Posterior Rectal Wall Research Articles

Full bladder, empty rectum? Revisiting aparadigm in the era of adaptive radiotherapy.

Many patients find it challenging to comply with instructions regarding rectum and bladder filling during pelvic radiotherapy. With the implementation of online adaptive radiotherapy, the reproducibility of organ volumes is no longer aprerequisite. This study aims to analyze the sparing of the bladder and the posterior rectum wall (PRW) in conditions of full versus empty bladder and rectum. 280 fractions from 14 patients with prostate cancer who underwent adaptive radiotherapy using the Varian Ethos system were analyzed post-hoc. Various metrics for the bladder and PRW were correlated with respect to organ volume. Our analysis quantitatively confirms the advantage of afull bladder during radiotherapy, as metrics V48Gy and V40Gy significantly inversely correlate with bladder filling for each patient individually. While bladder volume did not show agradual decrease over the course of radiotherapy, it was observed to be higher during planning CT scans compared to treatment sessions. Afull rectum condition either significantly improved (in 2 out of 7 patients) or at least did not impair (in 5 out of 7 patients) PRW sparing, as represented by the V30Gy metric, when patients were compared individually. The average V30Gy across all patients demonstrated asignificant improvement in PRW sparing for the full rectum condition, with a[Formula: see text]-value of 0.039. Despite the implementation of adaptive therapy, maintaining ahigh bladder filling remains important. However, the recommendation for rectum filling can be abandoned, as reproducibility is not critical for adaptive radiotherapy and no dosimetric advantage per se is associated with an empty rectum. Patients may even be encouraged not to void their bowels shortly before treatment, as long as this is tolerated over the treatment session.

A New Approach to Ultra-Low Anterior Resection-Intersphincteric Dissection With Total Hiatal Ligament Excision for Very Low Rectal Cancer Located in the Posterior Wall of the Rectum: A More Satisfactory Technique for Local Recurrence Control.

The hiatal ligament, as the anatomical landmark for the completion of total mesorectal excision (TME) for ultra-low rectal cancer, represents a continuation of the longitudinal muscle of the rectum. It receives vascular supply from the median sacral artery and contains lymphatic vessels. In cases where ultra-low rectal cancer is located in the posterior rectal wall, the hiatal ligament may theoretically serve as an anatomical region susceptible to direct tumor cell spread or distant metastasis. To evaluate the effect of circumferential tumor location (CTL) on postoperative survival of low rectal cancer and to determine the effect of total hiatal ligament excision (THLE) on the prognosis of patients with posterior rectal cancer. Patients with ultra-low rectal cancer who underwent laparoscopic surgery between March 2014 and October 2021 were enrolled in this study. Propensity score matching (PSM) analysis was used to compare the clinicopathological characteristics and prognosis of patients in the posterior group and the non-posterior group. Prognostic factors were identified using COX regression. PSM analysis was also used in the posterior tumor subgroup to compare the clinicopathological characteristics and prognosis of patients in the hiatal ligament traditional transection (HLTT) and THLE groups. After PSM, OS, and DFS were comparable between the posterior and non-posterior groups. Similarly, no difference was noted in the local recurrence rate between the two groups (p = 0.23). The prognosis of ultra-low rectal cancer was not affected by CTL. However, the local recurrence rate was significantly lower in the THLE group compared with the HLTT group (p = 0.023). Multivariate analysis of the posterior group identified CRM, TNM stage III, and HLTT as independent risk factors for local recurrence-free survival. CTL is not a prognostic risk factor for low rectal cancer. In posterior wall tumors, THLE significantly reduces the local recurrence rate for low rectal cancer.

The "Ins and Outs" of Dynamic Magnetic Resonance Imaging for Female Pelvic Organ Prolapse.

Concurrent pelvic organ and rectal prolapse have an incidence of 38%. Dynamic pelvic magnetic resonance imaging (MRI) is the modality of choice for workup. We discuss dynamic pelvic MRI indications, interpretation, and clinical application to pelvic floor disorders. The pubococcygeal line (PCL) extends from the pubic symphysis to the last coccygeal joint. The "H line" demonstrates the levator hiatus size, drawn from the inferior pubic symphysis to the posterior rectal wall at the anorectal junction. The "M line" represents vertical descent of the levator hiatus and extends perpendicularly from the PCL to the posterior aspect of the H line. With rectovaginal fascial defects, the small bowel, the peritoneum, and the sigmoid colon can prolapse. Posterior compartment abnormalities include rectocele, rectal prolapse, and descending perineal syndrome. Pelvic MRI can evaluate functional disorders such as anismus, where the anorectal angle is narrowed and associated with lack of pelvic floor descent and incomplete evacuation. Particularly for patients with concurrent urogynecological and colorectal complaints, previous pelvic reconstructive surgery, or when clinical symptomatology does not correlate with physical examination, dynamic pelvic MRI can impact management. It is critical for pelvic reconstructive surgeons to be familiar with this imaging modality to counsel patients and interpret radiographic findings.

Diagnosis and treatment of retrorectal cystic hamartoma: clinical case

Background. Retrorectal tumors are a rare group of tumors that can be benign or malignant in origin; in most cases, they are asymptomatic. They mainly arise in the presacral space, which is limited by Waldeyer’s fascia posteriorly, the rectal fascia proper anteriorly, the ureters and lateral ligaments of the rectum laterally, the levator ani muscles and coccyx inferiorly, and the transition of the pelvic peritoneum between the second and third sacral segments superiorly. Magnetic resonance imaging (MRI) is crucial for diagnosis and surgical planning. Most retrorectal tumors require surgical treatment without preoperative biopsy. Here, we present a case of a retrorectal cystic hamartoma that was treated with surgery.Clinical case. Patient N., 45 years old, presented with suspected pelvic malformation. The patient reported experiencing pain in the sacrum area since May 2023, with no history of trauma. She sought medical help at a local polyclinic, where an ultrasound of the pelvic organs revealed a pelvic mass. The patient was then referred to an oncologist at the Multidisciplinary Clinical Medical Center “Medical City”. Physical examination showed no specific features, except upon rectal examination, where a non-displaced tumor measuring up to 2 cm was palpated along the posterior rectal wall. MRI of the pelvic organs confirmed the presence of a mass behind the lower ampullary rectum. Surgical treatment was subsequently performed, and the diagnosis of teratoma was confirmed through morphological and immunohistochemical studies.Conclusion. Early comprehensive diagnostics and an experienced surgical team are key factors for successful treatment of patients with retrorectal tumors.

The use of dose surface maps as a tool to investigate spatial dose delivery accuracy for the rectum during prostate radiotherapy.

This study aims to address the lack of spatial dose comparisons of planned and delivered rectal doses during prostate radiotherapy by using dose-surface maps (DSMs) to analyze dose delivery accuracy and comparing these results to those derived using DVHs. Two independent cohorts were used in this study: twenty patients treated with 36.25Gy in five fractions (SBRT) and 20 treated with 60Gy in 20 fractions (IMRT). Daily delivered rectum doses for each patient were retrospectively calculated using daily CBCT images. For each cohort, planned and average-delivered DVHs were generated and compared, as were planned and accumulated DSMs. Permutation testing was used to identify DVH metrics and DSM regions where significant dose differences occurred. Changes in rectal volume and position between planning and delivery were also evaluated to determine possible correlation to dosimetric changes. For both cohorts, DVHs and DSMs reported conflicting findings on how planned and delivered rectum doses differed from each other. DVH analysis determined average-delivered DVHs were on average 7.1%±7.6% (p ≤ 0.002) and 5.0±7.4% (p ≤ 0.021) higher than planned for the IMRT and SBRT cohorts, respectively. Meanwhile, DSM analysis found average delivered posterior rectal wall dose was 3.8±0.6Gy (p=0.014) lower than planned in the IMRT cohort and no significant dose differences in the SBRT cohort. Observed dose differences were moderately correlated with anterior-posterior rectal wall motion, as well as PTV superior-inferior motion in the IMRT cohort. Evidence of both these relationships were discernable in DSMs. DSMs enabled spatial investigations of planned and delivered doses can uncover associations with interfraction motion that are otherwise masked in DVHs. Investigations of dose delivery accuracy in radiotherapy may benefit from using DSMs over DVHs for certain organs such as the rectum.

Rectal Ewing’s Sarcoma: A Case Report of An Unusual Extra-Skeletal Tumor Presentation

Introduction: Extraskeletal Ewing’s sarcoma (EES) is a rare malignant soft tissue tumor. Those aggressive mesenchymal tumors are characterized by genetic alterations of the Ewing sarcoma gene (EWS) on chromosome 22. Signs and symptoms are usually non-specific. The clinical diagnosis of EES is challenging. Case Presentation: A 31-year-old female patient presented to our hospital with rectal bleeding. Physical examination revealed a painful and erythematous bleeding rectal mass. A pelvic MRI revealed a right-sided well-circumscribed perianal mass measuring 6.8 × 6.0 cm. Surgical excision of the rectal mass was subsequently performed. The resected specimen, including the rectal mass with a pedicle from the posterior rectal wall was sent for histopathological examination. The postoperative period was uneventful. Histopathology examination was suggestive of EES of the rectum. Clinical Discussion: EES is an unusual entity of Ewing's Sarcoma Family of Tumors, which are characterized by pathognomonic translocations. The clinical features of EES include localized pain and/or swelling. Diagnosis of EES relies on histopathology and immunohistochemistry analysis. Imaging modalities such as CT, MRI, and PET/CT are crucial to evaluate EES metastasis and assess local tumor resectability. Conclusion: Due to the rare entity of EES of the rectum, we report the case of a 31-year-old female with rectal bleeding, found to be rectal Ewing’s sarcoma.

Endoscopic Closure of Iatrogenic Rectal Perforation Using the Tulip Bundle Technique.

CASE REPORT Cleansing enemas are commonly used for constipation, but rectal perforation is a rare complication, with a mean incidence of 0.02%–0.23%.1,2 A 75-year-old woman was referred to the emergency department with severe constipation. Physical examination revealed solid stools in the rectum, and a cleansing enema was applied. Immediately, she presented with abundant hematochezia. Rectosigmoidoscopy revealed a large perforation in the posterior rectal wall because of the tip of the enema. Pelvic computed tomography showed extraluminal air in the perirectal fat, suggestive of rectal perforation (Figure 1). To prevent complications, she was admitted under antibiotics and repeated rectosigmoidoscopy.Figure 1.: Pelvic computed tomography showing perirectal free air and fat stranding, suggestive of rectal perforation.We attempted to close the perforation (Figure 2) using an over-the-scope clip, but it did not adequately fit the defect. Because therapeutical failure was imminent, we performed mucosal closure using a clip-fixed endoloop in a single-channel colonoscope. First, a clip was inserted in the working channel of the endoscope; as an independent device outside the scope, the tip of the endoloop was attached to the clip's teeth; next, the clip and endoloop were housed inside the scope channel until completely hidden, and both the scope and the endoloop were inserted in the rectum. The clip-fixed endoloop was then fixed onto the normal mucosa near the mucosal defect; 3 additional clips were used to anchor the endoloop circumferentially along the tear margins. Finally, the endoloop was tightened to close the perforation (Figure 3). The patient recovered uneventfully and was discharged after 7 days. Two weeks later, only a small scar was identified.Figure 2.: Rectosigmoidoscopy revealing a rectal perforation in the posterior rectal wall.Figure 3.: Endoscopic closure of the rectal perforation after using an endoloop. The endoloop was anchored with clips to the normal mucosa near the perforation's edges and closed in a purse-string fashion.An early approach of rectal perforations is critical to prevent complications and reduce mortality.1 Endoscopic techniques, such as over-the-scope clips or through-the-scope clips, are preferred when surgery has high risk of morbimortality.3 New techniques, such as endoloop, have been increasingly used, but choice depends on the type and size of the perforation, available devices, and endoscopist expertise (Video 1, https://links.lww.com/AJG/C770).4,5 {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 1","caption":"Endoscopic closure of iatrogenic rectal perforation after a cleansing enema, by using the tulip bundle technique.","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"10.14309/crj.0000000000000898.vid1"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} DISCLOSURES Author contributions: F. Pires acquired data, drafted the manuscript, and performed video editing. AC Carvalho acquired data and performed video editing. R. Araújo was responsible for conception and performance of the endoscopic procedure and critically revised the report. All authors read and approved the final version of the manuscript. F. Pires is guarantor of the article. Financial disclosure: None to report. Informed consent was obtained for this case report.

Natural Orifice Endosonographic Colposuspension With Rectopexy for Combined Pelvic Organ Prolapse: A Feasibility Study.

We describe a natural orifice technique for simultaneous endoluminal lateral suspension of apical vaginal wall and rectal prolapse fixation with ultrasound and fluoroscopic assistance. The technique is minimally invasive, can be performed under regional anaesthesia, and avoids laparotomy or use of a mesh in addition to preserving the uterus. This technique involves suprapubic transvaginal ventral suture colposuspension, fixation of the anterior rectal wall to the undersurface of the anterior abdominal wall and tack fixation of the posterior rectal wall to the underlying sacral promontory through a submucosal tunnel performed endoscopically with fluoroscopic and ultrasound assistance. Seven patients with a mean age of 63 years were followed between 3 to 11 months. This is a novel minimally invasive transluminal procedure that repairs concomitant rectal and vaginal prolapse in the same sitting. Improvement in the instrument design and incorporation of endoluminal robotic systems will enhance the technical ease. The study needs validation in larger series of patients with longer follow-up.

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

PurposeThis 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 MethodsSixty-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.ResultsThe 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 D1.0cc–D2.5cc extracted on the posterior rectal wall.ConclusionsThe 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.

Pulsion diverticula of the rectum: Radiological diagnosis and clinical implications.

The aim of this study was to investigate the appearance of acquired rectal diverticula on barium enema and computed tomography (CT) and to review the pertinent clinical data about this entity. This series included 3 men and 6 women, who ranged in age from 47 to 82years (average: 64years). Air-contrast barium enema in 6 patients with history of anorectal disease or obstructed defecation demonstrated rectal diverticula. In these cases, multiple radiographs of the rectosigmoid region were obtained in upright position while the patient was relaxing or straining without any attempt to evacuate the barium. In 3 cases, the lateral rectal diverticula were incidental finding on CT studies that were performed for various unrelated abdominal complaints. Pulsion type of diverticulum presenting as a wide-neck outpouching was detected on the lateral rectal wall in 5 and on the posterior wall in 4 patients. They measured 2-3cm in diameter when filled with contrast material or gas, and became even larger when the intraluminal pressure was increased by straining. Pulsion diverticula of the rectum present as a wide-neck outpouching of the lateral or posterior rectal wall in adult patients. This acquired abnormality is usually associated with coexisting anorectal lesions or defecation disorders. The practising radiologists and colorectal surgeons should be aware of this uncommon condition, its appearance on barium enema and other imaging studies, and its clinical implications.

Anorectal injury related to a personal watercraft: a case report and literature review

BackgroundDouche injury is a rare consequence of water recreation activities. Generally, this type of trauma occurs when people fall into the water in a sitting position during high-speed activities such as using a personal watercraft (PWC). Here, we report a rare case of anorectal injury caused by water jets from a PWC during sudden acceleration from rest.Case presentationA 21-year-old male passenger on a PWC fell off backward from the rear seat when the craft suddenly accelerated. He fell into the water in a supine position with his legs open, and the water jets of the PWC struck his perineum directly. Thereafter, bleeding from the anus was seen, and he was transferred to our hospital. On physical examination, there was a deep laceration interrupting the external anal sphincter in the posterior rectal wall. Abdominal computed tomography revealed a full-layer perforation of the posterior rectal wall and leakage of feces into the extraperitoneal space, but intraperitoneal free air was not seen. Laparoscopic sigmoid loop colostomy and primary suturing of the sphincter and mucosa were performed. He did not have any complications and was discharged from our hospital 16 days after the surgery. His anal function was almost perfectly preserved, and his diverting colostomy was closed 4 months later.ConclusionAnorectal injuries related to PWCs can occur not only while traveling at high speeds, but also when suddenly accelerating from rest. A diverting colostomy should be performed for this type of trauma. In these trauma cases, clinicians must suspect complex and life-threatening anorectal injuries early.

The median sacral artery in rectal blood supply: A cadaveric study.

Insufficient blood supply to the posterior rectal remnant after proctectomy is a possible mechanism for anastomotic leakage. The median sacral artery (MSA) is not generally considered to participate in the rectal blood supply, although some case studies have reported the rectum being supplied by it. The aim of this study is to elucidate the anatomy of the MSA in relation to the posterior rectal wall. Nineteen embalmed cadavers (12 males, seven females; mean age: 76 ± 9 years) were injected with a colored radio-opaque mixture in the aortic bifurcation, radiographed and subsequently dissected along the sacrum. The relationship between the MSA and the rectum was observed and the diameter of the MSA was measured 2 cm below the aortic bifurcation. MSAs were identified in 16 (84.2%) of the 19 cadavers. Nine MSAs (47.4%) reached the rectal wall and penetrated it. MSAs that reached the posterior rectum took two different routes in the presacral space. Dissection and radiography showed four penetrating MSAs (21.1%) ending in a branching pattern and five (26.3%) as a tapering vessel. Seven MSAs (36.8%) did not reach the rectal wall. The mean MSA diameter was 1.98 ± 0.12 mm. Almost half the MSAs reached and penetrated the posterior rectal wall, suggesting possible participation in the rectal blood supply. A large portion of the MSAs that penetrate the rectal wall run outside surgical margins and could continue to provide blood supply to the rectal remnant, potentially preventing anastomotic leakage.

Association between acute histopathological changes of rectal walls and late radiation proctitis following radiotherapy for prostate cancer.

The impact of acute histopathological changes (HC) of the rectum on development of late clinical proctitis (LCP) after external radiotherapy (RT) for prostate cancer is poorly explored and was the primary end point of this prospective study. In 70patients, 15HC of early rectal biopsies after RT were identified, whereby RT was conventional 2D RT in 41cases and conformational 3D RT in 29. Associations of HC in anterior and posterior rectal walls (ARW, PRW) with LCP, acute endoscopic (AEP) and acute clinical proctitis (ACP) were statistically evaluated considering as explicative variables the patient general characteristics and the HC. The mean patients' follow-up was 123.5months (24-209). The median prostatic dose was 72 Gy (2 Gy/fraction). For the 41 and 29patients the ARW and PRW doses were 64 and 49 Gy vs. 63 and 50 Gy, respectively. The incidence of LCP ≥ grade 2 at 10years was 12.9%. The univariate (p = 0.02) and Kaplan-Meyer methods (p = 0.007) showed that the gland (or crypts) loss in the ARW was significantly associated with LCP. AEP and ACP occurred in 14.3 and 55.7% of cases. At multivariate level AEP significantly correlated with hemorrhoids (p = 0.014) and neutrophilia in ARW (p = 0.042). Early after RT, substantial gland loss in ARW is predictive of LCP. To reduce this complication with conventional fractionation, we suggest keeping the mean dose to ARW ≤48-52 Gy.

Buried Superior Gluteal Artery Perforator Flap for Dead Space Coverage in the Sacral Area

Partial sacrectomy is a common treatment for sacral sarcomas, which often results in a large defect and exposed rectal wall. The defect could be covered using a gluteus maximus (GM) advancement flap. However, seroma and wound dehiscence are often observed after GM advancement flap coverage, delaying the wound healing process. We present a case of buried superior gluteal artery perforator (SGAP) flap following GM muscle splitting. An 11-year-old male patient with epithelioid sarcoma in the sacrum underwent partial sacrectomy. The sacral defect size was 9×6 cm, and the GM muscle was intact. We designed a 7×4-cm elliptically-shaped SGAP flap skin paddle, after which perforator dissection was performed underneath the GM muscle. To minimize dead space, the GM muscle was split and the flap was de-epithelized and advanced to the posterior rectal wall. There were no wound complications during admission and the patient was discharged on postoperative day 16. No atrophy of the flap was found on postoperative magnetic resonance imaging, either. This case demonstrates that using a buried SGAP flap for covering dead space could be a good surgical method to cover wide sacral defects.

CHRONIC CONSTIPATION IN INFANTS: THINK ABOUT RECTAL DUPLICATION

Rectum is the least common site of gastrointestinal duplication. Up to now fewer than 100 cases have been reported in the literature. We present two infants with cystic rectal duplications manifested with chronic constipation as a main clinical symptom. The first patient was a 4-year-old boy who was admitted to emergency department because of chronic constipation unresponsive to fiber supplements and laxatives. Digital rectal exam revealed mass adjacent to posterior rectal wall. Abdominal ultrasound and magnetic resonance imaging confirmed oval, homogenous and hypoechogenic cystic mass (87x65x60 mm in size) behind the rectum. The size and location of the cystic mass was confirmed by magnetic resonance imaging. The second patient was an 11-month-old boy who was hospitalized due to rectal bleeding. He was suffering from chronic constipation over the last five months. Digital rectal exam revealed a mass behind the rectum. Abdominal ultrasound and computed tomography showed unilocular cyst (33X33 mm in size) in front of the urinary bladder, partly extending into retrorectal space. Both patients were operated on. Postoperative periods were uneventful in both of them. Cystic rectal duplication must be ruled out in all infants with chronic constipation unresponsive to conservative treatment. Different imaging techniques are currently used to determine the precise size and location of duplication. Surgery is the only possible therapy option.

1924 Bleeding Beyond the Line: Anorectal Melanoma as a Cause of Lower Gastrointestinal Bleeding

INTRODUCTION: Anorectal melanoma is a rare malignancy that can present as hematochezia similar to other gastrointestinal bleeding sources. The diagnosis of anorectal melanoma may be challenging given its rarity, nonspecific presentation, and need for histopathology, but accurate and timely diagnosis is essential given that associated bleeding may not respond to conventional treatments. CASE DESCRIPTION/METHODS: An 88-year-old male was admitted for septic shock after being found lethargic at his nursing facility. He was started on intravenous antibiotics and vasopressors and intubated for airway protection. Though slowly improving overall, on hospital day 6, he had 4 episodes of large red clots per rectum. Rectal examination showed bright red blood and a rubbery mass palpable on the posterior rectal wall without visible hemorrhoids. Due to the acute drop in hemoglobin to 6.3 g/dL, the patient was transfused 2 units of packed red blood cells, empirically started on intravenous pantoprazole, and administered parenteral Vitamin K and a dose of desmopressin. Over the next two days, the patient continued to have multiple bowel movements with blood clots requiring additional blood transfusions. Given these findings, the patient underwent flexible sigmoidoscopy. DISCUSSION: Flexible sigmoidoscopy revealed a 3 cm ulcerated mass in the distal rectum which involved the dentate line. Endoscopic hemostasis was not feasible, but a biopsy was obtained which showed malignant melanoma invading the lamina propria and muscularis with associated ulceration. Considering the patient's age, clinical status, and advanced dementia, the medical team and unrepresented patient committee agreed that it was ethically appropriate to not pursue further work-up or treatment of the patient's melanoma. Following medical stabilization, the patient was transitioned to home comfort care. This case illustrates a rare etiology of bright red blood per rectum and the importance of additional investigation in the setting of clinically significant anemia and/or inadequate response to conservative measures. Anorectal melanoma, similar to other rare disorders which can mimic internal hemorrhoidal bleeding, frequently requires endoscopic techniques for diagnosis and management. Despite this patient's clinical course and the generally poor prognosis of anorectal melanoma, early diagnosis can allow for surgical excision and/or adjuvant therapies that may provide a potentially curative outcome or delay disease progression and mitigate bleeding complications.

First Reported Case of a Well-Differentiated Neuroendocrine Tumor (WDNET) Arising Within Diffuse Ganglioneuromatosis (DGN) in a Patient With Neurofibromatosis Type 1 (NF-1)

Abstract Case Report A 51-year-old female with NF-1 underwent flexible sigmoidoscopy, which revealed a 1.8-cm mass in the upper rectum. The noncircumferential mass was located predominantly at the posterior rectal wall and was suspicious for a neurofibroma. The biopsy revealed a WDNET arising in a ganglioneuroma that extended to the edges of the biopsy tissue. The patient underwent a segmental resection, and sections revealed residual grade 1 WDNET intimately admixed with DGN. The area of DGN also showed multifocal microscopic clusters of neuroendocrine cells limited to the lamina propria. Discussion NF-1 involves the gastrointestinal tract in 10% to 25% of affected individuals. DGN is a poorly circumscribed, frequently transmural gastrointestinal lesion composed of spindled and ganglion cells that may be seen in PTEN hamartomatous tumor syndrome, multiple endocrine neoplasia syndrome type 2B, and (less commonly) NF-1. Though malignant transformation of neurofibromas to malignant peripheral nerve sheath tumors is well documented in NF-1, malignant transformation of DGN is extremely rare. To our knowledge, this is the first reported case of a WDNET arising in DGN. In addition to being the first reported case of WDNET in this setting, this is the first case to describe microscopic neuroendocrine cell nests in DGN. Similar proliferations have been described in the setting of inflammatory bowel disease, termed microcarcinoid or neuroendocrine cell micronests, which are not thought to have malignant potential. However, given the presence of these microscopic neuroendocrine cell nests within the larger DGN lesions and adjacent to the WDNET, we hypothesize that in the setting of NF-1, microscopic neuroendocrine cell clusters may serve as a precursor of WDNET. While this is a rare situation, these novel findings should prompt careful examination for WDNET and microscopic neuroendocrine cell nests in future cases of DGN.

Rectal wall dose-volume effect of pre- or post KUSHEN Ningjiaos relationship with 3D brachytherapy in cervical cancer patients

BackgroundThe present prospective study evaluated the safety and efficacy of the rectum following KUSHEN Ningjiaos in cervical cancer. We compared rectal wall changes during brachytherapy with or without KUSHEN Ningjiaos in cervical cancer patients and analyzed the difference in spatial dose distribution, including whole rectum-wall (R-w), anterior rectum-wall (R-a) and posterior rectum-wall (R-p).Methods and materialsOne hundred cervical cancer patients with and without KUSHEN Ningjiaos were treated with brachytherapy (600 cGy). The whole R-w was divided into two areas of R-a and R-p, and R-w dose surface map were constructed. The volume of each R-w was compared in patients pre- and post-KUSHEN Ningjiaos.ResultsWhen the pre- vs. post-KUSHEN groups were compared the volume of R-w increased. In the post-KUSHEN group, a significantly higher proportion of the D2cc of VR-w and VR-a compared with the pre-KUSHEN group showed that the D2ccmean increased from 532.45 cGy to 564.7 cGy and 533.51 cGy to 565.26 cGy, respectively; however, results demonstrated a decrease in the D2ccmean of R-p from 260.5 cGy to 240.0868 cGy (P < 0.05). The insertion of KUSHEN Ningjiaos resulted in a reduction of the relative volume of R-p exposed to high doses, and regressive analysis showed that the DR-p-max correlated most strongly with VR-w and D2ccR-p (P < 0.01 and P < 0.05, respectively).ConclusionThe insertion of KUSHEN Ningjiaos can protect the rectum. KUSHEN Ningjiaos appears to be safe and well tolerated; therefore, we believe that there will be fewer adverse events after brachytherapy for patients.Trial registrationA multi-center, prospective clinical trial for KUSHEN Ningjiaos was inserted into rectum to reduce the rate of radiation proctitis in three-dimensional brachytherapy of cervical cancer. ChiCTR1900021631. 2 Mar 2019-Retrospectively registered.

Patterns in ano-rectal dose maps and the risk of late toxicity after prostate IMRT

Purpose: The aim of this work was to determine how the spatial pattern of dose in the ano-rectal wall is related to late gastro-intestinal toxicity for prostate cancer patients treated with mainly IMRT.Patients and methods: Patients from the DUE-01 multicentre study with patient-reported (prospective) follow-up and available dosimetric data were included. Conventionally fractionated patients received 74–80 Gy and hypofractionated patients received 65–75.2 Gy. A large majority of the patients were treated with intensity-modulated radiotherapy (IMRT). Dose-surface maps (DSMs) for the anal canal and rectum as a single structure, and for the anal canal and the rectum separately, were co-registered rigidly in two dimensions and, for the patients with and without toxicity, respectively, the mean value of the dose in each pixel was calculated. A pixel-wise t-test was used to highlight the anatomical areas where there was a significant difference between the ‘mean dose maps’ of each group. Univariate models were also fitted to a range of spatial parameters. The endpoints considered were a mean grade ≥1 late fecal incontinence and a maximum grade ≥2 late rectal bleeding.Results: Twenty-six out of 213 patients had fecal incontinence, while 21/225 patients had rectal bleeding. Incontinence was associated with a higher dose in the caudal region of the anal canal; the most relevant spatial parameter was the lateral extent of the low and medium isodoses (5–49 Gy in EQD2). Bleeding was associated with high isodoses reaching the posterior rectal wall. The spatial dose parameters with the highest AUC value (.69) were the lateral extent of the 60–70 Gy isodoses.Conclusions: To avoid fecal incontinence it is important to limit the portion of the anal canal irradiated. Our analysis confirms that rectal bleeding is a function of similar spatial dose parameters for patients treated with IMRT, compared to previous studies on patients treated with three-dimensional conformal radiotherapy.

Penetrating Rectal Wound in Domestic Injury

An 11-year-old boy tried to jump over a metal rod but landed on it presented with perianal pain and rectal bleeding. On examination, there is a 1.5cm perineal laceration. His blood results showed a normal TWC with a normal abdominal and chest radiographs. His vital signs were within normal limits. He was planned for bedside T&amp;S by ED team but deferred as persistent blood oozing from rectal, thus referred to Paediatric Surgery. Upon review, there was 2x1cm perianal laceration at 7 o’clock, abrasion wound at 10 &amp; 12 o’clock. Ultrasound showed no free fluid. He was taken to emergency OT for EUA, intraoperative findings were a perianal laceration, on table sigmoidoscopy showed posterior rectal wall irregularities with slow oozing blood from it, however, no obvious perforation seen. The patient developed fever with lower abdominal tenderness on the following day. Urgent CECT abdomen pelvis performed and showed features of extraperitoneal rectal perforation. He was treated conservatively with antibiotics and NBM with parenteral nutrition support. He made a good recovery and was discharged home on day 9. Pediatric perineal impalement injuries often caused by falls on an offending object. These children are prone to severe injuries as compared to adults and the lesions in the pediatric perineum may appear innocuous, but can be potentially life-threatening and surgically challenging. Perineal impalement injuries in children are classified as transanal or perineal and further subdivided as extraperitoneal or intraperitoneal. This classification method is used to predict potential injuries and develop treatment guidelines. Evaluation of perineal impalement injuries in children needs to be thorough even in the presence of minimal or no symptoms.