Exoanal ultrasound of the anal sphincter: normal anatomy and sphincter defects

To describe the sonographic appearance of normal anal sphincter anatomy and sphincter defects evaluated with a conventional 5 MHz convex transducer placed on the perineum. Design Prospective, single-blind study. Setting Department of Obstetrics and Gynecology, University of Michigan Medical Center, USA. Population Twenty-five women with symptoms of faecal incontinence, 11 asymptomatic nulliparous women, and 32 asymptomatic parous women. Methods A convex scanner was placed on the perineum with the woman in lithotomy position. Images were taken at three levels of the sphincter canal. Pictures were evaluated by two examiners who were blinded to the case history of the women and to the results of each other for the presence or absence of sphincter defects. Main outcome measures Description of anal sphincter appearance on endoanal ultrasound. Reproducibilty of the evaluation of sphincter defects. Results The internal anal sphincter is visible as a hypoechoic circle; the external anal sphincter shows a hyperechoic pattern. Proximally the sling of the puborectalis muscle is visible. Sphincter defects were detected in 20 women. In all five women who subsequently underwent surgery, the presence and location of the defect was confirmed at the time of surgery. Examiners were in agreement 100% of the time on the presence or absence of internal defects. They disagreed in one patient on the presence of an external defect. Conclusion Exoanal ultrasound provides information on normal anatomy and on defects of the anal sphincter.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75125/1/j.1471-0528.1997.tb12056.x.pd

The effects of childbirth on the pelvic-floor

Basically, vaginal delivery is associated with the risk of pelvic floor damage. The pelvic floor sequelae of childbirth includes anal incontinence, urinary incontinence and pelvic organ prolapse. Pathophysiology, incidence and risk factors for the development of the respective problems are reviewed. Where possible, recommendations for reducing the risk of pelvic floor damage are given

Long-Term Survival With Tafamidis in Patients With Transthyretin Amyloid Cardiomyopathy

BACKGROUND: Tafamidis is approved in many countries for the treatment of transthyretin amyloid cardiomyopathy. This study reports data on the long-term efficacy of tafamidis from an ongoing long-term extension (LTE) to the pivotal ATTR-ACT (Tafamidis in Transthyretin Cardiomyopathy Clinical Trial). METHODS: Patients with transthyretin amyloid cardiomyopathy who completed ATTR-ACT could enroll in an LTE, continuing with the same tafamidis dose or, if previously treated with placebo, randomized (2:1) to tafamidis meglumine 80 or 20 mg. All patients in the LTE transitioned to tafamidis free acid 61 mg (bioequivalent to tafamidis meglumine 80 mg) following a protocol amendment. In this interim analysis, all-cause mortality was assessed in patients treated with tafamidis meglumine 80 mg in ATTR-ACT continuing in the LTE, compared with those receiving placebo in ATTR-ACT transitioning to tafamidis in the LTE. RESULTS: Median follow-up was 58.5 months in the continuous tafamidis group (n=176) and 57.1 months in the placebo to tafamidis group (n=177). There were 79 (44.9%) deaths with continuous tafamidis and 111 (62.7%) with placebo to tafamidis (hazard ratio, 0.59 [95% CI, 0.44-0.79]; P<0.001). Mortality was also reduced in the continuous tafamidis (versus placebo to tafamidis) subgroups of: variant transthyretin amyloidosis (0.57 [0.33-0.99]; P=0.05) and wild-type transthyretin amyloidosis (0.61 [0.43-0.87]; P=0.006); and baseline New York Heart Association class I and II (0.56 [0.38-0.82]; P=0.003) and class III (0.65 [0.41-1.01]; P=0.06). CONCLUSIONS: In the LTE, patients initially treated with tafamidis in ATTR-ACT had substantially better survival than those first treated with placebo, highlighting the importance of early diagnosis and treatment in transthyretin amyloid cardiomyopathy. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01994889 and NCT02791230

Management of obstetric anal sphincter injury: a systematic review & national practice survey

BACKGROUND: We aim to establish the evidence base for the recognition and management of obstetric anal sphincter injury (OASI) and to compare this with current practice amongst UK obstetricians and coloproctologists. METHODS: A systematic review of the literature and a postal questionnaire survey of consultant obstetricians, trainee obstetricians and consultant coloproctologists was carried out. RESULTS: We found a wide variation in experience of repairing acute anal sphincter injury. The group with largest experience were consultant obstetricians (46.5% undertaking ≥ 5 repairs/year), whilst only 10% of responding colorectal surgeons had similar levels of experience (p < 0.001). There was extensive misunderstanding in terms of the definition of obstetric anal sphincter injuries. Overall, trainees had a greater knowledge of the correct classification (p < 0.01). Observational studies suggest that a new 'overlap' repair using PDS sutures with antibiotic cover gives better functional results. However, our literature search found only one randomised controlled trial (RCT) on the technique of repair of OASI, which showed no difference in incidence of anal incontinence at three months. Despite this, there was a wide variation in practice, with 337(50%) consultants, 82 (55%) trainees and 80 (89%) coloproctologists already using the 'overlap' method for repair of a torn EAS (p < 0.001). Although over 50% of colorectal surgeons would undertake long-term follow-up of their patients, this was the practice of less than 10% of obstetricians (p < 0.001). Whilst over 70% of coloproctologists would recommend an elective caesarean section in a subsequent pregnancy, only 22% of obstetric consultants and 14% of trainees (p < 0.001). CONCLUSION: An agreed classification of OASI, development of national guidelines, formalised training, multidisciplinary management and further definitive research is strongly recommended

Hierarchy Theory of Evolution and the Extended Evolutionary Synthesis: Some Epistemic Bridges, Some Conceptual Rifts

Contemporary evolutionary biology comprises a plural landscape of multiple co-existent conceptual frameworks and strenuous voices that disagree on the nature and scope of evolutionary theory. Since the mid-eighties, some of these conceptual frameworks have denounced the ontologies of the Modern Synthesis and of the updated Standard Theory of Evolution as unfinished or even flawed. In this paper, we analyze and compare two of those conceptual frameworks, namely Niles Eldredge’s Hierarchy Theory of Evolution (with its extended ontology of evolutionary entities) and the Extended Evolutionary Synthesis (with its proposal of an extended ontology of evolutionary processes), in an attempt to map some epistemic bridges (e.g. compatible views of causation; niche construction) and some conceptual rifts (e.g. extra-genetic inheritance; different perspectives on macroevolution; contrasting standpoints held in the “externalism–internalism” debate) that exist between them. This paper seeks to encourage theoretical, philosophical and historiographical discussions about pluralism or the possible unification of contemporary evolutionary biology

Linear, Deterministic, and Order-Invariant Initialization Methods for the K-Means Clustering Algorithm

Over the past five decades, k-means has become the clustering algorithm of choice in many application domains primarily due to its simplicity, time/space efficiency, and invariance to the ordering of the data points. Unfortunately, the algorithm's sensitivity to the initial selection of the cluster centers remains to be its most serious drawback. Numerous initialization methods have been proposed to address this drawback. Many of these methods, however, have time complexity superlinear in the number of data points, which makes them impractical for large data sets. On the other hand, linear methods are often random and/or sensitive to the ordering of the data points. These methods are generally unreliable in that the quality of their results is unpredictable. Therefore, it is common practice to perform multiple runs of such methods and take the output of the run that produces the best results. Such a practice, however, greatly increases the computational requirements of the otherwise highly efficient k-means algorithm. In this chapter, we investigate the empirical performance of six linear, deterministic (non-random), and order-invariant k-means initialization methods on a large and diverse collection of data sets from the UCI Machine Learning Repository. The results demonstrate that two relatively unknown hierarchical initialization methods due to Su and Dy outperform the remaining four methods with respect to two objective effectiveness criteria. In addition, a recent method due to Erisoglu et al. performs surprisingly poorly.Comment: 21 pages, 2 figures, 5 tables, Partitional Clustering Algorithms (Springer, 2014). arXiv admin note: substantial text overlap with arXiv:1304.7465, arXiv:1209.196

Current diagnosis and treatment algorithms for anal incontinence

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75666/1/j.1464-410X.2006.06307.x.pd