Feasibility and safety of outside the cage subcostal robotic anatomical lung resections: results of a phase I clinical trial

Introduction

The reduction of surgical trauma using minimally invasive techniques in the treatment of lung cancer has been shown to improve surgical outcomes without compromising oncological results (1-7). Robotic-assisted thoracic surgery (RATS) has been shown to be a promising minimally invasive surgery (MIS) alternative to standard thoracoscopy, and its adoption is increasing rapidly for the surgical treatment of lung cancer (8,9).

The traditional RATS technique for lobectomy involves the use of up to five intercostal ports (10,11). Single port RATS lobectomy has also been described in order to attempt to minimize surgical trauma (12). Unfortunately, current standard RATS approaches to lobectomy still involve intercostal incisions, potentially harming the intercostal bundles with resulting consequences. Recent publications on the feasibility of major pulmonary resections through MIS subxiphoid and subcostal incisions have reported on lower postoperative pain compared to traditional video-assisted thoracoscopic surgery (VATS) (13,14).

Compelled by this data and in efforts to improve postoperative recovery, we developed a novel non-intercostal approach for RATS lobectomy. This approach integrates the strengths of surgical robotic technology with the potential benefits of avoiding intercostal instrumentation. Utilizing a currently widely available robotic platform, our approach enables lung resections through subcostal incisions (Figure 1). The operation is performed from “outside the thoracic cage” (OTC), and not through it, thereby preserving the integrity of intercostal structures.

Figure 1 Illustration showing port disposition for OTC RATS lobectomy. (A) Biportal approach for right sided lobectomy. (B) 4-port approach for left sided lobectomy. OTC, outside the thoracic cage; RATS, robotic-assisted thoracic surgery.

Additionally, our OTC RATS approach not only avoids intercostal instrumentation but also grants the surgeon with direct control of robotic staplers, without the need of an experienced and highly trained bedside assistant.

Following promising results of a successful initial pilot series (15), we decided the initiation of this clinical trial aiming to prospectively evaluate the feasibility and safety of this innovative approach. We present this article in accordance with the TREND reporting checklist (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1505/rc).

Methods

Design and population

This study prospectively evaluated the feasibility and safety of OTC RATS lobectomy. Consecutive patients with suspected or confirmed resectable non-small cell lung cancer (NSCLC) clinical stages I–IIIA planned to undergo a VATS or RATS lobectomy at the Centre Hospitalier de l’Université de Montréal (CHUM), Montréal, Québec, Canada were approached and offered to participate during the preoperative clinic visit. Exclusion criteria were pregnancy, inability to provide informed consent, age younger than 18 years and planned thoracotomy (Figure 2). Given the results of our pilot series (15) and due to the nature of this single arm, intention to treat, pilot phase 1 trial, we evaluated that a total of 20 patients would provide sufficient data to promote a subsequent multicenter trial.

Figure 2 Consort diagram of the OTC RATS phase 1 clinical trial. OR, operating room; OTC, outside the thoracic cage; RATS, robotic-assisted thoracic surgery; VATS, video-assisted thoracoscopic surgery.

Ethics

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by institutional ethics board of the Centre hospitalier de l’Université de Montréal (CHUM) on February 14th, 2023 [IRB number: 22.228 (2023-11187)] and informed consent was obtained from all individual participants. The study was registered the trial at clinicaltrials.gov (NCT05832112).

Outcomes

The two independent primary outcomes were feasibility and safety and were measured by the conversion rate to either intercostal VATS/RATS or open surgery and 30-day mortality respectively. Benchmarks were specified for each outcome measure proportions to identify critical deviations with sufficient precision in this evaluative context. Feasibility required a conversion rate of ≤10% (≤2/20 patients), while safety demanded 0% 30-day mortality. Exploratory secondary outcome measures included perioperative measures such as operative time (OT), estimated blood loss (EBL), transfusion rate, perioperative complications, significant adverse events (SAE), length of hospital stay (LOS), duration of chest tube (DCT), and quality of recovery (QOR) as exploratory measure.

Statistical analysis

IBM SPSS Statistics 29 was used for descriptive statistics and graphical representations. Continuous variables were summarized as mean ± standard deviation or median with interquartile range, depending on their distribution. Categorical variables were presented as frequencies and proportions for all patient demographics, baseline characteristics, and surgical outcomes.

To compare differences in mean QOR scores between baseline and postoperative time points over a 30-day period, a two-sided paired t-test was used with a 95% confidence interval (CI) and P<0.01 was the threshold applied for statistical significance. A scatter plot graphic with a fitted trend line was used to illustrate the relationship between time and QOR scores.

Study methods

Consented patients underwent lobectomy by OTC RATS following the same surgical steps of a standard VATS/RATS technique with the only difference being the port placement in the subcostal plane rather than in the intercostal spaces. All procedures in this study were performed by a single, highly experienced robotic surgeon and the same core surgical team. The OTC RATS technique used was previously detailed by our group in a recent publication (15). Essentially, the Davinci Xi^® by Intuitive Surgical^® (Sunnyvale, CA, USA) surgical system was used to perform the lobectomies through subcostal ports with a standard anterior fissure-less technique including mediastinal and hilar systematic lymph nodes (LNs) dissection. Patients received standard postoperative care and pain management pathways used for MIS lobectomy in our center. Pain management protocols included intraoperative paravertebral block (standard lidocaine/bupivacaine solution) and standard doses of regular acetaminophen, celecoxib and hydromorphone administered on demand according to preexisting care protocols following a 0–10/10 numerical rating scale (NRS) routinely assessed by the nurses on the unit. Any deviation from the standard pain management protocols was registered. Chest tube removal and patient discharge were decided by the treating surgical team, following the same criteria as the standard MIS lobectomies.

Quality of life (QOL) was assessed using the QOR-15, a patient-reported, multidimensional questionnaire used to analyze postoperative functional recovery (16) (Figure S1). It generates a global score (from 0= worst recovery to 150= optimal recovery) with interim cutoffs indicating “poor” [0–89], “moderate” [90–121], “good” [122–135] and “excellent” [136–150] QOR (17). The questionnaire was administered at the moment of enrollment during the preoperative visit, in the post-anesthesia care unit (PACU) before discharge to the ward, on each of the first 2 postoperative days (POD) and again during the 30-day visit at the clinic (POD1, POD2 and POD30, respectively).

Clinical data, complications, readmissions, SAE (assigned as complications with a Clavien-Dindo classification score ≥III), questionnaire results and outcome measures were recorded up to the 30-day follow-up visit. No missing data were encountered in the cohort.

Surgical technique

The OTC RATS lobectomy technique involves the completion of the procedure with robotic assistance through subcostal ports without disrupting the intercostal spaces. The subcostal accesses are created right below the ribs composing the costal margins. There are anatomical differences between both hemi-thoraces that impact the manner of approaching each of them (Figure 1). On the right side, the anatomy allows flexibility for a variety of access options that range from a single incision to a 2-port and a 4-port approaches (Figure 3). All these different strategies were feasible in our early pilot series (15), however, in this study the 2-port approach was the standard for right sided procedures (Video 1). On the left hemithorax we only utilized the 4-port technique (Figures 1,4) because it provides a better exposure of the anatomy, decreasing the risk of injury to mediastinal structures (Video 2).

Figure 3 Illustration showing the different approach options to OTC RATS lobectomy. (A) Uniportal OTC RATS approach for right side lobectomy. (B) Two-port approach for right side procedures. (C) Right side 4-port approach. (D) Left side 4-port approach for lobectomy. OTC, outside the thoracic cage; RATS, robotic-assisted thoracic surgery.

Figure 4 Image showing position and marks of port placement for left OTC RATS lobectomy. OTC, outside the thoracic cage; RATS, robotic-assisted thoracic surgery.

Right OTC RATS lobectomy

Under general anesthesia and single-lung ventilation, patients were positioned in a left lateral decubitus position. The robotic surgical cart was approximated from the left side of the operating table at the level of the patient’s head, with a fully extended boom rotated 90 degrees anticlockwise perpendicular to the longitudinal axis of the chest wall. The procedures were completed through two ports without CO₂ insufflation: an anterior working access and a posterior assisting port (Figure 1, Video 1).

The confection of the anterior access started by a 4 cm incision performed slightly lateral to the xiphoid process, parallel to the costal margin. Dissection with cautery proceeded along the lower edge of the anterior aspect of the costal margin through the abdominal muscles insertions that were carefully detached until the periosteum or perichondrium of the costal margin was reached, allowing then to perform a subcostal tunnel between this structure and the diaphragm with blunt maneuvers. After the initial subcostal blunt dissection, the robotic camera was approximated in a downside-up setting and dissection of the working port was completed under vision. The confection of the subcostal tunnel continued cephalad until the pleural space was entered. The completion of the tunnel dissection was carefully performed preserving the integrity of the transversus abdominis fascia, avoiding entering the abdominal cavity.

Once the pleura was opened, a wound retractor was placed to maintain exposure of the working port open. Next, a second subcostal incision was performed posteriorly below the 10th rib and medial to the 11th rib tip to insert a 12 mm trocar under thoracoscopic vision. The costal margin was palpated, and the abdominal muscles were carefully disinserted in this area with cautery until reaching the periosteum of the 10th rib. Then, a blunt 12 mm trocar was advanced subcostally towards the pleural space between the rib plane and the diaphragm insertion, avoiding disrupting the transverse abdominis aponeurosis and therefore entering the abdominal cavity.

Robotic Arm 1 was docked to the posterior trocar with an 8 mm reducer and equipped with a tip up fenestrated forceps that was used for retraction during the procedure. The rest of the arms were positioned in the anterior access: Arm 2 equipped with the 30 degrees robotic camera in an upside-down setting was positioned at the lateral edge of the incision; Arm 3 (with a left-hand set-up) was as placed centrally in the port with an 8 mm trocar and a Cadiere or fenestrated bipolar forceps; Arm 4 (with a right-hand set-up) was accommodated at the medial edge of the incision with a 12 mm trocar and an 8 mm reducer equipped with a bipolar Maryland forceps. Robotic staplers were used through Arms 1 and 4 according to convenience to divide hilar structures and fissures.

The lobectomies were performed using a standard fissure-less anterior approach with systematic mediastinal and hilar LNs dissection. The surgical specimen was retrieved through the working port. A chest tube was introduced through the posterior port, and it was fixed with a stay suture. Additionally, a “U” stitch with a silk 0 was placed through the skin and muscle layers around the chest tube. This “U” stitch closed the gap left at the moment of chest tube removal, and it was retrieved during the first postoperative consult 4 weeks after discharge. Closure of the working port was performed by planes carefully approximating the abdominal muscles to the costal margin.

Left OTC RATS lobectomy

Resections on the left side were performed through 4 left subcostal ports and CO₂ insufflation (Video 2). The patient was positioned in a right lateral decubitus with the same anesthesia technique and robotic surgical cart set-up as for right-sided resections (Figure 4).

Access was initiated with an 8 mm incision at the left mid-axillary line, below the 10th rib. As in every subsequent port, the abdominal muscles were carefully disinserted in this area with cautery from the costal margin and then, using a blunt trocar, a tunnel was created bluntly between the rib plane and the diaphragm insertion, avoiding disrupting the transverse abdominis aponeurosis and therefore entering the abdominal cavity. The first trocar inserted at this site was a 5 mm optical trocar and 5 mm thoracoscope that allowed for direct vision during the creation of this tunnel. Once the pleural cavity was entered, CO₂ insufflation (up to 8 mmHg) was initiated. This insufflation was crucial on the left side because it facilitated lung collapse, induced a slight mediastinal shift to the right, and depressed the diaphragm, significantly enhancing exposure and creating a safe working space for subsequent port placement under direct vision. The insufflation separated the mediastinum from the chest wall, minimizing risk of injury to the phrenic nerve and mediastinal structures while introducing the rest of the ports. At this point, guided by the camera view, a 12 mm robotic port was placed subcostally beneath the 10th rib and medial to the 11th rib tip along the posterior axillary line. Next, the thoracoscope was moved to this 12 mm posterior port and, under thoracoscopic guidance, an 8 mm robotic port was placed approximately 4 cm lateral to the xiphoid. Next, the thoracoscope was moved to this last port and another 8 mm robotic port was placed at the level of the anterior axillary line under vision. Finally, under thoracoscopic guidance, the initial 5mm port was exchanged for an 8 mm robotic trocar. Switching the camera between ports ensured optimal visualization during each port placement.

Robotic Arm 1 was equipped with a Cadiere or bipolar forceps and docked in the most anterior port with a left hand set up; the 30-degree robotic camera was inserted in Arm 2 docked to the anterior axillary line port and set up in an upside-down configuration; Arm 3 was supplied with a Maryland bipolar or a monopolar hook through the mid-axillary line port; finally, Arm 4 was equipped with an 8 mm port reducer and a tip-up fenestrated grasper and docked in the posterior 12 mm port. This posterior port was used for the robotic staplers.

The lobectomies were completed using an anterior, fissure-less technique. Following lung resection and LNs dissection, the most anterior incision was extended to allow for specimen retrieval in a bag. Once hemostasis was completed, the diaphragmatic port sites were meticulously closed with non-absorbable figure-of-eight sutures. Finalizing, a single chest tube was placed through the mid-axillary line port site fixed to the skin by a stay suture. A “U” stitch with a silk 0 was placed through the skin and muscle layers around the chest tube, with identical management than on the right sided procedures. The incisions are then closed by planes with absorbable sutures taking care of approximating the muscle planes separated during the confection of the ports.

Results

Between February and May of 2023, a total of twenty-six patients were screened for eligibility and approached to participate. Three patients declined and a total of twenty-three patients were allocated for the intervention. Two of the allocated patients ended up undergoing VATS lobectomy due lack of availability of the robot at the time of surgery and one patient underwent OTC RATS lobectomy however after target accrual was achieved. Consequently, a total of twenty patients were included in the analysis (Figure 2).

The demographic data is shown in Table 1. There was a larger proportion of female patients (n=15, 75%), median age was 63 [33–79] years, mean body mass index (BMI) was 28.6 [21.16–44.12] kg/m², most had an American Society of Anesthesiologists (ASA) score of III (n=15, 75%) and a positive smoking history (n=16, 80%). Clinical stage IA disease was the most frequent (n=16, 80%) and 15% (n=3) of patients presented with clinical stage IIIA having received neoadjuvant chemo-immunotherapy (NACT/IO) prior to surgery. The prevalence rates of comorbidities are described in Table 1.

There were no conversions of the surgical technique and no mortality at 30 days which were accordingly the feasibility and safety primary outcomes of this study (0%, 0/20; 95% CI: 0.0–16.8%).

Surgical outcomes are displayed in Table 2. The vast majority of procedures were completed using a biportal approach (n=15, 75%), which was utilized to perform right upper lobe (RUL) (n=8, 40%) and right lower lobe (RLL) (n=5, 25%) lobectomies. One case of right middle lobe (RML) lobectomy (n=1, 5%) was performed using a uniportal OTC RATS approach. The remaining cases included left upper lobe (LUL) (n=3, 15%) and left lower lobe (LLL) (n=1, 5%) lobectomies, which were completed using 4 ports. Mean OT was 109 [70–149] minutes with a mean EBL of 56 [45–200] mL. No patient required blood transfusion. Only one case (n=1, 5%) had an intraoperative complication, namely a pulmonary artery (PA) injury that was solved without the need for conversion, the rest of the cases (n=19, 95%) underwent uneventful procedures.

Pathological stage I NSCLC was the most frequent diagnosis (pIA: n=12, 60% and pIB: n=1, 5%). The median LOS was 2 [1–19] days and the median DCT was 1 [1–10] days. The post-operative complication rate was 25% (n=5)—represented mostly by prolonged air-leaks (n=4, 20%)—and only one patient (5%) presented a SAE (represented by a pneumothorax after chest tube removal). There were no readmissions within the 30-day post-op observation period. There was no significant difference between the baseline and the POD30 QOR scores (t=1.187, two-sided P=0.25) (Figure 5). The minimum mean QOR scores resulted in “moderate” levels on PACU [94.45%±17.4% (32–145%)], POD1 [103.40%±9.3% (48–142%)] and POD2 [111.20%±8.4% (61–143%)]. The QOR-15 means and paired-samples t-test results are displayed in Table 3. No patient required supplemental analgesia, and no pain-related complications were observed within the studied 30-day postoperative period.

Figure 5 Scatter dot graphic with interpolation curve showing results of QOR-15 scores at baseline and on each POD analyzed. POD, postoperative day; QOR, quality of recovery.

Discussion

Since its development in the late 90s, VATS has shown postoperative benefits compared to open surgery (1-7). This situation has influenced the thoracic surgical community to seek less invasive approaches for lung resections as well as adopting the use of RATS as an alternative to VATS. Over the years, both MIS techniques increasingly reduced their size and number of incisions (5), resulting recently in the development of a uniportal RATS intercostal technique (12).

Notwithstanding the efforts made, all aforementioned approaches require intercostal incisions which put patients at risk of developing persistent or chronic neuropathic pain—a common postoperative complication in thoracic surgery, estimated to occur in 30–40% of cases with impact on recovery and QOL after surgery (18)—resulting from intercostal nerve instrumentation.

Following the rationale of avoiding intercostal nerve injury to prevent persisting pain, subxiphoid and subcostal approaches have been developed and described in the last decades for major pulmonary resections (14). Reported in 1999 by Kido et al. (19) followed by Zielinski et al. (20), the subxiphoid approach was firstly implemented for mediastinal pathology and later adopted for subxiphoid uniportal VATS procedures (21). Since then, other authors have reported widely on this technique, namely for complex pulmonary resections and even simultaneous bilateral resections through this single non-intercostal incision (13,14,22-24).

Although beneficial in some respects, the subxiphoid approach presents disadvantages such as the need to resect the xiphoid process, and its medial position implying increased risk of cardiac impairment during lung resections, specially on the left side. Comparatively, subcostal incisions are a less traumatizing non-intercostal option, as they do not require the resection of the xiphoid process and they avoid the disturbance of the mediastinum due to their more lateral position, all of which could possibly impact on the safety of the procedure (5).

Hence, OTC RATS was developed to leverage combining the technical benefits offered by the most widely available robotic platform with the potential advantages of avoiding intercostal instrumentation by completing the resections through a subcostal approach.

The demographic results of this study correlate with those obtained by previous publications observing the same target population (25), thus the sample seems representative of our “real world” practice. The study successfully met its primary endpoints, with no conversions and zero 30-day mortality observed (0%, 0/20; 95% CI: 0.0–16.8%), this result, combined with the lack of transfusions, pain related complications and readmissions, suggests the feasibility and safety of this approach for the intended target population. Of notice, the upper confidence limit exceeded our pre-specified 10% feasibility and safety benchmarks, therefore, statistical confirmation was not achieved. However, this pilot study provides preliminary evidence supporting progression to larger studies.

Regarding technical aspects, due to the anatomical differences mentioned, the right hemithorax allows for flexibility on the number of ports needed to complete a resection (Figure 3). As an example, even when the 2-port technique was the standard for right sided procedures in this study, we were able to complete a middle lobectomy through a single port. It was the case of a 2 cm pure ground-glass opacity (GGO) RML lesion in which the resection and a mediastinal LN sampling were performed utilizing three robotic arms through the single 4 cm anterior subcostal incision described in the 2-port technique without the need of placing a posterior assisting port (Figure 6).

Figure 6 Right uniportal OTC RATS lobectomy: positioning, incision, and robotic arms docking. OTC, outside the thoracic cage; RATS, robotic-assisted thoracic surgery.

In our experience, although it was not used for patients included in this study, a 4-port right approach with the use of CO₂ insufflation provides better exposure when operating on patients with prominent abdomen as it allows for lung collapse, and a certain level of contralateral mediastinal shifting as well as diaphragm depression that increase the intrathoracic space. The technique mirrors the 4-port approach described in the methods section for left sided procedures in this study.

Contrarily, the anatomy of the left hemithorax does not allow for flexibility (Figure 3). The increased intrathoracic space and the separation of the heart from the chest wall facilitated by the CO₂ insufflation allows for a smooth and safe under vision placement of the trocars, which is the reason why we use a 4-port approach as standard for left lobectomies (Video 2). We have chosen not to attempt 2-port or single-port attempts on the left side as mediastinal impairment is more likely to happen. While this did not impact feasibility or safety in our cohort, it highlights an inherent technical asymmetry that surgeons must appreciate when adopting this technique.

The OT observed in results is also related to safety. A prolonged OT (above 150 minutes) during MIS pulmonary resections has been associated with increased post-operative complications (26-28). The resulting mean OT of 109 [70–149] minutes in our study reconfirms the safety of this approach for lobectomy. Moreover, this value was obtained early on in our learning curve, we suspect to observe a decrease in OT over time as our experience with this novel technique increases. The unique intraoperative complication (n=1, 5%) was represented by a PA branch lesion during a RUL case on a post induction chemo-immunotherapy patient. Of note, the event was not derived from any aspects of the approach itself (such as suboptimal triangulation, reach, instrument fighting, maneuverability restrictions, etc.) but rather due to the challenging dissection. A small segmental PA branch tear occurred while resecting a station 11 LN strongly adhesive due to treatment response. Furthermore, the problem was corrected without requiring conversion of the technique, with a total blood loss of 200 cc at the end of the case, and without the need of blood transfusions intraoperatively or in the 30-day follow up period (Table 2).

Of the three patients (n=3, 15%) who received NACT/IO prior to surgery, none required conversion to open or 30-day mortality. Pulmonary resections after chemo-immunotherapy have been characterized as technically challenging due to the treatment response which often results in fibrosis, predominantly at the site of the lesion and lymphatic tissue, thus increasing the complexity of the resection, especially when present on hilar LNs (29-32). Reports of surgical outcomes on resected patients after chemo-immunotherapy showed 30-day mortality rates ranging from 3% to 10% and postoperative complications rates ranging from 11% to 69% (32). A recent post-hoc analysis of the surgical outcomes of the CheckMate 816 trial also revealed an 11% conversion rate to open (29). Although the number of post chemo-immunotherapy cases is limited in our study, these results indicate that this approach could be safe for such cases amenable to MIS resection.

Postoperative complications were present in 25% (n=5) of cases. Four (20%) were prolonged air-leaks (air-leak greater than 5 days) in patients previously diagnosed with severe chronic obstructive pulmonary disease (COPD); all of which were discharged with Heimlich valves removed during subsequent follow-up visits, held 10 days at the latest. One of these cases had a pneumothorax immediately after chest tube removal which required pleural drainage—representing the only SAE (n=1, 5%) in this study. The rates of common complications such as prolonged air-leaks correlate to those found in our historical local data and recent published meta-analysis (25,33). The observed LOS and DCT are also consistent with the average performance of patients undergoing lobectomy via other MIS techniques in our center (25). All this implies that OTC RATS lobectomy could, at least, provide non-inferior outcomes to alternative MIS lobectomy approaches performed by our group.

To explore the hypothesis which incited the development of this approach, specifically that performing RATS anatomical lung resections avoiding intercostal instrumentation could enhance the postoperative recovery of the patients, we chose to prospectively assess the recovery of patients via the QOR-15—a questionnaire previously used and validated in thoracic surgery to evaluate different surgical and anesthesia techniques (16,34-36). This questionnaire not only focused on pain but also on physical independence, comfort, and psychological state. Although the sample size was very limited, this initial study could provide data that could serve as a baseline or trigger for future studies. When considering the results of the means and medians of each of the defined time points, we observed that QOR was not characterized as “poor” at any point during the postoperative course. Furthermore, patients seemed to have almost fully recovered by POD30 as there was no significant difference between the baseline and POD30 QOR-15 scores (t=1.187, two-sided P=0.25), whereas their QOR scores were significantly different at the other registered time points (Figure 5). Although these results are indicative of a fairly well tolerated procedure and a fast postoperative recovery, the lack of statistical power will require further assessment in future studies, likely with a larger sample size and a comparative design. Additionally, while 30-day mortality is a standard metric for initial safety assessment, future studies should consider including 90-day mortality to provide a more comprehensive evaluation of postoperative outcomes. An important weakness of the study is that there was no control group and therefore QOR could not be compared to standard intercoastal RATS or VATS lobectomy patients.

The single-center and single arm design of this pilot study implies the inherent risk for selection and performance bias. Additionally, the modest cohort size and the technical variations employed limit the statistical strength of our findings, rendering the analysis of secondary outcomes as exploratory. Consequently, any perceived benefits in postoperative recovery or reduced pain could not be directly attributed to the OTC approach and must be interpreted as preliminary. Furthermore, all procedures were performed by a single, highly experienced robotic surgeon, and the outcomes may reflect this expertise. The impact of the learning curve for this novel approach in less experienced hands remains to be evaluated. That said, the compelling safety and feasibility results reinforced our early findings (15), and successfully met the core objective of this initial trial paving the way to the ongoing larger, multicentric and comparative studies with a standardized approach that are necessary to further assess safety, reproducibility, postoperative pain, recovery outcomes, and the actual clinical relevance of the technique.

Conclusions

This feasibility and safety trial was positive; OTC RATS lobectomy for resectable NSCLC could be feasible and safe. These results confirmed the outcomes of our first series and provided valuable data to support the progression to larger, multicentric, comparative studies to rigorously assess its postoperative benefits, reproducibility, and actual clinical relevance of this novel non-intercostal approach for thoracic surgery.

Acknowledgments

Abstract of the article has been presented in the International Thoracic Surgical Oncology Summit (ITSOS) of the American Association for Thoracic Surgery (AATS), in September 2023 at New York, NY, USA.

Footnote

Reporting Checklist: The authors have completed the TREND reporting checklist. Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1505/rc

Data Sharing Statement: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1505/dss

Peer Review File: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1505/prf

Funding: This research was supported by the Centre hospitalier de l’Université de Montréal (CHUM).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1505/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. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by institutional ethics board of the Centre hospitalier de l’Université de Montréal (CHUM) on February 14th, 2023 [IRB number: 22.228 (2023-11187)] and informed consent was obtained from all individual participants.

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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