Hysteroscopic Evaluation of Fallopian Tubal Patency
Condition: Infertility of Tubal Origin; Infertility, Female; Fallopian Tube Occlusion; Uterus Abnormal
MeSH terms: Infertility; Infertility, Female
Study type: Interventional

Summary: 
      Hysteroscopy is an important tool in the evaluation of sterility. Assessing tubal patency
      during hysteroscopy seems highly relevant, particularly when it allows for a low cost, fast,
      gentle, and accurate way of gathering information that may guide clinical care. Therefore, it
      is important to know which technique is the best. Thus, the primary aim of this study is to
      evaluate the reliability of (1.) the hysteroscopic visualization of a "tubal flow" and (2.)
      the "Parryscope technique" as compared to the gold standard, namely laparoscopic
      chromopertubation. In a prospective, randomized study, the following women are enrolled: (1.)
      The patient is subfertile, defined as being unable to become pregnant within a year despite
      unprotected sexual intercourse. It is also within the standard of care to be presumed
      subfertile if one has tried for six months and has known risk factors that would hinder
      conception, including but not limited to anovulation and endometriosis. (2.) A concurrent
      diagnostic hysteroscopy and laparoscopy with chromopertubation are performed at the Clinical
      Division of Gynecological Endocrinology and Reproductive Medicine at the Medical University
      of Vienna. Hysteroscopic evaluation of tubal patency (either by a positive "tubal flow" or a
      visible flow of air bubbles in the "Parryscope technique") and the result of the laparoscopic
      chromopertubation (tubal patency existing or not existing) will be the primary outcome
      parameters. A total 60 patients are enrolled (30 patients in the "flow assessment" group, 30
      patients in the "Parryscope" group) and randomization is performed as block randomization in
      4 blocks.
    

Detailed description: 
      Introduction and scientific background:

      Hysteroscopy is an important tool in the evaluation of sterility. It allows direct
      visualization of the uterine cavity and enables the diagnosis of numerous pathologies.
      Hysteroscopy shows high reliability and is considered the gold standard for intrauterine
      evaluation.

      When performing hysteroscopy, experts often assess the patency of the tubes via the
      visibility of flow of the hysteroscopic fluid going through the ostia of the tubes. In the
      recently published study "Assessment of tubal patency: A prospective comparison of diagnostic
      hysteroscopy and laparoscopic chromopertubation" - it has been demonstrated that visualizing
      contrasting substances disperse through the ostia is a significant and meaningful metric for
      tubal patency.

      Pre- and posthysteroscopic vaginal sonography for the evaluation of the hysteroscopic fluid
      in the pouch of Douglas, selective hysteroscopic pertubation of the tubes and the visibility
      of air bubbles traversing through the Fallopian tube ostia after an air infusion into the
      uterine cavity have been reported to be reliable methods for hysteroscopic tubal patency
      assessment. Particularly the last one, also called the "Parryscope technique", named after
      its inventor, seems to be highly reliable, easy to conduct and clinically relevant. The
      "Parryscope technique" seems to perform even better than the technique evaluating the "tubal
      flow".

      Assessing tubal patency during hysteroscopy is highly relevant, particularly when it allows
      for a low cost, fast, gentle, and accurate way of gathering information that may guide
      clinical care. Therefore, it is important to know which of the above-mentioned techniques is
      the best. This prospective randomized study aims to compare the hysteroscopic assessment of
      the tubes via "tubal flow" and the "Parryscope technique".

      Study aims:

      The primary aim of this study is to evaluate the reliability of (1.) the hysteroscopic
      visualization of a "tubal flow" and (2.) the "Parryscope technique" as compared to the gold
      standard, namely laparoscopic chromopertubation.

      Study hypotheses:

      Null hypothesis: The hysteroscopically visualizable "tubal flow" and the "Parryscope
      technique" are similarly reliable in the evaluation of tubal patency.

      Alternative hypothesis: The hysteroscopically visualizable "tubal flow" shows a lower
      sensitivity and specificity than the "Parryscope technique" for the evaluation of tubal
      patency.

      Study design:

      Prospective, randomized study.

      Recruitment:

      Women will be invited to participate by medical professionals at the Department of Obstetrics
      and Gynecology of the Medical University of Vienna using the above mentioned criteria in the
      course of their admission to the ward one day before surgery. Potential participants are
      informed about the procedure, clinical relevance and the balance of risk and benefits
      incurred through study participation. Patients willing to participate will express this
      through written affirmation (a "consent form").

      Additional considerations:

        1. Since in the "flow"-group air bubbles might develop spontaneously and, thus, should be
           assessed, conducting the "Parryscope"-technique is only possible after the evaluation of
           the tubal flow.

        2. Reactive tubal spasms could occur especially during a prolonged hysteroscopy.

        3. This is why in one particular patient only one technique should be performed.

      Sample size calculation:

      The calculation is based upon the following considerations:

        1. Direct comparison of the two groups is not possible. Hence, separate evaluation of the
           two methods will be performed. Evaluating both methods in one particular patient in the
           course of a single intervention is impossible without a mutual interference (see:
           "Additional considerations" above).

        2. The "flow effect" is considered the less reliable method and thus, the sample size was
           aligned to this method. An odds ratio of approximately 10, an alpha of 5%, a power of
           80%, a general disease likelihood of 39% and a sensitivity of 66% for occluded tubes
           result in a total amount of 59 tubes and, accordingly, 30 patients.

        3. Thus, the group for the "Parryscope"-technique should also contain 59 tubes (= 30
           patients).

        4. The randomization of the total 60 patients is performed as block randomization in 4
           blocks via the software "R".

      Statistical analysis:

      Numerical data will be reported as mean and standard deviations, nominal variables as number
      and frequency. The McNemar Test will be used for the calculation of the reliability of the
      hysteroscopic assessment of the tubes. The sensitivity, specificity, positive and negative
      predictive values will be provided including the according 95% confidence intervals (95% CI)
      for both study groups (evaluated technique versus gold standard laparoscopic
      chromopertubation). Whether the according odds ratio is over 10 will be evaluated by the use
      of a binary logistic regression model. Statistical analyses were performed with the software
      "R". Differences were considered significant if p<0.05.

      Data quality evaluation:

      Extreme values will be double-checked. In addition, a random checks by two independent
      investigators to ensure the accuracy of the data will be conducted.
    

Intervention name(s): Hysteroscopic Fallopian tube assessment using the "Parryscope" technique; Hysteroscopic Fallopian tube assessment using the "Tubal flow" technique
Intervention type(s): Diagnostic Test; Diagnostic Test
Intervention description(s): A small amount of air is introduced into the iv tubing by inverting the drip chamber to create air bubbles. When air enters the uterine cavity, a single large air bubble or stream of air bubbles traversing the ostia is considered indicative of tubal patency. At least 10 seconds of intracavitary evaluation is typically performed before air bubble entry to allow pressure equilibration if a hydrosalpinx is present [10]. At least 30 seconds of observation per ostia is performed if patency is not observed.; a positive "flow" is defined as the observation of saline directly traversing the ostia, endometrial structures floating toward the ostia, or air bubbles traversing the ostia.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Diagnostic
Keywords: hysteroscopy; Parryscope; chromopertubation