An episiotomy is a surgical incision of the female perineum performed at the time of delivery to increase the diameter of the soft tissue pelvic outlet and facilitate a vaginal delivery. It is one of the most commonly performed surgical procedures in women in the United States yet it is controversial.
The episiotomy was thought to provide protection to the female genital tract and to facilitate an easier vaginal repair compared to a spontaneous laceration.1,2 It is thought to prevent perineal tearing by substituting a straight surgical incision for a ragged spontaneous laceration that may have a worse outcome after repair. It was also believed that an episiotomy resulted in decreased postoperative pain and improved healing when compared to a tear. These original beliefs have been challenged. There is a growing body of evidence demonstrating increased injury to the pelvic floor with the routine use of an episiotomy.3-6 A Cochrane database review of eight randomized controlled trials concluded that a restrictive use of an episiotomy lowers the incidence of posterior perineal trauma, decreases the amount of suturing, and results in fewer complications as compared to routine episiotomy.7 Current recommendations favor a restrictive use of episiotomy.8,9 The rate of episiotomy has steadily declined in the recent decades. As an example, the rates of episiotomy between 2006 and 2012 decreased from 17.3% to 11.6% in a cohort of 2.3 million women.10
There is a place for the episiotomy in modern obstetrics. The indications for an episiotomy today are based primarily on the clinical situation at the time of delivery (e.g., need to expedite delivery for suspected non-reassuring fetal status). Another important reason to make an episiotomy is the prevention of a long and irregular spontaneous perineal laceration. The repair of a controlled surgical incision might be easier and the anatomic planes easier to recognize. Good clinical judgment is still the best guide to use to determine whether or not to proceed with an episiotomy.11
ANATOMY AND PATHOPHYSIOLOGY
The perineum is a diamond-shaped region bounded by the bony structures of the pelvic outlet (i.e., the pubic symphysis, inferior pubic rami, and coccyx). An important anatomic area in obstetrics is the perineal body. It is located toward the center of the perineum between the lower vagina and the anus. The most critical area of the perineum is the distance from the vestibular fossa to the anus. It is usually 3 to 4 cm in length in the nonpregnant woman.11,12 The perineal body is a complex fibromuscular mass into which many structures insert.
The perineal body is the center of the hub of a wheel that includes the transverse perineal muscles, the capsule of the external anal sphincter muscle, and the bulbospongiosus muscle (Figure 163-1). ...