Vulvar-Vaginal Reconstruction

Anatomy and Physiology

Pelvic anatomy and physiology are expansive. Surgery for malignancies and subsequent reconstruction are performed by several subspecialists, including gynecologic oncologists, colorectal surgeons, urologists, and plastic surgeons. Most vulvar cancers are located superficially and are cured with wide local excision of the primary lesion. The vulva is a broad term for the female external anatomy. This includes the labia majora and minora, vestibule, introitus, mons pubis, clitoris, Bartholin glands, Skene glands, and urethral meatus. The vulva protects a woman’s sexual organs and is responsible for much of the female sexual response. This area is innervated by the pudendal nerve, which exits the sacral spine and enters the pelvis just medial to the ischial spine. The pudendal nerve provides sensation to the vulva and is responsible for urination, defecation, and orgasm. It divides into three main branches: the inferior rectal nerve, the perineal nerve, and the dorsal nerve to the clitoris. The internal pudendal artery, a branch of the internal iliac artery, provides the blood supply to most of the external genitalia. The superficial external pudendal artery, a branch of the femoral artery, supplies the labia majora. Venous drainage follows the superficial and deep systems from which they came.[5]

The vagina is an elastic, muscular tube that connects the vulva to the cervix and is integral to sexual intercourse and childbirth. The anterior branch of the internal iliac artery continues as the vaginal artery and is the main blood supply. Vaginal innervation is largely autonomic.[6]

The anatomic relation of the vulva and vagina with the pelvic floor muscles, bladder, and rectum is crucial for understanding the functional interactions and dynamics of the lower female reproductive and urinary tract.

Indications

The primary indication of vulvar and vaginal reconstruction is to restore the structure, body image, sexual function, and integrity of the genitalia and pelvic floor. This is most commonly indicated after colorectal or gynecologic cancer resection. Treatment for these types of cancer varies from chemotherapy, radiation, surgical excision, or multi-modality therapy.[7]

Surgical treatments for these lesions include pelvic exoneration, abdominoperineal resection, vulvectomy, and vaginectomy. These complex wounds often cannot heal on their own or after primary closure and benefit from flap reconstruction. Flap reconstruction of pelvic defects has been shown to decrease perineal wound morbidity secondary to the obliteration of dead space and the addition of a new healthy blood supply to the wound bed.[8]

Contraindications

There are no absolute contraindications to vulvar-vaginal reconstruction. The American Society of Anesthesiologists (ASA) physical status class III, increased operative times, obesity, smoking, and preoperative radiation are all risk factors for peri- and postoperative complications. However, no single risk factor has shown to be an absolute contraindication.[9]

Equipment

The required operative equipment is the same for any standard external surgery. For internal surgery, including the vagina or introitus, spreading retractors such as a Gelpi or Weitlaner and a speculum will be necessary, as are deeply curved retractors such as the Deaver. It is recommended to have various-sized retractors and instruments available. Patient positioning most often involves stirrups for lithotomy positioning.

Personnel

Ideally, the surgical scrub team should receive training at the hospital where these procedures are performed. The surgical or gynecological oncology team and the reconstructive team should be present at a time-out. While in the hospital, nursing staff familiar with flap monitoring should be utilized. Appropriate staff training is imperative for optimal operative outcomes.

Preparation

As for all surgeries, a thorough history and physical are required. Risks and comorbidities are reviewed and optimized when appropriate. Pressure-reducing pads are placed on bony prominences to decrease the risk of pressure sores. The patient is prepped and draped in the usual sterile fashion.

Technique or Treatment

When appropriate, small superficial defects may be amenable to split-thickness skin grafting. This is reliant on a well-vascularized wound bed and in the absence of preoperative radiation.

Please refer to the basic flap design StatPearls for an overview before continuing.[10]

The flap selected for perineal reconstruction depends on the size and location of the defect, functional goals of reconstruction, prior radiation field, and other coexisting factors such as previous abdominal surgery. Different defects and different ways to reconstruct them are presented in this section. Regardless of defect and location, the chosen flap should have a reliable blood supply and provide enough tissue to close the defect.

Vulvar Defects

Like any area on the body, reconstruction of the vulva depends on the location and depth of the defect. Small areas of excision may be closed primarily without significant loss of form or function, but larger areas will need adjacent tissue transfer or more distant flap reconstruction. The vestibule of the vulva can be divided into three subunits, each with its own unique anatomy. The upper third consists of the mons and upper labia, the middle third is the labia proper, and the lower third consists of the vaginal orifice and perineum.[11]

The perineum’s blood supply rivals that of the face, allowing the reconstructive surgeon many options for reconstruction with adjacent tissue transfer. The blood supply to the perineum was first described in 1889 by Car Manchot. The anterior portion of the vulva’s blood supply originates from the superficial external pudendal artery, while the posterior section is supplied by the deep external pudendal artery. The internal pudendal artery also supplies this area and gives rise to cutaneous perforators on which several reconstructive flaps are based. These arteries have a vast anastomotic network with each other, as well as branches from the contralateral side. Small- to medium-sized shallow defects of the vulva and vagina may be reconstructed with rotational flaps. This has also been described as a lotus flap because the design of these flaps is similar to that of lotus leaves. The lotus flap is based on cutaneous perforators from the internal pudendal artery with the pivot point near the midline of the perineum. This allows for easy translocation of the flap to the defect. With a maximum size of 18 cm x 6 cm and mirrored anatomy, it can be used for unilateral or bilateral defects.[12][13] 

When designing the flap, suitable perforators of the internal pudendal artery are found using a pencil-tipped Doppler. The flap is then dissected from the tip to the base in either an adipocutaneous or fasciocutaneous manner. The flap is transposed into the defect, and the donor site is closed primarily.

Superior vulvar defects may be amenable to a mons pubis or suprapubic flap. These flaps obtain their blood supply from the superficial external pudendal artery and the superficial inferior epigastric artery, and their respective veins. These flaps have a maximum dimension of 10 cm x 4 cm and are used primarily for defects of the superior, anterior vulva, anterior commissure, and labia minora/majora. The mons pubis flap may be used as a transposition flap or a V-Y advancement because of its reliable vascular pedicle. A line drawn from the anterior commissure of the labia provides guidance for the base of this flap. The flap is then drawn, similar to the defect. An incision is made and dissected deep beneath the Scarpa fascia but superficial to the inguinal ligament. The flap is raised and transposed into the defect, with the donor site closed primarily. A V-Y advancement may also be created for superior oval defects of the anterior commissure.[14]

Vaginal Defects

Vaginal defects can be generally classified as partial (Type 1) or circumferential (Type 2). Type 1 defects can be further classified as anterior or lateral defects (Type 1A), which come from resection of primary vaginal or bladder cancers, and posterior defects (Type 1B), which usually arise from invading rectal or anal cancers and are more common than Type 1A. Type 2 circumferential defects can be further divided into upper two-thirds (Type 2A) or total vaginal defects (Type 2B). Type 2A defects are frequently caused by uterine or cervical cancers, while Type 2B is most commonly caused by total pelvic exoneration.  

Most vaginal defects can be reconstructed using three pedicled flaps: pudendal (Singapore or lotus), gracilis, and rectus flaps. Type 1A defects without a large amount of missing tissue are amenable to pudendal flaps, unilateral or bilateral myocutaneous gracilis flaps. Type 1B posterior wall defects are best reconstructed with rectus flaps. Type 2A upper two-thirds vaginal defects are best reconstructed with tubed rectus flaps, and Type 2B total vaginal defects are best reconstructed with bilateral myocutaneous gracilis flaps.[14]

The myocutaneous gracilis flap used for vaginal or vulvar reconstruction can be unilateral or bilateral. The gracilis muscle is the most superficial of the adductor muscles originating from the pubic symphysis and inserts on the medial surface of the tibia within the pes anserinus. This flap is based on the descending branch of the medial femoral circumflex artery. The perforating vessel is found approximately 10 cm inferior to the pubic tubercle in between the adductor longus and adductor magnus. After the muscle is divided from its insertion and origin, it may be translocated to the defect.[15]

The rectus flap is an excellent choice for Type 1B and 2B defects. It is based on the deep inferior epigastric artery, a branch of the external iliac artery. For open procedures, the skin paddle can be incorporated into the original incision, and the long pedicle length allows the reconstructive surgeon to reach the pelvic defect. The skin paddle can be designed for many defects and even tubed for circumferential defects. After designing the skin paddle over the rectus muscle, the superior epigastric artery and vein are ligated, and the flap is flipped through the abdomen into the pelvis.[16] With the advent of minimally invasive robotic surgery, new techniques have arisen for rectus flap harvest.[17]

Complications

Vaginal reconstruction is not without complications. These complications range from minor complications such as wound dehiscence, skin necrosis, or partial flap loss to major complications such as flap failure, fistulas, or hernias. Complications are significantly more likely in patients with preoperative radiation. Immediate flap reconstruction decreases the likelihood of major complications but does not eliminate the risk. Patients should be counseled preoperatively about all possible complications.[18]

Total or partial flap loss is a relatively low-risk complication, given the hardy nature of the pedicled flaps typically utilized in vulvar-vaginal reconstruction. Flap loss complications can largely be avoided with appropriate preoperative planning and stringent attention to avoiding flap tension and twisting or kinking of the vascular pedicle.

The major complications often seen in pelvic exenteration include evisceration or deep pelvic abscesses. Bringing healthy vascularized tissue for filling dead space and tissue replacement, as opposed to tense primary closure, helps avoid these complications.

Clinical Significance

Defects of the vulva and vagina can result from resection of primary vulvovaginal malignancy or loco-regional extension of anogenital or bladder malignancy, which is more common.[19] As these more common defects arise from more advanced tumors, the medical and psychological effects can be profound. The patient is often undergoing multi-modality therapy for an advanced-stage malignancy in a very intimate area, and there are significant lifestyle changes even with successful reconstruction.[20]

The vulva and vagina each contain discreet anatomic subunits, and the most successful functional and aesthetic reconstruction relies on considering each of these subunits independently in the reconstructive plan.[21] Loco-regional flaps form the mainstay of vulvar-vaginal reconstruction in the absence of prior radiation therapy to the area, as a rich blood supply facilitates large-volume flaps.[22] In the setting of previous radiation therapy to the pelvic region, free tissue transfer may be required.[23]

Enhancing Healthcare Team Outcomes

In a busy reconstructive practice, the plastic surgeon is involved with a vast number of different specialties and subspecialties to heal wounds and provide solutions to complicated problems. These patients frequently are topics of discussion during interdisciplinary rounds. This interprofessional approach to managing complex injuries or wounds provides the patient with an optimal outcome.