The evolution of robotic single-port dedicated platforms

1.1 Introduction

While the idea of using a “single port” for diagnostic and simple interventions has been in place in the surgical field for many decades, it was only in the early 1990s that the first complete extirpative procedure was reported in gynecology. In the mid-2000s, the fascinating concept of “scarless surgery” was revived creating momentum for a new “wave” of preclinical and clinical investigations in different surgical specialties. Both “natural orifice transluminal endoscopic surgery” and “laparoendoscopic single-site surgery” (LESS) were developed to further reduce the morbidity and scarring associated with minimally invasive surgical intervention. These techniques shared a common underlying “hypothesis,” that a reduction in the number of transcutaneous points of access (i.e., trocar sites) may ultimately translate into better outcomes, less complications, and faster postoperative recovery.

In history of LESS in urology started in 2005 with a report by Hirano et al. on a retroperitoneoscopic adrenalectomy via a “single port.” In 2007 Rane et al. presented at the 25th World Congress of Endourology in Cancun the first successful LESS case in urology. Soon after, Cadeddu et al. from UTSW Dallas independently reported the first series of LESS transumbilical nephrectomies. Kaouk and Gill from the Cleveland Clinic also pioneered the early adoption of this groundbreaking concept by showing the “feasibility” of the entire spectrum of urologic procedures. The initial enthusiasm was, however, tempered by the technical challenges related to the use of a single access point, forcing the surgeon to work with laparoscopic instruments in parallel and causing by default reduced range of instrument movements, limited extraabdominal working space, unfavorable ergonomics, and more importantly, increasing the risk of the procedure. These limitations de facto restrained the implementation of LESS to few surgeons worldwide and in few selected cases.

The recognized benefits of the robotic-assisted laparoscopy over conventional laparoscopy include superior ergonomics, optical magnification of the operative field, enhanced surgeon dexterity, and precision of surgical manipulation. It was, therefore, natural to try to use the da Vinci robotic system to facilitate LESS. In 2009 Kaouk and his team reported the first successful series of “single-port” robotic procedures in humans, including cases of radical prostatectomy, dismembered pyeloplasty, and radical nephrectomy. The authors immediately noted less challenging intracorporeal dissection and suturing using robotic instrument compared to standard LESS. With the adoption of robotic technology, a new era seemed to start, but it soon became clear that technical challenges still existed, given the lack of a purpose-built robotic system.

In this chapter, we discuss the evolution of robotic “single-site” or “single-port” surgery in urology, including trends, techniques, challenges, outcomes, and technological advances made until the release of the first commercially available purpose-built robotic platform (da Vinci SP System, Intuitive Surgical, Sunnyvale, CA, USA).

1.2 Da Vinci Single Site (VESPA)

Given the limitations of using the standard multiport da Vinci Si robot, Intuitive Surgical initially developed and launched a novel set of single-site instruments and accessories specifically dedicated to LESS ( Fig. 1.1 ). The set included a multichannel access port with room for four cannulas and an insufflation valve: two curved cannulas were for robotically controlled instruments, and the other two cannulas were straight, one 8.5 mm cannula for the robotic endoscope and a 5-mm for bedside-assistant port. The curved cannulas were integral to the system, since their configuration allowed the instruments to be positioned to achieve triangulation of the target anatomy. This triangulation was achieved by crossing the curved cannulas midway through the access port. Same-sided hand–eye control of the instruments was maintained through assignment of the Si system software enabling the surgeon’s right hand to control the screen right instrument even though the instrument was in the left robotic arm and, reciprocally, the left hand to control the screen left instrument which was in fact the right robotic arm. Robotic arm collisions were minimized externally because the curved cannulas angle the robotic arms away from each other. The single-site instruments and accessories were intended to be used with the da Vinci Si surgical system, being of similar construction to existing EndoWrist instruments, except they did not have a wrist at the distal end of the instrument, which turned out of a major limitation to future clinical adoption.

1.2.1 Preclinical experience

This first robotic instrumentation purposely made for LESS procedures was initially tested in preclinical animal model in 2010 by Haber et al. at the Cleveland Cinic. Sixteen kidney procedures were performed without additional ports or need for conversion. During this feasibility evaluation, limitations of the platform were noted, including the lack of articulation at the tip of the instruments, making intracorporeal suturing more challenging. Soon after, Kaouk et al. reported the use of the “second generation” of da Vinci Single-Site instruments for R-LESS to perform different kidney procedures in the cadaver model. The procedures were completed successfully without the addition of extra ports. The working space was not problematic for the surgeon, but significant collision against the robotic arms was experienced by the assistant, which at times restricted retraction and suction. A positive feature was the easy insertion and exchange of the instruments. The lack of wrist articulation was confirmed as the main limitation of these instruments, particularly for procedures involving suturing.

1.2.2 Clinical experience

In the clinical arena, cholecystectomy has been the most widely used application of LESS within general surgery. This has also been the case for the “single-site” da Vinci platform, which was launched by Intuitive to primarily “target” general surgeons performing cholecystectomies. In 2011 two groups independently reported the first clinical experience with the novel da Vinci Single-Site platform.

In urology, Cestari et al. from Italy tested the technical feasibility and short-term perioperative outcomes of the da Vinci Single-Site instrumentation platform for the treatment of upper ureteropelvic junction obstruction in a selected group of patients. Another study from Italy confirmed single-site robotic pyeloplasty to be feasible in selected patients, with good cosmetic results and excellent short-term clinical outcomes. Not many other clinical series in urology followed.

The introduction of the single-site instrumentation was initially seen as a step forward, as it was addressing some of the existing drawbacks of robotic LESS, mainly the clashing and lack of triangulation. However, the lack of EndoWrist technology at the instrument tips, which certainly represent a key feature of robotic surgery, represented a main limitation and there the interest in urology for this platform quickly faded away. The “ideal” robotic platform for LESS should have a low external profile, the possibility of being deployed through a single access site, and the possibility of restoring intraabdominal triangulation while maintaining the maximum degree of freedom for precise maneuvers and strength for reliable traction ( Fig. 1.2 ).

1.3 Da Vinci SP

1.3.1 SP999 prototype

In 2014 a group of investigators from the Cleveland Clinic and University of Lille reported a clinical study supported by the Intuitive Surgical on the use of the first ever robotic system specifically built for “single-port” robotic surgery, the da Vinci SP Surgical System (SP999). As for the standard multiport da Vinci robot, the three major system components were: surgeon console, patient side cart, and vision cart ( Table 1.1 ). The da Vinci SP EndoWrist (also known as EndoWrist SP) instruments had 7 degrees of freedom at the distal end, and the system software was designed to provide exact translation of the surgeon’s hand and finger movements at the console to precise and tremor-free movements of the instruments. The EndoWrist SP instruments incorporated an additional joint providing an “elbow” so that instruments could triangulate at the surgical site through a single port. The EndoWrist SP instruments were also longer and incorporating a “snake-style” wrist like the standard 5-mm multiport EndoWrist instruments ( Fig. 1.3 ). This seminal work paved the way for subsequent developments.

Table 1.1

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