Ramirez Component Separation Technique

Overview

• Sabiston Textbook of Surgery, p. 1117
• Mulholland and Greenfield's Surgery, p. 3739

Anatomy of the Abdominal Wall (Relevant Layers)

Indications

• Large ventral or incisional hernias where the linea alba cannot be reapproximated by simple mobilization
• Defects typically >10-12 cm in width
• Contaminated fields where prosthesis should be avoided (the original indication)
• Emergency abdominal wall reconstruction
• After treatment of abdominal compartment syndrome (ACS)
• Massive traumatic tissue loss
• Reoperative hernia surgery where simpler planes have already been used

Operative Steps (Open Anterior Component Separation)

1. Laparotomy, hernia sac reduction, lysis of adhesions - adhesions to the anterior abdominal wall are taken down fully.
2. Development of subcutaneous flaps - skin and subcutaneous fat are raised off the anterior rectus sheath and the external oblique aponeurosis. Flaps are extended laterally to the linea semilunaris (lateral edge of the rectus sheath).
3. External oblique fasciotomy - the external oblique aponeurosis and muscle belly are incised 2 cm lateral to the semilunar line, in a longitudinal direction. This incision is extended:
   • Superiorly over the costal margin (at least 5-7 cm cranial to it for defects near the xiphoid)
   • Inferiorly to the inguinal ligament
4. Separation of external from internal oblique - the external oblique is dissected off the internal oblique in a relatively avascular plane, toward the midaxillary line, as far laterally as possible.
5. Posterior rectus sheath release - the posterior rectus sheath is incised along the edge of the linea alba and the rectus abdominis is freed from its posterior fascial envelope.
6. Medial advancement - the combined release allows the internal oblique-transversus abdominis muscle and rectus abdominis complex to slide medially by up to 10 cm per side in the mid-abdomen, enabling closure of defects up to 20 cm wide.
   • Release of posterior rectus sheath alone: ~5 cm of mobilization in mid-abdomen
   • Full anterior component separation: ~3-10 cm per side
7. Fascial closure - running slowly absorbable suture reapproximates the midline fascia.
8. Mesh reinforcement (preferred) - placed in the surgeon's preferred position (onlay, sublay/retromuscular, or underlay).
9. Drains - closed suction drains placed in the subcutaneous space.

• Sabiston Textbook of Surgery, p. 1119
• Mulholland and Greenfield's Surgery, p. 3738-3740

Modifications

Periumbilical Perforator-Sparing Anterior Component Separation

Endoscopic (Minimally Invasive) Component Separation

• 2-4 cm incisions below the costal margin in the anterior axillary line
• A balloon dissector develops the plane between external and internal oblique under camera guidance
• External oblique aponeurosis is then divided endoscopically
• Can be followed by open, laparoscopic, or robotic-assisted hernia repair
• Advantages: reduces wound complications by approximately 50%, shorter postoperative stay, useful in patients with stomas
• Limitation: adequacy of myofascial advancement may be slightly less than open technique
• Must ensure the correct interparietal plane to prevent lateral bulging or hernia
• Mulholland and Greenfield's Surgery, p. 3741

Posterior Component Separation: Transversus Abdominis Release (TAR)

1. Retrorectus dissection is established first
2. The posterior rectus sheath (posterior lamella of internal oblique) is incised 1 cm medial to the neurovascular bundles
3. The transversus abdominis muscle (upper abdomen) or its aponeurosis (mid/lower abdomen) is divided, entering the pretransversalis or preperitoneal plane
4. Dissection is extended laterally to at least the midaxillary line, sometimes to the psoas muscle
5. Superiorly can extend under the diaphragm; inferiorly into the Space of Retzius exposing the symphysis pubis and Cooper ligament
6. This disinsertion of the transversus abdominis releases circumferential tension, allowing further rectus medialization
7. A large retromuscular space is created for wide-overlap mesh placement

• Mulholland and Greenfield's Surgery, p. 3741-3742

Degree of Fascial Advancement (Summary)

Complications

Key Points

• Originally described by Ramirez 1990 as a tissue-only repair for contaminated fields
• The external oblique fasciotomy 2 cm lateral to the semilunar line is the defining step
• Neurovascular bundles are safe because they run deep to the internal oblique
• Mesh is not mandatory but is routinely added in the modern era to reduce recurrence
• Posterior component separation (TAR) has become increasingly preferred for complex cases and achieves greater mobilization with better mesh placement
• Recent meta-analyses (PMID 39192038, PMID 38632220) confirm acceptable recurrence rates with TAR and favor minimally invasive approaches when feasible for wound-related outcomes

• Sabiston Textbook of Surgery, pp. 1115-1119 (Component Separation section)
• Mulholland and Greenfield's Surgery, pp. 3738-3742 (Anterior CS and TAR sections)
• Maingot's Abdominal Operations, p. 170