An early experience in robotic ileoanal pouch surgery with robotic intracorporeal single‐stapled anastomosis (RiSSA) at a tertiary referral centre

A robotic approach to ileal pouch–anal anastomosis (IPAA) surgery offers advantages over other approaches in terms of precision, improved access to the pelvis and less muscular fatigue for the surgeon. The integrity of the anastomosis is also fundamental to successful IPAA surgery. The robotic platform can permit intracorporeal suturing deep within the pelvis to create a single‐stapled, double purse‐string anastomosis, which may reduce the risk of anastomotic complications. This study describes the safety and early outcomes of robotic intracorporeal single‐stapled anastomosis (RiSSA) amongst patients operated consecutively at a tertiary centre immediately before and following the pandemic.

early outcomes of robotic intracorporeal single-stapled anastomosis (RiSSA) amongst patients operated consecutively at a tertiary centre immediately before and following the pandemic.
Method: A retrospective study of prospectively collected data analysing the outcome of patients undergoing robotic IPAA between 2019 and 2022 was conducted. All procedures were performed with the da Vinci Xi Surgical System (with a hand-assisted suprapubic incision to fashion the pouch). All pouch-anal anastomoses were performed using a double purse-string, single-stapled (RiSSA) method. Demographic, clinical and outcome data were collected.
Results: Twenty consecutive patients (nine with ulcerative colitis and 11 with familial adenomatous polyposis) were included with a median age of 25 years (range 16-52); 18 had American Society of Anesthesiologists classification II, and mean body mass index was 24 kg/m 2 (range 18.1-34.3). Nine patients (eight ulcerative colitis and one familial adenomatous polyposis) had undergone prior subtotal colectomy and therefore underwent restorative proctectomy with IPAA. Eleven patients underwent restorative proctocolectomy.
All procedures were completed robotically. The median length of stay was 9 days (5-49).
There were no unplanned admissions to intensive care and no deaths. Three patients were readmitted following hospital discharge for (i) an ileus managed conservatively, (ii) small bowel obstruction managed conservatively and (iii) small bowel obstruction due to constriction at the stoma site necessitating surgery. There were two additional reoperations

INTRODUC TI ON
Since it was first described the technique of ileal pouch-anal anastomosis (IPAA) has undergone a number of modifications [1]. IPAA is a complex procedure with appreciable morbidity. The second

Association of Coloproctology of Great Britain and Ireland Ileoanal
Pouch Registry Report in 2017 reported on more than 5000 pouch operations undertaken over four decades. It highlighted overall morbidity rates of over 30%, a pelvic sepsis rate of 14.6% and a pouch failure rate of 10.5% [2]. These data were collected through voluntary submissions and could therefore still reflect significant bias due to underreporting. Pursuit of IPAA surgery for most patients reflects a desire to undergo a major operation with the intention of restoration of continuity and consequent avoidance of a permanent stoma.
The integrity of the IPAA is probably the best predictor of a successful pouch. Difficult pelvic access, compromised views and limited ergonomics associated with conventional laparoscopic instruments can result in compromise to the IPAA. Abdominal stapling approaches may risk oblique rectal transection requiring multiple firings, a factor associated with increased leak rates [3]. Perineal approaches look to solve the issues of firing staplers within a confined space with transanal techniques. Transanal approaches have been tried in recent years as an alternative to the problems cited above. Specifically, transanal total mesorectal excision (TaTME) [4] and more recently transanal transection and single-stapled (TTSS) anastomosis are examples of this [5]. Although concerns have been raised about TaTME in the context of rectal cancer surgery, transanal approaches do have useful applications for benign disease [6]. Thus, despite meaningful modifications over the years, IPAA surgery remains an operation that may benefit from improvements in technique and approach.
Robotic techniques are being used increasingly in colorectal surgery, offering potential advantages in magnified 3D vision, enhanced ergonomics and endowrist instrumentation with motion scaling.
There has been an increase in the uptake of robotic platforms for benign and malignant diseases [7]. With its improved vision and dexterity in the pelvis, we hypothesized that a robotic approach could offer meaningful gains in surgical outcomes for IPAA. Specifically, we sought to combine the innovations of robotic proctocolectomy surgery with an intracorporeal double purse-string anastomosisthe robotic intracorporeal single-stapled anastomosis (RiSSA) [8].
The aim of this case series is to describe the early experience of performing robotic IPAA surgery with RiSSA.

ME THOD
Patients were prospectively included if undergoing restorative proctocolectomy or restorative proctectomy for ulcerative colitis

Surgical procedure
A video describing the RiSSA technique has been published previously [8].
both for drain complications, one for drain removal and one for drain erosion. On mobilization of the pouch in the latter case, an anastomotic defect was observed. In total, 19/20 patients underwent RiSSA without postoperative anastomotic problems.

Robotic panproctocolectomy/proctectomy A Pfannenstiel incision is used as a primary access point. An
Alexis® wound retractor is inserted and a laparoscopic 12-mm AirSeal® port is used to achieve pneumoperitoneum. Four 8-mm robotic ports are inserted in an oblique line from the right anterior superior iliac spine to the left subcostal margin. The robot is docked, first targeting the right upper quadrant. We use two right hands with robotic shears and Cadière forceps and a left hand with a bipolar fenestrated forceps. Identification and transection of ileocolic and middle colic vessels and mobilization of the right colon are undertaken. The mobilization of the transverse colon is continued and the splenic flexure is mobilized from the cranial aspect.
The inferior mesenteric vein is divided high adjacent to the duodenum. The robot is now re-oriented and re-docked aiming towards the pelvis. Transection of the inferior mesenteric artery and full TME dissection are undertaken.
In the case of a proctectomy only (previous subtotal colectomy) the ileostomy is taken down first and an Alexis® retractor is inserted. This access port is used for a robotic 12-mm cannula, and three further ports are inserted in a horizontal line. The robot is docked and targeted towards the pelvis. A standard robotic TME is performed.

Pouch construction
The J-pouch is created using a stapled technique. First, the sta-

RiSSA technique
The aim of RiSSA is to avoid cross-stapling whilst performing a circular single-stapled pouch-anal anastomosis. Once the mesorectal dissection has been completed, the surgeon assesses the preferred level of the rectotomy by digital rectal examination and rigid rectoscopy. Extensive wash-out of the rectum is undertaken.
The ideal level is at around 3 cm proximal to the dentate line. After applying the circular stapler, this will lead to an anastomotic level of 0.5-1 cm above the dentate line. The rectotomy is performed transabdominally with robotic shears, using diathermy. The anorectal stump exceeds the pelvic floor by 1-2 cm at this point. Two  Table 1.

Operative results
All operations were completed robotically. In one case an adhesiolysis was performed via a small open midline incision before closing and completing the restorative proctectomy robotically. See Table 2 for a summary of operative details. The median operating time for restorative proctectomy was 362 min versus 488 min for restorative proctocolectomy.
Eighteen patients had a J-pouch formed extracorporeally through a mini Pfannenstiel incision, one patient (described above) had theirs formed via their laparotomy and one via their ileostomy incision. All anastomoses were constructed using a double pursestring, single-stapled method. Proctectomy was undertaken in the TME plane in 18 patients and two patients underwent close rectal dissection. As per our standard operative procedure all patients had a defunctioning loop ileostomy at the time of IPAA except for one patient where high BMI prevented the ileum from safely reaching the abdominal skin surface (an ileostomy was required at a subsequent reoperation for pelvic sepsis-see below). The mean longitudinal pouch length was 16.7 cm and the mean rectal cuff length was 2.3 cm.

Patient outcomes
The median length of stay was 9 days (5-49). There were no unplanned admissions to intensive care and no deaths. The clinical outcomes are described in Table 3; eight patients had postoperative complications (Table 4). Three patients experienced high output ileostomies which were managed conservatively with loperamide, patient education and St Mark's electrolyte solution. Three patients were readmitted following discharge: one for an ileus which was managed conservatively, one for small bowel obstruction which was managed conservatively, and the last patient who necessitated a return to theatre (after 28 days) for a refashioning of the ileostomy (a widening of the abdominal wall stomal fascial defect). In addition to this patient there were two further patients who required reoperation. The first patient required a general anaesthetic to remove a drain adhered to the back of the pouch within the first week after surgery. The final patient requiring reoperation was due to the pelvic drain eroding into the back of the pouch. There was no evidence of anastomotic dehiscence on the preoperative scan that detected the drain erosion.
At the time of laparotomy (on the sixth postoperative day) following significant pouch mobilization an anastomotic defect was observed in the posterior IPAA. It is suspected that the anastomotic defect occurred due to the mobilization. A repair of the defect in the posterior pouch was undertaken and an ileostomy was exteriorized (due to the patient's raised BMI it had not been possible to raise a stoma at the primary procedure). Endosponge therapy and staged closure was undertaken for the defect in the ileoanal anastomosis.

Postoperative outcomes
All patients are amenable to ileostomy reversal and, in consequence, restoration of continuity. To date, the majority, 70% (14/20), of patients have had their anastomosis checked postoperatively with a pouchogram and pouchoscopy but other modalities such an examination under anaesthesia were also used. All patients will require successful pouchography prior to reversal. To date seven patients have successfully had their ileostomy reversed ( Table 5). The median time period between the initial surgery and reversal is 7.5 months.
There have not been any complications following ileostomy reversal.
All patients have had their urinary catheters successfully removed and no male patients have reported erectile dysfunction. An ileostomy was created at a subsequent procedure.

DISCUSS ION
The adoption of the robotic platform in colorectal surgery is increasing. We describe the experience of a specialist centre that has adopted the robotic platform for pelvic dissection as well as per- the distal rectum transection [11]. Transanal pouch anastomoses have been demonstrated to result in decreased patient morbidity, and an overall lower comprehensive complication index, compared with a transabdominal minimally invasive approach [12]. Spinelli and colleagues recently compared the three different approaches (laparoscopic double-stapled (DS), TaTME and TTSS anastomosis techniques) with respect to anastomotic leak. They found that (i) the leak rate was highest in the DS group, followed by the TaTME group; (ii) the operating time was the longest in the TaTME group; and (iii) 90day complications and the reintervention rate were highest in the DS group; which led them to the conclusion that TTSS is feasible and safe, with a lower associated cost and easier learning curve than other approaches [13]. robotic IPAA cases. They found that the operative approach did not influence the complication rate on multivariable analysis. The complication rate was 25%, the overall leak rate was 4%, the reoperation rate was 6% and the readmission rate was 21% [16]. Lightner et al. compared retrospective data for laparoscopic and robotic approaches and demonstrated that the complication rate between the approaches was comparable, as were readmission (24.1% vs. 17.6%; P = 0.35) and reoperation (6.9% vs. 5.4%; P = 0.72) rates [11]. Flynn and colleagues recently performed a systematic review and metaanalysis of nine studies (n = 640 patients) and found the complication rate to be 34% for laparoscopic and 44% for robotic approaches [17]. As such, our data are comparable in terms of complication rates.
We acknowledge, however, that in our series two patients had drain The limitations of this study include a small single-centre experience over the pandemic when practice and patients may not be generalizable. There is also a learning curve and specialist knowledge that make this operation only appropriate in high volume specialist units. Saqib et al. suggested that a proficient laparoscopic surgeon started to plateau in the learning curve after 30 proctored cases [18]. When considering future directions, one concedes that robotic operations are currently longer and more expensive. There is evidence, however, that suggests that there is a shorter learning curve from open to robotic surgery than between open and laparoscopic surgery. In a recent review of robotic surgery, Anderson and Grucela concluded that a longer operating time (mean 28 min) was acceptable in the context of the additional benefits gained through a robotic approach versus laparoscopic subtotal colectomy operating times [19]. Furthermore, with increased commercial competition and with more robotic platforms becoming available, it is likely that the costs associated with robotic surgery will decrease over time. Whilst this study has demonstrated its aim in terms of feasibility the real question will lie with long-term functional outcome and QoL data.
These outcomes will be essential metrics for any centre undertaking pouch surgery.

CON CLUS ION
We present an early case series where we demonstrate the efficacy of our robotic approach to IPAA surgery with RiSSA with acceptable quality and safety.

FU N D I N G I N FO R M ATI O N
None.

CO N FLI C T O F I NTE R E S T
None.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available from the corresponding author upon reasonable request.

E TH I C A L A PPROVA L
Ethical approval was not required for this study.