Pipelle Versus Karman Endometrial Biopsy Under Standardized Paracervical Block

Comparison of Pipelle and Karman Endometrial Biopsy Methods Under Standardized Paracervical Block: A Prospective Randomized Study

Endometrial biopsy is a commonly used outpatient procedure to evaluate abnormal uterine bleeding and postmenopausal bleeding. Different sampling methods are available, but their diagnostic adequacy and patient experience may vary.

This prospective randomized study compares two commonly used endometrial biopsy methods, Pipelle and Karman cannula, under standardized paracervical block anesthesia. All participants receive the same local anesthetic technique to minimize pain-related differences between methods.

The primary objective is to compare the rate of clinically adequate endometrial samples obtained with each method. Secondary outcomes include patient-reported pain, patient satisfaction, procedure duration, need for additional diagnostic procedures, and hospital-related costs.

Study findings are expected to support clinical decision-making regarding the most effective and practical endometrial biopsy method when adequate pain control is provided.

Endometrial biopsy is an essential diagnostic procedure in the evaluation of abnormal uterine bleeding and postmenopausal bleeding. Office-based endometrial sampling techniques are widely used because these techniques are minimally invasive and cost-effective; however, diagnostic adequacy, patient tolerance, and resource utilization may differ between methods.

Pain during the procedure is a major factor affecting patient experience and may confound comparisons between sampling techniques. To address this limitation, participants receive a standardized paracervical block using the same anesthetic agent, dose, and technique, allowing the comparison to focus on the intrinsic performance of the biopsy methods rather than differences in analgesia.

This is a prospective, randomized, parallel-group study. Eligible participants undergoing endometrial biopsy are randomly assigned in a 1:1 ratio to either Pipelle endometrial biopsy or Karman cannula endometrial sampling. Randomization is stratified by menopausal status. Procedures are performed in an outpatient setting according to routine clinical practice.

Histopathological evaluation of endometrial samples is performed by pathologists blinded to the sampling method. Sample adequacy is assessed based on predefined criteria, with a focus on whether the specimen provides sufficient information for clinical decision-making.

In addition to diagnostic adequacy, patient-reported outcomes, including pain and satisfaction with the procedure, are assessed. Procedure duration, need for additional diagnostic interventions due to inadequate sampling, and hospital-related costs associated with each method are also evaluated.

Standardized analgesia and inclusion of clinical, patient-centered, and economic outcomes are intended to provide practical evidence to guide the selection of endometrial biopsy methods in routine gynecologic practice.

Inclusion Criteria:

• Female participants aged 18 years or older
• Abnormal uterine bleeding or postmenopausal bleeding requiring endometrial sampling
• Ability to provide written informed consent
• Eligible for office-based endometrial biopsy

Exclusion Criteria:

• Pregnancy
• Active pelvic infection
• Known cervical or endometrial cancer
• Severe cervical stenosis preventing endometrial sampling
• Known bleeding disorders or use of anticoagulant therapy that contraindicates biopsy
• Inability or unwillingness to provide informed consent