Evaluation of transanal minimally invasive surgery for submucosal rectal resection in cadaveric canine specimens.

OBJECTIVE: To evaluate the feasibility of transanal minimally invasive surgery (TAMIS) for submucosal rectal resection in large breed dogs. STUDY DESIGN: Cadaveric study. SAMPLE POPULATION: Canine cadavers (n = 6) weighing between 37.5 and 60 kg. METHODS: Dogs were positioned in sternal recumbency. After rectal cleansing, a transanal access platform was placed in the rectum, and a pneumorectum was established. An area of ventral rectal wall approximately 2 × 2 cm was resected in a submucosal plane by using laparoscopic instruments and submitted for histopathological evaluation. The rectal wall defect was closed with a single-layer continuous suture pattern with barbed suture. Postoperatively, the rectum was removed en bloc and evaluated for suture or surgical penetration of the serosal surface. RESULTS: Submucosal rectal resection was successfully completed by using TAMIS in all dogs. The median length of resected specimens after fixation was 24.5 mm (range 9.8-26.5). In two of six dogs, suture was macroscopically visible on the serosal surface, but no dogs had evidence of iatrogenic full-thickness surgical penetration of the rectum. The median distance from the aborad extent of the suture closure line to the anocutaneous junction was 35 mm (range, 35-105). CONCLUSION: Submucosal resection of the canine rectal wall was feasible in large breed dogs by using TAMIS. No evidence of full-thickness penetration of the rectal wall was seen in these cadaveric specimens. CLINICAL SIGNIFICANCE: Transanal minimally invasive surgery may provide an alternative minimally invasive approach for resection for benign adenomatous rectal polyps in large breed dogs that might otherwise require a rectal pull-through.

[Innovation, development and improvement of transanal endoscopic instruments].

According to the main features of transanal total mesorectal excision (taTME), we have designed a series of patented operating techniques, such as anal retractor, anal speculum and transanal port, to reduce the difficulty of transanal operation, shorten the surgeon's learning curve, and expand the indications of transanal surgery.

[Initial report of laparoscopic single incision plus one port with simultaneous robotic-assisted transanal total mesorectal excision for low rectal cancer surgery].

Robotic-assisted transanal total mesorectal excision (R-TaTME) has unique advantage in low rectal cancer. Single incision plus oneport (SIPOP) laparoscopic operation can synchronously cooperate with robotic-assisted transanal operation, in order to the difficulty of operation, improve the quality of operation and shorten the time of operation. A retrospective analysis was conducted on the clinical and pathological data of one patient who underwent SIPOP synchronously combined with R-TaTME + sigmoid-anal anastomosis + ileostomy at the Department of General Surgery, Army Characteristic Medical Center on September 11, 2019. This 71-year-old patient was male with body mass index of 24.08 kg/m(2) and received preoperative chemotherapy. Rectal adenocarcinoma was confirmed by colonoscopy biopsy, and distance from tumor lower edge to anal verge was 3 cm. MRI indicated T2N1 stage. The operation was completed successfully, and the transabdominal and robotic transanal surgery totaled 117 minutes, with 15 minutes for the robotic transanal preparation step. There was about 20 ml of intraoperative blood loss and no blood transfusion was performed. The patient was discharged 6 days after operation. No intraoperative or postoperative complications occurred. The postoperative TNM staging was stage I (pyT2N0cM0). No recurrence or metastasis was found at postoperative 7 month. It is a safe, effective and feasible technique for patients with low rectal cancer.

Sphinkeeper™ for faecal incontinence: a preliminary report.

AIM: A new artificial anal sphincter placed into the intersphincteric space, SphinKeeper™, has recently been proposed to improve outcomes in the treatment of faecal incontinence (FI). We report our preliminary results with short-term follow-up, comparing preoperative and postoperative data after implant of SphinKeeper™ in patients suffering from FI. METHODS: All patients older than 18 years were included with FI of at least 6 months, incontinence episodes occurring more than once a week and resistance to other conservative treatments. Anorectal manometry, endoanal ultrasound, Cleveland Clinic FI Score, FI Quality of Life score and total number of episodes of FI per week were recorded preoperatively and at the end of the 6-month follow-up period. RESULTS: Thirteen consecutive patients were treated with SphinKeeper™. No intra-operative nor postoperative complications were reported. Two cases of prosthesis extrusion occurred, and in one case an anterior dislocation was detected. Maximum resting pressure, total number of episodes of FI per week and Cleveland Clinic FI Score were improved after 6 months (P < 0.05). CONCLUSIONS: SphinKeeper™ could be a minimally invasive procedure for FI with good postoperative outcomes. If these results are confirmed by studies with more patients and longer follow-up, it could be a first-line approach in FI.

The outcomes of two robotic platforms performing transanal minimally invasive surgery for rectal neoplasia: a case series of 21 patients.

Colorectal cancer remains the third most common cancer effecting adults. Surgical guidelines recommend transanal excision of early rectal neoplasia up to 8 cm from the anal verge. A retrospective review of two novel approaches for transanal robotic local excision with R0 resections of rectal cancers which was, on average, higher than 8 cm. Twenty-one cases of robotic assisted transanal surgery for early stage disease (T0-T1, N0) were reviewed. The first 10 cases performed with the da Vinci® Si robotic platform between 2013 and 2016, and the first 11 cases performed using the Flex® Medrobotics platform between August 2017 and August 2018. The average distance from the anal verge was 11.1 cm and 9.5 cm for the da Vinci® Si and Flex® Colorectal Drive, respectively. The average operative time was 167.6 min for the da Vinci® Si and 110.1 min for the Flex® Colorectal Drive; the average EBL was 37.5 cc and 9.1 cc for the da Vinci® Si and Flex® Colorectal Drive. In the da Vinci® series, four cases required intraoperative conversion. In the Flex® series, one case was aborted due to unfavorable robotic positioning. All margins were histologically negative when surgically complete with no recurrences to date. Transanal robotic surgery may provide a method to address rectal lesions farther from the anal verge than previously described. The Flex® Colorectal Drive platform may provide superior ability to navigate the nonlinear anatomy of the rectum and distal sigmoid colon.

Evaluación a largo plazo de la cirugía transanal con sutura automática en la enfermedad de Hirschsprung / Long term evaluation of transanal surgery with automatic suture in Hirschsprung's disease

Objetivo. Estudio retrospectivo descriptivo de pacientes con en-fermedad de Hirschsprung (EH) intervenidos en nuestro centro por vía transanal. Material y métodos. Se seleccionaron a los pacientes con diagnóstico de EH intervenidos por vía transanal con sutura automática circular en nuestro centro entre los años 2006 y 2018. Se realizó biopsia laparoscópica de la zona previa a la dilatación en todos los casos. Tras la confirmación de la presencia de células, se procedió al descenso transanal tipo De la Torre hasta alcanzar la zona de la biopsia. La anastomosis se realizó con sutura automática circular (CEEA 21 o 25 mm). Resultados. Se intervinieron 21 pacientes, 16 niños y 5 niñas, con una mediana de edad de 12 meses (5-62). Ningún paciente presentó enterocolitis preoperatoria. La mediana de la longitud resecada fue de 14,5 cm (3-45), sin incidencias intraoperatorias. Un paciente (5%) presentó absceso rectosigmoideo postoperatorio, resuelto con antibióticos. Un caso (5%) necesitó de nueva cirugía por eventración del acceso umbilical. Un paciente (5%) presentó estenosis, resuelta mediante sección y otro (5%) compresión del manguito seromuscular, que fue tratada con sección laparoscópica. No hubo casos de enterocolitis postoperatoria. Tras una mediana de seguimiento de 97 meses (12-159), un niño presenta encopresis (5%) tratada mediante sistema de irrigaciones transanales periódicas y otro caso (5%) cursa con estreñimiento, en tratamiento con enemas periódicos. El resto se hallan asintomáticos. Conclusión. En definitiva, podemos afirmar que en nuestra serie el descenso transanal con sutura automática circular es una técnica segura y eficaz, que presenta una tasa baja de complicaciones intra y postoperatorias, con buenos resultados a largo plazo

Objective. Retrospective and descriptive study of patients with diagnosis of Hirschsprung disease (HD) in whom transanal pull-through was performed in our center. Material and methods. All patients with diagnosis of HD in whom transanal surgery was performed between 2006 and 2018 in our center were selected. In all cases laparoscopic biopsy was performed in the previous dilated area. Once intraoperatory biopsy revealed the presence of ganglionic cells, transanal De la Torre surgery was performed, until reaching the localization of the biopsied area. Circular automatic suture was performed in all cases. Results. Surgery was performed in 21 patients (16 boys and 5 girls) with a median age of 12 months (5-62). No patient had enterocolitis. The median resection length was 14.5 cm (3-45) and no intraoperative complications happened. One patient (5%) developed a rectosigmoideal abscess, which was solved with antibiotic. One case (5%) needed another surgery due to umbilical trochar eventration. No patient had enterocolitis after the surgery. One patient (5%) had stenosis, solved by its section and other case (5%) had sleeve compres-sion which was solved by laparoscopic section. After a median follow up of 97 months (12-159), one child (5%) developed encopresis, which is treated with periodic anal irrigations and other patient (5%) has chronic constipation, which require periodic enemas. The rest of the patients have no symptomatology. Conclusion. In conclusion, in our series of cases, transanal pull-through with circular automatic suture was a safe and useful technique. It has a low rate of operative and postoperative complications and provides good prospective results

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.

Assessment of the Versius surgical robotic system for dual-field synchronous transanal total mesorectal excision (taTME) in a preclinical model: will tomorrow's surgical robots promise newfound options?

BACKGROUND: The aim of this study was to evaluate the feasibility of the Versius surgical robotic system for transanal total mesorectal excision (taTME) in a preclinical setting. METHODS: Dry laboratory and cadaveric sessions were first conducted for three experienced colorectal surgeons in order to gain familiarity with the modular surgical system and the robotic workstation. After introduction, the system was configured to allow for synchronous, totally robotic taTME in a cadaver. RESULTS: Using the modular robotic system, one surgeon performed the abdominal portion of the operation, including colonic mobilization and vascular pedicle ligation while simultaneously a second surgeon performed the transanal portion of the operation to the point of rendezvous at the peritoneal reflection, where the operation was completed cooperatively. The operation was successfully completed in 195 min demonstrating preclinical feasibility of this unique approach with an emerging robotic system. CONCLUSIONS: This is the first preclinical assessment of the Versius surgical robotic system for taTME. The ability to work simultaneously carries the theoretical advantage of reducing surgical time and thereby reducing overall operative costs. It may also allow surgeons to maintain focus on critical parts of the operation by halving the fatigue associated with long, complex cases such as taTME.

Radial incision and cutting method using a transanal approach for treatment of anastomotic strictures following rectal cancer surgery: a case report.

BACKGROUND: Development of an anastomotic stricture following rectal cancer surgery is not uncommon. Such strictures are usually managed by manual or instrumental dilatation techniques that are often insufficiently effective, as evidenced by the high recurrence rate. Various surgical procedures using minimally invasive approaches have also been reported. One of these procedures, endoscopic radial incision and cutting (RIC), has been extensively reported. However, RIC by transanal minimally invasive surgery (TAMIS) is yet to be reported. We here report a novel application of TAMIS for performing RIC for anastomotic rectal stenosis. CASE PRESENTATION: A 67-year-old man had suffered from constipation for 6 years after undergoing low anterior resection for stage II rectal cancer 7 years ago. Colonoscopy showed a 1-cm diameter stricture in the lower rectum. Balloon dilatation was performed many times because of repeated recurrences. Thus, surgical management was considered and the stricture was successfully excised via a RIC method using a TAMIS approach. Postoperatively, the patient had minimal leakage that resolved with conservative treatment. CONCLUSIONS: A RIC method using a TAMIS approach is an effective minimally invasive means of managing anastomotic strictures following rectal cancer surgery.

TAMIS: ¿Un nuevo estándar para el tratamiento de los pólipos de recto? Revisión de la bibliografía y reporte de nuestra experiencia / TAMIS: A new standard for the treatment of rectal polyps? Literature review and report our experience

La morbilidad y alteración de la calidad de vida asociadas a la resección anterior del recto y amputación abdominoperineal determinaron un gran interés en el desarrollo del abordaje transanal. En los últimos años se ha visto un marcado desarrollo tecnológico en los dispositivos disponible para este abordaje. La cirugía por vía transanal ofrece ventajas en cuanto a sus resultados y complicaciones cuando se la compara a la cirugía por vía abdominal. La cirugía transanal mini-invasiva surge como una alternativa de abordaje videoendoscópico del recto. La resección local por cirugía endoscópica para los pólipos grandes de recto se ha convertido en un nuevo estándar de tratamiento en la mayoría de los centros, obteniendo piezas no fragmentadas con una alta tasa de márgenes negativos. En el presente estudio realizamos una revisión sobre la aplicación de TAMIS (TransAnal Minimally Invasive Surgery) al tratamiento de los pólipos de recto. (AU)

A great interest has developed in implementing trans anal minimally invasive surgery for the treatment of rectal adenomas and early rectal tumors. It present advantages when compare to radical surgery and peace meal endoscopic resections. TAMIS delivers non-fragmented specimens with clear resection margin in the majority of the cases. Such good technical results are mirrored with a low recurrence rate when evaluating rectal adenomas. This is a review of the application of TAMIS for the treatment of rectal adenomas. (AU)

Analysis of Endonasal Endoscopic Transsphenoidal (EET) surgery pathway and workspace for path guiding robot design.

BACKGROUND: Endoscopic Endonasal Transsphenoidal Surgery (EETS) is the standard method to treat pituitary adenoma, tumor in the pituitary gland which would affect human beings in terms of hormonal malfunction and other symptoms. This procedure provides extra minimal invasive access in severe cases. The objective of this paper is to design and develop a prototype of EET robot with navigation guidance system based on the study of EET workspace and pathway to determine a safe space for surgical tool insertion. METHODS: The EET workspace and its pathway were studied via data collected from EET experiments on 70 cadavers. An optical tracking system was used to detect and record the movement of the surgical tools during the experiments. Delaunay triangulation and Voronoi diagram were utilized to determine the cloud position of the gathered data for EET workspace. Moreover, in order to determine the EET pathway voxelization methods were incorporated. RESULTS: The average diameter of the workspace calculated was 19.08 with 3.32 S. D, the average length and volume of the workspace were 53.9 mm and 15.9cm3, respectively. The S.D values determined for length and volume were 7.2 and 6.02, respectively. For the pathway, a high density area was determined via data obtained through cloud position. CONCLUSION: Dimension of the EET workspace and characters of EET pathway determine robot's requirements to design and develop EET robotic system. This article demonstrates the conceptual design of an EET robot and successfully accomplishes the goal of guidance and aids in assisting the EET procedures.