A precise approach to robotic intracorporeal rectal transection and hand‐sewn purse‐string anastomosis for low anterior resection

This study presents a new technique for robotic‐assisted intracorporeal rectal transection and hand‐sewn anastomosis for low anterior resection that overcomes some limitations of conventional techniques. By integrating the advantages of the robotic platform, ensuring standardized exposure during rectal transection, and emphasizing the importance of avoiding complications associated with staple crossings, this innovation has the potential to significantly improve outcomes and reduce costs for patients with lower rectal tumors.

rectal transection with single-stapled (TTSS) anastomosis have both emerged as advanced options. 6,7Although effective, these methods require a combined approach, posing technical complexities, especially in patients with a less favorable anatomy for endorectal access. 1 These steps can be fully facilitated by a robotic platform, which provides excellent endopelvic exposure.Despite some described intracorporeal series, finding methods to avoid double stapling in colorectal anastomoses remains an urgent necessity in colorectal surgery.This study describes an original precise technique for fully robotic intracorporeal rectal transection with appropriate margins and a single-staple anastomosis (RTSS).The feasibility of this technique was further demonstrated in 15 consecutive patients undergoing total mesorectal excision (TME) for rectal cancer.

| METHODS
We describe the first 15 consecutive cases of anterior rectal resection with robotic-assisted TME to treat rectal cancer, performed at our hospital in patients aged 18-80 years in 2023.All robotic surgeries were performed using the Da Vinci Si Surgical System.Two experienced surgeons (PRSF and SAJ), each with a minimum of 100 robotic surgeries for rectal cancer, performed all procedures.One surgeon supervised all cases (PRSF).The remaining participants underwent colorectal surgery and were assisted with the procedures.

This study was approved by our Institutional Research Ethics
Committee.We analyzed the demographic and clinicopathological characteristics, perioperative details, and postoperative outcomes of all patients.

| Intra-abdominal rectal transection steps
The steps illustrated in Figures 1 and 2 are further detailed in Supplementary Video 1.
A transanal intraluminal purse-string suture was applied immediately distal to the lesion, using a 2-0 suture or an equivalent, before initiating the operation, thereby isolating the longest possible length of the distal rectal segmental stump free of tumor.
We exclusively employed the permanent cylindrical trunk anoscope for transanal endoscopic operations (TEO PlatformStorz), performing a purse-string suture with a conventional needle holder.This is a rapid step that lasts less than 10 min.A permanent cylindrical trunk anoscope (>34 mm in diameter) or a disposable option such as the CK34M model from Frankenman Int. Ltd., are both excellent alternatives.Finally, the distal rectal stump was washed with 0.9% saline and chlorhexidine.Subsequently, the patient was placed in a modified lithotomy, Trendelenburg position, right side-down position with a pneumoperitoneum of 12 mmHg pressure, and the robot was docked.Robotic approaches to TME have been described previously. 2 After total mesorectal dissection and complete mobilization of the left colon, rectal sectioning was performed.To facilitate perfect exposure and visualization of the closed free rectal stump, an auxiliary surgeon introduced a plug (manually made with gauze and coated with a surgical glove; Figures 1 and 2).The entire free distal rectum was then presented endorectally for precise low transection with endopelvic visualization.Following the guidelines for rectal cancer, we prioritized achieving a distal margin from the tumor of > 2 cm.We emphasize that regardless of the location of middle or lower rectal tumors, anastomosis is always low because of the necessity of total mesorectal excision (TME).For tumors of the distal rectum, we prioritized achieving a distal margin of >1.0 cm after neoadjuvant treatment to enable circular stapled anastomosis.
The same cautery hook and scissors used for rectal dissection were applied in this procedure (no need for additional tweezers).
The robot facilitated this transection phase by sectioning a safe area determined by a free homogeneous margin that was immediately cleaned after the initial complete intraluminal pursestring suture.

F I G U R E 1
Steps to achieve intra-abdominal rectal transection.(A) Endorectal purse-string suture with a free margin and washing with 0.9% saline solution and chlorhexidine.(B) Exposure of the area for rectal transection; the precise lower rectal transection and endorectal plug exposure; the residual rectal stump.
After completing rectal transection, a wound protector was used to exteriorize and remove the intestinal segments from the cavity.The decision to perform exteriorization via a small Pfannenstiel incision or the endorectal route was based on the size of the surgical specimen.
Endorectal exteriorization also requires greater mobilization of the splenic flexure to achieve complete descent of the left colon into the perineum.Exteriorization through a small Pfannenstiel incision was performed in approximately 74% of cases.
We routinely performed a perfusion test with indocyanine green (ICG) fluorescence angiography (FA).After verifying distal colon perfusion, a purse-string suture was made in the exteriorized colon to place the anvil of a circular stapler (29 mm) and then returned to the pelvic cavity.
A purse-string invagination was performed in the rectal stump via robotic intrapelvic access to prepare it for the introduction of a circular stapler (Figure 2).The stapler was normally introduced into the rectum; moreover, after positioning, the trocar was opened, and the previously prepared purse was fixed very tightly over the trocar.We prefer suturing using unidirectional anchors to facilitate this step by making the segment progressively tighter (Figure 2).

| RESULTS
The RTSS was used in 15 consecutive cases of middle/lower rectal adenocarcinoma surgery at our institution.The clinical characteristics and preoperative and postoperative data are shown in Table 1.Our protocol for the closure of a protected ileostomy lasted 15-30 days after primary surgery or hospital discharge.Preoperative flexible sigmoidoscopy was performed to confirm integrity of the anastomosis.Gastrografin enema was not routinely performed.

| DISCUSSION
8][9] Technical challenges in achieving the optimal distal margin include the absence of standardized linear stapler dimensions and load sizes, as well as a standardized access portal.The conventional double-stapling technique has been criticized for its higher risk of complications compared to approaches such as TaTME 6,9 and TTSS, 3,8 along with the costly use of staplers and additional loads.
Recent studies have highlighted the benefits of robotic platforms in surgeries with a limited space, such as pelvic cavity procedures in TME and low anastomosis. 2We devised a method to expose the distal rectal area for precise transection, sequentially progressing after TME, utilizing integrated robotic features.This approach reduces costs by eliminating the need for TaTME equipment, perineal retractors, linear staplers, and additional loads. 10Anal canal fiber stretching and fissures have not been addressed in endorectal anastomosis studies and may have been mitigated by protective stomas.
In a prior study, Kim et al. 11  The standard approach for the anterior resection of the rectum with total mesorectal excision involves a protective stoma.Although The mean patient age was 60 years, and 73% (n = 11) of the patients were classified as ASA class II.The median postoperative hospital stay was 6 days (range: 3-12 days).The mean operative time was 262 min (222-283 min).No intra-operative complications or conversions were observed.A pelvic drain was placed intraoperatively, and serum C-reactive protein (CRP) levels were measured on the third postoperative day.Follow-up tomography images were obtained for patients with a hospital stay exceeding 7 days, abdominal distension, or CRP > 15 on the third postoperative day.None of the patients developed intraoperative complications, anastomotic leakage, drain changes, or presented with images suggestive of anastomotic complications.One patient had a slightly longer hospital stay (ten days) due to gastroparesis, the need for a nasogastric tube, and multiple comorbidities (smoking 100 packs/year, pulmonary emphysema, systemic arterial hypertension, and diabetes mellitus).Two other patients required a temporary nasogastric tube because of ileus.Table 2

F I G U R E 2
Steps to achieve hand-sewn purse-string anastomosis.(A) ICG FA of the colon and anastomosis area.(B) Purse-string suture of the residual rectal stump.(c) A circular stapler was inserted into the rectum.(d) The area residual ring was stapled.(E) Precise circumferential distal margin rectal was performed.(F) Endoscopic aspect of the late colorectal anastomosis was performed.STEVANATO FILHO ET AL.| 941 ileostomy may potentially interfere with the diagnosis of an anastomotic leak, patients were monitored for drain appearance, serum C-reactive protein levels, and early follow-up endoscopic images with flexible sigmoidoscopy before stoma closure.Our evaluation did not reveal any clinically significant changes that might preclude restoration of intestinal transit.RTSS provides a consistent approach, opposing some points in traditional surgical techniques, and integrating the robotic platform with previously described excellent mesorectal quality and functional outcomes, especially in obese patients, men, and patients with lower lesions.This proof-of-concept study established the feasibility and safety of adhering to the oncological, functional, and surgical ergonomic criteria.Standardized exposure to transection and colorectal anastomosis might aid in the learning curve, reduce costs, and enhance outcomes in patients with lower rectal tumors.5 | CONCLUSIONSAvoiding double stapling of low colorectal anastomoses is an urgent necessity in colorectal surgery.Our novel approach addresses the challenges associated with anastomotic leakage.By integrating the advantages of the robotic platform and incorporating technical facilitation, the RTSS has emerged as an intriguing technique for standardization and prospective comparisons among different approaches.
Demographics, preoperative, and operative data.
compared intracorporeal singlestapled and double-stapled anastomoses in laparoscopic low anterior T A B L E 1