Keywords

1 Introduction

Over the past few decades, multiport laparoscopy has become the standard surgical approach in the treatment of colorectal diseases. Several randomized trials have, in fact, proven a number of advantages of laparoscopy over open surgery in performing colonic or rectal resections [1].

By aiming to further minimize trauma to the abdominal wall and improve cosmetic outcomes, in the late 2000s, technological advances allowed pioneer surgeons to explore new techniques such as single-incision laparoscopic surgery (SILS) and natural orifice transluminal endoscopic surgery (NOTES), as less invasive alternatives to conventional laparoscopy. However, their widespread adoption has been limited due to intrinsic problems such as the lack of camera and instrument triangulation, limited range of motion with reduced dexterity, and instrument collision. Although some of these issues have been partially solved with a cross-handing technique, use of curved instruments and adoption of robotic platforms, these techniques remain only for skilled surgeons who have completed an adequate learning curve.

In 2018, Intuitive Surgical released for clinical application the da Vinci SP (dV SP), a unique platform specifically designed for single-incision surgery. This system utilizes a C-shaped arm connected to a 25-mm port with four channels to allow the parallel entry of an 8-mm flexible 3D camera and three 6-mm instruments. All instruments are fully wristed with 7 degrees of movement and have an additional elbow flexion for proper triangulation around the target. A hologram located in the bottom center of the display tracks, in real-time, the spatial location of the camera and instruments, thus permitting minimization of internal collisions. In addition, the platform’s boom can rotate 360° outside and inside the port’s remote center. This facilitates multiquadrant surgeries and the coordinated movement of the camera and robotic instruments as one unit, helping, for example, to visualize all four quadrants of the rectum. This maneuverability coupled with camera control represents a significant improvement over previous robotic platforms. Overall, it seems that the dV SP platform addresses many of the limitations of single-port transabdominal or transanal surgery. At present the dV SP is not yet available in Europe. Therefore, most of the experiences come from eastern countries and the USA.

The aim of this chapter is to analyze available data in the field of colorectal surgery and to present the authors’ initial experience in a cadaveric model to highlight the pros and cons of this new platform.

2 Clinical Results of the da Vinci SP in Colorectal Surgery

Limited data still exist on the use of the dV SP in colorectal surgery. The first report was published in 2020 by Noh et al. [2], who described their initial experience with five right colectomies and two anterior resections with favorable short-term clinical outcomes and adequate pathologic results in terms of number of harvested lymph nodes, length of proximal and distal margins and quality of mesocolic or mesorectal fascias. Thereafter, few studies from both eastern [3,4,5,6,7] and western [8,9,10] institutions confirmed the technical feasibility of different types of colic (right and left colectomies, transverse colectomy) and transabdominal rectal resections, including intersphincteric and abdominoperineal resections. At the time of drafting the present chapter, the largest series of dV SP procedures has been reported by Choi et al. [11]. The authors analyzed 57 consecutive patients with rectal cancer who underwent 34 low anterior resections, 14 ultra-low anterior resections, 7 intersphincteric resections and 2 abdominoperineal resections, with satisfactory short-term outcomes. In fact, despite a 36% overall 30-day morbidity rate, only 2 patients (3.6%) suffered from major (Clavien IIIb–IV) complications, the most frequently recorded being intra-abdominal fluid collection and urinary retention (7 patients each). Final pathology confirmed the excellent performance of the dV SP in rectal resections, with a median number of harvested lymph nodes of 15.8 ± 6.1 and a positive circumferential resection margin rate of 5.3%. Interestingly, due to technical difficulties, 10 surgeries were completed with a single-port laparoscopic hybrid technique using the same robotic access without any additional trocar. Of note, most of the conversions to the laparoscopic approach happened during the first 16 cases. Analysis of the operative time, docking time and surgeon console time also permitted the authors to analyze the learning curve, showing an improvement in surgical performance after 21 cases.

In recent years, an increasing number of total mesorectal excisions (TME) have been made from bottom to up transanally (TaTME), either laparoscopically [12] or robotically (rTaTME) [13]. After the demonstration, in a preclinical cadaveric model [14], that the dV SP can be a viable option to safely and proficiently realize the transanal phase of TaTME, Marks et al. [15] reported the first clinical experience of dV SP rTaTME in two patients who underwent proctosigmoidectomy with hand-sewn coloanal anastomosis. In both patients the authors completed the TME phase transanally; interestingly, while in one patient, the abdominal phase of the operation was completed through an abdominal single-incision with robot re-docking, in the second patient the operation was entirely performed transanally as a pure NOTES procedure.

Over the last decade, the transanal minimally invasive surgery (TAMIS) technique has been increasingly used in the treatment of rectal benign lesions and low-risk T1 adenocarcinomas. Several studies have shown that this approach has several benefits over traditional transanal surgery. However, it remains a challenging procedure due to several shortcomings, such as the lack of a stable platform, the limited space for the surgeon and assistant between the patient’s legs, the difficulty of tissue dissection and suturing due the poor ergonomics and antagonism of contralateral instruments, a limited reach and a long learning curve [16]. The new dV SP has the potential to surpass all the technical challenges of conventional TAMIS. After exploring in a cadaveric study the potential of the dV SP in performing TAMIS procedures [17], Marks et al. evaluated, in a phase II trial on 26 patients, the feasibility and safety of a dV SP rTAMIS [18]. They documented excellent outcomes including no piecemeal extractions and 100% negative margins on final pathology with no mortality and a 15.8% morbidity rate. Although two patients were converted to TME, the authors showed the potential of this new platform in this type of surgery.

3 Authors’ Experience in Cadaveric Models

In March 2018, we had the opportunity to use the dV SP on cadavers. Access to the robotic platform, laboratory time and cadavers were provided by Intuitive Surgical, Inc. After 3 hours of training lab with the dV SP platform to familiarize with control of the flexible endoscope and instruments and use of the holographic navigation aid, two different operations were performed: a rTaTME and a transvaginal right colectomy with complete mesocolic excision (CME) and D3 lymphadenectomy.

3.1 Robotic Transanal Total Mesorectal Excision with the da Vinci SP

The cadavers were placed in the modified lithotomy position in Allen stirrups. A slight Trendelenburg (~10°) position was adopted. The patient-side cart was placed at a 90° angle to the left of the body with the vision cart over the left shoulder.

Two different scenarios were imagined, simulating a distance of the tumor’s inferior margin to the anorectal junction of 1 cm in one cadaver and 4 cm in the other.

The first case initiated by manually creating a purse-string closure of the rectal lumen, at the level of the dentate line. Then, a partial intersphincteric resection was performed robotically and the dissection was continued cephalad until the levator ani plane was reached, allowing introduction of the GelPOINT Path Transanal Access Platform (Applied Medical, Inc.). This part of the operation was done positioning the remote center of the robotic trocar approximately 15 cm from the anus. The setup of the instruments and camera was as follows: the camera was inserted through the camera port, a Cadiere forceps, monopolar curved scissors, and a fenestrated bipolar forceps were inserted through ports 1, 2 and 3, respectively. The second case began with the introduction of the transanal platform. The robotic trocar was positioned at 12 o’clock of the gelatinous membrane of the device, and a 10-mm port was inserted in the inferior part of the GelSeal cap. After docking the dV SP, the instruments were set up as in the other case. A 15-mmHg pneumorectum was established and closure of the rectum with a full thickness purse-string was constructed and tightened with the robotic instruments (needle driver in arm 2). After circumferentially marking the site of rectotomy, a full thickness and perpendicular transection of the rectal wall was performed with monopolar scissors. Then, the initial dissection was conducted until the posterior avascular presacral plane was encountered. The mesorectal dissection proceeded in the posterior quadrants first, followed by dissection of the distal anterior plane. Then, the lateral sides were approached. Thereafter, dissection following the TME plane proceeded cephalad in a cylindrical fashion until the abdominal cavity was entered by opening the peritoneum of the Douglas pouch. The specimen was extracted to evaluate the quality of TME which was graded as “complete” with an intact mesorectum in both cases.

3.2 Robotic Transvaginal Right Colectomy with the da Vinci SP

Cadaver, patient-side cart and vision cart were placed as during the dV SP rTaTME, adding a 10° left rotation of the cadaver. The operation started with performing a posterior colpotomy through which an Alexis Wound Protector-Retractor (Applied Medical, Inc.) was inserted. Then the robotic trocar was placed transvaginally with the tip of the cannula in the abdominal cavity. The plastic sheath of the Alexis was closed around the trocar with an umbilical tape before establishing a 12-mmHg pneumoperitoneum. A 12-mm trocar was placed 5 cm above the left iliac spine. After docking the dV SP, a fenestrated bipolar forceps, monopolar curved scissors and a Cadiere forceps were placed in ports 1, 2 and 3. After positioning the small bowel in the left upper quadrant, a bottom-to-up right colectomy procedure with CME and D3 lymphadenectomy was performed, as previously described with the da Vinci Xi (dV Xi) [19]. Of note, the anastomosis was performed mechanically with a linear stapler introduced through the assistant trocar. The ileocolic anastomosis was mechanical, side-to-side, isoperistaltic with the enterotomies closed with a manual continuous barbed suture. The specimen was extracted transvaginally and inspected to evaluate the quality of the mesocolic dissection, which was graded C.

3.3 Technical Considerations

In the authors’ experience performing rTaTME with the dV SP facilitated all critical steps of the procedure as compared to standard TaTME or rTaME with the dV Xi. First, it solved issues related to the limited space for the surgeon and assistant between the patient’s legs while providing a stable surgical field with an enhanced 3D vision. Second, since all three instruments and endoscope are oriented parallel, external collisions between the arms or with the patient’s thigh were avoided. Third, the instruments’ articulation facilitated the initial posterior dissection which must be performed at a markedly caudal and posterior angle to enter the proper plane. In addition, improved ambidexterity and ergonomics enhanced the ease of performing the lateral dissection, a critical step for the risk of pelvic nerve injuries. This ease of dissection was further improved by the possibility to rotate the boom with coordinated instrument and camera movements to optimize the instruments’ angle of approach throughout the procedure. Overall, all steps were simplified by the possibility of utilizing a third arm for traction/exposure. This represents a major advance compared to the da Vinci Si/Xi rTaTME or laparoscopic TaTME, where only two arms/instruments are available. In fact, a proper exposure has the potential to improve preservation of the integrity of the mesorectal envelope. All of these advantages might translate to a reduction of the surgeon’s fatigue, stress and discomfort, resulting in an increased surgical performance.

In right colectomy, while no major differences in terms of instrument maneuverability, precise tissue handling, and meticulous dissection were observed compared to the dV Xi platform, the specific design for single-port surgery permitted us to explore a new surgical access. Although no objective data are available comparing the mechanical force of the dV SP and dV Xi instruments, we felt that in some steps the mechanical force was a little weak. In addition, compared to the multiport system, we noted a limited range in third arm traction, which in some circumstances might be a partial obstacle. An additional limitation is represented by the lack of a suction, stapling, and, more importantly, vessel sealing device.

In all our surgeries, the dV SP demonstrated to be straightforward to set up, easy to use and precise in dissection and suturing.

4 Conclusions

The available data and the authors’ personal experience indicate that in colorectal surgery there is significant potential for the use of the dV SP, which might become competitive with the dV Xi. Many questions remain to be answered in the coming years. In particular, future studies will have to define the clinical role of this technology and establish which patients will benefit the most from its application.