Skin Grafts, Omental Flaps, Advancement and Rotational Flaps




BACKGROUND



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The condition and appearance of a woman’s genitalia strike at the core of her identity. Many patients experience severe sexual dysfunction, disturbed body image, and deranged pelvic anatomy after pelvic cancer surgery that compromise quality of life. Despite these important concerns, vulvovaginal reconstruction after pelvic cancer resection is not currently considered standard therapy.



Competent, safe, and functional vulvovaginal reconstructions are essential components of the care of patients with pelvic malignancies. The reconstruction cannot be achieved by doing a few standard procedures; it requires specialists familiar with general principles of reconstructive surgery to select the most appropriate among many possible techniques for each individual patient. To this end, the plastic and reconstructive surgeon should play an integral role in the care of the patient with pelvic cancer.



The surgeon and patient’s therapeutic partnership is central to the outcome of the reconstruction. Operations in this anatomic region have a significant bearing on quality of life, and patients and families should be involved in decision making when appropriate. Patients must be educated about their disease, prognosis, treatment options, and the likely deficits in structure and function that can result from their cancer operation. Reconstructive options must be thoroughly described along with reasonable expectations about future sensibility, function, and aesthetic outcome. It cannot be overemphasized that joint oncologic-reconstructive endeavors are first and foremost for cancer treatment; barring unique circumstances, oncologic resection should never be compromised to facilitate reconstructive efforts.



The overarching goal of vulvovaginal reconstruction is the anatomic and functional restoration of these structures in an oncologically safe fashion that minimizes the risk of morbidity while optimizing the cosmetic outcome. Improved integration of reconstruction with primary treatment will improve aesthetic and functional results, and, thus, the ­quality of life of patients with pelvic neoplastic diseases. In this chapter, we explore the role of 3 essential tools in the armamentarium of plastic and reconstructive surgeons; skin grafts, omental flaps, and advancement and rotational flaps in vulvar and vaginal reconstructive surgery.




INDICATIONS AND CLINICAL APPLICATIONS



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Squamous cell carcinoma is the most common histologic type of vulvar malignancy and the most frequent setting in which vulvar reconstruction occurs. It is diagnosed in 2 women per 100,000 every year in developed countries, and the age at diagnosis is most commonly in the sixth and seventh decades of life. Vulvar intraepithelial neoplasia (VIN) grade III represents a precursor lesion characterized by cellular atypia and abnormal maturation of the vulvar epithelium; it is typically found in a much younger patient population (around the fourth decade). VIN grade III is a surgical diagnosis, given that a 9% incidence of invasive carcinoma has been observed in untreated patients.



Primary carcinoma of the vagina is rare, accounting for about 1% of reproductive cancers in women, with squamous cell carcinoma being the most common histologic type. Vaginal resection occurs much more commonly due to advanced and recurrent malignancies in the adjacent organs, including cervix, endometrium, vulva, urethra, and most frequently bladder and rectum. Because the vaginal anatomy may be variably affected by resection, versatile methods are paramount to achieving successful reconstruction.



The most widely used, oncologically safe, and cosmetically acceptable methods in vulvovaginal reconstruction are included in the discussion that follows. Skin grafting alone for neovaginal reconstruction has largely been ­supplanted by more modern techniques; however, skin grafting remains a viable option for coverage of thin resection beds in vulvar reconstruction. Neovaginal reconstruction with omental flaps may proceed in conjunction with skin grafting to create a neovaginal canal. The omental flap has also proven to be an excellent solution to the problem of pelvic dead space following pelvic exenteration and resection for anorectal malignancy. An exciting and rapidly evolving area in vulvovaginal reconstruction relates to applications of advancement and rotational flaps. An impressive assortment of V-Y advancement flaps has been developed to reconstruct vulvar defects, combining a favorable aesthetic and functional outcome with reduced donor site morbidity. Emerging methods such as abdominoplasty advancement flaps will be discussed briefly. The Singapore flap for neovaginal reconstruction provides an excellent illustration of a rotational flap that continues to find use today.




SKIN GRAFTS AND OMENTAL FLAPS IN VULVOVAGINAL RECONSTRUCTION



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Anatomic Considerations



Successful reconstruction of vulvovaginal defects is predicated on a careful appreciation of the specific surgical defect. This includes an assessment of exactly which structures were removed and which remain, along with their postresection configuration. Numerous classification systems have been developed to help characterize residual defects and propose optimal reconstructive options. The system devised by Cordeiro et al1 is still widely used today and divides vaginal defects into either type I or II (Figure 16-1). Höckel and Dornhöfer2 outline an algorithm of vulvovaginal reconstruction in which vulvar and vaginal defects are divided into ­partial, total, and extended defects. Each defect is accompanied by a number of suggested reconstruction options (Figures 16-2 and 16-3).




Fig. 16-1.


Type IA defects are partial defects of the anterior and/or lateral vaginal wall, frequently resulting from resection of urinary tract malignancies or primary malignancies of the vaginal wall. Type IB defects involve the posterior vaginal wall and result from resections of locally advanced colorectal carcinoma. Type IIA defects are circumferential and include the upper two-thirds of the vagina, most commonly resulting from resection for uterine and cervical disease. Type IIB defects represent circumferential, total vaginal resection frequently seen in the setting of pelvic exenteration. (Reproduced with permission from Cordeiro PG, Pusic AL, Disa JJ. A classification system and reconstructive algorithm for acquired vaginal defects. Plast Reconstr Surg. 2002;110(4):1058-1065.)






Fig. 16-2.


Classification scheme of vulvar defects and proposed reconstructive options. (Reproduced with permission from Höckel M, Dornhöfer N. Vulvovaginal reconstruction for neoplastic disease. Lancet Oncol. 2008;9(6):559-568.)






Fig. 16-3.


Classification scheme of vaginal defects and proposed reconstructive options. (Reproduced with permission from Höckel M, Dornhöfer N. Vulvovaginal reconstruction for neoplastic disease. Lancet Oncol. 2008;9(6):559-568.)





Among the first methods of vaginal reconstruction was the application of full and partial-thickness skin grafts for creation of a neovagina. First described by Abbe3 in 1898 for treatment of congenital absence of the vagina, these methods marked a new era in vaginal reconstruction that would find applications for acquired defects. In 1938, McIndoe et al4 would use prosthetic vaginal stents lined with skin grafts to avert the problems with stenosis and shaping in earlier methods, which became known as the McIndoe technique. Local and regional flap techniques have since been developed to address more complex pelvic surgical procedures, and skin grafting for vaginal reconstruction remains mostly of historic interest today, except used in conjunction with omental flaps (discussed below).



Two types of skin graft are widely used in vulvar reconstruction. These include full-thickness skin grafts (FTSGs) and partial or split-thickness skin grafts (STSGs). Full-thickness skin grafts contain the epidermis and entire dermis and, therefore, leave a residual defect at the donor site exposing subcutaneous tissue. This defect must be closed primarily or covered at the time of graft harvest. By contrast, STSGs contain a variable amount of dermis, and remaining hair follicles and epithelial appendages ultimately regenerate the overlying epidermis. The differences between these 2 types of skin grafts have important implications for operative planning and outcomes and are highlighted in Table 16-1.




Table 16-1.Characteristics of split and full-thickness skin grafts.



Skin grafts rely entirely on the vascularity of the recipient bed, and grafting onto contaminated or infected wounds, bare tendons without paratenon, or bone without periosteum is generally unsuccessful. It is also important to consider that skin grafts do not provide a significant protective barrier for vital underlying structures and should not be applied over great vessels, nerves, or bone.



Early animal studies by Senn5 in 1888 were among the first to document the use of the greater omentum in surgery, where it was applied for protection and support of healing intestinal anastomoses. Later, in 1937 Graham6 would uncover its utility in closing perforated duodenal ulcers. However, the value of omental flaps in extraperitoneal surgery was not appreciated until the mid-20th century. Since that time the omentum has been used in the reconstruction of defects all over the body, including chest wall and head and neck wounds, breast reconstruction, and for the treatment of rectovaginal and vesicovaginal fistulae.



The omentum is a thin apron of fat-containing peritoneum, attaching to the greater curvature of the stomach and transverse colon. It drapes the anterior surface of the small intestine, extending inferiorly almost to the level of the pelvis. An omental flap can be based on either the right or left gastroepiploic artery and the omental vascular arcade, and may be designed in a pedicled or free fashion. Most commonly, it is harvested as a pedicle flap, and the right gastroepiploic artery is usually dominant with regard to caliber and length. A right gastroepiploic artery pedicle generally permits a greater arc of rotation than the left.



Preoperative Preparation



Box 16-1 KEY SURGICAL INSTRUMENTATION


Skin grafts


• Dermatome


• Skin graft mesher


• Light bolster dressing or negative pressure therapy device


• 3-0 or 4-0 chromic sutures


Omental flaps


• Laparoscopic equipment setup (trocars, graspers, video monitors; if laparoscopic harvest)


• Vascular clamps, vessel clips, or silk ties


• Bowel retractors


• Vaginal stent


• Dermatome




Skin grafts may be used to cover large perineal resection beds for anatomic reconstruction following superficial “skinning” vulvectomy, commonly performed for VIN grade III and carcinoma in situ. These defects are amenable to skin grafts because they are superficial and often have healthy, vascular wound beds. For these reasons, skin grafting of vulvar defects can be used in the setting of pre- or postoperative radiation with excellent outcomes. Vulvar skin grafts are useful when tissue bulk is not required for optimal reconstruction, or when patient preferences dictate that more anatomic or functional methods be avoided. In such cases primary closure of the vulvectomy defect may be reasonable if a tension-free closure can be accomplished (Figure 16-4).




Fig. 16-4.


(Left) Intraoperative photograph of perineum after vulvectomy. (Right) Intraoperative photograph after primary closure of vulvectomy defect.





The omental flap is unique among the reconstructive methods described here in that it necessitates violation of the peritoneal cavity. Flap harvest usually requires no additional incisions given that a laparotomy or other large exposure incision is necessitated by the pelvic cancer operation. In cases in which reconstruction is performed in a delayed or staged fashion, the omentum can be harvested through ­transdiaphragmatic or laparoscopic and minimally invasive techniques in addition to the standard open abdominal approach. Contraindications to the use of omental flaps include adhesions, concomitant abdominal disease, or evidence of any peritoneal or omental metastasis. Both reconstructive and oncologic teams should be keenly aware of oncologically safe technique during joint operations. This can be facilitated by having 2 or more separate scrub tables in the operating room, each with several extra pairs of gloves and ample sterile equipment to avoid any possible contamination of healthy tissues with malignant cells.



Surgical Procedure



1. Skin grafting


Box 16-2 MASTER SURGEON’S PRINCIPLES


Skin grafts


• Débride ischemic or threatened tissue at the recipient site prior to grafting


• Choose donor sites that can be closed primarily or well concealed by normal clothing


• A preset graft thickness of 0.014–0.018 in. is preferred


• Consider meshing or pie-crusting sheet graft to increase surface area or allow fluid egress


• A bolster or negative pressure wound dressing should cover the skin graft


• The donor site should be covered with nonadherent petrolatum gauze or similar dressing


Omental Flaps


• The right gastroepiploic artery is often preferred due to greater size and rotation


• Omental fixation at the pelvic rim allows for optimal neovaginal positioning


• A vaginal stent with draining capacity should be used and continued postoperatively


• The J portion of the omental flap must completely envelop the dermal side of the skin graft


• Stent migration is prevented by suturing stent to the labia and placing mattress sutures at the skin graft apex




Recipient Site Preparation. Prior to skin graft harvest, the recipient wound must be thoroughly assessed. The exact dimensions of the wound should be recorded, and the wound inspected for its degree of perfusion (capillary refill, skin blanching, or discoloration) or any evidence of infection. Ischemic or necrotic tissue at the wound edges should be sharply excised with the use of a tenotomy scissor, 15-blade, or other fine tissue-cutting instrument. The wound base may also be sharply debrided to establish a uniform thickness, and the wound is copiously irrigated with saline solution and gently dabbed dry with sterile gauze. Lightly moistened gauze is then gently placed over the wound bed and attention is directed to the donor site.



Donor Site Preparation. Options for the skin graft donor site should be discussed with the patient preoperatively; however, patient positioning, skin quality and availability, and preexisting skin lesions all factor into the final donor site selection. Common STSG donor sites include the lower abdomen, suprapubic region, lateral hairless inguinal region, upper medial and lateral thigh, and buttocks. For FTSGs, the groin is often the donor site of choice.



After the donor site is selected, a marking pen is used to outline a rectangle of skin, with dimensions slightly exceeding the recipient site in both length and width. Harvesting of the STSG is most easily accomplished with the use of a dermatome. One should bear in mind that using a dermatome restricts the maximum width of STSG that can be harvested at any given time, although there is no such restriction on the length of graft harvested. Scarring will ultimately occur at the donor site, and grafts should be arranged so as to minimize scar exposure in regular clothing if possible.



Graft Harvest and Care. It is critical to assess the integrity and function of the dermatome prior to each use; failure to do so is frighteningly common and may have ­catastrophic results. Verify that the appropriate blade is securely attached and that there are no mobile parts on the dermatome. The blade is set to a predefined thickness; for most STSGs, a thickness of approximately 0.014 to 0.018 in. is preferred. The dermatome motor is tested by turning it on for a several seconds before harvesting the graft.



A layer of mineral oil is placed over the outlined donor site. To harvest the graft, the dominant hand should hold the dermatome, while the nondominant hand provides traction on the surrounding skin to create a flat surface conducive to harvesting a graft of uniform thickness. The dermatome is turned on and approaches the skin directly in line with the outlined donor skin at an angle of approximately 45 degrees. The skin is contacted firmly and gentle pressure is maintained as the dermatome is advanced along the skin, without changing the angle. Once the end of the donor site is encountered, the dermatome is gently lifted away from the skin, and a toothed forceps is used to very carefully remove the skin graft from the dermatome.

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Jan 12, 2019 | Posted by in GYNECOLOGY | Comments Off on Skin Grafts, Omental Flaps, Advancement and Rotational Flaps
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