WIH International Hospital is one of Asia’s leading centers for gender-affirming surgery (GAS).
Under the leadership of Dr. Chettasak Tulayapanich (formerly Dr. Chettawut) — a globally recognized plastic and reconstructive surgeon with over 30 years of experience — we have refined techniques that deliver life-changing results for transgender women.

At the heart of our approach is Dr. Chet’s NPI Technique (Non-Penile Inversion), designed to achieve two equally important goals:

Preserve intimate sensation by protecting key nerve pathways
Create realistic, beautifully natural female genitalia

This technique has helped thousands of patients from over 50 countries achieve results that feel, look, and function naturally.

Why Choose NPI for Gender-Affirming Surgery

Traditional penile inversion methods often rely heavily on using penile skin to construct both the vaginal canal and external genitalia, which can sometimes limit aesthetic refinement and compromise sensation.

Dr. Chettasak’s NPI Technique takes a different approach:

The penile skin is not used to line the vaginal canal.
Instead, it is reserved for the creation of delicate external structures — the inner labia and vaginal opening — ensuring a soft, natural appearance.
For the vaginal lining, peritoneal tissue, colon segment, or skin graft may be used, depending on patient needs and anatomy.

This separation of roles allows for better aesthetics, improved long-term tissue quality, and exceptional sensation preservation.

Preserving Intimate Sensation — The Science Behind NPI

A defining strength of the NPI technique is sexual sensation preservation. Dr. Chettasak meticulously protects the pudendal nerve, dorsal nerve of the clitoris, and surrounding nerve plexuses. These structures are critical for both surface and deep orgasmic response.

Three Key Sensory Zones Preserved

1. Clitoral Complex & Clitoral Hood

The clitoris is reconstructed using the tip of the glans penis, where natural nerve endings are most concentrated.
A clitoral hood is designed to cover and protect the clitoris, mimicking natural female anatomy.
These steps allow patients to retain orgasmic capacity in nearly 100% of cases.

2. Inner Labia (Labia Minora)

Created from prepuce (foreskin) mucosa, which is naturally thin, pink, and highly sensitive.
For circumcised patients, alternative techniques maximize use of remaining tissue to still achieve functional, sensate inner labia.

3. Prostate Sensory Zone

The prostate gland is preserved during surgery because:

It contains dense nerve networks linked to the G-spot zone in cisgender women.
The urethra passes through the prostate; removal would compromise both sensation and urinary safety.

This zone contributes significantly to deep orgasmic sensation during vaginal intercourse.

Result: The NPI technique preserves all three orgasmic pathways — clitoral, labial, and deep G-spot — ensuring a complete feminine sensory experience.

Preserving Intimate Sensation — The Science Behind NPI

Three Key Sensory Zones Preserved

1. Clitoral Complex & Clitoral Hood

The clitoris is reconstructed using the tip of the glans penis, where natural nerve endings are most concentrated.
A clitoral hood is designed to cover and protect the clitoris, mimicking natural female anatomy.
These steps allow patients to retain orgasmic capacity in nearly 100% of cases.

2. Inner Labia (Labia Minora)

Created from prepuce (foreskin) mucosa, which is naturally thin, pink, and highly sensitive.
For circumcised patients, alternative techniques maximize use of remaining tissue to still achieve functional, sensate inner labia.

3. Prostate Sensory Zone

The prostate gland is preserved during surgery because:

It contains dense nerve networks linked to the G-spot zone in cisgender women.
The urethra passes through the prostate; removal would compromise both sensation and urinary safety.

This zone contributes significantly to deep orgasmic sensation during vaginal intercourse.

Result: The NPI technique preserves all three orgasmic pathways — clitoral, labial, and deep G-spot — ensuring a complete feminine sensory experience.

Aesthetics Perfected — Achieving a Natural Feminine Appearance

While preserving intimate sensation is essential, the visual and anatomical results are equally important. Dr. Chettasak’s NPI Technique focuses on meticulously recreating the delicate details of cisgender female anatomy to achieve a soft, natural, and harmonious appearance.

The inner labia are carefully designed to begin just below the clitoris and extend smoothly down to the vaginal opening, framing the area naturally. The vaginal opening itself is sculpted into a soft V-shaped contour, mimicking cisgender female anatomy and providing a beautifully balanced look.

Equally important is urethral refinement. The urethral opening is positioned in a naturally feminine location, and all residual erectile tissue is thoroughly removed to prevent unwanted swelling or “stump formation” during arousal. This precise approach ensures a smooth, clean, and realistic appearance of the urethral area.

Finally, attention is given to the outer aesthetics. The overall result features beautifully proportioned labia minora and majora, a smooth perineal contour, and minimal, well-concealed scarring. Every detail is carefully considered to create a natural feminine appearance that patients can feel confident and proud of.