Fecal peritonitis secondary to colonic perforation is a life-threatening condition, and emergency surgical management is associated with high morbidity and mortality rates. Despite advances in surgical techniques and perioperative management, surgical outcomes after colonic perforation have not improved [1-4]. It is important to preoperatively evaluate the severity of peritonitis and identify the associated risk factors for mortality because patients with severe peritonitis require immediate surgical management and high-quality intensive care. Additionally, the severity of the peritonitis, potential predictors, and the likelihood of mortality should be included in the information provided to patients and their families.

Several studies have investigated the prognostic factors associated with the mortality and morbidity of patients with fecal peritonitis; consequently, several scoring systems are available [1,5-7]. However, these risk factors and scoring systems have only been validated in small-population studies and are not clinically prevalent. Nonetheless, many studies are ongoing to determine other risk factors associated with mortality in patients who undergo colonic perforation.

Hartmann’s procedure is the standard surgical procedure for treating left colonic perforation [8,9]. Hartmann’s procedure is associated with low quality of life because of the colostomy care required [10], and restoration of intestinal continuity is associated with morbidity and mortality [11]. The reversal rate of Hartmann’s procedure tends to be lower than 50% in most reported articles [12]. However, it is inconclusive whether primary resection and anastomosis without fecal diversion is safer than Hartmann’s procedure for left colonic perforation.

Thus, the aim of this observational retrospective study was to review the outcomes of patients who underwent emergency surgery for fecal peritonitis secondary to colonic perforation. The primary objective was to compare various factors between survivors and non-survivors. Accordingly, we aimed to predict outcomes based on patient conditions before and during surgery. The secondary objective was to evaluate the necessity of fecal diversion in patients with left colonic perforation without prognostic factors.

Two hundred and twenty-four patients were included in this study. The patient characteristics are presented in Table 1. The mean patient age was 67.5±15.3 years (102 male, 122 female). The most common perforation site was the sigmoid colon in 124 patients (55.4%); 59 patients (26.3%) had perforations on the right side and 165 (73.7%) had perforations on the left side. Resection and anastomosis (50.0%) were the most frequently performed surgeries, followed by Hartmann’s procedure (27.7%). Malignancy was the most common cause of perforation in both groups, but stercoral and ischemic colitis were more common in the non-survivors.

A comparison of the factors associated with survivors and non-survivors indicated that age (66±15.5 years vs. 73.4±13.2 years, p=0.004), organ failure (19.6% vs. 53.3%, p<0.001), systolic blood pressure (117.7±22 mmHg vs. 105.4±30.3 mmHg, p=0.003), and heart rate (87.5±16.1 beats/min vs. 94.5±20.6 beats/min, p=0.041) were significantly different (Table 2). Analysis of laboratory values indicated that CRP, creatinine, prothrombin time, and lactate levels were significantly different between the groups. Analysis of the factors associated with characteristics of peritonitis indicated that free fluid (50.6% vs. 76.7%, p=0.003), feculent fluid (36% vs. 55.6%, p=0.027), diffuse peritonitis (52.6% vs. 82.2%, p=0.001), and right-sided perforation (22.9% vs. 40%, p=0.033) were significantly different. The operative outcomes are summarized in Table 3. There were 89 patients (39.7%) with Clavien-Dindo classification ≥III, of whom 45 (20.1%) died within 1 month after surgery. Of the total, 120 patients (53.6%) underwent fecal diversions, such as Hartmann’s procedure, ileostomy, or colostomy, and 64 (72.7%) of the 88 surviving patients underwent stoma closure.

The univariate and multivariate regression analyses are presented in Table 4. Age of >70 years, ≥2 comorbidities, organ failure, renal failure, prolonged prothrombin time, free fluid, feculent fluid, diffuse peritonitis, and right-sided perforation were associated with mortality. When multivariate analysis was performed to determine whether the aforementioned factors were prognostic, only advanced age, organ failure, right-sided perforation, and diffuse peritonitis were statistically significant.

Sub-analysis between the group that underwent fecal diversion (n=30) and the group that underwent surgical methods without fecal diversion (n=29) revealed that there was no significant difference between the groups in terms of preoperative and intraoperative findings such as age and comorbidities. This suggests that there were no preoperative differences in other risk factors for mortality. Moreover, there were nine patients (30.0%) whose stoma could not be reversed. Nonetheless, there was no significant difference in mortality and morbidity between the groups (Table 5).

Colonic perforation causes widespread dissemination of bacteria and feces into the intraperitoneal space and can lead to peritonitis, septic shock, and multiple organ failure. The mortality rate associated with colon perforation reportedly ranges from 6.2% to 33.3% [1,5-7,14-17]. Similarly, the mortality rate in our study was 20.1%. Our results also showed that old age, organ failure, right-sided perforation, and diffuse peritonitis were associated with mortality. In addition, in the absence of diffuse peritonitis, even patients with left colon perforations showed comparable surgical outcomes with or without fecal diversion. Thus, considering that there are several complications associated with stoma reversal and that many patients have a permanent stoma, a stoma can be omitted if there are no associated risk factors.

Fecal peritonitis due to colonic perforation is largely associated with mortality due to factors such as patient characteristics (including age, ASA PS classification, concurrent medical disease, immunosuppression, and performance status), peritonitis severity, or an interaction between them. Factors such as organ failure and various deteriorations of the blood represent an interaction between patient characteristics and peritonitis severity. Moreover, there are reports of worsening prognosis in patients with lactic acidosis, leukopenia, and bleeding tendency [9,18,19].

In a large cohort of patients with fecal peritonitis, the strongest independent risk factors for mortality were increased age, renal dysfunction, hypothermia, and low hematocrit levels [20]. Furthermore, Tan et al. [21] showed that there was a significant association between mortality and morbidity rates and ASA PS classification, as well as the acute physiology component of the Acute Physiology and Chronic Health Evaluation II score in patients with colon cancer perforation. These findings are further supported by those of Yoo et al. [22]. Thus, a scoring system is useful for objectively describing patient conditions, thereby aiding surgical decisions for patients with fecal peritonitis [5].

While the predictive value of factors that reflect the severity of peritonitis has been previously studied, it is difficult to quantitatively measure the degree of peritonitis. Until now, only a scoring system based on the peritonitis scope and spillage content has been developed. Nevertheless, these studies emphasize the importance of diffuse peritonitis. There are reports that the spread of ascites on a preoperative CT scan is significant for predicting mortality [18]. Similarly, we showed that prognosis was not affected by the degree of contamination of the ascites, but rather the extent to which it had spread. These results support the speculation that the spread of ascites indicates the severity of peritonitis or the duration from the onset of perforation. While mortality rates have been shown to increase with the interval length between the time of hollow organ perforation and the time of surgery [23], our results did not reveal interval length as a prognostic factor for mortality.

Furthermore, our result that diffuse peritonitis is an important prognostic factor is similar to results from studies on colorectal cancer obstruction. When perforation occurs proximal to the obstructing tumor, it tends to be severe due to intestinal distension, and peritoneal contamination is diffuse and fecal. This leads to severe septic shock, which increases the risk of perioperative mortality. In contrast, when perforation occurs at the cancer site, the contamination is usually localized, typically leading to purulent collection and resulting in a lower risk of severe peritonitis [24]. In our study, this is also the reason that peritonitis on the right side had a worse prognosis than that on the left side. In cases of perforation on the right side, more diffuse peritonitis occurred, which led to a worse prognosis.

The optimal surgical treatment for colonic perforation remains controversial, and the treatment strategy depends on the patient’s general condition and the experience of the primary surgeon. Despite advancements in surgical techniques, Hartmann’s procedure is still frequently performed to treat left colonic perforation [8,9]. The literature that primary anastomosis has comparable surgical outcomes to Hartmann’s procedure has mainly been studied in patients with diverticular perforation [25]. Primary anastomosis without fecal diversion has a longer operative time, and Hartmann’s procedure is a safer option for patients with severe medical illness. Therefore, it is important to determine the patient’s overall condition and account for risk factors and conditions that are associated with mortality prior to surgery. In the absence of diffuse peritonitis, primary anastomosis and stoma omission had similar operative outcomes to Hartmann’s procedure even in patients with left colon perforation.

Our study has some limitations. First, this was a single-center study, and we could not proceed with the validation process. Second, our study had a retrospective design; thus, we could not obtain some patient information, such as CRP and lactate levels. Third, because this study included patients who underwent surgery, there may be limitations in the clinical course of fecal peritonitis. Finally, the surgeries were performed by 10 different surgeons, which may have led to inconsistent quality. However, there was no significant difference in the postoperative outcomes based on the surgeon’s specialty.

In conclusion, advanced age, organ failure, right-sided perforation, and diffuse peritonitis were found to be prognostic factors for colon perforation accompanied by fecal peritonitis. Thus, these findings demonstrate that it is important to determine the type of surgery, extent of resection, and whether fecal diversion should be performed.