What is the management of a pathological process involving the greater omentum?

Management of Pathological Processes Involving the Greater Omentum

The management of pathological processes involving the greater omentum should be tailored to the specific condition, with surgical resection of the affected portion being the primary treatment approach in most cases.

Anatomical and Functional Considerations

• The greater omentum is a highly vascularized fibroadipose structure in the peritoneal cavity with important functions including fat accumulation, adhesion to traumatized tissues, local hemostasis, immune response, and revascularization 1
• Its large size (average 400 cm²) and anterior position in the abdomen allow for accurate visualization on CT and MR imaging, which can provide important diagnostic clues for underlying abdominal disorders 2
• The omentum has specialized immune cells and plays roles in fluid absorption, phagocytosis, and foreign body reactions 1

Diagnostic Approach

• CT and MRI are the primary imaging modalities for evaluating pathological processes of the greater omentum, with careful assessment providing important diagnostic information 2
• Laparoscopy is an effective diagnostic tool that allows direct visualization of the omentum and can simultaneously facilitate therapeutic intervention 3
• Progressive peritonitis often necessitates surgical exploration, as accurate diagnosis is rarely made before surgery in cases such as idiopathic segmental infarction 3

Surgical Management by Pathology Type

Gastric Cancer Involvement

• For T3 (serosa-positive) or deeper gastric tumors, removal of the greater omentum should be integrated into the standard gastrectomy 4
• For T1/T2 gastric tumors, the omentum more than 3 cm away from the gastroepiploic arcade may be preserved 4
• When the posterior gastric wall serosa is infiltrated by tumor, removal of the inner peritoneal surface of the bursa omentalis (bursectomy) may be performed to remove microscopic tumor deposits, though this should be avoided in T1/T2 tumors to prevent injury to the pancreas and adjacent vessels 4

Ovarian Cancer Involvement

• Complete omentectomy is a standard component of surgical management for ovarian cancer 4
• For advanced ovarian cancer, the omentum may be entirely replaced, forming an "omental cake" 4
• Two surgical approaches for omentectomy in ovarian cancer include:
  • Dissecting the omentum off the transverse colon in the avascular plane 4
  • Opening the lesser sac off the greater curvature of the stomach 4
• Splenectomy may be necessary when the hilum of the spleen is involved by extension of bulky omental ovarian metastasis 4

Idiopathic Segmental Infarction

• Resection of the necrotic part of the greater omentum is the therapy of choice for idiopathic segmental infarction, ensuring fast recovery and pain control 3
• Laparoscopic approach is preferred when feasible, as it allows both exploration and surgical intervention 3
• Careful exploration of the whole abdominal cavity should be performed, as serohemorrhagic ascites is a common finding 3

Inflammatory and Infectious Processes

• The greater omentum serves a critical function in the containment of inflammatory and infectious processes within the abdominal cavity 2
• Surgical management should focus on addressing the underlying cause while preserving omental function when possible 2

Reconstructive Applications

• The greater omentum can be used as a flap for reconstruction of complex defects due to its unique properties of defense, detersion, and revascularization 5
• It can be used as a pedicle flap based on either the left or right gastro-omental vessels, with the right pedicle being dominant 5
• After appropriate mobilization, the omentum can reach the entire anterior surface of the trunk, proximal limbs, and base of the neck 5
• Free omental grafts with microsurgical revascularization can be used for distant sites 5, 6
• Primary indications include poorly defined, deep, torpid, infected defects and cases of radiation necrosis 5

Surgical Considerations and Pitfalls

• In cases requiring omentectomy, care must be taken to avoid injury to adjacent structures, particularly the pancreas and splenic vessels 4
• If splenectomy is performed due to omental disease extension, post-operative immunization against encapsulated organisms (Streptococcus pneumoniae, meningococcus, and Haemophilus influenzae) is necessary 4
• When the omentum is used for reconstruction, the limitation is the requirement for laparotomy, which may not be feasible in patients with respiratory failure or following multiple abdominal operations 5
• For perforated gastric or marginal ulcers, laparoscopic suture repair with omental patch reinforcement is recommended when technically possible 4

Emerging Applications

• The greater omentum is gaining interest as a potential site for pancreatic islet and cell transplantation due to its high vascularity and immunological properties 1
• Research continues to explore both surgical and immunological aspects of the omentum for various clinical applications 6