The Omental Free Flap—A Review of Usage and Physiology

Abstract

The omental free flap is a valuable option for reconstructive efforts in nearly all anatomic regions. This is a result of its inherent anatomy and vascularity, and its angiogenic, immunogenic, and lymphatic properties.

Comparison of Outcomes in Oncoplastic Pelvic Reconstruction with VRAM versus Omental Flaps: A Large Cohort Analysis

“…6,[12][13][14][15][16] Omental flap physiology has also been well-described and documented success has been observed due to its anatomic suitability for harvest and wound coverage, as well as suspected properties related to wound healing. 17 This is the first study to compare specific oncologic and reconstructive flap outcomes between VRAM and omentum flaps in a large cohort of patients who underwent pelvic reconstruction following oncologic resection of abdominoperineal contents. In both univariate and multivariate analyses, controlled for all comorbidities and factors collected, VRAM flaps had a much lower recurrence rate compared with omental flaps and this was statistically significant (5.1 vs. 13.9%, respectively, p ¼ 0.03).…”

Biomaterial Implants in Abdominal Wall Hernia Repair: A Review on the Importance of the Peritoneal Interface

“…The omentum is a highly vascularized tissue that lies posterior to the abdominal wall and serves as coverage and protection for the intraabdominal contents [43]. It is of greatest importance in adhesion formation, since it is involved in 92% of postsurgical adhesions and in 100% of spontaneous adhesions [44].…”

“…It is of greatest importance in adhesion formation, since it is involved in 92% of postsurgical adhesions and in 100% of spontaneous adhesions [44]. It exhibits a particular predisposition to attach to foreign materials like surgical meshes in the abdominal cavity [45,46], which is probably due to its particular cell composition that provides this tissue with an immunologic role [47,48] and tissue remodeling properties [43]. It is mainly composed of white adipose tissue in a lobular configuration septated by connective tissue and delineated by a mesothelial layer.…”

“…The existence of this organ in the abdominal cavity largely conditions the host tissue response to a biomaterial implant in this location. The omentum shows a rapid response to abdominal injury, with the mobilization of cells comprising the milky spots that proliferate and spread over the omental tissue [49] and secrete growth factors and cytokines related to tissue repair and remodeling [43,49]. MCs (especially those near milky spots) have shown changes in their phenotype in response to injury, returning to normality only after tissue repair [50].…”

“…MCs (especially those near milky spots) have shown changes in their phenotype in response to injury, returning to normality only after tissue repair [50]. Besides, fibrocytes, pericytes and fibroblasts contained in the omentum provide an environment that supports tissue growth via angiogenic factors and cytokines that promote wound closure, vascular development and remodeling as well as collagen deposition [43]. A different progression of the omental tissue involved in adhesions to an adipose or fibrotic phenotype has been observed and correlated to the presence of different isoforms of TGF-β (TGF-β1 and TGF-β3) and the concomitant expression of the soluble or the membrane-bound form of betaglycan (type III TGF-β receptor) [49].…”