Review links prior bariatric surgery to higher seroma and hematoma odds after abdominoplasty

What happened

A systematic review compared abdominoplasty complications among patients with and without a history of metabolic or bariatric surgery. The authors searched for observational studies available through April 15, 2025 and combined their comparative results in a meta-analysis.

The review included 27 studies, of which 26 were retrospective and one was prospective. Across the included literature, 6,328 patients had previously undergone metabolic or bariatric surgery. The analysis found higher pooled odds of seroma, which is a collection of fluid beneath the surgical area, and hematoma, which is a collection of blood.

The authors did not find a statistically clear difference between the groups for wound dehiscence, surgical-site infection, skin necrosis, fat necrosis, deep-vein thrombosis, or reoperation. In other words, the pooled estimates could not distinguish the groups for those endpoints. That is not proof that the risks were equal.

The researchers also examined possible risk factors within the post-bariatric group. Their study-level meta-regression associated a lower BMI at the time of abdominoplasty with more wound dehiscence. This was an association across the available studies, not evidence that lowering BMI causes a wound to separate.

What it means

The results make the risk discussion more specific than saying body contouring is simply more dangerous after bariatric surgery. In the pooled comparisons, the detectable excess was concentrated in seroma and hematoma. That can help patients and surgical teams focus on fluid collection, bleeding, wound care, nutrition, smoking, other medical conditions, and the operative plan during preparation and follow-up.

The review also shows why complication categories should be discussed separately. A patient may have one risk profile for fluid accumulation and another for infection, clotting, tissue injury, or repeat surgery. Individual estimates depend on the operation, health history, weight stability, laboratory findings, and the surgeon's assessment.

What it does not mean

The review does not show that bariatric surgery itself caused later complications. Nearly all included studies looked back at existing records, so the two patient groups may have differed in nutrition, amount of weight loss, comorbidities, smoking, surgical technique, or follow-up. Pooling those studies can improve precision, but it cannot remove every source of confounding or inconsistent outcome reporting.

The PubMed abstract does not provide absolute event rates or the pooled odds ratios. Without those values, the summary cannot tell a patient how many additional events occurred per 100 operations. A nonsignificant result for the other outcomes may also reflect limited data or imprecision rather than identical safety.

The unexpected BMI association should not be used as a target for gaining weight or scheduling surgery at a higher BMI. Meta-regression uses study-level patterns and can produce findings that do not hold for an individual. Timing and readiness should be decided with the bariatric and plastic-surgery teams.