AAPS Home AAPS Annual Meeting
Annual Meeting Home
Program
Past & Future Meetings
 

Back to Annual Meeting Program


A Multivariate Logistic Regression Analysis of Complications Following Microsurgical Breast Reconstruction
Samir Rao, MD1, Ellen C. Stolle, BS1, Sara Sher, MD1, Lin Chun Wang, BS1, Bahram Momen, PhD2, Maurice Y. Nahabedian, MD1.
1Georgetown University Hospital, Washington, DC, USA, 2Univeristy of Maryland, College Park, MD, USA.

PURPOSE: Complications following microsurgical breast reconstruction have been examined for years. Most studies examining these complications are univariate analyses focusing on a specific risk factor and its impact on outcomes. A multivariate analysis takes into account several predictive variables simultaneously, offering the potential to model the risk factors and complications with more accuracy.
METHODS: We performed a retrospective review of all patients who underwent microsurgical breast reconstructions by the senior author (M.Y.N) between July 2005-July 2010. Patient records were analyzed for risk factors (age, BMI, smoking history, medical history, adjunct therapies, timing of reconstruction, type of reconstruction), and complications (hematoma, seroma, infection, wound dehiscence, PE, DVT, pneumonia, fat necrosis, leech use, partial flap loss, total flap loss.)
We then used the LOGISTIC Procedure of the SAS System (SAS 9.2, Carry, North Carolina) to relate the complications (dependent variables) and risk factors (independent variables). We used the STEPWISE option of the LOGISTIC procedure to select the explanatory variables with significant effects. The FREQ procedure of the SAS System was used to generate contingency tables and exact p-values if a cell within a contingency table was smaller than 5.
RESULTS: During the study perioid, 352 patients underwent 490 microvascular breast reconstructions. Average patient age was 49.6 years (range 27-74 years) and average BMI was 27.7 (range 19.0-47.0). The risk factor data is presented in Table 1 and complications data is presented in Table 2. Statisitically significant associations were identified between the risk factors and complications listed in Table 3.
Table 1. Risk factors & Reconstruction data (n=490)
Smoking
Non380
Active25
Former85
Diabetes24
Hypertension86
CAD5
Connective Tissue Disease10
Steroid Use3
Breast Cancer363
ASA Class
1309
2174
37
40
Chemotherapy
Pre-reconstruction182
Post-reconstruction37
Radiation
Pre-reconstruction151
Post-reconstruction9
Timing of Reconstruction
Immediate249
Delayed241
Unilateral Reconstructions214
Bilateral Reconstructions138
Side of Reconstruction
Left244
Right246
Flap Type
Free TRAM6
MS1 TRAM42
MS2 TRAM102
1 perforator DIEP223
2 perforator DIEP86
3+ perforator DIEP12
SGAP19

Table 2. Complications data (n=490)
Complication# of occurences%
Hematoma326.5%
Seroma71.4%
Infection214.3%
Wound dehiscence132.7%
PE30.6%
DVT00.0%
Pneumonia61.2%
Fat necrosis204.1%
Leech use122.4%
Partial flap loss40.8%
Total flap loss224.5%

Table 3. Statistically significant associations
Risk FactorComplicationp-valueOdds ratio95% Confidence Interval
Smoking (active)Seroma<0.0001365.9-193.9
Infection0.00814.31.3-14.1
Pneumonia<0.000117.13.3-89.9
Unilateral ReconstructionFat Necrosis0.008341.4-11.4

BMI is a continuous variable with a range of values, so odds ratios could not be calculated. However, a positive coefficient of 0.1617 for BMI indicates that as BMI increases, the chance of infection increases (p < .0001).
No other risk factors or reconstructive parameters listed in Table 1 were found to have statistically significant associations with complications listed in Table 2.
CONCLUSIONS: This study identified a statistically significant increase in seroma, infection, and pneumonia in active smokers undergoing microsurgical breast reconstructions. Additionally, fat necrosis was found to be more likely in unilateral reconstructions than bilateral reconstructions, likely from the use of Zone 3 and sometimes Zone 4 of the abdominal flaps, whereas bilateral reconstructions are restricted to a hemi-abdomen. Finally, the chance of infection was found to increase as BMI increases.


Back to Annual Meeting Program

 

Note to Visitors: The AAPS does not act as a clearing house for medical information, patient referral, or physician access.
© 2018 American Association of Plastic Surgeons. All Rights Reserved. Read the Privacy Policy.