Para-cervical Block Prior to Laparoscopic Hysterectomy as an Adjuvant Treatment to Reduce Postoperative Pain.
Condition: Pain, Postoperative
MeSH terms: Pain, Postoperative
Study type: Interventional
Phase: Phase 3

Summary: 
      This is a prospective randomized controlled trial in which patients that are scheduled to
      undergo a laparoscopic hysterectomy would be allocated to one of two groups: Paracervical
      block with local anesthetic (bupivacaine 0.5%), or placebo. This would be achieved using
      block randomization. The intervention would be performed after the patient is under general
      anesthesia, prior to starting the surgery. Patients would be consented in the office or
      preoperative area (before receiving sedatives). As far as the intervention itself, it would
      consist of injecting 5 mL of 0.5% bupivacaine into the cervical stroma at 3 and 9 o'clock,
      which is standard technique for para-cervical block. The remainder of the procedure will then
      continue in a regular fashion. Alternatively, patients in the control group will be injected
      with 5 mL of normal saline. The surgeon would be blinded as to patient allocation. Research
      staff will have previously prepared the formulations (saline or bupivacaine) and have sent
      them to the operating room prior to beginning the procedure depending on assigned group. At
      the end of the case, pain will be assessed using a visual analogue scale with a range from 0
      to 10 by one of the researches who will also be blinded to the group. This will be done at 30
      and 60 minutes after surgical stop time. Additional pain control in the postanesthesia care
      unit (PACU) will be standardized to all patients.

      Hypothesis:

      Performing a para-cervical block with local anesthetic prior to a laparoscopic hysterectomy
      significantly reduces pain after the procedure
    

Detailed description: 
      Specific aims:

      -Determine if infiltrating the cervical stroma with local anesthetic prior to performing a
      hysterectomy will reduce postoperative pain scores, and hence increase patient satisfaction.

      Secondary aims:

        -  Determine if there is a difference in baseline pain depending on additional procedures
           performed, and their response to the paracervical block.

        -  Determine if there is a difference in response to paracervical block based on history of
           cesarean deliveries or uterine weight.

      Background/Significance:

      Hysterectomy is one of the most common surgical procedures performed in the United States,
      with more than 600,000 done annually. Over the last decade, there has been major changes in
      regards to the surgical approach utilized. With the advent of laparoscopy and robotic
      surgery, the rate of procedures done vaginally or abdominally has decreased significantly.
      One of the major drivers to this change is the demand for a faster recovery and decreased
      postoperative discomfort. Additionally, several adjuvant methods such as a TAP (transverse
      abdominal plain) block, ERAS (expedited recovery after surgery) pathway, etc. have been
      developed in order to minimize pain after surgery and hence increase patient satisfaction.
      Paracervical block is a particular technique that has been evaluated in multiple studies as a
      way to reduce pain after vaginal surgery. Studies have been successful in demonstrating an
      improvement in pain scores after these types of procedures. However, to our knowledge, there
      has never been follow-up to evaluate this method during the laparoscopic approach, with or
      without robotic assistance. The rationale of why this technique may be beneficial during a
      hysterectomy is that after infiltrating the cervical stroma with local anesthetic, it will
      diffuse towards the pelvic sidewalls via the lymphatic and capillary systems, which would
      allow for the anesthetic agent to come in direct contact with the nerve plexuses that
      innervate the pelvic structures. Safety of the technique has been proven over the years,
      given that it is widely used during office procedures that involve manipulation of the
      cervix. Although much of the focus regarding reducing postoperative pain has been centered on
      the abdominal wall and port sites, it is undeniable that a significant portion of pain
      actually arises from the pelvic surgical site; particularly since laparoscopic trocars have
      become smaller, resulting in less trauma. Our aim is to determine if infiltrating the
      cervical stroma with local anesthetic prior to performing a hysterectomy will reduce
      postoperative pain scores, and hence increase patient satisfaction.

      Methods

      Study design

      This is a prospective randomized controlled trial in which patients that are scheduled to
      undergo a laparoscopic hysterectomy would be allocated to one of two groups: Paracervical
      block with local anesthetic (bupivacaine 0.5%), or placebo. This would be achieved using
      block randomization. The intervention would be performed after the patient is under general
      anesthesia, prior to starting the surgery. Patients would be consented in the office or
      preoperative area (before receiving sedatives). As far as the intervention itself, it would
      consist of injecting 10 mL of 0.5% bupivacaine into the cervical stroma at 3 and 9 o'clock,
      which is standard technique for para-cervical block. The remainder of the procedure will then
      continue in a regular fashion. Alternatively, patients in the control group will be injected
      with 10 mL of normal saline. The surgeon would be blinded as to patient allocation. The
      formulations (saline or bupivacaine) will be previously prepared in a syringe in the
      operating room by a member of the research time prior to beginning the procedure. At the end
      of the case, pain will be assessed using a visual analogue scale with a range from 0 to 10
      (Wong-Baker faces - appendix 1) by one of the researches who will also be blinded to the
      group. This will be done at 30 and 60 minutes after surgical stop time. Additional pain
      control in the PACU will be standardized to all patients.

      Study Subjects

      Subjects will be selected based mainly on the fact they are undergoing a hysterectomy.

      Sample Size

      Investigators expect to detect a 25% reduction in pain reported on the visual analogue scale
      (VAS). Based on previous publications, it was determined that the mean VAS pain score after a
      laparoscopic hysterectomy is 5 with a standard deviation of 1.5. In order to detect the
      expected change after the proposed intervention, with a significance level of 5% and a power
      of 80%, a sample of 46 patients is required.

      Data Collection

      Data points to be collected are as follows:

        -  Age

        -  BMI

        -  Operating time

        -  History of cesarean deliveries

        -  Preoperative indication for surgery (pain, prolapse, tumor, bleeding, etc)

        -  Procedures performed (if ovaries/tubes were removed, if robotic assistance was used, if
           any additional procedures that are exceptions from the exclusion criteria were
           performed).

        -  Specimen weight

        -  Uterine pathology

        -  Pain score at 30 minutes (see appendix 1 for Wong-Baker scale)

        -  Pain score at 60 minutes

        -  Number of days in the hospital (zero if discharged on same-day)

      Data Handling

      A master key will be generated during randomization. It will contain patient initials and
      medical record number, and an individual code. Only the primary investigator will have access
      to this master key. A separate de-identified database using the individual code as index will
      be used for collection of all data points. The data that can be collected on the day of
      surgery (baseline characteristics, operating time, pain scores, etc) will be collected that
      day using a standardized form (appendix 2). This will later be transferred to the
      de-identified database. Using the master key, investigators will research pathology reports
      when available to complete final data points (uterine weight, histology, etc).

      The data-collection sheets will be destroyed as soon as they are transferred into the
      de-identified database.

      Data Analysis

      Investigators will use T-Student tests to assure groups are homogenous to age, BMI, operating
      time, history of cesarean deliveries, and uterine weight. ChiSquare and Ancova analysis will
      be utilized to determine if there is a significant difference in reported pain scores between
      groups. Investigators will also stratify subjects based on uterine weight, history of
      cesarean delivery, additional procedures, etc. and determine if this has an effect on the
      reported pain scores.

      Time Frame

      Investigators expect to be able to consent and enroll at least two patients per week (average
      range of hysterectomy procedures per week from the surgeons that will participate is 5-10).
      Investigators expect the data collection phase to span over 30 weeks approximately.

      Strength/Innovation

      Patient satisfaction is a center point in today's healthcare. Faster recovery with less
      discomfort is not only standard of care, but may also translate into major economic
      advantages, such as less narcotic use and a decreased rate of postoperative admission. Using
      this technique as an adjuvant treatment for pain after laparoscopic hysterectomies has never
      been explored. There is data published for similar procedures, which demonstrates a clear
      benefit. If this study demonstrates significant improvement in pain scores, it has the
      potential to change standard of care for pain control during hysterectomy procedures.

      Limitations

      The main confounding factors are difference in operating style between surgeons and baseline
      surgical characteristics (large uteri that may require more dissection and tissue
      manipulation, etc.). To control for this investigators are only recruiting patients from 3
      surgeons who have a similar operating technique. In addition to this, investigators are
      documenting operating time and specimen weight, which can be used to compare both groups and
      assure that they are homogeneous to these potential confounders. Further analysis will also
      be made specifically stratifying the data based on these characteristics.

      Risks

      The risks of the procedure are minimal. Regarding possible adverse reactions to the local
      anesthetic, there is no additional risk given that this is already routinely administered
      during surgery. Patients will be screened to confirm they do not have a history of allergies
      to the medication. Possible reactions include hypotension, bradycardia, headaches, tremors,
      etc. The paracervical block is routinely performed in the office setting before most invasive
      procedures involving the cervix, and risks are minimal, similar to those involving any
      subdermal injection. Possible risks include bleeding from injection site.

      There is also the potential risk of accidental disclosure of the health information that will
      be collected.

      Benefits

      This study may find new methods of improving postoperative analgesia for patients undergoing
      minimally invasive hysterectomy procedures which may lead to less narcotic use, faster
      discharge from hospital, and greater satisfaction.

      Costs

      There is no additional costs. Local anesthetic and saline are products that are routinely
      used during all laparoscopic hysterectomy surgeries. The additional operating time it would
      take to perform the block is also negligible, since it is a procedure that can be
      accomplished in less than 2 minutes.
    

Intervention name(s): Bupivacaine; 0.9% Sodium Chloride
Intervention type(s): Drug; Drug
Intervention description(s): Inject 10 mL of 0.5% bupivacaine into cervical stroma; Inject 10 mL of 0.9% NaCl into cervical stroma
Other intervention name(s): Marcaine; Sensorcaine; Normal Saline
Intervention MeSH terms: Bupivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: para-cervical block; laparoscopic hysterectomy