Abdominal Incisions

• A single dose of intravenous antibiotics 1 hour before incision reduces the incidence of surgical site infections
  • 2 grams of cefazolin
• Penicillin allergy
  • Metronidazole and aminoglycoside
  • Vancomycin

• Hair
  • Avoid removal if possible
  • Use of clippers rather than straight razor decreases wound infection
• Preparation solution
  • Iodine versus chlorhexidine ± alcohol equivalent
  • Alcohol preparations must be allowed to dry before surgery because of an increased risk of fire

Transverse Incisions

• Pfannenstiel
• Cherney
• Maylard
• Küstner

Pfannenstiel Incision

The Pfannenstiel incision is a transverse skin incision, two finger-breadths above the symphysis pubis, which is extended in the direction of the anterior superior iliac spine (ASIS) and ends 2–3 cm medial to ASIS on both sides.

Advantages

• More cosmetic
  • Scar is almost imperceptible
  • Hidden in the pubic hairline
  • Obscured by a skin crease
• Less painful
• Less pulmonary depression
• Excellent postoperative strength

Disadvantages

• No upper abdominal exposure
• Possible increased hematoma rate

Separate Fascia

The fascia is separated from rectus muscle superiorly and inferiorly.

Entering Peritoneum 

The rectus muscle is separated in the midline and the peritoneum is incised longitudinally.

Rectus Muscle Reapproximation

Sutures may be placed in the rectus muscle to close a rectus diastasis. Muscle reapproximation is not routine. 

The sheath is closed with continuous suture, and the skin is approximated with a subcuticular suture.

Fascia is closed with continuous delayed-absorbable suture. 

Subcutanous tissue closure if > 2 cm depth.

Skin is approximated with subcuticular, absorbable monofilament suture.

Cherney Incision

The Cherney incision is similar to the Pfannenstiel incision, except it involves incising the rectus tendons and is placed slightly lower on the abdomen. 

Advantages

• Excellent pelvic exposure
• Dehiscence or hernia is rare
• Incision of choice to “extend” Pfannenstiel

Disadvantages

• Limited upper abdominal exposure

Cherney Incision: Opening

Transverse incision of rectus sheath.

• The lower sheath is separated from rectus muscles
• The tendons are exposed and incised 1.5 cm above periosteum of symphysis

Cherney Incision: Closing

The tendons are sutured to lower rectus sheath above symphysis

Maylard Incision

Advantages

• Excellent exposure, including upper abdomen • Dehiscence or hernia is rare

Disadvantages

• Risk of femoral nerve injury from retractor
• Risk of subfascial hematoma
• Poor choice for patients with extensive vascular disease

Maylard Incision: Opening

• The incision of rectus sheath is extended laterally to iliac spine to expose rectus muscle
• The rectus muscles are cut transversely

• Cut edges of muscles are sutured to the rectus sheath
• Ligated epigastric vessels and exposed transversalis fascia
• Transversalis fascia and peritoneum are incised transversely
• Urachus is ligated

Küstner Incision

The Küstner incision is not commonly used. 

Advantages

• More cosmetic
• Increased exposure versus Pfannenstiel

Disadvantages

• Visible erythema in area of fat dissection postoperatively
• Unable to extend around the umbilicus
• More painful than transverse fascial incision

Küstner Incision: Opening

• Transverse incisions to sheath
• Subcutaneous tissue separated from linea alba

Vertical Incisions

• Midline
• Paramedian

Vertical Midline Incision

Advantages

• Versatile, rapid, low blood loss
• Excellent exposure

Disadvantages

• More painful
• Increased pulmonary depression
• Less cosmetic

• The line alba is incised and muscles are separated in the midline
• The peritoneum is opened at cephalic pole of incision
• The peritoneal incision is expanded longitudinally, slightly off midline to avoid urachus

Vertical Paramedian Incision

Advantages

• Theoretical decreased risk of herniation
• Improved lateral exposure

Disadvantages

• More likely to encounter the inferior epigastric vessels compared with midline incision
• Less cosmetic

• The anterior rectus sheath is opened for the full length of the incision 2-3 cm from the midline
• The rectus muscle is retracted laterally and the posterior sheath is incised longitudinally under the muscle bed

• The lateral paramedian incision is placed near the lateral border of the rectus muscle
• When the muscle is retracted laterally, the inferior deep epigastric artery is seen
• Finally, the posterior sheath is closed

Transverse Versus Vertical Incision

• Multiple prospective randomized trials
  • No difference between vertical and transverse incisions in fascial disruption

Scalpel: One is Enough

• No difference in wound infection rate
• Skin knife usually is sterile
• Knife blade is not a vehicle for bacterial contamination
• No bacteriological evidence to justify the use of different blades

Electrocautery Versus Scalpel

• Equal inflammation and infection rates
• No differences in pain or wound healing
• Less blood loss with electrocautery
• More rapid incision with scalpel

Peritoneal Closure: To Do or Not To Do

• Peritoneal reformation results from transformation of subperitoneal fibroblasts
• Surgical closure prevents autolysis of early fibrinous attachments
• Even minimally reactive sutures increase tissue necrosis and foreign body reaction

Peritoneal Closure

• Peritoneal reformation results from transformation of subperitoneal fibroblasts
• Surgical closure prevents autolysis of early fibrinous attachments
• Even minimally reactive sutures increase tissue necrosis and foreign body reaction
• OB Cochrane review recommends against this 

Edges do not need to be closed to enhance healing

• No increase in infectious complications
• No influence on wound integrity
• Avoiding closure decreases adhesion formation, including bowel adhesions
• Not closing decreases surgical time and may shorten hospital stay

Variables

• Active infection
• Cancer
• Diabetes
• Ileus
• Immunosuppression (steroids)
• Malnutrition
• Obesity
• Postoperative wound infection
• Pulmonary disease
• Radiation therapy

Risks

• Hernia
  • 2-5% of benign surgeries
  • 10-20% of malignant surgeries
• Evisceration
  • Less than 1%

• Continuous sutures versus interrupted sutures
• Absorbable sutures versus permanent sutures
• Suture placement
• Significant decrease in incisional hernia with continuous sutures odds ratio (OR), 0.73. 95% confidence interval (CI), 0.55-0.99
• No difference in wound infection or dehiscence rate
• Continuous suture more rapid, less risk to staff, and less expensive
• Suture to wound length ratio should be ≥ 4

Should I Stay or Should I Go

• Absorbable suture associated with higher incidence of incisional hernia (OR, 0.68. 95% CI, 0.52-0.87)
• No difference in wound infection or dehiscence rate
• Permanent suture associated with higher incidence of wound pain and suture sinuses

Size Matters

• Suture diameter and cross-sectional area differ markedly despite same gauge
• Permanent sutures have greater tensile strength but higher incidence of stitch sinus and incision pain
• Monofilament sutures have lower incidence of infection

Look Good to Be Good

• Large bites, loosely tied is stronger
• Square knot is strongest
• Surgeon’s knot decreases breaking strength
• Surgeons use too many throws
  • Four or fewer is sufficient for silk or braided
  • Six or fewer is sufficient for monofilament

The Solution to Pollution is Dilution

• Antibiotic solutions have no effect on non contaminated wounds
• Volume, volume, volume
• Recommend omitting intraabdominal irrigation (in CD) and perform subcutaneous irrigation

• Controversial with conflicting data
• If drain is included, the following should be used:
  • Closed-suction system
  • Separate exit wound
• See JAMA article by Tuuli et al., 2020: Effect of prophylactic negative pressure wound therapy versus standard wound dressing on surgical-site infection in obese women after cesarean delivery.

• In obese patients (more than 2 cm of subcutaneous fat), closure of subcutaneous fat at cesarean delivery decreased superficial wound disruption by 35%
• If performed, use fine absorbable suture in continuous fashion

Drains and Subcutaneous Closure

• Multicenter randomized trial of women undergoing cesarean delivery
  • Greater than 4 cm of subcutaneous fat
    • Suture closure: 17% wound morbidity
    • Suture closure plus drain: 22% wound morbidity
• Addition of a drain to subcutaneous closure does not prevent wound complications

Staples May Be Worse Than Subcuticular Sutures

In a prospective randomized study of 416 women who underwent cesarean delivery, the wound separation rate was significantly higher at 17% in the staple group, compared with 5% in the suture group.

New and Potentially Exciting

Staple closure was an independent risk factor for wound separation after controlling for:

• Gestational age
• Repeat cesarean delivery
• Obstetric complications
• Maternal comorbidities
• Body mass index (BMI) greater than 30
• Incision type
• Operating room time
• Insurance

Facts

• Staple closure required more scheduled and unscheduled office visits for wound care
• Mean gestational age of 38 weeks
• Mean age of 29 years
• 70% white
• 60% BMI greater than 30

• Stainless steel staples in 197 women versus 4-0 absorbable monofilament on a PS2 needle in 219 women
• Adhesive closure strips placed after removing staples and at subcutaneous closure
• Subcutaneous closure in both if greater than 2 cm
• Composite wound complication rate was 22% in stapled closure compared with 9% in suture closure
• Composite rate included:
  • Wound separation
  • Wound infection or need for antibiotics
  • Follow-up visits for wound
  • Hospital admission for wound

• Dry, adherent dressing traditional
• Wound healing facilitated by moist environment (semiocclusive dressing)
  • Faster healing, less pain, and less scarring
  • No increase in infection rate
  • Leave on for 24-48 hours