Revisiting the anatomy of the retroperitoneum and renal fascia. Aspects applied to radiology, laparoscopic and robotic surgery - a narrative review.

This review aims to provide a comprehensive analysis of the anatomy of the retroperitoneal and abdominal fascias. We analyzed papers published in the past 70 years in the databases of Pubmed, Embase and Scielo. We excluded case reports, editorials and opinions of specialists. Studies were excluded if they lacked clear anatomical descriptions of the fascias, if full-text access was unavailable, or if they were published in languages other than Portuguese, English, or Spanish. This narrative review addresses the anatomical integration, surgical techniques, and functional importance of the fascias. Renal fascia is a dense connective tissue encasing kidney, perirenal fat, adrenal gland; composed of anterior (Gerota's) and posterior (Zuckerkandl-related/renal) layers that fuse laterally and superiorly. Toldt fascia is a plane formed where the mesocolon (ascending or descending) fuses to the posterior parietal peritoneum / posterior abdominal wall. The lateroconal fascia is a lateral continuation of the renal fascia where anterior and posterior renal layers fuse to form a sheet toward the lateral abdominal wall and Fredet's fascia is a fusion plane between the visceral peritoneum of the hepatic flexure/transverse mesocolon and the anterior surface of the duodenum/pancreatic head (anterior to pancreatic head/duodenum) with a critical landmark in right colectomy.