The presence of skin bacteria in the sternal wound and contamination of implantation materials during cardiac surgery.

BACKGROUND: Sternal wound infections (SWIs) and aortic graft infections (AGIs) are serious complications after cardiac surgery. Staphylococcus aureus and coagulase-negative staphylococci are the most common causes of SWIs, whereas AGIs are less studied. AGIs may occur from contamination during surgery or postoperative haematogenous spread. Skin commensals, such as Cutibacterium acnes, are present in the surgical wound; however, their ability to cause infection is debated. AIM: To investigate the presence of skin bacteria in the sternal wound and to evaluate their potential to contaminate surgical materials. METHODS: Fifty patients undergoing coronary artery bypass graft surgery and/or valve replacement surgery at Örebro University Hospital from 2020 to 2021 were included. Cultures were collected from skin and subcutaneous tissue at two timepoints during surgery, and from pieces of vascular graft and felt that were pressed against subcutaneous tissue. The most common bacterial isolates were tested for antibiotic susceptibility with disc diffusion and gradient tests. FINDINGS: Cultures from skin had bacterial growth in 48% of patients at surgery start and in 78% after 2 h, and cultures from subcutaneous tissue were positive in 72% and 76% of patients, respectively. The most common isolates were C. acnes and S. epidermidis. Cultures from surgical materials were positive in 80-88%. No difference in susceptibility was found for S. epidermidis isolates at surgery start compared with after 2 h. CONCLUSION: The results suggest that skin bacteria are present in the wound and may contaminate surgical graft material during cardiac surgery.

Triclosan-coated sutures and sternal wound infections: a prospective randomized clinical trial.

Surgical site infection is a common complication following cardiac surgery. Triclosan-coated sutures have been shown to reduce the rate of infections in various surgical wounds, including wounds after vein harvesting in coronary artery bypass grafting patients. Our purpose was to compare the rate of infections in sternotomy wounds closed with triclosan-coated or conventional sutures. A total of 357 patients that underwent coronary artery bypass grafting were included in a prospective randomized double-blind single-center study. The patients were randomized to closure of the sternal wound with either triclosan-coated sutures (Vicryl Plus and Monocryl Plus, Ethicon, Inc., Somerville, NJ, USA) (n = 179) or identical sutures without triclosan (n = 178). Patients were followed up after 30 days (clinical visit) and 60 days (telephone interview). The primary endpoint was the prevalence of sternal wound infection according to the Centers for Disease Control and Prevention (CDC) criteria. The demographics in both groups were comparable, including age, gender, body mass index, and rate of diabetes and smoking. Sternal wound infection was diagnosed in 43 patients; 23 (12.8%) sutured with triclosan-coated sutures compared to 20 (11.2%) sutured without triclosan (p = 0.640). Most infections were superficial (n = 36, 10.1%), while 7 (2.0%) were deep sternal wound infections. There were 16 positive cultures in the triclosan group and 17 in the non-coated suture group (p = 0.842). The most commonly identified main pathogens were Staphylococcus aureus (45.4%) and coagulase-negative staphylococci (36.4%). Skin closure with triclosan-coated sutures did not reduce the rate of sternal wound infection after coronary artery bypass grafting. (clinicaltrials.gov: NCT01212315).

Bacterial growth and wound infection following saphenous vein harvesting in cardiac surgery: a randomized controlled trial of the impact of microbial skin sealant.

The aim of the present study was to compare microbial skin sealant versus bare skin on the leg regarding intraoperative bacterial presence in the surgical wound and time to recolonization of the adjacent skin at the saphenous vein harvesting site. A second aim was to evaluate the incidence of leg wound infection 2 months after surgery. In this randomized controlled trial, 140 patients undergoing coronary artery bypass grafting (CABG) between May 2010 and October 2011 were enrolled. Bacterial samples were taken preoperatively and intraoperatively at multiple time points and locations. OF the patients, 125 (92.6 %) were followed up 2 months postoperatively regarding wound infection. Intraoperative bacterial growth did not differ between the bare skin (n = 68) and the microbial skin sealant group (n = 67) at any time point. At 2 months postoperatively, 7/61 patients (11.5 %) in the skin sealant versus 14/64 (21.9 %) in the bare skin group (p = 0.120) had been treated with antibiotics for a verified or suspected surgical site infection (SSI) at the harvest site. We found almost no intraoperative bacterial presence on the skin or in the subcutaneous tissue, irrespective of microbial skin sealant use. In contrast, we observed a relatively high incidence of late wound infection, indicating that wound contamination occurred postoperatively. Further research is necessary to determine whether the use of microbial skin sealant reduces the incidence of leg wound infection at the saphenous vein harvest site.

EuroSCORE II and N-terminal pro-B-type natriuretic peptide for risk evaluation: an observational longitudinal study in patients undergoing coronary artery bypass graft surgery.

BACKGROUND: Postoperative heart failure remains the major cause of death after cardiac surgery. As N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a predictor for postoperative heart failure, the aim was to evaluate if preoperative NT-proBNP could provide additional prognostic information to the recently launched EuroSCORE II. METHODS: A total of 365 patients with acute coronary syndrome (ACS) undergoing isolated coronary artery bypass graft (CABG) surgery were studied prospectively. Preoperative NT-proBNP and EuroSCORE II were evaluated with regard to severe circulatory failure after operation according to prespecified criteria. To assess what clinical outcomes are indicated by NT-proBNP levels in different risk categories, the patients were stratified according to EuroSCORE II. Based on receiver operating characteristics analysis, these cohorts were assessed with regard to preoperative NT-proBNP below or above 1028 ng litre(-1). The follow-up time averaged 4.4 (0.7) yr. RESULTS: Preoperative NT-proBNP≥1028 ng litre(-1) [odds ratio (OR) 9.9, 95% confidence interval (CI) 1.01-98.9; P=0.049] and EuroSCORE II (OR 1.24, 95% CI 1.06-1.46; P=0.008) independently predicted severe circulatory failure after operation. In intermediate-risk patients (EuroSCORE II 2.0-10.0), NT-proBNP≥1028 ng litre(-1) was associated with a higher incidence of severe circulatory failure (6.6% vs 0%; P=0.007), renal failure (14.8% vs 5.4%; P=0.03), stroke (6.6% vs 0.7%; P=0.03), longer intensive care unit stay [37 (35) vs 27 (38) h; P=0.002], and worse long-term survival. CONCLUSIONS: Combining EuroSCORE II and preoperative NT-proBNP appears to improve risk prediction with regard to severe circulatory failure after isolated CABG for ACS. NT-proBNP may be particularly useful in patients at intermediate risk according to EuroSCORE II. CLINICAL TRIAL REGISTRATION: NCT00489827.

Bacterial recolonization of the skin and wound contamination during cardiac surgery: a randomized controlled trial of the use of plastic adhesive drape compared with bare skin.

BACKGROUND: Sternal wound infection after cardiac surgery is a serious complication. Various perioperative strategies, including plastic adhesive drapes, are used to reduce bacterial contamination of surgical wounds. AIM: To compare plastic adhesive drape to bare skin regarding bacterial growth in wound and time to recolonization of the adjacent skin intraoperatively, in cardiac surgery patients. METHODS: This single-blinded randomized controlled trial (May 2010 to May 2011) included 140 patients scheduled for cardiac surgery via median sternotomy. The patients were randomly allocated to the adhesive drape (chest covered with plastic adhesive drape) or bare skin group. Bacterial samples were taken preoperatively and intraoperatively every hour during surgery until skin closure. RESULTS: Disinfection with 0.5% chlorhexidine solution in 70% alcohol decreased coagulase-negative staphylococci (CoNS), while the proportion colonized with Propionibacterium acnes was not significantly reduced and was still present in more than 50% of skin samples. P. acnes was significantly more common in men than in women. Progressive bacterial recolonization of the skin occurred within 2-3 h. At 120 min there were significantly more positive cultures in the adhesive drape group versus bare skin group for P. acnes (63% vs 44%; P = 0.034) and for CoNS (45% vs 24%; P = 0.013). The only statistically significant difference in bacterial growth in the surgical wound was higher proportion of CoNS at the end of surgery in the adhesive drape group (14.7% vs 4.4%; P = 0.044). CONCLUSION: Plastic adhesive drape does not reduce bacterial recolonization. P. acnes colonized men more frequently, and was not decreased by disinfection with chlorhexidine solution in alcohol.

Cost analysis of re-exploration for bleeding after coronary artery bypass graft surgery.

BACKGROUND: Re-exploration for bleeding after cardiac surgery is an indicator of substantial haemorrhage and is associated with increased hospital resource utilization. This study aimed to analyse the costs of re-exploration and estimate the costs of haemostatic prophylaxis. METHODS: A total of 4232 patients underwent isolated, first-time, coronary artery bypass graft (CABG) surgery during 2005-8. Each patient re-explored for bleeding (n=127) was matched with two controls not requiring re-exploration (n=254). Cost analysis was based on resource utilization from completion of CABG until discharge. A mean cost per patient for re-exploration was calculated. Based on this, the net cost of prophylactic treatment with haemostatic drugs for preventing re-exploration was calculated. RESULTS: Patients undergoing re-exploration had higher exposure to clopidogrel before operation, prolonged stays in the intensive care unit, and more blood transfusions than controls. The mean incremental cost for re-exploration was €6290 [95% confidence interval (CI) €3408-€9173] per patient, of which 48% [€3001 (95% CI €249-€2147)] was due to prolonged stay, 31% [€1928 (95% CI €1710-€2147)] to the cost of surgery/anaesthesia, 20% [€1261 (95% CI €1145-€1378)] to the increased number of blood transfusions, and <2% [€100 (95% CI €39-€161)] to the cost of haemostatic drugs. A cost model, at an estimated 50% efficacy for recombinant activated clotting factor VIIa and a 50% expected risk for re-exploration without prophylaxis, demonstrated that to be cost neutral, prophylaxis of four patients needed to result in one avoided re-exploration. CONCLUSIONS: The resource utilization costs were substantially higher in patients requiring re-exploration for bleeding. From a strict cost-effectiveness perspective, clinical interventions to prevent haemorrhage might be underutilized.

Incidence, microbiological findings, and clinical presentation of sternal wound infections after cardiac surgery with and without local gentamicin prophylaxis.

Sternal wound infection (SWI) is a serious complication after cardiac surgery. In a previous randomized controlled trial, the addition of local collagen-gentamicin in the sternal wound before wound closure was found to significantly reduce the incidence of postoperative wound infections compared with the routine intravenous prophylaxis of isoxazolyl-penicillin only. The aims of the present study were to analyse the microbiological findings of the SWIs from the previous trial as well as to correlate these findings with the clinical presentation of SWI. Differences in clinical presentation of SWIs, depending on the causative agent, could be identified. Most infections had a late, insidious onset, and the majority of these were caused by staphylococci, predominantly coagulase-negative staphylococci. The clinically most fulminant infections were caused by gram-negative bacteria and presented early after surgery. Local administration of gentamicin reduced the incidence of SWIs caused by all major, clinically important bacterial species. Propionibacterium acnes was identified as a possible cause of SWI and may be linked to instability in the sternal fixation. There was no indication of an increase in the occurrence of gentamicin-resistant bacterial isolates in the treatment group. Furthermore, the addition of local collagen-gentamicin reduced the incidence of SWIs caused by methicillin-resistant coagulase-negative staphylococci. This technique warrants further evaluation as an alternative to prophylactic vancomycin in settings with a high prevalence of methicillin-resistant Staphylococcus aureus.

Influence of more than six sternal fixation wires on the incidence of deep sternal wound infection.

BACKGROUND: The aim of the present study was to examine the influence of the number of sternal fixation wires used on deep sternal wound infection rate and to analyze any possible interaction between this and local collagen-gentamicin prophylaxis evaluated in a previous trial. METHODS: The number of sternal fixation wires in all patients from one of two participating centers was counted. The patients were categorized according to six or fewer (standard technique, ST group) vs. seven or more wires (extra wires, XW group). RESULTS: The incidence of deep sternal wound infection was 4.2 % in the ST group and 0.4 % in the XW group ( P = 0.001). An analysis of the effect of local gentamicin, excluding the ST group from the analysis, showed an approximately 70 % reduction in sternal wound infection for all depths. CONCLUSION: This study supports the theory that additional fixation wires at the lower sternum actually reduce the incidence of deep wound infections. We suggest that a rigid sternal fixation is required to achieve the full benefit of local collagen-gentamicin prophylaxis.

Experiences of intentional carotid stenting in endovascular repair of aortic arch aneurysms--two case reports.

Endovascular repair of thoracic aneurysms has emerged as an attractive alternative especially in patients at high risk. However, the left common carotid artery limits the use of stent-grafts in aneurysms located in the aortic arch or close to the left subclavian artery. We report two cases with aneurysms in the distal arch and proximal descending aorta, where we have used a carotid stent in juxtaposition to an aortic stent-graft, to gain a longer proximal neck in the aortic arch in an attempt not to rely only on a by-pass graft feeding the left carotid artery.

Frostbite of the face and ears: epidemiological study of risk factors in Finnish conscripts.

OBJECTIVE: To determine the incidence of and the risk factors for local cold injuries of the face and ears in peacetime military service. DESIGN: Prospective, controlled epidemiological study using a questionnaire. SETTING: Finnish defence forces, 1976-89. SUBJECTS: 913 young male conscripts with local frostbite of the head that needed medical attention and 2478 uninjured control conscripts. MAIN OUTCOME MEASURES: Type of activity, clothing, and other risk factors at the time of cold injury. Odds ratios were used to calculate risk. Controls were handled as one group. RESULTS: The mean annual incidence of frostbite was 1.8 per 1000 conscripts. Frostbite of the ear was most common (533 conscripts (58%)), followed by frostbite of the nose (197 (22%)) and of the cheeks and other regions of the face (183 (20%)). Most conscripts (803 (88%)) had mild or superficial frostbite. Risk factors included not wearing a hat with earflaps (odds ratio 18.5 for frostbite of the ear); not wearing a scarf (odds ratio 2.1 and 3.8 for frostbite of the ear and cheeks respectively); using protective ointments (odds ratio 3.3, 4.5, and 5.6 for frostbite of the cheeks, ear, and nose respectively); being extremely sensitive to cold and having hands and feet that sweat profusely (odds ratio 3.5 for frostbite of the nose); and being transported in the open or in open vehicles under windy conditions (odds ratio 2.2 for frostbite of the cheek). CONCLUSIONS: Wearing warm clothing, including a scarf and a hat with earflaps, helps to prevent frostbite. Each person's sensitivity to cold may also be important. The routine use of protective ointments should not be recommended.

Instability in spondylolisthesis.

Anteroposterior translation as a sign of segmental instability was documented by traction-compression radiography in the majority of lumbar segments presenting lytic or degenerative spondylolisthesis with normal disc space height. Severity of lower back pain symptoms correlated with the degree of instability, but not with the amount of static spondylolisthetic displacement. Unstable spondylolistheses exhibited decreased viscoelastic behavior with creep, the degree of the vertebral displacement being dependent on the amount and duration of load. Disc degeneration and traction spurs seemed to be factors that may stabilize spondylolisthesis, even at an early age.

Functional radiography of the lumbar spine.

Functional methods utilising the effects of gravity on the upright lordotic spine were developed for both static and dynamic radiography. Static standing orthoradiography of the lumbar spine and weight-bearing joints of the lower extremities shows constitutional and functional abnormalities not visible in conventional recumbent radiography, e.g., postural scoliosis, hypo- or hyperlordosis, "kissing spine"-syndrome and signs of segmental instability. In dynamic traction-compression radiography segmental instability is provoked by axial traction and compression of the spine. With this method translatory instability of 5 to 15 mm was found in about half of the patients with lytic spondylolisthesis of L5 for which flexion-extension radiography had consistently failed to produce any abnormal movement. The amount of anterior spondylolisthetic and posterior retro-olisthetic instability correlated significantly with the severity of back pain symptoms, the degree of maximal static slip, however, being without significance. Functional radiography showed positive findings in most patients suffering from chronic low back pain of otherwise unknown aetiology.

Factors determining the preference of takeoff leg in jumping.

The takeoff (= push-off) leg in jumping, handedness, and leg length inequality as measured radiographically were recorded for 892 young healthy subjects, 62 of whom were top-level athletic jumpers, 654 competetive athletes representing other sports, and 176 Finnish Army conscripts. Correlation between the laterality of takeoff leg and handedness was poor, but a significant majority (81.4% of jumpers, 65.1% of other athletes, and 76.8% of conscripts) invariably used the longer leg for takeoff. Incidence of leg length inequality was highest in the group of athletic jumpers, the difference between top-level jumpers and runners being statistically significant.

Accuracy and precision of clinical estimation of leg length inequality and lumbar scoliosis: comparison of clinical and radiological measurements.

The results of 196 clinical determinations of leg length inequality and postural pelvic tilt scoliosis in 21 patients were analysed and compared with reliable radiological measurements. Clinical methods proved to be inaccurate and highly imprecise, the observer error being +/- 8.6 mm for direct and +/- 7.5 mm for indirect measurement of leg length inequality, and +/- 6.4 degrees for the estimation of postural lumbar scoliosis. More than half (53%) of the observations were erroneous when the criterion of leg length inequality was 5 mm. Failure to determine the presence or absence of length inequality of more than 5 mm occurred in 54 measurements (27% of the total). In 12% of the direct and in 13% of the indirect measurements, the observers erred in deciding which leg was longer; discrepancies occurred even when radiological reading gave a leg length inequality of as much as 25 mm.

Lower limb asymmetry and patellofemoral joint incongruence in the etiology of knee exertion injuries in athletes.

The association between different knee exertion injuries and lower limb malalignments was studied in 121 male athletes with knee exertion injuries and in 20 male athletes without knee symptoms. The associations between different malalignments was also analyzed. Leg length inequality (LLI), knee valgus, and different indexes of patellofemoral joint congruence were measured using radiological methods. Male athletes with patellar apicitis (n = 59) had significantly more LLI (P less than 0.001) and patella alta (P less than 0.05) than athletes without knee symptoms. The knee valgus was of the same numerical value in the shorter and longer leg sides in subjects with LLI of at least 5 mm (n = 58). A positive correlation was found between lateral patellar displacement (LPD) and patella alta (LT/LP) (P less than 0.001). Negative correlations were found between the sulcus angle (SA) and the lateral patello-femoral angle (LPA) (P less than 0.001) as well as between the LPD and the LPA (P less than 0.001).

Lumbar instability: a dynamic approach by traction-compression radiography.

Translatory segmental instability was provoked by successive axial traction and compression of the lumbar spine in 117 patients with a known spondyl- or retro-olisthetic displacement. Lateral spot radiography showed an anteroposterior translatory movement of 5 mm or more in 24 of 45 patients with lytic spondylolisthesis of L5, in all of 7 patients with degenerative spondylolisthesis of L4, and in 37 of 65 patients with a retro-olisthetic displacement of L3, L4, or L5. In cases of spondyl- and retro-olisthetic instability the upper vertebra moved posteriorly during traction and anteriorly during compression. Severity of low-back pain (LBP) symptoms did not show any correlation with the degree of the maximal displacement but correlated significantly with the amount of instability both in the case of spondyl- and retro-olisthesis. Traction-compression radiography proved a simple and practical method to diagnose and measure translatory segmental instability even when conventional flexion-extension load failed to provoke any abnormal movement (eg, in the case of spondylolisthesis).

The statics of postural pelvic tilt scoliosis; a radiographic study on 288 consecutive chronic LBP patients.

Standing orthoradiography of the lumbar spine, the hip and knee joints revealed a lateral lumbar curve of 5-22° (mean=9·0°, s.d.=4·2°) secondary to leg length inequality in 186 or 64·6% of 288 consecutive patients with chronic low back pain (LBP). The incidence of leg length inequality in LBP patients (mean=10·6mm, s.d.=6·7mm) was significantly higher (P<0·001) than in 366 asymptomatic controls (mean=5·1 mm, s.d.=2·4 mm). In 170 cases (91·4%), the lumbar curve was convex toward the short leg side, correlating significantly with the degree of lateral inclination of the sacrum (r=+0·97) and with the amount of leg length inequality (r=-0·81). The curvature was generally coupled with an axial rotation of the vertebrae moving the spinous processes toward the concavity, as well as with an opposite rotation of the pelvis (r=+0·77), which were calculated to result in a significant torsional stress on the L5-S1 segment.