Surgical technical aspects of uniportal hybrid RATS and biportal pure RATS using a subcostal port

Introduction

Since 2021, multiportal robot-assisted thoracic surgery (RATS) has developed into a more minimally invasive approach, uniportal RATS (1,2), as conventional multiportal video-assisted thoracic surgery (VATS) has developed into uniportal VATS. Uniportal RATS employs a 4-cm single incision operating three robotic arms through each 8-mm trocar. Comparative studies and reviews reported feasible short-term safety and recovery outcomes (3-6). A recent comparative study revealed that uniportal RATS had lower postoperative analgesic requirements and shorter hospital stays than multiportal RATS (7). In uniportal pure RATS (2,8), the console surgeon controls robotic stapling by converting an 8-mm trocar to a 12-mm trocar. This allows surgeons to perform a minimally invasive approach in which all procedures are robotically controlled. Although uniportal pure RATS seems to be the ultimate surgical approach, this approach is not applicable to every patient owing to the following technical issues. The handling difficulties of the robotic stapler in uniportal pure RATS due to the insufficient distance from the trocar to the hilar structure seem to limit the surgical indications in some patients, such as patients with short stature and those undergoing middle lobectomy. We observed that the robotic stapler exhibited unintentional movement when the surgeon pulled the stapler further when it was too close to the target structure.

Alternative approaches are therefore required to overcome the limitations of uniportal pure RATS. In hybrid RATS, a bedside assistant handles the VATS staplers (9). The uniportal VATS technique can be used for uniportal hybrid RATS (10). As VATS staplers have a relatively shorter distance from the hinge to the top of the stapler than robotic staplers, handling VATS staplers in uniportal hybrid RATS is more feasible for any patient. Another more feasible minimally invasive approach is a second port placement in addition to a 4-cm wound; this is biportal RATS (11-13). An additional port placed caudally allows surgeons to handle the staplers more freely, even in robotic stapling. Biportal RATS is recommended to enable surgeons to become accustomed to reduced-port RATS before initiating uniportal RATS (8). However, even after the adoption of uniportal RATS, biportal RATS remains valuable in some patients who have difficulty adapting to uniportal RATS.

Herein, we present our innovative techniques for uniportal hybrid RATS and biportal pure RATS with a subcostal port as alternatives to uniportal pure RATS. In uniportal hybrid RATS, we describe the placement of standard 8-mm trocars in a triangular configuration and the manipulation of forceps in head-to-tail positioning to avoid collisions between the trocars and robotic arms. In biportal pure RATS, we describe the insertion of an additional port placed under the costal arch to expect lower pain in the port and provide sufficient distance from the hilar structure. These surgical approaches are particularly useful for patients of short stature, those undergoing middle lobectomy, complex segmentectomies in the lower lobe, and dissection of the inferior pulmonary vein. In the videos, we highlight the operation of robotic forceps to avoid collision in a 4-cm wound in uniportal RATS and subcostal port placement in biportal RATS. We present this article in accordance with the SUPER reporting checklist (available at https://jovs.amegroups.com/article/view/10.21037/jovs-2025-1-63/rc).

Preoperative preparations and requirements

The study was approved by the Institutional Review Board for Clinical Research of Kansai Medical University Medical Center (No. 2024278) and was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Individual consent for this study, accompanying images, and the videos was waived by the Institutional Review Board.

All procedures were performed at Kansai Medical University Medical Center. The operation was performed by the thoracic surgery team in an operating room equipped for robotic thoracic surgery.

The console surgeon and assistant surgeon in a patient cart performing uniportal RATS need to be proficient in uniportal VATS, due to a downward-looking 30-degree camera view located at the cranial edge of the access port and cramped manipulation of robotic forceps. However, those performing biportal RATS do not necessarily need to be experienced in uniportal VATS because of more feasible manipulation of robotic forceps compared to uniportal RATS. The surgical team must be experienced in robotic surgery.

Uniportal hybrid RATS and biportal RATS (Figure 1) are especially indicated in cases of limited adaptation to uniportal pure RATS, such as in patients with short stature (approximately less than 150 cm), those undergoing middle lobectomy, complex segmentectomies in the lower lobe, and dissection of the inferior pulmonary vein. For any patient, biportal RATS is technically more feasible and appears to be a universally available approach for thoracic surgery. Therefore, biportal RATS seems to have no contraindication.

Figure 1 Placement of three trocars in uniportal RATS (A) and biportal RATS (B). RATS, robotic-assisted thoracic surgery.

Patients undergo oncological evaluation via chest CT, head MRI, and PET scans, and their surgical tolerance is assessed through electrocardiograms, echocardiograms, pulmonary function tests, and blood tests.

Step-by-step description

Placement of three trocars and robotic arms in a 4-cm wound

Three standard 8-mm trocars could not be placed in line in a 4-cm wound because of their volume. Therefore, the three trocars were arranged alternately in a 4-cm access port. A 30° robotic camera was utilized, providing a downward-looking view, similar to that in uniportal VATS, located at the cranial edge of the access port. Therefore, the camera arm was inserted slightly tangential to the chest wall. The middle trocar and robotic arm in the 4-cm wound were alternately inserted slightly perpendicular to the chest wall to avoid collision with the camera arm. The remaining trocar and robotic arm on the other side of the wound were inserted slightly tangential to the chest wall to prevent collision with the middle arm. Figure 1A shows the actual arrangement of the three trocars and robotic arms, which resembles a triangle. Maintaining the trocar arrangement as much as possible avoids collisions between the trocars and robotic arms.

Operation of robotic forceps to avoid collision in a 4-cm wound

Operation of the two robotic arms inserted through a 4-cm access port with the camera is quite limited, owing to the collisions between the robotic forceps and the camera. Generally, spreading forceps inside the chest cavity in the direction of the skin incision causes easier collisions between the trocars and robotic arms outside. The operation that causes the collision is illustrated using the model shown in Figure 2A. Inside the chest cavity, positioning the forceps in the head-to-tail direction as much as possible can avoid external collisions of the trocars and robotic arms, as shown in Figure 2B. The operation of the two forceps in head-to-tail positioning appears to be difficult; however, it allows for any operation without collisions (Figure 2B).

Figure 2 Operation of robotic forceps using the model. Spreading forceps inside the chest cavity in the direction of the skin incision causes easier collisions between the trocars and robotic arms outside (A). Positioning the forceps in the head-to-tail direction avoids external collisions of the trocars and robotic arms (B). Reprinted from the reference (14) with permission from Nankodo.

Subcostal port placement in biportal RATS

An additional port aside from a 4-cm access port, that is, biportal RATS, allows for a much easier operation of the forceps than uniportal RATS. Among the variations of additional port placement in biportal RATS (8,11-13), the subcostal port is expected to reduce pain by avoiding the intercostal route in the additional port and provide sufficient distance to the hilar structure for a highly flexible operation, especially in robotic stapling.

The insertion of the subcostal port is shown (Video 1). A small incision for an 8-mm or 12-mm trocar was made under the costal arch, and the fascia between the costal arch and the peritoneum and diaphragm was dissected using a finger and Kelly forceps. The trocar was inserted into the thoracic cavity through the diaphragm outside the peritoneum (Figure 1B).

Settings of uniportal hybrid RATS

The da Vinci Xi Surgical System (Intuitive Surgical Inc., Sunnyvale, CA, USA) was used without CO₂ insufflation. Incisions were made in the sixth or seventh intercostal space along the mid-axillary line (Figure 3A). The skin incisions were 4 cm long, and a wound protector was placed on the incision. We used three standard 8-mm trocars for a 4-cm incision and three robotic arms. A 30° camera was placed on the posterior and upper edges of the incision. Fenestrated and Maryland bipolar devices were used for the other two arms. Three trocars and robotic arms were placed to avoid collisions, as shown in Figure 1A. The space between the three trocars allowed the assistant to insert and remove the devices and the dissected lymph nodes (LNs). For lung and vascular stapling, a bedside assistant used a VATS stapler.

Figure 3 Location of the skin incisions. (A) Skin incision for uniportal RATS; (B) biportal RATS with a subcostal port. RATS, robotic-assisted thoracic surgery.

Settings of biportal pure RATS with a subcostal port

The use of the da Vinci Xi Surgical System, with no CO₂ insufflation, creation of an access port with a 4-cm skin incision, and the use of a wound protector were the same as those used for uniportal hybrid RATS. In the additional port, an 8-mm or 12-mm trocar was inserted under the costal arch (Figure 3B) through the diaphragm into the thoracic cavity. The space between the two trocars in the access port is broader than that in uniportal RATS, allowing the assistant to insert and remove the devices and dissected LNs more easily. Stapling was performed using a robotic stapler through the additional port.

A case of uniportal hybrid RATS in right lower lobectomy and resection of a thymic cyst

A 73-year-old woman with asthma underwent right lower lobectomy for lung adenocarcinoma (T1bN0M0) and resection of an anterior mediastinal tumor for a thymic cyst.

The patient was placed in the left lateral decubitus position, and the incision and setup were as follows. An access port measuring 4 cm was placed in the 7^th intercostal space at the mid-axillary line using a wound protector. A 30° camera was placed on the dorsal side of the access port. Two robotic arms were inserted through the remaining space of the access port using 8-mm trocars.

The surgical procedures for right lower lobectomy in uniportal hybrid RATS are shown in Figure 4 and Video 2, focusing on the dissection of the hilar and mediastinal LNs. Figure 4A shows the dissection of the pulmonary artery, and Figure 4B,4C show the dissection of the hilar LNs (4B: #11s LN and 4C: #11i LN) between the lobes. Figure 4D,4E show the dissection of the hilar LNs (#11s LN) from the dorsal side. Figure 4F shows the dissection of the subcarinal LNs (#7 LN).

Figure 4 A case of uniportal hybrid RATS in right lower lobectomy. The dissections were performed for the pulmonary artery (A), the hilar LN (B: intralobar #11s LN, C: intralobar #11i LN, D: #11s LN viewed from the back, and E: #11s LN removed as a single mass), and the subcarinal LN (F). LN, lymph node; RATS, robotic-assisted thoracic surgery.

In Video 2, first, the movement of robotic arms was demonstrated from the outside. Adhesion to the chest wall was released. The interlobar folds were peeled back to expose the pulmonary artery. The hilar LNs were dissected. A Penrose was inserted to serve as a guide for excising the incomplete lobulation between the middle and lower lobes, and the incomplete lobe was dissected using a VATS stapler. More hilar LNs were dissected from the ventral and dorsal sides. The pulmonary ligament was dissected. The subcarinal LNs were dissected. A Penrose was inserted to serve as a guide for excising the pulmonary artery, and the artery was dissected using a VATS stapler. The pulmonary vein and bronchus of the lower lobe were dissected using a VATS stapler. The thymic cyst was resected. The right lower lobe and thymic cyst were placed in a bag and removed from the thoracic cavity. Finally, no air leaks were confirmed.

To prevent interference, the robotic arms are consistently positioned with the right arm cranial and the left arm caudal within the surgical field. In any procedure, the surgical field can be developed without assistance by retracting the lungs using a forceps shaft and barrel-shaped gauze. In this case, VATS staplers (Powered ECHELON FLEX 7^® and Powered ECHELON 3000^®; Ethicon Endo-Surgery, Inc., Cincinnati, OH, USA) were used.

The operative and console times were 149 and 117 min, respectively. The intraoperative blood loss was 10 mL. The chest drainage tube was removed on postoperative day 2. The patient was discharged on postoperative day 5. After discharge, the patient experienced no postoperative complications and has shown no signs of recurrence in the year following surgery.

A case of biportal pure RATS with a subcostal port in middle lobectomy

An 82-year-old woman with aortic valve stenosis underwent middle lobectomy for lung adenocarcinoma (T1cN0M0). Her height was 142 cm.

The patient was placed in the left lateral decubitus position, and the incision and setup were as follows. A 4-cm access port was placed in the 7^th intercostal space at the mid-axillary line with a wound protector, and an additional port was placed under the costal arch. A 30° camera was placed on the dorsal side of the access port. One robotic arm was inserted through the remaining space of the access port with an 8-mm trocar, and the other robotic arm was inserted through the additional port with an 8-mm trocar.

The surgical procedures for middle lobectomy in biportal pure RATS are shown in Figure 5 and Video 3, focusing on the angle of the robotic stapler and the location of the top of the stapler. All robotic stapling procedures were performed using 30-mm and 45-mm SureForm^® (Intuitive Surgical, Inc.). As the stapler was inserted into the target structures at an angle that required minimal bending of the hinge, the top of the stapler was visible to the surgeon and free from adjacent tissues, without causing any injury. Figure 5 shows the pulmonary artery (Figure 5A,5B), pulmonary vein (Figure 5C), and middle lobar bronchus (Figure 5D). In the patient with short stature, robotic stapling in the middle lobectomy was safely performed in biportal RATS.

Figure 5 A case of biportal pure RATS in middle lobectomy. The staplings were performed for the pulmonary artery (A: A4, B: A5), pulmonary vein (C), and bronchus (D). RATS, robotic-assisted thoracic surgery.

In Video 3, the interlobar folds were peeled back to expose the pulmonary artery. The pulmonary vein was exposed and the hilar LNs were dissected. A Penrose was inserted to serve as a guide for excising the incomplete lobulation between the middle and lower lobes, and the incomplete lobe was dissected using a 30-mm SureForm^®. The pulmonary artery A5 was dissected using a 30-mm SureForm^® and incomplete lobe between the upper lobe and middle lobe was dissected using a 45-mm SureForm^®. The pulmonary artery A4 was dissected using a 30-mm SureForm^®. Using a Penrose as a guide, the pulmonary vein was dissected using a 30-mm SureForm^®. The bronchus of the middle lobe was dissected using a 30-mm SureForm^®. The middle lobe was removed and no air leaks were confirmed.

The operative and console times were 105 and 65 min, respectively. The intraoperative blood loss was 5 mL. The chest drainage tube was removed on postoperative day 2. The patient was discharged on postoperative day 4. After discharge, the patient experienced no postoperative complications and has shown no signs of recurrence for two years following the procedure.

Postoperative considerations and tasks

With the subcostal port in biportal RATS, air may enter the abdominal cavity due to damage to the peritoneum. However, since CO₂ insufflation is not performed, this does not obstruct the surgical field during the procedure. It does not cause any problems postoperatively, and the air is absorbed within a few days. Postoperative patient management is not specific to uniportal hybrid RATS or biportal pure RATS. Following lung resection, appropriate postoperative management is required, keeping the following common complications in mind: bleeding, air leak, atelectasis, pneumonia, arrhythmia, and surgical site infection. There are no specific monitoring methods directly related to these surgical techniques. Patients are allowed to drink water 4 h after surgery and start walking inside the ward for early mobilization (15). Patients are instructed to perform incentive spirometry to facilitate pulmonary recovery and an effective cough. The chest drainage tubes were removed on postoperative day 1 or 2.

The mean length of hospital stay after surgery was 5 days for 32 consecutive patients who underwent uniportal RATS and 6 days for 30 consecutive patients who underwent biportal RATS with a subcostal port; there were no readmissions or deaths within 90 days for either procedures in the series of patients.

These surgical approaches do not require a specific follow-up program. During a follow-up visit 1–2 weeks after discharge, the postoperative condition in patients who performed those surgeries is assessed through laboratory data and chest X-rays. If no adjuvant chemotherapy is administered, follow-up visits are scheduled every 3–6 months.

Tips and pearls

In uniportal RATS, the console surgeon must move the two robotic arms in parallel. If only one is moved sideways, the trocar and the robotic arms will collide. In particular, when using three standard 8-mm trocars, a triangular formation of the three trocars and positioning of the forceps in a head-to-tail orientation can help prevent collisions between the trocars and the robotic arms. However, these surgical procedures can be quite stressful for console surgeons. While modifying and using a flare trocar may raise safety concerns related to the modification, it is expected to ease restrictions on surgical maneuvers and reduce stress for console surgeons.

In biportal RATS, the operative restrictions in uniportal RATS described above are significantly relaxed. In particular, robotic staplers are likely to become much easier to use for the console surgeons. Therefore, when transitioning from conventional RATS to reduced-port RATS, the first type of approach to aim for is biportal RATS.

Discussion

Technical difficulties limit surgical indication in procedures of uniportal RATS, especially for robotic stapling in uniportal pure RATS. In this report, we discussed the technical issues associated with uniportal hybrid RATS and biportal pure RATS with a subcostal port as alternatives to uniportal pure RATS. In uniportal RATS, we presented the placement of three trocars in a triangular configuration and the manipulation of the forceps in a head-to-tail positioning, which helps avoid collisions between the trocars and robotic arms. In biportal pure RATS, we presented the insertion of a subcostal port as an additional port to reduce pain in the additional port site and obtain sufficient distance for the safe manipulation of robotic staplers.

In uniportal pure RATS, there is certainly an issue of insufficient distance of the robotic stapling. One practical solution to this problem is to operate the robotic stapler with the trocar retracted by a few centimeters. Bongiolatti and colleagues reported this technique as “fly-mode” (16). There are several points to note regarding this operation. First, shifting the trocar a few centimeters outside the body causes the fulcrum of the robotic forceps to shift outside the body. If the robotic forceps are moved significantly in this state, excessive force is applied to the ribs, posing a risk of fracture. Second, if the trocar is shifted further outward so that the hinge of the stapler is close to the wound, the stapler may move in the opposite direction to that intended by the surgeon. Due to these precautions, when moving the trocar out of the body, the console and assistant surgeons must work together to monitor the position of the trocar and the movement of the robotic stapler. Alternatively, the approaches introduced in this manuscript can be used.

Reduced-port RATS, such as uniportal and biportal RATS, can provide minimally invasive and precise robotic instrument control. However, there is no one-size-fits-all approach to reduced-port RATS, as each RATS approach has limitations. Regarding minimally invasive procedures, uniportal RATS is the best among biportal and multiportal RATS, because of the minimal size of the wound. In terms of material cost, robotic staplers are more expensive than VATS staplers. Therefore, hybrid RATS using a VATS stapler is more adaptable than pure RATS using a robotic stapler in this respect. For assistants who are not accustomed to uniportal VATS, pure RATS is safer than hybrid RATS, because it allows surgeons to control all procedures. For surgeons who are not accustomed to performing reduced-port RATS, biportal RATS is more feasible than uniportal RATS, owing to the technical difficulties of uniportal RATS. Given these aspects, including minimal invasiveness, material cost, assistance and surgeon expertise, the appropriate surgical approach should be selected based on the institutional situation.

In patients who are less likely to be eligible for uniportal pure RATS, such as those with short stature, uniportal hybrid RATS and biportal pure RATS are alternative surgical approaches. Biportal RATS is feasible for surgeons, assistants, and patients.

Conclusions

In this paper, we present uniportal hybrid RATS and biportal pure RATS with a subcostal port. Reduced-port RATS can provide minimally invasive and precise control of the robotic instruments. Although uniportal RATS is the most minimally invasive, biportal RATS appears to be universally feasible. Studies are needed to verify the efficacy of these procedures.

Acknowledgments

The authors would like to thank Dr. Takahito Nakano for his contribution to the establishment of surgical procedures for uniportal and biportal RATS.

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-2025-1-63/rc

Peer Review File: Available at https://jovs.amegroups.com/article/view/10.21037/jovs-2025-1-63/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-2025-1-63/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 approved by the Institutional Review Board for Clinical Research of Kansai Medical University Medical Center (No. 2024278) and was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Individual consent for this study, accompanying images, and the videos was waived by the Institutional Review Board.

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. 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]
2. 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]
3. Serratosa I, Déniz C, Macia I, et al. Advancing minimally invasive thoracic surgery: comparative insights into uniportal and multiportal robotic approaches for non-small cell lung cancer. Gen Thorac Cardiovasc Surg 2026;74:400-9. [Crossref] [PubMed]
4. Alturki A, Alturki F, Koziej PH, et al. Perioperative outcomes of uniportal robotic‑assisted thoracic surgery (U-RATS) for lung resection: state of the art—a narrative review. Curr Chall Thorac Surg 2024;6:33.
5. Wilson-Smith AR, Wilson-Smith CJ, Anning N, et al. The perioperative outcomes of uniportal robotic-assisted thoracic surgeries-a systematic review and meta-analysis of surgical cohort studies and case reports. Ann Cardiothorac Surg 2023;12:73-81. [Crossref] [PubMed]
6. Kaneda H, Nakano T, Utsumi T, et al. Feasibility and safety of uniport robotic-assisted thoracoscopic surgery in initial series of anatomical pulmonary resections under learning curve. Gen Thorac Cardiovasc Surg 2025;73:52-7. [Crossref] [PubMed]
7. Kuo TF, Kuo SW, Lin MW, et al. Uniportal versus multiportal robotic-assisted thoracic surgery pulmonary resections: a propensity score-matched analysis. BMC Surg 2025;25:465. [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. Tane S, Tanaka Y, Nishikubo M, et al. Console and bedside surgeon fused robot-assisted thoracic surgery. Gen Thorac Cardiovasc Surg 2023;71:730-2. [Crossref] [PubMed]
10. E H. Hybrid uniportal robotic-assisted thoracoscopic surgery using video-assisted thoracoscopic surgery staplers: technical aspects and results. Ann Cardiothorac Surg 2023;12:34-40. [Crossref] [PubMed]
11. Kuzmych K, Nachira D, Congedo MT, et al. Biportal robotic-assisted surgery for lung segmentectomies: a surgical technique overview. J Vis Surg 2025;11:11.
12. Kocher GJ, Wegener S, Deckarm S, et al. Uniportal & biportal robotic anatomic lung resection (without CO2 insufflation): technique, initial experience and cost. J Vis Surg 2024;10:6.
13. 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]
14. Kaneda H, Nakano T, Utsumi T, et al. Technical Aspects of Solo Surgery in Uniportal Robot-assisted Thoracic Surgery (RATS) and Dual-portal RATS. Kyobu Geka 2025;78:50-5.
15. Kaneda H, Saito Y, Okamoto M, et al. Early postoperative mobilization with walking at 4 hours after lobectomy in lung cancer patients. Gen Thorac Cardiovasc Surg 2007;55:493-8. [Crossref] [PubMed]
16. Bongiolatti S, Gatteschi L, Gonfiotti A, et al. Pure Robot-Assisted Uniportal Anatomical Lung Resection for Non-Small Cell Lung Cancer: Technical Aspects and Early Outcomes. Int J Med Robot 2025;21:e70114. [Crossref] [PubMed]