Anatomy of muscle connections in the male urethra and anorectal canal

OBJECTIVES

To elucidate the male urethral muscular structure and its relationship with the anorectal canal muscles, as establishing an anatomical foundation for urethral function will contribute to the prevention, diagnosis, and treatment of urinary incontinence.

METHODS

Eight male cadavers were used. Using a multifaceted approach, we performed macroscopic anatomical examination, histological analysis of wide-range serial sectioning and immunostaining, and three-dimensional (3D) reconstruction from histological sections. In the macroscopic anatomical examination, pelvic halves were meticulously dissected in layers from the medial aspect. In the histological analysis, the tissue, including the urethra and anorectal canal, was serially sectioned in the horizontal plane. The muscular structures were reconstructed and visualised in 3D.

RESULTS

The membranous portion of the urethra had three muscle layers: the longitudinal and circular muscles (smooth muscle) and the external urethral sphincter (skeletal muscle). The circular muscle was connected posteriorly to the longitudinal rectal muscle. The external urethral sphincter had a horseshoe shape, with its posterior ends continuing to the external anal sphincter, forming a 3D ring-like sphincter.

CONCLUSION

This study revealed skeletal and smooth muscle connections between the male urethra and anorectal canal, enabling urethral compression and closure. These anatomical muscle connections suggest a functional linkage between them.

Variation in Episiotomy Use Among Nulliparous Individuals by Maternity Care Provider and Associated Rates of Obstetric Anal Sphincter Injury

OBJECTIVES

To quantify variation in the association between episiotomy and obstetric anal sphincter injury (OASI) by maternity care provider in spontaneous and operative vaginal deliveries (SVDs and OVDs).

METHODS

Population-based retrospective cohort study of vaginal, term deliveries among nullipara in Canada (2004-2015). Adjusted rate ratios (ARRs) and 95% CIs were estimated using log-binomial regression to quantify the associations between episiotomy and OASI, stratified by care provider (obstetrician [OB], family physician [FP], or registered midwife [RM]) while adjusting for potential confounders.

RESULTS

The study included 631 642 deliveries. Episiotomy use varied by provider: among SVDs, the episiotomy rate was 19.6%, 14.4%, and 8.4% in the OB, FP, and RM groups, respectively. The rate of OASI was higher among SVDs with versus without episiotomy (5.8% vs 4.6%). Conversely, OASI occurred less frequently in operative vaginal deliveries with episiotomy (15.3%) compared with those without (16.7%). In all provider groups, the ARR for OASI was increased with episiotomy in SVD and decreased with episiotomy with forceps delivery. No differences in these associations were observed by provider except among vacuum delivery (ARR with episiotomy vs. without, OB: 0.88, 95% CI 0.84-0.92; FP: 0.89, 95% CI 0.83-0.96, RM: 1.22, 95% CI 1.02-1.48).

CONCLUSIONS

In nullipara, irrespective of maternity care provider, there is a positive association between episiotomy and OASI among SVDs and an inverse association between episiotomy and deliveries with forceps. The relationship between episiotomy and OASI is modified by maternity care providers among vacuum deliveries.

A case of a rare type of cancer: Anal squamous cell carcinoma in a patient without significant risk factors

INTRODUCTION

Anal carcinoma is a relatively uncommon tumor that accounts for less than 2% of large bowel malignancies and approximately 1-6% of anorectal tumors. Most anal cancers originate in the mucosa between the anorectal junction and the anal verge. Risk factors for anal carcinoma include human papillomavirus (HPV), immunosuppression, older age, female gender, and smoking. Approximately 85% of anal cancers are squamous cell carcinoma, and the pathophysiology is believed to be linked to HPV-related inflammation, leading to dysplasia and progression to cancer.

CASE PRESENTATION

We present the case of a 65-year-old woman who sought medical attention at the emergency department (ED) due to rectal pain and concurrent rectal lesions persisting for the past three months. Before admission, she reported abdominal discomfort and constipation for 2-3 months, during which she took laxatives for relief. Laboratory findings in the ED were significant for anemia and leukocytosis, with all other values within normal limits. Blood tests, including antibodies for HPV and human immunodeficiency virus, were negative. A computed tomography scan of the abdomen and pelvis was largely unremarkable. On physical examination, perianal lesions with heaped-up edges were observed. A punch biopsy was subsequently performed, revealing squamous cell carcinoma (SCC). About three weeks following discharge, after one week of admission to the general medicine ward, the patient started chemoradiation therapy and reported some improvement in her symptoms. Seven weeks later, she was in remission.

DISCUSSION

Squamous cell carcinoma (SCC) of the anus, a rare disease entity, is often a slow and progressive malignancy. The length of time for patients to become symptomatic, in combination with its mimicking clinical presentation to common gastrointestinal tract diseases and its rarity, makes diagnosis challenging. Additionally, a patient lacking traditional risk factors for anal cancer, such as HPV and smoking, may further complicate diagnosis, treatment, and quality of life.

CONCLUSION

This case report emphasizes the pathogenesis and the similarities in clinical presentation of anal cancer to mild diseases, which may lead to a delay in diagnosis. Patients with anal carcinoma often delay seeking medical care, which is anecdotal in relation to the considerable overlap in symptoms of benign diseases such as hemorrhoids. Therefore, patients with "hemorrhoid" complaints, rectal bleeding, or rectal mass should warrant further physical examination and prompt referral to a gastroenterologist or a colorectal surgeon for additional evaluation.

The Role of Magnetic Resonance Imaging in Pre-operative Assessment of Anorectal Fistula With Surgical Correlation

Background Anorectal fistulas are chronic inflammations of peri-anal tissues that form a connection between the perineal skin and the anal canal. Accurate preoperative evaluation of the main fistula's trajectory and pelvic tissues is essential for effective surgical treatment of anal fistulas. The inability to detect concealed lesions may result in the recurrence of fistulas and the conversion of a simple fistula into a complex fistula. Magnetic resonance imaging (MRI) imaging can detect concealed pathways and abscesses, thereby exposing the intricate connection between the fistula and anal-sphincter complex. This data serves as a roadmap for making surgical decisions, thereby reducing the likelihood of illness recurrence and complications after surgery. Aim To evaluate the role of MRI in pre-operative assessment of an anorectal fistula, compare its findings with surgical results. Materials and methods The research was conducted at the Radiology Department, Apollo Hospital, Hyderabad. It was a prospective observational study. IBM SPSS Statistics for Windows, Version 17 (released 2008; IBM Corp., Armonk, New York, United States) was utilized for data analysis. The mean and standard deviation were computed. We further applied appropriate statistical tests to determine the significance of MRI features with pre-operative findings. Results MRI accurately detects features like abscesses (sensitivity-100%, specificity-97.06%), secondary tracts of the fistula (sensitivity-93.55%, specificity-94.12%), horseshoe appearance, and supralevator extension (sensitivity-100%, specificity-97.50%, and 97.62%, respectively). Conclusion When comparing our results with intraoperative findings, MRI showed high sensitivity and specificity in detecting abscesses, secondary tracts, horseshoe appearances, and supralevator extensions. Our findings suggest that MRI can offer anatomical and pathological information for the pre-operative care and surgical planning of perianal fistulas.

Endoscopic underwater detection and resection of anal squamous intraepithelial lesions in non-anesthetized patients - a feasibility study and comparison with standard surgical treatment

BACKGROUND

Anal squamous intraepithelial lesions (ASILs) correspond to premalignant changes preceding the development of anal squamous cell carcinoma.

OBJECTIVE

To describe a new endoscopic technique to detect and remove ASILs in non-anesthetized patients and compare it with standard surgical treatment.

METHODS

For endoscopic treatment, high resolution (HR) flexible endoscopes with a distal attachment were used. Underwater inspection of the anal canal was performed in near-focus mode with white light and narrow-band imaging. Detected lesions were resected with a diathermia snare after local injection of xylocaine/adrenaline. We did a retrospective comparison of all patients who underwent endoscopic or standard surgical treatment for ASILs at Ersta hospital in Stockholm between 2018 and 2020. Patient files were reviewed for number of lesions, treatments until macroscopic radicality, degree of dysplasia, bleeding, pain and other complications.

RESULTS

Endoscopic (n = 37) and surgical (n = 43) treatment displayed comparable number of lesions per patient (p = .37). The number of procedures until macroscopic radicality was higher for endoscopy than surgery (p = .04). However, in endoscopic follow up of 12 of the surgically treated patients, residual ASIL was found in 10 cases. Post-procedural bleeding requiring healthcare occurred in two endoscopy patients and one surgically treated patient.

CONCLUSIONS

Underwater resection using a HR flexible endoscope in non-anesthetized is a new, feasible and well tolerated method for ASILs treatment. Its efficacy and risk of complications seem comparable to standard surgical treatment while avoiding general anesthesia. However, minor lesions might be overlooked at surgery.

High prevalence of high-risk HPV genotypes in individuals attending an infectious diseases clinic from 2018 to 2022 in Milan, Italy

Human papillomavirus (HPV) is the most common sexually transmitted infection, linked to several types of lesions. HPV, specifically HPV 16, accounts for most of anal cancer cases. In this study, we evaluated the proportion of samples tested positive for HPV and characterized genotypes distribution in anal specimens collected from individuals at risk of anal HPV infection attending from 2018 to 2022 a large Infectious Diseases Department in Italy. The presence of HPV DNA was investigated through a commercial kit detecting 12 HR-HPV, 8 probable/possible HR-HPV, and 8 LR-HPV genotypes. Among 1514 samples, 84% (1266/1514) resulted positive for any type of HPV. The prevalence of high-risk HPV types remained high during all the years of the study period, from 2018 to 2022, ranging from 65% to 73%. Most of HR-HPV, LR-HPV and HPV 16 positive samples were collected from men >45 years. HPV 16 was also the most frequent type in men and women. We did not observe significant variations between years in detection of HR-HPV, instead of LR-HPV, that significantly decreased. In conclusion, the high prevalence of oncogenic HPV genotypes underlines the necessity of clear anal HPV screening guidelines and, along with frequent HR-HPV coinfections, reinforces the urge to intensify the anti-HPV vaccination campaign.

Penetrative anal intercourse may require high axial loading forces

BACKGROUND

Despite increases in the lifetime prevalence of anal intercourse, little is known about the safety of inflatable penile prosthesis use during anal intercourse or the forces required for anal penetration.

AIM

We sought to determine the force required for anal penetration.

METHODS

A digital force gauge device was secured to a silicone phallus with a length and girth representative of the average male phallus in the United States and inserted into the anal canal of 6 male participants for a total of 5 measurements per participant. The maximum axial forces on insertion were recorded. Participants then completed a survey eliciting demographic information and past experience with receptive anal intercourse.

OUTCOMES

The outcome measure was the force recorded during insertion of a force gauge device into the anal canal.

RESULTS

The median maximal force recorded on anal penetration was 26.5 N (2.7 kg; range: 16.1-51.7 N or 1.64-5.27 kg). Participants who engaged in receptive anal intercourse more than once per month tended to use lesser median maximal forces (25.7 N or 2.62 kg) than participants who engaged less frequently in receptive anal intercourse (41.6 N or 4.24 kg).

CLINICAL IMPLICATIONS

Compared with the forces required for vaginal penetration, anal penetration forces may cause additional mechanical stress to the phallus.

STRENGTHS AND LIMITATIONS

While the study is limited primarily in its small sample size and in the use of a single device for anal penetration with a set size and rigidity, the resulting findings presented here are to our knowledge the first reported data pertaining the force required for anal penetration.

CONCLUSION

As the forces required for anal penetration exceeded those for vaginal penetration, clinicians may need to carefully counsel patients on the safe use of an inflatable penile prosthesis for anal intercourse.

An Updated Review on Imaging and Staging of Anal Cancer-Not Just Rectal Cancer

Anal cancer is a rare disease, but its incidence has been increasing steadily. Primary staging and assessment after chemoradiation therapy are commonly performed using MRI, which is considered to be the preferred imaging modality. CT and PET/CT are useful in evaluating lymph node metastases and distant metastatic disease. Anal squamous-cell carcinoma (ASCC) and rectal adenocarcinoma are typically indistinguishable on MRI, and a biopsy prior to imaging is necessary to accurately stage the tumor and determine the treatment approach. This review discusses the histology, MR technique, diagnosis, staging, and treatment of anal cancer, with a particular focus on the differences in TNM staging between anal and rectal carcinomas.

PURPOSE

This review discusses the histology, MR technique, diagnosis, staging, and treatment of anal cancer, with a particular focus on the differences in TNM staging between anal squamous-cell carcinoma (ASCC) and rectal adenocarcinoma.

METHODS AND MATERIALS

To conduct this updated review, a comprehensive literature search was performed using prominent medical databases, including PubMed and Embase. The search was limited to articles published within the last 10 years (2013-2023) to ensure their relevance to the current state of knowledge.

INCLUSION CRITERIA

(1) articles that provided substantial information on the diagnostic techniques used for ASCC, mainly focusing on imaging, were included; (2) studies reporting on emerging technologies; (3) English-language articles.

EXCLUSION CRITERIA

articles that did not meet the inclusion criteria, case reports, or articles with insufficient data. The primary outcome of this review is to assess the accuracy and efficacy of different diagnostic modalities, including CT, MRI, and PET, in diagnosing ASCC. The secondary outcomes are as follows: (1) to identify any advancements or innovations in diagnostic techniques for ASCC over the past decade; (2) to highlight the challenges and limitations of the diagnostic process.

RESULTS

ASCC is a rare disease; however, its incidence has been steadily increasing. Primary staging and assessment after chemoradiation therapy are commonly performed using MRI, which is considered to be the preferred imaging modality. CT and PET/CT are useful in evaluating lymph node metastases and distant metastatic disease.

CONCLUSION

ASCC and rectal adenocarcinoma are the most common histological subtypes and are typically indistinguishable on MRI; therefore, a biopsy prior to imaging is necessary to stage the tumor accurately and determine the treatment approach.

The effects of progesterone on the healing of obstetric anal sphincter damage in female rats

We aimed to evaluate the effects of postpartum progesterone on obstetric anal sphincter injury (OASI) healing in female rats using an experimental OASI model. Twenty-eight female rats were divided into four groups after birth: sham-30, sham-90, progesterone (P4)-30, and P4-90. Moreover, OASI model was established in all groups. Subsequently, except for the sham groups, medroxyprogesterone acetate (0.15 mg) was intramuscularly injected into the P4 groups. After 30 and 90 days, the rats were euthanized under general anesthesia after recording the data. The anal sphincter region was collected for histopathological examination. Progesterone and thiol/disulfide homeostasis studies were performed on blood samples. No significant differences were observed between the groups regarding the external anal sphincter (EAS), internal anal sphincter (IAS), or connective tissue thickness (p = 0.714, p = 0.135, and p = 0.314, respectively). No statistically significant differences in the total thiol, native thiol, disulfide, and progesterone levels were found between the groups (p = 0.917, p = 0.503, p = 0.361, and p = 0.294, respectively). The endometrial thickness was lower in the P4 groups than in the sham groups (p = 0.031). Postpartum progesterone administration did not affect IAS and EAS or connective tissue thickness or disrupt the thiol-disulfide balance. However, this administration led to endometrial thinning.

Infantile perianal pyramidal protrusion: A retrospective review of 27 patients

BACKGROUND

Infantile perianal pyramidal protrusion (IPPP) is a rare benign skin condition that is typically seen in infant girls. This condition is often mistaken for other skin lesions such as acrochordons, condyloma acuminatum, and sequelae of sexual abuse. Many clinicians are unfamiliar with IPPP which can lead to aggressive workup and treatment. The purpose of this study was to elucidate demographic data, clinical features, diagnostic workup, and management of IPPP in a large cohort of patients seen at an academic medical center.

METHODS

A retrospective review of patients diagnosed with IPPP at Mayo Clinic, Rochester, MN was conducted. Demographic data, examination findings, diagnostic workup, and treatments were noted.

RESULTS

Twenty-seven patients with IPPP, 24 of which were girls and 3 were boys from the ages of 1 day to 4 years (mean 10.8 months, median 8.6 months) were identified. Symptoms were reported in 63% (17/27) of patients. Four patients received treatment with topical corticosteroid or local anesthetic. No patient underwent skin biopsy.

CONCLUSION

IPPP is commonly observed in healthy prepubertal girls. Constipation is a common symptom. Awareness of this entity may prevent overtreatment and unnecessary evaluation.

[Perianal Fistula: An Overview]

Perianal fistula is a common inflammatory condition in the general population and affects the area around the anal canal. Although most cases are benign, they cause serious morbidity and require surgical treatment due to a high risk of recurrence. MR imaging is a gold standard technique for the evaluation of perianal fistulas and provides accurate information on the anatomy of the anal canal, its relationship to the anal sphincter complex, accurate identification of secondary tracts or abscesses, and reporting associated complications. MR imaging can help monitor treatment effects and determine treatment methods. Crohn's disease-related fistulas often require medical rather than surgical treatment. The radiologist is required to know the anatomy and MR imaging findings of the perianal fistula to present an accurate diagnosis to the clinician.

Case report: a precancerous lesion associated with HPV in the anal canal diagnosed by magnifying endoscopy with narrow-band imaging and resected by endoscopic submucosal dissection

Although anal cancer remains rarely diagnosed in the world, its frequency is rising, especially in high-risk groups. The prognosis of advanced anal cancer is poor. However, there are still few reports on the endoscopic diagnosis and treatment of early anal cancer and its precancerous lesions. A 60-year-old woman was referred to our hospital for endoscopic treatment of a flat precancerous lesion in the anal canal, which was identified by narrow-band imaging (NBI) and confirmed by pathological examination in another hospital. The pathological results showed a high-grade squamous intraepithelial lesion (HSIL) in the biopsy specimen, and immunochemistry staining showed P16 positive, suggesting HPV infection. We performed pre-resection endoscopic examination for the patient. A lesion with a clear margin and tortuous dilated vessels was revealed under magnifying endoscopy with NBI (ME-NBI), which stayed unstained after iodine spraying. The lesion was successfully removed en bloc using ESD without complications, and the resected specimen was a low-grade squamous intraepithelial lesion (LSIL) with positive immunochemistry staining of P16. The patient underwent follow-up coloscopy a year after ESD, and the anal canal healed well with no suspicious lesions found. From this case, we can learn that ESD is safe and effective for curative resection of precancerous lesions of the anal canal.

Goblet cell adenocarcinoma of the anal canal with perianal Paget disease: A rare case report with literature review

INTRODUCTION

AS an uncommon neoplasm, goblet cell adenocarcinoma (GCA) is characterized by mixed endocrine-exocrine features. It is almost exclusively found in the appendix. Primary GCA of the anal canal is extremely rare.

CASE PRESENTATION

Herein we describe a novel rare case of 74-year-old Chinese female who is diagnosed with GCA in the anal canal with perianal Paget disease, including a brief review of the literature. In the lesion of anal canal, the tumor was composed of signet-ring-like cells on confluent growth model and copious mucin was produced as well. Simultaneously, the results of immunohistochemistry showed signet-ring-like cells were positive for CK20, CDX2, synaptophysin (Syn), CD56, carcinoembryonic antigen (CEA) and Villin. Meanwhile, the Ki67-labeling index reached 40%. In the lesion of perianal Paget disease, the small groups of atypical neoplastic cells were present in the epidermis. Immunohistochemically, the neoplastic cells were positive for CK20, CDX2 and epithelial membrane antigen, but negative for CK7, GCDFP15, S100, HMB45, and P63. The Ki67-labeling index reached 60% in the most concentrated spot.

CONCLUSIONS

Extra-appendiceal GCA was rare and easily under-recognizable. The diagnosis of GCA was seldom made preoperatively. Occasionally, GCA could occur in the anal canal accompanied by perianal Paget disease. So careful rectal examination was important in the patient with perianal Paget disease for avoid missing diagnosis of GCA on anal canal. GCA may show aggressive clinical behavior compared with typical well-differentiated neuroendocrine tumors. Therefore, we should pay more attention on the recognization of this rare disease.

Brazilian Society of Surgical Oncology: Guidelines for the management of anal canal cancer

BACKGROUND

Anal canal squamous cell carcinoma (SCC) is a relatively uncommon neoplasia, and it is mostly a local-regional cancer, of low metastatic potential (only 15%), resulting in cure in most cases treated with definitive chemoradiation. On the other hand, its incidence has been steadily increasing over the last decades, which makes it an important public health problem. In an effort to provide surgeons and oncologists who treat patients with anal cancer with the most updated information based on the best scientific evidence, the Brazilian Society of Surgical Oncology (SBCO) has produced the present guideline for the management of anal canal SCC, focused on the main topics related to daily clinical practice.

OBJECTIVES

The SBCO developed the present guidelines to provide recommendations on the main topics related to the management of anal canal squamous cell carcinoma (SCC) based on current scientific evidence.

METHODS

Between October 2022 and January 2023, 14 experts met to develop the guidelines for the management of anal canal cancer. A total of 30 relevant topics were distributed among the participants. The methodological quality of a final list with 121 sources was evaluated, all the evidence was examined and revised, and the management guidelines were formulated by the 14-expert committee. To reach a final consensus, all the topics were reviewed in a meeting that was attended by all the experts.

RESULTS

The proposed guidelines contained 30 topics considered to be highly relevant in the management of anal canal cancer, covering subjects related to screening recommendations, preventive measures, tests required for diagnosing and staging, treatment strategies, response assessment after chemoradiotherapy, surgical technique-related aspects, and follow-up recommendations. In addition, screening and response assessment algorithms, and a checklist were proposed to summarize the important information and offer an updated tool to assist surgeons and oncologists who treat anal canal cancer and in providing the best care to their patients.

CONCLUSION

These guidelines summarize recommendations based on the most current scientific evidence on relevant aspects of anal canal cancer management and are a practical guide to help surgeons and oncologists who treat anal canal cancer make the best therapeutic decisions.

Anal Canal Duplication in a 25-Year-Old Female Patient

Anal canal duplication (ACD) is a congenital malformation that typically presents and is diagnosed early in life. It can be associated with other syndromes or congenital malformations. ACD is one of the rarest duplications of the gastrointestinal tract, with no more than 90 to 100 cases reported in the literature. It can be confused with more frequent pathologies such as perianal fistula, especially when it occurs in adulthood. We present the case of a 25-year-old female patient who presents with a second orifice above the native anal orifice. An arthroscopic examination was performed, an incidental diagnosis of ACD was made, and a complete excision of the duplicated anal canal was performed. The aim of the study is to expand the information on this rare pathology in order to take it into account as a differential diagnosis in patients with abscesses, recurrent fistulous tracts, or any other anorectal pathology.

Multivisceral transplantation of pelvic organs in rats

Background

Multivisceral transplantation of pelvic organs would be a potential treatment for severe pelvic floor dysfunction with fecal and urinary incontinence, extensive perineal trauma, or congenital disorders. Here, we describe the microsurgical technique of multivisceral transplantation of pelvic organs, including the pelvic floor, in rats.

Donor operation

We performed a perineal (including the genitalia, anus, muscles, and ligaments) and abdominal incision. The dissection progressed near the pelvic ring, dividing ligaments, muscles, external iliac vessels, and pudendal nerves, allowing pelvic floor mobilization. The aorta and vena cava were isolated distally, preserving the internal iliac and gonadal vessels. The graft containing the skin, muscles, ligaments, bladder, ureter, rectum, anus and vagina, uterus and ovarian (female), or penile, testis and its ducts (male) was removed en bloc, flushed, and cold-stored.

Recipient operation

The infrarenal aorta and vena cava were isolated and donor/recipient aorta-aorta and cava-cava end-to-side microanastomoses were performed. After pelvic floor and viscera removal, we performed microanastomoses between the donor and the recipient ureter, and the rectum and pudenda nerves. The pelvic floor was repositioned in its original position (orthotopic model) or the abdominal wall (heterotopic model). We sacrificed the animals 2 h after surgery.

Results

We performed seven orthotopic and four heterotopic transplantations. One animal from the orthotopic model and one from the heterotopic model died because of technical failure. Six orthotopic and three heterotopic recipients survived up to 2 h after transplantation.

Conclusion

The microsurgical technique for pelvic floor transplantation in rats is feasible, achieving an early survival rate of 81.82%.

Current and future perspectives on the utility of provocative tests of anal sphincter function: A state-of-the-art summary

BACKGROUND

The maintenance of fecal continence depends upon coordinated interactions between the pelvic floor, anorectum, and anal sphincter complex orchestrated by central and peripheral neural activities. The current techniques to objectively measure anorectal function rely on fixed diameter catheters placed inside the anal canal with a rectal balloon to obtain measurements of anal resting and squeeze function, and rectal compliance. Until recently it had not been possible to measure the distensibility of the anal canal, or in other words its ability to resist opening against an increasing pressure, which has been proposed as the main determinant of a biological sphincter's function. Anal acoustic reflectometry (AAR) and the functional lumen imaging probe (FLIP) are two novel, provocative techniques that dynamically assess the anal sphincter complex under volume-controlled distension. In doing so, both provide information on the viscoelastic properties of the anal canal and offer new insights into its function.

PURPOSE

This review details the current and potential future applications of AAR and FLIP and highlights the unanswered questions relevant to these new technologies.

Transanal total mesorectal excision for treating a lower rectal inflammatory myofibroblastic tumor: A case report

Rectal inflammatory myofibroblastic tumors are extremely rare, with no reports of their preoperative diagnosis. A 17-year-old woman who presented with low-grade fever, repeated diarrhea, constipation, and a 1-month history of anal pain was referred to our hospital. Rectal examination revealed a palpable hard mass with a smooth surface at the posterior wall 4 cm from the anal verge. Colonoscopy revealed a 4.0-cm submucosal tumor in the upper edge of the anal canal. Computed tomography and magnetic resonance imaging revealed a 5.0 × 4.0 cm-sized well-defined tumor contacting the rectum. Computed tomography-guided biopsy was performed, and an inflammatory myofibroblastic tumor was diagnosed. There have been no reports of surgery for a rectal inflammatory myofibroblastic tumor using transanal total mesorectal excision. We preoperatively diagnosed the patient with an inflammatory myofibroblastic tumor in the lower rectum and achieved anorectal preservation and curative resection with transanal total mesorectal excision, providing good view of the deep pelvis.

The anorectal defaecation reflex: a prospective intervention study

AIM

Our hypothesis is that there may be a neural pathway with sensory afferent neurons in the anal canal that leads to rectal contraction to assist defaecation. We aimed to compare rectal motility between healthy participants with or without anal anaesthesia.

METHOD

This prospective intervention study consisted of two test sessions: a baseline session followed by an identical second session. During each session we performed the anal electrosensitivity test, the rectoanal inhibitory reflex test and rapid phasic barostat distensions. Prior to the second session, participants were randomly assigned to receive either a local anal anaesthetic or a placebo.

RESULTS

We included 23 healthy participants aged 21.1 ± 0.5 years, 13 of whom received an anal anaesthetic and 10 a placebo. All participants showed a transient rectal contraction during the first test session, which decreased significantly after anal anaesthesia (18.6 ml vs. 4.9 ml, p = 0.019). The maximum rectal contraction was comparable to the baseline results in the placebo group. Furthermore, the electrosensitivity at the highest centimetre of the anal canal correlated with the maximum rectal contraction (r = -0.452, p = 0.045).

CONCLUSION

All healthy study participants display an involuntary, reproducible rectal reflex contraction that appears to be innervated by afferent nerves in the proximal anal canal. The rectal reflex contraction appears to play a role in defaecation and we therefore refer to this phenomenon as the anorectal defaecation reflex. Knowledge of the anorectal defaecation reflex may have consequences for the diagnostics and treatment of constipation.

Human Papillomavirus-Associated Lymphoepithelioma-Like Carcinoma of the Anal Canal: A Case Report and Literature Review

Lymphoepithelioma-like carcinoma is a rare type of tumor that is histologically identical to lymphoepithelial carcinoma of the nasopharynx. Lymphoepithelioma-like carcinomas (LELCs) are closely associated with viral infections. Human papillomavirus (HPV)-associated LELCs have been reported in a variety of anatomic sites. We reported an extremely rare case of a 25-year-old woman with LELC derived from the anal canal, which is the second case reported at this site. The tumor was diffusely positive for p16 staining, and was correlated with high-risk HPV-16; Epstein-Barr virus-encoded small RNA was negative; PD-L1 positivity and abundant CD8+ T cell infiltration were observed, indicating a “hot” immune microenvironment. In reporting this case, we highlight the potential for misdiagnosis and suggested an association of HPV infection with LELC in the anal canal.

Clinical Quiz-A Rare Case of Anal Canal Duplication in the Context of Currarino Syndrome

Currarino syndrome (CS) is a rare condition that presents with any combination of a sacral defect, a presacral mass, and an anorectal malformation. This collection, referred to as Currarino's triad, may not necessarily present as all three abnormalities in the diagnosis of the syndrome. Anal canal duplication (ACD) is an even rarer occurrence. We present a case that lies on the CS spectrum with an associated ACD and discuss a complex surgical challenge that necessitated a customized management plan, devised through a multidisciplinary approach.

Malignant Degeneration to Leiomyosarcoma of the Anorectal Junction Invading the Prostate

While colonic leiomyomas are common, leiomyosarcomas of the GI tract are rare. Increased mitotic rate, as well as lymph node involvement, portend a worse prognosis in leiomyosarcomas. They can arise anywhere along the GI tract, but anal canal occurrence is extremely rare. We present the case of a 75-year-old male diagnosed eight years prior with leiomyoma of the anorectal junction. There was a recurrence after endoscopic resection. He was referred to colorectal surgery due to symptoms of bleeding, skin irritation, anal pruritus, and rectal pain. On exam, he had a palpable mass at the dentate line. Workup revealed a 3.5 cm mass at the anorectal junction with pathology showing a leiomyosarcoma with moderate atypia and a high mitotic rate. MRI revealed invasion into the prostate. Robotic pelvic exenteration, including cystoprostatectomy, abdominoperineal resection, and ileal conduit, was performed. Final pathology results showed a grade 2 leiomyosarcoma invading the prostate and skeletal muscle and incidentally found Gleason 3+4 prostate cancer, pT2.  A very small percentage of anorectal leiomyosarcoma cases were located in the anal canal. Surgery remains the best curative option, as chemotherapy and radiation data are limited. This rare tumor, which previously has not been documented to have degenerated from a benign rectal leiomyoma, was diagnosed as a result of close monitoring after previous local resections and cured by local resection and radiation.

Colonic disease recurrence following proctectomy with end colostomy for anorectal Crohn's disease

AIM

In patients with anorectal Crohn's disease, it remains uncertain whether a total proctocolectomy with end ileostomy or proctectomy with end colostomy should be recommended due to the unknown rate of disease recurrence in the remaining colon.

METHODS

A retrospective review of all patients with a known diagnosis of Crohn's disease who underwent a proctectomy with end colostomy for distal Crohn's disease between January 1, 2010 and January 1, 2019 at two IBD referral centres was conducted. Data collected included patient demographics, surgical variables at the time of proctectomy, and postoperative clinical, endoscopic and surgical recurrence rates.

RESULTS

A total of 63 patients were included; mean age was 47 years (SD 15 years) and 32 (50.8%) were female. The majority of patients underwent a proctectomy with end colostomy (n = 56; 88.9%) while the remaining seven patients (11.1%) underwent a proctectomy with end colostomy and concurrent ileocectomy. A total of 55 patients (87.3%) had proctitis, 51 (81%) had perianal fistulating disease, and 34 (54%) had anal canal stenosis or ulceration. Most patients had medically refractory disease (n = 54; 85.7%) versus neoplasia (n = 9; 14.3%). The median length of long-term follow-up was 17.7 months (IQR: 4.72, 38.7 months). During that time, 14 (22.2%) experienced clinical recurrence, 10 of 34 evaluated (29.4%) had endoscopic recurrence, and 3 (4.76%) required a completion total abdominal colectomy for recurrent medically refractory disease in the colon.

CONCLUSION

Colonic recurrence remains low following proctectomy and descending colostomy suggesting this operative management strategy is reasonable in Crohn's patients with distal disease.

Late Gastrointestinal Tolerance After Prostate Radiotherapy: Is the Anal Canal the Culprit? A Narrative Critical Review

Introduction

Late gastro-intestinal toxicities (LGIT) secondary to pelvic radiotherapy (RT) are well described in the literature. LGIT are mainly related to rectal or ano-rectal irradiation; however, involvement of the anal canal (AC) in the occurrence of LGIT remains poorly described and understood.

Materials and Methods

The aim of this work was to explore the potential role of the AC in the development of LGIT after prostate irradiation and identify predictive factors that could be optimized in order to limit these toxicities. This narrative literature review was realized using the Pubmed database. We identified original articles published between June 1997 and July 2019, relating to LGIT after RT for localized prostate cancer and for which AC was identified independently. Articles defining the AC as part of an anorectal or rectal volume only were excluded.

Results

A history of abdominal surgery or cardio-vascular risk, anticoagulant or tobacco use, and the occurrence of acute GIT during RT increases the risk of LGIT. A dose-effect relationship was identified between dose to the AC and development of LGIT. Identification and contouring of the AC and adjacent anatomical structures (muscles or nerves) are justified to apply specific dose constraints. As a limitation, our review mainly considered on 3DCRT which is no longer the standard of care nowadays; we did not identify any reports in the literature using moderately hypofractionated RT for the prostate and AC specific dosimetry.

Conclusion

These results suggest that the AC may have an important role in the development of LGIT after pelvic RT for prostate cancer. The individualization of the AC during planning should be recommended in prospective studies.

A Rare Case of Primary Anorectal Malignant Melanoma

Malignant melanoma affecting the anorectum is very rare. We present a 63-year-old female who presented with features of bleeding per rectum and painful defecation. On examination, the patient had a palpable mass on the right side of the anorectum, with predominant exophytic growth and intraluminal extension. Biopsy and imaging studies were diagnostic of malignant melanoma. The patient was discussed on the tumor board and planned for abdominoperineal resection. Postoperatively, the patient was started on chemotherapy. The patient was followed up for two years, and there was no evidence of any recurrence.

Widespread anorectal lymphovascular networks and tissue drainage: analyses from submucosal India ink injection and indocyanine green fluorescence imaging

AIM

Abdominoperineal resection is associated with poor prognosis in patients with advanced lower rectal cancer. This study aimed to analyse the functional lymphovascular network and tissue drainage in the anorectal region.

METHODS

In this descriptive study, we performed microanatomical evaluations and intra-operative imaging analysis in a cadaver and patients with rectal cancer. Specimens with India ink injection were collected from a cadaver and from six patients who underwent abdominoperineal resection. Intra-operative indocyanine green fluorescence imaging was performed on four patients who underwent surgery for lower rectal cancer. India ink was injected into the submucosa at the dentate line of specimens. Tissue sections were examined by immunohistochemistry for D2-40 and CD31. Intra-operative indocyanine green was injected into the submucosa at the dentate line. Lymph flow was traced using a near-infrared camera system.

RESULTS

Fascia branching from the rectal longitudinal muscle layer extended to the posterior hiatal ligament and lateral endopelvic fascia connective tissue lamina on the surface of the levator ani muscle. The fascia contained veins labelled with ink in their lumina and initial lymphatics. Intra-operative indocyanine green fluorescence imaging revealed extensive lymph flow from the muscle layer of the anal canal to the hiatal ligament and endopelvic fascia along the longitudinal muscle layer fibres.

CONCLUSIONS

The anorectal region contained widespread venous and lymphatic networks in proportion to its specific connective tissue framework around the longitudinal-muscle-layer-extending muscle bundles, which provides extensive networks for tissue fluid and cells.

Rectal damage control: when to do and not to do

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

Clinical, endoscopic and histological profile of colorectal cancers seen on colonoscopy in Kano, North-Western Nigeria

Background

Colorectal cancer (CRC) is the most prevalent gastrointestinal (GI) cancer. With 5% risk of developing CRC in life, it became the third leading cause of cancer death in developed nations. In Nigeria, it is the most common GI cancer. However, there are limited data on CRC in the study area (North-Western part of Nigeria). The aim of this study was to identify the clinical, endoscopic and histological profile of CRC seen on colonoscopy.

Methodology

This was a retrospective descriptive study where colonoscopic and histological records of suspected CRC in the study centre between January 2008 to December 2017 were evaluated.

Results

Records of 135 patients were reviewed, and males constituted 63.7%. The mean age was 46.61 ± 16.80 years, with 30-39 years as a modal group. Common presentations were diarrhoea (86.7%) and bleeding per rectum (68.9%). Areas affected were rectosigmoid colon (63%), ascending colon (14.1%), descending colon (8.9%), transverse colon (7.4%) and anal canal (6.7%). Histologically, adenocarcinoma was reported in 57.8%, mucinous adenocarcinoma in 8.1% and signet ring cell adenocarcinoma in 3.7%. Tubular and villous adenomas were 3% each. Others were carcinoid tumours (1.5%), metastatic adenocarcinoma, squamous cell carcinoma, basal cell carcinoma, GI stromal tumour, inflammatory myofibroblastic tumour, angiosarcoma and adenoid cyst carcinoma reported in 0.7% each.

Conclusion

Majority of the patients with CRC were in their young age. The most common presentations were diarrhoea, weight loss and anaemia. The most common site of affectation was in the left colon, while the most common histological finding was adenocarcinoma.

Clinical-epidemiological review 2000-2019

INTRODUCTION

Anal cancer is a rare pathology which has increased over the last few decades, and, therefore, gained importance for the quality of life of affected individuals. Thus, a review has been conducted in the Colombian coffee region (Departments of Caldas, Quindío y Risaralda) describing its behaviour and clinical-epidemiological profile.

MATERIALS AND METHODS

Descriptive review of 437 patients of Western SAS Oncologists between January 2000 and December 2019 with a diagnosis of anal cancer.

RESULTS

62% of cases presented in women with a median age of 62 years, 30% in the sixth decade; centred at 65% in three main cities designated as capitals (Manizales, Pereira and Armenia); 62% as localised disease, with 40% stage II-A and 6% as initial metastasis; 29% presented positive ganglia, particularly N1a; squamous cell or epidermoid histology in 90%; 16% poorly differentiated; 5% related to Human Immunodeficiency Virus infection; localisation in the medial area of the anal canal in 63% of cases; 83% completed treatment, and 92% of them received chemotherapy/radiation therapy with 87% based on the Nigro protocol; finally, 11% presented with relapse in the liver in 10% of cases and 55% local.

CONCLUSION

Four hundred and thirty-seven patients evaluated over 20 years with follow up at median 34.13 months (standard deviation 41.75) with median survival at later ages decreasing to 62% in patients older than 80 years, and differences in survival in localised disease at 78% in comparison to 46% in advanced metastasis. Finally, the overall 5-year survival rate is 69% with a median survival of 191 months in the study.

High-grade neuroendocrine small-cell carcinoma of the anal canal: Long-term remission with chemoradiotherapy

Primary small-cell carcinoma of the anal canal is an exceedingly rare tumor with a poor prognosis even when aggressive therapy is initiated. We present the case of a 53-year-old male patient who presented with chronic anal pain. Examination under general anesthesia revealed the presence of a mass in the anal canal. A biopsy was performed, and histopathological examination showed a high-grade neuroendocrine small-cell carcinoma. Assessment with endoscopic ultrasound showed an invasion of the internal anal sphincter. The patient was treated with a chemoradiotherapy (CRT) regimen consisting of cisplatin and etoposide, combined to radiotherapy. The patient achieved long-term remission with CRT. This is one of the first reports in the literature of a case of a high-grade neuroendocrine small-cell carcinoma of the anal canal where long-term remission was achieved with non-surgical management of a tumor invading the anal sphincter. This favorable evolution with CRT suggests that remission could still be achieved with anal small-cell carcinomas. More cases are however required to validate this approach.

RELEVANCE FOR PATIENTS

This case presentation suggests that long-term remission can still be achieved using CRT and without an extensive surgical resection in patients with small-cell carcinoma of the anal canal.

Long-term results from modified sphincteroplasty in patients with traumatic sphincter injury: a retrospective study

BACKGROUND

The results from sphincteroplasty may worsen over time. Reseparation of the rectum and vagina/scrotum in conjunction with sphincteroplasty achieves good results. Improving the surgical effect of sphincteroplasty through perineal body reconstruction is crucial.

OBJECTIVE

To evaluate the long-term results from anterior sphincteroplasty and perineal body reconstruction (modified sphincteroplasty) among patients with traumatic sphincter injury.

DESIGN AND SETTING

Retrospective study among patients who underwent modified sphincteroplasty in a university hospital between January 2006 and December 2018. Fifty patients were evaluated in detail.

METHODS

The following variables were evaluated: gender, age, additional disease status, time interval between trauma and surgery, surgical technique, duration of hospitalization, follow-up period after surgery, manometric values, electromyography results, magnetic resonance imaging scans, Wexner scores, satisfaction levels with surgery and surgical outcomes.

RESULTS

The patients' mean age was 44.6 ± 15.1 years. The median follow-up period was 62 months (range, 12-118). The mean Wexner scores preoperatively, postoperatively in first month (M1S) and at the time of this report (AAS) were 15.5 ± 3.2, 1.9 ± 3.15 and 3.9 ± 5.3, respectively. Although improvements in the patients' mean Wexner scores became impaired over time, the postoperative Wexner scores were still significantly better than the preoperative Wexner scores (P = 0.001).

CONCLUSION

Good or excellent results were obtained surgically among patients with traumatic sphincter injury. Performing perineal body reconstruction in addition to sphincteroplasty can provide better long-term continence. Surgical outcomes were found to be better, especially among patients younger than 50 years of age and among patients who underwent surgery within the first five years after trauma.

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

Introduction

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

Materials and methods

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

Results

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

Conclusions

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

Prevalence of high-risk human papilloma virus infection and abnormal cytology of the anal transformation zone in women with cervical dysplasia. Bogotá, Colombia, 2017-2019

OBJECTIVE

To determine the prevalence of anal infection caused by high risk human papilloma virus (HR-HPV) and of abnormal anal cytology in women with confirmed cervical dysplasia.

METHODS

Cross sectional study that included patients between 30 and 65 years of age with a new diagnosis of cervical dysplasia by histopathology attended in two lower genital tract colposcopy and pathology units (one public and one private institution), conducted between December 2017 and April 2019. Women with human immunodeficiency virus (HIV) infection, immune compromise (use of steroids, transplant, chemo therapy), pregnancy or anorectal malformations were excluded. Consecutive sampling. Socio demographic variables, intercourse type, degree of cervical dysplasia, positive results of HR HPV Polymerase Chain Reaction test in anal canal and HR - HPV type indentified (16-18 or others) were evaluated. Descriptive statistics were used.

RESULTS

Of 188 candidates, 100 were included in the analysis. A 32 % prevalence of high-risk HPV infection and a 2.8 % prevalence of abnormal cytology in the anal canal (ASCUS) were found. Of the HR-HPV infections in the anal canal, 68.8 % corresponded to HR-HPV genotypes different from 16 or 18.

CONCLUSIONS

Prevalence of HR HPV infection in women with lower genital tract dysplasia was 32%. It is important to determine the usefulness of screening for anal mucosa compromise by HPV virus associated with a high risk of cancer in women with cervical dysplasia. Studies are needed on the prognosis of anal HR-HPV infection in women with cervical dysplasia.

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

BACKGROUND

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

METHODS

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

KEY RESULTS

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

CONCLUSIONS AND INFERENCES

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

The use of impedance planimetry (Endoscopic Functional Lumen Imaging Probe, EndoFLIP® ) in the gastrointestinal tract: A systematic review

BACKGROUND AND PURPOSE

The EndoFLIP® system is a method of delineating impedance and was first designed to investigate the characteristics of the esophago-gastric junction. In the last decade, its use was widened to investigate other sphincteric and non-sphincteric systems of the gastrointestinal tract. The objective of the present systematic review was to summarize the available data in literature on the use of the EndoFLIP® system in the gastrointestinal tract, including sphincteric and non-sphincteric regions. We performed a systematic review in accordance with recommendations for systematic review using PRISMA guidelines without date restriction, until June 2020, using MEDLINE-PubMed, Cochrane Library, and Google Scholar databases. Only articles written in English were included in the present review. Five hundred and six unique citations were identified from all database combined. Of those, 95 met the inclusion criteria. There was a lack of standardization among studies in terms of anesthetic drugs use, probe placement, and inflation protocol. In most cases, only small cohorts of patients were included. Most studies investigated the EGJ, with a potential use of the EndoFLIP® to identify a subgroup of patients with achalasia and for intraoperative assessment of treatment efficacy in achalasia. However, the use of EndoFLIP® in the esophageal body (esophageal panometry), other esophageal diseases (gastro-esophageal reflux disease, eosinophilic esophagitis), and other sphincter regions (anal canal, pylorus) will need further confirmatory studies. The EndoFLIP® system provides detailed geometric data of the gastrointestinal lumen but further works are needed to determine its use in clinical practice.

Smooth muscle of the male pelvic floor: An anatomic study

Knowledge of the anatomy of the male pelvic floor is important to avoid damaging the pelvic floor muscles during surgery. We set out to explore the structure and innervation of the smooth muscle (SM) of the whole pelvic floor using male fetuses. We removed en-bloc the entire pelvis of three male fetuses. The specimens were serially sectioned before being stained with Masson's trichrome and hematoxylin and eosin, and immunostained for SMs, and somatic, adrenergic, sensory and nitrergic nerve fibers. Slides were digitized for three-dimensional reconstruction. We individualized a middle compartment that contains SM cells. This compartment is in close relation with the levator ani muscle (LAM), rectum, and urethra. We describe a posterior part of the middle compartment posterior to the rectal wall and an anterior part anterior to the rectal wall. The anterior part is split into (1) a centro-levator area of SM cells localized between the right and left LAM, (2) an endo-levator area that upholsters the internal aspect of the LAM, and (3) an infra-levator area below the LAM. All these areas are innervated by autonomic nerves coming from the inferior hypogastric plexus. The core and the infra-levator area receive the cavernous nerve and nerves supplying the urethra. We thus demonstrate that these muscular structures are smooth and under autonomic influence. These findings are relevant for the pelvic surgeon, and especially the urologist, during radical prostatectomy, abdominoperineal resection and intersphincteric resection. Clin. Anat., 2019. © 2019 Wiley Periodicals, Inc.

Association of Hemorrhoid Vascular Injuries with Cigarette Smoking-An Evaluation with Interesting Prospects

Background  Hemorrhoids are vascular structures in the anal canal which are seldom used to evaluate vascular diseases. Cigarette smoking is well-known to cause both arterial and venous vascular injuries. However, the impact of smoking on hemorrhoid vasculature is unknown.

Objective  Considering that vasculature in the hemorrhoids has the same anatomy and pathophysiology of vascular damage as other systemic vasculatures, we conducted this study to evaluate the relation between smoking and incidence of hemorrhoidal vascular injury.

Design and Data Analysis  Retrospective review of all the screening colonoscopies performed at our Department of Gastroenterology (predominantly serving urban minority population) over 3 years was conducted and patients with recorded smoking history were included in the study ( n  = 242). Fisher's exact test with two-tailed p -value and odds ratio were used to evaluate for the association between smoking and incidence of hemorrhoids.

Results  We studied 242 subjects and found statistically significant association between smoking and hemorrhoids ( p  < 0.05) with the risk of developing hemorrhoids among smokers being 2.4 times that of a nonsmoker. We further noted no significant difference in the incidence of hemorrhoidal vascular injuries between the past versus current smokers and male versus female smokers.

Conclusion  This is one of the first studies to establish an association between smoking and hemorrhoids. Our study shows that the hemorrhoidal vasculature is impacted by smoking similar to other vascular systems. This study sheds light on the possibility of evaluating hemorrhoids for clues of other systemic and gastrointestinal vascular damage. This correlation can add clinical value especially given the flexibility of assessing hemorrhoids as an outpatient in a cost effective and comfortable manner.

Natural History of Anal Squamous Intraepithelial Lesions in HIV-Positive Men with Normal Baseline Cytology

The natural history of squamous intraepithelial lesions (SILs) in the anal canal of HIV-infected men is incompletely understood. We assessed the incidence and factors associated with SIL and invasive anal squamous cell carcinoma (IASCC) among HIV-infected men with normal cytology at baseline. We performed a single-center prospective cohort study [men who have sex with men (MSM) and men who have sex with women (MSW)]. The incidence of anal canal SIL (low grade and high grade) and IASCC were estimated and predictive factors analyzed. The study population comprised 297 HIV-infected men with a normal cytology result and no anal human papillomavirus (HPV)-related diseases. Of these, 251 (85%) had at least one evaluable set of cytology data during follow-up (172 MSM, 79 MSW). The median follow-up time was 4 years. The cumulative incidence of SIL was 43% (107/251): 52% in MSM (90/172) and 22% in MSW (17/79), p < 0.0001. The incidence rate of SILs was 109 (95% confidence interval = 90-132) per 1000 person-years: 142 in MSM and 49 in MSW, p < 0.0001. HPV infection, receiving antiretroviral treatment (ART), and being MSM were independently associated risk factors. The incidence of IASCC was 0.15 per 1000 person-years among MSM and 0 in MSW. HIV-infected men, both MSM and MSW, are at high risk of developing SIL despite having a normal anal cytology at baseline. The incidence of anal canal SIL was higher among MSM, but was also remarkable among MSW. Independent risk factors associated with SIL were being HIV-infected MSM at high risk for acquisition of STIs, time on ART, and HPV infection.

Coexistence of Dense and Sparse Areas in the Longitudinal Smooth Muscle of the Anal Canal: Anatomical and Histological Analyses Inspired by Magnetic Resonance Images

Magnetic resonance images of the anal canal show small, circular, low‐intensity areas arranged in a row and a high‐intensity area surrounding them internally and externally in the longitudinal muscle layer that cannot be explained by current anatomical findings. The purpose of this study was to elucidate the detailed structure of the longitudinal smooth muscle of the anal canal and to interpret the magnetic resonance image of the longitudinal muscle. Specimens for macroscopic anatomy and histology were obtained from six and seven cadavers, respectively. The histological nature of the longitudinal muscle was examined by staining serial transverse and coronal sections of the lateral wall of the anal canal with Masson's trichrome stain and using immunohistochemistry for smooth and skeletal muscle fibers. Dense and sparse areas of smooth muscle fibers coexisted in the longitudinal muscle layer. The dense areas formed columnar muscle bundles approximately 1.0–1.5 mm in diameter, and they continued from the longitudinal muscle bundles of the rectum. The columnar muscle bundles of the longitudinal anal muscle were internally and externally surrounded by sparsely arranged smooth muscle fibers that ran longitudinally. The coexistence of dense and sparse areas of smooth muscle fibers suggests that the structure of the smooth muscle is optimized for its function. This histological nature is probably reflected in the magnetic resonance image of the longitudinal muscle as the coexistence of low‐ and high‐intensity areas. Clin. Anat. 33:619–626, 2020. © 2019 Wiley Periodicals, Inc.

Mitomycin and 5-fluorouracil for second-line treatment of metastatic squamous cell carcinomas of the anal canal

Background

Metastatic squamous cell carcinomas (SCC) of the anal canal are rare and there is no international consensus on their second‐line management. 5‐Fluorouracil (5‐FU) and mitomycin in combination with radiotherapy is the standard for locally advanced forms but its efficacy in metastatic stage has never been evaluated.

Patients and methods

We report a retrospective analysis of patients treated with 5‐FU and mitomycin from 2000 to 2017 in our institution for a metastatic SCC of the anal canal after failure of platinum‐based regimen. The main outcome was progression‐free survival (PFS) and the secondary outcomes were overall survival (OS), response rate, and toxicity.

Results

Nineteen patients, 15 women and four men, with a median age of 57 years were identified (range, 40‐79 years). Patients received a median of three cycles (1‐7) of mitomycin 5‐FU. A dose reduction was necessary in six patients (31.6%), one patient had to discontinue treatment following toxicity and no death was due to treatment toxicity was reported. An objective response was observed in five patients (26.4%, 95% CI 6.6‐46.2) including one complete response, six patients (31.6%, 95% CI 10.7‐52.5) showed tumor stabilization. Median PFS and OS were 3 months [95% CI 1‐5] and 7 months [95% CI 2.2‐11.8]. Responder had a median duration of response of 4 months [95% CI 1.8‐6.1] and one patient had 23 months duration of response. No significant difference was noted for PFS and OS for patients previously treated with mitomycin and 5‐FU at a local stage.

Conclusion

Mitomycin and 5‐FU regimen provides tumor control with acceptable tolerance. It is an option for patients with metastatic SCC of the anal canal after failure of platinum‐based chemotherapy. [Correction added on 9 October 2019, after first online publication: '5‐FU' was inadvertently removed from the Results and Conclusion and has now been added to the text.]

Prevalence and incidence of anal human papillomavirus infection in Mexican men: Need for universal prevention policies

OBJECTIVE

Describe the natural history of anal HPV among men.

MATERIALS AND METHODS

Prospective study among men 18-70 years (n=665), from Cuernavaca, Mexico who completed questionnaires and provided specimens (HPV genotyped) at enrollment and 1+ follow-up visit. HPV prevalence and incidence were estimated. Prevalence ratios were calculated with Poisson regression using robust variance estimation. Person-time for incident HPV infection was estimated using number of events modeled as Poisson variable for total person-months.

RESULTS

Anal infection prevalence: any HPV type=15%, high-risk=8.4%, HPV16=1.4%, tetravalent vaccine types (4vHPV)=4.4%, nonavalent vaccine types (9vHPV)=6.3%. Factors associated with prevalence: 50+ lifetime female sex partners (adjusted prevalence ratio, a PR=3.25, 95% CI:1.12- 9.47), 10+ lifetime male sex partners (aPR=3.06, 95%CI:1.4- 6.68), and 1+ recent male anal sex partners (aPR=2.28, 95%CI:1.15-4.5). Anal incidence rate: high-risk HPV=7.8/1000 person-months (95%CI:6.0-10.1), HPV16=1.8/1000 personmonths (95%CI:1.1-2.9),4vHPV=3.4/1000 person-months (95%CI:2.3-4.9) and 9vHPV=5.5/1000 person-months (95%CI:4.1-7.5).

CONCLUSIONS

Implementation of universal HPV vaccination programs, including men, is a public health priority.

MRI anatomy and pathology of the anal canal

The normal function of the anal sphincter complex is crucial for quality of life, as it is the mechanism by which fecal continence is maintained. Additionally, the anal sphincter complex is an integral part of the coordinated effort of defecation. As imaging plays an important role in assessment of pathologic conditions involving the anal region, understanding the normal anatomy of the anal sphincter complex is important for correct image interpretation and accurate diagnosis. This review discusses the anatomy and function of the anal sphincter complex, important technical considerations for MRI, and various inflammatory, infectious, and neoplastic processes, as well as pathologic structural conditions that affect the anal region. Level of Evidence: 5 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;50:1018-1032.

High Prevalence of Human Papillomavirus on Anal and Oral Samples from Men and Women with External Anogenital Warts: The HERCOLES Study

Human papillomavirus (HPV) infection is highly prevalent in the sexually active population. This study estimates the prevalence of HPV DNA in anal and oral samples from a cohort of men and women with incident anogenital warts. Anal and/or oral samples from 541 patients with anogenital warts were tested for 35 HPV genotypes using a PCR assay. The overall prevalence of anal HPV and oral HPV DNA was 59.9% (n = 305/509; 95% confidence interval (CI) 55.6-64.1%) and 14.5% (n = 78/538; 95% CI 11.8-17.7%), respectively. Among patients with perianal warts, the anal HPV DNA prevalence was 92.3% (95% CI 87.0-95.5%). Anal HPV DNA prevalence in patients with genital warts but no perianal warts was 55.7% (95% CI 50.6-60.7%). Both anal and oral HPV infections were more common in men who have sex with men than in heterosexual men (90.4% versus 38.5% and 20.8% versus 11.8%, respectively). Anal high risk-HPV infection was more common in women (58.8%) and in men who have sex with men (67.7%). We found that anogenital warts represent a clinical marker for both anal and oral HPV infections, including anal high risk-HPV infections, particularly among women and men who have sex with men.

Three Tesla Multiparametric Magnetic Resonance Imaging: Comparison of Performance with and without Endorectal Coil for Prostate Cancer Detection, PI-RADS™ version 2 Category and Staging with Whole Mount Histopathology Correlation

PURPOSE

We investigated the performance of 3 Tesla multiparametric magnetic resonance imaging with and without an endorectal coil to detect prostate cancer with a whole mount histopathology reference.

MATERIALS AND METHODS

This retrospective HIPAA (Health Insurance Portability and Accountability Act) compliant, institutional review board approved, case-control study included patients who underwent 3 Tesla multiparametric magnetic resonance imaging with and without an endorectal coil from July 2009 to December 2016 prior to prostatectomy. The tumor detection rate was calculated for total and index lesions. Lesion magnetic resonance imaging and histopathology features were compared between the 2 groups. Using SPSS®, version 24 p <0.05 was considered significant.

RESULTS

A total of 871 whole mount histopathology lesions in 429 patients with a mean ± SD age of 61.8 ± 7 years were included in analysis. The subcohorts with and without an endorectal coil comprised 260 and 169 patients with a total of 529 and 342 lesions, respectively. The overall tumor detection rates in all patients, and in the endorectal coil and nonendorectal coil subcohorts were 49.6% (432 of 871 patients), 50.5% (267 of 529) and 48.2% (165 of 342), respectively. The index tumor detection rates overall, and in the endorectal coil and nonendorectal coil subcohorts were 77.6% (333 of 429 patients), 78.5% (204 of 260) and 76.3% (129 of 169), respectively. In the endorectal coil and nonendorectal coil subcohorts we detected 35.9% (66 of 184) and 48.4% (76 of 157) of anterior lesions (p = 0.019), 58% (200 of 345) and 48.1% (89 of 185) of posterior lesions (p = 0.025), 37.3% (41 of 110) and 54.4% (62 of 114) of transition zone lesions (p = 0.010), and 53.7% (225 of 419) and 45.2% (103 of 228) of peripheral lesions (p = 0.033), respectively. After adjusting for clinical and pathological factors the endorectal coil group only showed higher detection of peripheral and posterior prostate cancer.

CONCLUSIONS

We found that 3 Tesla multiparametric magnetic resonance imaging with and without an endorectal coil had similar detection of overall and index prostate cancer. However, the endorectal coil subcohort had significantly higher detection of posterior and peripheral prostate cancer, and lower detection of anterior and transition zone prostate cancer.

Anatomy of the smooth muscle structure in the female anorectal anterior wall: convergence and anterior extension of the internal anal sphincter and longitudinal muscle

AIM

The anatomy of the region between the vagina and anal canal plays an essential role when performing a proctectomy for low-lying tumours. However, the anatomical characteristics of this area remain unclear. The purpose of the present study was to clarify the configuration, and both lateral and inferior extensions, of the muscle bundles in the anorectal anterior wall in females.

METHODS

Using cadaveric specimens, macroscopic anatomical and histological evaluations were conducted at the anatomy department of our institute. Macroscopic anatomical specimens were obtained from six female cadavers. Histological specimens were obtained from eight female cadavers.

RESULTS

The smooth muscle fibres of the internal anal sphincter and longitudinal muscle extended anteriorly in the anorectal anterior wall of females and the muscle bundles showed a convergent structure. The anterior extending smooth muscle fibres merged into the vaginal smooth muscle layer, distributed subcutaneously in the vaginal vestibule and perineum and spread to cover the anterior surface of the external anal sphincter and the levator ani muscle. Relatively sparse space was observed in the region anterolateral to the rectum on histological analysis.

CONCLUSION

Smooth muscle fibres of the rectum and vagina are intermingled in the median plane, and there is relatively sparse space in the region anterolateral to the rectum. Therefore, when detaching the anorectal canal from the vagina during proctectomy, an approach from both the lateral sides should be used.

A CARE-compliant article: a case report of primary adenocarcinoma of the anal glands: Review of literature

RATIONALE

Adenocarcinoma of the anal canal is an uncommon malignancy. Primary adenocarcinoma, in particular, is extremely rare.

PATIENT CONCERNS

A 61-year-old man was referred to our institution with complaints of repeated hematochezia.

DIAGNOSIS

Digital rectal examination revealed a hard palpable ulcer in the anal canal, measuring 2 cm × 2 cm in size, at the 5 o'clock direction (in the lithotomy position). The pelvic enhanced magnetic resonance imaging revealed anal verge occupying mass. A diagnosis of carcinoma of the anal canal was considered. Colonoscopic examination revealed a poorly differentiated adenocarcinoma of the anal canal.

INTERVENTIONS

The patient underwent abdominoperineal resection (APR) of the rectum, and was administered 6 courses of adjuvant chemotherapy with mFOLFOX.

OUTCOMES

The patient was followed up for more than 1 year after operation, and no local recurrence or distant metastasis occurred.

LESSONS

The diagnosis and treatment of this disease is still a huge challenge because its incidence is very low. A study of more cases is required for uniformity in diagnosis and for the development of treatment protocols.

JOURNAL CLUB: Primary Anorectal Melanoma: MRI Findings and Clinicopathologic Correlations

OBJECTIVE

The purpose of this study is to evaluate the MRI features of primary anorectal malignant melanoma and to correlate these features with its clinical and pathologic characteristics.

MATERIALS AND METHODS

The medical records of 12 patients (five men and seven women; mean age [± SD], 60.8 ± 10.0 years) with pathologically proven primary anorectal melanoma were retrospectively reviewed. MRI findings were analyzed to determine the shape, size, distance from the anal verge, presence of perirectal or anal infiltration, signal intensity on T1- and T2-weighted images, presence of diffusion restriction, contrast enhancement pattern of the lesion, presence of lymphadenopathy, and occurrence of bowel obstruction. Subsequent follow-up data for the patients were recorded.

RESULTS

The most common presentation was hematochezia (41.7% of patients). Common findings on MRI included a large intraluminal polypoid mass (75.0% of lesions) with little perirectal or anal infiltration (100.0%), T1 hyperintensity (66.7%), high T2 signal intensity (54.5%) or mixed T2 signal intensity (45.5%), restricted diffusion (100.0%), and hyper-enhancement (100.0%). The mean length, width, and depth of these masses were 3.5, 2.9, and 2.3 cm, respectively. The mean distance from the anal verge was 1.8 cm. Lymphadenopathy was frequently identified (75.0% of cases), with lymph nodes larger than 2 cm noted in 28.5% of cases and most commonly involving the perirectal area (77.8% of cases). No colonic obstructions were observed. The mean patient follow-up was 32.7 months. A total of 25.0% of patients died as a result of disease progression.

CONCLUSION

The possibility of the presence of anorectal melanoma should be considered for patients with a bulky intraluminal polypoid mass in the anorectum without colonic obstruction, with the mass showing T1 hyperintensity, high or mixed signal T2 intensity, hyperenhancement, minimal perirectal or anal infiltration, and lymphadenopathy.

A Comparative Immunohistochemical Study of Anal Canal Epithelium in Humans and Swine, Focusing on the Anal Transitional Zone Epithelium and the Anal Glands

To better understand the cellular origins and differentiation of anal canal epithelial neoplasms, the immunohistochemical profiles of the anal canal epithelium in humans and swine were evaluated. Formalin-fixed tissue sections were immunostained for mucin (MUC: MUC2, MUC5AC, MUC5B), desmoglein 3 (DGS3), p63, CDX2, SOX2, and α-smooth muscle actin (α-SMA). The anal transitional zone (ATZ) epithelium covered the anal sinus and consisted of a stratified epithelium with mucous cells interspersed within the surface lining. Anal glands opened into the anal sinus. Ducts and acini of intraepithelial or periepithelial mucous type were the main structures of human anal glands, whereas those of swine were compound tubuloacinar mixed glands. Distal to the ATZ epithelium, non-keratinized stratified squamous epithelium merged with the keratinized stratified squamous epithelium of the perianal skin. MUC5AC expression predominated over MUC5B expression in the ATZ epithelium, while MUC5B expression was higher in the anal glands. SOX2 was positive in the ATZ epithelium, anal glands, and squamous epithelium except in the perianal skin. In humans, DGS3 was expressed in the ATZ epithelium, anal gland ducts, and squamous epithelium. p63 was detected in the ATZ epithelium, anal glands, and squamous epithelium. Myoepithelial cells positive for α-SMA and p63 were present in the anal glands of swine. Colorectal columnar cells were MUC5B⁺ /MUC2⁺ /CDX2⁺ /MUC5AC^- /SOX2^- . The ATZ epithelium seems to be a distinctive epithelium, with morphological and functional features allowing smooth defecation. The MUC5AC⁺ /SOX2⁺ /MUC2^- /CDX2^- profile of the ATZ epithelium and anal glands is a useful feature for diagnosing adenocarcinoma arising from these regions. Anat Rec, 301:796-805, 2018. © 2017 Wiley Periodicals, Inc.