Can you describe the step‑by‑step procedure of a cesarean section, focusing on the hysterotomy (uterine incision)?

Cesarean Section Procedure with Focus on Hysterotomy

The hysterotomy should be performed as a low transverse incision using a scalpel for the initial entry, followed by blunt cephalo-caudad (upward-downward) expansion to reduce surgical blood loss, with subsequent closure in 2 layers to minimize future uterine rupture risk. 1

Pre-Hysterotomy Preparation

Antibiotic Prophylaxis

• Administer IV first-generation cephalosporin within 60 minutes before skin incision
• Add azithromycin if patient is in labor or has ruptured membranes 1, 2

Skin Preparation

• Use chlorhexidine-alcohol for abdominal skin cleansing (superior to povidone-iodine)
• Perform vaginal preparation with povidone-iodine solution 1

Anesthesia

• Regional anesthesia is strongly preferred over general anesthesia 1
• Allow support person in operating room if requested by patient 2

Abdominal Entry

Skin Incision

• Low transverse incision is standard (used in 98% of cases) 3
• Either Joel-Cohen or Pfannenstiel technique is acceptable 4
• Can use scalpel or diathermy for initial incision 4

Layer-by-Layer Dissection

• Blunt dissection is preferred for subcutaneous tissue opening 4
• Sharp fascial incision initially, then blunt or sharp extension 4
• Blunt peritoneal entry and extension should be considered 4
• Inferior dissection of rectus muscle can be omitted 4

The Hysterotomy (Critical Step)

Bladder Management

• Omit bladder flap creation - not necessary in routine cases 4
• In complex cases with adhesions or previous cesareans, careful bladder mobilization is essential 5

Uterine Incision Technique

Initial Entry:

• Make a low transverse incision in the lower uterine segment
• Use scalpel for initial entry (used in 98.2% of cases) 3
• Create a small transverse incision (approximately 2-3 cm)

Expansion:

• Blunt cephalo-caudad expansion is strongly recommended to reduce surgical blood loss 1
• This means extending the incision upward and downward using fingers or blunt instruments rather than cutting with scissors
• Avoid sharp extension which increases bleeding risk

Key Technical Points:

• The incision should be wide enough to deliver the fetal head without trauma
• In breech or transverse presentations, make a wider incision to prevent uterine injury during delivery 6
• Avoid extending during uterine contractions 7

Common Pitfalls During Hysterotomy

Lateral Extensions:

• Risk injury to uterine arteries and venous plexuses
• Occur when simultaneous abdominal pressure is applied during difficult delivery 7

Inferior Vertical Extensions:

• Risk injury to cervical arteries and vaginal venous plexuses
• Can occur with impacted fetal head 7

Fetal Delivery

Standard Delivery

• Manual delivery of fetal head is preferred 4
• Gentle fundal pressure assists delivery
• Avoid excessive traction

Impacted Fetal Head Management

If the head cannot be delivered with usual technique:

• "Pull" methods (reverse breech extraction, Patwardhan method) are safer than "push" methods 7
• Vaginal push-up increases risk of uterine incision extensions, blood transfusion, and infections 7
• Consider tocolysis to relax uterus 7

Hysterotomy Closure

Two-layer closure is recommended to reduce future uterine rupture risk 1

Closure Technique

• Use delayed absorbable monofilament suture (Monocryl) or chromic catgut 1
• First layer: continuous suture through full thickness of myometrium
• Second layer: imbricating or continuous suture
• 90.4% of cases use double-layer closure in current practice 3

What NOT to Close

• Do not close peritoneum - increases operative time without improving outcomes 1
• Peritoneal closure does not reduce adhesions 1

Placental Management

• Allow spontaneous placental removal with gentle cord traction 4
• Delayed cord clamping: minimum 30 seconds (preterm) to 60 seconds (term) 1

Uterotomy Prevention Strategies

Hypothermia Prevention

• Use forced air warming devices
• Warm IV fluids
• Increase operating room temperature 1

Fluid Management

• Maintain perioperative euvolemia - avoid both hypovolemia and fluid overload 1
• Adequate perfusion optimizes uterine contractility and reduces bleeding

Abdominal Closure

• Close subcutaneous tissue if ≥2 cm thick 1
• Use subcuticular suture for skin (reduces wound separation compared to staples) 1
• 97% of cases use subcuticular skin closure 3

Critical Evidence Considerations

The 2018 ERAS Society guidelines provide moderate-quality evidence for blunt hysterotomy expansion and weak recommendations for two-layer closure 1. However, the consistency of these recommendations across multiple guidelines and the biological plausibility (reduced tissue trauma with blunt expansion, stronger scar with two-layer closure) support their implementation. The 2024 guidelines on impacted fetal head 7 provide the most recent high-quality evidence showing that "pull" methods significantly reduce maternal morbidity compared to traditional vaginal push techniques.

The wide variation in technique (493 different combinations observed among 85 surgeons) 3 highlights the need for standardization based on evidence to reduce complications and improve outcomes.