British Journal of Surgery

Morris, Arthur; Roberts, Sally; Grae, Nikki; Frampton, Chris

doi: 10.1093/bjs/znaf159.007pmid: N/A

AimThe impact of surgical prophylaxis timing within the hour before incision on surgical site infection (SSI) rates is undefined. We analysed the SSI rates for timing within the hour before incision to see if there was evidence for an optimal timing to reduce SSIs.MethodWe analysed the SSI rates for hip and knee arthroplasty and cardiac surgery procedures from the prospective Health Quality and Safety Commission’s (HQSC) national Surgical Site Infection Improvement Programme (SSIIP)1,2. Procedures from 2014–2023 were included. Patients were followed for 90-days after surgery and USA CDC NHSN SSI definitions were applied. The SSI rates for 10-min time periods within the hour before incision were compared. Late prophylaxis was defined as given at, or after incision and early as more than 60 min before incision. Uni- and multivariable analysis were performed.ResultsThere were 102 211 procedures; 66 292 (65%) had the timing of antibiotic prophylaxis recorded in minutes versus incision time (48 912 arthroplasties and 17 380 cardiac). 99.8% were clean procedures and cefazolin was the prophylactic antibiotic for 95% of operations. After multivariable analysis the independent risk factors for SSI in orthopaedic surgery were male sex (odds ratio 1.5), BMI (OR up to 2.4 for BMI > 40), surgical risk score (OR 2.9 for score ≥2), and revision procedures (OR 1.9) and for cardiac surgery they were female sex (OR 1.5), BMI (OR up to 3.2 for BMI > 40), type of procedure (bypass procedures OR 2.7), and diabetes (OR 1.6). For cardiac surgery the SSI rates were not associated with prophylaxis timing, for arthroplasties the lowest SSI rate was for prophylaxis given 1–10 min before incision (1.0%) and after multivariable analysis prophylaxis given 51–60 min and >60 min before incision had higher risk for SSI, ORs 2.4 (95% c.i. 1.5–3.9) and 2.1 (95% c.i. 1.1–3.8) respectively. When all procedures were combined the lowest SSI rate was for prophylaxis given 21–30 min before incision, Table:TableTiming of cefazolin prophylaxis and surgical site infection rates in clean orthopaedic and cardiac surgeryTime (mins)No SSISSITotalSSI %OR95% c.i.P valueLate17113717482.121.441.02–2.030.051–10780713979461.751.180.96–1.450.1211–2018 90334219 2451.781.21.03–1.410.02521–3018 54027918 8191.48REF31–4010 11720610 3232.01.351.13–1.620.00141–50450612446302.681.831.48–2.27<0.00151–6024398625253.412.341.83–2.99<0.001Early10203610563.412.351.65–3.34<0.001Total65 043124966 2921.88The SSI rate for prophylaxis given 1–30 min before incision was 1.7%, for prophylaxis >30 min before incision the SSI rate was 2.4% (OR 1.5, 95% c.i. 1.3–1.7, P < 0.001). REF- Reference group (the group that the other times were compared to).ConclusionThe SSI rates for prophylaxis given >30 min before surgery appear higher than prophylaxis given within 30 min of incision. However, combination of all data was needed to show this. More outcome data are required before firm recommendations can be made for fine tuning of prophylaxis within the hour before incision. The finding may not be applicable to non-clean procedures and for non-cefazolin prophylaxis.

Groenen, Hannah; Bontekoning, Nathan; Hannink, Gerjon; Hollman, Marcus W; de Jonge, Stijn W; Boermeester, Marja A; Wolfhagen, Niels

doi: 10.1093/bjs/znaf159.011pmid: N/A

BackgroundIncisional prophylactic intra-operative wound irrigation (pIOWI) with an aqueous antiseptic solution effectively reduces surgical site infections (SSIs); however, data on the use of aqueous chlorhexidine gluconate are limited and no direct comparisons to aqueous povidone iodine exist. Recognising the efficacy of chlorhexidine gluconate in skin antisepsis, we investigated its use as an aqueous solution for pIOWI, hypothesising it might offer similar advantages. We therefore compare the efficacy of aqueous chlorhexidine gluconate with aqueous povidone iodine for incisional pIOWI in prevention SSI in elective abdominal surgery.MethodsA post hoc analysis of data from the randomised controlled EPO2CH trial was conducted including 699 patients to assess the effect of aqueous chlorhexidine gluconate compared to aqueous povidone iodine for incisional pIOWI on the incidence of SSI. Multiple imputation with chained equations were used to impute missing values. The association between type of irrigation and SSI was assessed using inverse probability of treatment weighted logistic regression.FindingsWeighted regression analysis showed a lower SSI rate [−3.03%, 95% c.i. −7.04 to 0.98] for pIOWI with aqueous chlorhexidine gluconate (4.05%) versus aqueous povidone iodine (7.08%) (number needed to benefit 33.0 (NNTH 102.0 to ∞ to NNTB 14.2). There was a lower SSI rate [−3.65%, 95% c.i. −7.47 to 0.17] for superficial and a higher SSI rate [0.62%, 95% c.i. −0.61 to 1.85] for deep SSIs for aqueous chlorhexidine gluconate compared to aqueous povidone iodine.InterpretationWhile SSIs are lower for incisional pIOWI with aqueous chlorhexidine gluconate than with aqueous povidone iodine, the results are not statistically significant, with wide confidence intervals, indicating uncertainty. Based on these results, we recommend the use of aqueous povidone iodine for pIOWI and advise caution when considering aqueous chlorhexidine gluconate, given concerns about its potential to induce resistance and its limited clinical data.

Membrilla-Fernández, Estela; Velasquez Orozco, Fernando; Lorente Poch, Leyre; González-Castillo, Ana María; Pelegrina-Manzano, Amalia; Cremona, Simone; Manzo, Elena; De Miguel Palacio, Maite; Gómez-Zorrilla, Silvia Inés; Esteban Cuco, Sandra

doi:

Dean, Harry; Kinross, James; Tozer, Phil; Wilson, Ana; Vaizey, Carolynne; Hoyles, Lesley

doi: 10.1093/bjs/znaf159.006pmid: N/A

AimSurgical site infection (SSI) is the most common complication following colorectal surgery with the incidence following surgery for intestinal failure (IF) exceeding 50%. SSI is associated with a range of patient morbidity and a 200% increase in associated costs. The role of individual strains of bacteria in the pathogenesis of SSI remains uncertain. Next-generation whole-genome sequencing (WGS) and detailed bioinformatic analyses allow advanced microbial tracking with strain-level detail. A retrospective analysis in our centre previously identified Enterococcus faecium (EF), Escherichia coli (EC) and Staphylococcus aureus (SA) as the most frequent organisms isolated from SSI samples following surgery for IF. The aim of this study was to test the hypothesis that SSI following surgery for IF results from strains of EF, EC and SA originating from the patient’s commensal microbiota.MethodsWe conducted a prospective, observational, cohort study of adult patients scheduled to undergo elective surgery for treatment of IF or enterocutaneous fistula (ECF) at a single quaternary referral centre between January and October 2022. Swabs were collected from each patient’s nose, mouth, skin, fistula, stoma and vascular access device preoperatively. An intraoperative fascial swab was collected prior to skin closure. Patients were followed assiduously for the development of SSI, diagnosed according to the Centre for Disease Control criteria. Samples were cultured for EF, EC and SA based on presumptive identification with mass spectrometry. Isolates were cryogenically frozen and processed for Illumina sequencing. Bioinformatic analysis included identification of genes predicted to encode virulence factors (VF) and antimicrobial resistance (AMR) genes.ResultsTwenty-one patients were recruited with a median age of 51.5. The most frequent aetiology of IF was surgical complications (9/21) followed by inflammatory bowel disease (7/21). 71% had an ECF and 14% underwent a concomitant abdominal wall reconstruction. The SSI rate was 71%. 161 swabs were collected from which 49 pure isolates were recovered for sequencing. Species identification by WGS was superior to laboratory mass spectrometry with 6 of the 49 pure isolates confirmed as species other than EF, EC or SA on species-level (kmer-based) analysis. In three patients, identical strains of EC and EF were found preoperatively across anatomical sites. However, no exact matches were found between patients or between preoperative, intraoperative or infective strains.EC SSI isolates were predicted to encode 48% more VFs than those recovered from preoperative samples (mean 35.4 versus 24.0 per isolate). The mean number of AMR genes predicted from the preoperative, intraoperative and postoperative isolates was 41, 29 and 43, respectively. EC isolates were predicted to encode the greatest number of AMR genes on average (58), followed by Klebsiella pneumoniae (37), Enterococcus faecalis (23), SA (20) and EF (15).ConclusionsThis is the most detailed analysis of SSI organisms following gastrointestinal surgery to date. Strains of EC, EF, SA and other species that are genetically distinct from patient’s commensal organisms emerge during infection of the surgical site. These strains display enhanced virulence and AMR potential. WGS allows superior characterisation of pathogenic strains involved in SSI compared to standard laboratory techniques.

Petit, N; Gomes, Ana; Gomes, Paula; Browne, S

doi: 10.1093/bjs/znaf159.019pmid: N/A

AimChronic wounds including diabetic foot ulcers (DFU) develop due to impaired healing mechanisms associated with chronic hyperglycaemia, leading to dysregulated inflammatory and angiogenic processes. This condition makes DFUs prone to chronicity and bacterial infection. This study aimed to develop a multifunctional hyaluronic acid (HyA)-based hydrogel to enhance cellular adhesion and provide localised antimicrobial activity to accelerate the healing of DFUs.MethodsHyA was chemically modified with acrylate groups (AcHyA) and crosslinked with polyethylene glycol (PEG) dithiol to form stable hydrogels1. Thiolated gelatin was conjugated to the AcHyA (AcHyA-G) to enhance cell adhesion and bioactivity, while the cysteine-terminated peptide PP4-3.1 was incorporated (AcHyA-G-PP4-3.1) for its antimicrobial properties2. The biophysical properties (storage modulus, swelling behaviour, degradation kinetics, and molecular diffusion) of the HyA hydrogels as a function of gelatin concentration were assessed, as well as the response of human dermal fibroblasts (hDFs) and iPSC-derived endothelial cells (iECs). The antimicrobial efficacy of AMP-conjugated AcHyA was assessed against Staphylococcus aureus.ResultsThe biophysical characterisation of AcHyA-G hydrogels revealed rapid gelation, elastic properties, a uniform mesh size, and consistent molecular diffusion across all formulations. Additionally, the presence of gelatin improved stability without altering the hydrogel’s degradation profile. AcHyA-G hydrogels effectively supported the adhesion and spreading of key wound repair cells (HDFs and iECs), with 0.5% gelatin identified as the optimal concentration. Furthermore, incorporating the AMP conferred bactericidal activity against S. aureus, the most prevalent bacteria found in DFU.ConclusionThe AcHyA hydrogels functionalised with gelatin and AMPs demonstrate promising potential as multifunctional wound dressings for DFUs. These hydrogels provide structural support, enhanced bioactivity, and localised antimicrobial effect. Future research will focus on evaluating gelatin and AMP-functionalised AcHyA hydrogels in pre-clinical wound models to evaluate their effectiveness and long-term potential in promoting the healing of chronic wounds.

Dean, Harry; Deputy, Mohammed; Drami, Ioanna; Aylin, Paul; Bottle, Alex; Kinross, James; Tozer, Phil; Wilson, Ana; Vaizey, Carolynne; Faiz, Omar

doi: 10.1093/bjs/znaf159.009pmid: N/A

AimColorectal surgery is the highest contributor of surgical site infection (SSI) of any surgical specialty in England. SSI is an important metric for patient safety, yet there is significant variability in its reported incidence following colorectal surgery. National data is offered voluntarily and only includes diagnoses made in hospital. Enhanced recovery programmes mean that SSI frequently presents in primary care after discharge, meaning the true incidence is likely to be underestimated by hospital data alone. Using routinely collected data to estimate SSI is a potential alternative to resource intensive surveillance strategies. Comprehensive data regarding the frequency, distribution and risk factors for SSI may improve the recognition of at-risk groups and enable more targeted and effective prevention strategies.MethodsA cohort of adult patients undergoing elective or emergency colorectal resection in England between 2014 and 2019 was identified. Patients were included from linked databases combining Hospital Episode Statistics (HES) data from NHS hospitals and Clinical Practice Research Datalink (CPRD) data from GP practices. Cases were stratified according to disease, operative and patient factors. The frequency of SSI was analysed using MedCodes or ICD-10 codes for wound infection within 30 days of surgery. A generalised estimating equation with clustering by GP practice was used to determine risk factors for SSI.Results59 376 patients were included in the final analysis, with a median age of 67; 51.3% were male. 59.6% of operations were open procedures and 67.3% of cases were elective. The commonest procedures were rectal/anterior resection (39%) and right hemicolectomy (38%). The most frequent indication for surgery was cancer (55%).The overall SSI rate was 8.3%, strikingly similar to that reported by the UK government (8.7%) over this time period1. 3770 (76.3%) SSIs were diagnosed in hospital and 1168 (23.7%) were diagnosed in the community. Patients who developed an SSI had a significantly longer hospital stay (12 versus 8 days; P < 0.001). Only 23.5% of patients diagnosed with SSI in primary care required readmission to hospital. On regression modelling, SSI was associated with smoking (OR 1.14, 95%c.i. 1.07–1.22), diabetes (OR 1.30, 95%c.i. 1.19–1.41) and diverticular disease (OR 1.47, 95%c.i. 1.33–1.66; all P < 0.001). Laparoscopic approach (OR 0.63, 95%c.i. 0.59–0.67; P < 0.001) and elective admission (OR 0.90, 95%c.i. 0.84–0.96; P = 0.002) were protective.ConclusionThis study represents the largest national analysis of SSI incidence following colorectal surgery across primary and secondary care to date. With the necessary automation and data flows, existing linked population databases could provide consistent feedback on SSI incidence. This could form the basis of a coordinated local and national surveillance programme for colorectal SSI. Further validation studies are needed to explore differences in SSI recording between primary and secondary care, as well as following elective and emergency surgery.

González-sagredo, Albert; López García, Paula; Iborra, Elena; Videla, Sebastian

doi: 10.1093/bjs/znaf159.014pmid: N/A

IntroductionSurgical site infection is one of the most frightening complications in vascular surgery, due to its high morbimortality. There are retrospective studies showing that intradermal sutures might be associated with lower infection rates, compared to staples. To our knowledge, no multicenter clinical trial has been published on this topic. The primary objective of the study is to assess if skin closure with intradermal sutures is associated with lower surgical site infection incidence, compared to staples, at 28 days after surgery.MethodsPragmatic open-label parallel-group multicenter randomized clinical trial. The study received the approval of the Ethics Committee (PR047/22) and the protocol was published in Medicine®. Patients undergoing arterial surgery through a femoral approach were randomized (1:1 ratio) to intradermal suture (experimental group) or metallic staples (control group). The sample size was 224 patients, assuming 80% power, 5% alfa error and 10% dropout. The statistical analysis was performed by intention-to-treat, with R® 4.1.0 Windows® (Core [2020]). The main variable was evaluated by Chi-square test and was estimated the relative risk and its confidence interval of 95%.ResultsA total of 113 patients were randomized to the control group and 112 to the experimental group. There were no significant differences regarding their basal characteristics. The cumulative incidence of surgical site infection at 28 days was of 5.3% (6/113, IC95%: 2.5–11.1) in the control group and 7.1% (8/112, IC95%: 3.7–13.5) in the experimental group (RR 1.35, IC95%: [0.48–3.75]; P-valor = 0.769).ConclusionIntradermal suture is not associated with a reduction in surgical site infection incidence for femoral approach compared to metallic staples.

Bontekoning, Nathan; Huisman, Hiske; Ali, Mahsoem; Groenen, Hannah; Jamaludin, Faridi; Wolfhagen, Niels; de Jonge, Stijn W; Kazemier, Geert; Geerts, Bart Franciscus; Boermeester, Marja A

doi: 10.1093/bjs/znaf159.005pmid:

Suarez Enriquez, Ana Belen; Serrano, Esteban Diaz; Sudol, Silvia Bilas; Fondevila Campo, Constantino; Prieto Nieto, Isabel

doi: 10.1093/bjs/znaf159.028pmid: N/A

BackgroundInguinal hernias are a common surgical condition, typically presenting with reducible abdominal contents. The incarceration or strangulation of bowel segments within the hernia sac can lead to serious complications, including bowel perforation. Caecal perforation in an inguinal hernia is an exceptionally rare presentation, often associated with delayed diagnosis and high morbidity. This clinical case highlights the diagnostic and surgical challenges of a perforated cecum and ascending colon in an inguinal hernia, emphasizing the importance of early recognition, the different clinical presentation compared to intra-abdominal perforations and prompt intervention in preventing life-threatening complications.Case Report57-year-old man, with a medical history of Ebstein anomaly with atrial septal defect corrected in childhood. Multiple admissions for decompensated heart failure, the last 3 with cardiogenic shock. He required a heart transplant in 2021, and since then is treated with Tacrolimus. He attended the Emergency Department presenting with increasing pain in the last 10 days of a previously asymptomatic right inguinoscrotal hernia, associated with foul-smelling exudate from the scrotal skin. The physical examination showed an incarcerated large right inguinoscrotal hernia complicated with a skin fistula pouring faecal content and a severe scrotal soft-tissue infection. Upon examination there was no abdominal tenderness. Blood tests showed leucocytosis and elevated C-reactive Protein. A CT-scan showed an indirect inguinoscrotal hernia complicated with ischemic and perforated intestinal content and exteriorized through a large skin defect. Emergency laparotomy was performed, revealing cecum and ascending colon herniation that presented 2 perforations within the hernia sac, which had faecal content that had fistulized to the scrotal skin. There was also localized fasciitis and right testicular necrosis, but no peritonitis or other intra-abdominal alterations were found. Right hemicolectomy with ileocolic anastomosis, hernia repair with intraperitoneal mesh, scrotal debridement and right orchiectomy was performed. The first 4 postoperative days required management in the ICU due to renal impairment and a single episode of haematochezia, treated with transfusion of 2 units of RBC, but no vasopressors were required and he did not present other complications. The patient was discharged on the 10th postoperative day and did not require new hospital admissions.Educational HighlightsCecal and ascending colon perforation within an inguinal hernia is an extremely rare. An extrabdominal and fistulised perforation, can present a subacute and less severe clinical course. Early recognition, as well as prompt surgical intervention are essential to prevent life-threatening complications such as sepsis, shock, and organ failure. In patients with preexisting comorbidities, particularly those on immunosuppressive therapy, timely intervention is crucial to improving outcomes.This case demonstrates the rare occurrence of cecal perforation within an inguinal hernia, which present unique diagnostic and treatment challenges.It highlights the importance of early recognition and intervention, especially in patients with complex medical histories.Additionally, it underscores the value of a multidisciplinary approach in managing complicated cases that involve abdominal and extra-abdominal infections, hernia and scrotal complications.

Casanova-Portolés, Daniel; Sancho, Joan; Membrilla, Estela; Rubiés, Carles; Vásquez, Laura M; Pujol, Miquel; Badia, Josep M

doi: 10.1093/bjs/znaf159.010pmid: N/A

IntroductionSurveillance of surgical site infection (SSI) relies on manual methods that are time-consuming and prone to subjectivity. This study evaluates the diagnostic accuracy of ChatGPT for detecting SSI from electronic health records after colorectal surgery via comparison with the results of a nationwide surveillance programme.MethodsThis pilot, retrospective, multicentre analysis included 122 patients who underwent colorectal surgery. Patient records were reviewed by both manual surveillance and ChatGPT, which was tasked with identifying SSI and categorizing them as superficial, deep, or organ-space infections. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Receiver operating characteristic (ROC) curve analysis determined the model’s diagnostic performance.ResultsChatGPT achieved a sensitivity of 100%, correctly identifying all SSIs detected by manual methods. The specificity was 54%, indicating the presence of false positives. The PPV was 67%, and the NPV was 100%. The area under the ROC curve was 0.77, indicating good overall accuracy for distinguishing between SSI and non-SSI cases. Minor differences in outcomes were observed between colon and rectal surgeries, as well as between the hospitals participating in the study.ConclusionsChatGPT shows high sensitivity and good overall accuracy for detecting SSI. It appears to be a useful tool for initial screenings and for reducing manual review workload. The moderate specificity suggests a need for further refinement to reduce the rate of false positives. The integration of ChatGPT alongside electronic medical records, antibiotic consumption and imaging data results for real-time analysis may further improve the surveillance of SSI