Internal anal sphincter nerves - a macroanatomical and microscopic description of the extrinsic autonomic nerve supply of the internal anal sphincter

[Surgical anatomy of the anorectum]

The anorectum corresponds to the last segment of the gastrointestinal tract and is responsible for mediating fecal continence and controlled defecation. An understanding of the complex topographic anatomy is an indispensable prerequisite for the surgical treatment of benign and malignant diseases in the anorectal region. The detailed description of perirectal fascia, anorectal blood supply and lymph vessel drainage, pelvic autonomic nerves and components of the anal canal and anal sphincter complex has significantly contributed to improvement of the oncological and functional surgical outcome. In this article the state of knowledge relating to the anorectal anatomy is outlined providing a practical basis for rectal and proctological surgical procedures.

Novel Concepts on the Functional Neuroanatomy of the Anorectum: Implications for Anorectal Neuropathy and Neuromodulation Therapy

Anorectal neuropathy causes anorectal dysfunction, yet it is poorly recognized. This stems from both a lack of understanding of the extrinsic and intrinsic innervation of the anorectum and tools for evaluation of neuronal function. Our objective was to provide an improved understanding of the neuronal networks of the anorectum and discuss its functional significance. We performed a comprehensive and up-to-date review of the published literature on anorectal neuroanatomy to generate our findings. Anorectal nerve innervation appears to be much more complex than hitherto known with an extensive overlap, intercommunications, and variations. The innervations arise from 5 sources as evidenced by immunohistochemical markers: Sympathetic innervation arises from the superior hypogastric plexus, hypogastric plexus, and splanchnic nerves (T1-L2); the parasympathetic from pelvic splanchnic nerves (S1-S4); the mixed autonomic from inferior hypogastric plexus; the somatic from pudendal nerves; and the intercommunicating nerves. Furthermore, they are fine, closely packed nerves susceptible to damage from obstetric or spinal cord injury, or pelvic surgery that may not manifest with bowel problems immediately but later in life. This illustrated review provides a new understanding of the afferent and efferent pathways between the rectum, spinal cord, and brain, and a framework for clinical implications of anorectal neuropathy, such as anal sphincter or rectal sensory or rectal accommodation dysfunction, causing bowel problems. Insights into the functional neuroanatomy provide an improved mechanistic understanding of anorectal symptoms and could facilitate the development of neurophysiological tests such as translumbosacral anorectal magnetic stimulation and neuromodulation treatments such as sacral neuromodulation and translumbosacral neuromodulation treatment.

Effect of reboxetine and citalopram on anal opening pressure in healthy women: A randomized, double-blind, placebo-controlled crossover study

BACKGROUND

In placebo-controlled clinical trials, reboxetine, a selective noradrenaline reuptake inhibitor, increases urethral pressure and relieves stress urinary incontinence symptoms in women. Considering the close connection in neural regulation of the external urethral and anal sphincters, we hypothesized that reboxetine may also enhance anal sphincter pressure. Conversely, it is believed that selective serotonin reuptake inhibitors may contribute to fecal incontinence by reducing anal sphincter pressure. In this study, we investigated the effect of reboxetine and citalopram on anal opening pressure in healthy female volunteers.

METHODS

In a double-blind, three-way crossover trial, 24 female participants received single doses of 40 mg citalopram, 8 mg reboxetine, and matching placebos, with a minimum of 8-day washout between sessions. Using anal acoustic reflectometry, we measured anal opening pressure during both resting and squeezing conditions at the estimated time of peak plasma concentration for both study drugs.

KEY RESULTS

Compared with placebo, reboxetine increased anal opening pressure with 23.4 cmH2O (95% confidence interval [CI] 16.5-30.2, p < 0.001) during rest and with 22.5 cmH2O (95% CI 15.2-29.8, p < 0.001) during squeeze. Citalopram did not change anal opening pressure statistically significantly compared to placebo.

CONCLUSIONS & INFERENCES

An 8-mg dose of reboxetine increased anal opening pressure substantially in healthy women, suggesting potential benefits for fecal incontinence symptoms. In contrast, a 40-mg dose of citalopram showed a marginal and statistically insignificant effect on anal opening pressure, indicating that selective serotonin reuptake inhibitors do not contribute to fecal incontinence by reducing anal sphincter tone.

Sphincter-preserving effect of robotic-assisted intersphincteric resection for ultra-low rectal cancer: a propensity score matching analysis

Intersphincteric resection (ISR) is a viable option for sphincter preservation in early ultra-low rectal cancer, but postoperative anal dysfunction remains a concern. This study evaluates the outcomes of robotic ISR with coloanal anastomosis in early ultra-low rectal cancer, comparing its efficacy and safety with laparoscopic ISR. Retrospective analysis was conducted on data from 74 consecutive patients undergoing robotic intersphincteric resection (R-ISR) for early ultra-low rectal cancer between January 2017 and December 2018 (R-ISR group), matched with 110 patients undergoing laparoscopic intersphincteric resection (L-ISR). After 1:1 propensity score matching, each group comprised 68 patients. Comparative analyses covered surgical outcomes, complications, long-term results, and anal function. The R-ISR group showed longer total operative time than the L-ISR group (211.7 ± 25.3 min vs. 191.2 ± 23.0 min, p = 0.001), but less intraoperative bleeding (55.2 ± 20.7 ml vs. 69.2 ± 22.9 ml, p = 0.01). R-ISR group had fewer conversions to APR surgery (6/8.8% vs. 14/20.6%). Other perioperative indicators were similar. R-ISR exhibited a smaller tumor margin, superior mesorectal integrity, and comparable histopathological outcomes. Postoperative complications, 3-year and 5-year DFS, and OS were similar. At the 1-year follow-up, the Wexner Incontinence Score favored R-ISR (9.24 ± 4.03 vs. 11.06 ± 3.77, p = 0.048). Although R-ISR prolongs the operative time, its surgical safety and oncological outcomes are similar to conventional ISR procedures. Furthermore, it further shortens the margin of anal preservation, reduces the rate of conversion to APR surgery, and improves postoperative anal function.

Development and Validation of a Post-Radiotherapy Prediction Model for Bowel Dysfunction After Rectal Cancer Resection

BACKGROUND & AIMS

The benefit of radiotherapy for rectal cancer is based largely on a balance between a decrease in local recurrence and an increase in bowel dysfunction. Predicting postoperative disability is helpful for recovery plans and early intervention. We aimed to develop and validate a risk model to improve the prediction of major bowel dysfunction after restorative rectal cancer resection with neoadjuvant radiotherapy using perioperative features.

METHODS

Eligible patients more than 1 year after restorative resection following radiotherapy were invited to complete the low anterior resection syndrome (LARS) score at 3 national hospitals in China. Clinical characteristics and imaging parameters were assessed with machine learning algorithms. The post-radiotherapy LARS prediction model (PORTLARS) was constructed by means of logistic regression on the basis of key factors with proportional weighs. The accuracy of the model for major LARS prediction was internally and externally validated.

RESULTS

A total of 868 patients reported a mean LARS score of 28.4 after an average time of 4.7 years since surgery. Key predictors for major LARS included the length of distal rectum, anastomotic leakage, proximal colon of neorectum, and pathologic nodal stage. PORTLARS had a favorable area under the curve for predicting major LARS in the internal dataset (0.835; 95% CI, 0.800-0.870, n = 521) and external dataset (0.884; 95% CI, 0.848-0.921, n = 347). The model achieved both sensitivity and specificity >0.83 in the external validation. In addition, PORTLARS outperformed the preoperative LARS score for prediction of major events.

CONCLUSIONS

PORTLARS could predict major bowel dysfunction after rectal cancer resection following radiotherapy with high accuracy and robustness. It may serve as a useful tool to identify patients who need additional support for long-term dysfunction in the early stage.

CLINICALTRIALS

gov, number NCT05129215.

The Role of Percutaneous Tibial Nerve Stimulation (PTNS) in Low Anterior Resection Syndrome (LARS): A Systematic Review and Meta-analysis

PURPOSE

The aim of the present study was to evaluate the pooled efficacy of percutaneous tibial nerve stimulation (PTNS) in patients with low anterior resection syndrome (LARS).

MATERIAL AND METHODS

This study was based on the Cochrane Handbook for Systematic Reviews of Interventions and the PRISMA guidelines. The primary endpoint was the pooled effect size of PTNS in LARS score (LARSS). Secondary endpoints included incontinence (Fecal Incontinence Score-FIC, Obstructive Defecation Syndrome-ODS), sexual functionality and quality of life (QoL) questionnaires, and manometric evaluations. Continuous outcomes were reported as weighted mean difference (WMD), with the corresponding 95% confidence interval (95% CI). Quality evaluation was performed via the National Institutes of Health (NIH) quality assessment tool.

RESULTS

Overall, 5 studies were included. PTNS resulted to reduced LARSS values (WMD: - 5.68, 95%CI: - 7.73, - 3.63, p < 0.001). A similar effect was noted in St Mark's FIC (p < 0.001) and ODS (p = 0.02) score. An improvement in several QoL scales was found. There was no effect in sexual functionality and manometric measurements. Compared to sham, PTNS significantly improved LARSS.

CONCLUSIONS

The application of PTNS in patients with LARS results in an improvement in multiple clinical parameters, including defecation functionality and quality of life. Due to several study limitations, further high quality RCTs are required to delineate the exact efficacy of PTNS.

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.

The Middle Rectal Artery: Revisited Anatomy and Surgical Implications of a Neglected Blood Vessel

BACKGROUND

Although the middle rectal artery is a relevant anatomical landmark for rectal resection and lateral lymph node dissection, descriptions of this entity are highly divergent.

OBJECTIVE

Dissection, visualization, morphometry, and 3-dimensional reconstruction of the middle rectal artery to facilitate its management in surgery.

DESIGN

Macroscopic dissection, histologic study, morphometric measurements, and virtual modeling.

SETTING

University laboratory of applied surgical anatomy.

PATIENTS

This study includes formalin-fixed hemipelvis specimens (n=37) obtained from body donors (age, 67-97 y).

MAIN OUTCOME MEASURES

The main outcome measures are photo documentation of origin, trajectory, diameter, and branching pattern; immunolabeling of lymphatics; and 3-dimensional reconstruction of the middle rectal artery.

RESULTS

The middle rectal artery was present in 71.4% of body donors (21.4% bilateral, 50% unilateral), originated from the anterior division of the internal iliac artery, and branched either from the internal pudendal artery (45.5%), the inferior gluteal artery (22.7%), the gluteal-pudendal trunk (22.7%), or a trifurcation (9.1%). One to 3 branches of varying diameters (0.5-3.5 mm) entered the mesorectum from the ventrolateral (35.7%), lateral (42.9%), or dorsolateral (21.4%) aspect. The middle rectal artery was accompanied by podoplanin-immunoreactive lymphatic vessels and gave off additional branches (81.8%) to the urogenital pelvic organs. Three-dimensional reconstruction revealed the complex course of the middle rectal artery from the pelvic sidewall through the pelvic nerve plexus and parietal pelvic fascia into the mesorectum.

LIMITATIONS

Findings retrieved from body donors may be prone to age- and fixation-related processes.

CONCLUSIONS

The investigation disclosed the rather high prevalence of the middle rectal artery, its 3-dimensional topographic anatomy, and its proximity to the autonomic pelvic nerves. These features play a role in the surgical management of this blood vessel. The data provide the anatomical rationale for the lateral lymphatic spread of rectal cancer and an anatomical basis for nerve-preserving lateral lymph node dissection.

A preliminary clinical report of transvaginal natural orifice transluminal endoscopic Sacrospinous Ligament Fixation in the treatment of moderate and severe pelvic organ prolapse

Objective

To study the efficacy and safety of transvaginal natural orifice transluminal endoscopic Sacrospinous Ligament Fixation in the treatment of moderate and severe pelvic organ prolapse.

Design

Patients were selected into this study on a voluntary basis to evaluate the short-term efficacy of this surgery by comparing the OP-Q scores before the operation, three months after the operation, and six months after the operation.

Setting and Patients

Evaluate the clinical efficacy and safety by a retrospective analysis of the clinical data of the 18 patients with POP-Q grade III–IV pelvic organ prolapse treated by the Department of Gynecology of Nanjing Medical University Affiliated Changzhou No.2 People's Hospital from April 2020 to November 2020, and their post-operation follow-ups.

Interventions

Patients with postoperative follow-ups found no obvious relapse without intervention measures.

Measurements and Main Results

The transvaginal natural orifice transluminal endoscopic Sacrospinous Ligament Fixation was performed successfully, and the anterior and posterior walls of vagina and/or trans-vaginal hysterectomy were repaired as appropriate. Except the total vaginal length (TVL), the P values of numerical analysis for all points before, three months after, and six months after the operation were all <0.05, being statistically significant.

Conclusion

This method is effective in the treatment of moderate and severe pelvic organ prolapse with few complications, but more cases and longer-term follow-up data are needed to determine the long-term effect of this procedure. For the selection of puncture sites, more anatomical data are needed to get more accurate result.

An anatomical study on intersphincteric space related to intersphincteric resection for ultra-low rectal cancer

BACKGROUND

Intersphincteric resection (ISR) has been proposed to offer sphincter-sparing solution for patients with ultra-low rectal cancer. However, complete and accurate concepts about the intersphincteric space (ISS) related anatomy are not demonstrated clearly. This study aimed to provide a comprehensive description about the anatomic structure of ISS related to ISR.

METHODS

This was a descriptive morphological study. 28 pelvic specimens were obtained from body donors. Macroscopic and microscopic observation of ISS was performed via gross anatomy, plastinated sections and histologic staining. The anatomical parameters of the anal canal were measured. Images of laparoscopic ISS dissection procedures were real-timely captured during ISR.

RESULTS

The hiatal ligament, microvessels on supra fascia of LAM and rectal longitudinal muscle at the level of anorectal ring, especially at 1, 5, 7, and 11o'clock, could be the preferred entrance of ISS. The conjoint longitudinal muscle (CLM), the major component of ISS, was the continuum of the rectal longitudinal muscle and got reinforcement from the elastic fibers from LAM and EAS. Microvessels and neuro tissues were also found in ISS. The ISS was split into two spaces by the CLM in the middle and might subjectively be divided into three segments according to its different compositions. The length and width of ISS varied from different segments and directions.

CONCLUSIONS

We provided a systemic description of boundaries, contents and topographic structure of ISS, which may help proper determination of surgical approaches and dissection planes during ISR.

Quality of Life in Patients With Rectal Resections and End-to-End Primary Anastomosis Using a Standardized Perioperative Pathway

Objectives: Lower rectal resection is associated with a high rate of postoperative complications and, therefore, adversely impacts the postoperative health-related quality of life (QoL). Though sporadically practiced in different centers, there is no standard perioperative protocol for the management of patients with rectal growths. The aim of this analysis is to evaluate the patient-reported outcomes after low rectal resections followed by an end-to-end-reconstruction and temporary covering ileostomy using a multidisciplinary fail-safe-concept.

Methods: Between 2015 and 2020, we evaluated patient reported outcomes after open and laparoscopic rectal resections with end-to-end reconstruction with a primary straight anastomosis using a standardized perioperative pathway All patients with stoma were excluded from the study. The data for the QoL of patients was collected using the established Low Anterior Resection Syndrome (LARS)-score and the EORTC-C30 and CR-29 questionnaires at a single postoperative timepoint.

Results: We recruited 78 stoma-free patients for this analysis. Of 78 patients included in the study, 87.2% were operated laparoscopically and the mean global health status was 67.95 points, while a major LARS was detected in 48 (61.5%) patients. No anastomotic leakage (AL) occurred within the study cohort. There was no significant change in the LARS-score or the global health status depending on the follow-up-period.

Conclusion: This study shows that good QoL and functional outcomes with no AL are achievable following end-to-end straight anastomosis using a standardized perioperative surgical fail-safe protocol procedure.

[Low anterior resection syndrome-Causes and treatment approaches]

BACKGROUND

With improvement of the oncological prognosis and more sphincter-preserving procedures for rectal cancer of the lower third, the functional sequelae of anterior rectal resection become more and more predominant and are summarized under the term low anterior resection syndrome (LARS).

MATERIAL AND METHODS

In this narrative review the causes, associated factors, prevalence, diagnostics and treatment strategies are presented based on an evaluation of the international literature.

RESULTS

The central role of the rectum in the physiology of defecation and continence explains the frequency of symptoms following anterior rectal resection. In an unselected patient population a major LARS is to be expected in approximately 40% and a minor LARS in approximately 20%. The most important factor is the length of the remaining rectal stump. The diagnosis of LARS is made clinically and can be quantified by scores, especially by the LARS score. Treatment options range from patient counselling to stoma construction and a symptom-related, stepwise approach is generally accepted.

CONCLUSION

While the evidence for the causes, the quantification and determination of associated factors of LARS is good, the treatment options are based either on experience or on only few studies.

Embryological Development and Topographic Anatomy of Pelvic Compartments-Surgical Relevance for Pelvic Lymphonodectomy

Background: The oncological outcome of surgery for the treatment of pelvic malignancies can be improved by performing pelvic lymphonodectomy. However, the extent and regions of lymph node harvest are debated and require profound knowledge of anatomy in order to avoid collateral damage. Methods: The embryological development and topographic anatomy of pelvic compartments in relation to pelvic lymphonodectomy for rectal, uterine, and prostate cancer are reviewed. Based on pre-dissected anatomical specimens, lymph node regions and drainage routes of the posterior and urogenital pelvic compartments are described in both genders. Anatomical landmarks are highlighted to identify structures at risk of injury during pelvic lymphonodectomy. Results: The ontogenesis of urogenital and anorectal compartments and their lymphatic supply are key factors for adequate lymphonodectomy, and have led to compartment-based surgical resection strategies. However, pelvic lymphonodectomy bears the risk of injury to somatic and autonomic nerves, vessels, and organs, depending on the regions and extent of surgery. Conclusion: Embryologically defined, compartment-based resection of pelvic malignancies and their lymphatic drainage routes are based on clearly delineated anatomical landmarks, which permit template-oriented pelvic lymphonodectomy. Comprehensive knowledge of pelvic anatomy, the exchange of surgical concepts between specialties, and minimally invasive techniques will optimize pelvic lymphonodectomy and reduce complications.

Altered anal slow-wave pressure activity in low anterior resection syndrome: short case series in two independent specialist centres provide new mechanistic insights

AIM

Conventional parameters (anal resting and squeeze pressures) measured with anorectal manometry (ARM) fail to identify anal sphincter dysfunction in many patients with low anterior resection syndrome (LARS). We aimed to assess whether there are differences in anal canal slow-wave pressure activity in LARS patients and healthy individuals.

METHOD

High-resolution ARM (HR-ARM) traces of 21 consecutive male LARS patients referred to the Royal London Hospital, UK (n = 12) and Aarhus University Hospital, Denmark (n = 9) were compared with HR-ARM data from 37 healthy men.

RESULTS

Qualitatively (by visual inspection of HR-ARM recordings), the frequency of slow-wave pressure activity was strikingly different in 11/21 (52.4%) LARS patients from that observed in all the healthy individuals. Quantitative analysis showed that peaks of the mean spectrum in these 11 LARS patients occurred at approximately 6-7 cycles per minute (cpm), without activity at higher frequencies. An equivalent pattern was found in only 2/37 (5.4%) healthy individuals (P < 0.0001). Peaks of the mean spectrum in healthy individuals were concentrated at 16 cpm and 3-4 cpm.

CONCLUSION

Over half of the male LARS patients studied had altered anal slow-wave pressure activity based on analysis of HR-ARM recordings. Further studies could investigate the relative contributions of sex, human baseline variance and neoadjuvant/surgical therapies on anal slow waves, and correlate the presence of abnormal activity with symptom severity.

Management guidelines for low anterior resection syndrome - the MANUEL project

AIM

Little is known about the pathophysiology of low anterior resection syndrome (LARS), and evidence concerning the management of patients diagnosed with this condition is scarce. The aim of the LARS Expert Advisory Panel was to develop practical guidance for healthcare professionals dealing with LARS.

METHOD

The 'Management guidelines for low anterior resection syndrome' (MANUEL) project was promoted by a team of eight experts in the assessment and management of patients with LARS. After a face-to-face meeting, a strategy was agreed to create a comprehensive, practical guide covering all aspects that were felt to be clinically relevant. Eight themes were decided upon and working groups established. Each working group generated a draft; these were collated by another collaborator into a manuscript, after a conference call. This was circulated among the collaborators, and it was revised following the comments received. A lay patient revised the manuscript, and contributed to a section containing a patient's perspective. The manuscript was again circulated and finalized. A final teleconference was held at the end of the project.

RESULTS

The guidance covers all aspects of LARS management, from pathophysiology, to assessment and management. Given the lack of sound evidence and the often poor quality of the studies, most of the recommendations and conclusions are based on the opinions of the experts.

CONCLUSIONS

The MANUEL project provides an up-to-date practical summary of the available evidence concerning LARS, with useful directions for healthcare professional and patients suffering from this debilitating condition.

Perirectal Fascial Anatomy: New Insights Into an Old Problem

BACKGROUND

The architecture of perirectal fasciae is complex as mirrored by different anatomical concepts.

OBJECTIVE

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.

DESIGN

Macroscopic dissection and histologic studies of perirectal fasciae and autonomic pelvic nerves were performed.

SETTINGS

This study was conducted in a university laboratory of macroscopic and microscopic anatomy.

PATIENTS

Thirteen (5 female) pelvic specimens were obtained from body donors (67-92 years of age).

MAIN OUTCOME MEASURES

The primary outcomes measured were the photodocumentation of perirectal fasciae, spaces and fusion zones, and histologic and immunohistochemical analysis of key structures.

RESULTS

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.

LIMITATIONS

Because of the increased age of the body donors, the findings may be subjected to age-related degenerative processes.

CONCLUSIONS

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.

Low Anterior Resection Syndrome After Transanal Total Mesorectal Excision: A Comparison With the Conventional Top-to-Bottom Approach

BACKGROUND

Advances in sphincter-saving procedures improved the quality of life of patients with rectal cancer. However, many of them experienced functional disturbances after surgery, including low anterior resection syndrome.

OBJECTIVE

The aim of this study was to evaluate the severity of low anterior resection syndrome after transanal total mesorectal excision and compare it with the conventional transabdominal, top-to-bottom, total mesorectal excision.

DESIGN

This was a single-center, retrospective analysis.

SETTINGS

The study was conducted at a tertiary academic institution.

PATIENTS

This study analyzed patients who underwent total mesorectal excision for mid to low rectal cancer from January 2016 to April 2018. Cases were matched one-to-one according to the tumor height and history of pelvic irradiation using the propensity score.

MAIN OUTCOME MEASURES

The primary outcome measured was the severity of low anterior resection syndrome and fecal incontinence at 3, 6, and 12 months after surgery or stoma reversal, whichever was later.

RESULTS

There were 35 patients in each group after matching; 67.1% were male, and 41.4% had neoadjuvant radiotherapy. At 3 months, the median low anterior resection syndrome score was 37 after transanal total mesorectal excision, which was significantly higher than the conventional approach, 32 (p = 0.045). Apart from this, the low anterior resection syndrome score, severity grading, and the Wexner score were comparable at 6 and 12 months.

LIMITATIONS

A difference between the 2 groups might not be detected because of the study's small sample size and because of its retrospective nature.

CONCLUSIONS

A higher low anterior resection syndrome score was observed after transanal total mesorectal excision at the initial 3-month period, but such a difference was not observed thereafter. This study showed that both surgical techniques had similar anal and bowel functional outcomes in the long run. However, because of the limited case number and study design, further study is needed to prove this. See Video Abstract at http://links.lww.com/DCR/B146. SÍNDROME DE RESECCIÓN ANTERIOR BAJA DESPUÉS DE LA ESCISIÓN MESORRECTAL TOTAL TRANSANAL: UNA COMPARACIÓN CON EL ABORDAJE CONVENCIONAL DE SUPERIOR A INFERIOR: Los avances en los procedimientos para salvar esfínteres mejoraron la calidad de vida de los pacientes con cáncer rectal. Sin embargo, muchos de ellos sufrieron trastornos funcionales después de la cirugía, incluyendo el síndrome de resección anterior baja.El objetivo de este estudio fue evaluar la gravedad del síndrome de resección anterior baja después de la escisión mesorrectal total transanal y comparar con la escisión mesorrectal total convencional transabdominal, de arriba a abajo.El estudio se realizó en una institución académica terciaria.Este fue un análisis retrospectivo de un solo centro de pacientes que se sometieron a una escisión mesorrectal total por cáncer rectal medio a bajo desde enero de 2016 hasta abril de 2018. Los casos fueron emparejados uno a uno de acuerdo con la altura del tumor y los antecedentes de irradiación pélvica con puntaje de propensión.La gravedad del síndrome de resección anterior baja y la incontinencia fecal a los 3, 6 y 12 meses después de la cirugía o la reversión del estoma, lo que ocurriera más tarde.Hubo 35 pacientes en cada grupo después del emparejamiento. El 67.1% eran hombres. El 41,4% tenía radioterapia neoadyuvante. A los tres meses, la puntuación media del síndrome de resección anterior baja fue de 37 después de la escisión mesorrectal transanal total, que fue significativamente mayor que el enfoque convencional, 32 (p = 0.045). Aparte de esto, la puntuación baja del síndrome de resección anterior, la clasificación de gravedad y la puntuación de Wexner fueron comparables a los 6 y 12 meses.Es posible que no se detecte una diferencia entre los dos grupos debido al pequeño tamaño de la muestra del estudio. La naturaleza retrospectiva del estudio.Se observó una puntuación más alta en el síndrome de resección anterior baja después de la escisión mesorrectal total transanal en el período inicial de tres meses, pero dicha diferencia no se observó posteriormente. Este estudio mostró que ambas técnicas quirúrgicas tuvieron resultados similares de funcionamiento anal e intestinal a largo plazo. Sin embargo, debido al número limitado de casos y al diseño del estudio, es necesario realizar más estudios para demostrarlo. Consulte Video Resumen en http://links.lww.com/DCR/B146.

Detailed and applied anatomy for improved rectal cancer treatment

Rectal anatomy is one of the most challenging concepts of visceral anatomy, even though currently there are more than 23,000 papers indexed in PubMed regarding this topic. Nonetheless, even though there is a plethora of information meant to assist clinicians to achieve a better practice, there is no universal understanding of its complexity. This in turn increases the morbidity rates due to iatrogenic causes, as mistakes that could be avoided are repeated. For this reason, this review attempts to gather current knowledge regarding the detailed anatomy of the rectum and to organize and present it in a manner that focuses on its clinical implications, not only for the colorectal surgeon, but most importantly for all colorectal cancer-related specialties.

To what extent is the low anterior resection syndrome (LARS) associated with quality of life as measured using the EORTC C30 and CR38 quality of life questionnaires?

PURPOSE

Treatment of rectal cancer often results in disturbed anorectal function, which can be quantified by the Low Anterior Resection Syndrome (LARS) score. This study investigates the association of impaired anorectal function as measured with the LARS score with quality of life (QoL) as measured with the EORTC-QLQ-C30 and CR38 questionnaires.

METHODS

All stoma-free patients who had undergone sphincter-preserving surgery for rectal cancer from 2000 to 2014 in our institution were retrieved from a prospective database. They were contacted by mail and asked to return the questionnaires. QoL was evaluated in relation to LARS and further patient- and treatment factors using univariate and multivariate analysis.

RESULTS

Of the eligible patients (n = 331), 261 (78.8%) responded with a complete LARS score. Mean score for global QoL according to the EORTC-QLQ-C30 questionnaire was 63 ± 21 for all patients. If major LARS was present, mean score decreased to 56 ± 19 in contrast to 67 ± 20 in patients with no/minor LARS (p < 0.001). In regression analysis, major LARS was furthermore associated with reduced physical, role, emotional, cognitive and social functioning as well as impaired body image, more micturition problems and poorer future perspective. It was not related to sexual function. The variance explained by major LARS in the differences of QoL was approximately 10%.

CONCLUSION

The presence of major LARS after rectal resection for cancer is negatively associated with global health as well as many other aspects of QoL. Preserving anorectal function and treatment of LARS are potential measures to improve QoL in this patient group.

Alterations of anal physiological features after surgery for low rectal cancer and management strategies

The sphincter preserving operation has improved the quality of life (QOL) of patients with low rectal cancer. However, some patients complain of having postoperative fecal incontinence and low QOL due to sphincter injury, nerve injure, and decreased rectal capacity. Therefore, anal physiology evaluation must be done preoperatively, the sphincter muscle and nerve should be preserved in operation, and biofeedback treatment should be administered postoperatively.

Novel multi-image view for neuromapping meets the needs of the robotic surgeon

BACKGROUND

Pelvic intraoperative neuromonitoring during nerve-sparing robot-assisted total mesorectal excision (RTME) is feasible. However, visual separation of the neuromonitoring process from the surgeon console interrupts the workflow and limits the usefulness of available information as the procedure progresses. Since the robotic surgical system provides multi-image views in the surgeon console, the aim of this study was to integrate cystomanometry and internal anal sphincter electromyography signals to aid the robotic surgeon in his/her nerve-sparing technique.

METHODS

We prospectively investigated 5 consecutive patients (1 male, 4 females) who underwent RTME for rectal cancer at our institution in 2017. The robotic surgery was performed using the da Vinci Xi combined with pelvic intraoperative neuromapping with real-time electromyography and cystomanometry signal transmission by multi-image view during RTME.

RESULTS

The adapted two-dimensional pelvic intraoperative neuromonitoring imaging successfully simulcasted to the surgeon console view in all 5 cases. The technical note is complemented by an intraoperative video.

CONCLUSIONS

This report demonstrates the technical feasibility of an improved neuromonitoring process during nerve-sparing RTME. Robotic neuromapping can be fully visualized from the surgeon console.

Outcome of bowel function following anterior resection for rectal cancer-an analysis using the low anterior resection syndrome (LARS) score

PURPOSE

Severity of anorectal dysfunction after low anterior resection is associated with various patient- and treatment-related factors. We aimed to quantify anorectal dysfunction after treatment for rectal cancer using the low anterior resection syndrome (LARS) score.

METHODS

We retrieved from a prospective database 331 eligible patients on whom anterior resection for rectal cancer had been performed from 2000 to 2014. All patients were sent a LARS score accompanied by a supplementary questionnaire. Response rate was 78.8% (261 patients). The main outcome measure was the relation of the LARS score to potentially associated patient and treatment factors. Secondary endpoints were further measures that reflect anorectal dysfunction, e.g., Vaizey score.

RESULTS

Overall, 144 (55.2%) patients exhibited scores > 20 reflecting minor (n = 51 (19.5%)) or major (n = 93 (35.6%)) LARS. A significant difference for scores > 20 was found for intersphincteric resection (IR, 73.2% affected patients) compared to total mesorectal excision (TME, 58.4%) and partial mesorectal excision (PME, 38.0%, p = 0.001). Radio(chemo)therapy resulted in LARS scores > 20 in 64.6% of patients compared to 43.1% in patients without irradiation (p = 0.001). Type of procedure (TME and IR as compared to PME), radio(chemo)therapy, and younger age were independently associated with LARS in logistic regression analysis. However, younger age remained the only independent factor for higher scores after exclusion of PME.

CONCLUSIONS

The LARS score identified a substantial proportion of patients after surgery for rectal cancer with anorectal dysfunction. The extent of surgical procedure is independently associated with the severity of symptoms whereas the role of radiotherapy needs further assessment.