Preoperative determinants of recovery time in adult Fallot patients after late pulmonary valve replacement.
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Age Factors↗
Biomedical subjects
Mark G Hazekamp
Publications and source records attributed to Mark G Hazekamp.
Long-term follow-up of homograft function after pulmonary valve replacement in patients with tetralogy of Fallot.
AIMS: To analyse the long-term outcomes after pulmonary valve replacement (PVR) in patients with a previous correction for tetralogy of Fallot. METHODS AND RESULTS: In a retrospective study, 158 adult patients with a diagnosis of tetralogy of Fallot, who had undergone a PVR after initial total correction in childhood, were identified from the CONCOR (CONgenital CORvitia) registry. All patients underwent 175 PVRs between June 1986 and June 2005. To analyse the predictors for homograft dysfunction and adverse events (death, reoperations, balloon angioplasty), Cox-regression analysis was performed. Overall freedom from significant homograft dysfunction was 66% after 5 years and 47% after 10 years. We could not identify predictors for combined homograft dysfunction. Event-free survival was 78% at 10 years and 68% at 15 years after PVR. Both early significant pulmonary regurgitation (PR) (HR 6.8, P = 0.017) and pulmonary stenosis (PS) (HR 4.0, P = 0.037) after surgery were associated with adverse events. When analysing direct post-operative PR or PS, we observed that in patients with severe, pre-operative PR, right ventricular aneurysm/patch resection resulted in a lower post-operative PR (mean difference grade 0.38 +/- 0.14, P = 0.01). Less significant post-operative PS was associated with a higher diameter of the homograft (HR 0.37, P = 0.006). CONCLUSION: While 47% of the patients in our study were free from homograft dysfunction at 10 years after PVR, event-free survival after PVR remained fairly good (78%). Significant residual lesions directly after surgery influenced event-free survival. A smaller diameter of the pulmonary homograft and severe pre-surgical PR were related to early homograft dysfunction after surgery.
Adult↗
Aortic root dysfunctioning and its effect on left ventricular function in Ross procedure patients assessed with magnetic resonance imaging.
BACKGROUND: This study evaluated the diameters and distensibility of the aortic root as well as the degree of aortic regurgitation (AR) and its effect on left ventricular (LV) function in patients 8.2 +/- 3.1 years after they underwent the Ross procedure, with a comparison of these parameters between patients and matched healthy subjects. METHODS: Eighteen Ross procedure patients (16 male patients, age [mean +/- SD] 19.2 +/- 3.8 years) and 18 matched healthy subjects (16 male patients, age [mean +/- SD] 19.7 +/- 4.2 years) underwent magnetic resonance imaging. Measurements for diameters (at 4 levels) and the distensibility of the aortic root were performed using a steady-state free precession sequence. Aortic flow was assessed with a velocity-encoded phase-contrast sequence. Left ventricular systolic function was assessed with a gradient-echo sequence in the short-axis plane. Comparison of parameters was performed using the Mann-Whitney U test. Correlations between diameters, distensibility, AR fraction, and LV systolic function were expressed with Spearman rank correlation coefficients. Linear regression analysis was used to identify predictors of LV systolic dysfunction. RESULTS: Aortic root diameters were increased in Ross procedure patients as compared with healthy subjects (mean difference 6.3-11.6 mm, P < or = .02 at all 4 levels). Distensibility of the aortic root was lower in patients (1.9 +/- 1.1 vs 7.8 +/- 3.3 mm Hg(-1), P < .01). An AR fraction > 5% was present in 14 of the 18 patients (mean AR fraction 8% +/- 5% vs 1% +/- 1%, P < .01). Left ventricular ejection fraction was lower in patients (50% +/- 6% vs 57% +/- 6%, P < .01). Dilatation, decreased distensibility, and AR fraction were correlated with impaired LV systolic function (P < .05 for all). The AR fraction predicted impaired LV systolic function (P < .01). CONCLUSIONS: Magnetic resonance imaging shows dilatation and decreased distensibility of the aortic root, AR, and consequent impaired LV systolic function in patients after the Ross procedure.
Adolescent↗
Phosphorylcholine coating of bypass systems used for young infants does not attenuate the inflammatory response.
BACKGROUND: Contact of blood with the artificial surfaces of the cardiopulmonary bypass (CPB) system is considered to be a main cause of complement activation. Improving the biocompatibility of the system by reduction of contact activation of blood elements and thereby producing less inflammatory response is evidently desired, especially for neonates and infants who are more susceptible to the deleterious effects of CPB. A phosphorylcholine coating, Phisio, is designed to mimic the natural interfaces of blood. The aim of this study is to compare the influence of a phosphorylcholine-coated CPB system versus an uncoated CPB system on complement activation and clinical outcomes. METHODS: In this prospective, randomized, blind, one-center study, 28 neonates and infants with a bodyweight between 3 and 6 kg who were undergoing cardiopulmonary bypass were divided in two groups, the phosphorylcholine group and the control group. Thirteen patients were assigned to the phosphorylcholine group and 15 patients to the control group. Patients with Down syndrome, prematurity, cyanosis, or reoperation were excluded. Complement factor C3b/c, human neutrophil elastase (HNE), interleukin-6, and C-reactive protein were measured before, during, and after CPB. Duration of intensive care stay, ventilation time, highest body temperature, and inotropic medication were the clinical variables. RESULTS: No significant differences were found between the groups for complement factor C3b/c, HNE, interleukin-6, or C-reactive protein during and after CPB. No clinical differences were observed between the groups. CONCLUSIONS: Phosphorylcholine coating does not attenuate the complement activation during CPB in neonates and infants.
Cardiopulmonary Bypass↗
Degeneration of the pulmonary autograft: an explant study.
OBJECTIVE: We sought to determine the histologic features of pulmonary autografts explanted after the Ross operation. METHODS: Histologic sections of 30 explanted autografts and 8 normal heart valves were compared and semiquantitatively scored by a blinded cardiovascular pathologist. RESULTS: Pulmonary autografts (n = 30) were explanted on average 6.1 +/- 0.6 years (median, 6.6 years; range, 0.1-11.7 years) after the Ross operation (n = 28) or removed at autopsy (n = 2). Twelve (43%) of the patients undergoing reoperation had no or negligible autograft insufficiency on early transthoracic echocardiography, 12 (43%) had grade 1 autograft insufficiency, and 4 (14%) had grade 1-2 autograft insufficiency. Valve regurgitation with root dilatation was the most common indication for reoperation after root replacement (n = 26 [93%]) and regurgitation after subcoronary implanted autografts (n = 2 [7%]). Microscopy of the autograft explants revealed normal laminar architecture and cellularity. Wall specimens were characterized by reduced and fragmented elastin and increased collagen levels (fibrosis). Medial elastin changes were associated with the presence of hypertrophic smooth muscle cells. Fibrosis was most severe in the adventitia. Intimal thickening was a common finding. Valve explants showed significant thickening caused by fibrocellular tissue on the ventricular surface and marked thickening of the free margin. An autopsy explant with normal function before death showed similar features. CONCLUSIONS: Pulmonary autograft explants showed severe aneurysmal degeneration of the wall, which was characterized by intimal thickening, medial elastin fragmentation, and adventitial fibrosis. Valve leaflets were thickened. The presence of these features in a nonfailing explant suggests these changes represent a common mode of remodeling.
Adolescent↗
Rhamnose and rhamnitol in dual sugar permeability tests.
Rhamnose is one of the sugars regularly used to conduct the dual sugar permeability test. For more than 30 years, it has been assumed that rhamnose is an inert sugar not metabolized by the human body and only fermented by some colonic bacteria into rhamnulose. While conducting an investigation on gut permeability in children undergoing cardiac surgery, increased concentrations of rhamnitol were found in the urine samples. The present report suggests that rhamnose is not an inert sugar and it is partially metabolized into rhamnitol by the human body.
Diagnostic Techniques, Digestive System↗
Time course of diastolic and systolic function improvement after pulmonary valve replacement in adult patients with tetralogy of Fallot.
OBJECTIVES: The aim of this research was to assess right ventricular diastolic and systolic function before and after pulmonary valve replacement (PVR) in adult patients after repair of tetralogy of Fallot. BACKGROUND: Pulmonary valve replacement (PVR) in adult patients late after repair of tetralogy of Fallot leads to rapid improvement of right ventricular (RV) systolic function. METHODS: A total of 16 patients and 8 healthy subjects were included. Median age at initial repair was 4.9 (0.9 to 13.1) years, and mean age at PVR was 28.7 (19.5 to 45.6) years. Cardiac magnetic resonance imaging was performed before and 8 and 22 months after PVR. Right ventricular volumes and function as well as RV in- and outflow patterns were assessed. RESULTS: The volume of the early filling of the RV (Evol) increased from 49.8 +/- 14.7 ml to 53.8 +/- 19.3 ml (not significant) and 62.0 +/- 18.9 ml, respectively (p < 0.05), whereas the volume of the atrial contraction (Avol) remained unchanged. Consequently, the Evol/Avol ratio increased from 1.4 +/- 0.7 before PVR to 1.6 +/- 0.7 at 8 months (not significant) and 2.3 +/- 1.2 at 22 months (p < 0.01). The Evol/Avol ratio was not significantly different from the healthy subjects at 22 months, indicating late recovery of diastolic function. Systolic function improved rapidly after PVR; the indexed RV end-systolic volume decreased from 93.7 +/- 33.0 ml/m2 to 60.9 +/- 18.4 ml/m2 (p < 0.01) and 54.8 +/- 21.0 ml/m2 (p < 0.01). CONCLUSIONS: In adult patients late after total repair of Fallot, PVR leads to late improvement of diastolic function. We speculate that the rapid volume unloading after PVR increases systolic performance, whereas improvement in diastolic function requires long-term remodeling.
Adolescent↗
Effect of dexamethasone on postoperative cardiac troponin T production in pediatric cardiac surgery.
OBJECTIVE: Pediatric cardiac surgery is associated with a temporary rise in cardiac troponin T (cTnT) during the postoperative period. We examined whether dexamethasone given before cardiopulmonary bypass has myocardial protective effects as assessed by the postoperative production of cTnT. DESIGN AND SETTING: Prospective randomized interventional study in the pediatric intensive care unit in a university hospital. INTERVENTIONS: Patients were randomly allocated to act as controls or receive a single dose of dexamethasone (1 mg/kg) during induction of anesthesia. MEASUREMENTS AND RESULTS: cTnT was measured four times postoperatively: immediately after admission to the pediatric intensive care unit (PICU) and 8, 15, and 24 h thereafter. The two groups had similar mean cTnT concentrations on PICU admission: those receiving dexamethasone 1.85 ng/ml (1.55-2.15) and those not receiving it 2 ng/ml (95% confidence interval 1.56-2.51). Concentrations of cTnT 8 h after admission to the PICU differed significantly after 8 h: 1.99 ng/ml (1.53-2.45) in those receiving dexamethasone and 3.08 ng/ml (2.46-3.69) in those not receiving it. After subgroup statistical analysis differences between the two groups remained significant only at 8 h, not those after 15 or 24 h. CONCLUSIONS: The use of dexamethasone (1 mg/kg) before cardiopulmonary bypass is associated with a brief but significant reduction in postoperative cTnT production. The clinical significance of this effect is unclear.
Anti-Inflammatory Agents↗
Right ventricular function late after total repair of tetralogy of Fallot.
Over the past decades, life expectancy in patients with congenital heart disease has increased dramatically. However, serious complications may develop late after total repair in infancy. These complications are usually the result of longstanding pulmonary regurgitation, which leads to dilatation of the right ventricle and an increased risk for severe arrhythmias. Therefore lifelong follow-up in these patients is required. Cardiac magnetic resonance imaging is the current imaging tool of choice because it offers superior imaging quality and enables accurate quantification of functional parameters such as flow volumes and systolic and diastolic performance.
Humans↗
Reduction of QRS duration after pulmonary valve replacement in adult Fallot patients is related to reduction of right ventricular volume.
AIMS: Late after total correction, Fallot patients with a long QRS duration are prone to serious arrhythmias and sudden cardiac death. Pulmonary regurgitation is a common cause of right ventricular (RV) failure and QRS lengthening. We studied the effects of pulmonary valve replacement (PVR) on QRS duration and RV volume. METHODS AND RESULTS: Twenty-six consecutive Fallot patients were evaluated both pre-operatively and 6-12 months post-operatively by cardiac magnetic resonance (CMR). In this study, we present the computer-assisted analysis of the standard 12-lead electrocardiograms closest in time to the CMR studies. For the whole group, QRS duration shortened by 6+/-8 ms, from 151+/-30 to 144+/-29 ms (P=0.002). QRS duration decreased in 18 of 26 patients by 10+/-6 ms, from 152+/-32 to 142+/-31 ms. QRS duration remained constant or increased slightly in eight of 26 patients by 3+/-3 ms, from 148+/-27 to 151+/-25 ms. CMR showed a decrease in RV end-diastolic volume from 305+/-87 to 210+/-62 mL (P=0.000004). QRS duration changes correlated with RV end-diastolic volume changes (r=0.54, P=0.01). CONCLUSION: Our study shows that PVR reduces QRS duration. The amount of QRS reduction is related to the success of the operation, as expressed by the reduction in RV end-diastolic volume.
Adult↗
Histological evaluation of decellularised porcine aortic valves: matrix changes due to different decellularisation methods.
OBJECTIVE: Several decellularisation techniques have been developed to produce acellular matrix scaffolds for the purpose of tissue engineering, mostly comprising (non-)ionic detergents or enzymatic extraction methods. However, the effect of chemically induced decellularisation on the major structural and adhesion molecules as well as glycosaminoglycans, and the possible replenishment of lost compounds have escaped attention. METHODS: Porcine aortic valves were treated with two different methods: detergent Triton X-100 and enzymatic Trypsine cell extraction. (Immuno-) histochemistry was used to address changes in extracellular matrix constitution (elastin, collagen, glycosaminoglycans, chondroitin sulfate, fibronectin and laminin) and the production of extracellular matrix components by seeded endothelial cells. RESULTS: The Trypsine treated group showed a fragmentation and distortion of elastic fibers. Changes in collagen distribution were observed in both groups. An almost complete washout of glycosaminoglycans and chondroitin sulfate was observed in the Triton and Trypsin treated group, but the latter with a smaller glycosaminoglycans reduction. Both treatments resulted in a considerable washout of the adhesion molecules laminin and fibronectin. Furthermore, seeded endothelial cells were capable of synthesising laminin, fibronectin and chondroitin sulfate. CONCLUSIONS: Chemically induced decellularisation by Triton or Trypsine resulted in changes in the extracellular matrix constitution, which could lead to problems in valve functionality and cell growth and migration. Seeded endothelial cells were capable of synthesising extracellular matrix components lost by cell extraction. Further studies on tissue engineering should focus more on the effect of chemically induced cell extraction on the extracellular matrix of the remaining scaffold and the in vitro or in vivo replenishment of lost compounds.
Animals↗
Intraoperative stenting of pulmonary arteries.
OBJECTIVE: The surgical treatment of pulmonary artery stenoses in small children with complex cardiac lesions can be technically difficult. A hybrid-approach combining corrective surgery and intraoperative stent placement may be complementary in these patients. METHODS: Descriptive study in 11 small children (age: one week to 12 years, median of 12 months, weight: 2.5-20 kg) after previous cardiac surgery. Intraoperative stenting of pulmonary arteries was performed involving paediatric cardiologist and cardiac surgeon. Stenting was combined with repair of pulmonary atresia (n=2), right ventricular outflow and pulmonary artery reconstruction (n=3), unifocalisation of pulmonary arteries (n=1), revision of distal anastomosis of RV-PA-conduit after truncus repair (n=1), revision of distal anastomosis of RV-PA-conduit after AVSD/Fallot repair (n=1), aortic arch patch reconstruction after anatomical correction for transposition of the great arteries (n=1), bidirectional cavopulmonary anastomosis after Norwood I operation for hypoplastic left heart syndrome, (n=1) retrieval of a dislodged stent from the left pulmonary artery (n=1). In seven patients stenting was planned electively while in four patients it took place on an emergency base. RESULTS: No complications occurred during stent implantation. One patient died three weeks postoperatively from diffuse bleeding due to a coagulation disorder. Ten patients left hospital after the surgical intervention with concomitant stent implantation. Stent re-dilatation was necessary in 4 patients 2-24 months postoperatively. After a median follow-up of 15 months ranging from 3 weeks to 7.5 years all stents were patent as diagnosed by angiography in 6 patients and by colour-Doppler in all other patients. One year after stent placement one stent was removed and another surgically opened during re-operation for conduit replacement in the smallest patient from this series. There was one late death during operative right ventricular outflow-tract reconstruction after initial stent placement. CONCLUSIONS: With intraoperative stent placement surgically difficult patch augmentation of small and fragile pulmonary vessels during repair of complex cardiac lesions can be avoided. Stents recruit pulmonary vessels and keep them open and amenable to future percutaneous or surgical interventions.
Arterial Occlusive Diseases↗
Results of the Ross operation in a pediatric population.
OBJECTIVE: To analyse the results of the mid-term clinical and echocardiographic follow-up of the pediatric Ross operation. METHODS: Echo-Doppler follow-up of 53 consecutive pediatric Ross procedures performed between 1994 and 2003. Median age was 9.7 years at time of operation (2 weeks-17.7 years). Six patients were younger than 3 months. Median age at follow-up was 15.6 years. Aortic valve/left ventricular outflow tract (LVOT) anomalies were congenital in 49 (92%). Seventy percent had previous surgery or balloon valvuloplasty. Root replacement was used in all. Thirteen patients (25%) had LVOT enlargement. Mean cross-clamp time was 113 (69-189) minutes. RESULTS: Early mortality occurred in 3 patients after emergency surgery following balloon failure (n=1) and extended Ross following interrupted arch/VSD repair (n=2). Late mortality was due to LV fibroelastosis in 2 patients and complicated pulmonary artery stenting in another. RVOT reoperations were required because of late homograft obstruction in 2 patients and because of pulmonary artery stenosis in another. Five patients (9.4%) were reoperated for pulmonary autograft dilatation (n=3) and for leaflet fibrosis or perforation (n=2). Autografts were repaired in two patients, while a mechanical valve was inserted in 3 cases. At 9 years the actuarial survival and event free survival were 89 and 74%, respectively. At last follow-up 90% of autograft diameters indexed to body surface area was above the 90th percentile of normal aortic root diameters. LVOT and RVOT gradients were low and autograft insufficiency was trivial to mild in 84% and mild to moderate in 16%. Autograft stenosis was not noticed. CONCLUSIONS: The pediatric Ross procedure remains an important tool but autograft dilatation also occurs in the pediatric population. The significance of this finding has yet to be determined.
Adolescent↗
Dexamethasone reduces gut permeability in pediatric cardiac surgery.
OBJECTIVES: Little attention has been paid to the effect of the systemic inflammatory response syndrome on intestinal dysfunction in the postoperative period. Several proinflammatory cytokines have been reported to increase the permeability of intestinal mucosa in vitro. We investigated the effect of dexamethasone on gut permeability in pediatric patients undergoing cardiac surgery by using the dual sugar permeability test and absorption of 2 other saccharides. METHODS: Thirty-four patients scheduled for cardiac surgery with cardiopulmonary bypass were prospectively randomized to either act as control subjects or to receive dexamethasone (1 mg . kg -1) during induction of anesthesia. Intestinal permeability was measured with 3-O-methyl-D-glucose, D-xylose, L-rhamnose, and lactulose administered orally after induction of anesthesia and 12 and 24 hours later. RESULTS: Lactulose/rhamnose ratios were increased from the outset in both groups (mean 0.57 [95% confidence interval, 0.24-0.91] for the control group and 0.76 [95% confidence interval, 0.35-1.17] for patients receiving dexamethasone). Although the ratios decreased 12 hours (0.29 [95% confidence interval, 0.17-0.42]) and 24 hours later (0.17 [95% confidence interval, 0.08-0.15]) in the dexamethasone group, in the control group there was a rise at 12 hours (0.77 [95% confidence interval, 0-1.64]), with a slight reduction 24 hours later (0.46 [95% confidence interval, 0.06-0.85]). CONCLUSIONS: Infants and children undergoing cardiac surgery with cardiopulmonary bypass show a significant reduction in gut permeability when dexamethasone is used during induction of anesthesia. Dexamethasone does not affect the intestinal barrier at the functional level, as assessed on the basis of 3-O-methyl-D-glucose and D-xylose absorption.
Adolescent↗
Gut permeability in neonates after a stage 1 Norwood procedure.
OBJECTIVE: Intestinal mucosal ischemia can occur during and after cardiac surgery. Severe decreases in mucosal perfusion may be a causative factor for postoperative mortality or complications such as necrotizing enterocolitis. Mesenteric perfusion is challenged preoperatively due to an imbalance between the systemic and pulmonary circulations and challenged intraoperatively due to hypothermic circulatory arrest. We have investigated gut permeability in seven patients undergoing stage 1 of the Norwood procedure, applying the dual sugar permeability test with L-rhamnose and lactulose. DESIGN: Seven patients with hypoplastic left heart syndrome: clinical presentation, gut permeability findings, and outcome. SETTING: A 10-bed mixed pediatric intensive care unit in a university hospital. PATIENTS: Seven patients admitted for postoperative care after cardiac surgery. INTERVENTIONS: Determination of gut permeability with the dual sugar permeability test using lactulose and rhamnose. Intestinal permeability was measured after induction of anesthesia and 12 and 24 hrs later. MEASUREMENTS AND MAIN RESULTS: : All patients had abnormal lactulose/rhamnose ratios. One patient, who had a lactulose/rhamnose ratio 12 hrs after surgery of 2.3 (46-times normal), developed necrotizing enterocolitis postoperatively and died 3 days after surgery. CONCLUSIONS: Gut permeability as assessed by the dual sugar permeability test is abnormal in patients with hypoplastic left heart syndrome before and after surgery. Lactulose/rhamnose ratios 46 times the normal value reflect a highly permeable small intestine. This may be a sign of a low output state and may help to identify patients at risk of developing necrotizing enterocolitis.
Cardiopulmonary Bypass↗
Use of autologous arterial patches for tracheal reconstruction in young infants.
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Aorta↗
Median sternotomy for reoperation of the distal aortic arch in postcoarctectomy patients.
We report the usefulness of a median sternotomy approach for the surgical treatment of residual aortic gradients or recoarctation and aortic aneurysms. This series confirms that excellent surgical results can be obtained in this technically challenging group of patients needing postcoarctation repair.
Adolescent↗
Right ventricular function after pulmonary valve replacement in patients with tetralogy of Fallot.
PURPOSE: To assess the time course of right ventricular (RV) function improvement after pulmonary valve replacement (PVR) in patients 25.2 years +/- 7.0 after repair of tetralogy of Fallot. MATERIALS AND METHODS: The medical ethics committee approved this study, and informed consent was obtained. Cardiac magnetic resonance (MR) imaging was performed before, 7 months after, and 19 months after PVR in 25 consecutive patients with tetralogy of Fallot with a 1.5-T MR imager. RV function was assessed with gradient-echo sequences in the short-axis plane. Pulmonary flow was assessed with a velocity-encoded phase-contrast sequence. Paired t test was used to evaluate follow-up data. Independent samples t test was used to assess differences based on the presence of recurrent pulmonary regurgitation (PR). RESULTS: Mean indexed RV end-diastolic volume decreased from 166.9 mL/m(2) +/- 41.3 before PVR to 113.5 mL/m(2)+/- 35.7 (P < .001) at 7-month follow-up and 111.7 mL/m(2)+/- 41.1 (P = .46) at 19-month follow-up. The RV ejection fraction was corrected for PR and improved from 25.0% +/- 7.7 before surgery to 44.1% +/- 11.9 (P < .001) and 45.2% +/- 11.1 (P = .39), at 7- and 19-month follow-up, respectively. Recurrent PR after PVR was found in 11 patients; 14 patients did not have recurrent PR. Total reduction of indexed RV end-diastolic volume at 19 months follow-up was more prominent in patients who did not have recurrent PR than in patients who did have recurrent PR (P < .05). Furthermore, improvement of RV ejection fraction corrected for regurgitation was more marked in patients who did not have recurrent PR than in patients who did have recurrent PR (P < .05). CONCLUSION: In patients with tetralogy of Fallot, RV function improves rapidly after PVR and is sustained at 19-month follow-up in most patients; however, recurrence of PR after PVR appears to reduce recovery of RV systolic function.
Adolescent↗