A novel robotic-assisted thoracic surgery (RATS) technique: dual-portal RATS (DRATS) as a reduced-port RATS

Introduction

Background

In 1999, a robotic surgical system was introduced into the operating room, providing surgeons with three-dimensional vision and angled movements not possible with traditional video-assisted thoracic surgery (VATS) instruments (1). This superiority has contributed to the rapid spread of robotic-assisted thoracic surgery (RATS) worldwide. However, robotic surgery has some limitations, namely medical cost, operative time, requirement for specialized equipment, and lack of tactile sensation (2). On the other hand, to date, several studies evaluating the efficacy and safety of RATS have demonstrated its superiority over VATS (3-8). These studies report that the RATS group has less blood loss, a lower conversion rate to open surgery, a shorter hospital stay, greater lymph node dissection, and better 5-year disease-free survival compared with the VATS group (3-8).

Rationale

Almost two decades have passed since the first robotic pulmonary lobectomy was performed (9), and many thoracic surgeons have improved surgical techniques in robotic procedures based on their experience. On the other hand, the evolution of the uniportal approach is also growing very fast with the help of the latest technology during the last decade. The ability to combine the uniportal approach with robotic technology would be a tremendous improvement in terms of feasibility, safety, oncologic outcomes, and improved postoperative recovery. Recent studies have described the uniportal RATS (URATS) technique (10,11). However, URATS is an approach that requires specialized techniques and knowledge. In particular, small patients with small thoracic cavities, it is expected to suffer from interference from robotic forceps and robotic staplers. It is important that the benefits of robotic surgery, namely surgical maneuverability and staple stability, are maintained in the approach to reduced-port RATS. For the reason, before starting URATS, it is recommended that surgeons start with biportal RATS, which adds an additional port to the main access port (11).

Objective

Given the perspectives on assuring surgical safety, the implementation of biportal RATS may be a realistic step in the transition to URATS. Therefore, our surgical team has been using the two port RATS, hereafter referred to as dual-portal RATS (DRATS), since December 2022. In this paper, we present our DRATS technique for early stage lung cancer. In this paper, we present our DRATS technique for early stage lung cancer. We present this article in accordance with the SUPER reporting checklist (available at https://vats.amegroups.com/article/view/10.21037/vats-23-70/rc).

Preoperative preparations and requirements

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). The Institutional Review Board of the Ethics Committee of Yamagata University (No. 2023-197) approved this study on behalf of all participating institutions and waived the need for individual consent for this retrospective analysis and publication.

Based on our experience with uniportal VATS and multiportal RATS (MRATS), the DRATS concept was developed and initiated in December 2022. Seventy-two patients underwent anatomical lung resection via DRATS at three Japanese institutions from December 2022 to November 2023. The details of our experience with the procedure and perioperative results are shown in Table 1.

The surgical team at each hospital consisted of three surgeons: one chief surgeon at the console and two as bedside assistants. A surgeon from Yamagata University Hospital was always present at each operation to exchange information. Before the introduction of DRATS, each surgeon performed MRATS or uniportal VATS.

The patient is placed in the lateral decubitus position under general anesthesia with single-lung ventilation. At our institution, we use the da Vinci Xi Surgical System^® (Intuitive Surgical Inc., Sunnyvale, CA, USA). For the right approach, the robot is docked from the right side of the patient and the arm of the patient cart is rotated 90° toward the patient’s head. Conventional targeting is not required. For the right approach, arms 2, 3 and 4 are used, while arm number 1 is canceled (Figure 1). For the left approach, arms 2, 3 and 4 are used, while arm number 1 is canceled (Figure 1). To avoid collision, all arms are centered in the FLEX position and parallel. The same is set up on the left approach.

Figure 1 llustration for the port placement and set up of robotic arms in right upper lobectomy. Arm 1 is canceled, arm 2 is used for the camera (●), arm 3 is for the left hand (★), and arm 4 (▲) is for the right hand. The cross of the laser should be placed in the upper part of the skin incision posteriorly, parallel to the spine. An assistant surgeon was positioned at the patient’s right side.

In the DRATS approach, a 3–4 cm working port with a wound protector (Alexis Wound Retractors XS^®, Applied Medical, Rancho Santa Margarita, CA) is created in the 5th intercostal space (ICS) for upper lobe resection or in the 6th ICS for middle and lower lobe resection along the posterior axillary line as the main port (Figure 2). Additionally, a secondary port is made in the 6th or 7th ICS along the anterior axillary line for the right approach and in the 8th or 9th ICS along the posterior axillary line for the left approach. This secondary port is adjusted according to the body shape. We almost always use a 30 mm curved tip stapler (EndoWrist Stapler^®, Intuitive Surgical Inc.) and a 45 mm curved tip stapler (Sureform^®, Intuitive Surgical Inc.). The 60 mm stapler is rarely used due to angulation limitations. If we use the 60 mm stapler, it is used for the interlobar lung parenchyma located furthest from the secondary port. Using an 8 mm cannula in the second port allows the assistant to assist from the second port. If the assistance of an assistant from the second port is not needed, we insert the 12 mm port directly into the second port to shorten the exchange time to the 8 mm port. One of the reasons for placing another incision in a caudal location is to allow for proper internal articulation of the staplers. As this method allows us to avoid CO₂ insufflation, there is no need for caps seal. A slight cost reduction is achieved by eliminating the caps seal.

Figure 2 Typical images of the body surface. (A) Preoperative skin marking for right upper lobectomy. (B) A postoperative image with chest tube placed in the second port.

Step-by-step description

The robotic instruments most commonly used in DRATS are the left-hand bipolar fenestrated grasper for tissue grasping and the right-hand bipolar Maryland forceps for dissection. For certain maneuvers, we use the tip-up fenestrated grasper when we encounter a large artery or vein. Monopolar instruments allow for rapid dissection but generate heat that is harmful to adjacent structures. Bipolar instruments allow precise dissection around structures such as the pulmonary artery sheath, parabronchial tissue, and nerves.

The camera should be at 30 degrees and normally with a downwards orientation. However, when dissecting blood vessels, adhesions, or using staplers, it could be necessary to switch the angulation of the camera, with 30° upwards, working with the instruments above the camera. By changing the angle of the camera and adjusting the arm position according to the vertical position, any position in the thoracic cavity can be reached without restriction.

Another important aspect is the role of the assistant surgeon. To develop a good surgical field, we use long curved suction forceps and cotton forceps (Delta forceps^® SUGAI CORPORATION, Japan) with the help of the assistant surgeon. Other forceps used in uniportal VATS are also very effective in DRATS (Figure 3). These additional devices must be inserted below the trocar used for the camera to minimize interference with the robotic instruments. A single chest tube was placed in the second port by the assistant surgeon.

Figure 3 Forceps used by assistants in various surgeries. (A) Forceps usually used during uniportal video-assisted thoracoscopic surgery. (B) Longer surgical instruments designed for uniportal robotic-assisted thoracic surgery (Delta forceps^®; Sugai Corporation, Japan).

Right upper lobectomy is the most commonly performed anatomic lung resection

The incision is placed in the 5th ICS between the middle and posterior axillary lines. The thoracic cavity is observed and a secondary port is placed in the appropriate ICS. If the fissure is present in DRATS, after the posterior part of the fissure is divided, it seems more natural to first staple the upper lobe bronchus and then the pulmonary artery because the angle for stapling is the same as in MRATS. A vessel loop may be very helpful. After the artery is stapled, the anterior part of the fissure is divided and then the pulmonary vein is stapled (Video 1). If the fissure is incomplete, it seems more favorable to staple the vein first before stapling the artery (anterior trunk), bronchus, and finally the fissure.

Postoperative considerations and tasks

After the completion of surgery, we perform intracoastal nerve blocks (3–4 ICS) with 0.25% levobupivacaine and check for hemostasis and air leaks. The chest tube is carefully placed in the second port to avoid infection or pulmonary herniation. The ability to place a chest tube in a second port is another advantage of DRATS. Postoperative management follows the enhanced recovery after surgery protocol (12).

Tips and pearls

Docking of the da Vinci Xi can be performed quickly and easily due to the lesser number of skin incisions. It is important to note that the angle between the right and left arms should be 180 degrees vertically so that the arms do not interfere with each other. For example, the right arm of the robot is up in the monitor and the left arm is down. If the arms become locked due to interference, this can be corrected by moving the camera or synchronizing both hands. Once these new movements are mastered and the correct technique is learned, experienced URATS surgeons never experience collisions. There is no study on the learning curve for URATS anatomical lung resection, but experience with the uniportal VATS technique is expected to shorten this period.

Discussion

Surgical highlights

The reduced-portal access for RATS presents itself as a natural evolution of minimally invasive thoracic surgery. RATS was initially started as a multiportal approach and hybrid procedure with the use of thoracoscopic staplers by the assistant surgeon. However, due to the improvement of the da Vinci Surgical System, the main surgeon can now use the staplers from the console. The major benefits of robotic surgery for the main surgeon are surgical maneuverability and staple stability. It is important that the benefits be maintained even when performing reduced-port RATS.

Strengths and limitations

DRATS offers the advantages of robotic surgery, which may result in less pain and better postoperative outcomes (13). Compared with MRATS, the docking time and port placement in DRATS are faster without the need for targeting. Furthermore, because we use only three arms (two instruments instead of three) and no air seal and caps seal is required, DRATS is less expensive than MRATS. From a safety standpoint, the two ports in DRATS make it possible to perform an emergency thoracotomy to control excessive bleeding. Furthermore, a 4 cm skin incision is created in DRATS, making it easy to stick a hemostatic agent such as a TachoSil in the event of a vascular injury. The access into the thorax can be done either by uniportal VATS or by thoracotomy, depending on the situation and the preference of the surgeon. However, this surgical technique has some limitations. The assistant surgeon must be more skilled to assist in DRATS than in MRATS or uniportal VATS. Furthermore, the intraoperative instrumentation is different in DRATS compared with MRATS, so there is a learning curve for experienced robotic surgeons to learn how to avoid instrument collisions (as there is in URATS) (14). In addition, the assistant surgeon must be familiar with the uniportal VATS technique before assisting with DRATS. Once the new movements are mastered and the correct technique is learned, surgeons experienced in URATS have fewer instrument collisions. However, despite the short docking time, the time for DRATS lobectomy may be increased by the need for the assistant to replace one of the 8 mm trocars with a 12 mm trocar for stapler insertion, requiring readjustment of the arms each time. If the assistance of an assistant from the second port is not needed, we insert the 12 mm port directly into the second port to shorten the exchange time to the 8 mm port.

Comparison with other surgical techniques and studies

A meta-analysis of VATS reported that the blood loss, complications, and hospital stay do not significantly differ between uniportal VATS and biportal VATS (15). However, VATS results should not be used directly as RATS results, but may be used as a reference. DRATS results in less pain and better postoperative outcomes than three-port RATS lobectomy (13). We consider that more cases are needed to evaluate the technique and postoperative outcome in detail.

Implications and recommended actions

The advancement of surgery must follow the principles of the least invasive approach while adopting the most effective and precise technology. We are confident that URATS will gain more interest and popularity among thoracic surgeons in the coming years. However, URATS requires specific skills, and the robot stapler is particularly difficult to maneuver when performing URATS in small patients. Therefore, we introduced the DRATS technique, which adds a stapler port on the caudal side in addition to the main surgical incision. Now that the existing da Vinci Xi platform has been proven to be suitable for all types of intrathoracic resections with excellent results, the possibilities for improvement are promising. The development of dedicated thinner trocars, narrow instruments, and 8 mm staplers will help to facilitate the adoption of the DRATS technique worldwide.

Conclusions

Our experience suggests that DRATS is currently an improvement over the current URATS technique with its associated difficulties. The present study is only one of the first steps towards URATS. However, as the da Vinci Xi Surgical System^® (Intuitive Surgical Inc.) is not a single-port platform, DRATS is also a valid approach in its current state. We consider that DRATS is safe, feasible, and addresses the issues associated with URATS.

Acknowledgments

We thank Kelly Zammit, BVSc, from Edanz Group (https://en-author-services.edanzgroup.com/) for editing a draft of this manuscript.

Funding: None.

Footnote

Reporting Checklist: The authors have completed the SUPER reporting checklist. Available at https://vats.amegroups.com/article/view/10.21037/vats-23-70/rc

Peer Review File: Available at https://vats.amegroups.com/article/view/10.21037/vats-23-70/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://vats.amegroups.com/article/view/10.21037/vats-23-70/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. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). The Institutional Review Board of the Ethics Committee of Yamagata University (No. 2023-197) approved this study on behalf of all participating institutions and waived the need for individual consent for this retrospective analysis and publication.

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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