Moving Toward the Outpatient DIEP Flap: Factors Influencing Early Discharge

Authors: Graziano, Plotsker EL, Amakiri UO, Shammas RL, Vingan PS, Mehrara BJ, Stern CS, Nelson JA, Matros E, Allen RJ

Affiliations: Memorial Sloan Kettering Cancer Center

Journal: Plast Reconstr Surg, 2025.

PMID: 39737758

Key takeaways

• Among 278 unilateral DIEP patients, median length of stay (LOS) was 2.25 days; most were discharged on POD2.

• Longer LOS was linked to older age, longer operative time, history of diabetes or immunologic disease; longer operative time was also linked to delayed milestone completion.

• Implementing ERAS and switching the institutional goal from POD2→POD1 reduced median LOS (2.25→1.54 days) without complication increase; 51% met the new POD1 goal vs 82% meeting old POD2 goal; earlier discharge cohorts met milestones sooner.

Background

Discharge timing after DIEP is a multifactorial decision based on pain control, patient expectations, and monitoring for complications. Enhanced recovery after surgery (ERAS) protocols after DIEP flaps using TAP (transversus abdominis plane) blocks, multimodal analgesia/antiemetics, early mobilization, and explicit milestone education/posters have pushed patients toward shorter stays. Because most return-to-OR events have been shown to occur within 24 hours, properly selected patients may be safe for as short as a 24-hour hospital stay.

Objective

Evaluate current time to discharge and identify factors associated with prolonged LOS. Evaluate the safety/feasibility of a POD1 discharge goal versus POD2 within a mature ERAS program.

Methods

• Design/setting: Single-center retrospective cohort at Memorial Sloan Kettering; Level III.

• Cohort: 278 unilateral DIEP reconstructions (Jan 2021–Dec 2022). Grouped by actual discharge: POD0–1, POD2, POD≥3.

• Intervention: TAP blocks (exparel/marcaine/injectable saline), early ambulation, multimodal prophylaxis, clinical milestones (PT eval, flap health, pain, nausea/vomiting, vital signs, incisions, JP output) and educational milestones (drain care, use of lovenox, incision care, showering); goal changed from POD2→POD1 in Sept 2022.

• Variables of Interest: Demographics (age, race/ethnicity, smoking status, BMI, insurance type, travel distance, marital status), operative details (operative time, timing of reconstruction, ASA classification), comorbidities (diabetes, CVD, HTN, immunologic disease, COPD, psychiatric conditions)

• Endpoints: LOS, post-op complications, time to complete clinical, and educational milestones

Results

• LOS distribution: Median LOS 2.25 days; 8.9% POD0–1, 74.8% discharged POD2, 16.2% POD≥3; POD≥3 group with higher smoking incidence and greater operative time

• Predictors of longer LOS (multivariable): Increasing age β=0.01 days/year (P=0.037); increasing operative time β=0.09 days/hour (P<0.001); history of diabetes β=0.35 days (P=0.004); history of immunologic disease β=0.30 days (P=0.007).

• Milestones: Increased operative time was only variable associated with prolonged time to milestone completion (R²=0.11). Earlier discharge cohorts completed milestones earlier (Pearson’s correlation coefficient 0.524-0.585, p<0.001).

• Discharge-goal subanalysis: POD1 goal (n=35) vs POD2 goal (n=243)

  • Median LOS 1.54 vs 2.25 days; 51.43% vs 82.30% met goal; complication rates similar.

• Complications by actual discharge day: POD≥3 had higher rates of hematoma (13.3% vs 3.9%), delayed wound healing (4.4% vs 0%), mastectomy skin flap necrosis (8.9% vs 0.5%), and urgent-care visits (15.6% vs 5.3%) versus POD2.

• Microvascular safety: No returns to the OR for microvascular compromise among early discharges; flap failure not increased.

Conclusion

Within a mature ERAS program, LOS after unilateral DIEP is largely driven by operative time, age, diabetes, and immunologic disease; setting a POD1 goal shortens stay without increasing complications, but only about half of patients achieved POD1 discharge.

Strengths & Limitations:

• Uniform ERAS pathway with explicit milestone tracking; thorough multivariable modeling of LOS and milestone timing

• Retrospective single-center study design and small sample size with POD1-goal subgroup (n=35) and only 18 patients successfully discharged POD1; limit data quality and power to show differences between groups

• ERAS intervention is multi-part; difficult to attribute LOS reduction to any one specific sub-intervention

• This was a very healthy population with median BMI 27.2 and low rates of comorbidities. The median operative time 5.8 hours. Thus, these findings may not be widely applicable to comorbid patients or centers with longer operative times

Future directions

Prospective validation of a POD1 pathway with preoperative risk scoring (age, diabetes, immune disease) and explicit expectation-setting; define practical age thresholds, quantify cost benefits.

Clinical relevance

Can certainly aim for shorter hospital stays with implementation of ERAS, but important to risk-stratify preoperatively (age, diabetes, immunologic disease), optimize OR effiency/decrease OR time, and check institutional data to look at rate of microvascular complications beyond 24H to see if POD1 is safe target. For successful targeted discharge date, need to set firm, expectations with patients and staff and reinforce milestone education to support safe, early discharge.