Rectal damage control: when to do and not to do

Rectal trauma is uncommon, but it is usually associated with injuries in adjacent pelvic or abdominal organs. Recent studies have changed the paradigm behind military rectal trauma management, showing better morbidity and mortality. However, damage control techniques in rectal trauma remain controversial. This article aims to present an algorithm for the treatment of rectal trauma in a patient with hemodynamic instability, according to damage control surgery principles. We propose to manage intraperitoneal rectal injuries in the same way as colon injuries. The treatment of extraperitoneal rectum injuries will depend on the percentage of the circumference involved. For injuries involving more than 25% of the circumference, a colostomy is indicated. While injuries involving less than 25% of the circumference can be managed through a conservative approach or primary repair. In rectal trauma, knowing when to do or not to do it makes the difference.

Dose rate in the highest irradiation area of the rectum correlates with late rectal complications in patients treated with high-dose-rate computed tomography-based image-guided brachytherapy for cervical cancer

The purpose of this study was to evaluate the effect of dose rate to the rectum on late rectal complications in patients treated with computed tomography (CT)-based image-guided brachytherapy (IGBT) for cervical cancer. The subjects were 142 patients with cervical cancer who underwent Ir-192 high-dose-rate (HDR)-IGBT between March 2012 and January 2018. The dose rate to the rectum was calculated using in-house software. The minimum, mean and maximum effective dose rate (EDR) was calculated for voxels of the rectal volume covered by cumulative doses >D0.1cc, >D2cc, and > D5cc. The average EDR of three to four brachytherapy sessions was calculated (EDR for patients; EDRp). The total dose of the rectum was calculated as the biologically equivalent dose in 2-Gy fractions (EQD2). The associations between EDRp for D0.1cc, D2cc, and D5cc and the respective rectal EQD2 values with late rectal complications were then analyzed. The median follow-up period was 40 months. Patients with rectal complications of ≥Grade 1 received a significantly higher mean EDRp for D0.1cc-5cc and had a greater EQD2 for D0.1cc-5cc. Multivariate analysis was performed using the mean EDRp for D2cc, EQD2 for D2cc, heavy smoking and BMI. Of these four variables, mean EDRp for D2cc (HR = 3.38, p = 0.004) and EQD2 for D2cc (HR = 2.59, p = 0.045) emerged as independent predictors for late rectal complications. In conclusion, mean EDRp and EQD2 were associated with late rectal complications in patients treated with HDR CT-based IGBT for cervical cancer.

Immune Checkpoint Inhibition as a Strategy in the Neoadjuvant Treatment of Locally Advanced Rectal Cancer

The treatment of locally advanced rectal cancer (LARC) has seen major advances over the past 3 decades, with multimodality treatment now standard of care. Combining surgical resection with radiotherapy and/or chemotherapy can reduce local recurrence from around 20% to approximately 5%. Despite improvements in local control, distant recurrence and subsequent survival rates have not changed. Immune checkpoint inhibitors have improved patient outcomes in several solid tumor types in the neoadjuvant, adjuvant, and advanced disease setting; however, in colorectal cancer, most clinical trials have been performed in the metastatic setting and the benefits confined to microsatellite instability-high tumors. In this article, we review the current preclinical and clinical evidence for using immune checkpoint inhibition in the treatment of LARC and discuss the rationale for specifically exploring the use of this therapy in the neoadjuvant setting. We summarize and discuss relevant clinical trials that are currently in setup and recruiting to test this treatment strategy and reflect on unanswered questions that still need to be addressed within future research efforts.

Risk of bowel fistula following surgical management of deep endometriosis of the rectosigmoid: a series of 1102 cases

STUDY QUESTION

What are the risk factors and prevalence of bowel fistula following surgical management of deep endometriosis infiltrating the rectosigmoid and how can it be managed?

SUMMARY ANSWER

In patients managed for deep endometriosis of the rectosigmoid, risk of fistula is increased by bowel opening during both segmental colorectal resection and disc excision and rectovaginal fistula repair is more challenging than for bowel leakage.

WHAT IS KNOWN ALREADY

Bowel fistula is known to be a severe complication of colorectal endometriosis surgery; however, there is little available data on its prevalence in large series or on specific management.

STUDY DESIGN, SIZE, DURATION

A retrospective study employing data prospectively recorded in the North-West Inter Regional Female Cohort for Patients with Endometriosis (CIRENDO) from June 2009 to May 2019, in three tertiary referral centres.

PARTICIPANTS/MATERIALS, SETTING, METHODS

One thousand one hundred and two patients presenting with deep endometriosis infiltrating the rectosigmoid, who were managed by shaving, disc excision or colorectal resection. The prevalence of bowel fistula was assessed, and factors related to the complication and its surgical management.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 1102 patients enrolled in the study, 52.5% had a past history of gynaecological surgery and 52.7% had unsuccessfully attempted to conceive for over 12 months. Digestive tract subocclusion/occlusion was recorded in 12.7%, hydronephrosis in 4.5% and baseline severe bladder dysfunction in 1.5%. An exclusive laparoscopic approach was carried out in 96.8% of patients. Rectal shaving was performed in 31.9%, disc excision in 23.1%, colorectal resection in 35.8% and combined disc excision and sigmoid colon resection in 2.9%. For various reasons, the nodule was not completely removed in 6.4%, while in 7.2% of cases complementary procedures on the ileum, caecum and right colon were required. Parametrium excision was performed in 7.8%, dissection and excision of sacral roots in 4%, and surgery for ureteral endometriosis in 11.9%. Diverting stoma was performed in 21.8%. Thirty-seven patients presented with bowel fistulae (3.4%) of whom 23 (62.2%) were found to have rectovaginal fistulae and 14 (37.8%) leakage. Logistic regression model showed rectal lumen opening to increase risk of fistula when compared with shaving, regardless of nodule size: adjusted odds ratio (95% CI) for disc excision, colorectal resection and association of disc excision + segmental resection was 6.8 (1.9–23.8), 4.8 (1.4–16.9) and 11 (2.1–58.6), respectively. Repair of 23 rectovaginal fistulae required 1, 2, 3 or 4 additional surgical procedures in 12 (52.2%), 8 (34.8%), 2 (8.7%) and 1 patient (4.3%), respectively. Repair of leakage in 14 patients required 1 procedure (stoma) in 12 cases (85.7%) and a second procedure (colorectal resection) in 2 cases (14.3%). All patients, excepted five women managed by delayed coloanal anastomosis, underwent a supplementary surgical procedure for stoma repair. The period of time required for diverting stoma following repair of rectovaginal fistulae was significantly longer than for repair of leakages (median values 10 and 5 months, respectively, P = 0.008)

LIMITATIONS, REASONS FOR CAUTION

The main limits relate to the heterogeneity of techniques used in removal of rectosigmoid nodules and repairing fistulae, the lack of accurate information about the level of nodules, the small number of centres and that a majority of patients were managed by one surgeon.

WIDER IMPLICATIONS OF THE FINDINGS

Deep endometriosis infiltrating the rectosigmoid can be managed laparoscopically with a relatively low risk of bowel fistula. When the type of bowel procedure can be chosen, performance of shaving instead of disc excision or colorectal resection is suggested considering the lower risk of bowel fistula. Rectovaginal fistula repair is more challenging than for bowel leakage and may require up to four additional surgical procedures.

STUDY FUNDING/COMPETING INTEREST(S)

CIRENDO is financed by the G4 Group (The University Hospitals of Rouen, Lille, Amiens and Caen) and the ROUENDOMETRIOSE Association. No financial support was received for this study. H.R. reports personal fees from ETHICON, Plasma Surgical, Olympus and Nordic Pharma outside the submitted work. The other authors declare no conflict of interests related to this topic.

Rectum Protection by Rectal Gel Injection in Cervical Cancer Brachytherapy: A Dosimetric Study via Deformable Surface Dose Accumulation and Machine-Learning-Based Discriminative Modeling

Purpose

This retrospective study aimed to evaluate the dosimetric effects of a rectal insertion of Kushen Ningjiao on rectal protection using deformable dose accumulation and machine learning–based discriminative modelling.

Materials and Methods

Sixty-two patients with cervical cancer enrolled in a clinical trial, who received a Kushen Ningjiao injection of 20 g into their rectum for rectal protection via high–dose rate brachytherapy (HDR-BT, 6 Gy/f), were studied. The cumulative equivalent 2-Gy fractional rectal surface dose was deformably summed using an in-house-developed topography-preserved point-matching deformable image registration method. The cumulative three-dimensional (3D) dose was flattened and mapped to a two-dimensional (2D) plane to obtain the rectal surface dose map (RSDM). For analysis, the rectal dose (RD) was further subdivided as follows: whole, anterior, and posterior 3D-RD and 2D-RSDM. The dose–volume parameters (DVPs) were extracted from the 3D-RD, while the dose geometric parameters (DGPs) and textures were extracted from the 2D-RSDM. These features were fed into 192 classification models (built with 8 classifiers and 24 feature selection methods) for discriminating the dose distributions between pre-Kushen Ningjiao and pro-Kushen Ningjiao.

Results

The rectal insertion of Kushen Ningjiao dialated the rectum in the ambilateral direction, with the rectal column increased from pre-KN 15 cm³ to post-KN 18 cm³ (P < 0.001). The characteristics of DGPs accounted for the largest portions of the top-ranked features. The top-ranked dosimetric features extracted from the posterior rectum were more reliable indicators of the dosimetric effects/changes introduced by the rectal insertion of Kushen Ningjiao. A significant dosimetric impact was found on the dose–volume parameters D_1.0cc–D_2.5cc extracted on the posterior rectal wall.

Conclusions

The rectal insertion of Kushen Ningjiao incurs significant dosimetric changes on the posterior rectal wall. Whether this effect is eventually translated into clinical gains requires further long-term follow-up and more clinical data for confirmation.

When Should We Expect Curative Results of Neoadjuvant Treatment in Locally Advanced Rectal Cancer Patients?

This review on recently published literature aims to summarize published data on pathologic complete response following neoadjuvant treatment in biopsy proven locally advanced rectal cancer patients. Published articles referring to pCR rectal cancer patients were identified using PubMed search. Eleven relevant articles were selected, based on tumor, treatment, and patient characteristics reporting. As a conclusion, rectal cancer patients with the highest chances of complete clinical or pathological response to neoadjuvant treatment are males, who are around 60 years, diagnosed with well or moderate differentiated locally advanced rectal cancer.

Primary rectal monophasic synovial sarcoma

Synovial sarcoma is a rare malignant mesenchymal neoplasm that often occurs in the extremities. Less than 70 cases of primary synovial sarcoma occurring in the digestive system have been reported. We present a case of a 48-year-old woman with a spindle cell tumor in the rectum that stained positive for AE1/3 (focal), vimentin, CD99, BCL2, EMA (focal), and MiB-1 (15%). Ultimately, the lesion was diagnosed as a primary rectal monophasic synovial sarcoma and confirmed by molecular testing for SYT/SSX1 gene fusion. Analysis of previous publications indicated that patients of advanced age or a large tumor size (≥5 cm) have a higher risk of progressing rapidly to death after diagnosis of synovial sarcoma in the digestive system.

Immunohistochemical Screening of HER2 in Canine Carcinomas: A Preliminary Study

HER2 overexpression has been reported in various human and canine tumours. The aim of this study is to investigate the expression of HER2 protein in different histotypes of canine carcinomas in order to identify potential tumours that could benefit from the HER2-targeted therapy. Eighty-two (82) canine carcinomas (squamous cell, gastro-intestinal, rectal, pulmonary, prostatic, urothelial, and ovarian) from paraffin-embedded samp les were immunohistochemically evaluated. The degree of HER2 expression was scored based on the ASCO/CAP 2018 guidelines. Intestinal carcinomas were those with greater HER2 overexpression (3+) with 81% of positive cases, followed by 42% of rectal carcinomas and 28% of squamous cell carcinomas. These observations suggest that HER2 overexpression could be a driver in the oncogenesis of several types of canine carcinomas and lay the foundations for the identification of different types of canine carcinomas that could benefit from HER2-targeted therapy.

Creation of the first national linked colorectal cancer dataset in Scotland: prospects for future research and a reflection on lessons learned

INTRODUCTION

Current understanding of cancer patients, their treatment pathways and outcomes relies mainly on information from clinical trials and prospective research studies representing a selected sub-set of the patient population. Whole-population analysis is necessary if we are to assess the true impact of new interventions or policy in a real-world setting. Accurate measurement of geographic variation in healthcare use and outcomes also relies on population-level data. Routine access to such data offers efficiency in research resource allocation and a basis for policy that addresses inequalities in care provision.

OBJECTIVE

Acknowledging these benefits, the objective of this project was to create a population level dataset in Scotland of patients with a diagnosis of colorectal cancer (CRC).

METHODS

This paper describes the process of creating a novel, national dataset in Scotland.

RESULTS

In total, thirty two separate healthcare administrative datasets have been linked to provide a comprehensive resource to investigate the management pathways and outcomes for patients with CRC in Scotland, as well as the costs of providing CRC treatment. This is the first time that chemotherapy prescribing and national audit datasets have been linked with the Scottish Cancer Registry on a national scale.

CONCLUSIONS

We describe how the acquired dataset can be used as a research resource and reflect on the data access challenges relating to its creation. Lessons learned from this process and the policy implications for future studies using administrative cancer data are highlighted.

Cystic Lesion of Dissected Pararectal Lymph Node in a Female Patient With Rectal Carcinoma: A Rare Pattern of Nodal Metastasis Mimicking a Serous Inclusion Cyst

Nodal metastatic foci of colorectal carcinoma are usually solid nodules. Serous inclusions are occasionally found in lymph nodes, particularly in female patients, and they occasionally form cysts. An 86-year-old woman was treated with laparoscopic low anterior resection and D3 lymph node dissection for advanced rectal carcinoma. A cyst with serous fluid and no necrotic debris was found within one of the dissected pararectal lymph nodes. Histologically, the cyst was lined by low columnar-to-cuboid epithelium with mild nuclear atypia, mimicking a serous inclusion cyst. Immunohistochemically, the epithelial cells were positive for caudal type homeobox 2 and negative for Wilms' tumor suppressor gene1. Immunohistochemistry for p53 showed a diffuse strong positivity, indicating a mutant TP53 as seen in primary rectal carcinoma. Thus, the nodal cystic lesion was confirmed to be a metastatic lesion. It is important to carefully assess a nodal cystic lesion to confirm whether it is benign or malignant.

Systematic Review: Recommendations of Levels of Physical Activity among Colorectal Cancer Patients (2010-2019)

BACKGROUND

It is necessary to engage in an appropriate level of physical activity to improve the prognoses of colorectal cancer patients, yet no guidelines currently exist. The goals of this systematic review are to determine the impact of levels of physical activity on the prognoses of colorectal cancer patients and to suggest recommended guidelines for levels of physical activity.

METHODS

This systematic review was conducted along PRISMA guidelines. Per the inclusion criteria, papers published in academic journals in English from 2010 to 2019 were selected. A literature search was performed on PubMed (Medline), and the results of the selected studies were qualitatively synthesized.

RESULTS

Of the 13 cohort studies included in this systematic review, most studies were conducted in the United States (N = 7). Immobility or low levels of physical activity adversely affected the prognoses of colorectal cancer patients. Contrarily, high levels of physical activity increased the survival rate in people with colorectal cancer.

CONCLUSION

For colorectal cancer patients, a level of physical activity of 17.5 to 35 MET hours per week is strongly recommended, which has been shown to reduce mortality by approximately 30 to 40%. Patients with limited physical capacity should maintain a minimum level of physical activity (≥3.5 MET hours/week).

Indications for lateral lymph node dissection in patients with rectal neuroendocrine tumors: A case report and review of the literature

The optimal surgical indications for small rectal neuroendocrine tumors (NETs) are controversial. Generally, treatment guidelines for rectal NETs >2 cm or with potential lymph node (LN) metastasis recommend formal oncologic low anterior resection (LAR) with total mesorectal excision (TME). However, rectal NETs have the potential to metastasize to the lateral lymph nodes (LLNs). To the best of our knowledge, there are no detailed reports in English on LLN metastasis from rectal NETs. A 47-year-old man diagnosed with a rectal NET underwent endoscopic submucosal dissection (ESD). The pathological diagnosis was NET G1. The tumor was 10 mm in diameter, and the tumor depth reached the submucosal layer. A period of 3 years after ESD, the patient was diagnosed with LN metastasis in the mesorectum and LLN metastasis on the left side from the NET. Robotic TME and bilateral LN dissection were performed. The pathological findings indicated that two of the 18 LNs in the mesorectum were metastatic, and all the LLNs on the left side were negative. In contrast, 1 of the 6 LLNs on the right side was metastatic. Early-stage rectal NETs can metastasize to the LLNs, and it is very difficult to detect LLN metastasis based on size alone. TME alone may be insufficient to treat rectal NETs, and additional LLN dissection may be an important treatment strategy. However, it is increasingly difficult to determine the surgical indications for optimally timed LLN dissection.

Different Medical Features and Strategies of Large Rectal Gastrointestinal Stromal Tumor: A Multi-Central Pooling Analysis

Purpose

The rectum is a rare site for gastrointestinal stromal tumors (GISTs). Tumors in this critical anatomical site are prone to develop local recurrence, and this occurs at a high level even in low-risk tumors. Previous studies found that high-risk was the most common category in rectal gastrointestinal stromal tumors (RGISTs), and size was the most important factor affecting the long-term prognosis. We aimed to find out the most influential factor on clinical outcomes, and describe demographics, oncological differences, and surgical procedures in patients with poor prognosis.

Patients and Methods

Data on consecutive patients with RGIST, who were diagnosed at Peking University People’s Hospital, Shandong Province Hospital, and The First Affiliated Hospital of Shandong First Medical University from 2010 to 2020, were retrospectively evaluated. Further, a literature search was conducted by retrieving data from PubMed, EMBASE, and the Cochrane Library databases from inception up to March 20, 2020.

Results

In all, 50 patients were diagnosed with RGIST at three medical centers, and 86 published records were finally included in the literature review. Combined analysis of the whole individual patient data showed that 5.5 cm was deemed an appropriate cut-off value for L-RGIST, and that patients usually showed a male predominance (67.59%), younger age at onset (56.61 years), higher operative difficulty, and poorer prognosis.

Conclusion

Separation of patients with large RGIST from general patients may contribute to the recognition of the oncological characteristics and clinical management of this rare type of tumor.

Case Series: Removal of Rectal Foreign Bodies

Introduction: Foreign rectal body is one of the less common presentations in the emergency department and has a variety of etiologies. Our aim is to study the mode of injury, clinical presentation, diagnosis, surgical intervention and outcomes associated with a rectal foreign body.

Methods: This cross-sectional case series was conducted from January 2019 to July 2019 in the surgical unit of a tertiary care teaching hospital in Pakistan. Mode of injury was classified as voluntary - for sexual gratification, involuntary ingestion, assault and fall. We also noted the presenting complaint, diagnosis, surgical intervention and outcome of the case.

Results: Foreign body in the rectum was more common in men (86.3%) than women (13.7%). The mean age of participants was 40 ± 15 years. Various causes include sexual gratification (45.4%), involuntary ingestion (27.2%), assault (22.7%) and history of fall (4.5%). Participants were diagnosed with sub-acute intestinal obstruction (59%), peritonitis (22.7%) and perianal injury (36.3%).

Conclusion: Sexual gratification was the most common reason for the retained rectum body. Timely diagnosis and management are required to prevent perforation and improve prognosis.

A Human Cellular Model for Colorectal Anastomotic Repair: The Effect of Localization and Transforming Growth Factor-β1 Treatment on Collagen Deposition and Biomarkers

Anastomotic leakage (AL) is a devastating complication after colorectal surgery, possibly due to the loss of stabilizing collagen fibers in the submucosa. Our aim was to assess the formation of collagen in the colon versus the rectum with or without transforming growth factor (TGF)-β1 exposure in a human cellular model of colorectal repair. Primary fibroblasts were isolated by an explant procedure from clinically resected tissue rings during anastomosis construction in 19 consecutive colorectal patients who underwent laparoscopy. The cells, identified as fibroblasts by morphologic characteristics and flow cytometry analysis (CD90⁺), were cultured for 8 days and in 12 patients in the presence of 1 ng/mL TGF-β1. Total collagen deposition was measured colorimetrically after Sirius red staining of fixed cell layers, and type I, III, and VI collagen biosynthesis and degradation were specifically determined by the biomarkers PINP, PRO-C3, PRO-C6, and C3M in conditioned media by competitive enzyme-linked immunosorbent assays. Total collagen deposition by fibroblasts from the colon and rectum did not significantly differ. TGF-β1 treatment increased PINP, PRO-C6, and total collagen deposition. Mechanistically, TGF-β1 treatment increased COL1A1 and ACTA2 (encoding α-smooth muscle actin), and decreased COL6A1 and MMP2 mRNA levels in colorectal fibroblasts. In conclusion, we found no effect of anatomic localization on collagen production by fibroblasts derived from the large intestine. TGF-β1 represents a potential therapeutic agent for the prevention of AL by increasing type I collagen synthesis and collagen deposition.

Schistosomiasis is associated with rectal mucosal inflammation among Kenyan men who have sex with men

Background: Schistosoma mansoni infection is hyperendemic in Lake Victoria communities and associated with cervicovaginal immune alterations and HIV acquisition. We assessed the hypothesis that schistosomiasis correlates with greater rectal inflammation in men who have sex with men (MSM) in Kisumu, Kenya. Methods: In this cross-sectional study of 38 HIV-negative MSM aged 18-35 years, schistosomiasis was diagnosed by urine circulating cathodic antigen (CCA). Microbiome was assessed in rectal swabs by 16S rRNA gene amplicon sequencing, and rectal inflammation by quartile normalized summative score of inflammatory cytokines (IL-1α, IL-1β, IL-8, and TNF-α). Elastic net (EN) regression identified taxa associated with inflammation. Multivariable linear regression estimated the association between inflammation score and schistosomiasis and bacteria identified in EN. Results: Most men were CCA positive (24/38; 63%), and median rectal inflammation score was significantly higher in these participants (11 vs. 8, p = 0.04). In multivariable regression, CCA-positive men had 2.85-point greater inflammation score (p = 0.009). The relative abundance of Succinivibrio (coefficient = -1.13, p = 0.002) and Pseudomonas (coefficient = -1.04, p = 0.001) were negatively associated with inflammation. Discussion: CCA positivity was associated with rectal mucosal inflammation, controlling for rectal microbiome composition. Given its high prevalence and contribution to inflammation, schistosomiasis may have important implications for HIV transmission in this vulnerable population.

Rectal actinomycosis mimicking malignancy

Abdominal actinomycosis is a chronic suppurative infection caused by Actinomyces species. The ileo-cecal region is most commonly affected, while the left side of the colon is more rarely involved. The infection has a tendency to infiltrate adjacent tissues and is, therefore, rarely confined to a single organ. Presentation may vary from non-specific symptoms and signs to an acute abdomen. We present a 56-year-old male who underwent a colonoscopy for complaints of bleeding per rectum that showed an ulcero-proliferative lesion at the recto-sigmoid junction that seemed like malignancy. Multiple biopsies done were reported this lesion to be Actinomycosis. He responded well to medical management that avoided a major surgical procedure.

Neuroendocrine neoplasms of the appendix, colon and rectum

Neuroendocrine neoplasms of the appendix, colon and rectum are classified according to the most recent WHO classification as neuroendocrine tumors (NET), neuroendocrine carcinomas (NEC) and mixed neuroendocrine-non neuroendocrine neoplasms (MiNENs). NECs and MiNENs are aggressive neoplasms requiring multimodal treatment strategies. By contrast, NETs are, in most cases, indolent lesions occurring as incidental findings in the appendix or as polyps in the rectum. While most appendiceal and rectal NETs are considered relatively non-aggressive neoplasms, a few cases, may show a more aggressive clinical course. Unfortunately, clinical/pathological characteristics to select patients at high risk of recurrence/metastases are poorly consolidated. Diagnosis is generally easy and supported by the combination of morphology and immunohistochemistry. Differential diagnostic problems are for NECs/MiNENs with poorly differentiated adenocarcinomas, when immunohistochemical neuroendocrine markers are not obviously positive, whereas for NETs they are represented by the rare appendiceal tubular and clear cell variants (which may be confused with non-neuroendocrine cancers) and rectal L-cell tumors which may be chromogranin negative and prostatic marker positive.

Transperineal Ultrasound in the Diagnosis of Proctitis in the Emergency Department

BACKGROUND

Patients with anorectal complaints commonly present to the emergency department (ED). In patients with prior history of pelvic radiation and those with risk factors for sexually transmitted infections, proctitis is frequently on the differential diagnosis. Computed tomography (CT) scans are frequently done in patients with atypical presentations and those with broader differential diagnoses. Although in cases with suspected uncomplicated proctitis, conducting a point-of-care transperineal ultrasound (TPUS) may provide sufficient data to confirm the diagnosis and ascertain a safe plan for outpatient management, thus limiting the need for CT scan, a frequent flow-limiting step in the ED.

CASE REPORT

In this article, we present a brief case series of patients presenting to the ED with anorectal complaints in whom TPUS revealed circumferential symmetric rectal wall edema and pericolonic stranding suggestive of proctitis. History and subsequent imaging further supported these diagnoses; we also briefly detail the patients' clinical course and outcomes. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: We propose the use of TPUS as the screening imaging for anorectal pathologies and those with suspected proctitis to increase its use among emergency physicians. We review the main sonographic features of proctitis alongside reports from clinical cases, as well as the potential advantages of TPUS as a first-line imaging modality as compared with CT or magnetic resonance imaging. Although the complexities of anorectal anatomy can make TPUS a more difficult ultrasound modality to master, integrating TPUS into clinical practice will prove beneficial to both physician and patient.

Large intestine in pheasant (phasianus colchicus) and see-see partridge (ammoperdix griseogularis). A comparative morphological and histological study

Anatomical and histological studies of the large intestine in birds are essential for necropsy and histopathological examinations. On the other hand, large intestine plays a critical role in the immune system and absorption. The present study's objective was to provide information about the morphological, morphometric and histological characteristics of the large intestine in see-see partridges (Ammoperdix griseogularis) and pheasants (Phasianus colchicus). These two members of the Galliformes order are found in large areas of Iran. In this study, ten male see-see partridges and ten male pheasants were randomly selected. Also, the histological studies were carried out on tissue specimens using haematoxylin for staining. In both species, the cecum was visible as two large tubes at the beginning of the rectum. The cecum and rectum's outer surfaces were flat and had no sacculation in both of the birds. Histologically, intestinal villi in all the large intestine parts and increase their height from the base to the apex is remarkable. The muscularis mucosae was distinct, and lymph nodes and Liberkuhn glands were found in all parts of the large intestine, approximately. It can be concluded that the morphology of the large intestine is very similar to the other avian species, but there are more differences in the histological features. These structural features are in full accordance with the bird's habits and diet.

Gastrointestinal stromal tumors of the colon and rectum

Gastrointestinal stromal tumors (GISTs) are rare neoplasms, colorectal location being met in less than 5% of cases. Knowledge about this site related particularities are limited. The aim of this study is to present our experience with colorectal GISTs between 2005 and 2018 from the clinical, morphological, and immunohistochemical perspectives, with emphasis on prognostic factors. From a total of 203 gastrointestinal stromal tumors registered, 12 were colorectal (6%). The number of colonic tumors surpassed that of the rectum (9 : 3) and on the right side were registered more cases than on the left side (6/3). 9 were primary tumors and 3 were recurrences. Men and women were represented equally and the age range was between 22 and 76. Tumor dimensions varied between 0.5 and 14 cm. Microscopically, spindle cell type was dominant. Mitotic rate was variable between 1 and 115/50HPFs. Accordingly, for primary tumors progression risks were assigned (low risk: 2 cases, intermediate risk: 3 cases and high risk: 4 cases). All GISTs were CD117 and DOG1 positive. Four of the patients died of the disease.

Proctalgia secondary to rectal arteriovenous malformation and inferior mesenteric vein stenosis in a patient post liver transplant

Background

Chronic proctalgia can have a major impact upon quality of life. There are many potential aetiologies however, in some patients no cause can be identified.

Case presentation

We present a patient post liver transplant with intractable proctalgia, despite multidisciplinary management including opioids, nerve blocks and surgical intervention. An underlying rectal arteriovenous malformation (AVM) was subsequently identified and successfully treated with embolotherapy. The onset of symptoms coincided with the development of inferior mesenteric vein stenosis, likely leading to engorgement of the malformation due to impaired venous outflow. Neovascularisation secondary to the liver transplant procedure may also have contributed to growth of the lesion.

Conclusion

This is a rare presentation of rectal AVM. These lesions can be treated with minimally invasive embolisation/sclerotherapy and should be considered in cases of unexplained proctalgia.

Rectum migration of an intrauterine device

Intrauterine device (IUD) is a well-accepted means of contraception. Although it is safe and effective, some serious complications may occur. It should be paid attention to a 45-year-old female admitted to the hospital for aggravated abdominal pain and dyspareunia for 2 months. She was found to have two IUDs in her body, one in the uterine cavity and the other outside. They were removed through laparoscopic and hysteroscopy. When IUD perforation occurs, whether symptomatic or not, surgical removal is necessary. Laparoscopy is thought to be the first choice. However, when serious adhesions coexist, laparotomy would be recommended.

Robotic-assisted versus conventional laparoscopic surgery for colorectal cancer: Short-term outcomes at a single center

Background

The robotic technique has been established as an alternative approach to laparoscopy for colorectal surgery. The aim of this study was to compare the short-term outcomes of robot-assisted and laparoscopic surgery in colorectal cancer.

Methods

The cases of robot-assisted or laparoscopic colorectal resection were collected retrospectively between July 2015 and September 2018. We evaluated patient demographics, perioperative characteristics, and pathologic examinations. Short-term outcomes included time to passage of flatus and length of postoperative hospital stay.

Results

A total of 580 patients were included in the study. There were 271 patients in the robotic colorectal surgery (RCS) group and 309 in the laparoscopic colorectal surgery (LCS) group. The time to passage of flatus in the RCS group was 3.62 days shorter than the LCS group. The total costs were increased by 2,258.8 USD in the RCS group compared to the LCS group (P < 0.001).

Conclusion

The present study suggests that colorectal cancer robotic surgery was more beneficial to patients because of a shorter postoperative recovery time of bowel function and shorter hospital stays.

Tumor Macroscopic Morphology Is an Important Prognostic Factor in Predicting Chemotherapeutic Efficacy and Clinical Outcomes of Patients With Colorectal Neuroendocrine Neoplasms, One Multicenter Retrospective Cohort Study

BACKGROUND AND AIMS

Locally advanced and metastatic colorectal neuroendocrine neoplasm (NEN) is a rare disease with a dismal prognosis. We aimed to explore the value of the macroscopic morphology of NENs in the management of TNM stage II-IV colorectal NENs, which has not been fully elucidated in previous reports.

METHODS

We retrospectively enrolled 125 eligible patients with TNM stage II-IV colorectal NENs who were diagnosed between 2000 and 2020 from three Chinese hospitals. All were categorized into either protruding or ulcerative NEN groups through endoscopic evaluation of their macroscopic morphology. Clinicopathological data were collected and compared between the two groups. Survival analysis was performed to assess the survival outcomes between the two groups.

RESULTS

A total of 77 and 48 patients had protruding and ulcerative NENs, respectively. Patients with ulcerative NENs had a larger median tumor size (P<0.001) and higher median Ki-67 index (P<0.001), and a larger proportion of these patients had grade G3 disease (P=0.001) and poorly differentiated neoplasms (P=0.001), as well as higher frequencies of T3 and T4 tumors (P=0.006) than patients with protruding NENs. In addition, patients with ulcerative NENs showed a much lower response to first-line chemotherapy [50% (95% CI: 27.3% - 72.7%) versus 20% (95% CI: 3.1% - 36.9%), P=0.03] and a worse 3-year progression-free survival (PFS) rate [19.7% (95% CI: 7.2% - 32.2%) versus 49.5% (95% CI: 37.5% - 61.5%), P=0.001] and 3-year overall survival (OS) rate [30.7% (95% CI: 15.6% - 45.8%) versus 76.9% (95% CI: 66.5% - 87.3%), P<0.001] than those with protruding NENs. The multivariate analysis results indicated that the macroscopic shape of NENs was an independent prognostic factor affecting both PFS (HR = 1.760, 95% CI: 1.024 - 3.026, P = 0.04) and OS (HR = 2.280, 95% CI: 1.123 - 4.628, P = 0.02).

CONCLUSIONS

Ulcerative NENs were more malignant and chemotherapy resistant than protruding NENs. Tumor macroscopic morphology is a valuable prognostic factor for stage II-IV colorectal NENs.

The series of smooth muscle structures in the pelvic floors of men: Dynamic coordination of smooth and skeletal muscles

Introduction

Recent studies have revealed the extended nature of smooth muscle structures in the pelvic floor, revising the conventional understanding of the “perineal body.” Our aim was to clarify the three‐dimensional configuration and detailed histological properties of the smooth muscle structures in the region anterior to the rectum and anal canal in men.

Materials and methods

Four male cadavers were subjected to macroscopic and immunohistological examinations. The pelvis was dissected from the perineal side, as in the viewing angle during transperineal surgeries. Serial transverse sections of the region anterior to the rectum and anal canal were stained with Masson's trichrome and immunohistological stains to identify connective tissue, smooth muscle, and skeletal muscle.

Results

There was a series of smooth muscle structures continuous with the longitudinal muscle of the rectum in the central region of the pelvic floor, and three representative elements were identified: the anterior bundle of the longitudinal muscle located between the external anal sphincter and bulbospongiosus; bilateral plate‐like structures with transversely‐oriented and dense smooth muscle fibers; and the rectourethral muscle located between the rectum and urethra. In addition, hypertrophic tissue with smooth muscle fibers extended from the longitudinal muscle in the anterolateral portion of the rectum and contacted the levator ani.

Conclusions

The series of smooth muscle structures had fiber orientations and densities that differed among locations. The widespread arrangement of the smooth muscle in the pelvic floor suggests a mechanism of dynamic coordination between the smooth and skeletal muscles.

Clinical evidence, diagnostic approach and challenging therapeutic modalities for malignant melanoma of the anorectum

Primary anorectal malignant melanoma (ARMM) is a rare, aggressive tumour that accounts for approximately 1.2% of all melanomas. This rare entity represents less than 5% of anorectal malignant tumours and 0.05-1% of all malignant colorectal neoplasms. The incidence increases with age while there is a higher prevalence in Caucasians. ARMM is often asymptomatic or presents with no disease-specific evidence so that it can mimic other rectal disorders, malignant or benign. Colonoscopy is obligatory as a diagnosing mean for ARMM. Furthermore, endoscopic ultrasonography, computed tomography and magnetic resonance imaging can be utilized for the evaluation of tumour infiltration and lymph node metastases. Moreover, diagnostic establishment of ARMM requires an undeniable demonstration of essential melanocytic features in histology and immunohistochemistry. Even though the standard of treatment remains surgical resection, the choice between wide local excision and abdomino-perineal resection is still controversial. Recently, there have been recommendations regarding new techniques which could be utilized for the surgical treatment of ARMM. Newer treatments that have been proposed such as immune-checkpoint inhibitors and targeted therapies need further validation. A multicenter study would allow clarification of the most appropriate therapeutic strategy for this uncommon nosological entity.

Differential Expression of miR-20a and miR-145 in Colorectal Tumors as Potential Location-specific miRNAs

BACKGROUND

MicroRNAs (miRNAs), as tissue specific regulators of gene transcription, may be served as biomarkers for Colorectal Cancer (CRC).

OBJECTIVE

This study aimed to investigate the potential role of the cancer-related hsa-miRNAs as biomarkers in Colon Cancer (CC) and Rectal Cancer (RC).

METHODS

A total of 148 CRC samples (74 rectum and 74 colon) and 74 adjacent normal tissues were collected to examine the differential expression of selected ten hsa-miRNAs using quantitative Reverse Transcriptase PCR (qRT-PCR).

RESULTS

The significantly elevated levels of miR-21, miR-133b, miR-18a, miR-20a, and miR-135b, and decreased levels of miR-34a, miR-200c, miR-145, and let-7g were detected in colorectal tumors compared to the healthy tissues (P<0.05). Hsa-miR-20a was significantly overexpressed in rectum compared to colon (p =0.028) from a cut-off value of 3.15 with a sensitivity of 66% and a specificity of 60% and an AUC value of 0.962. Also, hsa-miR-145 was significantly overexpressed in colon compared to the rectum (p =0.02) from a cut-off value of 3.9 with a sensitivity of 55% and a specificity of 61% and an AUC value of 0.91.

CONCLUSION

In conclusion, hsa-miR-20a and hsa-miR-145, as potential tissue-specific biomarkers for distinguishing RC and CC, improve realizing the molecular differences between these local tumors.

The Outcome of Neoadjuvant Imatinib Therapy Combined With Surgery for Rectal Gastrointestinal Stromal Tumors: A Report of Three Cases and a Review of the Literature

Gastrointestinal stromal tumors (GISTs) represent the most frequent mesenchymal tumors of the gastrointestinal tract. They occur most frequently in the stomach. Rectal localization remains rare and represents only 5% of all GIST cases and 0.1% of all rectal tumors. Immunohistochemical staining (CD117, DOG1) and molecular analysis remain the gold standard for diagnosis; DOG1 represents a very sensitive marker regardless of CD117 expression. Complete en-bloc resection constitutes the only curative treatment; however, surgical management of rectal GIST remains challenging and can involve extensive surgery such as abdominoperineal resection with significant morbidity. The role of neoadjuvant Imatinib therapy in rectal GISTs is controversial and mainly indicated in a locally advanced tumor or sphincter invasion to increase the chance of complete resection and sphincter preservation. Herein, we report three cases of a rectal GIST treated with neoadjuvant Imatinib therapy and who underwent extensive surgery with complete resection (R0), as well as a recent review of the literature, to study clinicopathological features, surgical challenges, and perioperative Imatinib therapy outcome of rectal GISTs.

NRF2 and the Ambiguous Consequences of Its Activation during Initiation and the Subsequent Stages of Tumourigenesis

NF-E2 p45-related factor 2 (NRF2, encoded in the human by NFE2L2) mediates short-term adaptation to thiol-reactive stressors. In normal cells, activation of NRF2 by a thiol-reactive stressor helps prevent, for a limited period of time, the initiation of cancer by chemical carcinogens through induction of genes encoding drug-metabolising enzymes. However, in many tumour types, NRF2 is permanently upregulated. In such cases, its overexpressed target genes support the promotion and progression of cancer by suppressing oxidative stress, because they constitutively increase the capacity to scavenge reactive oxygen species (ROS), and they support cell proliferation by increasing ribonucleotide synthesis, serine biosynthesis and autophagy. Herein, we describe cancer chemoprevention and the discovery of the essential role played by NRF2 in orchestrating protection against chemical carcinogenesis. We similarly describe the discoveries of somatic mutations in NFE2L2 and the gene encoding the principal NRF2 repressor, Kelch-like ECH-associated protein 1 (KEAP1) along with that encoding a component of the E3 ubiquitin-ligase complex Cullin 3 (CUL3), which result in permanent activation of NRF2, and the recognition that such mutations occur frequently in many types of cancer. Notably, mutations in NFE2L2, KEAP1 and CUL3 that cause persistent upregulation of NRF2 often co-exist with mutations that activate KRAS and the PI3K-PKB/Akt pathway, suggesting NRF2 supports growth of tumours in which KRAS or PKB/Akt are hyperactive. Besides somatic mutations, NRF2 activation in human tumours can occur by other means, such as alternative splicing that results in a NRF2 protein which lacks the KEAP1-binding domain or overexpression of other KEAP1-binding partners that compete with NRF2. Lastly, as NRF2 upregulation is associated with resistance to cancer chemotherapy and radiotherapy, we describe strategies that might be employed to suppress growth and overcome drug resistance in tumours with overactive NRF2.

Histological Classification and Immunohistochemical Study of Feline Colorectal Epithelial Tumors

Among 113 feline gastrointestinal epithelial tumors diagnosed between 2006 and 2019, 78 (69%) were detected in the colorectum. Fifty colorectal tumors were selected for further pathological evaluations, of which 9 (18%) were histopathologically diagnosed as adenomas and 41 (82%) as carcinoma. The carcinomas included 33 tubular adenocarcinomas (TAC), 5 tubulovillous adenocarcinomas (TVAC), 2 mucinous adenocarcinomas, and 1 undifferentiated carcinoma. Histopathologically, TAC frequently showed vascular invasion (17/33 cases, 52%). In TAC cases, serosal infiltration (13/15 cases, 87%) and lymph node metastasis (8/9 cases, 89%) were common in bowel resection and lymphadenectomy samples, respectively. Immunohistochemically, the tumor cells of most cases were positive for cytokeratin (CK) 20 (50/50 cases, 100%) and CDX2 (48/50 cases, 96%). Focal immunopositivity for CD10 (11/50 cases, 22%) and CK7 (15/50 cases, 30%) was observed irrespective of the histological subtype. Only a few cases showed diffuse nuclear accumulation of β-catenin (2/50 cases, 4%) and p53 (5/50 cases, 10%). A lack of tubule formation, female sex, and low CDX2 labeling were statistically associated with carcinoma compared to adenoma (ρ = 0.615, P < .001; ρ = 0.279, P = .050; and ρ = -0.265, P = .063, respectively). Other features, including mucin profiles, Ki67 labeling index, and accumulation of β-catenin and p53, were not associated with malignancy. A sequence analysis revealed KRAS mutations in 3/7 TAC cases. These results suggest that KRAS mutations-rather than excessive Wnt/β-catenin signaling and the inactivation of TP53-contribute to the tumorigenesis of feline colorectal carcinoma.

Mechanistic differences underlying HIV latency in the gut and blood contribute to differential responses to latency-reversing agents

OBJECTIVE

While latently HIV-infected cells have been described in the blood, it is unclear whether a similar inducible reservoir exists in the gut, where most HIV-infected cells reside. Tissue-specific environments may contribute to differences in the mechanisms that govern latent HIV infection and amenability to reactivation. We sought to determine whether HIV-infected cells from the blood and gut differ in their responses to T-cell activation and mechanistically distinct latency reversing agents (LRAs).

DESIGN

Cross sectional study using samples from HIV-infected individuals (n = 11).

METHODS

Matched peripheral blood mononuclear cells (PBMC) and dissociated total cells from rectum ± ileum were treated ex vivo for 24 h with anti-CD3/CD28 or LRAs in the presence of antiretrovirals. HIV DNA and 'read-through', initiated, 5' elongated, completed, and multiply-spliced HIV transcripts were quantified using droplet digital PCR.

RESULTS

T-cell activation increased levels of all HIV transcripts in PBMC and gut cells, and was the only treatment that increased multiply-spliced HIV RNA. Disulfiram increased initiated HIV transcripts in PBMC but not gut cells, while ingenol mebutate increased HIV transcription more in gut cells. Romidepsin increased HIV transcription in PBMC and gut cells, but the increase in transcription initiation was greater in PBMC.

CONCLUSION

The gut harbors HIV-infected cells in a latent-like state that can be reversed by T-cell activation involving CD3/CD28 signaling. Histone deacetylation and protein kinase B may contribute less to HIV transcriptional initiation in the gut, whereas protein kinase C may contribute more. New LRAs or combinations are needed to induce multiply-spliced HIV and should be tested on both blood and gut.

Rectal cancer staging using MRI: adherence in reporting to evidence-based practice

Background

Magnetic resonance imaging (MRI) is the first-line imaging modality for local staging of rectal cancer. The radiology report should deliver all relevant available imaging information to guide treatment.

Purpose

To explore and describe if there was a gap between the contents in MRI reports for primary staging of rectal cancer in Sweden in 2010 compared to evidence-based practice.

Material and Methods

A total of 243 primary MRI staging reports from 2010, collected from 10 hospitals in four healthcare regions in Sweden, were analyzed using content analysis with a deductive thematic coding scheme based on evidence-based practice. Focus was on: (i) most frequently reported findings; (ii) correlation to key prognostic findings; and (iii) identifying if any findings being reported were beyond the information defined in evidence-based practice.

Results

Most frequently reported findings were spread through the bowel wall or not, local lymph node description, tumor length, and distance of tumor from anal verge. These items accounted for 35% of the reporting content. Of all reported content, 86% correlated with the evidence-based practice. However, these included more information than was generally found in the reports. When adjusting for omitted information, 48% of the reported content were accounted for. Of the reported content, 20% correlated to key pathological prognostic findings. Six types of findings were reported beyond the evidence-based practice, representing 14% of the total reporting content.

Conclusion

There was a gap between everyday practice and evidence-based practice in 2010. This indicates a need for national harmonization and implementation of standardized structured reporting templates.

The relationships between the results of contemporary tests of anorectal structure and sensorimotor function and the severity of fecal incontinence

BACKGROUND

Diagnostic investigations for fecal incontinence (FI) assess the structure and sensorimotor function of the anorectum. Investigations include anorectal manometry, anorectal sensory testing, pudendal nerve terminal motor latencies (PNTML), and endoanal sonography. The severity of FI and results of investigations are often discordant and the rate of symptom resolution following treatment remains <40%. High-resolution anorectal manometry (HRAM) and three-dimensional endoanal ultrasound (3D-US) have been introduced during the last decade. This study aims to assess the strength of relationships between contemporary investigation results and FI severity.

METHODS

Adults presenting for investigation of FI were assessed using the St Mark's FI severity score (SMIS), HRAM, anorectal sensory testing, PNTML, and 3D-US.

KEY RESULTS

246 patients were included. There were significant relationships between the SMIS and HRAM (resting pressure r_s = -0.23, 95% CI = (-0.34, -0.11), P < .001; squeeze pressure (r_s  = -0.26, 95% CI = (-0.37, -0.14), P < .001) and 3D-US (anterior EAS length r_s = -0.22, 95% CI = (-0.34, -0.09), P = .001). The relationships between SMIS and HRAM had a greater effect size in those with urge-predominant symptoms (resting pressure: r_s = -0.40, 95% CI = (-0.57, -0.20), P < .001, squeeze pressure: r_s = -0.34, 95% CI = (-0.52, -0.12), P = .003). Overall, the variance in SMIS accounted for by anorectal investigations was 8.6% (R² = 0.098, adjusted R² = 0.086, P < .001).

CONCLUSIONS AND INFERENCES

Anorectal investigations are not strong predictors of FI severity. These findings may reflect the multifactorial, heterogeneous pathophysiology of FI, the limitations of the SMIS and anorectal investigations, and contributing factors extrinsic to the anorectum.

European Society of Coloproctology Colorectal Robotic Surgery Training for the Trainers Course - the first pilot experience

AIM

Currently, there is no established colorectal specific robotic surgery Train the Trainer (TTT) course. The aim was to develop and evaluate such a course which can then be further developed to be incorporated within the planned European Society of Coloproctology (ESCP)/European School of Coloproctology (ESC) robotic colorectal surgery training curriculum.

METHOD

After identifying the need for such a course within a training programme, the course was developed by a subgroup of the ESCP/ESC. A scoping literature review was performed and the content and materials for the course were developed by a team consisting of two gastroenterologists with a combined experience of 30 years of facilitating TTT courses, a robotic surgeon and proctor with laparoscopic TTT faculty experience and experienced robotic and laparoscopic colorectal trainers. The course was evaluated by asking delegates to complete pre- and post-course questionnaires.

RESULTS

There were eight delegates on the course from across Europe. Delegates increased their knowledge of each of the course learning objectives and identified learning points in order to change practice. The feedback from the delegates of the course was positive across several areas and all felt that they had achieved their own personal objectives in attending the course.

CONCLUSION

This pilot robotic colorectal TTT course has achieved its aim and demonstrated many positives. There is a need for such a course and the evaluation processes have provided opportunities for reflection, which will allow the development/tailoring of future robotic colorectal TTT courses to help develop robotic training further.

Differential Diagnosis of Endometriosis by Ultrasound: A Rising Challenge

Ultrasound is an effective tool to detect and characterize endometriosis lesions. Variances in endometriosis lesions’ appearance and distorted anatomy secondary to adhesions and fibrosis present as major difficulties during the complete sonographic evaluation of pelvic endometriosis. Currently, differential diagnosis of endometriosis to distinguish it from other diseases represents the hardest challenge and affects subsequent treatment. Several gynecological and non-gynecological conditions can mimic deep-infiltrating endometriosis. For example, abdominopelvic endometriosis may present as atypical lesions by ultrasound. Here, we present an overview of benign and malignant diseases that may resemble endometriosis of the internal genitalia, bowels, bladder, ureter, peritoneum, retroperitoneum, as well as less common locations. An accurate diagnosis of endometriosis has significant clinical impact and is important for appropriate treatment.

Gastrointestinal Disorders and Risk of First-Ever Ischemic Stroke

BACKGROUND AND PURPOSE

Recent studies suggest that alteration of the normal gut microbiome contributes to atherosclerotic burden and cardiovascular disease. While many gastrointestinal diseases are known to cause disruption of the normal gut microbiome in humans, the clinical impact of gastrointestinal diseases on subsequent cerebrovascular disease remains unknown. We conducted an exploratory analysis evaluating the relationship between gastrointestinal diseases and ischemic stroke.

METHODS

We performed a retrospective cohort study using claims between 2008 and 2015 from a nationally representative 5% sample of Medicare beneficiaries. We included only beneficiaries ≥66 years of age. We used previously validated diagnosis codes to ascertain our primary outcome of ischemic stroke. In an exploratory manner, we categorized gastrointestinal disorders by anatomic location, disease chronicity, and disease mechanism. We used Cox proportional hazards models to examine associations of gastrointestinal disorder categories and ischemic stroke with adjustment for demographics and established vascular risk factors.

RESULTS

Among a mean of 1 725 246 beneficiaries in each analysis, several categories of gastrointestinal disorders were associated with an increased risk of ischemic stroke after adjustment for established stroke risk factors. The most notable positive associations included disorders of the stomach (hazard ratio, 1.17 [95% CI, 1.15-1.19]) and functional (1.16 [95% CI, 1.15-1.17]), inflammatory (1.13 [95% CI, 1.12-1.15]), and infectious gastrointestinal disorders (1.13 [95% CI, 1.12-1.15]). In contrast, we found no associations with stroke for diseases of the anus and rectum (0.97 [95% CI, 0.94-1.00]) or neoplastic gastrointestinal disorders (0.97 [95% CI, 0.94-1.00]).

CONCLUSIONS

In exploratory analyses, several categories of gastrointestinal disorders were associated with an increased risk of future ischemic stroke after adjustment for demographics and established stroke risk factors.

Primary Squamous Cell Carcinoma of Colon and Rectum: A Systematic Review of the Literature

Background - Objective: Primary colorectal squamous cell carcinoma is an extremely rare neoplasm with an incidence of 0.1 to 0.25 per 1,000 diagnosed colorectal carcinomas.The objective of this study was to evaluate its biological behavior and highlight the role of a surgical approach for its management.Methods: PubMed and Cohrane databases were independently searched (last search: April 10th, 2020) for articles concerning colorectal squamous cell carcinoma in adult population.Results: Seventy-one studies met predefined inclusion criteria and involved 99 patients (54.5% females) with an age of 56.98 ± 12.19 years (mean ± SD). The most frequent site of occurrence was the rectum (63.5%). Open surgery was conducted at 95% of patients, while 21.4% and 30.3% received neoadjuvant and adjuvant therapy respectively.Postoperative complications were developed in 31.3% of patients, while 6.1% died withing the first month following operation. Five-years survival rate was 49.5% (95% CI: 33.7%-63.4%). Female sex (HR: 0.24; 95% CI: 0.11-0.54; p-value: 0.001) and presence of postoperative complications (HR: 4.10; 95%CI: 1.47-1.46; p-value: 0.007) significantly affected the survival.Conclusions: Colorectal Squamous Cell Carcinoma is a rare tumor with an aggressive behavior. Surgery is the standard of treatment for the colontumors, while the role of chemoradiotherapy is promising especially for rectal tumors. Further clinical trials are necessary to determine the preferred treatment approach.

Multi-omics Analysis Reveals Adipose-tumor Crosstalk in Patients with Colorectal Cancer

Obesity and obesity-driven cancer rates are continuing to rise worldwide. We hypothesize that adipocyte-colonocyte interactions are a key driver of obesity-associated cancers. To understand the clinical relevance of visceral adipose tissue in advancing tumor growth, we analyzed paired tumor-adjacent visceral adipose, normal mucosa, and colorectal tumor tissues as well as presurgery blood samples from patients with sporadic colorectal cancer. We report that high peroxisome proliferator-activated receptor gamma (PPARG) visceral adipose tissue expression is associated with glycoprotein VI (GPVI) signaling-the major signaling receptor for collagen-as well as fibrosis and adipogenesis pathway signaling in colorectal tumors. These associations were supported by correlations between PPARG visceral adipose tissue expression and circulating levels of plasma 4-hydroxyproline and serum intercellular adhesion molecule 1 (ICAM1), as well as gene set enrichment analysis and joint gene-metabolite pathway results integration that yielded significant enrichment of genes defining epithelial-to-mesenchymal transition-as in fibrosis and metastasis-and genes involved in glycolytic metabolism, confirmed this association. We also reveal that elevated prostaglandin-endoperoxide synthase 2 (PTGS2) colorectal tumor expression is associated with a fibrotic signature in adipose-tumor crosstalk via GPVI signaling and dendritic cell maturation in visceral adipose tissue. Systemic metabolite and biomarker profiling confirmed that high PTGS2 expression in colorectal tumors is significantly associated with higher concentrations of serum amyloid A and glycine, and lower concentrations of sphingomyelin, in patients with colorectal cancer. This multi-omics study suggests that adipose-tumor crosstalk in patients with colorectal cancer is a critical microenvironment interaction that could be therapeutically targeted.See related spotlight by Colacino et al., p. 803.

Robotic surgical procedure for diffuse cavernous hemangioma of the rectum: A case report

Diffuse cavernous hemangioma of the rectum (DCHR) is a relatively rare benign vascular disease. DCHR is marked by recurrent bleeding and anemia, and it is difficult to diagnose correctly. Here, we report the case of a 34-year-old man diagnosed with DCHR by colonoscopy, CT, and endoscopic ultrasonography. The patient underwent a robot-assisted anterior abdominal excision and subsequently recovered well from the surgery. Ileostomy closure was performed 3 months after surgery. Eight months after surgery, he had no evidence of rectal bleeding, and his defecation function was good, with no fecal incontinence. Regardless of the characteristics of DCHR and the susceptible age of DCHR, it is important to diagnose DCHR correctly as soon as possible and to treat it without a permanent colostomy. Robot-assisted resection may be a good option for the treatment of DCHR.

Surgical and postoperative evaluations of rectal adenomas excised with a rigid proctoscope

PURPOSE

This study presents the surgical and postoperative results achieved with a rigid proctoscope using the transanal endoscopic technique to excise rectal adenomas. The results are compared to the results obtained with other currently employed transanal techniques.

METHODS

We investigated the medical records of patients who underwent transanal endoscopic operations from April 2000 to June 2018 at two tertiary referral centers for colorectal cancer.

RESULTS

This study included 99 patients. The mean age was 65.3 ± 13.3 years. The average size of the adenomas was 4.6 ± 2.3 cm, and their average distance to the anal border was 5.6 ± 3.3 cm. The average operative time was 65.3 ± 41.7 min. In 48.5% of the operations, the specimen was fragmented, and in 59.6% of the cases, the microscopic margins were free. The rates of postoperative complications and relapse were 5% and 19%, respectively. The mean follow-up was 80 ± 61.5 months.

CONCLUSIONS

The described proctoscope proved to be a viable technique with results similar to other techniques, with the advantage that it allowed greater accessibility for surgeons. Therefore, its use could be implemented and become widespread in surgical practice.

Is nonanatomic rectal resection a valid therapeutic option for rectal gastrointestinal stromal tumors? A proposed decision algorithm

BACKGROUND AND OBJECTIVES

The best surgical approach to rectal gastrointestinal stromal tumors (GISTs) is still debated, and both nonanatomic rectal resection (NARR) and anatomic rectal resection (ARR) are applied. The aim of this study was to evaluate the feasibility and oncological outcomes of NARR and ARR for rectal GISTs (R-GISTs).

METHODS

Through a large French multicentre retrospective study, 35 patients were treated for R-GIST between 2001 and 2013. Patients who underwent NARR and ARR were compared.

RESULTS

There were 23 (65.7%) patients in group ARR and 12 (34.3%) in group NARR. Significantly more patients in the group with ARR had a neoadjuvant treatment (86%) with tyrosine kinase inhibitor (TKI) (imatinib) compared to those with NARR (25%) (p < .01). The median preoperative tumor size was significantly different between the groups without and with neoadjuvant TKI: 30 ± 23 mm versus 64 ± 44.4 mm, respectively (p < .001). Overall postoperative morbidity was 20% (n = 7) (26% for ARR vs. 8% for NARR; p = .4). After a median follow-up of 60.2 (3.2-164.3) months, the 5-year disease-free survival rates were 79.5% (confidence interval [CI] 95%: 54-100) for the NARR group and 68% (CI 95%: 46.4-89.7) for the ARR group (p = .697), respectively.

CONCLUSION

The use of NARR for small R-GIST's does not seem to impair the oncological prognosis.

In Vitro Antagonistic Effect of Gut Bacteriota Isolated from Indigenous Honey Bees and Essential Oils against Paenibacillus Larvae

The aim of study was to isolate and identify the gut bacteria of Apis mellifera and to evaluate antagonistic effect of the bacteriota against Paenibacillus larvae, which causes American foulbrood (AFB) in honeybees. The dilution plating method was used for the quantification of selected microbial groups from digestive tract of bees, with an emphasis on the bacteriota of the bees' intestines. Bacteria were identified using mass spectrometry (MALDI-TOF-MS Biotyper). Overall, five classes, 27 genera and 66 species of bacteria were identified. Genera Lactobacillus (10 species) and Bacillus (8 species) were the most abundant. Gram-negative bacteria were represented with 16 genera, whereas Gram-positive with 10 genera. Delftia acidovorans and Escherichia coli were the most abundant in the digestive tract of honey bee. Resistance to a selection of antimicrobials was assessed for the bacterial isolates from bee gut and confirmed against all antimicrobials included in the study, with the exception of cefepime. Lactobacillus spp., especially L. kunkeei, L. crispatus and L. acidophilus. showed the strongest antimicrobial activity against P. larvae, the causal pathogen of AFB. Antimicrobial activity of essential oils against isolated bacteria and two isolates of P. larvae were assessed. Application of a broad selection of plant essential oils indicated that Thymus vulgaris had the highest antimicrobial activity against P. larvae.

Extragenital testing increases case detection of gonorrhea and chlamydia: The impact of implementing nucleic acid amplification testing

Background

Nucleic acid amplification testing (NAAT) was validated in Ontario in 2018 to test for chlamydia and gonorrhea at extragenital (pharyngeal, rectal) sites. Prior to this validation, extragenital testing could be done only by culture in Ontario. The objective of this study was to determine the number and proportion of gonorrhea and chlamydia cases that were detected exclusively through extragenital (pharyngeal and/or rectal) testing after the implementation of extragenital NAAT for these two infections at Sexual Health Clinic among gay, bisexual, and other men who have sex with men (gbMSM).

Methods

Case and laboratory data from before and after NAAT implementation were used to compare the rates of diagnosis of gonorrhea and chlamydia among gbMSM who presented at Sexual Health Clinics and the percent increase in diagnoses in gbMSM in the entire population.

Results

Among gbMSM seen at the clinic after implementation of NAAT testing, 70% of gonorrhea cases and 65% of chlamydia cases were detected exclusively at extragenital sites, corresponding to a four and two-fold increase, respectively, in the average annual number of cases diagnosed. As well, although approximately 50% more pharyngeal than rectal testing occurred, a higher proportion of chlamydia cases were detected rectally than would have been expected; this was not the case for gonorrhea, where most infections were pharyngeal.

Conclusion

It is important that clinicians perform extragenital testing among gbMSM who have sexual contact involving extragenital sites with more than one partner.

A Case of Pneumatic Rectal Perforation Caused by Compressed Air

Rectal perforation is a rare cause of acute abdomen. The most common cause of rectal perforation is trauma. Barotrauma due to the injection of compressed air in the rectum is an extremely rare cause of rectal perforation. We report a case of extensive pneumoperitoneum with abdominal compartment syndrome caused by rectal perforation secondary to the forceful injection of compressed air through the perineum. The patient was successfully managed by immediate relief of abdominal compartment syndrome by needle decompression followed by surgical repair of rectal perforation.

Investigation of Bowel Function with Anorectal Manometry in a Rat Spinal Cord Contusion Model

Bowel dysfunction after chronic spinal cord injury (SCI) is a common source of morbidity and rehospitalization. Typical complications include constipation, fecal impaction, incontinence, abdominal distention, autonomic dysreflexia, and the necessity of interventions (i.e., suppositories, digital stimulation) to defecate. Numerous surveys have confirmed that the remediation of bowel complications is more highly valued for quality of life than improvements in walking. Much of what is known about bowel function after SCI for diagnosis and research in humans has been gained using anorectal manometry (ARM) procedures. However, ARM has been underutilized in pre-clinical animal work. Therefore, a novel combination of outcome measures was examined in the current study that incorporates functional output of the bowel (weekly fecal measurements), weight gain (pre-injury to terminal weight), and terminal ARM measurement with external anal sphincter electromyography under urethane anesthesia. The results indicate higher fecal output after contusion during the sub-acute period (4-7 days) post-injury, changes in the composition of the feces, and functionally obstructive responses in a specific section of the rectum (increased baseline pressure, increased frequency of contraction, and reduced ability to trigger a giant contraction to a distension stimulus). These results demonstrate significant bowel dysfunction in the rodent SCI contusion model that is consistent with data from human research. Thus, the combined measurement protocol enables the detection of changes and can be used, with minimal cost, to assess effectiveness of therapeutic interventions on bowel complications.

Risk of rectal puncture due to needle entry into the presacral space: Importance of measuring the distance between the rectum and sacrococcyx, and the thickness of the sacrococcyx

During ganglion impar block, the needle may approach the presacral space and the sacrum may be penetrated during caudal anesthesia. Because the rectum is in front of the sacrococcyx and is thus at risk for puncture, it is important to determine the distance between the sacrococcyx and rectum, as well as the thickness of the sacrococcyx.Computed tomography was used to measure the distance between the rectum and sacrococcyx, as well as the thickness of the sacrococcyx. The distances between the coccyx and rectum, sacrococcygeal joint and rectum, sacral level 5 ('sacrum 5') and rectum, and 'sacrum 4 to 5 junction' and rectum were measured. The results were compared based on the presence or absence of stools in the rectum. The thickness of the sacrococcyx was measured at the sacrum 4 to 5 junction and sacrococcygeal joint.In total, 1264 patients were included in this study. All distances were less than 1 mm in both males and females, with the exception of the distance between the coccyx and rectum in males. In both males and females, there was no significant difference in distance between the sacrococcyx and rectum according to the presence or absence of feces in the rectum, but there was a difference in the distance between sacrum 5 and the rectum in males (P = .048). Several male and female patients showed thicknesses of less than 5 mm at the sacrococcygeal joint.Some patients have a distance of less than 1 mm between the sacrum and rectum. Practitioners should exercise caution when applying a needle to the presacral space. If the sacrum is accidentally penetrated during caudal block, rectum puncture cannot be ruled out. Excretion of feces does not influence the distance between the sacrococcyx and rectum in females.

Primary signet ring cell carcinoma with tubular adenoma of the rectum: A case report and a review of the literature

RATIONALE

Among the various forms of colorectal carcinomas, primary signet ring cell carcinoma (SRCC) of rectum is infrequent. Primary SRCC with adenoma is even rarer. Due to its low morbidity and lack of obvious manifestations at early stages, it is difficult to make an early diagnosis and perform surgical intervention in time. Herein, we reported a case of primary SRCC with tubular adenoma of rectum and also performed a review of the literature of such cases, in hopes of expanding the general understanding regarding such cases.

PATIENT CONCERNS

A 61-year-old male patient presented with rectal bleeding for 1 week.

DIAGNOSES

A neoplasm could be palpated through a rectal examination, with a size of 4.0 cm by 3.0 cm, at a distance of 5 cm from the anal edge. Magnetic resonance imaging examination and colonoscopies were performed to confirm the finding, and 4 tissue specimens were obtained for histopathologic biopsy. The result of biopsy was high-grade intraepithelial neoplasia with an adenoma component.

INTERVENTIONS

Surgical resection was performed, and histopathologic and immunohistochemical staining examination of the resection confirmed the diagnosis of SRCC with tubular adenoma.

OUTCOMES

The patient was discharged from hospital 12 days postsurgery, without any complications. Further chemotherapy and supportive treatments were suggested to him and will be followed at a local hospital.

LESSONS

Primary rectal SRCC has a rather low morbidity. Furthermore, a rectal SRCC with adenoma which was presenting in this case is even more rare. Besides lack of clinical characters, delay of diagnosis and treatment frequently occur. So far, a surgical procedure has still been one of the most effective treatments. Considering of metastasis and the poor prognosis, early diagnosis, in-time radical resection, and a comprehensive followed treatment are recommended for a higher 5-year overall survival.

Increased incidence of early onset colorectal adenocarcinoma is accompanied by an increased incidence of rectal neuroendocrine tumors

Recent studies have reported an increasing incidence of early onset colorectal cancer (CRC). Few studies compared the changing incidence of CRC by the major histological type, adenocarcinoma and neuroendocrine tumors (NETs). Using data from the Surveillance, Epidemiology, and End Results Program (SEER), we identified CRC from 1992 to 2015 with site and histological codes. Standardized incidence rates of CRC by anatomical locations (proximal, distal and rectal colon) and histological types (adenocarcinoma, NETs and others) were calculated over calendar years. Annual percent changes (APC) and joint-point regression were further computed. A significant increase of cancers in the distal colon and rectum was observed in young populations (20-44 and 45-54 years) but not in the proximal colon. Further analyses found that the highest rise of rectal NETs was in the 45-54 years which contributed 53.47% to the total increase of rectal cancer. The APCs for NETs in the rectum were 2.9 (95% CI: -0.1, 6.0) and 6.1 (95% CI: 3.8-8.4) for 20-44 years or 45-54 years respectively. The increase of NETs in the rectum was still significant in the older than 55 years (APC=3.7, 95% CI: 2.8-4.7), although the total CRC in this group was decreasing. Incidence of NETs in the distal colon is not apparently changing. The increase of CRC incidence among young populations (age < 55) is mainly due to the increased incidence in the rectum and distal colon. Moreover, the increase of early onset cancer in the rectum could be ascribed to increased incidence of adenocarcinoma and NETs.

Plasma protein expression differs between colorectal cancer patients depending on primary tumor location

Colorectal cancer (CRC) includes tumors in the right colon, left colon, and rectum, although they differ significantly from each other in aspects such as prognosis and treatment. Few previous mass spectrometry-based studies have analyzed differences in protein expression depending on the tumor location. In this study, we have used mass spectrometry-based proteomics to analyze plasma samples from 83 CRC patients to study if differences in plasma protein expression can be seen depending on primary tumor location (right colon, left colon, or rectum). Differences were studied between the groups both regardless of and according to tumor stage (II or III). Large differences in plasma protein expression were seen, and we found that plasma samples from patients with rectal cancer separated from samples from patients with colon cancer when analyzed by principal component analysis and hierarchical clustering. Samples from patients with cancer in the right and left colon also tended to separate from each other. Pathway analysis discovered canonical pathways involved in lipid metabolism and inflammation to be enriched. This study will help to further define CRC as distinct entities depending on tumor location, as shown by the widespread differences in plasma protein profile and dysregulated pathways.