New anti-mesenteric delta-shaped stapled anastomosis: Technical report with short-term postoperative outcomes in patients with Crohn’s disease

Abstract

BACKGROUND

Medical treatment for Crohn’s disease (CD) has continuously improved, which has led to a decrease in surgical recurrence rates. Despite these advancements, 25% of patients will undergo repeat intestinal surgery. Recurrence of CD commonly occurs on the mesentery side of the anastomosis site.

AIM

To compare the new anti-mesenteric side-to-side delta-shaped stapled anastomosis (DSA) with the conventional stapled functional end-to-end anastomosis (CSA).

METHODS

This retrospective study included CD patients who underwent ileo-ileal or ileo-colic anastomosis between January 2020 and December 2023. The DSA technique employed a stapler to maintain the concept of anti-mesentery side-to-side anastomosis by performing a 90° vertical closure of the open window compared with the CSA technique. At the corner where the open window is closed, the DSA avoids forming a pouch and creates an anastomosis resembling a delta shape within the intestinal lumen. We compared demographics, preoperative condition, operative findings, and operative outcomes for the two techniques.

RESULTS

The study included 175 patients, including 92 in the DSA group and 83 in the CSA group. The two groups were similar in baseline characteristics, preoperative medical treatment, and operative findings except for the Montreal classification location. The 30-days postoperative complication rate was significantly lower in the DSA group compared with the CSA group (16.3% vs 32.5%, P = 0.009). Ileus incidence was significantly lower in the DSA group than in the CSA group (4.3% vs 14.5%, P = 0.033), and the hospital stay was shorter in the DSA group than in the CSA group (5.67 ± 1.53 days vs 7.39 ± 3.68 days, P = 0.001).

CONCLUSION

The DSA technique was feasible and showed comparable postoperative outcomes with lower short-term complications compared with the CSA technique. Further studies on CD recurrence and long-term complications are warranted.

Key Words: Crohn’s disease; Surgery; Anastomosis; Complication; Recurrence

Core Tip: This study introduced a new anti-mesenteric side-to-side delta-shaped stapled anastomosis (DSA) technique employed to maintain the concept of anti-mesentery anastomosis by performing a 90° vertical closure of the open window. The DSA technique avoids pouch formation at the corner and creates a delta-shaped anastomosis within the intestinal lumen. Patients with Crohn’s disease who underwent intestinal surgery using the DSA technique had a significantly shorter hospital stay and a lower rate of postoperative complication compared with those who underwent conventional side-to-side anastomosis. The DSA technique appears to be a safe and more suitable anastomosis technique for surgical treatment of Crohn’s disease.

INTRODUCTION

Crohn’s disease (CD) is a chronic inflammatory condition affecting the gastrointestinal tract and is a major type of inflammatory bowel disease (IBD)[1]. Over the past two decades, treatment for CD has continuously improved, and as a result the surgical recurrence rate has decreased[2]. Despite pharmaceutical advancements, approximately 60%-80% of patients with CD will require major intestinal surgery during their lifetime. Among these patients, 25% will undergo repeat intestinal surgery[3,4].

Most recurrences after intestinal surgery for CD occur on the mesentery side of the bowel and proximal to the anastomosis[5]. This trend suggests that the actual surgery may play a role in the anastomosis site recurrence and that fecal stasis could contribute to this risk particularly in stapled side-to-side anastomosis. Despite the unknown impact of anastomotic configuration on recurrence, an anti-mesenteric hand-sewn end-to-end anastomosis (Kono-S anastomosis) technique was developed to prevent postoperative recurrence[5,6]. The Kono-S anastomosis, introduced in 2011, is a novel technique designed specifically for CD bowel anastomosis[7]. It was shown to be superior to other anastomotic techniques in preventing clinical and endoscopic recurrence of postoperative CD[5].

Although Kono-S anastomosis has demonstrated good long-term results, hand-sewing results in a longer operation time, with a median time ranging from 157-215 minutes[5,7]. Due to this disadvantage, newer techniques, such as stapled Kono-S anastomosis, have recently been introduced[8,9]. These methods are generally more efficient as they reduce the operation time for anastomosis construction. Additionally, stapled anastomosis may be superior to hand-sewn anastomosis in terms of minimizing the risk of anastomotic leaks and recurrence of CD.

To address the need for a faster procedure while maintaining the principles of Kono-S anastomosis, we modified the conventional stapled functional end-to-end anastomosis (CSA) by incorporating a 90° vertical closure of the open window. This novel anastomotic technique, referred to as anti-mesenteric side-to-side delta-shaped stapled anastomosis (DSA), offers potential benefits such as wider anastomotic lumen and improved mesenteric alignment at the center of the second staple line. This study sought to describe the technical aspects and determine the potential advantages of DSA. In addition, we compared the short-term postoperative outcomes of the DSA technique with the CSA technique.

MATERIALS AND METHODS

Patients and variables

This retrospective study evaluated patients who underwent intestinal surgery for CD at the Asan Medical Center, Seoul, Korea between January 2020 and December 2023. The study included patients who had undergone small bowel resection and anastomosis, ileocecal resection, or right colectomy. Exclusion criteria included patients who had undergone only strictureplasty, stoma closure or formation, combined left colon or rectal surgery, upper gastrointestinal surgery, three or more bowel resections and anastomoses, or those with combined malignancy.

Medical records of the included patients were reviewed for various factors, including demographic characteristics (age at diagnosis and operation, sex, body mass index at operation, family history, and history of smoking), preoperative disease characteristics, such as the Montreal classifications and medical treatments immediately preceding surgery (immunomodulators, anti-tumor necrosis factor alpha, corticosteroids, and combination therapy), operative indications (stricture or obstruction, fistula or abscess, perforation, and bleeding), emergency operation status, surgical approach (open or laparoscopic), anastomotic technique (DSA or CSA), types of operations, number of anastomoses, hospital stay after surgery, operation time, intra-abdominal blood loss, transfusion after surgery, postoperative complications within 30 days post-operation, including infectious (wound, intra-abdominal abscess, anastomotic leak, and other infection) and non-infectious (ileus, bleeding, and other complications) outcomes, and short-term surgical recurrence of CD. The study cohort was divided into two groups (DSA and CSA) based on the anastomotic method used.

New anti-mesenteric side-to-side DSA technique

After preparing the mesentery side of the intestine for excision, small anti-mesenteric incisions were made on both the proximal and distal bowels. A linear stapler was then inserted into the small incision for the anastomosis (Figure 1A). In the CSA technique, the opened window is typically closed transversely (Figure 1B). In contrast, the DSA technique uses a vertical closure of the open window with a linear stapler (Figure 1C). This method results in the anastomosis being positioned exactly 90° outward from the direction of the mesentery, causing the open window to be pushed into the mesentery. The opened mesentery was subsequently closed, and reinforcement sutures were applied to prevent the distal part of the functional end-to-end anastomosis from forming a pouch. Upon observing the anastomosis within the intestinal lumen, it appears delta shaped (Figure 2A), as opposed to the ovoid shape of existing functional end-to-end anastomosis (Figure 2B). All surgeries in this study were performed by three experienced IBD surgeons who had conducted more than 200 IBD surgeries.

Figure 1 Methods of the new anti-mesenteric side-to-side delta-shaped stapled anastomosis and the conventional functional end-to-end anastomosis technique. A: After a small anti-mesenteric incision was made, a linear stapler was inserted into the incision to perform the anastomosis; B: The conventional functional end-to-end anastomosis closed the open window transversely; C: The anti-mesenteric functional end-to-end delta-shaped stapled anastomosis technique was performed with a vertical closure of the open window using a linear stapler.

Figure 2 Comparison of intestinal lumen between the delta-shaped stapled anastomosis technique and the conventional functional end-to-end anastomosis technique. A: When observing the anastomosis in the intestinal lumen, the anti-mesenteric functional end-to-end delta-shaped stapled anastomosis technique appears as a delta shape; B: An ovoid shape is formed after completion of the conventional functional end-to-end anastomosis.

Ethical standards

The study protocol was approved by the Institutional Review Board of Asan Medical Center (Registration No. 2024-0322). The study was conducted in accordance with the ethical standards set by the Declaration of Helsinki. As this was a retrospective study, informed consent was waived for the study subjects.

Postoperative complications

Postoperative complications were defined as grade II or higher on the Clavien-Dindo classification within the first 30 days after surgery. Complications were categorized as infectious and non-infectious. Infectious complications included wound infections, intra-abdominal abscess determined by a notable change in drainage or abdominopelvic computed tomography, anastomotic leaks confirmed through clinical evaluation and requiring surgical interventions, and other site infections including Clostridium difficile infection and urinary tract infection. Non-infectious complications included postoperative ileus (occurring within the first 5 days post-operation), bleeding at the anastomosis site or an intra-abdominal hematoma necessitating transfusion, interventions such as pig-tail drain placement or surgery, close monitoring due to massive hematochezia (occurring more than three times per a day), and thromboembolic events, including portal vein thrombosis.

Statistical analysis

Discrete variables were compared using the χ² test, while continuous variables were assessed using the unpaired Student’s t-test. To minimize treatment selection bias and potential confounding in this observational study, rigorous adjustments were made for significant differences in patient characteristics through weighted logistic regression models, employing the inverse probability of treatment weighting (IPTW) technique[10]. With IPTW, the weights for patients who received the CSA were calculated as the inverse of “1 - propensity score”, while the weights for patients who received the DSA were calculated as the inverse of the propensity score. Propensity scores were estimated through multiple logistic regression analyses. All prespecified covariates were included in the full non-parsimonious models comparing DSA and CSA treatments. The discrimination and calibration abilities of each propensity score model were evaluated using the C statistic and the Hosmer-Lemeshow statistic. Baseline covariates between the two groups were compared before and after weighting as standardized mean difference, in which a difference of < 15% was deemed acceptable. All reported P values are two-sided, with values of P < 0.05 considered to indicate statistical significance. Statistical analyses were conducted using SAS software version 9.4 (SAS Institute, Inc, Cary, NC, United States).

RESULTS

Baseline characteristics of the study cohort

The study cohort comprised 175 patients, with a mean follow-up period of 20.7 ± 13.7 months. Among them, 92 patients were part of the DSA group, while 83 patients were in the CSA group. The DSA group had a shorter follow-up period compared with the CSA group (17.2 ± 10.8 months vs 24.6 ± 15.5 months, P = 0.001). Regarding the Montreal classification location, a higher proportion of patients in the DSA group had a colonic location compared with the CSA group, showing a statistically significant difference (14.1% vs 2.4%, P = 0.021) (Table 1). In order characteristics such as age at diagnosis and operation, sex, body mass index at operation, history of previous abdominal operation, history of perianal fistula, family history of CD, history of smoking, Montreal classification behavior, and preoperative medical treatment, no statistical differences were observed between the two groups. These baseline characteristics were adjusted using the IPTW to account for potential confounding factors in significant differences (Table 1).

Table 1 Baseline characteristics between the new anti-mesenteric side-to-side delta-shaped stapled anastomosis and the conventional side-to-side stapled anastomosis groups.

Variables	Delta-shaped	Conventional	P value	SMD1	Delta-shaped	Conventional	SMD1
	n = 92	n = 83			n = 92	n = 83
Age at diagnosis, years, mean ± SD	26.87 ± 9.25	28.10 ± 10.57	0.414	0.123	27.9 ± 9.29	27.53 ± 11.46	0.036
Age at operation, years, mean ± SD	35.22 ± 10.01	34.37 ± 11.47	0.604	0.078	34.88 ± 9.89	34.64 ± 11.51	0.022
Sex, n (%)			0.607	0.095			0.019
Female	26 (28.3)	20 (24.1)			22 (24.3)	19 (23.5)
Male	66 (71.7)	63 (75.9)			70 (75.7)	64 (76.5)
Body mass index at operation, kg/m2, mean ± SD	19.56 ± 3.10	20.12 ± 3.54	0.261	0.170	20.09 ± 3.43	19.82 ± 3.51	0.078
History of previous abdominal operation, n (%)			0.198	0.195			0.042
Yes	27 (29.3)	32 (38.6)			33 (36.4)	29 (34.4)
History of perianal fistula, n (%)			0.645	0.145			0.075
None	63 (68.5)	62 (74.7)			68 (74.2)	64 (77.3)
Currently having perianal fistula	5 (5.4)	3 (3.6)			4 (4.4)	3 (3.8)
Healed state after treatment	24 (26.1)	18 (21.7)			20 (21.4)	16 (18.9)
Family history of CD, n (%)			0.709	0.079			0.025
Yes	3 (3.3)	4 (4.8)			3 (3.3)	3 (3.8)
History of smoking, n (%)			0.236	0.259			0.093
None	53 (57.6)	49 (59.0)			51 (55.6)	49 (59.3)
Ex-smoker	26 (28.3)	16 (19.3)			21 (22.6)	19 (22.4)
Current smoker	13 (14.1)	18 (21.7)			20 (21.8)	15 (18.3)
Montreal classification behavior, n (%)			0.779	0.108			0.118
Non-stricturing, non-penetrating (B1)	12 (13.0)	8 (9.6)			10 (11.3)	12 (14.4)
Stricturing (B2)	31 (33.7)	29 (34.9)			34 (37.3)	27 (32.7)
Penetrating (B3)	49 (53.3)	46 (55.4)			47 (51.4)	44 (52.9)
Montreal classification location, n (%)			0.021a	0.439			0.041
Ileum (L1)	46 (50.0)	45 (54.2)			45 (49.1)	42 (51.1)
Colon (L2)	13 (14.1)	2 (2.4)			8 (8.2)	6 (7.7)
Ileocolon (L3)	33 (35.9)	36 (43.4)			39 (42.7)	34 (41.2)
Medical treatment just before surgery, n (%)
No medication	23 (25.0)	17 (20.5)	0.477	0.108	20 (21.8)	19 (22.3)	0.013
Immunomodulators, only	27 (29.3)	34 (41.0)	0.107	0.245	33 (35.9)	28 (33.8)	0.043
Anti-TNF-α antibodies, only	21 (22.8)	14 (16.9)	0.325	0.150	18 (19.3)	16 (19.0)	0.006
Corticosteroids, only	5 (5.4)	7 (8.4)	0.433	0.118	6 (6.2)	6 (6.6)	0.018
Combined immunomodulators with anti-TNF-α antibodies	10 (10.9)	10 (12.0)	0.807	0.037	11 (12.1)	12 (14.6)	0.073
Combined immunomodulators with corticosteroids	5 (5.4)	2 (2.4)	0.448	0.156	4 (4.1)	3 (3.6)	0.028
Combined anti-TNF-α antibodies with corticosteroids	2 (2.2)	1 (1.2)	> 0.999	0.075	1 (1.6)	1 (1.2)	0.032

^aP < 0.05.

¹Standardized mean difference: (1) Discrimination: c-statistics = 0.722; and (2) Calibration: Hosmer-Lemeshow statistics: χ² = 4.0785; df = 8; P value = 0.85.

CD: Crohn’s disease; TNF: Tumor necrosis factor; SMD: Standardized mean difference.

Operation details

In the DSA and CSA groups, the most common operative indications were fistula or abscess, accounting for 84.8% and 90.4% of cases, respectively. The next most common indication was stricture or obstruction in both groups, representing 13.0% and 6.0% of cases, respectively. There was no statistically significant difference between the two groups concerning operative indication. Additionally, no statistical differences were found between the two groups for emergency operation, the operative approach (open vs laparoscopic), the distribution of operative types, or number of anastomoses (Table 2).

Table 2 Operative findings between the delta-shaped stapled anastomosis and conventional side-to-side stapled anastomosis groups.

Variables	Delta-shaped	Conventional	Before IPTW	After IPTW
	n = 92	n = 83	P value	P value
Operative indication, n (%)			0.185	0.411
Stricture or obstruction	12 (13.0)	5 (6.0)
Fistula (enteric-) or abscess	78 (84.8)	75 (90.4)
Perforation (peritonitis)	2 (2.2)	1 (1.2)
Bleeding	0 (0)	2 (2.4)
Emergency operation, n (%)			0.425	0.430
Yes	2 (2.2)	4 (4.8)
Operative approach, n (%)			0.852	0.829
Open	18 (19.6)	18 (21.7)
Laparoscopy	74 (80.4)	65 (78.3)
Operative name, n (%)			0.425	0.160
Ileocecal resection	28 (30.4)	25 (30.1)
Right hemicolectomy	26 (28.3)	17 (20.5)
Small bowel resection and anastomosis	38 (41.3)	41 (49.4)
Number of anastomosis, n (%)			0.682	0.810
1	76 (82.6)	71 (85.5)
2	16 (17.4)	12 (14.5)

IPTW: Inverse-probability-of-treatment weighted.

Postoperative outcomes

The DSA group had a statistically significant shorter hospital stay after surgery compared with the CSA group (5.7 ± 1.5 days vs 7.4 ± 3.7 days, P = 0.001). The shorter hospital stay in the DSA group was confirmed even after adjustment with IPTW (P < 0.001) (Table 3). Despite the use of the new anastomosis technique, there was no difference in operative time between the DSA and CSA groups (107.2 ± 25.2 minutes vs 112.5 ± 28.5 minutes, P = 0.192). There were no statistically significant differences in the amount of intraoperative blood loss, cases requiring postoperative transfusion, or the average number of packed red blood cell transfusions between the two groups. However, there was a significant difference in the distribution of intraoperative blood loss, with more patients in the DSA group experiencing blood loss (including blood loss less than 10 mL) compared with the CSA group (69.6% vs 53.0%, P = 0.031).

Table 3 Postoperative outcomes between the delta-shaped stapled anastomosis and conventional side-to-side stapled anastomosis groups.

Variables	Delta-shaped	Conventional	Before IPTW	After IPTW
	n = 92	n = 83	P value	P value
Hospital stay after surgery, days, mean ± SD	5.67 ± 1.53	7.39 ± 3.69	< 0.001a	< 0.001a
Operation time, minutes, mean ± SD	107.23 ± 25.16	112.54 ± 28.48	0.192	0.480
Intraoperative blood loss, n (%)			0.075	0.031a
< 10 mL	64 (69.6)	44 (53.0)
10-200 mL	26 (28.3)	35 (42.2)
> 200 mL	2 (2.2)	4 (4.8)
Transfusion after surgery, n (%)			0.104	0.054
Yes	8 (8.7)	14 (16.9)
No	84 (91.3)	119 (82.1)
Number of pack RBC after surgery, mean ± SD	0.16 ± 0.72	0.35 ± 0.88	0.123	0.175
Postoperative complications, n (%)	15 (16.3)	27 (32.5)	0.014a	0.002a
Number of complication, n (%)			0.037a	0.002a
0	78 (84.8)	58 (69.9)
1	13 (14.1)	20 (24.1)
2	1 (1.1)	5 (6.0)
Clavien-Dindo classification, n (%)			0.021a	0.006a
II	11 (12.0)	21 (25.3)
IIIa	4 (4.3)	3 (3.6)
IIIb	0 (0.0)	3 (3.6)
Infectious complications, n (%)	10 (10.9)	13 (15.7)
Wound	5 (5.4)	5 (6.0)	> 0.999	0.964
Intra-abdominal abscess	4 (4.3)	4 (4.8)	> 0.999	0.603
Anastomotic leakage	0 (0.0)	1 (1.2)	0.474	0.255
Other infectious complication1	1 (1.1)	2 (2.4)	0.604	0.432
Non-infectious complications, n (%)
Ileus	4 (4.3)	12 (14.5)	0.033a	0.022a
Bleeding	1 (1.1)	3 (3.6)	0.347	0.031a
Other2	0 (0)	1 (1.2)	0.474	0.314
Surgical recurrence, n (%)			0.224	0.137
Yes	0 (0)	2 (2.4)

^aP < 0.05.

¹Other infectious complication includes Clostrium difficile infection and urinary tract infection.

²Other complication includes portal vein thromobosis after surgery.

IPTW: Inverse-probability-of-treatment weighted.

The overall complication rate was significantly lower in the DSA group compared with the CSA group (16.3% vs 32.5%, P = 0.014). There was a significant difference in the Clavien-Dindo classification, which measures the severity of postoperative complications (DSA vs CSA for grade II: 12.0% vs 25.3%; grade IIIa: 4.3% vs 3.6%; and grade IIIb: 0% vs 3.6%, P = 0.006). The incidence of postoperative ileus and intra-abdominal hematoma were significantly lower in the DSA group compared with the CSA group (ileus: 4.3% vs 14.5%, P = 0.022; bleeding: 1.1% vs 3.6%, P = 0.031). There were no significant differences in the rate of anastomotic leak and anastomotic bleeding between the two groups (Table 3). The DSA group demonstrated a significantly lower risk of overall postoperative complications compared with the CSA group in both the crude regression model and the weighted logistic regression model (Table 4). Although the follow-up period was relatively short, there were 2 cases of surgical recurrence in the CSA group, whereas there were no cases of surgical recurrence in the DSA group (P = 0.137).

Table 4 Logistic regression analysis for overall postoperative complication.

Overall complication		No	Yes	Logistic regression analysis
Model	Anastomosis			OR	95%CI		P value
Crude model
	Conventional, n (%)	56 (64.5)	27 (32.5)	1
	Delta, n (%)	77 (83.7)	15 (16.3)	0.404	0.197	0.829	0.014a,2
Weighted model with IPTW1
	Conventional, n (%)	54 (65.1)	29 (34.9)	1
	Delta, n (%)	79 (85.7)	13 (14.3)	0.312	0.149	0.653	0.002a

^aP < 0.05.

¹Inverse-probability-of-treatment weighted, weighted logistic regression model.

²Logistic regression model.

OR: Odds ratio; CI: Confidential interval; IPTW: Inverse-probability-of-treatment weighted.

DISCUSSION

This study introduced a novel technique that modified the CSA technique by incorporating a 90° vertical closure of the open window. This DSA technique has several advantages including a wider actual anastomosis lumen compared with the CSA technique, mesentery side concealment achieved through mesenteric alignment in the middle of the second staple line, and a shorter operation times. We developed the DSA technique to overcome shortcomings of the Kono-S anastomosis technique. The Kono-S anastomosis technique creates a supporting column located posteriorly on the mesenteric border and has been shown to have lower surgical recurrence rates than conventional anastomosis techniques[7]. The SuPREMe-CD trial further demonstrated a significant reduction of clinical and endoscopic recurrence with Kono-S anastomosis compared with the conventional side-to-side anastomosis[11]. Despite these benefits, Kono-S anastomosis involves longer operation times and complex surgical techniques.

Although long-term recurrence results are still needed, the results of this study suggest that DSA offers the advantage of preventing corners and external exposure of the mesentery side without extending operation times compared with CSA. This technique aligns with stapled Kono-S anastomosis and is characterized by minimal deviation from the CSA technique, ensuring speed and reproducibility. DSA shares similarities with the mesentery alignment of the Kono-S anastomosis, placing the mesenteric side in the middle of the stapled line[12]. This configuration may be advantageous in addressing complications such as CD-related ulcers or fistulas. Furthermore, while DSA employs side-to-side anastomosis, the stapler intersection area is positioned on the bowel side rather than the mesentery, resulting in circular connected stapler lines on simple abdominal imaging (Supplementary Figure 1).

Despite improvements in biologic treatments, surgery still remains a key treatment modality for CD[13-15]. IBD surgeons face challenges in minimizing surgical interventions and avoiding repeat surgeries due to surgical or disease-related reasons. The CSA technique can sometimes lead to enterocutaneous fistulas or intra-abdominal abscesses due to the recurrence of penetrating disease, particularly around the protruding corner area (Figure 3). These patterns of recurrence suggest potential etiologies such as fecal stasis or inflammation-driven mesentery side issues[12,16].

Figure 3 Exposure of the corner area after the conventional functional end-to-end anastomosis technique. After performing conventional functional end-to-end anastomosis, the transverse end on the mesentery side protrudes, and the saccular or pouch-like part is formed.

In contrast, the DSA technique replaces the transverse closure with a vertical closure, positions the mesentery side at the center of the stapled line, and allows for straightforward invagination sutures, all of which help prevent complications and recurrence. We anticipate that the DSA technique may reduce clinical, endoscopic, and surgical recurrence of CD by optimizing the closure site positioning in the center of the mesentery and improving the lumen width. Although the follow-up period of our study was short, two cases of surgical recurrence were noted in the CSA group, whereas none were observed in the DSA group. The DSA technique offers advantages over the existing CSA technique in terms of wider anastomotic lumen and mesenteric alignment, which may lead to improved long-term recurrence-free outcomes.

The DSA technique demonstrated significantly lower short-term postoperative complications compared with the CSA technique, particularly concerning the incidence of ileus. These results may be attributed to the shorter operative time and the relatively wide, appropriate lumen shape provided by the DSA technique. While the hand-sewn Kono-S anastomosis, which excludes the mesentery, has gained popularity for its comparable postoperative outcomes and reduced burden of anastomotic recurrence after intestinal resection for CD[5,6,17,18], this study introduced a simpler technique with a shorter operative time and a lower rate of postoperative complications. Side-to-side stapled anastomosis can result in a lower leak rate, fewer postoperative complications, reduced duration of surgery, and shorter hospital stays compared with end-to-end hand-sewn anastomosis after CD resection[19-21].

Recently, stapled Kono-S anastomosis was introduced, combining the benefits of stapled anastomosis and Kono-S anastomosis[8]. However, this combined technique has cost and operative time limitations due to the increased number of staplings compared with the CSA technique. Another method, stapled antimesenteric functional end-to-end anastomosis, also incorporates concepts of Kono-S anastomosis[9]. Although this approach hides both distal end parts on the mesentery side, it requires some hand-sewn anastomosis and uses more staples than the CSA technique. Given these factors, the DSA technique offers a meaningful balance between concept and practicality compared to the newer forms of stapled Kono-S anastomosis.

This study had inherent limitations typical of a retrospective study. First, it was conducted at a single center with a relatively small sample size, which may lead to sampling error and selection bias. However, all patients who had surgery recently were included. IPTW was implemented to reduce sampling error, but differences in Montreal classification location remained. Although there were more cases in the colon in the DSA group, only patients with right colon involvement were included. In addition, the operation name was performed with ileocecal resection or right hemicolectomy and was not different between the two groups. Second, the DSA technique was performed by three experienced IBD surgeons, raising questions about generalizability. However, since the DSA technique is not significantly different from the CSA technique, the learning curve is expected to be short. Third, due to the relatively short follow-up period, the results on surgical recurrence and long-term postoperative outcomes are limited and may not fully capture the potential long-term implications.

CONCLUSION

The DSA technique introduced in this study appears to be a safe and more suitable option for CD surgery compared with the CSA technique. The DSA technique demonstrated comparable or superior outcomes in terms of operative time and postoperative complications. Additionally, the DSA technique combined the conceptual aspects of antimesentery anastomosis with the practical benefits of an improved anastomosis shape. In the future, further research is warranted to examine the long-term postoperative complications as well as clinical, endoscopic, and surgical recurrence.

ACKNOWLEDGEMENTS

The statistical part of this study was conducted by Min-Ju Kim of the Department of Clinical Epidemiology and Biostatistics.