vNOTES vs Laparoscopy: Respiratory Mechanics and Hemodynamics

Official title

Comparison of the Effects of vNOTES and Laparoscopic Gynecological Surgery on Intraoperative Respiratory Mechanics and Hemodynamics: A Prospective Observational Cohort Study

Overview

Pneumoperitoneum and Trendelenburg position are unavoidable in laparoscopic surgery and are known to have adverse effects on intraoperative respiratory mechanics and hemodynamics. These conditions increase the risk of ventilator-induced lung injury (VILI) and highlight the importance of lung-protective ventilation strategies. vNOTES (Vaginal Natural Orifice Transluminal Endoscopic Surgery) is a minimally invasive technique that requires less Trendelenburg tilt and lower insufflation pressures compared to conventional laparoscopic surgery, and may therefore offer a more favorable intraoperative profile. This prospective, observational, single-center, parallel-group cohort study aims to compare respiratory mechanics parameters (Ppeak, Pplateau, DP, MPtot, MPdyn, Crs) and hemodynamic parameters (MAP, HR, vasopressor requirement) between vNOTES (n=15) and laparoscopic gynecological surgery (n=15) groups at four intraoperative time points.

Detailed description

This study aims to compare vNOTES (Vaginal Natural Orifice Transluminal Endoscopic Surgery) and laparoscopic gynecological surgery in terms of intraoperative respiratory mechanics and hemodynamics in patients scheduled for elective gynecological surgery.

The findings of this study will contribute to more effective planning of ventilation and hemodynamic management by anesthesiologists in vNOTES cases, the development of lung-protective ventilation protocols, and the improvement of perioperative anesthesia quality.

This study is designed as a prospective, observational, single-center, parallel-group cohort study. Patients scheduled for elective gynecological surgery will be divided into two groups according to the surgical technique: Group 1 (vNOTES, n=15) and Group 2 (Laparoscopic surgery, n=15). No randomization will be performed; the surgical technique, insufflation pressure, and Trendelenburg angle will be left to the clinician's discretion.

Measurements will be performed at four time points: T0 (10th minute after intubation, before insufflation), T1 (15th minute after pneumoperitoneum and Trendelenburg positioning), T2 (45th minute after pneumoperitoneum; or the last 5 minutes before desufflation in cases where the 45th minute is not reached), and T3 (15th minute after desufflation). At each time point, respiratory mechanics parameters (Ppeak, Pplateau, DP, MPtot, MPdyn, Crs), hemodynamic parameters (MAP, HR, vasopressor requirement), and intraoperative opioid consumption will be recorded. Insufflation pressure, Trendelenburg angle, and surgical duration will be recorded as confounding variables.

Interventions

• Procedure vNOTES (Vaginal Natural Orifice Transluminal Endoscopic Surgery
  Elective gynecological surgery performed via vaginal natural orifice transluminal endoscopic surgery with lower Trendelenburg angle and insufflation pressure compared to conventional laparoscopy.
• Procedure Laparoscopic Gynecological Surgery
  Conventional laparoscopic gynecological surgery performed with standard pneumoperitoneum and Trendelenburg positioning.

Primary outcome measures

• Driving Pressure (DP) [Time frame: Intraoperative (T0: 10th minute after intubation before insufflation; T1: 15th minute after pneumoperitoneum and Trendelenburg positioning; T2: 45th minute after pneumoperitoneum; T3: 15th minute after desufflation)]
• Peak Airway Pressure (Ppeak) [Time frame: Intraoperative (T0: 10th minute after intubation before insufflation; T1: 15th minute after pneumoperitoneum and Trendelenburg positioning; T2: 45th minute after pneumoperitoneum; T3: 15th minute after desufflation)]
• Plateau Pressure (Pplateau) [Time frame: Intraoperative (T0: 10th minute after intubation before insufflation; T1: 15th minute after pneumoperitoneum and Trendelenburg positioning; T2: 45th minute after pneumoperitoneum; T3: 15th minute after desufflation)]
• Respiratory System Compliance (Crs) [Time frame: Intraoperative (T0: 10th minute after intubation before insufflation; T1: 15th minute after pneumoperitoneum and Trendelenburg positioning; T2: 45th minute after pneumoperitoneum; T3: 15th minute after desufflation)]
• Mean Arterial Pressure (MAP) [Time frame: Intraoperative (T0: 10th minute after intubation before insufflation; T1: 15th minute after pneumoperitoneum and Trendelenburg positioning; T2: 45th minute after pneumoperitoneum; T3: 15th minute after desufflation)]
• Heart Rate (HR) [Time frame: Intraoperative (T0: 10th minute after intubation before insufflation; T1: 15th minute after pneumoperitoneum and Trendelenburg positioning; T2: 45th minute after pneumoperitoneum; T3: 15th minute after desufflation)]

Secondary outcome measures (3)

• Mechanical Power (MPtot and MPdyn) [Time frame: Intraoperative (T0: 10th minute after intubation before insufflation; T1: 15th minute after pneumoperitoneum and Trendelenburg positioning; T2: 45th minute after pneumoperitoneum; T3: 15th minute after desufflation)]
• Vasopressor Requirement [Time frame: ntraoperative (from surgical start to end of surgery)]
• Intraoperative Opioid Consumption [Time frame: Intraoperative (from surgical start to end of surgery)]

Eligibility criteria

Inclusion criteria

• Female patients aged 18 to 75 years
• Patients scheduled for elective gynecological surgery
• Patients undergoing mechanical ventilation under general anesthesia
• ASA physical status I-III
• Patients providing written informed consent

Exclusion criteria

• Severe or uncontrolled chronic obstructive pulmonary disease, asthma, or other chronic pulmonary diseases
• Cardiac arrhythmia
• ASA physical status IV or above
• Patients developing intraoperative hemodynamic instability
• Patients receiving spinal or epidural anesthesia
• Cases requiring conversion to laparoscopy or laparotomy
• Patients refusing to participate

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

Turkey (Türkiye) · 1 center

• Bursa Yuksek Ihtisas Training and Research Hospital — Bursa

Publications

• Tontu F, Akca H, Berktas CK, Asar S, Ozcan FG. The impact of pneumoperitoneum and steep Trendelenburg positioning on novel oxygenation and saturation indices in robot-assisted laparoscopic prostatectomies: A prospective observational study. Saudi J Anaesth. 2025 Jul-Sep;19(3):271-276. doi: 10.4103/sja.sja_600_24. Epub 2025 Jun 16. PMID 40642630
• Neto AS, Hemmes SN, Barbas CS, Beiderlinden M, Fernandez-Bustamante A, Futier E, Gajic O, El-Tahan MR, Ghamdi AA, Gunay E, Jaber S, Kokulu S, Kozian A, Licker M, Lin WQ, Maslow AD, Memtsoudis SG, Reis Miranda D, Moine P, Ng T, Paparella D, Ranieri VM, Scavonetto F, Schilling T, Selmo G, Severgnini P, Sprung J, Sundar S, Talmor D, Treschan T, Unzueta C, Weingarten TN, Wolthuis EK, Wrigge H, Amato M PMID 26947624
• Sarikaya S, Taskin MI, Bozhuyuk Sahin T, Guney G, Kececioglu M, Afsar S, Guney SS. Comparison of Perioperative Outcomes Between V-NOTES and Total Laparoscopic Hysterectomy: A Retrospective Analysis. J Invest Surg. 2025 Dec;38(1):2488131. doi: 10.1080/08941939.2025.2488131. Epub 2025 May 1. PMID 40313045

Identifiers

NCT: NCT07667907 · BursaYIERHTanriverdi-001

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗