Trocar site hernia following laparoscopic cholecystectomy: a 10-year single center experience.

INTRODUCTION: Laparoscopic cholecystectomy (LC) is the gold standard of treatment for patients with symptomatic cholelithiasis. Compared to open cholecystectomy, LC is associated with significantly lower postoperative complications. Trocar site hernia (TSH) is an uncommon, but potentially dangerous, complication of LC. The aim of this study was to evaluate the incidence of TSH following LC. METHODS: The records of all patients who underwent elective LC between January 2004 and December 2013 were retrospectively reviewed. The open technique with a vertical incision infraumbilically was used to establish pneumoperitoneum. Two or three other skin incisions were made and trocars were inserted. In all cases, only the fascia at the site of infra-umbilical incision was closed. Following hospital discharge, all patients were regularly re-examined 1, 4 and 52 weeks postoperatively and were contacted by phone during November-December 2015. Based on the findings from clinical and telephone follow-ups, the incidence of TSH was recorded. Using univariate/multivariate analysis, we investigated several variables to identify risk factors for TSH development. RESULTS: During the study period, 1172 patients were eligible and included in the final analysis. Seven patients (0.6%) presented TSH at 1-year follow-up. At the end of the study and with a mean follow-up of 65.86 ± 25.19 months, 11 patients (0.94%) presented TSH. Interestingly, all TSHs were developed at the infra-umbilical site. Multivariate analysis identified obesity as an independent risk factor for TSH. CONCLUSION: The incidence of TSH following LC is considerably low. Obesity is an independent risk factor for TSH development, while closure of fascial incision of 10 mm below the xiphoid is not justified.

Time-resolved x-ray diffraction techniques for bulk polycrystalline materials under dynamic loading.

We have developed two techniques for time-resolved x-ray diffraction from bulk polycrystalline materials during dynamic loading. In the first technique, we synchronize a fast detector with loading of samples at strain rates of ~10(3)-10(4) s(-1) in a compression Kolsky bar (split Hopkinson pressure bar) apparatus to obtain in situ diffraction patterns with exposures as short as 70 ns. This approach employs moderate x-ray energies (10-20 keV) and is well suited to weakly absorbing materials such as magnesium alloys. The second technique is useful for more strongly absorbing materials, and uses high-energy x-rays (86 keV) and a fast shutter synchronized with the Kolsky bar to produce short (~40 µs) pulses timed with the arrival of the strain pulse at the specimen, recording the diffraction pattern on a large-format amorphous silicon detector. For both techniques we present sample data demonstrating the ability of these techniques to characterize elastic strains and polycrystalline texture as a function of time during high-rate deformation.