Risk factors for surgical site infection in patients undergoing colorectal surgery: A meta-analysis of observational studies

Surgical Site Infections in Colorectal Cancer Surgeries: A Systematic Review and Meta-Analysis of the Impact of Surgical Approach and Associated Risk Factors

BACKGROUND

Surgical site infections (SSIs) represent a noteworthy contributor to both morbidity and mortality in the context of patients who undergo colorectal surgery. Several risk factors have been identified; however, their relative significance remains uncertain.

METHODS

We conducted a meta-analysis of observational studies from their inception up until 2023 that investigated risk factors for SSIs in colorectal surgery. A random-effects model was used to pool the data and calculate the odds ratio (OR) and 95% confidence interval (CI) for each risk factor.

RESULTS

Our analysis included 26 studies with a total of 61,426 patients. The pooled results showed that male sex (OR = 1.45), body mass index (BMI) ≥ 25 kg/m2 (OR = 1.09), American Society of Anesthesiologists (ASA) score ≥ 3 (OR = 1.69), were all independent risk factors for SSIs in colorectal surgery. Conversely, laparoscopic surgery (OR = 0.70) was found to be a protective factor.

CONCLUSIONS

The meta-analysis conducted revealed various risk factors, both modifiable and non-modifiable, associated with surgical site infections (SSIs) in colorectal surgery. These findings emphasize the significance of targeted interventions, including optimizing glycemic control, minimizing blood loss, and using laparoscopic techniques whenever feasible in order to decrease the occurrence of surgical site infections in this particular group of patients.

Influence of additional prophylactic oral antibiotics during mechanical bowel preparation on surgical site infection in patients receiving colorectal surgery

BACKGROUND

Prophylactic antibiotics (PAs) are standard for preventing surgical site infections (SSIs) post-colorectal surgery. This study aims to compare the effect of additional empiric oral antibiotics (OAs) alongside routine PAs to identify SSI risk factors.

METHODS

A retrospective observatory analysis was conducted from January 2019 to December 2022 at Asan Medical Center, Seoul, Korea. The cohort was divided into two groups: PA given 1 h before surgery and discontinued within 24 h, and OA administered empiric OAs during mechanical bowel preparation in addition to PA.

RESULTS

From a total of 6736 patients, 3482 were in the PA group and 3254 in the OA group. SSI incidence showed no significant intergroup difference (p = 0.374) even after propensity score matching (p = 0.338). The multivariable analysis revealed male sex [odds ratio (OR): 2.153, 95% confidence interval (CI): 1.626-2.852, and p = 0.001], open surgery (OR: 3.335, 95% CI: 2.456-4.528, and p = 0.001), dirty wound (OR: 2.171, 95% CI: 1.256-3.754, and p = 0.006), and an operation time of more than 145 min (OR: 2.110, 95% CI: 1.324-3.365, and p = 0.002) as SSI risk factors. In rectal surgery subgroup, OA demonstrated a protective effect against SSI (OR: 0.613, 95% CI: 0.408-0.922, and p = 0.019) and in laparoscopic approach (OR: 0.626, 95% CI: 0.412-0.952, and p = 0.028).

CONCLUSIONS

OA did not affect SSI incidence in colorectal surgeries. Male sex, open surgery, dirty wounds, and longer operation time were risk factors for SSI. However, for rectal and laparoscopic surgery, OA was a protective factor for SSI.

Impact of Coronavirus Disease 2019 (COVID-19) Pandemic on Surgical Site Infection in Patients with Inflammatory Bowel Disease-A Monocentric, Retrospective Cohort Study

(1) Background: Surgical site infections (SSIs) are a relevant problem with a 25% incidence rate after elective laparotomy due to inflammatory bowel disease (IBD). The aim of this study was to evaluate whether stricter hygienic measures during the COVID-19 pandemic influenced the rate of SSI. (2) Methods: This is a monocentric, retrospective cohort study comparing the rate of SSI in patients with bowel resection due to IBD during COVID-19 (1 March 2020-15 December 2021) to a cohort pre-COVID-19 (1 February 2015-25 May 2018). (3) Results: The rate of SSI in IBD patients with bowel resection was 25.8% during the COVID-19 pandemic compared to 31.8% pre-COVID-19 (OR 0.94; 95% CI 0.40-2.20; p = 0.881). There were seventeen (17.5%) superficial and four (4.1%) deep incisional and organ/space SSIs, respectively, during the COVID-19 pandemic (p = 0.216). There were more postoperative intra-abdominal abscesses during COVID-19 (7.2% vs. 0.9%; p = 0.021). The strictness of hygienic measures (mild, medium, strict) had no influence on the rate of SSI (p = 0.553). (4) Conclusions: Hygienic regulations in hospitals during COVID-19 did not significantly reduce the rate of SSI in patients with bowel resection due to IBD. A ban on surgery, whereby only emergency surgery was allowed, was likely to delay surgery and exacerbate the disease, which probably contributed to more SSIs and postoperative complications.

A low prognostic nutritional index is associated with increased remote infections within 30 days of colorectal surgery: A retrospective cohort study

OBJECTIVE

This study aimed to identify risk factors for remote infection (RI) within 30 days after colorectal surgery.

METHODS

This retrospective study included 660 patients who underwent colorectal surgery at Yamaguchi University Hospital or Ube Kosan Central Hospital between April 2015 and March 2019. Using electronic medical records, we identified the incidence of surgical site infection and RI within 30 days after surgery and obtained information on associated factors. Univariate and multivariable analyses were performed to identify significant risk factors in 607 (median age, 71 years) patients.

RESULTS

Seventy-eight (13%) and 38 (6.3%) patients had surgical site infection and RI, respectively. Of the 38 patients diagnosed with RI, 14 (36.8%) had a bloodstream infection, 13 (34.2%) had a urinary tract infection, 8 (21.1%) had a Clostridioides difficile infection, and 7 (18.4%) had respiratory tract infections. Multivariable analysis showed that a preoperative prognostic nutritional index of ≤40 (OR, 2.30; 95% CI, 1.07-4.92; P = .032), intraoperative blood transfusion (OR (odds ratio), 3.06; 95% CI, 1.25-7.47; P = .014), and concomitant stoma creation (OR, 4.13; 95% CI, 1.93-8.83; P = .0002) were significant RI predictors.

CONCLUSIONS

Nutritional interventions prompted by low preoperative prognostic nutritional index in colorectal surgery may lead to decreases in postoperative RI.

A meta-analysis of the risk factors of surgical site infection after hysterectomy for endometrial cancer

Surgical Site Infection (SSI) is one of the common postoperative complications after hysterectomy for endometrial cancer (EC). Previous studies have investigated the risk factors for SSI in patients with EC. However, big differences in research results exist, and the correlation coefficients of different research results are quite different. A meta-analysis was conducted to examine the risk factors related to SSI in patients with EC. We searched English databases to collect case-control studies or cohort studies published before July 20, 2023, including PubMed, Web of Science, Embase and ScienceDirect. The risk of bias in the included studies was assessed via Newcastle-Ottawa Scale. The analysis was performed using RevMan 5.4.1 tool. A total of 6 articles (n = 3647) were selected in this meta-analysis. The following risk factors were presented to be significantly correlated with SSI in EC: laparotomy (OR = 2.66, 95% CI [1.57, 4.54]), postoperative blood sugar ≥10 mmol/L (OR = 4.38, 95% CI [2.83, 6.78]), Federation International of Gynaecology and Obstetrics (FIGO) stage-III or IV (OR = 2.27, 95% CI [1.49, 3.46]). The occurrence of SSI is influenced by a variety of factors. Thus, we should pay close attention to high-risk subjects and take crucial targeted interventions to lower the SSI risk after hysterectomy. Owing to the limited quality and quantity of the included studies, more rigorous studies with adequate sample sizes are needed to verify the conclusion.

Surgical Site Infections During the Pandemic: The Impact of the "COVID Bundle"

BACKGROUND

A reduction in surgical site infections (SSIs) has been reported in several discrete patient populations during the COVID-19 pandemic. Herein, this study evaluates the impact of the COVID-19 pandemic on SSI in a large patient cohort incorporating multiple surgical disciplines. We hypothesize that enhanced infection control and heightened awareness of such measures is analogous to an SSI care bundle, the hypothetical "COVID bundle", and may impact SSI rates.

METHOD

Data collected for the American College of Surgeons National Surgical Quality Improvement Program between January 1, 2015, and April 1, 2021, were retrospectively analyzed. SSI rates were compared among time-dependent patient cohorts: Cohort A (pre-pandemic, N = 24,060, 87%) and Cohort B (pandemic, N = 3698, 13%). Time series and multivariable analyses predicted pre-pandemic and pandemic SSI trends and tested for association with timing of surgery.

RESULTS

The overall SSI incidence was reduced in Cohort B versus Cohort A (2.8% vs. 4.5%, p < 0.001). Multivariable analysis indicated a downward SSI trend before pandemic onset (IRR 0.997, 95% CI 0.994, 1). At pandemic onset, the trend reduced by a relative factor of 39% (IRR 0.601, 95% CI 0.338, 1.069). SSI then trended upward during the pandemic (IRR 1.035, 95% CI 0.965, 1.111). SSI rates significantly trended downward in general surgical patients at pandemic onset (IRR 0.572, 95% CI 0.353, 0.928).

CONCLUSION

Although overall SSI incidence was reduced during the pandemic, a statistically significant decrease in the predicted SSI rate only occurred in general surgical patients at pandemic onset. This trend may suggest a positive impact of the "COVID bundle" on SSI rates in these patients.

Surveillance of surgical site infection after colorectal surgery: comprehensiveness and impact of risk factors

OBJECTIVE

The incidence of surgical site infection (SSI) is highest after colorectal surgery. We assessed the impact of risk factors for SSI using the population attributable fraction (PAF).

DESIGN

Retrospective cohort study.

SETTING

Portuguese hospitals performing regular surveillance.

PATIENTS

We identified patients who underwent colorectal procedures in hospitals that reported colorectal surgeries every year between 2015 and 2019. Among 42 reporting hospitals, 18 hospitals were included.

METHODS

Risk-factor incidence was estimated using the National Epidemiological Surveillance platform from 2015 to 2019. This platform follows the methodology recommended by the European Centre for Disease Prevention and Control. American Society of Anaesthesiologists (ASA) physical classification, wound classification, open surgery, urgent operation, antibiotic prophylaxis, operation time, and male sex were included as risk factors. Measures of association were retrieved from published meta-analyses. PAFs were calculated using the Levin formula. To account for interaction between risk factors, communality of risk factors was used in a weighted-sum approach, providing a combined value that serves as a measure of the comprehensiveness of surveillance.

RESULTS

Among 11,219 reported procedures, the cumulative SSI incidence was 16.8%. The proportion of SSI attributed to all risk factors was 61%. Modifiable variables accounted for 31% of procedures; the highest was laparotomy (16.8%), and urgent operations (2.7%) had the lowest value. Nonmodifiable factors accounted for 28.7%; the highest was wound classification (14.3%).

CONCLUSIONS

A relevant proportion (39%) of SSI remains unaccounted for by current surveillance. Almost one-third of SSI cases have potentially modifiable factors. Interventions focusing on shorter, less invasive procedures may be optimally effective in reducing the SSI incidence.

Comparison of olanexidine versus povidone-iodine as a preoperative antiseptic for reducing surgical site infection in both scheduled and emergency gastrointestinal surgeries: A single-center randomized clinical trial

Aim

Surgical site infection (SSI) is one of the most common postoperative complications in gastrointestinal surgery. To clarify the superiority of 1.5% olanexidine, we conducted a randomized prospective clinical trial that enrolled patients undergoing gastrointestinal surgery with operative wound classes II-IV.

Methods

To evaluate the efficacy of 1.5% olanexidine in preventing SSIs relative to 10% povidone-iodine, we enrolled 298 patients in each group. The primary outcome was a 30-day SSI, and the secondary outcomes were incidences of superficial and deep incisional SSI and organ/space SSI. In addition, subgroup analyses were performed.

Results

The primary outcome of the overall 30-day SSI occurred in 38 cases (12.8%) in the 1.5% olanexidine group and in 53 cases (18.0%) in the 10% povidone-iodine group (adjusted risk ratio: 0.716, 95% confidence interval: 0.495-1.057, p = 0.083). Organ/space SSI occurred in 18 cases (6.1%) in the 1.5% olanexidine group and in 31 cases (10.5%) in the 10% povidone-iodine group, with a significant difference (adjusted risk ratio: 0.587, 95% confidence interval: 0.336-0.992, p = 0.049). Subgroup analyses revealed that SSI incidences were comparable in scheduled surgery (relative risk: 0.809, 95% confidence interval: 0.522-1.254) and operative wound class II (relative risk: 0.756, 95% confidence interval: 0.494-1.449) in 1.5% olanexidine group.

Conclusion

Our study revealed that 1.5% olanexidine reduced the 30-day overall SSI; however, the result was not significant. Organ/space SSI significantly decreased in the 1.5% olanexidine group. Our results indicate that 1.5% olanexidine has the potential to prevent SSI on behalf of povidone-iodine.

Predictors for surgical site infection in patients undergoing therapeutic or prophylactic intra-abdominal onlay mesh (IPOM) implantation in clean and contaminated surgical fields

BACKGROUND

Prophylactic intra-abdominal onlay mesh (IPOM) implantation has been shown to reduce the rate of fascial dehiscence and incisional hernia. However, surgical site infection (SSI) in presence of an IPOM remains a concern. The aim of this study was to assess predictors for SSI following IPOM placement in hernia and non-hernia abdominal surgery in clean and contaminated surgical fields.

METHODS

Observational study including patients undergoing IPOM placement at a Swiss tertiary care hospital 2007-2016. IPOM implantation was performed in hernia and non-hernia elective and emergency abdominal surgery, including contaminated and infected surgical fields. The incidence of SSI was prospectively assessed by Swissnoso according to CDC criteria. The effect of disease- and procedure-related factors on SSI was assessed in multivariable regression analysis, adjusting for patient-related factors.

RESULTS

A total of 1072 IPOM implantations were performed. Laparoscopy was performed in 415 patients (38.7%), laparotomy in 657 patients (61.3%). SSI occurred in 172 patients (16.0%). Superficial, deep, and organ space SSI were found in 77 (7.2%), 26 (2.4%), and 69 (6.4%) patients, respectively. Multivariable analysis revealed emergency hospitalization (OR 1.787, p = 0.006), previous laparotomy (1.745, p = 0.029), duration of operation (OR 1.193, p < 0.001), laparotomy (OR 6.167, p < 0.001), bariatric (OR 4.641, p < 0.001), colorectal (OR 1.941, p = 0.001), and emergency (OR 2.510, p < 0.001) surgery, wound class ≥ 3 (OR 3.878, p < 0.001), and non-polypropylene mesh (OR 1.818, p = 0.003) as independent predictors for SSI. Hernia surgery was independently associated with a lower risk for SSI (OR 0.165, p < 0.001).

CONCLUSION

This study revealed emergency hospitalization, previous laparotomy, duration of operation, laparotomy, as well as bariatric, colorectal, and emergency surgery, abdominal contamination or infection, and usage of non-polypropylene mesh as independent predictors for SSI. In contrast, hernia surgery was associated with a lower risk for SSI. The knowledge of these predictors will help to balance benefits of IPOM implantation against the risk for SSI.

Incidence and impact of surgical site complications on length of stay and cost of care for patients undergoing open procedures

Background

Surgical site complications (SSCs) can have serious and life-threatening consequences for patients; however, their frequency and impact on healthcare utilization across surgical procedures, particularly for non-infectious SSCs, are unknown. This study examined incidence of overall SSCs and non-infectious SSCs in patients undergoing open surgical procedures in the United States and their effect on length of stay (LOS) and costs.

Methods

This retrospective study utilizing 2019-2020 data from Medicare and Premier Health Database identified patients with SSCs during hospitalization or within 90 days of discharge. Propensity score matching was used to calculate incremental LOS and costs attributable to SSCs. Mean LOS and costs attributable to SSCs for the index admission, readmissions, and outpatient visits were summed by procedure and Charlson Comorbidity Index score to estimate the overall impact of an SSC on LOS and costs across healthcare settings.

Results

Overall and non-infectious SSC rates were 7.3 % and 5.3 % respectively for 2,696,986 Medicare and 6.7 % and 5.0 % for 1,846,254 Premier open surgeries. Total incremental LOS and cost per SSC were 7.8 days and $15,339 for Medicare patients and 6.2 days and $17,196 for Premier patients. Incremental LOS and cost attributable to non-infectious SSCs were 6.5 days and $12,703 and 5.2 days and $14,477 for Medicare and Premier patients respectively.

Conclusions

This study utilizing two large national databases provides strong evidence that SSCs, particularly non-infectious SSCs, are not uncommon in open surgeries and result in increased healthcare utilization and costs. These findings demonstrate the need for increased adoption of evidence-based interventions that can reduce SSC rates.

Optimal timing for antimicrobial prophylaxis to reduce surgical site infections: a retrospective analysis of 531 patients

It has been revealed that the administration of an antimicrobial prophylaxis (AP) reduces the rate of surgical site (SSI) following colorectal cancer surgery. Nevertheless, the optimal timing of this medication remains unclear. The aim of this study was to determine more precisely the optimal time for administering antibiotics and to see if this could reduce the number of possible surgical site infections. The files of individuals who underwent colorectal cancer surgery at the University Hospital Brandenburg an der Havel (Germany) between 2009 and 2017 were analyzed. Piperacillin/tazobactam, cefuroxime/metronidazole and mezlocillin/sulbactam were administered as AP regimens. Timing of AP was obtained. The primary objective was the rate of SSIs based on CDC criteria. Multivariate analysis took place to identify risk factors for SSIs. A total of 326 patients (61.4%) received an AP within 30 min, 166 (31.3%) between 30 and 60 min, 22 (4.1%) more than 1 h before surgery, and 15 (2.8%) after surgery. In 19 cases (3.6%) a SSI occurred during hospital stay. A multivariate analysis did not identify AP timing as a risk factor for the occurrence of SSIs. With significance, more surgical site occurrences (SSO) were diagnosed when cefuroxime/metronidazole was given. Our results suggest that AP with cefuroxime/metronidazole is less effective in reducing SSO compared with mezlocillin/sulbactam and tazobactam/piperacillin. We assume that the timing of this AP regimen of < 30 min or 30-60 min prior to colorectal surgery does not impact the SSI rate.

Hospital context in surgical site infection following colorectal surgery: a multi-level logistic regression analysis

BACKGROUND

Surgical site infections (SSIs) are associated with poor health outcomes. Their incidence is highest after colorectal surgery, with little improvement in recent years. The role of hospital characteristics is undetermined.

AIM

To investigate whether SSI incidence after colorectal surgery varies between hospitals, and whether such variance may be explained by hospital characteristics.

METHODS

Data were retrieved from the electronic platform of the Directorate General of Health, from 2015 to 2019. Hospital characteristics were retrieved from publicly available data on the Portuguese public administration. Analysis considered a two-level hierarchical data structure, with individuals clustered in hospitals. To avoid overfitting, no models were built with more than one hospital characteristic. Cluster-level associations are presented through median odds ratio (MOR) and intraclass cluster coefficient (ICC). Beta coefficients were used to assess the contextual effects.

FINDINGS

A total of 11,219 procedures from 18 hospitals were included. The incidence of SSI was 16.8%. The ICC for the null model was 0.09. Procedural variables explained 25% of the variance, and hospital dimension explained another 17%. More than 50% of SSI variance remains unaccounted for. After adjustment, heterogeneity between hospitals (MOR: 1.51; ICC: 0.05) was still found. No hospital characteristic was significantly associated with SSI.

CONCLUSION

Procedural variables and hospital dimension explain almost half of SSI variance and should be taken into account when implementing prevention strategies. Future research should focus on compliance with preventive bundles and other process indicators in hospitals with significantly less SSI in colorectal surgery.

Incidence and impact of surgical site infections on length of stay and cost of care for patients undergoing open procedures

Background

Surgical site infections (SSIs) are associated with increased morbidity and mortality; however, current SSI rates across open procedures and their effect on healthcare delivery are unknown. The objective of this study was to examine incidence of SSIs for open surgical procedures in the United States and impact on length of stay (LOS) and costs.

Methods

This retrospective study utilizing 2019-2020 data from Medicare and Premier identified patients with SSIs occurring during hospitalization or within 90 days of discharge. Propensity score matching was used to calculate incremental LOS and costs attributable to SSIs. Mean LOS and costs attributable to SSIs for the index admission, readmissions, and outpatient visits were summed by procedure and Charlson Comorbidity Index score to estimate the overall impact of an SSI on LOS and costs across healthcare settings.

Results

SSI rates were 2.0% for 2,696,986 Medicare and 1.8% for 1,846,254 Premier open surgeries. Total incremental LOS and cost per SSI, including index admission, readmissions, and outpatient visits were 9.3 days and $18,626 for Medicare patients and 7.8 days and $20,979 for Premier patients. SSI rates were higher for urgent/emergency surgeries compared to overall SSI rates. Although less common that superficial SSIs, deep SSIs resulted in higher incremental LOS and index costs for the index admission and for SSI-related readmissions.

Conclusions

This study of SSIs utilizing two large national databases provides robust data and analytics reinforcing and bolstering current evidence that SSIs occur infrequently but are detrimental to patients in terms of increased LOS and care costs.

The impact of sarcopenia on the postoperative outcome in colorectal cancer surgery

Background and aim

Malnutrition-induced sarcopenia predicts poorer clinical outcomes for patients with cancer. Postoperative complications such as wound infection, anastomotic leak (AL), cardiorespiratory events are the most frequent and devastating postoperative complications in colorectal cancer surgery and are frequently associated with malnutrition.

Methods

We reviewed the recent available literature to assess the relationship between the patient nutritional status and sarcopenia in colorectal surgery. The PubMed database was searched for publications. The included studies were original articles, prospective and randomized trials, clinical, systematic reviews and meta-analyses. The information was structured in a narrative review form.

Results

A simple method to assess malnutrition is to define the presence of sarcopenia (skeletal muscle mass reduction and modified composition) by radiological image analysis. Quantifying the material composition and quality is a novel method in patient-specific therapy. This could be a new perspective in colorectal surgery to reduce postoperative mortality, improve surgical planning, and enhance clinical outcomes. A few recent studies have objectively investigated the presence of sarcopenia in colorectal cancer and its impact on morbidity and mortality, but sometimes the results are contradictory.

Conclusion

There is evolving research to find the most appropriate management method, surgeons must be aware of the existence of sarcopenia to identify this risk factor in the occurrence of postoperative complications in colorectal cancer surgery.

Predictors of Readmission After Pulmonary Resection in Patients With Lung Cancer: A Systematic Review and Meta-analysis

Objective: Postoperative readmissions are considered an indicator of healthcare quality. The purpose of this study was to assess the factors associated with readmission following pulmonary resection for lung cancer. Methods: A comprehensive search was performed in PubMed, Web of science, the Cochrane Library, and databases of CNKI and Wanfang. We collected the factors associated with readmission following pulmonary resection from the included studies, and data analysis was conducted with STATA SE12.0 software. Results: A total of 11 studies (386 012 participants) were included. The meta-analysis results showed that age (standardized mean difference [SMD] = 0.093), male sex (odds ratio [OR] = 1.260), Charlson score (SMD = 1.408), forced expiratory volume in 1 second predicted (SMD = -0.203), congestive heart failure (OR = 1.708), peripheral vascular disease (OR = 1.436), and histology (OR = 0.804) were associated with readmission (P < .05), while hypertension was not. Patients with postoperative empyema, pneumonia, air leak, and arrhythmia (all P < .05) had higher odds of hospital readmission. Conclusion: The predictive factors for readmission can help in establishing individualized discharge and follow-up plans and programs for reducing hospital readmissions after pulmonary resection in patients with lung cancer.

A meta‐analysis examined the effect of stoma on surgical site wound infection in colorectal cancer

To assess the impact of a stoma on surgical site wound infection in colorectal cancer, we conducted a meta-analysis. A thorough review of the literature up to September 2022 revealed that 3223 participants had colorectal cancer at the start of the investigations; 258 of them had a stoma, while 2965 did not have a stoma. Using dichotomous or contentious methods and a random or fixed-effect model, odds ratios (OR) and mean difference (MD) with 95% confidence intervals (CIs) were estimated to evaluate the impact of a stoma on surgical site wound infection in colorectal cancer. The stoma present had significantly higher surgical site wound infections (OR, 4.37; 95% CI, 3.08-6.21; P < 0.001) with no heterogeneity (I2 = 12%) compared to stoma absent in colorectal cancer. The stoma present had significantly higher surgical site wound infections compared to the stoma absent in colorectal cancer. The low number of selected studies in the meta-analysis calls for care when analysing the results.