To the best of our knowledge, although several similar meta-analyses have compared ileostomy and colostomy complications[29, 30], this is the first meta-analysis that included TSA analysis. This study shows strong evidence of a lower incidence of prolapse for ileostomy than for colostomy [3, 31]. However, for the other three complications, including wound infection, fistula, and intestinal obstruction, weak evidence showed no difference between ileostomy and colostomy. In addition, the difference in the incidence of stoma complications between the two groups was also compared using 30 RCT studies on stoma complications.
With the high incidence of colorectal cancer, the utilization rate of ostomy is also increasing annually[1, 32]. Approximately 725 to 1 million people in the United States have undergone ostomies. In China, the number of people undergoing permanent ostomies has exceeded 1 million, and the number is rapidly increasing by 100,000 annually. In a 1998 study, these two types of stoma were used equally: 36.1% for colostomy and 32.2% for ileostomy (and 31.7% for urostomy). However, ileostomy is currently more frequently used than colostomy. Owing to the different positions of the stoma tube in the digestive tract, there are significant differences in the characteristics and flow rates of the diversion. Therefore, the incidence of complications between the two groups should have also been different.
Stoma prolapse refers to the protrusion of the intestinal stoma loop through the stoma, which is more common in loop stomas. Symptoms such as edema, bleeding, ulcers, and incarceration can be observed in the protruding bowel [31]. Stoma retraction, prolapse, and early hernia formation can be attributed to excessive abdominal wall defects. Age, obesity, and increased intra-abdominal pressure are risk factors for prolapse[33, 34]. The data indicated that the incidence of prolapse was lower for the ileostomy group than for the colostomy group, and the TSA analysis indicated a significant difference. There is currently no high-level evidence in the literature to explain this phenomenon. However, the authors speculate that there are several reasons for this finding. First, the walls of the small intestine and colon are the same and are composed of mucosal, submucosal, muscular, and serosal layers. However, the wall thickness of the normally filled small intestine is < 3 mm, and the colon wall is slightly thicker than that of the small intestine; therefore, it may be more prone to prolapse. Second, the stoma opening size may also be an influencing factor of stoma prolapse. The incidence of prolapse differs between colostomy and ileostomy due to the thickness of the colonic lumen compared to the small intestine and the surgeon's habits. In addition, stool in the colon is a semi-solid material that moves faster than the peristaltic waves in the ileum. Geng, Nasier [35] suggested that this phenomenon makes poststomal colonic prolapse more likely to occur than ileal prolapse. In the case of stoma prolapse, nonsurgical or surgical treatment should be performed according to the degree of retraction, as appropriate. Nonsurgical treatment can be used to subdue edema, such as bed rest, wet compression with hypertonic solution, and manual reduction. Emergency surgery should be performed in patients with stoma prolapse who have volvulus, obstruction, or ischemia. Surgical treatment should be considered in patients who cannot undergo repair. After removing the prolapsed intestinal segment, the stoma should be reconstructed in a suitable position.
In addition to the above comparison items, other complication rates were compared. However, because these complications were not fully addressed in these five RCTs, the scope of the included literature was expanded to include all RCTs that investigated the complications of ileostomy and colostomy. A total of 25 RCTs that examined the incidence of other interventions (e.g., early temporary ileostomy versus standard closure in patients with rectal cancer[26]) limited to ileostomy or colostomy were added. Due to differences in surgeons, medical conditions, diagnosis, and treatment processes, a meta-analysis was not performed, and only the chi-square test was performed. A difference in incidence rates > 20% was considered the difference, and the higher incidence rates were marked. The results are shown in the Table 2. According to the conclusions in the Table 2, the incidence of colostomy prolapse was significantly higher than that of ileostomy, which is consistent with the conclusions of the meta-analysis. Although there was no difference in the incidence of wound infection and leak in the meta-analysis, the incidence of colostomy was higher than that of ileostomy, and the incidence of colostomy was also higher in the Table 2. However, the difference in wound infection was not significant. In the meta-analysis, the incidence of ileus was similar between the two groups. However, the incidence of ileus in the ileostomy group was higher than that of the colostomy group, as shown in the Table 2. Hence, more evidence is still required to prove this conclusion.
Except for the four complications stated above, the general data analysis showed differences in the incidence of complications between the two groups. The incidence of skin irritation, parastomal hernia, dehydration, pneumonia, and urinary tract infections was higher for ileostomy. In contrast, the incidence of parastomal fistula, stenosis, hemorrhage, and enterocutaneous fistula was higher for colostomy. For skin irritation and dehydration, probably because the colonic and ileal contents are different, the colon has a strong absorptive capacity and can absorb more than 5 L of fluid and electrolytes daily. For patients with ileostomy, the output increases in the early stage and normalizes in the later stage; this process lasts for 1–8 weeks[36]. However, a sustained ileostomy output of > 1500 ml may lead to dehydration, electrolyte imbalance, and acute kidney injury. Dehydration is the most common cause of readmission[37]. The pH of the intestinal fluid is relatively alkaline and contains digestive enzymes. When directly exposed to the skin, it causes skin irritation symptoms, such as redness, ulceration, itching, and pain, resulting in a higher incidence of skin irritation in ileostomy than in colostomy.
The advantages of this study are that it updates the previous meta-analyses, consolidates the conclusions using TSA analysis, adopts stricter quality control, and includes more RCT studies to obtain more abundant conclusions. However, this study had some limitations. First, the study included only five comparative RCTs, including 317 participants (157 with ileostomy and 160 with colostomy). The small number of RCTs, small number of participants, and low incidence of complications may be one of the reasons for only partially positive conclusions. Twenty-five high-quality RCTs were included for comparison, with a total of 3679 participants (1977 with ileostomy and 1702 with colostomy) to solve this problem. The other aspects of the conclusions were positive, but owing to differences in operators, medical conditions, and diagnosis and treatment processes, the evidence level of this aspect was low. Second, five RCTs included in this study were conducted at a relatively early age, and the description of experimental and bias control methods was not precise; hence, the control of data bias could not be guaranteed. In recent years, few comparative RCT studies of ileostomy and colostomy have been published, making it difficult for some conclusions that have become an expert consensus to be confirmed by a higher level of evidence.
This study found differences in the incidence of various complications between patients with ileostomy and colostomy by comparing the incidence of complications of ileostomy and colostomy. There was no significant difference in the incidence of complications, except that the incidence of stoma prolapse was lower in the ileostomy group than in the colostomy group. More high-quality RCTs are required to conclude with more significant differences in the incidence of complications.