Postoperative MRI Findings Following Conventional and Extralevator Abdominoperineal Excision in Low Rectal Cancer.

Aim: The disparity in outcomes for low rectal cancer may reflect differences in operative approach and quality. The extralevator abdominoperineal excision (ELAPE) was developed to reduce margin involvement in low rectal cancers by widening the excision of the conventional abdominoperineal excision (c-APE) to include the posterior pelvic diaphragm. This study aimed to determine the prevalence and localization of inadvertent residual pelvic diaphragm on postoperative MRI after intended ELAPE and c-APE. Methods: A total of 147 patients treated with c-APE or ELAPE for rectal cancer were included. Postoperative MRI was performed on 51% of the cohort (n = 75) and evaluated with regard to the residual pelvic diaphragm by a radiologist trained in pelvic MRI. Patient records, histopathological reports, and standardized photographs were assessed. Pathology and MRI findings were evaluated independently in a blinded fashion. Additionally, preoperative MRIs were evaluated for possible risk factors for margin involvement. Results: Magnetic resonance imaging-detected residual pelvic diaphragm was identified in 45 (75.4%) of 61 patients who underwent ELAPE and in 14 (100%) of 14 patients who underwent c-APE. An increased risk of margin involvement was observed in anteriorly oriented tumors with 16 (22%) of 73 anteriorly oriented tumors presenting with margin involvement vs. 7 (9%) of 74 non-anteriorly oriented tumors (p = 0.038). Conclusion: Residual pelvic diaphragm following abdominoperineal excision can be depicted by postoperative MRI. Inadvertent residual pelvic diaphragm (RPD) was commonly found in the series of patients treated with the ELAPE technique. Anterior tumor orientation was a risk factor for circumferential resection margin (CRM) involvement regardless of surgical approach.

The Validity of Registered Synchronous Peritoneal Metastases from Colorectal Cancer in the Danish Medical Registries.

INTRODUCTION: Treatment options for peritoneal metastases (PM) from colorectal cancer (CRC) have increased, their efficiency should be monitored. For this purpose, register-based data on PM can be used, if valid. PURPOSE: We aimed to evaluate the completeness and positive predictive value (PPV) of synchronous peritoneal metastases (S-PM) registered among CRC patients in the Danish National Patient Register (DNPR) and/or the Danish National Pathology Register (the DNPatR) using the Danish Colorectal Cancer Group database (DCCG) as a reference. PATIENTS AND METHODS: We identified Danish patients with newly diagnosed primary CRC in the DCCG during 2014-2015. S-PM were routinely registered in the DCCG. We excluded patients with non-CRC cancers and identified S-PM using all three registries. We estimated the completeness and the PPV of registered S-PM in the DNPR, the DNPatR and the DNPR and/or the DNPatR (DNPR/DNPatR) in combination using the DCCG as the reference. We stratified by age, gender, WHO performance status, tumour location and distant metastases to liver and/or lungs. RESULTS: We identified 9142 patients with CRC in DCCG. In DCCG, 366 patients were registered with S-PM, among whom 213 in DCCG only, whereas 153 in DCCG and in at least one of DNPR and/or DNPatR. In DNPR/DNPatR, S-PM was registered with a completeness of 42% [95% CI: 37-47] and a PPV of 60% [95% CI: 54-66]. In the DNPR only, the completeness was 32% [95% CI: 27-37] and the PPV 57% [95% CI: 50-64]. The completeness in the DNPatR was 19% [95% CI: 15-23] and the PPV was 76% [95% CI: 68-85]. In the DNPR/DNPatR patients aged <60 years (57% [95% CI: 46-69]), patients with WHO performance status 0 (46% [95% CI: 37-54]) and patients with no distant metastases (58% [95% CI: 50-65]) were registered with a higher completeness. CONCLUSION: Our algorithm demonstrates that the DNPR/DNPatR captures less than half of CRC patients with S-PM. Potential candidates for curative treatment options are registered with a higher completeness. Clinicians should be encouraged to register the presence of S-PM to increase the validity of register-based S-PM data.

Validity of Contrast-enhanced Ultrasonography and Dynamic Contrast-enhanced MR Enterography in the Assessment of Transmural Activity and Fibrosis in Crohn's Disease.

BACKGROUND AND AIMS: Increased small intestinal wall thickness correlates with both inflammatory activity and fibrosis in Crohn's disease [CD]. Assessment of perfusion holds promise as an objective marker distinguishing between the two conditions. Our primary aim was to determine if relative bowel wall perfusion measurements correlate with histopathological scores for inflammation or fibrosis in CD. METHODS: A total of 25 patients were investigated before elective surgery for small intestinal CD. Unenhanced ultrasonography [US] and magnetic resonance enterography [MRE] were applied to describe bowel wall thickness. Perfusion was assessed with contrast-enhanced US [CEUS] and dynamic contrast-enhanced MRE [DCE-MRE]. Histopathology was used as gold standard. RESULTS: Compared with histopathology, the mean wall thickness was 0.4 mm greater on US [range -0.3 to 1.0, p = 0.24] and 1.4 mm greater on MR [0.4 to 2.3, p = 0.006]. No correlation was found between the severity of inflammation or fibrosis on histopathology, and either DCE-MRE [r = -0.13, p = 0.54 for inflammation and r = 0.41, p = 0.05 for fibrosis] or CEUS [r = 0.16, p = 0.45 for inflammation and r = -0.28, p = 0.19 for fibrosis]. Wall thickness assessed with US was correlated with both histological inflammation [r = 0.611, p = 0.0012] and fibrosis [r = 0.399, p = 0.048]. The same was not true for MR [r = 0.41, p = 0.047 for inflammation and r = 0.29, p = 0.16 for fibrosis]. CONCLUSIONS: Bowel wall thickness assessed with US is a valid marker of inflammation in small intestinal CD. However, relative contrast enhancement of US or of MRE cannot distinguish between inflammatory activity and fibrosis.

Objective measurement of the distal resection margin by MRI of the fresh and fixed specimen after partial mesorectal excision for rectal cancer: 5 cm is not just 5 cm and depends on when measured.

BACKGROUND: Most studies have directly established the optimal perioperative in situ clearance margin in surgery for rectal cancer from the histologically observed extent of distal spread, neglecting the tissue variability that occurs after resection and fixation of the rectal specimen. PURPOSE: To measure the length of the distal resection margin in the fresh and fixed specimen following partial mesorectal excision for rectal cancer using magnetic resonance imaging (MRI) to document tissue shrinkage after surgical removal and fixation. MATERIAL AND METHODS: The length of the distal resection margin was measured by MRI of the fresh and fixed specimen and at histopathological examination of the fixed specimen in 10 patients who underwent surgery for upper rectal cancer. In addition, tissue shrinkage was estimated by measuring the total length of the fresh and fixed specimen and distance from the peritoneal reflection anteriorly to the distal cut edge of the specimen. RESULTS: Measured by MRI, the distal resection margin was in the range of 0.6-10.2 cm (mean, 4.6 cm) in the fresh specimen, and 0.5-6.2 cm (mean, 3.2 cm) in the fixed specimen. The tissue shrinkage ratio was a mean of 69% (interquartile range, 61-77%). Taking all ratios from MRI and histopathological examination of tissue shrinkage into account, the collective tissue shrinkage ratio was 70% (95% confidence interval, 67-73%) CONCLUSION: The length of the distal resection margin was reduced by 30% after surgical removal and fixation of the specimen.

Improving the quality of colon cancer surgery through a surgical education program.

PURPOSE: Recent evidence has demonstrated the importance of dissection in the correct tissue plane for the resection of colon cancer. We have previously shown that meticulous mesocolic plane surgery yields better outcomes and that the addition of central vascular ligation produces an oncologically superior specimen compared with standard techniques. We aimed to assess the effect of surgical education on the oncological quality of the resection specimen produced. METHODS: We received clinicopathological data and specimen photographs from 263 resections for primary colon cancer from 6 hospitals in the Capital and Zealand regions of Denmark before a national training program. Ninety-three cases were from Hillerød Hospital, where surgeons had previously implemented a surgical educational training program in complete mesocolic excision with central vascular ligation and adopted the procedure as standard practice. The specimen photographs were assessed for the plane of surgery and tissue morphometry was performed. RESULTS: Hillerød specimens had a higher rate of mesocolic plane surgery (75% vs 48%; P < .0001) compared with the other hospitals. The surgeons at Hillerød Hospital also removed a greater length of colon in both fresh (median, 315 vs 247 mm; P < .0001) and fixed (269 vs 207 mm; P < .0001) specimens with a greater distance between the tumor and the closest vascular tie in both fresh (105 vs 84 mm; P = .006) and fixed (82 vs 67 mm; P = .002) specimens. This resulted in the removal of more mesentery in both fresh (14,466 vs 8706 mm; P < .0001) and fixed (9418 vs 6789 mm; P < .0001) specimens and a greater median lymph node yield (28 vs 18; P < .0001). CONCLUSIONS: We have shown that adoption of complete mesocolic excision with central vascular ligation results in a change to the production of an oncologically superior specimen compared with standard techniques. This should improve outcomes toward those reported by centers that have long practiced meticulous colon cancer surgery.