Autologous breast reconstruction with medial thigh flaps

Introduction

The transverse upper gracilis (TUG) flap, also known as the transverse musculocutaneous gracilis (TMG) flap, with the variations in flap design, is a useful donor site when abdominal flaps are not an option.

Careful patient selection is essential for optimal breast and donor site outcomes. This flap can be harvested in the supine position thereby allowing a two-team approach. It provides soft and easily moldable tissue with an early recovery.

Operative considerations focus on minimizing donor site morbidity, ensuring adequate tissue harvest and contouring of the flap.

The following refinements have been implemented to reduce morbidity and allow adequate tissue harvest: More posterior shift of the skin paddle, caudal extension of sub-Scarpa’s fat, recruitment of posterior thigh fat, preservation of the saphenous vein with the accompanying lymphatics and limiting the muscle harvest.

Aesthetically pleasing breast shape can be achieved by molding the flap in three ways, to match the breast morphology. The use of intercostal perforators as the recipient vessels, adjunctive procedures such as immediate lipofilling of the pectoralis or the gracilis muscle, additional flaps and use of implants increase the applications of the flap. The main criticisms of the TUG flap are limited flap volume, short pedicle and donor site issues.

The variations in skin paddle design including the extended TUG and the diagonal upper gracilis (DUG) flaps are useful variations of this flap.

History

The gracilis muscle flap was first described by Pickrell for rectal sphincter reconstruction in 1952. Two decades later, Orticochea, first use of the gracilis musculocutaneous flap to reconstruct an ankle defect. In 1976, Harii and colleagues reported the first free gracilis musculocutaneous flap where they presented canine models, cadaver dissections and clinical applications for reconstruction of the head and neck and lower extremity.

Orticochea was the first to describe the use of the gracilis musculocutaneous flap without the delay maneuver. He recognized that the skin survival was based on the vascular supply of the underlying muscle.

McCraw and colleagues developed the concept of musculocutaneous perforators. The skin paddle over the muscle remained unreliable with a longitudinal skin paddle. They described partial flap necrosis in 27% of their patients and major flap necrosis in 9%. In a larger review of 192 gracilis musculocutaneous flaps the results of flap necrosis with a longitudinal skin paddle remained high.

The TUG musculocutaneous flap was first used in breast reconstruction in 1992 by Yousif and colleagues. They mapped the musculocutaneous perforators and devised the transverse skin paddle within the upper third of the muscle which provided a significantly more reliable skin paddle ( Fig. 35.1 ).

Hallock reported modifications of the TUG flap by identifying the perforators off the medial circumflex femoral artery. He used this flap predominantly for lower leg reconstruction for trauma patients. The free TUG flap was used for breast reconstruction by Arnez in seven patients, in which he had five successful reconstructions. In 2004, Schoeller and Wechselberger described the use of 12 TUG flaps for breast reconstruction that were all successful. It is this work that has led to the popularity for the TUG flap for breast reconstruction.

Peek et al . delineated the anatomy of the blood supply to the gracilis muscle and surrounding skin and described variations of the TUG perforator flap for breast reconstruction. They found an average of five perforators per thigh in a study of 43 cadaver dissections.

Basic science/disease process

The gracilis muscle is a type II musculocutaneous flap in the Mathes and Nahai classification. The musculocutaneous gracilis flap can be designed with several skin paddle types and there are numerous acronyms. These include TUG, TMG, DUG, vertical upper gracilis (VUG), and bilateral stacked vertical upper gracilis (BUG). This chapter will focus on the TUG flap ( Fig. 35.2 ).

Anatomical studies have demonstrated that the angiosome of the upper gracilis muscle lies at 90° to the muscle, hence a transverse skin paddle proved to be more reliable.

Diagnosis/patient presentation

The common use of the TUG flap is for immediate breast reconstruction with a skin-sparing mastectomy approach. The TUG flap with immediate nipple reconstruction lends itself well to this procedure. A smaller proportion of patients present in a delayed manner with either no reconstruction or complications of their implant-based reconstruction. Lastly, the TUG flap has also been useful in the reconstruction of partial breast defects or when used in conjunction with implants or a second free flap.

In our practice, the TUG flap has replaced the use of latissimus dorsi (LD) musculocutaneous flap for breast reconstruction. The TUG flap provides a skin island comparable to the LD flap. The LD is the largest muscle of the back and carries a reliable skin paddle. The flap can be raised with ease and mitigates the need for microsurgery. All these factors have led to its popularity and widespread use. However, there has been associated functional impairment and weakness found in those who have this muscle harvested. In addition, the volume of muscle from the LD decreases with time as it atrophies. These problems are largely not applicable with the use of the TUG flap. It provides a similar vascular envelope with another choice of concealed scar.

Tip

Delayed reconstructions often require more skin, which can be a challenge in comparison to immediate reconstruction following skin-sparing mastectomy ( Fig. 35.3 ).

Patient selection

If the abdomen cannot be used as a donor site due to multiple scars or patient preference, autologous reconstruction using the medial thigh can be considered as a second choice.

The typical patient for TUG flap reconstruction is a slim patient with a small to moderate sized breast in which the abdomen cannot be used ( Fig. 35.4 ). The indications of the TUG flap have increased and many more patients can be considered for a TUG flap; however, additional measures are required with the larger reconstructions and these are discussed later in the chapter ( Figs. 35.5–35.9 ).

Treatment/surgical technique

The patient is marked in the standing position with the donor leg one foot length forward. The upper border of the flap is marked a finger-breadth below the thigh–groin junction and with a pinch test the lower border of the flap is decided. Typically, the width of the crescent is 7 cm although in those with an excessive laxity, up to 12 cm can be taken. The crescent is completed posteriorly, reaching the gluteal crease almost to the ischial tuberosity. Fat is recruited beyond the skin island, predominantly from the inferior border medially and posteriorly ( Fig. 35.10 ). The original description was to take a cutaneous skin paddle centered over gracilis, but in our experience skewing the flap design more posteriorly helps with fat recruitment, concealing the scar in the medial thigh and infra-gluteal crease and reduces the possibility of injury to the lymphatic tissues.

Patient positioning

The patient is positioned supine on the operating table, the whole thigh is prepared and abducted with the hip and knee flexed during the procedure with the operating surgeon standing on the contralateral side to flap harvest ( Fig. 35.11 ).

Tip

The leg is free-draped such that this can be moved during the procedure to aid harvest and closure of the flap (see Fig. 35.11 ).