Anterior Rectum Research Articles

Influence of different sphincter-preserving surgeries on postoperative defecation function

Advances in surgical techniques and treatment concept have allowed more patients with low rectal cancer to preserve sphincter without sacrificing survival benefit. However, postoperative dysfunctions such as fecal incontinence, frequency, urgency, and clustering often occur in patients with low rectal cancer. The main surgical procedures for low rectal cancer include low anterior rectum resection (LAR), intersphincteric resection (ISR), coloanal anastomosis (Parks) and so on. The incidence of major LARS after LAR is up to 84.6%. The postoperative function of ISR is even worse than LAR. Moreover, the greater the extent of resection ISR surgery, the worse the postoperative function. There are few studies on the function of Parks procedure. Current evidence suggests that the short-term function of Parks procedure is inferior to LAR, but function can gradually recovered over time. Colorectal surgeons have attempted to improve postoperative defecation by modifying bowel reconstructions. Current evidence suggests that J pouch or end-to-side anastomosis during LAR does not reduce the incidence of defecation disorders. Pouch reconstruction during ISR cannot reduce the incidence of severe LARS either. In general, the protection of postoperative defecation function in patients with low rectal cancer still has a long way to go.

Colostomy for Fournier's Gangrene with Rectum Exposure

Fournier's gangrene (FG) can be treated with prompt surgical debridement. Stoma revision has also been performed to prevent fecal contamination. However, recent advances in stool and wound management have reduced the need for colostomy. We report four cases of severe FG with an exposed rectum and discuss the conditions under which colostomy is indispensable. All four peoples developed FG, and an emergency debridement was performed, resulting in exposure of the rectum. Two peoples with perirectal infectious inflammation extending to the anterior rectum underwent colostomy because the inflammation had reached the retroperitoneum, but the other two, where the inflammation was confined to the dorsal-lateral rectum, were treated successfully without colostomy. We believe that colostomy can be avoided by using suitable wound management devices, except in severe cases where soft tissue infection and necrosis extend to the peritoneum and retroperitoneum and there is concern about rectal ischemia. Number of similar cases published: 0.

Combined Robotic Ventral Rectopexy and Sacrocolpopexy- a Single Institution Approach

<h3>Study Objective</h3> To describe the multidisciplinary workup of pelvic organ prolapse and rectal prolapse or intussusception and to describe our technique of robotic ventral rectopexy and sacrocolpopexy. <h3>Design</h3> N/A. <h3>Setting</h3> N/A. <h3>Patients or Participants</h3> This is a patient with multi-compartment pelvic organ prolapse and rectal intussusception. <h3>Interventions</h3> The surgery is begun with the sacral dissection. The peritoneum is then opened in continuation along the right side of the rectum. Once the peritoneal reflection has been opened, it is carried down and further dissected from the posterior vagina. The deep pelvic dissection is then performed in the rectovaginal septum to the levator ani muscles, about five to six centimeters deep. Once the levator muscles are exposed, a ruler is introduced into the pelvis and the rectal width is measured. The anterior bladder dissection is then performed. A single sheet of flat, large pore, polypropylene mesh is then introduced and first secured to the levators bilaterally. Next the mesh is secured to the anterior rectum, sewing distal to proximal. This single sheet of mesh is then also used for the entire sacrocolpopexy by next securing the mesh to the posterior vagina. The mesh is then folded over the vaginal apex to the anterior vagina and before it is secured, the sacral tail is created by using the midportion of the mesh pulled out over the apex. The remaining steps of the procedure are completed in the same fashion as a standard sacrocolpopexy. <h3>Measurements and Main Results</h3> The patient had excellent anterior, apical, and posterior support with the use of a single flat sheet of lightweight mesh. The surgery had no complications with a minimal EBL. <h3>Conclusion</h3> Multidisciplinary treatment of concomitant pelvic organ and rectal prolapse by urogynecology and colorectal surgery allows for a safe and effective treatment of both conditions concurrently via a robotic ventral rectopexy and sacrocolpopexy with a single lightweight flat mesh sheet.

S2373 A Case of a Deep Infiltrative Rectal Endometriosis Presenting as a Solitary Ulcer and Lumbosacral Shingles

Introduction: Deep bowel endometriosis is a rare, clinically challenging diagnosis mimicking many gastrointestinal diseases. There are no clear guidelines for the evaluation of patients with suspected bowel endometriosis, therefore a high index of suspicion is warranted. Case Description/Methods: A 39 year old female with a history remarkable for fibroidectomy and constipation presents for rectal bleeding and discomfort for 1 month. In 2012, FOBT was positive and colonoscopy findings were significant for a solitary rectal ulcer. Biopsies showed inflammation. Due to persistent symptoms, a flexible sigmoidoscopy (2013) with repeat biopsies confirmed the diagnosis of deep bowel endometriosis located at the anterior portion of the rectum. Hormonal therapy offered complete resolution of her symptoms. In 2021, due to menopausal symptoms, hormonal therapy was discontinued leading to recurrence of symptoms and new onset right sided lumbosacral shingles. Colonoscopy findings were significant for luminal narrowing and nodularity at the anterior portion of the rectum. Biopsies were nonspecific. Discussion: Given that endometriosis rarely infiltrates the submucosa or mucosa (6.4% of cases), initial colonoscopy and biopsy findings may be nonspecific. Hence, an initial inappropriate diagnosis may occur, demonstrating how challenging this diagnosis may become. Even though the gold standard for diagnosis is direct laparoscopic visualization or tissue diagnosis, imaging modalities such as transvaginal and transrectal US and MRI may diagnose and determine the extent of deep bowel endometriosis. Response to hormonal treatment in deeply infiltrating bowel endometriosis is unpredictable and may require a surgical approach. The natural course of bowel endometriosis has not been formally established. Some authors describe inactive endometriosis as a nodular and fibrotic lesion associated with adhesions and strictures. This correlated with the findings of our patient's latest colonoscopy. Association of endometriosis with rheumatological and autoimmune disorders have been established, where theories based on genetic dysregulation of immune, adhesion, and inflammatory processes take part in the disease pathology. This may explain the greater likelihood of shingles reactivation, such experienced by our patient, during an immunocompromised state such as menopause. Even though deep bowel endometriosis is poorly understood, a high index of suspicion is crucial to offer patients a correct diagnosis and appropriate treatment options.Figure 1.: Deep bowel endometriosis. (Top, left to right) Colonoscopy findings from 2012 (first 2 images) and 2013 respectively showing an abnormal mucosal lesion in the proximal portion of the anterior rectum. (Bottom, left to right) Colonoscopy findings from 2021 showing mucosal nodularity in the proximal portion of the anterior rectum.

Defining benchmarks for robotic-assisted low anterior rectum resection in low-morbid patients: a multicenter analysis

PurposeTo define the best possible outcomes for robotic-assisted low anterior rectum resection (RLAR) using total mesorectal excision (TME) in low-morbid patients, performed by expert robotic surgeons in German robotic centers. The benchmark values were derived from these results.MethodsThe data was retrospectively collected from five German expert centers. After patient exclusion (prior surgery, extended surgery, no prior anastomosis, hand-sewn anastomosis), the benchmark cohort was defined (n = 226). The median with interquartile range was first calculated for the individual centers. The 75th percentile of the median results was defined as the benchmark cutoff and represents the “perfect” achievable outcome. This applied to all benchmark values apart from lymph node yield, where the cutoff was defined as the 25th percentile (more lymph nodes are better).ResultsThe benchmark values for conversion and intraoperative complication rates were ≤ 4.0% and ≤ 1.4%, respectively. For postoperative complications, the benchmark was ≤ 28% for “any” and ≤ 18.0% for major complications. The R0 and complete TME rate benchmarks were both 100%, with a lymph node yield of > 18. The benchmark for rate of anastomotic insufficiency was < 12.5% and 90-day mortality was 0%. Readmission rates should not exceed 4%.ConclusionThis outcome analysis of patients with low comorbidity undergoing RLAR may serve as a reference to evaluate surgical performance in robotic rectum resection.

The Reproducibility of Ultrasonographic Findings of Rectosigmoid Endometriosis Among Examiners With Different Level of Expertise.

ObjectiveTo analyze the reproducibility of ultrasonographic (US) findings of rectosigmoid endometriosis among examiners with different level of expertise using stored three‐dimensional (3D) volumes of the posterior compartment of the pelvis as a part of SANABA (Sardinia‐Navarra‐Barcelona) collaborative study.Materials and methodsSix examiners in 3 academic Department of Obstetrics and Gynecology, with different levels of experience and blinded to each other, evaluated 60 stored 3D volumes from the posterior compartment of the pelvis and looked for the presence or absence of features of rectosigmoid endometriotic lesions defined as an irregular hypoechoic nodule with or without hypoechoic foci at the level of the muscularis propria of the anterior wall rectum sigma. Multiplanar view and virtual navigation were used. All examiners had to assess the 3D volume of posterior compartment of the pelvis and classify it as present or absent disease. To analyze intra‐observer and the inter‐observer agreements, each examiner performed the assessment twice with a 2‐week interval between the first and second assessments. Reproducibility was assessed by calculating the weighted Kappa index.ResultsIntra‐observer reproducibility was moderate to very good for all observers (Kappa index ranging from 0.49 to 0.96) associated with a good diagnostic accuracy of each reader. Inter‐observer reproducibility was fair to very good (Kappa index range: 0.21–0.87).ConclusionsThe typical US sign of rectosigmoid endometriosis is reasonably recognizable to observers with different level of expertise when assessed in stored 3D volumes.

Safety and efficacy of preoperative mFOLFOX6 regimen chemotherapy for locally resectable advanced rectal cancer.

Neoadjuvant chemotherapy combined with radical surgery has become the treatment model for locally advanced rectal cancer. The purpose of this study was to evaluate the safety and efficacy of postoperative mFOLFOX6 regimen chemotherapy for locally resectable advanced rectal cancer. This was a prospective study. A total of 82 patients with locally advanced rectal cancer admitted to Affiliated Nanhua Hospital, University of South China from February 2015 to December 2017 were selected as the subjects. The patients received 4 courses of mFOLFOX6 chemotherapy and underwent surgery within 4-6 weeks after chemotherapy. The incidences of chemotherapy-related adverse reactions, postoperative complications, and clinical pathological reactions were analyzed. In the period from mFOLFOX6 chemotherapy to preoperative, 82 patients with locally advanced rectal cancer was reported chemotherapy-related adverse reactions, including Grade 4 neutropenia (2.4%), catheter related infection (2.4%), and anorexia (2.4%), Grade 3 nausea (2.4%) and anorexia (2.4%), Grade 2 neutropenia (14.6%) and peripheral neuropathy (7.3%). Finally, 76 patients with locally advanced rectal cancer completed surgery, including 56 (73.7%) with anterior rectum resection, 16 (21.1%) with abdominal perineal resection, and 72 (94.7%) with pelvic nerve preservation. A total of 22 (28.9%) patients had surgical complications, including 8 (10.5%) with complications of Grade 3 or above. The complications with high incidence were intestinal obstruction, anastomotic leakage, and sepsis. Among the 76 patients who completed chemotherapy and surgery, T stage was decreased in 28 (36.8%) and N stage was decreased in 44 (57.9%); forty-two (55.3%) were in pathological Stage I, 20 (26.3%) in Stage IIA, 12 (15.8%) in Stage IIB, and 2 (2.6%) in Stage IIIA. Ten patients were suspected of tumor invasion of surrounding organs before chemotherapy, of which 4 patients did not need to extend the resection of surrounding organs after chemotherapy and achieved R0 resection of tumor; 2 in T4b stage before chemotherapy received extended resection of surrounding organs, and the postoperative pathological result was T3, and achieved R0 resection; 1 diagnosed as poorly differentiated adenocarcinoma with seminal vesicle invasion in the evaluation before chemotherapy had T-stage progression after operation. There were 66 (86.8%) patients of partial response (PR), 9 (11.8%) of stable disease (SD) and 1 (1.3%) of progressive disease (PD). There was no complete response (CR) and no new lesion. Preoperative mFOLFOX6 regimen chemotherapy for locally resectable advanced rectal cancer is a safe and feasible treatment strategy, and it is worthy of clinical application.

Inter- and Intra-Fractional Target Changes During Stereotactic Body Radiotherapy to the Prostate Bed With an Endorectal Balloon

Mature toxicity outcomes from the first phase I trial using stereotactic body radiotherapy (SBRT) to the prostate bed for recurrent prostate cancer have been recently reported. From that study, we herein report inter- and intra-fractional positional changes in the clinical target volume (CTV) and rectum with the use of an endorectal balloon. Prostate bed SBRT was delivered over 5 fractions in escalating doses of 35, 40, and 45 Gy. Three fiducial markers were planted in the CTV volume. A subset of 10 patients on the trial received both pre- and post-treatment CBCT for each fraction and were the subject of this analysis. An endorectal balloon was placed during both simulation and daily treatments. Patients were instructed to maintain a full bladder. On pre-treatment CBCT we localized to the anterior surface of the balloon to align the anterior rectal wall and CTV. Inter-fractional variation was measured using registrations based on pelvic anatomy. Intra-fractional changes in balloon position were assessed with soft-tissue registration. The t-test was used to evaluate the significance of correlation coefficient with significance level set at 0.05. The average daily air-filled balloon volume (±standard deviation) was 77.0±5.0 cc (range: 60.6 cc – 88.5 cc), and the average pre-treatment bladder volume was 235.0±109.7 cc. Compared to the planning CT, the pre-treatment bladder volume changed by -35.0±87.9 cc (range: -227.1 – 123.1 cc). Relative to the planning positions, the anterior rectal wall had an average inter-fractional shift of -1.6±5.6 mm (range: -15.2 – 7.5 mm) in the antero-posterior (AP) direction at the mid-section of the balloon (negative value: shifts posteriorly), with ≥ 3mm shift in 66% of total fractions. Correlation between daily bladder volume variations and anterior rectum position variations in the AP direction was statistically significant (Pearson’s correlation coefficient = 0.76, p = 0.02). The average time between the pre- and post-treatment CBCT scans was 9.8±4.0 minutes (range: 6 – 29 minutes). The post-treatment bladder volume increased significantly (p < 0.01) by an average of 58.9±51.6 cc. The balloon volume changed by <5% in each treatment. The center-of-mass of the balloon had average intra-fractional variation of 0.3±0.8 mm in the left-right (LR) direction (range: -1.3 – 2.5 mm), -0.9±2.4 mm in the AP direction (range: -11.0 – 3.0 mm), and -1.7±2.2 mm in the superoinferior (SI) direction (range: -10.9 – 0.7 mm) (negative value: shift anteriorly). No correlation was seen between increased bladder volume and intrafractional AP shifts, since the majority of greater than 3 mm shifts were attributed to one patient. Although not statistically significant, we observed higher than expected intrafractional AP and SI shifts. Our future phase II trial will incorporate larger margins to account for this finding.

Multivariate normal tissue complication probability models for rectal and bladder morbidity in prostate cancer patients treated with proton therapy

Background and purposeNormal tissue complication probability (NTCP) models applied for model-based patient selection to proton therapy (PT) have usually been derived using dose/volume histogram (DVH) parameters from photon-based radiotherapy. This study aimed to derive PT-specific multivariate NTCP models that also accounted for the spatial dose distribution (rectum only) as well as non-dose/volume related factors. Materials and methodsThe study included rectum and bladder DVHs, 2D rectal dose maps and relevant patient/treatment characteristics from 1151 prostate cancer cases treated with PT. Prospectively scored Grade 2 late rectal bleeding (CTCAE v3.0, also procedural interventions separately) (n = 156 (15%)) and Grade 3+ GU morbidity (n = 51 (4%)) were entered into a multivariate logistic regression analysis. Model evaluation included assessment of the area under the receiver operating characteristic curve (AUC). ResultsAnticoagulant use was a dominant predictor, chosen in four of the six rectum models and in the bladder model. Age was a dominant predictor in all procedural only rectum models while prostate volume, bladder D5% and V75Gy were predictors in the bladder model. The selection frequency of the dose/volume predictors varied widely, where the percentage of the anterior rectum surface receiving >=75 Gy was the most robust. AUC values ranged from 0.58 to 0.70 across all models, with no clear difference between the DVH- and spatial-based models for the rectum. ConclusionAnticoagulant use and age were the most prominent predictors in the NTCP models. V75Gy of the rectal wall and the bladder was a predictor in the DVH-based models of the rectum and bladder respectively.

Avoiding urethral and rectal injury during transperineal abdominoperineal resection in male patients with anorectal cancer.

In abdominoperineal resection (APR) in male patients with rectal cancer, high margin involvement and urethral injury have been reported to result from difficulty in dissecting the anterior anorectum. Recently, the efficacy of an endoscopic down-to-up rectal dissection was reported. Here, we present a safe and simple technique for anterior dissection using a simultaneous laparoscopic and transperineal endoscopic approach. We perform transperineal APR (TpAPR) using both the laparoscopic and transperineal approach (a 2-team approach). Anterior dissection commences just behind the superficial transverse perineal muscle. Next, the striated muscle complex surrounding the rectum (levator ani and puborectalis muscle) is divided. At this point, it is difficult to identify the dissection plane between the membranous urethra and anterior rectum; thus, dissection along the lateral aspect of neurovascular bundle from the lateral to anterior side with the assistance of the laparoscopic team is helpful in identifying the posterior surface of the prostate. Once the prostate is identified, it is relatively easy to divide the rectourethralis muscles. The key steps of our procedure are shown in the video. Between April 2016 and July 2019, we performed 14 TpAPR procedures in male patients with rectal cancer without distant metastasis. Extended surgery was performed in 8 patients, including pelvic sidewall dissection and combined resection of adjacent organs. Median operative time was 453min and median blood loss was 46g. There was 1 (7.1%) circumferential-positive case, but no cases of urethral injury or rectal perforation. The 2-team TpAPR procedure is beneficial for appropriate dissection of the anterior side during APR surgery.

Probing the Honey Bee Diet-Microbiota-Host Axis Using Pollen Restriction and Organic Acid Feeding.

Microbial metabolites are considered important drivers of diet-based microbiota influence on the host, however, mechanistic models are confounded by interactions between diet, microbiota function, and host physiology. The honey bee harbors a simple microbiota that produces organic acids as fermentation products of dietary nectar and pollen, making it a model for gut microbiota research. Herein, we demonstrate that bacterial abundance in the honey bee gut is partially associated with the anterior rectum epithelium. We used dietary pollen restriction and organic acid feeding treatments to obtain information about the role of undigested pollen as a microbiota growth substrate and the impact of bacterial fermentation products on honey bee enteroendocrine signaling. Pollen restriction markedly reduced total and specific bacterial 16S rRNA abundance in the anterior rectum but not in the ileum. Anterior rectum expression levels of bacterial fermentative enzyme gene transcripts (acetate kinase, lactate dehydrogenase, and hydroxybutyryl-CoA dehydrogenase) were reduced in association with diet-induced microbiota shifts. To evaluate the effects of fermentative metabolites on host enteroendocrine function, pollen-restricted bees were fed an equimolar mixture of organic acid sodium salts (acetate, lactate, butyrate, formate, and succinate). Organic acid feeding significantly impacted hindgut enteroendocrine signaling gene expression, rescuing some effects of pollen restriction. This was specifically manifested by tissue-dependent expression patterns of neuropeptide F and allatostatin pathways, which are implicated in energy metabolism and feeding behaviors. Our findings provide new insights into the diet-microbiota-host axis in honey bees and may inform future efforts to improve bee health through diet-based microbiota manipulations.

Feasibility of robotic assisted bladder sparing pelvic exenteration for locally advanced rectal cancer: A single institution case series.

Pelvic exenteration for locally advanced rectal cancer involving prostate has been performed via open surgery. Robotic pelvic exenteration offers benefits of better pelvic visualisation and dissection for bladder preserving prostatectomy with vesicourethral anastomosis, while achieving clear margins. To determine the feasibility of robotic assisted bladder sparing pelvic exenteration. We describe robotic assisted pelvic exenteration in three cases of locally advanced rectal cancer involving prostate and seminal vesicles (SV). The da Vinci S robotic system was used. Robotic console was docked at left oblique position for abdominal phase and redocked to between the patient's legs for pelvic phase. All three cases were performed fully robotically at Tan Tock Seng Hospital by colorectal and urological teams. Case 1: 67-year-old with low rectal tumour 3cm from anal verge involving the prostate. He underwent neo-adjuvant chemoradiotherapy and robotic abdominoperineal resection with en-bloc prostatectomy. Case 2: 66-year-old with low rectal tumour 3cm from anal verge involving prostate and bilateral SV. He underwent neo-adjuvant chemoradiotherapy and robot assisted ultra-low anterior resection with coloanal anastomosis and en-bloc prostatectomy. Case 3: 57-year-old with metachronous rectal tumour in the rectovesical pouch inseparable from the anterior mid rectum, prostate and bilateral SV. He underwent robot assisted ultra-low anterior resection with en-bloc prostatectomy. Bladder neck margin revealed cauterized tumour cells, and he underwent total cystectomy and ileal conduit creation. Histology revealed no residual tumour. All patients are currently disease free. Robot assisted bladder sparing pelvic exenteration can be safely performed in locally advanced rectal cancer with acceptable surgical outcome while preserving benefits of minimally invasive surgery.

Mesh Migration Results in Asymptomatic Sigmoid Perforation as Long-Term Complication After Difficult TAPP: a Case Report

Hernia surgery is the most common surgical procedure worldwide. Complications are very rare and usually manifest in recurrence or chronic pain. We report a rare case of mesh migration 14 years after initially complicated transabdominal preperitoneal plastic for left-sided inguinal hernia. The mesh migration resulted in a covered sigmoid perforation, which was completely asymptomatic and only noticed as a chance finding in a staging CT scan prior to irradiation therapy. However, after the onset of immunosuppressive therapy, an exacerbation of chronic, localized inflammation was expected. Therefore, open surgical anterior rectum resection was performed, and after a short hospital stay, the patient could be discharged home free of complaints. This case report aims to raise awareness of possible long-term complications of hernia repair when using non-absorbable meshes.

Anal Incontinence after Anterior Rectum Resection in Cancer Patients

Aim . To study the functioning of the anal sphincter after performing anterior rectum resection in cancer patients. Materials and methods. The anal sphincter function was studied in 144 patients with colorectal cancer, equally in 72 men and 72 women. The study was carried out at the Rostov Cancer Research Institute. All patients underwent R0 anterior rectum resection with the total mesorectumectomy and the formation of a preventive ileostomy. An assessment of the retention function was performed by sphincterometry using a manometric complex with a nonperfusion water-filling sensor according to the generally accepted method. Results . Disturbances in the normal functioning of the sphincter were noted in 24 (16.7 %) patients. The use of sphincterometry allowed disturbances in the functioning of the internal and external anal sphincters in men and women to be identified, along with differences between the groups. The results indicate a higher incidence of anal incontinence (AI) in women compared to men ( t ≥ 2, the differences are significant). In addition, patients with a lower localisation of the anastomosis demonstrated a higher incidence of AI and more pronounced AI manifestations. Conclusions. The obtained data on the functioning of the anal sphincter after anterior rectum resection in cancer patients indicate gender differences in the incidence of late complications after surgery, as well as the importance of taking into account the localisation of the tumour for selecting an adequate amount of surgical intervention.

Transvaginal rectopexy using the Flex® Colorectal Drive Robotic System: a proof-of-concept approach to rectal prolapse.

The aim of this study was to demonstrate a proof-of-concept approach to rectopexy that would provide the durability of the transabdominal procedure through use of sacral rectopexy with the decreased morbidity of a perineal procedure. This was done by utilizing a transvaginal approach and developing the rectovaginal space to accommodate sacral rectopexy placement using the Flex® Colorectal Drive Robotic System by Medrobotics (Medrobotics Corp., Raynham, MA, USA). A fresh female cadaver was acquired and placed in the high lithotomy position. The rectovaginal space was developed to accommodate the trocar of the Flex robot using blunt and sharp dissection between the posterior vaginal wall and anterior rectum. A piece of mesh was introduced into the space and using an endoscopic tacker, which was secured to the sacral promontory. The mesh was secured to the anterior rectal wall using interrupted vicryl sutures. The purse string suture was removed and the rectovaginal orifice was closed using a running vicryl suture. At the completion of the procedure, a low midline laparotomy was conducted to verify anchoring of the mesh appropriately at the sacral promontory. This proof-of-concept protocol is the first description of the Flex® Colorectal Drive being used successfully to perform a transvaginal rectopexy for rectal prolapse in a cadaver. This is also the first description of the Flex® Colorectal Drive robot being used transvaginally. This proof-of-concept approach demonstrates that transvaginal rectopexy using the Flex® Colorectal Drive is a potential surgical option to address rectal prolapse that could provide patients the durability of a transabdominal approach with the decreased morbidity of a perineal approach. While early results are promising, additional cadaveric studies are required before this procedure can be attempted in vivo.

Spontaneous Rectal Perforation with Transanal Evisceration

We present the case of an 83-year-old woman that visited the emergency room of our hospital for correcting the transanal small bowel evisceration after a defecatory effort, without any history of rectal trauma. Emergency laparotomy was indicated, with the intraoperative finding of perforation in the anterior superior rectum, with a defect of approximately 3 cm. Due to the absence of fecaloid peritonitis, it was decided to perform a primary closure with double sutures. The patient evolved favorably.

2117 Anal Squamous Cell Carcinoma Presenting as a Rectal Mass

INTRODUCTION: Anal squamous cell carcinoma (SCC)typically presents as an anal mass. It rarely presentsin the rectumalone. Limited literature exists to discuss regarding optimal management for this unique presentation. We present a patient withanal SCC manifesting as a rectal mass and reviewher management. CASE DESCRIPTION/METHODS: A 73 year-old woman with esophageal reflux presented to our office with chronicrectal bleedingand constipation.She denied anal pain. Colonoscopy revealed a 1.2 cm massin the anterior rectum, 2 cm from the anal verge (Figure 1). Biopsies revealed focally invasive nonkeratinizing SCC (Figure 2). On rectal endoscopic ultrasound (EUS), the mass was confined to the anus andextended from the anorectal canal into the rectum (Figure 3). Submucosal invasion was noted, but not through the rectal muscularis propria. PET CT showed no perirectal invasion, lymphadenopathy, metastatic disease orother sources of primary SCC. Final staging was T2N0. She underwentchemoradiationwith5-fluorouricil and mitomycin. Surgery was deferred to preserve anal function.Her tumor showed a complete response after 6 weeks and she is currently being followed with routine surveillance. DISCUSSION: Anal SCC makes up2.6% of digestive system cancers in the United States, but its incidence is rising in men and women, possibly due to changes in sexual behavior and increasing rates of HPV exposure. Gastroenterologists should recognizeatypical presentations ofanal SCC, especially in high-risk populations: men who have sex with men, HIV positive patients, and women with high risk HPV. Rectal bleeding and altered bowel habits arethe most commonlyreported symptoms. Other symptoms include anal mass, pain, itching, and mucous discharge, but up to 20% of patients with anal cancer are asymptomatic. The absence of anal pain and external lesions as well as the rectal mass on in our patient suggested an alternative diagnosis. Given that management of rectal cancer has traditionally centered around resection, this emphasizes the utility of EUS to make the correct diagnosis and direct management. The management of this unique presentation of anal SCC has not been fully established, but our patient received standard chemoradiation with good results. Anal SCC has a range of presentations and can present as a rectal mass. Given that anal SCC rates are increasing, our case highlights the importance of disease screening, recognition, and prevention.

Itʼs Not Always the Diverticula: A Rare Case of Obscure Overt Lower Gastrointestinal Bleed Resulting From a Fistulous Tract Between Rectum and Seminal Vesicle Secondary to Metastatic Prostate Adenocarcinoma

Diverticula and hemorrhoids are the most common etiology of lower gastrointestinal bleed (LGIB) with other causes including angioectasias, malignancy, colitis (ischemic, infectious, and inflammatory), post procedural, and disorders of the anorectal region. In rare instances of surgical prostatic manipulation, LGIB has occurred. We present a rare case of fistulous tract formation resulting in ongoing obscure, overt LGIB secondary to metastatic adenocarcinoma of the prostate. We present a case of a 74 year old male with a past medical history of hypertension, paroxysmal atrial fibrillation not on anticoagulation, hemorrhoids, benign prostatic hypertrophy, and diverticulosis, who presented to his urologist with complaints of urinary retention Computed tomography (CT) of the abdomen and pelvis revealed enlarged prostate and seminal vesicle mass thought likely to be a cyst which led to a transrectal biopsy. Approximately 1 month later, patient developed acute lower gastrointestinal bleeding and underwent colonoscopy that revealed pan mild diverticulosis and hemorrhoids. The patient continued to have intermittent lower gastrointestinal bleeding requiring multiple hospitalizations and blood transfusions. Multitude of testing including EGD, multiple colonoscopies, tagged red blood cell scans and computed tomography angiography failed to localize the bleeding and patient underwent sigmoidectomy. He continued to bleed flexible sigmoidoscopy noted a brief jet of bright red blood coming from the anus near the dentate line that stopped spontaneously.. Patient underwent surgical exploration with colorectal and urology and tumor, confirmed as adenocarcinoma of the prostate, was found to be replacing the space between the rectum and the seminal vesicle likely stemming from the seminal vesicles and a noted defect in the left anterior rectum which was identified as the site of the fistula approximately 2 centimeters in size. The defect was closed during surgery. Following these procedures there was resolution of the hematochezia Although rare, metastatic adenocarcinoma of the prostate can lead to the development of a rectal-seminal vesicle fistula causing LGIB. Brief review of the literature did not return any reported cases of rectal-seminal vesicle fistula caused by tumor involvement. A thorough evaluation of the entire patient including all comorbities should be completed when evaluating etiology of recurrent lower gastrointestinal bleeding.

Safety of rectum anastomosis after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

In highly selected patients with peritoneal carcinomatosis, cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) can be an aggressive but worthwhile treatment regimen. Resection of the rectosigmoid is frequently performed with CRS. The aim of the study was to assess the safety of the rectal anastomosis in this setting. Between 2005 and 2016, 436 patients underwent CRS/HIPEC. Clinical data were analyzed with respect to the morbidity associated with a rectum resection. In 436 patients, 174 rectum resections (40%) were performed with CRS, including 149 anterior resections of the rectosigmoid, 23 low anterior rectum resections, and 2 abdominoperineal rectum excisions. A total of 141 rectum anastomoses were performed; 33 patients received a permanent ostomy, and 48 patients received a protective ileostomy. After changing the operation technique of the rectum anastomosis, the number of protective ileostomies decreased from 65% to 20%. The overall postoperative morbidity was 31%. Rectal anastomotic leakages were seen in only 5% of cases. Anastomotic leakages of the rectum are rarely seen after CRS/HIPEC. HIPEC performed immediately after surgery seems to have no negative effect on the rectum anastomosis. Performing rectum anastomoses after CRS/ HIPEC appears to be a safe procedure.

A feature alignment score for online cone-beam CT-based image-guided radiotherapy for prostate cancer.

To develop a method for scoring online cone-beam CT (CBCT)-to-planning CT image feature alignment to inform prostate image-guided radiotherapy (IGRT) decision-making. The feasibility of incorporating volume variation metric thresholds predictive of delivering planned dose into weighted functions, was investigated. Radiation therapists and radiation oncologists participated in workshops where they reviewed prostate CBCT-IGRT case examples and completed a paper-based survey of image feature matching practices. For 36 prostate cancer patients, one daily CBCT was retrospectively contoured then registered with their plan to simulate delivered dose if (a) no online setup corrections and (b) online image alignment and setup corrections, were performed. Survey results were used to select variables for inclusion in classification and regression tree (CART) and boosted regression trees (BRT) modeling of volume variation metric thresholds predictive of delivering planned dose to the prostate, proximal seminal vesicles (PSV), bladder, and rectum. Weighted functions incorporating the CART and BRT results were used to calculate a score of individual tumor and organ at risk image feature alignment (FASTV_OAR ). Scaled and weighted FASTV_OAR were then used to calculate a score of overall treatment compliance (FASglobal ) for a given CBCT-planning CT registration. The FASTV_OAR were assessed for sensitivity, specificity, and predictive power. FASglobal thresholds indicative of high, medium, or low overall treatment plan compliance were determined using coefficients from multiple linear regression analysis. Thirty-two participants completed the prostate CBCT-IGRT survey. While responses demonstrated consensus of practice for preferential ranking of planning CT and CBCT match features in the presence of deformation and rotation, variation existed in the specified thresholds for observed volume differences requiring patient repositioning or repeat bladder and bowel preparation. The CART and BRT modeling indicated that for a given registration, a Dice similarity coefficient >0.80 and >0.60 for the prostate and PSV, respectively, and a maximum Hausdorff distance <8.0 mm for both structures were predictive of delivered dose ± 5% of planned dose. A normalized volume difference <1.0 and a CBCT anterior rectum wall >1.0 mm anterior to the planning CT anterior rectum wall were predictive of delivered dose >5% of planned rectum dose. A normalized volume difference <0.88, and a CBCT bladder wall >13.5 mm inferior and >5.0 mm posterior to the planning CT bladder were predictive of delivered dose >5% of planned bladder dose. A FASTV_OAR >0 is indicative of delivery of planned dose. For calculated FASTV_OAR for the prostate, PSV, bladder, and rectum using test data, sensitivity was 0.56, 0.75, 0.89, and 1.00, respectively; specificity 0.90, 0.94, 0.59, and 1.00, respectively; positive predictive power 0.90, 0.86, 0.53, and 1.00, respectively; and negative predictive power 0.56, 0.89, 0.91, and 1.00, respectively. Thresholds for the calculated FASglobal of were low <60, medium 60-80, and high >80, with a 27% misclassification rate for the test data. A FASglobal incorporating nested FASTV_OAR and volume variation metric thresholds predictive of treatment plan compliance was developed, offering an alternative to pretreatment dose calculations to assess treatment delivery accuracy.