However, the tradeoff is longer operative times. Despite longer anesthesia, this approach leads to a quicker recovery time with comparable oncologic outcome (33). Zhang et al. argues that dissecting level II, particularly IIb, is easier endoscopically than transcervical; however, the procedure requires around 40 cases to become facile (33). In contrast, level I and V can be challenging to resect (32). An additional advantage to this approach is that it doesn’t require special instrumentation - although the use of plastic surgery or otolaryngology instruments may occur and in China, the use of special working space retractors and suction retractor has been described (35).

In Lin et al, inclusion criteria for thyroidectomy, CND, and LND using a video-assisted anterior chest approach were well differentiated PTC, tumors <3cm, lack of extrathyroidal extension, suspected clinically positive level II-IV LNM with LN <2cm in size (40). Kitagawa et al. was more stringent on a primary tumor size <1cm, although two patients in their sample were between 1-2cm (39). Patients with suspected level I or V LNM were excluded, as were those with a prior neck surgery or radiation, suspected perinodal infiltration of LNM, or distant metastases (40).

Table 2 summarizes the 2 studies on this approach. In Lin et al, the only significant difference in outcomes between groups was a longer operative time in the ACA group (mean 135 min vs 108 in transcervical group) and lower intraoperative blood loss (60 ml vs 100 ml in transcervical group) (40). Only Lin et al. noted the LN yield, which was 16-21 and similar to the transcervical group. Mean follow up time was 48 months for the ACA group and 35 months for the transcervical group. There was no remnant thyroid tissue on imaging, mean serum thyroglobulin (sTg) levels were <1ng/mL at 6 months postoperatively in both groups, and there was no recurrence in the follow up periods. Importantly, the functional outcomes (voice swallowing, arm abduction, and neck impairment) were not different between groups and cosmetic assessment scores demonstrated ACA patients were more satisfied with their results (40). The authors also noted that while the operative time was longer for the ACA group, this decreased over time as they became more facile at the procedure. The only post operative complications were transient hypoparathyroidism, 1 case in the ACA group and 2 in the transcervical group, all of which resolved within 2 weeks. In Kitagawa’s cohort, there was one intraoperative anterior jugular vein injury during the subplatysmal dissection (39). There were no RLN injuries or post operative hemorrhage in either study.

The advantages of this approach are a larger working space and elimination of an anterior neck scar compared to the ANA and less flap dissection than remote access techniques (such as transaxillary or breast). Further, total thyroidectomy is possible via this approach. With the combination of the lateral neck incision, level II can be synergistically dissected with the anterior chest incision, whereas in the transoral approach, level II is very difficult to access. An additional advantage to this gasless technique is no CO² insufflation and potential complications that accompany it. Limitations to this approach include difficulty with dissection of the contralateral LN in the tracheoesophageal groove and a relatively large anterior chest scar (40).

Inclusion criteria varied slightly, but the indications for the anterior chest/breast approach generally included patients with differentiated thyroid cancer (DTC) with a primary tumor less than between 2-4cm (depending on the study), suspected or confirmed lateral LNM, LNM diameter <2cm, and a cosmetic demand. Contraindications were previous neck surgery or radiation, distant metastases, level I or V disease (except in the studies that included Vb), fixed or fused LNM, or surrounding tissue invasion (i.e., trachea, esophagus, IJV, RLN). In Wang et al, the authors excluded recurrent disease. Guo et al. excluded patients >60 years-old and Yan et al. >50 years-old (42–44).

Over all studies, mean operative times for endoscopic subtotal and total thyroidectomy, CND, and LND ranged from 235 min to 338.2 min ( Table 3 ). These were significantly longer than transcervical groups by a mean difference of 53-99 min (43, 45). In two studies that reported it, LOS was similar across groups (43, 45). Mean LN yield ranged from 18.3 to 35.5, the upper end of the range likely due to the addition of level Vb.

Only 3 studies noted the mean follow up time, ranging from 5.6 to 24 months. Serum thyroglobulin (sTg) was only noted in one study and was low in the majority of patients (44). Three patients (0.97%) had local recurrence (44, 45) (75). There was no statistical difference in the LN yield between groups or post operative complications. In the studies that compared operative times, they found the EALND group to be longer but they had shorter length of hospital stay (LOS) (43, 45). Further, the EALND group had less neck discomfort and better cosmetic scores, like other studies (43, 75).

Among the comparative studies, there were no other significant differences in complications rates between the ABA and transcervical groups, with the exception of Yan et al’s rate of IJV rupture (43, 45). They found IJV rupture was significantly higher in the ABA group than transcervical, 12.26% (n=19/155) vs 2.94% (n=3/102), p<0.01 (45). The authors hypothesized multiple reasons for the increased rate of IJV injury, including accidental clamping of the vessel during dissection, more wall tearing due to no direct touch with the vessels, and limited working space and noted that all were repaired endoscopically with no conversions to open in their 155 cases (45). Across studies, there were 268 patients and only 1 developed permanent hypoparathyroidism (0.37%), 17 temporary hypocalcemia (6.34%), 12 temporary RLN palsy (4.48%), 4 accessory nerve injuries (1.49%), 2 wound infections (0.75%), 24 IJV or large blood vessel injury (8.96%), 7 chyle leaks (2.61%), 1 Horner’s syndrome (0.37%), 1 chest wall ecchymosis (0.37%), and 1 skin burn (0.37%) (41–46). One hypoglossal nerve injury (0.37%) and 7 cervical plexus injuries (2.61%) were additionally reported, all in the same study (46).

The major advantage of this approach is the improved cosmetic results compared to transcervical or video-assisted approaches as this technique circumvents an anterior neck scar. It is less expensive than robotic approaches (43, 45). Similar to the video-assisted infraclavicular approach, Wang et al. state that dissection of level IIb was easier via ABA compared to the transcervical approach, and the symmetric view makes a total thyroidectomy easier than a unilateral approach, such as transaxillary or retroauricular (44). Disadvantages include a steep learning curve, the need for careful patient selection, expert knowledge of the anatomy to avoid complications, and a longer operative time compared to the conventional approach (43, 45). There may also be an inadvertent blind spot due to the clavicle, making level IV (and VI) dissection difficult via this approach. Furthermore, if there are suspected LNM in level I or V, authors note that necessitates a different approach or the addition of a neck incision (43). One concern about endoscopic techniques that utilize CO₂ insufflation is the potential for tumor rupture and spillage via the “chimney effect” (41, 76). Kim et al. published a case report of tumor recurrence in the subcutaneous tunnel and operative bed after ABA but did note the presence of a capsular tear intraoperatively (76). This was the only report of track recurrence that was identified, but it should be kept in mind in the event of intraoperative tumor rupture. Lastly, while the LOS did not differ between groups in these studies, that may be less generalizable in countries where the LOS after transcervical LND are shorter than in Asian countries and different health systems (69).

Indications for endoscopic transoral thyroidectomy and LND were unilateral PTC with primary tumor <2cm. Tan et al. also limited their study to lobectomies (24). Additional inclusion criteria were no capsular or surrounding structure invasion, suspected/confirmed LNM in level III or IV only, no thyroiditis, and strong cosmetic demand. Contraindications were previous neck surgery or radiation, distant metastases, fused or fixed nodes, and BMI >30 (24). Higher BMI was a contraindication due to the technical challenges of creating skin flaps in higher BMI patients.

In Tan et al’s cohort, the mean LOS was 6.8 ± 1.8 days with a mean operative time of 146 ± 18.7 minutes compared to Ngo et al’s operative time of 170 minutes. The LN yield was relatively low in both studies, with 10.9 (range 6-16) for level III-IV and 8 LN in the case report despite Ngo et al’s addition of level II. Mean follow up was 24.3 months, and there was no residual disease or recurrences on follow up imaging (24). One patient (5.00%) developed transient RLN palsy, which recovered within a month and a half (24). Two patients (10.00%) developed seromas, with resolution after drainage at two weeks postoperative.

Advantages to this natural orifice approach include the avoidance of a neck scar. It also has a smaller dissection tract to the neck and remains minimally invasive compared to other remote access techniques that require a large dissection area, such as anterior chest/breast, axillary, and bilateral axillo-breast approaches. It also provides a symmetric view, allowing for total thyroidectomy and CND. Additionally, while this technique can be performed robotically, costs are lower with the endoscopic technique using laparoscopic instruments. When comparing the mean operative times of this approach to other remote access techniques, transoral are shorter, albeit with longer operative times compared to transcervical LND. A disadvantage is the challenge of dissecting level II completely, and level V is also difficult to access due to lateral border of SCM, which calls into question its oncologic safety (18, 69). There are also the risks of mental nerve injury, skin trauma/burns, and as with any laparoscopic surgery using insufflation, CO₂ embolism associated with this approach (47). Lastly, one disadvantage to all transoral procedures is the potential to introduce oral bacteria into the neck, necessitating prophylactic antibiotics in many institutions (21).

General indications for BTOA were PTC with no severe invasion, confirmed LNM with largest diameter of <2 cm, and a strong cosmetic demand. Primary tumor size cutoff varied but was <4 cm in two studies, while Wang et al. had a more stringent size limit of < 2cm. Contraindications included prior neck surgery or radiation, metastases to level I or V, fused or fixed LNM, invasion of surrounding tissue (i.e., trachea, esophagus, RLN), distant metastases, oral abscess, uncontrolled hyperthyroidism, or thyroiditis. Chen et al. also excluded patients with BMI >40kg/m² (18).

Mean post operative LOS was specified in 2 studies and was 4.9-5.8 days for 49 patients (18, 52). Mean operative times ranged from 256.0 to 362.1, with an outlier of 437 minutes for the case report by Wang et al. ( Table 5 ). Mean LN yield appears to be slightly higher by this approach than ABA alone and much higher than transoral alone, with a mean LN yield for level II-IV between 27.1-36.6 nodes. In the case report by Wang et al, they harvested 66 LN but do not specify levels nor describe their technique (44). There were no formal assessments of cosmetic outcomes in these studies, but the authors do note that all patients were satisfied with the cosmetic results in all cases (18, 50, 52).

Overall complications included transient hypocalcemia (n=17/63, 26.98%) and transient RLN palsy (n=2/63, 3.17%), but no cases of permanent RLN injury, hypocalcemia, hematoma, seroma, or wound infections. In Chen et al’s case series of 24 patients, there was one case of chyle leak and IJV injury (18). In Wang et al’s comparison study, there was one case of Horner’s syndrome and 1 case of accessory nerve injury in the 7-step group (52). Transient chin or mandibular numbness also occurred in 4/63 patients (6.35%) but generally resolved within 2 weeks (50, 51).

An advantage to this approach is the lack of an anterior neck scar, similar to both the ABA and transoral approaches. The additional level IV transoral dissection did yield more LN than the breast approach alone, which were positive in 3/13 patients (23.1%) (50). While there were longer operative times compared to open cases in the ABA comparative studies, the addition of further dissection transorally does not measurably increase mean operative times compared to the ABA alone ( Table 3 ). Again, a disadvantage of the transoral approach is the potential to introduce oral flora into the neck, often requiring prophylactic antibiotics.

Indications for TAA LND generally included DTC with a primary tumor <4 cm, with minimal invasion to the anterior thyroid capsule and strap muscles, clinically positive small lateral LNM, and a strong patient preference/cosmetic demand. Contraindications were tumor invasion to surrounding structures (i.e., trachea, esophagus, RLN), multilevel LNM, perinodal invasion, prior neck surgery or radiation, a pathologic neck or shoulder condition, recurrent disease, or distant metastases (54–62).

Mean operative times for all studies ranged from 271.8 to 334.5 minutes ( Table 6 ). In half the comparative studies, TAA was a significantly longer operation than an open transcervical thyroidectomy and LND, while the other studies found no significant difference in mean operative time (55–57, 60). Because larger body habitus has been suggested to make this approach more challenging, one large case series stratified operative times and complication rates by BMI less than or more than 25kg/m² and found no significant difference between groups (62, 78). When they performed their sub-analysis with a BMI of 30kg/m², there again were no differences between groups (62). Mean LN harvested via this approach ranged from 16-36.02, with >95% (1058/1111) patients having a mean LN yield of more than 30. Mean LOS was variable between South Korean studies, ranging 3.92 to 9.18 days. Kang et al. found that their robotic group had a significantly shorter hospital LOS compared to transcervical, 6.0 ± 2.5 vs 8.0 ± 5.2, p=0.008, respectively (55). In the North American study, mean LOS was 1.8 days (60). The longer length of stay across South Korean groups, compared to those in other countries, is attributed to health system differences, wherein South Korea medical insurance covers longer hospitalizations for cancer patients (57, 69). Two studies had a relatively short mean follow up times of 7 and 8.4 months, while the rest were 12 to 38 months.

Three studies had recurrences (58, 59, 62). In each of Song et al’s studies, there was one recurrence detected by ultrasound at level III, 18 months after surgery, despite no uptake on whole body iodine scans after RAI ablation and undetectable postoperative serum thyroglobulin (58, 59). Of the 5/500 recurrences in Kim et al’s series, one was in the contralateral neck, three were in the central neck, and one was in the central and contralateral neck (62).

In Lee et al, multiple quality of life parameters were also assessed, including neck and shoulder function (57). At 6 months after surgery, the transcervical group had a higher rate of swallowing impairment but showed no difference between groups in neck dissection impairment index, arm abduction test, or voice handicap index. The authors posited that this difference in swallowing impairment could be because the strap muscles are not divided at midline in TAA, perhaps resulting in less adhesions to the subcutaneous tissues. Questionnaires were used to assess pain at the surgical scar and cosmetic outcome scores. There were no differences in scar pain, but the cosmetic satisfaction for TAA was significantly higher due to the decreased visibility of scars (57). Similarly, Song et al. also assessed postoperative pain, paresthesia, and cosmetic satisfaction (59). They also found that the TAA group had higher anterior chest pain and paresthesia up to 1 month after surgery, but this difference was no longer significant by 3 months postoperatively. However, the higher cosmetic satisfaction scores of TAA remained significant throughout the follow up period.

Of the studies that reported complications (n=764), the most common complication was transient hypocalcemia, occurring in 271 patients (35.47%), followed by chyle leaks in 43cases (5.63%), 30 transient RLN palsies (3.93%), and 33 seromas (4.32%) (54–60, 62, 79). When looking at individual studies, the rates of transient hypocalcemia ranged from 30.40% to 51.52%. There were 20/500 cases (4.00%) of permanent hypocalcemia (defined as lasting more than 6 months) in the large case series by Kang et al, as well as 2 cases of Horner’s syndrome and 1 vagus nerve injury. Two studies had a total of 3 wound infections (57, 62).

Advantages to robotic surgery over endoscopic or a transcervical open procedure include better visualization, improved freedom of movement, and elimination of tremors. The available studies show comparable oncologic outcomes, with less swallowing symptoms, and the cosmetic satisfaction appears to be greater for TAA compared to a conventional approach, as discussed above (55, 57, 59). This approach being gasless, without the risk of complications related to CO₂ insufflation is another advantage. Kim et al. also claim that there is decreased risk of traction injury to the RLN via this approach due to the oblique view (62).

A main concern regarding this technique is the risk of brachial plexus injuries from arm positioning. This can be mitigated by careful positioning, reducing traction on the brachial plexus by flexing the ipsilateral arm in a 90-degree position (21, 80). Further, injury to cervical plexus sensory nerves can lead to anterior chest paresthesia, which is commonly seen after TAA, although often temporary (21, 57). In Lee et al, the presence of paresthesia or hyperesthesia in the neck and anterior chest questionnaires demonstrated that changes in the anterior chest were significantly more common in the robotic group whereas the opposite was true in the neck, with the open group having a higher incidence of neck numbness (57). Additional concerns include possible injury to the thoracic outlet vessels, aerodigestive injuries, fibrosis, tract hemorrhage, tract recurrence, or adhesions to the IJV after thyroidectomy that make reoperation, by any approach, more difficult (80, 81). Due to the unilateral approach, if the patient requires a contralateral MRND, this is not feasible via this approach and would necessitate bilateral transaxillary incisions. Lastly, the increased operative time and costs associated with TAA may be prohibitive in many settings.

Indications for BABA included DTC with clinically suspicious or confirmed lateral LNM, and a cosmetic demand for the remote access technique. Contraindications generally included primary tumors >4cm, invasion into adjacent organs (i.e., trachea, esophagus, RLN), prior history of neck radiation or surgery, extranodal invasion, LNM that were fused or fixed or encased the common carotid or IJV, if the LNM were above the digastric muscle or below the clavicle, or distant metastases (63–65, 67–69).

Hospital LOS was 3.1 days to 6.5 days across studies ( Table 7 ). One study found shorter LOS in the BABA group (3.92 vs. 4.71 days, p=0.056) (69). Mean operative times were significantly longer in the BABA group (201-382.3 minutes), but comparable to other remote access techniques. The outlier in the group, with a mean operative time of 533 minutes, consisted of four cases, all of which were bilateral LND (67). Interestingly, when Choi et al. subdivided their mean operative time to exclude flap creation, they found the operative times for the actual procedure were comparable to a transcervical approach, 200.33 ± 26.86 vs 191.43 ± 60.43 minutes, p=0.523 (69). He et al. note that all 260 patients had sensory impairment of the anterior chest, nipples, or neck, but this resolved within 4-12 months (68). All patients were either satisfied or extremely satisfied with their cosmetic results (68). The mean LN yield was 17.9 to 36.5 across studies, save for one that included level VI in their totals. There were no differences in LN harvest between BABA and transcervical groups (66, 69). Stimulated sTG levels were similar after RAI ablation (63, 69). Mean follow up times were 15.9 to 27.3 months, and there was one (0.30%) recurrence at level IV, for which the patient had an open procedure to remove one metastatic LN (68).

Across studies, there were 360 patients who underwent BABA, with 19.17% (n=69) developing transient hypocalcemia (range 7.14-46.67%). There were fewer cases of transient hypocalcemia in the BABA group than open in one comparison study (16.7% vs 53.6% transcervical, p=0.041), but no differences in other complication rates (69). The second most common complication was transient RLN palsy (9/360, 2.50%), with 1 case of permanent RLN palsy (66). Four studies had a total of 5 chyle leaks (1.39%), all managed conservatively, and two studies had a case of Horner’s syndrome each (63–66, 68). In the case series of 260 patients, there were 3 (1.15%) seromas, a wound infection (0.38%), and a tracheal fistula caused by ultrasonic scalpel cauterization (0.38%) (68).

A multidirectional approach with a symmetric view is an advantage of this technique, similar to a transcervical approach. Because this anatomy is more familiar to surgeons, some claim this technique is easier to adapt to (65). It has been shown to have comparable safety and oncologic outcomes compared to transcervical thyroidectomy and LND (65, 84). Multiple authors note the benefit of a robotic magnified view, making identification and preservation of parathyroids, nerves, and lymphatics easier (63, 69). Choi et al. hypothesized that the shorter LOS in the BABA could be attributed to less postoperative pain and the lower incidence of transient hypocalcemia in their study (69). When comparing the cost of BABA and a conventional transcervical procedure, the robotic procedure was almost 3-4 times more expensive (63, 69). This, and the longer operative times, are disadvantages to robotic remote access techniques, but the cosmetic benefit may be a reasonable tradeoff, especially for younger patients whose quality of life is significantly impacted by a large neck scar. Choi et al. note that due to the inferior-to-superior view, level IV dissection is challenging via this approach and requires adequate binding of lower breasts to change the pivot point (69). The larger area of dissection may also be a deterrent to choosing this approach, given the sensory changes associated. Further, the use of CO₂ insufflation and possible complications, such as CO₂ embolism, is another consideration.

Indications for RAA include patients with DTC and LNM in the neck, no prior history of thyroid cancer, and no invasion of nearby structures. The contraindications were recurrence, extensive extrathyroidal spread or invasion of local structures, extranodal spread of LNM, and prior neck surgery or radiation (71).

Mean hospital LOS was 3.4 days in Brazil and 11 days in South Korea, which may speak to the health system differences more than morbidity of the surgery (70, 71). Mean operative times were 306.1 to 340 minutes, with the LND alone taking 153.1-251 min. Part of this increased time could be attributed to redocking the robotic arms for the LND, ipsilateral thyroidectomy, and contralateral thyroidectomy, respectively (70). Mean LN yield in the two series were 33.1 and 27.2, although the latter also included level VI (70, 71). All Byeon et al’s patients underwent RAI ablation and had low sTg at follow up (70). There was no evidence of recurrence in either study at mean follow up of 11.3-17.4 months.

Of the 19 patients total, there were 4 (21.05%) cases of transient hypocalcemia and 3 (15.79%) cases of transient RLN palsy, which all resolved by 3 months postoperative. There was 1 chyle leak in each series, one of which was managed conservatively and the other requiring reoperation. There was a total of 1 seroma, managed conservatively, and 1 wound infection. There were no cases of permanent hypocalcemia or RLN palsy. Lira et al. found their complication rates were comparable to MD Anderson Cancer Center’s published benchmarks for quality assessment in low acuity head and neck procedures (71).

When compared to other remote access techniques below the clavicles, this approach provides more direct access to the upper neck and requires a smaller area of dissection. As with other remote access techniques, patients avoid an anterior neck scar, with the cosmetic benefit being its biggest advantage. This approach can be done in higher BMI patients, and there no risk of brachial plexus or chest paresthesias, all of which are limitations to axillary approaches (21, 23). Because it is gasless, it avoids risks associated with insufflation. A limitation of this procedure is that most patients will experience hyperesthesia in the distribution of the greater auricular nerve which, while transient, can affect quality of life (23, 87). Another limitation is that performing a contralateral MRND is not possible from a unilateral approach and requires bilateral incisions, which may also be the case for contralateral lobectomy in some institutions, depending on surgeon comfort. Lastly, as with all robotic procedures, it is associated with increased cost.

Indications for TARA included PTC with clinical LNM, no prior treatment for thyroid cancer, no extranodal spread of the LNM on pre-operative imaging, and cosmetic demand. Contraindications were recurrence, suspected extracapsular spread of LNM, or distant metastases (73).

When comparing 22 TARA and 25 transcervical cases of total thyroidectomy, CND, and MRND (levels II-V), Kim et al. reported no conversions to open (73). Mean LOS was 9.2 days and not significantly different between groups. Mean operative times were longer in the TARA group compared to the transcervical open group, 209.4 ± 38.2 vs 143.1 ± 30.5 minutes respectively, p=0.000. The only significant difference between groups was found on scar satisfaction scores, which were on a 5-point scale. The mean scar satisfaction score for the TARA group was 3.9 ± 1.0 vs. 2.8 ± 1.0 for the open group, p=0.000. The mean LN yield was 33.14 and similar to the open group, even when subdividing by each level. Both groups had similar sTg levels, and during the follow up period of 15.9 months, there were no recurrences (73).

There were no significant differences in complication rates. In the TARA group there were 6 (27.27%) cases of transient hypocalcemia, 2 (9.09%) transient RLN palsy, 1 (4.54%) hematoma, 2 (9.09%) seroma, and 1 (4.54%) chyle leak (73). All complications were managed conservatively, and the cases of transient hypocalcemia was resolved within 2 months. There were 6 patients who experienced postoperative earlobe numbness.

This approach has the advantage of avoiding an anterior neck scar and superior cosmetic satisfaction scores compared to transcervical conventional LND. The benefits of robotic surgery in terms of visualization and dexterity remain. Access to the upper neck levels is an advantage over other remote access techniques such as TAA or transoral. Many remote access LNDs do not include Va and IIb, however this approach includes those levels under direct vision. When comparing TARA to RAA or even TAA alone, the large dissection flap eliminates the advantage of a less invasive procedure. Contralateral MRND is not possible by this approach without performing bilateral TARA, which is a limitation. Further, this procedure is 7 times more expensive than a transcervical procedure in South Korea, which may be financially prohibitive for many patients (73).

Indications for this approach included PTC with LNM in level II-V. Contraindications included a history of neck surgery or radiation, large fused LNM, extensive invasion of surrounding structures, recurrent disease, distant metastases, or extensive multi-level LNM (47, 49).

Mean operative time for the case series was 299 minutes for the transoral group and 431 minutes for the combined transoral and retroauricular approach. Thirteen patients underwent total thyroidectomy, CND, and SLND, while one patient had a lobectomy, CND, and SLND (49). One case was not completed via the transoral route but was converted to the retroauricular approach for uncontrolled IJV bleeding. The authors opted to convert to the gasless retroauricular approach rather than open transcervical due to strong patient preference to avoid a neck scar (49). The levels dissected varied ( Table 4 ) but the mean LN yield was 30.7, similar to the case report yield of 29. Of the 10 patients that only underwent LND via the transoral approach, the mean LN yield was 23, while it was 38.3 for the combined approach (n=4) (49). Mean follow up time was 14.5 months and there were no recurrences on imaging studies.

There were no complications in the case report but the follow up time is also not specified. In the case series, 3 patients (21.43%) had transient hypocalcemia. There was 1 (7.14%) case each of chyle leak and transient RLN palsy. Four (28.57%) seromas occurred that resolved with repeated aspiration. There were no cases of permanent nerve injuries, hypocalcemia, wound infection, or hematoma (49).

Compared to the endoscopic transoral studies, the LN yield appears to be higher with the robotic approach, 23.1 ± 10.6 vs 10.9 ± 2.8 in Tan et al’s case series (n=20) (24). The robot is more ergonomic for the surgeon, with a 3-dimensional view of the surgical field and 7 degrees of freedom in wrist movement. The authors claim this makes flap creation, as well as superior pole dissection easier (49). In these studies, they also have the benefit of a third operative arm to aid in retraction, although this does require a small incision in the axilla. The biggest disadvantage to this approach is the increased time under anesthesia and costs associated with increased operative time and the use of the robot. Also, level II dissection is challenging without the additional postauricular incision.