Robot-assisted cervical esophagectomy with simultaneous transhiatal abdominal procedure for thoracic esophageal carcinoma

Abstract

Background

Minimally invasive robot-assisted cervical esophagectomy has been sporadically reported as a novel thoracic esophagectomy technique for patients with thoracic esophageal carcinoma. Most reports indicate that the abdominal component of robot-assisted cervical esophagectomy is performed sequentially after the cervical phase. However, if the cervical and abdominal phases are performed simultaneously using a nerve integrity monitoring system with no administration of muscle relaxants, there are two major advantages: a reduced risk of recurrent nerve palsy and a shorter operative time. We herein report our experience performing novel robot-assisted transcervical esophagectomy with a simultaneous transhiatal abdominal approach using a nerve integrity monitoring system.

Methods

Thirty cases of robot-assisted cervical esophagectomy performed from 2023 to April 2024 were reviewed. The operative and short-term surgical outcomes of this procedure were compared with those of robot-assisted cervical esophagectomy using a sequential abdominal approach, and the feasibility and efficacy of the simultaneous procedure were analyzed.

Results

All patients successfully underwent robot-assisted cervical esophagectomy with no intraoperative adverse events. There were no differences in the patients’ demographic or operative data between the two groups. There was no difference in the mean operation time for the cervical procedure (p = 0.23). However, there was a significant difference in the total time for the whole procedure (sequential group: 453.8 ± 26.8 min, simultaneous group: 291.2 ± 36.1 min; p < 0.01). There were no differences in postoperative surgical complications between the groups. There was also no difference in the total number of surgically harvested mediastinal lymph nodes (p = 0.33).

Conclusions

Robot-assisted transcervical esophagectomy, a new technique for thoracic esophageal cancer, was safe and feasible under intraoperative management using nerve integrity monitoring without muscle relaxants. This procedure facilitates intraoperative monitoring of recurrent laryngeal nerve activity, significantly shortening the total operative time.

Surgery for thoracic esophageal cancer has become much less invasive in recent decades. Until the 1990s, open thoracic surgery with large incisions was common. However, this method is now associated with disadvantages such as postoperative respiratory compromise due to destruction of the chest wall over a wide area and inadequate identification of microanatomical structures by gross observation. With the widespread use of thoracoscopic surgery in recent years, less invasive esophageal cancer surgery has become more common. This development has resulted in smaller surgical wounds and faster recovery [1, 2]. In addition, thoracoscopic surgery has gradually transitioned to robot-assisted esophageal surgery, which allows for more precise instruments manipulation and three-dimensional viewing, enabling even higher-definition surgical maneuvers to be performed with relatively high reproducibility [3]. However, robot-assisted thoracoscopic surgery is an extension of conventional thoracoscopic surgery, which essentially requires intraoperative isolated lung ventilation, and it does not appear to be significantly superior to conventional thoracoscopy in terms of the incidence of postoperative complications.

Use of a mediastinoscope is the most recently developed surgical technique for minimally invasive resection and reconstruction of esophageal cancer, but its prototype has long been described [4, 5]. We previously reported the use of esophagectomy for esophageal cancer using bilateral transcervical esophagectomy (TCE) [6], a technique that not only involves resection of the esophagus but also allows dissection of the lymph nodes, including the superior mediastinum. Numerous reports have described this technique in recent years, mainly focusing on the short-term results [6, 7]. However, one problem with this approach is the relatively high incidence of recurrent nerve palsy due to physical interference between the forceps and the recurrent nerve around the thoracic inlet. In addition, the reproducibility of the technique is lower than that of thoracoscopic surgery, and the details of the surgical approach have not yet been widely standardized [7–9].

Robot-assisted surgery, which has become increasingly popular in the field of esophageal cancer surgery in recent years, offers the surgeon a high degree of freedom within the body of the instruments because of its articulated function and other features. This provides the surgeon with simplicity and meticulous procedural control [3, 10]. Robotic surgery has been suggested to be beneficial when performing esophageal cancer surgery via a transcervical approach. Previous reports have described the performance of mediastinoscopic surgery using linear forceps to manipulate the narrow mediastinum, resulting in interference with the surrounding area. This is a major factor contributing to reduced operability and the development of recurrent nerve palsy [11]. Robot-assisted TCE is expected to improve the safety and accuracy of esophagectomy [12, 13], and in fact we found high efficacy of this technique in a pilot study in which the esophagus was approached transcervically with a mediastinoscope using robotic technology [14].

Continuous use of a nerve integrity monitoring (NIM) system is important to reduce the risk of recurrent nerve palsy, which is problematic in mediastinoscopic esophagectomy. The importance of using an NIM system in TCE has been well documented in recent reports [11]. When using NIM, however, muscle relaxants must be omitted from the general anesthetic regimen. Therefore, the use of NIM sacrifices the original advantage of mediastinoscopic esophageal surgery, which can be performed simultaneously from the neck and abdomen, thereby shortening the operative time. Furthermore, if a robot with joint functions can perform the cervical phase while simultaneously performing the abdominal phase under NIM, the advantages of mediastinoscopic surgery can be maximized. This will substantially shorten the operative time and reduce the incidence of postoperative recurrent nerve palsy.

We herein present a case series of robotic TCE performed using an NIM system without the use of muscle relaxants. We discuss the progression of the procedure and the patient outcomes by comparing the effectiveness of the use of muscle relaxants to cases in which no simultaneous cervicoabdominal manipulation was performed.

Materials and methods

Patients

This retrospective study was performed to evaluate the feasibility and safety of robot-assisted cervical esophagectomy with a simultaneous abdominal approach for thoracic esophageal cancer. Patients who underwent robot-assisted cervical esophagectomy for esophageal cancer at the National Cancer Center Hospital East were included in this study. Preoperative diagnosis was made using imaging studies, specifically upper gastrointestinal examination, endoscopy, and conventional computed tomography. Histological evaluation of endoscopic biopsy specimens was performed in all patients. The preoperative tumor stage, histopathological findings, surgical procedure, and outcomes were recorded.

This study was approved by the institutional review board of our hospital (approval number 2018-322), and the study conformed to the provisions of the Helsinki Declaration (revised in 2004).

Anesthesia and intraoperative management during thoracic esophagectomy

The detailed anesthetic procedure has been previously described [15]. Upon the patient’s arrival in the operating room, routine monitoring was initiated using electrocardiography, noninvasive blood pressure monitoring, pulse oximetry, and capnography. An epidural catheter was then inserted into the fifth to sixth thoracic intervertebral space and advanced 5 cm beyond the tip of the introduction needle. Anesthesia was then induced with propofol (1.5–2.5 mg/kg), fentanyl (1–2 μg/kg), and vecuronium (0.1 mg/kg) and maintained with sevoflurane (3% minimal alveolar concentration) in oxygen until tracheal intubation. After intubation, anesthesia was maintained with 2% sevoflurane in 40% oxygen (air/oxygen mixture, 4 L/min) supplemented with fentanyl and vecuronium. The muscle relaxant was reversed after intubation, and stable vital signs were confirmed.

After surgery, the endotracheal tube was removed. Once the patients had achieved a modified Aldrete score of > 9, they were transferred from the operating room to the intensive care unit as previously described [15].

Surgical procedure

Robot-assisted TCE was performed with a bilateral cervical approach in the supine position for all patients using the da Vinci Xi surgical robot (Intuitive Surgical, Inc., Sunnyvale, CA, USA). Details of the setting of the cervical procedure have been previously described [14]. In brief, a 3.5-cm skin incision was made along the medial sternocleidomastoid muscle skin fold. The actual port placements for robot-assisted cervical esophagectomy are shown in Fig. 1a. A single-opening access port was placed, and three robotic arm access ports were placed in this single-opening access port to perform the procedure (Fig. 1b). The cervical approach was generally performed from the right side first. A representative image of the intraoperative findings during the right cervical approach is shown in Fig. 2a. Dorsal and ventral esophageal dissection is performed using a vessel sealer, while fine manipulation around the recurrent nerve is performed mainly using a monopolar scissors. Upon completion of the right cervical approach, the robotic left cervical approach was conducted. A representative image of the left cervical approach is shown in Fig. 2b. The robot-assisted transcervical procedures were performed as previously described in detail [14]. Regarding the instrument of the procedure, as in the right cervical manipulation, the left side of the esophagus is dissected using a vessel sealer, while detailed procedures around the left recurrent nerve are performed mainly using a monopolar scissors. The tracheal bifurcation and then the epicardial surface were reached, and lymph node dissection at the tracheal bifurcation was performed if necessary. Simultaneously with the transcervical robotic procedure, a transhiatal approach from the abdomen was generally performed using conventional laparoscopy; this was followed by lymph node dissection in the middle and lower mediastinum. Images of the docking of the robot during this simultaneous procedure are shown in Fig. 3. In the robot-assisted transcervical approach, the robot is docked from the left lateral side of the patient (Fig. 3b). An actual operative image captured from the right side of the patient during the simultaneous procedure is shown in Fig. 4. With this robot docking method, we were able to perform the robot-assisted transcervical approach simultaneously with the laparoscopic abdominal approach using no muscle relaxant. We usually monitored the status of contentious recurrent laryngeal nerve activity using the TilePro function of the robot at the surgeon console together while also monitoring the progression of the abdominal procedure (Fig. 5).

Fig. 1.

Overview of port placement for bilateral cervical manipulation in robot-assisted cervical esophagectomy. a Photograph of port positioning in the left and right cervical approaches. A GelPOINT access platform (Applied Medical, Inc., Rancho Santa Margarita, CA, USA) is placed in the cervical region, and the port is placed at the apex of an isosceles triangle in the craniocaudal direction. The da Vinci Xi (Intuitive Surgical, Inc., Sunnyvale CA, USA) is adjusted appropriately according to the depth and length of the cervical region. b View from the caudal direction after port placement and robotic docking in the left cervical approach. As with the right cervical approach, the port is placed at the apex of an isosceles triangle in the craniocaudal direction in the left cervical approach. This arrangement allows space for simultaneous abdominal manipulation

Fig. 2.

Typical surgical field and landmarks in robot-assisted cervical esophagectomy from the a right and b left neck approaches. a Photograph of right dorsal esophageal dissection during the right cervical approach. During this phase, the left robotic arm manipulates the instruments to push the esophagus or trachea ventrally, exposing the anterior aspect of the perivertebral fascia, dorsal part of the trachea, right part of the esophagus, and whole structure of the right recurrent laryngeal nerve. b Photograph of left esophageal dissection during left cervical approach. During this phase, the left robotic arm pushes the aortic arch and descending aorta, exposing the recurrent point of the left recurrent laryngeal nerve while preserving the structure of the thoracic duct at the dorsal surface. This process enables us to concentrate all target tissue in the left upper mediastinal area to the left tracheal side for subsequent dissection. Eso esophagus, Pl pleura, Rt-Rec right recurrent laryngeal nerve, Tra trachea, Ve vertebral column, VN vagal nerve, AA aortic arch, DA descending aorta, Lt-Bro left bronchus, Lt-Rec left recurrent laryngeal nerve

Fig. 3.

Image of robot docking at the neck and simultaneous manipulation of the neck and abdomen. a Schematic representation of the skin incision for the simultaneous cervical and abdominal procedure. b Schematic representation of the robot docking at the neck and simultaneous procedure of the abdominal laparoscopic phase. Docking of the robot at the neck should be performed from the left side of the patient and positioned sufficiently headward to provide the necessary space for the simultaneous laparoscopic approach to the abdomen. This docking technique allows simultaneous manipulation of the neck and abdomen even in patients as short as 150 cm in height

Fig. 4.

Photograph of an actual surgical scene, viewed from the right side of the patient, in which abdominal manipulation is being performed simultaneously with robotic manipulation of the neck. By using the nerve integrity monitoring system to monitor recurrent nerve activity without the use of muscle relaxants, the risk of recurrent nerve palsy can be reduced and the operation time can be shortened during robotic manipulation in the neck with simultaneous manipulation of the abdomen. NIM APS, the cord of the nerve integrity monitoring system leading to the automatic periodic stimulation electrode at the right vagal nerve

Fig. 5.

Photograph of simultaneous cervicoabdominal manipulation on the surgeon console display. The surgeon’s console display allows real-time monitoring of the right recurrent nerve activity obtained from the nerve integrity monitoring system on the lower left sub-monitor (white arrow) while performing surgery under the image of right cervical manipulation on the main monitor. The progress of the abdominal manipulation can also be monitored in real time on the lower right sub-monitor (white arrow head). Eso esophagus, Pl pleura, Rt-Rec right recurrent laryngeal nerve, Tra trachea, Ve vertebral column (Color figure online)

In the group of patients who underwent the simultaneous procedures, the procedures were performed without muscle relaxant agents. The esophagectomy was completed by connecting the dissection site from the cervical maneuver with the esophageal hiatus. After completion of the whole esophageal dissection procedure, the optimal amount of muscle relaxant agent was administered, and the intraoperative monitoring of recurrent laryngeal nerve activity was stopped. Reconstruction was generally performed using a gastric tube via the posterior sternal route, and anastomosis was performed at the cervical site. A cervical anastomosis site was used in all cases.

Perioperative management

Postoperatively, the same clinical management pathway was used for all patients regardless of the abdominal approach. All patients received enteral nutrition via a jejunostomy tube until oral intake was started on postoperative day (POD) 6. Fluid balance was achieved using peripheral lines, and enteral feeding was added on POD 1.

Perioperative management was performed by the same clinical staff of the same facility within the intensive care unit (PODs 1 and 2) followed by the wards (POD 3 onward). The endotracheal tube was removed in the operating room or immediately upon arrival in the intensive care unit. On POD 6, contrast swallow X-rays were obtained to identify anastomotic and transit obstruction. If this examination revealed no leakage or obstruction, the nasogastric tube was removed and oral intake was initiated in accordance with the clinical management pathway. If no complications had occurred, the patient was enrolled in a postoperative rehabilitation program and discharged on POD 12 to 20 as previously described [15].

Clinically abnormal findings, such as postoperative hypoxia, leukocytosis, and abnormal pleural effusion, were investigated by computed tomography and/or other radiographic studies to diagnose and optimally manage the abnormality as soon as possible, as previously described [15].

Definition of surgical complications

Surgical complications were assessed using the Clavien–Dindo classification system. Grade ≥ 1 complications were defined as surgical complications. The patients underwent laryngoscopy on the first POD after extubation, and postoperative recurrent nerve palsy was diagnosed in the presence of asymmetrical vocal fold movements newly observed after surgery. The severity of paralysis was determined by the Clavien–Dindo criteria. Surgical site infection was defined in accordance with the Surgical Wound Infection Task Force 1 guidelines and included infection at the incision site or within any organ/space manipulated during surgery. Respiratory infection was defined as the presence of a new or progressive infiltrate on chest radiography plus at least two of the following signs: temperature of > 38 °C, purulent sputum, white blood cell count of > 1 × 10⁴/mm³ or < 4 × 10³/mm³, and signs of inflammation on auscultation, as previously described [15, 16].

Statistical analysis

Statistical analyses were performed using R software (R Foundation, Vienna, Austria). Intergroup differences were compared using the chi-square test and the Mann–Whitney U-test. A p value of < 0.05 was considered statistically significant.

Results

Patient demographics

Robot-assisted bilateral cervical esophagectomy was performed in both groups of patients with no intraoperative problems. The patients’ demographics in both groups are shown in Table 1. In both groups, the patients’ mean age was close to 75 years. This relatively high age was due to our institution’s procedural indication criteria. In principle, the transcervical approach is mainly indicated for clinically vulnerable patients, such as those with a history of respiratory disease or older patients with less tolerance for conventional transthoracic esophagectomy.

Table 1.

Patient demographics

Variable	Sequential procedure (n = 15)	Simultaneous procedure (n = 15)	p-values
Age (mean ± S.D.)	73.4 ± 8.2	75.0 ± 10.8	0.77
Gender (M: F)	13: 2	13: 2	1.0
Body mass index (mean ± S.D.)	24.4 ± 5.2	23.8 ± 3.4	0.86
ASA grade			1.0
Grade 1	3	2
Grade 2	12	13
Basic disease			0.82
Cardiovascular	3	3
Respiratory	7	8
Diabetes	2	3
Main location of tumor			0.23
Upper	1	4
Middle	6	6
Lower	9	5
Preoperative treatment			0.10
Chemotherapy	4	8
Chemo-radiation	0	3
Clinical stage (UICC 8th)			0.51
Stage I	9	6
Stage II	1	2
Stage III	5	4
Stage IV	0	3

UICC 8th, Union Internationale Contre le Cancer, 8th edition

M male, F female, S.D. standard deviation

There were no significant differences between the patients who underwent the sequential procedures and those who underwent the simultaneous procedures. The surgical data in both groups are shown in Table 2. In the sequential procedure group, four patients underwent preoperative chemotherapy in the neoadjuvant setting. In the simultaneous procedure group, however, 11 of 15 patients underwent preoperative chemotherapy or chemoradiation because of their advanced disease stage. Bilateral paratracheal lymph node dissection was performed in all patients. Generally, patients with advanced cancer of the middle third of the esophagus did not undergo this procedure because of safety issues associated with attempting to achieve a radical cure. Reconstructive procedures were performed via the retrosternal route in all patients.

Table 2.

Patient operative data

Variables	Sequential procedure (n = 15)	Simultaneous procedure (n = 15)	p-values
Field of lymph dissection  Two fields  Three fields	15 0	13 2	0.48
Reconstruction Route  Retrosternal  Posterior mediastinal	15 0	15 0	1.0
Anastomosis  Modified Collard  Circular staple	15 0	12 3	0.22
Convert to open procedure  Convert to thoracotomy  Convert to laparotomy	0 0	0 0	1.0
Total time of transcervical procedure (mean ± S.D.)	172.3 ± 22.4	168.9 ± 24.1	0.23
Total amount of blood loss (mean ± S.D.)	148.4 ± 48.0	136.2 ± 38.8	0.18
Total number of surgically harvested mediastinum LN	32.5 ± 9.2	31.4 ± 8.6	0.33

S.D. standard deviation

Representative surgical view of transcervical procedure

Representative images of the intraoperative surgical view during the cervical approach are shown in Fig. 2a, b. In general, the bilateral transcervical approach was carried out using the right cervical approach first. In brief, the dorsal esophagus and anterior perivertebral fascia were dissected first, followed by dissection of the left dorsal side of the esophagus to the point at which the thoracic duct was visible. The details of the procedure have been previously described [14].

After the right transcervical approach, the left transcervical approach was carried out. A representative image of the intraoperative surgical view during the left cervical approach is shown in Fig. 2b. In brief, the left lateral and left dorsal side of the esophagus were dissected and connected to the dissected layer of the esophagus obtained in the right cervical manipulation. The left recurrent nerve was then checked to ensure that it was well preserved to the neck. The esophagus was detached from the left recurrent nerve, and left upper mediastinal lymph node dissection was carried out. The details of the procedure have been previously described [14]. Dissection of the tracheal bifurcation lymph nodes was performed on a case-by-case basis and was not necessarily performed through the cervical approach in all cases.

Patient operative data

The operative results are summarized in Table 2. In both groups, most of the patients underwent the two-field dissection procedure. The anastomotic procedures were mainly carried out in the neck with a linear stapled procedure, such as the modified Collard technique. No patient in either group required conversion to the transthoracic approach during the thoracic phase. All abdominal procedures were performed using minimally invasive laparoscopy, and no patients required conversion to laparotomy, including during the transhiatal part of the procedure.

There were no significant differences in the duration of the robot-assisted transcervical procedure (p = 0.23) or total blood loss (p = 0.18) between the two groups (Table 2). However, a significant difference was observed in the total procedure time between the two groups (p < 0.01) (Fig. 6). There was no difference in the total number of harvested lymph nodes between the two groups (p = 0.33) (Table 2).

Fig. 6.

Comparison of total operative time between sequential and simultaneous cervicoabdominal procedure groups. Simultaneous cervicoabdominal manipulation can be safely performed by monitoring nerve activity using the nerve integrity monitoring system without intraoperative muscle relaxants. In the present study, this allowed a significant reduction in the overall operative time in the simultaneous operation group compared with the sequential operation group (p < 0.01)

Short-term postoperative outcomes

The short-term postoperative outcomes in both groups are shown in Table 3. No in-hospital deaths occurred in either group, and all patients were successfully discharged from the hospital. The median postoperative hospital stay in the sequential and simultaneous groups was 20 (range, 13–91) and 18 (range, 12–45) days, respectively, with no significant difference (p = 0.15). There was no significant difference in the incidence of postoperative arrhythmia, postoperative pneumonia, postoperative vocal cord paralysis, or anastomotic leakage between the sequential and simultaneous groups (20.0% and 6.6%, respectively; p = 0.59). Three patients in the sequential procedure group developed anastomotic leakage; one had a history of long-term steroid use for rheumatic disease, and the other two had a history of long-term diabetes mellitus. Patients with a history of definitive chemoradiation in the simultaneous procedure group developed anastomotic leakage. No patients in either group developed necrosis of the tissue surrounding the stomach tube. All cases of anastomotic leakage were successfully treated with no need for reoperation.

Table 3.

Short-term postoperative outcomes

Variables	Sequential procedure (n = 15)	Simultaneous procedure (n = 15)	p-values
Pneumonia (%)	6.6	6.6	1.0
Arrhythmia (%)	13.3	6.6	1.0
Vocal cord paralysis (%)	13.3	13.3	1.0
Anastomotic leakage (%)	20.0	6.6	0.59
Success accomplishment of CMP (%)	66.6	80.0	0.68
In-hospital death (%)	0	0	1.0
Postoperative stay (median)	20 (13–91)	18 (12–45)	0.15

CMP clinical management pathway

Discussion

TCE is increasingly being reported and is now commonly referred to as mediastinoscopic surgery [17]. Because TCE does not require one-lung ventilation and can be performed under normal bilateral lung ventilation, as is usual for abdominal surgery, it reduces the physiological lung burden associated with one-lung ventilation. In addition, because the TCE procedure can be performed in the supine position, it can be performed simultaneously with abdominal surgery in many cases. The minimally invasive nature of this technique can also shorten the operation time. Furthermore, because TCE does not involve destruction of the chest wall, it can be performed relatively safely even in patients with reduced pulmonary function or severe intrapleural adhesions [18]. Previous reports have also indicated that TCE is associated with fewer respiratory-related postoperative complications such as pneumonia as well as faster recovery than with conventional transthoracic thoracoscopic surgery [5]. Recent reports of TCE using the da Vinci robot-assisted surgical system have also emerged, and the efficacy of this system has been gradually verified [12–14]. Although most previous reports were cadaveric studies, several reports of TCE in clinical practice have been published [19, 20]. Among them, a recent report examining the largest number of cases to date in which TCE was performed using a robot demonstrated the safety and validity of the procedure [14]. TCE is thus expected to become a new minimally invasive surgical technique in future [20].

There are two main cervical approaches in TCE: the bilateral cervical approach and the left cervical approach [6, 21]. The bilateral cervical approach has the advantage of facilitating accurate dissection of the lymph nodes around the right recurrent laryngeal nerve, but it carries the risk of right recurrent nerve palsy. Previous reports have demonstrated the usefulness of bilateral cervical approach technique with respect to these issues [21].

A problem associated with adequate mediastinal lymph node dissection in nonrobotic conventional TCE is the relatively high rate of recurrent nerve palsy [11, 22]. According to previous reports, this complication occurs in 30% to 50% of cases of TCE when the lymph nodes surrounding the recurrent nerve are adequately dissected [21, 22]. Of course, the frequency of nerve palsy may vary depending on the extent of mediastinal lymph node dissection around the recurrent nerve. The incidence of recurrent nerve palsy may be decreased if superior mediastinal lymph node dissection is performed less frequently. A recent systematic review of conventional TCE showed that the incidence of recurrent nerve palsy was approximately 30% [6]. Because most cases of recurrent nerve palsy are diagnosed based on hoarseness alone, the actual frequency of nerve palsy is likely to be higher if accurately diagnosed using laryngoscopy [6, 23, 24]. This higher frequency of recurrent nerve palsy with TCE suggests the effects of nerve compression due to interference when manipulating tissue in the narrow mediastinal cavity with linear forceps [25–27], a phenomenon that generally cannot be avoided with conventional TCE.

For this reason, advanced centers have reported that TCE is often combined with continuous use of an NIM system to monitor intraoperative nerve stress [11]. Intraoperative monitoring of nerve activity with an NIM system is important to reduce the incidence of postoperative recurrent nerve palsy; this is achieved by intraoperative monitoring of nerve damage caused by forceps interference [11]. However, adequate monitoring with an NIM system requires general anesthesia with no or limited muscle relaxants, and it is generally considered difficult to perform abdominal operations at the same time. This makes it difficult to perform simultaneous cervicoabdominal manipulation, which is an important minimally invasive characteristic of TCE, in order to monitor recurrent nerve palsy. This requires the surgeon to balance the priorities of shortening the operative time and reducing the risk of postoperative recurrent nerve palsy. Furthermore, the large docking space of the robot during robotic TCE makes it physically difficult to perform cervicoabdominal operations at the same time; therefore, the abdominal operation is performed after the robotic TCE phase has been completed, as reported by Fujita [14] and Nakauchi. [27].

In the present study, we successfully demonstrated that intraoperative anesthetic management without the use of muscle relaxants allows simultaneous manipulation of the cervicoabdominal region with intraoperative recurrent nerve monitoring using an NIM system and a robot docking technique. All 15 patients underwent the operation with no major problems. In addition, by performing simultaneous cervicoabdominal surgery using an NIM system without muscle relaxants, the operation time was shortened by approximately 150 min compared with conventional robotic TCE with intraoperative use of muscle relaxants. Notably, there was no increase in postoperative complications. No instability or inadequacy of abdominal manipulation was observed when muscle relaxants were not used, and abdominal lymph node dissection could be performed systematically and adequately. Although the postoperative rate of anastomotic leakage was higher in the simultaneous than sequential group, the difference was not statistically significant. This indirectly suggests that simultaneous cervicoabdominal manipulation without the use of muscle relaxants does not negatively affect the passive handling and dissection of the stomach during abdominal manipulation.

This study had several limitations. First, it involved a relatively small number of cases at a single institution. Second, the anesthetic team was sufficiently experienced, which may not apply to all centers. The success of the procedure depends on the experience of the anesthetic team, which needs to be verified for safety and acceptability in the absence of muscle relaxants. The third limitation involves the safety and efficacy of the robotic TCE procedure itself. In the present study, the incidence of transient recurrent nerve palsy was 13%, and the incidence of respiratory complications was 6.6%; these rates are considered acceptable considering the incidences in previous reports [6, 20, 22, 23]. Furthermore, neither chemotherapy nor chemoradiation should have a particular impact on the procedure at the dose used for preoperative adjuvant therapy. However, further studies are needed to evaluate the efficacy of robotic TCE procedures compared with ordinal approaches such as conventional TCE or the transthoracic robotic approach. Conventional mediastinoscopy is a bit unique as a technique. Especially in the early stages of cervical manipulation, some surgeons prefer to dissect with as direct a field of view as possible, making it difficult to share information about the operative field and potentially leading to an uncertain and ambiguous procedure. In addition, conventional mediastinoscopy tends to be unstable in terms of surgeon and assistant ergonomics, which can lead to nerve palsy. RACE certainly addresses the above concerns. In terms of procedural reproducibility, many studies have suggested that robotic surgery is more reproducible than conventional nonrobotic techniques. These findings suggest that robotic-assisted transcervical esophagectomy may gradually become more widespread in the future.

In conclusion, to the best of our knowledge, this is the first report of robot-assisted TCE for thoracic esophageal cancer in which a simultaneous cervicoabdominal procedure was performed using an NIM system without muscle relaxants. This technique enabled a significant reduction in the operative time and incidence of complications, including intraoperative events and postoperative recurrent nerve palsy. Although our findings suggest the usefulness of this technique, further studies are needed to accumulate more cases and standardize the technique.

Funding

This research did not receive any specific funding from any agencies in the public, commercial, or not-for-profit sectors.

Declarations

Disclosures

Takeo Fujita, Kazuma Sato, Naoto Fujiwara, Daisuke Kajiyama, Yuto Kubo, and Hiroyuki Daiko have no conflicts of interest or financial ties to disclose.