Techniques of mastectomy

tips and pitfalls

Introduction

Mastectomy is used to treat approximately 35% of all breast cancers. The procedure can be accomplished using one of a wide variety of techniques, depending on the clinical setting. Any mastectomy should be sensitive to the aims and principles of oncoplastic breast surgery, namely that optimal treatment of the malignancy should be achieved with minimal impact on quality of life.

Techniques of mastectomy are largely not evidence based. A few small trials exist but much of what is described in this chapter is based on reports of case series, expert opinion and personal preference. It is not intended to be prescriptive or dogmatic but merely a description of an approach to a commonly performed operation. Factors such as breast size, physical activities, preference for certain clothes (necklines) and expectations are all important discussion points that may influence choice of technique in many situations.

General considerations

The patient may have risk factors for poor wound healing, which include:

• previous radiotherapy;

• previous surgery to the breast;

• severe comorbidities.

Of these, smoking is the most commonly encountered factor that can be improved to optimise outcome within the timescale of the urgent case. This and other factors may affect technique selection.

There are more than 4000 chemicals present in cigarette smoke, including nicotine and carbon monoxide.¹ One effect of nicotine is to cause vasoconstriction of the dermal–subcutaneous vascular plexus. This has important consequences, as mastectomy flaps rely on this plexus for survival.² As well as inducing a hypoxic state and causing vasoconstriction, smoking can lead to increased platelet aggregation, which results in the formation of tiny thromboses in capillaries. This is detrimental to wound healing, which relies heavily on blood flow in newly formed capillaries. Smokers have higher levels of fibrinogen and haemoglobin, which increase blood viscosity, which further increases the likelihood of blood clotting, and blood velocity can be reduced by up to 42% in smokers.³ The combination of decreased oxygen delivery to tissues and the thrombogenic effects of smoking, together with increased viscosity and reduced velocity, explain why wound healing in smokers is significantly impaired.

The link between smoking and wound healing was first documented in the 1970s. One study of 425 patients undergoing mastectomy and breast-conserving surgery identified smoking as an independent predictor for wound infection and skin necrosis regardless of the number of cigarettes smoked.⁴

Another study of 716 patients having free transverse rectus abdominis myocutaneous (TRAM) flaps showed mastectomy flap necrosis, abdominal flap necrosis and abdominal hernias were significantly higher in smokers.⁵ This study did demonstrate a dose effect with smokers who had a history of more than a pack a day for 10 years being at increased risk of developing problems compared with smokers who had smoked for a smaller number of pack years (55.8% vs. 23.8%). One observation in this study was that delayed breast reconstruction in smokers was associated with a significantly lower rate of wound complications compared with immediate breast reconstruction in smokers. The risk of wound complications in delayed reconstructions in smokers was similar to the rate in non-smokers. Complications were also less common in women who stopped smoking 4 or more weeks before surgery.

There was one small study of 108 patients investigating smoking cessation prior to surgery that was a randomised clinical trial with 40 patients in the control group and 68 patients in the interventional group.⁶ Patients assigned to intervention were given counselling and nicotine replacement therapy. This study showed a significant reduction in complications in the intervention group, with a reduction in both wound-related complications and the need for secondary surgery.

In this study patients stopped smoking 6–8 weeks before surgery and did not smoke for 10 days after the operation. In the literature there is no consensus on the optimal duration of preoperative smoking cessation but there is evidence from a variety of studies that there are potential benefits from even a brief period of abstention. Part of the problem is that the majority of studies are retrospective and have inherent weaknesses in their design.

Considerations for simple mastectomy

In addition to general considerations, four questions should be answered:

1. Is it necessary/desirable to excise skin overlying the cancer?

In principle, skin only requires to be excised if the cancer is involving the skin or is so close that a clear margin cannot clearly be achieved around the cancer without skin resection.

2. Is there likely to be a lateral dog ear/redundant tissue?

The all too frequently seen but completely avoidable complication of mastectomy is redundant tissue, also known as a dog ear, which is unsightly, causes difficulty with bra fitting and often chafes on the prosthesis, arm or bra (Fig. 5.1).

Figure 5.1 Poor result from mastectomy.

3. Would the patient benefit from a contralateral breast reduction?

This is a simple and very effective option to enable women with a heavy breast to wear a lighter prosthesis and feel less unbalanced (Fig. 5.2a). In some cases a woman may choose a bilateral mastectomy to achieve better overall symmetry.

Figure 5.2 (a) A low mastectomy scar with contralateral reduction. (b) Delayed reconstruction with LD flap.

4. Is a delayed breast reconstruction planned?

The scar should be sympathetic to the method of delayed reconstruction planned. In most cases a low scar is best (as in Fig. 5.2a). It allows a flap-based reconstruction to be set at the inframammary fold, with the upper scar low enough to be hidden in low- neckline clothes (Fig. 5.2b).

Planning a mastectomy

• Examine the patient sitting up to assess lateral tissue and plan the likely lateral end of scar. The predicted lateral extent of the incision can be marked.

• The extent of the scar is important if radiotherapy is planned as the whole scar will be covered and can result in large volumes of tissue being treated if the scar extends a long distance posteriorly.

• Mark any skin that needs to be removed over the cancer.

• Decide if a second incision is required for sentinel node biopsy (usually not necessary).

Technique

Most scars can be based around the inframammary fold (IMF). The incision pattern is drawn in theatre initially with a line at or just below the IMF (in women with any intertrigo the scar should be placed below this). Then with repeated upward and downward movement of the breast the planned transposition of this line on the breast skin can be marked (Fig. 5.3). In most cases the upper incision line passes a little above the areola. Attention should be paid to the degree of tension applied to the upward or downward breast movement as this represents the tension that will be exerted on the wound on closure. The upper and lower incision lines should be planned so that they meet comfortably but without excess laxity. Incisions should be planned to avoid any dog ear. To achieve this it is often best to continue the incision along the bra line laterally, curving up slightly until the upper and lower lines meet (Fig. 5.4) or, if there is doubt about how to fashion the lateral end, stop the incision at the lateral edge of the breast and fashion it once the mastectomy is complete, before closure (see comments regarding dog ear below). Transverse mastectomy scars are commonly used but rarely, if ever, can be closed without significant excess of tissue, particularly laterally. It is beholden on all surgeons to be familiar with a range of mastectomy incisions and given that there are always better alternatives, transverse mastectomy scars should be avoided.