Perineural 5% Dextrose Injection Treatment and Central Core Excision of the 12:00 Vestibule as Adjunctive Therapies to Complete Vestibulectomy in Select Patients with Neuroproliferative Vestibulodynia
Authors: Yee A , Uloko M , Mueller J , Goldstein I 
Published: July 2022

ABSTRACT

Introduction
Complete vestibulectomy with vaginal advancement flap (CVVAF) for the treatment of neuroproliferative vestibulodynia (NPV) involves excision of the 1:00 to 11:00 region surrounding the urethral meatus and introitus, allowing the vagina and urethral meatus to be anastomosed to the vulva. The vestibule, however, extends above the urethral meatus and below the clitoris (12:00 region). In NPV patients, the entire vestibule including the 12:00 region contains excess mast cells/nerves, however the 12:00 region is not usually addressed during CVVAF surgery. While CVVAF surgery is associated with an approximately 80% success rate, we have observed some patients with significant pain at the 12:00 region pre-operatively who continue to have persistent entrance dyspareunia post-operatively.

Objective
We report on novel medical/surgical adjunctive strategies for NPV patients with pre-operative 12:00 pain implemented to reduce post-operative pain: using perineural 5% dextrose injection treatments pre-operatively; and performing a limited central core excision of the 12:00 vestibule during CVVAF. Perineural 5% dextrose injections have been shown to reduce neuropathic pain, in part by blocking the transient receptor potential vanilloid - TRPV-1 receptor.

Methods
In patients scheduled for CVVAF to treat suspected NPV, we performed preoperative vulvoscopy and baseline cotton-tip swab testing at the 12:00 region. In those with significant pain/tenderness at 12:00 (&gt; 4/10 pain), we offered pre-operative perineural 5% dextrose treatments for the three days prior to CVVAF. Each day, cotton-tip swab testing of the 12:00 region was repeated prior to application of local anesthesia with 20% benzocaine, 8% lidocaine, 6% tetracaine. After anesthesia was established, betadine was applied to the region. Insulin syringes (31-gauge needle, 5/16”, 1 ml) filled with 5% dextrose were administered at six locations (total 6 ml) circling the 12:00 region, and compression applied for three minutes. The day after the final treatment, the patient underwent CVVAF including central core excision of the 12:00 region. All vestibular specimens were sent for immunohistochemical staining.

Results
14 women, mean age 29 ± 9 years, had 12:00 pain &gt; 4/10 on cotton swab testing at baseline, and confirmed immunohistochemical findings of excess mast cells/nerves consistent with NPV in all specimens. Baseline cotton-tip swab testing mean pain score prior to treatment was 7.3/10 (range 5-10/10) involving the entire 12:00 region. After three perineural 5% dextrose injection treatments, the cotton-tip swab testing mean pain score was reduced to 2.8/10 (range 0-5/10), focused on the central core region of the 12:00 vestibule. Side effects of perineural 5% dextrose injection were limited to mild bruising at injection sites in all patients. The central core excised specimens included the 12:00 minor vestibular gland ostia, and was oval-shaped, on average 2 mm thick, 6 mm wide and 7 mm long. Interrupted vertical sutures of 3-0 vicryl allowed for a horizontal closure of the defect. In patients who returned for in-person post-operative vulvoscopy at 6 months, the post-op cotton-tip swab testing mean pain score was 2.3/10 (range 0-4/10).

Conclusions
While more research is needed, preliminary results with these adjunctive therapies in selective NPV patients are encouraging.

Disclosure
No