[The third component in surgical anatomy and its impacts]

Area of Science:

• Surgical Anatomy
• Oncology
• Gastrointestinal Pathology

Background:

• Conventional surgical anatomy focuses on organs and blood supply, neglecting enveloping fascia and serous membranes.
• This "third component" has been historically overlooked due to lack of recognition and understanding of its function.
• Re-evaluation of this component impacts local anatomy, tumor pathology, and surgical oncology principles.

Purpose of the Study:

• To highlight the significance of the fascia and serous membranes as a distinct component in surgical anatomy.
• To elucidate the role of this "third component" in the spread and surgical management of alimentary tract cancers.
• To propose a refined classification of surgical operations for alimentary tract cancers based on membrane anatomy.

Main Methods:

• Conceptual framework development based on anatomical and pathological re-evaluation.
• Classification of alimentary tract cancers into three types: in, at, and outside the mesentery.
• Definition of surgical principles including complete mesentery excision and lymphadenectomy.

Main Results:

• Surgical anatomy is redefined to include membrane anatomy (mesentery and its bed).
• Impairment of membrane integrity is linked to cancer metastasis leakage during surgery.
• A new classification for alimentary tract cancers (mesenteric, marginal, extramesenteric) is proposed.
• Surgical approaches are categorized into D type (lymphadenectomy), C type (mesentery completeness), and D+C type (combined).

Conclusions:

• The "third component" (membranes) is fundamental to surgical anatomy and oncology.
• Preventing cancer leakage and ensuring complete mesentery excision are key surgical goals.
• The D+C type operation, integrating lymphadenectomy and complete mesentery excision, represents an advanced surgical principle.