Nowadays, with innovations in surgical instrumentation, IA using linear staples and barbed suture material allows for the increasing application of total laparoscopic right hemicolectomies. In 2008, Bergamaschi et al. described one standardized IA procedure performed during a right colectomy for cancer, which showed favorable short-term results [5]. However, many surgeons still hesitate to use IA for laparoscopic right hemicolectomy, and EA remains the method of choice. Besides its technical difficulty, some concerns exist, including the possibility of increasing the risk of infection and exposure of tumor cell with this technique because the intestinal tract is opened during the anastomosis.
In this study, we compared the outcomes of patients who underwent laparoscopic right hemicolectomy for right-sided colon cancer using IA with that of those who underwent laparoscopic right hemicolectomy for right-sided colon cancer using EA. Surgical time was found to be significantly longer in the IA group than in the EA group. This is mainly attributed to the need for hand-sewing and knotting inside the abdominal cavity, and many surgeons required further training to perform intracorporeal sutures efficiently. The longer surgical time required to perform IA is also mentioned by several studies [5, 8, 11, 12]; however, we predict that this may shorten with increased surgical experience and the establishment of a standard approach. Given that EA requires grasping of the colon and ileum for subsequent anastomosis, a trans-umbilical incision is usually chosen and the length of the wound is inevitably longer; however, using IA, any incision site can be selected for specimen retraction and the length of the wound can be shorter for grasping one longer specimen. Many studies have revealed that patients with a lower abdominal incision experience less postoperative pain, a quicker return to ambulation and normal bowel function, and fewer pulmonary complications [13–16]. In our institution, we mainly choose the Pfannenstiel incision for tumor retraction because of its better postoperative outcomes and cosmetic results. In this study, the pain scale (visual analogue scale) score showed a significant improvement on postoperative day 3 in the IA group. Moreover, some studies have shown a lower rate of incisional hernias with the use of the Pfannenstiel incision compared to that with an umbilical incision [14, 17, 18]. In our series, no incision hernia was found in the IA group at the 3-year follow-up, which is consistent with the findings of studies from western countries.
There are many advantages of IA for bowel management; one is the better visualization of both limbs of bowel. The EA method requires the bowel to be pulled through a small incision, which may cause small lacerations of the mesentery or torsion of the bowel while manipulating it during externalization. On the other hand, the IA method requires less mobilization of the bowel and can achieve better incisions that allow for a proper surgical margin to be obtained with better visualization using a direct-camera view. Less bowel manipulation is thought to enhance bowel function recovery. In this study, the times to first flatus, tolerating a soft diet, and bowel movement were significantly shorter in the IA group, which is similar to that found in other studies [8, 10, 19]. Another advantage of IA is that it allows for better alignment of the bowel during anastomosis with isoperistaltic ileocolic anastomosis, less inversion of the ileum, and its mesentery may also contribute to better recovery of bowel function.
During the pathological review, the number of harvested lymph nodes was not significantly different between the IA and EA groups in our study; although, some studies demonstrated a higher number of retrieved lymph nodes with the IA method [8, 10]. Only a few studies have compared the difference in specimen length and surgical margin between IA and EA groups. Magistro et al. compared these parameters in 40 patients undergoing a TLC with that of 40 patients undergoing a LAC and found a longer specimen length in the IA group (37.7 ± 12 cm vs. 29.8 ± 8.2 cm, p = 0.001) [8]. Another study by Biondi et al. revealed that better specimen and vascular pedicle lengths are achieved using the IA method. In this study, a greater colon length was achieved with the IA method than with the EA method (20.36 vs. 17.45 cm, p = 0.01) [10]. In a single-blind, randomized clinical trial conducted by Bollo et al., the colon length was also longer in the IA group than in the EA group (25.3 vs. 22.7 cm, p = 0.026) [20]. In the subgroup analysis, we noted no significant difference in colon length when the lesions were located in the cecum or appendix. Interestingly, the further the lesion was from the cecum, the greater the difference in colon length was between the IA and EA groups. When the tumor was located at the hepatic flexure or transverse colon, the colon length and nearest margin were greater when using the IA method. This finding may be explained by the greater visualization of the bowel, achieving a more precise incision, and minimizing bowel compromise during resection by avoiding the need to exteriorize a thick specimen through a small laparotomy incision with IA.
To date, there is only one study that compared the postoperative laboratory data of IA and EA groups. Mari et al. compared preoperative and serial postoperative serum inflammatory markers between 30 patients who underwent a TLC and 30 patients who underwent a LAC and found significantly lower interleukin-6, CRP, and WBC levels on postoperative days 1, 3, and 5 in the IA group [21], indicating that the IA group had a lower surgical stress response that might play a role in bowel recovery. In contrast, this study revealed significantly higher WBC and CRP levels on postoperative day 3 in the IA group. Although these high inflammatory markers were present, there was no difference in the incidence of postoperative complications, such as intra-abdominal infection, abscess formation, wound infection, or anastomosis insufficiency, between the groups. The incidence of postoperative ileus was also comparable between the two groups, suggesting that the risk of infection and postoperative complications was not increased when opening the intestinal tract during IA.
In this study, the mean LOS after surgery was significantly shorter in the IA group, especially a LOS less than 5 days. The shorter LOS represents an overall better recovery after surgery with the IA method, which includes less wound pain, less stress on the bowel, and better recovery of bowel function. Many systemic reviews and meta-analyses have demonstrated similar findings [22–25]. The IA method has the following advantages: lower analgesic use, faster time to bowel movement and flatus passage, shorter time to solid food intake, and shorter length of hospitalization. The postoperative complications were comparable between the two methods [7, 8, 22–26].
Hanna et al. demonstrated comparable 5-year overall survival (66% vs. 78%, p = 0.698) and disease-free survival (86% vs. 78%, p = 0.999) between the IA and EA groups, comprising of 195 patients undergoing a laparoscopic right hemicolectomy [9]. Another study by Lee et al. also showed comparable overall survival (71% vs. 76%, p > 0.05) and disease-free survival (82% vs. 85%, p > 0.05) between the IA and EA groups at the 3-year follow-up [7]. In the present study, no significant difference in overall survival and disease-free survival was observed between the IA group and EA group. To survey whether local seeding is increasing because of opening the intestinal tract during the IA procedure, we focused on the occurrence of local peritoneal seeding during the follow-up. Among all participants studies, there were equivalent numbers of local recurrence between the IA and EA groups, indicating no increased risk of tumor cell dissemination even if we open the intestinal tract inside the peritoneal cavity. Ambe et al. analyzed the cytology specimens acquired from the endoscopic retrieval bag after intracorporeal resection of the colorectal cancer laparoscopically and found no malignant cells. Furthermore, peritoneal recurrence was not observed during the 14-month follow-up [27]. We noted that the primary T stage of the resected tumor in our series was T3 or T4, which may imply that the tumor factor itself is more critical than the surgical factor.
The strength of this study is that, to our knowledge, we are the first to compare, in detail, the length of specimens and margins according to the tumor location between patients who underwent IA and those who underwent EA to confirm the hypothesis that IA offers a precise resection of the specimen. Moreover, we are the first to compare whether local recurrence is increased with the IA procedure to answer the question whether surgeons should avoid opening the intestinal tract during the surgery for better oncological results. This study is limited by its retrospective nature; however, by applying PSM, the demographic characteristics of both groups used in the analysis were the same.