Clinical classification and salvage of congestion crisis following free perforator flap transplantation

Objective To investigate the causes, degree and classification of congestion crisis following free perforator flap transplantation and summarize the related treatment strategies and clinical efficacy. Methods A retrospective case series study was made on 187 cases of congestion crisis after free perforator flap transfer from January 2006 to December 2015. There were 128 males and 59 females, with a mean age of 41.3 years(range, 9-68 years). Based on the area, characteristics, and progress of ecchymosis showing on the flap surface, the flap congestion was divided into type 1 (compensation type), type 2 (limited petechiae type), type 3 (scattered petechiae type) and type 4 (progressive petechiae type). Conservative treatments were applied to 109 cases including 37 cases of type 1, 68 type 2 and 4 type 3. Other 78 cases including 35 cases of type 3 and 43 type 4 underwent surgical revision. After exploration, 35 cases (45%) of type 4 were due to venous obstruction, 29 cases (37%) of type 3 due to arterial occlusion, and 14 cases (18%) consisting of 6 type 3 and 8 type 4 due to both arterial and venous obstruction. Flap survival or necrosis was detected after treatments. Results After conservative treatment, the flaps showed complete survival in 94 cases (86.2%), superficial partial necrosis in 13 (11.9%) and complete necrosis in 2 (1.8%). After surgical revision, the flaps with venous obstruction showed complete survival in 29 cases (83%), partial necrosis in 4 (11%) and complete necrosis in 2 (6%), the flaps with arterial obstruction showed complete survival in 17 cases (59%), partial necrosis in 3 (10%) and complete necrosis in 9 (31%), and the flaps with both venous and arterial obstruction showed complete survival in 8 cases (57%), partial necrosis in 4 (29%) and complete necrosis in 2 (14%). A total of 132 patients were followed up for 3-21 months (mean, 8.7 months). Texture and color of the fully salvaged flaps were similar to the non-crisis flaps, but it was tougher and darker in the salvaged flaps. Conclusions Venous obstruction or arterial insufficiency can lead to venous congestion in the flaps. Clinical classifications of congestion crisis in the free perforator flaps are objective that can assist surgeons to identify the causes and degree of congestion as well as contribute to an early accurate diagnosis and treatment for the congestion. Conservative methods are mainly used to save the congested flaps in type 1 or 2, and surgical revision is a preferred choice for the congested flaps in type 3 or 4. Key words: Soft tissue injuries; Surgical flaps; Perforator flaps