Stapled transperineal rectovaginal fistula repair for low- and mid-level rectovaginal fistulas: A comparison study with rectal mucosal advancement flap repair.

BACKGROUND: As an innovative treatment, stapled transperineal rectovaginal fistula repair (STR) for rectovaginal fistula (RVF) has demonstrated effectiveness in preliminary reports. This study aims to compare STR with rectal mucosal advancement flap repair (RAF), a widely utilized surgical procedure, for the surgical outcome of the low- and mid-level RVF. METHODS: In this retrospective cohort study, patients with low- and mid-level RVF who underwent STR or RAF were included from both the Sixth Affiliated Hospital of Sun Yat-sen University and Xi'an Daxing Hospital. Among the 99 total patients, 77 underwent STR and 22 underwent RAF. Patient demographics, operative data, and outcomes were collected and analyzed. Recurrence rate and associated risk factors were evaluated. RESULTS: There were no statistically significant differences among patients in terms of clinical characteristics like age, BMI, aetiology, and fistula features. During the follow-up period of 20 months (interquartile range 3.0-41.8 months), a total of 28 patients relapsed, with a significantly lower recurrence rate in the STR group (20.8 %) than in the RAF group (54.6 %) (P = 0.005). In the multivariate Cox analysis, STR was an independent protective factor against recurrence (HR: 0.37, 95%CI: 0.17-0.79, P = 0.01). Logistic regression indicated that there was no statistically significant difference between these two procedures in terms of surgical complications (OR: 0.53, 95%CI: 0.19-1.48, P = 0.23). CONCLUSION: For low- and mid-level RVF, STR may be an alternative option for treatment modality that offers a lower recurrence rate, without observed disadvantage in terms of surgical complication rates.

A magnetic resonance imaging-based decision-making tool for predicting complex anal fistulas healing in the early postoperative period.

BACKGROUND: Magnetic resonance imaging (MRI) has excellent accuracy in diagnosing preoperative lesions before anal fistula surgery. However, MRI is not good in identifying early recurrent lesions and effective methods for quantitative assessment of fistula healing are still warranted. This retrospective study aimed to develop and validate a specific MRI-based nomogram model to predict fistula healing during the early postoperative period. METHODS: Patients with complex cryptoglandular anal fistulas who underwent surgery between January 2017 and October 2020 were included in this study. MRI features and clinical parameters were analyzed using univariate and multivariate logistic regression analysis. A nomogram for predicting fistula healing was constructed and validated. RESULTS: In total, 200 patients were included, of whom 186 (93%) were male, with a median age of 36 (18-65) years. Of the fistulas, 58.5% were classified as transsphincteric and 19.5% as suprasphincteric. The data were randomly divided into the training cohort and testing cohort at a ratio of 7:3. Logistic analysis revealed that CNR, ADC, alcohol intake history, and suprasphincteric fistula were significantly correlated with fistula healing. These four predictors were used to construct a predictive nomogram model in the training cohort. AUC was 0.880 and 0.847 for the training and testing cohorts, respectively. Moreover, the decision and calibration curves showed high coherence between the predicted and actual probabilities of fistula healing. CONCLUSIONS: We developed a predictive model and constructed a nomogram to predict fistula healing during the early postoperative period. This model showed good performance and may be clinically utilized for the management of anal fistulas.

Single-Cell RNA Sequencing Reveals Heterogeneity in the Tumor Microenvironment between Young-Onset and Old-Onset Colorectal Cancer.

BACKGROUND: The incidence of sporadic young-onset colorectal cancer (yCRC) is increasing. Compared with old-onset colorectal cancer (oCRC), yCRC has different clinical and molecular characteristics. However, the difference in the tumor microenvironment (TME) between yCRC and oCRC remains unclear. METHODS: Fourteen untreated CRC tumor samples were subjected to single-cell RNA sequencing analysis. RESULTS: B cells and naïve T cells are enriched in yCRC, while effector T cells and plasma cells are enriched in oCRC. Effector T cells of yCRC show decreased interferon-gamma response and proliferative activity; meanwhile, Treg cells in yCRC show stronger oxidative phosphorylation and TGF-ß signaling than that in oCRC. The down-regulated immune response of T cells in yCRC may be regulated by immune and malignant cells, as we observed a downregulation of antigen presentation and immune activations in B cells, dendritic cells, and macrophages. Finally, we identified malignant cells in yCRC and oCRC with high heterogeneity and revealed their interactions with immune cells in the TME. CONCLUSIONS: Our data reveal significant differences of TME between yCRC and oCRC, of which the TME of yCRC is more immunosuppressive than oCRC. Malignant cells play an essential role in the formation of the suppressive tumor immune microenvironment.

Mucocele: a rare complication following stapled haemorrhoidopexy.

BACKGROUND: Stapled haemorrhoidopexy (SH) has resulted in a unique collection of procedural complications with postoperative mucocele a particularly rare example. This study is designed to comprehensively describe the characteristics of rectal mucocele and discuss its pathogenesis following SH surgery. METHODS: A database of patients presenting with a rectal mucocele following an SH procedure was established and studied retrospectively. RESULTS: Seven patients (5 males; median age 32 years, range 20-75 years) were identified. All patients complained of variable anal discomfort with 5/7 presenting with inconstant anal pain, 2 with de novo evacuatory difficulty. These cases appeared at a median time of 6 months (range 2-84 months) after SH surgery. CONCLUSION: Rectal Mucocele develops when mucosal fragments become embedded and isolated under the mucosa. It is a preventable complication of SH surgery by ensuring correct purse string placement prior to stapled haemorrhoid excision.