New double-stapling technique without staple-crossing line in laparoscopic low anterior resection: effort to reduce anastomotic leakage
Article information
Abstract
Purpose
This study aimed to demonstrate the safety of new double-stapling technique (nDST), without a crossing line and dog ears, by comparing with conventional DST (cDST) in laparoscopic low anterior resection (LAR).
Methods
We retrospectively reviewed 98 consecutive patients who underwent laparoscopic LAR for rectal cancer from January 2018 to December 2020. The inclusion criterion was an anastomosis level below the peritoneal reflection and 4 cm above the anal verge. In the nDST group, the staple line of the linear cutter was sutured using barbed sutures to shorten the staple line before firing the circular stapler. Therefore, there were no crossing lines after firing the circular stapler. A 2:1 propensity score matching was performed between the cDST and nDST groups.
Results
After propensity score matching, 39 patients were in the cDST group and 20 were in the nDST group. There were no significant differences in patient demographics between the 2 groups. There was no difference in the total operation time between the cDST and nDST groups (124.0±26.2 minutes vs. 125.2±20.3 minutes, P=0.853). Morbidity rates were similar between the 2 groups (9 cases [23.1%] vs. 5 cases [25.0%], P=0.855). There was no significant difference in leakage rate (4 cases [10.3%] vs. 1 case [5.0%], P=0.847) and anastomotic bleeding rate (1 case [2.6%] vs. 3 cases [15.0%], P=0.211).
Conclusion
The nDST to eliminate the crossing line and dog ears in laparoscopic LAR is technically feasible and safe. However, more attention should be paid to anastomotic bleeding in such cases.
INTRODUCTION
Laparoscopic low anterior resection (LAR) is an established approach in patients with rectal cancer [1, 2]. Anastomosis is a very important step in surgery and several methods have been developed. Among them, the double-stapling technique (DST) for laparoscopic rectal surgery has been widely used for its advantages and convenience [3–5], but anastomotic leakage is still known to cause postoperative morbidity and mortality. The DST inevitably creates a crossing line and stapled corner (the so-called dog ears), which are considered potential ischemic sites leading to anastomotic leakage [5–7]. In addition, there have been concerns regarding local recurrence in dog ears [8].
Several studies have been conducted on DST without crossing lines in laparoscopic anterior resection [3, 7, 9, 10]. Usually, an intracorporeal purse-string suture is used to remove the crossing line, but in LAR, it is difficult to operate the laparoscopic instrument in the narrow pelvis; therefore, there have been limited studies [11]. However, with the development of barbed sutures and laparoscopic surgical equipment, the intracorporeal suture became easier, and the visibility in the narrow pelvis improved to an extent.
Therefore, we developed a new DST (nDST) technique that can remove dog ears from LAR. Through this study, we aimed to determine the safety of nDST by comparing the rate of anastomotic leakage between nDST and conventional DST (cDST).
METHODS
Ethics statement
This study was reviewed and approved by the Institutional Review Board of Incheon St. Mary’s Hospital (No. OC22RASI0054). The requirement for informed consent was waived due to the retrospective nature of the study. The study was conducted in compliance with the principles of the Declaration of Helsinki.
Study design and patients
We retrospectively reviewed 98 consecutive patients who underwent laparoscopic LAR for rectal cancer from January 2018 to December 2020. Patients were divided into 2 groups depending on the anastomosis type (cDST and nDST), and the anastomotic leakage rate was analyzed. All procedures were performed by an experienced single colorectal surgeon.
The inclusion criteria were anastomosis below the peritoneal reflection and 4 cm above the anal verge, regardless of clinical staging. Patients who underwent diverting ileostomy or neoadjuvant chemoradiation therapy were excluded from the study. The primary outcome was the incidence of anastomotic leakage, following the definition outlined by the International Study Group of Rectal Cancer [12]. We defined anastomotic bleeding as immediate or delayed bleeding occurring at the staple line, requiring suturing or endoscopic intervention to achieve hemostasis.
Surgical technique
All surgeries were performed using laparoscopic LAR with tumor-specific mesorectal excision and high ligation of the inferior mesenteric artery. Mobilization of the splenic flexure colon was selectively performed for tension-free anastomosis. The distal rectum was resected using a linear stapler. When the specimen was removed and ready for anastomosis, an additional continuous suture was performed approximately at 1 cm intervals from one corner of the rectal stump to the opposite corner using a barbed suture (V-Loc 3-0, Medtronic) to shorten the staple line. When the staple line was short enough, a circular stapler (25- or 29-mm CDH stapler, Ethicon Inc) was introduced to the center of the staple line and connected to the anvil. Subsequently, end-to-end anastomosis was performed without a crossing line and dog ears, and a leakage test was performed (Figs. 1, 2).
Steps of a new double-stapling technique. (A, B) The staple line of linear cutter was sutured with barbed suture to shorten the staple line before firing of the circular stapler. (C, D) There are no staple-crossing lines after firing the circular stapler.
Schematic illustration of new double-stapling technique. (A) A continuous suture of entire staple line was performed approximately at 1 cm intervals. (B) Pull the suture to shorten the staple line. (C)The trocar of circular stapler was advanced through the center of the rectal stump just avoiding the staple line, then the anastomosis was created.
Perioperative management
Preoperative preparation and postoperative treatment were the same in both groups. All patients received mechanical bowel preparation with 4 L of Colyte powder (Taejoon Pharmaceutical Co) 2 days before surgery. A second-generation cephalosporin was administered within 30 minutes prior to surgical incision. Diets were usually started on the 2nd postoperative day according to the critical pathway of rectal cancer.
Statistical analysis
R ver. 4.0.0 (R Foundation for Statistical Computing) was used as the statistical tool. The independent t-test, chi-squared test, and Fisher exact test were adjusted for statistical analysis. Statistical significance was set at P<0.05. The propensity score matching (PSM) method was used to reduce bias in retrospective studies, in which we were unable to conduct a randomized controlled study. Propensity scores were calculated using bivariate logistic regression. PSM was performed for both the cDST and nDST groups using the nearest neighbor method in a 2:1 proportion. Variables considered for matching included age, sex, body mass index, American Society of Anesthesiologists (ASA) physical status, diabetes mellitus, cardiovascular disease, chronic obstructive pulmonary disease, current smoker, and height of anastomosis from the anal verge (cm). After PSM, statistical analysis was performed to compare the 2 groups using the same method. The primary outcome was the incidence of anastomotic leakage. The secondary outcomes were other short-term outcomes.
RESULTS
Of the 98 patients, 74 were in the cDST group and 20 were in the nDST group. After PSM, there were 39 patients in the cDST group and 20 in the nDST group. After PSM, there were no significant differences in patient demographics or cancer characteristics (Table 1).
Patients’ demographics and cancer characteristics
Operative data are presented in Table 2. There was no significant difference in the operation time, including the suturing time for nDST. The additional suturing time for nDST after PSM was 346.9±90.2 seconds. The distance of anastomosis from the anal verge was comparable between cDST and nDST (5.5±2.0 cm vs. 5.5±1.5 cm, P=0.980). The intraoperative complication rate was not significantly different between the 2 groups. However, there was a tendency for intraoperative complications to increase in the nDST group compared with the cDST group. All intraoperative complications were resolved during surgery. A total of 5 cases occurred in the nDST group, and leakage was found in 2 cases, and additional suture was performed. There were 2 cases of intraoperative anastomotic bleeding and 1 case of small intestinal bleeding. None of the patients required blood transfusion. None of the patients received a diverting stoma.
Operative data
Tables 3 and 4 show postoperative outcomes. There were no significant differences in the postoperative morbidity or recovery. After PSM, anastomotic leakage occurred in 4 cases (10.3%) in the cDST group and in 1 case (5.0%) in the nDST group (P=0.847). Anastomotic bleeding occurred in 1 case (2.6%) in the cDST group and in 3 cases (15.0%) in the nDST group (P=0.211).
Short-term outcome
Details in morbidity
DISCUSSION
Anastomosis is a unique concern in rectal cancer surgery, and although many studies have been conducted, it is still considered a difficult complication. Previous studies have shown that staple-crossing line formation caused by DST is an important risk factor of anastomotic leakage [5–7]. In addition, local recurrence appears to be more frequent in DST with dog ears than in single-staple anastomosis [4]. Various methods have been implemented to eliminate the staple-crossing line and dog ears in laparoscopic anterior resection for left side colon cancer [3, 10, 13]. On the other hand, there are few studies in laparoscopic LAR because the technique was considered difficult [14, 15].
In this study, we investigated whether nDST, which eliminates the crossing line, is superior to cDST for anastomotic leakage using PSM in laparoscopic LAR. Anastomotic leakage occurred less frequently in the nDST group, but the difference was not statistically significant. Despite the statistical insignificance, we consider that nDST can reduce the occurrence of anastomotic leakage by eliminating the crossing line and also reduce the cause of cancer recurrence by removing the dog ear.
However, there are concerns regarding the results of nDST for anastomotic bleeding. Although the difference was not statistically significant, anastomotic bleeding occurred more frequently in the nDST group than in the cDST group. First, when the circular stapler is fired, the tissue is thickened due to stump suturing; therefore, there are cases in which hemostasis is not achieved properly. This problem may be solved by prolonged compression during stapling or using a recently released electric circular stapler to reduce microvascular trauma [16]. Second, the mesorectum can become trapped between the anastomoses, caused by narrowing of the staple line due to stump suturing, which can cause bleeding. To solve this problem, mesorectal clearing should be meticulously performed before firing the stapler.
In addition, as 1 procedure, considered a difficult method, is added to the existing surgery, the operation time is expected to be longer, but there was no significant difference in the operation time after PSM matching (cDST group, 124.0±6.2 minutes; nDST group, 125.2±0.3 minutes; P=0.853). The mean suturing time was 346.8±90.2 seconds. This is because the existing intracorporeal suture and tie were difficult to perform in laparoscopic LAR due to the narrow pelvis; however, the recent development of barbed suture eliminated the need to tie, and intracorporeal suture became easier because of the development of laparoscopic displays and instruments [17]. Moreover, the application of nDST to robotic surgery can further reduce the operation time and improve safety.
Our study demonstrates that nDST for laparoscopic LAR is not a difficult and time-consuming procedure. Furthermore, we believe that the new DST has the potential for further development, which can lead to the development of methods to minimize the rate of anastomotic leakage and local recurrence in laparoscopic LAR.
Considering the limitations of this study, we used a retrospective and uncontrolled single-center design, with a small sample size. Larger studies are required to confirm our results.
Notes
Conflict of interest
No potential conflict of interest relevant to this article was reported.
Funding
None.
Author contributions
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