The robotic intracorporeal single-stapled anastomosis (RiSSA) technique in robotic left-sided colorectal resection: a technical note

Chih-Chien Wu; Yung-Lin Tan; Chao-Wen Hsu; Hsin-Ping Tseng; Danilo Miskovic; Shih-Feng Huang

doi:10.3393/ac.2025.00486.0069

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Technical Note Technical tips or video clip The robotic intracorporeal single-stapled anastomosis (RiSSA) technique in robotic left-sided colorectal resection: a technical note: Chih-Chien Wu^1,2, Yung-Lin Tan¹, Chao-Wen Hsu^1,2, Hsin-Ping Tseng¹, Danilo Miskovic^3,4, Shih-Feng Huang¹; Annals of Coloproctology 2025;41(4):357-360.
DOI: https://doi.org/10.3393/ac.2025.00486.0069
Published online: August 18, 2025

¹Division of Colorectal Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan

²School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan

³Department of Colorectal Surgery, St Mark’s Hospital and Academic Institute, Harrow, UK

⁴Department of Surgery and Cancer, Imperial College, St Mary’s Hospital, London, UK

Correspondence to: Shih-Feng Huang, MD Division of Colorectal Surgery, Kaohsiung Veterans General Hospital, No. 386, Ta-Chung 1st Rd, Kaohsiung 81346, Taiwan Email: odafeng@hotmail.com

• Received: April 19, 2025 • Revised: May 16, 2025 • Accepted: May 18, 2025

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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INTRODUCTION
TECHNIQUE
DISCUSSION
ARTICLE INFORMATION
SUPPLEMENTARY MATERIALS
REFERENCES

INTRODUCTION

In colorectal surgery, creating a secure and effective anastomosis is crucial. Various anastomotic techniques are currently used, including hand-sewn, double-stapling, and single-stapling methods, performed either intracorporeally or extracorporeally. Although historically important, hand-sewn anastomosis has largely been replaced by stapling techniques, which offer greater consistency and speed. Double-stapling techniques, widely adopted in laparoscopic and robotic surgery, involve 2 crossing staple lines (one from a linear stapler and the other from a circular stapler). Some studies suggest this may increase the risk of anastomotic leakage, a potentially life-threatening complication [1, 2]. To mitigate this risk, alternative anastomotic strategies have been developed, including modified double- and single-stapling techniques. Both alternatives appear feasible for reducing anastomotic complications compared to conventional double-stapling [3].

The single-stapling technique is not a novel concept in laparoscopic colorectal surgery. By using only 1 staple line, single-stapling techniques potentially reduce complications associated with the overlapping staple lines typical in double-stapling methods [4]. Single-staple anastomosis can be performed using transanal approaches, such as transanal total mesorectal excision or transanal transection, or intracorporeally via laparoscopy or robotic platforms. However, intracorporeal procedures are technically challenging, especially in laparoscopic low anterior resections for ultralow tumors or narrow pelvic spaces. The robotic intracorporeal single-stapled anastomosis (RiSSA) technique addresses these challenges by leveraging the enhanced dexterity of robotic surgery, particularly for intracorporeal suturing. Consequently, RiSSA is easier to perform than laparoscopic single-stapling methods. Although gaining adoption, clinical data specific to RiSSA in robotic colorectal procedures remain limited. The existing literature is primarily focused on stapling techniques in laparoscopic or open surgery, with few studies specifically addressing RiSSA in the robotic setting.

In this technical note, we describe the RiSSA technique in robotic surgery for left-sided colorectal cancer and report the short-term clinical outcomes of consecutive patients treated with this approach since its introduction in our unit.

TECHNIQUE

RiSSA technique

A standard robotic colectomy is performed by dissecting the colon or rectum to the targeted distal resection point. In selected cases, natural orifice specimen extraction (NOSE) can be employed. After transecting the distal colon/rectum using a single firing of a linear stapler (60-mm Echelon+ Stapler, Ethicon), the staple line of the distal colonic/rectal stump is excised with robotic monopolar electrocautery scissors. If NOSE is utilized, an extra-small Alexis wound retractor (Applied Medical) is inserted through the anus for specimen extraction. The anvil head of a circular stapler (29-mm Echelon Circular Powered Stapler, Ethicon) is introduced into the pelvis via the anus. The proximal colon is similarly transected with another linear stapler, and its staple line is excised. A 2-0 V-Loc (Medtronic) purse-string suture is placed at the proximal lumen. The anvil head is then inserted into the lumen, and the suture is tightened. Another 2-0 V-Loc purse-string suture is placed at the distal rectal stump. The shaft of the circular stapler is introduced transanally, its spike is fully extended, and the distal purse-string suture is tightened. After connecting the anvil to the spike, the proximal and distal ends are approximated and compressed before stapler firing. The circular stapler is then safely removed. An air leak test is performed to confirm anastomotic integrity. A detailed step-by-step procedure is provided in Supplementary Video 1. By adopting the RiSSA technique, the entire procedure—from the first incision of the visceral peritoneum to the completion of the anastomosis—can be performed robotically.

Overall, 31 consecutive patients undergoing surgery for left-sided colon and rectal cancer using RiSSA at Kaohsiung Veterans General Hospital (Kaohsiung, Taiwan) between May 2023 and February 2025 were analyzed. Patient demographics and baseline characteristics are detailed in Table 1. The technique exhibited safety and feasibility, with an acceptable operative time (median, 283 minutes), minimal blood loss (median, 50 mL), no conversions, no anastomotic leakage, and a low complication rate (16.1%), including only 1 major complication requiring reoperation. The median hospital stay was 7 days, with no 30-day readmissions or unplanned intensive care unit (ICU) admissions. Postoperative clinical outcomes are summarized in Table 2. Detailed information regarding postoperative complications in this series is provided in Supplementary Table 1.

Contamination control measures

To minimize the risk of intraoperative contamination during the RiSSA procedure, several strategies were routinely implemented. Unless contraindicated, patients underwent preoperative mechanical bowel preparation the day before surgery using sodium picosulfate or polyethylene glycol. Oral antibiotics (neomycin and metronidazole) were administered concurrently. All patients received prophylactic intravenous antibiotics at the start of surgery in accordance with institutional protocols. During surgery, the rectal stump was irrigated with diluted betadine solution before staple line excision. After dividing the rectal staple line, gauze soaked with diluted betadine was placed in the pelvic cavity. Following gentle cleansing of the proximal and distal bowel limbs, this gauze was retrieved transanally through the rectal cuff to minimize the risk of surgical site infection from intra-abdominal contamination. After completion of the anastomosis, the pelvic cavity was thoroughly irrigated, and a pelvic drain was routinely placed. Postoperative systemic antibiotics were prescribed if intraperitoneal contamination was strongly suspected based on intraoperative findings.

Ethics statement

This retrospective observational study was approved by the Institutional Review Board of Kaohsiung Veterans General Hospital (No. 241028-3). The requirement for informed consent was waived due to the retrospective nature of the study. All patient data were anonymized prior to analysis to protect patient confidentiality. The study was conducted in accordance with the Declaration of Helsinki.

DISCUSSION

In this study, we describe the RiSSA technique and report our early experience with its application in robotic left-sided colorectal cancer surgery. The technique demonstrated favorable short-term outcomes, with no conversions, no anastomotic leakage, and a low overall complication rate (16.1%), including only 1 major event that required reoperation. This complication involved a postoperative ureteral stricture, likely caused by severe adhesions and possible intraoperative injury, either from thermal effects or inadvertent suture placement. It was identified postoperatively and successfully treated with adhesiolysis and double J catheterization. The absence of mortality, 30-day readmission, and unplanned ICU admissions further supports the feasibility and safety of this approach.

RiSSA addresses a key limitation of the traditional double-stapling technique: overlapping staple lines, associated with increased risk of anastomotic leakage [5]. By eliminating this configuration, the single-stapled approach may offer improved anastomotic integrity, a longer distal margin, and a reduced risk of stenosis. These advantages, described in prior research, are further enhanced by robotic assistance, which facilitates precise resection and intracorporeal suturing. These benefits are particularly impactful in anatomically challenging cases, such as those of male patients with a narrow pelvis [6].

A highlight of this study is the use of the NOSE technique in most cases (27 of 31, 87.1%). This method is also referred to as the natural orifice intracorporeal anastomosis and extraction (NICE) procedure when combined with intracorporeal anastomosis, as described by Minjares-Granillo et al. [7] in 2019. The NOSE technique is well-established in laparoscopic surgery, with its safety and efficacy widely discussed in the literature. Advantages of NOSE include reduced postoperative pain, accelerated recovery of bowel function, and shorter hospital stays [8]. These benefits are likely intensified when combined with robotic techniques, such as the NICE procedure. However, the successful implementation of NOSE is heavily dependent on careful patient selection. If the specimen is too large, improper application may cause specimen rupture at the sphincter level, raising concerns about potential tumor spread. The routine use of a wound retractor, as employed in our procedures, helps mitigate this risk by preventing direct contact between the specimen and normal tissue [9]. Furthermore, tumor location—particularly its distance from the anal verge—significantly influences the technical feasibility of both specimen extraction and anastomosis. A longer rectal stump, common with more proximally located tumors, can complicate the NOSE technique due to limited maneuverability and anatomical angulation, although it may also facilitate purse-string suture placement by providing better luminal exposure. Conversely, shorter rectal stumps simplify specimen extraction through the anus but can present greater technical challenges during robotic purse-string suturing due to the restricted pelvic workspace. In our series, the median tumor distance from the anal verge was 17.9 cm, suggesting that most cases were well-suited for robotic manipulation and intracorporeal suture placement. As our team gained experience and confidence, we progressively expanded the indications to include tumors closer to the anal verge, with careful patient selection and tailored strategies to accommodate more challenging pelvic anatomy.

Although RiSSA has previously been described in video format, published clinical outcome data remain limited, particularly in Asian populations. To our knowledge, this is the first report of preliminary short-term outcomes of robotic RiSSA colectomy in this demographic. While our results are encouraging, limitations include a small sample size, retrospective study design, and lack of long-term oncologic data.

From a technical standpoint, the RiSSA procedure follows a standardized sequence, which may facilitate reproducibility across centers. Although intracorporeal purse-string suture placement is traditionally considered technically demanding, the enhanced dexterity provided by the robotic platform significantly improves feasibility. Notably, none of the patients in our cohort underwent coloanal anastomosis. For ultralow rectal tumors, we generally prefer transanal approaches such as transanal transection and single-stapling (TTSS) or transanal total mesorectal excision (TaTME), which enable more controlled distal access. While robotic intracorporeal purse-string suturing in the deep pelvis can be challenging, certain intraoperative strategies may improve success rates. These include placing a suction device in the pelvis to evacuate electrocautery smoke and maintain a clear surgical field, strategically angling a 30° upward-facing endoscope for better visualization, and extensive mobilization of the distal rectoanal stump to facilitate exposure and accurate suture placement. These technical adjustments may be particularly helpful in patients with a narrow pelvis or deep-seated tumor.

In our initial experience, operative time gradually decreased as the number of cases increased, stabilizing after approximately 15 to 20 procedures. A formal analysis of this trend using the cumulative sum methodology was conducted as part of a separate investigation and thus is not detailed here. Future studies could further quantify the procedural learning curve.

Larger prospective studies and multicenter collaborations are needed to validate the oncological safety and long-term efficacy of RiSSA. Comparative studies with double-stapled techniques may also help clarify specific advantages in different patient subgroups.

In conclusion, the RiSSA technique appears to be a safe and practical alternative to conventional double-stapled anastomosis in robotic colorectal surgery. It provides technical and clinical benefits, aligns with the goals of minimally invasive surgery, and may improve postoperative recovery in selected patients.

ARTICLE INFORMATION

Conflict of interest

No potential conflict of interest relevant to this article was reported.

Funding

None.

Author contributions

Conceptualization: CCW, DM; Investigation: CCW, YLT, CWH; Methodology: HPT, SFH; Project administration: HPT; Visualization: CWH; Writing–original draft: CCW; Writing–review & editing: all authors. All authors read and approved the manuscript.

SUPPLEMENTARY MATERIALS

Supplementary Table 1.

Detailed list of postoperative complications

ac-2025-00486-0069-Supplementary-Table-1.pdf

Supplementary Video 1.

Step-by-step procedure.

Supplementary materials are available from https://doi.org/10.3393/ac.2025.00486.0069.

Table 1.

Patient demographics and baseline characteristics (n=31)

Characteristic	Value
Age (yr)	60.3 (45.4–98.5)
Sex
Male	20 (64.5)
Female	11 (35.5)
Body mass index (kg/m²)	23.7 (17.2–28.7)
ASA physical status
I	1 (3.2)
II	27 (87.1)
III	3 (9.7)
Neoadjuvant therapy	5 (16.1)
Tumor size (cm)	3.5 (0.7–9.8)
Tumor location
Rectum	17 (54.8)
Rectosigmoid junction	10 (32.3)
Sigmoid colon	3 (9.7)
Descending colon	1 (3.2)
Tumor distance from anal verge (cm)	17.9 (8.0–40.0)

Values are presented as median (range) or number (%).

ASA, American Society of Anesthesiologists.

Table 2.

Postoperative clinical outcomes (n=31)

Outcome	Value
Anastomotic leakage	0 (0)
Complication	5 (16.1)
Minor (Clavien-Dindo grade I–II)	4 (12.9)
Major (Clavien-Dindo grade ≥III)	1 (3.2)
Reoperation (within 30 days after surgery)	1 (3.2)
Readmission (within 30 days after surgery)	0 (0)
Unexpected ICU admission	0 (0)
30-day Mortality	0 (0)
Length of hospital stay (day)	7 (3–14)
Time to first flatus/defecation (day)	2 (1–5)

Values are presented as number (%) or median (range).

ICU, intensive care unit.

REFERENCES

1. Akiyoshi T, Ueno M, Fukunaga Y, Nagayama S, Fujimoto Y, Konishi T, et al. Incidence of and risk factors for anastomotic leakage after laparoscopic anterior resection with intracorporeal rectal transection and double-stapling technique anastomosis for rectal cancer. Am J Surg 2011;202:259–64. Article PubMed
2. Kim NS, Kim JH, Lee YS, Lee IK, Kang WK. New double-stapling technique without staple-crossing line in laparoscopic low anterior resection: effort to reduce anastomotic leakage. Ann Coloproctol 2024;40:573–9. Article PubMed PMC PDF
3. Kitaguchi D, Ito M. Optimal anastomotic technique in rectal surgery to prevent anastomotic leakage. Ann Coloproctol 2023;39:97–105. Article PubMed PMC PDF
4. Brunner M, Zu'bi A, Weber K, Denz A, Langheinrich M, Kersting S, et al. The use of single-stapling techniques reduces anastomotic complications in minimal-invasive rectal surgery. Int J Colorectal Dis 2022;37:1601–9. Article PubMed PMC PDF
5. Guerra F, Coletta D, Giuliani G, Turri G, Pedrazzani C, Coratti A. Association between cross-stapling technique in mechanical colorectal anastomosis and short-term outcomes. Dis Colon Rectum 2024;67:1258–69. Article PubMed
6. Lightner AL, Kelley SR, Larson DW. Robotic platform for an IPAA. Dis Colon Rectum 2018;61:869–74. Article PubMed
7. Minjares-Granillo RO, Dimas BA, LeFave JJ, Haas EM. Robotic left-sided colorectal resection with natural orifice IntraCorporeal anastomosis with extraction of specimen: the NICE procedure: a pilot study of consecutive cases. Am J Surg 2019;217:670–6. Article PubMed
8. Saurabh B, Chang SC, Ke TW, Huang YC, Kato T, Wang HM, et al. Natural orifice specimen extraction with single stapling colorectal anastomosis for laparoscopic anterior resection: feasibility, outcomes, and technical considerations. Dis Colon Rectum 2017;60:43–50. Article PubMed
9. Guan X, Liu Z, Longo A, Cai JC, Tzu-Liang Chen W, Chen LC, et al. International consensus on natural orifice specimen extraction surgery (NOSES) for colorectal cancer. Gastroenterol Rep (Oxf) 2019;7:24–31. PubMed PMC

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The robotic intracorporeal single-stapled anastomosis (RiSSA) technique in robotic left-sided colorectal resection: a technical note

Ann Coloproctol. 2025;41(4):357-360. Published online August 18, 2025

DOI: https://doi.org/10.3393/ac.2025.00486.0069

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The robotic intracorporeal single-stapled anastomosis (RiSSA) technique in robotic left-sided colorectal resection: a technical note

Characteristic	Value
Age (yr)	60.3 (45.4–98.5)
Sex
Male	20 (64.5)
Female	11 (35.5)
Body mass index (kg/m²)	23.7 (17.2–28.7)
ASA physical status
I	1 (3.2)
II	27 (87.1)
III	3 (9.7)
Neoadjuvant therapy	5 (16.1)
Tumor size (cm)	3.5 (0.7–9.8)
Tumor location
Rectum	17 (54.8)
Rectosigmoid junction	10 (32.3)
Sigmoid colon	3 (9.7)
Descending colon	1 (3.2)
Tumor distance from anal verge (cm)	17.9 (8.0–40.0)

Outcome	Value
Anastomotic leakage	0 (0)
Complication	5 (16.1)
Minor (Clavien-Dindo grade I–II)	4 (12.9)
Major (Clavien-Dindo grade ≥III)	1 (3.2)
Reoperation (within 30 days after surgery)	1 (3.2)
Readmission (within 30 days after surgery)	0 (0)
Unexpected ICU admission	0 (0)
30-day Mortality	0 (0)
Length of hospital stay (day)	7 (3–14)
Time to first flatus/defecation (day)	2 (1–5)

Table 1. Patient demographics and baseline characteristics (n=31)

Values are presented as median (range) or number (%).

ASA, American Society of Anesthesiologists.

Table 2. Postoperative clinical outcomes (n=31)

Values are presented as number (%) or median (range).

ICU, intensive care unit.