Episiotomy and Episiotomy Repair



Episiotomy and Episiotomy Repair


Michael A. Belfort



GENERAL PRINCIPLES



Physical Examination



  • The anatomy of the pelvic floor is shown in Figure 4.1.1.


  • The anatomy of the anus and rectum is shown in Figure 4.1.2.








  • The anal canal (Figure 4.1.3) is ˜2.5 to 3.5 cm long and extends from the puborectalis sling in the rectal ampulla to the intersphincteric groove (which separates the anal margin externally from the anal verge internally).


  • Collectively, the perianal margin and the anal verge comprise the anoderm, with the skin of the anal verge being hairless and smooth and that of the perianal margin being pigmented and having follicles and glands.


  • The anal canal is surrounded by the internal and external anal sphincter (EAS) muscles (Figure 4.1.3).


  • There are a series of longitudinal ridges called the anal columns (of Morgagni) in the superior portion of the anal canal, extending from the anorectal junction superiorly to the anal valves inferiorly.


  • The anal valves are arranged in an irregular (dentate or pectinate) line (colored purple in the diagram) dividing the anal canal into two different regions (superior and inferior).



    • Each region has completely different arteries, veins, lymphatics, nerve connections, and even different epithelial linings.


Differential Diagnosis



  • The classification (Table 4.1.1) (1) has been adopted by the International Consultation on Incontinence (4) and the RCOG (1) and differs slightly from that of ACOG (4). The most significant difference is that the ACOG classification does not include the vaginal mucosa in first-degree injuries and limits this designation to the perineal skin only. The RCOG classification includes the vaginal mucosa and thus, by definition, would have a lower rate of second-degree injuries as compared to that defined by the ACOG classification in which any injury to the perineal skin and vaginal mucosa is classified as a second-degree laceration. This complicates efforts to understand true incidences of injury on either side of the Atlantic.










    • Second-degree tear: Injury to the perineum involving perineal muscles but not involving the anal sphincter


    • Third-degree tear: Injury to perineum involving the anal sphincter complex:



      • Grade 3a tear: <50% of EAS thickness torn


      • Grade 3b tear: >50% of EAS thickness torn


      • Grade 3c tear: Both EAS and internal anal sphincter (IAS) torn


    • Fourth-degree tear: Injury to the perineum involving the anal sphincter complex (EAS and IAS) and anorectal mucosa



      • Injuries involving the anal sphincter and/or rectum are called obstetric anal sphincter injury(s) (OASIS). The rate in the United States is 3% to 11% (3).


      • Rectal button hole tear: If there is a tear into the rectal mucosa without damage to the anal sphincter, the injury should not be classified as a fourth-degree tear. The RCOG recommends that this should be documented as a rectal button hole tear (1).


Nonoperative Management

Sep 8, 2022 | Posted by in OBSTETRICS | Comments Off on Episiotomy and Episiotomy Repair

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