Comparison of Carbon Dioxide Absorption Rates in Gynecologic Laparoscopy with a Valveless versus Standard Insufflation System: Randomized Controlled Trial.

STUDY OBJECTIVE: The primary objective was to compare carbon dioxide (CO2) absorption rates in patients undergoing gynecologic laparoscopy with a standard versus valveless insufflation system (AirSeal; ConMed, Utica, NY) at intra-abdominal pressures (IAPs) of 10 and 15 mm Hg. Secondary objectives were assessment of surgeons' visualization of the operative field, anesthesiologists' ability to maintain adequate end-tidal CO2 (etCO2), and patients' report of postoperative shoulder pain. DESIGN: A randomized controlled trial using an equal allocation ratio into 4 arms: standard insufflation/IAP 10 mm Hg, standard insufflation/IAP 15 mm Hg, valveless insufflation/IAP 10 mm Hg, and valveless insufflation/IAP 15 mm Hg. SETTING: Single tertiary care academic institution. PATIENTS: Women ≥ 18 years old undergoing nonemergent conventional or robotic gynecologic laparoscopic surgery. INTERVENTIONS: A standard or valveless insufflation system at IAPs of 10 or 15 mm Hg. MEASUREMENTS AND MAIN RESULTS: One hundred thirty-two patients were enrolled and randomized with 33 patients per group. There were 84 robotic cases and 47 conventional laparoscopic cases. CO2 absorption rates (mL/kg*min) did not differ across groups with mean rates of 4.00 ± 1.3 in the valveless insufflation groups and 4.00 ± 1.1 in the standard insufflation groups. The surgeons' rating of overall visualization of the operative field on a 10-point Likert scale favored the valveless insufflation system (median visualization, 9.0 ± 2.0 cm and 9.5 ± 1.8 cm at 10 and 15 mm Hg, respectively) over standard insufflation (7.0 ± 3.0 cm and 7.0 ± 2.0 cm at 10 and 15 mm Hg, respectively; p <.001). The anesthesiologists' ability to maintain adequate etCO2 was similar across groups (p = .417). Postoperative shoulder pain scores were low overall with no significant difference across groups (p >.05). CONCLUSION: CO2 absorption rates, anesthesiologists' ability to maintain adequate etCO2, and postoperative shoulder pain did not differ based on insufflation system type or IAP. Surgeons' rating of visualization of the operative field was significantly improved when using the valveless over the standard insufflation system.

Evaluating ureteral patency in the post-indigo carmine era: a randomized controlled trial.

BACKGROUND: Many gynecologic, urologic, and pelvic reconstructive surgeries require accurate intraoperative evaluation of ureteral patency. OBJECTIVE: We performed a randomized controlled trial to compare surgeon satisfaction with 4 methods of evaluating ureteral patency during cystoscopy at the time of benign gynecologic or pelvic reconstructive surgery: oral phenazopyridine, intravenous sodium fluorescein, mannitol bladder distention, and normal saline bladder distention. STUDY DESIGN: We conducted an unblinded randomized controlled trial of the method used to evaluate ureteral patency during cystoscopy at time of benign gynecologic or pelvic reconstructive surgery. Subjects were randomized to receive 200 mg oral phenazopyridine, 25 mg intravenous sodium fluorescein, mannitol bladder distention, or normal saline bladder distention during cystoscopy. The primary outcome was surgeon satisfaction with the method, assessed via a 100-mm visual analog scale with 0 indicating strong agreement and 100 indicating strong disagreement with the statement. Secondary outcomes included comparing visual analog scale responses about ease of each method and visualization of ureteral jets, bladder mucosa and urethra, and operative information, including time to surgeon confidence in the ureteral jets. Adverse events were evaluated for at least 6 weeks after the surgical procedure, and through the end of the study. All statistical analyses were based on the intent-to-treat principle, and comparisons were 2-tailed. RESULTS: In all, 130 subjects were randomized to phenazopyridine (n = 33), sodium fluorescein (n = 32), mannitol (n = 32), or normal saline (n = 33). At randomization, patient characteristics were similar across groups. With regard to the primary outcome, mannitol was the method that physicians found most satisfactory on a visual analog scale. The median (range) scores for physicians assessing ureteral patency were 48 (0-83), 20 (0-82), 0 (0-44), and 23 (3-96) mm for phenazopyridine, sodium fluorescein, mannitol, and normal saline, respectively (P < .001). Surgery length, cystoscopy length, and time to surgeon confidence in visualization of ureteral jets were not different across the 4 randomized groups. During the 189-day follow-up, no differences in adverse events were seen among the groups, including urinary tract infections. CONCLUSION: The use of mannitol during cystoscopy to assess ureteral patency provided surgeons with the most overall satisfaction, ease of use, and superior visualization without affecting surgery or cystoscopy times. There were no differences in adverse events, including incidence of urinary tract infections.