LAP flap reconstruction

What the operation is

A LAP flap — short for Lumbar Artery Perforator flap — is a relatively recent autologous breast reconstruction technique that uses skin and fat from the lower back (the “love handle” area), transferred to the chest with its own blood supply and reconnected under an operating microscope. Like DIEP and PAP, it is a perforator-based, muscle-sparing flap.

LAP is a second-line autologous option, used when the abdomen is not a suitable donor site. The choice between LAP and other second-line options such as PAP or gluteal flaps depends on individual donor-site anatomy, body habitus, and the experience of the reconstructive team. It is performed in fewer centres because it is technically demanding and the donor-site anatomy is more variable than for DIEP, but it offers a useful additional choice for patients who would otherwise have no autologous option.

When LAP is offered

LAP is considered when:

The abdomen is not a usable donor site — usually because of previous surgery, insufficient tissue, or anatomical reasons.
The thigh (PAP) is also not suitable — for example because of prior thigh surgery, insufficient tissue, or vascular reasons.
Tissue volume is needed in the lower back / love handle area that is consistent with what is wanted for the breast reconstruction.
The patient wants an autologous reconstruction despite the more limited donor-site options, rather than choosing implant-based reconstruction or aesthetic flat closure.

It is not a routine first choice. For most patients with autologous reconstruction in mind, DIEP is the preferred starting point when the abdomen is suitable. LAP and PAP are among the second-line options when the abdomen cannot be used — the best choice depends on your anatomy and the team’s experience.

How the operation works

The flap is taken from the lumbar region — the area between the iliac crest (the top of the pelvis) and the lower ribs at the back. Pre-operative imaging (CT angiogram or MRI) maps the lumbar artery perforators, which arise from the lumbar arteries that branch off the aorta. Three to four perforators are typically present on each side, with significant individual variability — which is one reason imaging is important.

The skin, fat, and one or more perforators are raised as a single unit, while the underlying muscle is preserved. Because the lumbar perforator vessels are short, the flap is usually anastomosed using vein grafts to extend the vascular pedicle so it reaches the recipient vessels in the chest. This is technically more demanding than DIEP or PAP and is one reason LAP is performed in a smaller number of specialist centres.

At the chest, the vessels are reconnected under an operating microscope, usually to the internal mammary artery and vein. The flap is shaped into the new breast contour and inset into the mastectomy cavity.

The lumbar donor site is closed with the skin advanced from above and below, leaving a horizontal scar across the lower back that sits roughly at the level of the underwear waistband.

What the operation involves

Anaesthetic: general anaesthetic.
Length of operation: typically 6–8 hours for unilateral; 10–12 hours for bilateral due to intraoperative repositioning.
Hospital stay: typically 5–6 nights.
Drains: chest drain and lumbar donor-site drain.
Microsurgery: the operation requires microsurgical capability, including expertise in vein-graft microsurgery. Performed jointly with a plastic-surgery colleague.
Sentinel lymph node biopsy is performed at the same operation if relevant.

LAP is a longer and more demanding operation than DIEP, both for the surgical team and for the patient. The recovery is correspondingly more involved.

Flap failure rates for LAP are higher than for DIEP — published UK and European series report total flap loss in the order of 6–10%, compared with around 1–2% for DIEP. This is one of the reasons LAP is reserved for cases where DIEP and PAP are not feasible.

Recovery

First two weeks — in hospital initially, then at home with drains. Sitting and lying are restricted in specific ways to protect the lumbar wound; specific positioning advice is given.
Weeks 2–4 — at home, gradually increasing mobility. Driving usually resumes around 5–6 weeks, gated by comfortable seated tolerance rather than by chest healing.
From around 6 weeks — return to desk-based work, depending on lumbar wound comfort when seated. Continuing attention to the lumbar wound; supportive garments may be recommended.
Three months — most physical activity resumed. The lumbar donor site usually settles by this point but may continue to feel different for several months.
One year — most patients are at their final outcome.

The lumbar donor site is the main practical recovery difference from other autologous flaps. Most patients tolerate it well; specific things — sitting, leaning back, certain forms of exercise — take longer to be comfortable than abdominal or thigh donor sites.

Cosmetic outcome and what to expect

The reconstructed breast has the natural feel and weight of body tissue, like other autologous reconstructions. LAP flaps usually provide enough volume for small-to-medium reconstructions, with the precise shape determined at the operation.
The lumbar scar is horizontal across the lower back, typically well hidden by underwear and most clothing. It is a long scar that fades over 12–18 months.
The lower back contour can change after LAP — most patients have a slight flattening of the love-handle area on the operated side. For unilateral LAP, mild contour asymmetry between the two sides of the lower back is possible. Bilateral LAP gives more symmetric results but is a larger operation.
Sensation in the lower back is reduced in the area of the flap; this often improves over months but may not return fully.

A revision at 6–12 months for breast shape, scar refinement, or lumbar contour is part of the usual reconstructive arc for some patients.

Common questions The questions patients ask first

Why is LAP not done more often?

Two reasons. First, DIEP and PAP cover most autologous patients, so LAP is needed only when both are unsuitable. Second, LAP is technically more demanding — the vascular pedicle is short and often needs vein grafting — so fewer centres offer it routinely. It is a useful option in the right hands but it is not a first-line choice.

Is LAP available in the UK?

Yes, in a small number of specialist centres with the microsurgical experience to perform it reliably. Within the practice, LAP is performed jointly with a plastic-surgery colleague who has specific training and experience in this flap.

Will my insurance cover LAP reconstruction?

Yes, where it is part of breast cancer treatment and the indication is clear. Pre-authorisation requires the procedure code and documentation that other autologous donor sites are not suitable in your case. The PA can liaise with your insurer.

How does the recovery compare to DIEP?

Recovery is similar in overall length but the donor-site experience is different — sitting, lying, and certain forms of bending are more affected by a lumbar wound than by an abdominal one. The chest part of the recovery is essentially the same. Total recovery time to full activity is typically 3–6 months, similar to DIEP.

Can I have LAP after a previously failed DIEP?

Possibly, depending on the chest-wall anatomy after the previous operation and the lumbar donor-site anatomy on the imaging. This is a case-by-case decision made jointly with the plastic-surgery colleague.

Is the result similar to DIEP?

The reconstructed breast itself is similar in feel and behaviour to a DIEP — autologous tissue, no implant, ages with the body. The donor-site outcomes are different (lumbar vs abdominal) and the operation is more demanding. The choice between LAP and other options is rarely about the reconstructed breast itself; it is usually about which donor sites are feasible.