The Role of Sentinel Lymph Node Biopsy in the Management of Merkel Cell Carcinoma: A Systematic Review and Meta-analysis.

Background: Merkel cell carcinoma (MCC) is a rare cutaneous malignancy with high metastatic potential. Sentinel lymph node biopsy (SLNB) is used to assess locoregional spread, facilitate staging, and inform prognosis. Positive nodal status is associated with higher recurrence rates and reduced overall survival. Methods: A systematic search was conducted. Eligible articles included patients diagnosed with MCC, who would be candidates for or who had SLNB. The Covidence tool was used for screening and data extraction, including additional treatments, disease-free survival, overall survival, and recurrence. Methodological quality was assessed using the Newcastle-Ottowa Scale criteria. Results: SLNB was associated with increased likelihood of completion lymphadenectomy (223 versus 41), regional radiotherapy (2167 versus 808), and systemic chemotherapy (138 versus 31). Overall survival for patients undergoing SLNB was 81% at 2 years, 75% at 3 years, and 72% at 5 years (odds ratio: 0.79). Hazard ratio for positive SLNB versus negative was 3.36 (P < 0.001). Five-year disease recurrence was 23.3% in patients undergoing SLNB. Conclusions: Lymph node metastases are associated with reduced overall survival and increased recurrence of MCC. Determining nodal status early can inform prognosis, facilitate staging, and determine need for adjuvant treatment. Adjuvant treatments are associated with reduced mortality and improved overall survival; SLNB is an important influencer of their use. Early prophylactic intervention should be considered in MCC in both positive and negative nodal status to improve overall outcomes. Widespread use of SLNB will allow more accurate assessment of the role of nodal status on adjuvant treatment and long-term outcomes.

Hand and Wrist trauma: Antimicrobials and Infection Audit of Clinical Practice (HAWAII ACP) protocol.

Aims: Hand trauma, consisting of injuries to both the hand and the wrist, are a common injury seen worldwide. The global age-standardized incidence of hand trauma exceeds 179 per 100,000. Hand trauma may require surgical management and therefore result in significant costs to both healthcare systems and society. Surgical site infections (SSIs) are common following all surgical interventions, and within hand surgery the risk of SSI is at least 5%. SSI following hand trauma surgery results in significant costs to healthcare systems with estimations of over £450 per patient. The World Health Organization (WHO) have produced international guidelines to help prevent SSIs. However, it is unclear what variability exists in the adherence to these guidelines within hand trauma. The aim is to assess compliance to the WHO global guidelines in prevention of SSI in hand trauma. Methods: This will be an international, multicentre audit comparing antimicrobial practices in hand trauma to the standards outlined by WHO. Through the Reconstructive Surgery Trials Network (RSTN), hand surgeons across the globe will be invited to participate in the study. Consultant surgeons/associate specialists managing hand trauma and members of the multidisciplinary team will be identified at participating sites. Teams will be asked to collect data prospectively on a minimum of 20 consecutive patients. The audit will run for eight months. Data collected will include injury details, initial management, hand trauma team management, operation details, postoperative care, and antimicrobial techniques used throughout. Adherence to WHO global guidelines for SSI will be summarized using descriptive statistics across each criteria. Discussion: The Hand and Wrist trauma: Antimicrobials and Infection Audit of Clinical Practice (HAWAII ACP) will provide an understanding of the current antimicrobial practice in hand trauma surgery. This will then provide a basis to guide further research in the field. The findings of this study will be disseminated via conference presentations and a peer-reviewed publication.

The cost of keeping warm: a relationship between a rise in the cost of domestic energy and burn injuries caused by personal heating equipment.

INTRODUCTION: During 2022-2023, the UK found itself in the midst of a domestic energy crisis, with the average domestic gas and electricity bill rising by 75% between 2019 and 2022. As a result, the use of hot water bottles, radiant heaters, and electric blankets increased. An unintended consequence of this may be an increase in burn injuries caused by misfortune, misuse, or the use of items in a state of disrepair. PURPOSE: The aim of this study was to explore any increase in referrals to a single burns centre in England for injuries caused by hot water bottles, radiant heaters, or electric blankets. METHODS: This was a retrospective study of a prospectively maintained database of referrals. All referrals between January 2022 and January 2023 were selected and compared with the same period from 2020-2021 (before the rise in energy prices). Referrals were screened for the terms "hot water bottle," "electric heater," "electric blanket," and "heater." Total referrals in each period, demographic data (age, gender), anatomical location and the mechanism of injury were compared between cohorts. RESULTS: We found a statistically significant increase in the number of burns relating to heating implements between 2020/21 and 2022/23, rising from 54 to 81 (p = 0.03) - a 50% increase in injuries. Injuries in working age adults increased significantly (52% to 69%, p < 0.05). The most frequently injured area was the leg (30%) followed by the hand (18%). The commonest type of injury described was scald (72%). We found a moderately-strong correlation between the number of referrals and the average cost of energy in 2022-23. CONCLUSION: The number of injuries sustained by people using personal heating equipment is significantly increasing, which correlated with the rise in domestic energy prices. The most affected demographic appears to be working age adults, with wider implications around lost work-time yet to be explored. Further prospective, population-based work is indicated to assess the strength of the correlation seen in this study.

The incidence and cost implications of surgical site infection following lymph node surgery for skin malignancy.

BACKGROUND: Lymph node surgery is commonly performed in the staging and treatment of metastatic skin cancer. Previous studies have demonstrated sentinel lymph node biopsy (SLNB) and, particularly, lymph node dissection (LND) to be plagued by high rates of wound complications, including surgical site infection (SSI) and seroma formation. This study evaluated the incidence of wound complications following lymph node surgery and provided the first published cost estimate of SSI associated with lymph node surgery in the UK. PATIENTS AND METHODS: A retrospective cohort study of 169 patients with a histological diagnosis of primary skin malignancy who underwent SLNB or LND of the axilla and/or inguinal region at a single tertiary centre over a 2 year period was conducted. Demographic, patient risk factor, and operation characteristics data were collected and effect on SSI and seroma formation was analysed. Cost-per-infection was estimated using National Health Service (NHS) reference and antibiotic costs. RESULTS: A total of 146 patients underwent SLNB with a SSI rate of 4.1% and a seroma incidence of 12.3%. Twenty-three patients underwent LND with a SSI rate of 39.1% and a seroma incidence of 39.1%. Seroma formation was strongly associated with the development of SSI in both the SLNB (odds ratio (OR) = 18.0, p < 0.001) and LND (OR = 21.0, p = 0.007) group. The median additional cost of care events and treatment of SSI in the SLNB and LND groups was £199.46 and £5187.04, respectively. CONCLUSION: SSI remains a troublesome and costly event following SLNB and LND. Further research into perioperative care protocols and methods of reducing lymph node surgery morbidity is required and could result in significant cost savings to the NHS.

Electrochemotherapy vs radiotherapy in the treatment of primary cutaneous malignancies or cutaneous metastases from primary solid organ malignancies: A systematic review and narrative synthesis.

BACKGROUND: Electrochemotherapy has gained international traction and commendation in national guidelines as an effective tool in the management of cutaneous malignancies not amenable to surgical resection. Despite this, no level 5 evidence exists comparing it to radiotherapy in the treatment of cutaneous malignancies. This systematic review aimed to examine the literature directly and indirectly comparing electrochemotherapy and radiotherapy in the treatment of primary cutaneous malignancies or cutaneous metastases from primary solid organ malignancies. MATERIALS & METHODS: The protocol for this review was registered on the PROSPERO International Prospective Register of Systematic Reviews with the protocol ID CRD42021285415. Searches of MEDLINE, Embase, CINAHL, CENTRAL and ClinicalTrials.gov databases were undertaken from database inception to 28 December 2021. Studies in humans comparing treatment with electrochemotherapy to radiotherapy and reporting tumour response with a minimum four week follow-up were eligible. Risk of bias was assessed using the ROBINS-I tool. Results are provided as a narrative synthesis. RESULTS: Two case series with a total of 92 patients were identified as relevant to this study. Both case series examined patients with cutaneous squamous cell carcinoma. One case series examined elderly patients with predominantly head/neck lesions. The other examined younger patients with predominantly limb lesions who had cutaneous squamous cell carcinoma directly attributable to a rare skin condition. CONCLUSION: There is little literature presenting comparative data for electrochemotherapy and radiotherapy in the treatment of primary cutaneous malignancies or cutaneous metastases. Included studies were marred by serious risk of bias particularly due to confounding. The inherent bias and heterogeneity of the included studies precluded synthesis of a consolidated comparison of clinical outcomes between the two therapies. Further research is required in this domain in the form of clinical trials and observational studies to inform guidelines for electrochemotherapy treatment.

Considerations for an ideal post-surgical wound dressing aligned with antimicrobial stewardship objectives: a scoping review.

OBJECTIVE: Most surgical wounds heal by primary or secondary intention. Surgical wounds can present specific and unique challenges including wound dehiscence and surgical site infection (SSI), either of which can increase risk of morbidity and mortality. The use of antimicrobials to treat infection in these wounds is prevalent, but there is now an imperative to align treatment with reducing antimicrobial resistance and antimicrobial stewardship (AMS). The aim of this review was to explore the published evidence identifying general considerations/criteria for an ideal post-surgical wound dressing in terms of overcoming potential wound healing challenges (including infection) while supporting AMS objectives. METHOD: A scoping review examining evidence published from 1954-2021, conducted by two authors acting independently. Results were synthesised narratively and have been reported in line with PRISMA Extension for Scoping Reviews. RESULTS: A total of 819 articles were initially identified and subsequently filtered to 178 for inclusion in the assessment. The search highlighted six key outcomes of interest associated with post-surgical wound dressings: wound infection; wound healing; physical attributes related to comfort, conformability and flexibility; fluid handling (e.g., blood and exudate); pain; and skin damage. CONCLUSION: There are several challenges that can be overcome when treating a post-surgical wound with a dressing, not least the prevention and treatment of SSIs. However, it is imperative that the use of antimicrobial wound dressings is aligned with AMS programmes and alternatives to active antimicrobials investigated.

Extracorporeal shockwave therapy for diabetic foot ulcers: a feasibility study.

OBJECTIVE: The purpose of this study was to assess the feasibility of delivering extracorporeal shockwave therapy (ESWT) to patients with diabetic foot ulcers (DFUs). It also aimed to explore any potential clinical effect of ESWT on wound healing and investigate whether ESWT offers any patient-reported benefits. METHOD: In this single-centre, mixed methods feasibility study, patients with a DFU who met the eligibility criteria underwent ESWT three times over a seven-day period. Primary outcome was feasibility of delivering the intervention. Secondary outcomes included wound size, number of DFUs healed at 12 weeks and quality of life (QoL). Semi-structured interviews explored participants' experience of undergoing ESWT. RESULTS: Of 106 patients screened, 24 (22.6%) were recruited. Following recruitment, two patients were withdrawn from the study with 22 patients included in the final analysis. The mean attendance at clinic was 90.9% and 65.1% for follow-up. The mean score for acceptability and tolerability was 9.86±0.48 (95% confidence interval (CI): 9.62-10.01) and 9.15±2.57 (95% CI: 7.87-10.42), respectively. There were no serious adverse events or side-effects. Of the DFUs, 45.5% healed during follow-up and QoL scores improved until eight weeks. Key themes identified from the qualitative interviews were: desire for fast healing; improved QoL; flexibility of new treatments; and accessibility of transport. CONCLUSION: This study has shown that it is possible to recruit and retain patents into a single-arm study of ESWT for DFUs. This study supports development of a large randomised control trial to determine the clinical and cost-effectiveness of ESWT for DFU healing.

Extracorporeal shockwave therapy compared with standard care for diabetic foot ulcer healing: An updated systematic review.

Emerging evidence suggests that extracorporeal shockwave therapy (ESWT) may improve time to DFU healing. The aim of this review was to appraise the evidence on role of ESWT in DFU healing and impact of different ESWT doses. Databases were searched for trials comparing ESWT plus standard care to standard care alone in participants with DFUs. Search results were reviewed by two independent reviewers. The Cochrane Risk of Bias 2 tool and GRADE approach was used to assess bias and certainty. The primary outcome was time to healing. The search identified 345 papers after duplicates removed. Six trials consisting of 471 participants were included. There was unclear or high risk of bias across all domains. Time to ulcer healing was probably shorter in patients treated with ESWT compared with standard ulcer care alone (GRADE: low certainty). Patients treated with ESWT were more likely to heal at 20 weeks post-ESWT compared with those treated with standard ulcer care alone (GRADE: low certainty). There was significant heterogeneity. ESWT remains a promising new treatment but the translation into routine clinical practice is still limited by the low certainty of evidence surrounding its effectiveness, case selection and optimum dose.

Long term outcomes of 'Christmas Tree' banding for haemodialysis access induced distal ischemia: A 13-year experience.

BACKGROUND: The reduction in distal arterial flow following arteriovenous fistula (AVF) creation can cause a perfusion deficit known as haemodialysis access induced distal ischemia (HAIDI). Various techniques have been advocated to treat this difficult problem with varying success. We present the long-term outcomes following a novel banding technique. METHODS: 46 patients in this cohort from 2008 to 2021 underwent a novel banding procedure using a Dacron™ patch shaped with one slit-end and saw-tooth edges (resulting in a 'Christmas-tree' pattern) to provide a ratchet mechanism to progressively constrict the fistula outflow. Real-time finger perfusion pressure monitoring allowed an accurate reduction in AVF flow whilst increasing distal arterial perfusion pressure. Baseline characteristic were recorded and Kaplan-Meier survival curves were obtained to calculate the post-intervention primary, assisted primary and secondary patency. RESULTS: 29 patients presented with rest pain and 11 presented with tissue loss due to distal ischemia. The post-intervention primary access patency was 100%, 98%, 78% and 61% at 30, 60 and 180 days and 1 year respectively. Complete resolution of symptoms was achieved in 74% (n = 34) of patients and a partial response needing no further intervention was achieved in 11% (n = 5) of patients. A Youden index calculation suggested that digital pressures of 41 mm Hg or lower in an open AVF were highly sensitive for symptomatic hand ischemia whereas pressures greater than 65 mm Hg ruled out distal ischemia. CONCLUSION: 'Christmas-tree' banding with on table finger systolic pressures is not only an efficacious and durable method for treating HAIDI but also preserves fistula patency.

The diagnostic test accuracy of telemedicine for detection of surgical site infection: A systematic review protocol.

Since the COVID-19 pandemic there has been a rapid uptake and utilisation of telemedicine in all aspects of healthcare. This presents a key opportunity in surgical site infection surveillance. Remote follow up methods have been used via telephone, with photographs and questionnaires for post-operative reviews with varying results. This review therefore aims to comprehensively synthesise available evidence for the diagnostic accuracy of all forms of SSI telemedicine monitoring. The protocol has been established as per both PRISMA-P (S1 Table) and the Cochrane handbook for reviews of diagnostic test accuracy. Medline, Embase, CENTRAL and CINAHL will be searched using a complete search strategy developed with librarian input, in addition to google scholar and hand searching. All study designs with patients over 18 and undergone a primarily closed surgical procedure will be eligible. Index tests will include all forms of telemedicine and a subgroup analysis performed for each of these. Comparative tests must include face to face review, and all reference standards will be included again for sub-group analyses. Search results will be screened by two investigators independently with a third providing consensus review on disagreements. Methodological quality will be assessed using the QUADAS-2 tool, first validated by two investigators as per the Cochrane handbook. Exploratory analysis will formulate summary receiver operating characteristic curves and forest plots with estimates of sensitivity and specificity of the included studies. Sources of heterogeneity will be identifying and investigated through further analysis. Potential benefits of telemedicine integration in surgical practice will reduce cost and travel time to patients in addition to avoiding wasted clinic appointments, important considerations in a peri-pandemic era. To avoid missed or further complications, there must be confidence in the ability to diagnose infection. This review will systematically determine whether telemedicine is accurate for surgical site infection diagnosis, which methods are well established and if further research is indicated.

Dermoscopy as an adjunct to surgical excision of nonmelanoma Skin lesions: a systematic review and Meta-analysis.

Background: Nonmelanoma skin cancers (NMSC) have an incidence of 152,000 cases per year in the United Kingdom (UK), which continues to rise. Incomplete excision rates for NMSC are estimated to be around 10 percent and result in patients having a higher risk of recurrence or having to undergo further treatment. Objective: The objective of our study was to determine whether the use of dermoscopy as an adjunct to clinical examination could improve the rates of incomplete excision in NMSC lesions. Methods: Electronic literature search of MEDLINE, EMBASE, and Cochrane Central databases plus manual reference checks of articles on dermoscopy use in surgery between inception and November 2020. Two levels of screening were used on 452 studies. A random effects model was used in the meta-analysis, with the DerSimonian-Laird method used to pool data. Results: A total of six fully extracted studies were included with a total of 592 patients; with five of these studies reported on basal cell carcinomas and one reported on squamous cell carcinomas. The odds ratio of incomplete excision when guided by dermoscopy was 0.29 (95%CI 0.25; 0.34). Heterogeneity was assessed with the I2 statistic and was found to be 0 percent. Limitations: The number of studies included was small, with three of the studies from the same authors. Studies included are nonrandomized and as such hold a significant risk of bias. Conclusion: Incomplete excision rates were reduced when using dermoscopy to mark surgical excision margins in comparison to naked eye evaluation alone.

Wound complications following surgery to the lymph nodes: A protocol for a systematic review and meta-analysis.

BACKGROUND: Malignancies that spread to the lymph nodes may be identified through surgical biopsy, and treatment of metastatic disease may be through lymph node dissection. These surgeries, however, may be associated with significant adverse outcomes, particularly wound complications, the true incidence of which remains unknown. Multiple studies have reported their individual rates of complications in isolation. The aim of this study will be to systematically evaluate data that presents the incidence of wound complications in patients undergoing these surgeries. METHODS: We have designed and registered a protocol for a systematic review and meta-analysis of studies presenting incidence data. We will search MEDLINE, EMBASE and CENTRAL for relevant articles. Meta-analysis will be undertaken to synthesise an overall incidence of surgical site infection, wound dehiscence, haematoma and seroma. Subgroup analyses will investigate the effects of anatomical location, primary malignancy and study design on pooled incidence. Risk of bias will be evaluated for each included study using bespoke tools matched to the study design. DISCUSSION: The results of this study will provide the incidence of wound complications and secondary complications following lymph node surgery. This will directly impact upon the consent process, and may influence the nature of future research studies aimed at reducing post-operative complications.

Diagnostic accuracy of telemedicine for detection of surgical site infection: a systematic review and meta-analysis.

The Sars-CoV-2 pandemic catalysed integration of telemedicine worldwide. This systematic review assesses it's accuracy for diagnosis of Surgical Site Infection (SSI). Databases were searched for telemedicine and wound infection studies. All types of studies were included, only paired designs were taken to meta-analysis. QUADAS-2 assessed methodological quality. 1400 titles and abstracts were screened, 61 full text reports were assessed for eligibility and 17 studies were included in meta-analysis, mean age was 47.1 ± 13.3 years. Summary sensitivity and specificity was 87.8% (95% CI, 68.4-96.1) and 96.8% (95% CI 93.5-98.4) respectively. The overall SSI rate was 5.6%. Photograph methods had lower sensitivity and specificity at 63.9% (95% CI 30.4-87.8) and 92.6% (95% CI, 89.9-94.5). Telemedicine is highly specific for SSI diagnosis is highly specific, giving rise to great potential for utilisation excluding SSI. Further work is needed to investigate feasibility telemedicine in the elderly population group.

The local physiological effects of a single-use topical negative pressure device in healthy volunteers: the PICO-1 study.

OBJECTIVE: This study aimed to investigate the effects of a single-use negative pressure wound therapy (sNPWT) device on tissue perfusion, oxygenation and pressure in the intact skin of healthy volunteers. METHOD: Healthy volunteers wore a PICO sNPWT device (Smith+Nephew, UK) on their right medial calf for one week. Perfusion, tissue oxygenation and tissue pressure were recorded in superficial and deep tissues over a period of seven days. At the baseline visit, measurements were recorded before and after dressing application without activation. Macrovascular flow and transduced needle pressure measures were recorded at 0 minutes, 30 minutes and 60 minutes after device activation. Superficial tissue perfusion and both oxygenation measures were recorded continuously over the hour following activation. All outcome measures were repeated at 24 hours and again after seven days, both with the dressing and following dressing removal. RESULTS: The device was associated with a measurable increase in perfusion of the limb in 12 healthy volunteers. Superficial tissue oxygenation adjacent to the dressing was reduced during wear, while deeper tissue demonstrated an increase in oxygenation levels. Superficial skin perfusion was observed to differ between skin overlying muscle and that overlying bone. Pressure in tissue underneath the dressing pad was increased throughout dressing wear and returned to baseline levels on dressing removal. CONCLUSION: sNPWT produced measurable changes in local physiology in healthy volunteers with intact skin, despite the absence of a wound. Effects may differ according to anatomical site and the composition of underlying tissues. Other factors that promote healing were not explored in this study. DECLARATION OF INTEREST: This study was funded by Smith+Nephew investigator-initiated grant IIS 684. The funder had no input into study design, conduct, analysis, manuscript preparation or dissemination. The authors have no conflicts of interest to declare.

Use of perioperative prophylactic antibiotics following excision of ulcerated skin lesions in the UK: a national, multispeciality survey of clinicians.

Skin cancer is the most common malignancy in the UK, and up to a third of lesions are ulcerated at the time of excision. Ulceration has been shown to increase the risk of developing surgical site infection following excision, with some studies finding infection rates of 33%. However, no specific guidelines for the use of antibiotic prophylaxis in such cases exist. We surveyed 129 clinicians (covering Dermatology, Plastic Surgery, Ear, Nose and Throat Surgery, and Oral and Maxillofacial Surgery) who all excise skin lesions on a regular basis. There was significant variability in their practice with regard to antibiotic prophylaxis, with 9% always prescribing them and 19% never prescribing them. Variation exists both among and between specialities. This variation increases the risk of antimicrobial resistance and shows a paucity of good clinical evidence, indicating that a well-designed clinical trial is needed to guide future practice.

Chlorhexidine versus povidone-iodine skin antisepsis before upper limb surgery (CIPHUR): an international multicentre prospective cohort study.

INTRODUCTION: Surgical site infection (SSI) is the most common and costly complication of surgery. International guidelines recommend topical alcoholic chlorhexidine (CHX) before surgery. However, upper limb surgeons continue to use other antiseptics, citing a lack of applicable evidence, and concerns related to open wounds and tourniquets. This study aimed to evaluate the safety and effectiveness of different topical antiseptics before upper limb surgery. METHODS: This international multicentre prospective cohort study recruited consecutive adults and children who underwent surgery distal to the shoulder joint. The intervention was use of CHX or povidone-iodine (PVI) antiseptics in either aqueous or alcoholic form. The primary outcome was SSI within 90 days. Mixed-effects time-to-event models were used to estimate the risk (hazard ratio (HR)) of SSI for patients undergoing elective and emergency upper limb surgery. RESULTS: A total of 2454 patients were included. The overall risk of SSI was 3.5 per cent. For elective upper limb surgery (1018 patients), alcoholic CHX appeared to be the most effective antiseptic, reducing the risk of SSI by 70 per cent (adjusted HR 0.30, 95 per cent c.i. 0.11 to 0.84), when compared with aqueous PVI. Concerning emergency upper limb surgery (1436 patients), aqueous PVI appeared to be the least effective antiseptic for preventing SSI; however, there was uncertainty in the estimates. No adverse events were reported. CONCLUSION: The findings align with the global evidence base and international guidance, suggesting that alcoholic CHX should be used for skin antisepsis before clean (elective upper limb) surgery. For emergency (contaminated or dirty) upper limb surgery, the findings of this study were unclear and contradict the available evidence, concluding that further research is necessary.

The impact of surgical site infection on hospitalisation, treatment costs, and health-related quality of life after vascular surgery.

Surgical site infections (SSI) substantially increase costs for healthcare providers because of additional treatments and extended patient recovery. The objective of this study was to assess the cost and health-related quality of life impact of SSI, from the perspective of a large teaching hospital in England. Data were available for 144 participants undergoing clean or clean-contaminated vascular surgery. SSI development, length of hospital stay, readmission, and antibiotic use were recorded over a 30-day period. Patient-reported EQ-5D scores were obtained at baseline, day 7 and day 30. Linear regressions were used to control for confounding variables. A mean SSI-associated length of stay of 9.72 days resulted in an additional cost of £3776 per patient (including a mean antibiotic cost of £532). Adjusting for age, smoking status, and procedure type, SSI was associated with a 92% increase in length of stay (P < 0.001). The adjusted episode cost was £3040. SSI reduced patient utility between baseline and day 30 by 0.156 (P = 0.236). Readmission rates were higher with SSI (P = 0.017), and the rate to return to work within 90 days was lower. Therefore, strategies to reduce the risk of surgical site infection for high-risk vascular patients should be investigated.

Global incidence of incomplete surgical excision in adult patients with non-melanoma skin cancer: study protocol for a systematic review and meta-analysis of observational studies.

BACKGROUND: Non-melanoma skin cancer, which includes basal cell carcinoma and cutaneous squamous cell carcinoma, is the commonest malignancy worldwide. The mainstay of treatment is surgical excision. Despite this being an exceptionally common procedure, it is not known what the accepted standard is for incomplete excision. Multiple single-centre, regional and national studies have previously reported their incidence of incomplete excision in isolation. Furthermore, is it not known what effect potential risk factors such as the operating group, location of lesions, type of reconstruction, histological components or use of loupe magnification have on the incidence of incomplete excisions. The objective of this study will be to systematically evaluate observational data that present incidence of incomplete surgical excision amongst adult patients with non-melanoma skin cancer worldwide. METHODS: We designed and registered a study protocol for a systematic review and meta-analysis of descriptive epidemiology data. A comprehensive literature search will be conducted (from January 2000 onwards) in MEDLINE, EMBASE, Scopus, CINAHL, EMCare and Cochrane Library. Grey literature will be identified through searching Open Grey, dissertation databases (e.g. Open Access Theses and Dissertations) and clinical trial registers (e.g. WHO ICTRP). Observational studies (cohort, cross-sectional, case series and clinical audits) reporting the incidence of incomplete surgical excision and conducted in adult patients with non-melanoma skin cancer will be included. The primary outcome will be the incidence of incomplete surgical excision (defined as residual tumour at either the peripheral or deep margin). Secondary outcomes will be risk factors that may affect incomplete excision (e.g. operating group, location of lesions, types of reconstruction, histological components). Data will not be extracted if the study uses other surgical techniques such as Mohs micrographic surgery, intra-operative frozen section, incision, shave or punch biopsies. Two investigators will independently screen all citations, full-text articles and abstract data. Potential conflicts will be resolved through discussion. No limitations will be imposed on publication status or language of publication. The study methodological quality (or bias) will be appraised using an appropriate tool. If feasible, we will conduct a random effect meta-analysis of observational data. Incidence estimates will be stratified according to cancer type (e.g. basal cell carcinoma vs squamous cell carcinoma) and operating group (e.g. dermatology, plastic surgery and general practice). Additional analyses will be conducted to explore the potential sources of heterogeneity (e.g. methodological quality, sample size). DISCUSSION: This systematic review will summarise the best available evidence and definitively establish the incidence of incomplete surgical excision in non-melanoma skin cancer. It will determine if there is variation observed amongst different operating groups and provide some evidence for potential other factors causing this difference. This knowledge will provide a standard for future audits and will contribute to improving the treatment of non-melanoma skin cancer treatment. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019157936.