The architecture of perirectal fasciae is complex as mirrored by different anatomical concepts.This study aimed to perform a comprehensive visualization of perirectal fasciae to facilitate strategies of rectal surgery such as total mesorectal excision, intersphincteric resection, and transanal total mesorectal excision.Macroscopic dissection and histologic studies of perirectal fasciae and autonomic pelvic nerves were performed.This study was conducted in a university laboratory of macroscopic and microscopic anatomy.Thirteen (5 female) pelvic specimens were obtained from body donors (67-92 years of age).The primary outcomes measured were the photodocumentation of perirectal fasciae, spaces and fusion zones, and histologic and immunohistochemical analysis of key structures.The retrorectal space is a mesofascial interface between the mesorectal fascia and the parietal pelvic fascia. The parietal pelvic fascia is composed of 2 lamellae ensheathing the autonomic pelvic nerves. The outer lamella of the parietal pelvic fascia and the presacral fascia confine the presacral space. The presacral fascia covers the median sacral blood vessels. Approximately at the fourth sacral vertebra, all fascial layers fuse in the midline and are densely connected to the posterior rectal wall via the rectosacral ligament. The parietal pelvic fascia fuses with the pubococcygeal and longitudinal rectal muscles at the anorectal junction. Anterolaterally, the neurovascular bundles are closely related to this fascial fusion zone and the rectogenital septum.Because of the increased age of the body donors, the findings may be subjected to age-related degenerative processes.The 2 lamellae of the parietal pelvic fascia and the fascial fusion zones are key structures of perirectal anatomy. For autonomic nerve preservation, the recognition of the inner lamella of the parietal pelvic fascia is crucial. To avoid inadvertent rectal perforation or accidental presacral dissection, the rectosacral ligament must be identified and transected for complete rectal mobilization. See Video Abstract at http://links.lww.com/DCR/B389. ANATOMÍA FASCIAL PERIRRECTAL: NUEVOS CONCEPTOS SOBRE UN ANTIGUO PROBLEMA: La arquitectura de las fascias perirrectales es compleja, reflejada por distintos conceptos anatómicos.Integración de conceptos sobre las fascias perirrectales para facilitar las estrategias de cirugía rectal, como la escisión mesorrectal total, la resección interesfintérica y la escisión mesorrectal total transanal.Disección macroscópica y estudios histológicos de fascias perirrectales y nervios pélvicos autonómicos.Laboratorio universitario de anatomía macroscópica y microscópica.Trece (5 mujeres) muestras pélvicas obtenidas de donantes de cuerpo (67-92 años).Foto documentación de fascias perirrectales, espacios y zonas de fusión, análisis histológico e inmunohistoquímico de estructuras claves.El espacio retrorectal es una interfaz mesofascial entre la fascia mesorrectal y la fascia pélvica parietal. Este último se compone de dos láminas que envuelven los nervios pélvicos autonómicos. La lámina externa de la fascia pélvica parietal y la fascia presacra definen el espacio presacro. La fascia presacra cubre los vasos sanguíneos sacros medianos. Aproximadamente en la cuarta vértebra sacra, todas las capas fasciales se unen en la línea media y están densamente conectadas a la pared rectal posterior a través del ligamento rectosacro. La fascia pélvica parietal se une con los músculos rectal pubococcígeo y longitudinal en la unión anorrectal. Anterolateralmente, los haces neurovasculares están estrechamente relacionados con esta zona de fusión fascial y el tabique rectogenital.Debido al aumento de la edad de los donantes de cuerpos, los hallazgos pueden estar sujetos a procesos degenerativos relacionados con la edad.Las dos láminas de la fascia pélvica parietal y las zonas de fusión fascial son estructuras claves de la anatomía perirrectal. Para la preservación del nervio autónomo de nervios pélvicos autonómicos, el reconocimiento de la lámina interna de la fascia pélvica parietal es importante. Para evitar la perforación rectal inadvertida o la disección presacra accidental, el ligamento rectosacro debe ser identificado y seccionado para una movilización rectal completa. Consulte Video Resumen en http://links.lww.com/DCR/B389.

Total mesorectal excision (TME) has greatly improved rectal cancer surgery outcomes by reducing local recurrence and enhancing patient survival. This review outlines essential knowledge and techniques for performing TME. TME emphasizes the complete resection of the mesorectum along embryologic planes to minimize recurrence. Key anatomical insights include understanding the rectal proper fascia, Denonvilliers fascia, rectosacral fascia, and the pelvic autonomic nerves. Technical tips cover a step-by-step approach to pelvic dissection, the Gate approach, and tailored excision of Denonvilliers fascia, focusing on preserving pelvic autonomic nerves and ensuring negative circumferential resection margins. In Korea, TME has led to significant improvements in local recurrence rates and survival with well-adopted multidisciplinary approaches. Surgical techniques of TME have been optimized and standardized over several decades in Korea, and minimally invasive surgery for TME has been rapidly and successfully adopted. The review emphasizes the need for continuous research on tumor biology and precise surgical techniques to further improve rectal cancer management. The ultimate goal of TME is to achieve curative resection and function preservation, thereby enhancing the patient's quality of life. Accurate TME, multidisciplinary-based neoadjuvant therapy, refined sphincter-preserving techniques, and ongoing tumor research are essential for optimal treatment outcomes.

Little is known about which urogenital nerves are liable to be injured along surgical planes in front of or behind Denonvilliers' fascia.Using semiserial histology for five fixed male pelves, we demonstrated that: 1) left/right communicating branches of bilateral pelvic plexuses run immediately in front of Denonvilliers' fascia; and 2) a lateral continuation of Denonvilliers' fascia separates the urogenital neurovascular bundle from the mesorectum. Notably, the mesorectum contains no or few extramural ganglion cells. At the level of the seminal vesicles, incision in front of Denonvilliers' fascia seems likely to injure superior parts of the pelvic plexus and the left/right communication. Moreover, at the prostate level, this incision misleads the surgical plane into the neurovascular bundle. Fresh cadaveric dissections of five unfixed male pelves confirmed that the surgical plane in front of Denonvilliers' fascia continues to a fascial space for the pelvic plexus containing ganglion cell clusters lateral and/or inferior to the seminal vesicles.To preserve all autonomic nerves for urogenital function, optimal total mesorectal excision for rectal cancer requires dissection behind Denonvilliers' fascia.

由于传统的全直肠系膜切除（TME）术后泌尿生殖功能障碍发生率居高不下，以致引起国内外学者对TME理念的争议及质疑，直肠癌手术保留Denonvilliers筋膜的必要性已受到越来越多国内外学者的赞同。然而，术中如何精准定位Denonvilliers筋膜，一直没有定论。通过反复临床实践，结合尸体标本解剖，首次发现Denonvilliers筋膜的顶部位于膀胱直肠陷凹(或直肠子宫陷凹)腹膜返折最低处，呈白色增厚线，这条线是辨认Denonvilliers筋膜最好的手术标记线。在该线前方游离则进入Denonvilliers筋膜的前方，而在线后方游离，则进入Denonvilliers筋膜的后方，从而完整地保留Denonvilliers筋膜，并更好地保护术后泌尿生殖功能。该手术标识线的发现，可为改良的保留Denonvilliers筋膜的TME术式提供标准化手术流程及入路，并为从事盆底手术操作的外科医生提供借鉴。

Anatomical detail with superb illustration

全直肠系膜切除（TME）是中低位直肠癌手术的金标准。传统的TME手术要求在Denonvilliers筋膜前方解剖并切除Denonvilliers筋膜，然而术后居高不下的排尿及性功能障碍发生率引起国内外学者对该理念的争议及质疑。对中低位直肠癌病人，应施行个体化治疗方案。对于肿瘤不位于直肠前壁及侧壁，或肿瘤局部分期较早的病人，应在保证肿瘤根治性的前提下，选择Denonvilliers筋膜后方施行TME手术，尽可能保留Denonvilliers筋膜的完整性，从而保护盆腔自主神经，避免术后排尿及性功能障碍，提高病人术后生活质量。

The term "lateral rectal ligament" in surgery for rectal cancer has caused confusion regarding its true existence and contents. In previous studies, investigators claimed the existence of the ligament and described its topographical features as neurovascular structures and their surrounding connective tissues located at the anterolateral aspect of the distal rectum or the posterolateral aspect of the middle rectum. The purpose of this study is to evaluate the structure of the so-called "lateral rectal ligament" in cadaver dissections.Dissection was performed in nine cadavers (eight males and one female, aged 73 to 94 years) in accordance with typical total mesorectal excision techniques. During dissection, structures related to "the ligament" were examined and images recorded.At the anterolateral aspect of the distal rectum, the middle rectal artery was noted to be crossing the fusion of Denonvilliers' fascia and the proper rectal fascia. At the posterolateral aspect of the middle rectum, there was a structure which consisted of the rectal nerves running through the fusion of the pelvic fasciae. Although called "ligaments," neither structure contained discrete strong connective tissue fixing the rectum to the pelvic wall.The proper rectal fascia and surrounding pelvic fasciae fuse firmly anterolaterally and posterolaterally where neurovascular structures course toward the rectum. During a total mesorectal excision, the surgical dissection plane coincides with the fused part of the fasciae, which had long been considered the "lateral rectal ligament."

The progress in the surgery of male neurological cancers relies on the anatomico-surgical approach to the pelvic neural structures. The objective of our study was to provide a better understanding of the inferior hypogastric plexus (IHP) and its anatomical relationships in order to spare it during radical prostatectomy. Fifteen male formalin-preserved cadavers which had no sub-umbilical scar were used. In five subjects, the superior hypogastric plexus (SHP) and the pre-sacral plexus were displayed then the IHP and its sacral afferents (pelvic splanchnic nerves or erector nerves of Eckhardt) were dissected out. Serial sections of the IHP were then studied in ten subjects. This allowed its identification on certain imaging sections obtained in pelvic tumor pathology and these made up the "reference cuts". The IHP lies within a fibro-fatty plate which is flat, rectangular, sub-peritoneal, sagittal and symmetrical. It arises at the level of the intersection between the vas deferens and the terminal pelvic ureter and follows the postero-lateral aspect and circumvolutions of the seminal vesicle, with which there is a plane of surgical cleavage. The seminal vesicle is, therefore, an essential landmark for this neural structure. The plane of this cleavage may be used in pelvic cancer surgery. The safest technical means of respecting sexual function and the integrity of the IHP is to keep it at a distance. The preservation of a lateral layer of the seminal vesicle is probably a method of limiting these complications as long as this does not conflict with the oncological clearance. An irregular communicating branch was found in one of five cases between the IHP, the sacral plexus and the pudendal nerve. This communicating branch lay immediately behind the intersection between the vas deferens and the ureter in the sacral concavity. It overhangs the IHP in the seminal vesicle. Impotence remains a frequent complication after radical prostatectomy. The methods of neural preservation at the prostatic apex are known but neural preservation should also be carried out posteriorly at the lateral pole of the seminal vesicle. The possibility of posterior neural preservation may be assessed pre-operatively by study of the "reference sections". The cleavage plane between the seminal vesicle and the IHP may be used intra-operatively to spare the IHP. The cavernous nerve in particular emerges at the antero-inferior border of the IHP before running along the postero-lateral aspect of the prostate. It therefore passes in contact with the seminal vesicle and may as a result be injured during radical prostatectomy with vesiculectomy. A proximal communicating branch between the IHP and the pudendal nerve is irregular. Such communicating branches may explain a better recovery of sexual function in curative neurological cancer surgery. The essential relationship of the IHP is with the seminal vesicle. The two are in tight contact and the seminal vesicle has a true plane of surgical cleavage with IHP. The risk of injuries to the posterior erectile mechanisms can be reduced either by using the cleavage plane between the IHP and seminal vesicle or by leaving a layer of the seminal vesicle when the oncological conditions allow. During celio-surgery, the operator must be careful to retract the little bands of the seminal vesicle and divide the fibrous and vascular tracts which tighten during this maneuver. During an abdominal approach, dissection of the seminal vesicle takes place at the bottom of a real pit. The operator must carry out the division leaving a layer of the seminal vesicle in place rather than trying to extract all the seminal vesicle by placing the forceps blindly. This maneuver is naturally dependent on the oncological situation. The anatomical confirmation of a regular or irregular proximal or distal communicating branch between the IHP and the pudendal nerve is probably an explanation for the sometimes uncertain results of new techniques of neural preservation in curative cancer surgery.

Urogenital dysfunction after rectal and pelvic surgery was significantly decreased with the introduction of nerve-preserving dissection and total mesorectal excision (TME). Profound topographic knowledge of the pelvic connective tissue spaces is indispensable for identification and preservation of autonomic pelvic nerves. The purpose of this cadaver study was to highlight the course of important autonomous nerve structures and to identify potential injury sites.Eleven cadavers were dissected according to TME with subsequent preparation of the pelvic nerves. The pelves of further three cadavers were sliced horizontally and cubed. Specimens were harvested and processed for light microscopy and immunohistochemistry to analyze both fascia and the types of nerves and their localization.The neurovascular bundle, arising from the inferior pelvic plexus, shows the highest nerve density. At the lateral edge of Denonvilliers' fascia, it pierces the parietal pelvic fascia. Several fine nerve branches spread into the loose periprostatic tissue up to the prostate or pass the prostate toward the urinary bladder. En route, we consistently find perikarya of autonomic nerves. Within the mesorectum, nerve fibers are distributed heterogeneously with laterally high densities, ventrally and dorsally low densities.The highest risk for pelvic nerve damage-apart from lesions of the superior hypogastric plexus itself-is anterolaterally of the rectum where the neurovascular bundle releases from the pelvic sidewall. Careful dissection helps to identify and protect these nerve structures. The retroprostatic Denonvilliers' fascia contains no important nerve structures.

The anatomy of the levator hiatus and tunnel has been studied, aiming at the elucidation of their functional role in mechanisms of defecation, urination, and continence. The material comprised 25 cadavers studied by dissection and serial histologic sections. The levator hiatus occupies the anterior portion of the levator plate which consists of two "crura," that bound the hiatus, and two "lateral masses." Three crural patterns could be identified: classic, crural overlap and crural scissor. The levator tunnel is a muscular tube which surrounds the intrahiatal organs along their way down from the levator hiatius to the perineum. It is double sheathed, with an inner coat of the suspensory sling and an outer of the puborectalis. Both coats are of striped muscle bundles. The inner coat is a tunnel "dilator," whereas the outer is a tunnel "constrictor." The puborectalis not only acts as a "common tunnel" sphincter but provides an "individual" sphincter for each intrahiatal organ. A detailed study of the hiatal ligament which firmly binds the levator plate to the intrahiatal organs is presented. A "tunnel septum" could be identified to line the levator tunnel, and separate it from the intrahiatal organs. Its surgical significance as a landmark for mobilizing the intrahiatal organs from within the tunnel is stressed. The levator plate consists of two functionally separate zones: a lateral "visceral support" zone and medial "dilator" one. The double sphincteric control provided to each intrahiatal organ by the "individual" and "common" sphincters would suggest that unless both sphincters are destroyed, continence could be maintained by either. The role of the "levator complex" which comprises levator crura, tunnel and hiatal ligament in fixation of intrahiatal structures, as well as in mechanisms of defecation, urination, and continence, is discussed. The understanding of the anatomic details of the levator hiatus and tunnel could be of value in mobilizing the intrahiatal structures from within the levator tunnel with preservation of their voluntary sphincteric mechanism.

Intersphincteric resection has become a widely used treatment for patients with rectal cancer. However, the detailed anatomy of the anal canal related to this procedure has remained unclear.The purpose of this study was to clarify the detailed anatomy of the anal canal.This is a descriptive study.Histologic evaluations of paraffin-embedded tissue specimens were conducted at a tertiary referral hospital.Tissue specimens were obtained from cadavers of 5 adults and from 13 patients who underwent abdominoperineal resection for rectal cancer.Sagittal sections from 9 circumferential portions of the cadaveric anal canal (histologic staining) and 3 circumferential portions from patients were studied (immunohistochemistry for smooth and skeletal muscle fibers).Longitudinal fibers between the internal and external anal sphincters consisted primarily of smooth muscle fibers that continued from the longitudinal muscle of the rectum. The levator ani muscle attached directly to the lateral surface of the longitudinal smooth muscle of the rectum. The length of the attachment was longer in the anterolateral portion and shorter in the posterior portion of the anal canal. In the lateral and posterior portions, the levator ani muscle partially overlapped the external anal sphincter; however, there was less overlap in the anterolateral portion. In the posterior portion, thick smooth muscle was present on the surface of the levator ani muscle and it continued to the longitudinal muscle of the rectum.We observed only limited portions in some surgical specimens because of obstruction by tumors.The levator ani muscle attaches directly to the longitudinal muscle of the rectum. The spatial relationship between the smooth and skeletal muscles differed in different portions of the anal canal. For intersphincteric resection, dissection must be performed between the longitudinal muscle of the rectum and the levator ani muscle/external anal sphincter, and the appropriate surgical lines must be selected based on the specific structural characteristics of each portion.

To assess oncologic outcome of patients treated by conservative radical surgery for tumors below 5 cm from the anal verge.Standard surgical treatment of low rectal cancer below 5 cm from the anal verge is abdominoperineal resection.From 1990 to 2003, patients with a nonfixed rectal carcinoma at 4.5 cm or less from the anal verge and without external sphincter infiltration underwent conservative surgery. Surgery included total mesorectal excision with intersphincteric resection, that is, removal of the internal sphincter, to achieve adequate distal margin. Patients with T3 disease or internal sphincter infiltration received preoperative radiotherapy.Ninety-two patients with a tumor at 3 (range 1.5-4.5) cm from the anal verge underwent conservative surgery. There was no mortality and morbidity was 27%. The rate of complete microscopic resection (R0) was 89%, with 98% negative distal margin and 89% negative circumferential margin. In 58 patients with a follow-up of more than 24 months, the rate of local recurrence was 2% and the 5-year overall and disease-free survival were 81% and 70%, respectively.The technique of intersphincteric resection permits us to achieve conservative surgery in patients with a tumor close to or in the anal canal without compromising local control and survival. Tumor distance from the anal verge is no longer a limit for sphincter-saving resection.

Intersphincteric resection (ISR) is an oncologically complex operation for very low-lying rectal cancers. Yet, definition, anatomical description, operative indications and operative approaches to ISR are not standardized. The aim of this study was to standardize the definition of ISR by reaching international consensus from the experts in the field. This standardization will allow meaningful comparison in the literature in the future.A modified Delphi approach with three rounds of questionnaire was adopted. A total of 29 international experts from 11 countries were recruited for this study. Six domains with a total of 37 statements were examined, including anatomical definition; definition of intersphincteric dissection, intersphincteric resection (ISR) and ultra-low anterior resection (uLAR); indication for ISR; surgical technique of ISR; specimen description of ISR; and functional outcome assessment protocol.Three rounds of questionnaire were performed (response rate 100%, 89.6%, 89.6%). Agreement (≥80%) reached standardization on 36 statements.This study provides an international expert consensus-based definition and standardization of ISR. This is the first study standardizing terminology and definition of deep pelvis/anal canal anatomy from a surgical point of view. Intersphincteric dissection, ISR and uLAR were specifically defined for precise surgical description. Indication for ISR was determined by the rectal tumour's maximal radial infiltration (T stage) below the levator ani. A new surgical definition of T3isp was reached by consensus to define T3 low rectal tumours infiltrating the intersphincteric plane. A practical flowchart for surgical indication for uLAR/ISR/abdominoperineal resection was developed. A standardized ISR surgical technique and functional outcome assessment protocol was defined.© 2023 Association of Coloproctology of Great Britain and Ireland.

The presacral venous plexus results from anastomoses between the lateral and median sacral veins, and courses into the pelvic fascia covering the anterior aspect of the body of the sacrum. The presacral venous plexus is not directly visible during rectal surgery, and injuries to this plexus may be life-threatening. Dissection of the retrorectal plane or anchoring of the rectum to the sacral promontory as in rectal prolapse surgery exposes the patient to the risk of injury to the presacral venous plexus. The aim of this study was to identify some avascular areas in the anterior aspect of the sacrum in order to lower the occurrence of such injuries during rectal surgery. The pelvis of 10 fresh cadavers was dissected after injection of a colored resin into the inferior vena cava, and the presacral venous plexus was studied. Four avascular tetragonal areas were common to all the specimens. The corners of a square with a side of 3 cm, centered on the anterior aspect of the body of sacrum, were always contained in the avascular areas. The upper side of this square was parallel to a line passing through the sacral promontory, at a 3 cm distance from it. Staples or sutures should be placed in the avascular areas to avoid injuries to the presacral venous plexus.

A new procedure of hemostasis during laparoscopic total mesorectal excision is described.In our surgical department, from January 2004 to December 2007, 128 patients underwent laparoscopic total mesorectal excision. Among them, 47 patients underwent laparoscopic anterior resection after preoperative radiotherapy, 68 patients underwent laparoscopic anterior resection without preoperative radiotherapy, and 13 patients underwent laparoscopic abdominal perineal amputation.In seven laparoscopic rectal surgery cases, we encountered unstoppable presacral bleeding, not amenable by conventional hemostatic solutions. In these cases we applied a simple staging hemostatic procedure. We first performed local compression: tamponing with a small gauze or absorbable fabric hemostat. If bleeding did not stop, we localized an epiploic or omental scrap and excised it by using bipolar forceps and use it as a plug on the tip of a grasping forceps. This plug is then put on the bleeding source and monopolar coagulation is applied by electrified dissecting forceps through the interposed grasping forceps. If bleeding did not stop, we used a little scrap of bovine pericardium graft and tacked it to the bleeding site using endoscopic helicoidal protack.Our experience suggests that this hemostatic step-by-step procedure is a valid option to control persistent presacral hemorrhages.

Presacral venous bleeding is an uncommon but potentially life threatening complication of rectal surgery. During the posterior rectal dissection, it is recommended to proceed into the plane between the fascia propria of the rectum and the presacral fascia. Incorrect mobilisation of the rectum outside the Waldeyer's fascia can tear out the lower presacral venous plexus or the sacral basivertebral veins, causing what may prove to be uncontrollable bleeding.A systematic search of the MEDLINE(®) and Embase™ databases was performed to obtain primary data published in the period between 1 January 1960 and 31 July 2013. Each article describing variables such as incidence of presacral venous bleeding, surgical approach, number of cases treated and success rate was included in the analysis.A number of creative solutions have been described that attempt to provide good tamponade of the presacral haemorrhage, eliminating the need for second operation. However, few cases are reported in the literature.As conventional haemostatic measures often fail to control this type of haemorrhage, several alternative methods to control bleeding definitively have been described. We propose a practical comprehensive classification of the available techniques for the management of presacral bleeding.

Presacral venous bleeding during rectal mobilization is uncommon but potentially life-threatening. Various methods have been proposed for controlling the bleeding, but each has some obvious limitations in clinical practice. We report a simple technique that was designated as circular suture ligation. This technique was efficient in controlling presacral venous bleeding encountered during rectal mobilization.The key point of circular suture ligation was to control the bleeding by suture ligating the venous plexus in one or more circles in the area with intact presacral fascia that surrounds the bleeding site while the bleeding site was temporarily controlled with fingertip pressure. From September 2007 to December 2011, 258 patients underwent rectal surgery in our department because of rectal cancer. Uncontrolled presacral venous bleeding with traditional methods was encountered in eight patients (3 %) with estimated blood loss from 300 to 5,000 ml.Bleeding was successfully controlled in all eight patients with the circular suture ligation. None of the patients required reoperation for bleeding or other issues. No patients developed chronic pelvic pain after the operation.Our experience suggests that circular suture ligation of venous plexus in the area with intact presacral fascia that surrounds the bleeding site is an effective and simple technique to control presacral venous bleeding when traditional techniques fail.

Surgical treatment of low rectal cancer is controversial, and one of the reasons is the lack of definition and standardization of surgery in low rectal cancer.We classified low rectal cancers in 4 groups with the aim of demonstrating that most patients with low rectal cancer can receive conservative surgery without compromising oncologic outcome.Patients with low rectal cancer <6 cm from anal verge were defined in 4 groups: type I (supra-anal tumors: >1 cm from anal ring) had coloanal anastomosis, type II (juxta-anal tumors: <1 cm from anal ring) had partial intersphincteric resection, type III (intra-anal tumors: internal anal sphincter invasion) had total intersphincteric resection, and type IV (transanal tumors: external anal sphincter invasion) had abdominoperineal resection. Patients with ultra-low sphincter-preserving surgery (types II-III) were compared with those with conventional sphincter-preserving surgery (type I).Postoperative mortality, morbidity, surgical margins, local and distant recurrence, and survival were analyzed.Of 404 patients with low rectal cancer, 135 were type I, 131 type II, 55 type III, and 83 type IV. There was no difference in local recurrence (5% to 9% vs 6%), distant recurrence (23% vs 23%), and disease-free survival (70%-73% vs 68%) at 5 years between ultra-low (types II-III) and conventional (type I) sphincter-preserving surgery. Predictive factors of survival were tumor stage and R1 resection but not the type of tumor or type of surgery.This study is limited by the retrospective analysis of a database, obtained from a single institution and covering a 16-year period.Classification of low rectal cancers and standardization of surgery permitted sphincter-preserving surgery in 79% of patients with low rectal cancer without compromising oncologic outcome. This new surgical classification should be used to standardize surgery and increase sphincter-preserving surgery in low rectal cancer.

Local recurrence rates in operable rectal cancer are improved by radiotherapy (with or without chemotherapy) and surgical techniques such as total mesorectal excision. However, the contributions of surgery and radiotherapy to outcomes are unclear. We assessed the effect of the involvement of the circumferential resection margin and the plane of surgery achieved.In this prospective study, the plane of surgery achieved and the involvement of the circumferential resection margin were assessed by local pathologists, using a standard pathological protocol in 1156 patients with operable rectal cancer from the CR07 and NCIC-CTG CO16 trial, which compared short-course (5 days) preoperative radiotherapy and selective postoperative chemoradiotherapy, between March, 1998, and August, 2005. All analyses were by intention to treat. This trial is registered, number ISRCTN 28785842.128 patients (11%) had involvement of the circumferential resection margin, and the plane of surgery achieved was classified as good (mesorectal) in 604 (52%), intermediate (intramesorectal) in 398 (34%), and poor (muscularis propria plane) in 154 (13%). We found that both a negative circumferential resection margin and a superior plane of surgery achieved were associated with low local recurrence rates. Hazard ratio (HR) was 0.32 (95% CI 0.16-0.63, p=0.0011) with 3-year local recurrence rates of 6% (5-8%) and 17% (10-26%) for patients who were negative and positive for circumferential resection margin, respectively. For plane of surgery achieved, HRs for mesorectal and intramesorectal groups compared with the muscularis propria group were 0.32 (0.16-0.64) and 0.48 (0.25-0.93), respectively. At 3 years, the estimated local recurrence rates were 4% (3-6%) for mesorectal, 7% (5-11%) for intramesorectal, and 13% (8-21%) for muscularis propria groups. The benefit of short-course preoperative radiotherapy did not differ in the three plane of surgery groups (p=0.30 for trend). Patients in the short-course preoperative radiotherapy group who had a resection in the mesorectal plane had a 3-year local recurrence rate of only 1%.In rectal cancer, the plane of surgery achieved is an important prognostic factor for local recurrence. Short-course preoperative radiotherapy reduced the rate of local recurrence for all three plane of surgery groups, almost abolishing local recurrence in short-course preoperative radiotherapy patients who had a resection in the mesorectal plane. The plane of surgery achieved should therefore be assessed and reported routinely.

The aim of this study was to determine the incidence of, and preoperative risk factors for, positive circumferential resection margin (CRM) after transanal total mesorectal excision (TaTME).TaTME has the potential to further reduce the rate of positive CRM for patients with low rectal cancer, thereby improving oncological outcome.A prospective registry-based study including all cases recorded on the international TaTME registry between July 2014 and January 2018 was performed. Endpoints were the incidence of, and predictive factors for, positive CRM. Univariate and multivariate logistic regressions were performed, and factors for positive CRM were then assessed by formulating a predictive model.In total, 2653 patients undergoing TaTME for rectal cancer were included. The incidence of positive CRM was 107 (4.0%). In multivariate logistic regression analysis, a positive CRM after TaTME was significantly associated with tumors located up to 1 cm from the anorectal junction, anterior tumors, cT4 tumors, extra-mural venous invasion (EMVI), and threatened or involved CRM on baseline MRI (odds ratios 2.09, 1.66, 1.93, 1.94, and 1.72, respectively). The predictive model showed adequate discrimination (area under the receiver-operating characteristic curve >0.70), and predicted a 28% risk of positive CRM if all risk factors were present.Five preoperative tumor-related characteristics had an adverse effect on CRM involvement after TaTME. The predicted risk of positive CRM after TaTME for a specific patient can be calculated preoperatively with the proposed model and may help guide patient selection for optimal treatment and enhance a tailored treatment approach to further optimize oncological outcomes.

This study aims to evaluate the clinical and anatomical factors, particularly pelvic dimensions that influence the difficulty of performing laparoscopic anterior resection for rectal cancer.We studied 50 consecutive patients who underwent laparoscopic anterior resection with double-stapling technique (DST) anastomosis for rectal cancer between January 2006 and February 2010. Staging was performed by computed tomography. Five pelvic dimensions (anteroposterior and transverse diameters of pelvic inlet and outlet, and pelvic depth) were measured using three-dimensional volume-rendering images. We also examined a number of other clinical characteristics, including gender, history of laparotomy, body mass index (BMI), operator, tumor location, tumor depth, nodal involvement, and tumor diameter. Univariate and multivariate analyses were performed to determine the predictive significance of these variables on surgical difficulty based on operative time and intraoperative blood loss.Males had significantly shorter pelvic inlets and outlets and significantly greater pelvic depth than females. However, gender did not significantly affect surgical outcomes, although males did tend to experience greater blood loss. Maximum tumor diameter (p=0.014), BMI (p=0.001), operator (p<0.001), and tumor location (p=0.009) were independent predictors of operative time, which, in turn, was related to intraoperative blood loss (p<0.001).Maximum tumor diameter, BMI, operator experience, and tumor location can be used to predict the operative time required to complete laparoscopic anterior resection with DST anastomosis for rectal cancer, with no correlations between pelvic dimensions and operative time. The difficulty of the procedure was not related to patients' pelvic dimensions, which led us to conclude that "narrow pelvis" is not a contraindication for this surgery. Based on these results, we suggest that laparoscopic anterior resection should be performed by experienced surgeons in patients with large tumors, high BMI, and/or extraperitoneal rectal cancer.

This study aims to report short-term clinical and oncological outcomes from the international transanal Total Mesorectal Excision (taTME) registry for benign and malignant rectal pathology.TaTME is the latest minimally invasive transanal technique pioneered to facilitate difficult pelvic dissections. Outcomes have been published from small cohorts, but larger series can further assess the safety and efficacy of taTME in the wider surgical population.Data were analyzed from 66 registered units in 23 countries. The primary endpoint was "good-quality TME surgery." Secondary endpoints were short-term adverse events. Univariate and multivariate regression analyses were used to identify independent predictors of poor specimen outcome.A total of 720 consecutively registered cases were analyzed comprising 634 patients with rectal cancer and 86 with benign pathology. Approximately, 67% were males with mean BMI 26.5 kg/m. Abdominal or perineal conversion was 6.3% and 2.8%, respectively. Intact TME specimens were achieved in 85%, with minor defects in 11% and major defects in 4%. R1 resection rate was 2.7%. Postoperative mortality and morbidity were 0.5% and 32.6% respectively. Risk factors for poor specimen outcome (suboptimal TME specimen, perforation, and/or R1 resection) on multivariate analysis were positive CRM on staging MRI, low rectal tumor <2 cm from anorectal junction, and laparoscopic transabdominal posterior dissection to <4 cm from anal verge.TaTME appears to be an oncologically safe and effective technique for distal mesorectal dissection with acceptable short-term patient outcomes and good specimen quality. Ongoing structured training and the upcoming randomized controlled trials are needed to assess the technique further.

In rectal surgery, some situations can be critical, such as anterior topography of locally advanced low tumors with a positive predictive radial margin, especially in a narrow pelvis of men who are obese. Transanal proctectomy is a new laparoscopic technique that uses the transanal endoscopic microsurgery device.The aim of this study is to evaluate the technical feasibility of laparoscopic transanal proctectomy in patients with unfavorable features.This is a single-center, prospective analysis of selected patients with rectal cancer operated on from January 2009 to June 2011.Intraoperative details and short-term postoperative outcome were described.Thirty men with advanced or recurrent low rectal tumors associated with unfavorable anatomical and/or tumor characteristics underwent a sphincter-sparing transanal endoscopic proctectomy. Twenty-nine patients had received preoperative treatment. We report a 6% conversion rate, no postoperative mortality, and a 30% morbidity rate. At the beginning of our experience, a urethral injury was diagnosed in 2 patients and easily sutured intraoperatively, without postoperative after-effect. The mesorectal resection was graded as "good" in all patients. R0 resection was achieved in 26 patients (87%). The short-term stoma closure rate was 85%. After a median follow-up of 21 months, 4 patients experienced locoregional recurrence alone. Overall survival rates at 12 and 24 months were 96.6% (95% CI, 78.0-99.5) and 80.5% (95% CI, 53.0-92.9). Relapse-free survival rates at 12 and 24 months were 93.3% (95% CI, 75.9-98.3) and 88.9% (95% CI, 69.0-96.3).Although the transanal endoscopic proctectomy was performed by trained surgeons, we report a slight increase in early postoperative morbidity and relatively poor early outcome. There was a clear selection bias related to the study cohort exclusively composed of high-risk patients, but we need to be cautious before generalizing this technique.The transanal endoscopic proctectomy is a feasible alternative surgical option to conventional laparoscopy for radical rectal resection in selected cases with unfavorable characteristics. Further investigations with larger cohorts are required to validate its safety and to clarify its best indication.