Biatrial Anastomosis Research Articles

Stenting for superior vena cava obstruction in pediatric heart transplant recipients

Superior vena cava (SVC) obstruction can be a complication in heart transplant recipients. We reviewed our experience with relief of SVC obstruction using endovascular stents in pediatric heart transplant recipients. Study cohort included pediatric heart transplant recipients, followed at our institution, who required endovascular stent placement for SVC obstruction. Data retrieved retrospectively included cardiac diagnosis, age, and weight at transplant, surgical technique of transplant (bicaval vs. biatrial anastomosis), previous cardiovascular surgeries, presenting symptoms, date of SVC stent placement, and need for reintervention. From March 1990 to June 2006, 5.1% (7/138) pediatric heart transplant recipients who were followed at our institution had SVC obstruction requiring stent placement. Median age and weight at transplant was 9 months and 8.7 kg, respectively. Four patients previously had a cavopulmonary anastomosis. Transplant surgery involved bicaval anastomosis in 6 and biatrial in 1. Of the 7 patients included in the study, 2 were asymptomatic, 2 were symptomatic (1 with chylothorax, 1 with headache), and 3 were identified at the time of transplant surgery. Median time from transplant surgery to SVC stent placement was 2 months (0-14 months). Three patients required reintervention as redilation of SVC stent (n = 1) or additional SVC stent (n = 2). In one patient the stent migrated to the pulmonary artery but was retrieved. SVC obstruction can be an important complication following heart transplantation, especially in infants with previous cavopulmonary anastomosis, undergoing heart transplant using bicaval technique. SVC obstruction can be safely and effectively treated using endovascular stents.

Lost P’s, but Not Yet Forgotten

A 30-year-old man presenting with 2 months of increasing cough and worsening dyspnea with minimal exertion was diagnosed with nonischemic dilated cardiomyopathy. An initial ECG revealed sinus tachycardia and left atrial enlargement. Despite maximal medical management, his symptoms and cardiac function did not improve. Orthotopic heart transplantation was performed using biatrial anastomosis from a 27-year-old donor. In this procedure, the donor atria are sutured to intact remnants of the native right and left atria, allowing for minimal interruption of blood flow from both vena cavae and all the recipient’s pulmonary veins while requiring fewer anastomotic connections. The recipient’s native right and left atrial remnants are physically and electrically intact and are sutured into and electrically isolated from the donor atria. A postoperative ECG was performed (Figure 1), revealing …

STENTING FOR SUPERIOR VENA CAVA OBSTRUCTION IN PEDIATRIC HEART TRANSPLANT RECIPIENTS.

Purpose Superior vena cava (SVC) obstruction can be a complication of reconstructive surgery done at the time of heart transplantation. Pediatric patients are at a higher risk compared with adults due to their smaller size, growth potential, multiple central line access, and complex native venous anatomy related to congenital heart disease. SVC obstruction can not only make these patients symptomatic but also limit access for obtaining cardiac biopsy. We reviewed our experience with relief of SVC obstruction using endovascular stents in pediatric heart transplant recipients. Methods A retrospective review of medical records of patients ( Results From March 1990 to June 2006, 138 pediatric patients were followed at our institution after heart transplantation. Of these, 7 developed SVC obstruction and formed the study cohort. Median age at transplant was 9 months (2.5-180 months); median weight was 8.7 kg (3.4-76 kg); cardiac diagnosis was heterotaxy syndrome (3), atrioventricular canal defect (1), double-outlet right ventricle (1), tricuspid atresia (1), hypoplastic left heart syndrome (1). Surgical technique at transplant involved cavocaval anastomosis in six and biatrial anastomosis in one. One patient had a SVC stent placed at transplant surgery due to severe obstruction. One patient presented with persistent pleural effusions and facial swelling; others were asymptomatic and diagnosed by echocardiography and/or cardiac catheterization. Median time from transplant surgery to SVC stent placement was 2 months (0-14 months). During a median follow-up of 4 years since transplant, one required redilation of SVC stent and two required an additional SVC stent. There were no complications related to stent placement. Conclusion SVC obstruction can be an important although uncommon complication, especially in infants undergoing heart transplant using cavocaval technique. This obstruction can be safely and effectively relieved using endovascular stents.

Norman E. Shumway, M.D., Ph.D. (1923 – 2006) Surgical Innovator

Norman E. Shumway, M.D., Ph.D. (1923 – 2006) Surgical Innovator

Our Experience in Cardiac Transplantation in Baskent University

Recently cardiac transplantation has an important place in treatment of end-stage cardiac failure. In Turkey between 2003 and 2005 at 10 centers 64 cardiac transplantations were performed including five at our facility. Herein we have presented our results. All patients were men of mean age 34.2 ± 10.7 (17 to 44) years. Upon preoperative echocardiography their mean ejection fraction was 18% ± 3.27% (17% to 23%). Pulmonary vascular resistance was 4.47 wood unit in one patient and in one case, there was Rh incompatibility between donor and recipient. We used HTK solution for protection of donor hearts. Mean ischemia time was 251.2 ± 62.7 minutes (155 to 314). Mean aortic clamping time was 84 ± 4.7 minutes (80 to 90). In all patients we performed a biatrial anastomosis technique. Hemofiltration was used to prevent hemodilution during operation. In the postoperative period four patients had acute renal dysfunction; one, a minor cerebrovascular accident; two, reoperated because of bleeding; one, cholestasis; one, temporary atrio-ventricular block; and one, mediastinitis. Mean follow-up time was 15.6 ± 19.7 months (2 to 50). Neither early nor late mortality has occurred. All patients are in New York Heart Association class I. In all cases we used triple immunosuppressive therapy. In the follow-up period the mean number of cardiac biopsies per patient was 4.2 ± 3.03 (2 to 8). Two cases had cardiac catheterization. As a complication of cardiac biopsy, pericardial tamponade developed in one patient; in another one we observed a right ventricular aneursym after cardiac biopsy. Cardiac transplantation was performed with low mortality and morbidity rates in end-stage cardiac failure patients with longer life expectancy and higher life quality. Unfortunately in our country, because of difficulties to find donor hearts, cardiac transplantations were small in number. For better results, we need a larger series.

Successful Heart Transplantation After 13 Hours of Donor Heart Ischemia With the Use of HTK Solution: A Case Report

Introduction For heart transplantation (HTx), the recommended ischemic time (IT) for donor heart is not to exceed 6 hours. Though Dr Christiaan Barnard used a donor heart with IT of 16 hours, 50 minutes with a portable hypothermic perfusion system in 1981, the recorded IT of donor hearts reported recently is 8 hours, with no adverse effects. Case report The patient, a 14-year-old boy of blood type O, was diagnosed with cardiomyopathy at age 12. In early September 2003, the patient was recommended for HTx. His condition deteriorated 18 days later with low CO, elevated pulmonary vascular resistance, and frequent ventricular tachycardia, further complicated by pneumonia and multiorganism infections, which were contraindications for HTx. On September 22, 2003, a donor heart of blood type O was available 370 km away. Another patient of blood type B with severe heart failure was matched for the HTx. During the intervening time, another donor heart of blood type B became available locally. We matched the type B donor heart to the type B recipient. Since the type O donor heart seemed to be wasted, we performed HTx for the boy. Though preserved for 12 hours in cold cardioplegia, the donor heart was implanted with biatrial anastomosis that took 1 hour. The total IT of this donor heart was 13 hours. The recipient recovered and was discharged 3 months later. Conclusions The IT of 13 hours for this donor heart is believed to be a world record. Our experience demonstrates that preservation time of donor heart may exceed 6 hours.

Mechanisms of tricuspid valve regurgitation after heart transplantation

Objectives: Tricuspid regurgitation (TR) is a common complication after heart transplantation (HTx). We investigated the mechanism of TR development in patients undergoing HTx using the standard biatrial anastomosis technique.

Heart transplantation at Cheng Hsin General Hospital in Taiwan: 15-year experience

Heart transplantation (HTx) in Taiwan, which started in 1987, now includes more than 500 cases. From July 1988 to September 2003, we performed 215 cases of orthotopic HTx in 164 male and 51 female recipients of mean age of 47.3 ± 14.3 years, (range 2.7 to 74.9 years). The leading etiologies were dilated cardiomyopathy (CMP), 68.5%; ischemic CMP, 20.2%; and valvular CMP, 4.2%. The actuarial survival rates at 1, 5, and 10 years are 88.3%, 77.1%, and 57.2%, respectively. We performed the first case of HTx in Asia after bridging for 14 days with an indigenous total artificial heart (TAH; the Phoenix-7 model); we performed the first case of infant HTx without blood transfusion and also the first case of autotransplantation of heart for repair of a left ventricular rupture after a mitral valve replacement. These cases were all successful with the longest surviving HTx recipient in Asia. We have used the biatrial anastomosis technique in all cases. We discovered familial CMP due to mitochondrial defects in two pediatric cases. Because of the scarcity of donor hearts, we have used size-mismatched hearts as well as suboptimal and hepatitis-positive donor hearts, all with satisfactory outcomes. Our experience has shown comparable results to Western programs, with efficacy and cost-effectiveness. We find the technique of biatrial anastomosis for orthotopic HTx to result in a low incidence of tricuspid regurgitationand conduction anomalies. The use of suboptimal and size-mismatched donor hearts is also promising.

840 Mechanism and prevention of tricuspid regurgitation in patients transplanted according to the biatrial anastomosis technique: an echocardiographic study on 150 patients

840 Mechanism and prevention of tricuspid regurgitation in patients transplanted according to the biatrial anastomosis technique: an echocardiographic study on 150 patients

Invited commentary

Wilhelmi and colleagues from Hannover Medical School have presented an echocardiographic assessment of long-term survivors of heart transplantation. Their results corroborate those demonstrated by other surveys, ie, (1) general “preservation” of left ventricular morphology and systolic function beyond the first decade and (2) a significant incidence of left atrial dysfunction, right ventricular enlargement and tricuspid regurgitation. The main problem with isolated surveys of graft left ventricular function after transplantation is the inherent bias in the survey method, ie, their authors are most often interested in the characteristics of current survivors rather than also in those that died. The study design biases the cohort in favor of normal graft function because significant graft dysfunction is fatal in short order. A more important statistic is the actuarial freedom from graft LV dysfunction at 10 years. This is a challenging calculation because one may not know when to include patients for whom LV dysfunction was a finding proximate to a fatal incidence of infection or rejection. The bias, in any case, allows little to be said about results and little to act upon. In designing clinical surveys, it is important to see the forest through the trees, ie, (1) the actuarial freedom from death at 10 years following transplantation is only 38%–42% in four recent reports and (2) the actuarial freedom from significant CAD decreases steadily with years post-transplantation and is 50%–70% at 10 years. In the present era, surveys of standard clinical databases should be designed to detect trends and suggest properly conducted studies of factors pertinent to survival and quality of life. The effectiveness of OKT3 induction, CMV prophylaxis, Ca++ channel blockers, and lipid-lowering agents were first suspected from such databases. The future dataset may include the plethora of both donor and recipient genotypes (beyond the major histocompatibility complex) pertinent to the immunological response. An example is the donor interleukin-4 promoter gene, which was recently presented by Bijlsma and colleagues from Utrecht. An analysis of their polymorphisms may pinpoint the most important immunological processes and thus suggest therapeutic interventions if not better donor/recipient matching. The authors’ data on right ventricular (RV) and tricuspid valve function suggest the “other evil” facing long-term survivors of transplantation. Twenty nine percent of patients had impaired RV function, often associated with significant tricuspid regurgitation. This finding may be consistent with the fact that, despite “well-preserved” left ventricular function, 23 out of their 65 patients were in NYHA Class III or IV. Prior studies, particularly by Chan and colleagues at Stanford, show that TR is common and, although initially asymptomatic, ultimately becomes so and may well require valve replacement. The time has come to understand the causes of this problem. If the problem relates primarily to the technique of bi-atrial anastomosis, the alternative technique should be used. If the problem is due primarily to the technique of endomyocardial biopsy, we should be compulsive in modifying the catheter sheath (as has been previously suggested), increasing the precision of the technique using echocardiographic guidance, and in continuing to seek sensitive and specific noninvasive methods of detecting acute rejection.

Cardiac pacemakers in the transplanted heart: short term with the biatrial anastomosis and unnecessary with the bicaval anastomosis.

Sinus node dysfunction occurs commonly after orthotopic heart transplantation and may be caused by surgical trauma, ischemia to the sinus node, rejection, drug therapy and increasing donor age. In the past, using the standard biatrial technique described originally by Lower and Shumway, many series have reported permanent pacing in more than 10% of patients. Unlike sinus node dysfunction in nontransplanted patients, which typically worsens with time, sinus node dysfunction in the transplanted heart usually improves over a period of weeks to months. Delaying the implantation of a permanent pacemaker may render it unnecessary. The development of the bicaval technique for implantation of the donor heart appears to have decreased even further or even eliminated the need for early permanent pacing. Because sinus node dysfunction in the transplanted heart does not predict subsequent development of atrioventricular (AV) node dysfunction, rate-responsive atrial pacing should be used in the majority of cases. Even after appropriate pacing for sinus node dysfunction, the sinus node may recover and permanent pacing may be discontinued. AV conduction abnormalities are far less common and generally occur late after transplantation. Dual-chamber pacing is required and permanent pacing should be continued indefinitely.

Tricuspid regurgitation severity after orthotopic heart transplantation is not reduced by a caval to caval anastomotic technique

Tricuspid regurgitation (TR) is common after orthotopic heart transplantation (OHT). It has been hypothesized that TR severity should be less with newer surgical techniques utilizing a caval to caval anastomosis since atrial size remains closer to normal. We compared TR severity approximately 1-2 months and 6-12 months following OHT in the first 56 transplant recipients who had a bicaval anastomosis pedormed at our institution with a similar cohort of patients who had a biatrial anastomosis (n=57). TR severity was graded from none (0) to severe (4) by visual assessment of color Doppler flow. The velocity of the TR jet was measured as an index of RV systolic pressure in those studies where TR was detected. Patients were excluded for incomplete data,