Transanal total mesorectal excision (TaTME) using flexible endoscope with laparoscopic assistance: a pilot study in porcine models.

BACKGROUND: Transanal total mesorectal excision (TaTME) is routinely performed to excise low rectal tumors. TaTME often relies on transanal endoscopic microsurgery (TEM) or transanal minimally invasive surgery (TAMIS) platform, all using rigid endoscopes. Our study reported a novel approach to TaTME which was completed using flexible endoscope, and we named it F-TaTME. METHODS: The feasibility of rectum resection using F-TaTME was evaluated in five pigs. Firstly, the superior rectal artery and vein were managed under the assistance of laparoscopy. Secondly, the flexible endoscope was used to complete the full-thickness rectotomy and rectal mobilization. Finally, the specimen was removed and the manual colon-rectal anastomosis was performed under direct vision. RESULTS: F-TaTME was accomplished in all 5 pigs. The mean procedure time was 136.6 min (97-162 min). The mean length from the lower edge of the lesion to circumferential dissection line was 1.4 cm (1.0-1.8 cm) and mean length of exteriorized rectum was 12.6 cm (11-14 cm). No injury to colorectal wall, adjacent pelvic or abdominal organs was found. CONCLUSIONS: Our preliminary data suggested that F-TaTME may be a feasible method for TaTME.

Comparison among different techniques for en-bloc resection of rectal lesions: transanal endoscopic surgery vs. endoscopic submucosal dissection vs. full-thickness resection device with Over-The-Scope Clip® System.

BACKGROUND: The aim of our retrospective study is to compare the efficacy and indications of transanal endoscopic microsurgery (TEM), endoscopic submucosal dissection (ESD), and endoscopic full-thickness resection device (FTRD) with Over-The-Scope Clip (OTSC®) System for en-bloc resection of rectal lesions. METHODS: This study collected 76 cases of rectal neoplasms from a single hospital institution. Primary endpoints were complete en-bloc resection, intraprocedural adverse events, R0 en-bloc resection and an early discharge of the patient. Secondary endpoints included procedure-related adverse events. RESULTS: Mean tumor sizes were statistically significant smaller among patients treated with FTRD rather than TEM and ESD. TEO and FTRD treated patients experienced a higher en-bloc resection rate, with a shorter procedure time and hospital stay. No significant difference concerning the R0 resection was found. TEO and FTRD recorded lower perforation rates as compared to ESD, whereas no difference emerged concerning the bleeding rate and the post-polypectomy syndrome rate. CONCLUSIONS: Our study showed that each technique has specific features, so that each one offers advantages and disadvantages. Nevertheless, all of them ensure high en-bloc resection rates, whereas no difference exists for R0 resection rate. TEO provides the possibility to remove low rectal large lesions as compared to ESD and FTRD.

[Application of KeyPort access to transanal endoscopic mircrosurgery].

Objective: To explore the effectiveness of KeyPort access in transanal endoscopic mircrosurgery (TEM). Methods: A descriptive case series study was performed. Clinicopathological data of 20 patients undergoing KeyPort access TEM in Beijing Chaoyang Hospital of Capital Medical University from December 2016 to April 2018 were collected and analyzed retrospectively. Procedure of KeyPort access TEM: general anesthesia or combined spinal epidural anesthesia (CSEA); lithotomy or prone jack-knife position; anal dilation; placement of the KeyPortaccess; connection of TEM pneumoperitoneum device, light source and imaging equipment; placement of 5 mm dedicated endoscope; insufflation of CO2 with pressure of 1.6-2.0 kPa (12-15 mmHg); after rinsing the intestinal lumen, circular resection marginlabeled by the needle-shaped electrocautery;electric coagulation or ultrasonic knife used to perform a full-thickness resection with a 0.5 cm-1 cm margin along the marking line. Indications of KeyPort access TEM: (1) benign large sessile polyps which were difficult to resect under colonoscopy; (2) submucosal lesions with diameter <2 cm; (3) Tis and T1 stage rectal carcinoma without lymph node metastasis; (4) palliative resection of T2 stage rectal carcinoma without lymph node metastasis. Contraindications: (1) accompanying serious diseases without the tolerance of anesthesia and operation; (2) distance from lesion to anal verge >20 cm. Results: There were 10 males and 10 females with age of (63±15) years old and BMI of (24.5±3.3) kg/m(2). The diameter of the lesions was (2.0±1.3) cm, and the distance from lesion to anal verge was (6.2±2.2) cm. One patient had 3 lesions at different positions in rectum with diameters of 0.5 cm, 0.5 cm, and 1 cm, respectively. All operations were accomplished through the KeyPort access TEM and no case was transferred to other methods. The duration of surgery was 75 (30-220) minutes; intraoperative blood loss was 10 (0-30) ml. Two patients with rectal anterior wall lesions underwent full-thickness resection of the intestine wall reaching the peritoneal reflex with penetration into the peritonealcavity, and received suture closure immediately. For the patient with 3 rectal lesions, the 1.0 cm lesion received a full-thickness resection and the other 2 lesions received submucosal resection. No postoperative complication occurred. Postoperative pathology showed that there were 1 case of chronic inflammatory lesion, 4 cases of benign tumor, 3 cases of carcinoma in situ, 4 cases of neuroendocrine tumor, 6 cases of pT1 rectal cancer, 2 cases of pT2 rectal cancer (both invading the superficial muscle layer). The median hospital stay was 6 (3-7) days. The postoperative follow-up was (7.2±3.8) months. No postoperative complication or recurrence was observed. Conclusion: TEM with KeyPort access is safe, rapid and effective in the treatment of rectal tumors.

Local excision for rectal cancer: a minimally invasive option.

Transanal excision (TAE) with conventional retractors and transanal endoscopic microsurgery (TEM) are two well established minimally invasive surgical options for the treatment of selected rectal cancers. TEM is nowadays considered the standard of care for the transanal excision of rectal tumors, since it is associated with significantly better quality of excision and lower rates of recurrence than TAE. When compared with rectal resection and total mesorectal excision, TEM has lower postoperative morbidity and better functional outcomes, with similar long-term survival rates in selected early rectal cancers. More recently, transanal minimally invasive surgery (TAMIS) has been developed as an alternative to TEM. Possible benefits of TAMIS are under evaluation.

Abordaje microquirúrgico transanal. Experiencia inicial. Indicaciones y resultados / Transanal microsurgical approach. Initial experience. Indications and results

Introducción: El tratamiento quirúrgico de las afecciones del recto bajo se encuentra en permanente revisión intentando mantener una adecuada función de continencia y urogenital. Una opción reciente es el abordaje microquirúrgico transanal. El objetivo del trabajo es evaluar una serie de pacientes tratados mediante dicho abordaje, analizando indicaciones, resultados inmediatos y alejados. Material y método: Se seleccionaron 41 pacientes operados en el período comprendido entre febrero de 2009 y febrero de 2015. Resultados: En 41 pacientes, las afecciones tratadas fueron: pólipos, 22; cáncer de recto, 14; estenosis de anastomosis, 2; absceso retrorrectal, 1; endometriosis, 1; poliposis adenomatosa familiar, 1. Los pacientes con pólipos llegaron a consulta: por primera vez, 15; recidivados, 4; segunda recidiva, 2; tercera recidiva, 1. Los procedimientos realizados fueron: resección local, 29; microcirugía transanal transabdominal (TATA), 6; dilatación de estenosis, 4; biopsia transrectal, 3; drenaje de absceso retrorrectal, 1; control de hemorragia, 1; colocación de stent, 1. En cáncer de recto: resección local, 7; biopsia transrectal, 2; TATA, 4; colocación de stent, 1. El tiempo operatorio promedio fue 48,6 minutos, y la estadía hospitalaria promedio 2,21 días. De los 29 pacientes en quienes se realizó resección local, fueron controlados 25 durante un período de 6 a 72 meses. Se complicaron 11 pacientes, sin mortalidad ni recidivas locales. Conclusiones: Este abordaje permite tratar lesiones del recto y último segmento del colon sigmoides. Otorga mejor visión permitiendo una disección más exacta, mejorando resultados postoperatorios inmediatos y alejados en patología benigna y maligna, minimizando la posibilidad de recidivas. (AU)

Introduction: The surgical treatment of conditions located at the low rectum is in constant review, triying to maintain proper urogenital and continence function. One of the most recent options is the transanal microsurgical. The aim of this paper is to analyze a series of patients treated with this approach, its indications, immediate and long term results. Material and Methods: 41 patients were analyzed retrospectively in the period between February 2009 and February 2015. Results: In these patients, treated conditions were polyps: 22; rectal cancer: 14; anastomotic stricture: 2; retrorectal abscess: 1; endometriosis: 1; familial adenomatous polyposis: 1. Patients affected with polyps reached the first consultation in 15 opportunities; 4 on first recurrence; 2 with second recurrence; 1 with third recurrence. The procedures were 29 local resections; 6 transanal transabdominal resections (TATA); 4 dilations of stenosis; 3 transrectal biopsies; 1 retrorectal abscess drainage; 1 hemorrhage control; 1 stent placement. In rectal cancer were: 7 local resection; 2 transrectal biopsies; 4 TATA; 1 stent placement. Mean operative time was 48.6 minutes and mean hospital stay was 2.21 days. Of the 29 patients in whom local resection was performed, 25 were controlled for a period of 6 to 72 months. 11 patients were complicated; no deaths or local recurrences were registered. Conclusions: This approach allows to treat lesions located throughout the rectum and the last segment of sigmoid colon. A better insight is obtained allowing a more accurate dissection, thus improving the immediate and remote postoperative results and minimizes the possibility of recurrence, particularly when it comes to benign conditions. (AU)

[Standardized development of transanal endoscopic microsurgery].

Transanal endoscopic microsurgery (TEM) is currently the only one-port system in endoscopic surgery, which a direct endoluminal approach can lead to the target organ through a natural opening of human body. TEM has been applied in colorectal surgery for over 3 decades. Compared with radical surgery, TEM has the advantages, such as quicker recovery, shorter hospital stay and fewer complications. One perfect TEM surgical system, which mainly consists of three parts, namely peculiar rectoscope for surgery, special surgical instruments and imaging system, is the foundation of standardized development of TEM. Accurate preoperative evaluation and staging is the key for good outcomes in TEM technology. In addition to digital examination of rectum, rigid sigmoidoscopy(or rectoscopy) should be routinely performed to confirm the location of the lesion and record it in a "time-in-clock" form. For lesions with undetermined nature, biopsy should be performed. For patients with rectal tumor, pelvic MRI examination can be used on the basis of routine endorectal ultrasonography (ERUS). Endoluminal suture is the challenge for standardized development of TEM, especially for those with large intestinal wall defects. Professional training is required to master suture technique. In 2016, the consensus of experts on TEM technology was formulated by TEM Study Group of Colorectal Cancer Specialty Committee of Chinese Anticancer Association. The recommended surgical indications for TEM include (1)rectal adenoma; (2)early rectal cancer with good histopathological features; (3)extended resection of locally malignant polyps by colonoscopy; (4)other rectal tumors suitable for local resection; (5)benign stricture or anastomotic stricture of the rectum; (6)repair of anastomotic leakage after low anterior resection of rectum; (7)diagnosis of rectal hemorrhage; (8)biopsy of rectum and surrounding lesions; (9)repair of rectovaginal fistula or mucosal flap transposition of the internal mouth of anal fistula; (10)treatment of rectal foreign body. With the maturity of TEM technology, the indication of TEM continues to expand. Nowadays, TEM is applicable to rectal neuroendocrine tumor or gastrointestinal stromal tumor resection, as well as rectovaginal fistula repair. It can even serve as a "bottom-up" operation platform for transanal total mesorectal excision (taTME). This article introduces the standardization of TEM, its current indications, novel implications, and future perspectives, expecting that TEM will be further popularized and healthily developed in China.

What is the best tool for transanal endoscopic microsurgery (TEM)? A case-matched study in 74 patients comparing a standard platform and a disposable material.

PURPOSE: Transanal endoscopic microsurgery (TEM) is the gold standard for local excision of rectal lesions, but no study exists concerning the best material. The objective was to compare TEM using a disposable material vs a standard platform through a case-matched study. METHODS: Patients who underwent TEM for rectal neoplasms were identified from prospective databases in two tertiary referral centers and matched according to four criteria (sex, tumor location, size, distance from the anal verge): TEM using a disposable material (GelPoint Applied®; group A) and TEM using a standard TEO® platform (Karl Storz, Tuttlingen, Germany; group B). RESULTS: A total of 74 patients were included and divided into group A (n = 33) and group B (n = 41). Full-thickness resection was less frequent in group A (85%) than B (100%; p = 0.01). Adenocarcinoma was less frequent in group A than B: 27 vs 42% (p = 0.03). No difference was noted regarding median operative time (53 vs 53 min; p = 0.6) and a peritoneal perforation rate (6 vs 20%; p = 0.17). Median length of stay was shorter in group A than B (4 vs 5 days; p < 0.008). No significant difference was noted for major morbidity (12 vs 10%; p = 0.66), R1 resection (21 vs 10%; p = 0.2), and recurrence rates (8 vs 7%; p = 0.62). No difference was noted for rectal stenosis (3 vs 12%; p = 0.22) and transit disorder rates (12 vs 17%; p = 0.74). CONCLUSIONS: Our study suggested that TEM can be performed using either a TEO® platform or a disposable material, with similar surgical results. The TEO® platform seems to be superior to obtain full-thickness and R0 resection.

Surgeons' perceptions of transanal endoscopic microsurgery using minilaparoscopic instruments in a simulator: the thinner the better.

BACKGROUND: Several issues have limited the widespread adoption of transanal endoscopic microsurgery (TEM). The need for specialized equipment and the steep learning curve represent one of them. To operate on within a 4-cm diameter, rectoscope represents a major technical challenge. However, minilaparoscopic surgery has been introduced to reduce invasiveness and abdominal wall trauma. In TEM, instrument miniaturization may lead to technique optimization. We hypothesized that visualization and maneuverability during TEM performed with 3-mm minilaparoscopic instruments would be superior to TEM performed with conventional 5-mm instruments. METHODS: Eighteen general and colorectal surgeons with experience with TEM under ten cases were recruited. Two tasks should be accomplished using the TEO(®)-Neoderma simulator. First, using conventional 5-mm TEO(®) curved-tip instruments, a "polypoid lesion" should be excised. Next, closure of the "rectal" defect should be undertaken. In the second part, the same participants repeated the same excision/closure tasks using 3-mm minilaparoscopic instruments. After tasks conclusion, participants fulfilled an evaluation questionnaire with seven questions regarding visualization and maneuverability when using 3-mm compared to 5-mm instruments. RESULTS: For each one of the seven questions in the questionnaire, the score results were significantly higher for the 3-mm instruments indicating that performance with the 3-mm minilaparoscopic instruments in the TEO simulator was in all cases between "better than expected" and "much better than expected." Appropriateness of the diameter of the minilaparoscopic instruments was the best evaluated parameter. The question addressing the ease of performing the tasks in the simulator presented the lowest mean score. CONCLUSIONS: The perceptions of participating surgeons indicated that there is better visualization and maneuverability during basic transanal endoscopic microsurgery tasks conducted in a simulator using 3-mm minilaparoscopic instruments when compared to conventional 5-mm instruments.