Donation after circulatory death: the current state and technical approaches to organ procurement.

PURPOSE OF REVIEW: In this review, we discuss the current state of donation after circulatory death (DCD). We define the DCD donor and describe the current protocols in management of the DCD patient. We then discuss current techniques in organ procurement of the lung and abdominal organs. RECENT FINDINGS: Although donation after brain death is preferable to DCD, recent data have demonstrated acceptable early outcomes in both thoracic and abdominal organ transplant. In spite of advancements in surgical techniques and organ preservation, much has yet to be learned to minimize warm ischemia time and reperfusion injury in the DCD population. SUMMARY: In light of the continually growing disparity between organ supply and demand, DCD has regained traction as a means to increase the donor pool.

Bariatric surgery to unload the stressed heart: a metabolic hypothesis.

Obesity is an independent risk factor for cardiovascular disease. Data from the Framingham Study have reported a higher incidence of heart failure in obese individuals compared with a normal cohort. The body initially copes with the abundance of fuel present in an obese milieu by storing it in adipose tissue. However, when the storage capacity is exceeded, the excess energy is taken up and stored ectopically as fat in vital organs such as the heart. Indeed, intramyocardial lipid overload is present in hearts of obese patients, as well as in hearts of animal models of obesity, and is associated with a distinct gene expression profile and cardiac dysfunction. By imposing a metabolic stress on the heart, obesity causes it to hypertrophy and ultimately to fail. Conventional measures to treat obesity include diet, exercise, and drugs. More recently, weight loss surgery (WLS) has achieved increasing prominence because of its ability to reduce the neurohumoral load, normalize metabolic dysregulation, and improve overall survival. The effects of WLS on systemic metabolic, neurohumoral, and hemodynamic parameters are well described and include an early normalization of serum glucose and insulin levels as well as reduction in blood pressure. WLS is also associated with reverse cardiac remodeling, regression of left ventricular hypertrophy, and improved left ventricular and right ventricular function. By targeting the source of the excess energy, we hypothesize that WLS improves contractile function by limiting exogenous substrate availability to the metabolically overloaded heart. These changes have also been found to be associated with increased levels of adiponectin and improved insulin sensitivity. Taken together, the sustained beneficial effects of WLS on left ventricular mass and function highlight the need to better understand the mechanism by which obesity regulates cardiovascular physiology.

Intraoperative Cortical Asynchrony Predicts Abnormal Postoperative Electroencephalogram.

BACKGROUND: Postoperative electroencephalograms (EEGs) can identify seizure activity and neurologic dysfunction in high-risk neonates requiring cardiac surgical procedures. Although intraoperative EEG monitoring is uncommon, variations in cerebral blood flow and temperature during antegrade cerebral perfusion (ACP) can manifest as cortical asynchrony during EEG monitoring. We hypothesized that intraoperative EEG cortical asynchrony would identify neonates at risk for abnormal postoperative EEG tracings. METHODS: Neonates requiring ACP for cardiac repair or palliation had continuous baseline, intraoperative, and postoperative hemodynamic and EEG monitoring. Synchronous and asynchronous cortical bursts were quantified during (1) cooling before ACP, (2) ACP, and (3) rewarming. Asynchronous bursts were defined as interhemispheric variations in electrical voltage or frequency. Neonates were divided into 2 groups, those with and without an abnormal postoperative EEG, which was defined as either persistent asynchrony for more than 2 hours or seizure activity on EEG. RESULTS: Among 40 neonates, 296 asynchronous bursts were noted, most commonly during rewarming. Eight (20%) neonates had an abnormal postoperative EEG (seizure activity, n = 3; persistent asynchrony, n = 5). Baseline demographics and intraoperative hemodynamics were similar between the groups. However, the total number of intraoperative asynchronous bursts was greater in neonates with an abnormal postoperative EEG (17 [11, IQR:24] vs 3 [IQR:1, 7]; P < .001). Multivariate analysis confirmed that the number of asynchronous bursts was independently associated with an abnormal postoperative EEG (odds ratio,1.35; confidence interval,:1.10, 1.65; P = .004). CONCLUSIONS: Neonates with a greater number of intraoperative asynchronous cortical bursts had an abnormal postoperative EEG.

Prolonged methylphenidate treatment alters the behavioral diurnal activity pattern of adult male Sprague-Dawley rats.

Methylphenidate (MPD) is becoming a drug of abuse among adult professionals and students, alike. Yet, few studies have investigated its long-term effects on the adult population. We hypothesized that prolonged administration of MPD leads to changes in the diurnal horizontal activity (HA) pattern, an effect persisting beyond acute drug effects. Four groups of adult male Sprague-Dawley rats (N=32) were divided into a saline/control, 0.6, 2.5, or 10.0 mg/kg MPD group. Each group was treated with saline on experimental day 1, followed by six consecutive days of designated treatment (days 2-7), then, after three consecutive days of washout (days 8-10), each group was re-challenged with its respective treatment (day 11). Activity was monitored continuously throughout the 11 experimental days. There was a dose-dependent increase in HA in the first hour post-injection. The 0.6 mg/kg MPD group exhibited changes in diurnal activity pattern only during the wash-out period. The 2.5 mg/kg MPD group exhibited the most profound changes in HA after 6 days of continuous injection, washout, and MPD re-challenge (p<0.05, p=0.001, p<0.001) respectively, and the 10.0 mg/kg MPD group exhibited changes during the washout and re-challenge periods (p<0.01, p<0.001), respectively. In conclusion, prolonged administration of MPD modulated the diurnal HA pattern in a dose-dependent manner.

Primary pulmonary leiomyosarcoma with invasion of the pulmonary vein-A case report.

INTRODUCTION: Primary pulmonary leiomyosacromas are a subset of the rare sarcomatous lung neoplasms, found to be less than 0.5% of the organ's primary malignant tumors (Attanoos et al., 1996). PRESENTATION OF CASE: We describe here a case of a 69-year-old woman who presented with heart palpitations, incidentally found to have a large lung mass abutting the left inferior pulmonary veins. Challenging tissue diagnosis led to invasive alternatives; attempted full neoplastic resection and pneumonectomy. DISCUSSION: The mainstay of treatment for these tumors is complete surgical resection. Chemotherapy and radiation can be helpful adjuncts as well. CONCLUSION: This case presents a unique invasion pattern of a primary leiomyosarcoma of the lung, our diagnostic process, and surgical intervention.

Native Mitral Stenosis Treated With Transcatheter Mitral Valve Replacement.

Surgical treatment of mitral stenosis with extreme calcification remains a challenge. Recently, the balloon-expandable valve prosthesis, anchored by radial force, offers a new option for these patients. We present 2 cases of transcatheter mitral valve replacement in patients with severe native mitral valve stenosis and annular calcification deemed too extensive for conventional surgical techniques.

Current and emerging management options for patients with Morquio A syndrome.

Morquio A syndrome is a lysosomal storage disease associated with mucopolysaccharidosis. It is caused by a deficiency of the lysosomal enzyme, N-acetylgalactosamine-6-sulfate sulfatase, which leads to accumulation of keratan sulfate and condroitin-6 sulfate in multiple organs. Patients present with multisystemic complications involving the musculoskeletal, respiratory, cardiovascular, and digestive systems. Presently, there is no definitive cure, and current management options are palliative. Enzyme replacement therapy and hematopoietic stem cell therapy have been proven effective in certain lysosomal storage diseases, and current investigations are underway to evaluate the effectiveness of these therapies and others for the treatment of Morquio A syndrome. This review discusses the current and emerging treatment options for Morquio A syndrome, citing examples of the treatment of other mucopolysaccharidoses.

Progressive regression of left ventricular hypertrophy two years after bariatric surgery.

BACKGROUND: Obesity is a systemic disorder associated with an increase in left ventricular mass and premature death and disability from cardiovascular disease. Although bariatric surgery reverses many of the hormonal and hemodynamic derangements, the long-term collective effects on body composition and left ventricular mass have not been considered before. We hypothesized that the decrease in fat mass and lean mass after weight loss surgery is associated with a decrease in left ventricular mass. METHODS: Fifteen severely obese women (mean body mass index [BMI]: 46.7+/-1.7 kg/m(2)) with medically controlled hypertension underwent bariatric surgery. Left ventricular mass and plasma markers of systemic metabolism, together with body mass index (BMI), waist and hip circumferences, body composition (fat mass and lean mass), and resting energy expenditure were measured at 0, 3, 9, 12, and 24 months. RESULTS: Left ventricular mass continued to decrease linearly over the entire period of observation, while rates of weight loss, loss of lean mass, loss of fat mass, and resting energy expenditure all plateaued at 9 [corrected] months (P <.001 for all). Parameters of systemic metabolism normalized by 9 months, and showed no further change at 24 months after surgery. CONCLUSIONS: Even though parameters of obesity, including BMI and body composition, plateau, the benefits of bariatric surgery on systemic metabolism and left ventricular mass are sustained. We propose that the progressive decrease of left ventricular mass after weight loss surgery is regulated by neurohumoral factors, and may contribute to improved long-term survival.

Body weight, insulin resistance, and serum adipokine levels 2 years after 2 types of bariatric surgery.

OBJECTIVE: Bariatric surgery reverses obesity-related comorbidities, including type 2 diabetes mellitus. Several studies have already described differences in anthropometrics and body composition in patients undergoing Roux-en-Y gastric bypass compared with laparoscopic adjustable gastric banding, but the role of adipokines in the outcomes after the different types of surgery is not known. Differences in weight loss and reversal of insulin resistance exist between the 2 groups and correlate with changes in adipokines. METHODS: Fifteen severely obese women (mean body mass index [BMI]: 46.7 kg/m(2)) underwent 2 types of laparoscopic weight loss surgery (Roux-en-Y gastric bypass=10, adjustable gastric banding=5). Weight, waist and hip circumference, body composition, plasma metabolic markers, and lipids were measured at set intervals during a 24-month period after surgery. RESULTS: At 24 months, patients who underwent Roux-en-Y were overweight (BMI 29.7 kg/m(2)), whereas patients who underwent gastric banding remained obese (BMI 36.3 kg/m(2)). Patients who underwent Roux-en-Y lost significantly more fat mass than patients who underwent gastric banding (mean difference 16.8 kg, P<.05). Likewise, leptin levels were lower in the patients who underwent Roux-en-Y (P=.003), and levels correlated with weight loss, loss of fat mass, insulin levels, and Homeostasis Model of Assessment 2. Adiponectin correlated with insulin levels and Homeostasis Model of Assessment 2 (r=-0.653, P=.04 and r=-0.674, P=.032, respectively) in the patients who underwent Roux-en-Y at 24 months. CONCLUSION: After 2 years, weight loss and normalization of metabolic parameters were less pronounced in patients who underwent gastric banding compared with patients who underwent Roux-en-Y gastric bypass. Our findings require confirmation in a prospective randomized trial.

Dramatic reversal of derangements in muscle metabolism and left ventricular function after bariatric surgery.

OBJECTIVE: The study objective was to define muscle metabolic and cardiovascular changes after surgical intervention in clinically severe obese patients. METHODS: Obesity is a state of metabolic dysregulation that can lead to maladaptive changes in heart and skeletal muscle, including insulin resistance and heart failure. In a prospective longitudinal study, 43 consecutive patients underwent metabolic profiling, skeletal muscle biopsies, and resting echocardiograms at baseline and 3 and 9 months after bariatric surgery. RESULTS: Body mass index decreased (mean changes, 95% confidence interval [CI]): 7.7 kg/m(2) (95% CI, 6.70-8.89) at 3 months and 5.6 kg/m(2) (95% CI, 4.45-6.80; P<.0001) at 9 months after surgery, with restoration of insulin sensitivity and decreases in plasma leptin at the same time points. Concurrent with these changes were dramatic decreases in skeletal muscle transcript levels of stearoyl coenzyme-A desaturase and pyruvate dehydrogenase kinase-4 at 3 and 9 months (P<.0001, for both) and a significant decrease in peroxisome proliferation activated receptor-alpha-regulated genes at 9 months. Left ventricular relaxation impairment, assessed by tissue Doppler imaging, normalized 9 months after surgery. CONCLUSION: Weight loss results in the reversal of systemic and muscle metabolic derangements and is accompanied by a normalization of left ventricular diastolic function.