Association of HbA1c and utilization of internal mammary arteries with wound infections in CABG

Background

Deep sternal wound infection (DSWI) remains a serious complication after coronary artery bypass grafting (CABG). We herein aimed to stratify diabetic patients who underwent CABG using bilateral internal mammary artery (BIMA) for levels of glycated hemoglobin A1C (HbA1c) and compare postoperative outcomes.

Methods

Between January 2010 and August 2020, 4,186 consecutive patients underwent isolated CABG at our center. In 3,229 patients, preoperative HbA1c levels were available. Primary endpoints were wound healing disorder (WHD), DSWI, and 30-day mortality. Patients were stratified according to preoperative HbA1c levels. Patients were further divided into subgroups according to utilization of BIMA.

Results

After adjustment, no differences in mortality and stroke rates were seen between group 1 (HbA1c < 6.5%) vs. group 2 (HbA1c ≥ 6.5%). WHD was more frequent in group 2 [2.8 vs. 5.6%; adjusted p = 0.002; adjusted odds ratio (OR), 1.853 (1.243-2.711)] but not DSWI [1.0 vs. 1.5%; adjusted p = 0.543; adjusted OR, 1.247 (0.612-2.5409)]. BIMA use showed a higher rate of WHD [no BIMA: 3.0%; BIMA: 7.7%; adjusted p = 0.002; adjusted OR, 4.766 (1.747-13.002)] but not DSWI [no BIMA: 1.1%; BIMA: 1.8%; adjusted p = 0.615; adjusted OR, 1.591 (0.260-9.749)] in patients with HbA1c ≥ 6.5%.

Conclusions

Intraoperative utilization of BIMA is not connected with an increase of DSWI but higher rates of WHD in patients with poor diabetic status and HbA1c ≥ 6.5%. Therefore, application of BIMA should be taken into consideration even in patients with poor diabetic status, while identification of special subsets of patients who are at particular high risk for DSWI is of paramount importance to prevent this serious complication.

[Mandibular fractures in cattle - a review of 108 cases]

INTRODUCTION

Mandibular fractures are among the most common fractures in cattle. The medical records of 108 cattle with a mandibular fracture, that were referred to the University of Zurich Veterinary Hospital from 2005 to 2019, were analysed to document the types of treatment, complications and long-term outcomes. Cattle, still alive at the time of retrospective analysis, underwent clinical and radiographic examinations. A fall was the single most common cause of a mandibular fracture (48,1 %), and a third of all cattle had a concomitant disease at the time of referral. Seventy-five cattle (69,4 %) had a single fracture, 26 (24,1 %) had two fractures and seven (6,5 %) had three fractures of the mandible. The molar part of the mandibular body was most commonly (40,7 %) fractured followed by the diastema (23,6 %), the pars incisiva (13,4 %), the ramus (12,1 %) and the symphysis (10,2 %) of the mandible. The majority of cattle (84/108, 77,8 %) had open fractures. Treatment was instituted in 63/108 animals (58,3 %) with 77/148 fractures. Of these fractures, 28 were treated with plate osteosynthesis, 25 with an external fixator, 8 with cerclage wire, 7 using mixed techniques, 4 with fragment excision, 4 underwent conservative treatment and one a mucosal suture. In total, 45/108 animals (41,7 %) were culled because of multiple fractures, concomitant diseases and because of economic reasons. Complications occurred in 34 (54,0 %) treated cattle; 22 had abnormal wound healing of which 18 developed osteomyelitis complicated by a sequestrum (14). Of the treated 63 cattle, 56 (88,9 %) were discharged. The mean postoperative productive life was 46 ± 29,2 months for animals that were deceased at the time of the study. Thirteen of the cattle with a sequestrum remained in the herd for 15 to 92 months (mean, 47 months) and one for 2 months. The life expectancy after treatment did not differ significantly from that of the Brown Swiss and Swiss Holstein dairy cattle populations, where the cattle of this study mainly came from. Eleven cattle were available for long-term follow-up; all had a good general health status but nine had dental abnormalities including missing teeth, steps or enamel points, which did not noticeably affect the body condition of the animals. Surgical treatment of selected mandibular fractures had a favourable prognosis (52/63 healed, 82,5 %) in cattle.

Seasonal impact on surgical site infections and wound healing disturbance in carpal tunnel surgery: A retrospective cohort study

Carpal tunnel syndrome is the most common entrapment syndrome of a peripheral nerve. The gold standard treatment is open carpal tunnel release which has a high success rate, a low complication rate, and predictable postoperative results. However, it has not been analysed yet if there is a seasonal influence on complications for carpal tunnel release, a highly elective procedure. In this retrospective study, we determine whether there is a seasonal impact on surgical site infections (SSI) and wound healing disorders (WHD) in primary carpal tunnel syndrome surgery. Between 2014 and 2018, we have assessed 1385 patients (65% female, 35% male) at a mean age of 61.9 (SD 15.3) years, which underwent open carpal tunnel release because of primary carpal tunnel syndrome. The seasonal data such as the warm season (defined as the period from 1st of June until 15th of September), the average daily and monthly temperature, and the average relative humidity were analysed. Patient demographics were examined including body mass index, alcohol and nicotine abuse, the use of anticoagulants and antiplatelet drugs as well as comorbidities. These data were correlated regarding their influence to the rate of surgical site infections and wound healing disorders in our study collective. A postoperative SSI rate of 2.4% and a WHD rate of 7% were detected. Our data confirms the warm season, the average monthly temperature, and male sex as risk factors for increasing rates of WHDs. Serious SSIs with subsequent revision surgery could be correlated with higher age and higher relative humidity. However there is no seasonal impact on SSIs. We therefore advise considering the timing of this elective surgery with scheduling older male patients preferably during the cold season to prevent postoperative WHDs.

Clinical and Microbiological Analysis of Deep Sternal Wound Infections in Fifty-Two Consecutive Patients

Background: Mediastinitis after cardiac surgery can lead to devastating consequences such as deep sternal wound infections (DSWI). Staphylococcus epidermidis and other coagulase-negative staphylococci belong to the physiological skin flora and therefore generally are not considered pathogenic agents. Thus, local resistance patterns of these bacterial species often recovered from wound specimens generally are ignored while choosing antibiotics for peri-operative prophylaxis in cardiac surgery as well as in the selection of empiric antibiotic therapy of DSWI. Methods: During the period May 2012-May 2013, 52 patients suffering from DSWI were treated at our institution. For every patient, deep tissue samples were obtained during surgical debridement procedures and submitted to microbiologic analysis. The frequency of and the time to occurrence of a DSWI was recorded, and baseline data, previous operative interventions, complications, and the technique used for soft tissue reconstruction, as well as the microbiologic results and individual risk factors, were documented. Results: There were 32 male patients (62%) and 20 female. The patients' age at the time of revision was a mean of 67 ± 11.5 years (range 35-83 years). There was bacterial growth in 31 cases (60%), the predominant species being S. epidermidis (20 patients; 65%). Extended antibiotic therapy was indispensable to controlling the infection. Conclusion: The local resistance patterns of antibiotics should have a greater influence on the standardized prophylaxis or empirical therapy of DSWI and need to be discussed specifically for this high-risk population. Because of its multi-resistance spectrum, S. epidermidis must be classified as a potential pathogen. In the cases reported here, extended antibiotic therapy was necessary to support wound healing and thus good patient outcomes.