Buess G

Transanal Endoscopic Microsurgery

Transanal endoscopic microsurgery, or TEM, is a technique that can be used for the treatment for early staged rectal cancer. This technique utilizes carbon dioxide insufflation through a 40 mm rectoscope to create better endoscopic visualization of the operative field. TEM has been praised for its access to middle and upper-third rectal cancers. However, one limitation of TEM is its inability to address local lymph node involvement. Therefore, an adequate preoperative assessment is crucial before using TEM as a curative modality. TEM can be used to remove virtually any benign lesion that can be brought into view. In addition, there are several studies that have shown TEM is a safe and effective way to treat T1 cancers and may have a role in the treatment of T2 and T3 cancers when combined with radiation and chemotherapy. TEM has lower recurrence rates, faster recovery, and fewer complications when compared to other local excision techniques and radical surgeries. The future of TEM is growing in acceptance as more surgeons learn to master this technique.

Technique of transanal endoscopic microsurgery

SummarySessile adenomas are predominantly localized in the rectum and lower sigma. Surgical removal is indicated but often implies an invasive surgical procedure. Using conventional transanal surgical techniques, only the lower rectum can be reached and there are high rates of recurrence. The new technique combines an endoscopic view of the rectum under gas insufflation via a stereoscopic telescope with conventional surgical preparation and suturing. Adenomas can be excised using the mucosectomy technique or full-thickness-excision, whereas carcinomas should be excised using full-thickness excision with a sufficient border of healthy mucosa. In carcinomas of the sacral cavity, we remove the retrorectal fat up to the fascia of Waldeyer, including the regional lymph nodes. Transanal endoscopic microsurgery is the most economical and tissue-saving surgical technique for the removal of rectal adenomas and early rectal carcinomas.

Clinical results of transanal endoscopic microsurgery

SummaryUsing the “transanal endoscopic microsurgery” technique, 140 patients were treated at the Department of Surgery in Cologne and Mainz. Of the patients with adenomas, 68.2% had typical symptoms preoperatively. The postoperative hospital attendance was 8.7 days, with an average resection size of 14.4 cm2. The postoperative complication rate was 5%, and there were no deaths related to the technique. In a prospective controlled trial, 2.2% of the patients with adenomas treated endoscopically in Mainz showed recidivation, requiring reoperation. The follow-up rate was 100%. In 30 cases, microscopic examination revealed carcinoma. Radical reoperation in 8 pT1 tumours showed neither remaining tumour nor lymph node metastases. Twelve patients with pT1 carcinoma treated by local surgery alone were recurrence-free with an average follow-up period of 12.3 months. So far, there have been no late results.

Local therapy of rectal tumors

PURPOSE: The aim of the study is to outline the rising importance of local treatment of rectal tumors and a changing strategy in therapy of early rectal cancer. METHODS: As the surgical procedure, transanal endoscopic microsurgery was used. Indications for the local procedure were pT1 low-risk tumors and tumors of higher stages in patients with severe risk factors and of those who refused the operation according to oncologic guidelines. RESULTS: A total of 236 rectal adenomas and 98 carcinomas were locally excised using the transanal endoscopic microsurgery technique. Mortality rate was 0.3 percent, and rate of complications requiring surgical reintervention was 5.5 percent in adenomas and 8 percent in carcinomas. Final histology of removed carcinomas revealed 56 pT1, 27 pT2, and 15 pT3 stages. After an average follow-up time of 24 months, two recurrences were observed in the group of patients with pT1 low-risk carcinomas who only underwent local therapy. In both cases, a second intervention for cure was undertaken but for tumors in a late stage. CONCLUSIONS: In selected cases, local therapy of rectal carcinoma avoids high morbidity and mortality of the classical operation. Quality of life will be improved, especially if an artificial anus can be avoided. In case of recurrence, the chance of a secondary procedure for cure is not to be underestimated.

Ultrasonic dissection for endoscopic surgery

With the development of endoscopic surgery, new hazards of high-frequency (HF) electrosurgery have been recognized. The potential risks of monopolar electrosurgery, the limitations of bipolar technique, and the need to reduce instrument interchange have favored the use of ultrasonic technology, which becomes more and more popular. This work aims at presenting the main features of the currently available ultrasonically activated scalpels, as well as their advantages, limitations, and indications.

Comparative study of two-dimensional and three-dimensional vision systems for minimally invasive surgery

AbstractBackground: The aim of this comparative study was to gain subjective and objective data to determine for which operative tasks three-dimensional (3-D) vision systems are superior to two-dimensional (2-D) systems and to demonstrate any advantages or disadvantages of 3-D systems. Methods: A model with five standardized tasks including sewing and knotting was developed to objectively measure performance times and to count technical faults. In our training center for minimally invasive surgery, surgeons involved in basic and advanced laparoscopic courses trained using both 2-D and 3-D vision systems. They subsequently completed analog scale questionnaires to record a subjective impression of comparative ease of operation tasks under 2-D and 3-D vision and to identify perceived deficiencies in the 3-D system. Results: Compared to 2-D vision, the objective performance time was significantly shorter and significantly less mistakes were made using 3-D vision. All operative tasks were subjectively judged significantly easier under 3-D vision. Conclusions: Users with a normal capability for spatial perception can perform standard tasks more quickly and safely using 3-D vision, and a greater benefit is apparent for more complicated surgical maneuvers.

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 surgeons 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.

The effect of high-definition imaging on surgical task efficiency in minimally invasive surgery: an experimental comparison between three-dimensional imaging and direct vision through a stereoscopic TEM rectoscope.

BackgroundIn 1995, when we first used a high-definition television (HDTV) video system during a laparoscopic cholecystectomy in Tuebingen, we were surprised by the excellence of the spatial impression achieved by an image with improved resolution. Although any improvement in vision systems entails a trade-off among cost, quality, and complexity, high-definition imaging may well become an essential part of 3-D video systems. The aim of this experimental study was to assess the impact of high definition on surgical task efficiency in minimally invasive surgery and to determine whether it is preferable to use a 3-D system or a 2-D system with perfect resolution and color—for instance, HDTV or the three-chip charge-coupled device (3CCD).MethodsWe compared a 3-D video system with the vision through a stereoscopic rectoscope for transanal endoscopic microsurgery (TEM). Because its stereoscopic direct vision is not restricted to either shutter technology or video resolution, TEM optics represents the state of the art. For objective comparison, inanimate phantom models with suturing tasks were set up. The setups allowed the approach of parallel instruments as in TEM operations or via a laparoscopic approach, with oblique instruments coming laterally. Both types of procedure were carried out by highly experienced laparoscopic surgeons as well as those inexperienced in endoscopic surgery. These volunteers worked under 3-D video vision and/or TEM vision. Altogether, the model tasks were performed by 54 different persons.ResultsThe evaluation did not show a significant (p >0.05) difference in performance time in all models, but there was a clear trend showing the benefit of a higher resolution.ConclusionWe found a tendency for both endoscopically inexperienced and experienced surgeons to benefit from the use of a system with improved resolution (direct vision) rather than a 3-D shutter video system.

EAES recommendations on methodology of innovation management in endoscopic surgery

BackgroundUnder 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.MethodsAn 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.ResultsThe 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.ConclusionsInnovations 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.

Training program for transanal endoscopic microsurgery.

SummaryTelevised endoscopy and the concept of the “assisted” endoscopic operation is of great help in teaching surgical endoscopic techniques. The use of training dummies provides a new method of training manual dexterity and surgical skills in special courses or in surgical skill laboratories. We have developed a training system for transanal endoscopic microsurgery. Operations with our technique were performed on 116 patients. Like other microsurgical techniques, our method requires a special introduction and intensive training. This paper presents our multistage, video-supported training course for teaching transanal endoscopic microsurgery. The one-day training session is divided into four steps: (1) becoming acquainted with the technology; (2) training on cloth phantom; (3) training on opened bowel; (4) training on closed bovine bowel distended by gas insufflation. Each step is introduced by a short videotape didactically demonstrating the particular aspects of the method.