The feasibility and safety of Natural Orifice Translumenal Endoscopic Surgery (NOTES) transanal endoscopic rectosigmoid resection using transanal endoscopic microsurgery (TEM) was previously demonstrated in human cadavers and a porcine survival model. We report the first clinical case of a NOTES transanal resection for rectal cancer using TEM and laparoscopic assistance, performed by a team of surgeons from Barcelona and Boston with extensive experience with NOTES and minimally invasive approaches to colorectal diseases.Transanal endoscopic rectal resection with total mesorectal excision using the TEM platform was performed in a 76-year-old woman with a T2N2 rectal cancer treated with preoperative chemoradiation. Laparoscopic visualization and assistance with retraction and exposure during rectosigmoid mobilization was provided through one 5-mm port, which was later used as the stoma site, and 2-mm needle ports, one of which was used as a drain site. The specimen was transected transanally followed by handsewn coloanal anastomosis.The procedure was completed successfully with an operative time of 4 hours and 30 minutes. Mesorectal excision was complete. The postoperative course was uneventful, and the patient was discharged on the fourth postoperative day. The final pathology demonstrated pT1N0 with 23 negative lymph nodes and negative proximal, distal, and radial margins.NOTES transanal endoscopic rectosigmoid resection using TEM and laparoscopic assistance is feasible and safe. Careful patient selection and improvement in NOTES instrumentation are critical to optimize this approach before widespread clinical application.

Transanal total mesorectal excision (TaTME) was introduced in 2009 as a dedicated approach for the treatment of mid-low rectal cancer. We aimed to describe and discuss the learning curve for 121 consecutive TaTME procedures performed by the same team.The primary outcome was the number of operations required to decrease the mean operative time (mOT). The secondary outcomes were the number of operations required to decrease the major complication (MC) rate, the anastomotic leakage (AL) rate, the clinical anastomotic failure rate, and the reoperation rate. A cumulative sum (CUSUM) curve analysis was used to identify the inflection points. As an integrative analysis, Bernoulli CUSUM curves, risk-adjusted CUSUM curves based on the observed-expected outcomes, and CUSUM curves targeting results reported in the literature were created.Seventy-one cases were needed to overcome the OT learning curve sufficiently to reach mastery. The MC and reoperation rates started to decrease after the 54th case and further decreased after the 69th case. The AL rate started to decrease after the 27th case and remained stable at 5-5.1%. The comparison between the different phases of the learning curves confirmed these turning points.TaTME had a learning curve of 71 cases for the mOT, 55-69 cases for MCs and reoperation, and 27 cases for AL. According to our results, attention should be paid during the first part of the learning curve to avoid an increased rate of MCs and AL.© 2020. The Author(s).

The primary goal of surgery for rectal cancer is to achieve an oncologically safe resection, i.e., a radical resection with a sufficient safe margin. Total mesorectal excision has been introduced for radical surgery of rectal cancer and has yielded greatly improved oncologic outcomes in terms of local recurrence and cancer-specific survival. Along with oncologic outcomes, functional outcomes, such as voiding and sexual function, have also been emphasized in patients undergoing rectal cancer surgery to improve quality of life. Intraoperative nerve damage or combined excision is the primary reason for sexual and urinary dysfunction. In the past, these forms of damage could be attributed to the lack of anatomical knowledge and poor visualization of the pelvic autonomic nerve. With the adoption of minimally invasive surgery, visualization of nerve structure and meticulous dissection for the mesorectum are now possible. As the leading hospital employing this technique, we have adopted minimally invasive platforms (laparoscopy, robot-assisted surgery) in the field of rectal cancer surgery and standardized this technique globally. Here, we review a standardized technique for rectal cancer surgery based on our experience at Severance Hospital, suggest some practical technical tips, and discuss a couple of debatable issues in this field.© Copyright: Yonsei University College of Medicine 2021.

Sparing the extrinsic autonomic innervation of the internal anal sphincter during total mesorectal excision is important for the preservation of anal sphincter function. This study electrophysiologically confirmed the topography of the internal anal sphincter nerve supply during laparoscopic-assisted transanal minimally invasive surgery for total mesorectal excision.This prospective study was conducted at two large multispecialty referral centers. Six patients (five males and one female) aged between 45 and 65 years with low rectal cancer (≤5 cm from the anal verge) were enrolled. Surgery was performed under electric stimulation of the pelvic autonomic nerves with observation of the electromyographic signals of the internal anal sphincter.The minimally invasive transanal surgical approach enabled advantageous visualization of the pelvic autonomic nerves in all patients. In particular, extrinsic innervation to the internal anal sphincter near the levator muscle was consciously spared under electrophysiological confirmation. The evoked absolute electromyographic amplitudes of the internal anal sphincter during transanal minimally invasive surgery were significantly lower than the initial results of the laparoscopic approach [3.7 μV (interquartile range 2.4; 5.7) vs. 4.3 μV (interquartile range 3.1; 8.6); p = 0.002]. Five key zones of risk for pelvic autonomic nerve damage were identified. No complications occurred.The electromyographic results of this preliminary study indicate advantages for sparing the internal anal sphincter innervation during transanal minimally invasive mesorectal dissection considering the specific in situ neuroanatomical topography.

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.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).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).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 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.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.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.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.

Controversies regarding the anatomical structure of Denonvilliers' fascia and its relationship with surrounding fasciae have sparked a heated discussion, especially concerning whether Denonvilliers' fascia is multilayered. This study aimed to expound on the anatomical structure of Denonvilliers' fascia and its correlation with the peritoneum from the sagittal view and clarify the complex fascial relationship.Our study was performed on 20 adult male pelvic specimens fixed in formalin, including 2 entire pelvic specimens and 18 semipelvic specimens. The local adjacent organs and fasciae were dissected, and Denonvilliers' fascia was observed and removed for histological examination.Denonvilliers' fascia was typically single-layered and tough. On the sagittal plane, the peritoneum constituting the peritoneal reflection and Denonvilliers' fascia formed a "Y" shape. Denonvilliers' fascia originated from the peritoneal reflection, extended along the ventral side of the seminal vesicles and prostate, continuing caudally; its bilateral sides closely connected to the urogenital fascia (UGF) of the pelvic wall. In addition, histology preliminarily indicated that the basal cell layers of the peritoneum and Denonvilliers' fascia were continuous and formed a "Y" shape. Furthermore, the basal cells of the two peritonea extended to Denonvilliers' fascia, creating a fused double-layered structure. Some tiny blood vessels or a network of such vessels extended from the peritoneum to Denonvilliers' fascia.Denonvilliers' fascia, the extension of the peritoneum in the pelvic floor, appears as a single-layered "Y"-shape on the sagittal plane. Our study provides new support for the peritoneal fusion theory. Understanding the anatomical characteristics of Denonvilliers' fascia and its relationship with the UGF is of guiding significance for inexperienced colorectal surgeons to conduct rectal cancer surgery.© 2023. The Author(s).

Anatomical detail with superb illustration

Anterior dissection of the rectum in the male pelvis represents one of the most complex phases of total meso-rectal excision. However, the possible existence of different anatomical planes is controversial and the exact anatomical topography of Denonvilliers' fascia is still debated. The aim of the study is to accurately define in a cadaveric simulation model the existence and boundaries of Denonvilliers' fascia, identifying the anatomical planes suitable for surgical dissection. The pelvises of 31 formalin-preserved male cadavers were dissected. Careful and detailed dissection was carried out to visualize the anatomical structures and the potential dissection planes, simulating an anterior meso-rectum dissection. Denonvilliers' fascia was identified in 100% of the pelvises, as a single-layer fascia that originates from the peritoneal reflection and descends until its firm adhesion to the prostate capsule. The fascia divides the space providing an anterior and a posterior plane. Anteriorly to the fascia, during the caudal dissection, its firm adhesion to the prostate capsule forces to section it sharply. The cadaveric simulation model allowed an accurate description of Denonvilliers' fascia, defining several planes for anterior dissection of the meso-rectum.© 2022. The Author(s).

Previous studies on total mesorectal excision suggested dissection anterior to Denonvilliers' fascia, which might lead to intraoperative pelvic autonomic nerves injury and a high incidence of urogenital dysfunction.We dissected 4 cases of cadavers, mainly focusing on anatomy of Denonvilliers' fascia, to study the relationship between Denonvilliers' fascia and rectum. In practice, instead of dissection 1 cm above peritoneal reflection, dissection of the peritoneum was performed at the lowest level of peritoneal reflection during laparoscopic resection for mid-low rectal cancer.The cadaveric study revealed that there were loose tissues between Denonvilliers' fascia and rectal specimen, thus a surgical plane posterior to Denonvilliers' fascia did exist. During laparoscopic resection for mid-low rectal cancer, some loose reticulate structures between Denonvilliers' fascia and proper fascia of rectum would present after dissection of peritoneum at the lowest level of peritoneal reflection. Then dissection within the surgical plane posterior to Denonvilliers' fascia became easy and feasible. In this plane, both the pelvic nerves and postoperative urogenital function could be well protected by Denonvilliers' fascia.The anterior surgical plane for total mesorectal excision should be reconsidered, and dissection posterior to Denonvilliers' fascia is feasible and practicable for patients without risk of positive anterior circumferential resection margin.

Denonvilliers' fascia is thought to be a multilayered fascial structure, based on its embryological development with the neurovascular bundle embedded within it. Recently, this theory had been proven histologically and by confocal microscopy in many published articles. However, the literature does not report on how surgeons can identify these structures. We aimed to determine the optimal surgical approach for preserving these critical structures.Eighteen cadavers (13 male/five female) were included and treated according to the ethical considerations stated in the donation consent of our institution. Dissection was performed with the assistance of binocular loupes for better anatomical detail. The compositions of the prerectal fascia and the neurovascular bundle were observed and recorded at different levels of dissection using a high-definition camera.The theoretical multilayered fascia was found in male specimens as three fascial layers originating from the perineal body, seminal vesicles and posterior bladder neck. The first layer merged posterolaterally and fused with the rectosacral fascia (Waldeyer's fascia). The neurovascular bundle in male specimens was observed piercing the second and third layers, while the first layer acted as a protective cover. Dissection of female specimens demonstrated only one layer in the prerectal space.Intiating anterior rectal mobilization by incising the peritoneum posterior to its reflection seems to be anatomically correct to preserve DVF. However, its applicability may be difficult in a narrow chanllenging pelvis. The lateral rectal ligaments and Waldeyer's fascia should be dissected from their attachments to the proper fascia of the rectum.Colorectal Disease © 2019 The Association of Coloproctology of Great Britain and Ireland.

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

Since robotic-assisted laparoscopic radical prostatectomy was introduced, different modifications in the technique have been described to improve cancer control and minimize the possibility of erectile dysfunction and incontinence.We reviewed the recent English literature on specific topics including when to preserve the neurovascular bundle (NVB), and we describe techniques to diminish the rate of positive margins and to preserve continence and potency.Identifying predictor factors of local advanced disease helps in deciding when to preserve the NVB without compromising cancer control. Techniques to decrease the positive margins based on experience and modifications of the apical dissection are reviewed. Minimal disruption or reconstruction of the anatomic structures of the periprostatic tissues helps to maintain continence. Different degrees of NVB preservation can be performed based on the characteristics of the cancer. Cautery-free techniques and other modifications in the dissection to minimize the NVB injury are also discussed.The understanding of the predictor factors of local advanced disease, together with modifications in the technique, helps to not only achieve cancer control but also improve quality of life after robotic-assisted laparoscopic radical prostatectomy.

Although lateral pelvic lymph node dissection is considered as a treatment option for advanced rectal cancer, it is technically demanding. Recently, transanal approach for total mesorectal excision has become increasingly utilized. In this technical note, we describe lateral pelvic lymph node dissection using a 2-team method that was assisted by the transanal approach.First, the lateral pelvic area was entered from the anal side by dissection between the S4 sacral splanchnic nerve and levator ani muscle. Then, the fatty tissues including the obturator compartment and the distal part of the internal iliac compartment were separated from the inferior and superior vesical vessels and the bladder wall. Next, the fatty tissues were separated from the lateral pelvic wall. The obturator nerve was isolated and preserved, while the obturator vessels were resected at their peripheral end. Then, the fatty tissues were dissected from the bottom plane. Finally, the fatty tissues were dissected from the ventral bladder wall and were completely isolated from the obturator nerve in cooperation with the transabdominal team.The 2-team method shortened the operative time dramatically and decreased mental and physical burden on the operators during lateral dissection. Assistance with the transanal approach helped with a secure and effective dissection, especially of the most distal parts, such as around the internal pudendal and inferior vesical arteries, as substantial skill is required for transabdominal approach alone.This procedure is useful for the safe and effective performance of lateral pelvic lymph node dissection for patients with rectal cancer.Copyright © 2021 The American Society of Colon and Rectal Surgeons.

Sometimes intraoperative urethral injury occurs in Transanal total mesorectal excision (TaTME). The aim of this study is to investigate the usefulness of indocyanine green (ICG) fluorescent catheter system for avoiding intraoperative urethral injury in TaTME in experimental model.A urethral catheter was filled with the mixture of albumin and ICG and raw hams were applied in layers as the surrogate model of rectourethral muscle. The detectability of ICG fluorescence in this catheter was investigated by using laparoscope-type fluorescence camera system.Fluorescence was detected when ICG was mixed with albumin or peripheral blood. ICG fluorescence could be detected within 4 mm depth of layered raw hams as the surrogate model. Quantitative analysis of the picture detected that ICG fluorescence plateaued in lower concentration than that of serum.ICG fluorescent catheter system may be useful for avoiding intraoperative urethral injury in TaTME. J. Med. Invest. 67 : 285-288, August, 2020.

The safe adoption of transanal total mesorectal excision (taTME) has occurred in Australasia as previously reported by the current authors. Planes beyond TME can be utilised in more advanced cases to achieve negative margins during transanal dissection.

The aim of this work was to define the role of transanal total mesorectal excision (taTME) in locally advanced rectal cancer (LARC) requiring resection beyond the mesorectal plane.We performed a retrospective review of the outcomes of a case series of patients undergoing taTME for rectal cancer with mesorectal fascia or adjacent organ involvement.Eleven patients (six men) underwent taTME for LARC requiring resection beyond total mesorectal excision (TME). All had a restorative procedure. The transabdominal approach was open in five and minimally invasive in six cases. All patients required the resection of at least one adjacent structure, including presacral fascia, internal iliac vessels, nerve roots, uterus, vagina or seminal vesicles. Four patients required a pelvic side-wall lymph node dissection and four had intraoperative radiotherapy. In all cases, the transanal approach was useful to disconnect the rectum distally, resect adjacent organs or control the R1 risk-point. Three patients had a complication of Clavien-Dindo grade III or above (one mechanical bowel obstruction, one pelvic collection and one urine sepsis). There were no anastomotic complications. Ten patients had an R0 resection. During a median follow-up of 11 (8.6-16) months there were no local recurrences, but two patients had distant metastases. During the study period, eight patients underwent closure of their stoma whilst the remaining three have had normal anastomotic assessments and will be closed in the future.This early series shows that implementation of taTME for resections beyond TME may be feasible and safe in a highly selected setting.© 2020 The Association of Coloproctology of Great Britain and Ireland.

The safe introduction of transanal total mesorectal excision (taTME) has been documented by the Australasian group previously. The most important prognostic indicator for rectal cancer is the ability to achieve a clear resection margin. By utilizing false planes for taTME surgery, the endopelvic fascia and or presacral fascia can be resected en bloc. This case highlights the utilization of a taTME platform to perform a distal taTME with presacral fascial stripping and a lateral pelvic sidewall transanal-assisted dissection in a 53-year-old otherwise healthy woman with a mid-rectal tumor. Radiologically the tumor was staged as a T3c/T4 rectal cancer with an N1c deposit extending beyond mesorectal fascia abutting the left piriformis muscle. An extramural venous invasion positive tumor was evident with a positive circumferential resection margin at 4 o' clock. In addition, the taTME platform was used to allow transanal intraoperative radiotherapy (IORT) delivery to the sacrum. An R0 resection was achieved and the patient recovered well without incident. Total operative time was 250 minutes with the patient being discharged on day 7 postoperatively without complication. Macroscopic evaluation revealed a grade III mesorectal excision with en bloc removal of presacral fascia. On microscopic evaluation, revealed a T3N1b tumor with 2 of 14 positive lymph nodes (0/5 pelvic sidewall nodes). The case highlights a novel application of taTME and is to the authors' best knowledge the first described use of a transanal platform to deliver intraoperative radiation therapy in the literature.