New Robotic Platforms in General Surgery: What’s the Current Clinical Scenario?

Background and Objectives: Robotic surgery has been widely adopted in general surgery worldwide but access to this technology is still limited to a few hospitals. With the recent introduction of new robotic platforms, several studies reported the feasibility of different surgical procedures. The aim of this systematic review is to highlight the current clinical practice with the new robotic platforms in general surgery. Materials and Methods: A grey literature search was performed on the Internet to identify the available robotic systems. A PRISMA compliant systematic review was conducted for all English articles up to 10 February 2023 searching the following databases: MEDLINE, EMBASE, and Cochrane Library. Clinical outcomes, training process, operating surgeon background, cost-analysis, and specific registries were evaluated. Results: A total of 103 studies were included for qualitative synthesis after the full-text screening. Of the fifteen robotic platforms identified, only seven were adopted in a clinical environment. Out of 4053 patients, 2819 were operated on with a new robotic device. Hepatopancreatobiliary surgery specialty performed the majority of procedures, and the most performed procedure was cholecystectomy. Globally, 109 emergency surgeries were reported. Concerning the training process, only 45 papers reported the background of the operating surgeon, and only 28 papers described the training process on the surgical platform. Only one cost-analysis compared a new robot to the existing reference. Two manufacturers promoted a specific registry to collect clinical outcomes. Conclusions: This systematic review highlights the feasibility of most surgical procedures in general surgery using the new robotic platforms. Adoption of these new devices in general surgery is constantly growing with the extension of regulatory approvals. Standardization of the training process and the assessment of skills’ transferability is still lacking. Further studies are required to better understand the real clinical and economical benefit.


Introduction
Twenty-two years after the clinical introduction of the first Intuitive Surgical Da Vinci system, only a limited percentage of general surgery procedures are performed via robotic excluded. Redundant studies were included and highlighted in the results. Abstract or congress communications were excluded. Only studies in English language were included.
The literature search and selection were performed by two independent reviewers (FM, LS). According to the PRISMA methodology, all records were first merged into a single database, then duplicates were removed, and the remaining articles were reviewed for relevance using the title and abstract. Disagreement was resolved by discussion and consensus; if no agreement was reached, a third senior author was consulted (NdA) in assessing study inclusion.
Finally, the two reviewers, supported by three supplemental reviewers (AZ, VL, OM) performed an independent full-text analysis to finalize the inclusion of pertinent articles.
The protocol has been registered in the International Prospective Register of Systematic Reviews database (PROSPERO: CRD42023416428).

Data Extraction and Synthesis
An electronic spreadsheet was filled with data extracted from the selected studies. The following items were collected: first author's name, year of publication, country, type of study design, time frame of the study, pathological state requiring surgical intervention, number of patients/procedures evaluated, type of surgical intervention, adopted robotic platform, number of robotic and assistant arms adopted, number of surgeons involved, surgeon experience, surgical team experience, patient's age, patient's sex, intraoperative surgical outcomes, postoperative surgical outcomes, short-term outcomes, long-term outcomes, functional outcomes, learning-curve, or cost analysis.

Quality Assessment
The risk of bias of the included studies was assessed according to the MINORS scoring system. The MINORS system attributes a score of 0 if the item is not reported, 1 if the item is reported but inadequate, or 2 if the item is reported and adequate. The global highest score is 16 for non-comparative studies and 24 for comparative studies. Case reports were not evaluated due to the high risk of bias by definition.

Results
The initial database search identified a total of 1054 studies, of which 266 were duplicates. After screening the titles and abstracts of the 788 remaining articles, 681 were excluded owing to non-pertinent specialty or intervention. After the full-text reading of the 107 eligible articles, a further 4 were excluded since 1 was a review article and 3 did not have a full-text version available. One-hundred and three studies met the inclusion criteria and were selected for the qualitative synthesis of the literature (Figure 1).
The most performed procedure according to the specialty was: cholecystectomy in hepatobiliary surgery, anterior rectal resection in colorectal surgery, transabdominal preperitoneal hernia repair in abdominal wall surgery, transaxillar hemithyroidectomy in endocrine surgery, transthoracic esophagectomy in upper gastrointestinal surgery, and nipple sparing mastectomy in breast surgery.
No major issues related to the robotic system were reported, except for five cases with the same robotic system, reported by three different authors, which did not generate consequent serious clinical events [48][49][50].

Patient Chart Architecture
Five systems (Medtronic Hugo ™ RAS; Cambridge Medical Robotics Versius ® ; Asensus Senhance ® ALF-X; Distalmotion Dexter; SS Innovation Mantra) are modular with independent arms ranging from three to four, including the optical arm.
Five platforms (Meerecompany Inc. Revo-i ™ ; Wego Micro Hand S; Medicaroid Hinotori ™ ; Avatera Medical Avatera ® ; Rob Surgical Systems S Bitrack System) have a multiarm architecture with three to four arms, including the optical arm.
Two systems (Intuitive Surgical Da Vinci SP ® ; Titan Medical Inc ENOS ™ ) are single port surgery platforms endowed with three to four arms, including the optical arm, characterized by flexible arms.
One robotic platform (Virtual Incision MIRA) shows a new miniaturized architecture allowing the entrance and the deployment of the two sterile arms and the optics directly into the body through a single incision.
One platform (Medrobotics Corp. Flex Robotic System) is a flexible endoscope with two operating arms.
One system (Moon Surgical Maestro) is intended to hold and position laparoscopes and laparoscopic instruments during laparoscopic surgical procedures, like an assisted laparoscopy rather than robotics (Table 3). not have a dedicated viewing system but adopts a laparoscopic screen, considering that the surgeon console is sterile, and the operating surgeon is in the surgical field.
Two robots have a closed console with a Da Vinci-like architecture (Intuitive Surgical Da Vinci SP ® ; Meerecompany Inc. Revo-i ™ ).
Two systems adopt a semi-open console (Avatera Medical Avatera ® ; Medicaroid Hinotori ™ ) with an immersive view into a closed viewer but without the bulky system, reducing the physical isolation of the operating surgeon.
One system (Medrobotics Corp. Flex ® Robotic System) does not have a real console but an open bidimensional screen to drive the endoscope and two mechanical arms directly controlled by the surgeon with no electromechanical mediation.
One system (Moon Surgical Maestro) is more a holder for laparoscope and instruments so it does not have a dedicated console ( Three platforms (Titan Medical Inc ENOS ™ ; Virtual Incision MIRA; Avatera Medical Avatera ® ) did not still specify the adopted access system but two of them (Titan Medical Inc ENOS ™ ; Virtual Incision MIRA) will probably opt for a single port commercial system.
All the described systems except for two (Asensus Senhance ® ALF-X; Moon Surgical Maestro) have wristed or flexible instruments. As an exception, some papers reported the adoption of wristed instruments (Radia ® ) for the the Asensus Senhance ® ALF-X [23, 72,93]. Furthermore, the Wego Micro Hand S system is equipped by some authors with a rigid advanced ultrasonic dissector [69,84,96,103,106,109,110].
One system is partially sterilizable but adopts disposable instruments (Medrobotics Corp. Flex ® Robotic System).
One robotic system (Medtronic Hugo ™ RAS) uses sterilizable instruments with some disposable tools, as the needle driver and the scissor.
One system (Moon Surgical Maestro) does not have robotic tools so laparoscopic instruments can be adopted (Table 3).

Advanced Energy and Staplers
All the platforms support monopolar and bipolar energy but only three systems (Asensus Senhance ® ALF-X; Wego Micro Hand S; Meerecompany Inc. Revo-i ™ ) offer advanced ultrasonic energy.
A complete gamma of staplers or advanced energy is not currently available for any of the investigated platforms (Table 3).

Registries
Two manufacturers (Asensus Surgical; Cambridge Medical Robotics) provided the surgeons with self-established registries whose results were published [94,124].

Costs
A cost analysis was performed by only one (1%) study [110]. The analysis compared the robotic total mesorectal excision performed with the Wego Micro Hand S or with its comparator benchmark, the Intuitive Surgical Da Vinci Si ® . The Micro Hand S group had lower total hospital costs (87,040.1 ± 24,676.9 yuan vs. 125,292.3 ± 17,706.7 yuan, p < 0.05) and surgery costs (25,772.3 ± 4117.0 yuan vs. 46,940.9 ± 10,199.7 yuan, p < 0.05) when compared to the Da Vinci group.

Discussion
Robotic surgery has increasingly been adopted in general surgery since 2001 [125]. For years, the only widely adopted system was the Intuitive Surgical Da Vinci robot but, more recently, several other robotic platforms have been launched and introduced in the current practice after clinical approval in the respective markets. The present systematic review constitutes a state of the art of their clinical application.
The literature reviewed was very recent, published between 2016 and 2023, and reported clinical outcomes of over 2800 patients undergoing a minimally invasive operation with new robotic platforms.
Despite the recent adoption of these newly introduced platforms, the majority of the surgical procedures were performed with no reported adverse outcome and a low rate of technical issues related to the robot malfunction, confirming the reliability of the described systems. The new robots were mostly adopted for hepatopancreatobiliary, colorectal, and abdominal wall surgeries while fewer cases were reported for endocrine, upper gastrointestinal, and breast surgery. While some specialties, such as colorectal surgery, seemed to have extensively benefited from the new devices, others like the hepatopancreatobiliary surgery did not fully exploit their potential as the most performed procedure in such specialty still remains cholecystectomy. One of the reasons for this difference could be the absence of advanced instruments like staplers and powered dissectors, still not available for most of the presented robots. Another explanation could be found in the adoption of the new robotic platforms by hospitals aiming to improve the surgical volume and the attractiveness, even on simple procedures such as hernia surgery and cholecystectomy [126].
Nevertheless, the clinical indications for the new platforms are growing thanks to the constant approval of new specialties and new procedures in different countries.
The robotic platforms that are less represented in this review are expanding their market and new reports are available on a daily basis, following the acquisition by hospitals [127,128]. This robotic surgery broadening favored even general emergency surgeries for routine indications, such as appendicitis or cholecystitis, following a current trend in the literature [129]. Included articles belong to different continents but more than 50% were from Asia, where market is mainly driven by China, Japan, South Korea, India, and Taiwan.
These countries represent a population of more than 3 billion people, and they are pushing towards the development of indigenous platforms with the aim to compete with the existing Da Vinci. Concerning the Chinese market, the import of foreign robots is subject to a very limited quota, which was fully covered by Intuitive Surgical before the arrival of new competitors. The increasing complexity in the regulations will likely cut out expensive imported robots from the local market in favor of newly developed Chinese systems but it is not clear whether other countries will benefit from the commercialization of these platforms [130,131]. Access to the new technologies from China is extremely limited mainly due to the language barrier and the limited sharing of technical information, but currently several devices appear to be under testing and commercialization [132][133][134]. As for China, even Japan has a long history in robotic surgery, and it recently pushed the development of an indigenous product (Medicaroid Hinotori ™ ). The company's philosophy is tailored to suit the local market, promoting a smaller robot for smaller patients. However, it is also considering global expansion plans, as substantiated by its newly announced partnership with Karl Storz for the vision system [135] and the installation of the robot into a European training center [136]. Likewise, South Korea and India also developed their own systems with the aim of reducing robotic surgery expenses and facilitating the access to their population [137,138].
All the platforms presented in this review differ in nature, history, development, and technology. Only half of the included robots demonstrated their clinical potential while the rest are still under approval or in the investigational stage. The multi-arm robotic architecture invented by the Intuitive Surgical experience was adopted only by five manufacturers, whereas five others developed a modular concept more inspired by laparoscopy. Although the concept of "new robot" refers to small, portable, modular devices equipped with small instruments, this point was not agreed upon by the authors when reviewing the currently available robotic architecture, which is largely inspired by the well-known Da Vinci system. [139]. New concepts are emerging in the existing literature such as the mini-robot by Virtual Incision MIRA or the single port systems by Intuitive Surgical and Titan Medical emerged from the literature, leading to debates regarding indications and results, as it was in the laparoscopic era [140]. Additionally, two mentioned systems introduced the opportunity to robotize two routine practices such as the colonoscopy (Medrobotics Flex ® ) and the common laparoscopy (Moon Surgical Maestro). These innovations require proper trials to demonstrate their usefulness due to the current lack of clinical evidence.
Furthermore, analysis of instruments and trocars reveal differences across platforms in terms of materials, dimensions, and degree of articulation. Cost reduction, processability of instruments, tools' precision, and CO 2 emission remain top priorities for manufacturers despite the absence of common consensus, moreover regarding the use of reusable or disposable instruments.
These profound differences complicate a direct comparison between available robotic platforms. The only studies that aimed to show differences between manufacturers, were related to the Chinese Wego Micro Hand S system. The authors produced redundant literature demonstrating the equivalence of their new system with the existing Intuitive Surgical Da Vinci. In addition, they reported a decrease in hospital and surgical costs which could represent an advantage [110]. Additional economic studies are necessary to understand the real economic impact of the new platforms in various surgical environments.
The heterogeneous global situation, the variety of robots, and the continuous market growth are expected to revolutionize the clinical scenario in general surgery. Healthcare professionals will probably encounter multiple platforms throughout their career.
Due to the new paradigm of multiple robotic platforms possible co-existing in the same hospital, a proper credentialing system becomes essential.
The training process in surgery has been a topic of debate for decades, both in elective and emergency surgery [141]. Despite more than two decades of robotic surgery adoption as a surgical treatment across multiple specialties, no definitive training and credentialing programs were defined. Recently, Stefanidis et al. [142] and Burke et al. [143] tried to cope with this issue in the United States and United Kingdom, respectively. Currently, the proficiency assessment on the single platform is guaranteed by the manufacturer and hospitals grant permission to utilize the robot according to regulatory policies. This paper highlights that only 43.7% of the studies reported the operating surgeon's previous experience. In addition, only 27.2% of the authors described the training process of the surgical team on the adopted platform. The involvement of the nurses and of the anesthesiologists is even more marginal, despite a growing interest in literature for the topic [144,145]. The proposed structured training from a single manufacturer confirms the technical ability of the surgeon to accomplish prefixed tasks in different settings (usually simulation, dry lab, wet lab on pigs and/or cadavers). Typically, the first clinical procedures performed are proctored, although this is reported by less than 6% of the authors.
These training modalities have been extensively adopted since the introduction of robotic surgery despite limited evidence and some conflict of interest. In fact, proficiency assessment is performed by the same company that has an interest in the robot's clinical adoption. As there is no standardized curriculum in robotic surgery, analyzed papers did not provide information on the transferability of the skills from one platform to another. In a simulation environment, Larkins et al. were able to demonstrate some degree of robotic console skill transferability between two different multiport robotic platforms [146], while Ghazi et al. concluded for a partial transferability when simulating multiport and singleport robotic surgery [147]. In urology, currently the main market for robotic companies, a transition towards new systems were observed with positive clinical results [148], and it is reasonable to expect a similar process of validation for general surgery.
In order to validate the transition to new robotic devices, robotic companies are developing their products in collaboration with clinicians, trying to differentiate their approach and to collect data from the clinical activities. Two recently published registry analyses concerning the adoption of the two mainly diffused new generation robots, namely Asensus Senhance ® and CMR Versius ® , reported 871 and 2083 cases, respectively [94,124]. The published databases will make the comparison of clinical outcomes simpler and more transparent. Furthermore, the registry promotion distinguished the competitors from Da Vinci.
The next stage of development will focus on the producer partnership to improve and ameliorate the existing products in order to better compete in a market still dominated by a single leader. The vision capabilities will be augmented thanks to the new technological standards, as announced in February 2023 by Asensus with its new Luna Surgical System endowed with a 4K-3D vision without the need to wear glasses.
In terms of clinical data analysis, the next major advancement will entail the adoption of artificial intelligence as proposed by Asensus or Medicaroid, in order to digitalize the surgical practice, opening the door to new opportunities such as the telesurgery [149,150].
The present review presents some limitations mainly related to the low-quality of existing evidence, the design and the small sample of studies included, and the absence of data on several robotic platforms. Nevertheless, this systematic review provides a good snapshot of the real clinical application of the recently introduced platforms in general surgery.

Conclusions
Robotic procedures with new robotic devices have been progressively described in hepatobiliary, colorectal, abdominal wall, upper gastrointestinal, endocrine and breast surgery. Despite the low-quality of the current evidence, this review suggests that most surgical interventions are feasible with no technical issues. More platforms are obtaining clinical approvals and their continuous development will be likely stimulated by the Asian market. However, the absence of an international training curriculum and credentialing program hinders the ability to evaluate surgical proficiency and the transferability of skills across different devices. Thus, the future holds substantial technological innovation whose clinical evidence is yet to be established.