Rectal cancers with microscopic circumferential resection margin involvement (R1 resections): Survivals, patterns of recurrence, and prognostic factors

Identifying timing and risk factors for early recurrence of resectable rectal cancer: A single center retrospective study

BACKGROUND

Colorectal cancer is a common malignancy and various methods have been introduced to decrease the possibility of recurrence. Early recurrence (ER) is related to worse prognosis. To date, few observational studies have reported on the analysis of rectal cancer. Hence, we reported on the timing and risk factors for the ER of resectable rectal cancer at our institute.

AIM

To analyze a cohort of patients with local and/or distant recurrence following the radical resection of the primary tumor.

METHODS

Data were retrospectively collected from the institutional database from March 2011 to January 2021. Clinicopathological data at diagnosis, perioperative and postoperative data, and first recurrence were collected and analyzed. ER was defined via receiver operating characteristic curve. Prognostic factors were evaluated using the Kaplan-Meier method and Cox proportional hazards modeling.

RESULTS

We included 131 patients. The optimal cut off value of recurrence-free survival (RFS) to differentiate between ER (n = 55, 41.9%) and late recurrence (LR) (n = 76, 58.1%) was 8 mo. The median post-recurrence survival (PRS) of ER and LR was 1.4 mo and 2.9 mo, respectively (P = 0.008) but PRS was not strongly associated with RFS (R² = 0.04). Risk factors included age ≥ 70 years [hazard ratio (HR) = 1.752, P = 0.047], preoperative concurrent chemoradiotherapy (HR = 3.683, P < 0.001), colostomy creation (HR = 2.221, P = 0.036), and length of stay > 9 d (HR = 0.441, P = 0.006).

CONCLUSION

RFS of 8 mo was the optimal cut-off value. Although ER was not associated with PRS, it was still related to prognosis; thus, intense surveillance is recommended.

Prognostic Value of the Circumferential Resection Margin After Curative Surgery for Rectal Cancer: A Multicenter Propensity Score-Matched Analysis

BACKGROUND

Recently, positive circumferential resection margin has been found to be an indicator of advanced disease with a high risk of distant recurrence rather than local recurrence.

OBJECTIVE

The study aimed to analyze the prognostic impact of the circumferential resection margin on long-term oncological outcomes in patients with rectal cancer.

DESIGN

This was a multicenter, propensity score-matched (2:1) analysis comparing the positive and negative circumferential resection margins.

SETTINGS

The study was conducted at 5 high-volume centers in Spain.

PATIENTS

Patients who underwent total mesorectal excision with curative intent for middle-low rectal cancer between 2006 and 2014 were included.

MAIN OUTCOME MEASURES

The main outcomes were local recurrence, distant recurrence, overall survival, and disease-free survival.

RESULTS

The unmatched initial cohort consisted of 1599 patients, of whom 4.9% had a positive circumferential resection margin. After matching, 234 patients were included (156 with a negative circumferential margin and 78 with a positive circumferential margin). The median follow-up period was 52.5 (22.0-69.5) months. Local recurrence was significantly higher in patients with a positive circumferential margin (33.3% vs 11.5%; p < 0.001). Distant recurrence was similar in both groups (46.2% vs 42.3%; p = 0.651). There were no statistically significant differences in 5-year overall survival (48.6% vs 43.6%; p = 0.14). Disease-free survival was lower in patients with a positive circumferential margin (36.1% vs 52.3%; p = 0.026).

LIMITATIONS

This study was limited by its retrospective design. The different neoadjuvant treatment options were not included in the propensity score.

CONCLUSIONS

The positive circumferential resection margin was associated with a higher local recurrence rate and worse disease-free survival in comparison with the negative circumferential resection margin. However, the positive circumferential resection margin was not a prognostic indicator of distant recurrence and overall survival. See Video Abstract at http://links.lww.com/DCR/B950 .

VALOR PRONSTICO DEL MARGEN DE RESECCIN CIRCUNFERENCIAL DESPUS DE LA CIRUGA CURATIVA PARA EL CNCER DE RECTO UN ANLISIS MULTICNTRICO EMPAREJADO POR PUNTAJE DE PROPENSIN

ANTECEDENTES:En los últimos años, se ha encontrado que el margen de resección circunferencial positivo es un indicador de enfermedad avanzada con alto riesgo de recurrencia a distancia más que de recurrencia local.OBJETIVO:El objetivo fue analizar el impacto pronóstico del margen de resección circunferencial sobre la recidiva local, a distancia y las tasas de supervivencia en pacientes con cáncer de recto.DISEÑO:Este fue un análisis multicéntrico emparejado por puntaje de propensión 2: 1 que comparó el margen de resección circunferencial positivo y negativo.AJUSTES:El estudio se realizó en 5 centros Españoles de alto volumen.PACIENTES:Se incluyeron pacientes sometidos a escisión total de mesorrecto con intención curativa por cáncer de recto medio-bajo entre 2006-2014. Las características clínicas e histológicas se utilizaron para el emparejamiento.PRINCIPALES MEDIDAS DE RESULTADO:Los resultadoes principales fueron la recurrencia local, la recurrencia a distancia, la supervivencia global y libre de enfermedad.RESULTADOS:La cohorte inicial no emparejada consistió en 1599 pacientes; El 4,9% tuvo un margen de resección circunferencial positivo. Tras el emparejamiento se incluyeron 234 pacientes (156 con margen circunferencial negativo y 78 con margen circunferencial positivo). La mediana del período de seguimiento fue de 52,5 meses (22,0-69,5). La recurrencia local fue significativamente mayor en pacientes con margen circunferencial positivo, 33,3% vs 11,5% [HR 3,2; IC 95%: 1,83-5,43; p < 0,001]. La recidiva a distancia fue similar en ambos grupos (46,2 % frente a 42,3 %) [HR 1,09, IC 95 %: 0,78-1,90; p = 0,651]. No hubo diferencias significativas en la supervivencia global a 5 años (48,6 % frente a 43,6 %) [HR 1,09, IC 95 %: 0,92-1,78; p = 0,14]; La supervivencia libre de enfermedad fue menor en pacientes con margen circunferencial positivo, 36,1% vs 52,3% [HR 1,5; IC 95%: 1,05-2,06; p = 0,026].LIMITACIONES:Este estudio estuvo limitado por el diseño retrospectivo. Las diferentes opciones de tratamientos neoadyuvantes no se han incluido en la puntuación de propensión.CONCLUSIONES:El margen de resección circunferencial positivo se asocia con una mayor tasa de recurrencia local y peor supervivencia libre de enfermedad en comparación con el margen de resección circunferencial negativo. Sin embargo, el margen de resección circunferencial positivo no fue un indicador pronóstico de recidiva a distancia ni de supervivencia global. Consulte el Video del Resumen en http://links.lww.com/DCR/B950 . (Traducción- Dr. Yesenia Rojas-Khalil ).

Regional variance in treatment and outcomes of locally invasive (T4) rectal cancer in Australia and New Zealand: analysis of the Bi-National Colorectal Cancer Audit

Backgrounds

Locally invasive T4 rectal cancer often requires neoadjuvant treatment followed by multi‐visceral surgery to achieve a radical resection (R0), and referral to a specialized exenteration quaternary centre is typically recommended. The aim of this study was to explore regional variance in treatment and outcomes of patients with locally advanced rectal cancer in Australia and New Zealand (ANZ).

Methods

Data were collected from the Bi‐National Colorectal Cancer Audit (BCCA) database. Rectal cancer patients treated between 2007 and 2019 were divided into six groups based on region (state/country) using patient postcode. A subset analysis of patients with T4 cancer was performed. Primary outcomes were positive circumferential resection margin (CRM+), and positive circumferential and/or distal resection margin (CRM/DRM+).

Results

A total of 9385 patients with rectal cancer were identified, with an overall CRM+ rate of 6.4% and CRM/DRM+ rate of 8.6%. There were 1350 patients with T4 rectal cancer (14.4%). For these patients, CRM+ rate was 18.5%, and CRM/DRM+ rate was 24.1%. Significant regional variation in CRM+ (range 13.4–26.0%; p = 0.025) and CRM/DRM+ rates (range 16.1–29.3%; p = 0.005) was identified. In addition, regions with higher CRM+ and CRM/DRM+ rates reported lower rates of multi‐visceral resections: range 24.3–26.8%, versus 32.6–37.3% for regions with lower CRM+ and CRM/DRM+ rates (p < 0.0001).

Conclusion

Positive resection margins and rates of multi‐visceral resection vary between the different regions of ANZ. A small subset of patients with T4 rectal cancer are particularly at risk, further supporting the concept of referral to specialized exenteration centres for potentially curative multi‐visceral resection.

What management for patients with R1 resection after total mesorectal excision for rectal cancer? A review of the literature

AIM OF THE STUDY

Treatment for rectal cancer is very standardized. However, for total mesorectal excision (TME) with positive margins at microscopic pathological examination (classified R1 ), there is no consensus regarding management. The objective of this update was, through a review of the literature, to identify the most suitable management to improve overall survival and/or recurrence-free survival after R1 TME for rectal cancer.

PATIENTS AND METHODS

Published national quality guidelines and original studies were searched on Pubmed. Only studies and recommendations concerning the specific management of patients who had undergone R1 TME resection were selected.

RESULTS

Five original non-randomized studies and seven published national quality guidelines were selected for review. For patients who have undergone R1 TME resection, the French and European published guidelines issued a Grade A recommendation in favor of post-operative radio-chemotherapy (RCT) for those in whom it had not already been performed pre-operatively. The French and European guidelines recommendation for adjuvant chemotherapy was based only on expert agreement. The original studies emphasized the survival benefit of adjuvant chemotherapy, as opposed to post-operative RCT, which did not seem to improve survival. Salvage surgery was not recommended in any of the studies.

CONCLUSION

After R1 TME resection for rectal cancer, adjuvant chemotherapy seems to be indicated when feasible, whereas post-operative RCT and salvage surgery do not appear to improve patient survival.

Prognostic importance of circumferential resection margin in the era of evolving surgical and multidisciplinary treatment of rectal cancer: A systematic review and meta-analysis

BACKGROUND

Circumferential resection margin is considered an important prognostic parameter after rectal cancer surgery, but its impact might have changed because of improved surgical quality and tailored multimodality treatment. The aim of this systematic review was to determine the prognostic importance of circumferential resection margin involvement based on the most recent literature.

METHODS

A systematic literature search of MEDLINE, Embase, and the Cochrane Library was performed for studies published between January 2006 and May 2019. Studies were included if 3- or 5-year oncological outcomes were reported depending on circumferential resection margin status. Outcome parameters were local recurrence, overall survival, disease-free survival, and distant metastasis rate. The Newcastle Ottawa Scale and Jadad score were used for quality assessment of the studies. Meta-analysis was performed using a random effects model and reported as a pooled odds ratio or hazard ratio with 95% confidence interval.

RESULTS

Seventy-five studies were included, comprising a total of 85,048 rectal cancer patients. Significant associations between circumferential resection margin involvement and all long-term outcome parameters were uniformly found, with varying odds ratios and hazard ratios depending on circumferential resection margin definition (<1 mm, ≤1 mm, otherwise), neoadjuvant treatment, study period, and geographical origin of the studies.

CONCLUSION

Circumferential resection margin involvement has remained an independent, poor prognostic factor for local recurrence and survival in most recent literature, indicating that circumferential resection margin status can still be used as a short-term surrogate endpoint.

Postoperative chemotherapy improves survival in patients with resected high-risk Stage II colorectal cancer: results of a systematic review and meta-analysis

AIM

The aim was to assess the benefit of adjuvant chemotherapy in high-risk Stage II colorectal cancer.

METHOD

A systematic literature review and meta-analysis was performed comparing survival in patients with resected Stage II colorectal cancer and high-risk features having postoperative chemotherapy vs no chemotherapy.

RESULTS

Of 1031 articles screened, 29 were included, reporting on 183 749 participants. Adjuvant chemotherapy significantly improved overall survival [hazard ratio (HR) 0.61, P < 0.0001], disease-specific survival (HR = 0.73, P = 0.05) and disease-free survival (HR = 0.59, P < 0.0001) compared to no chemotherapy. Adjuvant chemotherapy significantly increased 5-year overall survival (OR = 0.53, P = 0.0008) and 5-year disease-free survival (OR = 0.50, P = 0.001). Overall survival and disease-free survival remained significantly prolonged during subgroup analysis of studies published from 2015 onwards (HR = 0.60, P < 0.0001; HR = 0.65, P = 0.0001; respectively), in patients with two or more high-risk features (HR = 0.59, P = 0.0001; HR = 0.70, P = 0.03; respectively) and in colon cancer (HR = 0.61, P < 0.0001; HR = 0.51, P = 0.0001; respectively). Overall survival, disease-specific survival and disease-free survival during subgroup analysis of individual high-risk features were T4 tumour (HR = 0.58, P < 0.0001; HR = 0.50, P = 0.003; HR = 0.75, P = 0.05), < 12 lymph nodes harvested (HR = 0.67, P = 0.0002; HR = 0.80, P = 0.17; HR = 0.72, P = 0.02), poor differentiation (HR = 0.84, P = 0.35; HR = 0.85, P = 0.23; HR = 0.61, P = 0.41), lymphovascular or perineural invasion (HR = 0.55, P = 0.05; HR = 0.59, P = 0.11; HR = 0.76, P = 0.05) and emergency surgery (HR = 0.60, P = 0.02; HR = 0.68, P = 0.19).

CONCLUSION

Adjuvant chemotherapy in high-risk Stage II colorectal cancer results in a modest survival improvement and should be considered on an individual patient basis. Due to potential heterogeneity and selection bias of the included studies, and lack of separate rectal cancer data, further large randomized trials with predefined inclusion criteria and standardized chemotherapy regimens are required.

Defining and predicting early recurrence in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

BACKGROUND

The definition of "early recurrence (ER)" after rectal cancer surgery is currently unclear.

OBJECTIVE

To determine an evidence-based cut-off to distinguish early and late recurrence (LR) for patients with rectal cancer and compare the clinicopathological factors between the two groups.

METHODS

Patients who underwent neoadjuvant chemoradiotherapy (nCRT) and radical resection for locally advanced rectal cancer were included. A minimum p-value approach was used to evaluate the optimal cut-off value of recurrence-free survival to divide the patients into ER and LR groups based on overall survival. A logistic regression model was used to assess risk factors for ER.

RESULTS

A total of 763 patients were included, of which 167 (21.9%) experienced recurrence. The optimal cut-off value of recurrence-free survival to differentiate between ER (n = 125, 74.9%) and LR (n = 42, 25.1%) was 24 months (P = 0.000001). The median postrecurrence survival of ER and LR was 12 months and 22 months, respectively (p = 0.028). The most common recurrent sites in patients with ER and LR were lung metastases, the incidence of liver metastases, however, differed considerably in ER and LR (27.2% vs 9.5%, P = 0.019). Risk factors including elevated preoperative carcinoembryonic antigen (CEA), higher ypTNM stage, positive circumferential resection margin (CRM), and perineural invasion were significantly associated with ER.

CONCLUSION

A recurrence-free interval of 24 months is the optimal cut-off value for defining ER versus LR. Elevated preoperative CEA, higher ypTNM staging, positive CRM, and perineural invasion were associated with ER of locally advanced rectal cancer.

Raman spectroscopy for rapid intra-operative margin analysis of surgically excised tumour specimens

Raman spectroscopy, a form of vibrational spectroscopy, has the ability to provide sensitive and specific biochemical analysis of tissue. This review article provides an in-depth analysis of the suitability of different Raman spectroscopy techniques in providing intra-operative margin analysis in a range of solid tumour pathologies. Surgical excision remains the primary treatment of a number of solid organ cancers. Incomplete excision of a tumour and positive margins on histopathological analysis is associated with a worse prognosis, the need for adjuvant therapies with significant side effects and a resulting financial burden. The provision of intra-operative margin analysis of surgically excised tumour specimens would be beneficial for a number of pathologies, as there are no widely adopted and accurate methods of margin analysis, beyond histopathology. The limitations of Raman spectroscopic studies to date are discussed and future work necessary to enable translation to clinical use is identified. We conclude that, although there remain a number of challenges in translating current techniques into a clinically effective tool, studies so far demonstrate that Raman Spectroscopy has the attributes to successfully perform highly accurate intra-operative margin analysis in a clinically relevant environment.

Fluorescent-guided surgery for sentinel lymph node detection in gastric cancer and carcinoembryonic antigen targeted fluorescent-guided surgery in colorectal and pancreatic cancer

Sentinel lymph node procedures for gastric cancer resections using indocyanine green (ICG) linked to Nanocoll outperformed normal ICG but did not provide information on possible lymph node metastasis. Carcinoembryonic antigen targeted fluorescent imaging using SGM‐101 was successful in both pancreatic and colorectal cancer. A large phase III multicentre trial will soon be initiated in colorectal cancer patients.

Risk Factors Associated With Circumferential Resection Margin Positivity in Rectal Cancer: A Binational Registry Study

BACKGROUND

Rectal cancer outcomes have improved with the adoption of a multidisciplinary model of care. However, there is a spectrum of quality when viewed from a national perspective, as highlighted by the Consortium for Optimizing the Treatment of Rectal Cancer data on rectal cancer care in the United States.

OBJECTIVE

The aim of this study was to assess and identify predictors of circumferential resection margin involvement for rectal cancer across Australasia.

DESIGN

A retrospective study from a prospectively maintained binational colorectal cancer database was interrogated.

SETTINGS

This study is based on a binational colorectal cancer audit database.

PATIENTS

Clinical information on all consecutive resected rectal cancer cases recorded in the registry from 2007 to 2016 was retrieved, collated, and analyzed.

MAIN OUTCOME MEASURES

The primary outcome measure was positive circumferential resection margin, measured as a resection margin ≤1 mm.

RESULTS

A total of 3367 patients were included, with 261 (7.5%) having a positive circumferential resection margin. After adjusting for hospital and surgeon volume, hierarchical logistic regression analysis identified a 6-variable model encompassing the independent predictors, including urgent operation, abdominoperineal resection, open technique, low rectal cancer, T3 to T4, and N1 to N2. The accuracy of the model was 92.3%, with an receiver operating characteristic of 0.783 (p < 0.0001). The quantitative risk associated with circumferential resection margin positivity ranged from <1% (no risk factors) to 43% (6 risk factors).

LIMITATIONS

This study was limited by the lack of recorded long-term outcomes associated with circumferential resection margin positivity.

CONCLUSIONS

The rate of circumferential resection margin involvement in patients undergoing rectal cancer resection in Australasia is low and is influenced by a number of factors. Risk stratification of outcome is important with the increasing demand for publicly accessible quality data. See Video Abstract at http://links.lww.com/DCR/A512.

Image-guided surgery in cancer: A strategy to reduce incidence of positive surgical margins

Primary treatment for many solid cancers includes surgical excision or radiation therapy, with or without the use of adjuvant therapy. This can include the addition of radiation and chemotherapy after primary surgical therapy, or the addition of chemotherapy and salvage surgery to primary radiation therapy. Both primary therapies, surgery and radiation, require precise anatomic localization of tumor. If tumor is not targeted adequately with initial treatment, disease recurrence may ensue, and if targeting is too broad, unnecessary morbidity may occur to nearby structures or remaining normal tissue. Fluorescence imaging using intraoperative contrast agents is a rapidly growing field for improving visualization in cancer surgery to facilitate resection in order to obtain negative margins. There are multiple strategies for tumor visualization based on antibodies against surface markers or ligands for receptors preferentially expressed in cancer. In this article, we review the incidence and clinical implications of positive surgical margins for some of the most common solid tumors. Within this context, we present the ongoing clinical and preclinical studies focused on the use of intraoperative contrast agents to improve surgical margins. This article is categorized under: Laboratory Methods and Technologies > Imaging.

Safety and effectiveness of SGM-101, a fluorescent antibody targeting carcinoembryonic antigen, for intraoperative detection of colorectal cancer: a dose-escalation pilot study

BACKGROUND

Tumour-targeted fluorescence imaging has the potential to advance current practice of oncological surgery by selectively highlighting malignant tissue during surgery. Carcinoembryonic antigen (CEA) is overexpressed in 90% of colorectal cancers and is a promising target for colorectal cancer imaging. We aimed to assess the tolerability of SGM-101, a fluorescent anti-CEA monoclonal antibody, and to investigate the feasibility to detect colorectal cancer with intraoperative fluorescence imaging.

METHODS

We did an open-label, pilot study in two medical centres in the Netherlands. In the dose-escalation cohort, we included patients (aged ≥18 years) with primary colorectal cancer with increased serum CEA concentrations (upper limit of normal of ≥3 ng/mL) since diagnosis, who were scheduled for open or laparoscopic tumour resection. In the expansion cohort, we included patients (aged ≥18 years) with recurrent or peritoneal metastases of colorectal cancer, with increasing serum concentrations of CEA since diagnosis, who were scheduled for open surgical resection. We did not mask patients, investigators, or anyone from the health-care team. We assigned patients using a 3 + 3 dose design to 5 mg, 7·5 mg, or 10 mg of SGM-101 in the dose-escalation cohort. In the expansion cohort, patients received a dose that was considered optimal at that moment of the study but not higher than the dose used in the dose-escalation cohort. SGM-101 was administered intravenously for 30 min to patients 2 or 4 days before surgery. Intraoperative imaging was done to identify near-infrared fluorescent lesions, which were resected and assessed for fluorescence. The primary outcome was tolerability and safety of SGM-101, assessed before administration and continued up to 12 h after dosing, on the day of surgery, the first postoperative day, and follow-up visits at the day of discharge and the first outpatient clinic visit. Secondary outcomes were effectiveness of SGM-101 for detection of colorectal cancer, assessed by tumour-to-background ratios (TBR); concordance between fluorescent signal and tumour status of resected tissue; and diagnostic accuracy in both cohorts. This trial is registered with the Nederlands Trial Register, number NTR5673, and ClinicalTrials.gov, number NCT02973672.

FINDINGS

Between January, 2016, and February, 2017, 26 patients (nine in the dose-escalation cohort and 17 in the expansion cohort) were included in this study. SGM-101 did not cause any treatment-related adverse events, although three possibly related mild adverse events were reported in three (33%) of nine patients in the dose-escalation cohort and five were reported in three (18%) of 17 patients in the expansion cohort. Five moderate adverse events were reported in three (18%) patients in the expansion cohort, but they were deemed unrelated to SGM-101. No changes in vital signs, electrocardiogram, or laboratory results were found after administration of the maximum dose of 10 mg of SGM-101 in both cohorts. A dose of 10 mg, administered 4 days before surgery, showed the highest TBR (mean TBR 6·10 [SD 0·42] in the dose-escalation cohort). In the expansion cohort, 19 (43%) of 43 lesions were detected using fluorescence imaging and were not clinically suspected before fluorescent detection, which changed the treatment strategy in six (35%) of 17 patients. Sensitivity was 98%, specificity was 62%, and accuracy of fluorescence intensity was 84% in the expansion cohort.

INTERPRETATION

This study presents the first clinical use of CEA-targeted detection of colorectal cancer and shows that SGM-101 is safe and can influence clinical decision making during the surgical procedure for patients with colorectal cancer.

FUNDING

Surgimab.

[R1 resection of esophageal carcinoma]

The microscopic identification of residual tumor tissue in the oral or aboral resection margins (R1 resection) of esophageal specimens following oncologic esophageal resection, increases the risk of tumor recurrence and disease-related morbidity. Esophageal resection with its associated risks is only meaningful, if an R0 situation can be safely achieved. The relevance of microscopic involvement of the circumferential resection margin (CRM) in esophageal carcinoma in its different definitions by the British and the American Societies of Pathology has up to now never been investigated in a prospective study. According to the German S3 guideline, radiochemotherapy should be performed in a postoperatively proven R1 situation, which cannot be converted by a curative extended re-resection into an R0 situation or in unfavorable conditions for an extended re-resection, independent of neoadjuvant therapy. In the case of an R1 situation in the region of the CRM, an extended re-resection is not simply possible on account of the anatomical conditions with corresponding limitations by the aorta and the spinal column, in contrast to extensions of the re-resection orally or aborally.

Objective assessment of minimally invasive total mesorectal excision performance: a systematic review

INTRODUCTION

Laparoscopy is widely used in colorectal practice, but recent trial results have questioned its use in rectal cancer resections. Patient outcomes are directly linked to the quality of total mesorectal excision (TME) specimen. Objective assessment of intraoperative performance could help ensure competence and delivery of optimal outcomes. Objective tools may also contribute to TME intervention trials, but their nature, structure and utilisation is unknown.

AIM

To systemically review the available literature to report on the available tools for the objective assessment of minimally invasive TME operative performance and their use within multicentre laparoscopic TME randomised controlled trials.

METHODS

A systematic search of the PubMed and Cochrane databases was performed to identify tools used in the objective intraoperative assessment of minimally invasive TME performance in accordance with the PRISMA guidelines, independently by two authors. The identified tools were then evaluated within reported TME RCTs.

RESULTS

A total of 8642 abstracts were screened of which 12 papers met the inclusion criteria; ten prospective observational studies, one randomised trial and one educational consensus. Eight assessment methods were described, which include formative and summative tools. The tools were mostly adaptations of colonic surgery tools based on either operative video review or post-operative trainer rating. All studies reported objective assessment of intraoperative performance was feasible, but only 126 (7%) of the 1762 included laparoscopic cases were TME. No multicentre laparoscopic TME trial reported using any objective surgical performance assessment tool.

CONCLUSION

Objective intraoperative laparoscopic TME performance assessment is feasible, but most of the current tools are adaptation of colonic surgery. There is a need to develop dedicated assessment tools for minimal access rectal surgery. No multicentre minimally invasive TME RCT reported using any objective assessment tool.