Search

Medical accidents of perforation by a colonoscope still exist. The authors have planned to develop a new training simulation to learn the feel of a perforation by using porcine large intestines. In order to clarify the feasibility of using a porcine model as a training simulator, we conducted the following: 1) an in vivo test, 2) an in vitro test, and 3) a tensile test. The in vivo test did not reproduce the perforation of the large intestines despite the significant preparation. The in vitro extension test by colonoscope showed different strain between the circumference and diameter directions. From the tensile test, the effect of the tissue-cutting direction on the maximum stress showed no significant difference. Porcine large intestines from a slaughterhouse can be feasible both for analyzing the perforation mechanism and for a training simulator.

A report has stated that Betadine damages breast implants. However, careful examination of the report shows that it stated that in heat-cured silicone with a peroxide catalyst, iodine can attack the center methylene group of the trimethylene crosslink, attaching to the center carbon and resulting in a highly unstable crosslink with weakening of the fill tube. Because implant silicone shells are not made with peroxide-cured silicone, there is no problem with the implant shell itself. It is within the standard of care to use Betadine as an irrigant for the breast implant pocket and for soaking the implant to prevent infection as long as contact with a fill tube or the valve is not prolonged (3 days to 3 weeks). Betadine should be washed from the implant if soaked prior to implanting, and the pocket should be irrigated with saline if Betadine is used as an antimicrobial in the pocket.

Research and translational pilot study of regernerative medicine for CVD on-going at the National Cardiovascular Center, Japan, will be reported at this meeting.

Objective: To determine if hyperthermic intraperitoneal chemoperfusion (HIPEC) of colonic anastomoses is detrimental to subsequent anastomotic healing. Methods: 24 Wag/Rija rats were randomized into four groups of six animals each: group 1: control (n = 6), group 2: HIP (n = 6), group 3: HIPEC with mitomycin C in a concentration of 30 mg/m2 (n = 6), group 4: mitomycin i.p. in a concentration of 20 mg/m2 (n = 6). In all animals colon anastomosis approximataly 3 cm proximal to the peritoneal reflection was performed. After 10 days, the anastomic breaking strength and the number of anastomic complications were observed. Results: No postoperative deaths were reported. The postoperative morbidity rate was 18,7%. No severe locoregional or systemic toxity was observed. In HIPEC treated animals bursting pressure of anastomoses was lower than in group I. No significant difference in bursting pressure were found in groups I, II and IV. In group III one animal had a covered perforation and one animal showed extensive adhesions. Conclusion: The healing of colonie anastomoses did not differ between group I, II and IV. In contrast, anastomotic complications were significantly more common in HIPEC animals.

Introduction Breaking strength of incisional wounds is increased after topical application of Insulin Like Growth Factor I (IGF-I). However, for excisional wounds no benefit was demonstrated. We hypothesize that a new delivery system of IGF-I stimulates excisional wound healing.

Fracture toughness is the ability of a material to resist crack propagation under mechanical and other impacts.

Compact bone reacts to an implant only if extended absorption along the Haversian systems reaches the interface. In order to analyze fine differences in the bony reaction of the bed with standardized implants, one must implant in an epiphysial cancellous bone bed.

The presence of bacteria in surgical wounds will delay the formation of granulation tissue and thus the healing process. Sutures used for closing a wound must be able to compensate this delay by their strength. Otherwise it will cause complications that might be life - threatening for the patient. Especially in the case of absorbable sutures it is possible that the degradation is influenced - accelerated or delayed - by metabolism products of the bacteria or by bacterial enzymes. The in vivo data published in literature vary considerably, ranging from an acceleration of degradation (Dudley et al, (1)), to no influence (Thiede et al, (2)) and to a delay of the degradation of absorbable sutures (Williams, (3)) in the presence of bacteria.

Bioabsorbable non-woven fabrics were fabricated from polyglycolide(PGA) and poly-L-lactide(P-L-LA). Their degradation in vitro and in vivo was evaluated. Non-woven fabric made from PGA showed rapid degradation; retention of breaking strength is about 50% at 10 days, almost zero at 21day. The rate of degradation of non-woven fabrics made from P-L-LA was slow and in vivo the mechanical strength of the implanted samples of P-L-LA seemed to be increased as far as 4 weeks after implantation perhaps this is due to ingrowthed connective tissue. Both of non-woven fabrics showed neither strong reaction nor rejection.

For effective and long-term success of cruciate ligament replacement, the following requirements must be satisfied: (a) placement of the ligament must be isometric; (b) anchoring must benefit from both bone and soft tissue ingrowth; (c) the ligament must be of sufficient strength; (d) the stiffness of the ligament must be matched to that of the natural ligament; and (e) the ligament must retain sufficient strength after being subjected to several millions of tensile stress cycles. Placement has been discussed elsewhere by several workers.

The biologic effects of various electric potentials on cortical bone of animals and men were investigated. First typ results of stimulating osseous healing after osteotomy of rabbit tibia by direct current (DC) in the range 3–15 µA are reported. Experiences in stimulating human bone are also reported.

The results presented here are part of the studies performed on the mechanical properties of connective and supporting tissues. Besides the skin, various organs have been examined, using various experimental models, for example, breaking strength of shaft bones (VOGEL 1969, VOGEL & THER 1963, VOGEL & THER 1965), strength of epiphyseal plates (THER et al. 1963, VOGEL 1964, VOGEL 1969, VOGEL & THER 1963, VOGEL & THER 1964), tensile strength of tendons (VOGEL 1964, VOGEL 1969, VOGEL & THER 1965), and strength of granulation tissue (VOGEL 1970 a+b). Most of the data are derived from studies in rats; however, most of the conclusions were confirmed by experiments in other animal species. Ageing studies were also performed in samples from human skin.

We are turning our attention now to some smaller features of the Earth’s surface as compared with those which have been considered in the preceding parts of this book. Such features are relatively easily amenable to an investigation of their physical causes because of the very smallness of the scale of the phenomena.