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.

Denonvilliers筋膜综述:争议与共识

Denonvilliers筋膜(DVF)因其解剖部位及其与周围器官的关系,在直肠癌外科中具有重要意义。在全直肠系膜切除术中,DVF对直肠前方手术平面具有重要影响。解剖学和胚胎学研究有助于我们一定程度理解DVF这一结构,但仍存在诸多争议。基于胚胎起源有三个主要假说:腹膜融合假说、间充质凝聚假说和机械压力假说。从其结构看,DVF可以是单层、双层、多层或是一个复合单层结构。大多数学者认为女性也存在这一结构,但他们更愿意称其为直肠阴道隔而不是DVF。大多外科医生都会选择将DVF后方作为手术层面。本文对DVF方面的主要研究和主流意见进行了综述,并结合我们自身的术中观察,对上述争议与共识展开讨论。希望本文能帮助年轻结直肠外科医生更好地理解DVF,并为今后的进一步研究提供方向参考。