John A. Kern

Ischemia-reperfusion injury after lung transplantation increases risk of late bronchiolitis obliterans syndrome.

BACKGROUND Bronchiolitis obliterans syndrome (BOS) is the most common cause of long-term morbidity and mortality after lung transplantation. Our hypothesis was that early ischemia-reperfusion injury after lung transplantation increases the risk of BOS. METHODS Data on 134 patients who had lung transplantation between January 1, 1990 and January 1, 2000, was used for univariate and multivariate logistic regression analysis. RESULTS After lung transplantation, 115 patients (115 of 134, 86%) survived more than 3 months. In that group, 41 patients developed BOS, of which 23 had progressive disease. Univariate analysis revealed that ischemia-reperfusion injury (p = 0.017) and two or more acute rejection episodes (p = 0.032) were predictors of BOS onset, whereas ischemia-reperfusion injury (p = 0.011) and cytomegalovirus infection (p = 0.009) predicted progressive BOS. Multivariate logistic regression analysis showed that ischemia-reperfusion injury was an independent predictor for both BOS development and BOS progression. Two or more acute rejection episodes were also an independent predictor of BOS development, whereas cytomegalovirus infection was an independent predictor of progressive BOS. CONCLUSIONS Ischemia-reperfusion injury increases the risk of BOS after lung transplantation.

Thoracoscopy in the management of empyema in children

Many pediatric surgeons advocate early open drainage or decortication for children with acute empyema. Unfortunately, such procedures can be associated with significant morbidity. Since 1981, we have used early thoracoscopic adhesiolysis and pleural debridement as an alternative to open thoracotomy in 9 children with acute empyema. The average age was 7.8 +/- 1.8 years (range, 2 to 16). All patients had failed initial treatment, which included antibiotics and chest tube drainage. All procedures were performed under general anesthesia. Following thoracoscopy, 8 of the 9 patients were managed with a single drainage tube and the average duration of tube drainage was 8.4 +/- 1.4 days. One patient died of underlying leukemia. Of the 8 patients who recovered, the average postoperative hospital stay was 13.4 +/- 2.9 days. No complications resulted from the thoracoscopies and there was no need for further surgical intervention in any of these patients. We conclude that thoracoscopy allows for minimally invasive, yet effective treatment of acute empyema with loculated collections. Thoracoscopic visualization of the pleural cavity permits efficient debridement, thorough adhesiolysis, and optimal placement of drainage tubes. Since we have begun using early thoracoscopy in the treatment of pediatric empyema, open drainage or decortication has not been required in any of these patients. Thoracoscopy is a useful adjunct in the treatment of empyema in children and its early application may eliminate the need for decortication.

Percutaneous transluminal angioplasty and stenting in the treatment of chronic mesenteric ischemia: results and longterm followup

BACKGROUND The purpose of this study was to review the results of percutaneous transluminal angioplasty (PTA), stenting, or both in the treatment of patients who present with symptoms and angiographic findings most consistent with chronic mesenteric ischemia. STUDY DESIGN A retrospective analysis of 33 consecutive patients from a single institution who underwent PTA, stenting, or both for treatment of symptoms most characteristic of chronic mesenteric ischemia was performed. RESULTS There were 12 men and 21 women with a mean age of 63 years (range 40 to 89 years). Median weight loss was 28 lb (range 6 to 80 lb). Postprandial pain was present in 88% of the patients (29 of 33). All lesions treated were stenoses. PTA alone was performed in 21 patients (32 vessels), and PTA and stenting were performed in 12 patients (15 vessels). PTA was technically successful in 26 of 32 vessels (81.3%); PTA plus stenting was technically successful in 15 of 15 vessels (100%) (p = 0.073). Complete alleviation of symptoms occurred immediately in 27 of the patients (82%), and 2 patients (6%) had significant improvement in symptoms. There were four immediate clinical failures (12%): two patients were found to have occult malignancy and one had immediate relief of symptoms after surgical release of the median arcuate ligament. Followup data were obtained in all patients with clinically successful procedures (mean 38 months, median 25 months, range 1 to 123 months). Angiographic followup was available in 52% of the patients (15 of 29), at a mean of 20 months. The primary longterm clinical success rate was 83.3% (24 of 29). Four of the five patients with recurrent symptoms were successfully retreated with endovascular therapy. The primary assisted longterm clinical success rate was 96.6% (28 of 29). The 5-year survival rate was 76.1%. Major complications occurred in 13% of the procedures, with a 30-day mortality rate of 0%. CONCLUSION Endovascular therapy for treatment of mesenteric arterial stenoses is effective in the treatment of patients with symptoms and angiographic findings characteristic of chronic mesenteric ischemia.

Magnetic resonance imaging identifies the fibrous cap in atherosclerotic abdominal aortic aneurysm.

Background—MRI can distinguish components of atherosclerotic plaque. We hypothesized that contrast enhancement with gadolinium-DTPA (Gd-DTPA) could aid in the differentiation of plaque components in abdominal aortic aneurysm (AAA). Methods and Results—Twenty-three patients (19 males, age 70±8 years) with AAA underwent MRI on a 1.5-T clinical scanner 3±3 days before surgical grafting. T1- and T2-weighted (W) black blood spin echo imaging was performed in 1 axial slice, and the T1-W imaging was repeated after a Gd-DTPA–enhanced 3D magnetic resonance angiogram. A section of the aorta at the site of imaging was resected at surgery for histopathologic examination of tissue components and inflammatory cells. Signal-to-noise and contrast-to-noise ratios (CNR) were measured in visualized plaque components from multispectral MRI, and percent enhancement after contrast on T1-W imaging was calculated. The &kgr; value for agreement between pathology and MRI for the number of tissue components was 0.785. T2-W imaging identified thrombus as regions of high signal and lipid core as low signal, with a CNR of 6.43±3.41. Nine patients had a fibrous cap pathologically, which was visualized as a discrete area of uniform increased signal on T2-W imaging with a CNR of 4.52±1.93 compared with lipid core. Within the cap, the percent enhancement after Gd-DTPA on T1-W imaging was 91±63%. Conclusions—Higher signal on T2-W MRI identifies the fibrous cap and thrombus within AAA. Contrast enhancement improves delineation of the fibrous cap. The addition of contrast to MRI plaque imaging may enhance identification of vulnerable plaque.

Thoracoscopic diagnosis and treatment of mediastinal masses

Evaluation of mediastinal masses often involves an array of imaging procedures and percutaneous biopsy techniques. Despite this, surgical intervention with an open biopsy is often required, especially to diagnose mediastinal malignancies. We report 22 patients with mediastinal masses who were managed with thoracoscopic biopsy, as opposed to open biopsy. All of these patients either had unsuccessful fine-needle aspiration or were unacceptable candidates for percutaneous aspiration. The patients ranged in age from 11 months to 67 years with a mean age of 17.2 +/- 3.6 years. Thoracoscopy provided an accurate tissue diagnosis in 19 of the 22 patients (86%) without need for an open diagnostic procedure. In 1 patient, histoplasmosis was suspected from the thoracoscopic biopsy, but open thoracotomy was needed for confirmation. Of the 19 patients with a positive tissue diagnosis, 3 patients had bronchogenic cysts that were completely resected by thoracoscopy. The mean duration of chest tube drainage was 2.3 +/- 0.2 days, and there were no complications or procedure-related deaths. The average length of hospitalization was 6.0 +/- 0.8 days. We believe that thoracoscopy is a safe, rapid, and effective modality for the diagnosis of mediastinal masses. Accurate tissue diagnoses are obtained in most patients without the need for additional procedures. In addition, we have demonstrated that complete excision of certain benign lesions during thoracoscopy is possible.

Successful transplantation of marginally acceptable thoracic organs.

OBJECTIVE This study evaluates the efficacy of personally inspecting marginal thoracic organ donors to expand the donor pool. SUMMARY BACKGROUND DATA The present donor criteria for heart and lung transplantation are very strict and result in exclusion of many potential thoracic organ donors. Due to a limited donor pool, 20-30% of patients die waiting for transplantation. METHODS The authors have performed a prospective study of personally inspecting marginal donor organs that previously would have been rejected by standard donor criteria. RESULTS Fourteen marginal hearts and eleven marginal lungs were inspected. All 14 marginal hearts and 10 of the marginal lungs were transplanted. All cardiac transplant patients did well. The mean ejection fraction of the donor hearts preoperatively was 39 +/- 11% (range 15-50%). Postoperatively, the ejection fraction of the donor hearts improved significantly to 55 +/- 3% (p < 0.002). Nine of the ten lung transplant patients did well and were operative survivors. Our donor pool expanded by 36% over the study period. CONCLUSIONS The present donor criteria for heart and lung transplantation are too strict. Personal inspection of marginal thoracic donor organs will help to maximize donor utilization.

Rate Control versus Rhythm Control for Atrial Fibrillation after Cardiac Surgery.

BACKGROUND Atrial fibrillation after cardiac surgery is associated with increased rates of death, complications, and hospitalizations. In patients with postoperative atrial fibrillation who are in stable condition, the best initial treatment strategy--heart-rate control or rhythm control--remains controversial. METHODS Patients with new-onset postoperative atrial fibrillation were randomly assigned to undergo either rate control or rhythm control. The primary end point was the total number of days of hospitalization within 60 days after randomization, as assessed by the Wilcoxon rank-sum test. RESULTS Postoperative atrial fibrillation occurred in 695 of the 2109 patients (33.0%) who were enrolled preoperatively; of these patients, 523 underwent randomization. The total numbers of hospital days in the rate-control group and the rhythm-control group were similar (median, 5.1 days and 5.0 days, respectively; P=0.76). There were no significant between-group differences in the rates of death (P=0.64) or overall serious adverse events (24.8 per 100 patient-months in the rate-control group and 26.4 per 100 patient-months in the rhythm-control group, P=0.61), including thromboembolic and bleeding events. About 25% of the patients in each group deviated from the assigned therapy, mainly because of drug ineffectiveness (in the rate-control group) or amiodarone side effects or adverse drug reactions (in the rhythm-control group). At 60 days, 93.8% of the patients in the rate-control group and 97.9% of those in the rhythm-control group had had a stable heart rhythm without atrial fibrillation for the previous 30 days (P=0.02), and 84.2% and 86.9%, respectively, had been free from atrial fibrillation from discharge to 60 days (P=0.41). CONCLUSIONS Strategies for rate control and rhythm control to treat postoperative atrial fibrillation were associated with equal numbers of days of hospitalization, similar complication rates, and similarly low rates of persistent atrial fibrillation 60 days after onset. Neither treatment strategy showed a net clinical advantage over the other. (Funded by the National Institutes of Health and the Canadian Institutes of Health Research; ClinicalTrials.gov number, NCT02132767.).

Postoperative Atrial Fibrillation Significantly Increases Mortality, Hospital Readmission, and Hospital Costs

BACKGROUND New-onset postoperative atrial fibrillation (POAF) is the most common complication following cardiac surgery. However, the magnitude of POAF on length of stay, resource utilization, and readmission rates remains an area of clinical interest. The purpose of this study was to examine the risk-adjusted impact of POAF on measures of mortality, hospital resources, and costs among multiple centers. METHODS A total of 49,264 patient records from a multi-institutional Society of Thoracic Surgeons (STS) certified database for cardiac operations (2001 to 2012) were extracted and stratified by the presence of POAF (19%) versus non-POAF (81%). The influence of POAF on outcomes was assessed by hierarchic regression modeling, adjusted for calculated STS predictive risk indices. RESULTS Mean age was 64±11 years, and median STS predicted risk of mortality for patients who developed POAF were incrementally higher (2% vs 1%, p<0.001) compared with non-POAF patients. The rate of POAF was highest among those undergoing aortic valve replacement+coronary artery bypass grafting, aortic valve, and mitral valve replacement operations. The POAF patients had a higher unadjusted incidence of mortality, morbidity, hospital readmission, longer intensive care unit (ICU) and postoperative length of stay, and higher hospital costs. After risk adjustment, POAF was associated with a twofold increase in the odds of mortality (adjusted odds ratio=2.04, p<0.001), greater hospital resource utilization, and increased costs; POAF was associated with 48 additional ICU hours (p<0.001), 3 additional hospital days (p<0.001), and

Mitral repair is superior to replacement when associated with coronary artery disease.

3,000 (p<0.001) and

Superiority of moderate control of hyperglycemia to tight control in patients undergoing coronary artery bypass grafting

9,000 (p<0.001) of increased ICU and total hospital-related costs, respectively. CONCLUSIONS New onset POAF is associated with increased risk-adjusted mortality, hospital costs, and readmission rates. Protocols to reduce the incidence of POAF have the potential to significantly impact patient outcomes and the delivery of high-quality, cost-effective patient care.