Pelvic CT in addition to MRI to differentiate between rectal and sigmoid cancer on imaging using the sigmoid take-off as a landmark.

BACKGROUND: The sigmoid take-off (STO) is a recently established landmark to discern rectal from sigmoid cancer on imaging. STO-assessment can be challenging on magnetic resonance imaging (MRI) due to varying axial planes. PURPOSE: To establish the benefit of using computed tomography (CT; with consistent axial planes), in addition to MRI, to anatomically classify rectal versus sigmoid cancer using the STO. MATERIAL AND METHODS: A senior and junior radiologist retrospectively classified 40 patients with rectal/rectosigmoid cancers using the STO, first on MRI-only (sagittal and oblique-axial views) and then using a combination of MRI and axial CT. Tumors were classified as rectal/rectosigmoid/sigmoid (according to published STO definitions) and then dichotomized into rectal versus sigmoid. Diagnostic confidence was documented using a 5-point scale. RESULTS: Adding CT resulted in a change in anatomical tumor classification in 4/40 cases (10%) for the junior reader and in 6/40 cases (15%) for the senior reader. Diagnostic confidence increased significantly after adding CT for the junior reader (mean score 3.85 vs. 4.27; P < 0.001); confidence of the senior reader was not affected (4.28 vs. 4.25; P = 0.80). Inter-observer agreement was similarly good for MRI only (κ=0.77) and MRI + CT (κ=0.76). Readers reached consensus on the classification of rectal versus sigmoid cancer in 78%-85% of cases. CONCLUSION: Availability of a consistent axial imaging plane - in the case of this study provided by CT - in addition to a standard MRI protocol with sagittal and oblique-axial imaging views can be helpful to more confidently localize tumors using the STO as a landmark, especially for more junior readers.

Laparoscopic Management of Concomitant Sigmoid Colon Cancer and Type 2 Endoleak Following Endovascular Aneurysm Repair.

The co-occurrence of abdominal aortic aneurysm (AAA) and colorectal malignancy creates a significant surgical dilemma over which entity should be addressed first. A 73-year-old male was referred to our hospital due to a painful pulsatile abdominal mass. Computed tomographic angiography revealed an infrarenal aortic aneurysm measuring 5.8 cm in diameter and incidentally, a synchronous mass lesion in the sigmoid colon. The patient underwent an emergency EVAR using a Gore Excluder endograft. Postoperative CT staging for colon cancer revealed a type 2 endoleak on the grounds of a patent wide inferior mesenteric artery. The patient underwent a standard laparoscopic left colectomy with high ligation of the inferior mesenteric artery in order to simultaneously address the ongoing type 2 endoleak. Follow-up examinations with computed tomographic angiography were performed confirming the resolution of the endoleak. Synchronous laparoscopic sigmoidectomy and high ligation of inferior mesenteric artery for type 2 endoleak treatment appears to be applicable with hopeful results.

Sigmoid colon Schwannoma simulating colon cancer.

Schwannomas tumours are uncommonly developed in the gastrointestinal tract (2-6%), located in 12% of cases in small and large intestines. An 87-year-old woman was studied due to epigastric pain and dyspepsia. CT scan and colonoscopy showed a neoplastic process in the sigmoid colon. It was performed an oncologic laparoscopic sigmoidectomy. Histological study described a schwannoma and a positive immunohistochemistry to S-100. The diagnostic challenge is that this is a submucosa lesion, therefore, endoscopy biopsy is realized only in the mucosa. This becomes the differential diagnostic very difficult in order to differentiate from another mesenchymal tumor (GIST or leiomyoma). The immunohistochemistry helps in the diagnostic if it is positive to S- 100 and negative to C-KIT, CD-34, actine and desmine (findings of GIST tumors and leiomyoma). In conclusion, schwannoma diagnostic is tough. Those are asymptomatic tumors with nonspecific radiological findings. Diagnostic confirmation is a S-100 positive immunohistochemistry in the histological study.

The sigmoid take-off as a landmark to distinguish rectal from sigmoid tumours on MRI: Reproducibility, pitfalls and potential impact on treatment stratification.

PURPOSE: The sigmoid take-off (STO) was recently introduced as a preferred landmark, agreed upon by expert consensus recommendation, to discern rectal from sigmoid cancer on imaging. Aim of this study was to assess the reproducibility of the STO, explore its potential treatment impact and identify its main interpretation pitfalls. METHODS: Eleven international radiologists (with varying expertise) retrospectively assessed n = 155 patients with previously clinically staged upper rectal/rectosigmoid tumours and re-classified them using the STO as completely below (rectum), straddling the STO (rectosigmoid) or completely above (sigmoid), after which scores were dichotomized as rectum (below/straddling STO) and sigmoid (above STO), being the clinically most relevant distinction. A random subset of n = 48 was assessed likewise by 6 colorectal surgeons. . RESULTS: Interobserver agreement (IOA) for the 3-category score ranged from κ0.19-0.82 (radiologists) and κ0.32-0.72 (surgeons), with highest scores for the most experienced radiologists (κ0.69-0.76). Of the 155 cases, 44 (28%) were re-classified by ≥ 80% of radiologists as sigmoid cancers; 36 of these originally received neoadjuvant treatment which in retrospect might have been omitted if the STO had been applied. Main interpretation pitfalls were related to anatomical variations, borderline cases near the STO and angulation of axial imaging planes. CONCLUSIONS: Good agreement was reached for experienced radiologists. Despite considerable variation among less-expert readers, use of the STO could have changed treatment in ±1/4 of patients in our cohort. Identified interpretation pitfalls may serve as a basis for teaching and to further optimize MR protocols.

[A Case of Double Colorectal Cancer Diagnosed by Preoperative CT Colonography].

A 66‒year‒old man was admitted to our hospital because of anemia and a positive fecal occult blood test in the medical examination. Colonoscopy revealed a type 2 advanced sigmoid colon cancer with circular stenosis. Computed tomography (CT)colonography was performed to examine the oral colon. The apple core signs were found both in the sigmoid and transverse colon. We diagnosed a double colon cancer and performed a laparoscopic left hemicolectomy and sigmoidectomy. The tumor was histopathologically diagnosed as a multiple cancer including a transverse and a sigmoid colon cancer. Although evaluations of the intestine for colon cancer with stenosis are performed by enema examination or endoscopic examination after colon stent placement, both examinations are invasive. CT colonography is considered to be a minimally invasive and an effective preoperative examination for colorectal cancer with stenosis.

Routine CT evaluation of central vascular ligation in patients undergoing complete mesocolic excision for sigmoid colon cancer.

AIM: Objective and reproducible quality measures of complete mesocolic excision (CME) for colon cancer are not currently available. This study aimed to measure the inferior mesenteric stump length following CME for sigmoid colon cancer and explore surgical, pathological and oncological outcomes in patients with a stump length of <10 mm vs. ≥10 mm. METHOD: This was a single-centre, retrospective cohort study including patients undergoing minimally invasive surgery for sigmoid colon cancer between May 2013 and May 2015. Follow-up CT scans were reviewed, and a vascular stump cut-off of <10 mm for adequate central ligation of the inferior mesenteric artery was applied. Differences in perioperative, histopathological and oncological outcome parameters (overall, disease-free and recurrence-free survival) were explored between <10 mm vs. ≥10 mm groups. RESULTS: A total of 127 patients (43% female) with a median age of 68 years were included. The median follow-up time was 68 months. CT measurements showed good interrater agreement (90% absolute agreement) and reliability among raters (kappa = 0.77, 95% CI 0.53-1.00, p < 0.001). A stump length ≥10 mm was associated with longer operating time (150 vs. 180 min, p = 0.021), intramesocolic resection (p = 0.008), and a shorter distance from the bowel wall to vascular tie (120 vs. 102 mm, p = 0.005). CONCLUSION: An arterial stump length ≥10 mm in sigmoid resection for colon cancer was associated with key clinical quality measures. Measurement of arterial stump length using routine follow-up CT may serve as a quality indicator of vascular ligation in CME surgery.

Local recurrence in sigmoid cancer is a hidden problem, could CT prognostic factors be of value in their prevention? A multi-centre study of 414 patients.

INTRODUCTION: The incidence and patterns of local recurrence of colon cancer are not well reported. The aim of this study was to investigate the contemporary rates and patterns of local recurrence after sigmoid cancer resection, comparing pre and post-operative biomarkers in predicting local disease recurrence. MATERIALS AND METHODS: A multi-centre, retrospective analysis of 414 patients undergoing resectional surgery for sigmoid colon cancer was conducted. Multivariable Cox Proportional Hazard models were created to identify variables associated with local disease recurrence. Patterns of recurrence and prognostic significance of pre and post-operative variables were identified. RESULTS: In 414 patients, the local recurrence rate was 12.6%. The R1/R2 rate was 2.4%. Local recurrence occurred most commonly within the peri-anastomotic region (50%), followed by the peritoneum (33%). On multivariate analysis, local recurrence was predicted by pathological T stage (HR 1.15) and R1 resection (HR 2.95), but also computerised tomography (CT) identified tumour deposits (HR 2.40) and local peritoneal infiltration (2.70). CONCLUSIONS: Contemporary local recurrence rates for sigmoid cancer are high at 12.6%. Outcomes may be improved if local recurrence is reduced at the most common sites such as the peri-anastomotic area or peritoneum. Extra-nodal CT-imaging biomarkers of local peritoneal infiltration and tumour deposits were prognostically significant on multivariate analysis in addition to pathology staging variables.

Magnetic resonance imaging as a predictor of surgical outcome in patients with local pelvic recurrence of colorectal cancer.

INTRODUCTION: Pelvic local recurrence of colorectal cancer (PRCRC) may be cured if radical surgery is performed. Preoperative assessment normally includes magnetic resonance imaging (MRI). The aim of this study was to evaluate the influence of specific MRI-related findings on outcome of surgery of PRCRC. MATERIALS AND METHODS: Clinical data from 95 consecutive patients, operated with a curative intent for PRCRC at Karolinska University Hospital during 2003-2013, were collected from medical records. Preoperative MRI examinations of the PRCRC were re-evaluated. The potential influence of clinical factors and specific MRI-findings (location, solid/mucinous, size, volume and border) on surgical resection margins (R0-R1) and survival were calculated with logistic and cox regression. RESULTS: Eighty-seven patients had available MRI scans and were included in the study. Sixty-five patients (75%) had a R0 resection and 22 patients (25%) had a R1 resection of their PRCRC. In all, 47 patients (54%) had an involved lateral compartment. Lateral location was the only MRI finding associated with both an increased risk of R1 resection (OR 3.97, 95%CI: 1.31-12.04) and death (HR 1.94, 95%CI: 1.07-3.51). Lateral location entailed an increased risk of death also after R0 resection (HR2.09, 95%CI: 1.07-4.10). Five-year survival was 35% for all patients, 44% after R0 resection and 7% after R1 resection. CONCLUSION: Tumour involvement of the lateral and posterior compartments on MRI was a predictor for R1 resection, but only lateral involvement was associated with an increased risk of death. An increased risk of death associated with lateral involvement was still present after R0 resection.

A new spray-type adhesion barrier (AdSpray) improves condition for surgical treatment in the reversal of Hartmann procedure: A case report.

RATIONALE: Hartmann procedure (HP) often causes severe postoperative adhesions in the pelvic space; therefore, the reversal of Hartmann procedure (RHP) is a challenging surgery. A new spray-type antiadhesion agent, AdSpray, has been reported to be useful in three-dimensional fields such as the liver. However, there are no reports of its use in HP. We present a case of a male patient with rectal cancer who underwent laparoscopic HP with AdSpray to prevent postoperative adhesions. PATIENT CONCERNS: A 52-year-old man presented with melena and constipation. DIAGNOSIS: Colonoscopy revealed an almost obstructive type II tumor at the rectosigmoid colon, and histopathological examination revealed moderately differentiated adenocarcinoma. Enhanced abdominal computed tomography revealed slightly enlarged regional lymph nodes but no ascites around the tumor, and there was no metastasis to the liver or lungs. Therefore, we diagnosed clinical stage T4aN1bM0 rectosigmoid colon cancer. Intraoperatively, a metastatic tumor of the liver surface and a high degree of valve retention in the oral colon were identified. INTERVENTIONS: After performing laparoscopic HP with AdSpray, we scheduled a laparoscopic RHP with staged hepatic surgery for synchronous liver metastasis from colorectal cancer 1 month later. OUTCOMES: No postoperative inflammatory adhesions were observed in the pelvis or around the rectal stump, allowing us to perform RHP by a single-incision laparoscopic surgery from the stoma site without any problem. The operation time for RHP was 80 minutes; the patient was in good general condition after the operation, and he was discharged on postoperative day 7. LESSONS: In laparoscopic HP, Adspray was easy to use for three-dimensional fields such as the pelvis and effectively prevented postoperative inflammatory adhesions. Thus, RHP may become less risky and be performed more as a minimally invasive surgery.

Laparoscopic surgery for sigmoid colon cancer with complicated communication between the superior and inferior mesenteric arteries.

To perform complete mesocolic excision with central vessel ligation, it is important to recognize the vessel anomaly and the location of the tumor. For left-sided colon cancer, the variations in the course of the left colic artery and accessary middle colic artery must be recognized preoperatively. Here, we describe our experience with a 57-year-old man who was diagnosed with sigmoid colon cancer with complicated inter-mesenteric connections between the inferior mesenteric artery (IMA) and superior mesenteric artery (SMA), possibly due to median arcuate ligament syndrome. We performed laparoscopic sigmoidectomy with low ligation of the IMA to preserve the extremely enlarged left colic artery. The total operative time was 155 minutes, and the estimated total blood loss was 10 mL. The patient was discharged on postoperative day 9 without any postoperative complications. For patients with vascular anomalies in the left-sided mesocolon, preoperatively ruling out SMA stenosis by using angiography and 3-D CT might be important.

[Clinicopathological characteristics, diagnosis, and treatment of 29 cases of signet ring cell carcinoma of the rectum and sigmoid colon].

Objective: To investigate the clinicopathological characteristics and the therapeutic effects of signet ring cell carcinoma (SRCC) of rectum and sigmoid colon. Methods: Clinical data and the follow-up information of 29 SRCC patients treated in our tertiary care center from 2008 to 2018 were retrospectively reviewed. The clinicopathological features, diagnostic and therapeutic effects, and the prognostic outcomes were analyzed. Results: Among the 29 patients, 17 were male, 12 were female. The average age was (48.7±14.3) years. Colonoscopy revealed the features of diffuse circumferential thickening of the bowel wall in 20/29 cases (69.0%), while in 9/29 cases (31.0%), endoscopic biopsies showed false negative results. Twenty-five% (4/16) and 17.6% (3/17) lesions were misdiagnosed as the inflammatory changes by endoscopic rectal ultrasonography exam and rectal MRI scan, respectively. Thirteen of the 29 patients received the neoadjuvant chemoradiotherapy (NCRT), 27 patients underwent the radical resection surgeries, and 8 underwent the postoperative radiotherapy. With a median follow-up of 38.5 (3.5-87.0) months, the cumulative 3-years overall survival (OS) rate was 54.0%, and the cumulative 3-years disease-free survival (DFS) rate was 43.0%. The OS rates of patients treated with or without NCRT (non-NCRT) were 46.2% and 69.2%, respectively, without significant difference (P>0.05). The DFS rates of patients treated with or without NCRT were 45.8% and 39.2%, respectively, without significant difference (P>0.05). Parameters including age younger than 40 years and tumor size larger than 5 cm were independent potential risk factors for shortened OS (P<0.05). Conclusions: SRCC of the rectum and sigmoid colon is a rare malignant tumor with special clinical manifestations. It is younger-onset, highly malignant and with very poor prognosis. Therefore, in-depth researches with focus upon the progress of molecular oncology are urgently needed to substantially improve the therapeutic effect of this disease.

Comparison of the sigmoid take-off with other definitions of the rectosigmoid junction: A retrospective comparative cohort analysis.

BACKGROUND: The diversity in definitions for the rectosigmoid junction is becoming a major obstacle in standardizing optimal treatment of rectal cancers. The study aimed to determine the average distance of the sigmoid take-off from the anal verge and its association with individual factors. MATERIALS AND METHODS: Patients diagnosed with rectal and sigmoid colon cancer in our centre from January 2010 to December 2018 were retrospectively enrolled in the cancer group. The results of 200 controls without colorectal disease were also reviewed (normal group). The distance of different landmarks and margins of cancer from the anal verge were retrieved from computed tomography (CT), magnetic resonance imaging (MRI), and endoscopy findings. RESULTS: The cancer group comprised 635 patients (381 men, median age: 64 years). The average distances of the sigmoid take-off from the anal verge measured in CT and MRI were comparable (P = 0.483). On MRI, the average distance of the sigmoid take-off from the anal verge in the cancer group was comparable with that of the normal group (P = 0.070). Multivariate regression revealed that the distance of the sigmoid take-off from the anal verge was associated with the distances of the sacral promontory (P < 0.001) and peritoneal reflection (P < 0.001) from the anal verge. CONCLUSION: The cancer distributions of patients varied widely with the application of different definitions. The point of sigmoid take-off is an intuitive landmark influenced by individual factors. The measurement of the sigmoid take-off by different researchers in both CT and MRI revealed good consistency. Further studies regarding the clinical significance of this definition are still needed.