title: Comparison of Pneumoperitoneum Stability Between a Valveless Trocar System and Conventional Insufflation: A Prospective Randomized Trial.
abstract: OBJECTIVE
  To compare the variation in pneumoperitoneum and physiologic effects of patients undergoing laparoscopic renal surgery using the valveless trocar insufflation system (VI) vs a conventional insufflation system (CI).
  
  
  METHODS
  We conducted a single-center, randomized controlled trial in patients undergoing renal surgery at 15 mm Hg insufflation using a VI system vs a CI system. The primary outcome measured was variation in insufflation pressure, and end-tidal CO2 at 10 and 25 minutes.
  
  
  RESULTS
  Fifty-six patients (VI n = 28 or CI n = 28) met inclusion criteria and were randomized. There was significantly less variability in pressure readings, as measured by coefficient of variation, during VI compared to CI (7.8% vs 15.6%, P < .001). There was significantly less time spent within the range with pressure readings ≥18 mm Hg (median 0.2% vs 16.5%, P < .001) and ≤12 mm Hg (median 1.7% vs 5.6%, P = .011) during VI compared to CI. Additionally, there was significantly less time spent with pressure readings in the "unacceptable" range of ≥20 mm Hg (median 0% vs 0.08%, P < .001) and ≤10 mm Hg (median 0.09% vs 2.6%, P < .001) during the cases with VI compared to CI. End-tidal CO2 was significantly lower at 10 minutes (P = .036) after insufflation in the valveless trocar group compared to the conventional treatment group. There were no other significant differences in physiologic metrics.
  
  
  CONCLUSIONS
  Compared with a CI, the VI provides a significantly more stable pneumoperitoneum during laparoscopic renal surgery and lower end-tidal CO2 at 10 minutes.
authors.affiliation: Department of Urology, University of California, Irvine, Irvine, CA.
authors.forename: Philip
authors.initials: P
authors.lastname: Bucur
authors.affiliation: Department of Urology, University of California, Irvine, Irvine, CA.
authors.forename: Martin
authors.initials: M
authors.lastname: Hofmann
authors.affiliation: Department of Urology, University of California, Irvine, Irvine, CA.
authors.forename: Ashleigh
authors.initials: A
authors.lastname: Menhadji
authors.affiliation: Department of Urology, University of California, Irvine, Irvine, CA.
authors.forename: Garen
authors.initials: G
authors.lastname: Abedi
authors.affiliation: Department of Urology, University of California, Irvine, Irvine, CA.
authors.forename: Zhamshid
authors.initials: Z
authors.lastname: Okhunov
authors.affiliation: Department of Anesthesiology & Perioperative Care, University of California, Irvine, Irvine, CA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Rinehart
authors.affiliation: Department of Urology, University of California, Irvine, Irvine, CA. Electronic address: landmanj@uci.edu.
authors.forename: Jaime
authors.initials: J
authors.lastname: Landman
mesh_terms: D005260:Female; D006801:Humans; D007327:Insufflation; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D011028:Pneumoperitoneum, Artificial / Q000295:instrumentation / Q000379:methods*; D011446:Prospective Studies; D013525:Surgical Instruments; D013520:Urologic Surgical Procedures / Q000379:methods*