This study demonstrated that the PGA sheet contributes to a decrease in the risk of anastomotic leakage in patients with left-sided colon and rectal cancers who underwent DST anastomosis. Since DST anastomosis with the PGA sheet is easy to perform and the PGA sheet is relatively inexpensive, this procedure has the potential to make anastomotic leakage a rare complication.
The PGA sheet, which is an absorbable reinforcement material, increases the physical pressure resistance by forming a barrier due to thickening of the collagen tissue during hydrolysis [23, 24]. This material has been widely used in daily practice to prevent air leakage after lung surgery [25, 26] and to prevent pancreatic fistula after pancreatic surgery [27, 28]. As there have been no experimental animal studies, the effect of PGA sheets on fibrosis in the gastrointestinal tract is unknown. However, it is speculated that the PGA sheet can exert its protective effect in the gastrointestinal tract, given that the PGA sheet is effective in lung surgery, which deals with air that requires stricter control than liquids. Furthermore, in the previous basic research, PGA sheets have been reported to contribute to the increase in physical pressure resistance by stabilizing staples [29, 30]. As described above, PGA sheets may be useful in preventing anastomotic leakage. However, very few clinical studies have been conducted on DST anastomosis with PGA sheets. This study is the first to statistically verify the efficacy of PGA sheets for preventing anastomotic leakage in patients with left-sided colon or rectal cancer who underwent DST anastomosis.
Three intraoperative factors associated with anastomotic leakage have been reported: (i) incomplete anastomosis, such as thinned rectal wall, inadequate donut, and staple malformation; (ii) tension; and (iii) blood supply [11, 31, 32]. The risk of anastomotic leakage associated with tension and blood supply can be avoided by performing sufficient mobilization for tension-free anastomosis and evaluating blood flow using ICG fluorescence [9–13]. Regarding physical pressure resistance, additional suture reinforcements have been proposed for reliable anastomosis; in other words, a robust anastomosis that is clinically sufficient to prevent anastomotic leakage [20, 21]. However, the DST anastomosis with the PGA sheet proposed in this study is more effective than the conventional reinforcement methods. The reasons for this are as follows. While the effect of reinforcing sutures at the crossing point of staple lines and the use of a linear stapler with a pre-attached bioabsorbable PGA felt on preventing anastomotic leakage has been reported [20, 21, 33, 34], Ikeda et al. reported that anastomotic leakage was often observed at the circular staple lines as well as the crossing point of staple lines [35]. Therefore, the reinforcing sutures at the crossing point of the staple lines, or the use of a linear stapler with pre-attached bioabsorbable PGA felt alone are insufficient reinforcements, because circular staple lines cannot be reinforced by these procedures. Based on these facts, it is considered that the DST anastomosis with the PGA sheet may be a safer procedure, in that it enables all-round reinforcement including crossing points of the staple lines. Furthermore, suturing the posterior wall is often technically difficult due to insufficient working space, and suturing itself is difficult in cases of ultralow anastomosis. In contrast, DST anastomosis with the PGA sheet does not require training and can be easily performed by any surgeon, even in cases of lower anastomosis.
In addition to the prevention of anastomotic leakage, no anastomotic bleeding was observed in the PGA sheet group, although this was different from the main purpose of using a PGA sheet. PGA sheets may even prevent anastomotic bleeding by stabilizing staple formation and promoting wound healing.
The only disadvantage of DST anastomosis with a PGA sheet is that the PGA sheet interferes with the identification of the leakage point when the leakage test is positive. However, the leakage point could still be identified by flipping the sheet. We experienced one case of positive leakage test, but no postoperative anastomotic leakage occurred by identifying the leakage point and reinforcing it with additional intracorporeal sutures.
This study has several limitations. First, this was a retrospective study with a small cohort in a single center. Second, improvements in the circular stapler over the last few years may have contributed to the prevention of anastomotic leakage. Third, although no patients developed anastomotic stenosis, long-term surveillance for anastomotic stenosis was not performed. Fourth, a variety of patient-related factors such as, smoking, diabetes mellitus, and anemia may contribute to the development of anastomotic leakage.