Subcutaneous application of gentamicin collagen implants as prophylaxis of surgical site infections in laparoscopic colorectal surgery: a randomized, double-blinded, three-arm trial.

PURPOSE: Despite a standardized prophylaxis with antibiotics, surgical site infections (SSI) are a characteristic problem in colorectal surgery. Local administration of gentamicin-collagen sponges (GCS) has been shown to decrease the infection rate after contaminated procedures. So far, the effect has not been tested for standardized laparoscopic colorectal resections. METHODS: We conducted a randomized, double-blind, placebo-controlled trial to investigate the efficacy of GCS to reduce wound infection after laparoscopic colorectal resections. Patients underwent a standardized operative procedure with standardized incision treatment. The intervention was the application of a GCS in the subcutaneous tissue of the bowel extraction site (GCS group). In the collagen group, a collagen sponge without antibiotics was used, and no sponge was used in the control group. The primary endpoint was SSI within 30 days postoperatively, according to the Center of Disease Control and Prevention definition. RESULTS: We randomly assigned 291 patients to all three groups. There was no difference between the groups regarding demographic characteristics and perioperative course. SSI was diagnosed in 8.2 % (GCS group), 13.5 % (collagen group), and 11.3 % (control group) of patients. No significant difference was found among the groups. CONCLUSION: The local administration of GCS showed no significant benefit regarding wound infection after standardized laparoscopic colorectal resections. However, there was a trend toward reduced SSI in the GCS group. Therefore, a larger trial or meta-analysis is necessary to validate this result.

Soluble CD14 is essential for lipopolysaccharide-dependent activation of human intestinal mast cells from macroscopically normal as well as Crohn's disease tissue.

Mast cells are now considered sentinels in immunity. Given their location underneath the gastrointestinal barrier, mast cells are entrusted with the task of tolerating commensal microorganisms and eliminating potential pathogens in the gut microbiota. The aim of our study was to analyse the responsiveness of mast cells isolated from macroscopically normal and Crohn's disease-affected intestine to lipopolysaccharide (LPS). To determine the LPS-mediated signalling, human intestinal mast cells were treated with LPS alone or in combination with soluble CD14 due to their lack of surface CD14 expression. LPS alone failed to stimulate cytokine expression in human intestinal mast cells from both macroscopically normal and Crohn's disease tissue. Upon administration of LPS and soluble CD14, there was a dose- and time-dependent induction of cytokine and chemokine expression. Moreover, CXCL8 and interleukin-1ß protein expression was induced in response to activation with LPS plus soluble CD14. Expression of cytokines and chemokines was at similar levels in mast cells from macroscopically normal and Crohn's disease-affected intestine after LPS/soluble CD14 treatment. In conclusion, human intestinal mast cells appear to tolerate LPS per se. The LPS-mediated activation in mast cells may be provoked by soluble CD14 distributed by other LPS-triggered cells at the gastrointestinal barrier.

Teaching and training in laparoscopic inguinal hernia repair (TAPP): impact of the learning curve on patient outcome.

BACKGROUND: On the basis of lower incidence of postoperative pain and faster recovery compared with open techniques, the laparoscopic transabdominal preperitoneal patch plastic (TAPP) technique was established as a leading mode of inguinal hernia repair. In contrast to open hernia repairs, which are well integrated in the training of young surgeons, TAPP is still considered a more difficult surgical procedure, raising the questions of how to include this technique in trainee programs and how to provide appropriate training. METHODS: Out of 15,101 TAPP procedures performed in our department between 1993 and 2007, we analyzed 254 operations that occurred from April 2004 to February 2007 by young trainees (between the second and fourth years of surgical training). The analysis compared the trainees' TAPP operations with 3,200 TAPP procedures performed by experienced surgeons in the same time period, and with the first 254 TAPP operations in our department performed by pioneers who introduced this technique in 1993. RESULTS: In the 254 operations performed by young trainees, the mean operation time was 59 min, the morbidity rate was 3.2 %, and the recurrence rate was 0.4 %. Compared to experienced surgeons, we found no significant difference in recurrence rate and morbidity. For operation time, however, the young trainees demonstrated a learning curve with continuous improvement until the end of the study period approaching expert level. Pioneers also demonstrated a clear learning curve in operation time and additionally also regarding morbidity and recurrence rate. CONCLUSIONS: Our study demonstrates that the TAPP learning curve of young trainees is only related to operation time. Therefore, TAPP is a safe and reproducible technique when performed by young trainees under the supervision of experienced laparoscopic surgeons. With an adequate program, the technique can be learned quickly, skillfully, and safely when a standardized technique is used. It should be included as a fundamental part of state-of-the-art trainee programs.

Expression of matrix metalloproteinases, cytokines, and connexins in diabetic and nondiabetic human keratinocytes before and after transplantation into an ex vivo wound-healing model.

OBJECTIVE: Wound healing is known to require a well-organized balance of numerous factors, e.g., cytokines, matrix metalloproteinases (MMPs), and their inhibitors, as well as direct cell-cell communication (connexins). Disruption of this balance may lead to the formation of chronic wounds such as diabetic foot ulcers. The transplantation of autologous keratinocytes is a promising therapy for diabetic foot ulcers; however, little is known about their characteristics on a molecular level. Therefore, we intended to characterize transplanted keratinocytes from diabetic and nondiabetic origin before and after transplantation. RESEARCH DESIGN AND METHODS: We isolated human keratinocytes from diabetic and nondiabetic origins and transplanted them into an ex vivo wound healing model. To characterize the keratinocytes, we investigated mRNA expression of MMP-1, MMP-2, and MMP-9; tissue inhibitor of MMP (TIMP)-1 and TIMP-2; interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha; Cx26 (connexin 26) and Cx43; and, for connexins, immunolocalization. RESULTS: We found no significantly increased expression of the molecules investigated in cultured keratinocytes from diabetic compared with nondiabetic origin, even though there were significant differences for MMP-2, IL-1beta, and TNF-alpha in skin biopsies. Expression of IL-1beta was significantly lower in keratinocytes from diabetic origin. In the course of wound healing, differences in the dynamics of expression of MMP-1, IL-1beta, and Cx43 were observed. CONCLUSIONS: Our results suggest that keratinocytes from diabetic origin are as capable for transplantation into chronic wounds as keratinocytes from healthy origin at the starting point of therapy. However, differences in expression dynamics later on might reflect the systemic influence of diabetes resulting in a memory of the transplanted keratinocytes.