29. Episiotomy

Manishi Mittal¹

(1)

Mittal Maternity and Superspeciality Hospital, Yamunanagar, Haryana, India

Manishi Mittal

29.1 Introduction

Episiotomy is a surgical incision given at the perineum during the second stage of labour, in order to enlarge the vaginal orifice and facilitate delivery of the baby. The earliest description of episiotomy can be dated back to 1741, when Ould described “an incision made towards the anus with a pair of crooked probe-scissors introducing one blade between the head and the vagina, as far as shall be thought necessary” [1].

Large disparity has been reported between rates of episiotomy used throughout the world varying from 9.7% (Sweden) to 30% (Europe) [2] to 100% (Taiwan) [3]. In the USA, episiotomy use has decreased from 62.50% in 1983 [4] to 30–35% in 2003 [5]. Few studies describing rates of episiotomy in institutions or otherwise are available from India. In a cross-sectional study performed in Karnataka, including 3595 women, rate of episiotomy was observed to be 23.5% [6]. In another study conducted at Chennai, episiotomy rate was found to be 67%. The investigators observed that doctors had more predilection to conduct episiotomy (77.4%) as compared to nurses (53.1%) or trained birth attendants (5%). Moreover, it was higher in tertiary care centres. Instrumental deliveries and primiparae were seen to be high risk factors for episiotomy [7].

Evidence promotes selective episiotomy over routine. Many authors recommend that rate of episiotomy should not be more than 30% of vaginal deliveries [8].

29.2 Technique

During the second stage of labour, if there is insufficient space for the head, or the perineum is rigid, perineal tear may occur. To prevent this, an episiotomy is given.

Reasons for popularity of episiotomy:

Smooth and easier to repair surgical incision, instead of laceration.
Postoperative pain was thought to be less, with early healing. This belief, however, was found to be incorrect [9].
Preservation of muscle tone with maintained sexual function and a decreased risk of prolapse and faecal/urinary incontinence [10].
Lesser chance of third-degree tears.
Shortened second stage of labour—less fetal asphyxia and cranial trauma.
More space for instrumental deliveries or if rotation manoeuvres are required, e.g. in shoulder dystocia.

29.2.1 Timing

Too early incision causes excessive bleeding from site of cut, while delayed one will be unable to prevent any lacerations. Usually, the episiotomy is performed just before crowning during contraction, when the fetal head is visible up to a diameter of 3–4 cm. Incision is given when the perineum is stretched at the height of contraction. If performed with forceps delivery, incision is usually given after application of blades.

29.2.2 Analgesia

The latest National Institute of Health and Care Excellence (NICE) guidelines recommend that appropriate analgesia should be given before performing episiotomy, though it may be deferred in case of fetal distress [11]. Local lignocaine (10 mL of 1% solution) application in the subcutaneous tissue before incision is the most commonly used method (Fig. 29.1).

../images/421078_1_En_29_Chapter/421078_1_En_29_Fig1_HTML.png — Fig. 29.1

Two fingers are introduced between the fetal head and vaginal wall. Lignocaine solution is introduced into the subcutaneous tissue starting from the posterior fourchette, after aspiration to check for infiltration into blood vessels

Pudendal nerve block: It has the advantage of minimal blood loss and no fetal depression. It is given transvaginally by injection of 10 mL of 1% lignocaine on each side into the pudendal nerve, where it nears the ischial spine, by going through the sacrospinous ligament. Aspiration of the syringe to check for inadvertent entry into the pudendal artery should be done before injecting.

29.2.3 Types of Episiotomy (Fig. 29.2):

1.

Median (midline or medial) episiotomy

This type starts from the posterior fourchette and extends along the midline posteriorly, covering around half of the length of the perineum. The angle with the midline remains between 0° and 25°.
2.

Mediolateral episiotomy

This term most commonly identifies the incision originating from the posterior fourchette (within 3 mm of the midline) and extending laterally and downwards away from the rectum at an angle of 45–60° from the midline. However, the mediolateral episiotomy is defined in a wide variety of ways in different obstetric textbooks.
3.

Lateral episiotomy

This episiotomy originates 1 or 2 cm lateral to the midline in the introitus, going towards the ischial tuberosity. It is usually longer than other episiotomies. Lateral episiotomy is not preferred, because of many adverse effects like injury to Bartholin’s duct. However, it is said to be more common than documented as often inaccurately given mediolateral episiotomy becomes lateral.
4.

J-shaped episiotomy

This episiotomy starts as a midline incision, then curving laterally 2–5 cm away from the anus towards the ischial tuberosity. Curved scissors are used for this procedure.
5.

Modified median episiotomy

It is a modification of the midline episiotomy. A transverse incision is added to each side of the midline episiotomy (total measuring 2–5 cm) just anterior to the expected location of the anal sphincter. This technique was said to increase the outlet diameter by 83% [12]. However, it is not a popular technique.
6.

Radical lateral episiotomy (Schuchardt incision)

This procedure is not common in obstetrics. The incision goes deep into a vaginal sulcus and then curves downwards and laterally around the rectum. It provides access to the parametrium in radical vaginal hysterectomy or trachelectomy and allows removal of a neglected vaginal pessary. Rarely, it may be used in difficult labour (large head, difficult breech, or shoulder dystocia) [13].
7.

Anterior episiotomy

For women with a history of infibulation (closure of the vaginal vestibule by fusion of the labia majora, done in some cultures to prevent intercourse), anterior episiotomy or deinfibulation is required during delivery. The obstetrician’s finger is inserted through the introitus and directed towards the pubis. The scar is corrected by incising the fused labia till the external urethral meatus is visible. Clitoral remnants should not be incised. Additionally, mediolateral episiotomy may be necessary during delivery.

../images/421078_1_En_29_Chapter/421078_1_En_29_Fig2_HTML.png — Fig. 29.2

Types of episiotomy. (1) Median episiotomy, (2) modified median episiotomy, (3) “J”-shaped episiotomy, (4) mediolateral episiotomy, (5) lateral episiotomy, (6) radical lateral (Schuchardt incision)

Table 29.1

Comparison of commonly used techniques [14]

Complications	Median episiotomy	Mediolateral episiotomy
Surgical repair	Easy	Difficult
Healing	Good	Occasionally faulty
Postoperative pain	Less	More
Restoration of anatomy	Good	May be inaccurate
Blood loss	Less	More
Sexual dysfunction	Rare	Occasional
Extensions into third- or fourth-degree tears	Common	Uncommon
Voluntary extension of incision	Not possible	Possible
Incision of muscles	Negligible	Muscles are cut
Injury to anal sphincter complex	More	Less

Despite the many advantages of median episiotomy, mediolateral episiotomy is preferred due to the important complication of the extension of episiotomy into the anal canal (Table 29.1). In a Dutch study involving more than 43,000 deliveries, a fourfold fall in severe perineal lacerations was found with mediolateral technique [15]. When performed, mediolateral episiotomy is given on a stretched perineum starting from the posterior fourchette. The incision is preferably given at an angle of 45–60° to the right of the midline [11, 16]. A 60° incision angle is seen to be associated with lesser anal sphincter trauma, anal incontinence and perineal pain [17]. In another study, it was estimated that there is a 50% relative decrease in the occurrence of third-degree tears for every 6° angle away from the midline [18].

Structures cut during episiotomy:

1.

Posterior vaginal wall
2.

Muscles: Superficial and deep transverse perineal muscles, bulbospongiosus, part of levator ani
3.

Transverse perineal branches of pudendal nerve and vessels
4.

Subcutaneous tissue, fascia and skin

29.2.4 Episiotomy Repair

It is mostly performed after complete expulsion of the placenta, spontaneous or assisted. Complete aseptic precautions should be taken. Repair is performed with patient in lithotomy position. Most commonly used suture material is 1-0 or 2-0 chromic catgut. Other suture materials have been recommended like polyglycolic acid derivatives, e.g. vicryl and vicryl rapide. Polyglycolic acid sutures have higher tensile strength, with smooth passage through tissue, and are easy to handle with excellent knotting ability and secure knots. A review of 18 randomized controlled trials (RCTs) conducted on suture materials for episiotomy reported that synthetic absorbable sutures, when compared with catgut, had lesser postoperative pain, decreased use of analgesia, reduced wound breakdown and decreased requirement for re-suturing compared to catgut [19]. However, standard synthetic sutures (Vicryl) had to be removed more often than catgut or rapidly absorbed synthetic sutures. Use of catgut has been discontinued in most European countries, but, being comparatively cheaper, it is still being used in India. But when compared on a large scale, use of synthetic sutures appears to be less expensive in the long run rather than catgut with its associated morbidities.

Basic principles of episiotomy repair are correct reapproximation, proper haemostasis and suturing without tension. The episiotomy is usually stitched in three layers—the mucosa, muscle layer and skin (Fig. 29.3). Suturing of the mucosa is started 1 cm above the apex of the incision, wherein any retracted vessels are ligated. This step is very important to prevent the formation of haematoma. Continuous sutures are then applied till the hymenal ring, approximating the mucosa and submucosal tissue. After this, the underlying muscle layer is sutured in either interrupted or running manner. Care should be taken not to leave any dead space. After proper reapproximation of these layers, the perineal skin is sutured. This is done with subcuticular or interrupted mattress sutures. Some authors recommend complete incision to be closed in continuous fashion. An RCT by Kettle et al. in 1542 women showed that continuous suturing was associated with less perineal pain [20].

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Mar 28, 2021 | Posted by admin in OBSTETRICS | Comments Off

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29. Episiotomy

29. Episiotomy

29.1 Introduction