Residency · Residency · Plastic Surgery

Perineal and Vaginal Reconstruction

Introduction

Perineal and vaginal defects arise from oncologic resection (vulvar, rectal, anal, cervical, and vaginal cancers), trauma, radiation necrosis, infection (necrotizing fasciitis, Fournier gangrene), and congenital anomalies. The perineum is a complex anatomic region with critical functional requirements: continence (urinary and fecal), sexual function, ambulation, and wound closure in a contaminated field. Reconstruction must provide durable tissue coverage, obliterate dead space, and restore function when possible. Plastic surgery involvement is essential for complex defects that cannot be closed primarily.

Anatomy of the Perineum

The perineum is a diamond-shaped region bounded by the pubic symphysis anteriorly, coccyx posteriorly, and ischial tuberosities laterally. Divided by a transverse line between the ischial tuberosities into: Anterior (urogenital) triangle: contains the external genitalia and urethra. Posterior (anal) triangle: contains the anal canal and ischiorectal fossae.

Pelvic floor muscles: levator ani (pubococcygeus, iliococcygeus, puborectalis) and coccygeus; form the muscular diaphragm of the pelvis. Perineal body: fibromuscular central tendon where the perineal muscles converge; critical for pelvic floor integrity. Pudendal nerve and artery: course through Alcock's canal along the lateral ischiorectal fossa; provide motor and sensory innervation and blood supply to the perineum. Blood supply: internal pudendal artery (primary), branches of the inferior gluteal artery, obturator artery, and inferior epigastric perforators.

Vaginal Anatomy

Muscular tube lined by nonkeratinized stratified squamous epithelium. Blood supply: uterine artery branches (upper), vaginal artery (middle), and internal pudendal artery branches (lower). Supported by cardinal and uterosacral ligaments (upper), levator ani and endopelvic fascia (middle), and perineal body (lower). Length approximately 7-10 cm; capacity for significant distension.

Indications for Reconstruction

Oncologic

Abdominoperineal resection (APR) for rectal/anal cancer: creates a large perineal defect with pelvic dead space. Radical vulvectomy for vulvar cancer: anterior perineal soft tissue loss. Pelvic exenteration (total, anterior, posterior): massive combined defect requiring complex reconstruction. Vaginal cancer or cervical cancer requiring vaginectomy.

Non-Oncologic

Fournier gangrene: necrotizing fasciitis of the perineum; requires serial debridement followed by reconstruction. Radiation necrosis: chronic non-healing perineal wounds from prior pelvic radiation. Traumatic injuries: straddle injuries, obstetric perineal lacerations (fourth-degree tears). Congenital: vaginal agenesis (Mayer-Rokitansky-Kuster-Hauser syndrome).

Perineal Reconstruction

Defect Assessment

Size and location of the soft tissue defect. Presence of pelvic dead space (after APR or exenteration). Prior radiation: irradiated tissue is fibrotic, hypovascular; requires well-vascularized flap from outside the radiation field. Presence of stomas: location may affect flap design and donor site selection. Need for vaginal reconstruction (concurrent or staged).

Reconstructive Options

Primary Closure

Appropriate for small defects (<5 cm) with healthy, non-irradiated tissue. Rarely sufficient after oncologic resection.

Skin Grafts

Limited role in perineal reconstruction; poor take in radiated fields and contaminated wounds. Useful for superficial defects after Fournier gangrene once wound bed is granulating.

Gluteal Flaps

Inferior gluteal artery perforator (IGAP) flap: fasciocutaneous flap based on perforators of the inferior gluteal artery. Excellent for posterior perineal defects (APR wounds). Provides bulk to fill pelvic dead space. Bilateral flaps for large or midline defects.

Gluteal fold V-Y advancement flap: simple, reliable; advances gluteal skin and fat into the perineal defect; preserves muscle. Gluteus maximus myocutaneous V-Y advancement or rotation: provides substantial bulk for large pelvic dead space.

VRAM Flap (Vertical Rectus Abdominis Myocutaneous)

Workhorse flap for perineal and pelvic reconstruction. Pedicled on the inferior epigastric artery (deepest pedicle; robust). Delivered through the pelvis by dividing the rectus muscle from its insertion and routing the flap posteriorly through the pelvic floor defect. Provides large volume of well-vascularized tissue to fill pelvic dead space and cover perineal defects.

Can simultaneously create a neovagina by tubing the skin paddle. Advantages: reliable, long pedicle reach, fills dead space, brings non-irradiated tissue into irradiated field. Disadvantages: abdominal wall weakness/hernia (15-20%); not available if prior abdominoplasty or DIEP flap harvest has divided inferior epigastric pedicle. Mesh reinforcement of the abdominal wall donor site recommended.

Gracilis Myocutaneous Flap

Based on the dominant pedicle (medial circumflex femoral artery), entering the muscle 8-10 cm inferior to the pubic tubercle. Thin, pliable flap; well-suited for vaginal reconstruction and anterior perineal defects. Bilateral gracilis flaps can be tubed to create a neovagina. Advantages: minimal donor site morbidity, concealed donor scar, expendable muscle. Disadvantages: limited volume for filling large pelvic dead space; unreliable distal skin paddle.

Posterior Thigh Flap

Based on the descending branch of the inferior gluteal artery or posterior thigh perforators. V-Y advancement or rotation into perineal defect. Useful for large posterior perineal defects. Provides substantial tissue bulk.

<image>Illustration of the VRAM flap for perineal reconstruction after abdominoperineal resection. Panel A shows an anterior view of the abdomen with a vertical rectus abdominis myocutaneous flap designed on the right rectus abdominis muscle. The skin paddle is shown as a vertical ellipse on the lower abdomen centered over the rectus muscle. The inferior epigastric artery and vein are labeled as the pedicle, entering the deep surface of the rectus muscle. Panel B shows a sagittal cross-section of the pelvis after APR, with the rectum removed and a large pelvic dead space visible. The VRAM flap is shown being delivered through the pelvis: the rectus muscle is detached from its pubic insertion, and the flap is tunneled posteriorly through the pelvic floor defect. The skin paddle emerges at the perineum to provide external skin coverage, while the muscle belly fills the pelvic dead space. The inferior epigastric pedicle is shown as the blood supply, coursing from the external iliac artery beneath the rectus muscle. Panel C shows the perineal view with the skin paddle inset at the perineal wound, the surrounding gluteal skin closed, and the colostomy shown on the anterior abdomen. Labels identify the rectus abdominis muscle, inferior epigastric artery and vein, pelvic dead space, sacrum, and skin paddle.</image>

Vaginal Reconstruction

Indications

After vaginectomy for malignancy (concurrent with perineal reconstruction or as isolated procedure). Vaginal agenesis (MRKH syndrome). Vaginal stenosis from radiation. Gender-affirming surgery (vaginoplasty).

Flap Options for Neovagina

VRAM neovagina: skin paddle tubed into a cylinder; provides adequate depth and width; reliable blood supply; preferred after pelvic exenteration. Bilateral gracilis neovagina: two gracilis myocutaneous flaps tubed and joined to create a lined vaginal canal; good depth and caliber; popular for MRKH syndrome. Singapore flap (pudendal thigh flap): fasciocutaneous flap from the medial thigh crease; based on branches of the internal pudendal artery; useful for partial vaginal reconstruction. ALT flap: free or pedicled; for very large defects or when local options are exhausted.

Bowel neovagina (sigmoid, ileum): full-thickness bowel segment used to create a self-lubricating neovagina; requires laparotomy; mucus discharge; risk of diversion colitis, prolapse.

Postoperative Vaginal Care

Vaginal stent or mold for 3-6 months to prevent stenosis. Progressive dilation starting at 4-6 weeks. Long-term dilation compliance is essential to maintain vaginal patency.

Fournier Gangrene Reconstruction

After serial debridement and infection control (average 3-5 debridements). Scrotal reconstruction: bilateral medial thigh advancement flaps; scrotal skin is remarkably elastic and regenerates well. Testicular coverage: if scrotal skin insufficient, testes can be implanted in subcutaneous thigh pockets temporarily. Perineal and perianal wounds: skin grafts on granulation tissue (most common); local flaps for larger or complex defects. Penile coverage: split-thickness skin graft (unmeshed sheet graft preferred for cosmesis).

<image>Illustration of bilateral gracilis myocutaneous flaps for neovaginal reconstruction. Panel A shows an anterior view of the medial thighs with bilateral gracilis muscle flaps designed. On each side, the gracilis muscle is outlined with a skin paddle on the medial thigh overlying the muscle. The dominant pedicle from the medial circumflex femoral artery is labeled, entering the muscle approximately 8-10 cm below the pubic tubercle. Panel B shows the flaps elevated bilaterally with the skin paddles attached to the underlying gracilis muscles. The pedicle is preserved and the distal muscle is divided. Panel C shows the two flaps brought together in the midline at the perineum, with each skin paddle tubed into a half-cylinder and the two halves sutured together to create a complete neovaginal canal. The muscular component of each flap provides bulk around the neovagina. A vaginal stent or mold is shown inside the neovaginal canal to maintain the lumen during healing. Labels identify the gracilis muscle, medial circumflex femoral artery pedicle, skin paddle, neovaginal canal, and vaginal stent.</image>

Complications

Wound dehiscence: most common complication (20-30%); higher in irradiated fields. Wound infection: contaminated field; meticulous debridement and perioperative antibiotics essential. Flap necrosis: partial (10-15%) or complete (3-5%); risk increased with radiation, diabetes, smoking. Pelvic abscess: persistent dead space or inadequate obliteration; may require drainage.

Vaginal stenosis: inadequate stenting or noncompliance with dilation; 15-30%. Hernia: abdominal wall donor site after VRAM harvest (15-20%); perineal hernia (3-10%). Perineal hernia: bowel herniation through the pelvic floor defect; presents as perineal bulge; may require mesh repair.

Key Clinical Pearls

The VRAM flap is the workhorse for perineal reconstruction after APR and pelvic exenteration; it provides a large volume of well-vascularized tissue from outside the radiation field that fills pelvic dead space and can be simultaneously used for neovaginal construction. In irradiated perineal wounds, local tissues are unreliable and primary closure has unacceptable dehiscence rates; always bring well-vascularized tissue from outside the radiation field (VRAM, gracilis, or gluteal flaps). Bilateral gracilis myocutaneous flaps are the preferred technique for neovaginal reconstruction in vaginal agenesis (MRKH syndrome) because they provide adequate vaginal depth with concealed donor scars and minimal morbidity. Vaginal stenting and long-term dilation compliance are essential after neovaginal construction; failure to dilate leads to vaginal stenosis in 15-30% of patients. After Fournier gangrene, scrotal reconstruction with bilateral medial thigh advancement flaps is reliable because scrotal skin has remarkable elasticity and regenerative capacity; testicular coverage should not be delayed.

References

• Butler CE, Gundeslioglu AO, Rodriguez-Bigas MA. Outcomes of immediate vertical rectus abdominis myocutaneous flap reconstruction for irradiated abdominoperineal resection defects. J Am Coll Surg. 2008;206(4):694-703.
• Salgado CJ, Mardini S, Jamali AA, Ortiz J, Gonzalez R, Chen HC. Muscle versus nonmuscle flaps in the reconstruction of chronic osteomyelitis and prosthetic joint infection. J Reconstr Microsurg. 2006;22(5):299-304.
• Wexner SD, Ruiz DE, Genua J, Nogueras JJ, Weiss EG, Zmora O. Gracilis muscle interposition for the treatment of rectourethral, rectovaginal, and pouch-vaginal fistulas: results in 53 patients. Ann Surg. 2008;248(1):39-43.
• Mughal M, Baker RJ, Muneer A, Mosahebi A. Reconstruction of perineal defects. Ann R Coll Surg Engl. 2013;95(8):539-544.

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