To further understand the membrane anatomy of the lower abdomen preperitoneal space and verify several understandings of preperitoneal space anatomy.

From January 2020 to June 2021, 281 cases of single incision laparoscopic totally extraperitoneal (TEP) utilizing the posterior sheath approach were performed. The membrane anatomical structure of lower abdomen was observed from the perspective of the posterior sheath. The anatomical structures observed during surgery were further described through surgical videos, photos and literature review.

The posterior fascia of rectus abdominis exists independently, the transverse fascia (TF) is derived from the lateral flat muscle, and there are three different types of it. TF is monolayer solid structure on pneumoperitoneum state, and the iliopubic tract is the continuation of TF.

The discovery of the posterior sheath field further verified some anatomy understandings and may be contributed to the understanding of lower abdomen preperitoneal space membrane anatomy.