Predictors and outcomes of sternal wound complications in patients after coronary artery bypass graft surgery

We sought to assess predictors and outcomes of sternal wound complications in patients after coronary artery bypass grafting (CABG). A nested, case-control study from a 10-year hospitalization cohort with prospective data collection was conducted. Included in the cohort were patients age 18 and above undergoing CABG surgery between March 1997 and July 2003 (n = 7889). Patients who underwent any surgery other CABG were excluded. Cases were matched to controls 1:3 on year of surgery. Cases were CABG patients with sternal wound complications, which was defined as requiring antibiotics and/or topical treatment, requiring extra nursing care, dehiscence, or requiring surgical intervention (n = 89). Controls were CABG patients without sternal wound complications (n = 267). The study examined 29 risk factors and 10 outcome variables. Univariate analysis on the risk factors revealed 10 significant risk factors. Logistic regression analysis was conducted and the risk factors that significantly predicted sternal wound complications after CABG surgery included older age (odds ratio [OR] = 0.85, 95% confidence interval [CI] 0.808-0.892), previous CABG surgery (OR = 3.9, 95% CI 1.03-15.37), and in class three or four of the New York Heart Association functional class (OR = 2.8, 95% CI 1.27-6.12). There was a significant difference between CABG patients with and without sternal wound complications on nine outcome variables. Of the 29 predictors of post-CABG sternal wound infections being examined, 10 proved to be significant. Further analysis demonstrated only three variables that significantly predicted sternal wound complications. Older age, previous CABG surgery, and class three or four of the New York Heart Association functional class predispose CABG patients to sternal wound infections.     

Risk factors of deep sternal wound infections in coronary artery bypass graft surgery

BACKGROUND: Major infections of sternal wounds after coronary artery bypass graft surgery (CABG) occur infrequently, but when they do, they contribute substantial morbidity and mortality. We identified significant risk factors of deep sternal wound infection (DSWI) following CABG and hoped to plan prophylactic measures for high risk patients in order to reduce the incidence of infection. METHODS: From 1996 to 1997, a total of 620 patients received CABG at a medical center in Taiwan. The surgical wound was examined every day. Wound infections were defined and classified according to Centers for Diseases Control (CDC) definitions. DSWI were defined as those involving the mediastinum, bone or cartilage, and infections beneath the subcutaneous tissue. Several risk factors were analyzed. RESULTS: We identified 17 (2.7%) DSWI. Univariate analysis indicated that ASA scores, surgical risk index, surgeon, postoperative low cardiac output, re-operation for bleeding, re-wiring of sternum, length of postoperative stay in the intensive care unit, postoperative duration of mechanical ventilation, operation time, duration of cardiopulmonary bypass. Independent predictors by multivariate logistic regression analysis were re-operation for bleeding and operation time. A total of 16 organisms were isolated among 14 patients. Staphylococcus accounted for most isolates (93.8%) and the most of them were methicillin-resistant (80%). CONCLUSIONS: Re-operation for bleeding and operation time were the independent predictors.     

Risk factors for leg harvest surgical site infections after coronary artery bypass graft surgery

OBJECTIVE: Harvest site infections are more common than chest surgical infections after coronary artery bypass surgery, yet few studies detail risk factors for these infections. We sought to determine independent risk factors for leg surgical site infections using our institutional Society of Thoracic Surgeons database. METHODS: We retrospectively analyzed data collected from 1980 coronary artery bypass patients undergoing surgery at our institution from January 1, 1996, through June 30, 1999, using The Society of Thoracic Surgeons database. Independent risk factors for leg harvest site infection were identified by multivariate logistic regression. RESULTS: Seventy-six patients (4.5%) were coded as having had a leg harvest site infection, of which 67 were confirmed by infection control. The length of hospital stay after surgery was significantly longer in patients with leg harvest site infection (mean 10.1 days) compared with that of patients without infection (mean 7.1 days, P <.001), and infected patients were more likely to be readmitted to the hospital within 30 days of surgery. Independent risk factors for leg harvest site infection included previous cerebrovascular accident (odds ratio, 2.9), postoperative transfusion of 5 units or more of red blood cells (odds ratio, 2.8), obesity (odds ratio, 2.5), age 75 years or older (odds ratio, 1.9), and female gender (odds ratio, 1.8). CONCLUSIONS: Consistent with previous studies, female gender and obesity were identified as independent risk factors for leg harvest site infection, while previous cerebrovascular accident, postoperative transfusion, and older age are newly described risk factors. The Society of Thoracic Surgeons database is a useful tool for identification of predictors of leg harvest site infections.     

Predictors of type II neurologic complications after coronary artery bypass graft surgery

The study objective was to determine predictors, and adverse outcomes of postoperative type II neurologic complications. An 11-year cohort (N=12,706) study with 595 coronary artery bypass graft (CABG) patients with a neurologic complication, and 7793 patients without any neurologic complications was conducted. This study examined 26 potential risk factors and 13 outcome variables. Logistic regression analysis found that patients were more likely to experience a neurologic complication after CABG if they were older than 70 years of age [odds ratio (OR), 3.8; 95% confidence interval (CI), 3.1-4.5; P < 0.001], had a previous intervention within 10 days before surgery (OR, 3.4; 95% CI, 1.4-8.3; P = 0.008), or had a higher creatinine level (OR, 0.9; 95% CI, 0.95-0.99; P = 0.013). Additionally, there was a significant difference between CABG patients with and without neurologic complications on 12 outcome variables. Type II neurologic complications after CABG are common and associated with an increased risk of postoperative morbidity and mortality.     

Risk factors for sternal wound infection and mid-term survival following coronary artery bypass surgery

Objective: To identify risk factors for sternal wound infection following coronary artery bypass surgery (CABG), and to compare early and mid-term survival outcome. Methods: Data were prospectively collected for 4228 patients who underwent CABG surgery between April 1997 and March 2001. One hundred and nine (2.6%) patients developed sternal wound infection. We used logistic regression to identify independent risk factors associated with post-operative sternal wound infection. Patient records were linked to the National Strategic Tracing Service, which records all deaths in the UK, to establish current vital status. Deaths occurring over time were described using Kaplan–Meier techniques. To control for differences in patient characteristics, we used Cox proportional hazards analysis to calculate adjusted hazard ratios (HR) and 95% confidence intervals (CI). Results: The results of the logistic regression analysis found that the independent predictors of sternal wound infection were obesity (odds ratio (OR) 2.0; P<0.001), New York Heart Association class ≥3 (OR 1.6; P=0.022), use of bilateral internal mammary arteries (OR 3.2; P<0.001), increasing number of grafts (OR 1.5; P<0.001), re-exploration for bleeding (OR 3.1; P=0.011), and increased duration of mechanical ventilation (for every 10 h (OR 1.12; P<0.001)). Three hundred and forty one (8.1%) deaths occurred during the study period with mean follow up of 3.2±1.3 years. The crude HR of mid-term mortality for sternal wound infection patients was 2.51 (95% CI 1.59–3.94, P<0.001). After adjustment for pre, intra and post-operative factors, the adjusted HR of mid-term mortality for sternal wound infection patients was 1.64 (95% CI 1.03–2.61, P=0.037). The adjusted freedom from death for sternal wound infections at 30 days, and 1, 2 and 4 years was 96.8, 93.7, 91.4 and 86.7%, respectively, compared with 98.1, 96.1, 94.7 and 91.7% for patients without sternal wound infections. Conclusions: In conclusion, we have identified risk factors for sternal wound infection, many of which are modifiable. We have also shown that there is a significant increase in mortality in patients with sternal wound infection during a 4-year follow-up period after CABG.     

The vacuum-assisted closure system for the treatment of deep sternal wound infections after cardiac surgery

BACKGROUND: The VAC system (vacuum-assisted wound closure) is a noninvasive active therapy to promote healing in difficult wounds that fail to respond to established treatment modalities. The system is based on the application of negative pressure by controlled suction to the wound surface. The method was introduced into clinical practice in 1996. Since then, numerous studies proved the effectiveness of the VAC System on microcirculation and the promotion of granulation tissue proliferation. METHODS: Eleven patients (5 men, 6 women) with a median age of 64.4 years (range 50 to 78 years) with sternal wound infection after cardiac surgery (coronary artery bypass grafting = 5, aortic valve replacement = 5, ascending aortic replacement = 1) were fitted with the VAC system by the time of initial surgical debridement. RESULTS: Complete healing was achieved in all patients. The VAC system was removed after a mean of 9.3 days (range 4 to 15 days), when systemic signs of infection resolved and quantitative cultures were negative. In 6 patients (54.5%), the VAC system was used as a bridge to reconstructive surgery with a pectoralis muscle flap, and in the remaining 5 patients (45.5%), primary wound closure could be achieved. Intensive care unit stay ranged from 1 to 4 days (median 1 day). Duration of hospital stay varied from 13 to 45 days (median 30 days). In-hospital mortality was 0%, and 30-day survival was 100%. CONCLUSIONS: The VAC system can be considered as an effective and safe adjunct to conventional and established treatment modalities for the therapy of sternal wound infections after cardiac surgery.     

Role of intraoperative transesophageal echocardiography in patients having coronary artery bypass graft surgery

Background

Previous studies have shown that intraoperative transesophageal echocardiography provides important preoperative and postoperative information in various cardiac and noncardiac surgeries that may alter patient management and outcome. The role of intraoperative transesophageal echocardiography in patients in whom isolated coronary artery bypass graft surgery is anticipated has been reported only in small selected groups. This study was designed to prospectively evaluate the role of intraoperative transesophageal echocardiography in a large, nonselected group of patients undergoing primarily coronary artery bypass graft surgery.

Methods

From January 2001 to December 2003, 474 consecutive patients (76% men, 24% women) aged 30 to 89 years (mean age of 70 ± 10 years) who were undergoing coronary artery bypass graft surgery had prebypass and postbypass intraoperative transesophageal echocardiography. New findings and alterations in the surgical plan were documented prospectively.

Results

New prebypass findings were found in 10% of patients, and the surgical plan was altered in 3.4% of patients. New postbypass findings were found in 3.2% of patients, altering the surgical plan in 2% of patients.

Conclusions

This large consecutive, nonselected, prospective study reveals the significant impact of intraoperative transesophageal echocardiography in patients having coronary artery bypass graft surgery as a primary procedure. New findings (prebypass and postbypass) were found in 13% of patients overall, and the surgical plan was altered in 5.5% of patients. This study supports the use of intraoperative transesophageal echocardiography in patients undergoing primarily coronary artery bypass graft surgery.     

Laparoscopic omental flap for the treatment of major sternal wound infection after cardiac surgery

BACKGROUND: The ideal reconstructive procedure after sternal debridement is still a matter of debate. The omentum might be theoretically preferable for its favorable properties, but it is seldom used because it entails the added trauma of a laparotomy. METHODS: Three female patients with severe osteomyelitis after myocardial revascularization underwent sternal debridement and filling of the defect with a laparoscopically prepared omental flap. Sternal wound closure was achieved as a single-stage procedure in 2 patients. The third patient had a poststernotomy septicemia and required a 2-stage procedure. The abdominal procedures were conducted through 3 operating 5-mm ports. Omental flaps were developed by complete separation from the transverse colon and lengthening by division of some anastomosing arteries between gastroepiploic vessels and Barkow's arcade. Thoracic transposition of the omentum was achieved through a 5-cm diaphragmatic incision. The flaps were able to reach the base of the neck and fill the sternal defect in all patients. RESULTS: A smooth postoperative course was observed. Oral intake was started from day 2; sole oral nutrition was maintained from day 3 or 4. Optimal wound healing was observed with minimal or absent local discomfort. Minor transient paradoxical movements of the anterior chest wall disappeared within 1 month. Postoperative hospital stay was 9, 14, and 14 days, respectively. CONCLUSIONS: Laparoscopic omentoplasty, compared with the open procedure, entails several advantages for the treatment of sternal osteomyelitis. The introduction of minimally invasive techniques may widen the indications for the use of the omentum in the treatment of major sternal wound infections.     

非体外循环冠状动脉旁路移植术后的阿司匹林抵抗

目的 通过检测非体外循环冠状动脉旁路移植术(OPCAB)后患者血小板聚集率以及尿11-脱氢-血栓烷B2(11-DH-TXB2)指标，动态观察术后阿司匹林抵抗(AR)的发生情况，探索术后AR的危险因素。方法 冠心病患者290例，首次行OPCAB患者145例(手术组)，接受内科药物治疗患者145例(非手术组)。手术组患者于术前及术后服用阿司匹林后第1、4、10天及6个月，检测血小板聚集率以及尿11-DH-TXB2。非手术组患者于服药前及服药后第1、4、10天检测上述指标。同时记录患者各项临床资料。结果 手术组患者服用阿司匹林后第1天的AR发生46例(32％)(抵抗组)，其余为非抵抗组。用药后第4天和第10天AR患者下降至19例(13％)和5例(3％)。半年随访中未发现有AR患者存在。非手术组患者，服药后第1天，血小板聚集率均下降至20％以下，平均(8.8±6.8)％，未见AR现象出现。手术组患者术后血小板计数显著高于术前(P＜0.05)。Logistic回归分析发现，OPCAB患者中，体重大于75 kg(OR =0.38，95％CI:0.18～0.79)和术后引流量超过500 ml(OR=3.12，95％CI:1.29～7.53)为术后出现AR的危险因素。结论 OPCAB术后早期，阿司匹林的抗血小板作用受到不同程度抑制，部分患者出现AR现象，予以更为积极有效的抗血小板治疗有重要临床意义。