D. R. Ziazadeh2, E. L. Kalbfell2, R. N. Matar2, S. Mauch2, L. R. Mohey2, J. L. Parker3, M. Melnik1,2 1Spectrum Health,Surgical Oncology,Grand Rapids, MICHIGAN, USA 2Michigan State University,College Of Human Medicine,Grand Rapids, MICHIGAN, USA 3Spectrum Health,Biostatistics & Research,Grand Rapids, MICHIGAN, USA
Introduction: Wide local excision is the current gold standard for patients diagnosed with histologically confirmed cutaneous melanoma. There is no published consensus on the infection rate for common melanoma surgeries. We set out to evaluate the rate of infection in adult patients in wide local excision of melanoma.
Methods: From 11/19/2011 to 11/18/2014, adult patients 18 years and older underwent wide local excision of melanoma at Spectrum Health. The primary outcome variable was presence or absence of infection at surgical site. Clinical patient characteristics and data were extracted from our local electronic medical record. Patients were propensity matched for age, gender, BMI, smoking status, autoimmune diseases, and diabetes yielding 21 well-matched pairs. Operative data collected included method of infection diagnosis, site and size of excision, procedures, complications, histological results and melanoma classification.
Results: A total of 200 patients were identified. Of these, 23 developed a post-operative infection (12.2%) after melanoma excision. Infection sites differed, with 12 occurring at the site of wide local excision, 10 at the site of lymph node biopsy, and one at the skin graft site. 60.8% of those infected were diagnosed clinically and 39.2% were culture confirmed. There was no significant difference in age (61±17 vs 58±17 yr), gender (61±49% vs 43±51% male), BMI (29±7 vs 33±9 kg/m2), history of smoking (35±48% vs 48±51%), autoimmunity (7±25% vs 4±21%), or diabetes (18±39% vs 22±42%) before propensity matching in non-infected vs infected patients. Table 1 summarizes pertinent operative factors and comorbidities on rates of infection after propensity matching. Infection rate varied by specialty: Surgical Oncology, 12.4% (19/153), Plastic Surgery, 8% (2/25), and General Surgery, 7.4% (2/27) respectively.
Conclusion: In wide local excision of melanoma, surgical time, excisional size, Breslow Thickness, and Clark Level provided equivalent clinical outcomes on the rate of infection. Future analysis is pending regarding the impact of histological stage/grade, LNB location, and wound closure on the rate of infection.
