Early Kidney Injury Biomarkers in Gynecologic Laparoscopic Surgery

Comparative Analysis of Urinary NGAL and KIM-1 Levels in Predicting Subclinical Acute Kidney Injury Secondary to Pneumoperitoneum and Deep Trendelenburg Position in Gynecological Laparoscopic Surgery

This prospective observational study aims to evaluate early subclinical acute kidney injury associated with pneumoperitoneum and Trendelenburg positioning during gynecological laparoscopic surgery. Urinary neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) levels will be measured and normalized to urinary creatinine. Biomarker changes will be compared between patients undergoing surgery in 30° and 45° Trendelenburg positions. The study seeks to determine whether these biomarkers can detect early renal injury before clinically significant changes in serum creatinine occur.

Study Overview

• Status: Not yet recruiting
• Conditions: Acute Kidney Injury; Subclinical Acute Kidney Injury
• Intervention / Treatment: Procedure: Pneumoperitoneum and Trendelenburg Positioning

Detailed Description

This single-center, prospective observational study aims to evaluate the effects of pneumoperitoneum and Trendelenburg positioning on early renal tubular injury during elective gynecological laparoscopic surgery. Although laparoscopic surgery provides well-established surgical benefits, carbon dioxide pneumoperitoneum combined with prolonged Trendelenburg positioning may reduce renal perfusion through alterations in intra-abdominal pressure and systemic hemodynamics. Conventional assessment of renal function relies primarily on serum creatinine, which may not increase until substantial nephron injury has occurred, limiting the early detection of subclinical acute kidney injury (AKI).

Adult patients scheduled for elective gynecological laparoscopic procedures with an anticipated operative duration of at least 90 minutes will be screened for eligibility. To minimize perioperative variability, anesthetic management, intraoperative fluid therapy, and perioperative care will be standardized for all participants according to the Enhanced Recovery After Surgery (ERAS) recommendations. Intra-abdominal pressure will be maintained within the routine clinical range of 12-14 mmHg throughout the procedure.

Participants will be allocated into two cohorts according to the Trendelenburg angle required for the planned surgical procedure: a 30° Trendelenburg group and a 45° Trendelenburg group. No intervention regarding patient positioning will be performed for study purposes, and group allocation will be based solely on routine surgical practice.

Urine samples will be collected at predefined time points: after induction of anesthesia and urinary catheterization (baseline) and at the sixth postoperative hour. Urinary neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) concentrations will be measured using enzyme-linked immunosorbent assay (ELISA). To reduce the influence of urine dilution and hydration status, biomarker concentrations will be normalized to urinary creatinine and expressed as NGAL/creatinine and KIM-1/creatinine ratios.

The study sample size was determined by power analysis, with a target enrollment of 50 participants. Statistical analyses will evaluate perioperative changes in urinary NGAL/creatinine and KIM-1/creatinine ratios between baseline and the postoperative period. Biomarker changes will be compared between the 30° and 45° Trendelenburg groups and analyzed in relation to the duration of pneumoperitoneum.

This study aims to determine whether perioperative changes in urinary NGAL and KIM-1 are associated with the degree of Trendelenburg positioning and the duration of pneumoperitoneum during gynecological laparoscopic surgery. The findings are expected to improve the understanding of early renal tubular stress associated with laparoscopic surgery and provide preliminary evidence for future studies investigating strategies to preserve renal function during minimally invasive surgical procedures.

• Study Type: Observational
• Enrollment (Estimated): 50

Contacts and Locations

• Study Contact: Name: Isilay Ayar Gecginer, MD; Phone Number: 10233 +902124607000; Email: iayar@medipol.edu.tr

Study Locations

• Turkey (Türkiye)
  • Istanbul
    • Istanbul, Istanbul, Turkey (Türkiye), 34214
      • Medipol Mega University Hospital
      • Contact: Isilay Ayar Gecginer, MD; Phone Number: 10233 +902124607000; Email: iayar@medipol.edu.tr
      • Principal Investigator: Isilay Ayar Gecginer, MD
      • Sub-Investigator: Ipek Keser Basbayandur, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population will consist of adult women undergoing elective gynecological laparoscopic surgery at a single tertiary care center. Eligible participants are those with an anticipated pneumoperitoneum duration of at least 90 minutes and a planned intraoperative Trendelenburg position of approximately 30° or 45°, according to routine surgical practice. Participants will be enrolled prospectively after providing written informed consent.

Description

Inclusion Criteria: Female participants aged 18 years or older. Scheduled for elective gynecological laparoscopic surgery. Expected duration of pneumoperitoneum of at least 90 minutes. Planned intraoperative Trendelenburg position of approximately 30° or 45°. Ability to provide written informed consent. -

Exclusion Criteria: Age younger than 18 years. Pre-existing chronic kidney disease (estimated glomerular filtration rate <60 mL/min/1.73 m² or serum creatinine above the institutional upper limit of normal).

Acute kidney injury before surgery. History of kidney transplantation or renal replacement therapy. Active urinary tract infection. Pregnancy. Conversion from laparoscopic to open surgery. Intraoperative conditions requiring major deviation from the standardized anesthetic or surgical protocol.

Inability to provide written informed consent.

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Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
30° Trendelenburg Group; Participants undergoing elective gynecological laparoscopic surgery requiring approximately 30° Trendelenburg positioning as part of routine surgical practice. Perioperative urinary NGAL, KIM-1, and urinary creatinine will be measured to evaluate changes in renal tubular injury biomarkers. Group allocation is based solely on the surgical positioning required for the planned procedure, with no study-related intervention.	Procedure: Pneumoperitoneum and Trendelenburg Positioning; Standard intraoperative carbon dioxide pneumoperitoneum combined with either 30° or 45° Trendelenburg positioning during laparoscopic surgery
45° Trendelenburg Group; Participants undergoing elective gynecological laparoscopic surgery requiring approximately 45° Trendelenburg positioning as part of routine surgical practice. Perioperative urinary NGAL, KIM-1, and urinary creatinine will be measured to evaluate changes in renal tubular injury biomarkers. Group allocation is based solely on the surgical positioning required for the planned procedure, with no study-related intervention.	Procedure: Pneumoperitoneum and Trendelenburg Positioning; Standard intraoperative carbon dioxide pneumoperitoneum combined with either 30° or 45° Trendelenburg positioning during laparoscopic surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perioperative Changes in Urinary Renal Tubular Injury Biomarkers	Perioperative changes in urinary neutrophil gelatinase-associated lipocalin (NGAL)/creatinine and kidney injury molecule-1 (KIM-1)/creatinine ratios from baseline (after induction of anesthesia and urinary catheterization) to the sixth postoperative hour. Biomarker changes will be compared between participants undergoing surgery in approximately 30° and 45° Trendelenburg positions	Baseline (after induction of anesthesia and urinary catheterization) and postoperative 6 hours.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Association Between Urinary Biomarker Changes and Duration of Pneumoperitoneum	Association between perioperative changes in urinary NGAL/creatinine and KIM-1/creatinine ratios and the total duration of pneumoperitoneum	From induction of anesthesia until completion of surgery, with biomarker assessment at baseline and postoperative 6 hours
Comparison of Urinary Biomarker Changes According to Trendelenburg Position	Comparison of perioperative changes in urinary NGAL/creatinine and KIM-1/creatinine ratios between the 30° and 45° Trendelenburg cohorts	Baseline (after induction of anesthesia and urinary catheterization) and postoperative 6 hours.

Collaborators and Investigators

• Sponsor: Medipol University
• Investigators: Principal Investigator: Isilay Ayar Gecginer, MD, Istanbul Medipol University Faculty of Medicine

Publications and helpful links

General Publications

• Srisawat N, Kongwibulwut M, Laoveeravat P, Lumplertgul N, Chatkaew P, Saeyub P, Latthaprecha K, Peerapornratana S, Tiranathanagul K, Eiam-Ong S, Tungsanga K. The role of intraoperative parameters on predicting laparoscopic abdominal surgery associated acute kidney injury. BMC Nephrol. 2018 Oct 22;19(1):289. doi: 10.1186/s12882-018-1081-4.
• Villa G, Fiorentino M, Cappellini E, Lassola S, De Rosa S. Renal implications of pneumoperitoneum in laparoscopic surgery: mechanisms, risk factors, and preventive strategies. Korean J Anesthesiol. 2024 Dec;77(6):575-586. doi: 10.4097/kja.24011. Epub 2024 Apr 26.
• Kiseli M, Caglar GS, Yilmaz H, Gursoy AY, Candar T, Pabuccu EG, Bengisun ZK, Tuzuner F. Neutrophil Gelatinase-Associated Lipocalin Levels During Pneumoperitoneum. JSLS. 2017 Jan-Mar;21(1):e2016.00091. doi: 10.4293/JSLS.2016.00091.

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): February 1, 2027
• Study Completion (Estimated): March 1, 2027

Study Registration Dates

• First Submitted: July 9, 2026
• First Submitted That Met QC Criteria: July 9, 2026
• First Posted (Actual): July 15, 2026

Study Record Updates

• Last Update Posted (Actual): July 15, 2026
• Last Update Submitted That Met QC Criteria: July 9, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Biomarker; Pneumoperitoneum; Acute Kidney Injury; NGAL; Renal Injury; KIM-1; Gynecologic Laparoscopy; Trandelenburg Position
• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Digestive System Diseases; Renal Insufficiency; Peritoneal Diseases; Acute Kidney Injury; Pneumoperitoneum; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Posture; Head-Down Tilt
• Other Study ID Numbers: E-10840098-202.3.02-990; 2026/19 (Other Grant/Funding Number: Istanbul Medipol University Scientific Research Projects Coordination Unit)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be made publicly available. Data were collected for the purposes of this investigator-initiated academic study and may contain information that could compromise participant confidentiality. Only aggregated study results will be reported in publications and presentations.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No