Mutational Signature Changes in Patients With Metastatic Squamous Cell Carcinoma of the Anal Canal.

PURPOSE: We examined the concordance of genetic mutations between pretreatment tumor tissue and posttreatment circulating tumor DNA (ctDNA) in patients with metastatic squamous cell carcinoma of the anal canal (SCCA) and assessed the impact of therapy on this concordance. METHODS: We analyzed next-generation sequencing reports from pretreatment tumor tissue and posttreatment ctDNA in 11 patients with metastatic SCCA treated at Vanderbilt University Medical Center between 2017 and 2021. RESULTS: Among the mutations identified in posttreatment ctDNA, 34.5% were also found in pretreatment tumor tissue, while 47.6% of pretreatment tumor tissue mutations were found in posttreatment ctDNA. Four patients had preservation of potentially actionable mutations in both pretreatment tissue and posttreatment ctDNA, while 7 patients had newly identified mutations in posttreatment ctDNA that were not present in pretreatment tumor tissue. CONCLUSION: Patients with SCCA demonstrate a high degree of temporal mutational heterogeneity. This supports the hypothesis that ctDNA can serve as a real-time tracking mechanism for solid tumors' molecular evolution in response to therapy. Our findings highlight the potential of ctDNA in identifying emerging actionable mutations, supplementing information from tissue-based genomic assessments. Further research, ideally with larger and multi-institutional cohorts, is needed to validate our findings in this relatively rare tumor type.

Rational treatment options for T1/2N0M0 squamous cell carcinoma of the anal canal: a population-based study combined with external validation.

BACKGROUND: Treatment options for T1/2N0M0 anal squamous cell carcinoma include chemotherapy, radiotherapy, chemoradiotherapy, and local excision, although the optimal treatment method has not been determined. METHODS: The National Cancer Institute Surveillance, Epidemiology and Results database was used to search and screen 1465 patients with cT1/2N0M0 anal squamous cell carcinoma who were clinically diagnosed between 2004 and 2016. Survival analysis was performed using the Kaplan-Meier method and log-rank test. Cox proportional hazards regression analysis was performed to screen independent prognostic factors and build a nomogram survival prediction model. According to the risk score, patients were divided into low, medium, and high risk groups using X-tile software. RESULTS: Age, sex, grade and cT stage were identified as independent prognostic factors for cT1/2N0M0 anal squamous cell carcinoma and were included in the nomogram to construct a prediction model. The C-index of the model was 0.770 [95% confidence interval (CI), 0.693-0.856], which was higher than the C-index of T stage 0.565 (95% CI, 0.550-0.612). Low-risk patients benefited from local resection, moderate-risk patients benefited from radiotherapy, and high-risk patients benefited from radiotherapy or chemoradiotherapy. This was confirmed using external validation data from the center. CONCLUSION: The nomogram developed in this study effectively and comprehensively evaluated the prognosis of patients with cT1/2N0M0 squamous cell carcinoma of the anal canal. Local excision is recommended for low risk patients, radiotherapy for moderate-risk patients, and radiotherapy or chemoradiotherapy for high-risk patients.

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.

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.

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.

Significance of lateral lymph node dissection in squamous cell carcinoma of the anal canal: a retrospective cohort study.

PURPOSE: The JCOG (Japan Clinical Oncology Group) 0212 study did not confirm the noninferiority of mesorectal excision (ME) alone to ME with LLND for rectal or anal adenocarcinomas. Furthermore, the significance of LLND for SCCs remains unknown. We evaluated the significance of lateral lymph node dissection (LLND) of squamous cell carcinoma (SCC) of the anal canal. METHODS: This retrospective cohort study was conducted in 435 patients with SCCs among 1,781 patients with anal canal tumors. In 40 patients who underwent LLND, the 5-year relapse-free survival (5y-RFS) and 5-year overall survival (5y-OS) were compared between groups with positive and negative histopathological findings. In 71 patients with negative lateral lymph node metastasis in the preoperative diagnosis, the 5y-RFS, 5y-OS, and 5-year local recurrence-free survival were compared between patients who did and did not undergo LLND. RESULTS: The clinical and pathological T stages predicted pathological lateral pelvic lymph node metastasis. There was no statistically significant difference in 5y-RFS and 5y-OS between patients who did and did not undergo LLND. Among patients who underwent LLND, 5y-RFS in those with positive histopathological findings (15.0%) was worse than that in those without (59.2%) (p = 0.002). CONCLUSIONS: In patients who underwent LLND, 5y-RFS in those with positive histopathological findings than in those without LLND did not contribute to prognosis.

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.

Three-Dimensional Transperineal Ultrasound Assessment of the Anal Sphincter Immediately After Vaginal Birth: An Exploratory Study.

OBJECTIVES: To assess the feasibility of acquiring adequate transperineal ultrasound (TPUS) volumes of the anal sphincter (AS) immediately after vaginal birth, the reproducibility of its measurements, and detecting defects therein. METHODS: Secondary analysis of TPUS volumes of the AS, acquired immediately after vaginal birth with a transversely oriented convex probe. Two independent experts ranked off-line image quality as "inadequate," "adequate," or "ideal" using the Point-of-Care Ultrasound Image Quality scale. On "adequate" and "ideal" quality volumes, the length of the external AS at 6 and 12 o'clock, and the volume of the external and internal AS were measured. Additionally, volumes were screened for AS defects on tomographic ultrasound imaging. Subsequently, we rated the intra- and interrater agreement on those findings. RESULTS: Of 183 volumes, 162 were considered "adequate" or of "ideal" quality (88.5%). Reasons for "inadequacy" were shadow artifacts (16/21), poor resolution (3/21), incomplete acquisition (1/21), or aberrant AS morphology (1/21). The intrarater reliability of two-dimensional (2D) and three-dimensional (3D) measurements was excellent, whereas interrater reliability was fair to good for 2D measurements and good for 3D measurements. In those tomographic ultrasound imaging (TUI) sequences including AS defects, the intra- and interrater reliability of the defect measurement were excellent [intraclass correlation coefficient (ICC) = 0.92 (0.80-0.94)] and moderate [ICC = 0.72 (0.63-0.79)]. In this cohort, there were only few (4/48; 8.3%) AS defects. However, grading them was poorly reproducible between experts. CONCLUSION: TPUS of the AS immediately after vaginal birth yields adequate image quality and allows for reproducible measurements. In the few patients with AS defects, there was good agreement on the presence, but it was poor for the extent of defects.

The inguinal lymph nodes as regional lymph nodes in anal canal adenocarcinomas: a nationwide database analysis in Japan.

PURPOSE: To establish if it is appropriate to treat the inguinal lymph node (LN) of anal canal adenocarcinoma (ACA) as the intermediate LN according to the Japanese classification. METHODS: The characteristics of 346 ACA patients were examined from the nationwide registry. The effect of LN dissection was evaluated using the therapeutic value index (TVI). Furthermore, the prognostic classification ability of N factors and stage was evaluated using Akaike's information criterion (AIC), the concordance index (C-index), and the 5-year overall survival (OS) rate. RESULTS: The rate of metastasis of the inguinal LN was 7.5% and the TVI was 3.05. Evaluation using AIC and the C-index showed better results when the inguinal LN was treated as the intermediate LN. The 5-year OS rate for 66 patients with perirectal or intermediate LN metastasis, 7 with inguinal LN metastasis, and 13 with inguinal and perirectal or intermediate LN metastasis were 49.2%, 68.6%, and 47.6%, respectively. When inguinal LN metastases were treated as N3, the 5-year OS rates were 66.7% for those with T1N3 and T2N3 disease, and 49.2% for those with T3N3 disease. CONCLUSIONS: The inguinal LN of ACA was evaluated and staged as the intermediate LN to devise an appropriate treatment strategy.

Multimode ultrasound imaging of an anal canal gastrointestinal stromal tumour (GIST).

Gastrointestinal stromal tumours (GISTs) can develop throughout the entire gastrointestinal tract, but these tumours are usually found in the stomach and small intestine. In this case, a rare GIST arising from the anal canal was investigated using high-frequency endoanal ultrasound and external three-dimensional ultrasound with tomographic ultrasound imaging. The endoanal approach revealed the inner structure of the tumour. External ultrasound was used to determine the relationship between the lesion and surrounding tissues. In the limited reports of anal canal GISTs, no other lesions have been correctly diagnosed preoperatively or displayed in detail on imaging. The multilayer structure of the anal sphincter and these lesions can be clearly displayed by a variety of ultrasound imaging methods, which are nonradiative, low-cost and easily accessible. Modern ultrasound has the potential for broad application in anal canal tumour diagnosis and surveillance.

[Anal canal cancer : epidemiology, work-up, treatment and perspective]. / Le cancer du canal anal : épidémiologie, bilan, traitement et futur.

Although rare, around 2 % of digestive tumours, anal canal tumours remain a pathology that should not be neglected. These are frequently underdiagnosed due to the affected region and the symptoms that can be confused with more common and benign pathologies such as haemorrhoids or anal fissures. The treatment of these tumours is mainly based on radio-chemotherapy to avoid heavy surgical treatment which remains the salvage option. This article aims to review the epidemiology, diagnosis, management, monitoring and future developments for these cancers.

Bien que rares (environ 2 % des tumeurs digestives), les tumeurs du canal anal restent une pathologie à ne pas négliger. Elles sont souvent sous-diagnostiquées en raison de la région touchée et de la symptomatologie non spécifique, et confondues avec des pathologies plus fréquentes et bénignes comme des hémorroïdes ou des fissures anales. Le traitement de ces tumeurs repose principalement sur la radio-chimiothérapie, afin d'éviter une prise en charge chirurgicale lourde qui reste l'option de sauvetage. Cet article a pour but de passer en revue l'épidémiologie, le diagnostic, la prise en charge, le suivi et les futurs développements pour ces cancers.

Retrospective study of risk markers for developing high-grade anal intraepithelial neoplasm in men who have sex with men living with HIV. / Estudio retrospectivo que evalúa marcadores de riesgo de desarrollar lesión escamosa intraepitelial anal de alto grado en hombres que tiene sexo con hombres y viven con el virus de inmunodeficiencia humana.

High-grade anal intraepithelial squamous lesion is significantly prevalent among men who have sex with men and are infected with the human immunodeficiency virus. This condition-the precursor to anal cancer-significantly increases the risk of developing it. Conversely, low-grade anal intraepithelial squamous typically follow a benign course and usually regress spontaneously. MATERIALS AND METHODS: To describe a population of men who have sex with men living with human immunodeficiency virus followed in a specialized anal cancer screening unit we conducted an observational, retrospective, and single-center study was. RESULTS: Ninety-four patients were analyzed, with a mean age of 39 ± 9 years, and a 87% positivity rate for high-risk human papillomavirus (HR-HPV). At the initial visit, 47% presented with low-grade squamous intraepithelial lesions. The progression rate to high-grade squamous intraepithelial lesion was 37.2 per 100,000 patients/year. None of the patients developed anal cancer. Tobacco and alcohol consumption were associated with this progression. DISCUSSION: In this series, longer duration of HIV infection, tobacco and alcohol use and the presence of HR-HPV were significantly associated with the occurrence of high-grade intraepithelial lesions. A lower risk of progression was seen in patients with higher education. CONCLUSION: In men who have sex with men living with HIV, the association of factors such as smoking, alcohol, the presence of HR-HPV and an increased burden of human papillomavirus disease makes these patients more susceptible to develop high-grade anal squamous lesions.

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.

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.

Training and external validation of pre-treatment FDG PET-CT-based models for outcome prediction in anal squamous cell carcinoma.

OBJECTIVES: The incidence of anal squamous cell carcinoma (ASCC) is increasing worldwide, with a significant proportion of patients treated with curative intent having recurrence. The ability to accurately predict progression-free survival (PFS) and overall survival (OS) would allow for development of personalised treatment strategies. The aim of the study was to train and external test radiomic/clinical feature derived time-to-event prediction models. METHODS: Consecutive patients with ASCC treated with curative intent at two large tertiary referral centres with baseline FDG PET-CT were included. Radiomic feature extraction was performed using LIFEx software on the pre-treatment PET-CT. Two distinct predictive models for PFS and OS were trained and tuned at each of the centres, with the best performing models externally tested on the other centres' patient cohort. RESULTS: A total of 187 patients were included from centre 1 (mean age 61.6 ± 11.5 years, median follow up 30 months, PFS events = 57/187, OS events = 46/187) and 257 patients were included from centre 2 (mean age 62.6 ± 12.3 years, median follow up 35 months, PFS events = 70/257, OS events = 54/257). The best performing model for PFS and OS was achieved using a Cox regression model based on age and metabolic tumour volume (MTV) with a training c-index of 0.7 and an external testing c-index of 0.7 (standard error = 0.4). CONCLUSIONS: A combination of patient age and MTV has been demonstrated using external validation to have the potential to predict OS and PFS in ASCC patients. CLINICAL RELEVANCE STATEMENT: A Cox regression model using patients' age and metabolic tumour volume showed good predictive potential for progression-free survival in external testing. The benefits of a previous radiomics model published by our group could not be confirmed on external testing. KEY POINTS: • A predictive model based on patient age and metabolic tumour volume showed potential to predict overall survival and progression-free survival and was validated on an external test cohort. • The methodology used to create a predictive model from age and metabolic tumour volume was repeatable using external cohort data. • The predictive ability of positron emission tomography-computed tomography-derived radiomic features diminished when the influence of metabolic tumour volume was accounted for.

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.

Mucosectomy of the anal canal via transanal minimally invasive surgery combined with transanal total mesorectal excision for familial adenomatous polyposis: A technical note.

AIM: Total proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the standard surgical treatment modality for familial adenomatous polyposis (FAP). It is challenging to perform proctectomy and preserve anal sphincter function. In this video, precise mucosectomy of the anal canal via transanal minimally invasive surgery (MAC-TAMIS) is reported. METHODS: An asymptomatic 35-year-old man was found to have a positive faecal occult blood test in routine screening examination and was diagnosed with FAP on colonoscopic examination. The patient was scheduled for total proctocolectomy with IPAA using the TAMIS approach combined with transanal total mesorectal excision. MAC-TAMIS was performed to preserve the internal anal sphincter during laparoscopy. RESULTS: The total duration of surgery was 543 min, blood loss was minimal, and the postoperative course was uneventful. The postoperative hospital stay was 12 days. The pathological findings demonstrated no evidence of malignancy. Gastrographic imaging from the ileostomy showed sufficient size of the J pouch and good tonus of the anus at 6 months after surgery. The Wexner scores at 1, 3 and 6 months after ileostomy closure were 5, 3 and 0, respectively. CONCLUSION: The MAC-TAMIS technique is safe and feasible during total proctocolectomy with IPAA in patients with FAP. This technique allows us to precisely preserve the internal anal sphincter using a laparoscopic approach.

Isolation and Characterization of Stem Cells from the Anal Canal Transition Zone in Pigs.

BACKGROUND: Utilization of autologous stem cells has been proposed for the treatment of anal incontinence despite a lack of understanding of their mechanism of action and of the physiological healing process of anal sphincters after injury. AIMS: We aim to develop a technique allowing isolation and further study of local mesenchymal stem cells, directly from anal canal transition zone in pig. METHODS: Anal canal was resected "en bloc" from two young pigs and further microdissected. The anal canal transition zone was washed and digested with 0.1% type I collagenase for 45 min at 37 °C. The isolated cells were plated on dishes in mesenchymal stem cell medium and trypsinized when confluent. Cells were further used for flow cytometry analysis and differentiation assays. RESULTS: The anal canal transition zone localization was confirmed with H&E staining. Following culture, cells exhibited a typical "fibroblast-like" morphology typical of stem cells. Isolated cells were positive for CD90 and CD44 but negative for CD14, CD34, CD45, CD105, CD106, and SLA-DR. Following incubation with specific differentiation medium, isolated cells differentiated into adipocytes, osteoblasts, and chondrocytes, confirming in vitro multipotency. CONCLUSIONS: Herein, we report for the first time the presence of mesenchymal stem cells in the anal canal transition zone in pigs and the feasibility of their isolation. This preliminary study opens the path to the isolation of human anal canal transition zone mesenchymal stem cells that might be used to study sphincters healing and to treat anal incontinence.

Recto-anal Pressures in Constipated Men and Women Undergoing High-Resolution Anorectal Manometry.

BACKGROUND: In constipated individuals, high-resolution anorectal manometry (HRM) may suggest the presence of a defecatory disorder. Despite known physiological differences between men and women, our understanding of functional anorectal pathophysiology is based upon predominantly female cohorts. Results are generalized to men. AIMS: To evaluate whether recto-anal pressure patterns in constipated men are similar to those in constipated women. METHODS: The electronic health records at Mayo Clinic, Rochester were used to identify constipated adult patients, without organic anorectal disease, who had undergone HRM and balloon expulsion testing (BET) in 2018, 2019, and 2020. Comparative analyses were performed. RESULTS: Among 3,298 constipated adult patients (2,633 women, 665 men), anal and rectal pressures were higher in men. Women more likely to have HRM findings suggestive of a defecatory disorder (39% versus 20%, P < 0.001). Women were more likely to exhibit a type 4 pattern (27% versus 14%, P < 0.001), and less likely to exhibit a type 1 pattern (14% versus 38%, P < 0.001), of dyssynergia. Men were more likely to have an abnormal balloon expulsion test (BET, 34% versus 29%, P = 0.006). Nominal logistic regression demonstrates that male sex, age over 50 years, reduced recto-anal gradient during simulated evacuation, and types 2 and 4 dyssynergia are associated with an abnormal BET. CONCLUSIONS: In this large retrospective study, constipated men and women exhibited different patterns of dyssynergia both in the presence and absence of an abnormal BET. These findings were independent of sex-specific baseline physiological differences.

State-of-the-art surgery for Crohn's disease: part III-perianal Crohn's disease.

PURPOSE: Diagnosis and treatment of perianal Crohn's disease is challenging and requires its own domain of therapy. Different types of perianal disease require a spectrum of treatment strategies. Treatment options range from conservative therapy, including immunosuppressives, biologics, or stem cell therapy, to surgical treatment with specific indications depending on the underlying lesion. This is part III of the series "state-of-the-art surgery for Crohn's disease," focusing on the management of perianal disease. We discuss the definition and diagnosis of perianal Crohn's disease, the treatment of perianal lesions, and specific surgical indications and techniques. RESULTS AND CONCLUSION: Pitfalls and complications play a substantial role in the treatment of perianal Crohn's disease, and surgical therapy may fail. Realistic treatment goals and an individual patient-oriented treatment approach are crucial in the treatment of perianal Crohn's disease.