A comparative clinical outcome study of power-assisted vs. manually-operated circular staplers for deep colorectal anastomosis

Abstract

Introduction

The objective of this study is to compare the perioperative clinical outcomes between power-assisted circular staplers (PCS) and manually-operated circular staplers (MCS) with directional stapling technology (DST) for deep colorectal anastomoses.

Materials and methods

A retrospective analysis of a prospective database of 64 consecutive patients who underwent elective surgery for low colorectal anastomosis (< 7 cm from the anal verge) between February 2020 and December 2022 at a tertiary referral center for colorectal surgery at the University Hospital of Tours, France. Patients were divided into two groups according to the stapler used: PCS group II; (n = 35) and MCS (group I; n = 29). Data collected included demographic characteristics, intraoperative parameters, postoperative complications

(Dindo-Clavien), and oncological outcomes.

Results

The PCS group had significantly lower overall rates of postoperative complications compared to the MCS group (31.4% vs. 62%, p = 0.022). In particular, anastomotic bleeding (AB) was less frequent in the PCS group (0% vs. 17.2%, p = 0.015). While no significant differences in recurrence or survival events were observed between groups during follow-up, the PCS group demonstrated a lower incidence of symptomatic anastomotic leaks (8.6% vs.13.6%, p = 0.069) and postoperative ileus (0% vs. 20.7%, p = 0.025).

Conclusion

In our study, the use of PCS for deep rectal anastomosis was associated with a significantly lower overall postoperative complication rate, rate of symptomatic anastomotic leackage (AL) and AB. Our data support the potential preferential use of PCS in clinical practice. However, larger prospective randomized trials should be conducted to further investigate the potential clinical benefits and cost-effectiveness of using PCS in selected patient populations.

Background

Over the past decade, colorectal surgery (CRS) has undergone significant advances, primarily driven by the adoption of minimally invasive techniques along with the implementation of enhanced recovery after surgery (ERAS) pathway [1, 2]. However, despite these advances, CRS remains inherently associated with a significant risk of postoperative complications, most notably anastomotic leakage (AL). Its occurrence is associated with significant mortality rates [3], reoperation rate, and ultimately impaired functional postoperative outcomes (anal incontinence, low anterior resection syndrome, and ultimately increased permanent stoma requirement (reaching nearly 30% of patients) [4]. AL depends on several non-modifiable risk factors such as patient characteristics and comorbidities (age, gender, ASA score, diabetes, tobacco use, corticosteroid use, administration of neoadjuvant treatments, location of colorectal anastomosis (< 7 cm from the anal verge) [3–5] as well as histopathologic factors related to the disease (i.e. benign disease, colorectal cancer (CRC)), i.e. neoadjuvant treatment [6–8]. On the contrary, potentially modifiable risk factors have been identified, such as malnutrition, minimally invasive surgical technique, ERAS program [2], high ligation of the mesenteric artery [9], and the use of sophisticated surgical technique [3]. A critical technical component in many of these procedures is the formation of anastomoses, which involves reconnecting the colon after resection of a segment. This step is critical to restoring gastrointestinal continuity and function, making the choice of surgical technique and technology particularly important. Circular staplers are commonly used in CRS to facilitate anastomosis. Three types of circular staplers can be used to perform a colorectal anastomosis: Two-row manual circular staplers (MCS), three-row manual staplers (MCS-DST), and two-row power circular staplers (PCS). A recent meta-analysis showed that PCS had a significantly lower risk of AL and anastomotic bleeding (AB), while MCS-DST showed a risk reduction only for AL. However, the risk reduction for AL was higher in patients treated with PCS than with MCS-DST [10]. So far, only 2 studies compared MCS with directional stapling technology (MSC-DST) to PCS [11, 12]. Both studies reported lower complication rates and lower rates of AB and AL with the use of PCS. Despite the perceived advantages of PCS, the comparative safety and efficacy of motorized versus non-motorized circular staples continues to be the subject of ongoing study and debate in the surgical community. Although many studies have investigated the use of powered stapling devices in colorectal surgery, few have specifically examined deep colorectal anastomoses (defined as those located less than 7 cm from the anal verge) performed by one colorectal surgeon using a standardized low-tie technique. This uniformity in the approach to the procedure enhances the internal validity of the study, enabling a more precise evaluation of the technical impact of different stapler types. While the surgical procedures included left-sided colectomy and sigmoidectomy, the study only included participants with confirmed deep colorectal anastomoses at a distance of less than 7 cm from the anal verge, as determined intraoperatively. It is important to note that the extent of proximal colonic resection was not a criterion for inclusion in the study.

Methods

Legal background and study population

This study was conducted as a retrospective analysis based on a prospective database of colorectal surgeries performed between 02/05/2020 and 31/12/2022 at the University Hospital of Tours, France. The last follow-up of the last study patient took place on December 31, 2023. The study protocol was conducted in accordance with the ethical standards of the Human Experimentation Committee of our institution and complies with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines [13]. Study variables were age, sex, ASA score, malignant disease, diagnosis, diagnosis of benign disease, long-term radiochemotherapy, neoadjuvant treatment, surgical procedure, surgical techniques, ERAS strategy and anastomotic stapling technique. The first study period from 05.02.2020 to 06.05.2021 was group II (control group) with the use of MCS-DST (31 mm) devices (EEA™ Autosuture Circular Stapler with DST Series technology COVIDIEN™), the study group (group I) was treated from 06.05.2021 to 31.12.2022 with the use of PCS devices (Echelon Circular™ Powered Stapler ETHICON™. From February 2020 to May 2021, all surgical procedures were performed using the MCS-DST system. From June 2021 onwards, the PCS was systematically implemented for all eligible cases. Patients were included consecutively and device selection was determined solely by the time of surgery, thus eliminating operator bias. A total of 64 consecutive patients were included in the two groups, depending on which circular stapler was used to perform the anastomosis (MCS-DST vs. PCS). Inclusion criteria were adults older than 18 years with a colorectal anastomosis after left colectomy, sigmoidectomy, Hartmann’s reversal, anterior rectal resection for benign or malignant pathology (left colon, upper or middle rectum). All colorectal anastomoses were termino-lateral between 1 cm and 7 cm from the anal verge. Patients who underwent surgical intervention and were diagnosed with a confirmed deep colorectal anastomosis, measured intraoperatively at a distance of 0–7 cm from the anal verge, met the inclusion criteria. Preoperative investigations included clinical examination (digital pelvic exam, anuscopy) and paraclinical investigations (complete colonoscopy with biopsies, rectal endoscopic ultrasound, pelvic magnetic resonance imaging (MRI), thoracoabdominal computed tomography (CT) scan). Evaluation of T stage depended on endoscopic ultrasound (EUS) according to Hildebrandt et al. [14] and preoperative MRI. These studies confirmed the location of the rectal cancer (middle, 5 cm to 10 cm; upper, 10 cm to 15 cm) and helped to assess lymph node involvement. Upper rectal tumors were treated with partial mesorectal excision (PME) or total mesorectal excision (TME). Middle rectal tumors were treated with TME. The study was approved by the Committee for Informatics and Liberties (CIL) under the reference number 2020–067. According to Article R1121-1 of the French Public Health Code, research involving the retrospective analysis of anonymized health data is exempt from the requirement to obtain prior approval from an ethics committee (Comité de Protection des Personnes).

Neoadjuvant and adjuvant treatment

Patients with stage T3/4 and any T-stage N + tumors of the lower/mid rectum received long-term neoadjuvant radiochemotherapy (RCTx). It consisted of chemotherapy with 5-fluorouracil or capecitabine (CTx) in combination with external pelvic radiotherapy (RTx) of 50 Gy administered in 25 fractions over 5 weeks. Short-course RTx was chosen for age or personal reasons to achieve a close sequence of treatment sessions. All patients underwent clinical follow-up 6 weeks after completion of neoadjuvant therapy (digital examination, anoscopy, or occasionally anal examination under general anesthesia). The EUS examination was performed by the same team as the initial examination. Response to neoadjuvant therapy at T and N stage was assessed by repeated MRI and EUS examinations according to RECIST version 1.1 criteria [15]. Adjuvant CTx was performed in patients with incomplete resection and/or positive lymph node involvement. It consisted of CTx with 5-fluorouracil, capecitabine or oxaliplatin.

ERAS protocol and conventional perioperative care protocols

In January 2016, an ERAS protocol was implemented in our department in addition to standard perioperative care protocols. We considered a patient to be treated according to the ERAS protocol if at least 75% of the predefined items of the ERAS protocol were fulfilled.

Surgical procedures

All procedures were performed by a dedicated colorectal surgery expert (MO), with no changes in perioperative care or surgical principles throughout the study. Procedures with left-sided circular stapled anastomosis were performed via robotic-assisted, open, laparoscopic, or hand-assisted minimally invasive approaches, depending on the surgeon’s preference. The laparoscopic approach was the standard except for T4 tumors where an open approach was preferred. PME and TME were performed as follows: the inferior mesenteric vein was ligated at the inferior border of the pancreas, followed by mobilization of the left colon, splenic flexure and ligation of the inferior mesenteric artery. The left colic artery (LCA) was preserved in all cases. The rectum was transected using the double staple technique (Green ENDOGIA Staple COVIDIEN™). The proximal colon was transected approximately 10 cm above the tumor surface. The specimen was removed from the peritoneal cavity through a small abdominal incision [4]. A diverting stoma (ileostomy) was routinely created for PME and TME. The integrity of the colorectal anastomoses was checked intraoperatively by transanal instillation of methylene blue into the rectum at each procedure.

Short-term postoperative outcome

Anastomotic leakage (AL) was defined according to the guidelines of the International Study Group of Rectal Cancer [16]. Any clinical (sepsis, peritonitis, gas, pus, or fecal leakage from the pelvic drain, purulent discharge from the anus, or rectovaginal fistula) and/or biological suspicion of AL led to early CT scan evaluation. Symptomatic treatment included antibiotics, radiologic or trans-anal drainage, and/or early redo abdominal surgery [17]. Postoperative 30-day complications were recorded according to the Dindo-Clavien classification [18].

Pathology reports

Primary tumors were analyzed according to a standardized protocol [19]. Tumors were staged according to the TNM classification of the 8th edition of the American Joint Committee of Cancer. Circumferential and distal margins were defined as positive (R+) if equal to or less than 1 mm radially/1 cm proximally (primary tumor nodules or tumor deposits in the mesorectum) and negative (R0) if greater than 1 mm radially/1 cm proximally. TME or PME, degree of colloid component, degree of differentiation, presence of vascular and lymphatic or peri-nervous emboli, resected lymph nodes, rectal and colic cuff height were included and documented accordingly.

Oncological outcome at follow up

Postoperative follow-up included clinical, biochemical and radiological examinations every three months during the first year after surgery. Surviving patients were described for disease recurrence and location. Follow-up data were obtained from medical records and interviews with patients or their physicians.

Statistical analysis

Descriptive statistics were reported for all variables. Absolute values and frequencies were calculated for qualitative variables. The normality of quantitative variables was assessed using the Shapiro-Wilk test, with data expressed as median and range. Categorical variables were compared using the chi-squared test or Fisher’s exact test when the assumptions for the chi-squared test were not met. The possible relationship between the quantitative variables and the objective variables was then examined using parametric (Student) or non-parametric (Wilcoxon) tests, depending on the distribution of the variables. A p-value < 0.05 was considered statistically significant. The analysis was performed with SPSS software (29.0.2.0 version).

Results

Demographic and preoperative characteristics

A total of 64 patients were enrolled. The follow-up period was until December 31, 2022. 35 patients were enrolled in group I (PCS) and 29 patients in group 2 (MCS-DST). The two groups did not differ significantly with respect to age, gender, BMI, tumor location and neoadjuvant therapy. While group I had significantly more patients with complicated diverticulitis (75% vs. 0%, p = 0.014), group 2 had significantly more patients with ASA score III (48.3 vs. 20%, p < 0.001), history of prior tumor disease (86.2 vs 48.5%, p = 0.007) and present tumor disease (86.2% vs 54.3%, p = 0.007). Table 1 summarizes demographic data.

Table 1.

Demography and preoperative characteristics between group I vs. group II

Data items	Overall population	Group I PCS	Group II MCS-DST	P-value
N (%)	64 (100)	35 (54.6)	29 (45.4)	-
Age (years), median (IQR)	66 (54–73)	64 (52.0–72)	67 (57-74.5)	0.141
≥ 60 years	42 (64%)	22 (62.9%)	20 (68.9%)	0.798
< 60 years	22 (36%)	13 (37.1)	9 (31.1%)
Sex ratio (Female/Male)	23/41	14/21	9/20	0.602
BMI (kg/m2) Median (IQR)	26 (23–30)	26 (21.0-29.5)	27 (24–30)	0.283
ASA Score
1	17 (26.6%)	15 (42.9%)	2 (6.9%)	< 0.001
2	26 (40.6%)	13 (37.1%)	13 (44.8%)
3	21 (32.8%)	7 (20%)	14 (48.3%)
Comorbidities
Renal insufficiancy	2 (3.1%)	1 (2.8%)	1 (3.4%)	1.000
Cerebral stroke	3 (4.6%)	1 (2.8%)	2 (6.8%)	0.586
Hepatic insuffisiancy	1 (2%)	0	1 (3.4%)	0.453
chronic obstructive pulmonary disease	1 (2%)	1 (2.9%)	0	1.000
Peripheric vascular pathology	1 (2%)	0	1 (3.4%)	0.453
Previous cancer	42 (66%)	17 (48.5%)	25 (86.2%)	0.002
Arterial hypertension	16	6	10	0.150
Cardiac insufficiency	5 (%)	1 (2.8%)	4 (%)	0.167
Diabetes mellitus	9 (14%)	3 (8.6%)	6 (20.7%)	0.278
Malignant Colonic Disease	44 (68.7%)	19 (54.3%)	25 (86.2%)	0.007
Benign Colonic Disease	20 (31.2%)	16 (45.7%)	4 (13.8%
Chronic diverticulitis/Hartman removal	8 (12.5%)	4/16 (25%) *	4/4 (100%) **	0.014
Complicated diverticulitis	12 (18.7%)	12/16 (75%)	0	0.014
Abscess	11 (17.2%)	11/16 (68.5%)	0	-
Colovesical fistula	1 (1.5%)	1/16 (6.2%)	0
Colorectal adenocarcinoma location
Left colonic cancer	17/44(38.6%)	6/19 (31.5%)	11/25 (44%%)	0.633
Upper Rectal cancer (10–15 cm AV)	17/44 (38.6%)	9/19 (47.4%)	8/25 (32%)
Mid Rectal cancer (5–10 cm AV)	10/44(22.3%)	4/19 (21.1%)	6/25 (24%)
Neoadjuvant treatment	16/44 (36.4%)	6/19 (31.6%)	10/25 54%)	0.753
Long course radiochemotherapy	12/16 (75%)	4/6 (66%)	8/10 (80%)	0.604
Short course of radiotherapy	4/16 (25%)	2/6 (37%)	2/10 (20%)

Legend: ASA American Society of Anesthesiologists, AV Anal verge, BMI body mass index, IQR interquartile range

* = (1 x colorectal anastomosis redo, 2 x Hartman restoration after diverticulitis peritonitis, 1 x chronic diverticulitis)

** = (2 x Hartman restoration after diverticulitis peritonitis, 2 x chronic diverticulitis) MCS-DST three-row manual staplers, PCS and two-row power circular staplers

Intraoperative parameters

All patients successfully completed ERAS. None of the studied intraoperative parameters (surgical approach, surgical procedures and technical details and intervention time) differed significantly between the two groups. The intraoperative details are summarized in Table 2.

Table 2.

Comparison operative characteristics between group I vs. group II

Data items	Overall Population	Group I PCS	Group II MCS-DST	p-value
N (%)	64 (100%)	35 (54.6%)	29 (45.4%)	-
ERAS protocol, n (%)	64 (100%)	35 (100)	29 (100%)	1.000
Median operative time, Min (IQR)	240 (172–261)	242 (195–262)	230 (139–260)	0.305
Surgical approach, n (%)
Laparoscopic approach	43 (67.2%)	21(60%)	22 (75%)	0.077
Conversion	8 (12.5%)	2/23 (8.6%)	6/25 (24%)	0.248
Primary Open	16 (25%)	12 (34.3%)	4 (13.8%)	0.083
Robot Assisted	4 (6.2%)	1 (2.9%)	3 (10.3%)	0.321
Surgical procedure, n (%)
TME	16 (25%)	6 (17.1%)	10 (34.4%)	0.149
PME	20 (31.2%)	10 (28.5%)	10 (34.5%)	0.787
Left Colectomy	37 (57.8%)	22 (62.8%)	15 (51.7%)	1.000
Hartman reversal	4 (6.25%)	2 (5.7%)	2 (6.9%)	0.681
Splenic flexure mobilization	59 (92.2%)	31 (88.6%)	28 (96.6%)	0.366
Protective ileostomy in TME and PME patients	22/35 (62.9%)	11/16 (68.9%)	11/19 (57.9%)	0.727
Anastomosis technique, n (%)
Termino-terminal	64 (100%)	35 (100%)	29 (100%)	1.000

Legend:TME total mesorectal excision, PME partial mesorectal excision, ERAS Enhanced Recovery After Surgery, IQR Interquartile Range, MCS-DST Three-row manual staplers, PCS and two-row power circular staplers

Anatomopathological characteristics

Two thirds (68.7%) of the overall study population underwent surgery for tumor disease. However, the proportion of tumor patients was significantly higher in group II compared to group I (86.2% vs. 54.3%, p = 0.007). More than half of all patients suffered from a tumor stage T2 (22.3%) or T3 (43.2%). There were no significant differences between the two groups with regard to tumor stage, number of removed lymph nodes, perineural, lymphatic and vascular infiltration and tumor differentiation. The data on the pathological results are shown in Table 3.

Table 3.

Anatomopathological characteristics of group I vs. group II

Data items	Total study Population	Group I PCS	Group II MCS-DST	p-value
N (%)	64 (100)	35 (54.6%)	29 (45.4%)
Cancer, n (%)	44 (68.7%)	19 (54.3%)	25 (86.2%)	0.007
Median tumor size, cm (IQR)	3.8 (2.5-5)	3.5 (2.3-5.0)	3,7 (2.5–5.2)	0.454
TNM classification
T0	5 (11.3%)	2 (10.5%)	3 (12%)	0.612
T1	5 (11.3%)	3 (15.8%)	2 (8%)
T2	10 (22.3%)	6 (31.6%)	4 (16%)
T3	19 (43.2%)	6 (31.6%)	13 (52%)
T4	5 (11.4%)	(10.5%)	3 (12%)
N0	28 (63.4%)	13 (68.4%)	15 (60%)	0.753
N1	11 (25%)	5 (26.3%)	6 (24%)	1.000
N2	5 (11.3%)	1 (5.2%)	4 (16%)	0.370
R0	44 (100%)	19 (100%)	25 (100%)	1.000
Median of Lymph nodes resected, n (IQR)	32 (23–46)	33 (25–46)	30 (21–45)	0.909
T-Stage
I	16 (36.4%)	7 (36.8%)	9 (36%)	1.000
II	15 (34.1%)	6 (31.6%)	9 (36%)	1.000
III	14 (31.8%)	6 (31.6%)	8 (32%)	1.000
IV	0	0	0	1.000
Perineural invasion, n (%)	9 (20.4%)	4 (21.1%)	5 (20%)	1.000
Lymphovascular invasion, n (%)
Lymphatic embolus	13 (29.5%)	5 (26.3%)	8 (32%)	0.748
Vascular Embolus	19 (43.2%)	10 (52.6%)	9 (36%)	0.360
Cancer Cell Differentiation n (%)
Well differentiated	10 (22.7%)	5 (26.3%)	5 (20%)	0.881
Moderately differentiated	31 (70.4%)	13 (68.4%)	18 (72%)
Poorly differentiated	3 (6.8%)	1 (5.2%)	2 (8%)
Rectal cuff (cm), median (IQR)	1.5 (1–2)	1.5 (1–2)	1.5 (1–2)	0.759
Median colic cuff lenght, cm (IQR)	1.7(1.5-2.0)	1.6 (1.5-2.0)	1.8 (1–2)	0.859

Tumors were staged according to the TNM classification of the 8th edition of the American Joint Committee of Cancer. MCS-DSTThree-row manual staplers, PCS and two-row power circular staplers

Legend: IQR interquartile range

Short-term outcomes

The overall morbidity rate was 45.3%. Symptomatic AL (SAL) occurred in 7 (11%) patients, postoperative fluid collections were observed in 3(5%) of patients, 9 (14%) patients had bladder symptoms, and peritonitis occurred in 4 (6%). Repeat emergency surgery was required in 4 (6%) patients. Transfusion, conservative treatment (antibiotics only) and CT-guided drainage were required in 5 (8%), 4 (6%) and 1 (2%) patient, respectively. The mean hospital stay was 8.5 (IQR: 7.0–13.5) days. The analysis of the short-term results based on the respective study group showed that significantly fewer complications occurred in group 1 (PCS) (31.4% vs. 62%, p = 0.022). There was also a difference in anastomotic bleeding (AB) between group I and II (0% vs. 17.2%, p = 0.015) but with no significant difference in symptomatic AL (8.6% vs. 13.8%, p = 0.069). Postoperative ileus occurred significantly more frequently (0% vs. 20.7%, p = 0.025) in group II. No difference was found in the median length of hospital stay Table 4.

Table 4.

Comparison of early outcome between group I vs. group II

Data items	Overall study population	Group I PCS	Group II MCS-DST	p-value
n = number of patients (%)	64 (100)	35 (54.6%)	29 (45.4%)
Dindo-Clavien score, n (%)
Total complications	29 (45.3.%)	11 (31.4%)	18 (62%)	0.022
I/II	23 (36%)	10 (28.6%)	13 (44.8%)	0.200
III/IV	6 (9%)	1 (2.8%)	5 (17.2%)	0.083
V	0	0	0	1.000
SAL, n (%)	7 (11%)	3 (8.6%)	4 (13.8%)	0.692
Postoperative collections, n (%)	3 (5%)	0	3 (10.3%)	0.087
Rectal Bleeding, n (%)	5 (8%)	0	5 (17.2%)	0.015
Bladder Symptoms, n (%),	9 (14%)	3 (8.6%)	6 (20.7%)	0.278
Postoperative Ileus, n (%)	6 (9%)	0	6 (20.7%)	0.025
Peritonitis, n (%)	4 (6%)	1 (2.9%)	3 (10.3%)	0.321
Transfusion, n (%)	5 (8%)	1 (2.9%)	4 (13.8%)	0.167
Antibiotics treatment only for AL, n (%)	4 (6%)	2 (5.7%)	2 (6.8%)	1.000
CT-guided drainage for AL, n (%)	1 (2%)	0	1 (3.4%)	0.453
Surgical approach for reoperation, n (%)
Open abdominal drainage	3 (5%)	1 (2.9%)	2 (6.9%)	0.583
Laparoscopic drainage	0	0	0	1.000
Hartmann	1 (2%)	0	1 (3.4%)	0.453
Median hospital stay, days (IQR)	8.5 (7,0-13.5)	9 (7–14)	8 (7–13)	0.431

Legend: AL anastomotic leak, SAL symptomatic AL, CT computed tomography, IQR interquartile range, MCS-DST three-row manual staplers, PCS and two-row power circular staplers

At the end of follow-up

Overall, adjuvant chemotherapy (CTx) was performed in 21.9% of patients, with no significant difference between the two groups (p = 0.372). The median time required for protective ileostomy closure was 3.46 months (range, 2.3–4.9 months). There was no significant difference in the median time to closure between the two groups (p = 0.415; PCS vs. MCS-DST: 3.48 vs. 3.44). Among patients receiving MCS-DST, only one patient developed a definitive stoma following postoperative peritonitis. Postoperative ileostomy complications were not observed. The overall late stenosis rate was 1.6%. The median follow-up time was significantly shorter in group I (12 versus 19 months, p = 0.043). At the end of the follow-up period, local and distant recurrence rates, as well as overall survival, appeared similar between the two groups. The median follow-up duration was 12 months in Group I and 19 months in Group II (p = 0.043). Outcomes at follow-up were reported descriptively, as no formal survival analysis was performed. Comparative data are presented in Table 5.

Table 5.

Comparison at the end of follow up between group I vs. group II

	Overall Population	Group I PCS	Group II MCS-DST	p-value
N (%)	64 (100)	35 (54.6)	29 (45.4)	-
Adjuvant chemotherapy, n (%)	14 (21.9)	6 (17.1)	8 (27.6)	0.372
Recurrence pattern, n (%) at the end of follow up
Local recurrence	9 (14.1)	6 (17.1)	3 (10.3)	0.494
Distant recurrence	8 (12.5)	3 (8.6)	5 (17.2)	0.451
Both	4 (6.3)	2 (5.7)	2 (6.9)	1.000
Median time to recurrence, month (IQR)	11 (4–19)	4 (3–9)	16 (12–20)	0.085
Median time of follow up, months (IQR)	14 (6–28)	12 (6–23)	19 (7–34)	0.043
Ileostomy closure at the end of follow up, n (%)	22 (100)	11 (100)	11 (100)	1.000
Time to ileostomy closure (Months), median ((IQR))	3.46 (2.3–4.9)	3.48 (2.3–4.6)	3.44 (2.26–7.1)	0.415
Definitive stoma at the end of follow up	1 (1.6)	0	1 (3.4)	0.453
Death at one year	1 (1.5%)	1 (2.8%)	0	1.000
Late complications, n (%) at the end of follow up
Anastomotic stenosis	1 (1.6)	2 (5.7%)	0	0.496

Legend: IQR interquartile range, MCS-DST Three-row manual staplers, PCS and two-row power circular staplers

Discussion

This study evaluated the outcomes of power circular staplers (PCS) versus manual circular staplers with directional stapling technique (MCS-DST) in patients undergoing left-sided colorectal surgery with anastomosis. Our results suggest that the use of PCS is associated with a lower overall rate of postoperative complications, particularly in the early postoperative period, while long-term oncologic outcomes appear to be comparable to those of MCS-DST.

Our results are comparable to the current literature, which reports that the use of PCS is associated with a lower overall risk of early postoperative complications, but also with a lower risk of anastomotic bleeding (AB) and postoperative ileus [20–24]. Regarding the incidence of postoperative AB, our study also shows that the use of PCS leads to a significantly lower incidence of AB compared to the MCS-DST group (5.7% versus 12.2%). This lower incidence of AB is currently attributed to the fact that the use of PCS leads to more uniform tissue compression and thus reduces the risk of anastomotic bleeding [25–27]. Overall, it has been reported that the use of MCS is associated with a high number of technical errors leading to increased postoperative complications and tissue trauma [21, 28]. This observation is also supported by data from a recent meta-analysis [10]. A salient ergonomic benefit of PCS is its motorized activation, which obviates the necessity for manual compression force. This innovation not only mitigates surgeon fatigue but also enhances accessibility for individuals with reduced grip strength, including female surgeons and trainees. Furthermore, the uniformity of the pressure applied by the staple may contribute to more uniform tissue compression and reduced technical variability, particularly in narrow pelvic spaces where precision is critical.

Although follow-up allowed us to document some events related to recurrence and survival, this study was not designed or statistically powered to assess long-term oncologic outcomes. Therefore, no formal conclusion can be drawn regarding local recurrence or overall survival between the two groups. Nevertheless, data from previous studies suggest that complications such as AL and postoperative infection are associated with a significant decrease in OS and an increase in recurrence rates. Postoperative complications have been identified as an independent risk factor associated with worse overall survival and higher recurrence rates [29].

In a study of a cohort of 6779 patients who underwent curative resection for colorectal cancer, both OS and recurrence rates were significantly negatively affected by the occurrence of postoperative complications [30]. This finding underscores the importance of the postoperative complication rate in negatively impacting oncologic outcome. Although the Kaplan-Meier method of survival analysis provides valuable insight into long-term outcomes, it was not used in this study because the study focused primarily on perioperative morbidity and technical outcomes. Additionally, the median follow-up duration of 14 months (interquartile range [IQR] 6–28) was insufficient for a comprehensive survival analysis. Nevertheless, recurrence and survival data were reported descriptively to provide contextual relevance.

The strengths of this study include the fact that the consecutive patient group was operated on by a single surgeon and the surgical technique remained identical throughout the study period. The creation of a deep rectal anastomosis is a critical factor. Additionally, previous data show that a larger stapler diameter (PCS and MCS-DST > 31 mm) is associated with a lower postoperative complication rate. Smaller staplers (28/29 mm) are associated with a higher incidence of stricture formation than larger staplers (31/33 mm). These findings underscore the importance of carefully considering the pros and cons when choosing the diameter for creating a rectal anastomosis [31]. The fact that in our study staplers with comparable diameters were used equally in both study groups means that differences in postoperative complications related to the anastomosis are largely due to differences in the staplers used (PCS vs. MCS-DST) and not to different users and different diameters of the device.

However, our study has several limitations. The study includes a relatively small number of treated patients and is a retrospective analysis. Another important limitation is the fact that significantly more patients in the control group suffered from tumor disease and therefore had a higher ASA risk score II and III. Patients with tumor disease also have classic coagulopathies [32]. This fact would also explain why anastomotic bleeding in the MSC-DST group was not due to the stapler technology, but also due to the tumor disease. Furthermore, increasing ASA status in previous studies was associated with postoperative ileus in large studies [33]. On the other hand, in the PCS group almost 75% of the treated patients suffered from complicated diverticulitis. Large prospective cohort studies show that preoperative inflammation with elevated C-reactive protein significantly increases the risk of postoperative complications [34]. McSorley et al. found that postoperative systemic inflammation, as measured by the modified Glasgow Prognostic Score, was associated with long-term outcomes in colorectal cancer surgery [35]. However, their study had one limitation: the follow-up period was just one year for both groups. Due to this study design, information on long-term outcomes is lacking; however, the one-year follow-up period was sufficient for evaluating anastomosis-related complications.

Conclusions

The findings of this study suggest that using PCS may help reduce postoperative complications. However, this result should be interpreted with caution due to the high prevalence of inflammatory diseases among patients who received PCS. Considering these factors, routinely implementing PCS could be beneficial, especially for patients with multiple comorbidities or those undergoing complex cancer surgeries. Nevertheless, the additional costs of PCS devices must be carefully weighed against their potential benefits. Future studies should include randomized, multicentre trials that incorporate cost-effectiveness analyses to enhance clinical decision-making.

Abbreviations

AB

Anastomotic bleeding

AL

Anastomotic leakage

ASA

American Society of anesthesiology score

AV

Anal verge

BMI kg/m²

Body mass index

MRI

Magnetic resonance imaging

CRS

Colorectal surgery

CT

Computed tomography

CTx

Chemotherapy

CRC

Colorectal cancer

CI

Confidence interval

DST

Directional stapling technology

ERAS

Enhanced recovery after surgery

EUS

Endorectal ultrasound

HR

Hazard ratio

IQR

Interquartile range

LCA

Left colonic artery

PCS

Manual two rows stapler

MCS-DST

Manual three rows stapler

MGPS

Modified glasgow prognostic score

OS

Overall survival

PCS

Powered circular staplers

PME

Partial mesorectal excision

PSM

Propensity Score Matching

RCTx

Radiochemotherapy

RTx

Radiotherapy

SAL

Symptomatic AL

TME

Total mesorectal excision

TMN

Tumor node metastasis

Authors’ contributions

Study concept and design: MO, TM. Acquisition of data: TM, NM, EK, MLV Analysis and interpretation: MO, UGP Drafting the manuscript: MO, UGP. Critical review of the manuscript: UGP MO. Statistical analysis: MO, NM, UGP Administrative, technical, and material support: MO. Study supervision: MO. All authors have read and approved the manuscript.ACKNOKWELGMENTSThe authors are deeply grateful to Guillaume PROUTHEAU and the Association Tourangelle de recherche en oncologie du Val de Loire (AT-ROVL), Tours, France for their invaluable assistance.

Funding

The authors did not receive support from any organization for the submitted work.

Data availability

The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

This study was approved by the local comity of informatics and liberty (CIL) (n° 2020–067). According to the French law (Code de la santé publique, Article R1121–1 Modifié par Décret n°2017–884 du 9 mai 2017 - art.2) no permission of the IRB for this purely retrospective study was required. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Written informed consent was obtained from all individual participants included in the study.

Consent for publication

Not applicable.

Competing interests

Tarik Mahdjoub, Nicolas Michot, Elias Karam, Martine Le Verger, and Urs Giger-Pabst have no conflicts of interest or financial ties to disclose. Dr. Mehdi Ouaissi has no conflicts of interest to disclose. He has received personal fees for a pedagogical manuscript from the Medtronic company.