Comparison of titanium and absorbable polymeric surgical clips for use in laparoscopic cholecystectomy

The use of hemostatic surgical clips is crucial in laparoscopic surgery. Metal clips can cause significant interference with computerized tomography, may have poor holding power, and may erode into important anatomic structures. Polymeric absorbable clips, which have advantages over metallic clips, are evaluated in this study. In vitro and in vivo studies were undertaken to evaluate the hold force, rate of degradation, tissue reactivity and safety of absorbable polymeric clips. Absorbable and titanium clips were applied across excised canine cystic ducts and both axial and transverse pull-off forces were measured. In the second phase, absorbable clips were implanted subcutaneously into male rats and the strength remaining within the clips was measured after 7, 10, 14, or 21 days. In phase 3, 30 pigs were randomized into six groups and each animal underwent a laparoscopic cholecystectomy. The cystic duct and artery were ligated with absorbable polymeric clips (experimental group) or titanium clips (control group). Animals were sacrificed at 7, 14, or 28 days and a celiotomy was performed. Intraabdominal adhesions were assessed and scored. The force required to dislodge the absorbable clip was significantly greater than for metallic clips for both axial and transverse forces. Absorbable clip strength retention decreased over time as expected with a retention of 11% original strength by the 21st day. Adhesions were highest when bile spillage occurred, but did not differ significantly between either clip type. Absorbable polymeric clips were hemostatically effective in this laparoscopic model and may offer advantages over metallic clips.