Oral antibiotics combined with mechanical bowel preparation reduces the risk of surgical site infections in minimally invasive colorectal cancer surgery

Oral antibiotics combined with mechanical bowel preparation reduces the risk of surgical site infections in minimally invasive colorectal cancer surgery | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Oral antibiotics combined with mechanical bowel preparation reduces the risk of surgical site infections in minimally invasive colorectal cancer surgery Eun Ji Park, Min Young Park, Yoon Dae Han, Min Soo Cho, Hyuk Hur, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5823484/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Purpose Colorectal surgeries are associated with high rates of surgical site infection (SSI), which significantly impact postoperative recovery and outcomes. Use of preventive measures, such as mechanical bowel preparation (MBP) and preoperative oral antibiotics (POA), is widely debated. This study investigated the effectiveness of POA plus MBP before elective minimally invasive colorectal cancer surgery. Methods This study retrospectively analyzed 1,506 patients who underwent elective minimally invasive colorectal cancer surgery between January 2020 and December 2023 to evaluate the effectiveness of MBP plus POA in preventing SSIs and other postoperative complications. Patients were divided into MBP alone (n = 811) and POA + MBP (n = 695) groups. Results Overall SSI rates were significantly lower in the POA + MBP group than in the MBP alone group (11.6% vs. 5.5%, p = 0.008), with significant reductions in grade 1–2 SSIs. POA + MBP was particularly effective in patients undergoing colon cancer surgery. In this subgroup, POA + MBP was associated with a 5.6% lower rate of SSIs than MBP alone, with no difference in anastomosis leakage rates between regimens. In patients undergoing rectal cancer surgery, POA + MBP was associated with a significantly higher anastomosis leakage rate (6.9% vs. 2.2%, p = 0.016), with no difference in SSI rates between regimens. Multivariable analysis confirmed that MBP alone was a risk factor for SSIs (odds ratio, 1.5; 95% confidence interval, 1.13–2.18; p = 0.007). Conclusion This study highlights the differential effects of POA + MBP in minimally invasive surgery for colon versus rectal cancer and underscores the need for further investigations to determine the optimal bowel preparation regimen for specific surgical sites. Surgical procedures minimally invasive Colorectal cancer Enhanced recovery after surgery Preoperative period Figures Figure 1 Figure 2 Introduction Colorectal surgery is associated with one of the highest rates of surgical site infections (SSIs) among all types of elective surgery [ 1 ]. SSIs after colorectal surgery are a major cause of postoperative morbidity. They can significantly delay postoperative recovery and the initiation of adjuvant systemic treatments, thereby affecting overall management [ 2 ]. Thus, measures to prevent SSIs are directly related to quality control in colorectal surgery. Preoperative bowel preparation plays an important role in the prevention of SSIs and includes any strategy that physically, chemically, or physiologically removes solid stool and microbial flora from the bowel lumen. A 2014 Cochrane meta-analysis found that mechanical bowel preparation (MBP) alone does not effectively reduce gut bacteria; preoperative antibiotics (oral, intravenous, or both) regimens covering both anaerobic and aerobic bacteria are also necessary to adequately reduce bacterial concentrations [ 3 ]. However, use of preoperative MBP, preoperative oral antibiotics (POA), or both has fallen in and out of favor over the past few decades [ 4 ] [ 5 – 7 ]. Most recently, studies from the American College of Surgeons National Surgical Quality Improvement Program have once again highlighted the effectiveness of combining POA with MBP for lowering SSI rates after colorectal surgery [ 8 , 9 ]. Many previous studies have evaluated colorectal surgeries as a group and failed to examine colon surgery and rectal surgery separately when comparing the effects of POA plus MBP versus MBP alone. A recent report using Korean national health insurance data from 227,638 patients reported that the percentage of procedures in which MBP was omitted in real-world practice differed notably between right-sided colon and rectal surgeries (25.2% vs. 15.9%, respectively), although SSI rates were similar between the two locations (13.6% vs. 15.5%, respectively). It is also known that SSIs occur more frequently after rectal surgery than after colon surgery [ 10 ], and preoperative MBP protocols usually differ between the two types of surgery in clinical practice. Discrepancies in protocols between colon and rectal surgeries emphasize the need to investigate the two types of surgery separately [ 11 ]. The purpose of this study was to compare the effectiveness of POA plus MBP versus MBP alone for preventing SSIs in patients undergoing minimally invasive elective surgery for colorectal cancer. We also performed subgroup analyses comparing the effectiveness of the two bowel preparation regimens separately for patients undergoing colon surgery and those undergoing rectal surgery. Methods Patient selection We retrospectively screened a prospectively maintained database at our institution (a tertiary medical center) for patients who underwent curative-intent surgery from January 2020 to December 2023 for adenocarcinoma of the colon or rectum. All patients underwent elective minimally invasive surgery, either laparoscopically or robotically. We excluded patients who were less than 18 years of age, were diagnosed with inflammatory bowel disease or a hereditary syndrome affecting the colorectal region, had poor general health status (making MBP inappropriate), or were already receiving enteral and/or parenteral antibiotics for any reason. We also excluded patients who required emergency surgery or for whom any type of enterostomy was created during their operation. Perioperative treatment regimens As shown in Fig. 1 , patients scheduled for elective colorectal surgery were prescribed MBP 1 or 2 days before the day of surgery, according to whether MBP was begun after hospital admission or at home before admission. Patients who received preoperative antibiotics were prescribed two doses of oral rifaximin 400 mg, at 12-hour intervals 1 day before their operation. All patients received intravenous cephalosporin within 1 hour before surgery, and no patient received routine antibiotics after surgery. Outcomes The primary study endpoint was the rate of SSIs within 30 days postoperatively. SSIs were classified as follows: grade 1, superficial SSI; 2, deep incisional infection; and 3, organ space infection. The secondary study endpoints included postoperative complications and anastomosis leakage, also within 30 days after surgery. Postoperative complications were categorized according to the Clavien-Dindo classification system. Anastomosis leakage was defined as clear evidence of anastomosis site disruption of any size, as detected radiologically or via direct visualization during surgical exploration. Statistical analysis Descriptive statistics included the number of patients observed for each variable and the percentage of patients in the corresponding cohorts. Average values were calculated as mean with standard deviation (SD) or median with interquartile range (IQR), depending on whether the data were normally distributed. Chi-square test was used to examine differences in bivariate frequencies, and Wilcoxon rank-sum test was used to compare differences between groups for continuous variables. Variables were compared between the POA + MBP group and the MBP alone group. P values ≤ 0.05 were considered statistically significant. We used binary logistic regression models to assess the association between the occurrence of SSI and variables previously reported to be risk factors for SSIs. All variables that were statistically significant during univariable analysis were included in the multivariable analysis. Subgroup analyses using the same statistical methods were performed separately for the colon and rectal surgery cohorts. All analyses were performed using SPSS 27.0. Results Patient characteristics Of the 1506 patients who underwent elective minimally invasive surgery for colorectal cancer during the study period, 695 were prescribed oral antibiotics and MBP preoperatively (POA + MBP group), and the other 811 received only preoperative MBP (MBP alone group). The study included 820 males (54.4%) and 686 females (45.6%) (Table 1 ). The median patient age at diagnosis was 64 years (IQR, 55–72 years), and the mean body mass index (BMI) was 23.5 kg/m 2 (SD, 3.2 kg/m 2 ). The American Society of Anesthesiologists (ASA) physical status class of most patients ranged from 1 to 3 (n = 1487, 98.7%). The primary lesion was located in the colon in 1032 patients (68.5%) and in the rectum in 474 patients (31.5%). Most operations (n = 1346, 89.4%) were performed laparoscopically, with the remaining 160 procedures (10.6%) performed robotically. Table 1 Baseline characteristics Total (N = 1506) POA + MBP (n = 695) MBP alone (n = 811) P value Male, n (%) 820 (54.4) 384 (55.3) 4.6 (53.8) 0.57 Female, n (%) 686 (45.6) 311 (44.7) 375 (46.2) Age at diagnosis, years, median (IQR) 64 (55–72) 64 (56–72) 64 (55–72) 0.82 BMI, kg/m 2 , mean (SD) 23.5 (3.2) 23.5 (3.3) 23.6 (3.2) 0.59 ASA physical status class, n (%) 0.07 1 63 (4.2) 21 (3.0) 42 (5.2) 2 914 (60.7) 412 (59.3) 502 (61.9) 3 510 (33.9) 253 (36.4) 257 (31.7) 4 19 (1.3) 9 (1.3) 10 (1.2) Cancer location, n (%) 0.003* Colon 1032 (68.5) 450 (64.7) 582 (71.8) Rectum 474 (31.5) 245 (35.3) 229 (28.2) Operation method, n (%) < 0.001* Laparoscopic 1346 (89.4) 584 (84.0) 762 (94.0) Robotic 160 (10.6) 111 (16.0) 49 (6.0) * P values ≤ 0.05. Abbreviations: ASA, American Society of Anesthesiologists; BMI, body mass index; IQR, interquartile range; MBP, mechanical bowel preparation; POA, preoperative oral antibiotics; SD, standard deviation. Sex, age, BMI, and ASA class were not significantly different between the POA + MBP and MBP alone groups (Table 1 ). Surgery for colon cancer was more common in the MBP alone group than in the POA + MBP group (71.8% vs. 64.7%, p = 0.003). The rate of laparoscopic surgery was also higher in the MBP alone group than in the POA + MBP group (94.0% vs. 84.0%, p < 0.001). Median operation time was longer in the MBP alone group than in the POA + MBP group (169 minutes [IQR, 138–216 minutes] vs. 156 minutes [IQR, 125–195 minutes]) ( p = 0.001 ) . Median estimated blood loss was also higher in the MBP alone group than in the POA + MBP group (20 mL [IQR, 0–50 mL] vs. 10 mL [IQR, 0–30 mL], p = 0.025). Median hospital stay after surgery was similar between groups (MBP alone vs. POA + MBP: 6 days [IQR, 5–7 days] vs. 5 days [IQR, 5–6 days], p = 0.58). Surgical site infections and other postoperative complications Postoperative complications were observed in 258 patients (17.1%) and were mostly classified as Clavien-Dindo class 1 or 2 (n = 211, 14.5%) (Table 2 ). Grade 1–2 complications occurred more frequently in the MBP alone group than in the POA + MBP group (16.7% vs. 11.9%, p = 0.009), but rates of class 3–4 complications were similar between groups. Anastomosis leakage occurred in a total of 41 patients (2.7%), with similar rates between groups (MBP alone vs. POA + MBP: 2.2% vs. 3.3%, p = 0.21). Table 2 Surgical site infections and other postoperative complications Total (N = 1506) POA + MBP (n = 695) MBP alone (n = 811) P value Surgical site infections, n (%) 174 (11.6) 65 (9.4) 109 (13.4) 0.015* Grade 1–2, n (%) 113 (7.5) 38 (5.5) 75 (9.2) 0.008* Grade 3, n (%) 67 (4.4) 30 (4.3) 37 (4.6) 0.90 Grade 3 SSI without AL, n (%) 30 (2.0) 9 (1.3) 21 (2.6) 0.05* Total complications, n (%) 258 (17.1) 100 (14.4) 158 (19.5) 0.009* CD grade 1–2 complications, n (%) 211 (14.5) 80 (11.9) 131 (16.7) 0.009* CD grade 3–4 complications, n (%) 48 (3.7) 21 (3.4) 27 (4.0) 0.66 Anastomosis leakage, n (%) 41 (2.7) 23 (3.3) 18 (2.2) 0.21 * P values ≤ 0.05. Abbreviations: AL, anastomosis leakage; CD, Clavien-Dindo; MBP, mechanical bowel preparation; POA, preoperative oral antibiotics; SSI, surgical site infection. SSIs occurred in 174 patients (11.6%); 113 (7.5%) were grade 1 or 2 SSIs, and 67 (4.4%) were grade 3 SSIs (Table 2 ). The rate of grade 1–2 SSIs was significantly higher in the MBP alone group than in the POA + MBP group (9.2% vs. 5.5%, p = 0.008). The rate of grade 3 SSIs was similar between groups (MBP alone vs. POA + MBP: 4.6% vs. 4.3%, p = 0.90). Of the 67 grade 3 SSIs in the entire cohort, 30 were not associated with anastomosis leakage. The rate of grade 3 SSIs without anastomosis leakage was significantly higher in the MBP group than in the MBP + POA group (2.6% vs. 1.3%, p = 0.05). Table 3 shows the results of regression analyses evaluating potential risk factors for SSI. On multivariable analysis, use of MBP alone was associated with a higher likelihood of SSI (odds ratio [OR], 1.57; 95% confidence interval [CI], 1.13–2.18; p = 0.007). Other risk factors for SSI on multivariable analysis were male sex (OR, 1.39; 95% CI, 1.00–1.94; p = 0.049) and higher ASA physical status class (OR, 1.85; 95% CI, 1.34–2.55; p < 0.001). Multivariable analyses for other outcomes revealed that use of MBP alone was also associated with increased odds of grade 1–2 SSIs and total postoperative complications (Fig. 2 a). Table 3 Regression analysis of potential risk factors associated with surgical site infections Univariable Multivariable OR (95% CI) P value OR (95% CI) P value Male 1.47 (1.06–2.03) 0.02* 1.39 (1.00–1.94) 0.049* Age > 64 years 1.03 (0.75–1.42) 0.84 High ASA physical status class 1.86 (1.35–2.56) < 0.001* 1.85 (1.34–2.55) < 0.001* High BMI 1.15 (0.84–1.58) 0.39 Rectal cancer 1.17 (0.84–1.63) 0.36 EBL < 10 mL 1.17 (0.85–1.61) 0.33 No preoperative oral antibiotics 1.51 (1.09–2.08) 0.014* 1.57 (1.13–2.18) 0.007* * P values ≤ 0.05. Abbreviations: ASA, American Society of Anesthesiologists; BMI, body mass index; CI, confidence interval; EBL, estimated blood loss; OR, odds ratio. Colon versus rectal cancer surgery To assess the effects of the two bowel preparation regimens based on the location of primary lesion, patients were divided into colon cancer (n = 1032) or rectal cancer (n = 474) cohorts. Baseline characteristics were generally comparable across groups (supplement Table 1 ). In patients with colon cancer, multivariable analyses revealed that use of POA + MBP was significantly associated with reduced odds of overall SSIs, grade 1–2 SSIs, and total postoperative complications (Fig. 2 b). The odds of anastomosis leakage were not associated with the type of bowel preparation (POA + MBP vs. MBP alone) in patients with colon cancer. Other perioperative outcomes between two cohorts can be found in supplement Table 2 . In patients with rectal cancer, use of POA + MBP was not significantly associated with the occurrence of SSIs. Male sex was the only factor significantly associated with SSI on univariable analysis in this cohort (OR, 0.45; 95% CI, 0.25–0.82; p = 0.009). However, the rate of anastomosis leakage was higher in the POA + MBP group than in the MBP alone group (6.9% vs. 2.2%, p = 0.016). Multivariable analyses likewise showed that the use of POA + MBP was associated with increased odds of anastomosis leakage (OR, 0.30; 95% CI, 0.11–0.83, but no other outcomes were associated with the type of bowel preparation regimen in patients with rectal cancer (Fig. 2 c). Discussion In our prospectively followed cohort of 1,506 patients who underwent elective minimally invasive surgery for colon or rectal cancer, use of POA combined with MBP was associated with significantly reduced SSI rates, compared to use of MBP alone. Specifically, use of POA plus MBP was associated with a 4.0% lower rate of overall SSIs (all grades) and 3.7% lower rate of grade 1–2 SSIs. This finding was consistent with the results of recent meta-analyses, which found that patients undergoing colorectal surgery were less likely to develop SSIs when POA was used in combination with MBP. Reported rates of SSI after colorectal cancer surgery typically range from 10–30%. The overall rate of SSI in our patients was 11.7%, suggesting that our study cohort can be considered a representative population. Use of POA plus MBP was also associated with reduced odds of total complications and Clavien-Dindo grade 1–2 complications. The beneficial effects of POA plus MBP in preventing SSIs and postoperative minor complications observed in our entire study cohort were likewise observed during subgroup analyses of patients undergoing colon cancer surgery. Use of POA combined with MBP was associated with a 5.6% lower rate of SSIs, compared to MBP alone, in patients undergoing colon cancer resection. Many surgeons consider bowel preparation unnecessary prior to colon cancer surgery because intraluminal residual content, which predisposes to SSIs, is relatively small in volume and less likely to result in infection. A few previous studies, such as that by Suzuki et al. [ 12 ], specifically evaluated the outcomes of patients with colon cancer based on preoperative bowel preparation regimen (no MBP, MBP alone, or MBP plus POA). However, these studies included small sample sizes and reported SSI rates of 2–6%, which are well below the average reported SSI rates of 10–15% for colon cancer surgery. Additionally, these studies often included patients undergoing open laparotomy, which significantly affects the interpretation of risks of grade 1–2 SSIs. Based on our findings suggesting that POA plays a protective role against SSIs in patients with colon cancer, we recommend the use of preoperative MBP plus POA for all elective minimally invasive colon cancer surgery, unless contraindicated. Our results for patients with rectal cancer were more intriguing. We found that while POA plus MBP was not associated with a significantly reduced risk of SSIs, the combination was associated with an increased risk of anastomosis leakage (6.9% in the POA + MBP group vs. 2.2% in the MBP group). By contrast, a recent randomized controlled trial focusing solely on rectal resection [ 13 ] found that POA plus MBP was associated with lower rates of SSIs and anastomosis leakage, compared with MBP alone. However, most patients in that study underwent rectal resection with a protective stoma. In our study, we deliberately excluded patients with a protective stoma, as stomas can be associated with increased risk of wound infection and true organ space infection. Additionally, anastomosis leakage within the 30-day postoperative observation period may not be detected, thereby affecting the study results. For studies investigating the effects of POA plus MBP in elective colorectal surgery with SSI as the primary endpoint, exclusions such as those used in our study help reduce the effects of confounding factors like protective stomas. Furthermore, a small propensity score–matched study by Lei et al. found that use of POA plus MBP was beneficial for patients undergoing left-sided colon or rectal resection but not right-sided colon resection [ 14 ]. It should be noted that the overall rates of anastomosis leakage (4.6%) and SSIs (12.2%) observed in our rectal surgery cohort were considerably lower than those reported in similar studies, suggesting that preoperative bowel preparation (MBP with or without POA) is beneficial for patients undergoing rectal cancer surgery. Although there was higher rate of anastomosis leakage when POA was combined with MBP in our rectal cancer cohort, overall rate of anastomosis leakage was lower than commonly reported average rate of 10 percent [ 15 – 17 ]. As anastomosis methods, preoperative treatment regimes, and other factors are intertwined in causing anastomosis leakage in rectal cancer, whether this difference observed in our study is truly due to bowel preparation method warrants further study. One concern about using POA relates to the possibility of an increased risk of Clostridioides difficile infection. This concern also formed the basis for current guidelines recommending against the routine use of postoperative prophylactic antibiotics after colorectal surgery. No cases of C. difficile infection were observed in our study population. A study by Kim et al. reported that using POA with MBP was associated with a lower risk of C. difficile colitis, compared with not using any form of bowel preparation [ 18 ]. An increased risk of C. difficile colitis may be more associated with empiric use of prophylactic antibiotics postoperatively, a frequent practice before the development of recent guidelines. Other studies have also shown that POA use is not a risk for C. difficile infection [ 19 – 21 ]. Our study has some limitations. Although it included a moderate number of patients, it was still a retrospective study. Some potentially important variables, such as the incision site for specimen extraction, the anastomosis method for right-sided colon cancer (intracorporeal vs. extracorporeal), and the method of wound irrigation, were not controlled. For patients with rectal cancer, comparisons could not be adjusted for common risk factors associated with anastomosis leakage. Additionally, the differential effects of POA plus MBP in preventing SSIs observed between colon and rectal cancer surgery were not consistent with the results of previous studies. These discrepancies may be related to the failure to include some patients with left-sided colon cancer in the rectal cancer population because of the nature of data collection in our study. Our findings align with recent evidence from multiple randomized clinical trials and meta-analyses that POA combined with MBP can improve postoperative outcomes, including reducing the likelihood of SSIs, when used prior to colorectal surgery. However, clinical usage of POA plus MBP is lower than expected based on the available evidence. A survey conducted in the United Kingdom among members of the Association of Coloproctology of Great Britain and Ireland reported that approximately 5.5–18.6% of surgeons chose to use POA plus MBP, while more than 53% thought that the combination could reduce the incidence of SSIs. Thus, although evidence (including that reported in the present study) supports the use of POA plus MBP, surgeons appear to be hesitant to abandon their practice of using MBP alone, a regimen that has been used for decades. Further studies exploring the effects of POA in very specific patient groups are necessary to definitively determine the optimal preoperative bowel preparation for each type of surgical cohort and promote widespread acceptance of the most appropriate regimens. Conclusion In patients undergoing colon cancer surgery, the combination of POA plus MBP was effective in reducing the risk of SSIs, compared with MBP alone. However, this beneficial effect was not observed in patients undergoing rectal cancer surgery. Further studies are required to determine the most appropriate bowel preparation regimens for specific surgical sites. Declarations Competing interests All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript. Ethics approval This study was performed in accordance with the principles of the Declaration of Helsinki. The protocol was approved by the Ethics Committee of Yonsei University School of Medicine (IRB No. 4-2024-0834). Funding The authors did not receive support from any organization for the submitted work and there was no funding received to assist with the preparation of this manuscript. Author Contribution Conceptualization: EJP, SYYData Curation: EJP, SYYFormal analysis: EJP, SYYInvestigation: EJP, SYYMethodology, MYP, YDH, MSC, HH, KYLProject administration: EJP, SYYVisualization: EJPWriting original draft: EJPWriting review and editing: EJP, SYYAll authors have read and approved the final manuscript Acknowledgments None References Migaly J et al (2019) The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Use of Bowel Preparation in Elective Colon and Rectal Surgery. Dis Colon Rectum 62(1):3–8 Vo E et al (2018) Association of the Addition of Oral Antibiotics to Mechanical Bowel Preparation for Left Colon and Rectal Cancer Resections With Reduction of Surgical Site Infections. 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Ann Surg 257(4):665–671 Zhang W et al (2017) Multicenter analysis of risk factors for anastomotic leakage after middle and low rectal cancer resection without diverting stoma: a retrospective study of 319 consecutive patients. Int J Colorectal Dis 32(10):1431–1437 Kim EK et al (2014) A statewide colectomy experience: the role of full bowel preparation in preventing surgical site infection. Ann Surg 259(2):310–314 Al-Mazrou AM et al (2018) Effect of Inclusion of Oral Antibiotics with Mechanical Bowel Preparation on the Risk of Clostridium Difficile Infection After Colectomy. J Gastrointest Surg 22(11):1968–1975 Khorasani S et al (2020) Association Between Preoperative Oral Antibiotics and the Incidence of Postoperative Clostridium difficile Infection in Adults Undergoing Elective Colorectal Resection: A Systematic Review and Meta-analysis. Dis Colon Rectum 63(4):545–561 Krapohl GL et al (2011) Bowel preparation for colectomy and risk of Clostridium difficile infection. Dis Colon Rectum 54(7):810–817 Additional Declarations No competing interests reported. Supplementary Files supplementarytable1.docx supplementarytable2.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5823484","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":402362412,"identity":"df408065-b892-4d82-96b6-fd24b37ddc60","order_by":0,"name":"Eun Ji Park","email":"","orcid":"","institution":"Yonsei University College of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Eun","middleName":"Ji","lastName":"Park","suffix":""},{"id":402362413,"identity":"61fbc93f-f098-4607-9aa3-76c4da910df4","order_by":1,"name":"Min Young Park","email":"","orcid":"","institution":"Yonsei University College of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Min","middleName":"Young","lastName":"Park","suffix":""},{"id":402362414,"identity":"38ffd066-69cd-4030-9692-34b023f1439b","order_by":2,"name":"Yoon Dae Han","email":"","orcid":"","institution":"Yonsei University College of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Yoon","middleName":"Dae","lastName":"Han","suffix":""},{"id":402362415,"identity":"cc720857-3185-4c03-bdcc-27f5f22ffe6b","order_by":3,"name":"Min Soo Cho","email":"","orcid":"","institution":"Yonsei University College of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Min","middleName":"Soo","lastName":"Cho","suffix":""},{"id":402362416,"identity":"524fa1f1-2bb6-4b0f-811a-c111e3e6497f","order_by":4,"name":"Hyuk Hur","email":"","orcid":"","institution":"Yonsei University College of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Hyuk","middleName":"","lastName":"Hur","suffix":""},{"id":402362417,"identity":"a71327ca-2c1c-4cb5-bb5f-e3bf698bd351","order_by":5,"name":"Byung Soh Min","email":"","orcid":"","institution":"Yonsei University College of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Byung","middleName":"Soh","lastName":"Min","suffix":""},{"id":402362418,"identity":"31be734e-6200-48c1-a6f6-4db7ffca4b69","order_by":6,"name":"Kang Young Lee","email":"","orcid":"","institution":"Yonsei University College of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Kang","middleName":"Young","lastName":"Lee","suffix":""},{"id":402362419,"identity":"d55902d1-0411-4493-be4d-30d1dd04cc17","order_by":7,"name":"Seung Yoon Yang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAw0lEQVRIiWNgGAWjYLCCDwYSPPwMDGzE62CcUWEjJ9lAihZmnjNpxgYHiNUiPyPHTIK37XDi5hs5Zg9/MNjJE9RiAFQpIQnUsu1GjrkxD0OyYQNBLRJALYYQLWbSQEcmEOewRJDDgAzJHwz1hLUwgBx2AOR9kHU8DIcJazE486zYsgEYyBJnnpVJ8xgcJ+wX+fbkjbf/gKKyPXmb5I+KasIhxiCQYSIBYYCcZEBYAwMD//HHHyCMA8QoHwWjYBSMgpEIANn1O7ALv6BnAAAAAElFTkSuQmCC","orcid":"","institution":"Yonsei University College of Medicine","correspondingAuthor":true,"prefix":"","firstName":"Seung","middleName":"Yoon","lastName":"Yang","suffix":""}],"badges":[],"createdAt":"2025-01-14 02:53:06","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5823484/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5823484/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":74247898,"identity":"d84d3886-ed82-488e-b103-a5bfb1d77d08","added_by":"auto","created_at":"2025-01-20 10:07:58","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":73708,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart of perioperative bowel preparation protocols.\u003c/p\u003e\n\u003cp\u003eThe laxatives used include Picosulfate solution and polyethylene Glycol solution.\u003c/p\u003e\n\u003cp\u003eAbbreviations: BID, twice per day; D-2, 2 days before surgery; D-1, 1 day before surgery; IV, intravenous; MIS, minimally invasive surgery; OP, operative; PO, oral\u003c/p\u003e","description":"","filename":"Picture1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5823484/v1/de68f31811000e0b6f77bfd5.jpg"},{"id":74249671,"identity":"97039238-5a85-410c-8f28-3d0c09e49e79","added_by":"auto","created_at":"2025-01-20 10:15:58","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":19006,"visible":true,"origin":"","legend":"\u003cp\u003eForest plots showing the likelihood ofvarious postoperative outcomes associated with mechanical bowel preparation alone, compared to preoperative oral antibiotics plus mechanical bowel preparation. Red triangles and confidence intervals represent statistically significant odds ratios (\u003cem\u003ep ≤ \u003c/em\u003e0.05).Abbreviations: AL, anastomosis leakage; SSI, surgical site infection; SSI (1–2), grade 1 or 2 SSI; SSI (3), grade 3 SSI\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5823484/v1/ca4c5e65670f5e88bb8c19a6.png"},{"id":76150004,"identity":"5850cb25-ae87-4358-9568-57bbd20589a9","added_by":"auto","created_at":"2025-02-12 22:16:38","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":763093,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5823484/v1/9842671c-03e0-42db-af09-06573346be9f.pdf"},{"id":74247896,"identity":"c49d29c9-657f-4f91-9f52-8e246e994d7b","added_by":"auto","created_at":"2025-01-20 10:07:58","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":20851,"visible":true,"origin":"","legend":"","description":"","filename":"supplementarytable1.docx","url":"https://assets-eu.researchsquare.com/files/rs-5823484/v1/16c6c9834f567590ce6bd64a.docx"},{"id":74247899,"identity":"da160f97-9705-4bb5-8f1b-9bb192c80cc9","added_by":"auto","created_at":"2025-01-20 10:07:58","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":19823,"visible":true,"origin":"","legend":"","description":"","filename":"supplementarytable2.docx","url":"https://assets-eu.researchsquare.com/files/rs-5823484/v1/f39acee2d91418051a6d84ac.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Oral antibiotics combined with mechanical bowel preparation reduces the risk of surgical site infections in minimally invasive colorectal cancer surgery","fulltext":[{"header":"Introduction","content":"\u003cp\u003eColorectal surgery is associated with one of the highest rates of surgical site infections (SSIs) among all types of elective surgery [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. SSIs after colorectal surgery are a major cause of postoperative morbidity. They can significantly delay postoperative recovery and the initiation of adjuvant systemic treatments, thereby affecting overall management [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Thus, measures to prevent SSIs are directly related to quality control in colorectal surgery.\u003c/p\u003e \u003cp\u003ePreoperative bowel preparation plays an important role in the prevention of SSIs and includes any strategy that physically, chemically, or physiologically removes solid stool and microbial flora from the bowel lumen. A 2014 Cochrane meta-analysis found that mechanical bowel preparation (MBP) alone does not effectively reduce gut bacteria; preoperative antibiotics (oral, intravenous, or both) regimens covering both anaerobic and aerobic bacteria are also necessary to adequately reduce bacterial concentrations [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. However, use of preoperative MBP, preoperative oral antibiotics (POA), or both has fallen in and out of favor over the past few decades [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] [\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Most recently, studies from the American College of Surgeons National Surgical Quality Improvement Program have once again highlighted the effectiveness of combining POA with MBP for lowering SSI rates after colorectal surgery [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMany previous studies have evaluated colorectal surgeries as a group and failed to examine colon surgery and rectal surgery separately when comparing the effects of POA plus MBP versus MBP alone. A recent report using Korean national health insurance data from 227,638 patients reported that the percentage of procedures in which MBP was omitted in real-world practice differed notably between right-sided colon and rectal surgeries (25.2% vs. 15.9%, respectively), although SSI rates were similar between the two locations (13.6% vs. 15.5%, respectively). It is also known that SSIs occur more frequently after rectal surgery than after colon surgery [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], and preoperative MBP protocols usually differ between the two types of surgery in clinical practice. Discrepancies in protocols between colon and rectal surgeries emphasize the need to investigate the two types of surgery separately [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe purpose of this study was to compare the effectiveness of POA plus MBP versus MBP alone for preventing SSIs in patients undergoing minimally invasive elective surgery for colorectal cancer. We also performed subgroup analyses comparing the effectiveness of the two bowel preparation regimens separately for patients undergoing colon surgery and those undergoing rectal surgery.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePatient selection\u003c/h2\u003e \u003cp\u003eWe retrospectively screened a prospectively maintained database at our institution (a tertiary medical center) for patients who underwent curative-intent surgery from January 2020 to December 2023 for adenocarcinoma of the colon or rectum. All patients underwent elective minimally invasive surgery, either laparoscopically or robotically. We excluded patients who were less than 18 years of age, were diagnosed with inflammatory bowel disease or a hereditary syndrome affecting the colorectal region, had poor general health status (making MBP inappropriate), or were already receiving enteral and/or parenteral antibiotics for any reason. We also excluded patients who required emergency surgery or for whom any type of enterostomy was created during their operation.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003ePerioperative treatment regimens\u003c/h3\u003e\n\u003cp\u003eAs shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003e, patients scheduled for elective colorectal surgery were prescribed MBP 1 or 2 days before the day of surgery, according to whether MBP was begun after hospital admission or at home before admission. Patients who received preoperative antibiotics were prescribed two doses of oral rifaximin 400 mg, at 12-hour intervals 1 day before their operation. All patients received intravenous cephalosporin within 1 hour before surgery, and no patient received routine antibiotics after surgery.\u003c/p\u003e\n\u003ch3\u003eOutcomes\u003c/h3\u003e\n\u003cp\u003eThe primary study endpoint was the rate of SSIs within 30 days postoperatively. SSIs were classified as follows: grade 1, superficial SSI; 2, deep incisional infection; and 3, organ space infection. The secondary study endpoints included postoperative complications and anastomosis leakage, also within 30 days after surgery. Postoperative complications were categorized according to the Clavien-Dindo classification system. Anastomosis leakage was defined as clear evidence of anastomosis site disruption of any size, as detected radiologically or via direct visualization during surgical exploration.\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eDescriptive statistics included the number of patients observed for each variable and the percentage of patients in the corresponding cohorts. Average values were calculated as mean with standard deviation (SD) or median with interquartile range (IQR), depending on whether the data were normally distributed. Chi-square test was used to examine differences in bivariate frequencies, and Wilcoxon rank-sum test was used to compare differences between groups for continuous variables. Variables were compared between the POA\u0026thinsp;+\u0026thinsp;MBP group and the MBP alone group. \u003cem\u003eP\u003c/em\u003e values \u0026le; 0.05 were considered statistically significant. We used binary logistic regression models to assess the association between the occurrence of SSI and variables previously reported to be risk factors for SSIs. All variables that were statistically significant during univariable analysis were included in the multivariable analysis. Subgroup analyses using the same statistical methods were performed separately for the colon and rectal surgery cohorts. All analyses were performed using SPSS 27.0.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003ePatient characteristics\u003c/h2\u003e \u003cp\u003eOf the 1506 patients who underwent elective minimally invasive surgery for colorectal cancer during the study period, 695 were prescribed oral antibiotics and MBP preoperatively (POA\u0026thinsp;+\u0026thinsp;MBP group), and the other 811 received only preoperative MBP (MBP alone group). The study included 820 males (54.4%) and 686 females (45.6%) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The median patient age at diagnosis was 64 years (IQR, 55\u0026ndash;72 years), and the mean body mass index (BMI) was 23.5 kg/m\u003csup\u003e2\u003c/sup\u003e (SD, 3.2 kg/m\u003csup\u003e2\u003c/sup\u003e). The American Society of Anesthesiologists (ASA) physical status class of most patients ranged from 1 to 3 (n\u0026thinsp;=\u0026thinsp;1487, 98.7%). The primary lesion was located in the colon in 1032 patients (68.5%) and in the rectum in 474 patients (31.5%). Most operations (n\u0026thinsp;=\u0026thinsp;1346, 89.4%) were performed laparoscopically, with the remaining 160 procedures (10.6%) performed robotically.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBaseline characteristics\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;1506)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePOA\u0026thinsp;+\u0026thinsp;MBP\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;695)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMBP alone\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;811)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e820 (54.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e384 (55.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.6 (53.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e686 (45.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e311 (44.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e375 (46.2)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge at diagnosis, years, median (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e64 (55\u0026ndash;72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e64 (56\u0026ndash;72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e64 (55\u0026ndash;72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.82\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI, kg/m\u003csup\u003e2\u003c/sup\u003e, mean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.5 (3.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.5 (3.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23.6 (3.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.59\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eASA physical status class, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.07\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e63 (4.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21 (3.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e42 (5.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e914 (60.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e412 (59.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e502 (61.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e510 (33.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e253 (36.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e257 (31.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19 (1.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9 (1.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10 (1.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCancer location, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.003*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eColon\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1032 (68.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e450 (64.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e582 (71.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRectum\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e474 (31.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e245 (35.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e229 (28.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOperation method, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLaparoscopic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1346 (89.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e584 (84.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e762 (94.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRobotic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e160 (10.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e111 (16.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e49 (6.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e* \u003cem\u003eP\u003c/em\u003e values\u0026thinsp;\u0026le;\u0026thinsp;0.05.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eAbbreviations: ASA, American Society of Anesthesiologists; BMI, body mass index; IQR, interquartile range; MBP, mechanical bowel preparation; POA, preoperative oral antibiotics; SD, standard deviation.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eSex, age, BMI, and ASA class were not significantly different between the POA\u0026thinsp;+\u0026thinsp;MBP and MBP alone groups (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Surgery for colon cancer was more common in the MBP alone group than in the POA\u0026thinsp;+\u0026thinsp;MBP group (71.8% vs. 64.7%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.003). The rate of laparoscopic surgery was also higher in the MBP alone group than in the POA\u0026thinsp;+\u0026thinsp;MBP group (94.0% vs. 84.0%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003eMedian operation time was longer in the MBP alone group than in the POA\u0026thinsp;+\u0026thinsp;MBP group (169 minutes [IQR, 138\u0026ndash;216 minutes] vs. 156 minutes [IQR, 125\u0026ndash;195 minutes]) (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001\u003cem\u003e)\u003c/em\u003e. Median estimated blood loss was also higher in the MBP alone group than in the POA\u0026thinsp;+\u0026thinsp;MBP group (20 mL [IQR, 0\u0026ndash;50 mL] vs. 10 mL [IQR, 0\u0026ndash;30 mL], \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.025). Median hospital stay after surgery was similar between groups (MBP alone vs. POA\u0026thinsp;+\u0026thinsp;MBP: 6 days [IQR, 5\u0026ndash;7 days] vs. 5 days [IQR, 5\u0026ndash;6 days], \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.58).\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSurgical site infections and other postoperative complications\u003c/h3\u003e\n\u003cp\u003ePostoperative complications were observed in 258 patients (17.1%) and were mostly classified as Clavien-Dindo class 1 or 2 (n\u0026thinsp;=\u0026thinsp;211, 14.5%) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Grade 1\u0026ndash;2 complications occurred more frequently in the MBP alone group than in the POA\u0026thinsp;+\u0026thinsp;MBP group (16.7% vs. 11.9%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.009), but rates of class 3\u0026ndash;4 complications were similar between groups. Anastomosis leakage occurred in a total of 41 patients (2.7%), with similar rates between groups (MBP alone vs. POA\u0026thinsp;+\u0026thinsp;MBP: 2.2% vs. 3.3%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.21).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSurgical site infections and other postoperative complications\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;1506)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePOA\u0026thinsp;+\u0026thinsp;MBP\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;695)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMBP alone\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;811)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurgical site infections, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e174 (11.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e65 (9.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e109 (13.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.015*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade 1\u0026ndash;2, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e113 (7.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e38 (5.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e75 (9.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.008*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade 3, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e67 (4.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e30 (4.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e37 (4.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.90\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade 3 SSI without AL, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e30 (2.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e9 (1.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e21 (2.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.05*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal complications, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e258 (17.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e100 (14.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e158 (19.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.009*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCD grade 1\u0026ndash;2 complications, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e211 (14.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e80 (11.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e131 (16.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.009*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCD grade 3\u0026ndash;4 complications, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e48 (3.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21 (3.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e27 (4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.66\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnastomosis leakage, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e41 (2.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e23 (3.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e18 (2.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.21\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e* \u003cem\u003eP\u003c/em\u003e values\u0026thinsp;\u0026le;\u0026thinsp;0.05.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eAbbreviations: AL, anastomosis leakage; CD, Clavien-Dindo; MBP, mechanical bowel preparation; POA, preoperative oral antibiotics; SSI, surgical site infection.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eSSIs occurred in 174 patients (11.6%); 113 (7.5%) were grade 1 or 2 SSIs, and 67 (4.4%) were grade 3 SSIs (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The rate of grade 1\u0026ndash;2 SSIs was significantly higher in the MBP alone group than in the POA\u0026thinsp;+\u0026thinsp;MBP group (9.2% vs. 5.5%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.008). The rate of grade 3 SSIs was similar between groups (MBP alone vs. POA\u0026thinsp;+\u0026thinsp;MBP: 4.6% vs. 4.3%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.90). Of the 67 grade 3 SSIs in the entire cohort, 30 were not associated with anastomosis leakage. The rate of grade 3 SSIs without anastomosis leakage was significantly higher in the MBP group than in the MBP\u0026thinsp;+\u0026thinsp;POA group (2.6% vs. 1.3%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the results of regression analyses evaluating potential risk factors for SSI. On multivariable analysis, use of MBP alone was associated with a higher likelihood of SSI (odds ratio [OR], 1.57; 95% confidence interval [CI], 1.13\u0026ndash;2.18; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.007). Other risk factors for SSI on multivariable analysis were male sex (OR, 1.39; 95% CI, 1.00\u0026ndash;1.94; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.049) and higher ASA physical status class (OR, 1.85; 95% CI, 1.34\u0026ndash;2.55; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Multivariable analyses for other outcomes revealed that use of MBP alone was also associated with increased odds of grade 1\u0026ndash;2 SSIs and total postoperative complications (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003ea).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eRegression analysis of potential risk factors associated with surgical site infections\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eUnivariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eMultivariable\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOR (95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOR (95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.47 (1.06\u0026ndash;2.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.02*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.39 (1.00\u0026ndash;1.94)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.049*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u0026thinsp;\u0026gt;\u0026thinsp;64 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.03 (0.75\u0026ndash;1.42)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHigh ASA physical status class\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.86 (1.35\u0026ndash;2.56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.85 (1.34\u0026ndash;2.55)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHigh BMI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.15 (0.84\u0026ndash;1.58)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRectal cancer\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.17 (0.84\u0026ndash;1.63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEBL\u0026thinsp;\u0026lt;\u0026thinsp;10 mL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.17 (0.85\u0026ndash;1.61)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo preoperative oral antibiotics\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.51 (1.09\u0026ndash;2.08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.014*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.57 (1.13\u0026ndash;2.18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.007*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e* \u003cem\u003eP\u003c/em\u003e values\u0026thinsp;\u0026le;\u0026thinsp;0.05.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eAbbreviations: ASA, American Society of Anesthesiologists; BMI, body mass index; CI, confidence interval; EBL, estimated blood loss; OR, odds ratio.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eColon versus rectal cancer surgery\u003c/h3\u003e\n\u003cp\u003eTo assess the effects of the two bowel preparation regimens based on the location of primary lesion, patients were divided into colon cancer (n\u0026thinsp;=\u0026thinsp;1032) or rectal cancer (n\u0026thinsp;=\u0026thinsp;474) cohorts. Baseline characteristics were generally comparable across groups (supplement Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). In patients with colon cancer, multivariable analyses revealed that use of POA\u0026thinsp;+\u0026thinsp;MBP was significantly associated with reduced odds of overall SSIs, grade 1\u0026ndash;2 SSIs, and total postoperative complications (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). The odds of anastomosis leakage were not associated with the type of bowel preparation (POA\u0026thinsp;+\u0026thinsp;MBP vs. MBP alone) in patients with colon cancer. Other perioperative outcomes between two cohorts can be found in supplement Table \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eIn patients with rectal cancer, use of POA\u0026thinsp;+\u0026thinsp;MBP was not significantly associated with the occurrence of SSIs. Male sex was the only factor significantly associated with SSI on univariable analysis in this cohort (OR, 0.45; 95% CI, 0.25\u0026ndash;0.82; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.009). However, the rate of anastomosis leakage was higher in the POA\u0026thinsp;+\u0026thinsp;MBP group than in the MBP alone group (6.9% vs. 2.2%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.016). Multivariable analyses likewise showed that the use of POA\u0026thinsp;+\u0026thinsp;MBP was associated with increased odds of anastomosis leakage (OR, 0.30; 95% CI, 0.11\u0026ndash;0.83, but no other outcomes were associated with the type of bowel preparation regimen in patients with rectal cancer (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003ec).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eIn our prospectively followed cohort of 1,506 patients who underwent elective minimally invasive surgery for colon or rectal cancer, use of POA combined with MBP was associated with significantly reduced SSI rates, compared to use of MBP alone. Specifically, use of POA plus MBP was associated with a 4.0% lower rate of overall SSIs (all grades) and 3.7% lower rate of grade 1\u0026ndash;2 SSIs. This finding was consistent with the results of recent meta-analyses, which found that patients undergoing colorectal surgery were less likely to develop SSIs when POA was used in combination with MBP. Reported rates of SSI after colorectal cancer surgery typically range from 10\u0026ndash;30%. The overall rate of SSI in our patients was 11.7%, suggesting that our study cohort can be considered a representative population. Use of POA plus MBP was also associated with reduced odds of total complications and Clavien-Dindo grade 1\u0026ndash;2 complications.\u003c/p\u003e \u003cp\u003eThe beneficial effects of POA plus MBP in preventing SSIs and postoperative minor complications observed in our entire study cohort were likewise observed during subgroup analyses of patients undergoing colon cancer surgery. Use of POA combined with MBP was associated with a 5.6% lower rate of SSIs, compared to MBP alone, in patients undergoing colon cancer resection. Many surgeons consider bowel preparation unnecessary prior to colon cancer surgery because intraluminal residual content, which predisposes to SSIs, is relatively small in volume and less likely to result in infection. A few previous studies, such as that by Suzuki et al. [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], specifically evaluated the outcomes of patients with colon cancer based on preoperative bowel preparation regimen (no MBP, MBP alone, or MBP plus POA). However, these studies included small sample sizes and reported SSI rates of 2\u0026ndash;6%, which are well below the average reported SSI rates of 10\u0026ndash;15% for colon cancer surgery. Additionally, these studies often included patients undergoing open laparotomy, which significantly affects the interpretation of risks of grade 1\u0026ndash;2 SSIs. Based on our findings suggesting that POA plays a protective role against SSIs in patients with colon cancer, we recommend the use of preoperative MBP plus POA for all elective minimally invasive colon cancer surgery, unless contraindicated.\u003c/p\u003e \u003cp\u003eOur results for patients with rectal cancer were more intriguing. We found that while POA plus MBP was not associated with a significantly reduced risk of SSIs, the combination was associated with an increased risk of anastomosis leakage (6.9% in the POA\u0026thinsp;+\u0026thinsp;MBP group vs. 2.2% in the MBP group). By contrast, a recent randomized controlled trial focusing solely on rectal resection [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] found that POA plus MBP was associated with lower rates of SSIs and anastomosis leakage, compared with MBP alone. However, most patients in that study underwent rectal resection with a protective stoma. In our study, we deliberately excluded patients with a protective stoma, as stomas can be associated with increased risk of wound infection and true organ space infection. Additionally, anastomosis leakage within the 30-day postoperative observation period may not be detected, thereby affecting the study results. For studies investigating the effects of POA plus MBP in elective colorectal surgery with SSI as the primary endpoint, exclusions such as those used in our study help reduce the effects of confounding factors like protective stomas.\u003c/p\u003e \u003cp\u003eFurthermore, a small propensity score\u0026ndash;matched study by Lei et al. found that use of POA plus MBP was beneficial for patients undergoing left-sided colon or rectal resection but not right-sided colon resection [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. It should be noted that the overall rates of anastomosis leakage (4.6%) and SSIs (12.2%) observed in our rectal surgery cohort were considerably lower than those reported in similar studies, suggesting that preoperative bowel preparation (MBP with or without POA) is beneficial for patients undergoing rectal cancer surgery. Although there was higher rate of anastomosis leakage when POA was combined with MBP in our rectal cancer cohort, overall rate of anastomosis leakage was lower than commonly reported average rate of 10 percent [\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. As anastomosis methods, preoperative treatment regimes, and other factors are intertwined in causing anastomosis leakage in rectal cancer, whether this difference observed in our study is truly due to bowel preparation method warrants further study.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003eOne concern about using POA relates to the possibility of an increased risk of \u003cem\u003eClostridioides difficile\u003c/em\u003e infection. This concern also formed the basis for current guidelines recommending against the routine use of postoperative prophylactic antibiotics after colorectal surgery. No cases of \u003cem\u003eC. difficile\u003c/em\u003e infection were observed in our study population. A study by Kim et al. reported that using POA with MBP was associated with a lower risk of \u003cem\u003eC. difficile\u003c/em\u003e colitis, compared with not using any form of bowel preparation [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. An increased risk of \u003cem\u003eC. difficile\u003c/em\u003e colitis may be more associated with empiric use of prophylactic antibiotics postoperatively, a frequent practice before the development of recent guidelines. Other studies have also shown that POA use is not a risk for \u003cem\u003eC. difficile\u003c/em\u003e infection [\u003cspan additionalcitationids=\"CR20\" citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOur study has some limitations. Although it included a moderate number of patients, it was still a retrospective study. Some potentially important variables, such as the incision site for specimen extraction, the anastomosis method for right-sided colon cancer (intracorporeal vs. extracorporeal), and the method of wound irrigation, were not controlled. For patients with rectal cancer, comparisons could not be adjusted for common risk factors associated with anastomosis leakage. Additionally, the differential effects of POA plus MBP in preventing SSIs observed between colon and rectal cancer surgery were not consistent with the results of previous studies. These discrepancies may be related to the failure to include some patients with left-sided colon cancer in the rectal cancer population because of the nature of data collection in our study.\u003cdiv class=\"BlockQuote\"\u003e\u003cp\u003eOur findings align with recent evidence from multiple randomized clinical trials and meta-analyses that POA combined with MBP can improve postoperative outcomes, including reducing the likelihood of SSIs, when used prior to colorectal surgery. However, clinical usage of POA plus MBP is lower than expected based on the available evidence. A survey conducted in the United Kingdom among members of the Association of Coloproctology of Great Britain and Ireland reported that approximately 5.5\u0026ndash;18.6% of surgeons chose to use POA plus MBP, while more than 53% thought that the combination could reduce the incidence of SSIs. Thus, although evidence (including that reported in the present study) supports the use of POA plus MBP, surgeons appear to be hesitant to abandon their practice of using MBP alone, a regimen that has been used for decades. Further studies exploring the effects of POA in very specific patient groups are necessary to definitively determine the optimal preoperative bowel preparation for each type of surgical cohort and promote widespread acceptance of the most appropriate regimens.\u003c/p\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn patients undergoing colon cancer surgery, the combination of POA plus MBP was effective in reducing the risk of SSIs, compared with MBP alone. However, this beneficial effect was not observed in patients undergoing rectal cancer surgery. Further studies are required to determine the most appropriate bowel preparation regimens for specific surgical sites.\u003c/p\u003e "},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eAll authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eEthics approval\u003c/strong\u003e \u003cp\u003e This study was performed in accordance with the principles of the Declaration of Helsinki. The protocol was approved by the Ethics Committee of Yonsei University School of Medicine (IRB No. 4-2024-0834).\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThe authors did not receive support from any organization for the submitted work and there was no funding received to assist with the preparation of this manuscript.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eConceptualization: EJP, SYYData Curation: EJP, SYYFormal analysis: EJP, SYYInvestigation: EJP, SYYMethodology, MYP, YDH, MSC, HH, KYLProject administration: EJP, SYYVisualization: EJPWriting original draft: EJPWriting review and editing: EJP, SYYAll authors have read and approved the final manuscript\u003c/p\u003e\u003ch2\u003eAcknowledgments\u003c/h2\u003e \u003cp\u003eNone\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMigaly J et al (2019) The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Use of Bowel Preparation in Elective Colon and Rectal Surgery. Dis Colon Rectum 62(1):3\u0026ndash;8\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVo E et al (2018) Association of the Addition of Oral Antibiotics to Mechanical Bowel Preparation for Left Colon and Rectal Cancer Resections With Reduction of Surgical Site Infections. JAMA Surg 153(2):114\u0026ndash;121\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNelson RL, Gladman E, Barbateskovic M (2014) Antimicrobial prophylaxis for colorectal surgery. Cochrane Database Syst Rev, 2014(5): p. Cd001181.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePetrou NA, Kontovounisios C (2022) The Use of Mechanical Bowel Preparation and Oral Antibiotic Prophylaxis in Elective Colorectal Surgery: A Call for Change in Practice. Cancers (Basel), 14(23)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKonishi T et al (2006) Elective colon and rectal surgery differ in risk factors for wound infection: results of prospective surveillance. Ann Surg 244(5):758\u0026ndash;763\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGoto S et al (2016) Differences in surgical site infection between laparoscopic colon and rectal surgeries: sub-analysis of a multicenter randomized controlled trial (Japan-Multinational Trial Organization PREV 07\u0026thinsp;\u0026ndash;\u0026thinsp;01). Int J Colorectal Dis 31(11):1775\u0026ndash;1784\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFry DE (2011) Colon preparation and surgical site infection. Am J Surg 202(2):225\u0026ndash;232\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRollins KE et al (2019) The Role of Oral Antibiotic Preparation in Elective Colorectal Surgery: A Meta-analysis. Ann Surg 270(1):43\u0026ndash;58\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eToh JWT et al (2018) Association of Mechanical Bowel Preparation and Oral Antibiotics Before Elective Colorectal Surgery With Surgical Site Infection: A Network Meta-analysis. JAMA Netw Open 1(6):e183226\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGomila A et al (2017) Risk factors and outcomes of organ-space surgical site infections after elective colon and rectal surgery. Antimicrob Resist Infect Control 6(1):40\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJung SW, Young Ki HSL, Hong J, Hong H (2023) A study on the effects of combined oral antibiotic administration during mechanical bowel preparation before colorectal cancer surgery on postoperative complications and prognosis. National Health Insurance Service, Ilsan Hospital, National Health Insurance Service\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSuzuki T et al (2020) Usefulness of Preoperative Mechanical Bowel Preparation in Patients with Colon Cancer who Undergo Elective Surgery: A Prospective Randomized Trial Using Oral Antibiotics. Dig Surg 37(3):192\u0026ndash;198\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKoskenvuo L et al (2024) Morbidity After Mechanical Bowel Preparation and Oral Antibiotics Prior to Rectal Resection: The MOBILE2 Randomized Clinical Trial. JAMA Surg 159(6):606\u0026ndash;614\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLei P et al (2020) Preoperative mechanical bowel preparation with oral antibiotics reduces surgical site infection after elective colorectal surgery for malignancies: results of a propensity matching analysis. 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Dis Colon Rectum 63(4):545\u0026ndash;561\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKrapohl GL et al (2011) Bowel preparation for colectomy and risk of Clostridium difficile infection. Dis Colon Rectum 54(7):810\u0026ndash;817\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Surgical procedures, minimally invasive, Colorectal cancer, Enhanced recovery after surgery, Preoperative period","lastPublishedDoi":"10.21203/rs.3.rs-5823484/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5823484/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003eColorectal surgeries are associated with high rates of surgical site infection (SSI), which significantly impact postoperative recovery and outcomes. Use of preventive measures, such as mechanical bowel preparation (MBP) and preoperative oral antibiotics (POA), is widely debated. This study investigated the effectiveness of POA plus MBP before elective minimally invasive colorectal cancer surgery.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis study retrospectively analyzed 1,506 patients who underwent elective minimally invasive colorectal cancer surgery between January 2020 and December 2023 to evaluate the effectiveness of MBP plus POA in preventing SSIs and other postoperative complications. Patients were divided into MBP alone (n\u0026thinsp;=\u0026thinsp;811) and POA\u0026thinsp;+\u0026thinsp;MBP (n\u0026thinsp;=\u0026thinsp;695) groups.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eOverall SSI rates were significantly lower in the POA\u0026thinsp;+\u0026thinsp;MBP group than in the MBP alone group (11.6% vs. 5.5%, p\u0026thinsp;=\u0026thinsp;0.008), with significant reductions in grade 1\u0026ndash;2 SSIs. POA\u0026thinsp;+\u0026thinsp;MBP was particularly effective in patients undergoing colon cancer surgery. In this subgroup, POA\u0026thinsp;+\u0026thinsp;MBP was associated with a 5.6% lower rate of SSIs than MBP alone, with no difference in anastomosis leakage rates between regimens. In patients undergoing rectal cancer surgery, POA\u0026thinsp;+\u0026thinsp;MBP was associated with a significantly higher anastomosis leakage rate (6.9% vs. 2.2%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.016), with no difference in SSI rates between regimens. Multivariable analysis confirmed that MBP alone was a risk factor for SSIs (odds ratio, 1.5; 95% confidence interval, 1.13\u0026ndash;2.18; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.007).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThis study highlights the differential effects of POA\u0026thinsp;+\u0026thinsp;MBP in minimally invasive surgery for colon versus rectal cancer and underscores the need for further investigations to determine the optimal bowel preparation regimen for specific surgical sites.\u003c/p\u003e","manuscriptTitle":"Oral antibiotics combined with mechanical bowel preparation reduces the risk of surgical site infections in minimally invasive colorectal cancer surgery","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-20 10:07:54","doi":"10.21203/rs.3.rs-5823484/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"383da931-a601-494f-b24e-868b9facc11a","owner":[],"postedDate":"January 20th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-02-12T22:08:31+00:00","versionOfRecord":[],"versionCreatedAt":"2025-01-20 10:07:54","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5823484","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5823484","identity":"rs-5823484","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}