From basic to clinical:Anatomy of Denonvilliers’fascia and its application in laparoscopic radical resection of rectal cancer

The total mesorectal excision(TME)approach has been established as the gold standard for the surgical treatment of middle and lower rectal cancer.This approach is widely accepted to minimize the risk of local recurrence and increase the long-term survival rate of patients undergoing surgery.However,standardized TME causes urogenital dysfunction in more than half of patients,thus lowering the quality of life of patients.Of note,pelvic autonomic nerve damage during TME is the most pivotal cause of postoperative urogenital dysfunction.The anatomy of the Denonvilliers’fascia(DVF)and its application in surgery have been investigated both nationally and internationally.Nevertheless,controversy exists regarding the basic to clinical anatomy of DVF and its application in surgery.Currently,it is a hotspot of concern and research to improve the postoperative quality of life of patients with rectal cancer through the protection of their urinary and reproductive functions after radical resection.Herein,this study systematically describes the anatomy of DVF and its appli-cation in surgery,thus providing a reference for the selection of surgical treatment modalities and the enhancement of postoperative quality of life in patients with middle and low rectal cancer.

直肠阴道隔的解剖学研究及其临床意义

目的:为直肠癌切除术,阴道塌陷及影像学提供解剖学依据。方法:25例福尔马林固定的成年女性盆腔标本,14例行正中失状切,在体式镜下观察,11例制成250～750μm厚的水平和矢状位火棉胶切片。结果:直肠阴道隔由前后两层组成,前层是Denonvilliers'fascia,后层是直肠固有筋膜。二者紧贴在一起,向上在直肠子宫陷凹处的腹膜折返下方分开,向下在会阴体上方分开,两侧在阴道后外侧分开。Denonvilliers'fascia在不同水平其两侧的止点不同:在宫颈平面止于宫旁组织,在阴道上部止于阴道旁组织,在阴道中部止于盆筋膜腱弓,在阴道下部止于肛提肌出口的外侧。结论:直肠阴道隔由前方的Denonvilliers'fascia和后方的直肠固有筋膜组成。

Identification of the surgical indication line for the Denonvilliers’fascia and its anatomy in patients with rectal cancer

Background:The high rate of urogenital dysfunction after traditional total mesorectal excision(TME)has caused doubts among scholars on the standard fashion of dissection.We have proposed the necessity to preserve the Denonvilliers’fascia in patients with rectal cancer.However,how to accurately locate the Denonvilliers’fascia is unclear.This study aimed to explore anatomical features of the Denonvilliers’fascia by comparing autopsy findings and observations of surgical videos so as to propose a dissection method for the preservation of pelvic autonomic nerves during rectal cancer surgery.Methods:Five adult male cadaver specimens were dissected,and surgical videos of 135 patients who underwent TME for mid-low rectal cancer between January 2009 and February 2019 were reviewed to identify and compare the structure of the Denonvilliers’fascia.Results:The monolayer structure of the Denonvilliers’fascia was observed in 5 male cadaver specimens,and it was located between the rectum,the bottom of the bladder,the seminal vesicles,the vas deferens,and the prostate.The Denonvilliers’fascia was originated from the rectovesical pouch(or rectum-uterus pouch),down to fuse caudally with the rectourethral muscle at the apex of the prostate,and fused to the lateral ligaments on both sides.The fascia was thinner on the midline with a thickness of 1.06±0.10 mm.The crown shape of the Denonvilliers’fascia was slightly triangular,with a height of approximately 5.42±0.16 cm at midline.Nerves were more densely distributed in front of the Denonvilliers’fascia than behind,especially on both sides of it.Under laparoscopic view,the Denonvilliers’fascia was originated at the lowest point of the rectovesical pouch(or rectum-uterus pouch),with a thickened white line which was a good mark for identifying the Denonvilliers’fascia.Conclusion:Identification of the surgical indication line for the Denonvilliers’fascia could help us identify the Denonvilliers’fascia,and it would improve our ability to protect the pelvic autonomic function of patients undergoing TME for rectal cancer.

Review of Denonvilliers’fascia:the controversies and consensuses

The Denonvilliers’fascia(DVF)plays an important role in rectal surgery because of its anatomic position and its relationship to the surrounding organs.It affects the surgical plane anterior to the rectum in the procedure of total mesorectal excision(TME).Anatomical and embryological studies have helped us to understand this structure to some extent,but many controversies remain.In terms of its embryonical origin,there are three mainstream hypotheses:peritoneal fusion of the embryonic cul-de-sac,condensation of embryonic mesenchyme,and mechanical pressure.Regarding its architecture,the DVF may be a single,two,or multiple layers,or a composite single-layer structure.In women,most authors deem that this structure does exist but they are willing to call it the rectovaginal septum rather than the DVF.Operating behind the DVF is supported by most surgeons.This article will review those mainstreamstudies and opinions on the DVF and combine them with what we have observed during surgery to discuss those controversies and consensuses mentioned above.We hope this review may help young colorectal surgeons to have a better understanding of the DVF and provide a platform from which to guide future scientific research.