Safety Profile of Trocar and Insufflation Needle Access Systems in Laparoscopic Surgery

BACKGROUND: The most common laparoscopic complications are associated with trocar insertion. The purpose of this study was to develop an objective method of evaluating the safety profile of various access devices used in laparoscopic surgery. STUDY DESIGN: In 20 swine, 6 bladed and 2 needle access devices were evaluated. A force profile was determined by measuring the force required to drive the trocar or needle through the fascia and into the peritoneum, at 0 and 10 mmHg. The amount Of tissue deformation, the length of blade exposed, and the duration of exposure were measured using a high-speed digital imaging system. RESULTS: The needle system without the sheath required the least driving force and had the most favorable force profile. In contrast, the bladed, nonretractable trocar system required a higher driving force and a rapid loss of resistance. Insertion under a pneumoperitoneum did not significantly alter the force profile of the various access devices except for the amount of tissue deformation. With the bladed system, the blade itself was exposed for an average of 0.5 to 1.0 seconds for a distance of 4.5 to 5.0 cm. In comparison, the needle system was exposed for 0.2 seconds for a distance of 1.8 cm. CONCLUSIONS: We developed a reproducible method of measuring the forces required to place the access systems, their pattern of resistance loss, and the characteristics of the blade exposure. These parameters may provide an adjunctive and objective measurement of safety, allowing for more direct comparison between various trocar designs. (J Am Coll Surg 2009;209:222-232. (C) 2009 by the American College of Surgeons)

Abnormal methylation at the KvDMR1 imprinting control region in clinically normal children conceived by assisted reproductive technologies

Genomic imprinting alterations have been shown to be associated with assisted reproductive technologies (ARTs) in animals. At present, data obtained in humans are inconclusive; however, some epidemiological studies have demonstrated an increased incidence of imprinting disorders in children conceived by ARTs. In the present study, we focused on the effect of ARTs [IVF and intracytoplasmic sperm injection (ICSI)] on the epigenetic reprogramming of the maternally methylated imprinting control region KvDMR1 in clinically normal children. Qualitative and quantitative methylation at KvDMR1 were assessed by the methylation-specific PCR approach and by the methylation-sensitive enzymatic digestion associated with real-time PCR method, respectively. DNA was obtained from peripheral blood of 12/18 and umbilical cord blood and placenta of 6/18 children conceived by IVF or ICSI. The methylation patterns observed in this group were compared with the patterns observed in 30 clinically normal naturally conceived children (negative controls) and in 3 naturally conceived Beckwith-Wiedemann syndrome patients (positive controls). Hypomethylation at KvDMR1 was observed in 3/18 clinically normal children conceived by ARTs (2 conceived by IVF and 1 by ICSI). A discordant methylation pattern was observed in the three corresponding dizygotic twins. Our findings corroborate the hypothesis of vulnerability of maternal imprinting to ARTs. Furthermore, the discordant methylation at KvDMR1 observed between dizygotic twins could be consequent to one of the following possibilities: (i) a differential vulnerability of maternal imprints among different embryos; or (ii) epimutations that occurred during gametogenesis resulting in the production of oocytes without the correct primary imprint at KvDMR1.