Inside-out autologous vein grafts fail to restore erectile function in a rat model of cavernous nerve crush injury after nerve-sparing prostatectomy.

Some autologous tissues can restore erectile function (EF) in rats after a resection of the cavernous nerve (CN). However, a cavernous nerve crush injury (CNCI) better reproduces ED occurring after a nerve-sparing radical prostatectomy (RP). The aim was to evaluate the effect on EF of an autologous vein graft after CNCI, compared with an artificial conduit. Five groups of rats were studied: those with CN exposure, exposure+vein, crush, crush+guide and crush+vein. Four weeks after surgery, the EF of rats was assessed by electrical stimulation of the CNs. The intracavernous pressure (ICP) and mean arterial pressure (MAP) were monitored during stimulations at various frequencies. The main outcome, that is, the rigidity of the erections, was defined as the ICP/MAP ratio. At 10 Hz, the ICP/MAP ratios were 41.8%, 34.7%, 20.9%, 33.9% and 20.5%, respectively. The EF was significantly lower in rats if the CNCI was treated with a vein graft instead of an artificial guide. Contrary to cases of CN resection, autologous vein grafts did not improve EF after CNCI. In terms of clinical use, the study suggests to limit an eventual use of autologous vein grafts to non-nerve-sparing RPs.

Transanal endoscopic proctectomy and nerve injury risk: bottom to top surgical anatomy, key points.

The transanal approach for rectal resection is a promising approach, because it increases the circumferential radial margin, especially for difficult cases. Meanwhile, functional sequelae are frequent after rectal cancer surgery and are often due to neurological lesions. There is little literature describing surgical anatomy from bottom to top. We combined our surgical experience with our fetal and adult anatomical research to provide a bottom-up surgical description focusing on neurological anatomy (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A148).

Biomechanical origin of the Denonvilliers' fascia.

INTRODUCTION: Since 1836 and the first description of the recto-genital fascia by Charles Denonvilliers, many anatomists have shown interest in this subject. Recently, pelvic surgeons have in turn shown similar interest, for they consider that perfect knowledge of this anatomical domain is crucial for optimal nerve conservation during surgery. Thanks to new anatomical description techniques, fascia location and relationships with pelvic nerves now appear clearer. OBJECTIVES: To describe and represent Denonvilliers' fascia and its relationships in the female foetus at different stages of gestation and in three-dimensional space (3D). MATERIEL/PATIENTS AND METHODS: Computer-assisted anatomical dissection technique was used. Serial histological sections were made from four human female foetuses. Sections were treated with conventional staining, as well as with nerve and smooth muscle immunostaining. Finally, the sections were digitalized and reconstructed in 3D. RESULTS: Denonvilliers' fascia was clearly located and visualized in three dimensions. It was present in the female foetus, being distinct from the fascia propria of the rectum. It appeared to be composed of multiple parallel layers situated between the vagina and the rectum. From a lateral view, it had an asymmetrical "Y-shaped" aspect that seemed to play the role of a protective sheet for the neurovascular bundles. CONCLUSION: This study betters our comprehension of the Denonvilliers' fascia in the female foetus and of its connections with pelvic nerves. It also provides a better understanding of safe planes during pelvic dissection. These findings also suggest a biomechanical theory for embryological origin of the Denonvilliers' fascia.

Optimal plane for nerve sparing total mesorectal excision, immunohistological study and 3D reconstruction: an embryological study.

AIM: Genito-urinary complications are frequent after rectal surgery and are often due to nerve damage. The relationship between the pelvic nerves and surgical planes are unclear. The aim of the study was to determine the relationship between the inferior hypogastric plexus and the fascia of the lateral pelvic wall and between Denonvilliers' fascia and the efferent branches of the inferior hypogastric plexus. METHOD: Computer-assisted anatomical dissection was used. Serial histological sections were made from six human foetuses and a male adult. Sections were stained with haematoxylin and eosin, Masson's trichrome and immunostainings. The sections were then digitalized and reconstructed in three dimensions. RESULTS: The inferior hypogastric plexus was situated in a virtual space between the fascia propria of the rectum and the fascia on the upper surface of the levator ani. During the lateral dissection, the optimal surgical plane is the plane of the fascia propria of the rectum. We located Denonvilliers' fascia in three dimensions. It plays the role of a protective sheet for the neurovascular bundle. The optimal plane for nerve preservation is situated behind Denonvilliers' fascia. CONCLUSION: This study has enabled a clear visualization of the optimal planes to perform total mesorectal excision while ensuring nerve preservation. Three-dimensional visualization clearly helps to bridge the gap between histological examination and the findings of surgery.

Where does pelvic nerve injury occur during rectal surgery for cancer?

AIM: Optimal treatment of rectal adenocarcinoma involves total mesorectal excision with nerve-preserving dissection. Urinary and sexual dysfunction is still frequent following these procedures. Improved knowledge of pelvic nerve anatomy may help reduce this and define the key anatomical zones at risk. METHOD: The MEDLINE database was searched for available literature on pelvic nerve anatomy and damage after rectal surgery using the key words 'autonomic nerve', 'pelvic nerve', 'colorectal surgery', and 'genitourinary dysfunction'. All relevant French and English publications up to May 2010 were reviewed. Reviewed data were illustrated using 3D reconstruction of the foetal pelvis. RESULTS: The ligation of the inferior mesenteric artery and dissection of the retrorectal space can cause damage to the superior hypogastric plexus and/or hypogastric nerve. Anterolateral dissection in the 'lateral ligament' area and division of Denonvilliers' fascia can damage the inferior hypogastric plexus and efferent pathways. Perineal dissection can indirectly damage the pudendal nerve. CONCLUSIONS: In most cases, the pelvic nerves can be preserved during rectal surgery. Complete oncological resection may require dissection close to the nerves where the tumour is located anterolaterally where it is fixed and when the pelvis is narrow.