Successful Endothelialization of Porcine Glutaraldehyde-Fixed Aortic Valves in a Heterotopic Sheep Model

PURPOSE

The purpose of our study was to evaluate the stability of an artificially seeded endothelial cell layer on porcine aortic prostheses under in vivo conditions in the arterial system.

DESCRIPTION

Ten female sheep were divided into two groups. Animals of the study group (n = 7) had dissection of their right external jugular vein for cell harvesting. Myofibroblasts and endothelial cells were labelled with PKH-26, seeded onto pretreated (10% citric acid) porcine glutaraldehyde-fixed aortic valves (Freestyle, Medtronic Inc, Duesseldorf, Germany), and the valves were implanted into the descending aorta. Controls (n = 3) received pretreated but unseeded valves. A shunt between the aortic arch and the left atrial appendage ensured systolic or diastolic leaflet motions, or both, that were documented by sonography. After 3 months the valves were explanted. Specimens for scanning electron microscopy and immunohistochemical staining were taken prior to implantation and after explantation.

EVALUATION

A neointimal proliferation was detected in the control group. No endothelial cells were found on the leaflets and the sinuses, but erythrocytes and thrombocytes were seen entrapped within the collagen fibers. Thrombus formation was documented macroscopically and histologically on the leaflets and the sinuses. In the study group a confluent endothelial cell layer was documented on the walls and leaflets. Neither neointimal proliferation nor any clots were seen. Some cells were still labelled positively indicating their origin from the initial cell seeding. No dilatation of any prosthesis was observed, but all valves showed slight thickening of the leaflets.

CONCLUSIONS

The artificially seeded endothelial cell layers remained stable under in vivo conditions in the arterial system. Biocompatibility of the prostheses seemed to be improved by reduction of thrombogenicity.

Freedom From Graft Vessel Disease in Heart and Combined Heart- and Kidney-transplanted Patients Treated With Tacrolimus-based Immunosuppression

BACKGROUND

In end-stage cardiomyopathy where concomitant chronic renal failure is a contraindication for cardiac transplantation (HTx), simultaneous heart and kidney transplantation (HKTx) may be the only feasible therapeutic option. Due to the increased donor shortage, the clinical outcome of combined HKTx patients on tacrolimus-based immunosuppression was assessed and compared with a group of HTx patients.

METHODS

Three hundred forty-nine HTxs, including 13 (4%) combined HKTxs, were performed since 1995. Two hundred twenty-one HTx and all HKTx recipients received tacrolimus-based immunosuppression. Acute rejection episodes (AREs), infections, renal function and clinical outcome were evaluated. Pre-operative renal diagnoses for HKTx patients included cystic nephropathy (n = 4), glomerulonephritis (n = 4), cytostatica-induced nephropathy (n = 1), chronic rejection after renal transplant (n = 1), reflux nephropathy (n = 2) and chronic calcineurin-inhibitor -induced nephropathy after HTx (n = 1). Twelve patients (92%) were on hemodialysis pre-operatively, 1 underwent implantation of a left ventricular assist device (LVAD) before HKTx.

RESULTS

After 4.7 +/- 2 years, 92% of HKTx compared with 85% of HTx patients had survived (p = 0.42). Acute cardiac rejection episodes were more frequent in HTx than in HKTx patients (0.04 +/- 0.09 vs 0.02 +/- 0.04 ARE/100 patient-days; p = 0.07). Incidence of infection was comparable (0.3 +/- 0.2 vs 0.5 +/- 0.4 infection/100 patient-days). Freedom from transplant vasculopathy was 100% in the HKTx group compared with 71% in the HTx group after 4 years (p = 0.04).

CONCLUSIONS

Tacrolimus-based immunosuppression yields promising long-term results in HKTx and HTx. The incidence of transplant vasculopathy seems to be lower after HKTx than after HTx. If these results are secondary to a protective effect of tacrolimus-induced tolerance or of tolerance-associated co-transplantation they will need to be investigated in prospective multicenter trials.

The Need for a Tailored Immunosuppression in Older Heart Transplant Recipients

Advanced recipient age is considered a relative contraindication for heart transplantation because it might be associated with increased morbidity and mortality. We analyzed 349 consecutive heart transplantations performed at our institution from 1995 to 2002 (n = 349, mean follow-up 3.5 +/- 2.5 years). The survival rate was lower in older recipients. Less chronic rejection but increased risk for infectious complications, renal failure and neoplasms indicate the need for decreased immunosuppression and effective infection prophylaxis in older recipients.

Mechanical Circulatory Support in Infants and Adults With the MEDOS/HIA Assist Device

Mechanical circulatory support is successfully applied to patients with low cardiac output. The MEDOS/HIA-System provides pulsatile ventricular assistance for pediatric and adult patients. Our experience with 13 consecutive patients with the MEDOS is reported. Perioperative survival was 84.6%, complications occurred in 61% (31% thrombembolism, 23% rethoracotomy, 7% infections). Mean duration of support was 17.6 +/- 14.6 days (1-45 days). Bilirubin decreased from 3.9 +/- 2.3 to 2.7 +/- 1.6 mg/dL; creatinine from 1.6 +/- 1 to 1.4 +/- 0.8 mg/dL; lactate from 5.8 +/- 4.2 to 1.7 +/- 1.5 (P = 0.027; Wilcoxon). All patients who underwent subsequent heart transplantation (6 of 13; 46%) were discharged from hospital. For 38.5% of the patients no organ offer was received. Mechanical circulatory support with the MEDOS/HIA-System can be performed successfully for bridging to transplantation. Secondary organ functions improve under this pulsatile circulatory assistance. Hemorrhage and thromboembolic events are the most frequent complications.

Mechanical Circulatory Support in Pediatric Patients with the MEDOS Assist Device

Mechanical circulatory support is successfully applied to patients with low cardiac output. The MEDOS-System provides pulsatile ventricular assistance for patients of all age groups, including neonates. We report our experience with seven consecutive pediatric patients with the MEDOS-VAD. The indication was bridge to transplantation in all patients. Mean age was 7.3 +/- 6.5 years (range 0.75-16.9 years) and mean weight was 26.3 +/- 21.7 kg (range 5.9-60 kg). Perioperative survival was 100%; complications occurred in six patients (86%; two cerebral embolism/bleeding, two rethoracotomy, two exchange of pump chamber due to thrombus formation after 4 and 9 days). Mean duration of support was 20.4 +/- 10.8 days (range 6-38 days). Bilirubin decreased from 3.5 +/- 2.6 mg/d to 2.1 +/- 1.2 mg/d. Hospital mortality was three of seven patients who did not receive an organ offer in time. All patients who underwent subsequent heart transplantation (four of seven patients; 57%) were discharged from the hospital. Mechanical circulatory support with the MEDOS-System can be performed successfully in pediatric patients of any age. Secondary organ functions improve under this pulsatile circulatory assistance. Hemorrhage and thromboembolic events are the most frequent complications.

Seeding of Human Endothelial Cells on Valve Containing Aortic Mini-Roots: Development of a Seeding Device and Procedure

PURPOSE

Complete covering of an artificial valvular scaffold with endothelial cells may prevent thromboembolic complications and lead to an excellent biocompatibility. For this purpose, we developed a seeding device for reproducible cell seeding on valve containing aortic roots.

DESCRIPTION

Human endothelial cells and fibroblasts were obtained from saphenous vein pieces. Cryopreserved aortic roots (n = 25) were put into an especially developed tube, set on a rotator, and incubated with the cell suspension. The device rotated in two axes (sagittal and axial), ensuring slight movements of the leaflets. The rotation alternated with resting periods, allowing cell attachment to the surface. Different resting periods were tested (groups 1, 2, and 3 were 30, 45, and 60 min, respectively; n = 5 each). Total incubation time was 24 hours followed by further culturing for 6 days. In two further groups (groups 4 and 5; n = 5 each), a modified inlay was used to allow the cell suspension to flow around the entire graft. In group 4 the grafts were again incubated with human endothelial cells; however, in group 5 pre-seeding with autologous fibroblasts was done in addition. Immunohistochemical staining with antibodies against factor VIII, CD31, laminin, collagen IV, and CD90 were done, and scanning electron microscopy was done after initial seeding and after 6 days in culture.

EVALUATION

Seeding resulted in homogenous cell layers on the luminal surface of the free walls in all groups. With resting periods of 45 minutes, these results were also obtained on the leaflets, whereas the other resting times resulted in defects of the endothelial cell layer on the cusps. After 6 days under culture conditions, the endothelial cell layers were confluent and viable, with the exception of the leaflets in group 1. With the modified inlay (groups 4 and 5), confluent cell layers were also achieved on the outer surface. In group 5 pre-seeding with autologous fibroblasts resulted in enhanced synthesis of extracellular matrix proteins, as was demonstrated with immunohistochemical staining for collagen IV and laminin.

CONCLUSIONS

With this newly developed seeding device, confluent cell layers on valve containing aortic roots were reproducibly achieved. The technique enables further experimental research and even clinical application.

A Low-Flow Adaptation Phase Improves Shear-Stress Resistance of Artificially Seeded Endothelial Cells

INTRODUCTION

The purpose of this study was to evaluate the effect of different adaptation phases on the shear-stress resistance of endothelial cells seeded artificially onto vascular prostheses and biological heart valves.

MATERIAL AND METHODS

Human endothelial cells (EC), fibroblasts (FB), and smooth muscle cells (SMC) were isolated from vena saphena magna pieces and expanded in culture. Group A: 15 polyurethane vascular grafts (20 mm diameter) were seeded with FB and SMC (53 +/- 1.2 million cells), followed by EC seeding (39 +/- 0.9 million cells). Group B: eight stentless porcine valves (Freestyle, Medtronic, USA) were seeded with FB (68 +/- 1.5 million cells) and EC (42 +/- 1.1 million cells). Shear-stress testing was done under pulsatile flow (pulse rate: 80 pulses/min.). Adaptation phase: flow was set to 0.9 +/- 0.3 l/min (systolic pressure: 40 - 50 mm Hg). High flow was 3.2 +/- 0.6 l/min. (systolic pressure: 140 - 160 mm Hg) and lasted over four hours in all groups. The vascular grafts were divided into three groups (n = 5 each): group 1 (high flow immediately), group 2 (adaptation phase of 15 minutes), and group 3 (adaptation phase of 30 minutes). The valves either were given high flow immediately (n = 4) or had an adaptation phase of 30 minutes (n = 4). Specimens were obtained after cell seeding, before, and after perfusion.

RESULTS

A confluent EC layer was achieved on all grafts. After perfusion without adaptation, large defects within the cell layer were found. No FB and SMC were seen at the bottom of these defects. In group B, the defects were largest on the ventricular surface of the leaflets. After an adaptation phase of 15 minutes in group A, only a few defects within the EC layer were detected with a still confluent FB and SMC. After a 30-minute adaptation phase defects within the EC layer were very rare and no interruption of the underlying FB and SMC layer was seen. Immunohistochemical staining for factor VIII and CD31 proved the EC to be viable and staining for collagen IV and laminin revealed the formation of a basement membrane. After perfusion, the specimen also stained positive for eNOS.

CONCLUSION

An adaptation phase of 30 minutes proved to be sufficient to allow artificially seeded endothelial cells to adapt to shear stress. The formation of a basement membrane was of great importance for the maintenance of a confluent EC layer.

Results of Pediatric Cardiac Transplantation - Long-Term Results of a 15-Year Experience

INTRODUCTION

Heart transplantation (HTx) has increasingly become a therapeutic option for end-stage heart failure of any origin in children. Short- and mid-term results are promising. However, long-term outcome has been a matter of concern because of acute or chronic rejection and side effects of immunosuppression. We performed a retrospective study of up to 15-years of follow-up on this patient entity.

METHODS

Between 1988 and 2004, 58 HTx were performed in 55 children (cardiomyopathy (DCM) 32, congenital heart disease (CHD) 23, Re-HTx 3). Mean age was 9.1 +/- 7.2 years (4 days - 17.9 years). Twenty-nine patients had a total of 51 previous operations.

RESULTS

Operative mortality was 4/58 (6.8 %) due to primary graft failure. Late mortality was 7/54 (12.1 %) due to acute rejection (2), pneumonia (2), intracranial hemorrhage (1), suicide (1) and lymphoma (1). Mean follow-up was 5.2 +/- 4.2 years. One-, 5-, and 10-year survival was 86 %, 80 % and 80 %, respectively, and improved significantly after 1995 (92 % and 92 %; p = 0.04). Survival was comparable for DCM and CHD patients (1-year: 88 % vs. 82 %; p = 0.19; 5-years: 84 % vs. 77 %; p = 0.12). Three patients with therapy resistant rejection and assisted circulation required retransplantation and are alive. Freedom from acute rejection was 46 % with primary cyclosporine immunosuppression and 63 % with tacrolimus. Ninety-eight percent of the survivors are at home and in excellent cardiac condition.

CONCLUSION

Pediatric heart transplantation is a curative treatment for DCM and CHD with excellent clinical mid-term results. However, further follow-up is necessary to evaluate long-term side effects of immunosuppressants. Donor shortage remains a problem.

Surgical epicardial left ventricular lead versus coronary sinus lead placement in biventricular pacing☆

OBJECTIVE

Biventricular pacing has demonstrated improvement in cardiac function in treating congestive heart failure (CHF). Two different operative strategies (coronary sinus vs. epicardial stimulation) for left ventricular (LV) pacing were compared.

METHODS

Since April 1999, a total of 86 patients (pts, age: 63+/-10 years) with depressed systolic LV function (mean ejection fraction 24+/-9%), left bundle-branch-block (mean QRS 182+/-22 ms) and congestive heart failure NYHA III or higher were enrolled. For biventricular stimulation coronary sinus (CS) leads were placed in 79 pts. Nine of these devices were converted to surgical epicardial LV-leads, because of CS-lead failure. In 7 patients epicardial LV-leads were initially implanted surgically, accounting for a total of 16 pts with surgical placed epicardial steroid-eluting LV-leads. For these, a limited left-lateral thoracotomy (7+/-4 cm) was used. Thirty-three (38%) pts had an indication for a defibrillator. The mean follow-up time was 16.4+/-15.4 months (0.1-45 months), representing 107.1 patient-years.

RESULTS

In the biventricular pacing mode, QRS duration decreased to 143+/-16 ms (P<0.001). Threshold capture of the CS-leads increased significantly compared to surgically placed epicardial leads (18 month control: 2.2+/-1.4V/0.5 ms vs. 0.7+/-0.3V/0.5 ms), which had no increase in threshold (P<0.001). At the 18 month follow-up 7 CS-leads had a threshold of >4V/0.5 ms vs. epicardial leads which were under 1.1V/0.5 ms, except for one (1.8V/0.5 ms). After CS-lead implantation 25 LV-lead related complications occurred, (failed implantation, CS-dissection, loss of pacing capture, diaphragm stimulation or lead dislodgment), vs. one dislodgement after surgical epicardial lead placement (P<0.05). Correct lead positioning (obtuse marginal branch area) was achieved in all surgical epicardial placements but only in 70% with CS-leads (P<0.03). In the follow up period, 9 pts died (4 cardiac related). Heart transplantation was necessary in 4 pts due to deterioration of the cardiomyopathy.

CONCLUSIONS

Surgical epicardial lead placement revealed excellent long-term results and a lower LV-related complication rate compared to CS-leads. Although, the approach via limited thoracotomy for biventricular pacing is associated with 'more surgery', it is a safe and reliable technique and should be considered as an equal alternative.

Cardiac Transplantation in Pediatric Patients: Fifteen-Year Experience of a Single Center

BACKGROUND

Pediatric heart transplantation is a surgical therapy for dilated cardiomyopathy and for complex congenital heart defects with low pulmonary artery resistance. However, it is still discussed as controversial because of uncertain long-term results. We report our experience with pediatric heart transplantation in a heterogeneous population.

METHODS

Since 1988, 50 heart transplants were performed in 47 patients (30 with dilated cardiomyopathy, 17 with congenital heart disease). Mean age was 9.4 +/- 6.9 years (range, 4 days to 17.9 years). Twenty-three patients had a total of 36 previous operations. Clinical outcome was evaluated retrospectively.

RESULTS

Perioperative mortality was 6% due to primary graft failure. Late mortality (12%) was caused by acute rejection (n = 2), pneumonia (n = 2), intracranial hemorrhage (n = 1), and suicide (n = 1). Mean follow-up was 5.24 +/- 3.6 years. Actuarial 1, 5, and 10 year survival was 86%, 86%, and 80% and improved significantly after 1995 (92% [1 year]; 92% [5 years]). There was no significant difference between patients with dilated or congenital heart disease (1 year: 86% vs 82%; 5 years: 83% vs 74%; 10 years 83% vs 74%; p = 0.62). Three patients with therapy resistant acute or chronic rejection and assisted circulation underwent retransplantation and are alive. Freedom from acute rejection after 5 years was 40% with primary cyclosporine immunosuppression regime and 56% with tacrolimus. Since the introduction of mycophenolate mofetil, freedom from acute rejection increased to 62%. All survivors are at home and in good cardiac condition.

CONCLUSIONS

Pediatric heart transplantation is the treatment of choice for end-stage dilated cardiomyopathy as for congenital heart disease with excellent clinical midterm results. It is a valid alternative to reconstructive surgery in borderline patients. However, further follow-up is necessary to evaluate the long-term side effects of immunosuppressants.

Interleukin-6 and procalcitonin in serum of children undergoing cardiac surgery with cardiopulmonary bypass

OBJECTIVE

The aim of our study was to investigate the systemic inflammatory response in children with congenital heart disease undergoing surgical correction with cardiopulmonary bypass. We wanted to discuss interleukin 6 and procalcitonin as components of the systemic inflammatory response syndrome to cardiopulmonary bypass and evaluate postoperative kinetics of these parameters in case of an uncomplicated course.

METHODS

Procalcitonin and interleukin 6 were determined before and after cardiopulmonary bypass surgery in 37 children on the day of surgery, the first and fourth postoperative day. The increased procalcitonin and interleukin 6 levels were evaluated in relationship to intraoperative variables such as duration of aortic cross clamping, incisional trauma and cardiac bypass temperature.

RESULTS

Peak levels of procalcitonin were detected on the first postoperative day, while interleukin 6 reached its highest values on the day of surgery. In contrast to interleukin 6 the median values of procalcitonin differed significantly between short versus long aortic clamping time and atriotomy versus ventriculotomy. Interleukin 6 reached normal levels on the fourth postoperative day, while procalcitonin was still clearly above normal.

CONCLUSIONS

Serum concentrations of procalcitonin and interleukin 6 were influenced by systemic inflammatory response syndrome following cardiac surgery with cardiopulmonary bypass. Even in case of an uncomplicated course both parameters were elevated for at least four days. While procalcitonin serum concentrations were dependent on aortic clamping time or incisional trauma, interleukin 6 showed no significant relation with these intraoperative variables.

The Aristotle score: a complexity-adjusted method to evaluate surgical results1

OBJECTIVES

Quality control is difficult to achieve in Congenital Heart Surgery (CHS) because of the diversity of the procedures. It is particularly needed, considering the potential adverse outcomes associated with complex cases. The aim of this project was to develop a new method based on the complexity of the procedures.

METHODS

The Aristotle project, involving a panel of expert surgeons, started in 1999 and included 50 pediatric surgeons from 23 countries, representing the EACTS, STS, ECHSA and CHSS. The complexity was based on the procedures as defined by the STS/EACTS International Nomenclature and was undertaken in two steps: the first step was establishing the Basic Score, which adjusts only the complexity of the procedures. It is based on three factors: the potential for mortality, the potential for morbidity and the anticipated technical difficulty. A questionnaire was completed by the 50 centers. The second step was the development of the Comprehensive Aristotle Score, which further adjusts the complexity according to the specific patient characteristics. It includes two categories of complexity factors, the procedure dependent and independent factors. After considering the relationship between complexity and performance, the Aristotle Committee is proposing that: Performance = Complexity x Outcome.

RESULTS

The Aristotle score, allows precise scoring of the complexity for 145 CHS procedures. One interesting notion coming out of this study is that complexity is a constant value for a given patient regardless of the center where he is operated. The Aristotle complexity score was further applied to 26 centers reporting to the EACTS congenital database. A new display of centers is presented based on the comparison of hospital survival to complexity and to our proposed definition of performance.

CONCLUSION

A complexity-adjusted method named the Aristotle Score, based on the complexity of the surgical procedures has been developed by an international group of experts. The Aristotle score, electronically available, was introduced in the EACTS and STS databases. A validation process evaluating its predictive value is being developed.

Sirolimus and mycophenolate mofetil as calcineurin inhibitor–free immunosuppression in a cardiac transplant patient with chronic renal failure

Chronic renal failure triggered by calcineurin inhibitor (CNI)-based immunosuppression is a common complication after cardiac transplantation. Sirolimus and mycophenolate mofetil (MMF) are 2 newer immunosuppressive agents with no documented nephrotoxic side effects. This case report describes a patient with ongoing chronic renal failure 10 months after cardiac transplantation on cyclosporine-based immunosuppressive therapy. Conversion of the immunosuppressive regimen from cyclosporine to sirolimus and MMF resulted in freedom from acute rejection, excellent cardiac graft function and consistently improved renal function. This case illustrates the beneficial potential of sirolimus and MMF as CNI-free and safe long-term immunosuppression in a patient with chronic renal failure after heart transplantation.

Renal recovery after conversion to a calcineurin inhibitor-free immunosuppression in late cardiac transplant recipients

OBJECTIVE

Calcineurin inhibitor (CNI)-related renal failure is a common problem after cardiac transplantation (HTx). The aim of this prospective study was to evaluate the safety and efficacy of a completely CNI-free immunosuppressive regimen [mycophenolate mofetil (MMF) and sirolimus (Sir)] in HTx-recipients with late post-transplant renal impairment.

METHODS

Since 2001, 30 HTx-patients (25 men, 6 women; 0.2-14.2 years after transplantation) with CNI-based immunosuppression and a serum creatinine >1.9 mg/dl were included in the study. Creatinine and cystatin levels were monitored to detect renal function. Conversion was started with 6 mg Sir or 500 mg MMF according to the pre-existing regimen and was continued with the dose adjusted to achieve target trough levels between 8 and 14 ng/ml (Sir) or 1.5 and 4 microg/ml (mycophenolate). Subsequently, the CNIs were tapered down and stopped. Clinical follow-up included endomyocardial biopsies, echocardiography and laboratory studies. Additionally, every HTx-patient treated at our centre between 1996 and 2001 due to chronic renal failure without immunosuppressive conversion and fulfilling the inclusion criteria were retrospectively analysed and acted as control group.

RESULTS

Patient demographics and 1-year survival [93 (conversion) vs 90% (control)] were compared. No acute rejection episode was detected in either group. Renal function improved significantly in the conversion group (creatinine: 3.18+/-0.71 vs 2.22+/-0.79 mg/dl, P=0.001; cystatin pre- vs post-conversion: 2.95+/-1.06 vs 2.02+/-1.1 mg/l, P=0.01). In three patients haemodialysis therapy was stopped completely after conversion. In the control group renal impairment was deteriorating, creatinine increased from 2.44+/-0.8 to 3.28+/-1 mg/dl (P=0.01). In 10 out of 33 patients chronic haemodialysis had to be initiated within 1 year. Although side effects of CNI-free immunosuppression were common (76%), no patient had to be excluded due to adverse effects.

CONCLUSIONS

Conversion from CNI-based immunosuppression to MMF and Sir in HTx-patients with chronic renal failure was safe, preserved graft function and improved renal function.

Mycophenolate mofetil and sirolimus as calcineurin inhibitor-free immunosuppression for late cardiac-transplant recipients with chronic renal failure

BACKGROUND

Calcineurin-inhibitor (CNI)-related renal failure is a common problem after cardiac transplantation (HTx). The aim of this study was to introduce a CNI-free immunosuppressive regimen to HTx recipients with late posttransplant renal impairment and to evaluate the impact of conversion to this new immunosuppression (mycophenolate mofetil [MMF] and sirolimus [Sir]) treatment on renal function.

METHODS AND RESULTS

Thirty-one HTx patients (25 men, 6 women; 0.2-14.2 years after transplantation) with CNI-based immunosuppression and a serum creatinine greater than 1.9 mg/dL were included in the study. Creatinine and cystatin levels were monitored to detect renal function. Mean patient age was 50+/-14 (range 19-74) years. Conversion was started with 6 mg Sir, continued with 2 mg, and the dose was adjusted to achieve target trough levels between 8 and 14 ng/mL. MMF was continued with trough level adjusted (1.5-4 microg/mL). Subsequently, the CNIs were tapered down and stopped. Clinical follow-up (first and every 3 months after conversion) included endomyocardial biopsies, echocardiography, and laboratory studies. Survival was 90% after a mean follow-up of 13+/-95 months. No acute rejection episode was detected during the study period. Renal function improved significantly after conversion: creatinine preconversion vs. postconversion: 3.14+/-0.76 mg/dL vs. 2.14+/-0.83 mg/dL, P =0.001. Cystatin preconversion vs. postconversion: 2.95+/-1.06 mg/L vs. 2.02+/-1.1 mg/L, P =0.01. In three patients, hemodialysis therapy was stopped completely after conversion. Graft function remained stable. Fractional shortening preconversion vs. postconversion: 36.9+/-6% vs. 36.4+/-6%. There were no serious adverse events. One patient had to be excluded because of noncompliance.

CONCLUSIONS

Conversion from CNI-based immunosuppression to MMF and Sir in HTx patients with chronic renal failure was safe, preserved graft function, and improved renal function.