Comparison of Ultrasound-guided Transgluteal and Finger-guided Transvaginal Pudendal Nerve Block Techniques
Condition: Neuralgia; Pudendal Nerve; Pudendal Nerve Block
MeSH terms: Neuralgia
Study type: Interventional

Summary: 
      Pudendal neuralgia (PN) is a painful and disabling condition, which reduces the quality of
      life as well. Pudendal nerve injections are essential for the diagnosis and the management of
      PN. The purpose of this study was to compare the effectiveness of finger-guided transvaginal
      pudendal nerve injection (TV-PNI) technique and the US-guided transgluteal pudendal nerve
      injection (TG-PNI) technique.
    

Detailed description: 
      Pudendal neuralgia (PN) is a painful neuropathic condition for which current prevalence is
      unknown due to often going under-recognized by gynecologists. Pudendal neuralgia typically
      presents as unilateral severe sharp and burning pain, numbness, or paranesthesia on the
      anatomic pathways of the pudendal nerve. The most common causes for PN include pudendal nerve
      injury during vaginal procedures, stretching and compression of the pudendal nerve during
      vaginal delivery, and prolonged sitting position.

      As in many neuropathic syndromes, there is currently no gold standard diagnostic test for
      assessing PN. In 2006, the Nantes criteria were described by a multidisciplinary working
      party to describe the clinical diagnostic criteria, and a standard approach was created for
      PN diagnosis. According to the Nantes criteria, patients should fulfil all five essential
      criteria without meeting any of the exclusion criteria. The five essential diagnostic
      criteria were defined as, 1: pain in the anatomic territory of the pudendal nerve, 2: that is
      worsened by sitting, 3: the patient is not woken at night by the pain, 4: no objective
      sensory loss on clinical examination, and 5: positive anesthetic pudendal nerve block.

      Pudendal nerve infiltration (PNI), which was defined as an essential step, is performed for
      diagnostic purposes and as an important treatment modality in patients with PN. This approach
      aims for long-term relief of pain, as in all forms of nerve entrapment syndromes, by treating
      a possible inflammatory component, it also provides neuroprotection to the central nervous
      system and reduces spontaneous ectopic activity of the affected nerve.

      Image-guided or finger-guided PNIs can be performed according to the experience of the
      physician, adequate equipment presence, and patient choice. The pudendal nerve is situated in
      the deepest area in the pelvis and it makes the PNI technically difficult if transperineal or
      transgluteal approaches are preferred. For this reason, it usually requires imaging guidance
      to target the injection site such as ultrasound, computed tomography, fluoroscopy, and
      magnetic resonance.

      Ultrasound-guided transgluteal (TG) PNI has been described to reach the pudendal nerve in the
      plane between the sacrotuberous and sacrospinous ligaments. This technique has many
      advantages such as visualization of the substantial structures (pudendal artery and the
      sciatic nerve) without radiation exposure it enables real-time images. However, finger-guided
      transvaginal (TV) PNI should be kept in mind as a PNI option with the advantages of
      familiarity for gynecologists and obstetricians as an essential part of obstetric anesthesia.
      Finger-guided blocks in women are easily performed via a vaginal approach by palpation the
      ischial spines and the injection is targeted slightly medially and posteriorly to the ischial
      spines.

      Over the past 20 years, studies have described the PNI techniques, but a limited number of
      studies have compared the efficacy of image-guided PNI techniques. To the best of our
      knowledge, there are no studies comparing the finger-guided TV-PNI and US-guided TG-PNI for
      the evaluation of pain relief in patients with PN. We hypothesized that the finger-guided TV
      technique is effective as US-guided TG-PNI when performed to relieve pain in patients with
      PN. The primary outcome of the present study was to evaluate the changes of mean VAS scores
      based on the mean daily maximum pain intensity score during the week before day 0 (D0), day 7
      (D7), day 21 (D21), and day 180 (D180). Secondly, the post-block complication rate was
      evaluated in overall blocks. Secondary outcome included the comparison of the success rates
      of both two techniques (from D0 to D180).
    

Intervention name(s): Ultrasound-guided transgluteal pudendal nerve injection (TG-PNI); Finger-guided transvaginal pudendal nerve injection (TV-PNI)
Intervention type(s): Procedure; Procedure
Intervention description(s): Ultrasound-guided transgluteal pudendal nerve local anesthetic injections; Finger-guided transvaginal pudendal nerve local anesthetic injections
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: neuralgia; pudendal nerve; pudendal nerve block; therapeutic local anaesthesia; transvaginal