Completion Total Mesorectal Excision: A Case-Matched Comparison With Primary Resection.

Objectives: The aim of this study was to compare the perioperative and oncological results of completion total mesorectal excision (cTME) versus primary total mesorectal excision (pTME). Background: Early-stage rectal cancer can be treated by local excision alone, which is associated with less surgical morbidity and improved functional outcomes compared with radical surgery. When high-risk histological features are present, cTME is indicated, with possible worse clinical and oncological outcomes compared to pTME. Methods: This retrospective cohort study included all patients that underwent TME surgery for rectal cancer performed in 11 centers in the Netherlands between 2015 and 2017. After case-matching, we compared cTME with pTME. The primary outcome was major postoperative morbidity. Secondary outcomes included the rate of restorative procedures and 3-year oncological outcomes. Results: In total 1069 patients were included, of which 35 underwent cTME. After matching (1:2 ratio), 29 cTME and 58 pTME were analyzed. No differences were found for major morbidity (27.6% vs 19.0%; P = 0.28) and abdominoperineal excision rate (31.0% vs 32.8%; P = 0.85) between cTME and pTME, respectively. Local recurrence (3.4% vs 8.6%; P = 0.43), systemic recurrence (3.4% vs 12.1%; P = 0.25), overall survival (93.1% vs 94.8%; P = 0.71), and disease-free survival (89.7% vs 81.0%; P = 0.43) were comparable between cTME and pTME. Conclusions: cTME is not associated with higher major morbidity, whereas the abdominoperineal excision rate and 3-year oncological outcomes are similar compared to pTME. Local excision as a diagnostic tool followed by completion surgery for early rectal cancer does not compromise outcomes and should still be considered as the treatment of early-stage rectal cancer.

Robot-assisted fluorescent sentinel lymph node identification in early-stage colon cancer.

BACKGROUND: Patients with cT1-2 colon cancer (CC) have a 10-20% risk of lymph node metastases. Sentinel lymph node identification (SLNi) could improve staging and reduce morbidity in future organ-preserving CC surgery. This pilot study aimed to assess safety and feasibility of robot-assisted fluorescence-guided SLNi using submucosally injected indocyanine green (ICG) in patients with cT1-2N0M0 CC. METHODS: Ten consecutive patients with cT1-2N0M0 CC were included in this prospective feasibility study. Intraoperative submucosal, peritumoral injection of ICG was performed during a colonoscopy. Subsequently, the near-infrared fluorescence 'Firefly' mode of the da Vinci Xi robotic surgical system was used for SLNi. SLNs were marked with a suture, after which a segmental colectomy was performed. The SLN was postoperatively ultrastaged using serial slicing and immunohistochemistry, in addition to the standard pathological examination of the specimen. Colonoscopy time, detection time (time from ICG injection to first SLNi), and total SLNi time were measured (time from the start of colonoscopy to start of segmental resection). Intraoperative, postoperative, and pathological outcomes were registered. RESULTS: In all patients, at least one SLN was identified (mean 2.3 SLNs, SLN diameter range 1-13 mm). No tracer-related adverse events were noted. Median colonoscopy time was 12 min, detection time was 6 min, and total SLNi time was 30.5 min. Two patients had lymph node metastases present in the SLN, and there were no patients with false negative SLNs. No patient was upstaged due to ultrastaging of the SLN after an initial negative standard pathological examination. Half of the patients unexpectedly had pT3 tumours. CONCLUSIONS: Robot-assisted fluorescence-guided SLNi using submucosally injected ICG in ten patients with cT1-2N0M0 CC was safe and feasible. SLNi was performed in an acceptable timespan and SLNs down to 1 mm were detected. All lymph node metastases would have been detected if SLN biopsy had been performed.

Economic analysis of open versus laparoscopic versus robot-assisted versus transanal total mesorectal excision in rectal cancer patients: A systematic review.

OBJECTIVES: Minimally invasive total mesorectal excision is increasingly being used as an alternative to open surgery in the treatment of patients with rectal cancer. This systematic review aimed to compare the total, operative and hospitalization costs of open, laparoscopic, robot-assisted and transanal total mesorectal excision. METHODS: This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA) (S1 File) A literature review was conducted (end-of-search date: January 1, 2023) and quality assessment performed using the Consensus Health Economic Criteria. RESULTS: 12 studies were included, reporting on 2542 patients (226 open, 1192 laparoscopic, 998 robot-assisted and 126 transanal total mesorectal excision). Total costs of minimally invasive total mesorectal excision were higher compared to the open technique in the majority of included studies. For robot-assisted total mesorectal excision, higher operative costs and lower hospitalization costs were reported compared to the open and laparoscopic technique. A meta-analysis could not be performed due to low study quality and a high level of heterogeneity. Heterogeneity was caused by differences in the learning curve and statistical methods used. CONCLUSION: Literature regarding costs of total mesorectal excision techniques is limited in quality and number. Available evidence suggests minimally invasive techniques may be more expensive compared to open total mesorectal excision. High-quality economical evaluations, accounting for the learning curve, are needed to properly assess costs of the different techniques.

Nationwide practice in CT-based preoperative staging of colon cancer and concordance with definitive pathology.

INTRODUCTION: In an era of exploring patient-tailored treatment options for colon cancer, preoperative staging is increasingly important. This study aimed to evaluate completeness and reliability of CT-based preoperative locoregional colon cancer staging in Dutch hospitals. MATERIALS AND METHODS: Patients who underwent elective oncological resection of colon cancer without neoadjuvant treatment in 77 Dutch hospitals were evaluated between 2011 and 2021. Completeness of T-stage was calculated for individual hospitals and stratified based on a 60% cut-off. Concordance between routine CT-based preoperative locoregional staging (cTN) and definitive pathological staging (pTN) was examined. RESULTS: A total of 59,558 patients were included with an average completeness of 43.4% and 53.4% for T and N-stage, respectively. Completeness of T-stage improved from 4.9% in 2011-2014 to 74.4% in 2019-2021. Median completeness for individual hospitals was 53.9% (IQR 27.3-80.5%) and were not significantly different between low and high-volume hospitals. Sensitivity and specificity for T3-4 tumours were relatively low: 75.1% and 76.0%, respectively. cT1-2 tumours were frequently understaged based on a low negative predictive value of 56.8%. Distinction of cT4 and cN2 disease had a high specificity (>95%), but a very low sensitivity (<50%). Positive predictive values of <60% indicated that cT4 and cN1-2 were often overstaged. Completeness and time period did not influence reliability of staging. CONCLUSION: Completeness of locoregional staging of colon cancer improved during recent years and varied between hospitals independently from case volume. Discriminating cT1-2 from cT3-4 tumours resulted in substantial understaging and overstaging, additionally cT4 and cN1-2 were overstaged in >40% of cases.

Implications of the new MRI-based rectum definition according to the sigmoid take-off: multicentre cohort study.

BACKGROUND: The introduction of the sigmoid take-off definition might lead to a shift from rectal cancers to sigmoid cancers. The aim of this retrospective cohort study was to determine the clinical impact of the new definition. METHODS: In this multicentre retrospective cohort study, patients were included if they underwent an elective, curative total mesorectal excision for non-metastasized rectal cancer between January 2015 and December 2017, were registered in the Dutch Colorectal Audit as having a rectal cancer according to the previous definition, and if MRI was available. All selected rectal cancer cases were reassessed using the sigmoid take-off definition. The primary outcome was the number of patients reassessed with a sigmoid cancer. Secondary outcomes included differences between the newly defined rectal and sigmoid cancer patients in treatment, perioperative results, and 3-year oncological outcomes (overall and disease-free survivals, and local and systemic recurrences). RESULTS: Out of 1742 eligible patients, 1302 rectal cancer patients were included. Of these, 170 (13.1 per cent) were reclassified as having sigmoid cancer. Among these, 93 patients (54.7 per cent) would have been offered another adjuvant or neoadjuvant treatment according to the Dutch guideline. Patients with a sigmoid tumour after reassessment had a lower 30-day postoperative complication rate (33.5 versus 48.3 per cent, P < 0.001), lower reintervention rate (8.8 versus 17.4 per cent, P < 0.007), and a shorter length of stay (a median of 5 days (i.q.r. 4-7) versus a median of 6 days (i.q.r. 5-9), P < 0.001). Three-year oncological outcomes were comparable. CONCLUSION: Using the anatomical landmark of the sigmoid take-off, 13.1 per cent of the previously classified patients with rectal cancer had sigmoid cancer, and 54.7 per cent of these patients would have been treated differently with regard to neoadjuvant therapy or adjuvant therapy.

Impact of a diverting ileostomy in total mesorectal excision with primary anastomosis for rectal cancer.

BACKGROUND: The role of diverting ileostomy in total mesorectal excision (TME) for rectal cancer with primary anastomosis is debated. The aim of this study is to gain insight in the clinical consequences of a diverting ileostomy, with respect to stoma rate at one year and stoma-related morbidity. METHODS: Patients undergoing TME with primary anastomosis for rectal cancer between 2015 and 2017 in eleven participating hospitals were included. Retrospectively, two groups were compared: patients with or without diverting ileostomy construction during primary surgery. Primary endpoint was stoma rate at one year. Secondary endpoints were severity and rate of anastomotic leakage, overall morbidity rate within thirty days and stoma (reversal) related morbidity. RESULTS: In 353 out of 595 patients (59.3%) a diverting ileostomy was constructed during primary surgery. Stoma rate at one year was 9.9% in the non-ileostomy group and 18.7% in the ileostomy group (p = 0.003). After correction for confounders, multivariate analysis showed that the construction of a diverting ileostomy during primary surgery was an independent risk factor for stoma at one year (OR 2.563 (95%CI 1.424-4.611), p = 0.002). Anastomotic leakage rate was 17.8% in the non-ileostomy group and 17.2% in the ileostomy group (p = 0.913). Overall 30-days morbidity rate was 37.6% in the non-ileostomy group and 56.1% in the ileostomy group (p < 0.001). Stoma reversal related morbidity rate was 17.9%. CONCLUSIONS: The stoma rate at one year was higher in patients with ileostomy construction during primary surgery. The incidence and severity of anastomotic leakage were not reduced by construction of an ileostomy. The morbidity related to the presence and reversal of a diverting ileostomy was substantial.

Comparison of three-year oncological results after restorative low anterior resection, non-restorative low anterior resection and abdominoperineal resection for rectal cancer.

INTRODUCTION: Oncological outcome might be influenced by the type of resection in total mesorectal excision (TME) for rectal cancer. The aim was to see if non-restorative LAR would have worse oncological outcome. A comparison was made between non-restorative low anterior resection (NRLAR), restorative low anterior resection (RLAR) and abdominoperineal resection (APR). MATERIALS AND METHODS: This retrospective cohort included data from patients undergoing TME for rectal cancer between 2015 and 2017 in eleven Dutch hospitals. A comparison was made for each different type of procedure (APR, NRLAR or RLAR). Primary outcome was 3-year overall survival (OS). Secondary outcomes included 3-year disease-free survival (DFS) and 3-year local recurrence (LR) rate. RESULTS: Of 998 patients 363 underwent APR, 132 NRLAR and 503 RLAR. Three-year OS was worse after NRLAR (78.2%) compared to APR (86.3%) and RLAR (92.2%, p < 0.001). This was confirmed in a multivariable Cox regression analysis (HR 1.85 (1.07, 3.19), p = 0.03). The 3-year DFS was also worse after NRLAR (60.3%), compared to APR (70.5%) and RLAR (80.1%, p < 0.001), HR 2.05 (1.42, 2.97), p < 0.001. The LR rate was 14.6% after NRLAR, 5.2% after APR and 4.8% after RLAR (p = 0.005), HR 3.22 (1.61, 6.47), p < 0.001. CONCLUSION: NRLAR might be associated with worse 3-year OS, DFS and LR rate compared to RLAR and APR.

Predicting Mortality Within 90 Days of First Intervention in Patients With Left-Sided Obstructive Colon Cancer.

BACKGROUND: Acute resection for left-sided obstructive colon carcinoma is thought to be associated with a higher mortality risk than a bridge-to-surgery approach using decompressing stoma or self-expandable metal stent, but prediction models are lacking. OBJECTIVE: This study aimed to determine the influence of treatment strategy on mortality within 90 days from the first intervention in patients presenting with left-sided obstructive colon carcinoma. DESIGN: This was a national multicenter cohort study that used data from a prospective national audit. SETTINGS: The study was performed in 75 Dutch hospitals. PATIENTS: Patients were included if they underwent resection with curative intent for left-sided obstructive colon carcinoma between 2009 and 2016. INTERVENTIONS: First intervention was either acute resection, bridge to surgery with self-expandable metallic stent, or bridge to surgery with decompressing stoma. MAIN OUTCOME MEASURES: The main outcome measure was 90-day mortality after the first intervention. Risk factors were identified using multivariable logistic analysis. Subsequently, a risk model was developed. RESULTS: In total, 2395 patients were included, with the first intervention consisting of acute resection in 1848 patients (77%), stoma as bridge to surgery in 332 patients (14%), and stent as bridge to surgery in 215 patients (9%). Overall, 152 patients (6.3%) died within 90 days from the first intervention. A decompressing stoma was independently associated with lower 90-day mortality risk (HR, 0.27; 95% CI, 0.094-0.62). Other independent predictors for mortality were age, ASA classification, tumor location, and index levels of serum creatinine and C-reactive protein. The constructed risk model had an area under the curve of 0.84 (95% CI, 0.81-0.87). LIMITATIONS: Only patients who underwent surgical resection were included. CONCLUSIONS: Treatment strategy had a significant impact on 90-day mortality. A decompressing stoma considerably lowers the risk of mortality, especially in older and frail patients. The developed risk model needs further external validation. See Video Abstract at http://links.lww.com/DCR/B975 .PREDICCIÓN DE LA MORTALIDAD A 90 DÍAS POSTERIORES A LA PRIMERA CIRUGÍA EN PACIENTES CON CÁNCER DE COLON OBSTRUCTIVO DEL LADO IZQUIERDOANTECEDENTES:Se cree que la resección aguda para el carcinoma de colon obstructivo del lado izquierdo está asociada con un mayor riesgo de mortalidad que un enfoque puente a la cirugía que utiliza un estoma de descompresión o un stent metálico autoexpandible, pero faltan modelos de predicción.OBJETIVO:Determinar la influencia de la estrategia de tratamiento sobre la mortalidad dentro de los 90 días desde la primera intervención utilizando un modelo de predicción en pacientes que presentan carcinoma de colon obstructivo del lado izquierdo.DISEÑO:Un estudio de cohorte multicéntrico nacional, utilizando datos de una auditoría nacional prospectiva.ENTORNO CLINICO:El estudio se realizó en 75 hospitales holandeses.PACIENTES:Se incluyeron los pacientes que se sometieron a una resección con intención curativa de un carcinoma de colon obstructivo del lado izquierdo entre 2009 y 2016.INTERVENCIONES:La primera intervención fue resección aguda, puente a cirugía con stent metálico autoexpandible o puente a cirugía con estoma descompresor.PRINCIPALES MEDIDAS DE VALORACIÓN:La principal medida de resultado fue la mortalidad a los 90 días después de la primera intervención. Los factores de riesgo se identificaron mediante análisis logístico multivariable. Posteriormente se desarrolló un modelo de riesgo.RESULTADOS:En total se incluyeron 2395 pacientes, siendo la primera intervención resección aguda en 1848 (77%) pacientes, estoma como puente a la cirugía en 332 (14%) pacientes y stent como puente a la cirugía en 215 (9%) pacientes. En general, 152 pacientes (6,3%) fallecieron dentro de los 90 días posteriores a la primera intervención. Un estoma de descompresión se asoció de forma independiente con un menor riesgo de mortalidad a los 90 días (HR: 0,27, IC: 0,094-0,62). Otros predictores independientes de mortalidad fueron la edad, la clasificación ASA, la ubicación del tumor y los niveles índice de creatinina sérica y proteína C reactiva. El modelo de riesgo construido tuvo un área bajo la curva de 0,84 (IC: 0,81-0,87).LIMITACIONES:Solo se incluyeron pacientes que se sometieron a resección quirúrgica.CONCLUSIONES:La estrategia de tratamiento tuvo un impacto significativo en la mortalidad a los 90 días. Un estoma descompresor reduce considerablemente el riesgo de mortalidad, especialmente en pacientes mayores y frágiles. Se desarrolló un modelo de riesgo, que necesita una mayor validación externa. Consulte Video Resumen en http://links.lww.com/DCR/B975 . (Traducción-Dr. Ingrid Melo ).

Cost analysis and cost-effectiveness of open versus laparoscopic versus robot-assisted versus transanal total mesorectal excision in patients with rectal cancer: a protocol for a systematic review.

INTRODUCTION: Nowadays, most rectal tumours are treated open or minimally invasive, using laparoscopic, robot-assisted or transanal total mesorectal excision. However, insight into the total costs of these techniques is limited. Since all three techniques are currently being performed, including cost considerations in the choice of treatment technique may significantly impact future healthcare costs. Therefore, this systematic review aims to provide an overview of evidence regarding costs in patients with rectal cancer following open, laparoscopic, robot-assisted and transanal total mesorectal excision. METHODS AND ANALYSIS: A systematic search will be conducted for papers between January 2000 and March 2022. Databases PubMed/MEDLINE, EMBASE, Scopus, Web of Science and Cochrane Library databases will be searched. Study selection, data extraction and quality assessment will be performed independently by four reviewers and discrepancies will be resolved through discussion. The Consensus Health Economic Criteria list will be used for assessing risk of bias. Total costs of the different techniques, consisting of but not limited to, theatre, in-hospital and postoperative costs, will be the primary outcome. ETHICS AND DISSEMINATION: No ethical approval is required, as there is no collection of patient data at an individual level. Findings will be disseminated widely, through peer-reviewed publication and presentation at relevant national and international conferences. TRIAL REGISTRATION NUMBER: CRD42021261125.

The learning curve of laparoscopic, robot-assisted and transanal total mesorectal excisions: a systematic review.

BACKGROUND: The standard treatment of rectal carcinoma is surgical resection according to the total mesorectal excision principle, either by open, laparoscopic, robot-assisted or transanal technique. No clear consensus exists regarding the length of the learning curve for the minimal invasive techniques. This systematic review aims to provide an overview of the current literature regarding the learning curve of minimal invasive TME. METHODS: A systematic literature search was performed. PubMed, Embase and Cochrane Library were searched for studies with the primary or secondary aim to assess the learning curve of either laparoscopic, robot-assisted or transanal TME for rectal cancer. The primary outcome was length of the learning curve per minimal invasive technique. Descriptive statistics were used to present results and the MINORS tool was used to assess risk of bias. RESULTS: 45 studies, with 7562 patients, were included in this systematic review. Length of the learning curve based on intraoperative complications, postoperative complications, pathological outcomes, or a composite endpoint using a risk-adjusted CUSUM analysis was 50 procedures for the laparoscopic technique, 32-75 procedures for the robot-assisted technique and 36-54 procedures for the transanal technique. Due to the low quality of studies and a high level of heterogeneity a meta-analysis could not be performed. Heterogeneity was caused by patient-related factors, surgeon-related factors and differences in statistical methods. CONCLUSION: Current high-quality literature regarding length of the learning curve of minimal invasive TME techniques is scarce. Available literature suggests equal lengths of the learning curves of laparoscopic, robot-assisted and transanal TME. Well-designed studies, using adequate statistical methods are required to properly assess the learning curve, while taking into account patient-related and surgeon-related factors.

A Prediction Model for Severe Complications after Elective Colorectal Cancer Surgery in Patients of 70 Years and Older.

Introduction Older patients have an increased risk of morbidity and mortality after colorectal cancer (CRC) surgery. Existing CRC surgical prediction models have not incorporated geriatric predictors, limiting applicability for preoperative decision-making. The objective was to develop and internally validate a predictive model based on preoperative predictors, including geriatric characteristics, for severe postoperative complications after elective surgery for stage I-III CRC in patients ≥70 years. PATIENTS AND METHODS: A prospectively collected database contained 1088 consecutive patients from five Dutch hospitals (2014-2017) with 171 severe complications (16%). The least absolute shrinkage and selection operator (LASSO) method was used for predictor selection and prediction model building. Internal validation was done using bootstrapping. RESULTS: A geriatric model that included gender, previous DVT or pulmonary embolism, COPD/asthma/emphysema, rectal cancer, the use of a mobility aid, ADL assistance, previous delirium and polypharmacy showed satisfactory discrimination with an AUC of 0.69 (95% CI 0.73-0.64); the AUC for the optimism corrected model was 0.65. Based on these predictors, the eight-item colorectal geriatric model (GerCRC) was developed. CONCLUSION: The GerCRC is the first prediction model specifically developed for older patients expected to undergo CRC surgery. Combining tumour- and patient-specific predictors, including geriatric predictors, improves outcome prediction in the heterogeneous older population.

Increased long-term mortality after open colorectal cancer surgery: A multicentre population-based study.

AIM: Unlike meta-analyses of randomized controlled trials, population-based studies in colorectal cancer (CRC) patients have shown a significant association between open surgery and increased 30- and 90-day mortality compared with laparoscopic surgery. Long-term mortality, however, is scarcely reported. This retrospective population-based study aimed to compare long-term mortality after open and laparoscopic surgery for CRC. METHOD: The Dutch Colorectal Audit and the Dutch Cancer Centre registry were used to identify patients from three large nonacademic teaching hospitals who underwent curative resection for CRC between 2009 and 2018. Patients with relative contraindications for laparoscopic surgery (cT4 or pT4 tumours, distant metastasis requiring additional resection and emergency surgery) were excluded. Multivariable regression was used to assess the effect of laparoscopic surgery on long-term mortality with adjustment for gender, age, American Society of Anesthesiologists score, TNM stage, chemoradiation therapy and other confounders. RESULTS: We included 4531 patients, of whom 1298 (29%) underwent open surgery. The median follow-up was 43 months (interquartile range 23-71 months). Open surgery was associated with an increased risk of long-term mortality (adjusted hazard ratio 1.26, 95% confidence interval 1.10-1.45, p = 0.001). Mixed-effects Cox regression with year of surgery as a random effect also showed an increased risk after open surgery (adjusted hazard ratio 1.33, 95% confidence interval 1.11-1.52, p = 0.004). CONCLUSION: Open surgery seems to be associated with increased long-term mortality in the elective setting for CRC patients. A minimally invasive approach might improve long-term outcomes.

Critical appraisal of oncological safety of stent as bridge to surgery in left-sided obstructing colon cancer; a systematic review and meta-analysis.

This meta-analysis aims to determine the long-term oncological outcomes of SEMS as bridge to surgery (BTS) versus emergency surgery (ES). A systematic search without restrictions was conducted, and all studies comparing SEMS with ES reporting on long-term outcomes were included. Methodological quality was assessed using the appropriate tools. Twenty-one comparative studies were selected, reporting on 1919 patients. Meta-analysis showed no significant difference regarding three- and five-year overall survival (OR = 0·85 (0·68-1·08) and OR = 1·04 (0·68-1·57), respectively), disease-free survival (OR = 0·96 (0·73-1·26) and OR = 0·86 (0·54-1·36), respectively) and local recurrence rate (OR = 1·32 (0·78-2·23)). Permanent stomas were significantly lower in the SEMS group (OR 0·49 (0·32-0·74)). Sensitivity analysis on three-year survival showed opposite outcomes, with a trend towards worse survival in the SEMS group when only RCTs are taken into account. In conclusion, when in experienced hands, SEMS placement as BTS seems oncologically safe.

Two versus five days of antibiotics after appendectomy for complex acute appendicitis (APPIC): study protocol for a randomized controlled trial.

BACKGROUND: Acute appendicitis is one of the most common indications for emergency surgery. In patients with a complex appendicitis, prolonged antibiotic prophylaxis is recommended after appendectomy. There is no consensus regarding the optimum duration of antibiotics. Guidelines propose 3 to 7 days of treatment, but shorter courses may be as effective in the prevention of infectious complications. At the same time, the global issue of increasing antimicrobial resistance urges for optimization of antibiotic strategies. The aim of this study is to determine whether a short course (48 h) of postoperative antibiotics is non-inferior to current standard practice of 5 days. METHODS: Patients of 8 years and older undergoing appendectomy for acute complex appendicitis - defined as a gangrenous and/or perforated appendicitis or appendicitis in presence of an abscess - are eligible for inclusion. Immunocompromised or pregnant patients are excluded, as well as patients with a contraindication to the study antibiotics. In total, 1066 patients will be randomly allocated in a 1:1 ratio to the experimental treatment arm (48 h of postoperative intravenously administered (IV) antibiotics) or the control arm (5 days of postoperative IV antibiotics). After discharge from the hospital, patients participate in a productivity-cost-questionnaire at 4 weeks and a standardized telephone follow-up at 90 days after appendectomy. The primary outcome is a composite endpoint of infectious complications, including intra-abdominal abscess (IAA) and surgical site infection (SSI), and mortality within 90 days after appendectomy. Secondary outcomes include IAA, SSI, restart of antibiotics, length of hospital stay (LOS), reoperation, percutaneous drainage, readmission rate, and cost-effectiveness. The non-inferiority margin for the difference in the primary endpoint rate is set at 7.5% (one-sided test at ɑ 0.025). Both per-protocol and intention-to-treat analyses will be performed. DISCUSSION: This trial will provide evidence on whether 48 h of postoperative antibiotics is non-inferior to a standard course of 5 days of antibiotics. If non-inferiority is established, longer intravenous administration following appendectomy for complex appendicitis can be abandoned, and guidelines need to be adjusted accordingly. TRIAL REGISTRATION: Dutch Trial Register, NTR6128 . Registered on 20 December 2016.