SciCombinator

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Journal: The Journal of thoracic and cardiovascular surgery

170

BACKGROUND: Preoperative extracorporeal membrane oxygenation (ECMO) is a risk factor for poor outcome and currently considered a contraindication to lung transplantation. The lung allocation score system was introduced in May 2005 and prioritizes lung allocation to those with the greatest respiratory impairment. The purpose of this study is to determine whether ECMO as a bridge to lung transplantation is an acceptable option to support those in respiratory failure until donor lungs become available in the lung allocation score era. METHOD: A retrospective review of 715 consecutive lung transplants performed between May 2005 and September 2011 was conducted using a prospectively collected institutional registry database. Twenty-four lung transplants (3.4%) were performed in the 31 patients with attempted pretransplant ECMO; 7 patients who received ECMO patients did not survive or were deemed unfit for transplantation. These patients were compared with a control group of 691 patients who did not receive pretransplant ECMO. RESULTS: The duration of pretransplant ECMO was 171 ± 242 hours (median, 91 hours). Venovenous ECMO was used for respiratory failure in 15 patients, whereas venoarterial ECMO was used for circulatory collapse due to pulmonary hypertension in 9 patients. Patients in the retransplant ECMO group were younger (46 ± 15 years vs 57 ± 14 years, P < .01) compared with the control group, with no difference in recipient gender (male/female: 10/14 vs 380/311), donor age (33 ± 14 years vs 36 ± 15 years), or donor gender (male/female: 10/14 vs 352/339). Emphysema was less common (1, 4% vs 260, 38%, P < .01), and cystic fibrosis (5, 21% vs 72, 10%, P = .09), redo lung transplant (3, 13% vs 28, 4%, P = .08), and bronchiectasis (2, 8% vs 6, 1%, P = .03) were more common in the pretransplant ECMO group. Patients in the pretransplant ECMO group had a significantly higher lung allocation score (87 ± 9 vs 44 ± 15, P < .01). All patients in the pretransplant ECMO group underwent double lung transplants on pump (cardiopulmonary bypass/ECMO), and single lung transplants were performed in 171 patients (25%) and pump was used in 243 patients (35%) in the control group. The cardiopulmonary bypass time was longer in the pretransplant ECMO group (277 ± 69 minutes vs 225 ± 89 minutes, P = .02), with no difference in ischemic time (343 ± 93 minutes vs 330 ± 98 minutes, P = .54). Cadaveric lobar lung transplants were performed because of the urgency to overcome size mismatch with an oversized donor more frequently in 25% (n = 6, no mortality with the longest follow-up at 6 years) of patients in the pretransplant ECMO group versus 0.3% (n = 2) of patients in the control group (P < .01). Post-transplant ECMO was used for primary graft dysfunction in 13 patients (54%) in the pretransplant ECMO group and 41 patients (6%) in the control group (P < .01). The median hospital stay was 46 days in the pretransplant ECMO group versus 27 days in the control group (P = .16). The actuarial survivals after lung transplants at 1, 3, 6, 12, and 24 months were 96%, 88%, 83%, 74%, and 74%, respectively, in the pretransplant ECMO group, and 97%, 94%, 90%, 83%, and 74%, respectively, in the control group (P = .787). CONCLUSIONS: Although the incidence of primary graft dysfunction requiring post-transplant ECMO is higher and the hospital stay is longer in patients receiving pretransplant ECMO, the graft survival is good (2-year survival, 74%). ECMO is efficacious as a bridge to lung transplantation with good post-lung transplant outcomes.

Concepts: Pulmonology, Cystic fibrosis, Organ transplant, Pulmonary hypertension, Lung transplantation, Extracorporeal, Extracorporeal membrane oxygenation, Lung allocation score

29

The present analysis of the Surgical Treatment for Ischemic Heart Failure randomized trial data examined the left ventricular volumes at baseline and 4 months after surgery to determine whether any magnitude of postoperative reduction in end-systolic volume affected survival after coronary artery bypass grafting alone compared with bypass grafting plus surgical ventricular reconstruction.

Concepts: Cardiology, Heart

28

Pulmonary venous obstruction (PVO) is an important cause of late mortality in total anomalous pulmonary venous connection (TAPVC). We aimed to describe current practices for the management of postoperative PVO and the efficacy of the different interventional procedures.

Concepts: Lung, Heart, Vein, Total anomalous pulmonary venous connection

28

The aim of the study was to determine whether routine left atrial appendage ligation in cardiac surgery would reduce the risk of postoperative atrial fibrillation-related cerebrovascular accident.

Concepts: Heart, Atrial fibrillation, Left atrial appendage occlusion, Left atrial appendage, Cerebrovascular disease

28

Cardiac surgery patients are treated with antifibrinolytic agents to reduce intra- and postoperative bleeding. Until 2007, lysine analogues (aminocaproic acid and tranexamic acid) and serine protease inhibitors (aprotinin) were recommended. In 2008, the U.S. Food and Drug Administration prohibited aprotinin use because of associated postoperative complications, including cerebrovascular accidents and renal failure. This work aimed at reevaluating the efficacy and safety of aprotinin versus tranexamic acid in patients undergoing elective coronary artery bypass surgery.

Concepts: Atherosclerosis, Heart, Artery, Coronary circulation, Serine protease, Cardiovascular system, Coronary artery bypass surgery, Antifibrinolytics

28

OBJECTIVE: A supra-annular aortic valve prosthesis is often used for aortic valve replacement in patients with a small aortic annulus. However, which suture technique provides the best valve performance has not been studied. We aimed to compare valve performance between 2 different suture techniques. METHODS: We reviewed 152 patients undergoing aortic valve replacement with a 19- or 21-mm Carpentier-Edwards Perimount Magna aortic bioprosthesis (Edwards Lifesciences, Irvine, Calif) between June 2008 and December 2010. Simple interrupted sutures were used in 102 patients (group A, 19-mm prosthesis in 47 patients and 21-mm prosthesis in 55 patients), and noneverting mattress sutures were used in 50 patients (group B, 19-mm prosthesis in 20 patients and 21-mm prosthesis in 30 patients). Transthoracic echocardiograms were performed at baseline and before discharge in all patients and 1 year after surgery in 141 patients. We compared the effective orifice area and incidence of prosthesis-patient mismatch (effective orifice area index <0.85 cm(2)/m(2)) between 2 groups. RESULTS: The mean postoperative effective orifice areas were 1.41 ± 0.32 cm(2)/m(2) in group A and 1.30 ± 0.28 cm(2)/m(2) in group B (P = .025). The incidence of prosthesis-patient mismatch was 29% in group A and 56% in group B (P = .002). A multivariate analysis has shown that simple interrupted suturing is a negative predictor of prosthesis-patient mismatch (odds ratio, 0.33; 95% confidence interval, 0.13-0.83; P = .018). At 1 year, the incidence of prosthesis-patient mismatch was 27% in group A and 47% in group B (P = .023). CONCLUSIONS: Simple interrupted sutures provide larger effective orifice areas and reduce the incidence of prosthesis-patient mismatch after aortic valve replacement with a small supra-annular bioprosthesis. This suture technique is preferred in those patients to maximize valve performance.

Concepts: Surgical suture, Aortic valve, Simple interrupted stitch

27

OBJECTIVE: Current pulsatile ventricular assist devices operate asynchronous with the left ventricle in fixed-rate or fill-to-empty modes because electrocardiogram-triggered modes have been abandoned. We hypothesize that varying the ejection delay in the synchronized mode yields more precise control of hemodynamics and left ventricular loading. This allows for a refined management that may be clinically beneficial. METHODS: Eight sheep received a Thoratec paracorporeal ventricular assist device (Thoratec Corp, Pleasanton, Calif) via ventriculo-aortic cannulation. Left ventricular pressure and volume, aortic pressure, pulmonary flow, pump chamber pressure, and pump inflow and outflow were recorded. The pump was driven by a clinical pneumatic drive unit (Medos Medizintechnik AG, Stolberg, Germany) synchronously with the native R-wave. The start of pump ejection was delayed between 0% and 100% of the cardiac period in 10% increments. For each of these delays, hemodynamic variables were compared with baseline data using paired t tests. RESULTS: The location of the minimum of stroke work was observed at a delay of 10% (soon after aortic valve opening), resulting in a median of 43% reduction in stroke work compared with baseline. Maximum stroke work occurred at a median delay of 70% with a median stroke work increase of 11% above baseline. Left ventricular volume unloading expressed by end-diastolic volume was most pronounced for copulsation (delay 0%). CONCLUSIONS: The timing of pump ejection in synchronized mode yields control over left ventricular energetics and can be a method to achieve gradual reloading of a recoverable left ventricle. The traditionally suggested counterpulsation is not optimal in ventriculo-aortic cannulation when maximum unloading is desired.

Concepts: Blood, Cardiology, Heart, Ventricle, Aorta, Left ventricle, Ventricular assist device, Aortic valve

27

OBJECTIVE: To introduce a modified Sakakibara classification system for a ruptured sinus of Valsalva aneurysm. METHODS: From February 1, 2006, to January 31, 2012, surgical repair was performed on 159 patients with a ruptured sinus of Valsalva aneurysm at Fu Wai Hospital. Of the 159 patients, 105 were men and 54 were women, with a mean age of 33.4 ± 10.7 years. The patients were divided into 5 types according to the site of the ruptured sinus of Valsalva aneurysm rupture. The 5 types were as follows: type I, rupture into the right ventricle just beneath the pulmonary valve (n = 66); type II, rupture into or just beneath the crista supraventricularis of the right ventricle (n = 17); type III, rupture into the right atrium (type IIIa, n = 21) or right ventricle (type IIIv, n = 6) near or at the tricuspid annulus; type IV, rupture into the right atrium (n = 46); and type V, other rare conditions, such as rupture into the left atrium, left ventricle, or pulmonary artery (n = 3). RESULTS: Repair of ruptured sinus of Valsalva aneurysm through aortotomy was used in 100% of those with type V and 50% of those with type IIIv. In most patients with types I, II, and IV, repair was achieved through the cardiac chamber of the fistula exit (71.2%, 64.7%, and 69.6%, respectively). Both routes of repair were used in 76.2% of patients with type IIIa. No early and late deaths occurred. The aortic valve was replaced in 33 patients. One patient (type IV) underwent reoperation for a residual shunt during the follow-up period. CONCLUSIONS: The modified classification system for ruptured sinus of Valsalva aneurysm is simple and practical for clinical use.

Concepts: Blood, Heart, Cardiovascular system, Right ventricle, Ventricle, Tricuspid valve, Left ventricle, Aortic valve

27

OBJECTIVE: We sought to investigate the impact of 22q11.2 deletion on perioperative outcome in tetralogy of Fallot. METHODS: We conducted a retrospective review of patients with tetralogy of Fallot who underwent complete surgical reconstruction at The Children’s Hospital of Philadelphia between 1995 and 2006. Inclusion criteria included diagnosis of tetralogy of Fallot and known genotype. Fisher exact and Mann-Whitney tests were used for categoric and continuous variables, respectively. Regression analysis was used to determine whether deletion status predicts outcome. RESULTS: We studied 208 subjects with tetralogy of Fallot, 164 (79%) without and 44 (20%) with 22q11.2 deletion syndrome. There were no differences in sex, race, gestational age, age at diagnosis, admission weight, and duration of mechanical ventilation. Presenting anatomy, survival, complications and reoperations were also comparable between patients with and without 22q11.2 deletion syndrome. Those with 22q11.2 deletion syndrome had more aortopulmonary shunts preceding complete surgical repair (21% vs 7%, P = .02). This association was present after adjustment for presenting anatomy (stenosis, atresia, or absence of pulmonary valve and common atrioventricular canal) and surgical era. In addition, those with 22q11.2 deletion syndrome had longer cardiopulmonary bypass time (84 vs 72 minutes, P = .02) and duration of intensive care (6 vs 4 days, P = .007). CONCLUSIONS: Genotype affects early operative outcomes in tetralogy of Fallot resulting, in particular, in longer duration of intensive care. Future studies are required to determine factors contributing to such differences in this susceptible population.

Concepts: Regression analysis, Hospital, Syndromes, Genetic disorders, Outcome, Tetralogy of Fallot, DiGeorge syndrome, Children's Hospital of Philadelphia

25

A hemiarch reconstruction, using deep hypothermic circulatory arrest, is the conventional approach for proximal aortic arch reconstruction, but it carries risks of neurologic events and coagulopathy. The addition of a hemiarch reconstruction to an aortic root replacement may prevent future aortic arch pathology. Outcomes of this approach at a tertiary care institution were examined to determine whether the addition of a hemiarch reconstruction to an aortic root replacement conferred any additional risk.

Concepts: Medicine, Hospital, Risk, Ascending aorta, Arteries of the thorax, Hazard prevention, Hedge, Volatility