Prophylactic antibiotic-loaded cement, absorbable and non-absorbable, for implant-based breast reconstruction

Authors: Nguyen A, Leach GA, Ahmed S, Clark RC, Sorice SC, Nazerali RS, Hassanein AH, Reid CM.

Affiliation: University of California San Diego; Indiana University; Stanford University.

Journal: Aesthetic Surgery Journal, accepted 2025

PMID: pending

Key takeaways

• In 295 tissue expander reconstructions, infections occurred in 7 breasts (2.4%); only 1 (0.3%) occurred after 6 weeks.

• Infection rates were similar between PMMA plates (4.3%) and calcium sulfate (CS) beads/discs (1.5%); difference not significant.

• CS was associated with lower wound dehiscence (0% vs 3.2%), less mastectomy flap necrosis (4.0% vs 13.9%), and fewer returns to the OR (4.7% vs 17.7%).

• No postoperative oral antibiotics were given; low infection rates suggest local delivery may safely replace routine oral prophylaxis.

Background

Periprosthetic infection after implant-based reconstruction is common and may lead to explantation. Local antibiotic delivery (via PMMA or CS) can extend pocket antibiotic exposure beyond the early postoperative period without systemic side effects.

Objective

Evaluate the efficacy and safety of prophylactic antibiotic-loaded cement—non-absorbable PMMA vs absorbable CS—in reducing infections in two-stage tissue expander reconstruction.

Methods

• Design/setting/level of evidence: Multi-institutional retrospective cohort; Level III.

• Time frame & surgeons: Consecutive cases November 2021–February 2025 by two surgeons at two institutions.

• Population: 189 patients, 295 breasts (two-stage tissue expander reconstructions). PMMA in 93 breasts (31.5%); CS in 202 (68.5%).

• Intervention/comparators:

  • PMMA plates loaded with vancomycin + tobramycin (non-absorbable).

  • CS beads/discs loaded with vancomycin + gentamicin (absorbable).

• Co-interventions: No postoperative oral antibiotic prophylaxis.

• Endpoints (90-day): Hematoma, infection (antibiotics ± operation), wound dehiscence, mastectomy flap necrosis, return to the operating room, implant loss.

• Statistical approach: Group comparisons and multivariable regression (odds ratios) assessing association of cement type with outcomes.

Results

• Any infection: 7/295 breasts (2.4%); 6 within 6 weeks (2.0%), 1 after 6 weeks (0.3%); mean onset 37 ± 18 days.

• By cement type: PMMA 4/93 (4.3%) vs CS 3/202 (1.5%), P = 0.21.

• Organisms cultured: Staphylococcus aureus (including penicillin-resistant), Staphylococcus lugdunensis, and Klebsiella oxytoca.

• Device loss: 4 explants (1.4%): 2 necrosis, 1 hematoma, 1 infection.

• Comparative safety signals (CS vs PMMA):

  • Wound dehiscence: 0.0% vs 3.2%, P = 0.03.

  • Mastectomy flap necrosis: 4.0% vs 13.9%, P = 0.004; adjusted OR for PMMA 3.43 (P = 0.047).

  • Return to the operating room: 4.7% vs 17.7%, P = 0.01; adjusted OR for PMMA 4.5 (P = 0.01).

  • Hematoma and implant loss: no significant differences.

• Context: Pre-intervention institutional infection rates were 6.1% and 16.7%; with local antibiotics and no postoperative orals, pooled rate was 2.4%.

Conclusion

Local antibiotic cement (PMMA or CS) during tissue expander reconstruction produced low infection and device-loss rates without oral antibiotics; CS showed fewer wound problems and fewer returns to the operating room than PMMA, with similar infection prevention.

Strengths & limitations

• Strengths: Multi-institutional cohort; clinically relevant endpoints; organism-level detail; regression adjusting for confounders.

• Limitations: No contemporaneous control without local antibiotics; potential selection and technique confounding; underpowered for small differences; later adoption of staging may bias comparisons toward CS.

Critiques and questions

• Causation vs association: The lower necrosis and return-to-OR rates with CS may reflect learning curve or patient population rather than an intrinsic material effect. A prospective, surgeon-balanced design is needed.

• Antibiotic choices and kinetics: The study mixes vancomycin + tobramycin (PMMA) with vancomycin + gentamicin (CS). Differences in aminoglycoside choice, elution, and geometry could alter coverage (e.g., S. lugdunensis, gram-negatives). Pocket-specific pharmacokinetics would clarify.

• Generalizability & next steps: Without a no-cement control, the absolute benefit over modern pocket prep plus perioperative IV antibiotics is uncertain. A multicenter randomized trial comparing standard care vs PMMA vs CS—with standardized flap-staging, drain policy, and an infectious-disease–guided no-oral-antibiotic pathway—would be practice-changing.

• Safety signals to monitor: CS resorption course and PMMA removal burden (comfort, contour) were not systematically measured; future work should include patient-reported chest wall discomfort and imaging artifacts.