[Current Status of Robot-assisted Cardiac Surgery in Japan].

Endoscopic surgery has been introduced as a minimally invasive procedure in other fields. On the other hand, the introduction of surgical robots has made endoscopic surgery possible in cardiac surgery. Coronary artery bypass surgery includes minimally invasive direct coronary artery bypass( MIDCAB) via small thoracotomy after robotic internal thoracic artery harvesting and totally endoscopic coronary artery bypass with a robotic anastomosis. We refer to intracardiac surgery performed via only ports as "keyhole cardiac surgery". Robotic keyhole mitral valve repair is far superior to median sternotomy or minimally invasive cardiac surgery( MICS). Currently, the "da Vinci surgical system" is the sole leader in surgical robotics, but there are already many surgical robots, including new concepts. In Japan, the "hinotori surgical robot system" is already on the market, and it is expected that the indications for surgery will expand in the future.

Combined robot-assisted mitral valve plasty and Nuss procedure via small ports.

Pectus excavatum (PE) can be associated with cardiac disorders that also require surgical repair. Totally endoscopic robot-assisted mitral valve plasty for mitral valve regurgitation was performed while elevating the sternum with the aid of our original electrical sternum lifting system. Then, the Nuss procedure was performed successfully via small incision. Simultaneous robot-assisted cardiac surgery and the Nuss procedure is effective. Sternal elevation during cardiac surgery is very important for a safe procedure. The Nuss technique prevents perioperative cardiac compression and allows for correction of the pectus deformity with good cosmetic and functional results.

First Major Clinical Outcomes of Totally Endoscopic Robotic Mitral Valve Repair in Japan　- A Single-Center Experience.

BACKGROUND: In 2018, Japan became the first country to have robotic cardiac surgery covered under the national health insurance. The number of patients undergoing robotic mitral valve (MV) repair has been estimated to increase remarkably, but no reports in Japan have yet described the outcomes of robotic MV repair. This study aimed to analyze the early clinical outcomes of patients undergoing totally endoscopic robotic MV repair (TERMVR) as a landmark national study for this procedure.Methods and Results:A total of 213 patients (152 men; mean age, 55±11 years) underwent TERMVR during May 2014 to December 2018. Preoperative demographics, operative profiles, and postoperative outcomes, including follow-up echocardiography, were analyzed. Successful TERMVR was achieved in all patients. Operation, cardiopulmonary bypass, and aortic cross-clamp times were 192±49.8, 127±23.8, and 70.1±16.2 min, respectively. Intraoperative transfusion was performed in 20 patients (10%). There were no in-hospital deaths. All patients were alive during the median follow-up period of 255 days (interquartile range, 32.5-208 days). Freedom from recurrence of MR >grade 2+ was 97.3%, 95.0%, and 90.7% at 6, 12, and 24 months, respectively. CONCLUSIONS: TERMVR is an effective and safe procedure with acceptable early postoperative outcomes.

Robot-assisted single-port surgery for mediastinal tumors.

We successfully performed totally endoscopic single-port robotic surgery. A 50-year-old man with a mediastinal tumor underwent robot-assisted tumor resection. Only one port was placed on the right side of the chest, and a robotic endoscope and two robotic instruments were inserted through the port. The instruments were crossed while avoiding collision. Single-port robotic surgery for a mediastinal tumor using the cross-arm technique was safely achieved with good clinical results and excellent cosmetic results.

Nonresectional Simplified Folding Technique in Robotic Mitral Valve Plasty: Comparison with Leaflet Resection Technique.

OBJECTIVE: The mitral valve plasty (MVP) technique for degenerative disease is typically leaflet resection and suturing. However, this technique is time consuming and unreproducible. To overcome this disadvantage, we developed a nonresectional folding technique, which is fast and reproducible. In this report, we examine our new folding technique in robotic MVP. METHODS: The new folding technique was performed in 10 patients (age 56 ± 15 years), and the conventional resection and suturing (RS) technique was performed in 22 patients (age 53 ± 8 years). In our new folding technique, we used two sutures to fold the prolapsed leaflet to the left ventricle side. The first folding suture line is a land mark, and the second line adjusts the height of the posterior leaflet to the anterior leaflet so that sufficient coaptation depth can be obtained. RESULTS: MVP was successful in all patients. In the folding technique group, the operation time, cardiopulmonary bypass time, and cross clamp time was faster than the conventional RS technique group (188 ± 31, 97 ± 32, and 55 ± 3 min, versus 242 ± 51, 137 ± 25, and 70 ± 15 min; P < .05). Hospital stays were significantly shorter in the folding technique group (13 ± 2 days versus 17 ± 7 days; P < .05). All patients were discharged without complications. The post-echocardiography revealed no mitral valve regurgitation in any patient. CONCLUSION: The new folding technique facilitated efficient MVP for posterior leaflet prolapse in mitral valve regurgitation, without the need for the resection of the leaflet.

Underwater robotic suturing.

BACKGROUND: Laparoscopic and robotic surgeries have become popular, and this popularity is increasing. However, the environment in which such surgeries are performed is rarely discussed. Similar to arthrosurgery performed in water, artificial ascites could be a new environment for laparoscopic surgery. This study was performed to determine whether robotic surgery is applicable to complicated suturing underwater. MATERIAL AND METHODS: A da Vinci Surgical System S was used. A weighted fabric sheet was placed at the bottom of a tank. Identical sets were made for each environment: One tank was dry, and the other was filled with water. The suturing task involved placement of a running silk suture around the perimeter of a small circle. The task was performed eight times in each environment. The task time and integrity score were determined. The integrity score was calculated by evaluating accuracy, tightness, thread damage, and uniformity; each factor was evaluated using a five-point scale. RESULTS: Although statistically significant differences were not shown in either task time or integrity score between the underwater and air environments, robotic suturing underwater is not inferior to performance in air. CONCLUSIONS: The feasibility of robotic suturing underwater was confirmed under the herein-described experimental conditions.

[Robot-assisted Coronary Artery Bypass Grafting].

The application for robot-assisted coronary surgery ranges from internal thoracic artery (ITA) harvesting with hand-sewn anastomoses to totally endoscopic coronary artery bypass grafting (TECAB), either on- or off-pump. The bilateral IMA can be harvested with the aid of a surgical robot and then multivessel bypass grafting can follow. Such robot-assisted minimally invasive direct coronary artery bypass grafting is called "ThoraCAB". Surgical robots cannot only endoscopically harvest the ITA but they can also anastomose the coronary artery in TECAB. But TECAB still has the difficulties, such as narrow surgical field in Japanese patients. Both procedures have the significant advantages of minimizing surgical trauma, such as reduced comlications, faster return back to normal activities and being improved cosmesis, and which have resulted in the development of minimally invasive surgery. Robot-assisted cardiac surgery for structural heart disease has been approved by the Ministry of Health, Labour and Welfare (MHLW) since December 2015, however, robot-assisted cardiac surgery for TECAB has not been approved yet in Japan.

[Anesthetic Management of Robotic Cardiac Surgery].

Traditional cardiac surgery is performed via median sternotomy to approach the mediastinum and coronary structures. Recently, the use of minimal invasive car- diac surgery (MICS) via right mini-thoracotomy has become introduced. Furthermore, robotic-assisted car- diac surgery, with da Vinci® Surgical System, has been introduced. We herein summarize anesthetic manage- ment for robotic-assisted mitral valve surgery. After the induction of anesthesia, the venous cannula was maintained through the right internal jugular vein. Intraoperative transesophageal echo (TEE) is important for guiding the cannula to the right position. Moreover, anesthesiologists must evaluate the myocardial function and the mitral valve before and after the surgical pro- cedure. One-lung ventilation is required to produce ports for the robotic arms. If hypoxemia occurs before beginning the robotic procedure, then bilateral lung ventilation is needed. As robotic cardiac surgery is a completely endo- scopic mitral valve surgery, anesthesiologists must understand the details of the surgical procedure and the findings of the TEE examination.

Two-Port Robotic Cardiac Surgery (TROCS) for Atrial Septal Defect (ASD) Using Cross-Arm Technique--TROCS ASD Repair.

BACKGROUND: We successfully performed totally endoscopic atrial septal defect (ASD) repair via 2 ports, and we named this procedure two-port robotic cardiac surgery (TROCS).Methods and Results:A 51-year-old woman with secundum ASD underwent robot-assisted ASD repair under ventricle fibrillation without aortic cross-clamping. Two ports were placed in the right side of the chest, and 1 port was for the robotic endoscope. Two robotic instruments were inserted through another port and crossed while preventing them from colliding. CONCLUSIONS: TROCS ASD repair using a cross-arm technique was achieved safely with good clinical results and excellent cosmetic results.

Thyroidectomy using pure natural orifice transluminal endoscopic surgery in a porcine model.

Surgical procedures for thyroid disease that provide cosmetically acceptable results are in demand. Natural orifice transluminal endoscopic surgery (NOTES) is performed through natural orifices and thus avoids incision of the body wall. This study aimed to develop an incision-free surgical procedure for thyroid lobectomy using pure NOTES with an oral approach. In six pig carcasses, an incision was made between the mandible and subcutaneous tissue under direct vision. After subcutaneous dissection and identification of the hyoid bone, the operative field was developed under endoscopic view. After the thyrohyoid membrane was identified, dissection was continued along the thyroid cartilage until the cricoid cartilage was identified and the thyroid isthmus was reached. An original retractor was inserted between dissected tissues to lift and fix the carcass. The thyroid gland was successfully removed through the incision. Similar macroscopic and histological findings were observed on the normal and treated sides, with no damage to the recurrent laryngeal nerves. The times required for securing the operative field and thyroidectomy improved with each operation. This study suggests the feasibility and safety of using pure NOTES for thyroidectomy through a subcutaneous route with an original retractor.

Ultra-minimally invasive cardiac surgery: robotic surgery and awake CABG.

The recognition of the significant advantages of minimizing surgical trauma has resulted in the development of minimally invasive surgical procedures. Endoscopic surgery confers the benefits of minimally invasive surgery upon patients, and surgical robots have enhanced the ability and precision of surgeons. Consequently, technological advances have facilitated totally endoscopic robotic cardiac surgery, which has allowed surgeons to operate endoscopically, rather than through a median sternotomy, during cardiac surgery. Thus, repairs for structural heart conditions, including mitral valve plasty, atrial septal defect closure, multivessel minimally invasive direct coronary artery bypass grafting and totally endoscopic coronary artery bypass graft surgery (CABG), can be totally endoscopic. On the other hand, general anesthesia remains a risk in patients who have severe carotid artery stenosis before surgery, as well as in those with a history of severe cerebral infarction or respiratory failure. In this study, the potential of a new awake CABG protocol using only epidural anesthesia was investigated for realizing day surgery and was found to be a promising modality for ultra-minimally invasive cardiac surgery. We herein review robot-assisted cardiac surgery and awake off-pump coronary artery bypass grafting as ultra-minimally invasive cardiac surgeries.

Saline-filled laparoscopic surgery: A basic study on partial hepatectomy in a rabbit model.

BACKGROUND: There is still a poor understanding of the effects of pneumoperitoneum with insufflation of carbon dioxide gas (CO2) on malignant cells, and pneumoperitoneum has a negative impact on cardiopulmonary responses. A novel saline-filled laparoscopic surgery (SAFLS) is proposed, and the technical feasibility of performing saline-filled laparoscopic partial hepatectomy (LPH) was evaluated in a rabbit model. MATERIAL AND METHODS: Twelve LPH were performed in rabbits, with six procedures performed using an ultrasonic device with CO2 pneumoperitoneum (CO2 group) and six procedures performed using a bipolar resectoscope (RS) in a saline-filled environment (saline group). Resection time, CO2 and saline consumption, vital signs, blood gas analysis, complications, interleukin-1 beta (IL-1ß) and C-reactive protein (CRP) levels were measured. The effectiveness of the resections was evaluated by the pathological findings. RESULTS: LPH was successfully performed with clear observation by irrigation and good control of bleeding by coagulation with RS. There were no significant differences in all perioperative values, IL-1ßand CRP levels between the two groups. All pathological specimens of the saline group showed that the resected lesions were coagulated and regenerated as well as in the CO2 group. CONCLUSIONS: SAFLS is feasible and provides a good surgical view with irrigation and identification of bleeding sites.

[Robot-assisted Mitral Valve Plasty].

In April 2014, Team Watanabe have completed 249 robot-assisted cardiac surgeries. Wide range of procedures include internal thoracic artery harvesting, totally endoscopic coronary artery bypass grafting(CABG), atrial septal defect closure, mitral valve plasty, cardiac tumor resection. The major benefit of robot-assisted cardiac surgery, which differentiates it from minimally invasive cardiac surgery, is that it only requires a few ports instead of small thoracotomy. Mitral valve plasty for regurgitation is one of the most suitable indication, which represents the advantage of robot-assisted cardiac surgery. The da Vinci surgical system completely changed the modality of cardiac surgeries from median sternotomy to endoscopic approach. Endoscopic surgery is expected not only to provide superior cosmesis but also to reduce complications and improve post-operative quality of life. In addition, we consider that sharing the same surgical view on the screen monitor is another great benefit from the educational point of view for the next-generation.

Robot-assisted minimally invasive direct coronary artery bypass grafting. ThoraCAB.

BACKGROUND: The aim of this study was to assess the outcome of robot-assisted minimally invasive direct coronary artery bypass grafting (MIDCAB), which is also termed "ThoraCAB". METHODS AND RESULTS: From 2005 to 2013, 35 consecutive patients underwent MIDCAB via a small thoracotomy on a beating heart. Before performing MIDCAB, the internal thoracic arteries (ITAs) were endoscopically harvested through 3 ports using the da Vinci Surgical System in a completely skeletonized fashion. Distal anastomosis was hand-sewn using a vacuum stabilizer, and a coronary artery active perfusion system was used to prevent myocardial ischemia during anastomosis. Successful robot-assisted ITA harvesting was achieved in all patients. There was an average of 1.7±0.8 grafts (range, 1-3 grafts) per patient. No patient needed mechanical ventilation for more than 24h. There were no deaths, strokes or myocardial infarctions, and none of the patients required conversion to median sternotomy. CONCLUSIONS: Robot-assisted ITA harvesting is safe and feasible. ThoraCAB is a relatively simple procedure and allows multivessel bypass grafting after a small thoracotomy. Therefore, it is expected that ThoraCAB will become the standard procedure for minimally invasive coronary revascularization and will be used in totally endoscopic CABG in the future.

Intraoperative free jejunum flap monitoring with indocyanine green near-infrared angiography.

The free jejunum flap technique has been regarded as the optimal approach during circumferential pharyngolaryngectomy reconstruction. Although classical patency tests are available, an intraoperative guarantee of the patency of anastomoses and microcirculations is inevitable. Indocyanine green near-infrared angiography (ICGA) was intraoperatively performed in six patients after reconstruction using the free jejunum flap. An adequate arterial as well as venous phase was observed. In addition to classical patency tests and doppler, we have successfully monitored the flap after total pharyngolalyngectomy intraoperatively using the ICGA. Our preliminary results implicate that this novel technique offers secure intraoperative monitoring of a free jejunum graft. This technique will provide us with advantages over regular patency test in selected cases.

Sternal lifting technique for patients with sternal depression during robotic mitral repair.

INTRODUCTION: Traditional surgical methods have been difficult for patients with chest wall deformities, but the use of the Electrical Sternum Lifting System (ESLS) has made the surgery easier. MATERIALS AND SURGICAL TECHNIQUE: Patients with a sternum-to-vertebral distance of less than 80 mm on preoperative computed tomography (CT) scan routinely underwent sternal lift using the ESLS. The ESLS was effective in securing the operative field while suspending the sternum, allowing adequate observation of the left atrium, left ventricle, and the mitral valve, and safe mitral valve plasty. The use of the lifting device did not interfere with the robot arms, and the space between the sternum and vertebrae was widened with only a 3 mm wound to move the mitral valve surface in the sagittal plane, making the repair easy and accurate under robotic assistance. The effort to attach the ESLS was not difficult, and the postoperative cosmetic outcomes were excellent. Sixty-three out of 1002 patients (6.3%) underwent sternal elevation using ESLS. There were 19 males and 44 females with a mean age of 50.9 ± 14.0 years. The average of sternum-to-vertebral (S/V) distance was 72.4 ± 8.9 cm. Two patients had S/V distance of more than 80 mm but ESLS was used because of scoliosis.

Successful launch of robot-assisted mitral valve repair in Japan under universal health coverage.

OBJECTIVES: We compared the clinical outcomes of mitral valve repair for mitral regurgitation via the robot-assisted approach and small right thoracotomy approach 3 years after the reimbursement of the robot-assisted approach in Japan. METHODS: Patients who underwent isolated mitral valve repair by minimally invasive approach between 2018 and 2020 from the Japan Cardiovascular Surgery Database were included. Patients in the robot-assisted approach group were matched to the small right thoracotomy approach group based on propensity scores estimated from patient and surgical characteristics. Perioperative outcomes were compared among all cases as well as in subgroups categorized on the basis of the yearly number of robot-assisted approach cases and small right thoracotomy approach cases (≥10 or <10) at the hospital. RESULTS: We identified 2443 patients who had undergone isolated mitral valve repair at 250 institutions in the database, and analysis of propensity-matched 577 patient-pairs demonstrated that operation time, cardiopulmonary bypass time, and aortic crossclamp time were significantly shorter with the robot-assisted approach. Although the intensive care unit stay was longer in the robot-assisted approach, the time to discharge was significantly shorter in the robot-assisted approach. There was no meaningful difference in the in-hospital mortality. The incidences of postoperative stroke, renal failure, and prolonged ventilation, and the number of patients who converted to mitral valve replacement were similarly low. Procedural time, blood transfusions, explorative procedures for bleeding, postoperative stroke, and prolonged ventilation occurred at a lower rate in the high-volume institutions. CONCLUSIONS: The study found that the robot-assisted approach is just as effective as the small right thoracotomy approach. The introduction of robot-assisted mitral valve repair in Japan has been successful.

Subxiphoid robot-assisted complete resection for postchemotherapy primary mediastinal yolk sac tumour.

The standard treatment for primary mediastinal yolk sac tumour involves neoadjuvant chemotherapy followed by residual tumour resection, typically performed through a median sternotomy or a thoracotomy. However, in this case, a 16-year-old patient with a large anterior mediastinal tumour underwent less invasive, subxiphoid, robot-assisted surgery using a 4-arm da Vinci Xi system with CO2 insufflation at 8 mmHg. The tumour, located in the right thymic lobe, was dissected using a technique similar to blunt dissection, bipolar electrocautery and vessel sealer. Pericardiotomy was performed suspecting tumour invasion, with the thickened pericardial border incised circularly from the left side. Preservation of the right phrenic nerve involved careful separation from the densely adherent tumour. A pulmonary wedge resection was also performed using a stapler. The pericardial defect was reconstructed using an expanded polytetrafluoroethylene sheet, sutured together with nylon threads, and the resected tumour was extracted with a retrieval bag. This subxiphoid robot-assisted approach is a minimally invasive option for malignant mediastinal tumours.

Transrectal robotic natural orifice translumenal endoscopic surgery (NOTES) applied to intestinal anastomosis in a porcine intestine model.

BACKGROUND: Natural orifice translumenal endoscopic surgery (NOTES) is a minimally invasive operation using devices such as flexible endoscopes and linear or circular staplers. Nevertheless, hand-sewn anastomosis in NOTES remains challenging. This study aimed to investigate the feasibility of transrectal robotic NOTES requiring intracorporeal small intestinal anastomosis and closure of the rectal anterior wall incision in a relevant human model. METHODS: The authors developed a flexible rectal proctoscope with a diameter of 43 mm for transrectal robotic NOTES. Small intestinal anastomosis was performed in a porcine intestinal transrectal NOTES model using two robotic arms and a camera inserted through the proctoscope and a rectal anterior wall incision. The quality of transrectal small intestinal anastomosis using the da Vinci surgical system (transrectal robotic NOTES group) was compared with that of transabdominal anastomosis using the da Vinci surgical system (transabdominal robot-assisted surgery group) and transrectal anastomosis using traditional transanal endoscopic microsurgery (TEM) instruments (TEM NOTES group). The quality of transrectal rectal anterior wall suturing in the transrectal robotic NOTES group was compared with that of the TEM NOTES group and the open surgical instruments group (open group). RESULTS: Robotic intracorporeal suturing was performed successfully in the porcine intestine model. During small intestinal anastomosis, burst pressure in the transrectal robotic NOTES group (67.7 ± 29.3 mmHg) was similar to that in the transabdominal robot-assisted surgery group (73.3 ± 18.2 mmHg) but significantly higher than in the TEM NOTES group (20.3 ± 24.0 mmHg; p < 0.01). During rectal anterior wall suturing, the burst pressure did not differ significantly between the transrectal robotic NOTES group (149.9 ± 81.1 mmHg) and the open group (195.0 ± 60.5 mmHg). CONCLUSIONS: The preliminary safety and efficacy of transrectal robotic NOTES was established. Further studies are required to determine the practical feasibility of this procedure.