Safer trocar insertion for closed laparoscopic access: ex vivo assessment of an improved Veress needle

Avinoam Nevler, Gil Har-Zahav, Danny Rosin, Mordechai Gutman

Laparoscopic surgery is widely practiced surgical technique in the modern surgical toolbox. The Veress needle insertion technique, while faster and easier, is associated with higher rates of iatrogenic complications (injury to internal organs, major blood vessels, etc.), morbidity and even mortality with a reported overall risk of 0.32 % during surgical interventions. In order to increase the safety and ease of closed insertion technique, we designed and tested an improved prototype of the Veress needle. The new Veress needle includes a distal expandable portion that allows elevation of the abdominal wall and safe insertion of the first trocar over it. The needle was assessed by measurement of ease of insertion, ease of trocar advancement, associated tissue damage, device integrity and weight-bearing capacity on an ex vivo Gallus domesticus animal model: The prototype was tested over 20 times using different traction forces. The experiment was qualitatively repeated on an ex vivo porcine model. In the G. domesticus model, the improved needle supported forces of up to 5.75 kg F. No damage or mechanical malfunction was seen at any stage of the experiment. Needle penetration, ease of trocar insertion, system anchoring and weight-bearing capacity were rated (1-5) by four raters-mean 4.9 ± 0.31. Inter-rater agreement was high (free marginal κ 0.75). The porcine experiment revealed similar ease of use with neither complication nor damage to the abdominal wall. We believe that the new Veress system is easy to use, requires no additional training, non-inferior in its capabilities compared to the traditional Veress needle, with the advantage of improving the safety of the first trocar insertion phase of the operation.