Simulation
Materials and Preparation
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- One simulator that will be used for this will have to be made. It is an easy, quick, low-cost model to simulate vaginal wall prolapse. A new model should be used for each participant. Each model costs less than $5.
- A pelvis and Lone Star retractor will be needed. Any bony pelvis task trainer model may be used or the ‘flower pot’ model (if no bony pelvis available).
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Vaginal wall prolapse
- Layers of the vagina:
- Vaginal epithelium: Girls pink microfiber tights or stockings, size 4-6
- Vaginal fibromuscular layer: Men’s white tube socks
- Bladder: 9" balloon, preferably yellow, filled with air or water
- Rectum and anus: transvaginal ultrasonography probe cover
- Braided suture
Pelvis
- Bony pelvis (any type) or flower pot, if no bony pelvis available (see ACOG TVH simulation)
- Lone Star retractor (small diamond) plus 5 blue hooks/stays (this can be reused for multiple iterations)
- Velcro ties or other fixation equipment
- Mayo stand/table
- Clamps to hold pelvis in place
- Layers of the vagina:
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Vaginal Prolapse Model
Figure 1 - All supplies or equipment needed for model (except pelvis). Figure 2 - White tube sock inverted (exposes "fibers") and one leg of pink tights cut. Figure 3 - Insert hand into pink tights and grab toe of inverted white tube sock, then pull pink tights over white sock. Figure 4 Figures 4-5 - Insert hand into tube sock, grab "toe" (the "cervix") and invert the vagina to approximately 8-10 cm. Figure 6 - Fill 9" balloon with water (preferred because it is heavier) or air to desired fullness to simulate the prolapse stage (more water simulates larger bulge). Figure 7 - Cut very small hole in pink tights and insert balloon between pink tights and tube sock. Figure 8 - Large anterior vaginal wall prolapse versus small anterior vaginal wall prolapse, depending on how big the balloon is filled. Figure 9 - Place balloon with knot (simulating bladder and urethra) in position, then cut very small hole in pink tights for "anus." Figure 10 - Use an instrument to grasp the tip of the transvaginal ultrasonography probe cover and place between the pink tights and white sock, then pull through small hole ("anus’). Figure 11 - Milk ultrasonography gel away from tip of probe cover and cut off rounded end of probe cover, then suture to the pink tights to create an anus. The probe cover should accommodate the surgeon’s finger snugly (and the gel provides lubrication). Figure 12 - Bony pelvis model (from Miya Model, pictured here) and Lone Star, held in place by Velcro ties bilaterally. Lab Sequence
(not all pictured)
Figure 13 - Sock model inserted into pelvis and held in place by Lone Star self-retaining retractor, using four blue hooks. Pelvis model anchored to table using clamps. Completed model ready for simulated anterior & posterior repair. Figure 14 - EAU: Assessing vaginal caliber and performance of rectal exam. Figure 15 - Anterior repair: Epithelial layer has been removed and fibromuscular layer has been dissected. A blue stay hook has been added to the distal portion of the incision. Plication of the fibromuscular layer is shown here. Figure 16 - Completed anterior repair. Figure 17 - Posterior repair: Excision of epithelium. Figure 18 - Posterior repair with perineorrhaphy: Plication shown. Figure 19 - Completed anterior and posterior repair, with black marker used to better illustrate the hymen. Figure 20 - Final caliber assessment, now two fingerbreadths.
Lab Sequence
- With patient in dorsal lithotomy, place transurethral Foley catheter for recognition of bladder neck and urethrovesical junction
- Use two Allis clamps to grasp the vaginal epithelium at the urethrovesical junction and at the vaginal apex
- Inject hydrodissection solution subepithelially (usually a mixture of local anesthetic, saline and vasoconstrictor)
- With a scalpel, incise the vaginal epithelium between the two Allis clamps, from the urethrovesical junction to the apex
- Dissect the underlying vaginal fibromuscular tissue from the epithelium to the margins of the dissection bilaterally
- Technique: Place an Allis clamp on the epithelial edge. Using your forefinger as traction, use Metzenbaum scissors to carefully dissect the fibromuscular layer away
- An assistant can maintain traction medially on the underlying muscularis tissue layer with atraumatic forceps (Providing traction and counter-traction is very important for a clean dissection)
- With absorbable suture, plicate the prolapsed fibromuscular layer in one or two mattress layers
- Wide, shallow bites should be taken bilaterally, starting at the pubic rami so that the prolapsed tissue can be reduced without injury to the underlying bladder
- If the prolapse is particularly large, consider imbricating in two layers or place a purse string suture first to reduce some of the prolapse
- Trim excess vaginal epithelium and reapproximate the vaginal epithelium with delayed absorbable suture
- Perform cystoscopy for evaluation of bladder integrity and ureteral patency
Contributing Authors
- Chi Chiung Grace Chen, MD
- Michael Fialkow, MD
- Christine Vaccaro, DO
The CREOG Surgical Skills Task Force created this simulation as part of a standardized surgical skills curriculum for use in training residents in obstetrics and gynecology.