Postoperative infections in Mohs micrographic surgery: Practicing antibiotic stewardship
Authors: Collin M. Costello, Yousif Yonan, Katie L. Kunze, Shari A. Ochoa
Journal: Journal of the American Academy of Dermatology (2021)

To the Editor: Antibiotic resistance continues to be a major threat to health care, and antibiotic stewardship will be a key step in preventing further resistance. Mohs micrographic surgery (MMS) is an outpatient surgical procedure that carries a <1% risk of postoperative infection.1Alam M. Ibrahim O. Nodzenski M. et al.Adverse events associated with mohs micrographic surgery: multicenter proscpective cohort study of 20,821 cases at 23 centers.JAMA Dermatol. 2013; 149: 1378-1385Crossref PubMed Scopus (97) Google Scholar We aim to characterize the choice of empiric antibiotic treatment in postoperative MMS infections.This study was approved by the Mayo Clinic Institutional Review Board. All MMS cases from January 2010 to December 2017 at Mayo Clinic in Scottsdale, Arizona were identified, a total of 6395 cases. All cases were performed by a single MMS surgeon. Of those, 30 had International Classification of Diseases codes for postoperative infection. Demographic, surgical, and postoperative infection complication data were obtained by chart review (Table I). Descriptive statistics were performed.Table IPostoperative infectionn (%)Tumor type Basal cell carcinoma13 (43.3) Squamous cell carcinoma17 (56.7)Tumor location Other head/neck19 (63.3) Scalp4 (13.3) Nose or ears3 (10) Upper extremities2 (6.7) Trunk1 (3.3) Lower extremities1 (3.3)No. of stages One17 (56.7) Two9 (30) Three1 (3.3) Four3 (10)Closure Primary26 (86.7) Flap3 (10) Skin graft1 (3.3)No. of allied staff present One12 (40) Two7 (23.3) Three10 (33.3) Four1 (3.3)Resident present Yes12 (40) Open table in a new tab A total of 30 patients developed a postoperative infection, a 0.47% infection rate. The mean age was 74.7 years (standard deviation 12.4 years) and 66.7% were male. One-third were immunosuppressed: 6.7% with transplantation and 26.7% with malignancy. The surgical site was prepped with chlorhexidine (76.7%), Techni-Care (Care-Tech Laboratories, Saint Louis, MO) (13.3%), and iodine (10%). Vaseline was the most common postoperative care (93.3%), followed by mupirocin (3.3%) and silver sulfadiazine (3.3%). No patients received prophylactic antibiotics after surgery. Later after an infection was suspected, all patients were cultured. Methicillin-sensitive Staphylococcus aureus (MSSA) was the most common cultured pathogen (76.7%), followed by methicillin-resistant S aureus (MRSA [10%]), other Gram-positive (6.7%), Pseudomonas aeruginosa (3.3%), and other Gram-negative (3.3%). Antibiotics prescribed included doxycycline (53.3%), cephalexin (23.3%), trimethoprim-sulfamethoxazole (16.7%), linezolid (3.3%), and ciprofloxacin (3.3%). Evaluating immunosuppressed patients, 90% had MSSA infections and none had MRSA infections.The overall infection rate is within the standard that has been previously reported. The most common pathogen was MSSA. MRSA made up only 10% of the infections; however, 73.3% of patients received antibiotics that empirically covered for MRSA. Further, doxycycline was the most commonly prescribed antibiotic; it has broad-spectrum coverage, including both MRSA and Gram-negative organisms. This suggests that antibiotic stewardship could be improved. Immunosuppressed patients were not at increased risk for MRSA infections.Significant strides have been made in antibiotic stewardship in dermatologic surgery, including an advisory statement for antibiotic prophylaxis and surgical site infection management.2Wright T.I. Baddour L.M. Berbari E.F. et al.Antibiotic prophylaxis in dermatologic surgery: advisory statement 2008.J Am Acad Dermatol. 2008; 59: 464-473Abstract Full Text Full Text PDF PubMed Scopus (159) Google Scholar Recommendations included culturing surgical site infections to determine antibiotic resistance and empiric treatment covering probable pathogens. Previous studies have found that preoperative assessment and treatment of S aureus carriers resulted in a decreased incidence of surgical site infections.3Tai Y.J. Borchard K.L. Gunson T.H. et al.Nasal carriage of Staphylococcus aureus in patients undergoing Mohs micrographic surgery is an important risk factor for postoperative surgical site infection: a prospective randomised study.Australas J Dermatol. 2013; 54: 109-114Crossref PubMed Scopus (41) Google Scholar,4Cordova K.B. Grenier N. Chang K.H. et al.Preoperative methicillin-resistant Staphylococcus aureus screening in Mohs surgery appears to decrease postoperative infections.Dermatol Surg. 2010; 36: 1537-1540Crossref PubMed Scopus (19) Google Scholar It remains unclear whether routine assessment of carrier status may result in more selective and judicious use of antibiotics. We suspect that most patients received empirical MRSA coverage to minimize the chance of undertreating possible MRSA and avoid changing antibiotic courses midtreatment when sensitivity results were finalized.The infection rate may be higher than the reported rate if patients presented to another institution for follow-up care.Based on our findings, we recommend routine bacterial culture and empiric narrow-spectrum coverage of MSSA for MMS surgical site infections, such as cephalexin or cefadroxil. Physicians should consider allowing culture results and susceptibilities dictate a transition to MRSA coverage. To the Editor: Antibiotic resistance continues to be a major threat to health care, and antibiotic stewardship will be a key step in preventing further resistance. Mohs micrographic surgery (MMS) is an outpatient surgical procedure that carries a <1% risk of postoperative infection.1Alam M. Ibrahim O. Nodzenski M. et al.Adverse events associated with mohs micrographic surgery: multicenter proscpective cohort study of 20,821 cases at 23 centers.JAMA Dermatol. 2013; 149: 1378-1385Crossref PubMed Scopus (97) Google Scholar We aim to characterize the choice of empiric antibiotic treatment in postoperative MMS infections. This study was approved by the Mayo Clinic Institutional Review Board. All MMS cases from January 2010 to December 2017 at Mayo Clinic in Scottsdale, Arizona were identified, a total of 6395 cases. All cases were performed by a single MMS surgeon. Of those, 30 had International Classification of Diseases codes for postoperative infection. Demographic, surgical, and postoperative infection complication data were obtained by chart review (Table I). Descriptive statistics were performed. A total of 30 patients developed a postoperative infection, a 0.47% infection rate. The mean age was 74.7 years (standard deviation 12.4 years) and 66.7% were male. One-third were immunosuppressed: 6.7% with transplantation and 26.7% with malignancy. The surgical site was prepped with chlorhexidine (76.7%), Techni-Care (Care-Tech Laboratories, Saint Louis, MO) (13.3%), and iodine (10%). Vaseline was the most common postoperative care (93.3%), followed by mupirocin (3.3%) and silver sulfadiazine (3.3%). No patients received prophylactic antibiotics after surgery. Later after an infection was suspected, all patients were cultured. Methicillin-sensitive Staphylococcus aureus (MSSA) was the most common cultured pathogen (76.7%), followed by methicillin-resistant S aureus (MRSA [10%]), other Gram-positive (6.7%), Pseudomonas aeruginosa (3.3%), and other Gram-negative (3.3%). Antibiotics prescribed included doxycycline (53.3%), cephalexin (23.3%), trimethoprim-sulfamethoxazole (16.7%), linezolid (3.3%), and ciprofloxacin (3.3%). Evaluating immunosuppressed patients, 90% had MSSA infections and none had MRSA infections. The overall infection rate is within the standard that has been previously reported. The most common pathogen was MSSA. MRSA made up only 10% of the infections; however, 73.3% of patients received antibiotics that empirically covered for MRSA. Further, doxycycline was the most commonly prescribed antibiotic; it has broad-spectrum coverage, including both MRSA and Gram-negative organisms. This suggests that antibiotic stewardship could be improved. Immunosuppressed patients were not at increased risk for MRSA infections. Significant strides have been made in antibiotic stewardship in dermatologic surgery, including an advisory statement for antibiotic prophylaxis and surgical site infection management.2Wright T.I. Baddour L.M. Berbari E.F. et al.Antibiotic prophylaxis in dermatologic surgery: advisory statement 2008.J Am Acad Dermatol. 2008; 59: 464-473Abstract Full Text Full Text PDF PubMed Scopus (159) Google Scholar Recommendations included culturing surgical site infections to determine antibiotic resistance and empiric treatment covering probable pathogens. Previous studies have found that preoperative assessment and treatment of S aureus carriers resulted in a decreased incidence of surgical site infections.3Tai Y.J. Borchard K.L. Gunson T.H. et al.Nasal carriage of Staphylococcus aureus in patients undergoing Mohs micrographic surgery is an important risk factor for postoperative surgical site infection: a prospective randomised study.Australas J Dermatol. 2013; 54: 109-114Crossref PubMed Scopus (41) Google Scholar,4Cordova K.B. Grenier N. Chang K.H. et al.Preoperative methicillin-resistant Staphylococcus aureus screening in Mohs surgery appears to decrease postoperative infections.Dermatol Surg. 2010; 36: 1537-1540Crossref PubMed Scopus (19) Google Scholar It remains unclear whether routine assessment of carrier status may result in more selective and judicious use of antibiotics. We suspect that most patients received empirical MRSA coverage to minimize the chance of undertreating possible MRSA and avoid changing antibiotic courses midtreatment when sensitivity results were finalized. The infection rate may be higher than the reported rate if patients presented to another institution for follow-up care. Based on our findings, we recommend routine bacterial culture and empiric narrow-spectrum coverage of MSSA for MMS surgical site infections, such as cephalexin or cefadroxil. Physicians should consider allowing culture results and susceptibilities dictate a transition to MRSA coverage. None disclosed.