Increased Transumbilical Incision Complication Rates With Laparoscopic Colorectal Resection: A Single-center Propensity Score-matched Cohort Study

Discussion

Transumbilical incisions have been commonly utilized in modern laparoscopic surgery given their convenience and practicality. Before and during the early days of laparoscopic surgery, transumbilical incisions were generally avoided given that such an area was considered unsanitary and that the navel was connected to the ligamentum teres (7). Nonetheless, Jesus reported in 1963 that transumbilical incisions were a safe surgical technique in laparotomy (8), while Peas et al. reported in 1987 that the were no significant differences in the rates of transumbilical incision infections and hernias after comparing transumbilical incisions with techniques that avoided the navel using an arc shape (9). Considering such backgrounds, we have been utilizing transumbilical incisions for organ removal since the early period following the introduction of laparoscopic surgery. The main advantages of transumbilical incisions are that it (i) provides better cosmetic outcomes and ease of extension in the craniocaudal direction, (ii) forgoes the need for establishing another incision just for organ removal, such as the Pfannenstiel incision, and (iii) allows the abdominal cavity to be safely and directly reached via the shortest anatomical distance. Moreover, the size of the incision can be minimized by adjusting it to the size of organs resected using the extensibility of the skin.

Only a few investigations have focused on the transumbilical incision itself and its complications. Our group had previously highlighted the usefulness of a transumbilical incision and its complication in laparoscopic colectomy, gastrectomy, hepatectomy, and pancreatectomy. Our previous reports described the efficacy of transumbilical incision in laparoscopic gastrointestinal procedures, consequently finding that incidence rates of SSIs and incisional hernias correlated with transumbilical incisions were significantly higher following colorectal than gastric resection (1-4).

Although the incidence of transumbilical SSIs was only 2.31% following all procedures, the current study was able to identify obvious risk factors for SSIs. A number of detailed studies on laparoscopic colectomy have reported a 3-8% incidence of umbilical port site infections (10, 11), with a meta-analysis revealing an SSI incidence rate of 2.42% following laparoscopic gastrectomy (12). Moreover, another study showed that high BMI and DM were among the several risk factors for transumbilical SSIs (13).

The incidence of transumbilical incision hernias in the current study was 3.93% following all procedures, with female sex and DM having been identified as independent risk factors for hernia formation. Evidence has shown that high BMI to be significantly associated with a greater risk for incisional hernia following laparoscopic hepatectomy. On the other hand, our research found no apparent risk factors for hernia formation following laparoscopic pancreatectomy (3, 4). A systematic review by Owens et al. found an umbilical incisional hernia incidence rate of 1.47% following laparoscopic colorectal resection (14), while Laurent et al. reported a rate of 7.74% following laparoscopic rectal resection, which was lower than that following laparotomy for rectal cancer (15). On the other hand, a study by Oscar et al. in Spain revealed that 16.18% of those who underwent colorectal resection developed umbilical and supraumbilical incisional hernias. Furthermore, the Pfannenstiel incision had been introduced at their institution for removal of resected organs during left colectomy (16). Other research by Comanjucosas et al., who prospectively evaluated patients undergoing cholecystectomy in Spain, found an umbilical incisional hernia incidence rate of 25.9% (17), while Jang et al. reported that 5.3% of patients who underwent laparoscopic gastrectomy in Korea developed umbilical incisional hernia (18). The aforementioned results therefore suggest considerable differences in incidence rates according to the country or institution, ethnicity, and procedure. With regard to risk factors for transumbilical incisional hernia, Comanjuncosas et al. described that incision enlargement, SSI, DM, and obesity were associated with hernia formation (17), whereas Nassar et al. found that sarcolemmal deficit was a risk factor for hernia formation following laparoscopic cholecystectomy (19). Another study by Swank et al. revealed that the use of pyramidal trocars, 12-mm trocars, surgical duration, age, and BMI were risk factors for hernia formation (20).

Considering all of the aforementioned studies, the incidences of transumbilical incision complications were comparable to that presented herein. Moreover, it remains clear why numerous risk factors have been identified. However, given the absence of comparative studies between surgical procedures, the current study can be considered somewhat novel. In the present study, laparoscopic colorectal, gastric, liver, and pancreatic resections were all performed in one facility, whereas the establishment of the transumbilical incision, extension of incision, organ removal, wound closure, sealing methods, and tools were all standardized and unified, thereby minimizing selection bias.

Our preliminary research in 2017 regarding transumbilical incisions revealed that colectomy led to more complications than gastrectomy (1). Given that resected organs were removed via the transumbilical incision and that mesenteric resection and anastomosis were performed as needed, the effects of bacterial fall while working above the transumbilical incision on complications had been considered. Another 2018 study concluded that falling bacteria had negligible effects, suggesting that colectomy itself might be a risk factor for transumbilical incision complications (2). Similar evaluations regarding transumbilical incision had been conducted for laparoscopic hepatectomy and pancreatectomy, with subsequent results showing an SSI incidence of 0% in both procedures and an incisional hernia incidence of 7.14% and 5.77%, respectively (3, 4). Differences between intestinal organs, such as the colorectum and stomach, which have been correlated with intestinal bacteria, and parenchymal organs, such as the liver and pancreas, had also been considered. Accordingly, previous studies have hypothesized that more transumbilical incision complications occur following intestinal resection or laparoscopic colectomy than following parenchymal organ resection or other procedures. As such, the current study was conducted to clarify differences in the incidence of transumbilical incision complications between surgical procedures. From these perspectives, propensity score analysis was conducted to adjust for confounding factors between surgical procedures. Firstly, a comparison of cases with or without hernia showed no significant difference in complications between surgical procedures for the intestinal tract and those for parenchymal organ resection. However, a significant difference had been noted between colectomy and the other procedures. Therefore, considering the possibility that colectomy itself might be a risk factor, PSM analysis was performed to eliminate background confounding factors between surgical procedures as much as possible. As hypothesized, those who underwent laparoscopic colorectal resection more frequently exhibited transumbilical incision complications compared to those who underwent other organ resection. Several possible factors might have caused this result. The most important factor to be considered was whether the resection or anastomosis had been performed outside the body, particularly above the transumbilical incision, for some colectomies. Moreover, concerns were present regarding the effects of Escherichia coli contamination due to improper handling of the intestinal tract, as well as the effects of a larger incisional length, given the need to place the entire mesentery outside the body. While it remains unclear to what extent bacterial fall affects wound infection, reports have shown that SSI does not contribute to hernia formation (1). Although the lengths of transumbilical incision were unclear due to the retrospective nature of the study, parenchymal organ resection, especially hepatectomy, often involves the removal of a large specimen via the transumbilical incision. Moreover, the need for a larger incision length with colectomy, relative to other procedures, cannot be clearly justified, with no such impression having been noted in actual clinical practice. Furthermore, it is obvious that the incisional length does not depend on the tumor diameter, thereby making its effect negligible. However, further prospective studies are certainly needed. SSIs were observed in parenchymal organ resection, suggesting that intestinal bacteria may have some effect. Although transumbilical incision hernias are expected to occur with any surgical procedure, more attention should be paid especially after colectomy.

Our multivariate analysis identified female sex and DM were as independent risk factors for transumbilical incision hernia formation. Furthermore, although BMI was not identified as a significant risk factor for complications during multivariate analysis, patients with a high BMI should remain vigilant regarding the development of transumbilical incision hernias after surgery. Considering that women have a relatively higher amount of subcutaneous fat than males and that DM causes obesity, including high BMI factors, achieving full-thickness suturing of the rectal sheath nodule might be difficult in such patients, with such technical factors perhaps sufficiently contributing to the occurrence of transumbilical incision hernias. Moreover, obese patients may be at risk for transumbilical incision hernias due to higher intra-abdominal pressure. Based on the aforementioned findings, rectal sheath nodule suturing in patients with factors related to obesity should be undertaken with even greater care and caution.

The findings presented herein should be interpreted in light of our study limitations. This retrospective study included patients from a single institution, potentially introducing selection bias. Furthermore, the possibility of a type 2 statistical error cannot be ruled out. Prospective randomized studies are therefore need in the near future. Nevertheless, given that only a few studies have focused on transumbilical incisional complications, we are confident that the findings presented herein would have a positive impact on future laparoscopic surgery. Based on available evidence thus far, it can be concluded that our transumbilical incision with wound closure and covering methods is feasible, with good tolerability and rationality for modern laparoscopic abdominal surgery.