Efficacy and safety of endoscopic submucosal tunnel dissection for rectal laterally spreading tumors

BACKGROUND

Evidence that comprehensively compares the efficacy and safety of endoscopic submucosal tunnel dissection (ESTD) with endoscopic submucosal dissection (ESD) for rectal laterally spreading tumors (LSTs) is limited.

METHODS

Between January 2009 and June 2018, 143 rectal LSTs in 143 patients who had undergone either ESD (n = 84) or ESTD (n = 59) were included in the study. One-to-one propensity score matching (PSM) was performed, and 50 pairs were selected. The data on patient demographics, treatment information, pathology reports, adverse events and follow-up were collected.

RESULTS

Before PSM, the median specimen area was significantly larger in the ESTD group than in the ESD group (12.56 cm² vs. 6.32 cm², respectively; p < 0.001). The median dissection speed was significantly higher in the ESTD group than in the ESD group (24.53 mm²/min vs. 15.16 mm²/min, respectively; p < 0.001). After PSM, the median dissection speed was significantly higher in the ESTD group than in the ESD group (23.80 mm²/min vs. 17.12 mm²/min, respectively; p < 0.001). In multiple linear regression analysis, significant factors related to a higher dissection speed were the treatment method of ESTD (p < 0.001) and larger specimen area (p < 0.001).

CONCLUSIONS

ESTD appears to be a safe and effective method to treat rectal LSTs. Compared with ESD, ESTD appears to achieve a higher dissection speed for rectal LSTs.

Primary Rectal Non-Hodgkin's Lymphoma Treated with Urgent Radiotherapy and Chemotherapy: A Case Report and Literature Review

Rectal malignancy is usually symptomatic due to its location, and most of the time presents with pain and bleeding due to its growth and ulceration. It is difficult to identify the primary as carcinoma or lymphoma based on symptoms only, as both have a similar presentation. As it presents the rarest form of histology, non-Hodgkin's lymphoma in the rectum is still difficult to diagnose initially, and its treatment is debatable. We describe the case of a 49-year-old male from Bangladesh with the same presentation. His treatment was delayed for more than a month as immunohistochemistry and staging delayed the final diagnosis. The disease was diagnosed as stage IE with the help of a positron emission tomography (PET)-CT scan, and due to the local progression the patient had a massive rectal bleeding that needed an urgent intervention. Radiotherapy was applied to stop the bleeding. Hypofraction followed by a conventional fraction of external beam radiotherapy (EBRT) with a total of 40 Gy was applied. Post-EBRT digital rectal examination showed no residual except scaring, and a PET scan was also negative for residual disease. Due to uncertainties and lack of any precious guideline, 6 cycles of adjuvant chemotherapy with the R-CHOP schedule were also completed. Without surgery, the combination of EBRT and chemotherapy helped to preserve the organ, and the patient has been disease free for more than 2.5 years since his treatment.

MRI of rectal cancer-relevant anatomy and staging key points

Rectal cancer has the eighth highest cancer incidence worldwide, and it is increasing in young individuals. However, in countries with a high human development index, mortality is decreasing, which may reflect better patient management, imaging being key. We rely on imaging to establish the great majority of clinical tumour features for therapeutic decision-making, namely tumour location, depth of invasion, lymph node involvement, circumferential resection margin status and extramural venous invasion. Despite major improvements in technique resulting in better image quality, and notwithstanding the dissemination of guidelines and examples of standardised reports, rectal cancer staging is still challenging on the day-to-day practice, and we believe there are three reasons. First, the normal posterior pelvic compartment anatomy and variants are not common knowledge to radiologists; second, not all rectal cancers fit in review paper models, namely the very early, the very low and the mucinous; and third, the key clinical tumour features may be tricky to analyse. In this review, we discuss the normal anatomy of the rectum and posterior compartment of the pelvis, systematise all rectal cancer staging key points and elaborate on the particularities of early, low and mucinous tumours. We also include our suggested reporting templates and a discussion of its comparison to the reporting templates provided by ESGAR and SAR.

Feasibility of Simultaneous Multislice Acceleration Technique in Diffusion-Weighted Magnetic Resonance Imaging of the Rectum

Objective

To assess the feasibility of simultaneous multislice-accelerated diffusion-weighted imaging (SMS-DWI) of the rectum in comparison with conventional DWI (C-DWI) in rectal cancer patients.

Materials and Methods

This study included 65 patients with initially-diagnosed rectal cancer. All patients underwent C-DWI and SMS-DWI with acceleration factors of 2 and 3 (SMS2-DWI and SMS3-DWI, respectively) using a 3T scanner. Acquisition times of the three DWI sequences were measured. Image quality in the three DWI sequences was reviewed by two independent radiologists using a 4-point Likert scale and subsequently compared using the Friedman test. Apparent diffusion coefficient (ADC) values for rectal cancer and the normal rectal wall were compared among the three sequences using repeated measures analysis of variance.

Results

Acquisition times using C-DWI, SMS2-DWI, and SMS3-DWI were 173 seconds, 107 seconds, (38.2% shorter than C-DWI), and 77 seconds (55.5% shorter than C-DWI), respectively. For all image quality parameters other than distortion (margin sharpness, artifact, lesion conspicuity, and overall image quality), C-DWI and SMS2-DWI yielded better results than did SMS3-DWI (Ps < 0.001), with no significant differences observed between C-DWI and SMS2-DWI (Ps ≥ 0.054). ADC values of rectal cancer (p = 0.943) and normal rectal wall (p = 0.360) were not significantly different among C-DWI, SMS2-DWI, and SMS3-DWI.

Conclusion

SMS-DWI using an acceleration factor of 2 is feasible for rectal MRI resulting in substantial reductions in acquisition time while maintaining diagnostic image quality and similar ADC values to those of C-DWI.

Case Report: Management of rectal squamous cell carcinoma - a treatment dilemma

Primary rectal squamous cell carcinoma is rare compared to adenocarcinoma, which is the predominant histologic type most commonly discovered at the time of colorectal carcinoma diagnosis. Due to the infrequent nature of this malignancy, data on tumor pathogenesis and risk factors remains sparse. Moreover, no standardized therapeutic regimen exists. This report describes a case of advanced rectal squamous cell carcinoma diagnosed in a 46-year-old female who initially presented with abdominal pain. Her clinical course was uncomplicated and she responded well to the selected therapy. Much work remains to be accomplished for patients with rectal squamous cell carcinoma.

Rectal endometriosis: predictive MRI signs for segmental bowel resection

OBJECTIVE

To retrospectively determine the accuracy of MRI rectal and pararectal signs in predicting the necessity for segmental resection in the case of lesions located in the rectum.

METHODS

MR images of consecutive patients treated for rectal endometriosis over a 5-year period were reviewed in consensus by two blinded readers. A systematic analysis of 7 rectal (lesion length, transverse axis, thickness and circumference, and presence of a convex base, submucosal oedema and hyperintense cystic areas) and 4 pararectal (posterior vaginal fornix, parametrial, ureteral and sacro-recto-genital septum involvements) signs was performed for each lesion. MRI results were compared to the surgical procedure performed (shaving versus segmental resection).

RESULTS

Among 61 patients studied, 32 received a segmental resection and 29, a shaving. Receiver operating characteristic curve analysis allowed determining cut-off values for length (≥ 32 mm), transverse axis (≥ 22 mm), thickness (≥ 14 mm) and circumference (≥ 3/8 radii). The 7 rectal signs, and only the sacro-recto-genital septum pararectal sign, were significantly associated with segmental resection in univariate analysis, nodular thickness ≥ 14 mm and circumference ≥ 3/8 radii being the most predictive signs (odds ratio 94.5 and 60.4, respectively). These 2 signs remained positively associated with segmental resection in multivariate analysis and, when combined, were predictive of segmental resection with an accuracy of 90.2%.

CONCLUSION

Assessing MRI rectal and pararectal signs may accurately predict the need for segmental resection versus a more conservative approach such as shaving for rectal lesion management.

KEY POINTS

• MRI analysis of rectal endometriosis, taking into account rectal and pararectal signs, may assist surgeons in the decision-making process, in counselling patients regarding the surgical procedure and in adequately allocating resources. • Among rectal signs, nodular thickness ≥ 14 mm and a circumference ≥ 38% were the most predictive signs of segmental resection. • Among pararectal signs, only the sacro-recto-genital septum involvement was significantly associated with segmental resection.

Primary Localized Amyloidosis of the Intestine: A Pathologist Viewpoint

Background

Localized amyloidosis of the intestine is a rare entity, which can clinically masquerade several conditions such as colitis, polyps, and malignant tumors. This study aims to evaluate the clinicopathological features of this entity.

Methods

To evaluate the clinicopathological features of this entity, a comprehensive search of the literature (1960 to 2019) was done using the following keywords: "amyloidosis" and "small intestine" or "duodenum" or "ileum" or "jejunum" or "colon". We identified 756 studies about gastrointestinal amyloidosis. Data were examined for 27 studies about localized intestinal amyloidosis. The clinicopathological features were described.

Results

The age at presentation ranged from 29 to 88 years. The male to female ratio was 3:1. The jejunum and sigmoid colon were the most commonly involved sites. Abdominal pain and intestinal obstruction (small intestine), or rectal bleeding (sigmoid region) were the most common clinical presentations. Colonoscopic findings included wall thickening, mucosal ulcerations (small intestine), and tumor-like masses (colon).

Conclusions

The clinical presentations of localized intestinal amyloidosis depend on the site of the deposition of the amyloid. In most cases, amyloid deposits consisted of light chain protein.

Diffusion tensor imaging of rectal carcinoma: Clinical evaluation and its correlation with histopathological findings

OBJECTIVE

This study sought to assess the feasibility of diffusion tensor imaging (DTI) to noninvasively evaluate histological grade and lymph node metastasis in patients with rectal carcinoma (RC).

METHODS

Thirty-seven consecutive patients with histologically confirmed RC were examined by 1.5-T MRI. DTI was performed using a single-shot echo-planar imaging sequence with b values of 0 and 1000 s/mm² and motion-probing gradients in nine noncollinear directions. Fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) maps were compared with histopathological findings.

RESULTS

The FA values (0.357 ± 0.047) of the RCs were significantly lower than those of the normal rectal wall, muscle, prostate, and uterus (P < 0.001 for all), while the AD, MD, and RD values (1.221 ± 0.131, 0.804 ± 0.075, and 0.667 ± 0.057 × 10^-3 mm²/s, respectively) were also significantly lower than their respective normal values (P < 0.001 for all). The FA, AD, MD, and RD values for RC additionally showed significant inverse correlations with histological grades (r = -0.781, r = -0.750, r = -0.718, and r = -0.682, respectively; P < 0.001 for all). Further, the FA (0.430 vs. 0.611), AD (1.246 vs. 1.608 × 10^-3 mm²/s), MD (0.776 vs. 1.036 × 10^-3 mm²/s), and RD (0.651 vs. 0.824 × 10^-3 mm²/s) (P < 0.001 for all) of the metastatic and nonmetastatic lymph nodes were significantly different.

CONCLUSIONS

DTI may be clinically useful for the noninvasive evaluation of histological grade and lymph node metastasis in patients with RC.

Well-differentiated rectal neuroendocrine tumors: analysis of histology, including insulinoma-associated protein 1 expression, and biologic behavior, involving a large cohort of 94 cases

Well-differentiated rectal neuroendocrine tumors (R-NETs) are increasingly being detected by screening colonoscopy, commonly manifesting as polyps. Chromogranin A is frequently negative in R-NETs. Insulinoma-associated protein 1 (INSM1) is a novel transcription factor that has recently shown excellent sensitivity and specificity for neuroendocrine (NE) differentiation in various anatomic sites but has not been systematically evaluated in R-NET. A retrospective histologic review of all available R-NETs was performed and stained for INSM1 immunohistochemistry, as well as for Ki-67 and chromogranin A, if not already available. Clinical and follow-up information was obtained from the medical chart. A total of 94 R-NETs were included in our cohort. Of these, 82 (87%) were <10 mm in greatest dimension, and submucosal involvement was noted in 70 patients (74%). The tumors displayed a variety of histologic patterns, and the majority of the cases had intratumoral fibrosis (61%). Synaptophysin and INSM1 were reactive in 100% cases, whereas chromogranin A was reactive in 45% cases. The mean Ki-67 proliferative index was 1.6% (range: 0.5-5%). The median follow-up of the cohort was 30 months (80 cases, range: 3-226 months). Only three patients were identified with regional lymph node metastasis, all of which showed a tumor size ≥10 mm and had lymphovascular invasion (LVI). R-NETs in our fairly large cohort display an indolent biologic behavior without distant metastasis. Metastatic disease in lymph nodes was associated with tumor size and the presence of LVI, but not with the Ki-67 proliferative index. This is also the first systematic study documenting INSM1 as a highly sensitive NE marker in R-NET.

Retrorectal tumor: a single-center 10-years' experience

Purpose

Retrorectal tumors (RTs) are a rare incidence and recommendations on the ideal surgical approaches are lacking. This study aimed to evaluate outcomes and follow-up results of patients undergoing excision of RTs at our institution.

Methods

A retrospective review was conducted for undergoing surgery for RT between January 2009 and January 2019. Demographic characteristics, presenting symptoms, preoperative diagnostic tests, surgical procedures, histopathological results, intraoperative and postoperative complications, postoperative hospital stay, postoperative 30-day mortality, 90-day unplanned readmission rate, and long-term outcomes were evaluated.

Results

Twenty patients with a mean age of 48.3 ± 14.2 were analyzed. The most common presenting complaint was perineal pain (35.0%). Magnetic resonance imaging and computed tomography was preferred in 18 and 2 patients, respectively. Tumor localization was below the level of the third sacral vertebrae in 14 patients for whom the posterior surgical approach was used. No postoperative mortality was recorded at the end of follow-up of 53.8 ± 40 months. Mean length of postoperative hospital stay was 8.6 ± 9.4 days. Ten percent of the patients had unplanned hospital readmission within 90 days after discharge. Recurrence developed in 1 patient, for whom pathology were reported as chordoma.

Conclusion

RT should be managed by a multidisciplinary team given the complexity and heterogeneity of these tumors despite the fact that the majority are benign. A good understanding of pelvic anatomy and characterization of lesions through detailed radiological imaging is crucial to optimize surgical planning. Complete surgical resection is key for prolonged disease-free and overall survival of patients diagnosed with RTs.

Endoscopy-assisted Removal of a Large Rectal Foreign Body by the Valsalva Maneuver

Although not as common as foreign bodies in the upper gastrointestinal tract, rectal foreign body insertion is often encountered in emergency departments. The diverse types of rectal foreign bodies have led to various removal methods. When removing a foreign body, the first thing to consider is which method is the least invasive and safest for the patient. This paper reports the successful removal of a rectal foreign body from the rectum using the Valsalva maneuver without anesthesia in a patient.

A case report of adult rectal duplication cyst resected by synchronous trans-abdominal and trans-anal total mesorectal excision

•

Rectal duplication cyst is extremely rare.

•

Adult onset rectal duplication cyst usually contains malignant formation.

•

Complete tumor resection is needed for the disease to prevent malignant change.

•

Synchronous trans abdominal and anal approach was effective for complete tumor resection.

Introduction

Rectal duplication cyst is extremely rare. Most of the cases diagnosed before two years old. Adult onset rectal duplication cyst usually contains malignant formation. Then complete tumor resection is needed for the disease to prevent malignant change.

Presentation of case

A 52-year-old man was referred to our hospital due to bloody stool. Colonoscopy showed 20-mm of sub-mucosal tumor at low rectum. Biopsy revealed no specific findings. Abdominal computed tomography showed that a 20-mm low density mass at posterior of lower rectum. As the existence of malignant lesion was unassailable, we planned two team, trans abdominal and trans-anal, laparoscopic low anterior resection. Perioperative course was good. Macroscopically, rectum had a submucosal cystic mass fulfilled mucinous content. Histologically, cyst wall was covered with heterotopic ciliated epithelium and composed of smooth muscle.

Discussion

Trans-anal total mesorectal excision (ta-TME) was introduced as beneficial approach for rectal malignancies.

Conclusion

Complete resection was possible by TME was necessary for patients with adult rectal duplication cyst, and synchronous trans-abdominal and trans-anal approach is a promising option.

Goblet cell carcinoid of the rectum: a case report

BACKGROUND

Goblet cell carcinoid (GCC) is a neuroendocrine tumor usually found in the appendix. GCCs exhibit characteristic findings with mixed endocrine-exocrine features such as staining positive for neuroendocrine markers and producing mucin. The primary GCC of the rectum is exceedingly rare.

CASE PRESENTATION

A 77-year-old Japanese male presented with hematochezia. Anal tenderness and a hard mass in the anal canal were found on the digital rectal examination, and colonoscopy was performed. Colonoscopy showed an irregularly shaped mass in the anal canal. Biopsy showed mixed features including adenocarcinoma in situ, well-differentiated adenocarcinoma, and mucinous carcinoma with invasive proliferation. No metastatic lesions were found on the computed tomography scan. Pelvic magnetic resonance imaging scan showed extramural growth of a tumor on the ventral side of the rectum without invasion to the prostate. Laparoscopic abdominoperineal resection was performed. The final diagnosis was well-differentiated adenocarcinoma in the mucosa and goblet cell carcinoid from the submucosa to the adventitia of the rectum. The patient was discharged from the hospital on postoperative day 16. Six months after resection, a computed tomography scan revealed multiple metastatic lesions in the liver. Several chemotherapy regimens were given, and the patient has stable disease 27 months after surgery.

CONCLUSION

We present a patient with rectal GCC with metachronous liver metastases. Since GCC grows intramurally and is biologically aggressive compared to typical carcinoid lesions, the disease is usually diagnosed at an advanced stage. The development of optimal adjuvant chemotherapy is needed for those patients.

High Compliance With Surgical Site Infection (SSI) Prevention Bundle Reduces Incisional SSI After Colorectal Surgery

PURPOSE

This study aimed to evaluate association between compliance with surgical site infection (SSI) prevention bundle and the development of superficial or deep incisional SSI following colorectal surgery and to evaluate the impact of incisional SSI on surgical outcomes.

METHODS

A prospectively collected database of consecutive patients undergoing elective colectomy and/or proctectomy from 2011 to 2019 in a university hospital was reviewed. The association between compliance with Thailand's SSI Prevention Bundle (10 level-1A interventions) and the incidence of incisional SSI was determined. Surgical outcomes were compared between those with incisional SSI and those without.

RESULTS

This study included 600 patients with a median age of 64 years (range, 18-102 years). Some 126 patients (21.0%) had stoma formation and 52 (8.7%) underwent laparoscopy. The incidence of incisional SSI was 5.5% (n = 33; 32 superficial incisional SSI and 1 deep incisional SSI). Higher compliance with care bundle tended to decrease incisional SSI (P = 0.20). In multivariate analysis, compliance of 70% or more was the only dependent factor for reducing incisional SSI (odds ratio, 0.39; 95% confidence interval, 0.15 to 0.99; P = 0.047). None of individual interventions were significantly associated with a lower probability of incisional SSI. Compared with counterparts, patients with incisional SSI had a 2-day longer length of postoperative stay (6 day vs. 4 day, P < 0.001) but comparable time for gastrointestinal recovery and similar rate of 30-day mortality or readmission.

CONCLUSION

High compliance with SSI prevention bundle (especially ≥ 70%) reduced incisional SSI after colorectal surgery.

Enhanced recovery after surgery in colon and rectal surgery: identification of predictive variables of failure in a monocentric series including 733 patients

To identify factors associated with early deviation and delayed discharge within an Enhanced Recovery after Surgery (ERAS) pathway. This is a retrospective review of prospectively collected data of consecutive patients who underwent laparoscopic or open colorectal surgery and managed with a standardized ERAS pathway between April 2015 and October 2018. ERAS items were assessed within 48 h after surgery. Patients with early complications were excluded. The influence of factors on length of stay was calculated by univariate and multivariate analysis. A binary logistic regression was used to model a predicting score. Seven hundred and thirty-three patients met the inclusion criteria. Multivariate analysis showed that age ≥ 75 years (P = 0.02), ASA score ≥ 3 (P = 0.03), open surgery or conversion to open (P = 0.001), non-compliance with the intra-operative balanced fluid therapy (P = 0.049), failure to early removal of the urinary catheter (P = 0.001), to discontinue IV fluid (P = 0.02) and to early mobilization (P = 0.001) were independently associated with ERAS failure. The generated score had a specificity of 84% and a positive predictive value of 72%. Patients who would have a length of stay longer than the median for each surgical procedure were properly identified (Area under ROC Curve = 0.753, P < 0.001). The delayed discharge could be predicted at 48 h from the intervention. The ability of the model to weight the specific role of each statistically significant variable might be a useful tool to identify the most frail patients.

Rectal perforations caused by cleansing enemas in chronically constipated patients: Two case reports

Constipation is a common disease that is frequently treated with cleansing enemas. Enemas are considered as effective and in some cases may cause serious adverse events. Iatrogenic perforations due to enemas lead to adverse outcomes in elderly patients with a poor general condition. Perforation remains an infrequent and rarely reported complication. In this work, we describe the cases of two patients with rectal perforation caused by a cleansing enema. The first patient had rectal perforation that led to a para-rectal abscess and the second patient had generalized peritonitis caused by rectal perforation.

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

BACKGROUND

The diversity in definitions for the rectosigmoid junction is becoming a major obstacle in standardizing optimal treatment of rectal cancers. The study aimed to determine the average distance of the sigmoid take-off from the anal verge and its association with individual factors.

MATERIALS AND METHODS

Patients diagnosed with rectal and sigmoid colon cancer in our centre from January 2010 to December 2018 were retrospectively enrolled in the cancer group. The results of 200 controls without colorectal disease were also reviewed (normal group). The distance of different landmarks and margins of cancer from the anal verge were retrieved from computed tomography (CT), magnetic resonance imaging (MRI), and endoscopy findings.

RESULTS

The cancer group comprised 635 patients (381 men, median age: 64 years). The average distances of the sigmoid take-off from the anal verge measured in CT and MRI were comparable (P = 0.483). On MRI, the average distance of the sigmoid take-off from the anal verge in the cancer group was comparable with that of the normal group (P = 0.070). Multivariate regression revealed that the distance of the sigmoid take-off from the anal verge was associated with the distances of the sacral promontory (P < 0.001) and peritoneal reflection (P < 0.001) from the anal verge.

CONCLUSION

The cancer distributions of patients varied widely with the application of different definitions. The point of sigmoid take-off is an intuitive landmark influenced by individual factors. The measurement of the sigmoid take-off by different researchers in both CT and MRI revealed good consistency. Further studies regarding the clinical significance of this definition are still needed.

Description of Prevotella rectalis sp. nov., a new bacterium isolated from human rectum

Using a taxonogenomics method, we describe here a Gram-negative bacterium named Prevotella rectalis sp. nov., strain Marseille-P4334T (= CSUR P4334) isolated from the rectum. Strain Marseille-P4334T has a genome that measure 3.03 Mbp with 43.3 mol% G + C content.

Tip-in versus conventional endoscopic mucosal resection for flat colorectal neoplasia 10 mm or larger in size

PURPOSE

A modified endoscopic mucosal resection (EMR) technique, Tip-in EMR, was recently introduced to enhance the complete resection of colorectal neoplasia (CRN). We aimed to evaluate the feasibility of Tip-in EMR for flat CRNs.

METHODS

From January to September 2018, conventional or Tip-in EMR was consecutively performed for 112 flat CRNs ≥ 10 mm in diameter. Tip-in EMR was performed when en bloc snaring was impossible with conventional EMR or when a lesion was inadequately lifted owing to a previous forceps biopsy. We retrospectively collected the clinical, procedural, and histologic data of the conventional and Tip-in EMR groups and compared the en bloc resection rate, complete resection rate, and complications between the two groups.

RESULTS

Among 112 flat CRNs of 80 patients, conventional EMR and Tip-in EMR were performed for 74 and 38 lesions, respectively. The median lesion size was 12 (10-27) mm. Tip-in EMR was superior to conventional EMR in terms of en bloc resection (94.7% vs. 77.0%, p = 0.018) and histologic complete resection (76.3% vs. 54.1%, p = 0.022). There was no difference in postprocedural bleeding between the two groups; however, overall adverse events, including bleeding and postpolypectomy electrocoagulation syndrome, were more frequent in the Tip-in EMR group.

CONCLUSIONS

Tip-in EMR is a feasible technique for flat colorectal lesions ≥ 10 mm and is superior to conventional EMR with respect to en bloc and complete resection rates. The safety profiles of Tip-in EMR and conventional EMR should be compared via large-scale prospective studies.

A critical literature review on the use of bellyboard devices to control small bowel dose for pelvic radiotherapy

Delivering curative radiotherapy doses for rectal and gynaecological tumours has historically been complicated by the dose tolerance of the small bowel. Acute radiation-induced small bowel toxicity includes side effects such as abdominal pain, nausea and diarrhoea. With the advent of new treatment delivery modalities, such as IMRT (Intensity modulated radiotherapy) and VMAT (Volumetric modulated Arc radiotherapy), there has been an expectation that small bowel doses can be better controlled with the use of these technologies. These capabilities enable the creation of treatment plans that can better avoid critical radiosensitive organs. The purpose of this review is to look beyond advances in linear accelerator technology in seeking improvements to small bowel dose and toxicity. This review examines whether an alternative prone patient positioning approach using a bellyboard device in conjunction with IMRT and VMAT treatment delivery can reduce small bowel doses further than using these technologies with the patient in a traditional supine position.

Grade 3 well-differentiated neuroendocrine tumor of the rectum: a case report

BACKGROUND

The 2019 revised World Health Organization (WHO) classification of tumors of endocrine organs classifies grade 3 gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN G3) into well-differentiated tumors (NET G3) and poorly differentiated carcinomas (NEC G3). There are few reported cases of NET G3 occurring in the rectum.

CASE PRESENTATION

A 71-year-old man complained of bright red blood in his stool. Total colonoscopy revealed a mass in the lower rectum. Pathologic examination yielded a diagnosis of group 1. Computed tomography revealed swollen paraintestinal lymph nodes and multiple liver metastases. We performed laparoscopic abdominoperineal resection not only to avoid the unbearable symptoms caused by tumor growth but to make a pathological diagnosis. The tumor measured 3.5 × 2.8 cm, and the pathological diagnosis was stage IV neuroendocrine carcinoma. He underwent chemotherapy with irinotecan plus cisplatin, followed by carboplatin plus etopside, but his disease did not respond to either regimen. Twenty-seven months after surgery, he died of his disease. Upon re-examination of the surgical specimen, the tumor was consistent with the 2019 WHO classification of NET G3.6 CONCLUSION: A definite diagnosis of NET G3 or NEC G3 must be made to determine the appropriate treatment strategy for patients with GEP-NEN G3. Further case reports and case series are needed to establish the optimal therapy.

Development and validation of a transanal endoscopic rectal purse string simulator

BACKGROUND

Rectal purse string placement for transanal mesorectal excision is challenging, and practice is difficult. The objective of this study is to build an endoscopic rectal purse string simulator and provide evidence for the validity of its use.

METHODS

A low-cost transanal endoscopic rectal purse string simulator was created and used to measure the performance of participants. Participants included general surgery residents, fellows, and staff surgeons from several Canadian university-affiliated institutions across Canada. The performance of the rectal purse string placement was measured by the time to completion of the task as well scoring with a modified objective structured assessment of technical skills (OSATS) score and a modified advanced laparoscopic suturing (ALS) score.

RESULTS

Thirty-nine participants were recruited into the study. Participants were split into three groups, based on prior experience with laparoscopic suturing, for the analysis of suturing a rectal purse string on the simulator based on three performance measures. There was a significant difference found in all three measures of performance in the three groups (time to completion p = 0.014, mean blinded OSATS score p = 0.007, mean blinded ALS score p = 0.020). Participants with previous laparoscopic suturing had significantly faster times to completion and higher skills scores when compared to residents (time: 5.1 ± 1.4 min vs 9.0 ± 4.8 min, p = 0.005; OSATS: 19.7 ± 2.8 vs 13.0 ± 5.8, p = 0.00398, ALS: 27.4 ± 4.0 vs 18.9 ± 8.5, p = 0.0151).

CONCLUSIONS

A transanal endoscopic purse string simulator was constructed and preliminary testing has shown variable performance based on prior laparoscopic suturing experience.

The Activation of Heat-Shock Protein After Copper(II) and/or Arsenic(III)-Induced Imbalance of Homeostasis, Inflammatory Response in Chicken Rectum

Arsenic and copper, two toxic pollutants, are powerful inducers of oxidative stress. Exposure to copper and arsenic can cause intestinal injury in cockerel. This study was carried out to investigate the effects of these two pollutants on the gastrointestinal tract of cockerels. Experimental results showed that the activity of antioxidant enzymes (catalase and glutathione peroxidase) was inhibited and the ionic balance was destroyed after exposure to copper sulfate (300 mg/kg) and/or arsenic trioxide (30 mg/kg). However, the expression of pro-inflammatory cytokines (nuclear factor kappa-B, cyclooxygenase-2, tumor necrosis factor-α, and prostaglandin E2 synthases) increased markedly. Damages to the biofilm structure and inflammatory cell infiltration were simultaneously observed during histological examination. Heat-shock proteins were also expressed in large quantities after exposure to the poisons. Collectively, exposure to arsenite and/or Cu²⁺ can cause rectal damage in cockerels, inducing inflammation and an imbalance in immune system responses. Sometimes, exposure to both pollutants can produce even more toxic effects. Heat-shock proteins can protect the tissue from the exotoxins but the specific mechanisms require exploration. After oral ingestion of toxins, the rectum can still be damaged, necessitating attention to the safety of poultry breeding, human food safety, and environmental protection.