Introduction
The most common postoperative complication in malignant rectal surgery is anastomotic leakage (AL). AL after anterior or low anterior resection in rectal tumors can be a fatal postoperative complication, and AL is said to increase the risk of local recurrence. The recent incidence of AL with stapler failure has been reported to range from 6.3% to 13.7%. Tissue tension may not be optimized, and manual circular staplers have been associated with technical errors and low satisfaction. Physicians with small hands or a weak grip, such as female physicians in particular, are less satisfied. However, the clinical results of this procedure have not yet been fully evaluated. We herein report the surgical short-term outcomes of circular stapler anastomosis performed at our institution.
In March of 2019, the first powered circular stapler expected to reduce the incidence of AL, the ECHELON CIRCULAR™ Powered Stapler (ECP; Ethicon Endo-Surgery, Inc., Cincinnati, OH, USA) was launched in the US and European markets. This powered circular stapler was introduced in Japan from 2018, and at present, we are actively using it in Gifu University Hospital.
A single-arm post-market multicenter trial to assess the intraoperative performance of the ECP during left-sided colectomy procedures was also recently completed [
1]. In this trial, ECP showed few technical issues, a favorable safety profile, and ease of use for the creation of left-sided anastomoses as reported by operating surgeons. However, no comparisons were made with conventional manual circular staplers. Therefore, building upon the current state of evidence regarding the ECP, we conducted a retrospective comparison of clinical outcomes using a historical cohort of patients who underwent rectal resection using conventional manual circular staplers.
Discussion
Laparoscopic surgery has been shown to be associated with higher complication rates when performed for rectal cancer than when performed for colon cancer because of technical difficulties and anatomical limitations in the pelvic cavity. According to the results of the CLASICC trial, the complication rate for rectal surgery was 13%, nearly twice higher than the 7% rate for colon surgery. In addition, the rate of AL was higher for rectal surgery (10.2%) than for colon surgery (2.3%;
p < 0.001) [
2]. Furthermore, postoperative morbidities can delay the administration of adjuvant therapy, increase the hospital stay, and reduce cost-effectiveness [
3‐
5].
Other publications reporting lower rates usually originated from dedicated centers. Analyses adjusted for confounding factors revealed male sex and high ASA grade as independent risk factors for AL, which is consistent with the literature. Other reported predictors of AL, such as high BMI, were not confirmed in the present analysis. Another well known risk factor for AL is comorbidity, reflected in the Charlson score and ASA classification in the present study [
6].
In surgical procedures, it is important to note that ???? has been reported to increase the number of linear staples used for rectal transection and was a risk factor for AL [
7]. Some previous studies reported that the number of linear staples used for rectal transection was also a risk factor for AL [
1]. There is concern that an increased number of staple firings may lead to small defects between staple lines and cause AL. Furthermore Kim et al. found that more than two staple firings was associated with AL [
8], and Fukada et al. reported that the number of linear staples used was significantly higher in males, patients with a tumor closer to the rectal verge, and longer operation times [
9]. At our institution, we have also reported an increase in AL when the number of linear staple firings exceeds three times. The most important thing the surgeon can do is to reduce the number of staplers.
In surgical procedures, some reports consider tension and the blood flow to the anastomosis to be even more important. To relieve tension at the anastomosis, mobilization of the colon of the proximal side is important. Sometimes, additional maneuver of the splenic flexure may be performed, but it is important to dissect on the proximal side of the colon and the distal anal rectal side to avoid tension on the anastomosis [
2].
This study assessed outcomes of the ECP trial cohort as indirectly compared with a retrospectively established historical cohort of patients undergoing rectal reconstructions with manual circular staplers [
10‐
12].
Recently, indocyanine green fluorescence angiography (ICG FA) technology has gradually been applied to colorectal surgery and is showing promising results in reducing the incidence of AL. ICG is a near-infrared fluorescent dye that can be detected by imaging systems [
13]. The mechanism of ICG FA to prevent AL is to reveal areas in the anastomosis with insufficient blood supply. If vascular perfusion via ICG FA is poor or delayed, the transection line of the proximal bowel must be shifted to a site with good vascular perfusion, and the anastomosis is performed at the changed transection line. A few studies have applied this novel method to prevent AL in colorectal surgery and have shown promising results [
14,
15]. In our institution, we also perform oral-side colon transfer to avoid tension at the anastomosis. Furthermore, we confirm that there is no tension at the time of the anastomosis and also check the blood flow in the oral side colon using ICG before anastomosis.
From this IPTW-adjusted comparison framework, use of the ECP was associated with significantly lower rates (incidence proportions) of several postoperative complications as well as of 30-day readmissions.
In rectal procedures, the rate of AL in this study was lower for the powered circular stapler than for the manual circular stapler. For all types of adverse events observed in our analysis, including serious adverse events.
Postoperative complications of Clavien-Dindo grade II or higher occurred in 23.9% and those of grade III or higher occurred in 8.4% of patients. Across all Clavien-Dindo grades, AL occurred in 5.9% of the patients.
There was significant difference in AL (OR 0.58, 95% CI 0.34–0.98, p = 0.044). In addition, there was no significant difference in postoperative complications of grade II or higher (OR 0.88, 95% CI 0.65–1.18, p = 0.394), and those of grade III or higher (OR 0.45, 95% CI 0.28–0.73, p = 0.001) were significantly and remarkably lower in the powered circular stapling group.
Daniel et al. reported that mean grip strength was significantly greater for male surgeons, although ease of use of the ECP was judged to be nearly equally high by surgeons of both genders, indicating that grip strength is not a factor for effective use of the device. It was designed specifically for stability during firing and generation of consistent compression, which may contribute to fewer staple-line leaks [
16].
In our study, the primary surgeon was a qualified surgeon certified by the Endoscopic Surgical Skill Qualification System of the Japanese Society of Endoscopic Surgery or an instructor was always present as the first assistant surgeon. Therefore, there was no difference in this study in regard to technical ability of the surgeons. Also, in terms of historical background, the study was limited to a recent 5-year period as this has been a period of relatively standardized technology with no changes in devices used in laparoscopic surgery. We thought it would be meaningful to examine AL by manual and ECP stapling during this period and that it would be possible to clarify whether manual circular staplers or ECP are better for AL in a retrospective study.
Pollack E reported that The ECP was also associated with 27 fewer length of stay (LOS) days, 0.38 fewer readmissions and 0.22 fewer non-home discharges related to anastomotic leaks annually. The incremental cost burden to a hospital that upgrades to ECP for 100 cases a year is estimated to be $11,400—a cost that is easily offset by preventing 1–2 anastomotic leak complications, given the mean incremental cost estimates for this complication [
17].
In addition, we decided to conduct an accurate statistical study using an IPTW comparison between these two groups.
The primary limitation of this report is the lack of a randomized comparison between the ECP stapler and a control circular stapler. The second limitation of this report is the problem that it is combined to performed by laparoscopic or via robotic-assisted laparoscopic methods. But it was no significant difference in anastomotic leakage between robotic-assisted and laparoscopic surgery in our study (data not shown).
However, our objective was to obtain an accurate estimation of technical issues and complications and adverse events associated with use of the novel ECP device.
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