Vulvar reconstruction in post-RT case using the versatile VRAM flap: reporting the rare extrapelvic approach

Discussion

An algorithmic approach to detect classification and flap reconstruction was presented by Pusic et al in 2006.

The anterior and/or lateral walls are involved in type IA abnormalities, which are partial. The posterior vaginal wall is affected by type IB abnormalities, which are also partial. Type IIA abnormalities affect the upper two-thirds of the vagina and are circumferential. Type IIB defects are total circumferential resections of the vagina, which most frequently occur after exenteration of the pelvis. They also stated that although the type of defect is the main factor in choosing a flap, patient features must also be considered. The rectus flap is preferred even for modest abnormalities, as in our case, where the patient had already received radiation treatment, as its muscle bulk will promote pelvic revascularisation.13

Even though primary surgery is generally considered to be the best course of action, inevitably, there will be patients with unresectable disease, either because anterior and/or posterior exenteration is necessary with the formation of a stoma, which the patient may not accept, or because the patient is not physically fit for major surgery or anaesthesia. Radical chemoradiotherapy should be taken into consideration for these women. Most evidence suggests that doses of at least 6000 cGy are needed, typically administered over two phases: part one administering 4500–5000 cGy to the pelvis/groins, followed by an additional 1500–2000 cGy photon or electron boost to gross disease. This is considered acceptable despite lacking randomised control trial-level evidence.

External beam radiation can, however, be followed in certain patients by an interstitial implant to treat any remaining illness in the vulva. Selective dose boosting may also be possible while using intensity-modulated radiotherapy. The primary site may receive doses of 4500–5000 cGy, and an interstitial boost is typically administered 3–4 weeks later to give the acute radiation effects time to settle.14

Unfortunately, not all centres have access to these resources, particularly those in low/middle-income nations. Therefore, there is a need for more reliable data to standardise neoadjuvant therapy for vulvar carcinomas.

A problem for the surgeon is vulvoperineal repair following oncological extirpative surgery, such as a radical, comprehensive vulvectomy. Extensive wounds in the perineal area that do not heal might cause devastating sequelae, such as severe soft tissue infections that are uncontrollable by conservative measures.15

As was observed in our case, VRAM flap restoration of irradiation defects minimises major perineal wound issues. Therefore, immediate VRAM flap reconstruction should be strongly considered for severe vulval defects in post-irradiated cases. According to Zhang et al, a pedicled graft like VRAM is recommended if the defect is substantial and there has been a history of local radiation or surgery.16

Among various flaps available, VRAM is a dependable, single-stage and technically feasible flap to fix most surgical defects.

Based on the deep inferior epigastric artery, the entire length of the rectus muscle can be lifted together with a sizeable flap of overlaying skin. The flap’s vertical borders extend inferiorly to the inguinal ligament, a few millimetres above the costal margin (although the skin above the costal margin is less reliable). The flap’s horizontal breadth can extend beyond the midline and lateral to the muscle boundary and is only constrained by the capacity to heal the abdominal skin defect.

Two centimetres lateral to the muscle edge on both sides can be safely taken to provide a 15 cm-wide flap, sufficient for coverage of most perineal defects. The final point is that elevation of this flap does not preclude the construction of urinary or faecal stomas.17

The RAM is separated from the rectus sheath’s posterior, medial and lateral sections to prepare the VRAM flap. To protect the vascular perforators, the anterior part of the sheath is left intact. The harvested rectus flap is tunnelled into the pelvis via an extrapelvic approach and rotated 180° on its deep inferior epigastric artery pedicle.

It is essential not to kink or strain the vascular pedicle.

The proper length of the graft is increased by tunnelling. However, the flap can be tunnelled to the perineum via an extrapelvic subcutaneous pathway, as was done in this instance where a laparotomy was unnecessary.

For the abdominal wall to remain intact and to prevent future herniation, meticulous donor site closure is essential. In our case, running or interrupted permanent sutures were used to seal the anterior sheath before mesh was added for support.

Several variations of VRAM flap are in use, like the RAM–only flap can be used for a partial vaginectomy defect where minimal pelvic dead space is to be obliterated.

The extended VRAM flap helps obtain more skin and fat in individuals with slender bodies and considerable perineal abnormalities requiring comprehensive vaginal reconstruction.18

If more skin or mass is required, a more extended VRAM flap can be made from tissue derived from a random blood supply in the subcostal area.

Fasciocutaneous flaps can be used to insert bulky tissue into a deficiency in addition to myocutaneous flaps such as the gracilis and VRAM flaps.

According to Horch et al (table 1),19 there might be some restrictions on harvesting a pedicled flap from the thigh when extensive neoadjuvant radiation of the groin or thigh has been done and lymphatic backflow in the limb is hampered, leading to donor site complications. This highlights the advantages of using well-perfused muscle, such as that present in a (transpelvic) VRAM flap, to repair areas of the perineum, vagina and/or gluteus that have been exposed to radiation. Similarly, we demonstrated a significant improvement in quality of life and wound healing.

After oncological excision, a variety of flaps are employed to repair modest-to-large vulvar abnormalities.

Small, medium-sized and even large defects can all be corrected with the fasciocutaneous V-Y flap, especially if posteriorly placed.

The pudendal thigh flap is not recommended for abnormalities, including the inguinal-crural crease, such as in vulvar recurrences, since pedicle vessels may have been removed during the initial oncological resection.

Additionally, tiny to medium-sized vulvar lesions that are vertically oriented are closed using the gluteal fold flap. However, the pedicled, distally based VRAM flap allows for the closure of any type of defect, including those that are deeper and those that extend into neighbouring regions.

When distal vaginal or anal resection is done in addition to vulvar and perineal resection, the gracilis myocutaneous flap is insufficient. This flap fails frequently, and its skin paddle is unstable, particularly in obese people.

The gluteus flap is thick, hard to shape and challenging to harvest. The tensor fascia lata flap cannot reach low perineal locations, leaves a substantial donor defect and lacks muscle coverage for radiation protection.

Due to a decreased donor site morbidity, Gentileschi et al have alternatively promoted ALT perforator flap repair after vulvar cancer extirpative surgery.20

However, there might be restrictions on using a pedicled flap harvested from the thigh when lymphatic backflow in the extremities is disrupted due to significant neoadjuvant radiotherapy to the groin or thigh.21

Lower rates of donor site problems are associated with the DIEP flap, which allows for sparing muscle and fascia from the abdominal wall.

Additionally, because vascular anastomoses are unnecessary, there is a low risk of thrombosis. However, DIEP harvesting necessitates a multidisciplinary surgical team, including oncological reconstructive surgeons, and requires extensive training and high-level surgical skills.22

Prior flap harvest is the only clear contraindication to VRAM harvest. Prior neurovascular surgery that compromised the supply is a relative contraindication for using VRAM flaps, as is history of radiation to the donor site.

Apart from these, history of liposuction (which may reduce flap volume or harm perforators), DIEP flap harvest for breast reconstruction, existence of a big ventral hernia and history of hernia treatment are other factors that preclude the use of this graft.

The contralateral RAM is often used to serve as the foundation for the VRAM flap if an ostomy was previously performed to make an artificial opening through one of the RAMs.

The right rectus muscle is used for VRAM flap restoration, whereas the left is typically employed to bring out a colostomy. The big, dependable skin paddle, excellent bulk for dead space obliteration, enough reach to the perineum, dependable vascularity, constant anatomy, relative simplicity of harvest and lack of necessity for additional scars in a separate donor location are all benefits of the VRAM flap. The main drawbacks of using VRAM are associated with its potential donor site morbidity, which includes delayed wound healing and abdominal wall weakening, bulging or hernia.

VRAM flap reconstruction, however, lowers severe perineal wound problems without raising early abdominal wall morbidity, according to research from MD Anderson.23

Studies have shown that the VRAM flap is safe and supports the idea that neovascularisation can enable free flaps to become independent from their vascular pedicle.24

Minimally invasive techniques can also obtain these VRAM flaps.25