scholarly journals Purse-string morphology of external anal sphincter revealed by novel imaging techniques

2014 ◽  
Vol 306 (6) ◽  
pp. G505-G514 ◽  
Author(s):  
Ravinder K. Mittal ◽  
Valmik Bhargava ◽  
Geoff Sheean ◽  
Melissa Ledgerwood ◽  
Shantanu Sinha
Keyword(s):  
Anal Canal ◽  
Anal Sphincter ◽  
Muscle Fiber ◽  
Anal Incontinence ◽  
External Anal Sphincter ◽  
Diffusion Tensor ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Purse String ◽  
Lidocaine Injection

The external anal sphincter (EAS) may be injured in 25–35% of women during the first and subsequent vaginal childbirths and is likely the most common cause of anal incontinence. Since its first description almost 300 years ago, the EAS was believed to be a circular or a “donut-shaped” structure. Using three-dimensional transperineal ultrasound imaging, MRI, diffusion tensor imaging, and muscle fiber tracking, we delineated various components of the EAS and their muscle fiber directions. These novel imaging techniques suggest “purse-string” morphology, with “EAS muscles” crossing contralaterally in the perineal body to the contralateral transverse perineal (TP) and bulbospongiosus (BS) muscles, thus attaching the EAS to the pubic rami. Spin-tag MRI demonstrated purse-string action of the EAS muscle. Electromyography of TP/BS and EAS muscles revealed their simultaneous contraction and relaxation. Lidocaine injection into the TP/BS muscle significantly reduced anal canal pressure. These studies support purse-string morphology of the EAS to constrict/close the anal canal opening. Our findings have implications for the effect of episiotomy on anal closure function and the currently used surgical technique (overlapping sphincteroplasty) for EAS reconstructive surgery to treat anal incontinence.

S1827 External Anal Sphincter Plication: A Novel Surgical Approach to Enhance the Anal Canal Function

2008 ◽  
Vol 134 (4) ◽  
pp. A-278
Author(s):  
Mahadevan R. Rajasekaran ◽  
Yanfen Jiang ◽  
Amir Motamedi ◽  
Ravinder K. Mittal
Keyword(s):  
Anal Canal ◽  
Anal Sphincter ◽  
Surgical Approach ◽  
External Anal Sphincter

scholarly journals Combined diffusion and strain tensor MRI reveals a heterogeneous, planar pattern of strain development during isometric muscle contraction

2011 ◽  
Vol 300 (5) ◽  
pp. R1079-R1090 ◽  
Author(s):  
Erin K. Englund ◽  
Christopher P. Elder ◽  
Qing Xu ◽  
Zhaohua Ding ◽  
Bruce M. Damon
Keyword(s):  
Muscle Contraction ◽  
Muscle Fiber ◽  
Diffusion Tensor ◽  
Strain Tensor ◽  
Three Dimensional ◽  
Fiber Direction ◽  
Strain Pattern ◽  
Isometric Muscle Contraction ◽  
Diffusion Tensors

The purposes of this study were to create a three-dimensional representation of strain during isometric contraction in vivo and to interpret it with respect to the muscle fiber direction. Diffusion tensor MRI was used to measure the muscle fiber direction of the tibialis anterior (TA) muscle of seven healthy volunteers. Spatial-tagging MRI was used to measure linear strains in six directions during separate 50% maximal isometric contractions of the TA. The strain tensor (E) was computed in the TA's deep and superficial compartments and compared with the respective diffusion tensors. Diagonalization of E revealed a planar strain pattern, with one nonzero negative strain (εN) and one nonzero positive strain (εP); both strains were larger in magnitude ( P < 0.05) in the deep compartment [εN = −40.4 ± 4.3%, εP = 35.1 ± 3.5% (means ± SE)] than in the superficial compartment (εN = −24.3 ± 3.9%, εP = 6.3 ± 4.9%). The principal shortening direction deviated from the fiber direction by 24.0 ± 1.3° and 39.8 ± 6.1° in the deep and superficial compartments, respectively ( P < 0.05, deep vs. superficial). The deviation of the shortening direction from the fiber direction was due primarily to the lower angle of elevation of the shortening direction over the axial plane than that of the fiber direction. It is concluded that three-dimensional analyses of strain interpreted with respect to the fiber architecture are necessary to characterize skeletal muscle contraction in vivo. The deviation of the principal shortening direction from the fiber direction may relate to intramuscle variations in fiber length and pennation angle.

T1341 Sustained Improvement in Anal Canal Function Following External Anal Sphincter Muscle Plication

2010 ◽  
Vol 138 (5) ◽  
pp. S-541
Author(s):  
Mahadevan R. Rajasekaran ◽  
Yanfen Jiang ◽  
Amir Motamedi ◽  
Valmik Bhargava ◽  
Ravinder K. Mittal
Keyword(s):  
Anal Canal ◽  
Anal Sphincter ◽  
External Anal Sphincter ◽  
Sphincter Muscle ◽  
Sustained Improvement ◽  
Anal Sphincter Muscle ◽  
External Anal Sphincter Muscle

scholarly journals The effect of vaginal delivery and Caesarean section on the anal Sphincter complex of Primipara based on optimized three-dimensional ultrasound image and nuclear regression Reconstruction Algorithm

2021 ◽  
Vol 37 (6-WIT) ◽  
Author(s):  
Naxin He ◽  
Liang Shi
Keyword(s):  
Caesarean Section ◽  
Anal Sphincter ◽  
External Anal Sphincter ◽  
Caesarean Delivery ◽  
Three Dimensional ◽  
Reconstruction Algorithm ◽  
Perineal Ultrasound ◽  
Central Plane ◽  
Sphincter Complex ◽  
Anal Sphincter Complex

Objective: The study used the optimized nuclear regression reconstruction algorithm to explore the value of three-dimensional perineal ultrasound evaluation of the effect of caesarean delivery and caesarean section on the anal sphincter complex of primipara. Methods: This study performed three-dimensional perineal ultrasound scanning of the anal sphincter complex of 157 primiparas 42 days after delivery. Among them, 77 were in caesarean delivery (spontaneous delivery group) and 80 were in caesarean section (caesarean delivery group) from September 2018 to December 2020 in our hospital. The thickness of the end plane, the middle plane, the distal plane and the distal plane of the external anal sphincter at 3, 6, 9, 12 o’clock direction, and measure the thickness of the central plane of the pubic rectum muscle at 4, 8 o’clock direction. At the same time, the study used tomography and volume contrast imaging to observe the morphology and integrity of the anal sphincter complex. Results: The thickness of the distal anal sphincter at the 12 o’clock direction, the proximal anal sphincter at 6, 12 o’clock, and the central plane at 9 and 12 o’clock in the obstetric group were smaller than those in the caesarean section group (all P < 0.05). There were no significant differences in the thickness of the remaining anal internal and external anal sphincter and puborectalis muscles between the two groups in different directions (all P>0.05). In the obstetric group, a perineal sphincter defect was found via three-dimensional perineal ultrasound. Conclusion: The delivery method has a certain influence on the shape of the anal sphincter complex. The thickness of the internal and external anal sphincter of the primiparous women in a certain direction is significantly smaller than that of caesarean section. Transperineally three-dimensional ultrasound can clearly show the morphological characteristics and integrity of the anal sphincter complex, and diagnose the defect of the anal sphincter complex. doi: https://doi.org/10.12669/pjms.37.6-WIT.4859 How to cite this:He N, Shi L. The effect of vaginal delivery and Caesarean section on the anal Sphincter complex of Primipara based on optimized three-dimensional ultrasound image and nuclear regression Reconstruction Algorithm. Pak J Med Sci. 2021;37(6):1641-1646.  doi: https://doi.org/10.12669/pjms.37.6-WIT.4859 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Mo1231 Magnetic Resonance Diffusion Tensor Imaging of the Anatomically Disrupted External Anal Sphincter: Comparison With Normal

2013 ◽  
Vol 144 (5) ◽  
pp. S-612
Author(s):  
Melissa Ledgerwood ◽  
Shantanu Sinha ◽  
Auroni Gupta ◽  
Valmik Bhargava ◽  
Ravinder K. Mittal
Keyword(s):  
Diffusion Tensor Imaging ◽  
Magnetic Resonance ◽  
Anal Sphincter ◽  
External Anal Sphincter ◽  
Diffusion Tensor
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