1097 17 Years of Treating Deep Sternal Wound Infections at A Single Institution: Outcomes and Lessons Learned

Introduction

Deep sternal wound infections (DSWI) are a serious complication following cardiac surgery that comprise of any infection penetrating the subcutaneous tissue of the sternum. DSWI have been found to increase mortality and worsen prognostic outcomes following surgery.

Method

We conducted a retrospective cohort study using hospital e-records from 2000 to 2017 of all adult patients operated on with a median sternotomy at our institution. Univariate and multivariate analysis along with mortality and Kaplan-Meier survival curves compared the DSWI population against the remaining study population, using SPSS-25 software.

Results

Of 15521 total patients in the study, 145 (0.9%) suffered a DSWI. Variables that were associated with DSWI included age at operation (p = 0.019), gender (p = 0.007), BMI (p = 0.001), diabetes (p < 0.0001), renal disease (p = 0.008), operative urgency (p = 0.007), type of operation (p = 0.02), Euroscore (p = <0.0001), bypass-time (p = 0.038) and crossclamp-time (p = 0.008). A logistic regression encompassing significant variables revealed that gender (p = 0.031 CI 1.45-1.96), BMI (p < 0.0001 CI 1.03-1.10), diabetes (p = 0.007 CI 1.20-3.67) and type of operation (p = 0.018 CI 1.23-1.87) remained significant when covariate contribution was eliminated. DSWI subgroup mortality was insignificant at 30 days (3.4%vs2.9%, p = 0.68) but significantly worse at 90 days (8.3%vs3.7%, p = 0.004) and at 1 year (17.2%vs5.4%, p < 0.0001). Kaplan-Meier analysis depicted a significantly worse survival distribution for the DSWI population compared to rest of study (Log-Rank<0.05).

Conclusions

At our centre, DSWI are attributable to certain modifiable and set demographics and contribute heavily to medium-term mortality. A better understanding of DSWI risk factors may pinpoint those at risk and benefit the multidisciplinary team to ultimately reduce the rate of DSWI.

302 Is Age Just A Number in Cardiac Surgery? Evaluating Outcomes of An Octogenarian Cohort at A Single Cardiac Centre

Introduction

Cardiac surgery in octogenarians contains many age-specific perioperative risk factors and outcomes yet to be fully understood.

Method

All adults (N = 4957) undergoing cardiac surgery between 2011-2017 at our institution were retrospectively studied, encompassing 312 octogenarians. Data was evaluated with univariate and multivariate testing and mortality with Kaplan-Meier and cox-regression analyses.

Results

Compared to septuagenarians, octogenarians revealed more patients having previous surgery (p = 0.016), less diabetic patients (p = 0.034), lower BMI (0.002), and longer hospital stay (p < 0.000). Compared to rest of study, octogenarians contained more females (p = 0.012), a greater Euroscore (p < 0.000), spent longer in ITU (p = 0.001) and contained more ITU readmissions (p = 0.023). The octogenarians did not contain significant 30- and 90-day mortality but revealed significant mortality at 1-year versus septuagenarians (p = 0.039) and rest of study (p = 0.001). Variables testing significant in a multivariate regression were inserted into a cox-regression that found octogenarian group-membership to be insignificant (p = 0.051) in a 12-covariate model. Independent risk factors for mortality included emergency surgery (p = 0.04), reoperation (p < 0.000), cardiac procedure (p = 0.007), ITU time (p = 0.041) and diabetes (p = 0.023).

Conclusions

We report specific differences for octogenarians in perioperative characteristics along with promising short- and medium-term survival. Such outcomes must constantly be monitored so that cardiac surgery can be further tailored to this elderly cohort.

White-out from a Wii: traumatic haemothorax sustained playing Nintendo Wii

A case is reported of a patient who sustained a significant haemothorax while playing with a Nintendo Wii console.

Predictors of operative death after oesophagectomy for carcinoma

BACKGROUND

Oesophagectomy for carcinoma provides a chance of cure but carries significant risk. This study defined risk factors for death after oesophageal resection for malignant disease.

METHODS

Between 1990 and 2003, 773 oesophagectomies for oesophageal cancer were performed. Continuous variables were categorized into quartiles for analysis. Predictors of operative mortality were identified by univariate and multiple logistic regression analysis.

RESULTS

The operative mortality rate was 4.8 per cent (37 of 773). In univariate analysis, advanced age, reduced forced expiratory volume in 1 s (FEV1), reduced forced vital capacity, presence of diabetes and tumour located in the upper third of the oesophagus were associated with a higher mortality rate. Multivariate analysis identified age (highest relative to lowest quartile, odds ratio (OR) 4.87 (95 per cent confidence interval (c.i.) 1.35 to 17.55); P = 0.009), tumour position (upper third relative to other locations, OR 4.23 (95 per cent c.i. 1.06 to 16.86); P = 0.041) and FEV1 (lowest relative to highest quartile, OR 4.72 (95 per cent c.i. 1.01 to 21.99); P = 0.018) as independent predictors of death.

CONCLUSION

Advanced age, impaired preoperative respiratory function and a tumour high in the oesophagus are associated with a significantly increased risk of death after oesophagectomy for carcinoma.

Protection from reperfusion injury after cardiac transplantation by inhibition of adenosine metabolism and nucleotide precursor supply

BACKGROUND

Adenosine (Ado) triggers numerous protective mechanisms in the heart that may attenuate ischemia-reperfusion injury in cardiac grafts. We aimed to establish whether sustained increase in endogenous Ado production by the combined application of Ado metabolism inhibitors and nucleotide precursors attenuates reperfusion injury in transplanted hearts.

METHODS AND RESULTS

Rat hearts were collected after the infusion of St Thomas' Hospital cardioplegic solution, stored at 4 degrees C for 4 hours, and heterotopically transplanted into the abdomen of recipient rats. A solution containing Ado deaminase inhibitor erythro-9(2-hydroxy-3-nonyl)adenine, Ado kinase inhibitor 5'-aminoadenosine, and nucleotide precursors adenine and ribose was administered at the time of reperfusion in the treated group, whereas saline was administered to control animals. After 1 or 24 hours, mechanical function of the transplanted hearts was evaluated in an ex vivo perfusion system followed by the determination of myocardial ATP with related metabolites and measurement of the activity of neutrophil-specific enzyme myeloperoxidase in cardiac homogenates. After 24 hours of reperfusion, maximum left ventricular developed pressure increased from 87.0+/-6.8 mm Hg (mean+/-SEM) in controls to 118.1+/-8.2 mm Hg in the treated group (P<0.05), ATP increased from 11.0+/-0.8 micromol/g dry wt in controls to 15.1+/-1.2 micromol/g dry wt in the treated group (P<0.01), and myeloperoxidase activity decreased from 2.23+/-0.60 U/g wet wt in controls to 0.58+/-0.12 U/g wet wt in the treated group (P<0.001). No differences in cardiac function, ATP, or myeloperoxidase activity were observed between the treated group and controls after 1 hour of reperfusion.

CONCLUSIONS

The administration of Ado metabolism inhibitors with nucleotide precursors causes a sustained increase in endogenous Ado production and exerts a potent protective effect against reperfusion injury in transplanted hearts. Improved cardiac function and elevated ATP concentration were accompanied by complete amelioration of neutrophil infiltration in treated hearts, suggesting that reduction in postischemic inflammation could be an important mechanism of this protective effect.

Heat shock protein 70 gene transfection protects mitochondrial and ventricular function against ischemia-reperfusion injury

BACKGROUND

Upregulation of heat shock protein 70 (HSP70) is beneficial in cardioprotection against ischemia-reperfusion injury, but the mechanism of action is unclear. We studied the role of HSP70 overexpression through gene therapy on mitochondrial function and ventricular recovery in a protocol that mimics clinical donor heart preservation.

METHODS AND RESULTS

Hemagglutinating virus of Japan (HVJ)-liposome technique was used to transfect isolated rat hearts via intracoronary infusion of either the HSP70 gene (HSP group, n=16) or no gene (CON group, n=16), which was heterotopically transplanted into recipient rats. Four days after surgery, hearts were either perfused on a Langendorff apparatus for 30 minutes at 37 degrees C (preischemia studies [n=8/group]) or perfused for 30 minutes at 37 degrees C, cardioplegically arrested for 4 hours at 4 degrees C, and reperfused for 30 minutes at 37 degrees C (postischemia studies [n=8/group]). Western blotting and immunohistochemistry confirmed HSP70 upregulation in the HSP group. Postischemic mitochondrial respiratory control indices (RCIs) were significantly better preserved in HSP than in CON hearts: NAD(+)-linked RCI values were 9.54+/-1.1 versus 10.62+/-0.46 before ischemia (NS) but 7.98+/-0.69 versus 1.28+/-0.15 after ischemia (P<0.05), and FAD-linked RCI values were 6.87+/-0.88 versus 6.73+/-0.93 before ischemia (NS) but 4.26+/-0.41 versus 1.34+/-0.13 after ischemia (P<0.05). Postischemic recovery of mechanical function was greater in HSP than in CON hearts: left ventricular developed pressure recovery was 72.4+/-6.4% versus 59.7+/-5.3% (P<0.05), maximum dP/dt recovery was 77.9+/-6.6% versus 52.3+/-5.2% (P<0.05), and minimum dP/dt recovery was 72.4+/-7.2% versus 54.8+/-6.9% (P<0.05). Creatine kinase release in coronary effluent after reperfusion was 0.20+/-0.04 versus 0.34+/-0.06 IU. min(-1). g wet wt(-1) (P<0.05) in HSP versus in CON hearts.

CONCLUSIONS

HSP70 upregulation protects mitochondrial function after ischemia-reperfusion injury; this was associated with improved preservation of ventricular function. Protection of mitochondrial function may be important in the development of future cardioprotective strategies.

Gene therapy for myocardial protection: transfection of donor hearts with heat shock protein 70 gene protects cardiac function against ischemia-reperfusion injury

BACKGROUND

Heat shock protein 70 (HSP70) gene transfection has been shown to enhance myocardial tolerance after normothermic ischemia-reperfusion. We investigated the effect of HSP70 gene transfection on mechanical and endothelial function in a protocol mimicking clinical heart preservation.

METHODS AND RESULTS

Rat hearts were infused ex vivo with Hemagglutinating Virus of Japan-liposome complex containing HSP70 gene (HSP, n=8) or no gene (CON, n=8), and heterotopically transplanted into recipient rats. Four days after surgery, transfected hearts were perfused on a Langendorff apparatus for 45 minutes, arrested with St Thomas' No. 1 cardioplegia for 4 hours at 4 degrees C, and reperfused for 1 hour. Mechanical and endothelial function was studied before and after ischemia. Creatine kinase was measured in reperfusion effluent. Hearts underwent Western blotting and immunohistochemistry to confirm HSP70 overexpression. Postischemic recovery of mechanical function (% preischemic+/-SEM) was greater in HSP versus CON: Left ventricular developed pressure recovery was 76.7+/-3.9% versus 60. 5+/-3.1% (P:<0.05); dP/dtmax recovery was 79.4+/-4.9% versus 56. 2+/-3.2% (P:<0.05); dP/dtmin recovery was 74.8+/-4.6% versus 57. 3+/-3.6% (P:<0.05). Creatine kinase release was attenuated in HSP versus CON: 0.22+/-0.02 versus 0.32+/-0.04 IU/min/g wet wt. (P:<0. 05). Recovery of coronary flow was greater in HSP versus CON: 76. 5+/-3.8% versus 59.2+/-3.2% (P:<0.05). Recovery of coronary response to 5-hydroxytryptamine (5 x 10(-)(5) mol/L) was 55.6+/-4.7% versus 23. 9+/-3.2% (P:<0.05); recovery of coronary response to glyceryltrinitrate (15 mg/L) was not different between HSP and CON: 87.4+/-6.9% versus 84.3+/-5.8% (NS).

CONCLUSIONS

In a clinically relevant donor heart preservation protocol, HSP70 gene transfection protects both mechanical and endothelial function.