The absent role of prophylactic antibiotics in low-risk patients undergoing laparoscopic cholecystectomy.

A retrospective chart review was done to determine the infection rate and the use of prophylactic antibiotics in consecutive laparoscopic cholecystectomies done in a single community. Incisional infections were discovered in 11 of 566 cases, 10 of whom had received prophylactic antibiotics. The infected patients were significantly older, had longer procedures, and had more comorbidity than the uninfected patients. They were also more likely to have a palpable mass preoperatively and past biliary surgery. A second, prospective study was done to evaluate the efficacy of the use of antibiotic prophylaxis in low-risk patients. Fifty-three patients were randomized into two double-blinded groups. No incisional infections occurred in either group within 30 days postoperatively. This suggests prophylactic antibiotics are not needed to prevent infections for low-risk patients undergoing laparoscopic cholecystectomy.

Mechanical comparison of 10 suture materials before and after in vivo incubation.

The material properties of ten 2-O suture materials were evaluated tensiometrically at time = 0 and again after 6 weeks incubation in rats. All suture material was incubated and tested without knots. Specialized machinery was used with a custom securing apparatus to pull suture material apart at constant speed. Stress-strain curves were derived, and from these strength, toughness, strain at rupture, and elastic modulus were determined. Sutures tested included Vicryl [poly(glycolide-lactide)], Dexon (polyglycolic acid), Ethibond (polyester), silk, plain gut, chromic gut, Maxon (polyglyconate), PDS (polydioxanone), nylon, and Prolene (polypropylene). Elastic modulus was greatest for braided, least for monofilament, and intermediate for gut sutures, regardless of chemical composition (ANOVA, P = 0.0001). Strength, strain, and toughness decreased in all of the sutures over time in vivo with the exception of braided polyester (Ethibond), which remained stable. Silk demonstrated the least strength and toughness while PDS and Maxon were the strongest and toughest at time = 0. Vicryl, Dexon, and gut sutures were absorbed to the point that they could not be tested after 6 weeks in vivo. Performance tables are provided for all sutures.

Endogenous versus toxin-induced diabetes in rats: a mechanical comparison of two skin wound-healing models.

This study was designed to compare skin wound healing in three groups of Wistar rats: normal, genetically diabetic, and streptozotocin-induced diabetic. All diabetic animals received daily insulin. Full-thickness midline dorsal skin wounds were analyzed biomechanically for strength, toughness, and elasticity (Young's modulus) at 1 and 3 weeks after wounding. Wounds from normal controls were the strongest, toughest, and least compliant. Genetically diabetic rat wounds were the weakest and had the lowest elastic modulus. Wounds from the streptozotocin-induced rats were intermediate for all parameters measured (ANOVA, p = 0.001). Toxin-induced diabetes is less detrimental to skin wound healing than diabetes of endogenous origin. Whether this is due to basic differences in the models or to differences in duration of diabetes is unknown.