CASE REPORT Persistent Seromas in Abdominal Free Flap Donor Sites After Postmastectomy Breast Reconstruction Surgery: Case Reports and Literature Review

Risk factors

Seroma formation is a common donor-site sequel after abdominal flap breast reconstruction, with reported figures of 2% to 10%.⁵ However, in practice, this is higher as seroma is often considered a minor complication and is thus underreported by patients and surgeons alike.⁵ Clinically most seromas last only a few weeks and either resolve spontaneously or by aspiration. The data are sparse for abdominal tissue breast reconstruction. Kim and Stevenson showed that cosmetic abdominoplasty seromas resolved after a mean of 2.5 aspirations.² In fact, it has recently been shown that the rate of seroma in DIEP flap surgery is even lower than abdominoplasy.⁶ In contrast, our patients required 3 to 17 aspirations (some of these following seroma sac excision), and their seromas persisted for an average of 12.7 months (range = 6–26 months). Several factors may have influenced this outcome.

The most frequently reported predisposing factors for seroma formation after the harvest of abdominal tissue are obesity and the use of SIEA flaps.^4,3 Another important risk factor is bilateral autologous tissue breast reconstructions, most probably because these patients usually have high BMIs and are prone to donor-site problems.⁴ All our patients were obese, they underwent bilateral reconstructions, and 2 of them had SIEA flaps. Although SIEA flaps are the quickest and least invasive method of obtaining an abdominal donor flap for breast reconstruction in patients with compatible anatomy,⁷ SIEA flaps have been associated with an increase in inpatient abdominal drain volume relative to DIEP flaps.³ There are no reports in the literature of the persistence of seromas beyond the early postoperative period of up to 6 weeks. Two of our 3 patients had undergone a SIEA flap, and a study comparing seroma persistence in DIEP and SIEA flap patients would be useful in determining whether this is an associated factor or not.

Raised BMI has been associated with an increased rate of donor-site complications following autologous microsurgical breast reconstruction.⁴ It is also a well-documented significant risk factor for seroma formation in latissimus dorsi flap breast reconstruction.⁸ The 3 patients in the present report were clinically obese (BMI ≥30) and would thus all be at an increased risk. It is also interesting that all our patients had bilateral breast reconstructions although this is not directly related to the abdominal donor site as the volume or quantity of tissue harvested is the same in bilateral and unilateral breast reconstructions albeit that only part of the resultant abdominal flap is used for the latter. It may be that bilaterality is merely a proxy for the size of the patient (high BMI).

Effects of persistent seromas on patient outcome

Persistent seromas create many problems for the patient and the healthcare system. First, they are a nuisance, both in terms of the patient having to take time off work and spend money on travel to and from the hospital; and in terms of using up valuable outpatient and inpatient hospital resources. As discussed earlier, these patients have repeated aspirations resulting in frequent outpatient clinic or dressing clinic attendances.

Second, if left untreated, seromas may lead to the formation of a “capsule” (the so-called pseudobursa), thus creating a secondary problem that must be treated surgically.⁹ Repeated skin puncturing for seroma aspiration may also lead to an infection of the fluid or surrounding tissues as happened in one of our patients following ultrasound-guided seroma fluid aspiration. Needle puncture can also cause bleeding into the seroma cavity, which was seen in 2 of the 3 patients; and in one such patient, repeated bleeding led to anemia needing a blood transfusion. These episodes of bleeding occurred spontaneously but in one case resulted from a traumatic fall onto the abdomen. Like anemia, repeated aspirations can lead to hypoproteinemia (because of loss of protein in the seroma fluid) with its consequent problems.

Prevention and treatment

These 3 cases highlight the possibility of seroma persistence for an inordinate amount of time and document possible complications. Thus where possible, patients at a high risk of forming persistent seromas should be counselled in how best to reduce their chances, for example, by reducing their BMI if this is feasible in the context of their cancer treatment. In addition, preventive measures such as the use of quilting sutures should be actively considered in such patients as the long-term benefits outweigh the immediate costs. Quilting reduces the incidence of seromas by minimizing the dead space intra- or postoperatively.¹¹ This is important as emphasized by Matarasso et al¹² and has been shown to be effective in Latissimus Dorsi flaps.¹³ However, quilting was not found to decrease seroma formation in TRAM flaps.¹⁴ Another technique for achieving this objective is to leave surgical drains in for a longer period, as is routinely done in the United States. However, quilting sutures have been shown to be most effective in abdominoplasty.¹⁵ Fibrin sealant has also been used for this.¹⁶ Other active interventions for the treatment of seroma could be undertaken earlier. Intraseromal steroid injections, useful in reducing reaccumulation of seroma in extended latissimus dorsi flaps,¹⁰ may present a simple, low cost, and safe method for reducing seroma incidence. In high-risk patients, it may be useful to undertake early “capsulectomy” (excision of the seroma sac), as these tend to be recalcitrant and promote seroma persistence.