Uniportal robotic-assisted thoracoscopic lung resection with the da Vinci Xi surgical system: technical modifications and practical guidance

Introduction

Background

Lung cancer remains the most frequently diagnosed cancer worldwide and the leading cause of cancer-related death, accounting for nearly 2.5 million new cases and 1.8 million deaths in 2022 (1). Because surgical resection continues to play a central role in the curative treatment of early-stage and selected locally advanced non-small cell lung cancer, continued refinement of minimally invasive surgical approaches is of substantial clinical importance. Minimally invasive surgery for lung tumors has evolved significantly, expanding from multi-portal video-assisted thoracoscopic surgery (M-VATS) to uniportal VATS (U-VATS) and multi-portal robotic-assisted thoracoscopic surgery (M-RATS). M-RATS has gained widespread surgical acceptance because of its superior articulated dexterity and high-definition, tremor-free three-dimensional (3D) visualization. Consequently, the standardized multi-portal approach, primarily developed in North American and Italian institutions, has proliferated globally (2-4). Conversely, recent studies have reported that the oncological outcomes of U-VATS for lung cancer are comparable to those of M-VATS, establishing its clinical efficacy (5). Furthermore, evidence suggests that M-RATS may be associated with more intense postoperative pain than VATS (6). Therefore, for institutions that have already established U-VATS for early-stage lung cancer, the advantages of adopting M-RATS may be limited, and the optimal clinical indications for U-VATS versus M-RATS remain a subject of debate in the field of minimally invasive surgery.

Rationale

To address these challenges, uniportal robotic thoracoscopic surgery (U-RATS) lung resection using the da Vinci Xi system (Intuitive Surgical Inc., Sunnyvale, CA, USA) was first reported by Gonzalez-Rivas et al. (7-9). This technique is an improved procedure that does not require special new instruments, utilizes the existing da Vinci Xi surgical system, and is performed through a single port, similar to U-VATS. Subsequently, dual-portal robotic-assisted thoracoscopic surgery (D-RATS) for anatomical lung resection, which utilizes an additional port and arm, has also been reported from Japanese investigators (10,11). These approaches are collectively referred to as “reduced-port RATS” and continue to evolve through various refinements implemented by surgical teams worldwide.

Although previously reported U-RATS and D-RATS techniques have demonstrated technical feasibility, several practical limitations remain. In the conventional parallel cannula configuration, all robotic cannulas and the bedside assistant’s instruments must share a single small utility incision, which may restrict the assistant’s working space and increase interference among the robotic arms, cannulas, and assistant-held instruments. In addition, safe stapler insertion and angulation may become difficult in a limited intrathoracic space. Therefore, further refinement of instrument arrangement and stapling strategy is necessary to improve reproducibility, ergonomics, and operative stability in uniportal robotic lung resection.

To address these issues, we adopted a cross-cannula configuration in U-RATS using the da Vinci Xi system. We also incorporated the use of a manual stapler with staple-line reinforcement material during selected stapling steps. These modifications were intended to reduce interference around the incision, improve the effective bedside working space, facilitate safer stapler insertion, and enhance the reliability of staple-line formation.

Objective

In this report, we present the surgical approach and key technical maneuvers of U-RATS lung resection procedure using the da Vinci Xi surgical system at our institution, supplemented by video footage of an actual surgical case. In particular, we focus on two practical modifications: the cross-cannula configuration to reduce interference and optimize assistant access, and the use of a manual stapler with staple-line reinforcement material to improve stapling safety and stability. This technique is a minimally invasive approach aimed at achieving curative resection for lung cancer. This manuscript has been prepared in accordance with the SUPER checklist. The accompanying video demonstrates key intraoperative techniques, including the two-handed bipolar forceps technique, the silk loop technique, hot tearing with SynchroSeal, exposure techniques for the console surgeon and bedside assistant, manual stapling with staple-line reinforcement, and key steps of hilar and mediastinal lymph node dissection. We present this article in accordance with the SUPER reporting checklist (available at https://jovs.amegroups.com/article/view/10.21037/jovs-2026-0012/rc).

Preoperative preparations and requirements

Ethical consideration

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments, and was approved by the Ethics Committees of Yokosuka Kyosai Hospital and Yokohama City University Hospital (Nos. 25-74 and F260200057, respectively). Written informed consent was obtained from the patients for the publication of this study, accompanying images and the video. A copy of the written consent is available for review by the editorial office of this journal.

Setting

Yokosuka Kyosai Hospital is a tertiary general hospital, while Yokohama City University Hospital is a university medical school affiliated hospital. This procedure requires an extremely high degree of cleanliness, generally falling under Class II (Standard Clean Operating Room) or higher.

Patient selection and indications

Between December 2022 and February 2026, patients who underwent uniportal robotic-assisted thoracoscopic lung resection using this technique were included in the present study. The inclusion and exclusion criteria are described below, and the cohort did not represent a strictly consecutive series due to limitation on the number of da Vinci Xi system available.

Eligible patients included those with primary lung cancer at clinical stages I to IIIA (excluding infiltrative N2a) and those with oligometastatic lung tumors. For patients who underwent induction therapy, including immune-checkpoint inhibitors, the indications were limited to those who presented with discrete lymph node metastases prior to treatment, achieved downstaging, and were eligible for systematic lymph node dissection and radical lung resection from an oncological perspective. Patients undergo preoperative electrocardiography, blood gas analysis, and echocardiography if necessary to confirm the absence of severe cardiovascular comorbidities. They receive a preoperative consultation with the anesthesiology department to assess suitability for general anesthesia, lateral position, and single-lung ventilation. Four units of packed red blood cells are routinely prepared for immediate transfusion if needed. Absolute contraindications to this approach include inability to tolerate general anesthesia or single-lung ventilation, uncontrollable bleeding requiring immediate open access, and situations in which curative resection cannot be achieved by a minimally invasive approach. Relative contraindications include extensive dense pleural adhesions, markedly limited intrathoracic working space, severe calcified hilar lymphadenopathy, advanced central tumors requiring complex bronchovascular reconstruction beyond the team’s current technical indication, and patients in whom safe stapler insertion or assistant maneuverability is expected to be insufficient through a uniportal setting.

Operators

When performing this procedure, a team consisting of a board-certified thoracic surgeon (operator) and one experienced assistant surgeon were required. A third surgeon was not necessarily required. Our team consists of the primary operator (Y.I.), who has approximately 20 years of clinical experience in thoracic surgery and over 200 cases of robotic surgery experience; the co-primary operator (D.N.), who has approximately 10 years of clinical experience in thoracic surgery and approximately 15 cases of robotic surgery experience; and primary assistants (S.S. and N.U.), who each have approximately 6 years of clinical experience in thoracic surgery.

For surgeons who are new to this procedure, a stepwise training strategy is recommended. Before introducing U-RATS, surgeons should have sufficient experience in minimally invasive thoracic surgery, particularly M-RATS and/or U-VATS. Initial experience with D-RATS, careful review of operative videos, appropriate case selection, and supervision by experienced surgeons may facilitate safer adoption of the technique.

Equipment

Long curved suction forceps

Similar to U-VATS, this procedure requires a long, curved suction tip. A longer instrument provides greater freedom of maneuverability to avoid interference between the robotic arms and the bedside surgeon (BSS). For U-VATS, we use a 35-cm, strongly curved suction forceps, whereas for U-RATS, we primarily use a 43-cm, weakly curved suction forceps (DELTA uniportal VATS forceps, SUGAI Corp., Mie, Japan; see Figure 1A).

Figure 1 Equipment specific to the uniportal robotic lung resection. Left: curved suction forceps (DELTA uniportal VATS forceps, SUGAI Corp., Mie, Japan) used in U-VATS and U-RATS. L to R: strong-curved suction forceps (total length 35 cm), weak-curved suction forceps (total length 43 cm). The right longer model is particularly useful in U-RATS. Right: the Kittner Roll Gauze (ADACHI Co. Ltd., Osaka, Japan) we use. Total length 5 cm, relatively firm, and highly absorbent. U-VATS, uniportal video-assisted thoracoscopic surgery; U-RATS, uniportal robotic-assisted thoracoscopic surgery.

Kittner roll gauze (Cigarette Sponge)

For tissue protection during lung mobilization, blood absorption, and maintaining surgical field visibility, pre-manufactured 5-cm Kittner roll gauze is preferred (ADACHI Co, Ltd, Osaka, Japan; Figure 1B). Although handmade versions are acceptable if tightly rolled, they should possess sufficient firmness to facilitate lung retraction and field exposure, as described later.

Cannulas

Regarding the cannulas attached to the robotic arm in U-RATS, the use of flared cannulas—which are marketed for the transoral robotic surgery (TORS)—has been proposed for conventional (parallel) techniques. This is to reduce interference among the three cannulas inserted through a single incision in the anterior chest and to improve operability at the console. Although the flare cannula has a protrusion for connecting to the counter electrode (red arrow in Figure 2A), this is unnecessary for this procedure; therefore, using a modified version with this protrusion removed (Figure 2B) significantly reduces interference between the two components and is highly effective.

Figure 2 The original flare cannula for TORS and its modified version for U-RATS. Left: an original cannula for TORS. The part indicated by the red arrows is the counter-electrode connector. Right: the flare cannula with the counter-electrode connection point removed. Since there is minimal interference between cannulas, this improves maneuverability, particularly during the parallel method of U-RATS. TORS, transoral robotic surgery; U-RATS, uniportal robotic-assisted thoracoscopic surgery.

Following the original protocol, we generally utilized flare cannulas; however, when employing the cross-cannula technique, flare cannulas are not mandatory, and standard 8-mm cannulas are also used. As the main port remains open to the atmosphere in this technique, CO₂ insufflation is not utilized.

Step-by-step description

Initial setup and port creation

The procedure is performed under general anesthesia with one-lung ventilation using a double-lumen endotracheal tube. The patient is placed in the lateral decubitus position on a flat bed. A 4.0-cm main port is created, and an Alexis^® Wound Retractor (Applied Medical, Rancho Santa Margarita, CA, USA) size XS or S is inserted. We prefer size S as our first choice because its stronger wound-edge retraction provides a broader working space.

Roll-in and robotic positioning

After the main port is created, the da Vinci Xi patient cart is rolled in from either the cranial or dorsal side of the patient. As the BSS typically stands slightly caudal to the main port on the ventral side, the patient cart is positioned directly lateral to the incision. The boom is extended over the main port, and the cross-laser is aligned with the posterior margin of the wound.

Cannulas and arm configuration

Three of the four robotic arms are utilized, with the most dorsal arm retracted. The cannulas are not fixed to the chest wall; instead, they remain “floating” within the main port, which is open to the atmosphere. Consequently, CO₂ insufflation is not performed because adequate operative exposure could be obtained with the described traction and exposure techniques, while avoiding the additional setup and potential physiologic effects associated with capnothorax.

The insertion depth of the cannulas is generally set such that the upper edge of the remote center is at skin level; however, this varies with the chest wall thickness of the patient. To mitigate interference between the cannula mounts, the insertion depths are slightly staggered. The cannulas for the right- and left-hand instruments may be inserted slightly more shallowly.

We performed 36 cases of U-RATS anatomical lung resection between December 2022 and February 2026, utilizing the following two techniques of arm arrangement.

Original (parallel) technique

As reported by Gonzalez-Rivas et al., a 4-cm incision is made along the 6^th or 7^th intercostal space near the anterior-to-midaxillary line (6).

Right-side surgery: the 1^st arm is not used. The 2^nd (camera), 3^rd (left hand), and 4^th (right hand) arms are inserted in sequence from dorsal to ventral.

Left-side surgery: the 4^th arm is not used. The 3^rd (camera), 2^nd (right hand), and 1^st (left hand) arms are inserted in sequence from dorsal to ventral.

A 30° downward-viewing endoscope is generally used, and targeting is directed toward the apex. TORS-specific flare cannulas are employed to reduce arm interference. We utilized this technique in our initial 21 cases.

Cross-cannula technique

Similar to the original technique, three arms are used; however, the two instrument cannulas are crossed just below the incision. A 4.0 cm incision is made along the 5^th intercostal space for upper lobectomy and the 6^th intercostal space for middle, lower lobectomy, or lingular resections, centered on the midaxillary line. The arm arrangement is based on the “neoDRATS” approach reported by Ujiie et al. (10). The standard placement is shown below, but the relative positioning of the two crossed cannulas within the wound does not significantly affect the dissection procedures even if reversed. Therefore, the method of crossing the two cannulas is determined based on which one facilitates easier stapling with the dominant hand of the console surgeon.

After setting up the three arms and cannulas, touch “Settings”, “Hand Controls Assignments”, and “Configure” in sequence on the console panel. Change the left/right assignments for the 2^nd and 4^th arms during right-side surgery, and for the 1^st and 3^rd arms during left-side surgery, before beginning surgical procedures. Patient cart targeting is generally directed toward the hilum of the lung lobe to be resected, following the direction of the ribs. However, for upper lobe resection when performing subcarinal dissection of the bronchial bifurcation, targeting is slightly more caudal (i.e., directed toward the interlobar pulmonary artery trunk).

Right-side surgery: the 1^st arm was not used. The 2^nd arm (right hand) was inserted from the most ventral side toward the cranial direction. The 3^rd arm (camera, 0°) was placed most dorsally. The 4^th arm (left hand) was inserted from the center of the wound toward the caudal direction (Figure 3).

Figure 3 Cannula placement during right-sided surgery using the cross-cannula technique. Arm and cannula placement within the main port for right-side surgery using the cross-cannula technique. Photograph showing the view from the abdominal side of the patient positioned in the left lateral decubitus; the right side of the photograph is cephalic, the left side is caudal. The black numbers indicate arm numbers. The 2^nd arm (for the right hand) is inserted into the thoracic cavity from the most ventral part of the incision, with the tip directed slightly cephalad. The 3^rd arm (for the 0° camera) is inserted into the most dorsal part of the incision. The 4^th arm (for the left hand) is inserted into the central part of the incision, oriented caudally. Subsequently, the left and right assignments of the 2^nd and 4^th arms are swapped. The 1^st arm is not used. While three flare cannulas were used in this case, the procedure can also be performed with standard 8-mm cannulas.

Left-side surgery: the 1^st arm (right hand) is inserted from the most ventral side of the incision toward the caudal direction. The 2^nd arm (camera, 0°) is placed most dorsally. The 3^rd arm (left hand) is inserted from the center toward the cranial direction. The 4^th arm is unused (Figure 4). This technique is suitable for displacing the 1^st arm and inserting the manual stapler from the ventral side of the incision. However, when using a robotic stapler to divide vessels in the left upper lobe particularly the left superior pulmonary vein, it is preferable to insert the stapler into the thoracic cavity from as ventral and caudal a position as possible. Therefore, reversing the positional relationship of the 1^st and 3^rd arms from the above configuration is also an option. Specifically, we begin the surgery by assigning the 3^rd arm—inserted from the most ventral part of the incision toward the head—to the left hand, and the first arm—inserted from the center of the incision toward the tail—to the right hand. If the console surgeon is right-handed, the arm assignments are switched when operating the robotic stapler, and the robotic stapler inserted via the 3^rd arm is operated with the right hand.

Figure 4 Cannula placement during left-sided surgery using the cross-cannula technique. Standard arms and cannulas placement within the main port for left-side surgery using the cross-cannula technique. Photograph showing the view from the abdominal side of the patient positioned in right lateral decubitus; the left side of the photograph is the cephalic, and the right side is the caudal. The black numbers indicate the arm numbers. The 1^st arm (for the right hand) is inserted at the most ventral part of the incision, pointing caudally. The 2^nd arm (for the 0° camera) is inserted at the most dorsal part of the incision. The 4^th arm (for the left hand) is inserted at the center of the incision, pointing cranially. Subsequently, the left/right assignments of the 1^st and 3^rd arms are swapped. The 4^th arm is not used. When a right-handed console surgeon operates the robotic stapler, reversing the front-back relationship of the 1^st and 3^rd arms is an option.

This cross-cannula technique secures wider angles between the three arms, minimizing cannula interference and providing the assistant with a larger working space. Consequently, standard 8-mm cannulas can be used effectively without TORS-specific flare cannula. We adopted this modified technique in the latter 15 cases.

Surgical staplers

Generally, SureForm is preferred because of its high wrist mobility, allowing the surgeon to intuitively insert instruments into tissues with the aid of detailed 3D images. However, it has the disadvantage of making insertion into structures near the main port difficult. Furthermore, for cases with chronic obstructive pulmonary disease (COPD) comorbidity or elderly patients with fragile lungs and pleura, combining staple line reinforcement (SLR), which is only available for manual staplers (e.g., powered Echelon FLEX^®, Endo GIA^TM, or Signia^TM), is effective in preventing postoperative air leaks. Additionally, in cases with interstitial pneumonia comorbidity, SureForm may be unable to resect hard, thick lung tissue. Therefore, the BSS may opt to use a manual stapler with SLR. Issues with manual stapler operation include the requirement of some experience with the BSS and interference with the arm within the main port. However, because interference is minimal with the cross-cannula technique, we prefer lung resection using a manual stapler. Our policy is to use ECHELON ENDOPATH^® SLR with the powered Echelon FLEX^®, or Reinforced Reload with Tri-Staple^TM Technology with the Endo GIA^TM or Signia^TM, during lung resection in elderly patients or those with comorbid pulmonary conditions.

Representative operative case

Case summary (Video 1, Figure 5)

Figure 5 Key preoperative images for the case 1 presented in the video. Preoperative CT and PET/CT findings in case 1. A solid nodule measuring 2.5 cm in maximum diameter was identified immediately beneath the ventral pleura and the horizontal fissure-side interlobar pleura in the right middle lobe segment S5 (red arrow). A transbronchial biopsy confirmed adenocarcinoma. PET/CT showed FDG abnormal accumulation with SUVmax =11.4 at the primary lesion (white arrow) and SUVmax =3.6 at the right hilar region (blue arrow). CT, computed tomography; FDG, fluorodeoxyglucose; PET, positron emission tomography; SUVmax, maximum standardized uptake value.

The patient was 81-year-old man. For adenocarcinoma of the right middle lobe, cT2a (invading the upper lobe) N1 (#12) M0, stage IIB [Union for International Cancer Control (UICC) tumor, node, metastasis (TNM) 9^th ed.], we performed U-RATS right middle lobectomy, combined partial resection of the S3 invasion site, and subcarinal and paratracheal lymph node dissection. Preoperative computed tomography (CT) and positron emission tomography (PET)/CT images are shown in Figure 5.

Surgical procedure

A 4-cm incision was made anteriorly from the middle axillary line in the 6^th intercostal space, and an Alexis^® Wound Retractor (size S) was inserted. First, the middle lobe vein (V4+5) and the base of V2 were dissected. While harvesting lymph node #12 from the ventral side, the anterior surface of the middle lobe bronchus was dissected. The visceral pleura adhering between the middle and lower lobes was dissected to reach the interlobar pulmonary artery. The base of V5 was clipped and divided using a SynchroSeal. The lung parenchyma between the middle and lower lobes was divided using a p-Echelon 3000 60-mm gold with an SLR. V4+5 was divided using a p-Echelon 7 Flex. Lymph nodes #11 and #12 were then dissected.

Next, the procedure moved to the dorsal side of the lower lobe, where preparation for subcarinal dissection and dissection of the lateral aspect of #11 were performed. Returning to the ventral side, lymph node #11 was dissected. The lateral side of the interlobar PA was dissected, and the lung parenchyma near the confluence of the three lobes was divided using a p-Echelon 3000 60 mm gold with SLR. A distal A4 was clipped at its base with an ML clip and divided with a SynchroSeal. The middle lobe bronchus was divided using a p-Echelon 3000 60-mm gold. All staplers used thus far were inserted via the ventral edge of the main port by moving the 2^nd arm externally. The proximal A4+5 was divided using a p-Echelon 7 Flex. Only during this procedure was the 4^th arm retracted to the side, and the manual stapler was inserted from the center of the main port. This provided a more suitable angle for inserting the stapler into the bronchus and prevented interference between the 2^nd arm (right hand) and the stapler shaft during the subsequent lung lobe elevation maneuver performed with the 2^nd arm.

V2 was dissected as far distally as possible, and the middle lobe and S3 were mobilized. A 2-cm cranial margin from the tumor was secured, and the pleura at the resection line was sutured with 4-0 polydioxanone suture (PDS) for marking. Along this line, combined resection of the middle lobe and adjacent part of S3b was performed using a p-Echelon 3000 60-mm (3 reloads: black, black, gold; all with SLR). This stapling was also performed by utilizing the space created by bringing the 2^nd arm cannulas outside the wound.

The specimen was extracted. Systematic dissection of the subcarinal and paratracheal lymph nodes was performed. During the sealing test, a minor air leak was observed from the pleura at the S8 interlobar surface under a pressure of 15 cmH₂O inflation; however, it resolved spontaneously at 10 cmH₂O, and we determined it would resolve conservatively. A 20 Fr chest tube was placed in the anterior thoracic cavity. The wound was closed in a routine manner, and the surgery was completed. The total duration of the procedure was 214 minutes, with 80 mL of blood loss.

Postoperative considerations and tasks

Standard postoperative care and follow-up were administered. Postoperative residual lung expansion was evaluated using chest radiography. The chest tube was removed when the following criteria were met: (I) no air leak was detected under a three-bottle drainage system and (II) chest tube output was <50 mL within 6 h postoperatively. Patients were considered eligible for discharge if chest radiography on postoperative day 3 showed good lung expansion and transparency of the lung field, and their general condition was stable. Follow-up after discharge was conducted every 3 months for the first year, and every six months thereafter.

For pain management, we routinely performed percutaneous intercostal nerve blocks using local anesthetics prior to wound closure, including in the present case. Postoperatively, we routinely administered oral loxoprofen sodium hydrate or acetaminophen, with additional tramadol hydrochloride administered as needed. Prospective follow-up using the S-LANSS scoring system (12) was conducted at 2 weeks, 3 months, and 6 months postoperatively to assess postoperative intercostal neuralgia; cases with a score of 12 or higher at any of these time points were considered to have intercostal neuralgia.

Potential postoperative complications include prolonged air leak, atelectasis, pneumonia, and postoperative bleeding. These were managed according to standard thoracic postoperative protocols, including continued chest drainage and radiographic follow-up for air leak, bronchoscopy or antibiotic treatment when clinically indicated, and prompt re-evaluation for suspected bleeding or poor lung expansion.

Tips and pearls

Monitoring arm interference via an overhead camera

Most surgeons transition to U-RATS after gaining experience with M-RATS. Adapting to interference between robotic arms is essential in the initial stages. Monitoring arm movements using overhead cameras, such as those integrated into surgical lights, is highly effective. Connecting this footage to TilePro allows the console surgeon to observe movements in real-time (Figure 6). In particular, in early U-RATS cases, this enables position confirmation during arm interference and aids in understanding arm behavior. Furthermore, it is extremely useful for BSSs to visually confirm in real-time via the console feed that no unexpected external forces from arm movements are affecting manual stapler operation.

Figure 6 Fusion of the surgical field view and da Vinci camera images. A console image created by fusing the camera view looking down the entire surgical field with the stock image on the console using the Tile pro function.

Two-handed bipolar forceps technique and lung protrusion control technique

In U-RATS, the bulky robotic arm is positioned directly above the incision site and occupies considerable space. Consequently, the BSS can typically insert only one instrument. Thus, the console surgeon must take the lead role during lung retraction and field exposure. We adopted the “two-handed bipolar forceps technique”, equipping both hands with bipolar energy instruments (e.g., long bipolar forceps, Maryland bipolar forceps, and SynchroSeal). This allows not only gentle grasping of the lung but also the use of rolled gauze sandwiched between instruments to mobilize the lung, ensuring an optimal surgical field. Placing rolled gauze near the tissue to be dissected and utilizing the bent wrist of the robotic instrument to hold the gauze allows for stable lung compression. In such cases, dissection must be performed using only the instrument in the opposite hand. Surgeons should routinely practice dissection using bipolar instruments in their nondominant hand.

Hot tearing technique and needle grasping technique using SynchroSeal

We primarily use SynchroSeal for dissection. It allows for the coagulation and division of tissue, including pulmonary vessels up to 5 mm in diameter, without instrument exchange, thus reducing operative time and the burden on the BSS. For thin tissues, such as the pleura, we frequently use the “hot tearing” technique, in which the tips are inserted shallowly and activated for sharp dissection. SynchroSeal can also serve as a needle holder for simple suturing; however, grasping the needle with the tip should be avoided owing to insufficient grip. The flexible silicone pad within the jaws provides a secure grip for stable needle manipulation.

The silk loop technique for vascular and bronchial traction

After dissecting the target vessel or bronchus, we frequently employ the silk loop method, which involves encircling and tractioning the target vessel or bronchus using a 15 cm × 2-0 silk suture. When tying two sutures into a loop, robotic clips may be used; however, employing the two-handed bipolar forceps technique to align both ends, twist them, and pass them through the loop to create a simple knot is more economical (Figure 7). This allows for an adjustable traction force, thereby promoting optimal stapling. This technique is advantageous in U-RATS procedures, as traction can be maintained with a single instrument when using a manual stapler. Silk thread allows for safe stapling and cutting, is less expensive than silicone or rubber vessel loops, and eliminates concerns about residual material remaining in the body. During bronchial dissection in segmentectomy, intentionally allowing the stapler to bite the silk thread loop enables effective traction of the resection area during subsequent lung dissection.

Figure 7 The actual method of the silk loop technique. Step-by-step instructions on how to move both hands while holding silk thread. Arrows labeled L and R indicate the left/right identification of the instrument and the direction of movement. (I) Encircle the bronchus, blood vessel, or surrounding lung tissue with a 2-0 silk suture cut to 15 cm. Align both ends and grasp them with a bipolar forceps in the left hand. Hook the left side of the tip of the bipolar forceps (SynchroSeal in this case) in the right hand. The silk thread must be slack at this point. If the silk thread is taut, tension would be applied to the tissue in the following steps. (II) Rotate the right-hand forceps clockwise approximately 360°, then tilt them backward and bring them forward again, twisting the two threads so that they wrap around the tip of the right-hand forceps. Keep holding both ends of the thread with the left hand. (III) Push the thread wrapped around the right forceps tip slightly deeper to prevent it from slipping off. (IV) Transfer the two ends held by the left forceps to the right forceps for grasping. (V) Release the thread ends previously held by the left forceps. Re-grip the two threads wrapped around the tip of the right forceps. Pull the newly grasped thread through the loop you previously created, bringing it toward your hand. (VI) Carefully tighten the newly formed loop, taking care not to apply tension to the vessel or other structures.

Transitioning to D-RATS during the learning curve

To understand arm interference and the limitations of the BSS, we recommend starting with D-RATS. We initiated U-RATS after performing six D-RATS cases. In cases with poor visualization, such as in patients with severe emphysema, or when stapling angles are restricted, adding a caudal port to transition to D-RATS should be considered. Maintaining safety must always take precedence over insisting on a uniportal approach.

Ensuring safety

The most critical aspect of ensuring safety during robotic lung resection is preventing and managing pulmonary vascular injury. The console surgeon and BSS must maintain constant communication. Whenever there is even the slightest safety concern—such as the presence of inflammatory adherent lymph nodes or metastatic lymph nodes showing extra-nodal infiltration in the pulmonary vessels, or the discovery of an anatomical misidentification during surgery—the procedure should be paused immediately for consultation.

If pulmonary vascular injury occurs, the console surgeon and BSS must collaborate to immediately cover the injured area with lung tissue, apply pressure, and achieve primary hemostasis. Once primary hemostasis is achieved, clear the surrounding surgical field, prepare adequate suction equipment, and then identify the bleeding point. If primary hemostasis is inadequate or the bleeding point is difficult to identify, convert to emergency open thoracotomy. Extend the previously used main port and initiate thoracotomy. In this situation, the cross-cannula technique offers an advantage over the original technique because the main port is positioned one intercostal space higher and closer to the hilum, facilitating hemostasis. This is one reason we currently prefer the cross-cannula technique.

In cases of dense or complete intrathoracic adhesions, safe exposure and robotic maneuverability may be severely limited. In such situations, surgeons should not persist with the uniportal approach, and prompt addition of a supplementary port or conversion to another approach, including thoracotomy when necessary, should be considered to maintain safety.

For practical use, technical success of U-RATS with the cross-cannula technique may be defined as completion of the planned anatomical lung resection and lymph node dissection through the intended uniportal robotic approach without unplanned additional port placement, conversion to thoracotomy, or major intraoperative vascular/bronchial injury. Conversely, technical difficulty or failure should be considered when persistent arm interference, inadequate assistant working space, poor exposure, or unsafe stapler angulation prevents continuation of the planned procedure in a safe and oncologically appropriate manner. In such situations, prompt addition of a supplementary port or conversion to another approach should not be regarded as a complication, but as an appropriate safety measure.

Clinical outcomes

A total of 36 patients underwent uniportal robotic-assisted thoracoscopic lung resection during the study period. The median age was 75 years (range, 52–84 years), and the cohort included 18 men and 18 women. Lobectomy was performed in 18 patients, segmentectomy in 17, and bi-segmentectomy in one. The simplified clinical stage distribution was as follows: stage 0 in three patients, stage IA in 21, stage IB in three, stage IIA in two, stage IIB in three, stage IIIA in one, and metastatic lesions in three. Detailed clinicopathological characteristics, including pathological stage and histology, are summarized in Table 1.

In an exploratory comparison between the parallel group (n=21) and the cross-cannula group (n=15), the cross-cannula group was younger and had a lower Charlson comorbidity index than the parallel group [70 (range, 52–81) vs. 77 (range, 53–84) years, P=0.02; 0 (range, 0–3) vs. 2 (range, 0–4), P=0.02, respectively]. Console time was significantly shorter in the cross-cannula group [155 (range, 96–224) vs. 209 (range, 150–261) min, P<0.001]. In lobectomy cases only, the dissected/harvested lymph node count was significantly higher in the cross-cannula group [27 (range, 12–60) vs. 16 (range, 1–24), P=0.03]. Blood loss, chest tube duration, air leak duration, postoperative length of stay, intercostal neuralgia, and postoperative complications were not significantly different between the two groups. Intercostal neuralgia, defined as an S-LANSS score of 12 or higher at any of the 2-week, 3-month, or 6-month postoperative assessments, was identified in six patients overall, including four of 21 patients in the parallel group and two of 15 patients in the cross-cannula group (Table 2).

Discussion

Compared with U-VATS, a potential advantage of U-RATS is that it combines the uniportal approach with the technical benefits of robotic surgery, including wristed instrument articulation, stable 3D visualization, and tremor filtration. These features may facilitate more precise hilar dissection, lymph node dissection, and fine manipulation in technically demanding situations, while maintaining the potential benefit of reduced chest wall invasiveness associated with a single-incision approach.

A key modification in our series is the cross-cannula technique, which effectively minimizes physical interference between the robotic arms within the limited space of a 4-cm incision. Unlike the original parallel technique, crossing the instrument cannulas just below the incision provides a wider working angle and increases the maneuverability of the assistant. Furthermore, our use of a manual stapler with SLR provides stability even in patients with fragile lung tissue or interstitial pneumonia, conditions in which robotic staplers may face limitations.

In U-RATS, the absence of a fourth lung retraction arm requires the console surgeon to take an active role in field exposure. We found the two-handed bipolar forceps technique, using rolled gauze sandwiched between robotic instruments, highly effective for stable lung compression and retraction. In addition, the silk loop technique allows adjustable traction of vessels and bronchi, which is particularly advantageous when the robotic system is limited to single-arm retraction during manual stapling.

In our experience of 36 cases, R0 resection was achieved in all patients without severe intraoperative vascular or bronchial injuries. Postoperative intercostal neuralgia was prospectively assessed using the S-LANSS at 2 weeks, 3 months, and 6 months after surgery. Intercostal neuralgia was identified in six of 36 patients overall, including four of 21 patients in the parallel group and two of 15 patients in the cross-cannula group, with no significant difference between the groups (Table 2). These findings suggest that the cross-cannula approach is not associated with an increased incidence of postoperative intercostal neuralgia, although any pain-related advantage remains to be established.

However, this technique has a learning curve, primarily due to arm interference and restricted assistant movements. We recommend adding a caudal port in difficult cases to maintain surgical safety.

The present comparative analysis should be interpreted cautiously. The comparison between the parallel and cross-cannula groups was exploratory, and the cohorts were sequential rather than randomized. In addition, the cross-cannula group was younger and had a lower comorbidity burden, and a learning-curve effect cannot be excluded. The study is also limited by its small sample size and the experience of only two institutions, and follow-up remains limited. Therefore, the present report should be interpreted primarily as a practical description of technique refinement rather than as definitive evidence of superiority over other minimally invasive approaches.

Despite these limitations, the clinical value of the cross-cannula technique lies in its ability to reduce interference around the incision, improve the ergonomic relationship between the console surgeon and bedside assistant, and facilitate safer manual stapling in selected patients. In addition, because this approach can be implemented using the existing da Vinci Xi platform without requiring a dedicated new robotic system, it may offer practical advantages for institutions seeking incremental refinement of reduced-port robotic surgery. Future studies should focus on reproducibility, training, safety, and procedure-specific outcomes of this modified U-RATS technique.

Conclusions

U-RATS using the da Vinci Xi system is a safe and feasible evolution in minimally invasive thoracic surgery. By integrating the technical precision of robotic instrumentation with a single-port approach, this technique may reduce chest wall trauma; however, any pain-related advantage should be interpreted cautiously and requires further validation in larger comparative studies.

Our modified approach—specifically, the “cross-cannula technique” and the use of manual staplers with reinforcement—successfully addresses the inherent challenges of instrument interference and field exposure in a restricted space. Although a learning curve exists and further large-scale, comparative studies are necessary to confirm its long-term benefits, our initial experience suggests that U-RATS is a promising surgical option that maintains oncological principles while aiming to reduce procedural invasiveness and support postoperative recovery. However, formal evaluation of patient-reported quality-of-life outcomes will be necessary in future studies.

Acknowledgments

None.

Footnote

Provenance and Peer Review: This article was commissioned by the Guest Editor (Hideki Ujiie) for the series “Reduced Port Robotic-assisted Thoracic Surgery” published in Journal of Visualized Surgery. The article has undergone external peer review.

Reporting Checklist: The authors have completed the SUPER reporting checklist. Available at https://jovs.amegroups.com/article/view/10.21037/jovs-2026-0012/rc

Peer Review File: Available at https://jovs.amegroups.com/article/view/10.21037/jovs-2026-0012/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jovs.amegroups.com/article/view/10.21037/jovs-2026-0012/coif). The series “Reduced Port Robotic-assisted Thoracic Surgery” was commissioned by the editorial office without any funding or sponsorship. The authors have no other 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, and was approved by the Ethics Committees of Yokosuka Kyosai Hospital and Yokohama City University Hospital (Nos. 25-74 and F260200057, respectively). Written informed consent was obtained from the patients for the publication of this study, accompanying images and the video. A copy of the written consent is available for review by the editorial office of this journal.

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/.

References

1. Bray F, Laversanne M, Sung H, et al. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin 2024;74:229-63. [Crossref] [PubMed]
2. Veronesi G, Galetta D, Maisonneuve P, et al. Four-arm robotic lobectomy for the treatment of early-stage lung cancer. J Thorac Cardiovasc Surg 2010;140:19-25. [Crossref] [PubMed]
3. Cerfolio RJ, Bryant AS, Minnich DJ. Starting a robotic program in general thoracic surgery: why, how, and lessons learned. Ann Thorac Surg 2011;91:1729-36; discussion 1736-7. [Crossref] [PubMed]
4. Dylewski MR, Ohaeto AC, Pereira JF. Pulmonary resection using a total endoscopic robotic video-assisted approach. Semin Thorac Cardiovasc Surg 2011;23:36-42. [Crossref] [PubMed]
5. Sudarma IW, Pertiwi PFK, Yasa KP, et al. Outcomes of Uniportal Video-Assisted Thoracoscopic Surgery in the Management of Lobectomy and Segmentectomy for Lung Cancer: A Systematic Review and Meta-Analysis of Propensity Score-Matched Cohorts. Ann Thorac Cardiovasc Surg 2025;31:24-00137. [Crossref] [PubMed]
6. Kawaguchi K, Ogura T, Kaneda S, et al. A prospective multi-institutional study to verify the non-inferiority of postoperative pain in robot-assisted thoracic surgery in comparison with video-assisted thoracoscopic surgery for lung cancer: The Japanese RATS interest group 01 (J-RATSIG 01). Lung Cancer 2024;196:107961. [Crossref] [PubMed]
7. Gonzalez-Rivas D, Bosinceanu M, Motas N, et al. Uniportal robotic-assisted thoracic surgery for lung resections. Eur J Cardiothorac Surg 2022;62:ezac410. [Crossref] [PubMed]
8. Gonzalez-Rivas D, Manolache V, Bosinceanu ML, et al. Uniportal pure robotic-assisted thoracic surgery-technical aspects, tips and tricks. Ann Transl Med 2023;11:362. [Crossref] [PubMed]
9. Yang Y, Song L, Huang J, et al. A uniportal right upper lobectomy by three-arm robotic-assisted thoracoscopic surgery using the da Vinci (Xi) Surgical System in the treatment of early-stage lung cancer. Transl Lung Cancer Res 2021;10:1571-5. [Crossref] [PubMed]
10. Watanabe H, Ebana H, Kanauchi N, et al. Dual-portal robotic-assisted thoracic surgery (DRATS) as a reduced port RATS: early experiences in three institutions in Japan. J Thorac Dis 2023;15:6475-82. [Crossref] [PubMed]
11. Ujiie H, Ebana H, Suzuki J, et al. Developing novel non-assistant help operation in dual-portal robotic-assisted thoracic surgery (neoDRATS). JTCVS Tech 2024;27:146-50. [Crossref] [PubMed]
12. Bennett MI, Smith BH, Torrance N, et al. The S-LANSS score for identifying pain of predominantly neuropathic origin: validation for use in clinical and postal research. J Pain 2005;6:149-58. [Crossref] [PubMed]