Topography of the extrinsic internal anal sphincter nerve supply during laparoscopic-assisted TAMIS TME: five key zones of risk from the surgeons' view

Intersphinktäre Resektion zum Schließmuskelerhalt beim ultratiefen Rektumkarzinom – Ein Update

Die Indikation zum Sphinktererhalt bei Patienten mit einem sehr tief sitzenden Rektumkarzinom ist in vielerlei Hinsicht eine Herausforderung und auch an die Beherrschung der intersphinktären Resektion gebunden. In dieser Arbeit sollen die zunehmend definierten Operationstechniken kurz vorgestellt und aktuell eingeordnet werden.

Transanal total mesorectal excision: short- and long-term results of four certified colorectal cancer centers in Germany

BACKGROUND

Transanal total mesorectal excision (TaTME), a novel approach for treating low rectal cancer, holds promise. However, concerns exist in certain countries about their oncologic safety due to less-than-optimal outcomes on global studies. This research seeks to evaluate the long-term oncologic outcomes focusing on local recurrence rate and overall survival after TaTME surgery in Germany.

PATIENTS AND METHODS

This study analyzed data from patients who underwent elective TaTME surgery between 2014 and 2021 in four certified colorectal cancer centers in Germany. Primary endpoints were 3-year local recurrence rate and local recurrence-free survival (LRFS). Secondary outcomes encompassed overall survival (OS), operative time, completeness of local tumor resection, lymph node resection, and postoperative complications.

RESULTS

A total of 378 patients were analyzed (mean age 61.6 years; 272 males, 72%). After a median follow-up period of 2.5 years, 326 patients with UICC-stages I-III and tumor operability included in survival analyses. Local recurrence was observed in 8 individuals, leading to a 3-year cumulative local recurrence rate of 2.2% and a 3-year LRFS rate of 88.1%. The 3-year OS rate stood at 88.9%. Within 30 days after surgery, anastomotic leakage occurred in 19 cases (5%), whereas a presacral abscess was present in 12 patients (3.2%).

CONCLUSION

TaTME proves effective in addressing the anatomical and technical challenges of low rectal surgery and is associated with pleasing short- and long-term results. However, its safe integration into surgical routine necessitates sufficient knowledge and a previously completed training program.

Functional outcomes after transanal total mesorectal excision (TaTME): a random forest analysis to predict patients' outcomes

PURPOSE

Anorectal, sexual, and urinary dysfunction are common issues after rectal cancer surgery, although seldom explored. The primary aim of this study was to investigate postoperative anorectal functional results.

METHODS

Patients with mid/low-rectal cancer treated with transanal TME (TaTME) with primary anastomosis with/without diverting stoma between 2015 and 2020 were reviewed and selected if they had a minimum follow-up of 6 months (from the primary procedure or stoma reversal). Patients were interviewed using validated questionnaires and the primary outcome was bowel function based on Low Anterior Resection Syndrome (LARS) scores. Statistical analyses were performed to identify clinical/operative variables correlated with worse outcomes. A random forest (RF) algorithm was computed to classify patients at a greater risk of minor/major LARS.

RESULTS

Ninety-seven patients were selected out of 154 TaTME performed. Overall, 88.7% of the patients had a protective stoma and 25.8% reported major LARS at mean follow-up of 19.0 months. Statistical analyses documented that age, operative time, and interval to stoma reversal correlated with LARS outcomes. The RF analysis disclosed worse LARS symptoms in patients with longer operative time (> 295 min) and stoma reversal interval (> 5.6 months). If the interval ranged between 3 and 5.6 months, older patients (> 65 years) reported worse outcomes. Finally, no statistical difference was documented when comparing the rate of minor/major LARS in the first 27 cases versus others.

CONCLUSION

One-quarter of the patients developed major LARS after TaTME. An algorithm based on clinical/operative variables, such as age, operative time, and time to stoma reversal, was developed to identify categories at risk for LARS symptoms.

Limitations and Concerns with Transanal Total Mesorectal Excision for Rectal Cancer

Transanal total mesorectal excision (TaTME) was developed to overcome the technical challenges of a minimally invasive (ultra-) low anterior resection. This new technique has recently come under careful scrutiny as technical pitfalls were reported, in specific relation to the transanal approach. Patients are at risk for urologic lesions. Moreover, carbon dioxide embolism is a rare but potentially life-threatening complication. The benefit of TaTME from an oncological point of view has neither been clarified. Hypothetically, better visualization of the lower rectum could lead to better dissection and total mesorectal excision (TME) specimens, resulting in better oncologic results. Up until now, retrospective multicenter reports seem to show that short-term oncologic results are not inferior after TaTME as compared with after laparoscopic TME. Alarming reports have however been published from Norway suggesting a high incidence and particular multifocal pattern of early local recurrence. In this article, a balanced overview is given of the most important technical pitfalls and oncological concerns arising with this new procedure.

Transanal versus laparoscopic total mesorectal excision: a comparative study of long-term oncological outcomes

BACKGROUND

Transanal total mesorectal excision (TaTME) is the most recent approach developed to improve pelvic dissection in surgery for mid and low rectal tumors. There are still inconsistencies regarding the technique's oncological results. The aim of this study was to analyze clinical and oncological outcomes of the learning curve of TaTME in comparison to laparoscopic TME (lapTME).

METHODS

Rectal cancer patients who had TaTME and lapTME in two Portuguese colorectal units between March 2016 and December 2018 were eligible. Primary endpoints were 5-year overall survival, disease-free survival, and local recurrence. Secondary endpoints were clinical and pathological outcomes.

RESULTS

Forty-four patients underwent TaTME (29 men) and 39 lapTME (27 men) with a median age of 69 and 66 (p = 0.093), respectively. No differences were observed concerning baseline characteristics, emphasizing their comparability. In the TaTME group, there were more hand-sewn anastomosis (0 lapTME versus 7 TaTME, p = 0.018) with significantly less distance to the dentate line (40 mm lapTME versus 20 mm TaTME, p = 0.005) and significantly more loop ileostomies performed (28 lapTME versus 41 TaTME, p = 0.001). There were no differences in post-operative mortality, morbidity, readmissions, and stoma closure. Groups were similar in relation to specimen quality, margins, and resectability; however, TaTME had a significantly higher node yield (14 lapTME versus 20 TaTME, p = 0.002). Finally, no disparities were noted in oncological outcomes, namely local and distant recurrence, 5-year overall survival, and disease-free survival.

CONCLUSIONS

Even with the disadvantage of the learning curve of a new technique, TaTME appears to be comparable to lapTME, with similar long-term oncological outcomes. It has, however, a demanding learning curve, significant risk for morbidity and should be used only for selected patients.

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.

Intraoperative neuromonitoring in rectal cancer surgery: a systematic review and meta-analysis

PURPOSE

The aim of this study is to evaluate the role of pelvic intraoperative neuromonitoring (pIONM) in rectal cancer surgery.

METHODS

A systematic review of the literature and a meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

Overall, nine studies were identified. Quantitative analysis was performed only in three trials. Bilateral pIONM improved postoperative anorectal and urogenital functional outcomes. However, unilateral pIONM displayed a significant effect only on erectile function (p = 0.001).

CONCLUSIONS

Our findings suggest a positive effect of pIONM on postoperative functional outcomes and quality of life after rectal cancer surgery. Due to several limitations, further trials are required in order to elucidate the exact role of pIONM.

Multicenter investigation of bowel evacuation function after transanal total mesorectal excision for mid-low rectal cancer

PURPOSE

To determine the effect of transanal total mesorectal excision (taTME) procedure on the postoperative bowel evacuation function of patients with low rectal cancer.

METHODS

Bowel evacuation function was investigated in 316 patients with rectal cancer after taTME in 18 hospitals in China. Low anterior resection syndrome (LARS) score, Wexner score, and EORTC QLQ-C30 were used for functional evaluation. The association between perioperative risk factors and LARS score was determined by univariate and multivariate analyses.

RESULTS

The prevalence rate of no LARS, minor LARS, and major LARS in patients after taTME was 39.9%, 28.2%, and 31.9%, respectively. The two most frequently reported symptoms of LARS after taTME were bowel clustering (72.8%) and fecal urgency (63.3%). Patients with major LARS had significantly higher Wexner score and worse global health status and financial difficulties according to the EORTC QLQ-C30 questionnaire than those without major LARS. Preoperative chemoradiotherapy was an independent risk factor of major LARS occurrence after taTME (OR: 3.503, P = 0.044); existing preoperative constipation (OR: 0.082, P = 0.040) and manual anastomosis (OR: 4.536, P = 0.021) were favorable factors affecting bowel evacuatory function within 12 months after taTME, but for patients whose follow-up time was longer than 12 months, postoperative chemoradiotherapy (OR: 8.790, P = 0.001) and defunctioning stoma (OR: 3.962, P = 0.010) were independent risk factors.

CONCLUSIONS

The bowel evacuation function after taTME is acceptable. Perioperative chemoradiotherapy, anastomotic method, and preoperative constipation are factors associated with bowel dysfunction after taTME.

Re-exploring the pelvic neuroanatomy from a new perspective and a potential guidance for TaTME: a "bottom-up" approach

Neuro-anatomy of the perineum has gained renewed attention due to its significance in the transanal procedures for rectal cancer (eg TaTME). Surgeons embarking on this technique must have sophisticated knowledge and a precise anatomical understanding of the perineum before proceeding with this reversed rectal approach. We report anatomical observations deriving from a relevant experience in the colorectal surgery field. The collective multicenter experience of the present study is clinically relevant and based on the rectal and transanal resections performed in colorectal centers of excellence from Greece, UK, and Italy over the last 10 years (2011-2020). From the original anatomical and intraoperative observations derived from collective cases operated by this multicenter group of colorectal surgical centers in three European countries, data were retrieved and analyzed in collaboration with specialist researchers of human anatomy and interpreted for their clinical significance and potential use for preoperative planning and intraoperative guidance during TaTME. This descriptive article demonstrates in detail the neurogenic pathways encountered in the perineum and pelvic cavity during transanal procedures. Specific anatomical and topographic implications are also included serving as a guide for colorectal surgeons to perform a nerve-sparing procedure. transanal approach for rectal excision offers new insights into the complex pelvic and perineal neuroanatomy while the procedure itself remains a challenge for surgeons. Preoperative anatomical planning and 3D reconstruction may help in anticipating technical difficulties, resulting in more precise surgical dissections and decreased postoperative complications.

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.

The value of force and torque measurements in transanal total mesorectal excision (TaTME)

Background

Transanal total mesorectal excision (TaTME) is associated with a relatively long learning curve. Force, motion, and time parameters are increasingly used for objective assessment of skills to enhance laparoscopic training efficacy. The aim of this study was to identify relevant metrics for accurate skill assessment in more complex transanal purse-string suturing.

Methods

A box trainer was designed for TaTME and equipped with two custom made multi-DOF force/torque sensors. These sensors measured the applied forces in the axial direction of the instruments (Fz), instrument load orientation expressed in torque (Mx and My) on the entrance port, and the full tissue interaction force (Fft) at the intestine fixation point. In a construct validity study, novices for TaTME performed a purse-string suture to investigate which parameters can be used best to identify meaningful events during tissue manipulation and instrument handling.

Results

Significant differences exist between pre- and post-training assessment for the mean axial force at the entrance port Fz (p = 0.01), mean torque in the entrance port Mx (p = 0.03) and mean force on the intestine during suturing Fft (p = 0.05). Furthermore, force levels during suturing exceed safety threshold values, potentially leading to dangerous complications such as rupture of the rectum.

Conclusions

Forces and torque measured at the entrance port, and the tissue interaction force signatures provide detailed insight into instrument handling, instrument loading, and tissue handling during purse-string suturing in a TaTME training setup. This newly developed training setup for single-port laparoscopy that enables objective feedback has the potential to enhance surgical training in TaTME.

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.

Transanal total mesorectal excision (TaTME): current status and future perspectives

Total mesorectal excision (TME) is the gold standard surgical treatment for mid- and low rectal cancer; however, it is associated with specific technical hurdles. Transanal TME (TaTME) is a new procedure developed to overcome these difficulties, through an enhanced visualization of the dissection plane. This potentially could result in a more accurate distal dissection with a lower rate of positive circumferential resection margins, increasing the rate of sphincter-saving procedures. The indications for TaTME are currently expanding, despite not being yet standardized, and structured training programs are ongoing to help overcome the steep learning curve related to the technique. The procedure is feasible and safe with similar intraoperative complications and readmission rates when compared with conventional open or laparoscopic TME. Favorable short-term oncologic results have been reported: in particular, TaTME is associated with mesorectal specimen of a better quality and a longer distal resection margin that is established at the beginning of the procedure under direct view. Robotics, when available, will probably overcome the steep learning curve related to the complexity of TaTME. Long-term follow-up and ongoing RCT trials data are awaited regarding functional results, local recurrence and survival, and to facilitate the comparison with standard laparoscopic or robotic rectal resections. The present review is focused on critically analyzing the theoretical benefits and risks of the procedure, its indications, short- and long-term results and future direction in the application of TaTME.

Intraoperative monitoring of pelvic autonomic nerves during laparoscopic low anterior resection of rectal cancer

Background

Some patients with low rectal cancer experience anorectal and urogenital dysfunctions after surgery, which can influence the long-term quality of life. In this study, we aimed to protect nerve function in such scenarios by performing intraoperative monitoring of pelvic autonomic nerves (IMPAN).

Patients and methods

We retrospectively investigated a series of 87 patients undergoing laparoscopic low anterior resection of rectal cancer. Nerve-sparing was evaluated both visually and electrophysiologically. IMPAN was performed by stimulating the pelvic autonomic nerves under processed electromyography of the internal anal sphincter. Urination, defecation, sexual function, and the quality of life were evaluated using validated and standardized questionnaires preoperatively and at follow-up, 12 months after surgery.

Results

Among a total of 87 patients (53 male and 34 female patients), IMPAN with simultaneous electromyography of the internal anal sphincter was performed in 58 (66.7%) patients. Bilateral positive IMPAN results for both measurements, indicating successfully confirmed pelvic autonomic nerve preservation, were obtained in 45 (51.7%) patients. No significant difference was found in terms of urogenital and anorectal functions between preoperative and postoperative patients with bilateral positive IMPAN (P>0.05). Compared to preoperative patients with IMPAN (unilateral) or without IMPAN, these patients exhibited higher International Prostate Symptom Score, a lower International Index of Erectile Function-5, and a lower Female Sexual Function Index score at 12 months postoperatively (P<0.05).

Conclusion

IMPAN is an appropriate method with which to laparoscopically protect nerve function.

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.

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

AIM

The internal anal sphincter (IAS) contributes substantially to anorectal functions. While its autonomic nerve supply has been studied at the microscopic level, little information is available concerning the macroscopic topography of extrinsic nerve fibres. This study was designed to identify neural connections between the pelvic plexus and the IAS, provide a detailed topographical description, and give histological proof of autonomic nerve tissue.

METHODS

Macroscopic dissection of pelvic autonomic nerves was performed under magnification in seven (five male, two female) hemipelvises obtained from body donors (67-92 years). Candidate structures were investigated by histological and immunohistochemical staining protocols to visualize nerve tissue.

RESULTS

Nerve fibres could be traced from the anteroinferior edge of the pelvic plexus to the anorectal junction running along the neurovascular bundle anterolaterally to the rectum and posterolaterally to the prostate/vagina. Nerve fibres penetrated the longitudinal rectal muscle layer just above the fusion with the levator ani muscle (conjoint longitudinal muscle) and entered the intersphincteric space to reach the IAS. Histological and immunohistochemical findings confirmed the presence of nerve tissue.

CONCLUSIONS

Autonomic nerve fibres supplying the IAS emerge from the pelvic plexus and are distinct to nerves entering the rectum via the lateral pedicles. Thus, they should be classified as IAS nerves. The identification and precise topographical location described provides a basis for nerve-sparing rectal resection procedures and helps to prevent postoperative functional anorectal disorders.

Operative vectors, anatomic distortion, fluid dynamics and the inherent effects of pneumatic insufflation encountered during transanal total mesorectal excision

BACKGROUND

Transanal total mesorectal excision (taTME) is an altogether different approach to rectal cancer surgery, and the effects of carbon dioxide (CO₂) on this dissection remain poorly described.

METHODS

This article critically examines the effect of carbon dioxide insufflation and the workspace it creates during the process of taTME. The unique aspects of insulation with this approach are governed by the laws of physics, especially the principles of fluid dynamics, an area that remains poorly described for laparoscopy and not at all described for taTME.

RESULTS

A summary of established factors which affect the operative field of the taTME surgeon is delineated and further explored. In addition, new concepts regarding gas delivery, such as insufflation vectors, anatomic distortion, hyper-dissection, and workspace volume rate of change as a function of taTME dissection time, are addressed. Collectively, these factors pose important challenges which increase case complexity and are thus essential for taTME trainers and trainees alike to understand.

CONCLUSIONS

Although an invisible gas, CO₂ insufflation with taTME produces markedly visible effects which are imposed upon the operative field. This can result in anatomic distortion and misperception of operative planes. Thus, practicing taTME surgeons should be cognizant of these effects.

[Minimally invasive approaches for transanal surgery]

Since the introduction of transanal endoscopic microsurgery (TEM) in the 1980 s, the minimally invasive transanal approach has been a treatment option for selected patients with colorectal diseases. Recently, transanal minimally invasive surgery (TAMIS) was introduced as an alternative technique. TAMIS is a hybrid between TEM and single-port laparoscopy and was followed by introduction of transanal total mesorectal excision (TaTME). Although the TaTME experience remains preliminary, it appears to be an attractive minimally invasive procedure for carefully selected patients with resectable rectal cancer. The objective of this review is to describe the latest technologies which enhanced progress of minimally invasive transanal approaches for endo- and extraluminal surgery in this area of colorectal surgery.

[Hybrid TAMIS total mesorectal excision. A new perspective in treatment of distal rectal cancer - Technique and results]

BACKGROUND

Transanal minimally invasive surgery (TAMIS) represents a promising technique for total mesorectal excision (TME) with respect to radicalness and preservation of function. There are only few publications in the literature describing results in patients with distal rectal cancer.

METHODS

Between May 2013 and March 2015, 24 selected patients with a rectal carcinoma < 6 cm from the anal verge underwent a laparoscopically assisted TAMIS TME (Hybrid-TAMIS TME) procedure. This prospective observational study was conducted to examine the safety of the technique and the quality of TME surgery in distal rectal cancer and to assess the short-term postoperative outcome.

RESULTS

The median age of patients (18 male and 6 female) at the time of surgery was 57 years (range 35-77 years) and 7 patients (29 %) had a body mass index (BMI) > 30 kg/m(2). Specimen excision was carried out transanally in 19 patients. Pathological grading of TME specimens was good in 22 (92 %) and moderate in 2 cases. After neoadjuvant radiochemotherapy a complete pathological remission was identified in five patients. The median distal resection margin was 7 mm (range 2-30 mm), the median circumferential resection margin was 6 mm (range <1 mm-30 mm) and in 2 patients the tumor was ≤ 1 mm from the positive circumferential margin. A colonic reservoir was created in 19 patients (79 %) and no 30-day mortalities occurred. Morbidity was 29 %, including 1 anastomotic leak, 2 hematomas and 1 neurogenic bladder.

CONCLUSION

Hybrid-TAMIS TME for distal rectal cancer is safe and can provide a sphincter-preserving high-quality TME in difficult cases. Studies with long-term follow-up assessing oncological and functional results are mandatory.

[Total mesorectal excision in rectal cancer management: laparoscopic or transanal?]

AIM

To evaluate and compare intraoperative features, early surgical outcomes, quality of excised specimen after laparoscopic and transanal total mesorectal excision (LA-TME and TA-TME).

MATERIAL AND METHODS

Prospective randomized study included 45 patients with confirmed rectal adenocarcinoma (cT2-4N0-2M0) since October 2013. LA-TME and TA-TME groups consisted of 23 and 22 patients respectively. Inclusion criteria were patients with primary-operable rectal cancer and satisfactory response after neoadjuvant chemo- and radiotherapy. Both groups were comparable in stages of cancer, age and body mass index (BMI). Median length from anal edge was 6.5 cm and 7 cm in TA-TME and LA-TME groups respectively. There was significantly greater number of patients after chemo- and radiotherapy in TA-TME group (86% vs. 48%, p=0.006).

RESULTS

Surgery time was 305 and 320 minutes in LA-TME and TA-TME groups recpectively, median blood loss -- less than 100 ml. Mean hospital-stay was 8.0 days in both groups. Each group had 1 conversion including laparoscopic procedure in TA-TME group. Transanal extraction of specimen was performed in 86% vs. 48% in TA-TME and LA-TME groups respectively (p=0.021). Complications (Clavien-Dindo sclale) were observed in 27% and 26% in TA-TME and LA-TME groups respectively without statistically significance. Complications IIIb, IVb and V degrees were not diagnosed in TA-TME group. Also in this group «good», «satisfactory» and «unsatisfactory» quality of TME was obtained in 68%, 14% and 18% of cases. At the same time in LA-TME group these values were 74%, 9% and 17% respectively (p=0.859). One of operated patients had «positive» lateral edge (TA-TME). Median distal edge of resection was 21 mm and 23 mm in TA-TME and LA-TME groups respectively.

CONCLUSION

Preliminary data show comparable early outcomes after transanal and laparoscopic techniques. Laparotomy and associated compications are avoided in case of transanal extraction of specimen. Further researches are necessary to study functional and long-term results.

Surgeons' assessment of internal anal sphincter nerve supply during TaTME - inbetween expectations and reality

Background: Intraoperative identification of nerve fibers heading from the inferior rectal plexus (IRP) to the internal anal sphincter (IAS) is challenging. The transanal total mesorectal excision (TaTME) is said to better preserve pelvic autonomic nerves. The aim of this study was to investigate the nerve identification rates during TaTME by transanal visual and electrophysiological assessment.

Material and methods: A total of 52 patients underwent TaTME for malignant conditions. The IRP with its posterior branches to the IAS and the pelvic splanchnic nerves (PSN) were visually assessed in 20 patients (v-TaTME). Electrophysiological nerve identification was performed in 32 patients using electric stimulation under processed electromyography of IAS (e-TaTME).

Results: The indication profile for TaTME was comparable between the v-TaTME and the e-TaTME group. The identification of IRP was more meaningful under electrophysiological assessment than under visual assessment for the left pelvic side (81% vs. 45%, p = 0.008) as well as the right pelvic side (78% vs. 45%, p = 0.016). The identification rates for PSN did not significantly differ between both groups, respectively (81% vs. 75%, p = 0.420 and 84% vs. 70%, p = 0.187).

Conclusions: The transanal approach facilitated visual identification of IAS nerve supply. In combination with electrophysiological nerve assessment the identification rate almost doubled. For further insights functional data are needed.

Transanal minimally invasive surgery (TAMIS) approach for large juxta-anal gastrointestinal stromal tumour

Gastrointestinal stromal tumours (GISTs) are rarely found in the rectum. Large rectal GISTs in the narrow pelvis sometimes require extended abdominal surgery to obtain free resection margins, and it is a challenge to preserve sufficient anal sphincter and urogenital function. Here we present a 56-year-old male with a locally advanced juxta-anal non-metastatic GIST of approximately 10 cm in diameter. Therapy with imatinib reduced the tumour size and allowed partial intersphincteric resection (pISR). The patient underwent an electrophysiology-controlled nerve-sparing hybrid of laparoscopic and transanal minimally invasive surgery (TAMIS) in a multimodal setting. The down-to-up approach provided sufficient dissection plane visualisation and allowed the confirmed nerve-sparing. Lateroterminal coloanal anastomosis was performed. Follow-up showed preserved urogenital function and good anorectal function, and the patient remains disease-free under adjuvant chemotherapy as of 12 months after surgery. This report suggests that the TAMIS approach enables extraluminal high-quality oncological and function-preserving excision of high-risk GISTs.

Continuous intraoperative monitoring of pelvic autonomic nerves during TME to prevent urogenital and anorectal dysfunction in rectal cancer patients (NEUROS): a randomized controlled trial

Background

Urinary, sexual and anorectal sequelae are frequent after rectal cancer surgery and were found to be related to intraoperative neurogenic impairment. Neuromonitoring methods have been developed to identify and preserve the complex pelvic autonomic nervous system in order to maintain patients’ quality of life. So far no randomized study has been published dealing with the role of neuromonitoring in rectal cancer surgery.

Methods/design

NEUROS is a prospective two-arm randomized controlled multicenter clinical trial comparing the functional outcome in rectal cancer patients undergoing total mesorectal excision (TME) with and without pelvic intraoperative neuromonitoring (pIONM). A total of 188 patients will be included. Primary endpoint is the urinary function measured by the International Prostate Symptom Score. Secondary endpoints consist of sexual, anorectal functional outcome and safety, especially oncologic safety and quality of TME. Sexual function is assessed in females with the Female Sexual Function Index and in males with the International Index of Erectile Function. For evaluation of anorectal function the Wexner-Vaizey score is used. Functional evaluation is scheduled before radiochemotherapy (if applicable), preoperatively (baseline), before hospital discharge, 3 and 6 months after stoma closure and 12 months after surgery. For assessment of safety adverse events, the rates of positive resection margins and quality of mesorectum are documented.

Discussion

This study will provide high quality evidence on the efficacy of pIONM aiming for improvement of functional outcome in rectal cancer patients undergoing TME.

Trial registration

Clinicaltrials.gov: NCT01585727. Registration date is 04/25/2012

Critical concepts and important anatomic landmarks encountered during transanal total mesorectal excision (taTME): toward the mastery of a new operation for rectal cancer surgery

Over the past 3 years, colorectal surgeons have begun to adapt the technique of transanal total mesorectal excision. As international experience has been quickly forged, an improved recognition of the pitfalls and the practical details of this disruptive technique have been realized. The purpose of this technical note was to express the various nuances of transanal total mesorectal excision as learned during the course of its clinical application and international teaching, so as to rapidly communicate and share important insights with other surgeons who are in the early adoption phase of this approach. The technical points specific to transanal total mesorectal excision are addressed herein. When correctly applied, these will likely improve the quality of surgery and decrease morbidity attributable to inexperience with the transanal approach to total mesorectal excision.

Surface Electromyography Reliably Records Electrophysiologically Evoked Internal Anal Sphincter Activity: A More Minimally Invasive Approach for Monitoring Extrinsic Innervation

BACKGROUND

Even in the case of minimally invasive pelvic surgery, sparing of the autonomic nerve supply is a prerequisite for maintaining anal sphincter function. Internal anal sphincter (IAS) innervation could be electrophysiologically identified based on processed electromyographic (EMG) recordings with conventional bipolar needle electrodes (NE). This experimental study aimed for the development of a minimally invasive approach via intra-anal surface EMG for recordings of evoked IAS activity.

METHODS

Six male pigs underwent nerve-sparing low anterior rectal resection. Electric autonomic nerve stimulations were performed under online-processed EMG of the IAS. EMG recordings were simultaneously carried out with conventional bipolar NE as the reference method and newly developed intra-anal surface electrodes (SE) in different designs.

RESULTS

In all experiments, the IAS activity could be continuously visualized via EMG recordings based on NE and SE. The median number of bipolar electric stimulations per animal was 27 (range 5-52). The neurostimulations resulted in significant EMG amplitude increases for both recording types [NE: median 3.0 µV (interquartile range, IQR 2.8-3.5) before stimulation vs. 7.1 µV (IQR 3.9-13.8) during stimulation, p < 0.001; SE: median 3.6 µV (IQR 3.1-4.3) before stimulation vs. 6.8 µV (IQR 4.8-10.3) during stimulation, p < 0.001].

CONCLUSIONS

Intra-anal SE enabled reliable EMG of electrophysiologically evoked IAS activity similar to the conventional recording via NE. The transfer of the method to access platforms for transanal total mesorectal excision or robotics may offer a practical more minimally invasive approach for monitoring extrinsic innervation.

Electrophysiology-based quality assurance of nerve-sparing in laparoscopic rectal cancer surgery: Is it worth the effort?

BACKGROUND

After low anterior resection for rectal cancer, visual assessment of pelvic autonomic nerve preservation can be difficult due to the complexity of neuroanatomy, as well as surgery- and patient-related factors. The present study aimed to evaluate nerve-sparing quality assurance using the laparoscopic neuromapping (LNM) technique.

METHODS

We prospectively investigated a series of 30 patients undergoing laparoscopic low anterior resection. Nerve-sparing was evaluated both visually and electrophysiologically. LNM was performed using stimulation of pelvic autonomic nerves under simultaneous cystomanometry and processed electromyography of the internal anal sphincter. Urogenital and anorectal functions were evaluated using validated and standardized questionnaires preoperatively, at short-term follow-up, and at mid-term follow-up at a median of 9 months (range 6-12 months) after surgery.

RESULTS

One patient reported new onset of urinary dysfunction, and another patient reported new onset of anorectal dysfunction. Of the 20 sexually active patients, five reported sexual dysfunction. Visual assessment by laparoscopy confirmed complete nerve preservation in 28 of 30 cases. For prediction of urinary and anorectal function, LNM sensitivity, specificity, positive and negative predictive value, and overall accuracy were each 100 %. LNM with combined assessment for prediction of sexual function yielded a sensitivity of 80 %, specificity of 93 %, positive predictive value of 80 %, negative predictive value of 93 %, and overall accuracy of 90 %.

CONCLUSIONS

LNM is an appropriate method for reliable quality assurance of laparoscopic nerve-sparing.

Short-term outcomes after transanal and laparoscopic total mesorectal excision for rectal cancer

BACKGROUND

Transanal total mesorectal excision (taTME) has potential benefits of better visual control, especially in male patients with a high body mass index and low rectal cancer. However, this method has not yet been validated in clinical trials. The aim of this study was to compare the short-term outcomes of transanal and laparoscopic (lap) TME.

METHODS

From October 2013 to January 2015, consecutive patients undergoing transanal or laparoscopic TME for biopsy-proven mrT1-4aN0-2M0 rectal cancer were included in a prospective database. Patients with Eastern Cooperative Oncology Group performance status 2 and higher and patients undergoing partial mesorectal excision were excluded. This analysis focused on short-term surgical outcomes.

RESULTS

From October 2013 to January 2015, 22 taTME procedures and 23 laparoscopic TME procedures were performed. Patient characteristics were comparable between groups, but more patients in the taTME group underwent neoadjuvant (chemo) radiotherapy (87 vs. 48 %, p = 0.006). Median operative time was 320 min in the taTME group and 305 min in the lapTME group. There was one conversion in each group, but the transanal procedure was converted to laparoscopic resection. Transanal specimen extraction was performed in 86 versus 48 % patients in taTME and lapTME groups accordingly (p = 0.021). There was no post-operative mortality and post-operative morbidity in the taTME and lapTME groups was similar (27 vs. 26 %). One patient in the taTME group had positive circumferential resection margins. Oncologic results from resected specimens were comparable.

CONCLUSIONS

Our initial experience demonstrates comparable short-term results for taTME and lap TME. Further investigation is necessary to assess long-term functional and oncologic outcomes.

Transanal total mesorectal excision: Towards standardization of technique

AIM: To describe the role of Transanal total mesorectal excision (TaTME) in minimally invasive rectal cancer surgery, to examine the differences in patient selection and in reported surgical techniques and their impacts on postoperative outcomes and to discuss the future of TaTME.

METHODS: MEDLINE (PubMed), EMBASE, and The Cochrane Library were systematically searched through the 1^st of March 2015 using a predefined search strategy.

RESULTS: A total of 20 studies with 323 patients were included. Most studies were single-arm prospective studies with fewer than 100 patients. Multiple transanal access platforms were used, and the laparoscopic approach was either multi- or single port. The procedure was initiated transanally or transabdominally. If a simultaneous approach with 2 operating surgeons was chosen, the operative time was significantly reduced.

CONCLUSION: TaTME was also associated with better TME specimens and a longer distal resection margin. TaTME is thus feasible in expert hands, but the learning curve and safety profile are not well defined. Long-term follow-up regarding anal function and oncological outcomes should be performed in the future.

Midterm functional results of taTME with neuromapping for low rectal cancer

BACKGROUND

Information on functional outcomes after laparoscopic-assisted transanal total mesorectal excision (taTME) is limited. This study analyzed the functional results in patients with low rectal cancer.

METHODS

Ten consecutive patients (nine males) undergoing electrophysiologically controlled nerve-sparing taTME were investigated prospectively and asked to complete functional questionnaires [the International Prostate Symptom Score (IPSS), International Index of Erectile Function, Female Sexual Function Index, Wexner score, and low anterior resection syndrome (LARS) score]. Bladder function was also assessed according to residual urine volume. Preoperative function was compared to the functional outcome 3 and 6 months, and 9 months if eligible, after stoma closure or surgery in the absence of a diverting stoma.

RESULTS

Prior to therapy, urinary and sexual function was impaired in 40 and 60% of patients, respectively. None of the patients developed pathological residual urine volumes after at least unilateral functional pelvic nerve-sparing. Median IPSS was lower than preoperative scores (p > 0.05). Two males with incomplete nerve preservation were considered impotent during a median follow-up of 15 months (range 6-20 months). The female was judged to be sexually inactive. The median Wexner score was 1 (range 0-7) prior to any therapy and increased to 7 (range 0-15) at 6 months (p = 0.029), with 40% of patients categorized as having no LARS and 50% minor LARS. The median LARS score was 28 (range 9-38) at 3 months and 26 (range 9-32) at 6 months (p = 0.165).

CONCLUSIONS

Despite a small sample size and confounding factors, data indicate that taTME has the potential to preserve continence, sufficient bowel function, and urogenital function.

Urogenital dysfunctions after treatment of rectal cancer

A significant part of rectal cancer survivors will experience urogenital dysfunction induced by the treatment. Significant progress has been made in order to improve the total mesorectal technique through different approaches (open, laparoscopic, robotic, transanal). Rectal cancer surgery is technically difficult notably deep in the pelvis, and therefore the most frequent cause of the postoperative dysfunction is the surgical nerve damage of the autonomic nerves at this level. The main objectives of these efforts were to obtain maximal oncological results and to achieve better functional outcomes including less postoperative urogenital dysfunctions. Our purpose was to build a comprehensive review of the existing literature data regarding this issue from past to present.

The new approach to the rectal cancer: 'down-to-up' double endolaparoscopic pelvic access. Preliminary evaluation of outcomes

Laparoscopic access in low anterior rectal resection is widely adopted, performing an 'up-to-down' dissection. The aim of this study is to present and analyze the outcomes of a novel surgical 'down-to-up' total mesorectal excision technique that could obviate to the well-known issues of the standard treatment. 18 suitable patients underwent double endolaparoscopic pelvic access (DEPA) 'down-to-up' technique. DEPA TME was completed in all patients, with intact mesorectum. Mean operative time was 365 min (range 280-510 min). The morbidity rate was 22%, including three radiologically detected leakage (grade A) and one pelvic abscess, requiring only a conservative management. Mortality rate at 30 and 90 days was 0%. Resection margins were negative in all patients. A median of 11 nodes (range 5-19) was retrieved per specimen. Mean length of hospital stay was 9 days (range 7-19 days). Patients were followed for an average of 14 months (range 0-42 months), with no recurrence. Despite exiguous patient's sample in this pilot study, transanal endoscopic TME with laparoscopic assistance seems to be feasible and safe, and is a promising alternative to open and laparoscopic TME. However, a conspicuous functional and oncologic long-term evaluation is required, before the widespread adoption could be recommended.