[Application status and progress of intraoperative nerve monitoring in pelvic autonomic nerve preserving radical resection of rectal cancer].

The current treatment strategy for rectal cancer is a comprehensive treatment centered on surgery. The application of total mesorectal excision (TME) has significantly reduced the local recurrence rate and improved the survival prognosis, but a series of pelvic organ dysfunction caused by pelvic autonomic nerve injury during the operation will reduce the postoperative quality of life of patients. Pelvic autonomic nerve preserving (PANP) radical proctectomy has emerged, but the biggest challenge in the implementation process of this technology is the accurate identification of nerves. A series of studies have shown that pelvic intraoperative autonomic monitoring (pIONM) can effectively assist surgeons to identify nerves, The purpose of this article is to introduce the function of pelvic autonomic nerve, the clinical manifestation of postoperative pelvic dysfunction and its relationship with nerve injury, the key points of implementing PANP, and the current situation and research progress of pIONM technology application.

Technical aspects of a new approach to intraoperative pelvic neuromonitoring during robotic rectal surgery.

It has been found that rectal surgery still leads to high rates of postoperative urinary, fecal, or sexual dysfunction, which is why nerve-sparing surgery has gained increasing importance. To improve functional outcomes, techniques to preserve pelvic autonomic nerves by identifying anatomic landmarks and implementing intraoperative neuromonitoring methods have been investigated. The objective of this study was to transfer a new approach to intraoperative pelvic neuromonitoring based on bioimpedance measurement to a clinical setting. Thirty patients (16 male, 14 female) involved in a prospective clinical investigation (German Clinical Trials Register DRKS00017437, date of first registration 31/03/2020) underwent nerve-sparing rectal surgery using a new approach to intraoperative pelvic neuromonitoring based on direct nerve stimulation and impedance measurement on target organs. Clinical feasibility of the method was outlined in 93.3% of the cases. Smooth muscle contraction of the urinary bladder and/ or the rectum in response to direct stimulation of innervating functional nerves correlated with a change in tissue impedance compared with the pre-contraction state. The mean amplitude (Amax) of positive signal responses was Amax = 3.8%, negative signal responses from a control tissue portion with no stimulation-induced impedance change had an amplitude variation of 0.4% on average. The amplitudes of positive and negative signal responses differed significantly (statistical analysis using two-sided t-test), allowing the nerves to be identified and preserved. The results indicate a reliable identification of pelvic autonomic nerves during rectal surgery.

[Classification system of radical surgery for rectal cancer based on membrane anatomy].

Because the classification system of radical surgery for rectal cancer has not been established, it is impossible to select the appropriate surgical method according to the clinical stage of the tumor. In this paper, we explained the theory of " four fasciae and three spaces " of pelvic membrane anatomy and then combined this theory with the membrane anatomical basis of Querleu-Morrow classification for radical cervical cancer resection. Based on this theory and the membrane anatomy of Querleu-Morrow classification of radical cervical cancer resection, we proposed a new classification system of radical rectal cancer surgery based on membrane anatomy according to the lateral lymph node dissection range of the rectum. This system classifies the surgery into four types (ABCD) and defines corresponding subtypes based on whether the autonomic nerve was preserved. Among them, type A surgery is total mesorectal excision (TME) with urogenital fascia preservation, type B surgery is classical TME, type C surgery is extended TME, and type D surgery is lateral extended resection. This classification system unifies the anatomical terminology of the pelvic membrane, validates the feasibility of using the " four fasciae and three fascial spaces " theory to classify rectal cancer surgery, and lays the theoretical foundation for the future development of a unified and standardized classification of radical pelvic tumor surgery.

Bloqueos Nerviosos. Bases Anatómicas del Dolor Somático Abdomino-Pélvico / Nerve Blocks. Anatomy of the Somatic Innervation of the Abdomino-Pelvic Cavity

El dolor abdominal es una de las sintomatologías que afectan con frecuencia la cavidad abdomino-pélvica. Dicha cavidad posee una inervación somática en la que intervienen del séptimo a doceavo nervios intercostales, ramos colaterales y terminales del plexo lumbar y el nervio pudendo; siendo objetivo de este trabajo la descripción anatómica del dolor abdominopélvico a través del plexo lumbar, nervios intercostales y nervio pudendo, sus diferentes patrones y variaciones de conformación, y las implicancias de éstas últimas en las distintas maniobras clínico-quirúrgicas. Se realizó un estudio descriptivo, observacional y morfométrico de la inervación somática de la cavidad abdomino-pélvica, en 50 preparaciones cadavéricas, fijadas en solución de formaldehído, de la Tercera Cátedra de Anatomía, Facultad de Medicina, Universidad de Buenos Aires, entre Agosto/2017-Diciembre/2019. La descripción clásica del plexo lumbar se encontró en 35 casos; la presencia del nervio femoral accesorio en ningún caso; así como también la ausencia del nervio iliohipogástrico en ningún caso; el nervio obturador accesorio se halló en 2 casos; el nervio genitofemoral dividiéndose dentro de la masa muscular del psoas mayor en 6 casos; el nervio cutáneo femoral lateral emergiendo únicamente de la segunda raíz lumbar en 6 casos y por último se encontró la presencia de un ramo del nervio obturador uniéndose al tronco lumbosacro en un caso. Los nervios intercostales y el nervio pudendo presentaron una disposición clásica en todos los casos analizados. Es esencial un adecuado conocimiento y descripción del plexo lumbar, nervios intercostales y nervio pudendo para un adecuado abordaje de la cavidad abdomino-pélvica en los bloqueos nerviosos.

SUMMARY: Abdominal pain is one of the symptoms that affect the abdominal-pelvic cavity. The abdominal-pelvic cavity has a somatic innervation involving the seventh to twelfth intercostal nerves, collateral and terminal branches of the lumbar plexus and the pudendal nerve. The objective of this work is the description of the lumbar plexus, intercostal nerves and pudendal nerve, its different patterns and structure variations, as well as its implications during pain management in patients. A descriptive, observational, and morphometric study of patterns and structure variations of the lumbar plexus, intercostal nerves and pudendal nerve was conducted in 50 formalin-fixed cadaveric dissections of the Third Chair of Anatomy at the School of Medicine in the Universidad de Buenos Aires from August 2017 to December/2019. The standard description of the lumbar plexus was found in 35 cases; accessory femoral nerve was not present in any of the cases; absence of the iliohipogastric nerve was also not found in any case, while the accessory obturating nerve was found in 2 cases; genitofemoral nerve dividing within the muscle mass of psoas in 6 cases; lateral femoral cutaneous nerve emerging only from the second lumbar root in 6 cases and finally, presence of a branch of the obturating nerve was found joining the lumbosacral trunk in one case. The pudendal and intercostal nerve patterns presented a typical pathway in all cases. Adequate knowledge and description of the lumbar plexus, intercostal nerves and pudendal nerve is essential for an adequate approach of the abdominal-pelvic cavity in nerve blocks.

Função sexual pós-histerectomia: quais os impactos e aspectos técnicos envolvidos? / Sexual function after hysterectomy: what are the impacts and technical aspects involved?

Objetivo: Identificar o impacto da histerectomia para patologias benignas sobre a sexualidade feminina. Métodos: Revisão de literatura com busca na plataforma PubMed, sendo selecionados 23 artigos em português e inglês publicados entre 2016 e 2021. Resultados: Foi descrita, majoritariamente, melhora na função sexual após histerectomia, semelhante às abordagens totais ou supracervicais e independentemente da via de acesso cirúrgico, apesar de impacto ligeiramente menor com a via laparoscópica. Na laparoscopia, houve melhor desfecho sexual no fechamento da cúpula vaginal, quando comparado ao fechamento via vaginal. Ademais, a ooforectomia concomitante apresentou resultados conflitantes e inconclusivos. Conclusão: A histerectomia afeta positivamente a saúde sexual feminina e aspectos técnicos podem interferir na função sexual, porém os dados são limitados. Devido à importância do tema, necessitam-se de mais estudos com metodologias padronizadas para possibilitar análises mais detalhadas.

Objective: To identify the impact of hysterectomy for benign pathologies on female sexuality. Methods: Literature review with search on PubMed platform, being selected 23 articles in Portuguese and English published between 2016 and 2021. Results: Improvement in sexual function after hysterectomy was mostly described, being similar in total or supracervical approaches and independent of the surgical access route, although it had slightly lower impact when laparoscopic. In the laparoscopic approach, there was better sexual outcome in the vaginal dome closure when compared to vaginal closure. In addition, concomitant oophorectomy showed conflicting and inconclusive results. Conclusion: Hysterectomy positively affects female sexual health and technical aspects may interfere with sexual function, but data are limited. Due to the importance of the theme, more studies with standardized methodologies are needed to enable more detailed analyses.

[Pelvic autonomic nerve preservation in rectal cancer: anatomical concept and clinical significance].

Colorectal cancer is one of the most common cancers in the world, and surgery is the mainstage treatment. Urogenital and sexual dysfunction after radical resection of rectal cancer has become an important problem for patients, which seriously affects the quality of life. Some patients give up radical surgery for rectal cancer because of the concerns about sexual and urinary dysfunction. The cause of this problem is intraoperative of injury pelvic autonomic nerve. The preservation of the hypogastric nerve during the surgery is important for the male ejaculation. Pelvic splanchnic nerves are mainly responsible for the male erection. The anatomical origin, distribution, and urogenital function of these two nerves are detailed described in this article. At the same time, this article introduces the classification, key points of the operation and the evaluation of autonomic nerve preservation surgery. With the rapid development of minimally invasive surgery, performing radical surgery for rectal cancer is important, we also need to fully understand the anatomical concept of pelvic autonomic nerves, and apply modern minimally invasive surgical techniques to preserve the patient's pelvic autonomic nerves as well. It is an compulsory course and an important manifestation for the standardization of rectal cancer surgery.

Beyond Total Mesorectal Excision: Compartment-based Anatomy of the Pelvis Revisited for Exenterative Pelvic Surgery.

OBJECTIVE: Magnetic resonance imaging-based subdivision of the pelvis into 7 compartments has been proposed for pelvic exenteration. The aim of the present anatomical study was to describe the topographic anatomy of these compartments and define relevant landmarks and surgical dissection planes. BACKGROUND: Pelvic anatomy as it relates to exenterative surgery is complex. Demonstration of the topographic peculiarities of the pelvis based on the operative situs is hindered by the inaccessibility of the small pelvis and the tumor bulk itself. MATERIALS AND METHODS: Thirteen formalin-fixed pelvic specimens were meticulously dissected according to predefined pelvic compartments. Pelvic exenteration was simulated and illustrated in a stepwise manner. Different access routes were used for optimal demonstration of the regions of interest. RESULTS: All the 7 compartments (peritoneal reflection, anterior above peritoneal reflection, anterior below peritoneal reflection, central, posterior, lateral, inferior) were investigated systematically. The topography of the pelvic fasciae and ligaments; vessels and nerves of the bladder, prostate, uterus, and vagina; the internal iliac artery and vein; the course of the ureter, somatic (obturator nerve, sacral plexus), and autonomic pelvic nerves (inferior hypogastric plexus); pelvic sidewall and floor, ischioanal fossa; and relevant structures for sacrectomy were demonstrated. CONCLUSIONS: A systematic approach to pelvic anatomy according to the 7 magnetic resonance imaging-defined compartments clearly revealed crucial anatomical landmarks and key structures facilitating pelvic exenterative surgery. Compartment-based pelvic anatomy proved to be a sound concept for beyond TME surgery and provides a basis for tailored resection procedures.

Visualization of the pelvic nerves using magnetic resonance imaging for rectal cancer surgery.

BACKGROUND: This study evaluated the visualization of the pelvic nerves using magnetic resonance imaging (MRI) combined with computed tomography (CT) to synthesize three-dimensional (3D) reconstruction images of the pelvic organs. METHODS: The CT and MRI scans were performed for patients with rectal cancer who underwent surgery. The out-of-phase image of LAVA-Flex was used to identify the pelvic nerves. The images of the pelvic nerves were extracted from the MRI scans, and those of the arteries and rectum and pelvis were extracted from the CT scans. Each extracted organ image was used to synthesize 3D reconstruction images. RESULTS: The MRI scan allowed adequate visualization of the pelvic splanchnic nerves, inferior hypogastric plexus, and obturator nerves. The comparison of 3D reconstruction images and intraoperative findings showed matched images. CONCLUSION: We visualized the pelvic nerves using MRI and synthesized 3D reconstruction images of the pelvic organs. Preoperative confirmation of the location of the pelvic organs is important to prevent unanticipated injury during rectal cancer surgery.

Exposure of the Middle Rectal Artery and Lateral Ligament of the Rectum Following the Gate Approach during Total Mesorectal Excision.

Controversial surgical anatomical landmarks in the deep pelvis can be visualized and identified using current technologies. Performing the gate approach technique during deep lateral dissection for total mesorectal excision facilitates visualization of the pelvic neurovascular structures following simple dissection steps to preserve the pelvic autonomic nerves and avoid accidental vascular injuries. Here, we discuss laparoscopic exposure of an infrequent disposition of the middle rectal artery anterior to the lateral ligament of the rectum while performing the gate approach.

Comprehensive anatomy of the superior hypogastric plexus and its relationship with pelvic surgery landmarks: defining the safe zone around the promontory.

BACKGROUND: Pelvic surgery carries an inherent risk of autonomic nerve injury leading to genitourinary and bowel dysfunction due to the close proximity of the superior hypogastric plexus (SHP). The aim of this study was to define the detailed anatomy of SHP and identify its relationship with the vascular landmarks and ureters for pelvic autonomic nerve-preserving surgery. METHODS: A cadaveric study on the detailed anatomy of the SHP was conducted in our surgical anatomy research unit. Between 02/2019 and 10/2019, macroscopic anatomical dissections were performed on 45 fresh adult cadavers (39 male, 6 female). Distances between the SHP, major vascular structures, and other anatomical landmarks were measured. RESULTS: Three types of SHP morphology were observed: mesh (64.8%), single nerve (24.4%), and fiber (10.8%). SHP bifurcation was located inferior to the aortic bifurcation in all cases; however, it was observed cranial to the promontory in 80% of the cases, whereas 18% were caudally and 2% were over the promontory. The closest vessels to the left and right of the SHP bifurcation were the left common iliac vein (LCIV) (86.2%, the mean distance was 8.49 ± 7.97 mm) and the right internal iliac artery (RIIA) (48.2%, mean distance was 13.4 ± 9.79 mm), respectively. At SHP bifurcation level, the lateral edge of the SHP was detected on the LCIV in 22 cases and on the RIIA in 10 cases for the left and right side of the plexus, respectively. The distance between the SHP bifurcation and the ureter was 27.9 mm on the right and 24.2 mm on the left. The width of the left (LHN) and right hypogastric nerves (RHN) were 4.35 mm and 4.62 mm at 2 cm below the SHP bifurcation, respectively. LHN was on the vascular structures in 13 cases, whereas RHN in only 1 case, 2 cm below the SHP bifurcation. CONCLUSIONS: Understanding the location of the SHP, including its relationship with important anatomical landmarks, might prevent iatrogenic injury and reduce postoperative morbidity in the pelvic surgery setting.

Fascial space priority approach for laparoscopic total pelvic exenteration in patients with locally advanced rectal cancer.

BACKGROUND: Total pelvic exenteration (TPE) with intent to achieve a pathological R0 resection is now considered as the only chance of a long-term survival for locally advanced rectal cancer (LARC) invading into adjacent organs. Lately, laparoscopic total pelvic exenteration (LTPE) is performed and achieved in several specialized centers and showed a promising application prospect. Although this is universally realized by surgeons, there are only few specialized centers to perform this complex surgery, due to concerns about the high morbidity and mortality. The techniques associated need to be disclosed and facilitated. OBJECTIVE: The aim of this article is to introduce a fascial space priority approach for laparoscopic TPE step by step (with video). METHODS: We describe here a fascial space priority approach for LTPE in highly selected patients with locally advanced rectal cancer. The main principle of this approach is that all of the pelvic organs are considered as a whole, the non-vascular spaces surrounding it are separated in the first place, the vascular pedicle and nerve pedicle of pelvic organs can be isolated and then transected precisely. Meanwhile, the associated key landmarks of this approach are disclosed (see the video). RESULTS: The ureterohypogastric nerve fascia (UHGNF) and the vesicohypogastric fascia (VHGF) are two vital embryological planes on the lateral compartment of pelvis. The spaces on either side of them together with the retrorectal space, the space of Retzius, are all non-vascular spaces, and dissection of these spaces in LTPE surgery can be achieved simply and practicably. The ureter, the umbilical artery, the arcus tendinous fasciae pelvis (ATFP), piriformis and the puboprostatic ligament (PPL) are all important landmarks during surgery. Step-by-step illustration with precise anatomical landmarks in the present video may lead to less intraoperative blood loss and complications. CONCLUSIONS: LTPE with fascial space priority approach might be a standard surgical procedure for total pelvic exenteration with clear anatomy and reduced blood loss.

A new method of intraoperative pelvic neuromonitoring: a preclinical feasibility study in a porcine model.

Low anterior resections (LAR) are frequently associated with complications such as urinary and fecal incontinence as well as sexual disorders. Typical risk factors are rectal cancer with low tumor location, preoperative radiotherapy, and surgery-related damage of pelvic autonomic nerves. As preserving the pelvic autonomic nerves without any technical assistance is challenging, the objective of this preclinical study was to investigate the technical feasibility of a new method for intraoperative pelvic neuromonitoring. Twelve female pigs undergoing low anterior resections were involved in a prospective preclinical study. Intraoperative pelvic neuromonitoring included direct pelvic nerve stimulation and tissue impedance measurement on the urinary bladder and the rectum for the identification of efferent pelvic nerves in the surgical area. Immunohistochemistry was used to verify the results. Smooth muscle contraction of the urinary bladder and/or the rectum in response to direct stimulation of the innervating nerves was detectable with impedance measurement. The macroscopic contraction of both the urinary bladder and the rectum correlated with a change in tissue impedance compared to the status before contraction. Thus, it was possible to identify pelvic nerves in the surgical area, which allows the nerves to be preserved. The results indicate a reliable identification of pelvic autonomic nerves, which allows nerve damage to be prevented in the future.

Vulvodynia: a neuroinflammatory pain syndrome originating in pelvic visceral nerve plexuses due to mechanical factors.

This short opinion aimed to present the evidence to support our hypothesis that vulvodynia is a neuroinflammatory pain syndrome originating in the pelvic visceral nerve plexuses caused by the failure of weakened uterosacral ligaments (USLs) to support the pelvic visceral nerve plexuses, i.e., T11-L2 sympathetic and S2-4 parasympathetic plexuses. These are supported by the USLs, 2 cm from their insertion to the cervix. They innervate the pelvic organs, glands, and muscles. If the USLs are weak or lax, gravitational force or even the muscles may distort and stimulate the unsupported plexuses. Inappropriate afferent signals could then be interpreted as originating from an end-organ site. Activation of sensory visceral nerves causes a neuro-inflammatory response in the affected tissues, leading to neuroproliferation of small peripheral sensory nerve fibers, which may cause hyperalgesia and allodynia in the territory of the damaged innervation. Repair of the primary abnormality of USL laxity, responsible for mechanical stimulation of the pelvic sensory plexus, may lead to resolution of the pain syndrome.

Near-infrared intraoperative imaging of pelvic autonomic nerves: a pilot study.

BACKGROUND: The pelvic autonomic nerves control and regulate anorectal and urogenital function. The dysfunction of pelvic autonomic nerves lead to disorders of anorectum, bladder and male sex organs. Thus the intraoperative identification of pelvic autonomic nerves could be crucial in complications prevention and diseases treatment. Our clinical trial aims at estimating the effectiveness and validity of intraoperative indocyanine green fluorescence imaging in pelvic autonomic nerves identification. METHODS: Intraoperative fluorescence imaging using indocyanine green was performed in ten patients and the feasibility was determined. From February 2019 to June 2019, the seven patients undergoing laparoscopic colorectal resection was administrated 4.5 mg/Kg indocyanine green 24 h before surgery. The near-infrared fluorescence imaging was conducted during surgery. A novel white light and near-infrared dual-channel laparoscopic equipment was applied. For each patient, signal-background ratio values for pelvic autonomic nerves were recorded and analyzed. RESULTS: We confirmed the dose and timing of indocyanine green administration was 4.5 mg/Kg and 24 h before surgery. Using the dual laparoscopic equipment, we could observe the splanchnic plexus, inferior mesenteric artery plexus, and sacral plexus successfully with a high signal background ratio value of 3.18 (standard deviation: 0.48). CONCLUSION: This pilot trial shows feasibility of intraoperative indocyanine green fluorescence imaging in pelvic autonomic nerves observation. It demonstrates that nerves can be visualized using alternative imaging techniques but it is not ready yet for prime time. This technique might aid observation with white light alone. REGISTRATION NUMBER: ChiCTR1900025336.

Chronic Pelvic Pain in Women: A Review.

IMPORTANCE: Chronic pelvic pain (CPP) is a challenging condition that affects an estimated 26% of the world's female population. Chronic pelvic pain accounts for 40% of laparoscopies and 12% of hysterectomies in the US annually even though the origin of CPP is not gynecologic in 80% of patients. Both patients and clinicians are often frustrated by a perceived lack of treatments. This review summarizes the evaluation and management of CPP using recommendations from consensus guidelines to facilitate clinical evaluation, treatment, improved care, and more positive patient-clinician interactions. OBSERVATIONS: Chronic pelvic pain conditions often overlap with nonpelvic pain disorders (eg, fibromyalgia, migraines) and nonpain comorbidities (eg, sleep, mood, cognitive impairment) to contribute to pain severity and disability. Musculoskeletal pain and dysfunction are found in 50% to 90% of patients with CPP. Traumatic experiences and distress have important roles in pain modulation. Complete assessment of the biopsychosocial factors that contribute to CPP requires obtaining a thorough history, educating the patient about pain mechanisms, and extending visit times. Training in trauma-informed care and pelvic musculoskeletal examination are essential to reduce patient anxiety associated with the examination and to avoid missing the origin of myofascial pain. Recommended treatments are usually multimodal and require an interdisciplinary team of clinicians. A single-organ pathological examination should be avoided. Patient involvement, shared decision-making, functional goal setting, and a discussion of expectations for long-term care are important parts of the evaluation process. CONCLUSIONS AND RELEVANCE: Chronic pelvic pain is like other chronic pain syndromes in that biopsychosocial factors interact to contribute and influence pain. To manage this type of pain, clinicians must consider centrally mediated pain factors as well as pelvic and nonpelvic visceral and somatic structures that can generate or contribute to pain.

Changes in the Neurochemical Coding of the Anterior Pelvic Ganglion Neurons Supplying the Male Pig Urinary Bladder Trigone after One-Sided Axotomy of Their Nerve Fibers.

The present study investigated the effect of unilateral axotomy of urinary bladder trigone (UBT)-projecting nerve fibers from the right anterior pelvic ganglion (APG) on changes in the chemical coding of their neuronal bodies. The study was performed using male pigs with immunohistochemistry and quantitative real-time PCR (qPCR). The animals were divided into a control (C), a morphological (MG) or a molecular biology group (MBG). APG neurons supplying UBT were revealed using the retrograde tracing technique with Fast Blue (FB). Unilateral axotomy resulted in an over 50% decrease in the number of FB+ neurons in both APG ganglia. Immunohistochemistry revealed significant changes in the chemical coding of FB+ cells only in the right ganglion: decreased expression of dopamine-B-hydroxylase (DBH)/tyrosine hydroxylase (TH) and up-regulation of the vesicular acetylcholine transporter (VAChT)/choline acetyltransferase (ChAT), galanin (GAL), vasoactive intestinal polypeptide (VIP) and brain nitric oxide synthase (bNOS). The qPCR results partly corresponded with immunofluorescence findings. In the APGs, genes for VAChT and ChAT, TH and DBH, VIP, and NOS were distinctly down-regulated, while the expression of GAL was up-regulated. Such data may be the basis for further studies concerning the plasticity of these ganglia under experimental or pathological conditions.

Optimal Complete Rectum Mobilization Focused on the Anatomy of the Pelvic Fascia and Autonomic Nerves: 30 Years of Experience at Severance Hospital.

The primary goal of surgery for rectal cancer is to achieve an oncologically safe resection, i.e., a radical resection with a sufficient safe margin. Total mesorectal excision has been introduced for radical surgery of rectal cancer and has yielded greatly improved oncologic outcomes in terms of local recurrence and cancer-specific survival. Along with oncologic outcomes, functional outcomes, such as voiding and sexual function, have also been emphasized in patients undergoing rectal cancer surgery to improve quality of life. Intraoperative nerve damage or combined excision is the primary reason for sexual and urinary dysfunction. In the past, these forms of damage could be attributed to the lack of anatomical knowledge and poor visualization of the pelvic autonomic nerve. With the adoption of minimally invasive surgery, visualization of nerve structure and meticulous dissection for the mesorectum are now possible. As the leading hospital employing this technique, we have adopted minimally invasive platforms (laparoscopy, robot-assisted surgery) in the field of rectal cancer surgery and standardized this technique globally. Here, we review a standardized technique for rectal cancer surgery based on our experience at Severance Hospital, suggest some practical technical tips, and discuss a couple of debatable issues in this field.

A Modified Technique of Laparoscopic Lateral Lymph Node Dissection Combining Fascia-Oriented Dissection and Routine Upfront Distal Visceral Vessels Ligation for Mid- to Low-Lying Rectal Cancer.

INTRODUCTION: Lateral pelvic recurrence can be a cause of local failure after surgery for low rectal cancer. Lateral lymph node dissection is often performed in East Asia for patients with enlarged lateral lymph nodes or because of the presence of risk factors. However, the outcomes of the conventional lateral lymph node dissection are unsatisfactory, with a considerably high local recurrence rate for patients with positive lateral nodes. Here, we introduce a modified technique to improve lateral nodes clearance. TECHNIQUE: This modified technique has 4 key steps: 1) separation of the ureterohypogastric nerve fascia medially, 2) identification of the visceral pelvic fascia and dissection along the inferior vesical or vaginal veins down to the pelvic floor, 3) division of the distal ends of visceral vessels according to the orientation of ureterohypogastric nerve fascia and visceral pelvic fascia for better nerve preservation, and 4) en bloc dissection through a lateral approach over the surfaces of the sacral plexus and piriformis muscle to reveal the course of distal internal iliac vessels before the division of visceral veins. RESULTS: Twenty-nine patients underwent laparoscopic lateral lymph node dissection successively with no conversion. The median blood loss for each lateral procedure was 37.5 mL (range, 0-300.0 mL). Eleven lateral nodes (median; range, 1-22 lateral nodes) were harvested for each lateral side. There was no perioperative mortality, and 4 patients developed major complications (Clavien-Dindo III-IV). CONCLUSION: This modified technique characterized by the routine division of visceral vessels based on ureterohypogastric nerve fascia and visceral pelvic fascia is feasible and safe. It provides good lymph node harvest, autonomic nerve preservation, and improved bleeding control. Additional investigation is warranted to evaluate the safety, functional outcomes, and oncologic outcomes.