MRI-defined height of rectal tumours

Defining the tumor location in rectal cancer - Practice variations and impact on treatment decision making

OBJECTIVE

To summarize differences in current guideline recommendations for rectal tumor localization and generate an overview of published MRI measurement methods and their correlation with endoscopy.

SUMMARYOF BACKGROUND DATA

Rectal tumor location is a well-known factor that impacts treatment planning, but there is currently no consensus on the optimal method to define it.

METHODS

A literature search was conducted to retrieve clinical and radiological rectal cancer guidelines as well as original research studies on MRI-based measurements. Guidelines were assessed for definitions, landmarks, modalities and measurement methods to define tumor location, and how these impact treatment planning. Research studies were evaluated to compare MRI-methods and their correlation with endoscopy.

RESULTS

18 clinical and 6 radiological guidelines were retrieved. In 83 % of clinical guidelines tumor location (low/middle/high) is included in the treatment algorithm as a factor impacting surgical and/or neoadjuvant treatment. Measurement cut-offs and landmarks vary significantly with the anal verge being the most commonly used landmark (28 %). Thirty-nine percent of clinical guidelines offer no definitions to define rectal tumor location. The majority of research studies (67 %) reported good-excellent agreement between MRI and endoscopy, though measurement differences of up to 2.5 cm were reported.

CONCLUSION

There is substantial variation in definitions and landmarks recommended in current guidelines to measure and classify rectal tumor location. This may affect treatment planning as well as trial inclusions, highlighting the need for standardized methods that better align between clinical and radiological guidelines.

Review of definition and treatment of upper rectal cancer

While the treatment of locally advanced lower and middle rectal cancer with total mesorectal excision (TME) after neoadjuvant therapy is now well defined, the treatment of locally advanced upper rectal cancer (LAURC) remains controversial. Although most teams and academic societies recommend upfront surgery (US) with partial mesorectal excision (PME), as this appears to be sufficient for these tumors, the literature remains conflicting regarding the additional use of neoadjuvant therapy and TME. Current recommendations for the treatment of LAURC do not reflect actual clinical practice. Notably, there is a paucity of published data specific to the treatment of LAURC since most of the data are from sub-analyses of different cohorts. Another important point responsible for the inconsistent data situation is the fact that the current definition of upper rectal cancer is based on anatomical criteria that are difficult to reproduce and therefore also differ between international professional societies. The aim of this review is to provide a deeper insight into the issues surrounding the treatment of LAURC based on an analysis of the current literature, including anatomic and embryologic data.

Perforated Peptic Ulcer: A Case Report of a Dreaded Complication of an Insidious Disease

Perforated peptic ulcers, though relatively rare, represent critical surgical emergencies with potentially life-threatening consequences. Their significance lies not only in their acute presentation but also in the diagnostic challenges they pose, particularly in patients with complex medical histories. Here we present a case of a 71-year-old female with a complex medical history, including insulin-dependent type 2 diabetes mellitus, hypertension, hyperlipidemia, hypothyroidism, dementia, diverticulitis, and chronic back pain, who initially were unresponsive and cyanotic. Despite challenges in diagnosis due to her medical complexity and opioid use, she was ultimately diagnosed with a perforated duodenal ulcer. Tragically, despite immediate surgical intervention, she succumbed to her illness, highlighting the complexities involved in managing perforated peptic ulcers, especially in patients with multiple chronic medical conditions. Peptic ulcer disease (PUD) can often remain asymptomatic, leading to delayed diagnosis and potentially life-threatening complications like perforation. Mortality rates associated with perforated peptic ulcers vary widely, ranging from 1.3% to 20%, with risk factors including nonsteroidal anti-inflammatory drug (NSAID) use, Helicobacter pylori infection, smoking, and corticosteroid use. Diagnosis necessitates a high index of suspicion, thorough clinical examination, and imaging modalities such as computed tomography (CT) scans with oral contrast. Treatment strategies range from nonoperative management with intravenous (IV) histamine H2-receptor blockers or proton pump inhibitors (PPIs) to surgical intervention, depending on the patient's hemodynamic stability. However, the case presented underscores the challenges in timely diagnosis and intervention, particularly in patients with complex medical histories, where symptoms may be masked or attributed to other comorbidities. Recent studies indicate a demographic shift toward older age and a higher prevalence among females, emphasizing the importance of increased awareness and vigilance among healthcare providers. Early recognition of symptoms, prompt investigation, and interdisciplinary collaboration are crucial in optimizing outcomes for patients presenting with perforated peptic ulcers, especially in the context of their underlying medical conditions.

Tumor size impact on TNM staging which define post-operative complications in rectal cancer

The purpose of this study was to see how accurate tumor size was at predicting T and N stages in rectal malignancies. Tumor sizes of 40 mm and greater than 40 mm were used to assess post-operative challenges in related to T1-T2 and T3-T4 stages, as well as between node N0 and node N1 and N2 patients. A total of 131 patients were treated for colorectal cancer, with 54 patients < 40 mm and 77 patients > 40 mm receiving Da Vinci colorectal surgery. Conferring to the Clavien-Dindo classification grade III, there's an increase in the percentage of tumors > 40 mm, which also impacts the percentage of intestinal obstruction, anastomotic leakage, GERD, and sepsis with a P < 0.05. A tumor size of more than 40 mm is strongly associated with advanced pT stages. Tumor size may serve in addition to clinical staging and improve the management of rectal cancer.

How to Study the Location and Size of Rectal Tumors That Are Candidates for Local Surgery: Rigid Rectoscopy, Magnetic Resonance, Endorectal Ultrasound or Colonoscopy? An Interobservational Study

1.

BACKGROUND

Preoperative staging of rectal lesions for transanal endoscopic surgery (TES) comprises digital rectal examination, intraoperative rigid rectoscopy (IRR), endorectal ultrasound (EUS), colonoscopy and rectal magnetic resonance imaging (rMRI). The gold standard for topographic features is IRR. Are the results of the other tests sufficiently reliable to eliminate the need for IRR? rMRI is a key test in advanced rectal cancer and is not operator-dependent. Description of anatomical landmarks is variable. Can we rely on the information regarding topographic features provided by all radiologists? 2.

MATERIALS AND METHODS

This is a concordance interobservational study involving four diagnostic tests of anatomical characteristics of rectal lesions (colonoscopy, EUS, rectal MRI and IRR), performed by four expert radiologists, regarding topographic rectal features with rMRI. 3.

RESULTS

Fifty-five rectal tumors were operated on by using TES. The distance of the tumor from the anal verge, location by quadrants, size by quadrants and size of tumor were assessed (IRR as gold standard). For most of the tumors, the correlation between IRR and colonoscopy or EUS was very good (ICC > 0.75); the correlation between rMRI and IRR in respect of the size by quadrants (ICC = 0.092) and location by quadrants (ICC = 0.292) was weak. Topographic landmarks studied by the expert radiologists had an excellent correlation, except for distance from the peritoneal reflection to the anal verge (ICC = 0.606). 4.

CONCLUSIONS

Anatomical description of rectal lesions by IRR, EUS, colonoscopy and rMRI is reliable. Topographic data obtained by EUS and colonoscopy can serve as a reference to avoid IRR. Determination of these topographic data by rMRI is less reliable. As performed by the expert radiologists, the anatomical study by rMRI is accurate and reproducible.

A boundary-guided transformer for measuring distance from rectal tumor to anal verge on magnetic resonance images

Accurate measurement of the distance from the tumor's lowest boundary to the anal verge (DTAV) provides an important reference value for treatment of rectal cancer, but the standard measurement method (colonoscopy) causes substantial pain. Therefore, we propose a method for automatically measuring the DTAV on sagittal magnetic resonance (MR) images. We designed a boundary-guided transformer that can accurately segment the rectum and tumor. From the segmentation results, we estimated the DTAV by automatically extracting the anterior rectal wall from the tumor's lowest point to the anal verge and then calculating its physical length. Experiments were conducted on a rectal tumor MR imaging (MRI) dataset to evaluate the efficacy of our method. The results showed that our method outperformed surgeons with 6 years of experience (p < 0.001). Furthermore, by referring to our segmentation results, attending and resident surgeons could improve their measurement precision and efficiency.

Lesion-to-anal-verge distance in rectosigmoid endometriosis on transvaginal sonography vs magnetic resonance imaging: prospective study

OBJECTIVES

To compare transvaginal sonography (TVS) and magnetic resonance imaging (MRI) with intraoperative measurement (IOM) using a rectal probe in the estimation of the location of rectosigmoid endometriotic lesions, i.e. lesion-to-anal-verge distance (LAVD), and to compare two different MRI techniques for measuring LAVD.

METHODS

This was a prospective single-center observational study that included women undergoing surgery for symptomatic rectosigmoid endometriosis by discoid (DR) or segmental (SR) resection from December 2018 to December 2019. TVS and MRI were performed presurgically for each participant to evaluate LAVD, and the measurements on imaging were compared with IOM using a rectal probe. Clinically acceptable difference and limits of agreement (LoA) between TVS and MRI compared with IOM were set at ± 20 mm. Two different measuring methods for MRI, MRI_Center and MRI_Direct , were proposed and evaluated, as there is currently no guideline to describe deep endometriosis on MRI. Bland-Altman plots and LoA were used to assess agreement of TVS and both MRI methods with IOM. Systematic and proportional biases were assessed using paired t-test and Bland-Altman plots.

RESULTS

Seventy-five women were eligible for inclusion. Twenty-eight women were excluded, leaving 47 women for the analysis. Twenty-three DR and 26 SR procedures were performed, with both procedures performed in two women. The Bland-Altman plots showed that there were no systematic differences between TVS or MRI_Center when compared with IOM for all included participants. MRI_Direct systematically underestimated LAVD for lesions located further from the anal verge. TVS, MRI_Center and MRI_Direct had LoA outside the preset clinically acceptable difference when compared with IOM. LAVD was within the clinically acceptable difference from IOM of ± 20 mm in 70% (33/47) of women on TVS, 72% (34/47) of women on MRI_Center and 47% (22/47) of women on MRI_Direct .

CONCLUSIONS

TVS should be the preferred method to estimate the location of a rectosigmoid endometriotic lesion, i.e. LAVD, as it is more available, less expensive and has a similar accuracy to that of MRI. Estimating LAVD can be relevant for planning colorectal surgery for rectosigmoid endometriosis. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Comparison of flexible endoscopy and magnetic resonance imaging in determining the tumor height in rectal cancer

BACKGROUND

Several modalities are available for the diagnosis of rectal cancer, including conventional gold standard rigid endoscopy and recent flexible endoscopy and magnetic resonance imaging (MRI). Each modality affects the management of these patients.

AIM

To compare the accuracy of flexible endoscopy and MRI in the measurement of tumor height in patients with rectal cancer.

METHODS AND RESULTS

This study included 174 patients with rectal cancer who underwent flexible endoscopy and MRI for the measurement of tumor height. Data on patient demographics, comorbidities, treatment, and histopathology were identified and collected. We evaluate intraclass correlation coefficient (ICC) and Bland-Altman plot to test the agreement between the measurements. ICC were excellent with an ICC of 89% (95%CI 48%-99%). The mean ± standard deviation of the distance from the anal verge to the distal part of the tumor was 7.73 ± .47 for flexible endoscopy and 6.21 ± 0.39 for MRI, with mean difference of 1.52 (p ˂ .001). The accordance between the two modalities was not affected by sex, age, body mass index, histopathology, or metastasis.

CONCLUSION

Excellent agreement between flexible endoscopy and MRI was noted, and no factor was found to affect such concordance.

Validation of pelvic magnetic resonance imaging as the method of choice to determine the distance to the anal margin in rectal cancer

INTRODUCTION

Distance from anal verge of rectal tumours and their anatomical relationships contribute to determine the multidisciplinary therapeutic strategy based on the combination of radio-chemotherapy and radical surgery. Our aims are to investigate which is the most accurate method for the preoperative measuring of the distance from the anal verge in rectal tumours and if the pelvic MRI can substitute the classical instrumental methods.

METHODS

Prospective study of diagnostic precision between flexible colonoscopy (FC), preoperative rigid rectosigmoidoscopy (pRR) and pelvic MRI in patients scheduled to radical surgery. Rigid intraoperative rectoscopy (iRR) was considered the reference test. The correlations between the different techniques and their determination coefficient as well as the intraclass correlation coefficient and the degree of agreement between the different tests were analyzed.

RESULTS

96 patients (65% males), mean age (SD): 68 (14.1) years were included. 72% received neoadjuvant treatment. The mean distance to the anal margin measured by FC = 103.5 mm, was significantly greater than others, which had similar values: pRR = 81.1; MRI = 77.4; iRR = 82.9 mm (P < .001). A significant intraclass correlation was observed and there was high agreement between all pre- and intraoperative measurements except for the performed by FC, which overestimated the results. MRI provided more individualized and accurate information.

CONCLUSIONS

There is variability between the measurement methods, being colonoscopy the least reliable. MRI offers objective, comparable, accurate and individualized values that can replace those obtained by pRR for tumours of any location in the rectum.

Accuracy of magnetic resonance imaging in defining dentate line in anal fistula

Purpose

To retrospectively assess the accuracy of magnetic resonance imaging (MRI) in defining dentate line in anal fistula.

Materials and methods

Seventy patients with anal fistulas were assessed by dynamic contrast-enhanced MRI. The distance from the dentate line to the anal verge for all patients was measured by MRI. To mitigate interference, 35 patients with anal fistulas whose internal openings were located on the dentate line were excluded from this study. Two observers independently judged the positional relationship between the internal opening and the MRI-defined dentate line, and compared with the results observed by surgeon to assess the accuracy.

Results

The distance between the MRI-defined dentate line and the anal verge depended on the location of the internal opening and the morphology of the anal canal mucosa. The distance based on the location the internal opening and the morphology of the anal canal mucosa was 18.2 ± 8.1 mm and 20.0 ± 5.3 mm on oblique coronal T2WI, respectively. Compared with the results observed by the surgeon, the accuracy of evaluating the positional relationship between the internal opening and the dentate line from the morphology of the anal canal mucosa on MRI exceeded 89.9%. Taking 18.2–20.0 mm as the distance between the dentate line and the anal verge on the MRI image, the accuracy of evaluating the relationship between the position of the internal opening and the dentate line was over 85.7%. Considering both the dentate line and the anal canal mucosa, the accuracy of evaluating the relationship between the internal opening and the dentate line was over 91.5%. The results of MRI-defined dentate line were in good agreement with the results of intraoperative surgeon evaluation, and the κ values were 0.70, 0.63, and 0.78, respectively.

Conclusion

MRI has high accuracy in defining the dentate line in anal fistulas.

Determination of the positional relationship of the second Houston valve and peritoneal reflection using computed tomographic colonography and magnetic resonance imaging

PURPOSE

The second Houston valve is used as a surrogate for estimating the position of the peritoneal reflection; however, the concordance between the positions of the valve and peritoneal reflection has not been investigated. This study aimed to clarify this positional relationship.

METHODS

The second Houston valve and peritoneal reflection positions were assessed using tomographic colonography and magnetic resonance imaging. In total, 117 patients were enrolled in this study.

RESULTS

The positions of the second Houston valve and peritoneal reflection were nearly concordant, although the space between them ranged from - 20.7 to 33.9 mm. A peritoneal reflection located further from the anal verge than the second Houston valve was defined as a shallow peritoneal reflection. Male sex, high body weight, and a high body mass index were significantly correlated with a shallower peritoneal reflection, as determined by a univariate analysis (sex: P = 0.0138, weight: P = 0.0097, body mass index: P = 0.0311). A multivariate analysis revealed a significantly shallower peritoneal reflection in males than in females (odds ratio: 2.75, 95% confidence interval: 1.15-6.56, P = 0.023).

CONCLUSIONS

The second Houston valve located near the peritoneal reflection can be a useful surrogate marker for estimating its position. In relatively heavy males, the peritoneal reflection is located more cranially than the second Houston valve.

How do they measure up: Assessing the height of rectal cancer with digital rectal exam, endoscopy, and MRI,

Background

Outcomes in rectal cancer are dependent on tumor height. Modalities for assessing tumor height include MRI, endoscopy, and digital rectal exam (DRE). We seek to identify correlations between these modalities.

Methods

Retrospective analysis of 120 rectal cancer patients at a single institution. Correlation coefficients and distance of the tumor to anal verge between MRI, endoscopy, and DRE were compared by region.

Results

The distances of tumor (cm) from anal verge were: MRI: 6.2 ± 3.0, endoscopy: 5.9 ± 2.9, DRE: 5.4 ± 2.4 (p = 0.238). Endoscopy and DRE strongly correlated with MRI (spearman coefficient 0.899 and 0.842, respectively). Endoscopy and DRE also strongly correlated (spearman coefficient 0.876). Correlation coefficients were highest in the middle rectum, weak in the low rectum, and non-correlated in the upper rectum.

Conclusions

MRI, endoscopy, and DRE strongly correlated overall. DRE demonstrated the lowest average distance. Correlations differed by region, suggesting high or low rectal tumors are difficult to characterize.

Measuring Rectal Cancer Tumor Height: Concordance Between Clinical Examination and MRI

BACKGROUND

Rectal cancer is categorized into categories on the basis of tumor height measurements. Tumor height is used to guide initial treatment and determines the eligibility for clinical trials.

OBJECTIVE

This study aimed to determine the concordance between tumor heights measured by MRI and by clinical examination.

DESIGN

This was an institutional review board-approved retrospective analysis of MRI and the clinical measurements of tumor height.

SETTING

This study was conducted at a single university center that was accredited by the Commission on Cancer National Accreditation Program for Rectal Cancer.

PATIENTS

Ninety-five patients who were treated between 2015 and 2019 and who had an MRI and clinical evaluation were included.

MAIN OUTCOME MEASUREMENTS

The mean difference of tumor height between MRI and clinical examination was calculated. Secondary outcomes were to assess whether position in the rectum, age, BMI, or sex would affect the difference and how the measurements would change eligibility for rectal cancer trials.

RESULTS

Tumor height measurement by MRI and clinical examination had a good correlation, with r = 0.89 and p < 0.001. The mean absolute difference of measurement of tumor height was 1.56 cm. Higher tumors had a larger absolute difference between measurements. Body mass index was significantly associated with the difference in measurements. The discordance in measurements led to a change in eligibility for clinical trials for 38.9% of patients. Clinical trial eligibility was not significantly associated with tumor height category, sex, or patient age.

LIMITATIONS

This study was conducted at a single center with retrospective methodology.

CONCLUSIONS

Although MRI and clinical measurements showed a strong correlation, nearly 40% of our patients had a change in clinical trial eligibility depending on measurement modality. We suggest that trial investigators be consistent in establishing measurement technique as their inclusion criterion. See Video Abstract at http://links.lww.com/DCR/B756.

MEDICIN DE LA ALTURA DEL TUMOR DE CNCER DE RECTO CONCORDANCIA ENTRE EL EXAMEN CLNICO Y LA RESONANCIA MAGNTICA

ANTECEDENTES:El cáncer de recto se clasifica en categorías basadas en las mediciones de la altura del tumor. La altura del tumor se usa para guiar el tratamiento inicial y determina la elegibilidad para los ensayos clínicos.OBJETIVO:Determinar la concordancia entre la altura de los tumores medida por resonancia magnética (RMN) y por examen clínico.DISEÑO:Este fue un análisis retrospectivo aprobado por el IRB de la resonancia magnética y las mediciones clínicas de la altura del tumor.AJUSTE:Esto se llevó a cabo en un único centro universitario que fue acreditado por el Programa Nacional de Acreditación del Cáncer de Recto de la Comisión de Cáncer.PACIENTE:Se incluyeron 95 pacientes que fueron atendidos entre 2015 y 2019 y que tuvieron una resonancia magnética y evaluación clínica.PRINCIPALES MEDIDAS DE RESULTADOS:Se calculó la diferencia media de la altura del tumor entre la resonancia magnética y el examen clínico. Los resultados secundarios fueron evaluar si la posición en el recto, la edad, el índice de masa corporal (IMC) o el sexo afectarían la diferencia y cómo las mediciones cambiarían la elegibilidad para los ensayos de cáncer de recto.RESULTADOS:La medición de la altura del tumor por resonancia magnética y el examen clínico tuvo una buena correlación con r = 0,89 y p < 0,001. La diferencia absoluta media de medición de la altura del tumor fue de 1,56 cm. Los tumores más altos tenían una diferencia absoluta más grande entre las mediciones. El IMC se asoció significativamente con la diferencia en las mediciones. La discordancia en las mediciones llevó a un cambio en la elegibilidad para los ensayos clínicos para el 38,9% de los pacientes. La elegibilidad para ensayos clínicos no se asoció significativamente con la categoría de altura del tumor, el sexo o la edad del paciente.LIMITACIONES:Se realizó en un solo centro con metodología retrospectiva.CONCLUSIONES:Aunque la resonancia magnética y las mediciones clínicas mostraron una fuerte correlación, casi el 40% de nuestros pacientes tuvieron un cambio en la elegibilidad para los ensayos clínicos según la modalidad de medición. Sugerimos que los investigadores del ensayo sean coherentes al establecer la técnica de medición como criterio de inclusión. Consulte Video Resumen en http://links.lww.com/DCR/B756.

Trajectory of change of low anterior resection syndrome over time after restorative proctectomy for rectal adenocarcinoma

BACKGROUND

Restorative proctectomy for rectal cancer is associated with a high incidence of low anterior resection syndrome (LARS), but few studies report longitudinal results for bowel function. The aim of our study was to examine the trajectory of change of LARS over the first 18 months after restorative proctectomy for rectal cancer.

METHODS

A prospective database measuring functional outcomes in rectal cancer patients from a single university-affiliated specialist colorectal referral center from 10/2018 to 03/2020 was queried. Patients were included in this study if they underwent restorative proctectomy for rectal cancer and had at least three assessments in the first 18 months after primary surgery or after closure of proximal diversion. Bowel function was assessed using the LARS score, administered at every surveillance follow-up after restoration of bowel continuity. Latent-class growth curve (trajectory) analysis was used to identify different trajectories of LARS changes over the first 18 months and group patients into these trajectory groups. These groups were then compared to identify predictors for each trajectory.

RESULTS

A total of 95 patients were included (63 males, mean age. 61.3 ± 12.5 years). Trajectory analysis identified three distinct trajectory groups. Group 1 had stable minimal LARS over time (26%). Group 2 had early LARS scores consistent with the minor LARS category and improved with time (28%). Group 3 had persistently high LARS scores (45%). Neoadjuvant therapy, intersphincteric resection, and proximal diversion were more common in group 3.

CONCLUSIONS

We identified three main trajectories of change of LARS in the 18 months after restorative proctectomy. These data may be used to better inform patients of their expected postoperative bowel function.

Validation of pelvic magnetic resonance imaging as the method of choice to determine the distance to the anal margin in rectal cancer

INTRODUCTION

Distance from anal verge of rectal tumors and their anatomical relationships contribute to determine the multidisciplinary therapeutic strategy based on the combination of radio-chemotherapy and radical surgery. Our aims are to investigate which is the most accurate method for the preoperative measuring of the distance from the anal verge in rectal tumors and if the pelvic MRI can substitute the classical instrumental methods.

METHODS

Prospective study of diagnostic precision between flexible colonoscopy (FC), preoperative rigid rectosigmoidoscopy (pRR) and pelvic MRI in patients scheduled to radical surgery. Rigid intraoperative rectoscopy (iRR) was considered the reference test. The correlations between the different techniques and their determination coefficient as well as the intraclass correlation coefficient and the degree of agreement between the different tests were analyzed.

RESULTS

96 patients (65% males), mean age (SD): 68 (14.1) years were included. 72% received neoadjuvant treatment. The mean distance to the anal margin measured by FC=103.5mm, was significantly greater than others, which had similar values: pRR=81.1; MRI=77.4; iRR=82.9mm (P<.001). A significant intraclass correlation was observed and there was high agreement between all pre- and intraoperative measurements except for the performed by FC, which overestimated the results. MRI provided more individualized and accurate information.

CONCLUSIONS

There is variability between the measurement methods, being colonoscopy the least reliable. MRI offers objective, comparable, accurate and individualized values that can replace those obtained by pRR for tumors of any location in the rectum.

Measurement of rectal tumor height from the anal verge on MRI: a comparison of internal versus external anal sphincter

PURPOSE

To determine the most accurate measurement technique to assess rectal tumor height on MRI using two different anatomic landmarks for the anal verge.

INTRODUCTION

Accurate measurements and standardized reporting of MRI for rectal cancer staging is essential. It is not known whether measurements starting from the internal anal sphincter (IAS) or external anal sphincter (EAS) more closely correlate with tumor height from the anal verge on endoscopy.

METHODS

This retrospective study included baseline staging MRI examinations for 85 patients after exclusions. Two radiologists blinded to endoscopic results measured the distance of rectal tumors from the internal anal sphincter and external anal sphincter on sagittal T2 images. The reference standard was endoscopic measurement of tumor height; descriptive statistics were performed.

RESULTS

For reader 1, the mean difference in measurement of tumor height between MRI and endoscopy was - 0.45 cm (SD ± 1.76 cm, range - 6.0 to 3.9 cm) for the IAS and 0.51 cm (SD ± 1.75 cm range - 4.7 to 4.8 cm) for the EAS. For reader 2, the mean difference in measurement of tumor height between MRI and endoscopy was - 0.57 (STD ± 1.81, range - 5.9 to 4.8 cm) for the IAS and 0.52 cm (STD ± 1.85, range - 4.3 to 5.6 cm) for the EAS. Interobserver ICC was excellent between reader 1 and reader 2 for measurements from both the IAS (0.955 95% CI 0.931-0.97) and EAS (0.952, 95% CI 0.928, 0.969).

CONCLUSION

Measurement of tumor height on MRI was highly reproducible between readers; beginning measurements from the EAS tends to slightly overestimate tumor height on average and from the IAS tends to slightly underestimate tumor height on average.

How to accurately measure the distance from the anal verge to rectal cancer on MRI: a prospective study using anal verge markers

PURPOSE

To determine an accurate method for localizing rectal cancer using the distance from the anal verge on preoperative MRI.

METHODS

This prospective study included 50 patients scheduled for MRI evaluation of rectal cancer. After rectal filling with gel, MRI was performed with two markers attached at the anal verge. The distance between the tumor and the anal verge on a sagittal T2-weighted image (T2WI) was measured independently by two radiologists using six methods divided into three groups of similar measurement approaches, and compared to those obtained on rigid sigmoidoscopy. The anal verge location relative to the external anal sphincter was assessed on oblique coronal T2WI in reference to the markers. Correlation analysis was performed using the intraclass correlation coefficient (ICC) for verification, and a paired t test was used to evaluate the mean differences.

RESULTS

The highest correlation (ICC 0.797-0.815) and the least mean difference (0.74-0.85 cm) with rigid sigmoidoscopy, and the least standard deviation (3.12-3.17 cm) were obtained in the direct methods group using a straight line from the anal verge to the tumor. The anal verge was localized within a range of - 1.4 to 1.5 cm (mean - 0.31 cm and - 0.22 cm) from the lower end of the external anal sphincter.

CONCLUSION

The direct methods group provided the most accurate tumor distance among the groups. Among the direct methods, we recommend the direct mass method for its simplicity. Despite minor differences in location, the lower end of the external anal sphincter was a reliable anatomical landmark for the anal verge.

Height of Rectal Cancer: A Comparison between Rectoscopic and Different MRI Measurements

Purpose

To compare rigid rectoscopy with three different MRI measurement techniques for rectal cancer height determination, all starting at the anal verge, in order to evaluate whether MRI measurements starting from the anal verge could be an alternative to rigid rectoscopy. Moreover, potential cut-off values for MRI in categorizing tumor height measurements were evaluated.

Methods

In this retrospective study, 106 patients (75 men, 31 female, mean age 64 ± 11.59 years) with primary rectal cancer underwent rigid rectoscopy as well as MR imaging. Three different measurements (MRI1-3) in T2w sagittal scans were used to evaluate the exact distance from the anal verge (AV) to the distal ending of the tumor (MRI1: two unbowed lines, AV to the upper ending of the anal canal and upper ending of the anal canal to the lower border of the tumor; MRI2: one straight line from the AV to the lower boarder of the tumor; MRI3: a curved line beginning at the AV and following the course of the rectum wall ending at the lower border of the tumor). Furthermore, agreement between the gold standard rigid rectoscopy (UICC classification: low part, 0-6 cm; mid part, 6-12 cm; and high part, >12 cm) and each MRI measuring technique was analyzed.

Results

Only a fair correlation in terms of individual measures between rectoscopy and all 3 MRI measurement techniques was shown. The proposed new cut-off values utilizing ROC analysis for the three different MRI beginning at the anal verge were low 0-7.7 cm, mid 7.7-13.3 cm, and high > 13.3 cm (MRI1); low 0-7.4 cm, mid 7.4-11.2 cm, and high > 11.2 cm (MRI2); and low 0-7.1 cm, mid 7.1-13.7 cm, and high > 13.7 cm (MRI3). For MRI1 and MRI3, the agreement to the gold standard was substantial (r = 0.66, r = 0.67, respectively).

Conclusion

This study illustrates that MRI1 and MRI3 measures can be interchangeably used as a valid method to determine tumor height compared to the gold standard rigid rectoscopy.

Impact of a multidisciplinary training programme on outcome of upper rectal cancer by critical appraisal of the extent of mesorectal excision with postoperative MRI

BACKGROUND

Optimal management of patients with upper rectal cancer remains unclear. Partial mesorectal excision (PME) without neoadjuvant therapy is currently advocated for the majority of patients. Recent studies, however, reported a high risk of local recurrence and suboptimal surgery. The aim of this study was to evaluate the effects of a quality assurance initiative with postoperative MRI to improve outcomes in these patients.

METHODS

Patients who underwent mesorectal excision with curative intent for rectal cancer in 2007-2013 were included. Postoperative MRI of the pelvis was performed 1 year after surgery. In 2011, a multidisciplinary workshop with focus on extent and completeness of surgery was held for training surgeons, pathologists and radiologists involved in treatment planning. Images of residual mesorectum and histopathological reports were reviewed with regard to the distal resection margin. Local recurrence after a minimum of 3 years' follow-up was compared between two cohorts from 2007-2010 and 2011-2013.

RESULTS

A total of 627 patients were included; postoperative MRI of the pelvis was done in 381 patients. The 3-year actuarial local recurrence rate in patients with upper rectal cancer improved from 12·9 to 5·0 per cent (P = 0·012). After the workshop, fewer patients with cancer of the upper rectum were selected to have PME (90·8 per cent in 2007-2010 versus 80·2 per cent in 2011-2013; P = 0·023), and fewer patients who underwent PME had an insufficient distal resection margin (61·7 versus 31 per cent respectively; P < 0·001).

CONCLUSION

Quality assessment of surgical practice may have a major impact on oncological outcome after surgery for upper rectal cancer.

A teaching project on rectal cancer and concentration of procedures: a comparison of oncological results between Catalonia and the rest of autonomous communities

INTRODUCTION

the goal of this study was to compare the oncological results (local recurrence, metastasis and overall survival) obtained by the Proyecto Docente del Cáncer de Recto of the Spanish Association of Surgeons (AEC) (Proyecto Vikingo, PV) in Catalonia versus the rest of Spanish autonomous communities.

METHODS

the PV database includes 4,508 patients who underwent a curative resection between March 2006 and December 2010, from the first 59 hospitals included in PV; 1,163 were from Catalonia and 3,345 were from the rest of Spain. There was a minimum follow-up of five years.

RESULTS

in Catalonia, the five-year cumulative incidence was 8% (95% CI: 6.4-9.9) for local recurrence, 17.7% (95% CI: 15.4-20.2) for metastasis and 75% (95% CI: 72.4-77.7) for overall survival. In the rest of autonomous communities, these figures were 7% (95% CI: 6.2-8.2) for local recurrence, 22.3% (95% CI: 20.7-23.9) for metastasis, and 71% (95% CI: 69.4-72.9) for overall survival. Variables associated with tumor recurrence in PV included Hartmann's procedure, intraoperative perforation and circumferential margin involvement.

CONCLUSION

the results obtained by the Proyecto Docente del Cáncer de Recto were homogeneous between Catalonia and the rest of the autonomous communities.

Structured training pathway and proctoring; multicenter results of the implementation of transanal total mesorectal excision (TaTME) in the Netherlands

Background

Transanal total mesorectal excision (TaTME) is a new complex technique with potential to improve the quality of surgical mesorectal excision for patients with mid and low rectal cancer. The procedure is technically challenging and has shown to be associated with a relative long learning curve which might hamper widespread adoption. Therefore, a national structured training pathway for TaTME has been set up in the Netherlands to allow safe implementation. The aim of this study was to monitor safety and efficacy of the training program with 12 centers.

Methods

Short-term outcomes of the first ten TaTME procedures were evaluated in 12 participating centers in the Netherlands within the national structured training pathway. Consecutive patients operated during and after the proctoring program for rectal carcinoma with curative intent were included. Primary outcome was the incidence of intraoperative complications, secondary outcomes included postoperative complications and pathological outcomes.

Results

In October 2018, 12 hospitals completed the training program and from each center the first 10 patients were included for evaluation. Intraoperative complications occurred in 4.9% of the cases. The clinicopathological outcome reported 100% for complete or nearly complete specimen, 100% negative distal resection margin, and the circumferential resection margin was positive in 5.0% of patients. Overall postoperative complication rate was 45.0%, with 19.2% Clavien–Dindo ≥ III and an anastomotic leak rate of 17.3%.

Conclusions

This study shows that the nationwide structured training program for TaTME delivers safe implementation of TaTME in terms of intraoperative and pathology outcomes within the first ten consecutive cases in each center. However, postoperative morbidity is substantial even within a structured training pathway and surgeons should be aware of the learning curve of this new technique.

Variation in landmarks for the rectum: an MRI study

AIM

This study aimed to assess the reliability of measurements and bony landmarks for the rectosigmoid junction on MRI.

METHOD

The staging MRI scans for 100 patients were reviewed. The junction of the mesorectum and mesocolon was used to identify the rectum and sigmoid. The performance of current metric measurements or bony landmarks was then compared against the actual anatomical bowel segment.

RESULTS

The mean distance of the sigmoid take-off from the anal verge was 12.6 cm (SD 1.8 cm, range 9.4-19.0 cm). At a cutoff of 12 cm, the anatomical bowel segment was found to be sigmoid colon rather than rectum in 35% of patients. At 15 and 16 cm the bowel segment was sigmoid in 84% and 96% of patients, respectively. At the sacral promontory and the third sacral segment, the bowel segment was sigmoid in 28% and 100% of patients, respectively.

CONCLUSION

Current definitions of the rectum that rely on arbitrary measurements or bony landmarks will not locate the correct point of transition between the rectum and sigmoid in the majority of patients. The sigmoid take-off offers an alternative, anatomically bespoke, landmark.

The influence of endorectal filling on rectal cancer staging with MRI

OBJECTIVE

To assess the influence of endorectal filling (EF) on rectal cancer staging.

METHODS

47 patients who underwent a staging MRI of rectal cancer in the period from 2011 to 2014 were included. The MRI protocol included T₂ weighted fast spin echo sequences without and with EF at 3 T (EF-MRI). Images were scored by two readers for T-stage, distance of the lower pole of the tumour to the anorectal junction, distance to the mesorectal fascia (MRF), and number of (suspicious) lymph nodes. Agreement in T-staging was calculated using the Cohen's κ value. Comparison of continuous variables was performed using Wilcoxon matched pairs signed-rank test.

RESULTS

The interobserver agreement for T-staging with and without EF-MRI showed a poor agreement between both readers (weighted κ = 0.156, weighted κ = 0.037, respectively). Tumours tended to be overstaged more prominently with EF-MRI. The accuracy of predicting the pathological T-stage slightly improved from 55% with EF to 64% without EF for Reader 1 and from 59 to 68% for Reader 2, respectively. The distance of the tumour to the anorectal junction increased from 33.9 to 49.3 mm (p < 0.001) after EF for Reader 2. EF-MRI did not significantly influence the number of (suspicious) lymph nodes and distance to the mesorectal fascia.

CONCLUSION

EF-MRI did not lead to an improved tumour staging and it has the potential to influence the distance to a key anatomical landmark. EF-MRI is therefore not recommended in primary staging rectal cancer. Advances in knowledge: EF-MRI may not be used as an additional tool to stage rectal cancer patients, as it does not seem to facilitate in locoregionally staging the disease.

Oncological results of the educational Rectal Cancer Project in Spain 10 years after its implementation

INTRODUCTION

The objective of this observational, prospective, multicenter and multilevel study was to evaluate the oncological outcomes (local recurrence, metastasis and overall survival) of the Rectal Cancer Project of the Spanish Association of Surgeons (AEC) 10 years after its initiation, comparing the results with Scandinavian registries.

METHODS

The AEC teaching project database includes 17,620 patients to date, of which 4,508 were operated on with a potentially curative resection between March 2006 and December 2010. All of them come from the first 59 hospitals included in the project, and therefore followed for at least 5 years, and are the subject of the present study.

RESULTS

The cumulative incidence of local recurrence was 7.3 (95% CI: 8.2-6.5), metastasis 21.0 (CI 95%: 22.4-19.7) and overall survival 72.3 (CI 95%: 80.3-77.6). The multilevel regression analysis with the hospital variable as a random effect, showed a significant variation among the hospitals for the cancer outcome variables: general survival, local recurrence and metastasis (δ2=0.053).

CONCLUSIONS

This study indicates that the results observed in the AEC' Rectal Cancer Project are inferior than those observed in the Scandinavian registries that we tried to emulate and that this is attributable to the variability of practice in some centers.

Comparison of MRI and colonoscopy in determining tumor height in rectal cancer

Background and aim

Endoscopy and magnetic resonance imaging (MRI) are used routinely in the diagnostic and preoperative work-up of rectal cancer. We aimed to compare colonoscopy and MRI in determining rectal tumor height.

Methods

Between 2002 and 2012, all patients with rectal cancer with available MRIs and endoscopy reports were included. All MRIs were reassessed for tumor height by two abdominal radiologists. To obtain insight in techniques used for endoscopic determination of tumor height, a survey among regional endoscopists was conducted.

Results

A total of 211 patients with rectal cancer were included. Tumor height was significantly lower when assessed by MRI than by endoscopy with a mean difference of 2.5 cm (95% CI: 2.1-2.8). Although the agreement between tumor height as measured by MRI and endoscopy was good (intraclass correlation coefficient (ICC) 0.7 (95% CI: 0.7-0.8)), the 95% limits of agreement varied from -3.0 cm to 8.0 cm. In 45 patients (21.3%), tumors were regarded as low by MRI and middle-high by endoscopy. MRI inter- and intraobserver agreements were excellent with an ICC of 0.8 (95% CI: 0.7-0.9) and 0.9 (95% CI: 0.9-1.0), respectively. The survey showed no consensus among endoscopists as to how to technically measure tumor height.

Conclusion

This study showed large variability in rectal tumor height as measured by colonoscopy and MRI. Since MRI measurements showed excellent inter- and intraobserver agreement, we suggest using tumor height measurement by MRI for diagnostic purposes and treatment allocation.

Defining the distal margin of rectal cancer for surgical planning

Accurate measurement of the distal rectal tumor margin is essential in selecting the appropriate surgical procedure. However, there is no standard measurement method. The National Cancer Institute consensus group recommends use of the anal verge (AV) as a landmark, and the European Society of Gastrointestinal and Abdominal Radiology recommends use of the anorectal ring (ARR). In addition, whether measurements should be made on double contrast barium enema (BE) radiographs or magnetic resonance (MR) images remains controversial. We measured the distal tumor margin on both BE and MR images obtained preoperatively from 52 patients who underwent sphincter-saving resection for rectal cancer. The distances from the distal end of the tumor to the AV and the ARR were measured on both types of images, and the variability was investigated by Bland-Altman analysis. The mean distance from the tumor to the AV was 8.9 cm on the BE radiographs and 7.7 cm on the MR images (P=0.013). The mean distances to the ARR were 6.8 and 5.6 cm, respectively (P=0.070). Significant proportional bias was shown as the measured distances increased, the difference between the BE- and magnetic resonance imaging (MRI)-based measurements increased. Use of one or the other landmark did not affect selection of the appropriate surgical procedure. We conclude that an approximate 1-cm underestimation should be taken into account when MRI-based measurement of the distal rectal tumor margin is used to choose between sphincter-saving resection and abdominoperineal resection.

Clinical outcomes and case volume effect of transanal total mesorectal excision for rectal cancer: a systematic review

Transanal total mesorectal excision (TaTME) has been developed to improve quality of TME for patients with mid and low rectal cancer. However, despite enthusiastic uptake and teaching facilities, concern exists for safe introduction. TaTME is a complex procedure and potentially a learning curve will hamper clinical outcome. With this systematic review, we aim to provide data regarding morbidity and safety of TaTME. A systematic literature search was performed in MEDLINE (PubMed), EMBASE (Ovid) and Cochrane Library. Case reports, cohort series and comparative series on TaTME for rectal cancer were included. To evaluate a potential effect of case volume, low-volume centres (n ≤ 30 total volume) were compared with high-volume centres (n > 30 total volume). Thirty-three studies were identified (three case reports, 25 case series, five comparative studies), including 794 patients. Conversion was performed in 3.0% of the procedures. The complication rate was 40.3, and 11.5% were major complications. The quality of the mesorectum was “complete” in 87.6%, and the circumferential resection margin (CRM) was involved in 4.7%. In low- versus high-volume centres, the conversion rate was 4.3 versus 2.7%, and major complication rates were 12.2 versus 10.5%, respectively. TME quality was “complete” in 80.5 versus 89.7%, and CRM involvement was 4.8 and 4.5% in low- versus high-volume centres, respectively. TaTME for mid and low rectal cancer is a promising technique; however, it is associated with considerable morbidity. Safe implementation of the TaTME should include proctoring and quality assurance preferably within a trial setting.

Effect of hospital caseload on long-term outcome after standardization of rectal cancer surgery in the Spanish Rectal Cancer Project

INTRODUCCIóN: The purpose of this prospective multicentre multilevel study was to investigate the influence of hospital caseload on long-term outcomes following standardization of rectal cancer surgery in the Rectal Cancer Project of the Spanish Society of Surgeons.

METHODS

Data relating to 2910 consecutive patients with rectal cancer treated for cure between March 2006 and March 2010 were recorded in a prospective database. Hospitals were classified according to number of patients treated per year as low-volume, intermediate-volume, or high volume hospitals (12-23, 24-35, or ≥36 procedures per year).

RESULTS

After a median follow-up of 5 years, cumulative rates of local recurrence, metastatic recurrence and overall survival were 6.6 (CI95% 5.6-7.6), 20.3 (CI95% 18.8-21.9) and 73.0 (CI95% 74.7 - 71.3) respectively. In the multilevel regression analysis overall survival was higher for patients treated at hospitals with an annual caseload of 36 or more patients (HR 0,727 [CI95% 0,556-0,951]; P=.02). The risk of local recurrence and metastases were not related to the caseload. Moreover, there was a statistically significant variation in overall survival (median hazard ratio [MHR] 1.184 [CI95% 1.071-1,333]), local recurrence (MHR 1.308 [CI95% 1.010-1.668]) and metastases (MHR 1.300 [CI95% 1.181; 1.476]) between all hospitals.

CONCLUSIONS

Overall survival was higher for patients treated at hospitals with an annual caseload of 36 or more patients. However, local recurrence was not influenced by caseload.

Recognition of Anterior Peritoneal Reflections and Their Relationship With Rectal Tumors Using Rectal Magnetic Resonance Imaging

Our goal was to explore the factors influencing the visualization of anterior peritoneal reflections (APRs) using rectal MRI. We evaluated the usefulness of rectal MRI in measuring the distance from the anal verge to the APR and determining the relationship between the APR and the rectal tumor. Clinical and imaging data from 319 patients who underwent surgery after MRI examination between October 2010 and December 2013 were retrospectively analyzed. The distance from the anal verge to the APR and the relationship between the APR and the location of the rectal tumor was evaluated. analysis of variance, logistic regression, independent samples t tests, and Kappa tests were used for statistical analysis. The APR was visible in 283 of 319 cases using rectal MRI. The APR was more readily observed in patients who were older than 58 years (P = 0.046), in patients whose subcutaneous fat thicknesses were >22.2 mm (P = 0.004), in patients with nondistended bladders (P = 0.001), and in those with an anteversion of the uterus (P = 0.001). There was a significant difference between the distance from the anal verge to the APR between females (10.4 ± 1.1 cm) and males (10.0 ± 1.2 cm; P = 0.014). The accuracy in predicting tumor location with respect to the APR was 70%, 50%, 98.2%, respectively for patients with tumors located above, at, and below the APR (compared with the location determined during surgery). Most of the APRs were visible using rectal MRI, whereas certain internal factors influence visualization. Rectal MRI could be a useful tool for evaluating the distance from the anal verge to the APR and relationship between rectal tumors and the APR.

[Hospital variation in anastomotic leakage after rectal cancer surgery in the Spanish Association of Surgeons project: The contribution of hospital volume]

OBJECTIVE

This multicentre observational study aimed to determine the anastomotic leak rate in the hospitals included in the Rectal Cancer Project of the Spanish Society of Surgeons and examine whether hospital volume may contribute to any variation between hospitals.

METHODS

Hospital variation was quantified using a multilevel approach on prospective data derived from the multicentre database of all adenocarcinomas of the rectum operated by an anterior resection at 84 surgical departments from 2006 to 2013. The following variables were included in the analysis; demographics, American Society of Anaesthesiologists classification, use of defunctioning stoma, tumour location and stage, administration of neoadjuvant treatment, and annual volume of elective surgical procedures.

RESULTS

A total of 7231 consecutive patients were included. The rate of anastomotic leak was 10.0%. Stratified by annual surgical volume hospitals varied from 9.9 to 11.3%. In multilevel regression analysis, the risk of anastomotic leak increased in male patients, in patients with tumours located below 12 cm from the anal verge, and advanced tumour stages. However, a defunctioning stoma seemed to prevent this complication. Hospital surgical volume was not associated with anastomotic leak (OR: 0.852, [0.487-1.518]; P=.577). Furthermore, there was a statistically significant variation in anastomotic leak between all departments (MOR: 1.475; [1.321-1.681]; P<0.001).

CONCLUSION

Anastomotic leak varies significantly among hospitals included in the project and this difference cannot be attributed to the annual surgical volume.

The anthropometric definition of the rectum is highly variable

PURPOSE

The precise definition of the rectum is essential for localizing colorectal pathology, yet current definitions are nebulous. The objective of this study is to determine the anthropometric definition of common pelvic landmarks in relation to patient characteristics.

METHODS

Seventy-one patients underwent open proctectomy with intra-operative measurements from the anal verge to various pelvic landmarks, and patient characteristics were evaluated. Analyses were performed using Spearman correlation and Wilcoxon rank sum.

RESULTS

The mean landmark distance was dentate line = 1.7 cm (range 0.8-4.0 cm), puborectalis muscle = 4.2 cm (range 2.0-8.0 cm), anterior peritoneal reflection = 13.2 cm (range 8.5-21.0 cm), sacral promontory = 17.9 cm (range 13.0-26.0 cm), and confluence of the taenia = 25.5 cm (range 16.0-44.0 cm). Men had longer mean distances to the dentate line (p = 0.0003), puborectalis muscle (p = 0.03), and anterior peritoneal reflection (p = 0.02). Patient weight significantly correlated with distance to all landmarks except for the confluence of the taenia, which did not correlate with any patient factor.

CONCLUSIONS

The location of common pelvic landmarks is highly variable. The use of predefined absolute measurements from the anal verge to localize rectal pathology is inaccurate and fails to account for patient variability.

Oncological outcome following anastomotic leak in rectal surgery

BACKGROUND

The influence of anastomotic leak on local recurrence and survival remains debated in rectal cancer.

METHODS

This was a multicentre observational study using data from the Spanish Rectal Cancer Project database. Demographics, American Society of Anesthesiologists classification, tumour location, stage, use of defunctioning stoma, administration of neoadjuvant and adjuvant treatment, invasion of circumferential resection margin, quality of mesorectal excision and anastomotic leakage were recorded. Anastomotic leak was defined as an anastomotic event requiring surgical intervention or interventional radiology, including pelvic abscesses without radiological evidence of leakage and early rectovaginal fistulas. Variables associated with oncological outcome were assessed by multivariable Cox regression analysis.

RESULTS

A total of 1181 consecutive patients were included. Rates of anastomotic leak and 30-day postoperative mortality were 9·4 and 2·4 per cent respectively. Data from 1153 patients were analysed after a median follow-up of 5 years. Cumulative rates of local recurrence, overall recurrence, overall survival and cancer-specific survival were 4·9, 19·4, 77·5 and 84·7 per cent respectively. In the multivariable regression analysis, anastomotic leakage was not associated with local recurrence (hazard ratio (HR) 0·80, 95 per cent c.i. 0·28 to 2·26; P = 0·669), overall recurrence (HR 1·14, 0·70 to 1·85; P = 0·606), overall survival (HR 1·10, 0·73 to 1·65; P = 0·648) or cancer-specific survival (HR 1·23, 0·75 to 2·02; P = 0·421).

CONCLUSION

Anastomotic leak after low anterior resection did not affect oncological outcomes in these patients.

Effects of Preoperative Chemoradiotherapy on the Likelihood of Sphincter Preservation Surgery in Locally Advanced Distal Rectal Cancer: A Longitudinal Study Based on Pelvic Magnetic Resonance Imaging

BACKGROUND

It is unclear whether preoperative chemoradiotherapy (pCRT) increases the rate of sphincter-preserving surgery (SPS), avoiding abdominoperineal resection (APR), for the treatment of distal rectal cancer. We examined whether pCRT increases the likelihood of SPS based on changes in tumor height using pelvic magnetic resonance imaging (MRI).

METHODS

Between January 2009 and December 2013, 105 patients underwent long-course pCRT for locally advanced distal rectal cancer (≤5 cm from the anal verge) and were included in this study. The surgical procedures were analyzed in terms of radiologic findings, including the distance from the inferior margin of tumor to the superior margin of the anorectal ring (tumor height) measured by pelvic MRI before and after pCRT.

RESULTS

Eighty-six (81.9 %) patients underwent SPS. Overall clinical downstaging occurred in 48 (45.7 %) patients. Tumor height increased significantly after pCRT (from 15.0 ± 15.3 to 18.1 ± 16.9 mm, change 3.1 ± 9.7 mm, p = 0.01). The mean change in tumor height was not significantly different between patients who underwent SPS or APR (mean change 3.3 ± 9.6 vs. 2.3 ± 10.5 mm, p = 0.68). The mean change was significantly greater in the double-stapled anastomosis group than in the handsewn anastomosis group (mean change 5.6 ± 9.9 vs. -0.6 ± 8.6 mm, p = 0.02).

CONCLUSIONS

This was the first MRI-based longitudinal study to show that pCRT does not appear to increase the likelihood of SPS in locally advanced distal rectal cancer, although it could improve the potential of double-stapled anastomoses.

Multicentre propensity score-matched analysis of conventional versus extended abdominoperineal excision for low rectal cancer

BACKGROUND

Abdominal perineal excision (APE) was originally described with levator ani removal for rectal cancer. An even wider, more aggressive extralevator resection for APE has been proposed. Although some surgeons are performing a very wide 'extralevator APE (ELAPE)', there are few data to recommend it routinely. This multicentre study aimed to compare outcomes of APE and ELAPE.

METHODS

A multicentre propensity case-matched analysis comparing two surgical approaches (APE and ELAPE) was performed. All patients who underwent abdominoperineal resection of a rectal tumour were considered for the analysis. Tumour height was defined by magnetic resonance imaging measurement and patients with stage II-III tumours had neoadjuvant radiochemotherapy. Involvement of the circumferential resection margin (CRM) and intraoperative tumour perforation were the main outcome measures. A logistic regression model was used to study the relationship between the surgical approaches and outcomes.

RESULTS

From January 2008 to March 2013 a total of 1909 consecutive patients underwent APE or ELAPE, of whom 914 matched patients (457 in each group) formed the cohort for analysis. Intraoperative tumour perforation occurred in 7.9 and 7.7 per cent of patients during APE and ELAPE respectively (P = 0.902), and there was CRM involvement in 13.1 and 13.6 per cent (P = 0.846). There were no differences between APE and ELAPE in terms of postoperative complication rates (52.3 versus 48.1 per cent; P = 0.209), need for reoperation (7.7 versus 7.0 per cent; P = 0.703), perineal wound problems (26.0 versus 21.9 per cent; P = 0.141), mortality rate (2.0 versus 2.0 per cent; P = 1.000) and local recurrence rate at 2 years (2.7 versus 5.6 per cent; P = 0.664).

CONCLUSION

ELAPE does not improve rates of CRM involvement, intraoperative tumour perforation, local recurrence or mortality.