Saddle Block With IT Morphine for Penile Inversion Vaginoplasty

Women's College Hospital

Status: Enrolling

Conditions: Pain, Postoperative

Treatments: Procedure: pudendal nerve block; Procedure: Saddle block

Study type: Interventional

Funder types: Other

Identifiers

NCT06556121

2024-0061-B

Details and patient eligibility

About

Penile Inversion Vaginoplasty (PIV) is a transition-related surgery (TRS) that is associated with severe postoperative pain. The optimal pain management strategies for this surgery remain unknown. We hypothesized that the addition of a saddle block with intrathecal morphine would yield clinically important analgesic benefits.

Full description

PIV is a TRS offered for male-to-female transition associated with severe postoperative pain despite contemporary analgesic strategies, including opioid-based multimodal systemic analgesia and local anesthetic-based pudendal nerve block. Intrathecal opioids directly target the nociceptors in the spinal cord and can provide potent analgesia for abdominopelvic procedures, including PIV, but are associated with important dose-related adverse effects with rostral spread within the cerebrospinal fluid.

Motor-sparing saddle block using ultra-low dose hyperbaric spinal anesthesia has been successfully implemented as the standard of care for anesthesia in patients undergoing ambulatory perianal procedures at WCH. Saddle block produces reliable sensory anesthesia and long-lasting analgesia of the perineum ("saddle") as the hyperbaric local anesthetic preferentially blocks the small pain fibers of the sacral nerve roots with gravity when the patient is placed in the seated position. With the aim to directly target the opioid nociceptors in the sacral roots and limit rostral opioid spread (and associated opioid-related adverse effects), we recently began to offer a presurgical saddle block with a low dose of intrathecal morphine (100mcg) to patients undergoing PIV at WCH with excellent anecdotal results. Therefore, we are undertaking the present randomized placebo-controlled study to determine whether or not the addition of a saddle block with IT morphine to multimodal systemic analgesia and surgeon-administered pudendal nerve block provides superior analgesia to multimodal systemic analgesia and surgeon-administered pudendal nerve block alone.

Enrollment: 40 estimated patients

Sex: Male

Ages: 18 to 70 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• ASA I-III patients
• Ages 18-70 years
• Penile Inversion Vaginoplasty

Exclusion criteria

• Local infection
• History of use of over 30mg oxycodone or equivalent per day.
• Contraindication to a component of multi-modal analgesia
• Complications or adverse events unrelated to the local anesthetic that precludes evaluation of the primary and secondary outcome measures.
• Unable to speak or read English.
• Revision and Vulvaplasty surgeries

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

---

40 participants in 2 patient groups

Saddle block with intrathecal morphine Group

Experimental group

Description:

Patients will receive a multimodal analgesic regimen with acetaminophen, NSAIDs and opioids plus a surgeon-administered pudendal nerve block by anatomical landmarks with 50mL of Normal Saline, 30mL of 0.25% Bupivacaine with epinephrine 1:200.000 and 20mL Lidocaine 1%. A volume of 20 mL of this mixture is used for the pudendal nerve block, and infiltration of the surgical incision and bilateral spermatic cord block is performed with an additional 20 mL of the same mixture of local anesthetic. 30ml of the solution is used to soak the vaginal plug made of gauze that is put inside the vaginal canal by the end of the procedure. Patients who are randomized to the saddle block with intrathecal morphine will receive an injection of 5mg of heavy Bupivacaine 0.75% plus 100mcg of morphine injected in the intrathecal space.

Treatment:

Procedure: Saddle block

Procedure: pudendal nerve block

Control Group

Sham Comparator group

Description:

As part of the analgesic plan, all patients will receive a multimodal analgesic regimen with acetaminophen, NSAIDs and opioids plus a surgeon-administered pudendal nerve block by anatomical landmarks with 50mL of Normal Saline, 30mL of 0.25% Bupivacaine with epinephrine 1:200.000 and 20mL Lidocaine 1%. A volume of 20 mL of this mixture is used for the pudendal nerve block, and infiltration of the surgical incision and bilateral spermatic cord block is performed with an additional 20 mL of the same mixture of local anesthetic. 30ml of the solution is used to soak the vaginal plug made of gauze that is put inside the vaginal canal by the end of the procedure. Patients in this group will receive a non-invasive sham saddle block in addition to the care standard.

Treatment:

Procedure: pudendal nerve block