直肠切除术中保留盆腔内脏神经的解剖学基础及要点

目的了解盆腔内脏神经的走行及与盆腔筋膜的关系,寻找安全的操作平面,减少直肠癌手术中对内脏神经的损伤。方法通过解剖12例人骨盆标本,观察盆腔内脏神经的走向分布及与筋膜间隙的关系。结果腹下神经全程走行于骶前筋膜内,下腹下丛走行于盆壁层筋膜内,并于直肠2点及10点处（截石位）在多个平面交叉穿入Denonvilliers筋膜汇入泌尿生殖血管束,Denonvilliers筋膜内存在横行的神经交通支。结论直肠后方及侧方的手术操作平面在直肠固有筋膜与骶前筋膜之间靠近直肠固有筋膜一侧,在直肠前方的手术操作应注意保护直肠2点及10点位置的泌尿生殖神经血管束及Denonvillers筋膜内的神经交通支。     

Controversias en la anatomía quirúrgica prostática. Revisión de la literarura

IntroductionRadical prostatectomy technique has improved in the last years based on accumulated surgical experience and new anatomical findings. We think it is time to update anatomical concepts to standardized the criteria for mentioning structures related with radical prostatectomyMaterial and MethodWith the followings key words: “cavernosal nerves, prostatectomy, anatomy, neurovascular bundle” we search in Medline/PubMed database selecting papers fulfilling the search criteria.ConclusionsThe prostate does not have a true capsule but rather an incomplete fibromuscular band as an intrinsic part of the gland. Periprostatic fascia seems to be a different structure from this fibromuscular band. Histologically Denonvilliers´s fascia is formed by two thin layers that cannot be separated during surgery. The longitudinal smooth muscle fibres located beneath the posterior bladder neck corresponds to the posterior longitudinal fascia of the detrusor muscle. Cavernosal nerves are located between the two layers of the endopelvic fascia, the inner layer could be named periprostatic fascia and the outer, levator ani fascia. Cavernosal nerves merged from the pelvic plexus running within a neurovascular bundle around the prostate that could be found as a singular bundle or spread all around the anterolateral surface of this gland. There are overlapping terms to designate the pelvic fascia, therefore it could be useful for Urologists to standardized them.     

从盆腔筋膜的外科解剖来理解直肠全系膜切除术的层次

目的探讨直肠系膜与盆腔筋膜和神经的关系，以明确直肠全系膜切除术合理的切除平面。方法对24具尸体的盆腔进行解剖。结果直肠周围的层次是连续的，可以分为2段3层，2段指耻骨联合至坐骨棘和坐骨棘至骶岬；3层分别为脏筋膜、膀胱腹下筋膜和壁筋膜。在膀胱腹下筋膜与脏筋膜之间存在盆丛及其膀胱、子宫神经分支，而在脏、壁筋膜之间存在腹下神经和盆内脏神经。结论直肠全系膜切除术的层次在直肠后方为脏、壁筋膜之间，而在直肠侧方实际上位于脏筋膜和膀胱腹下筋膜之间。侧后方的腹下神经、侧前方的盆丛及其分支是正确层次的标记。     

低位直肠癌保功能手术的解剖学基础

尽管全直肠系膜切除术（TME）是直肠癌根治术的金标准．但术后有一定的泌尿生殖功能障碍发生率。我们通过盆腔筋膜的解削研究明确了TME正确的手术层次,并进一步界定了手术层次与盆腔神经的关系．以期减少术巾神经损伤。值得注意的是,盆丛存在两种形态。如果盆丛为弥散状,完整的切除直肠系膜将不可避免地损伤盆丛,因而需通过深入的研究明确盆丛不同的功能单位。     

直肠系膜两个无血管层次的解剖特征

目的：探讨全直肠系膜切除的解剖学基础,明确全直肠系膜切除的切除平面。方法：对23具尸体的盆腔进行解剖,观察直肠系膜与周围筋膜、神经的关系。结果：在直肠的侧后方存在两个无血管层次．即直肠周围脂肪与脏筋膜之间的层次及脏层筋膜与壁层筋膜之间的层次。各层次内存在不同的组织结构,在直肠与脏筋膜间存在着直肠侧韧带．在脏、壁层筋膜间存在着腹下神经和盆内脏神经。结论：全直肠系膜切除的切除范围应包括脏层筋膜在内,解剖层次应为脏、壁层筋膜间层次;术中通过观察两个无血管层次中的结构可以判定是否进入了正确的全直肠系膜切除的切除层次。     

腹腔镜直肠癌手术中神经血管束显露保护及其损伤防治

全直肠系膜切除的提出推动了结直肠外科进入膜解剖时代,极大降低了直肠癌的局部复发率及改善了泌尿及性功能的保护。但由于盆丛及神经血管束与直肠系膜间存在多处微血管及神经的支配关系,导致直肠系膜在侧前方及侧后方与盆壁均存在致密粘连,神经血管束被分为多层的Denonvilliers筋膜包裹及分割,Denonvilliers筋膜后叶向后与盆筋膜壁层的前叶相延续,盆筋膜壁层分层包绕腹下神经、盆丛及神经血管束,保护Denonvilliers筋膜后叶及盆筋膜壁层的完整性是保护神经血管束的重要原则,神经纤维周围有微血管并行,来自髂内血管系统走向直肠系膜的滋养血管具有不同于盆筋膜壁层表面微血管的走行特征,可作为辅助筋膜辨识的重要标志。适当的牵拉暴露、分离手法,优化的手术流程,熟悉筋膜解剖以及微血管对筋膜辨认的作用是避免神经血管束损伤的关键措施。     

盆腔神经血管束的解剖及与下尿路手术的关系

目的 认识盆腔神经血管柬(NVB)与周围组织器官的关系。方法 对4个成人男性盆腔器官标本作NVB大体解剖或组织切片，观察NVB与周围组织器官的关系。结果 由盆丛发出的海绵体神经在前列腺基底部与前列腺血管形成NVB，NVB的密度沿前列腺下行时逐渐变稀，于尿道膜部外侧和后外侧穿过尿生殖膈。NVB在前列腺包膜外、盆筋膜内，NVB在前列腺基底部、尖部水平与前列腺包膜距离约1．5mm和3mm。结论 明确NVB与周围组织器官的关系，为下尿路手术中避免损伤海绵体神经，减少医源性ED有重要意义。     

Clinical indications and outcomes with nerve-sparing cystectomy in patients with bladder cancer

The autonomic sympathetic and parasympathetic nerve fibers from the pelvic plexus pass through the dorsomedial pedicle of the bladder ending as the paraprostatic neurovascular bundle or paravaginal plexus before supplying the urogenital diaphragm, sphincter, and erectile organs. Preservation of the autonomic innervation is important for sexual, lower urinary tract, and bowel function. Oncologic outcome is not compromised by a nerve-sparing cystectomy if adequate selection criteria are applied. During pelvic lymphadenectomy nerve sparing is not impaired as long as the dissection is performed on the lateral, not medial side of the ureters, where the nerves lie. Nerve-sparing radical cystectomy preserves sexual function and, in the case of orthotopic bladder substitution, better continence, and decreased catheterization rates (especially in women) are achieved. Therefore, under the proper circumstances, nerve-sparing radical cystectomy is to be strongly recommended.     

Anatomical analysis of the neurovascular bundle supplying penile cavernous tissue to ensure a reliable nerve graft after radical prostatectomy

PURPOSE: Urologists and anatomists have disagreed concerning pelvic neurovascular bundle (NVB) structure. Recently interposition nerve grafting has been performed to improve erectile function after radical prostatectomy. To refine this procedure we reviewed NVB structure from the surgical viewpoint. MATERIALS AND METHODS: Seven fresh cadavers and serial horizontal sections from 20 formalin fixed cadavers were used for gross dissection and histological examination. RESULTS: Fresh cadaver dissections demonstrated that the pelvic splanchnic nerve (PSN) joined the NVB at a point distal or inferior to the bladder-prostate (BP) junction. Histologically hypogastric nerve fibers were much more dominant than PSN fibers at the BP junction, and the NVB, covered by the lateral pelvic fascia, became evident at levels more than 20 to 30 mm below the BP junction. PSN components joined the NVB in a spray-like distribution at multiple levels more than 20 mm distal to the BP junction. At these low levels nerves tended to be located outside of the NVB at the dorsolateral margin of the prostate. The cranial end of the mimic interposition nerve graft was directed toward the hypogastric nerve rather than the PSN. CONCLUSIONS: In contrast to general clinical opinion, the NVB appears to supply few PSN components at the BP junction with caudal PSN branches reaching the dorsolateral prostate more than 20 mm below the BP junction. This anatomy has important implications for a reliable nerve graft.     

直肠癌根治术中保留骨盆自主神经的神经解剖学基础及临床意义

目的　探讨直肠癌根治术中保留神经的解剖学基础。　方法　解剖 6例完整尸体标本(男 4例 ,女 2例 )和 4例直肠及盆腔未受破坏的矢状半骨盆标本 ,观察骨盆神经组成及走行。　结果　显露下腹神经干 ,确定其在第 5腰椎处分为左、右下腹神经。其特点是较为粗大 ,位置固定 ,在腹主动脉分叉处易找到 ,呈网状联系 ,质地较实 ,为灰白色 ,与腹主动脉较近。分叉后左右下腹神经还有较粗大分支。骨盆内脏神经在大体标本上较难辨认 ,在矢状半骨盆标本中见到发自骶前孔 2～ 4的骨盆内脏神经 ,该神经较纤细 ,在侧韧带处呈丛状的细小纤维。　结论　保留下腹神经临床上较易完成。保留骨盆内脏神经则须细心操作 ,预保留神经的一侧在侧韧带水平的手术操作应尽量贴近直肠进行。     

Nerve-preserving aortoiliac reconstruction surgery: anatomical study and surgical approach

OBJECTIVE: Dysfunctional ejaculation and, to a lesser extent, dysfunctional erection caused by disruption of efferent sympathetic pathways is a common complication after aortoiliac reconstruction surgery. The aim was to give an anatomic motivation for a nerve-preserving approach on the basis of right-sided unilateral disruption of lumbar splanchnic nerves. METHODS: Anatomic and microscopic analysis of preaortic and para-aortic retroperitoneal regions in human cadavers was performed. Anatomic analysis was conducted of two aortoiliac reconstruction operations performed on human cadavers; one was performed according to a single-blind procedure, the second with a modified procedure. RESULTS: The lumbar splanchnic nerves supplying the superior hypogastric plexus from the right side were found to be less voluminous than the left-sided ones. The superior hypogastric plexus was found slightly shifted to the left of the midsagittal plane across the abdominal aorta and its bifurcation. Microscopic analysis revealed a thin fascia between the aorta and the subperitoneal tissue compartment. This fascia was used as a plain of dissection to mobilize the preaortic nerve-plexuses without damage from the aortic wall. Analysis of the specimens operated on showed a significant difference in nerve disruption. The standard procedure caused total disruption of the superior hypogastric plexus and extensive disruption of the inferior mesenteric plexus. The modified procedure only caused right-sided unilateral disruption of lumbar splanchnic nerves. CONCLUSION: The autonomic nerves supplying the bladder neck, the vas deferens, and the prostate are closely related to the abdominal aorta and its bifurcation. Right-sided unilateral disruption of lumbar splanchnic nerves without further damage to nervous structures would ensure at least one functional sympathetic pathway remaining after aortoiliac reconstruction surgery.     

人体前列腺外侧神经血管束显微解剖研究

目的了解人体前列腺外侧神经血管束的具体走行和分布。方法采用手术显微镜，对成年男性尸体前列腺外侧神经血管束进行解剖观察，同时采用组织切片神经性一氧化氮合酶(nNOS)免疫组织化学染色方法，对1具成年男尸标本前列腺外侧神经血管束进行染色分析。结果盆丛发出分支与血管一起构成神经血管束，分成两支沿前列腺后外侧和前外侧走行到达尿生殖膈。前列腺后外侧、前外侧神经血管束与尿生殖膈组成三角区，三角区中央可见前列腺包膜，该区无神经血管覆盖。后外侧和前外侧神经血管束中的神经穿过尿生殖膈上筋膜后，在截石位膜部尿道外会合成一支。前列腺外侧神经血管束nNOS免疫组织化学染色，前列腺后外侧和前外侧神经血管束中均存在大量nNOS神经元细胞体和神经纤维。结论前列腺外侧存在2条神经血管束，分别为前外侧和后外侧神经血管束，包含nNOS染色阳性神经节细胞。     

Radical prostatectomy with preservation of sexual function: anatomical and pathological considerations

The technique for radical retropubic prostatectomy has been modified to avoid injury to the branches of the pelvic plexus that innervate the corpora cavernosa. The surgical procedure is based on an understanding of the anatomical relationships between the branches of the pelvic plexus that innervate the corpora cavernosa, the capsular branches of the prostatic vessels that provide the scaffolding for these nerves, and the lateral pelvic fascia. The modifications involve two steps in the procedure: 1) the incision in the lateral pelvic fascia is placed anterior to the neurovascular bundle, which is located dorsolateral to the prostate along the pelvic sidewall; 2) the lateral pedicle is divided close to the prostate to avoid injury to the branches of the pelvic plexus that accompany the capsular vessels of the prostate. Pathologic evaluation of 16 prostatic specimens removed by this modified procedure demonstrated no compromise in the adequacy of the surgical margins. Postoperative sexual function was evaluated in 12 men who underwent the procedure 2-10 months previously. All have experienced erections and six have achieved successful vaginal penetration and orgasm. Of the six patients with sexual partners who have been followed 6 months or longer, five (83%) are fully potent. These data indicate that it is possible to cure localized prostatic cancer with surgery and maintain postoperative sexual function.     

Pelvic fasciae in urology

INTRODUCTION

Despite the vast literature on pelvic fascia, there is confusion over the periprostatic structures and their nomenclature, including their orientation, the neurovascular bundles and the existence of the prostatic ‘capsule’. In this review, we seek to clarify some of these issues.

MATERIALS AND METHODS

Review of published medical literature relating to the anatomy of the pelvic fascia including a Pubmed search using the terms – pelvic fascia, Denonvilliers'' fascia, prostate capsule, neurovascular bundle of Walsh, pubo-prostatic ligament and the detrusor apron.

CONCLUSIONS

The findings of the study were as follows:

1. The ‘capsule’ of the prostate does not exist. Rather, the fibromuscular band surrounding the prostate forms an integral part of the gland.
2. The prostate is surrounded by fascial structures – anteriorly/anterolaterally by the prostatic fascia and posteriorly by the Denonvilliers'' fascia. Laterally, the prostatic fascia merges with the endopelvic fascia.
3. The posterior longitudinal fascia of the detrusor comprises a ‘posterior layer’ of the detrusor apron, extending from the bladder neck to the prostate base.
4. The neurovascular structures tend to be located posterolaterally, but may not always form a bundle. A significant proportion of fibres may lie away from the main nerve structures, along the lateral/posterior aspects of the prostate.

     

Essential anatomy for total mesorectal excision and lateral lymph node dissection,in both trans-abdominal and trans-anal perspective

Background and PurposeTotal Mesorectal Excisions (TME) is the standard treatment of rectal cancer. It can be performed under laparoscopic, robotic or transanal approach. Inadvertent injury to surrounding structure like autonomic nerves is avoidable, no matter which approach is adopted. Lateral lymph node dissection (LLND) is a less commonly performed pelvic operation involving dissection in an unfamiliar area to most general surgeons. This article aims to clarify all the essential anatomy related to these procedures.MethodsWe performed thorough literature search and revision on the pelvic anatomy. Our cases of TME and LLND, under either laparoscopic or transanal approach, were reviewed. We integrated the knowledge from literatures and our own experience. The result was presented in details, together with original figures and intra-operative photos.Main findingsAnatomy of pelvic fascia, autonomic nerve system, anal canal and sphincter complex are core knowledge in performing TME and LLND.ConclusionsThorough understanding of the pelvic anatomy enables colorectal surgeons to master these procedures, avoid complication and perform extended resection. On the other hand, surgeons can appreciate the complex pelvic anatomy easier by seeing the pelvis in opposite angles (transabdominal and transaanal view).     

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.     

男性盆腔神经丛及神经血管束的应用解剖

目的认识盆丛、神经血管束（NVB）与周围组织器官的关系。方法对10例成人男性盆腔器官标本作盆丛、NVB大体解剖,1例43岁成人新鲜盆腔脏器作连续切片,观察盆丛、NVB与周围组织器官的关系。结果盆丛位于腹膜后、直肠的侧壁,呈网络状,精囊腺的后外侧,由盆丛发出的阴茎海绵体神经在前列腺后外侧走行,这些神经与前列腺被膜血管组成NVB。NVB的密度沿前列腺下行时逐渐变稀,在膜部尿道的外侧和后外侧分布于尿道旁的横纹肌中。结论明确盆丛、NVB位置以及与盆腔器官的毗邻关系,有助于术中有效鉴别和保护盆丛和NVB,达到保留性神经的盆腔、会阴部手术的目的。     

The pelvic plexus and antireflux surgery: topographical findings and clinical consequences

PURPOSE: Voiding dysfunction and urinary retention are rare complications of antireflux surgery. As mainly reported after bilateral antireflux surgery with extravesical technique, bladder insufficiency has been suspected to be caused by intraoperative damage to neural structures. We studied the topography of the pelvic plexus and assessed the injury to the plexus resulting from antireflux surgery. MATERIALS AND METHODS: Human cadavers fixed with Thiel solution were used for dissection. The superior hypogastric plexus and hypogastric nerves were identified as the pathway to the pelvic plexus. After dissecting the surrounding fatty tissue the S2 to S4 nerves and efferent nerve bundles from the pelvic plexus were identified. RESULTS: The main portion of the pelvic plexus was located about 1.5 cm. dorsal and medial to the ureterovesical junction. The bundles of the pelvic plexus ended at the distal ureter, trigone and rectum. When simulating an antireflux procedure, there was a high risk of injury to the pelvic plexus and its efferent nerves if dissection was performed distal to the ureter and dorsal trigone. CONCLUSIONS: Careful dissection close to the ureter avoids inadvertent injury to the pelvic plexus. To minimize the risk of voiding dysfunction bilateral antireflux surgery should be performed at 2 sessions unless the operative technique allows preservation of the neural structures.