The effectiveness and safety of isoperistaltic versus antiperistaltic side-to-side ileocolic anastomosis in minimally invasive radical right hemicolectomy: a systematic review and meta-analysis

Abstract

Background and purpose

Two main side-to-side anastomosis techniques are used in minimally invasive radical right hemicolectomy: the traditional antiperistaltic (ANTI) and the more recently adopted isoperistaltic (ISO) overlap method. Their comparative clinical efficacy remains controversial. This study aimed to evaluate the effectiveness and safety of ISO versus ANTI for ileocolic anastomosis, providing evidence-based guidance for surgical technique selection.

Methods

We systematically searched CNKI, Wanfang, VIP, Sinomed, PubMed, Embase, Web of Science, and Cochrane Library from database inception to January 2026 for studies comparing ANTI and ISO. Cohort study quality was assessed using the Newcastle-Ottawa Scale, and randomized controlled trials (RCTs) were assessed using the Cochrane tools. Meta-analysis, sensitivity analysis, and publication bias evaluation were performed using RevMan 5.3 and STATA 17.

Results

Six studies (5 cohorts, 1 RCTs) comprising 931 patients were included. The meta-analysis indicated that the incidence of bowel obstruction was higher in the ANTI group than in the ISO group, with a borderline significant difference [RR = 1.75, 95% CI (1.01, 3.05), P = 0.05], and the ANTI group required a longer anastomosis time [MD = 1.03, 95% CI (0.35, 1.71), P = 0.003]. No significant differences were found between the two techniques regarding anastomotic leakage, anastomotic bleeding, time to first flatus, time to first defecation, readmission rate, surgery-related mortality, intra-abdominal infection, wound infection, chronic diarrhea, operative time, hospital stay, intraoperative blood loss, or time to first oral intake (all P > 0.05). Sensitivity analysis revealed significantly longer total operative time for ANTI [MD = 8.75, 95% CI (6.11, 11.39), P < 0.00001]. No reversal occurred in the results for other outcomes, indicating robust findings in this study. Publication bias risk analysis showed that publication bias was unlikely in this study.

Conclusions

Both anastomotic methods are effective and safe in minimally invasive radical right hemicolectomy. The ISO may offer modest technical advantages, but current evidence does not justify a strong preferential recommendation.

Supplementary information

The online version contains supplementary material available at 10.1007/s00384-026-05160-4.

Introduction

Minimally invasive surgical techniques have advanced, and laparoscopic and robot-assisted radical right hemicolectomy have become the primary treatment modalities for early-to-mid-stage right hemicolonic cancer, offering advantages such as reduced trauma and faster recovery [1–5]. Gastrointestinal reconstruction is a critical component of the procedure, with ileocolic anastomoses categorized into isoperistaltic versus antiperistaltic approaches based on the direction of intestinal peristalsis [6]. The clinical choice between these two anastomosis techniques remains controversial, and the specific choice depends primarily on the surgeon’s expertise and preference. Some scholars argue that an ISO anastomosis better aligns with physiological principles and may facilitate recovery of intestinal function [7]. It is also reported to help reduce anastomotic tension [8]. Furthermore, this technique typically requires a shorter segment of free bowel, which may simplify the surgical procedure and reduce operating time [9]. Conversely, others contend that an ANTI anastomosis reduces the risk of mesenteric torsion and intestinal obstruction [10] and may form a pseudo-valve mechanism to lower the incidence of chronic diarrhea [11]. Relevant reviews indicate that, in addition to the choice of anastomotic technique affecting the recovery of bowel function and anastomotic complications, factors such as intracorporeal versus extracorporeal anastomosis, stapler type, manual suturing, and anastomotic reinforcement sutures may also influence anastomotic complications and postoperative recovery [12]. Anastomotic direction is closely linked to intracorporeal versus extracorporeal reconstruction, bowel mobilization, mesenteric orientation, stapler positioning, closure technique, robotic versus laparoscopic workflow, and surgeon preference. Perioperative recovery is influenced by many factors, making it a complex technical issue, and this meta-analysis evaluates it only from the perspective of anastomosis orientation. Existing studies suffer from limitations such as mixed disease types and inclusion of open surgeries [13], lacking systematic evaluations specifically addressing these two anastomotic methods in minimally invasive radical right hemicolectomy. Therefore, this study aimed to comprehensively evaluate the effectiveness and safety of ISO versus ANTI in minimally invasive radical right hemicolectomy through meta-analysis, providing evidence-based guidance for clinical procedure selection.

Methods

Research registration

This systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [14]. The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO). The registration number is CRD420261287323. Since this research is a systematic review and meta-analysis of previously published data, ethical approval is not necessary.

Search strategy

A detailed search was performed across the CNKI, WANFANG, VIP, Sinomed, PubMed, Embase, Web of Science, and Cochrane Library databases, supplemented by reference lists and relevant meta-analyses. The search terms include subject terms and free terms: colectomy, colectomies, large bowel resection, right hemicolectomy, right colon resection, radical resection of the right colon, hemicolectomy for cancer of the right hemicolon, right colon, colon cancer, colon tumor, right hemicolonic cancer, right hemicolon cancer, right-sided malignant colonic cancer, right laparoscopic hemicolectomy, malignant tumor of the right colon; isoperistaltic, isoperistaltic anastomosis, isoperistaltic side-to-side anastomosis, parallel overlapping anastomosis, overlap anastomosis, antiperistaltic anastomosis, antiperistaltic side-to-side anastomoses, side-to-side anastomoses, etc. The search period spans from database inception to January 2026. The supplementary data (S Table 1) provides detailed descriptions of the search strategies.

Selection criteria

Inclusion criteria

Retrieved articles that meet the following PICOS principles are included: ① P: patients with primary solitary right-sided colon cancer meeting surgical indications who underwent minimally invasive radical resection of right-sided colon cancer (laparoscopic or Da Vinci robotic); ② I/C: clinical study evaluating intraoperative use of staplers for ileocolic ISO and ANTI (Fig. 1a and b); ③ O: primary outcomes: anastomotic leakage, anastomotic bleeding, bowel obstruction, anastomotic time, time to first flatus, and time to first defecation; secondary outcomes: hospital readmission rate, operative-related mortality, intra-abdominal infection, wound infection, chronic diarrhea, operative time, hospital stay, intraoperative blood loss, and time to first oral intake; and ④ S: RCTs and cohort studies.

Fig. 1.

a Anti-peristaltic side-to-side anastomosis (ANTI). b Iso-peristaltic side-to-side anastomosis (ISO)

Exclusion criteria

(1) Benign tumors, multiple tumors, and tumors causing obstruction or perforation; (2) patients undergoing neoadjuvant therapy such as radiotherapy or chemotherapy before surgery; (3) open surgery or conversion to open surgery; (4) patients with inflammatory bowel disease, immune system disorders, hypoalbuminemia, psychiatric disorders, or significant organ dysfunction (e.g., cardiac, hepatic, renal) with severe underlying conditions; (5) non-clinical trials such as animal experiments, animal studies, or human autopsies; (6) duplicate publications, works unavailable in full text, conference proceedings, lectures, reviews, meta-analyses, or theses; and (7) non-Chinese or non-English language articles.

Literature screening and information extraction

Inclusion and exclusion criteria were established collaboratively by all participants. Two research members independently screened potential qualifying article titles and abstracts against the criteria, and then read the full texts. Two participants independently extracted the required data and cross-checked each other’s work. Disagreements during literature screening or data extraction were settled by group discussion or third-party adjudication. Extracted content included basic study information (e.g., first author, publication year, title, nationality), study characteristics (e.g., surgical approach, study type, patient baseline data), outcome measures, and information related to risk of bias.

Literature quality assessment

The quality assessment of cohort studies employed the Newcastle-Ottawa Scale (NOS) [15], comprising three major modules (selection of study population, comparability of groups, and assessment of outcomes) with nine items in total. Each item is scored individually, yielding a maximum of 9 points. Studies are categorized as low quality (0–3 points), moderate quality (4–6 points), or high quality (7–9 points). RCTs were assessed for quality using the Cochrane risk of bias tool (CRBT) [16], which evaluates the implementation of random allocation methods, allocation concealment, blinding, completeness of outcome data, selective reporting of results, and other potential biases. Studies with sound design and clear interpretation were classified as low risk; high risk was assigned if these criteria were not met; risk was deemed unclear when information was insufficient or evaluation impossible.

Statistical analysis

The analysis was carried out using the RevMan 5.3 software. Continuous variables were reported in mean differences (MD), while dichotomous variables were presented as relative risks (RR) with 95% confidence intervals (CI). Heterogeneity was assessed using the Q-test and I² statistic, where I² > 50% and/or P < 0.1 indicated significant heterogeneity. Data with high heterogeneity were analyzed using a random-effects model (REM); data with low heterogeneity were analyzed using a fixed-effects model (FEM). Publication bias was assessed by visually inspecting funnel plot symmetry and by performing Egger’s test in STATA 17. A P < 0.05 in Egger’s test indicated potential publication bias. To further validate the robustness of the results, trim-and-fill methods were employed for correction. Additionally, sensitivity analyses were performed by excluding studies with high heterogeneity to assess the stability of the findings. P < 0.05 was considered statistically significant.

Results

Literature review findings

The initial search yielded 936 articles. After duplicate screening using EndNote reference management software, 91 articles were excluded. Upon reviewing titles and abstracts, 822 articles clearly unrelated to the study were excluded, leaving 12 articles. After reading the full texts, six additional articles were removed. Ultimately, six articles were included in the meta-analysis (three in Chinese and three in English; four with first authors from China, one from Japan, and one from Spain). The selection procedure is shown in the PRISMA flow diagram (Fig. 2). A total of 931 cases were analyzed: 462 in the ANTI group and 469 in the ISO group.

Fig. 2.

PRISMA flow diagram depicting study screening and selection

Basic information of included studies

The basic information and clinical data of the selected literature are shown in Tables 1 and 2.

Table 1.

Baseline characteristics of the included studies

Reference	Country	Type of research	Sample size (n)		Sex (M/F)		Age (year) ($\overline{\mathrm{x}}\pm \mathrm{s}$)		BMI (kg/m2) ($\overline{\mathrm{x}}\pm \mathrm{s}$)
			ANTI group	ISO group	ANTI group	ISO group	ANTI group	ISO group	ANTI group	ISO group
Shiomi Akio et al., 2025 [17]	Japan	CS	23	55	10/13	30/25	M (range) 68 (37–76)	M (range) 68 69 (45–79)	M (range) 22.5 (18–26.9)	M (range) 24.2 (17.9–33.6)
Jie Zhou et al., 2025 [18]	China	CS	33	65	20/13	35/30	M (Q1, Q3) 56 (48, 65)	M (Q1, Q3) 57 (49, 65)	M (Q1, Q3) 21.0 (19.4, 25.4)	M (Q1, Q3) 22.9 (20.8, 25.8)
Guangyang Su et al., 2025 [19]	China	CS	133	70	73/60	37/33	NR	NR	M (range) 22.4 (20.7–25.3)	M (range) 23.7 (21.7–25.3)
Shenghe Hua et al., 2023 [20]	China	CS	120	110	86/34	78/32	61. 2 ± 10.88	60. 3 ± 11.55	NR	NR
Mingguang Zhang et al., 2022 [21]	China	CS	99	115	43/56	61/54	59.4 ± 12.2	60.4 ± 11.4	24.0 ± 3.6	24.1 ± 3.3
Noelia Ibáñez et al., 2019 [22]	Spain	RCTs	54	54	33/21	36/18	68.8 ± 10.3	68.2 ± 10.8	M (range) 27.16 (23.98–31.31)	M (range)27.28 (25.07–29.79)

Table 2.

Clinical and treatment characteristics of the included studies

Reference	Anastomosis method		Surgical method	Tumor size (cm) ($\overline{\mathrm{x}}\pm \mathrm{s}$)		Tumor staging		Outcome indicator	NOS	CRBT
				ANTI group	ISO group	ANTI group	ISO group
Shiomi Akio et al., 2025 [17]	ANTI	ISO	Robot	NR	NR	Ⅰ-Ⅲ	Ⅰ-Ⅲ	1.2.3.5.6.7.8.9.10	7	-
Jie Zhou et al., 2025 [18]	ANTI	ISO	Laparoscopic	NR	NR	Ⅰ-Ⅲ	Ⅰ-Ⅲ	1.4.5.7.8.12.13.15	7	-
Guangyang Su et al., 2025 [19]	ANTI	ISO	Laparoscopic	M (range) 5.0 (4.0–6.0)	M (range) 4.2 (3.5–6.0)	Ⅰ-Ⅲ	Ⅰ-Ⅲ	1.3.5.6.7.8.11.12.13	7	-
Shenghe Hua et al., 2023 [20]	ANTI	ISO	Laparoscopic	3. 42 ± 1.98	3. 21 ± 2.11	Ⅰ-Ⅲ	Ⅰ-Ⅲ	1.3.4.5.6.7.11.15	7	-
Mingguang Zhang et al., 2022 [21]	ANTI	ISO	Laparoscopic	M (range) 4.5 (1.0–9.5)	M (range) 4.0 (1.5–11.0)	Ⅰ-Ⅲ	Ⅰ-Ⅲ	1.3.4.5.6.7.8.9.10.11.12.14	9	-
Noelia Ibáñez et al., 2019 [22]	ANTI	ISO	Laparoscopic	NR	NR	Ⅰ-Ⅲ	Ⅰ-Ⅲ	1.2.3.4.5.6.7.8.9.10.13.14	-	5

Tips: “-” no data, NR not reported, M male, F female, BMI body mass index, M median, Q1 first quartile, Q3 third quartile, CS cohort studies, RCTs randomized controlled trials, NOS Newcastle-Ottawa Scale, CRBT Cochrane risk of bias tool; outcome indicator: 1. Operative time; 2. Anastomotic time; 3. Time to first flatus; 4. Time to first defecation; 5. Anastomotic leakage; 6. Anastomotic bleeding; 7. Bowel obstruction; 8. Hospital stay; 9. Hospital re-admission rate; 10. Operative-related mortality; 11. Intraoperative blood loss; 12. Intra-abdominal infection; 13. Wound infection; 14. Chronic diarrhea; 15. Time to first oral intake

Literature quality assessment

The six final studies included five cohort studies and 1 RCT (Table 2). The NOS and the Cochrane risk of bias assessment tool were used, respectively. All five cohort studies scored ≥ 7 points on the NOS (high quality) (Table 2). Specific scoring criteria are provided in the supplementary data (S Table 2). The single RCT had > 4 items rated as low risk (low bias). Specific assessment details: implementation of random allocation (low risk), concealment of allocation (low risk), use of blinding (low risk), completeness of outcome data (low risk), selective reporting of results (low risk), and other potential biases (unclear) (Table 2).

Meta-analysis results for primary outcomes

Anastomotic leakage

A total of six studies were involved. Heterogeneity testing (P = 1.00, I² = 0%) revealed no significant heterogeneity among studies. An FEM meta-analysis was performed, showing no statistically significant difference between ISO and ANTI groups in anastomotic leakage [RR = 1.27, 95% CI (0.54, 2.98), P = 0.58] (Fig. 3a).

Fig. 3.

Forest plots displaying outcome evaluations, including: a. Anastomotic leakage; b. Anastomotic bleeding; c. Bowel obstruction; d. Anastomotic time; e. Time to first flatus; f. Time to first defecation; g. Operative time

Anastomotic bleeding

A total of five studies were involved. After heterogeneity testing (P = 0.72, I² = 0%), no heterogeneity was found among the studies. A meta-analysis was performed using the FEM. The results showed no statistically significant difference in anastomotic bleeding between the ISO and ANTI groups [RR = 1.27, 95% CI (0.44, 3.69), P = 0.66] (Fig. 3b).

Bowel obstruction

A total of six studies were involved. After testing for heterogeneity, no heterogeneity was found among the studies (P = 0.46, I² = 0%). A meta-analysis was performed using the FEM. The results showed that the incidence of bowel obstruction was higher in the ANTI group than in the ISO group, with a borderline significant difference [RR = 1.75, 95% CI (1.01, 3.05), P = 0.05] (Fig. 3c).

Anastomosis time

Two studies were included. After heterogeneity testing (P = 0.39, I² = 0%), no heterogeneity was found between studies. A meta-analysis was performed using the FEM. The results showed that the ANTI group had a longer anastomosis time than the ISO group, with a statistically significant difference [MD = 1.03, 95% CI (0.35, 1.71), P = 0.003] (Fig. 3d).

Time to first flatus

A total of five studies were involved. Heterogeneity testing showed meaningful heterogeneity across studies (P < 0.00001, I² = 98%). A meta-analysis was performed using REM. The results showed no statistically significant difference in time to first flatus between the ISO and ANTI groups [MD = 0.24, 95% CI (−0.52, 1.00), P = 0.54] (Fig. 3e).

Time to first defecation

Four studies were included. Heterogeneity testing (P = 0.001, I² = 81%) revealed significant heterogeneity among studies. A REM meta-analysis was conducted. The results revealed no statistically significant difference in time to first defecation between the ISO and ANTI groups [MD = 0.31, 95% CI (−0.09, 0.71), P = 0.13] (Fig. 3f).

Meta-analysis results for secondary outcomes

Meta-analysis findings revealed no statistically significant differences between the ISO group and ANTI group in terms of hospital readmission rate, operative-related mortality, intra-abdominal infection, wound infection, chronic diarrhea, operative time, hospital stay, intraoperative blood loss, and time to first oral intake (all P > 0.05). Results are presented in Table 3. Forest plots are detailed in the supplementary data (S Fig. 3).

Table 3.

Summary of results

Outcomes	No. Studies	RR/MD (95%-CI) with P-value	Egger’s P-value	I2, % (P value)	T-F adjusted RR/MD (95% CI)	Filled studies
Dichotomous data
Anastomotic leakage (%)	6	1.27 (0.54, 2.98) with 0.58	0.7615	0 (1.00)	1.28 (0.56, 2.89)	1
Anastomotic bleeding (%)	5	1.27 (0.44, 3.69) with 0.66	0.6990	0 (0.72)	1.07 (0.39, 2.95)	1
Bowel obstruction (%)	6	1.75 (1.01, 3.05) with 0.05	0.5549	0 (0.46)	1.83 (1.03, 3.24)	1
Hospital re-admission rate (%)	3	1.28 (0.49, 3.30) with 0.62	0.7760	0 (0.63)	1.28 (0.49, 3.30)	0
Operative-related mortality (%)	3	0.67 (0.12, 3.83) with 0.65	0.5880	-	0.67 (0.18, 2.45)	2
Intra-abdominal infection (%)	3	1.06 (0.14, 8.21) with 0.96	0.0445	60 (0.08)	0.30 (0.05, 1.97)	2
Wound infection (%)	3	1.85 (0.73, 4.73) with 0.20	0.4766	0 (0.76)	2.25 (0.97, 5.24)	2
Chronic diarrhea (%)	2	1.18 (0.82, 1.69) with 0.36	0.6919	0 (0.69)	1.12 (0.82, 1.53)	1
Continuous data
Operative time (min)	6	4.82 (−12.20, 21.84) with 0.58	0.1025	97 (< 0.00001)	4.82 (−12.20, 21.84)	0
Anastomotic time (min)	2	1.03 (0.35, 1.71) with 0.003	0.3906	0 (0.39)	1.00 (0.32, 1.68)	1
Time to first flatus (day)	5	0.24 (−0.52, 1.00) with 0.54	0.3237	98 (< 0.00001)	0.24 (−0.52, 1.00)	0
Time to first defecation (day)	4	0.31 (−0.09, 0.71) with 0.13	0.4357	81 (0.001)	0.31 (−0.09, 0.71)	0
Hospital stay (day)	5	0.05 (−0.11, 0.21) with 0.53	0.0235	45 (0.12)	0.03 (−0.13, 0.19)	1
Intraoperative blood loss (ml)	3	0.01 (−0.70, 0.73) with 0.97	0.7977	0 (0.93)	0.01 (−0.70, 0.73)	0
Time to first oral intake (day)	2	0.53 (−0.54, 1.61) with 0.33	0.2696	93 (0.0001)	0.00 (−1.09, 1.09)	1

Tips: “-” no data, CI confidence interval, MD mean difference, RR risk ratio

Sensitivity analysis

Sensitivity analysis of operative time revealed heterogeneity originating from the studies by Guangyang Su (2025) and Shiomi Akio (2025). After excluding these two studies, heterogeneity decreased (P = 0.34, I² = 11%). Results revealed that the ANTI group had longer surgical times than the ISO group, with a statistically significant difference [MD = 8.75, 95% CI (6.11, 11.39), P < 0.00001] (Fig. 3g). Sensitivity analyses for other outcomes did not reverse the findings, indicating robust results in this study.

Publication bias

Publication bias was assessed for outcomes with relatively higher numbers of included studies (operative time and bowel obstruction) using funnel plots combined with Egger’s test. Results showed that the funnel plot for operative time was essentially symmetrical, with Egger’s test yielding P = 0.1025 (Fig. 4a). The funnel plot for Bowel obstruction was also largely symmetrical, with Egger’s test yielding P = 0.5549 (Fig. 4b). These findings suggest that publication bias is unlikely in this study. To correct for potential publication bias effects on outcomes, we performed a trim-and-fill test, as detailed in Table 3.

Fig. 4.

a Funnel chart for operative time. b Funnel chart for bowel obstruction

Discussion

This meta-analysis is the first to directly compare the effectiveness and safety of two types of ileocolic anastomosis—ISOVANTI—in minimally invasive radical right hemicolectomy. Our analysis indicates that ISO may offer advantages in reducing anastomotic time and lowering the incidence of bowel obstruction. However, no statistically substantial differences were found between the two anastomotic procedures across a range of outcome measures, including anastomotic leakage, anastomotic bleeding, speed of postoperative recovery, and other major complications.

First, regarding anastomotic-related complications, our findings align with some previous studies, indicating that ISO and ANTI carry comparable risks for anastomotic leakage and bleeding [13]. This suggests that both anastomotic techniques are safe and reliable when key technical principles are strictly adhered to. Second, regarding postoperative intestinal function recovery, this study found no meaningful distinction between the two anastomotic techniques in terms of time to first flatus or first defecation. This suggests that while ISO theoretically aligns more closely with physiological peristaltic direction, it may not directly translate into faster early intestinal function recovery. Previous research [13] reported no meaningful distinction between ISO and ANTI in bowel obstruction or anastomotic time, which contradicts the findings of this study. That study [13] demonstrated that ISO achieved earlier first flatus than ANTI with a statistically significant difference, which contradicts the conclusions of this study. The previous study included colorectal surgery sites, partially open procedures, and a heterogeneous population (encompassing benign tumors, malignant tumors, and inflammatory bowel disease). In contrast, this study exclusively enrolled right-sided colon cancer patients undergoing minimally invasive laparoscopic or robotic surgery, minimizing confounding factors. Consequently, its findings may offer greater specificity and clinical relevance. The substantial heterogeneity observed for time to first flatus and defecation limits the interpretability of the pooled neutral results, and conclusions regarding functional recovery remain uncertain.

The ANTI, also referred to as the Π anastomosis [20], was first described in 1968 using a linear stapler device [23]. Compared to manual suturing techniques, this method simplifies the surgical procedure, reduces operative time, and minimizes dependence on surgeon skill [23, 24]. The ISO, also referred to as overlap anastomosis, was first described by Inaba et al. [25] in 2010 for gastrointestinal reconstruction following total gastrectomy. It is an overlapping side-to-side anastomosis technique performed using a linear stapler. In recent years, it has gradually been applied to side-to-side anastomoses following partial intestinal resection [26]. Studies indicate [17] that overlap anastomosis requires less bowel and mesenteric mobilization compared to ANTI, reduces anastomotic tension, and is associated with fewer overall anastomotic complications and lower anastomotic stricture rates. Due to the aligned peristalsis direction, it avoids stasis of intestinal contents caused by counter-peristalsis, reducing the incidence of bowel obstruction [27]. This study found that the difference in the incidence of bowel obstruction was of marginal statistical significance, with a small effect size; the absolute incidence of the event was low, and the confidence interval was at the borderline level, indicating limited clinical value. The overlap anastomosis technique is simpler to perform and requires less anastomotic time. Although this study found that the anastomosis time difference was statistically significant, its clinical significance is limited.

Compared with laparoscopic surgery, robotic colon surgery has a lower overall complication rate and a shorter time to resume eating; however, robotic surgery takes longer, primarily due to increased system startup time [28]. Compared with extracorporeal anastomosis, intracorporeal anastomosis results in a significantly longer operative time and a markedly shorter time to first flatus [29]. The type of linear stapler and cartridge height can influence anastomotic integrity and luminal diameter. Most included studies used a linear cutting stapler for side-to-side anastomosis, consistent with evidence that stapled techniques reduce leak rates compared with handsewn methods [30]. However, variations in staple height and firing angles between isoperistaltic and antiperistaltic configurations may alter tension and angulation, potentially affecting functional outcomes. Subgroup analyses by stapler specifications were not possible due to limited reporting, precluding definitive conclusions. The necessity of mesenteric defect closure remains a matter of controversy. Relevant meta-analyses have found [31] that closure was associated with a reduced incidence of internal hernia but did not significantly lower small bowel obstruction rates, while other studies have suggested increased complications with closure. The peristaltic direction of the anastomosis may alter defect size and geometry, potentially interacting with the closure strategy to influence the risk of postoperative obstruction. As none of the included studies controlled for mesenteric defect management, it constitutes an unmeasured confounder. The enterotomy closure technique is a critical determinant of anastomotic safety. Milone et al. [32] demonstrated in a multicenter study of 1092 laparoscopic right colectomies that double-layer closure significantly reduced leak rates compared to single-layer closure, with running barbed sutures and deep corner reinforcement providing additive protection. As the enterotomy orientation differs between isoperistaltic and antiperistaltic configurations, tension distribution across the closure line may vary. The closure methods were not clearly reported in different studies, which is an important confounding factor that may obscure anastomotic complications and intestinal recovery.

Both configurations have been reported to be safe, with no significant difference in complication rates, supporting their viability in minimally invasive settings [12]. Additionally, the literature indicates that the selection of anastomotic configuration does not compromise oncological principles, as both techniques facilitate adequate lymphadenectomy and tumor clearance [33]. In the context of minimally invasive radical resection, they are associated with low morbidity and favorable short-term outcomes, with no clear superiority of one configuration over the other in terms of safety or efficacy [12, 34]. These findings are similar to those of this study. The choice of configuration may thus be tailored to surgeon preference and specific intraoperative considerations [35], without compromising patient safety or oncological adequacy.

Of course, this study has certain limitations. First, the search scope was limited to published Chinese and English literature, which may introduce publication bias, although our statistical tests did not indicate a significant impact. Second, most studies included were cohort studies, with only one RCT. Although the NOS scores for the retrospective cohort studies ranged from 7 to 9, this does not eliminate the possibility of confounding factors in such studies. A high NOS score does not equate to high certainty of evidence, and the results remain susceptible to confounding and surgeon selection bias. Third, technical differences between centers (such as stapler model, anastomotic size, and intra- vs. extra-corporeal anastomosis) may influence certain outcomes, leading to increased heterogeneity and affecting the results. In addition, differences in the definition of postoperative complications may also contribute to heterogeneity. These factors limit the comparability of pooled estimates. Future research should focus on designing rigorous, adequately powered prospective RCTs to generate higher-level evidence-based medical evidence [36].

Conclusion

In summary, both ISO and ANTI appear feasible and safe in minimally invasive right hemicolectomy. ISO may offer small technical advantages and possibly reduce bowel obstruction risk. However, the current evidence remains insufficient to support a strong recommendation over ANTI. Future adequately powered, prospective, standardized RCTs are needed.

Supplementary information

Below is the link to the electronic supplementary material.

Author contribution

Ren Hangjun and Shen Yan jointly conceptualized this study and drafted the initial manuscript. Zhang Quan and Ren Hangjun screened studies from the search results that might meet the inclusion criteria. Ren Hangjun and Shen Yan independently completed the data extraction, with contentious issues addressed by Lu Sen providing professional advice. Ren Hangjun created the charts in the paper. Lu Sen was responsible for study revision and supervision. Yi Sun provided valuable feedback during the revision of the paper. All authors read and approved the final manuscript.

Funding

This study was supported by the Clinical Medical Research Special Fund Project of Zhejiang Medical Association (No. 2025ZYC-A19).

Data availability

The original data reported in this study are accessible in the article/supplementary materials.

Declarations

Ethics approval and consent to participate

This article does not contain any studies with human participants or animals performed by any of the authors.

Competing interests

The authors declare no competing interests.