Bridging to Surgery Versus Palliation in Malignant Colorectal Obstruction: Complication Risks and Mediation by Clinical Success

Bridging to Surgery Versus Palliation in Malignant Colorectal Obstruction: Complication Risks and Mediation by Clinical Success | 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 Bridging to Surgery Versus Palliation in Malignant Colorectal Obstruction: Complication Risks and Mediation by Clinical Success Yuan Wan, Ke-tong Wu, Dan Li, Yang Liu, Hai-yang Lai, Tao Peng, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7750665/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 Background Self-expandable metal stents (SEMS) are routinely used in malignant colorectal obstruction (MCO) for palliation or as a bridge to surgery. However, whether treatment intent influences complication risk, and if clinical success mediates this relationship, remains unclear. Methods We retrospectively analyzed 413 patients with MCO who underwent SEMS placement between 2014 and 2024. Patients were categorized by therapeutic intent (palliation vs. bridge to surgery), and complication rates were compared. Mediation analysis was performed using the Sobel test, structural equation modeling (SEM), and bootstrap-based causal mediation to assess whether clinical success mediated the relationship between therapeutic purpose and complications. Results Complications occurred in 60 patients (14.5%). Palliation was associated with a higher complication rate compared to bridging (20.0% vs. 8.0%, p = 0.001). Clinical success significantly mediated the effect of therapeutic purpose on complications (Sobel p = 0.035). SEM confirmed a positive association between therapeutic purpose and clinical success (standardized β = 0.171, p < 0.001) and a negative association between clinical success and complications (β = –0.191, p = 0.009). Bootstrap mediation analysis revealed that 13.0% of the total effect was mediated through clinical success (p = 0.031). Conclusions Therapeutic intent affects SEMS complication risk, mediated by clinical success. Optimizing outcomes—especially in palliation—enhances safety and guides personalized management Malignant colorectal obstruction Self-expanding metallic stent Complication Mediation analysis Figures Figure 1 Figure 2 Figure 3 Highlights Longer Therapeutic purpose (palliation vs. bridge to surgery) significantly influences complication risk after SEMS placement for malignant colorectal obstruction. Clinical success partially mediates the relationship between therapeutic intent and complications, accounting for 13% of the total effect. Optimizing clinical success may reduce complications, particularly in palliative settings, and should be a key target in SEMS-related decision-making. Clinical Relevance Statement In patients with malignant colorectal obstruction, the choice between palliative stenting and bridging to surgery significantly affects complication risk. This study demonstrates that clinical success mediates part of this relationship, highlighting the importance of achieving effective decompression. These findings emphasize the need for strategic patient selection and procedural optimization to improve safety outcomes, particularly in palliative settings where risks remain high. Integrating mediation analysis into clinical research may further refine decision-making in colorectal cancer care. Introduction Malignant colorectal obstruction (MCO) is a common and life-threatening complication of advanced colorectal cancer, occurring in up to 20% of patients at initial diagnosis and often requiring urgent management to restore intestinal patency and prevent perforation or ischemia [1,2]. Self-expandable metal stents (SEMS) have become an established modality for decompression in MCO, providing rapid symptom relief and serving either as a definitive palliative treatment or as a bridge to curative-intent surgery [3,4]. The optimal therapeutic intent—palliation versus bridging to surgery—remains controversial, as outcomes vary depending on tumor stage, patient condition, and institutional protocols. Bridging to surgery may offer oncologic benefits by allowing for preoperative optimization and elective resection but carries risks of delayed complications or tumor dissemination [5,6]. Conversely, palliative SEMS placement avoids the morbidity of surgery but may be associated with higher rates of long-term complications such as re-obstruction, stent migration, and perforation [7,8]. Clinical success, typically defined as the resolution of obstructive symptoms without procedure-related adverse events, is a critical determinant of SEMS outcomes. However, the role of clinical success as a mediating factor between therapeutic intent and downstream complications has not been clearly elucidated. Emerging evidence suggests that procedural efficacy may partially account for the differing complication profiles observed between treatment strategies [9,10]. In this study, we aimed to evaluate the impact of therapeutic purpose—palliative versus bridge to surgery—on the risk of complications following SEMS placement for MCO, and to explore whether this effect is mediated by clinical success. We employed a comprehensive analytic approach combining causal mediation analysis, structural equation modeling, and logistic regression to better understand the interplay between treatment strategy, procedural success, and clinical outcomes. These findings may inform individualized decision-making and optimize therapeutic pathways for patients with malignant colorectal obstruction. Methods Patients and study design This retrospective observational study was conducted at The Sixth Affiliated Hospital of Sun Yat-sen University and enrolled consecutive patients with primary or secondary MCO who underwent SEMS placement between 2014 and 2024. As illustrated in Figure 1, a total of 505 patients were initially identified. After applying predefined exclusion criteria—21 patients lost to follow-up, 18 patients with technical failure during stent placement, and 53 patients with incomplete clinical or procedural data—a final cohort of 413 patients was included for analysis. Eligible patients met the following inclusion criteria: (1) age ≥18 years; (2) a diagnosis of malignant colorectal obstruction confirmed by imaging studies and/or endoscopic evaluation; and (3) SEMS placement performed at our institution within the study period. Patients were excluded if they (1) were lost to follow-up, (2) experienced technical failure during SEMS deployment, or (3) lacked essential clinical or outcome data required for analysis. All data were extracted from institutional electronic medical records and cross-verified by two independent researchers to ensure accuracy and completeness. The study protocol was approved by the Institutional Review Board of The Sixth Affiliated Hospital, Sun Yat-sen University. Given the retrospective design, the requirement for written informed consent was waived. All patient data were de-identified and handled in accordance with the Declaration of Helsinki and institutional data protection policies. SEMS placement All patients underwent SEMS placement using either an Enteral Wallstent (Boston Scientific, Natick, MA, USA) or an Evolution Colonic Stent (Cook Medical, Limerick, Ireland), with available stent lengths of 8, 10, or 12 cm. The selection of stent type and length was individualized based on procedural findings, taking into account the location, length, and severity of the malignant stricture as visualized under fluoroscopy. After sterile preparation and draping of the perineal area, liquid paraffin oil was applied to the anal verge to minimize discomfort during catheter insertion. A hydrophilic guidewire, followed by a 5-French diagnostic catheter and an 8-French guiding catheter, was introduced transanally. Contrast medium was injected through the catheter to perform colonography, which delineated the anatomy of the colon and precisely localized the site and length of the obstruction. Once the stricture was identified, the guidewire was advanced across the lesion under fluoroscopic guidance. In patients with a tortuous or redundant colon that limited catheter advancement, a 12-French, 90-cm Flexor® Check-Flo® Introducer sheath (Cook Medical, USA) was employed to straighten the colon and facilitate access. Following successful cannulation, the selected SEMS was carefully deployed across the stricture under real-time fluoroscopic control. Post-deployment, stent expansion and positioning were reassessed using contrast imaging. In cases of suboptimal expansion, a balloon catheter was utilized to achieve adequate luminal patency. Once satisfactory deployment was confirmed, all instruments were withdrawn. Patients were classified according to therapeutic intent into two groups: those receiving SEMS as a bridge to surgery (BTS), and those undergoing palliative stenting (PAL). Technical success was defined as accurate placement of the stent across the obstruction without immediate procedural complications, while clinical success was defined as resolution of obstructive symptoms and restoration of bowel function within 72 hours after the procedure [11]. Post-procedure outcomes were further categorized based on complication status: complication absent and complication present. Complications included stent migration, re-obstruction, or perforation, as recorded during the index hospitalization or subsequent follow-up. Statistical analysis All statistical analyses were performed using R software (Version 4.3.2; R Foundation for Statistical Computing, Vienna, Austria). Categorical variables were summarized as counts and percentages and compared using the Chi-square or Fisher’s exact test, as appropriate. Continuous variables were expressed as medians with interquartile ranges (IQRs) and compared using the Wilcoxon rank-sum test. A two-sided p value < 0.05 was considered statistically significant. To assess the mediating role of clinical success in the association between therapeutic purpose and complications, a multi-step analytic framework was applied. First, the Sobel test and its variants (Aroian and Goodman) were performed using the bda R package [12]. Second, structural equation modeling was conducted using the piecewiseSEM R package. Two logistic regression models were specified: one for clinical success as a function of therapeutic purpose, and the other for complication risk as a function of both therapeutic purpose and clinical success. Third, causal mediation analysis using nonparametric bootstrap resampling (1,000 simulations) was performed with the mediation R package to estimate the average causal mediation effect (ACME), average direct effect (ADE), total effect, and the proportion mediated, with percentile-based 95% confidence intervals. Clinical success was modeled as a continuous mediator, and complications were assessed via linear regression to allow additive effect decomposition. Model assumptions, including multicollinearity, fit, and residual behavior, were evaluated using diagnostic tools from the easystats R package. Results Patient characteristics A total of 413 patients with malignant colorectal obstruction who underwent SEMS placement were included in the final analysis. The baseline clinical characteristics of the study population, stratified by the presence or absence of complications, are summarized in Table 1. The median age of the cohort was 63 years (IQR: 51–72), with no significant difference between patients with and without complications ( p = 0.232). The majority of patients were male (69.5%), and while complications were numerically more common among female patients (41.7% vs. 28.6%), this difference did not reach statistical significance ( p = 0.060). Other baseline anthropometric measures, including height and weight, were similar between groups. Tumor markers showed a trend toward higher values in the complication group. Notably, CA19-9 levels were significantly elevated in patients with complications compared to those without (median: 44.25 vs. 17.07 U/mL, p = 0.027), whereas the difference in CEA levels was not statistically significant ( p = 0.099). Therapeutic intent differed significantly between groups. Among patients who experienced complications, 75.0% underwent SEMS for palliative purposes, compared to 51.0% in the non-complication group ( p = 0.001). Conversely, BTS was more commonly employed in patients without complications (49.0% vs. 25.0%). Regarding tumor staging, a greater proportion of patients in the complication group had stage IV disease (73.3% vs. 55.8%, p = 0.009). No significant differences were observed in the length or duration of obstruction, nor in the degree of luminal obstruction. Importantly, clinical success was achieved in 93.9% of the overall cohort but was significantly less frequent among patients with complications (85.0% vs. 95.5%, p = 0.005), highlighting its potential role in influencing post-procedural outcomes. Complication risk and mediation analysis To explore whether clinical success mediates the association between therapeutic purpose and post-stenting complications, multiple mediation approaches were applied. As shown in Table S1, the Sobel test and its Aroian and Goodman variants consistently indicated a significant indirect effect of therapeutic purpose on complication risk through clinical success ( p = 0.035, 0.039, and 0.030, respectively). Structural equation modeling further supported these findings. As illustrated in Figure 2A and summarized in Table 2, therapeutic purpose was significantly associated with increased likelihood of clinical success (β = 0.082, standardized estimate = 0.171, p < 0.001). In turn, clinical success was inversely associated with the occurrence of complications (β = –0.191, standardized estimate = –0.129, p = 0.009). Additionally, a direct negative effect of therapeutic purpose on complications remained significant (β = –0.105, standardized estimate = –0.148, p = 0.003), suggesting partial mediation. To quantify the mediation effect, a nonparametric bootstrap-based causal mediation analysis was conducted. As presented in Table 3 and visualized in Figure 2B, the ACME was –0.016 (95% CI: –0.038 to –0.001, p = 0.031), while the ADE was –0.105 (95% CI: –0.172 to –0.041, p = 0.004). The total effect of therapeutic purpose on complications was –0.120 ( p < 0.001), with 13.0% of the effect mediated through clinical success ( p = 0.031). Logistic regression and model evaluation To further evaluate the association between therapeutic purpose, clinical success, and complication risk, a multivariable logistic regression model was fitted with complication occurrence as the dependent variable and both therapeutic purpose and clinical success as independent variables. As shown in Figure S1, both predictors demonstrated meaningful contributions to the model, with clinical success exhibiting a negative association and therapeutic purpose (palliative intent) contributing positively to the likelihood of complications. Model performance and robustness were assessed through a series of diagnostic evaluations, summarized in Figure 3. Figure 3A presents the posterior predictive check, indicating that predicted intervals closely aligned with observed data, suggesting overall model adequacy. Figure 3B shows binned residual plots across predicted probabilities, with residuals generally falling within expected bounds, supporting model calibration. Figure 3C identifies a small number of influential observations based on leverage and sigma statistics, but no clear outliers exerting undue influence on the model were detected. Figure 3D confirms the absence of multicollinearity, with all variance inflation factors (VIFs) below critical thresholds when plotted on a log scale. Figure 3E, a Q–Q plot of model residuals, demonstrated a distribution approximating uniformity, supporting the validity of model assumptions. Discussion In this retrospective cohort study of patients with MCO treated with SEMS placement, we found that therapeutic purpose—whether palliative or as a bridge to surgery—was significantly associated with the risk of complications. Notably, clinical success emerged as a partial mediator of this relationship, suggesting that achieving effective decompression may mitigate adverse outcomes even in higher-risk therapeutic contexts [13,14]. Our findings are consistent with prior studies demonstrating differential outcomes based on treatment intent. SEMS placement as a bridge to surgery has been associated with lower complication rates and improved long-term outcomes compared to palliative stenting [15,16]. However, direct comparisons have often been confounded by differences in baseline tumor burden and patient fitness[6,10]. By incorporating a causal mediation framework, our study disentangles these effects and quantitatively demonstrates that clinical success accounts for approximately 13% of the total effect of therapeutic purpose on complication risk—supporting its mechanistic relevance. The observed protective effect of clinical success is biologically plausible. Prompt relief of luminal obstruction reduces mucosal ischemia, bacterial overgrowth, and the risk of perforation, which are key contributors to post-stenting complications [17–19]. Moreover, successful stent expansion improves patient nutritional status and allows for elective surgical planning in the bridge-to-surgery setting, potentially enhancing perioperative safety [20,21]. Our results also provide practical implications for clinical decision-making. The significantly higher complication rate observed in the palliative group underscores the need for cautious patient selection and optimization of procedural technique. Early identification and management of suboptimal stent deployment, including adjunctive balloon dilation, may further improve clinical success rates and reduce downstream adverse events [22]. Several limitations should be acknowledged. First, the retrospective design and single-center setting may introduce selection bias and limit the generalizability of our findings to broader patient populations or other clinical settings with varying protocols or expertise. Second, although we adjusted for key clinical variables, potential unmeasured confounders—such as operator experience, tumor histopathological subtype, comorbidities, or variations in peri-procedural care—could have influenced the observed associations. Third, while our mediation analyses demonstrated a statistically significant indirect effect of therapeutic intent via clinical success, the proportion mediated was modest, suggesting the presence of other unaccounted factors, such as tumor biology, immune status, or timing of intervention, that may contribute to complication risk. Additionally, we did not assess long-term oncologic outcomes, such as survival or tumor recurrence, which are critical when evaluating the broader implications of SEMS as a bridge to surgery versus palliative therapy. Furthermore, clinical success was operationalized as short-term symptom relief, which, although practical, may not fully capture functional recovery or quality-of-life impacts. The bootstrap and SEM-based mediation models, while robust, rely on assumptions of no unmeasured confounding and correct model specification, which warrant careful interpretation. Conclusions In patients with malignant colorectal obstruction undergoing SEMS placement, therapeutic intent was significantly associated with complication risk, partially mediated by clinical success. Achieving successful decompression markedly reduced adverse outcomes, regardless of treatment strategy. These findings underscore the importance of optimizing procedural success to improve patient safety, particularly in palliative settings. Abbreviations MCO: Malignant colorectal obstruction SEMS: Self-expanding metal stents BTS: Bridge to surgery PAL: Palliative treatment IQRs: Interquartile ranges ACME: Average causal mediation effect ADE: Average direct effect VIFs: Variance inflation factors Declarations Data Availability Statement The relevant data that support the findings of this study are available from the corresponding author upon reasonable request. Acknowledgment Supported by the program of Guangdong Provincial Clinical Research Center for Digestive Diseases (2020B1111170004). Funding This study was funded by the Medical Joint Fund of Jinan University (YXZY2024020) and the Scientific and Technological Project of Foshan City (2420001004035). Contributions Yuan Wan: Conceptualization; Methodology; Writing - original draft. Ke-tong Wu: Data curation; Resources; Visualization; Software. Dan Li: Validation; Investigation; Methodology; Formal analysis. Yang Liu, Hai-yang Lai and Tao Peng: Visualization; Validation. Huan-hua Wu: Writing - review & editing; Investigation; Funding acquisition; Project administration; Resources. Bo Zhang: Writing - review & editing; Investigation; Funding acquisition; Supervision; Project administration; Resources. All authors contributed to final approval of the paper. Guarantor The scientific guarantor of this publication is Dr. Bo Zhang from The Sixth Affiliated Hospital, Sun Yat-sen University. Conflict of interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Statistics and biometry One of the authors has significant statistical expertise. No complex statistical methods were necessary for this paper. Informed consent Written informed consent was waived by the Institutional Review Board. Ethical approval Institutional Review Board approval was obtained. The study was approved by the Ethics Committee of The Sixth Affiliated Hospital, Sun Yat-sen University, Approval Reference Number [2024ZSLYEC-149]. This study is a retrospective analysis, and requirement for patient informed consent was waived. All methods were carried out in accordance with guidelines and regulations related to the Declaration of Helsinki. Study subjects or cohorts overlap The study cohort has not been previously reported. Consent for publication Not applicable. References Griffiths S, Glancy DG. Intestinal obstruction. Intest Surg. 2023;41:47–54. Veld JV, Beek KJ, Consten ECJ, ter Borg F, van Westreenen HL, Bemelman WA, et al. Definition of large bowel obstruction by primary colorectal cancer: A systematic review. Colorectal Dis. 2021;23:787–804. Lee HH, Kim DH, Lim H, Kim J-W, Jung Y, Kim H-S, et al. 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Dig Endosc. 2022;34:43–62. Schmoyer CJ, Saidman J, Bohl JL, Bierly CL, Kuemmerle JF, Bickston SJ. The pathogenesis and clinical management of stricturing crohn disease. Inflamm Bowel Dis. 2021;27:1839–52. McKechnie T, Springer JE, Cloutier Z, Archer V, Alavi K, Doumouras A, et al. Management of left-sided malignant colorectal obstructions with curative intent: a network meta-analysis. Surg Endosc. 2023;37:4159–78. Chen E, Chen L, Zhang W, Zhou W. Self-expanding metal stent as a bridge to elective surgery versus immediate emergency surgery in left-sided obstructive colorectal cancer: a retrospective comparative study. Updates Surg. 2025;77:783–90. Tyberg A, Binmoeller K, Kowalski T. Lumen-apposing metal stents in 2024: troubleshooting and managing common and uncommon adverse events. Gastrointest Endosc. 2025;101:315–30. Tables Table 1. Clinical characteristics of 413 SEMS patients included. Variable a Patients (N =413) Complication Absent ( N =353) Complication Present (N =60) p value b Gender, n (%) 0.060 Male 287 (69.49%) 252 (71.39%) 35 (58.33%) Female 126 (30.51%) 101 (28.61%) 25 (41.67%) Age, year, (Median [IQR]) 63.00 [51.00;72.00] 63.00 [51.00;73.00] 61.00 [49.75;68.00] 0.232 Height, cm , (Median [IQR]) 1.65 [1.59;1.70] 1.65 [1.60;1.70] 1.62 [1.57;1.70] 0.231 Weight, kg , (Median [IQR]) 58.00 [50.00;65.00] 57.50 [50.00;65.00] 59.25 [47.75;68.25] 0.371 CEA , ng/ml, (Median [IQR]) 9.30 [3.41;43.72] 9.23 [3.36;36.73] 10.43 [4.82;72.74] 0.099 CA19.9 , U/ml, (Median [IQR]) 19.45 [4.92;165.38] 17.07 [4.72;128.18] 44.25 [6.91;799.58] 0.027 Therapeutic purpose , n (%) 0.001 Palliative treatment 225 (54.48%) 180 (50.99%) 45 (75.00%) Bridge to surgery 188 (45.52%) 173 (49.01%) 15 (25.00%) Tumor staging , n (%) 0.009 Ⅱ 87 (21.07%) 75 (21.25%) 12 (20.00%) Ⅲ 85 (20.58%) 81 (22.95%) 4 (6.67%) IV 241 (58.35%) 197 (55.81%) 44 (73.33%) Length of obstruction, cm , (Median [IQR]) 5.00 [3.80;6.00] 5.00 [3.90;6.00] 5.25 [3.40;6.00] 0.837 Duration of obstruction, days , (Median [IQR]) 9.00 [5.00;14.00] 9.00 [5.00;14.00] 9.00 [5.00;15.00] 0.813 Degree of obstruction , n (%) 0.788 Complete 244 (59.08%) 210 (59.49%) 34 (56.67%) Incomplete 169 (40.92%) 143 (40.51%) 26 (43.33%) Clinical success , n (%) 0.005 No 25 (6.05%) 16 (4.53%) 9 (15.00%) Yes 388 (93.95%) 337 (95.47%) 51 (85.00%) a Continuous variables were presented as median (IQR) and categorical variables as Number (%). b p values were calculated using the Wilcoxon Signed Rank test for continuous variables and the c 2 test or Fisher exact for categorical variables. SD = standard deviation, IQR = interquartile range. Table 2. Results of structural equation model. Response Predictor Estimate Std.Error Std.Estimate p value Clinical success Therapeutic purpose 0.082 0.023 0.171 < 0.001 Complication Clinical success -0.191 0.072 -0.129 0.009 Complication Therapeutic purpose -0.105 0.035 -0.148 0.003 Table 3. Results of causal mediation analysis: nonparametric bootstrap confidence intervals with the percentile method. Estimate 95% CI Lower 95% CI Upper p value ACME -0.016 -0.038 -0.001 0.031 ADE -0.105 -0.172 -0.041 0.004 Total Effect -0.120 -0.185 -0.058 < 0.001 Prop. Mediated 0.130 0.004 0.357 0.031 ACME = average causal mediation effects, ADE = average direct effect. Additional Declarations No competing interests reported. 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09:35:33","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":29370,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure2.png","url":"https://assets-eu.researchsquare.com/files/rs-7750665/v1/cfbeda21a01a9384e81e87a6.png"},{"id":95221012,"identity":"b5d5fb83-e0a0-4b02-872c-5fe0db186d37","added_by":"auto","created_at":"2025-11-05 16:17:50","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":143791,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure3.png","url":"https://assets-eu.researchsquare.com/files/rs-7750665/v1/b8bf844a0b938a10a0233c14.png"},{"id":95220941,"identity":"2cadc961-6798-450f-8429-066bb8c3c6d7","added_by":"auto","created_at":"2025-11-05 16:17:14","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":59359,"visible":true,"origin":"","legend":"\u003cp\u003eFlow diagram illustrating patient selection.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-7750665/v1/2e518bd33602fe9759fadb33.png"},{"id":95005673,"identity":"a1f0d300-2fbb-4aa4-8fa6-ca277c4aa1bb","added_by":"auto","created_at":"2025-11-03 09:35:33","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":120073,"visible":true,"origin":"","legend":"\u003cp\u003eMediation analysis illustrating the effect of therapeutic purpose on complications via clinical success. (A) Path diagram generated from structural equation modeling, with path coefficients displayed along the arrows. (B) Results of nonparametric bootstrap-based causal mediation analysis.\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-7750665/v1/0dfc669a16668fa63d0c22fb.png"},{"id":95220829,"identity":"466b31ce-7d55-4743-b5ff-26902b3662c7","added_by":"auto","created_at":"2025-11-05 16:15:08","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1369131,"visible":true,"origin":"","legend":"\u003cp\u003eVisual summary of the logistic regression model evaluating predictors of complication occurrence. (A). Posterior Predictive Check: Displays model-predicted intervals against observed data points. (B). Binned Residuals: Shows residuals grouped by predicted values. Points within error bounds suggest adequate model calibration. (C). Influential Observations: Identifies influential data points using leverage and sigma values. (D). Collinearity: Assesses multicollinearity via Variable Inflation Factors (VIF) on a log scale. (E). Uniformity of Residuals (Q-Q Plot): Compares sample quantiles of residuals to a standard uniform distribution.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-7750665/v1/bd054b742015aeb9ce104507.png"},{"id":101752693,"identity":"3709cbb9-d703-47ef-86cc-bb86ceb5d323","added_by":"auto","created_at":"2026-02-03 10:28:57","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2369264,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7750665/v1/7e1535e3-481c-4468-847a-cd4dc582ef1f.pdf"},{"id":95005678,"identity":"805d219f-7133-44a5-95a0-22397ea91be3","added_by":"auto","created_at":"2025-11-03 09:35:33","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":137400,"visible":true,"origin":"","legend":"","description":"","filename":"Supplements.docx","url":"https://assets-eu.researchsquare.com/files/rs-7750665/v1/1601c3bc0ca99c0b8105cedd.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Bridging to Surgery Versus Palliation in Malignant Colorectal Obstruction: Complication Risks and Mediation by Clinical Success","fulltext":[{"header":"Highlights","content":"\u003cul\u003e\n \u003cli\u003eLonger Therapeutic purpose (palliation vs. bridge to surgery) significantly influences complication risk after SEMS placement for malignant colorectal obstruction.\u003c/li\u003e\n \u003cli\u003eClinical success partially mediates the relationship between therapeutic intent and complications, accounting for 13% of the total effect.\u003c/li\u003e\n \u003cli\u003eOptimizing clinical success may reduce complications, particularly in palliative settings, and should be a key target in SEMS-related decision-making.\u003c/li\u003e\n \u003cli\u003e\u003cbr\u003e\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Clinical Relevance Statement","content":"\u003cp\u003eIn patients with malignant colorectal obstruction, the choice between palliative stenting and bridging to surgery significantly affects complication risk. This study demonstrates that clinical success mediates part of this relationship, highlighting the importance of achieving effective decompression. These findings emphasize the need for strategic patient selection and procedural optimization to improve safety outcomes, particularly in palliative settings where risks remain high. Integrating mediation analysis into clinical research may further refine decision-making in colorectal cancer care.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Introduction","content":"\u003cp\u003eMalignant colorectal obstruction (MCO) is a common and life-threatening complication of advanced colorectal cancer, occurring in up to 20% of patients at initial diagnosis and often requiring urgent management to restore intestinal patency and prevent perforation or ischemia [1,2]. Self-expandable metal stents (SEMS) have become an established modality for decompression in MCO, providing rapid symptom relief and serving either as a definitive palliative treatment or as a bridge to curative-intent surgery [3,4].\u003c/p\u003e\n\u003cp\u003eThe optimal therapeutic intent—palliation versus bridging to surgery—remains controversial, as outcomes vary depending on tumor stage, patient condition, and institutional protocols. Bridging to surgery may offer oncologic benefits by allowing for preoperative optimization and elective resection but carries risks of delayed complications or tumor dissemination [5,6]. Conversely, palliative SEMS placement avoids the morbidity of surgery but may be associated with higher rates of long-term complications such as re-obstruction, stent migration, and perforation [7,8].\u003c/p\u003e\n\u003cp\u003eClinical success, typically defined as the resolution of obstructive symptoms without procedure-related adverse events, is a critical determinant of SEMS outcomes. However, the role of clinical success as a mediating factor between therapeutic intent and downstream complications has not been clearly elucidated. Emerging evidence suggests that procedural efficacy may partially account for the differing complication profiles observed between treatment strategies [9,10].\u003c/p\u003e\n\u003cp\u003eIn this study, we aimed to evaluate the impact of therapeutic purpose—palliative versus bridge to surgery—on the risk of complications following SEMS placement for MCO, and to explore whether this effect is mediated by clinical success. We employed a comprehensive analytic approach combining causal mediation analysis, structural equation modeling, and logistic regression to better understand the interplay between treatment strategy, procedural success, and clinical outcomes. These findings may inform individualized decision-making and optimize therapeutic pathways for patients with malignant colorectal obstruction.\u003c/p\u003e"},{"header":"Methods","content":"\u003ch2\u003ePatients and study design\u003c/h2\u003e\n\u003cp\u003eThis retrospective observational study was conducted at The Sixth Affiliated Hospital of Sun Yat-sen University and enrolled consecutive patients with primary or secondary MCO who underwent SEMS placement between 2014 and 2024. As illustrated in Figure 1, a total of 505 patients were initially identified. After applying predefined exclusion criteria—21 patients lost to follow-up, 18 patients with technical failure during stent placement, and 53 patients with incomplete clinical or procedural data—a final cohort of 413 patients was included for analysis.\u003c/p\u003e\n\u003cp\u003eEligible patients met the following inclusion criteria: (1) age ≥18 years; (2) a diagnosis of malignant colorectal obstruction confirmed by imaging studies and/or endoscopic evaluation; and (3) SEMS placement performed at our institution within the study period. Patients were excluded if they (1) were lost to follow-up, (2) experienced technical failure during SEMS deployment, or (3) lacked essential clinical or outcome data required for analysis.\u003c/p\u003e\n\u003cp\u003eAll data were extracted from institutional electronic medical records and cross-verified by two independent researchers to ensure accuracy and completeness. The study protocol was approved by the Institutional Review Board of The Sixth Affiliated Hospital, Sun Yat-sen University. Given the retrospective design, the requirement for written informed consent was waived. All patient data were de-identified and handled in accordance with the Declaration of Helsinki and institutional data protection policies.\u003c/p\u003e\n\u003ch2\u003eSEMS placement\u003c/h2\u003e\n\u003cp\u003eAll patients underwent SEMS placement using either an Enteral Wallstent (Boston Scientific, Natick, MA, USA) or an Evolution Colonic Stent (Cook Medical, Limerick, Ireland), with available stent lengths of 8, 10, or 12 cm. The selection of stent type and length was individualized based on procedural findings, taking into account the location, length, and severity of the malignant stricture as visualized under fluoroscopy. After sterile preparation and draping of the perineal area, liquid paraffin oil was applied to the anal verge to minimize discomfort during catheter insertion. A hydrophilic guidewire, followed by a 5-French diagnostic catheter and an 8-French guiding catheter, was introduced transanally. Contrast medium was injected through the catheter to perform colonography, which delineated the anatomy of the colon and precisely localized the site and length of the obstruction.\u003c/p\u003e\n\u003cp\u003eOnce the stricture was identified, the guidewire was advanced across the lesion under fluoroscopic guidance. In patients with a tortuous or redundant colon that limited catheter advancement, a 12-French, 90-cm Flexor® Check-Flo® Introducer sheath (Cook Medical, USA) was employed to straighten the colon and facilitate access. Following successful cannulation, the selected SEMS was carefully deployed across the stricture under real-time fluoroscopic control.\u003c/p\u003e\n\u003cp\u003ePost-deployment, stent expansion and positioning were reassessed using contrast imaging. In cases of suboptimal expansion, a balloon catheter was utilized to achieve adequate luminal patency. Once satisfactory deployment was confirmed, all instruments were withdrawn. Patients were classified according to therapeutic intent into two groups: those receiving SEMS as a bridge to surgery (BTS), and those undergoing palliative stenting (PAL). Technical success was defined as accurate placement of the stent across the obstruction without immediate procedural complications, while clinical success was defined as resolution of obstructive symptoms and restoration of bowel function within 72 hours after the procedure [11]. Post-procedure outcomes were further categorized based on complication status: complication absent and complication present. Complications included stent migration, re-obstruction, or perforation, as recorded during the index hospitalization or subsequent follow-up.\u003c/p\u003e\n\u003ch2\u003eStatistical analysis\u003c/h2\u003e\n\u003cp\u003eAll statistical analyses were performed using R software (Version 4.3.2; R Foundation for Statistical Computing, Vienna, Austria). Categorical variables were summarized as counts and percentages and compared using the Chi-square or Fisher’s exact test, as appropriate. Continuous variables were expressed as medians with interquartile ranges (IQRs) and compared using the Wilcoxon rank-sum test. A two-sided \u003cem\u003ep\u003c/em\u003e value \u0026lt; 0.05 was considered statistically significant.\u003c/p\u003e\n\u003cp\u003eTo assess the mediating role of clinical success in the association between therapeutic purpose and complications, a multi-step analytic framework was applied. First, the Sobel test and its variants (Aroian and Goodman) were performed using the bda R package [12]. Second, structural equation modeling was conducted using the piecewiseSEM R package. Two logistic regression models were specified: one for clinical success as a function of therapeutic purpose, and the other for complication risk as a function of both therapeutic purpose and clinical success. Third, causal mediation analysis using nonparametric bootstrap resampling (1,000 simulations) was performed with the mediation R package to estimate the average causal mediation effect (ACME), average direct effect (ADE), total effect, and the proportion mediated, with percentile-based 95% confidence intervals. Clinical success was modeled as a continuous mediator, and complications were assessed via linear regression to allow additive effect decomposition. Model assumptions, including multicollinearity, fit, and residual behavior, were evaluated using diagnostic tools from the easystats R package.\u003c/p\u003e"},{"header":"Results","content":"\u003ch2\u003ePatient characteristics\u003c/h2\u003e\n\u003cp\u003eA total of 413 patients with malignant colorectal obstruction who underwent SEMS placement were included in the final analysis. The baseline clinical characteristics of the study population, stratified by the presence or absence of complications, are summarized in Table 1.\u003c/p\u003e\n\u003cp\u003eThe median age of the cohort was 63 years (IQR: 51–72), with no significant difference between patients with and without complications (\u003cem\u003ep\u003c/em\u003e = 0.232). The majority of patients were male (69.5%), and while complications were numerically more common among female patients (41.7% vs. 28.6%), this difference did not reach statistical significance (\u003cem\u003ep\u003c/em\u003e = 0.060). Other baseline anthropometric measures, including height and weight, were similar between groups. Tumor markers showed a trend toward higher values in the complication group. Notably, CA19-9 levels were significantly elevated in patients with complications compared to those without (median: 44.25 vs. 17.07 U/mL, \u003cem\u003ep\u003c/em\u003e = 0.027), whereas the difference in CEA levels was not statistically significant (\u003cem\u003ep\u003c/em\u003e = 0.099).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTherapeutic intent differed significantly between groups. Among patients who experienced complications, 75.0% underwent SEMS for palliative purposes, compared to 51.0% in the non-complication group (\u003cem\u003ep\u003c/em\u003e = 0.001). Conversely, BTS was more commonly employed in patients without complications (49.0% vs. 25.0%). Regarding tumor staging, a greater proportion of patients in the complication group had stage IV disease (73.3% vs. 55.8%, \u003cem\u003ep\u003c/em\u003e = 0.009). No significant differences were observed in the length or duration of obstruction, nor in the degree of luminal obstruction. Importantly, clinical success was achieved in 93.9% of the overall cohort but was significantly less frequent among patients with complications (85.0% vs. 95.5%, \u003cem\u003ep\u003c/em\u003e = 0.005), highlighting its potential role in influencing post-procedural outcomes.\u003c/p\u003e\n\u003ch2\u003eComplication risk and mediation analysis\u003c/h2\u003e\n\u003cp\u003eTo explore whether clinical success mediates the association between therapeutic purpose and post-stenting complications, multiple mediation approaches were applied. As shown in Table S1, the Sobel test and its Aroian and Goodman variants consistently indicated a significant indirect effect of therapeutic purpose on complication risk through clinical success (\u003cem\u003ep\u003c/em\u003e = 0.035, 0.039, and 0.030, respectively).\u003c/p\u003e\n\u003cp\u003eStructural equation modeling further supported these findings. As illustrated in Figure 2A and summarized in Table 2, therapeutic purpose was significantly associated with increased likelihood of clinical success (β = 0.082, standardized estimate = 0.171, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001). In turn, clinical success was inversely associated with the occurrence of complications (β = –0.191, standardized estimate = –0.129, \u003cem\u003ep\u003c/em\u003e = 0.009). Additionally, a direct negative effect of therapeutic purpose on complications remained significant (β = –0.105, standardized estimate = –0.148, \u003cem\u003ep\u003c/em\u003e = 0.003), suggesting partial mediation.\u003c/p\u003e\n\u003cp\u003eTo quantify the mediation effect, a nonparametric bootstrap-based causal mediation analysis was conducted. As presented in Table 3 and visualized in Figure 2B, the ACME was –0.016 (95% CI: –0.038 to –0.001, \u003cem\u003ep\u003c/em\u003e = 0.031), while the ADE was –0.105 (95% CI: –0.172 to –0.041, \u003cem\u003ep\u003c/em\u003e = 0.004). The total effect of therapeutic purpose on complications was –0.120 (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001), with 13.0% of the effect mediated through clinical success (\u003cem\u003ep\u003c/em\u003e = 0.031).\u003c/p\u003e\n\u003ch2\u003eLogistic regression and model evaluation\u003c/h2\u003e\n\u003cp\u003eTo further evaluate the association between therapeutic purpose, clinical success, and complication risk, a multivariable logistic regression model was fitted with complication occurrence as the dependent variable and both therapeutic purpose and clinical success as independent variables. As shown in Figure S1, both predictors demonstrated meaningful contributions to the model, with clinical success exhibiting a negative association and therapeutic purpose (palliative intent) contributing positively to the likelihood of complications.\u003c/p\u003e\n\u003cp\u003eModel performance and robustness were assessed through a series of diagnostic evaluations, summarized in Figure 3. Figure 3A presents the posterior predictive check, indicating that predicted intervals closely aligned with observed data, suggesting overall model adequacy. Figure 3B shows binned residual plots across predicted probabilities, with residuals generally falling within expected bounds, supporting model calibration. Figure 3C identifies a small number of influential observations based on leverage and sigma statistics, but no clear outliers exerting undue influence on the model were detected. Figure 3D confirms the absence of multicollinearity, with all variance inflation factors (VIFs) below critical thresholds when plotted on a log scale. Figure 3E, a Q–Q plot of model residuals, demonstrated a distribution approximating uniformity, supporting the validity of model assumptions.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this retrospective cohort study of patients with MCO treated with SEMS placement, we found that therapeutic purpose—whether palliative or as a bridge to surgery—was significantly associated with the risk of complications. Notably, clinical success emerged as a partial mediator of this relationship, suggesting that achieving effective decompression may mitigate adverse outcomes even in higher-risk therapeutic contexts\u0026nbsp;[13,14].\u003c/p\u003e\n\u003cp\u003eOur findings are consistent with prior studies demonstrating differential outcomes based on treatment intent. SEMS placement as a bridge to surgery has been associated with lower complication rates and improved long-term outcomes compared to palliative stenting\u0026nbsp;[15,16]. However, direct comparisons have often been confounded by differences in baseline tumor burden and patient fitness[6,10]. By incorporating a causal mediation framework, our study disentangles these effects and quantitatively demonstrates that clinical success accounts for approximately 13% of the total effect of therapeutic purpose on complication risk—supporting its mechanistic relevance.\u003c/p\u003e\n\u003cp\u003eThe observed protective effect of clinical success is biologically plausible. Prompt relief of luminal obstruction reduces mucosal ischemia, bacterial overgrowth, and the risk of perforation, which are key contributors to post-stenting complications\u0026nbsp;[17–19]. Moreover, successful stent expansion improves patient nutritional status and allows for elective surgical planning in the bridge-to-surgery setting, potentially enhancing perioperative safety\u0026nbsp;[20,21].\u003c/p\u003e\n\u003cp\u003eOur results also provide practical implications for clinical decision-making. The significantly higher complication rate observed in the palliative group underscores the need for cautious patient selection and optimization of procedural technique. Early identification and management of suboptimal stent deployment, including adjunctive balloon dilation, may further improve clinical success rates and reduce downstream adverse events\u0026nbsp;[22].\u003c/p\u003e\n\u003cp\u003eSeveral limitations should be acknowledged. First, the retrospective design and single-center setting may introduce selection bias and limit the generalizability of our findings to broader patient populations or other clinical settings with varying protocols or expertise. Second, although we adjusted for key clinical variables, potential unmeasured confounders—such as operator experience, tumor histopathological subtype, comorbidities, or variations in peri-procedural care—could have influenced the observed associations. Third, while our mediation analyses demonstrated a statistically significant indirect effect of therapeutic intent via clinical success, the proportion mediated was modest, suggesting the presence of other unaccounted factors, such as tumor biology, immune status, or timing of intervention, that may contribute to complication risk. Additionally, we did not assess long-term oncologic outcomes, such as survival or tumor recurrence, which are critical when evaluating the broader implications of SEMS as a bridge to surgery versus palliative therapy. Furthermore, clinical success was operationalized as short-term symptom relief, which, although practical, may not fully capture functional recovery or quality-of-life impacts. The bootstrap and SEM-based mediation models, while robust, rely on assumptions of no unmeasured confounding and correct model specification, which warrant careful interpretation.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn patients with malignant colorectal obstruction undergoing SEMS placement, therapeutic intent was significantly associated with complication risk, partially mediated by clinical success. Achieving successful decompression markedly reduced adverse outcomes, regardless of treatment strategy. These findings underscore the importance of optimizing procedural success to improve patient safety, particularly in palliative settings.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eMCO:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003eMalignant colorectal obstruction\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSEMS:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003eSelf-expanding metal stents\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eBTS:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003eBridge to surgery\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePAL:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003ePalliative treatment\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eIQRs:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003eInterquartile ranges\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eACME:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003eAverage causal mediation effect\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eADE:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003eAverage direct effect\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eVIFs:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003eVariance inflation factors\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eData Availability Statement\u003c/h2\u003e\n\u003cp\u003eThe relevant data that support the findings of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e\u003ch2\u003eAcknowledgment\u003c/h2\u003e\n\u003cp\u003eSupported by the program of Guangdong Provincial Clinical Research Center for Digestive Diseases (2020B1111170004).\u003c/p\u003e\n\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eThis study was funded by the Medical Joint Fund of Jinan University (YXZY2024020) and the Scientific and Technological Project of Foshan City (2420001004035).\u003c/p\u003e\n\u003ch2\u003eContributions\u003c/h2\u003e\n\u003cp\u003e\u003cstrong\u003eYuan Wan:\u0026nbsp;\u003c/strong\u003eConceptualization; Methodology; Writing - original draft. \u003cstrong\u003eKe-tong Wu:\u0026nbsp;\u003c/strong\u003eData curation; Resources; Visualization; Software. \u003cstrong\u003eDan Li:\u0026nbsp;\u003c/strong\u003eValidation; Investigation; Methodology; Formal analysis. \u003cstrong\u003eYang Liu, Hai-yang Lai and Tao Peng:\u003c/strong\u003e Visualization; Validation. \u003cstrong\u003eHuan-hua Wu:\u0026nbsp;\u003c/strong\u003eWriting - review \u0026amp; editing; Investigation; Funding acquisition; Project administration; Resources. \u003cstrong\u003eBo Zhang:\u0026nbsp;\u003c/strong\u003eWriting - review \u0026amp; editing; Investigation; Funding acquisition; Supervision; Project administration; Resources. All authors contributed to final approval of the paper.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGuarantor\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe scientific guarantor of this publication is Dr. Bo Zhang from The Sixth Affiliated Hospital, Sun Yat-sen University.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistics and biometry\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOne of the authors has significant statistical expertise. No complex statistical methods were necessary for this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInformed consent\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent was waived by the Institutional Review Board.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInstitutional Review Board approval was obtained. The study was approved by the Ethics Committee of The Sixth Affiliated Hospital, Sun Yat-sen University, Approval Reference Number [2024ZSLYEC-149]. This study is a retrospective analysis, and requirement for patient informed consent was waived. All methods were carried out in accordance with guidelines and regulations related to the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy subjects or cohorts overlap\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study cohort has not been previously reported.\u003c/p\u003e\n\u003ch2\u003eConsent for publication\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eGriffiths S, Glancy DG. Intestinal obstruction. Intest Surg. 2023;41:47\u0026ndash;54.\u003c/li\u003e\n\u003cli\u003eVeld JV, Beek KJ, Consten ECJ, ter Borg F, van Westreenen HL, Bemelman WA, et al. Definition of large bowel obstruction by primary colorectal cancer: A systematic review. Colorectal Dis. 2021;23:787\u0026ndash;804.\u003c/li\u003e\n\u003cli\u003eLee HH, Kim DH, Lim H, Kim J-W, Jung Y, Kim H-S, et al. Impact of perforation following self-expandable metal stent as a bridge to surgery for malignant colorectal obstruction: A multicenter study of the research group for stent in the korean society of gastrointestinal endoscopy. Surg Endosc. 2025;39:1544\u0026ndash;54.\u003c/li\u003e\n\u003cli\u003eHan JG, Wang ZJ, Dai Y, Li XR, Qian Q, Wang GY, et al. Short-term outcomes of elective surgery following self-expandable metallic stent and neoadjuvant chemotherapy in patients with left-sided colon cancer obstruction. Dis Colon Rectum [Internet]. 2023;66. Available from: https://journals.lww.com/dcrjournal/fulltext/2023/10000/short_term_outcomes_of_elective_surgery_following.8.aspx\u003c/li\u003e\n\u003cli\u003eMalik S, Loganathan P, Khan H, Shadali AH, Yarra P, Chandan S, et al. Transforming outcomes: The pivotal role of self-expanding metal stents in right- and left-sided malignant colorectal obstructions-bridge to surgery: a comprehensive review and meta-analysis. Clin Endosc. 2025;58:240\u0026ndash;52.\u003c/li\u003e\n\u003cli\u003eYamane K, Umino Y, Nagami T, Tarumoto K, Hattori K, Maemoto R, et al. Comparison of oncological and perioperative outcomes between self-expanding metal stents and decompression tubes for stages II and III obstructive colorectal cancer: a retrospective observational study. World J Surg. 2023;47:2279\u0026ndash;86.\u003c/li\u003e\n\u003cli\u003ePapachrysos N, Shafazand M, Alkelin L, Kilincalp S, de Lange T. Outcome of self-expandable metal stents placement for obstructive colorectal cancer: 7\u0026nbsp;years\u0026rsquo; experience from a swedish tertiary center. Surg Endosc. 2023;37:2653\u0026ndash;8.\u003c/li\u003e\n\u003cli\u003eVeld J, Umans D, van Halsema E, Amelung F, Fernandes D, Lee MS, et al. Self-expandable metal stent (SEMS) placement or emergency surgery as palliative treatment for obstructive colorectal cancer: a systematic review and meta-analysis. Crit Rev Oncol Hematol. 2020;155:103110.\u003c/li\u003e\n\u003cli\u003eZeng Z, Liu Y, Wu K, Li D, Lai H, Zhang B. Efficacy and safety of fluoroscopy-guided self-expandable metal stent placement for treatment of malignant colorectal obstruction. Dig Dis Sci. 2023;68:939\u0026ndash;47.\u003c/li\u003e\n\u003cli\u003eLee JS, Lee HS, Kim ES, Jung MK, Jung JT, Kim HG, et al. Comparison of different types of covered self-expandable metal stents for malignant colorectal obstruction. Surg Endosc. 2021;35:4124\u0026ndash;33.\u003c/li\u003e\n\u003cli\u003eKwon S-J, Yoon J, Oh EH, Kim J, Ham NS, Hwang SW, et al. Factors associated with clinical outcomes of palliative stenting for malignant colonic obstruction. Gut Liver. 2020;15:579.\u003c/li\u003e\n\u003cli\u003eHenry Nwankwo C. Comparison of tests of indirect effect in single mediation analysis. Am J Theor Appl Stat. 2016;5:64.\u003c/li\u003e\n\u003cli\u003eKye B-H, Kim J-H, Kim H-J, Lee Y-S, Lee I-K, Kang WK, et al. Oncologic oUTcomes of neoadjuvant chemotherapy for obSTructive colon cAncer after steNt decompression (OUTSTAND trial); a study protocol of multicenter non-inferiority randomized controlled trial. BMC Cancer. 2025;25:194.\u003c/li\u003e\n\u003cli\u003eMa W, Zhang J-C, Luo K, Wang L, Zhang C, Cai B, et al. Self-expanding metal stents versus decompression tubes as a bridge to surgery for patients with obstruction caused by colorectal cancer: a systematic review and meta-analysis. World J Emerg Surg. 2023;18:46.\u003c/li\u003e\n\u003cli\u003eZhang H-Y, Wang Z-J, Han J-G. Impact of self-expanding metal stents on long-term survival outcomes as a bridge to surgery in patients with colon cancer obstruction: current state and future prospects. Dig Endosc. 2024;36:1312\u0026ndash;27.\u003c/li\u003e\n\u003cli\u003eHo K, Chan K, Kwok S, Lau P ying-yu. Colonic self-expanding metal stent (SEMS) as a bridge to surgery in left-sided malignant colonic obstruction: an 8-year review. Surg Endosc. 2017;31:2255\u0026ndash;62.\u003c/li\u003e\n\u003cli\u003eMenni A, Stavrou G, Tzikos G, Shrewsbury AD, Kotzampassi K. Endoscopic salvage of gastrointestinal anastomosis leaks\u0026mdash;past, present, and future\u0026mdash;a narrated review. Gastrointest Disord. 2023;5:383\u0026ndash;407.\u003c/li\u003e\n\u003cli\u003eChan SM, Auyeung KKY, Lam SF, Chiu PWY, Teoh AYB. Current status in endoscopic management of upper gastrointestinal perforations, leaks and fistulas. Dig Endosc. 2022;34:43\u0026ndash;62.\u003c/li\u003e\n\u003cli\u003eSchmoyer CJ, Saidman J, Bohl JL, Bierly CL, Kuemmerle JF, Bickston SJ. The pathogenesis and clinical management of stricturing crohn disease. Inflamm Bowel Dis. 2021;27:1839\u0026ndash;52.\u003c/li\u003e\n\u003cli\u003eMcKechnie T, Springer JE, Cloutier Z, Archer V, Alavi K, Doumouras A, et al. Management of left-sided malignant colorectal obstructions with curative intent: a network meta-analysis. Surg Endosc. 2023;37:4159\u0026ndash;78.\u003c/li\u003e\n\u003cli\u003eChen E, Chen L, Zhang W, Zhou W. Self-expanding metal stent as a bridge to elective surgery versus immediate emergency surgery in left-sided obstructive colorectal cancer: a retrospective comparative study. Updates Surg. 2025;77:783\u0026ndash;90.\u003c/li\u003e\n\u003cli\u003eTyberg A, Binmoeller K, Kowalski T. Lumen-apposing metal stents in 2024: troubleshooting and managing common and uncommon adverse events. Gastrointest Endosc. 2025;101:315\u0026ndash;30.\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e Clinical characteristics of 413 SEMS patients included.\u003c/p\u003e\n\u003ctable width=\"728\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eVariable\u003csup\u003ea\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u003cstrong\u003ePatients (N\u003c/strong\u003e\u003cstrong\u003e=413)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u003cstrong\u003eComplication Absent \u003c/strong\u003e\u003cstrong\u003e(\u003c/strong\u003e\u003cstrong\u003eN\u003c/strong\u003e\u003cstrong\u003e=353)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u003cstrong\u003eComplication Present (N\u003c/strong\u003e\u003cstrong\u003e=60)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e value\u003csup\u003eb\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eGender, \u003cem\u003en\u003c/em\u003e (%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.060\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eMale\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 287 (69.49%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 252 (71.39%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 35 (58.33%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eFemale\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 126 (30.51%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 101 (28.61%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 25 (41.67%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eAge, year, (Median [IQR])\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e63.00 [51.00;72.00]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e63.00 [51.00;73.00]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e61.00 [49.75;68.00]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.232\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eHeight, cm\u003c/strong\u003e\u003cstrong\u003e, (Median [IQR])\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;1.65 [1.59;1.70]\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;1.65 [1.60;1.70]\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;1.62 [1.57;1.70]\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.231\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eWeight, kg\u003c/strong\u003e\u003cstrong\u003e, (Median [IQR])\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e58.00 [50.00;65.00]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e57.50 [50.00;65.00]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e59.25 [47.75;68.25]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.371\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eCEA\u003c/strong\u003e\u003cstrong\u003e, ng/ml,\u003c/strong\u003e \u003cstrong\u003e(Median [IQR])\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;9.30 [3.41;43.72]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;9.23 [3.36;36.73]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e10.43 [4.82;72.74]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.099\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eCA19.9\u003c/strong\u003e\u003cstrong\u003e, U/ml,\u003c/strong\u003e \u003cstrong\u003e(Median [IQR])\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e19.45 [4.92;165.38]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e17.07 [4.72;128.18]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e44.25 [6.91;799.58]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.027\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eTherapeutic purpose\u003c/strong\u003e\u003cstrong\u003e, \u003cem\u003en\u003c/em\u003e (%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; Palliative treatment\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 225 (54.48%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 180 (50.99%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 45 (75.00%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; Bridge to surgery\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 188 (45.52%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 173 (49.01%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 15 (25.00%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eTumor staging\u003c/strong\u003e\u003cstrong\u003e, \u003cem\u003en\u003c/em\u003e (%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.009\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eⅡ\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 87 (21.07%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 75 (21.25%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 12 (20.00%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eⅢ\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 85 (20.58%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 81 (22.95%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp; 4 (6.67%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eIV\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 241 (58.35%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 197 (55.81%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 44 (73.33%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eLength of obstruction,\u003c/strong\u003e\u003cstrong\u003e cm\u003c/strong\u003e\u003cstrong\u003e,\u003c/strong\u003e \u003cstrong\u003e(Median [IQR])\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;5.00 [3.80;6.00]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;5.00 [3.90;6.00]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;5.25 [3.40;6.00]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.837\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eDuration of obstruction,\u003c/strong\u003e\u003cstrong\u003e days\u003c/strong\u003e\u003cstrong\u003e,\u003c/strong\u003e \u003cstrong\u003e(Median [IQR])\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;9.00 [5.00;14.00]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;9.00 [5.00;14.00]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;9.00 [5.00;15.00]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.813\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eDegree of obstruction\u003c/strong\u003e\u003cstrong\u003e, \u003cem\u003en\u003c/em\u003e (%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.788\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eComplete\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 244 (59.08%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 210 (59.49%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 34 (56.67%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eIncomplete\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 169 (40.92%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 143 (40.51%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 26 (43.33%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003eClinical success\u003c/strong\u003e\u003cstrong\u003e, \u003cem\u003en\u003c/em\u003e (%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e0.005\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u0026nbsp; No\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 25 (6.05%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 16 (4.53%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 9 (15.00%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"189\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u0026nbsp; Yes\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"137\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 388 (93.95%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; 337 (95.47%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp; 51 (85.00%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"74\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"728\"\u003e\n\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e Continuous variables were presented as median (IQR) and categorical variables as Number (%).\u003c/p\u003e\n\u003cp\u003e\u003csup\u003eb\u003c/sup\u003e \u003cem\u003ep\u003c/em\u003e values were calculated using the Wilcoxon Signed Rank test for continuous variables and the c\u003csup\u003e2\u003c/sup\u003e test or Fisher exact for categorical variables.\u003c/p\u003e\n\u003cp\u003eSD = standard deviation, IQR = interquartile range.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2. \u003c/strong\u003eResults of structural equation model.\u003c/p\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eResponse\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003ePredictor\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eEstimate\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eStd.Error\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eStd.Estimate\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ep \u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003evalue\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eClinical success\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eTherapeutic purpose\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e0.082\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e0.023\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e0.171\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eComplication\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eClinical success\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e-0.191\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e0.072\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e-0.129\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e0.009\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eComplication\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eTherapeutic purpose\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e-0.105\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e0.035\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e-0.148\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd\u003e\n\u003cp\u003e0.003\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3. \u003c/strong\u003eResults of causal mediation analysis: nonparametric bootstrap confidence intervals with the percentile method.\u003c/p\u003e\n\u003ctable width=\"525\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003ctd width=\"107\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003e\u003cstrong\u003eEstimate\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"106\"\u003e\n\u003cp\u003e\u003cstrong\u003e95% CI Lower\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e\u003cstrong\u003e95% CI Upper\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ep \u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003evalue\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd width=\"107\"\u003e\n\u003cp\u003e\u003cstrong\u003eACME\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003e-0.016\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"106\"\u003e\n\u003cp\u003e-0.038\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e-0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e0.031\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"107\"\u003e\n\u003cp\u003e\u003cstrong\u003eADE\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003e-0.105\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"106\"\u003e\n\u003cp\u003e-0.172\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e-0.041\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e0.004\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"107\"\u003e\n\u003cp\u003e\u003cstrong\u003eTotal Effect\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003e-0.120\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"106\"\u003e\n\u003cp\u003e-0.185\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e-0.058\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"107\"\u003e\n\u003cp\u003e\u003cstrong\u003eProp. Mediated\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003e0.130\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"106\"\u003e\n\u003cp\u003e0.004\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e0.357\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e0.031\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"525\"\u003e\n\u003cp\u003eACME = average causal mediation effects, ADE = average direct effect.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\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":"Malignant colorectal obstruction; Self-expanding metallic stent; Complication; Mediation analysis","lastPublishedDoi":"10.21203/rs.3.rs-7750665/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7750665/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e Self-expandable metal stents (SEMS) are routinely used in malignant colorectal obstruction (MCO) for palliation or as a bridge to surgery. However, whether treatment intent influences complication risk, and if clinical success mediates this relationship, remains unclear.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e We retrospectively analyzed 413 patients with MCO who underwent SEMS placement between 2014 and 2024. Patients were categorized by therapeutic intent (palliation vs. bridge to surgery), and complication rates were compared. Mediation analysis was performed using the Sobel test, structural equation modeling (SEM), and bootstrap-based causal mediation to assess whether clinical success mediated the relationship between therapeutic purpose and complications.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e Complications occurred in 60 patients (14.5%). Palliation was associated with a higher complication rate compared to bridging (20.0% vs. 8.0%, p = 0.001). Clinical success significantly mediated the effect of therapeutic purpose on complications (Sobel p = 0.035). SEM confirmed a positive association between therapeutic purpose and clinical success (standardized β = 0.171, p \u0026lt; 0.001) and a negative association between clinical success and complications (β = –0.191, p = 0.009). Bootstrap mediation analysis revealed that 13.0% of the total effect was mediated through clinical success (p = 0.031).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e Therapeutic intent affects SEMS complication risk, mediated by clinical success. Optimizing outcomes—especially in palliation—enhances safety and guides personalized management\u003c/p\u003e","manuscriptTitle":"Bridging to Surgery Versus Palliation in Malignant Colorectal Obstruction: Complication Risks and Mediation by Clinical Success","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-03 09:35:28","doi":"10.21203/rs.3.rs-7750665/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":"5fcaf2fe-612b-4268-9882-1d212d3211bc","owner":[],"postedDate":"November 3rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-02-01T08:24:17+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-03 09:35:28","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7750665","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7750665","identity":"rs-7750665","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}