Sternohyoid and sternothyroid approach in reoperations for recurrent thyroid cancer: a comparative analysis

Introduction

Thyroid cancer (TC) is the most prevalent type of malignancy within the endocrine system, with its incidence rate continually rising in recent years, alongside persistently high recurrence rates (1). According to literature reports, the 10-year recurrence rate for differentiated thyroid carcinoma (DTC) post-surgery is approximately 10% to 30%, with a significant proportion of patients requiring reoperation (2,3). However, compared to initial surgeries, reoperations present increased technical challenges and intraoperative risks (4). Due to scar formation, obscured anatomical structures, and adhesion of critical nerves and blood vessels, reoperation for recurrent TC is complicated by difficulties in surgical field exposure, increased intraoperative bleeding, and a significantly higher incidence of postoperative complications such as recurrent laryngeal nerve injury (RLNI) and parathyroid gland injury (PGI) (5-7).

The standard cervical white line approach (SCWLA) involves incising the anterior cervical strap muscles—the sternohyoid and sternothyroid—to access the thyroid region, which is suitable for most initial thyroid surgeries (8,9). However, in reoperative procedures, this approach often becomes challenging due to pre-existing scar adhesions and tissue degeneration, leading to increased anatomical complexity and suboptimal surgical exposure. Consequently, this prolongs the operation time and heightens the risks of intraoperative bleeding and RLNI (10,11). Therefore, there is a clinical need to explore alternative surgical approaches that can circumvent scar tissue, enhance surgical field visibility, and improve procedural safety.

In recent years, the lateral intermuscular approach (LIA) has garnered increasing clinical attention as an alternative surgical route (12). This technique accesses the thyroid region through the natural gap between the sternohyoid and sternothyroid muscles, thereby avoiding scar adhesions in the midline and allowing for excellent exposure with a smaller incision, particularly suitable for unilateral thyroid lesions (13-15). A prospective randomized controlled trial by Sywak et al. compared the LIA to the SCWLA in initial thyroid surgeries, demonstrating that the LIA offers significant advantages in terms of surgical field exposure, postoperative pain, and complication management (16). Furthermore, previous studies have indicated that the LIA aids in protecting the recurrent laryngeal nerve (RLN) and parathyroid glands (PTG), thereby reducing the risk of postoperative complications (17).

Although the LIA has demonstrated certain advantages in initial thyroid surgeries, systematic research on its application in reoperations for recurrent TC remains scarce, with limited reports in both domestic and international literature (13). Given the complexity of scarring and anatomical challenges in recurrent surgeries, the LIA may potentially bypass areas of tissue disruption caused by previous operations, thereby providing a clearer surgical field. Preliminary retrospective analyses have suggested that the LIA might reduce bleeding, enhance surgical efficiency, and decrease the incidence of complications during reoperations (18).

This study is the first to systematically propose and evaluate the clinical utility of the LIA, situated between the sternohyoid and sternothyroid muscles, in reoperations for recurrent TC. Compared to the SCWLA, this method exploits the natural anatomical space between these strap muscles, allowing direct access to the target area with minimal trauma and reducing repeated interference with scarred tissue. Prior clinical data indicate that this approach markedly improves thyroid exposure and operative visualization, shortens operative and hospital duration, reduces intraoperative blood loss, and lowers postoperative complication rates (19-21).

This study aims to elucidate the advantages and safety of the LIA between sternohyoid and sternothyroid muscles in comparison to the conventional midline approach during reoperative surgery for recurrent TC. By analyzing clinical parameters such as operative duration, intraoperative bleeding, RLNI rate, and postoperative recovery time, this research seeks to provide a theoretical basis and practical guidance for optimizing surgical approaches in TC reoperation.

In summary, reoperation for recurrent TC presents both challenges and focal points in clinical surgical treatment. Existing studies indicate that the SCWLA has significant limitations, whereas LIA has demonstrated favorable outcomes and safety in initial surgeries (22). We hypothesize that applying the LIA in reoperations could potentially overcome the technical limitations of traditional approaches, thus emerging as a superior surgical pathway. We present this article in accordance with the STROBE reporting checklist (available at https://gs.amegroups.com/article/view/10.21037/gs-2025-393/rc).

Methods

General information

This single-center retrospective cohort study included 102 patients with recurrent TC who underwent reoperation at Taizhou Cancer Hospital between September 2013 and October 2018. Based on the surgical approach selected intraoperatively by the operating surgeon, patients were assigned to a SCWLA group and a LIA group, with 51 cases in each group. The SCWLA group underwent reoperation via the conventional anterior midline cervical approach, whereas the LIA group was reoperated through the intermuscular plane between the sternohyoid and sternothyroid muscles. Allocation was non-random, as depicted in the study flow chart (Figure 1).

Figure 1 Research flowchart. This retrospective cohort study included 102 patients who underwent reoperative surgery for recurrent TC between 2013 and 2018. LIA, lateral intermuscular approach; SCWLA, standard cervical white line approach; TC, thyroid cancer.

Inclusion criteria were as follows: (I) in all patients, the diagnosis of recurrent TC was confirmed by fine-needle aspiration (FNA) cytology and/or histopathology. Preoperative evaluation included high-resolution cervical ultrasonography, neck computed tomography, and relevant serological tests to assess tumour burden and cervical lymph node status and to guide surgical planning, rather than to establish the diagnosis; (II) initial surgery involved radical thyroidectomy with lymph node dissection, pathologically confirmed as TC postoperatively; (III) indication for reoperation included local recurrence of TC, central lymph node recurrence (IV) informed consent was obtained from patients and their families who voluntarily agreed to participate. Overall, DTC, including papillary and follicular carcinoma, accounted for the vast majority of cases, whereas a small number of patients with medullary or undifferentiated carcinoma were also included due to their similar indications for reoperation.

Exclusion criteria included: (I) presence of severe cardiac, hepatic, or renal dysfunction; (II) significant coagulation disorders; (III) severe mental illness that impedes treatment compliance and follow-up; (IV) permanent RLNI or permanent PGI post-first surgery, which could bias the assessment of new postoperative complications following reoperation; (V) recurrence or metastasis in lateral neck or contralateral neck lymph nodes unsuitable for unilateral approach surgery; or (VI) had thyroid carcinoma but did not undergo curative initial surgery for TC.

This study was approved by the Medical Ethics Committee of Taizhou Cancer Hospital (No. 2025-027). The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from all participants prior to enrollment.

Sample size calculation and evaluation

In this study, 130 patients initially met the criteria for reoperation due to recurrent TC. After applying inclusion and exclusion criteria, 28 patients were excluded, resulting in a final cohort of 102 patients.

The sample size estimation was based on the expected difference in the primary outcome measure, which is the incidence of temporary RLNI post-surgery. According to previous literature (23) and preliminary data from our center, the incidence of temporary RLNI in the SCWLA group is approximately 20%, which is expected to decrease to 5% with the LIA between the sternohyoid and sternothyroid muscles. With an α level of 0.05 (two-sided) and a power of 0.8, calculations using the formula for comparing two independent proportions indicated that each group required approximately 46 participants. Considering a potential 10% loss to follow-up or data attrition, the final sample size was set at 51 per group, with an actual enrollment of 102 participants, thus meeting the power requirements of the study.

Surgical procedures

Patients fasted for 8 hours before surgery. General anesthesia was induced with intravenous propofol, fentanyl, and cisatracurium, followed by oral endotracheal intubation and maintenance of mechanical ventilation. Each patient was placed in the supine position with the head extended and a shoulder roll to optimize exposure of the operative field. After standard skin preparation and draping, the incision was made along the original scar, followed by layered dissection of the skin, subcutaneous tissue, and platysma (Figure 2A,2B). The principal instruments included a 20-cm cervical retractor (domestic), a Medtronic NIM-Response 3.0 nerve monitoring system, a Storz cold light headlamp, a Valleylab FX8 electrosurgical unit, a Harmonic ACE+7 ultrasonic scalpel, and fine instruments such as suction tubes, hemostatic forceps, and ophthalmic scissors. This setup ensured a clear surgical field, precise manipulation, and maximal preservation of the RLN and PTG.

Figure 2 Illustration of surgical exposure via traditional median approach. (A-C) Intraoperative images demonstrate the original incision, layered dissection, and surgical field, showing evident scarring and adhesions. (D) Schematic of the median approach surgical procedure: (I) preoperative incision marking; (II) skin incision and fascial dissection; (III) retraction of the sternohyoid and sternothyroid muscles; (IV) exposure of the thyroid remnant and RLN. RLN, recurrent laryngeal nerve.

After induction of general anesthesia, the patient was placed in the supine position with the head extended. Following routine skin preparation and draping, the previous cervical incision was reopened, and the skin, subcutaneous tissue, and platysma were dissected in layers.

SCWLA group

Patients in the SCWLA group underwent reoperation via the midline approach through the cervical linea alba. The previous anterior cervical incision was reopened and dissected layer by layer down to the linea alba (Figure 2B). The anterior cervical strap muscles were fully exposed, and the linea alba was incised to the thyroid capsule. The sternohyoid and sternothyroid muscles on both sides were then separated (Figure 2C) and retracted laterally to expose the thyroid remnant and adjacent vital structures (Figure 2D). Residual thyroid lobes were excised stepwise, followed by central and/or lateral neck lymph node dissection as indicated (Figure 2D).

Typical case: a 31-year-old female patient had previously undergone left subtotal lobectomy, right total lobectomy, and regional lymph node dissection at another institution. Postoperative pathology revealed papillary thyroid carcinoma (0.6 cm in the left lobe, 2 cm in the right lobe) with metastases in two right level III/IV lymph nodes (2/2), while no metastasis was identified in left level III/IV nodes. Fifteen months later (November 2017), follow-up cervical CT demonstrated residual tissue in the left thyroid lobe and bilateral cervical lymphadenopathy consistent with metastasis. The patient underwent reoperation consisting of left thyroid remnant resection, bilateral central neck dissection, and bilateral lateral neck lymph node dissection.

LIA group

Patients in the LIA group underwent reoperation using the LIA between the sternohyoid and sternothyroid muscles (Figure 3A-3F). The procedure began with the reopening of the previous cervical scar incision (Figure 3A). The anterior cervical strap muscles were divided at the midline (Figure 3B), after which the surgical plane was developed between the sternothyroid and sternohyoid muscles on the affected side. Dissection was carried posteriorly toward the carotid sheath (Figure 3C,3D). The residual thyroid tissue was then separated stepwise from the vascular-neural sheath interface (Figure 3E), followed by resection of the thyroid remnant. Central neck lymph node dissection was performed as indicated (Figure 3F).

Figure 3 Steps of thyroid reoperation via original cervical incision. (A) Access the reoperation site through the original cervical scar incision. (B) Incise the skin, subcutaneous tissue, and platysma, mobilize the skin flap to expose the cervical white line and scar adhesions. (C) Dissect between the sternohyoid and sternothyroid muscles (indicated by arrows pointing to relevant muscle structures). (D) Proceed to the carotid sheath to expose the thyroid remnant. (E) Separate along the plane between the vascular sheath and thyroid remnant. (F) Schematic diagram of surgery: step 1, approach via original cervical scar incision; step 2, midline incision of pretracheal strap muscles; step 3, dissect and retract sternohyoid and sternothyroid muscles to expose thyroid remnant and carotid neurovascular sheath; step 4, excise residual thyroid tissue while preserving PTG and RLN. This image is published with the participant’s consent. PTG, parathyroid gland; RLN, recurrent laryngeal nerve.

Typical case: a 57-year-old female had undergone right lobectomy and partial left lobectomy for papillary thyroid carcinoma at another institution 20 years earlier. She was admitted after a 1-year history of a palpable anterior cervical mass. Preoperative ultrasonography revealed a 4 mm × 5 mm solid nodule in the left upper pole (suspicious for TC) and a 3 cm × 3 cm × 2 cm mixed solid-cystic nodule in the lower pole (suggestive of nodular goiter). In April 2018, she underwent left thyroid remnant resection combined with left central neck dissection. Intraoperatively, the LIA through the sternohyoid-sternothyroid interval (Figure 3C,3D) revealed adhesions between part of the sternothyroid muscle and the anterior surface of the remnant lobe. Lateral dissection allowed clear exposure of the upper pole (Figure 3E).

Observational metrics

• Comparison of thyroid exposure quality. Based on the reference literature, the exposure quality is categorized into four levels: excellent, good, fair, and poor. Each level is assigned a score ranging from 1 to 4, with excellent being 4 and poor being 1 (19). Evaluations are independently performed by two experienced surgeons, with the average taken as the final score. The scoring criteria for exposure quality are detailed in Table 1.

  Table 1

  Intraoperative exposure effect scoring criteria

  
  

  Scoring dimension	Score	Description
  Surgical field clarity	1	Extremely blurred surgical field with severe blood contamination, requiring frequent suction
  	2	Poor clarity, requiring intermittent cleaning of obstructions
  	3	Acceptable clarity, with occasional blockage
  	4	Relatively clear, main structures generally discernible
  	5	Clear field, all structures visible at a glance
  Anatomical structure identification	1	Key anatomical structures cannot be identified
  	2	Structures are blurred, requiring repeated retraction for identification
  	3	Partial structure identification possible
  	4	Most structures clearly identifiable
  	5	All key structures clearly identifiable
  Ease of surgical manipulation	1	Operation is difficult, with minimal retraction space
  	2	Operation is restricted, requiring frequent retraction adjustments
  	3	Operation is possible but still limited
  	4	Operation proceeds relatively smoothly
  	5	Operation is smooth, with ample space

• Comparison of surgery-related indicators. The comparison includes surgical duration, intraoperative blood loss, and length of hospital stay between the two groups of patients.
• Comparison of postoperative complication rates. The incidence of complications within six months post-surgery is observed in both patient groups. This includes temporary RLNI, permanent RLNI, temporary PGI, permanent PGI, postoperative hemorrhage, and wound swelling.

Quality of life (QoL) assessment

To evaluate the impact of different surgical approaches on patients’ QoL, this study incorporated patient-reported outcomes (PROs). All patients underwent QoL assessments at 3 months and 1 year postoperatively using the EORTC QLQ-C30 core module (Chinese version, 3rd Edition) and the TC-specific module QLQ-THY34 (Chinese version) (24,25). The EORTC QLQ-C30 core module (Chinese version, Version 3) (available online: https://cdn.amegroups.cn/static/public/gs-2025-393-1.zip) was used with permission from the EORTC and has undergone cross-cultural validation in international phase IV studies, but has not been separately validated in the local population. Questionnaires were self-administered by patients during outpatient follow-up visits. For illiterate patients, trained staff read the items aloud in a standardized manner and recorded the responses. Questionnaires were non-anonymous to allow linkage with clinical data. Patients with missing QoL data were excluded from the QoL analyses but were retained in the overall clinical analyses. Scores for each domain were standardized to a 0–100 scale according to the EORTC scoring manual. Higher scores in functional domains and global health indicate better functional status, whereas higher scores in symptom domains reflect greater symptom burden. Of the 102 patients, 94 (92.2%) completed the quality-of-life questionnaires at 3 months and 1 year postoperatively, while 8 patients were lost to follow-up and did not complete the assessments.

Statistical analysis

This study employed IBM SPSS Statistics 26.0 software (IBM Corp., Armonk, NY, USA) for statistical analysis. All tests were two-sided, with a significance level set at P<0.05. Continuous data are presented as mean ± standard deviation (x¯±s), and comparisons between groups were conducted using independent sample t-tests. If the data did not meet normal distribution or homogeneity of variance assumptions, the Mann-Whitney U test was applied.

Categorical data are expressed as frequencies and percentages (n, %), and group comparisons were performed using the Pearson χ² test. When the expected frequency was 1≤T<5, the continuity correction χ² test was used; if T<1 or in cases of small sample sizes, Fisher’s exact test was employed. For multiple group comparisons, analysis of variance or rank-sum tests were utilized based on data characteristics. The study reports 95% confidence intervals (CIs) for major effect indicators and uses receiver operating characteristic (ROC) curve analysis to evaluate diagnostic or predictive performance, calculating the area under the curve (AUC) and its 95% CI, with the optimal cutoff determined by the Youden index.

Results

Baseline characteristics of both patient groups are balanced

The two groups showed no statistically significant differences in terms of gender composition (male proportion: 15.7% vs. 11.8%), mean age (48.59±8.67 vs. 50.32±9.85 years), interval between initial and subsequent surgeries (6.78±2.95 vs. 6.86±3.42 years), pathological types, and reoperation methods (all P>0.05, Table 2). Among all 102 patients, 95 (93.1%) had DTC (papillary or follicular), whereas only 7 (6.9%) presented with medullary or undifferentiated carcinoma, and the distribution of these histologic subtypes was comparable between the two groups (all P>0.05).

The LIA demonstrates superior exposure in key anatomical areas compared to traditional approaches

In the upper pole (3.16±0.63 vs. 1.49±0.30, t=17.092) and lower pole (2.85±0.57 vs. 1.37±0.27, t=16.758) regions, the exposure scores of the LIA group were significantly higher than those of the SCWLA group (both P<0.001). The difference in the isthmus was not significant (1.69±0.34 vs. 1.57±0.31, P=0.07) (Figure 4). This indicates that the LIA offers markedly better surgical field exposure in critical anatomical areas (upper pole, lower pole, and lateral regions) compared to the SCWLA.

Figure 4 Comparison of surgical field exposure scores at different thyroid regions between two patient groups. The bar graph illustrates the intraoperative exposure scores (x¯±s, n=51 per group) for the superior pole, inferior pole, lateral side, and isthmus of the thyroid in both the LIA and SCWLA groups. Significant differences are indicated by *P<0.05, ***P<0.001. LIA, lateral intermuscular approach; SCWLA, standard cervical white line approach.

The LIA significantly enhances surgical efficiency and reduces recovery time

The LIA group demonstrated superior performance in terms of surgical efficiency and recovery metrics compared to the SCWLA group: the duration of surgery was significantly shorter (1.65±0.32 vs. 1.88±0.37 hours, P=0.001), intraoperative blood loss was reduced (23.95±4.75 vs. 42.58±8.51 mL, P<0.001), and the length of hospital stay was decreased (6.84±1.38 vs. 8.86±1.77 days, P<0.001) (Figure 5). The hospital stay was influenced by institutional postoperative observation protocols and routine serum calcium monitoring. In cases with complications such as bleeding or hypocalcemia, extended hospitalization was necessary. These results indicate that the LIA not only enhances surgical efficiency but also effectively minimizes trauma and accelerates recovery, offering improved surgical safety and clinical applicability.

Figure 5 Comparison of surgical parameters between two patient groups. The figure illustrates the distribution of operative time, intraoperative blood loss, and postoperative hospital stay in the LIA and SCWLA groups (n=51 per group). Statistical significance was assessed using independent-sample t-tests, with ***P<0.001. LIA, lateral intermuscular approach; SCWLA, standard cervical white line approach.

The LIA reduces the incidence of postoperative complications

A 6-month postoperative follow-up revealed no statistically significant difference between the LIA group and the SCWLA group regarding permanent RLNI and PGI. However, the LIA group exhibited a lower incidence of temporary complications, including RLNI (5.88% vs. 21.57%, P=0.04), PGI (13.73% vs. 27.45%, P=0.04), postoperative rebleeding (5.88% vs. 23.88%, P=0.01), and wound swelling (52.94% vs. 74.51%, P=0.04) (Figure 6A-6C). These results indicate that the LIA offers a distinct advantage in reducing postoperative complications.

Figure 6 Comparison of postoperative complication rates between two patient groups. (A) Incidence of RLN injury. (B) Incidence of PTG injury. (C) Incidence of postoperative rebleeding. Each group n=51. Bar graphs represent the incidence rates (%) for each group, with superimposed scatter plots showing individual data distribution. Statistical significance was assessed using Fisher’s exact test, with significance levels indicated as *P<0.05, and n.s. denoting no statistical significance. LIA, lateral intermuscular approach; PTG, parathyroid gland; RLN, recurrent laryngeal nerve; SCWLA, standard cervical white line approach.

Subgroup analysis reveals significant benefits for papillary carcinoma and short-interval reoperation patients

In patients with papillary carcinoma, the exposure scores for the superior, inferior, and lateral aspects of the thyroid in the LIA group were significantly higher than those in the SCWLA group (all P<0.001). Additionally, the LIA group experienced reduced intraoperative blood loss and a lower incidence of temporary RLNI (5.00% vs. 22.50%, P=0.04). Although a similar trend was observed in non-papillary carcinoma patients, the differences did not reach statistical significance (P>0.05). Among patients with a surgical interval of ≤5 years, the LIA group showed superior outcomes in surgical time, intraoperative blood loss, length of hospital stay, and incidence of complications compared to the SCWLA group (all P<0.05). For patients with an interval of >5 years, the LIA group maintained advantages in exposure scores and blood loss (Figure 7A-7G). Taken together, these findings indicate that the observed benefits of the LIA are most evident in patients with recurrent DTC, particularly papillary carcinoma, whereas the small number of non-DTC cases precludes definitive conclusions for medullary or undifferentiated carcinoma.

Figure 7 Comparative analysis of surgical techniques in reoperative TC subgroups. (A-C) Exposure scores of the thyroid upper pole (A), lower pole (B), and lateral (C) in patients with papillary and non-papillary carcinoma. (D) Intraoperative blood loss. (E) Duration of surgery. (F) Length of hospital stay. (G) Incidence of temporary RLNI. Bar graphs represent x¯±s, with overlaid scatter plots showing individual data distribution. Statistical significance was assessed using independent sample t-tests for continuous variables or Fisher’s exact test for binary variables. Significance levels are indicated as *P<0.05, ***P<0.001. Each group n=51. LIA, lateral intermuscular approach; RLN, recurrent laryngeal nerve; RLNI, recurrent laryngeal nerve injury; SCWLA, standard cervical white line approach; TC, thyroid cancer.

Analysis of the impact of surgical approaches on postoperative QoL

Among the 102 patients followed, those in the LIA group demonstrated significantly higher global health scores at both 3 months and 1 year postoperatively compared with the SCWLA group (3 months: 78.3±6.2 vs. 64.8±6.8, P<0.001; 1 year: 82.1±5.8 vs. 69.5±7.1, P<0.001; Figure 8A). The linear mixed-effects model adjusted for age, sex, baseline QoL score, time since initial surgery, and postoperative complications (P<0.01). At 1 year, the LIA group also achieved higher scores in functional domains—including emotional, social, and role functioning—than the SCWLA group (all P<0.05). Conversely, scores for symptom domains such as swallowing difficulty, voice problems, fatigue, and cervical discomfort were significantly lower in the LIA group (all P<0.05), indicating superior functional recovery and symptom control (Figure 8B).

Figure 8 Comparison of postoperative QoL in patients with different surgical approaches. (A) Trends in overall health score changes at 3 months and 1 year post-surgery. (B) Radar chart distribution of scores across eight QoL dimensions at 1 year post-surgery, including overall health, emotional function, social function, role function, swallowing difficulties, voice problems, fatigue, and neck discomfort. Scores are based on the EORTC QLQ-C30 and QLQ-THY34 questionnaires (0-100 scale, with higher scores in functional/overall health dimensions indicating better functional status, while higher scores in symptom dimensions indicate greater symptom burden). A difference of ≥10 points is generally considered clinically meaningful. Data are presented as x¯±s. Inter-group comparisons were conducted using independent samples t-tests with significance levels: ***, P<0.001. LIA, lateral intermuscular approach; QoL, quality of life; SCWLA, standard cervical white line approach.

Discussion

This study included 102 patients with recurrent TC to compare the comprehensive differences between the LIA between sternohyoid and sternothyroid muscles in the LIA group and the SCWLA in the SCWLA group regarding surgical field exposure, surgical efficiency, postoperative complications, and QoL after surgery. The results indicated that the LIA group had significantly higher scores for surgical field exposure at the upper pole, lower pole, and lateral areas. Additionally, there was a reduction in operative time, intraoperative blood loss, and hospital stay duration. The incidence of temporary postoperative complications was significantly lower, and QoL scores across all dimensions were notably superior to those of the SCWLA group (P<0.05). These findings systematically reveal the comprehensive advantages of the LIA in complex reoperations for recurrent TC.

In this study, the exposure scores obtained at the upper pole, lower pole, and lateral positions of the thyroid were significantly superior to those in the SCWLA group (P<0.001), aligning with existing literature on the lateral/backdoor approach. For instance, research has indicated that the LIA can markedly enhance the exposure of critical structures, reducing traction injury and recognition difficulties (20). Additionally, studies on the sternocleidomastoid muscle intermuscular approach (SMIA) have confirmed that this pathway improves surgical field visibility in the Berry ligament and upper pole regions (22,26). Unlike most literature focusing on primary surgeries, this study emphasizes recurrent surgical scenarios, maintaining advantages in environments with pronounced scarring and adhesions, thereby demonstrating innovative value.

In this study, the surgical duration for the LIA group was 1.65±0.32 hours (SCWLA group: 1.88±0.37 hours, P=0.001), with a blood loss of 23.95±4.75 mL (control: 42.58±8.51 mL, P<0.001) and a hospital stay of 6.84±1.38 days (control: 8.86±1.77 days, P<0.001). Previous studies on open SMIA have reported similar surgical efficiency and minimally invasive characteristics (22). Even in patients with recurrent and anatomically complex conditions, the procedural efficiency advantage of this technique is significantly validated.

In the LIA group, no permanent RLNI or PGI occurred within six months postoperatively. The incidence of temporary complications was also significantly reduced: RLNI occurred in 5.88% of cases compared with 21.57% in the SCWLA group (P=0.04), and PGI in 13.73% vs. 27.45%, respectively (P=0.04). These rates are lower than those reported in the literature for reoperative TC with central compartment dissection, underscoring the protective advantage of LIA in this high-risk setting. All patients in this cohort underwent reoperative surgery with central compartment dissection for recurrent TC, predominantly locally advanced PTC, a scenario that intrinsically carries a higher risk of bleeding and PTG injury than primary surgery because of scarring, hypervascularity and distorted anatomy (7). Routine laryngoscopy and postoperative serum calcium monitoring meant that even mild and transient events were captured, contributing to seemingly high overall rates of “bleeding” and complications (27). In the SCWLA group, repeated dissection along the midline and within the pericapsular scar, where fragile neovascularisation and dense venous adhesions are present under limited exposure, likely accounted for the higher rates of haemorrhage and PTG dysfunction (28). By contrast, LIA exploits a relatively undisturbed lateral intermuscular plane, allowing earlier vascular control and lateral identification and preservation of the RLN and PTGs, thereby reducing intraoperative blood loss and postoperative PTG dysfunction (20).

This study is the first to systematically employ the EORTC QLQ-C30 and the TC-specific module QLQ-THY34 to assess QoL in reoperations for recurrent TC. The scores for overall health, swallowing, voice, and emotional dimensions were significantly better in the LIA group than in the SCWLA group at 3 months and 1 year postoperatively (P<0.05). The QLQ-THY34 has undergone cross-cultural validation and is widely recommended for TC evaluation (25). Compared to studies utilizing robotic or endoscopic techniques lacking PRO evaluations, this research is more patient-centered and functionally oriented.

Stratified analysis revealed that among patients with papillary carcinoma and a surgical interval of ≤5 years, the LIA group demonstrated a more pronounced advantage, characterized by reduced bleeding, improved exposure scores, and a lower temporary nerve injury rate of 5.00% compared to 22.50% (P=0.04). Although the non-papillary carcinoma group exhibited similar trends, statistical significance was not achieved due to limited sample size (P>0.05). Previous studies have rarely conducted systematic stratification based on recurrence type and surgical interval; this study thus contributes empirical evidence supporting individualized surgical strategy selection.

Although techniques such as transaxillary or trans-cervical robotic reoperation have demonstrated improvements in QoL, these methods are limited by their high costs and restricted dissemination. Previous studies have indicated that robot-assisted surgery does not significantly reduce complication rates (29,30). In contrast, this study achieves similar functional protection and QoL benefits through an open LIA without relying on advanced equipment, offering greater potential for widespread adoption and applicability.

This surgical technique involves the longitudinal separation of the sternohyoid and sternothyroid muscles, creating a natural surgical corridor that directly accesses the lateral and superior structures of the thyroid gland. This approach minimizes traction on the trachea, RLN, and PTG. Studies have emphasized the importance of anatomical preservation by identifying Berry’s ligament and RLN (26,31). This technique effectively exploits anatomical spaces, aligning with neuroprotective mechanisms.

This study has several limitations inherent to its single-center retrospective design, including a limited sample size and potential selection bias. The uneven distribution of cases and the small proportion of non-papillary carcinoma patients reduce the robustness of some subgroup analyses. In addition, the follow-up period was only 6 months, so long-term data on QoL and recurrence are lacking, and QoL was assessed at only two time points. Finally, the surgical techniques may have varied according to the individual surgeon’s experience, which could have influenced the perioperative outcomes. Furthermore, QoL assessments were conducted at only two time points. Future research should consider prospective, multicenter, randomized controlled trials with extended follow-up periods. These studies should integrate evaluations of biomarkers, cost-effectiveness, and image-guided technologies to refine surgical optimization pathways. In addition, this cohort included different histologic subtypes of TC. Although DTC (papillary and follicular carcinoma) constituted the vast majority of cases, a small number of patients with medullary or undifferentiated carcinoma were also enrolled. Given the distinct tumor biology, progression patterns, and prognosis of these non-DTC entities, their inclusion inevitably introduces disease heterogeneity and may partly complicate the interpretation of between-group comparisons. Therefore, the conclusions of this study should be considered primarily applicable to patients with recurrent DTC, whereas the evidence for medullary and undifferentiated carcinoma remains limited and exploratory.

This study represents the first comprehensive evaluation of the multidimensional advantages of the LIA between sternohyoid and sternothyroid muscles in reoperations for recurrent TC. The approach offers superior surgical field exposure, enhanced operative efficiency, reduced complications, and significant improvements in QoL, particularly benefiting patients with papillary carcinoma and those undergoing surgery within shorter intervals. By integrating anatomical mechanisms, clinical data, and patient-centered outcomes, this technique demonstrates substantial potential for broader application. Future research should aim to further delineate the criteria for diverse patient populations and optimize individualized treatment strategies to provide more comprehensive solutions for complex recurrent surgeries.

Conclusions

This study compares the efficacy of two surgical approaches in reoperative procedures for recurrent TC. The findings indicate that the LIA Between the sternohyoid and sternothyroid muscles significantly enhances surgical field exposure at the superior, inferior, and lateral poles of the thyroid gland. It also reduces intraoperative bleeding, shortens both surgery and hospitalization durations, and decreases the incidence of complications such as temporary RLNI and PGI. This approach demonstrates high safety and practicality by avoiding midline scar tissue and accessing through intermuscular spaces, making it particularly suitable for patients with recurrences located at the superior or lateral poles. It enhances surgical precision and protects critical structures, providing an optimal operative pathway for reoperation with significant potential for broader application.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://gs.amegroups.com/article/view/10.21037/gs-2025-393/rc

Data Sharing Statement: Available at https://gs.amegroups.com/article/view/10.21037/gs-2025-393/dss

Peer Review File: Available at https://gs.amegroups.com/article/view/10.21037/gs-2025-393/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://gs.amegroups.com/article/view/10.21037/gs-2025-393/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This study was approved by the Medical Ethics Committee of Taizhou Cancer Hospital (No. 2025-027). The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from all participants prior to enrollment.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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