Jon A. Mathy

Importance: Surgical site infections (SSIs) represent a costly and preventable complication of cutaneous surgery. However, there is a paucity of randomized clinical trials investigating antibiotic prophylaxis for reducing SSIs in skin cancer surgery, and evidence-based guidelines are lacking. Incisional antibiotics have been shown to reduce the rate of SSIs before Mohs micrographic surgery, but this represents a small subset of skin cancer surgery.Objective: To determine whether microdosed incisional antibiotics reduce the rate of SSIs before skin cancer surgery.Design, Setting, and Participants: In this double-blind, controlled, parallel-design randomized clinical trial, adult patients presenting to a high-volume skin cancer treatment center in Auckland, New Zealand, for any form of skin cancer surgery over 6 months from February to July 2019 were included. Patient presentations were randomized to one of 3 treatment arms. Data were analyzed from October 2021 to February 2022.Interventions: Patients received an incision site injection of buffered local anesthetic alone (control), buffered local anesthetic with microdosed flucloxacillin (500 µg/mL), or buffered local anesthetic with microdosed clindamycin (500 µg/mL).Main Outcomes and Measures: The primary end point was the rate of postoperative SSI (calculated as number of lesions with SSI per total number of lesions in the group), defined as a standardized postoperative wound infection score of 5 or more.Results: A total of 681 patients (721 total presentations; 1133 total lesions) returned for postoperative assessments and were analyzed. Of these, 413 (60.6%) were male, and the mean (SD) age was 70.4 (14.8) years. Based on treatment received, the proportion of lesions exhibiting a postoperative wound infection score of 5 or greater was 5.7% (22 of 388) in the control arm, 5.3% (17 of 323) in the flucloxacillin arm, and 2.1% (9 of 422) in the clindamycin arm (P = .01 for clindamycin vs control). Findings were similar after adjusting for baseline differences among arms. Compared with lesions in the control arm (31 of 388 [8.0%]), significantly fewer lesions in the clindamycin arm (9 of 422 [2.1%]; P < .001) and flucloxacillin (13 of 323 [4.0%]; P = .03) arms required postoperative systemic antibiotics.Conclusions and Relevance: This study evaluated the use of incisional antibiotics for SSI prophylaxis in general skin cancer surgery and compared the efficacy of flucloxacillin vs clindamycin relative to control in cutaneous surgery. The significant reduction in SSI with locally applied microdosed incisional clindamycin provides robust evidence to inform treatment guidelines in this area, which are currently lacking.Trial Registration: anzctr.org.au Identifier: ACTRN12616000364471

Background Skin grafting reflects a common dermatological procedure for closing skin defects. Patient education is important for managing expectation and optimising skin graft take. While health information is increasingly accessed on the internet, there are no existing studies assessing their quality. Methods The first 25 results from Google, Microsoft Bing and Yahoo! search engines using the term 'skin graft' were analysed using a variety of standard instruments. Readability was assessed using the Flesch-Kincaid Grade score (FKG), Gunning Fog Index (GFI), Simple Measure of Gobbledygook (SMOG) and the New Dale-Chall Readability Index (NDC). Reliability was assessed using the DISCERN instrument and credibility with the Journal of the American Medical Association Benchmark Criteria (JAMA). Transparency was identified by presence of the Health On the Net Foundation Code certification (HON-code). Results Seventy-five websites were identified. After exclusion, forty-three remaining websites were analysed with average FKG, GFI and SMOG scores of 7.8, 10.1 and 10.7, respectively. The average NDC was 5.9. The average reliability was fair with a DISCERN score based on the first 15 questions of the instrument of 42.6. The mean JAMA score was 2, and 9 websites displayed the HON-code certificate. Conclusions Readability, reliability and credibility of online health information regarding skin grafting can be improved. Health care providers should critically assess existing online patient information or develop alternative material to educate patients undergoing skin graft surgery.

Circulating tumour DNA (ctDNA) analysis promises to improve the care of people with cancer, address health inequities and guide translational research. This observational cohort study used ctDNA to follow 29 New Zealand (NZ) unresectable advanced-stage cutaneous melanoma patients through multiple cycles of immunotherapy, to identify the breadth and complexity of tumour genomic information that ctDNA analysis can reliably report. During the course of treatment, a high level of dynamic mutational complexity was identified in blood plasma of these patients, including: multiple BRAF mutations in the same patient, clinically-relevant BRAF mutations emerging through therapy, and co-occurring sub-clonal BRAF and NRAS mutations. The technical validity of this ctDNA analysis was supported by high sample analysis-reanalysis concordance as well as by concordance between three ctDNA measurement technologies: droplet digital polymerase chain reaction (ddPCR), a custom melanoma-specific amplicon next-generation sequencing (NGS) panel and mass spectrometry. In addition, we observed >90% concordance in the detection of ctDNA when using cell-stabilising collection tubes followed by 7-day delayed processing, compared to standard EDTA blood collection protocols with rapid processing. We also found that undetectability of ctDNA at a proportion of treatment cycles was associated with both clinical benefit (best RECIST response) and prognosis (disease-specific survival). In summary, we found that multiple ctDNA processing and analysis methods consistently identified complex longitudinal patterns of clinically-relevant mutations, adding support for expanded implementation of this technology to guide in-treatment tailored cancer therapy.

Backgrounds: Surgical site infections (SSIs) represent one of the most common and potentially preventable sources of morbidity and healthcare cost escalation associated with skin cancer surgery. There is a lack of data reporting organisms cultured from SSIs in skin surgery, with guidelines for antibiotic prophylaxis based on common skin pathogens rather than actual cultured organisms. In this study, we sought to define the cultured microbiology of SSIs specific to skin cancer surgery and test these against empiric treatment guidelines.Methods: All consenting patients presenting to the Auckland regional skin cancer treatment centre over a 6‐month period were included. Patients receiving any form of antibiotics within a week prior to surgery were excluded. All wounds were assessed postoperatively, with clinically significant infections identified as those with a standardized wound infection score of 4 (range 0–7) and/or prescribed post‐operative antibiotics within 3 weeks of surgery. Wound cultures were recorded.Results: About 104 clinically significant SSIs were identified from 333 lesions treated, with cultures available in 27%. Cultured organisms included MSSA (79%), MRSA (14%), coagulase‐negative Staphylococci (11%), and ‘skin flora’ (14%). Empiric guidelines inaccurately predicted effective treatment in 14% of cases, exclusively due to MRSA.Conclusion: To our knowledge this is the first comprehensive report of SSI microbiology following skin cancer surgery. The overwhelmingly predominant organisms were Staphylococcus sp. (76%), with the rate of MRSA approaching prevalence warranting empiric first‐line treatment. These data help inform effective rationalized empiric antibiotic treatment, when indicated, for optimal outcome following skin surgery.

Melanoma is the most lethal skin cancer. Excision biopsy is generally recommended for clinically suspicious pigmented lesions; however, a proportion of cut

Background Clinical audit is a critical quality improvement exercise, yet efficient audit tools are lacking. The main objective of this study was to evaluate a recently deployed database in facilitating the process of clinical audit, and the secondary objective was to evaluate the outcomes of free flap reconstruction of the head and neck at our centre. Methods A head and neck cancer‐specific database was customized to suit the needs of our head and neck multidisciplinary team. Data has been entered prospectively into this database since March of 2018. An audit of free flap reconstruction of the head and neck over a 12‐month period was performed using the database and analysed as a case study to examine its efficacy as a clinical audit tool. Additionally, the outcomes of free flap reconstruction at our centre were compared to those reported in the international literature. Results The database allows flexible and specific queries, analysis and export of data, and can provide immediate results. However, issues with data quality and completeness were identified. In this audit, the overall 30‐day complication rate and 30‐day mortality in patients undergoing free flap reconstruction of the head and neck were 58% and 3%, respectively. Conclusion The database is fit for its intended purpose as an audit tool. Outcomes of free flap reconstruction of the head and neck at our centre are comparable to those of institutions overseas.

Background: Both bone forearm infective nonunions represent a rare but functionally limb threatening condition. Method: We report a successful salvage of a severe near total both bone diaphysial osteomyelitis by conversion to a one-bone forearm with free fibula flap. A literature review on forearm salvage addressing both bone defects was performed. Results: Bony union was achieved at 4 months with a highly functional extremity salvage in our case. Conclusion: While very little prior experience has been reported for long segmental both bone forearm infected nonunions, we report of this highly satisfactory salvage using one-bone free tissue transfer strategy. We also provided our literature review with history, indication and evolution of individualized treatment options for this difficult surgical condition.