Thin Patients are at Higher Risk for Venous Congestion During DIEP Reconstruction

Purpose:Our previous study¹ showed increased suprascarpal fatpad thickness (>23 mm) is associated with increased Superficial Inferior Epigastric Vessel (SIEV) caliber. This study will correlate preoperative fatpad thickness with clinical outcomes. We hypothesize patients with increased suprascarpal fatpad thickness have a more dominant superficial venous draining system and will be more likely to require SIEV revascularization.

Methods:This is an IRB- approved retrospective study performed at NewYork-Presbyterian Hospital-Weill Cornell Medical College.  Female patients who underwent unilateral or bilateral DIEP flap reconstruction from 2011 to 2015 by a single surgeon were included, with each flap treated individually. Radiographic measurements of suprascarpal fatpad thickness and SIEV diameter were collected per hemi-abdomen from pre-operative abdominal CTA imaging. The following clinical outcomes were investigated: intra-operative venous congestion, SIEV usage, post-operative flap revision, flap fat necrosis, and total flap failure. Statistical analysis explored if suprascarpal fatpad thickness correlated with clinical outcomes.

Results: 95 patients, 166 DIEP flaps (63 bilateral, 24 unilateral, 8 stacked) were included.  Mean age at surgery was 51.4 years ± 9.6(35-75). Flaps had a mean 1.5 ± 1.0(0-4) lateral perforators and 0.5 ± 0.9(0-4) medial perforators. 7(4.2%) flaps exhibited venous congestion after initial revascularization, 4(2.4%) required intra-operative SIEV salvage revascularization. Mean suprascarpal fatpad thickness was 20.6mm ± 10.8(4.9-65.4), mean SIEV diameter was 2.8mm ± 0.7(1.5-5.7).  Only 6 of 7 patients with venous congestion had pre-operative CTA imaging available. Decreased suprascarpal fatpad thickness was significantly associated with increased rates of venous congestion (p=0.049), while total fatpad thickness and subscapral fatpad thickness were not (p=0.096; p=0.701). All 6 cases of venous congestion occurred in flaps with suprascarpal fatpad thickness less than 18mm (p=0.009), with a mean suprascarpal fatpad thickness of 13.5mm ± 2.9(9.7-17.6), mean SIEV diameter of 2.8mm ± 0.3(2.5-3.3). Venous congestion was not associated with other demographic variables (p>0.1). Patients were followed post-operatively for a mean 9.5 months ± 7.7(0-32). 16(9.7%) flaps developed fat necrosis, 7(4.2%) required return to OR for flap revisions. There were 0 cases of total flap failure.

Conclusions:  There is a significantly increased risk of venous congestion with thinner radiographic suprascapral fatpad thickness, specifically <18mm, suggesting that DIEP flap venous congestion is not related to dominance of the superficial draining system. We recommend SIEV dissection in all patients with suprascarpal fatpad thickness <18 mm.