Transanal endoscopic microsurgery in treatment of rectal adenomas and T1 low-risk carcinomas.

BACKGROUND: Transanal endoscopic microsurgery as a local therapy option for rectal neoplasms is a tissue-sparing technique that protects the anal sphincter. The present retrospective analysis reports the course of observation after local excision of adenomas and T1 low-risk carcinomas using transanal endoscopic microsurgery. METHODS: In a retrospective analysis we examined data on 279 patients for local recurrence. A total of 144 patients had a rectal adenoma (n = 103) or a R0 resection of low-risk T1 carcinomas (n = 41). In this collective, we also examined parameters concerning perioperative management, complications, intraoperative blood loss and duration of hospital stay. RESULTS: Patients with adenoma were on average 64.9 (range 37 to 90) years old; 83.5% of the adenomas were located 3 to 11 cm from the anocutaneous line. In adenoma patients the recurrence rate was 2.9% for an observation period of 21.8 months. The postoperative course was without any complications in 98.1% of patients.Patients with T1 low-risk carcinoma were 64.6 (range 30 to 89) years old. In all cases, an R0 resection could be performed. The recurrence rate was 9.8% for an observation period of 34.4 months. In this group the postoperative course was free of complications in 97.6% of patients. CONCLUSIONS: The high efficacy of transanal endoscopic microsurgery ensures minimally invasive treatment of adenomas and low-risk T1 carcinomas with low complication rates and a low rate of therapeutic failure.

3D HD versus 2D HD: surgical task efficiency in standardised phantom tasks.

BACKGROUND: Common video systems for laparoscopy provide the surgeon a two-dimensional image (2D), where information on spatial depth can be derived only from secondary spatial depth cues and experience. Although the advantage of stereoscopy for surgical task efficiency has been clearly shown, several attempts to introduce three-dimensional (3D) video systems into clinical routine have failed. The aim of this study is to evaluate users' performances in standardised surgical phantom model tasks using 3D HD visualisation compared with 2D HD regarding precision and working speed. METHODS: This comparative study uses a 3D HD video system consisting of a dual-channel laparoscope, a stereoscopic camera, a camera controller with two separate outputs and a wavelength multiplex stereoscopic monitor. Each of 20 medical students and 10 laparoscopically experienced surgeons (more than 100 laparoscopic cholecystectomies each) pre-selected in a stereo vision test were asked to perform one task to familiarise themselves with the system and subsequently a set of five standardised tasks encountered in typical surgical procedures. The tasks were performed under either 3D or 2D conditions at random choice and subsequently repeated under the other vision condition. Predefined errors were counted, and time needed was measured. RESULTS: In four of the five tasks the study participants made fewer mistakes in 3D than in 2D vision. In four of the tasks they needed significantly more time in the 2D mode. Both the student group and the surgeon group showed similarly improved performance, while the surgeon group additionally saved more time on difficult tasks. CONCLUSIONS: This study shows that 3D HD using a state-of-the-art 3D monitor permits superior task efficiency, even as compared with the latest 2D HD video systems.

Single-port surgery and NOTES: from transanal endoscopic microsurgery and transvaginal laparoscopic cholecystectomy to transanal rectosigmoid resection.

Two different ways have been developed to perform endoscopic surgery. The standard way is multiport laparoscopic surgery. When entering through a natural orifice, we use single-port surgery for transanal work (transanal endoscopic microsurgery). In clinical routine, we moved from intralumenal surgery toward surgery in the perirectal area and finally the free abdomen. In the context of natural orifice translumenal endoscopic surgery, we have modified the length and diameter of optics and tube and developed new mechanisms for steering long curved instruments. This technology is then used for transvaginal cholecystectomy and transanal rectosigmoid resection. Global clinical application of transanal endoscopic microsurgery has proven superiority in preciseness and clinical results for adenomas and early cancer. The initial clinical study for transvaginal cholecystectomy is successfully performed in 6 female patients with an average operation time of 80 minutes and without major complication. Feasibility of transanal rectosigmoid resection is demonstrated in an ex vivo experimental model.

A novel single-port technique for transanal rectosigmoid resection and colorectal anastomosis on an ex vivo experimental model.

BACKGROUND: In the context of natural orifice translumenal endoscopic surgery (NOTES), we developed a new set of rigid instruments according to the principles of transanal endoscopic microsurgery (TEM).These instruments are long, curved, and steerable by rotating two wheels near its handle. Our success in transvaginal cholecystectomy in human with these instruments motivated us to explore the feasibility of rectosigmoid resection through the anus. METHODS: The young bovine large bowel with attached organs is collected en bloc and reintegrated into an anatomically designed trainer to reproduce the human anatomy. The technique comprises the following: (1) closure of the rectal lumen by an endolumenal pursestring suture; (2) transection of the rectal wall 1 cm distal to the pursestring suture and continuation of the dissection toward the fascia and upward excising the mesorectal tissue; (3) inferior mesenteric artery is divided near its origin; (4) the colon is mobilized up to the splenic flexure; (5) the mobilized colon is brought down to the pelvis, ligated twice at the intended proximal resection site, and divided between the ligatures; (6) specimen is delivered transanally; and (7) intestinal continuity is restored by stapled or hand-sutured anastomosis. RESULTS: Twelve rectosigmoid resections, 20 stapled, and 27 hand-sutured anastomoses were performed in two experimental setups. Mean operation time for the resection part was 78.6 min (standard deviation (SD)=9.9). The average specimen length was 37.2 cm. During dissection in the pelvis, as the specimen was pushed upward and toward abdomen, an "empty pelvis" view of the working field was achieved, facilitating dissection. The mean operation time for hand-sutured and stapled anastomoses were 47.7 (SD=6.9) and 43.3 (SD=7.1) min, respectively. Both groups had one anastomotic leak. CONCLUSIONS: Transanal rectosigmoid resection is feasible with TEM technology. The unobstructed "empty pelvis" view is likely to enhance the quality of mesorectal dissection.

Artificial tactile feedback can significantly improve tissue examination through remote palpation.

BACKGROUND: In laparoscopy, impaired feedback information from the operation site and reduced instrument dexterity lead to high demands on surgeons' skill and experience. Pre-clinical studies have shown that artificial tactile feedback (ATF) could significantly improve the quality of tactile feedback information. Additional information about interaction effects of tissue features when using ATF as well as related detection thresholds would be valuable for drawing conclusions on possible clinical application scenarios. OBJECTIVE: To identify surgical procedures in laparoscopy that could benefit from ATF in tissue examination through remote palpation. METHODS: We have developed a laparoscopic grasper capable of providing ATF by measuring the pressure distribution on one forceps jaw with a tactile sensor array. The data was presented graphically on the endoscopic screen. We conducted a study among surgeons and non-surgeons, comparing the capability to detect hidden objects through remote palpation with and without ATF. The data were analyzed using repeated-measures multiple analysis of variance (MANOVA) in two designs. RESULTS: ATF could enhance feedback information with significant positive effects on accuracy, speed, the reduction of the number of grasps, and user confidence. The positive effect of ATF turned out to be especially strong if hidden objects were either hard and too small or large and too soft to be recognized by remote palpation without ATF. CONCLUSIONS: Our study contributes to the discussion on promising application scenarios of ATF-enhanced instrumentation in laparoscopic surgery. Based on our study results, such instrumentation may be valuable for detection and examination of hidden bodies or structures through remote palpation.

EAES recommendations on methodology of innovation management in endoscopic surgery.

BACKGROUND: Under the mandate of the European Association for Endoscopic Surgery (EAES) a guideline on methodology of innovation management in endoscopic surgery has been developed. The primary focus of this guideline is patient safety, efficacy, and effectiveness. METHODS: An international expert panel was invited to develop recommendations for the assessment and introduction of surgical innovations. A consensus development conference (CDC) took place in May 2009 using the method of a nominal group process (NGP). The recommendations were presented at the annual EAES congress in Prague, Czech Republic, on June 18th, 2009 for discussion and further input. After further Delphi processes between the experts, the final recommendations were agreed upon. RESULTS: The development and implementation of innovations in surgery are addressed in five sections: (1) definition of an innovation, (2) preclinical and (3) clinical scientific development, (4) scientific approval, and (5) implementation along with monitoring. Within the present guideline each of the sections and several steps are defined, and several recommendations based on available evidence have been agreed within each category. A comprehensive workflow of the different steps is given in an algorithm. In addition, issues of health technology assessment (HTA) serving to estimate efficiency followed by ethical directives are given. CONCLUSIONS: Innovations into clinical practice should be introduced with the highest possible grade of safety for the patient (nil nocere: do no harm). The recommendations can contribute to the attainment of this objective without preventing future promising diagnostic and therapeutic innovations in the field of surgery and allied techniques.

Review on aspects of artificial tactile feedback in laparoscopic surgery.

Since direct manual tissue palpation is not possible in laparoscopic surgery, feedback information on tactile tissue properties is considerably diminished. Restoring part of the surgeon's sense of touch through devices capable of providing artificial tactile feedback (ATF) is an active field of applied research and development. Despite more than two decades of research, technical development of such devices is still basic, and pre-clinical as well as clinical experience is limited. This article provides an overview of the technological aspects of ATF in laparoscopic surgery, gives background information on principles of human perception of related feedback information, and reviews current research attempts in the field of ATF systems in laparoscopic surgery, broken down into three main system components: tactile sensor, display, and data processing. Tactile sensors have been developed to measure tissue compliance, reveal hidden structures or foreign bodies in tissue through measurement of pressure distribution, and to identify and locate arteries by detecting their pulsation. Furthermore, different solutions for presenting tactile data to the surgeon have been developed. Visual and auditory displays are easy to implement into the operating room equipment, while tactile displays still suffer from difficulties concerning their performance and requirements for clinical usability. The role of the data processing system as the linking component in an artificial tactile feedback system has been identified as crucial for effectiveness of the system and easy reception of tactile data by the surgeon. The investigations on theoretical and technological foundations of ATF have led to an extensive database in recent years. An application-driven development approach will likely be a driving factor in the future evolution of this field.

Microcirurgia endoscópica transanal no tratamento dos tumores do reto: estudo prospectivo em 50 pacientes / Transanal endoscopic microsurgery in the treatment of rectal tumors: a prospective study in 50 patients

RACIONAL: A literatura médica aceita ressecção local como opção válida em casos selecionados de tumores de reto. A seleção dos pacientes requer exata estimativa dos riscos e avaliação pré-operatória precisa, tanto no aspecto clínico como histopatológico. OBJETIVO: Avaliar os resultados da microcirurgia endoscópica transanal em seguimento de 18 meses. MÉTODOS: De abril de 2002 a abril de 2006, 50 pacientes com tumores de reto foram submetidos a microcirurgia endoscópica transanal, selecionados por suas características clínicas e histopatológicas. Os critérios de inclusão foram: adenomas sésseis maiores do que 3 cm e menores do que 8 cm não-circunferenciais; neoplasia intra-epitelial de alto grau; carcinoma retal pT1, e em casos especiais pT2. Todos esses tumores foram submetidos ao mesmo procedimento cirúrgico. RESULTADOS: O resultado histopatológico final revelou 9 adenomas, 26 neoplasias intra-epiteliais de alto grau, 13 carcinomas (9 pT1 e 4 pT2) e 2 carcinóides. A menor idade foi de 25 anos e a maior de 92. O menor tumor ressecado tinha 64 mm² (carcinóide) e o maior (adenoma) 90 mm². O tempo médio de operação foi de 90 minutos e o de internamento 5 dias. Houve uma morte não relacionada ao método. Um paciente com carcinoma de baixo risco pT1 apresentou recidiva 18 meses após microcirurgia endoscópica transanal e foi submetido a retossigmoidectomia curativa. Foi observado tumor residual em dois pacientes e a complicação mais grave foi uma fístula retovaginal. A taxa de complicação global foi de 9 por cento. CONCLUSÃO: Atualmente a microcirurgia endoscópica transanal é a técnica de escolha para o tratamento de adenomas sésseis, neoplasias intra-epiteliais de alto grau e carcinoma retal pT1 de baixo risco.

BACKGROUND: The medical literature accepts local resection as a valuable option in selected cases of rectal tumors. Selection of patients requires an exact perioperative estimation of risks with clinical and histopathological examination. Transanal endoscopic microsurgery aims a safe resection of the tumoral area which leads up to the cure. AIM: To evaluate transanal endoscopic microsurgery results in a follow-up time of 18 months. METHODS: From April 2002 to April 2006, 50 patients with rectal tumors were submitted to transanal endoscopic microsurgery, chosen by clinical history and lesion characteristics. The inclusion criteria were: sessile adenomas larger than 3 cm and smaller than 8 cm, not circumferentially distributed; intra epithelial neoplasia of high degree; and rectal carcinoma pT1, and special cases of pT2. All these rectal tumors were submitted to the same surgical act. RESULTS: The final histopathological results reveal 9 adenoma, 26 intra-epithelial neoplasia of high degree, 13 carcinoma (9 pT1-4 pT2) and 2 carcinoid. The lowest age was 25 and the higher, 92 years-old. The smallest resected tumor had 64 mm² (carcinoid) and the largest (adenoma), 90 cm². Operating time was in average 90 minutes and the overall time statement, 5 days. There was one death not related with the method. One patient with low risk carcinoma pT1 presented recurrence 18 months after transanal endoscopic microsurgery and was submitted to curative rectosigmoidectomy. It was proven a residual tumor after local surgery in two patients and the most important complication was one recto-vaginal fistula. The overall complications rate was 9 percent. CONCLUSION: Today transanal endoscopic microsurgery is chosen as the ideal technique for the treatment of sessile adenomas, intraepithelial neoplasia of high degree and rectal carcinoma pT1.

[Transanal endoscopic microsurgery in the treatment of rectal tumors: a prospective study in 50 patients]. / Microcirurgia endoscópica transanal no tratamento dos tumores do reto: estudo prospectivo em 50 pacientes.

BACKGROUND: The medical literature accepts local resection as a valuable option in selected cases of rectal tumors. Selection of patients requires an exact perioperative estimation of risks with clinical and histopathological examination. Transanal endoscopic microsurgery aims a safe resection of the tumoral area which leads up to the cure. AIM: To evaluate transanal endoscopic microsurgery results in a follow-up time of 18 months. METHODS: From April 2002 to April 2006, 50 patients with rectal tumors were submitted to transanal endoscopic microsurgery, chosen by clinical history and lesion characteristics. The inclusion criteria were: sessile adenomas larger than 3 cm and smaller than 8 cm, not circumferentially distributed; intra epithelial neoplasia of high degree; and rectal carcinoma pT1, and special cases of pT2. All these rectal tumors were submitted to the same surgical act. RESULTS: The final histopathological results reveal 9 adenoma, 26 intra-epithelial neoplasia of high degree, 13 carcinoma (9 pT1-4 pT2) and 2 carcinoid. The lowest age was 25 and the higher, 92 years-old. The smallest resected tumor had 64 mm(2) (carcinoid) and the largest (adenoma), 90 cm(2). Operating time was in average 90 minutes and the overall time statement, 5 days. There was one death not related with the method. One patient with low risk carcinoma pT1 presented recurrence 18 months after transanal endoscopic microsurgery and was submitted to curative rectosigmoidectomy. It was proven a residual tumor after local surgery in two patients and the most important complication was one recto-vaginal fistula. The overall complications rate was 9%. CONCLUSION: Today transanal endoscopic microsurgery is chosen as the ideal technique for the treatment of sessile adenomas, intraepithelial neoplasia of high degree and rectal carcinoma pT1.