The role of rectal magnetic resonance imaging in accurate localization and designation of colorectal cancer for optimal management: Case study

Colorectal cancer, developing from malignant transformation of the distal gut epithelium, is the second leading cause of cancer death in the United States. We present a gentleman in his 60s who was diagnosed with colorectal cancer during a routine screening colonoscopy with no evidence of distant metastasis on subsequent staging with positron emission tomography and computed tomography (PET-CT). The outside rectal MR (magnetic resonance) imaging report localized a mass to the upper rectum. Review of the MRI at an institutional, Multidisciplinary Tumor Board designated the tumor as "rectosigmoid," straddling the rectosigmoid junction at the level of the "sigmoid take-off" (STO) or alternatively at the level of the last sigmoid artery take-off (SAT) at the origin of the superior rectal artery. The anatomic differentiation between upper rectal and lower sigmoid colon cancers carries clinical importance which is highlighted in this case report and brief literature review. Optimal anatomic localization of colorectal cancers helps direct the clinical team to tailor an individualized patient care plan.

Pain and opioid use after colorectal resection for benign versus malignant disease: A single institution analysis

BACKGROUND

Studies comparing opioid needs between benign and malignant colorectal diseases are inconclusive.

METHODS

Single institution analysis of prospectively maintained colorectal surgery database. Multiple regression analyses done on perioperative numeric pain scores (NPS) and opioids prescribed at discharge.

RESULTS

641 patients in Benign and 276 patients in the Malignant group. Unadjusted comparison revealed significantly higher NPS for the Benign than the Malignant group preoperative and postoperative day 0 (after surgery), 1, 2, and 3 (all p ​≤ ​0.001). Opioids prescribed at discharge were significantly higher in the Benign group (60.0% vs 51.1%, p ​= ​0.018). After regression analysis, there was no longer a significant difference in NPS (B ​= ​0.703, p ​= ​0.095) and opioids prescribed between groups [OR ​= ​0.803 (95%CI 0.586, 1.1), p ​= ​0.173].

CONCLUSIONS

Pain and opioids prescribed at discharge are not significantly different between benign and malignant diseases in an enhanced recovery pain management pathway that maximizes non-opioid multimodal analgesic strategies.

Endoscopic submucosal dissection for rectal neuroendocrine tumours: A multicentric retrospective study

INTRODUCTION

Endoscopic Submucosal Dissection (ESD) has been reported as a feasible and effective treatment for Rectal Neuroendocrine Tumours (R-NETs). However, most of the experience on the topic comes from retrospective tertiary centre from Eastern Asia. Data on ESD for R-NETs in Western centres are lacking.

MATERIALS AND METHODS

This is a retrospective study, including patients who underwent endoscopic resection of R-NETS by ESD between 2015 and 2020 in Western Centres. Important clinical variables such as demographic, size of R-NETs, histological type, presence of lymphovascular invasion or distant metastasis, completeness of the endoscopic resection, recurrence, and procedure related complications were recorded.

RESULTS

40 ESD procedure on R-NETs from 39 patients from 8 centres were included. Mean R-NETs size was 10.3 mm (SD 4.01). Endoscopic en-bloc resection was achieved in 39/40 ESD (97.5 %), R0 margin resection was obtained in 87.5 % (35/40) of the procedures, one patient was referred to surgery for lymphovascular invasion, two procedures (5 %) reported significant episodes of bleeding, whereas a perforation occurred in one case (1/40, 2.5 %) managed endoscopically. Recurrence occurred in 1 patient (2.5 %).

CONCLUSION

ESD is an effective and safe treatment for R-NETs in western centres.

Charles Boyd Kelsey (1850-1917). The pioneer of rectal surgery in USA

Charles Boyd Kelsey (1850-1917) was a pioneer rectal surgeon. His surgical career was dedicated in the surgery of the rectum, anus, hemorrhoids, and pelvis. He invented also surgical instruments. He managed to be recognized as a pioneer of Rectal surgery not only in America but worldwide. He was a prolific writer and a famous teacher.

Hematochezia due to rectal invasion by an internal iliac artery aneurysm: A case report

BACKGROUND

This case report presents the rare occurrence of hematochezia due to an internal iliac artery aneurysm leading to an arterioenteric fistula, expanding the differential diagnosis for gastrointestinal bleeding. It emphasizes the importance of considering vascular origins in cases of atypical hematochezia, particularly in the absence of common gastrointestinal causes, and highlights the role of imaging and multidisciplinary management in diagnosing and treating such unusual presentations.

CASE SUMMARY

A 75-year-old man with a history of hypertension presented with 12 d of hematochezia, experiencing bloody stools 7-8 times per day. Initial computed tomography (CT) scans revealed an aneurysmal rupture near the right internal iliac artery with suspected hematoma development. Hemoglobin levels progressively decreased to 7 g/dL. Emergency arterial angiography and iliac artery-covered stent placement were performed, followed by balloon angioplasty. Despite initial stabilization, minor rectal bleeding and abdominal pain persisted, leading to further diagnostic colonoscopy. This identified a neoplasm and potential perforation at the proximal rectum. An exploratory laparotomy confirmed the presence of a hematoma and an aneurysm invading the rectal wall, necessitating partial rectal resection, intestinal anastomosis, and ileostomy. Postoperative recovery was successful, with no further bleeding incidents and normal follow-up CT and colonoscopy results after six months.

CONCLUSION

In cases of unusual gastrointestinal bleeding, it is necessary to consider vascular causes for effective diagnosis and intervention.

A survey of current practices in post-polypectomy surveillance in Korea

BACKGROUND/AIMS

We investigated the clinical practice patterns of post-polypectomy colonoscopic surveillance among Korean endoscopists.

METHODS

In a web-based survey conducted between September and November 2021, participants were asked about their preferred surveillance intervals and the patient age at which surveillance was discontinued. Adherence to the recent guidelines of the U.S. Multi-Society Task Force on Colorectal Cancer (USMSTF) was also analyzed.

RESULTS

In total, 196 endoscopists completed the survey. The most preferred first surveillance intervals were: a 5-year interval after the removal of 1-2 tubular adenomas < 10 mm; a 3-year interval after the removal of 3-10 tubular adenomas < 10 mm, adenomas ≥ 10 mm, tubulovillous or villous adenomas, ≤ 20 hyperplastic polyps < 10 mm, 1-4 sessile serrated lesions (SSLs) < 10 mm, hyperplastic polyps or SSLs ≥ 10 mm, and traditional serrated adenomas; and a 1-year interval after the removal of adenomas with highgrade dysplasia, >10 adenomas, 5-10 SSLs, and SSLs with dysplasia. In piecemeal resections of large polyps ( > 20 mm), surveillance colonoscopy was mostly preferred after 1 year for adenomas and 6 months for SSLs. The mean USMSTF guideline adherence rate was 30.7%. The largest proportion of respondents (40.8%-55.1%) discontinued the surveillance at the patient age of 80-84 years.

CONCLUSIONS

A significant discrepancy was observed between the preferred post-polypectomy surveillance intervals and recent international guidelines. Individualized measures are required to increase adherence to the guidelines.

Risk Factor Analysis of Lymph Node Metastasis for Rectal Neuroendocrine Tumors: Who Needs a Radical Resection in Rectal Neuroendocrine Tumors Sized 1-2 cm?

BACKGROUND

Rectal neuroendocrine tumors (NETs) have malignant potential, and lymph node (LN) or distant metastases can occur; however, treatment of NETs 1-2 cm in size is controversial.

OBJECTIVE

This study aimed to identify predictive factors for LN metastasis and prognostic factors for recurrence of rectal NETs, especially tumors 1‒2 cm in size.

METHODS

Between October 2004 and November 2020, 453 patients underwent endoscopic or surgical treatment for rectal NETs in Seoul National University Hospital. The data on these patients were prospectively collected in our database and reviewed retrospectively. In cases of local excision, we evaluated LN metastasis with radiologic imaging, including computed tomography or magnetic resonance imaging before treatment and during the follow-up periods.

RESULTS

LN metastasis was observed in 40 patients (8.8%). A higher rate of LN metastasis was observed in larger-sized tumors, advanced T stage, lymphovascular invasion (LVI), perineural invasion (PNI), and high tumor grade. In multivariable analysis, the significant risk factors for LN metastasis were tumor size (1 ≤ size < 2 cm: hazard ratio [HR] 64.07; size ≥2 cm: HR 102.37, p < 0.001) and tumor grade (G2: HR 3.63, p = 0.034; G3: HR 5.09, p = 0.044). In multivariable analysis for tumors 1-2 cm in size, the risk factor for LN metastasis was tumor grade (G2: HR 6.34, p = 0.013).

CONCLUSIONS

Tumor grade and size are important predictive factors for LN metastasis. In NETs 2 cm in size, tumor grade is also important for LN metastasis, and radical resection should be considered.

Palliative primary tumor resection may not offer survival benefits for patients with unresectable metastatic colorectal neuroendocrine neoplasms, one multicenter retrospective cohort study

BACKGROUND

The efficacy of palliative primary tumor resection (PTR) in improving prognosis for patients with unresectable metastatic colorectal neuroendocrine neoplasms (NENs) has not been fully explored.

METHODS

We performed one retrospective cohort study and recruited 68 patients with unresectable metastatic colorectal NENs from two Chinese medical centers between 2000 and 2022. All patients were assigned to PTR group and no PTR group. The clinicopathological manifestation data were carefully collected, and the survival outcomes were compared between the two groups using Kaplan-Meier methods. Propensity score matching (PSM) was conducted to minimize confounding bias. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify prognostic factors.

RESULTS

A total of 32 patients received PTR, and the other 36 patients did not. The median progression-free survival (PFS) and overall survival (OS) times were 4 and 22 months in the whole cohort, respectively. For patients who received no PTR, the median OS was 16 months, and the 1-year OS rate and 3-year OS rate were 56.4% and 39.6%, respectively. For patients who received PTR, the median OS was 24 months, and the 1-year OS rate and 3-year OS rate were 67.9% and 34.1%, respectively. However, the Kaplan-Meier survival curves and log-rank test demonstrated no significant survival difference between the two groups (P = 0.963). Moreover, palliative PTR was also not confirmed as a prognostic factor in subsequent univariable and multivariable Cox proportional hazards regression analyses in both the original and matched cohorts. Only histological differentiation was identified as an independent prognostic factor affecting PFS [hazard ratio (HR) = 1.86, 95% confidence interval (CI): 1.02-3.41, P = 0.043] and OS [HR = 3.70, 95% CI: 1.09-12.48, P = 0.035] in the original cohort.

CONCLUSIONS

Palliative PTR may not offer survival benefits for patients with unresectable metastatic colorectal NENs.

Multicenter Evaluation of a Weakly Supervised Deep Learning Model for Lymph Node Diagnosis in Rectal Cancer at MRI

Purpose To develop a Weakly supervISed model DevelOpment fraMework (WISDOM) model to construct a lymph node (LN) diagnosis model for patients with rectal cancer (RC) that uses preoperative MRI data coupled with postoperative patient-level pathologic information. Materials and Methods In this retrospective study, the WISDOM model was built using MRI (T2-weighted and diffusion-weighted imaging) and patient-level pathologic information (the number of postoperatively confirmed metastatic LNs and resected LNs) based on the data of patients with RC between January 2016 and November 2017. The incremental value of the model in assisting radiologists was investigated. The performances in binary and ternary N staging were evaluated using area under the receiver operating characteristic curve (AUC) and the concordance index (C index), respectively. Results A total of 1014 patients (median age, 62 years; IQR, 54-68 years; 590 male) were analyzed, including the training cohort (n = 589) and internal test cohort (n = 146) from center 1 and two external test cohorts (cohort 1: 117; cohort 2: 162) from centers 2 and 3. The WISDOM model yielded an overall AUC of 0.81 and C index of 0.765, significantly outperforming junior radiologists (AUC = 0.69, P < .001; C index = 0.689, P < .001) and performing comparably with senior radiologists (AUC = 0.79, P = .21; C index = 0.788, P = .22). Moreover, the model significantly improved the performance of junior radiologists (AUC = 0.80, P < .001; C index = 0.798, P < .001) and senior radiologists (AUC = 0.88, P < .001; C index = 0.869, P < .001). Conclusion This study demonstrates the potential of WISDOM as a useful LN diagnosis method using routine rectal MRI data. The improved radiologist performance observed with model assistance highlights the potential clinical utility of WISDOM in practice. Keywords: MR Imaging, Abdomen/GI, Rectum, Computer Applications-Detection/Diagnosis Supplemental material is available for this article. Published under a CC BY 4.0 license.

Multimodality Imaging to Direct Management of Primary and Recurrent Rectal Adenocarcinoma Beyond the Total Mesorectal Excision Plane

Rectal tumors extending beyond the total mesorectal excision (TME) plane (beyond-TME) require particular multidisciplinary expertise and oncologic considerations when planning treatment. Imaging is used at all stages of the pathway, such as local tumor staging/restaging, creating an imaging-based "roadmap" to plan surgery for optimal tumor clearance, identifying treatment-related complications, which may be suitable for radiology-guided intervention, and to detect recurrent or metastatic disease, which may be suitable for radiology-guided ablative therapies. Beyond-TME and exenterative surgery have gained acceptance as potentially curative procedures for advanced tumors. Understanding the role, techniques, and pitfalls of current imaging techniques is important for both radiologists involved in the treatment of these patients and general radiologists who may encounter patients undergoing surveillance or patients presenting with surgical complications or intercurrent abdominal pathology. This review aims to outline the current and emerging roles of imaging in patients with beyond-TME and recurrent rectal malignancy, focusing on practical tips for image interpretation and surgical planning in the beyond-TME setting. Keywords: Abdomen/GI, Rectum, Oncology © RSNA, 2024.

Case report of an unusual finding of intrauterine contraceptive device in the rectum

INTRODUCTION

Intrauterine contraceptive device (IUCD) is a safe and effective method of contraception. It is however rarely associated with complications. Migration of this device to the rectum is very rare. We report a case of IUCD migrating to the rectum with the history of missing IUCD strings.

PRESENTATION OF CASE

A 32-year-old multipara presented 8 weeks following IUCD insertion with missing thread, ultrasound scan done showed a viable pregnancy with IUCD in-situ. Following vaginal examination, IUCD could not be retrieved. Pregnancy was allowed to continue for IUCD to be retrieved at delivery. She presented again about 6 weeks later with IUCD strings protruding through the rectum and was subsequently removed.

DISCUSSION

Uterine perforation and migration of IUCD into the pelvic organs is an uncommon but major complication following insertion of the device. The risk of perforation appears to depend on type of device, skill of the operator and position of the uterus. Postpartum insertion, lactation and atrophic uterus also increase risk of perforation.

CONCLUSION

perforation and migration of IUCD to the rectum is a rare but possible complication of following insertion of the device. Family planning providers should continue to undergo training and retraining to minimize complications associated with the use of IUCD.

Somatostatin receptor 2 (SSTR2) expression is associated with better clinical outcome and prognosis in rectal neuroendocrine tumors

Somatostatin analogues have recently been used as therapeutic targets for metastatic or surgically unresectable gastroenteropancreatic (GEP) neuroendocrine tumors (NETs), and associated somatostatin receptor (SSTR) expression has been well demonstrated in most GEP NETs, with the exception of rectal NETs. SSTR2 immunohistochemical expressions were evaluated in 350 surgically or endoscopically resected rectal NETs and compared to clinicopathologic factors. SSTR2 expression was observed in 234 (66.9%) rectal NET cases and associated tumors with smaller size (p = 0.001), low pT classification (p = 0.030), low AJCC tumor stage (p = 0.012), and absence of chromogranin expression (p = 0.009). Patients with rectal NET and SSTR2 expression had significantly better overall survival than those without SSTR2 expression both by univariable (p = 0.006) and multivariable (p = 0.014) analyses. In summary, approximately two-thirds of rectal NETs expressed SSTR2. SSTR2 expression was significantly associated with favorable behavior and good overall survival in patients with rectal NETs. Furthermore, SSTR2 expression can be used as prognostic factors. When metastatic disease occurs, SSTR2 expression can be used a possible target for somatostatin analogues.

Changes in microbial composition and interaction patterns of female urogenital tract and rectum in response to HPV infection

BACKGROUND

Previous studies have shown that changes in the microbial community of the female urogenital tract are associated with Human papillomavirus (HPV) infection. However, research on this association was mostly focused on a single site, and there are currently few joint studies on HPV infection and multiple sites in the female urogenital tract.

METHODS

We selected 102 healthy women from Yunnan Province as the research object, collected cervical exfoliation fluid, vaginal, urethral, and rectal swabs for microbial community analysis, and measured bacterial load, and related cytokine content. The link between HPV, microbiota, and inflammation was comprehensively evaluated using bioinformatics methods.

FINDINGS

The impact of HPV infection on the microbial composition of different parts varies. We have identified several signature bacterial genera that respond to HPV infection in several detection sites, such as Corynebacterium, Lactobacillus, Campylobacter, and Cutibacterium have been detected in multiple sites, reflecting their potential significance in cross body sites HPV infection responses. There was a solid microbial interaction network between the cervix, vagina, and urethra. The interrelationships between inflammatory factors and different bacterial genera might also affect the immune system's response to HPV infection.

INTERPRETATION

It might be an effective strategy to prevent and treat HPV infection by simultaneously understanding the correlation between the microbial changes in multiple parts of the female urogenital tract and rectum and HPV infection, and controlling the microbial network related to HPV infection in different parts.

Radiation therapy of the primary tumour and/or metastases of digestive metastatic cancers

Metastatic gastrointestinal cancer is not an uncommon situation, especially for pancreatic, gastric, and colorectal cancers. In this setting, few data are available on the impact of the treatment of the primary tumour. Oligometastatic disease is associated with longer survival in comparison with more advanced disease. Metastasis-directed therapy, such as stereotactic body radiotherapy, seems related to better outcomes, but the level of evidence is low. In most tumour locations, prospective data are very scarce and inclusion in ongoing trials is strongly recommended.

Metastatic pancreatic cancer with multiple metastases confined to the large intestine: a case report and literature review

The incidence and mortality rate of pancreatic cancer are increasing worldwide. Regional lymph nodes, liver, lung, and peritoneum are common sites of metastasis from pancreatic cancer, but the gastrointestinal tract is rare as a metastatic organ from pancreatic cancer. An 80-year-old man was referred to our department for a hypovascular pancreatic mass on contrast-enhanced computed tomography (CECT). Endoscopic ultrasound-guided fine needle aspiration revealed adenocarcinoma, and he was diagnosed with pancreatic cancer. No lymph nodes or distant metastases were detected by either CECT or gadolinium-enhanced magnetic resonance imaging, and we evaluated this case as borderline resectable. However, total colonoscopy for positive fecal occult blood tests revealed a reddish and hemorrhagic mucosal thickening in the ascending and sigmoid colon and rectum, which was inconsistent with primary colorectal cancer. Biopsy specimens from these sites revealed cytokeratin (CK)7-positive and CK20- and CDX2-negative adenocarcinoma, consistent with cancer of pancreatic origin. The patient underwent palliative chemotherapy with gemcitabine but died from COVID-19 infection eight months after diagnosis. Performing total colonoscopy as a preoperative screening is important for accurate cancer staging of patients with possible resectable pancreatic cancer.

Machine learning and machine teaching in histopathology

An artificial intelligence (AI) platform was trained by a consultant histopathologist to classify whole slide images (WSIs) of large bowel biopsies. Six medical students viewed WSIs of five large bowel biopsy cases and assigned the WSIs to one of the nine diagnostic categories. Then the students compared their answers with those generated by the AI. This training was repeated for a total of six rounds of five cases, and the accuracy of the students was recorded for each round. Each case had one or more WSIs. The student with the best final accuracy was asked to describe the morphological features that they had deduced. All the students improved during their training, from a mean accuracy of 13.7% in the first round to a mean accuracy of 77.1% in the sixth round (p = 0.0011). The student-deduced diagnostic features were mainly accurate. Some students learned more quickly than others.

Rare synchronous colorectal carcinoma with three pathological subtypes: A case report and review of the literature

BACKGROUND

Synchronous colorectal carcinomas (SCRC) are two or more primary colorectal carcinomas identified simultaneously or within 6 mo of the initial presentation in a single patient. Their incidence is low and the number of pathological types of SCRC is usually no more than two. It is very unusual that the pathological findings of a patient with SCRC show more than two different pathological subtypes. Here, we report a rare case of SCRC with three pathological subtypes.

CASE SUMMARY

A 75-year-old woman who had no previous medical history or family history was admitted to the hospital because of intermittent hematochezia for more than a month. Colonoscopy displayed an irregularly shaped neoplasm of the rectum, a tumor-like lesion causing intestinal stenosis in the descending colon, and a polypoidal neoplasm in the ileocecum. Subsequently, she underwent total colectomy, abdominoperineal resection for rectal cancer, and ileostomy. After operation, the pathological report showed three pathological subtypes including well-differentiated adenocarcinoma of the ascending colon, moderately differentiated adenocarcinoma of the descending colon, and mucinous adenocarcinoma of the rectum. She is now recovering well and continues to be closely monitored during follow-up.

CONCLUSION

Preoperative colonoscopy examination, imaging examination, and extensive intraoperative exploration play important roles in reducing the number of missed lesions.

Endoscopic intermuscular dissection (EID) for removing early rectal cancers and benign fibrotic rectal lesions

In the current era of screening colonoscopy and increasing incidence of early rectal cancer, interventional endoscopy moves toward resections in deeper planes than the submucosal layer. Several reports support the use of endoscopic intermuscular dissection (EID) instead of endoscopic submucosal dissection (ESD) for the removal of deeply invasive rectal submucosal cancers. The resection plane into the intermuscular space, the space between the longitudinal (external) and circular (internal) muscle layer, allows radical removal of rectal invasive submucosal cancers. Furthermore, the technique offers the potential for dissection of scarred and severe fibrotic lesions in the rectum by cutting deeper and performing a partial myectomy avoiding the narrow submucosal space. We present 23 cases of EIDs both for deeply invasive rectal cancers and benign rectal lesions. This is the first report in the literature of EID resections for malignant and benign disease, including cases of severely fibrotic rectal lesions.

Anorectal Anatomy Quiz: Practical Review

Understanding anorectal and pelvic floor anatomy can be challenging but is paramount for every physician managing patients with anorectal pathology. Knowledge of anorectal anatomy is essential for managing benign, malignant, traumatic, and infectious diseases affecting the anorectum. This quiz is intended to provide a practical teaching guide for medical students, medical and surgical residents, and may serve as a review for practicing general surgeons and specialists.

Stratification of rate of lymph node metastasis according to risk factors and oncologic outcomes in patients who underwent radical resection for rectal neuroendocrine tumors

PURPOSE

Most predictive factors for lymph node metastasis in rectal neuroendocrine tumors (NETs) have been based on local and endoscopic resection. We aimed to evaluate the risk factors for lymph node metastasis in patients who underwent radical resection for rectal NETs and stratify the risk of lymph node metastasis.

METHODS

Sixty-four patients who underwent radical resection for rectal NETs between January 2001 and January 2018 were included. We investigated the risk factors of lymph node metastasis using clinicopathologic data. We also performed a risk stratification for lymph node metastases using the number of previously known risk factors. For oncologic outcomes, the 5-year overall survival and recurrence-free survival were evaluated in both groups.

RESULTS

Among the patients who underwent radical surgery, 32 (50.0%) had lymph node metastasis and 32 (50.0%) had non-lymph node metastasis. In the multivariable analysis, only the male sex was identified as a risk factor for lymph node metastasis (odds ratio, 3.695; 95% confidence interval, 1.128-12.105; P=0.031). When there were 2 or more known risk factors, the lymph node metastasis rate was significantly higher than when there were one or no risk factors (odds ratio, 3.667; 95% confidence interval, 1.023-13.143; P=0.046). There was also no statistical difference between the 2 groups in 5-year overall survival (P=0.431) and 5-year recurrence-free survival (P=0.144).

CONCLUSION

We found that the rate of lymph node metastasis increased significantly when the number of known risk factors is 2 or more.

Rare rectal gastrointestinal stromal tumor case: A case report and review of the literature

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal tract accounting for less than 1% of all gut tumors. GISTs occurring in the rectum are extremely rare, and these usually present at an advanced stage compared with other sites.

CASE SUMMARY

A 60-year-old male who presented with features of sensations of rectal tenesmus was referred to our department with a mass in the lower rectum that was detected during a routine checkup. Colonoscopy, transrectal ultrasound, perianal magnetic resonance imaging and ultrasonic contrast were used to diagnose the rectum GIST, and then the patient underwent complete transanal resection using the ultrasonic scalpel. The patient was discharged ten days after the operation and was defined as low risk. Therefore, he had no need to receive subsequent adjuvant therapies, and he had not suffered any anal dysfunction or had any evidence of recurrence at follow up.

CONCLUSION

Surgical resection with histologically negative margins is the standard curative treatment for rectal GISTs. Appropriate surgical techniques based on the location, size, and resectability of the tumor should attract great attention from clinicians.

Sigmoid take-off in rectosigmoid cancer as a landmark identifying benefit from neoadjuvant chemoradiation: A retrospective comparative cohort study

INTRODUCTION

There is no standard treatment strategy for rectosigmoid cancer because of the diverse definitions of the proximal rectal origin. This study aimed to evaluate sigmoid take-off compared with other landmarks of the rectosigmoid junction in guiding oncological therapy and outcomes.

MATERIALS AND METHODS

This retrospective, comparative cohort study included patients diagnosed with rectosigmoid carcinoma at our centre between January 2010 and December 2018. The patients were classified into the neoadjuvant treatment group and upfront surgery group. The oncological outcomes were compared between the two groups in relation to the tumor position.

RESULTS

A total of 656 patients (median age 64 years) were included. After propensity score matching, the 3- and 5-year overall survival and disease-free survival in patients in both the groups were comparable. However, when only patients with rectal cancer as defined by the sigmoid take-off point were included, the disease-free survival rate in the upfront surgery group was significantly lower than that in the neoadjuvant treatment group (p = 0.03 in patients who underwent computed tomography, p = 0.03 in patients who underwent magnetic resonance imaging). The turning point of the beneficial hazard ratio of neoadjuvant therapy was compared according to the different definitions of the rectosigmoid junction and the sigmoid take-off was found to be the most effective.

CONCLUSION

The sigmoid take-off point is a suitable landmark for identifying the rectosigmoid junction and is an important defining criterion for assessing the benefit of neoadjuvant therapy. The application of this definition in clinical practice and future trials is warranted.

Rectal malakoplakia mimicking advanced rectal cancer: A case report

Background

Malakoplakia is a rare acquired chronic infectious granulomatous condition, that is characterized by the accumulation of large granular macrophages containing basophilic inclusion bodies in the cytoplasm termed Michaelis-Gutmann (MG) bodies. Malakoplakia most commonly involves the genitourinary system, and the second most commonly affected site is the gastrointestinal tract. Rectal malakoplakia is an unusual entity that is difficult to diagnose due to its diverse clinical manifestations and radiological findings that are similar to different diseases and advanced cancers.

Case description

A 61-year-old male patient presented with difficulty in urination and defecation that started 4 months prior, along with a weight loss of 10 kg. Abdominal computerized tomography (CT) scanning revealed diffuse lesions of the perirectal region with multiple lymphadenopathies and involvement of the bladder, prostate, bilateral seminal vesicles, and left ureter. 18F-FDG PET/CT MIP showed intense FDG uptake in the rectal region, and a diagnosis of an occupying lesion was proposed. Colonoscopy and histological examination of rectal lesion biopsies showed the characteristic features of malakoplakia.

Conclusion

Malakoplakia of the rectum with lymph node involvement and adjacent organ extension has been extensively misdiagnosed in clinical practice, and mimics malignancy radiologically. It is of great importance for radiologists to be aware of malakoplakia when making the differential diagnosis of benign and malignant mass lesions of the rectum, although the radiologic findings are nonspecific. Endoscopic evaluation and pathologic examination of a biopsy should be recommended to make the correct diagnosis, which may prevent unnecessary surgical resection.

Stercoral colitis: CT imaging findings and clinical risk factors

PURPOSE

To describe and update stercoral colitis clinical risk factors, relative frequency, location, and CT imaging features correlated with surgical and pathological results.

METHODS

CT reports over a 5-year period (05/2017-05/2022) at a single medical center were searched. Main inclusion criteria were luminal distention with formed stool, wall thickening, and surrounding inflammation. Positive cases were graded as mild (early or developing stercoral colitis) versus moderate-to-severe based on CT findings. Medical records were reviewed for risk factors and outcome data in moderate-to-severe cases. P-values were tabulated for comparison.

RESULTS

545 total cases (71 (60, 82) years, 278 males) were identified on CT, including 452 mild (82.9%) and 93 moderate-to-severe cases (17%, 67 (55, 79) years, 48 females). Twenty cases showed evidence of perforation (3.7% total cohort, 22% moderate-to-severe cohort). Diagnosis as an incidental finding was frequent (46.0% of mild cases). Most cases involved the rectum (97.6% of mild cohort and 69% of moderate-to-severe cohort). The sigmoid was involved in 31% of moderate-to-severe cases, but 95% of the perforated subcohort (19/20, 13/20 without rectal involvement). Among the moderate-to-severe cohort, perforation was associated with slightly increased wall thickness (6.4 vs. 5.7 mm, p = 0.03), opioid use (50 vs. 23%, p = 0.04), and disease-specific mortality (11 vs. 0%, p =0.04). Perforation was less associated with major neurocognitive disorders (20 vs. 60%, p = 0.003), institutionalized status (5 vs. 38%, p = 0.005), and a prescribed bowel regimen (30 vs. 63%, p = 0.01).

CONCLUSION

Stercoral colitis may be under-reported. Perforation tends to favor sigmoid involvement and a less traditional patient cohort.

Endometriosis with colonic and rectal involvement: surgical approach and outcomes in 142 patients

PURPOSE

Endometriosis involving the colon and/or rectum (CRE) is operatively managed using various methods. We aimed to determine if a more limited excision is associated with 30-day complications, symptom improvement, and/or recurrence.

METHODS

This is a retrospective review of consecutive cases of patients who underwent surgical management of CRE between 2010 and 2018. Primary outcomes were the associations between risk factors and symptom improvement, 30-day complications, and time to recurrence. Multivariable logistic regression assessed the independent risk factors.

RESULTS

Of 2681 endometriosis cases, 142 [5.3% of total, mean age 35.4 (31.0; 39.0) years, 73.9% stage IV] underwent CRE excision (superficial partial = 66.9%, segmental = 27.5%, full thickness = 1.41%). Minor complications (14.8%) were associated with blood loss [150 (112; 288) vs. 100 (50.0; 200) mls, p = 0.046], Sigmoid involvement [45.5% vs. 12.2%, HR 5.89 (1.4; 22.5), p = 0.01], stoma formation [52.6% vs. 8.9%, HR 10.9 (3.65; 34.1), p < 0.001], and segmental resection [38.5% vs. 5.8%, HR 9.75 (3.54; 30.4), p < 0.001]. Superficial, partial-thickness resections were associated with decreased risk [(4.2% vs. 36.2%), HR 0.08 (0.02; 0.24), p < 0.001]. Factors associated with major complications (8.5%) were blood loss [250 (100; 400) vs. 100 (50.0; 200) mls, p = 0.03], open surgery [31.6% vs. 4.9%, HR 8.74 (2.36; 32.9), p = 0.001], stoma formation [42% vs. 3.3%, HR 20.3 (5.41; 90.0), p < 0.001], and segmental colectomy [28.2% vs. 0.9%, HR 34.6 (6.25; 876), p < 0.001]. Partial-thickness resection was associated with decreased risk ([.05% vs. 23.4%, HR 8.74 (2.36; 32.9), p < 0.001]. 19.1% experienced recurrence. Open surgery [5.2% vs. 21.3%, HR 0.14 (0.02; 1.05), p = 0.027] and superficial partial thickness excision [23.4% vs. 10.6%, HR 2.86 (1.08; 7.59), p = 0.027] were associated. Segmental resection was associated with decreased recurrence risk [7.6% vs. 23.5%, HR 0.27 (0.08; 0.91), p = 0.024].

CONCLUSION

Limiting resection to partial-thickness or full-thickness disc excision compared to bowel resection may improve complications but increase recurrence risk.

Simultaneous rectal neuroendocrine tumors and pituitary adenoma: A case report and review of literature

BACKGROUND

Neuroendocrine tumors (NET) are rare heterogeneous tumors that arise from neuroendocrine cells throughout the body. Acromegaly, a rare and slowly progressive disorder, usually results from a growth hormone (GH)-secreting pituitary adenoma.

CASE SUMMARY

We herein describe a 38-year-old patient who was initially diagnosed with diabetes. During colonoscopy, two bulges were identified and subsequently removed through endoscopic submucosal dissection. Following the surgical intervention, the excised tissue samples were examined and confirmed to be grade 2 NET. 18F-ALF-NOTATATE positron emission tomography-computed tomography (PET/CT) and 68Ga-DOTANOC PET/CT revealed metastases in the peri-intestinal lymph nodes, prompting laparoscopic low anterior resection with total mesorectal excision. The patient later returned to the hospital because of hyperglycemia and was found to have facial changes, namely a larger nose, thicker lips, and mandibular prognathism. Laboratory tests and magnetic resonance imaging (MRI) suggested a GH-secreting pituitary adenoma. The pituitary adenoma shrunk after treatment with octreotide and was neuroendoscopically resected via a trans-sphenoidal approach. Whole-exome sequencing analysis revealed no genetic abnormalities. The patient recovered well with no evidence of recurrence during follow-up.

CONCLUSION

18F-ALF-NOTATE PET/CT and MRI with pathological analysis can effectively diagnose rare cases of pituitary adenomas complicated with rectal NET.

Cystic Lymphangioma of Rectum-A Case Report and Review of Literature

Colorectal cystic lymphangiomas are rare benign lesions. They are characterized by the presence of either single or multi-cystic spaces lined by endothelium. Though there are multiple case reports of right and transverse colonic lymphangioma; only around 10 cases of lymphangioma of the rectum have been reported. We present a case report of rectal lymphangioma with the relevant literature review.

A novel physiologically based pharmacokinetic model of rectal absorption, evaluated and verified using clinical data on 10 rectally administered drugs

We present a physiologically based pharmacokinetic (PBPK) model simulating systemic drug concentrations following administration to the human rectum. Rectum physiology is parameterized based on literature data. The model utilizes in vitro release (IVRT) profiles from which drug mass transfer through the rectal fluid and tissue and into the systemic circulation are predicted. Due to a lack of data, rectal fluid and tissue absorption parameters are predicted either from colon absorption, with modifications relevant to rectal physiology, or optimized. The PBPK model is evaluated by simulating 29 clinical studies for 10 drugs. For 8 drugs (diazepam, diclofenac, indomethacin, naproxen, paracetamol, pentobarbital, phenobarbital and theophylline) the bias (average fold error, AFE) and precision (absolute average fold error, AAFE) of Cmax, AUC0-t and AUC0-inf simulations range from 0.87 to 2.22, indicating good agreement with observed values. For prochlorperazine and promethazine, the AFEs and AAFEs of Cmax predictions are 1.30 and 2.52, respectively. TheAUC0-t and AUC0-inf are overpredicted for both compounds(AFEs and AAFEs from 2.66 to 4.90). This results from a lack of reliable elimination data for prochlorperazine and the relevance of the IVRT profiles used in the promethazine model. The model paves the way for more mechanistic rectal drug absorption studies and virtual bioequivalence methods for rectal drug products.

Effectiveness of bladder filling control during online MR-guided adaptive radiotherapy for rectal cancer

BACKGROUND

Magnetic resonance-guided adaptive radiotherapy (MRgART) treatment sessions at MR-Linac are time-consuming and changes in organs at risk volumes can impact the treatment dosimetry. This study aims to evaluate the feasibility to control bladder filling during the rectum MRgART online session and its effectiveness on plan dosimetry.

METHODS

A total of 109 online adaptive sessions of 24 rectum cancer patients treated at Unity 1.5 T MR-Linac with a short course radiotherapy (25 Gy, 5 Gy × 5) for whom the adaptive plan was optimized and recalculated online based on the daily magnetic resonance imaging (MRI) were analysed. Patients were fitted with a bladder catheter to control bladder filling; the bladder is emptied and then partially filled with a known amount of saline at the beginning and end of the online session. A first MRI ([Formula: see text]) acquired at the beginning of the session was used for plan adaptation and the second ([Formula: see text]) was acquired while approving the adapted plan and rigidly registered with the first to ensure the appropriateness of the isodoses on the ongoing delivery treatment. For each fraction, the time interval between the two MRIs and potential bladder changes were assessed with independent metrics, and the impact on the plan dosimetry was evaluated by comparing target and organs at risk dose volume histogram cut-off points of the plan adapted on [Formula: see text] and recalculated on [Formula: see text].

RESULTS

Median bladder volume variations, DSC, and HD of 8.17%, 0.922, and 2.92 mm were registered within a median time of 38 min between [Formula: see text] and [Formula: see text]; dosimetric differences < 0.65% were registered for target coverage, and < 0.5% for bladder, small bowel and femoral heads constraints, with a p value > 0.05.

CONCLUSION

The use of a bladder filling control procedure can help ensure the dosimetric accuracy of the online adapted treatment delivered.

Application value of simultaneous multislice readout-segmented echo-planar imaging for diffusion-weighted MRI in differentiation of rectal cancer grade

OBJECTIVE

To analyze the association of apparent diffusion coefficient (ADC) values measured by readout-segmented echo-planar imaging (rs-EPI) using different simultaneous multislice (SMS) acceleration factors and the differentiation of rectal cancer grade.

MATERIALS AND METHODS

Patients with non-mucinous rectal adenocarcinoma diagnosed by biopsy (endoscope-guided biopsy or surgical resection) were retrospectively collected, and each patient underwent an MRI examination. ADC values of rs-EPI, 2 × SMS rs-EPI, and 3 × SMS rs-EPI were recorded as ADC1, ADC2, and ADC3, respectively.

RESULTS

The scanning time of 2 × SMS rs-EPI was 60 s, 56.2% shorter than 137 s of rs-EPI sequence, while that of 3 × SMS rs-EPI was 51 s, 72.8% less than that of rs-EPI time. The ADC value of the three groups dropped with the decrease in cancer grade (p < 0.05). The AUC values of ADC1, ADC2, and ADC3 in predicting highly differentiated rectal cancer were 0.74, 0.729, and 0.687, respectively. The difference in AUC values between ADC1 and ADC2 was not statistically significant (p = 0.889).

DISCUSSION

SMS technology with an acceleration factor of 2 could be applied clinically to evaluate the pathological differentiation of rectal cancer grade.

Inferior mesenteric artery ligation level in rectal cancer surgery: still no answer-a systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis is to summarize the current scientific evidence regarding the impact of the level of inferior mesenteric artery (IMA) ligation on post-operative and oncological outcomes in rectal cancer surgery.

METHODS

We conducted a systematic review of the literature up to 06 September 2022. Included were RCTs that compared patients who underwent high (HL) vs. anterior (LL) IMA ligation for resection of rectal cancer. The literature search was performed on Medline/PubMed, Scopus, and the Web of Science without any language restrictions. The primary endpoint was overall anastomotic leakage (AL). Secondary endpoints were oncological outcomes, intraoperative complications, urogenital functional outcomes, and length of hospital stay.

RESULTS

Eleven RCTs (1331 patients) were included. The overall rate of AL was lower in the LL group, but the difference was not statistically significant (RR 1.43, 95% CI 0.95 to 2.96). The overall number of harvested lymph nodes was higher in the LL group, but the difference was not statistically significant (MD 0.93, 95% CI - 2.21 to 0.34). The number of lymph nodes harvested was assessed in 256 patients, and all had a laparoscopic procedure. The number of lymph nodes was higher when LL was associated with lymphadenectomy of the vascular root than when IMA was ligated at its origin, but there the difference was not statistically significant (MD - 0.37, 95% CI - 1.00 to 0.26). Overall survival at 5 years was slightly better in the LL group, but the difference was not statistically significant (RR 0.98, 95% CI 0.93 to 1.05). Disease-free survival at 5 years was higher in the LL group, but the difference was not statistically significant (RR 0.97, 95% CI 0.89 to 1.04).

CONCLUSIONS

There is no evidence to support HL or LL according to results in terms of AL or oncologic outcome. Moreover, there is not enough evidence to determine the impact of the level of IMA ligation on functional outcomes. The level of IMA ligation should be chosen case by case based on expected functional and oncological outcomes.

Detection of mpox virus in ambient air in a sexual health clinic

Although transmitted mainly through direct (sexual) contact, mpox virus (MPXV) can be detected in ambient air. We explored the use of air sampling for diagnosis or (genomic) surveillance of mpox in a sexual health clinic. For six out of six patients who were infected with MPXV, all four of our ambient air PCR tests were positive. For 14 uninfected patients, PCR was positive in three ambient air samples, albeit with higher cycle threshold (Ct) values. Genomic sequencing of samples from two positive patients showed matching sequences between air and clinical samples.

Primary rectal mucosa-associated lymphoid tissue lymphoma treated with only endoscopic submucosal dissection: A case report

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphoma is a distinct subtype of non-Hodgkin B cell lymphoma that mostly involves the gastrointestinal tract. The stomach is the most commonly affected site whereas colorectal involvement occurs very rarely. Given its rarity, the management and clinical outcome of colorectal MALT lymphoma are not well established yet.

CASE SUMMARY

From the superficial capillary bed in the lower rectum. Endoscopic ultrasonography showed homogenous hypoechoic lesions in the deep mucosal layer. Endoscopic submucosal dissection (ESD) was done for accurate histologic diagnosis and treatment and both the rectal lesions were completely removed en bloc and subsequently diagnosed as primary rectal MALT lymphoma. Herein, we report a case of primary rectal MALT lymphoma in a 68-year-old woman that was treated by only ESD, and the 12-month follow-up revealed no tumour recurrence.

CONCLUSION

These results of our case and previous reports suggest that endoscopic resection alone may be a feasible and safe treatment for primary colorectal MALT lymphoma and allows organ preservation.

Leiomyosarcoma of the lower rectum managed by radiotherapy and surgery: A case report and review of literature

Rectal leiomyosarcoma is a very rare entity. Surgery is the main treatment, but the place of radiation therapy remains unclear. A 67-year-old woman was referred for a few-weeks' history of bleeding and anal pain intensified during defecation. Pelvic magnetic resonance imaging (MRI) showed a rectal lesion and biopsies revealed a leiomyosarcoma of the lower rectum. She was free of metastasis on computed tomography imaging. The patient refused radical surgery. After discussion by a multidisciplinary team, the patient received pre-operative long-course radiotherapy followed by surgery. The tumor was treated with 50Gy delivered in 25 fractions, within 5 weeks. The aim of radiotherapy was local control, allowing organ-preservation. Four weeks after radiation therapy, organ-preservation surgery could be performed. She had no adjuvant treatment. At 38-months follow-up, she had no local recurrence. However, distant recurrence (lung, liver, and bone) was detected 38 months after the resection and was managed by intra-venous doxorubicin 60mg/m² and dacarbazine 800mg/m² every 3 weeks. The patient was in a stable condition for nearly 8 months. The patient died 4 years and 3 months after the diagnosis.

Multiple distant metastases arising from a single, low-grade rectal neuroendocrine tumor: an autopsy case report

BACKGROUND

Rectal neuroendocrine neoplasms are rare epithelial neoplasms of the rectum. The incidence of these tumors has increased over the past decades. However, many questions remain unanswered regarding their clinicopathology, including the possible mechanisms in which these tumors may grow and metastasize.

CASE PRESENTATION

In this case report, we report the findings of an autopsy of a 65-year-old Japanese woman diagnosed with multiple liver metastases from a single, low-grade rectal neuroendocrine tumor. The diagnosis was made in late 2018 to early 2019, and subsequently the patient underwent several rounds of standard chemotherapy. However, due to unfavorable side effects, she opted for palliative care at our hospital instead from December 2020. The patient's condition was generally stable for the next 17 months, but in May 2022, she was hospitalized for increased abdominal pain. Despite enhanced pain control therapy, she eventually passed away. An autopsy was conducted to determine the exact cause of death. The primary rectal tumor was found to be small, but showed strong histological evidence of venous invasion. Metastases in the liver, pancreas, thyroid gland, adrenal glands, and vertebrae were also present. On the basis of the histological evidence obtained, we deduced that the tumor cells may have mutated and gained multiclonality as they spread vascularly to the liver, contributing to the distant metastases.

CONCLUSIONS

The results from this autopsy may provide an explanation for the possible mechanism by which small, low-grade rectal neuroendocrine tumors metastasize.

Incidental cancer in colectomy specimens from patients with familial adenomatous polyposis: single centre experience and literature review

BACKGROUND

Since cancer development is inevitable in patients with familial adenomatous polyposis (FAP), we aimed to determine the incidence of incidental malignancy in prophylactic colectomy specimens.

METHODS

The files of patients who underwent prophylactic surgery for FAP between 2010 and 2020 were retrospectively reviewed. The incidence of incidental malignancy in histopathological specimens was examined and a comprehensive literature review was made.

RESULTS

Fifty-five patients were included in the study, of whom 30 patients had a diagnosis of primary malignancy. Prophylactic colectomy was performed on 25 patients. The pathology results indicated that the specimens were benign in 12 patients (48%) and revealed carcinoma in situ in 11 patients (44%). Incidental malignancy was detected in 2 patients (8%). In the literature review, there were 243 patients who underwent prophylactic colectomy and incidental cancer was detected in 25 patients (10.3%) with the stages of 1 (7.4%), 2 (2.1%), and 3 (0.8%), respectively.

CONCLUSIONS

Incidental cancer is not rare in patients who have undergone prophylactic colectomy for FAP. Hopefully. they are usually at early stages and unexpected advanced cancers are seen rarely.

Clinical outcomes and risk factors associated with poor prognosis after endoscopic resection of 10-20 mm rectal neuroendocrine tumors: a multicenter, retrospective study of 10-year experience

BACKGROUND

The efficacy of endoscopic resection for of 10-20 mm rectal neuroendocrine tumor (NET) remains controversial. We aimed to evaluate the clinical outcomes and risk factors associated with poor prognosis after endoscopic resection of 10-20 mm rectal NET and to determine the optimal treatment.

METHODS

Patients who underwent endoscopic resection for rectal NET in four tertiary hospitals were enrolled, and data on with the clinical outcomes and risk factors related to poor prognosis were retrospectively analyzed.

RESULTS

A total of 105 patients who underwent endoscopic submucosal resection (ESD; n = 65, 61.9%), modified endoscopic mucosal resection (mEMR; n = 31, 29.5%), and conventional EMR (cEMR; n = 9, 8.6%) were enrolled. The mean follow-up period was 41.2 ± 21.9 months. In the morphologic findings, the mean diameter was 11.6 mm (range 10-19); the shape was sessile (50.5%) and mixed type (49.5%), and surface depression was observed in 41.9% of patients. In the histologic findings, 87.6% of patients had G1 and 12.4% G2 tumor grade, and 3.8% of patients had lymphovascular invasion. The overall en bloc and histologically complete (R0) resections were 99.1% and 76.2%, respectively. cEMR was a less-frequently developed R0 resection. In the univariate and multivariate analyses for R0 resection, only surface depression was significantly associated. Regional or distant organs metastasis during follow-up developed in three patients (2.9%) and was significantly associated with female sex, redness, G2 tumor grade, and non-ESD methods.

CONCLUSION

Patients who underwent endoscopic resection of 10-20 mm rectal NET had good prognosis; therefore, endoscopic resection can be considered as the first-line treatment, particularly for 10-14 mm rectal NET. However, the risk factors, such as female sex, redness, G2 tumor grade and non-ESD methods, were associated with regional or distant metastases during follow-up. Therefore, patients with these risk factors should be carefully monitored.

Long-Term Outcomes of the Excluded Rectum in Crohn's Disease: A Multicenter International Study

BACKGROUND

Many patients with Crohn's disease (CD) require fecal diversion. To understand the long-term outcomes, we performed a multicenter review of the experience with retained excluded rectums.

METHODS

We reviewed the medical records of all CD patients between 1990 and 2014 who had undergone diversionary surgery with retention of the excluded rectum for at least 6 months and who had at least 2 years of postoperative follow-up.

RESULTS

From all the CD patients in the institutions' databases, there were 197 who met all our inclusion criteria. A total of 92 (46.7%) of 197 patients ultimately underwent subsequent proctectomy, while 105 (53.3%) still had retained rectums at time of last follow-up. Among these 105 patients with retained rectums, 50 (47.6%) underwent reanastomosis, while the other 55 (52.4%) retained excluded rectums. Of these 55 patients whose rectums remained excluded, 20 (36.4%) were symptom-free, but the other 35 (63.6%) were symptomatic. Among the 50 patients who had been reconnected, 28 (56%) were symptom-free, while 22(44%) were symptomatic. From our entire cohort of 197 cases, 149 (75.6%) either ultimately lost their rectums or remained symptomatic with retained rectums, while only 28 (14.2%) of 197, and only 4 (5.9%) of 66 with initial perianal disease, were able to achieve reanastomosis without further problems. Four patients developed anorectal dysplasia or cancer.

CONCLUSIONS

In this multicenter cohort of patients with CD who had fecal diversion, fewer than 15%, and only 6% with perianal disease, achieved reanastomosis without experiencing disease persistence.

Surgical approaches to colonic and rectal anastomosis: systematic review and meta-analysis

PURPOSE

Postoperative complications after a colonic and rectal surgery are of significant concern to the surgical community. Although there are different techniques to perform anastomosis (i.e., handsewn, stapled, or compression), there is still no consensus on which technique provides the least number of postoperative problems. The objective of this study is to compare the different anastomotic techniques regarding the occurrence or duration of postoperative outcomes such as anastomotic dehiscence, mortality, reoperation, bleeding and stricture (as primary outcomes), and wound infection, intra-abdominal abscess, duration of surgery, and hospital stay (as secondary outcomes).

METHODS

Clinical trials published between January 1, 2010, and December 31, 2021, reporting anastomotic complications with any of the anastomotic technique were identified using the MEDLINE database. Only articles that clearly defined the anastomotic technique used, and report at least two of the outcomes defined were included.

RESULTS

This meta-analysis included 16 studies whose differences were related to the need of reoperation (p < 0.01) and the duration of surgery (p = 0.02), while for the anastomotic dehiscence, mortality, bleeding, stricture, wound infection, intra-abdominal abscess, and hospital stay, no significant differences were found. Compression anastomosis reported the lowest reoperation rate (3.64%) and the handsewn anastomosis the highest (9.49%). Despite this, more time to perform the surgery was required in compression anastomosis (183.47 min), with the handsewn being the fastest technique (139.92 min).

CONCLUSIONS

The evidence found was not sufficient to demonstrate which technique is most suitable to perform colonic and rectal anastomosis, since the postoperative complications were similar between the handsewn, stapled, or compression techniques.

Development of novel prediction models for nodal and distant metastasis in G1 and G2 colorectal neuroendocrine tumors

PURPOSE

We aimed to construct novel nomograms for nodal and distant metastasis for patients with G1 and G2 colorectal neuroendocrine tumors (NETs).

METHODS

A training set and validation set were obtained by including G1 and G2 colorectal NET patients from the Surveillance, Epidemiology, and End Results database and the Cancer Hospital Chinese Academy of Medical Science, respectively. The area under curve (AUC) values under receiver operating characteristic (ROC) curves, calibration plots, and the Hosmer‒Lemeshow tests were used to evaluate the discriminability and calibration of nomograms.

RESULTS

In total, 3690 and 172 patients were included in the training set and validation set, respectively. Tumor size, location, and T stage were included in the nomogram predicting nodal metastasis. The AUC values of the nomogram were 0.972 (95% confidence interval (CI): 0.964-0.980) and 0.897 (95% CI: 0.846-0.948) in the training set and validation set, respectively. The calibration plots and Hosmer‒Lemeshow test for the training set (P = 0.999) and validation set (P = 0.537) showed good model calibration. Tumor size, T stage, and N stage were incorporated into the nomogram predicting distant metastasis. The ROC curves demonstrated desirable discrimination both in the training set (AUC = 0.938 (95% CI: 0.921-0.954)) and validation set (AUC = 0.938 (95% CI: 0.890-0.988)). The calibration curves and Hosmer‒Lemeshow test indicated acceptable model calibration both in the training set (P = 0.908) and validation set (P = 0.722).

CONCLUSION

The proposed nomograms may be used as a reliable tool to predict the nodal and distant metastasis in G1 and G2 colorectal NETs.

Signet ring cell carcinoma of the rectal stump in a known ulcerative colitis patient

Colorectal carcinoma (CRC) is the third most commonly diagnosed cancer worldwide and is the second most common cause of cancer-related deaths. However, the Omani population shares the major burden as the most prevalent carcinoma. The disease is comparatively higher in males than females. Patients with pre-existing risk factors, including inflammatory bowel disease, are at increased risk of developing neoplasia. Among the various histopathological subtypes of adenocarcinoma in the rectum, signet ring cell carcinoma is the rarest and accounts for approximately 1% of the cases. Given the aggressive nature of this tumor, advanced presentation, stage, and poor prognosis, regular endoscopic surveillance is essential. Hereby, we report a rare case of signet ring cell carcinoma arising in the rectal stump in an already diagnosed and operated patient of Ulcerative colitis.

A rare case of a superficial squamous cell carcinoma (so-called cloacogenic carcinoma) of the rectum

A rare case of a squamous cell carcinoma (so-called cloacogenic carcinoma) showing extensive superficial spread to the rectum is presented. A 69-year-old woman had undergone colonoscopy for annual check-up, and a whitish, flat lesion with a central depressed area, 20 mm in size, was identified in the lower rectum. Narrow-band imaging with magnifying observation showed abnormal microvessels without the intrapapillary capillary loop patterns. Endoscopically, the margin of the lesion was unclear. Biopsy was performed, and a histological diagnosis of transitional cell carcinoma was made. Computed tomography showed no evidence of involvement of adjacent organs, lymph nodes or distant sites. Cystoscopy found no abnormality in the bladder mucosa. Owing to difficulty diagnosing this tumor accurately, local excision with transanal endoscopic microsurgery was performed. Cloacogenic carcinoma with submucosal invasion was diagnosed. A human papilloma virus (HPV) polymerase chain reaction test was positive. Judging from the histological findings and the positive HPV test, we hypothesis that the tumor was likely arising from the anal transitional zone with marked superficial spread to the rectum. Clinicians should keep in mind that this variant of squamous cell carcinoma may occur in the rectum, even if no endoscopic findings are seen in the anal transitional zone.

Excision of Deep Rectovaginal Endometriosis Nodules with Large Infiltration of Both Rectum and Vagina: What Is a Reasonable Rate of Preventive Stoma? A Comparative Study

STUDY OBJECTIVE

To compare postoperative complications and rectovaginal fistula rate in women undergoing excision of large rectovaginal endometriosis requiring concomitant excision of rectum and vagina during 2 time periods with differing policies for preventive stoma confection.

DESIGN

Retrospective before-and-after comparative cohort study on data prospectively recorded in a database. Patients managed from September 2018 to March 2020 (first period) were compared with those managed from April 2020 to June 2022 (second period).

SETTING

Endometriosis Institute.

PATIENTS

One hundred sixty-eight patients presenting with deep endometriosis infiltrating the rectum and vagina, with lesions more than 3 cm in diameter during 2 consecutive time periods with differing policies regarding use of preventive stoma.

INTERVENTIONS

Rectal disc excision or colorectal resection, concomitantly with large vaginal excision.

MEASUREMENTS AND MAIN RESULTS

A total of 87 and 81 women received surgery during the first and the second period, respectively, during which the rate of preventive stoma was, respectively, 32.2% and 8.6%. Deep rectovaginal nodule characteristics were comparable. The mean height (SD) of rectal sutures after disc excision and colorectal resection were, respectively, 6.5 cm (2.3 cm) and 7.2 cm (3.8 cm). Rectovaginal fistula was recorded in 17 patients, corresponding to an overall rate of 10.1%. The rates of rectovaginal fistula in the group of patients with and without preventive stoma, regardless of the period in which surgery was performed, were 11.4% and 9.8%, respectively (p = .76). The rates of fistula recorded during the first and the second period were, respectively, 9.2% and 11.1% (p = .80), and that of overall early main complications were 31% and 29.6% (p = .84). Regression logistic model identified an independent relationship between smoking and rectovaginal fistula (adjusted odds ratio [OR] 3.9, 95% confidence interval [CI] 1.1-14) after adjustment for the period (adjusted OR 1.4, 95% CI 0.4-4.9 related to the second period), stoma confection (adjusted OR 1.8, 95% CI 0.5-7.1 related to stoma confection), robotic surgery (adjusted OR 1.7, 95% CI 0.3-10.1 related to robotic assistance), and type of rectal surgery (adjusted OR 0.4, 95% CI 0.1-1.4 related to disc excision when compared with colorectal resection).

CONCLUSION

No statistically significant differences were found concerning risk of rectovaginal fistula in women with rectovaginal endometriosis requiring large rectal and vaginal excision after a decision to no longer routinely perform preventive stoma.

Sensory brain activation during rectal balloon distention: a pilot study in healthy volunteers to assess safety and feasibility at 1.5T

OBJECTIVE

Although increasing evidence suggests a central mechanism of action for sacral neuromodulation, the exact mechanism remains unclear. We set up a scanning paradigm to measure brain activation related to various stages of rectal filling using rectal balloon distention.

MATERIALS AND METHODS

Six healthy volunteers underwent rectal balloon distention during MRI scanning at a 1.5T scanner with a Tx/Rx head coil. MR images were collected at four levels of distention: empty balloon (EB), first sensation volume (FSV), desire to defecate volume (DDV), maximum tolerable volume (MTV). Data were analyzed using BrainVoyager 20.4. Whole brain and ROI-based fixed-effects general linear model analyses were performed on the fMRI time-course data from all participants.

RESULTS

Rectal filling until FSV evoked the most blood-oxygen-level-dependent responses in several clusters throughout the cortex, followed by the responses evoked by rectal filling until DDV. Interestingly, rectal filling until MTV evoked negative responses compared to baseline throughout the cortex. No negative side effects were found.

DISCUSSION

This study shows that a standardized paradigm for functional MRI combined with rectal filling is feasible and safe in healthy volunteers and is ready to be used in fecal incontinent patients to assess whether their brain activity differs from healthy controls.

Disk Excision Using End-to-End Anastomosis Circular Stapler for Deep Endometriosis of the Rectum: A 492-Patient Continuous Prospective Series

STUDY OBJECTIVE

To report a large series including women managed by disk excision using end-to-end anastomosis (EEA) circular transanal stapler to assess the feasibility of the technique, the features of nodules suitable for removal by disk excision, and the rate of major early complications.

DESIGN

Retrospective study on data prospectively recorded in 2 databases.

SETTING

Two tertiary referral centers.

PATIENTS

A total of 492 patients undergoing surgery for rectal endometriosis from May 2011 to June 2022.

INTERVENTIONS

Rectal disk excision using the EEA stapler.

MEASUREMENT AND MAIN RESULTS

Disk excision using EEA was performed in 492 patients (24.2%) of 2,029 women receiving surgery for deep endometriosis infiltrating the rectum during the 11-year study period. Deep endometriosis involved low rectum in 11% and mid rectum in 55.3%. The diameter of rectal nodules exceeded 3 cm in 65.9%. Mean operative time was 2 hours, mean diameter of rectal patches removed was 41 ± 11 mm, and the mean rectal suture height was 9.2 ± 5.5 cm. The presence of microscopic foci on the edges of rectal patches was identified in 30.2% of cases. Rectal fistula was recorded in 20 patients (4%). The distance from the anal verge was significantly lower in patients with fistula than women with no fistula (5.9 ± 2 cm vs 9.2 ± 5.6 cm, p = .027). Follow-up ranged from 1 to 120 months, with a median value of 36 months. Magnetic resonance imaging in 3 patients during follow-up revealed a recurrent nodule infiltrating the previous stapled line (0.6%) after a postoperative delay of, respectively, 36, 48, and 84 months.

CONCLUSION

Disk excision using the EEA stapler is suitable in nodules >3 cm if surgeons ensure deep shaving of the rectum, to allow complete inclusion of the shaved area into the stapler jaws. Postoperative rectal recurrences seem incidental, whereas bowel leakage rate is comparable with that after colorectal resection. This technique is suitable in almost a quarter of patients managed for rectal endometriosis nodules and is therefore a valuable technique that warrants more widespread use.

Influence of neo-adjuvant radiotherapy on the intestinal microbiota of rectal cancer patients

PURPOSE

Neo-adjuvant radiotherapy (NART) is a widely used pre-surgery radiotherapy for rectal cancer patients. Although NART is effective in reducing tumor burden before surgery, it may cause dysbiosis of intestinal microbiota. The intestinal microbiota shapes tumor inflammatory environment and influences cancer progression. However, how NART remodels the microbiota and how the microbiota affects therapeutic efficacy has been largely elusive. This study aimed to reveal the details of how NART affects the intestinal microbiota in patients with rectal cancer.

METHODS

Rectal cancer patients who received NART were recruited into the study, and their healthy family members on the same diet served as controls. Stool samples from five rectal cancer patients (28 in total) and five healthy individuals (16 in total) were collected for intestinal microbiota analysis by 16S rRNA gene amplicon sequencing. Samples from patients were divided into earlier- and later-NART according to the number of NART.

RESULTS

NART did not significantly affect the α diversity of intestinal microbiota. However, the abundance of bacterial genera associated with cancer progression tended to decrease in later-NART patients. More importantly, a variety of oral pathogenic bacteria were enriched in the intestine of later-NART patients. NART also affected functional pathways associated with the microbiota in DNA repair, metabolism, and bacterial infection.

CONCLUSION

NART significantly altered the microbiota composition and function in rectal cancer patients, and some oral pathogens were found to translocate to the intestine. This is the first report to study the effect of NART on intestinal microbiota in patients with rectal cancer, exploring the importance of intestinal microbiota during the process of NART.

Rectal stimulation with prebiotics and probiotics before ileostomy reversal: a study protocol for a randomized controlled trial

BACKGROUND

Ileostomy closure is associated with a high rate of postoperative morbidity, and adynamic ileus is the most common complication, with an incidence of up to 32%. This complication is associated with delayed initiation of oral diet intake, abdominal distention, prolonged hospital stay, and more significant patient discomfort. The present study aims to evaluate the rectal stimulus with prebiotics and probiotics before ileostomy reversal.

METHODS

This is a protocol study for an open-label randomized controlled clinical trial. Ethical approval was received (CAAE: 56551722.6.0000.0071). The following criteria will be used for inclusion: adult patients with rectal cancer stages cT3/4Nx or cTxN+ that underwent loop protection ileostomy, patients treated with neoadjuvant chemoradiotherapy, and patients who underwent laparoscopic or robotic total mesorectal excision. Patients will be randomized to one of two groups. The intervention group (with rectal stimulus): the patients will apply 500 ml of saline solution with 6 g of Simbioflora® rectally, once a day, for 15 days before ileostomy closure. The control group (without rectal stimulation): the patients will close the ileostomy with no previous rectal stimulus. The primary outcomes will be the adynamic ileus (need for postoperative nasogastric tube insertion; nausea/vomiting; or intolerance to oral feedings within the first 72 h) and intestinal transit (time to first evacuation/flatus).

RESULTS

The patient's enrollment starts in January 2023. We expect to finish in July 2025.

DISCUSSION

The findings of this randomized clinical study may have important implications for managing patients undergoing ileostomy reversal.

TRIAL REGISTRATION

This study is registered in the Brazilian Trial Registry (ReBEC) under RBR-366n64w. Registration date: 19/07/2022.

Artificial intelligence-based triage of large bowel biopsies can improve workflow

Background

Large bowel biopsies are one of the commonest types of biopsy specimen. We describe a service evaluation study to test the feasibility of using artificial intelligence (AI) to triage large bowel biopsies from a reporting backlog and prioritize those that require more urgent reporting.

Methods

The pathway was developed in the UK by National Health Service (NHS) laboratory staff working in a medium-sized general hospital.   The AI platform was interfaced with the slide scanner software and the reporting platform's software, so that pathologists could correct the AI label and reinforce the training set as they reported the cases.

Results

he AI classifier achieved a sensitivity of 97.56% and specificity of 93.02% for the case-level-diagnosis of neoplasia (adenoma and adenocarcinoma) and for an AI diagnosis of any significant pathology (i.e., adenomas, adenocarcinomas, inflammation, hyperplastic polyps, and sessile serrated lesions) sensitivity was 95.65% and specificity 92.96%. The automated AI diagnostic classification pathway took approximately 175 s per slide to download and process the scanned whole slide image (WSI) and return an AI diagnostic classification. Biopsies with an AI diagnosis of neoplasia or inflammation were prioritized for reporting while the remainder followed the routine reporting pathway. The AI triaged pathway resulted in a significantly shorter reporting turnaround time for pathologist verified neoplastic cases (P < 0.001) and inflammation (P < 0.05). The project's costs amounted to  £14800, excluding laboratory staff salaries. More time and resources were spent on developing the interface between the AI platform and laboratory IT systems than on the development of the AI platform itself.

Conclusions

NHS laboratory staff were able to implement an AI solution to accurately triage large bowel biopsies into several diagnostic classes and this improved reporting turnaround times for cases with neoplasia or with inflammation.