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About 30 years ago, first reports have appeared in the literature on successful substitution of gastrointestinal wall defects by synthetic materials. An either absorbable or non-absorbable polymer patch sutured into a full-thickness wall defect of stomach, small intestine, and even colon of different animal species generally showed to be initially integrated and overgrown by neomucosa, and eventually absorbed or intraor extraluminally extruded (Thompson et al., 1986; Harmon et al., 1979; Contieri et al., 1980; Smyrnis, 1982). Though this approach has been revived in several publications reporting good results (Oh et al., 2002; Uzun et al., 2010), treatment of damaged bowel by implantation of synthetic material has never gained general acceptance in the surgical community, and is, therefore, out of common clinical practice. This may be due to the general concern regarding the use of synthetic material in tissue which is naturally colonized with bacteria, as it is particularly the case in the colon. More recently, also natural materials like collagen sponge or acellular matrix have been tested for their ability either to support healing of an intestinal wall damage or to entirely substitute a full thickness defect. Implantation of patches of these natural biomaterials yielded good results with respect to histological and, to some extent, even functional reconstitution (Wang et al., 2005; Wang et al., 2003; Demirbilek et al., 2003; Badylak, S. et al., 2000; Isch et al., 2001; Kajitani et al., 2001; Mutter et al., 1996). As far as concerns the interposition of a synthetic or natural scaffold of tubular shape into esophagus or small intestine, results are less promising. Poor mucosal regeneration, stricture formation or high mortality rate of the experimental animals due to anastomotic leaks were reported, no matter whether the implanted biomaterial was synthetic absorbable (Thompson et al., 1986), non-absorbable (Fukushima et al., 1983; Watson et al., 1980), or of natural origin (Badylak, S. et al., 2000; Badylak, S.F., 2005; Chen & Badylak, 2001). There are no results reported in the current literature dealing with implantation of a tubular scaffold into the large intestine. In recent years there is a growing effort being done to apply tissue engineering methods for the complete, thus tubular, reconstruction of gastrointestinal organs. A driving force of the endeavours of gastrointestinal tissue engineering is the intention to circumvent transplantation and the associated lifetime need for immunosuppression as the sole alternative to the complete absence of the respective organ. Since loss of the entire colon is absolutely compatible with life, this is not a condition that would require transplantation, indeed. However, total colectomy leads to important changes in enterohepatic circulation

Introduction: Bipolar vessel-sealing devices (VSDs) have advantages in urological surgeries (less hemorrhage, shorter operating time). However, these instruments can cause thermal injuries, which can result in neural damage and necrosis. The objectives of this study were to establish a reproducible in vitro model for standardized assessment of electrosurgical devices and to evaluate whether optimized placement of surgical instruments can reduce the thermal spread. Methods: We evaluated thermal spread of two VSDs in vitro using thin bovine muscle strips. Thermal injury was measured using an infrared camera, temperature probes and histology. The recordings were made with the VSD alone and with a rectangular clamp next to the VSD. Results: Both instruments showed a significant temperature spread of 2.5 mm lateral to the VSD. The placement of a metal clamp next to the VSD significantly reduced the temperature spread. Histological examinations were able to underline these findings. Conclusions: In this study we describe a straightforward clinically relevant in vitro model for the evaluation of future electrosurgical instruments. We demonstrated that the thermal spread of VSD could be further reduced by optimized placement of an additional surgical instrument. Our results could help surgeons protect sensitive structures like nerves in the vicinity of the VSD.

Inadequate hemostasis is one of the most important causes of morbidity and mortality following urological surgery. Despite the long-term usage of coagulation, there is an ongoing development of new devices, including bipolar transurethral resection of the prostate or new vessel-sealing devices. A thorough understanding of the advantages and disadvantages of these new instruments can improve the operative experience for both the urologist and patient. The optimal coagulation system should be small, efficient, easy to handle and with low heat spread. In this article, we analyze different electrothermal coagulation systems and modern tissue-sealing devices in urological applications with the aim to substantiate the advantages and disadvantages of each technique in terms of efficacy and safety.

Urological research, 39 (2), ISSN:0300-5623, ISSN:1434-0879