Repair of common arterial trunk: palliation and delayed correction as a viable alternative strategy in selected patients

OBJECTIVES

Primary repair of common arterial trunk (CAT) is burdened by high mortality rates, especially in the presence of multiple risk factors. Timing, possible palliative methods, optimal management of associated cardiac lesions and handling of a poor preoperative state are still under discussion.

METHODS

We retrospectively analysed all patients who underwent surgery for CAT in our institution between 2008 and November 2020. We included 22 patients, 11 of whom received primary correction (PC) and 11 of whom underwent initial palliation by partial repair, leaving the ventricular septal defect open and connecting the right ventricle to the pulmonary arteries with a small valveless right ventricle-to-pulmonary artery conduit. A delayed correction (DC) was performed after 11.5 ± 3.6 months.

RESULTS

The overall operative mortality was 4.5%; 1 patient (affected by severe truncal valve stenosis and presenting in a poor state preoperatively) in the DC group died after palliation. The incidence of postoperative pulmonary hypertensive crisis was significantly higher in the PC group (P = 0.027). No patient from either group required postoperative extracorporeal support. Survival rates after 6 years differed slightly (PC group, 90%; DC group, 70%; log-rank = 0.270).

CONCLUSIONS

PC of CAT remains an optimal surgical approach for patients with an expected low mortality. However, our data support palliation and DC as a suitable alternative strategy, especially in the presence of significant risk factors like interrupted aortic arch, poor preoperative condition or complex surgical anatomy.

Reduction of exposure to plasticizers in stored red blood cell units

Introduction:

Plastic can be toxic and hazardous to an organism’s health, but it is being widely used in our daily lives. Di-2-ethylhexyl-phthalate is the most common plasticizer in medical devices made of polyvinylchloride and is commonly found in soft bags storing red blood cell units. Di-2-ethylhexyl-phthalate and its degradation product mono-2-ethylhexyl-phthalate can migrate into human body fluids, for example, blood and tissues. The aim of the study was to assess the concentration of plasticizers in red blood cell units according to storage time and after mechanical rinsing using a cell salvage device.

Methods:

Levels of di-2-ethylhexyl-phthalate and mono-2-ethylhexyl-phthalate were analysed in 50 unwashed red blood cell units using liquid chromatography coupled with tandem mass spectrometry. In addition, phthalate concentrations were measured before and after mechanical rinsing in six more washed red blood cell units with storage times ranging between 36 and 56 days. A linear regression model was determined by the daily increase of di-2-ethylhexyl-phthalate and mono-2-ethylhexyl-phthalate in the stored red blood cell units subject to their storage time (range = 4-38 days), and the effect of mechanical rinsing on their phthalate concentration was calculated.

Results:

A linear correlation was found between storage time of unwashed red blood cell units and the concentration of di-2-ethylhexyl-phthalate (p < 0.001) or mono-2-ethylhexyl-phthalate (p < 0.001). Stored red blood cell units older than 14 days had significantly higher concentrations of both contaminants than red blood cell units of shorter storage time (p < 0.001). Mechanical rinsing in washed red blood cell units attained a reduction in the di-2-ethylhexyl-phthalate and mono-2-ethylhexyl-phthalate concentration by a median of 53% (range = 18-68%; p = 0.031) and 87% (range = 68-96%; p = 0.031), respectively.

Conclusion:

Leaching of di-2-ethylhexyl-phthalate and mono-2-ethylhexyl-phthalate into red blood cell units depends on the duration of storage time. Plasticizers can be significantly reduced by mechanical rinsing using cell salvage devices, and thus, red blood cell units can be regenerated with respect to chemical contamination.

Deep hypothermic circulatory arrest or tepid regional cerebral perfusion: impact on haemodynamics and myocardial integrity in a randomized experimental trial

OBJECTIVES

Organ protective management during aortic arch surgery comprises deep hypothermic (18°C) circulatory arrest (DHCA), or moderate hypothermia (28°C/ 'tepid') with regional cerebral perfusion (TRCP). The aim of this experimental study was to evaluate the effect of distinct organ protective management on hemodynamic performance and myocardial integrity.

METHODS

Ten male piglets were randomized to group DHCA (n = 5) or TRCP (n = 5) group and operated on cardiopulmonary bypass (CPB) with 60 min of aortic cross-clamping. Blood gas analysis was performed throughout the experiment. Haemodynamic assessment was performed using a thermodilution technique before and after CPB. Myocardial biopsies were taken 2 h after CPB and evaluated using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labelling assay and western blot analysis.

RESULTS

At reperfusion, levels of central venous saturation were significantly higher (P = 0.016) and levels of lactate significantly lower (P = 0.029) in the DHCA group. After CPB, thermodilution measurements revealed higher stroke volume and lower peripheral resistance in the TRCP group (P = 0.012 and 0.037). At the end of the experiment, no significant differences regarding laboratory and haemodynamic parameters were evident. All specimens showed enrichment of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labelling-positive cells exclusively at the left ventricular subendocardium with no difference between groups and equal concentrations of cyclo-oxygenase-2.

CONCLUSIONS

TRCP is associated with decreased peripheral resistance and higher stroke volume immediately after CPB. However, this beneficial effect is contrasted by signs of lower body hypoperfusion, which is expressed by lower central venous saturations and higher lactate levels. Distinct strategies of organ protection did not seem to affect apoptotic/necrotic and inflammatory changes in the left ventricular myocardium.

Goal-directed-perfusion in neonatal aortic arch surgery

Reduction of mortality and morbidity in congenital cardiac surgery has always been and remains a major target for the complete team involved. As operative techniques are more and more standardized and refined, surgical risk and associated complication rates have constantly been reduced to an acceptable level but are both still present. Aortic arch surgery in neonates seems to be of particular interest, because perfusion techniques differ widely among institutions and an ideal form of a so called "total body perfusion (TBP)" is somewhat difficult to achieve. Thus concepts of deep hypothermic circulatory arrest (DHCA), regional cerebral perfusion (RCP/with cardioplegic cardiac arrest or on the perfused beating heart) and TBP exist in parallel and all carry an individual risk for organ damage related to perfusion management, chosen core temperature and time on bypass. Patient safety relies more and more on adequate end organ perfusion on cardiopulmonary bypass, especially sensitive organs like the brain, heart, kidney, liver and the gut, whereby on adequate tissue protection, temperature management and oxygen delivery should be visualized and monitored.

Aortic arch obstruction neonates with biventricular physiology: left-open compared to closed inter-atrial communication during primary repair--a retrospective study

Background

Leaving an inter-atrial communication (IAC) open for left atrial decompression is often recommended in neonates with aortic arch obstruction undergoing primary repair. In this study, outcomes in these patients were compared to those with intact atrial septum after repair.

Methods

Between 2000 and 2013, 53 consecutive neonates with severe aortic arch obstruction (hypoplasia: n = 45, interruption: n = 8) underwent primary repair from an anterior approach. Median age and weight were 8 days (range: 2–30) and 3.2 kg (range: 2.4-4.4), respectively. Cardiac morphology included a ventricular septal defect (VSD, large: n = 28, small: n = 7), malposition of great arteries (n = 10), and severe left ventricular outflow tract obstruction (LVOTO, n = 10). During corrective surgery IAC was closed (group-I, n = 37) or partially left-open (group-II, n = 16). Primary endpoints were hospital death, and re-intervention (surgery and/or balloon) due to aortic arch re-coarctation or recurrent LVOTO. Statistically significant variables by univariate analysis were incorporated in the corresponding multivariable regression model.

Results

Regarding morphological discrepancies more patients in group-II presented with LVOTO (p = 0.05), or the combination of arch hypoplasia, intact ventricular septum and normal ventriculo-arterial connection (p = 0.017). Hospital mortality was 8.1% in group-I and 37.5% in group-II (p = 0.016). Re-intervention was performed in 13 patients (group-I: n = 6 vs. group-II: n = 7) due to aortic arch re-coarctation (n = 12) and/or recurrent LVOTO (n = 3), and resulted in a Kaplan-Meier freedom from re-intervention of 87 ± 6% and 79 ± 8% in group-I, and 64 ± 14% and 64 ± 14% in group-II after 1 and 5 years, respectively (p = 0.016). Multivariate analysis revealed LVOTO as an independent risk factor for hospital death (p = 0.042), whereas both LVOTO and left-open IAC (p = 0.001 and 0.01) were independent risk factors for re-intervention.

Conclusions

A left-open IAC increases risk of re-intervention at the left heart aorta complex. Sustained left-to-right shunting on atrial level seems to induce preload reduction of the often restrictive left ventricle leading to decreased aortic blood flow.

Troponin I levels in extracorporeal membrane oxygenation following congenital heart surgery

BACKGROUND

Correlating postcardiotomy extracorporeal membrane oxygenation (ECMO) troponin I (TnI) levels and outcomes.

METHODS

Between January 2006 and August 2010, 34 patients needed postcardiotomy ECMO for low cardiac output. Bailout ECMO was required either after unsuccessful weaning from bypass (n = 17, 50%), postoperatively from prolonged hemodynamic failure (n = 8, 23.5%), or following resuscitation (n = 9, 26.5%). The TnI levels were measured following surgery or resuscitation during 10 days and compared between survivors (group I) and non-survivors (group II).

RESULTS

Median support duration was seven days (range: 0-31). Surgery involving hypoplastic aortic arch repair (Norwood palliation; n = 7, 20.6%, or biventricular repair; n = 11, 32.4%) led to most ECMO runs. Successful weaning from ECMO and hospital survival were 76.5% and 50%, respectively. In group I, peak TnI levels were reached by 24 hours postoperatively, comparable to levels in group II (36 ± 34 vs 49 ± 38 ng/mL; P = .98). However, in group II, TnI levels formed a plateau by the second postoperative day, whereas group I showed a steep decline in TnI levels, suggesting myocardial recovery (P = .028). All patients (n = 4) who reached or maintained peak TnI levels at 48 hours died. On days 8, 9 and 10, TnI levels were significantly higher in group II (P = .024, .019, and .013, respectively).

CONCLUSIONS

Postcardiotomy ECMO was most commonly required after aortic arch repair. In the absence of ongoing myocardial insult due to ECMO hardware issues, coronary insufficiency or residual lesions, plateau TnI levels at 48 hours may seem to indicate an unfavorable outcome due to irreversible myocardial damage.

Improved contractility with tepid modified full blood cardioplegia compared with cold crystalloid cardioplegia in a piglet model

OBJECTIVES

Experience regarding warm blood cardioplegia according to Calafiore results from its broad use in adult patients. In this experimental study, tepid (28°C) modified full blood cardioplegia (MBC) was adopted for paediatric use and compared with cold crystalloid cardioplegia (CCC).

METHODS

Twenty male piglets (mean weight: 11.1 ± 1.0 kg) were operated on cardiopulmonary bypass (CPB) in moderate hypothermia (28°C) and randomized to MBC (n = 8) or CCC (n = 12) for 60 min aortic cross-clamping. Blood levels of myocardial proteins [N-terminal pro-brain natriuretic peptide (NT-pro-BNP), myoglobin, creatine kinase type MB and troponin-I] were investigated at the beginning of the experiment and after CPB. Haemodynamic measurements included thermodilution and conductance-catheter technique inserted through the left ventricle-apex. Pressure-volume loop analysis was performed with dobutamine-stress test and inflow occlusion, enabling preload independent evaluation of myocardial performance. Changes of measured data post-CPB were calculated in relation to baseline-levels (%).

RESULTS

Baseline and operative data in both groups were similar. During the experiment, cardiac markers showed no significant variations between groups. Pressure-volume loop analysis during stress test revealed a significantly higher preload independent contractility (slope of end-systolic pressure-volume relation: Ees) with MBC compared with CCC (MBC: 123 ± 35% [confidence interval (CI95): 93-153] vs CCC: 78 ± 34% [CI95: 54-102]; P = 0.042), whereas cardiac output was not significantly different between groups {MBC: 122 ± 16% [95% confidence interval (CI95): 109-135] vs CCC: 105 ± 17% [CI95: 93-116]; P = 0.069}.

CONCLUSION

This randomized animal study proves feasibility and safety of MBC for paediatric use. Haemodynamic evaluation and cardiac markers did not show inferiority to standard CCC. Moreover, MBC seems to be associated with superior contractility post bypass, which encourages us to use MBC in paediatric patients in the near future.

Pericardial cyst or teratoma? Change of strategy during mediastinal tumor surgery

This report describes the management of an 8 × 8-cm cystic mass that arose from the anterior mediastinum and prolapsed into the right pleural cavity adherent to the pericardium in an asymptomatic 16-year-old girl. The patient was scheduled for a video-assisted thoracoscopic operation with exposure, puncture and suction of a suspected pericardial cyst. However, during the procedure the strategy was changed due to the solid consistency of the mass, and the lesion was extirpated in toto by a short anterolateral thoracotomy. The complete histopathological investigation showed a highly fibrous, cystic, mature teratoma.

Early failure of xenogenous de-cellularised pulmonary valve conduits--a word of caution!

OBJECTIVE

The longevity of valved right ventricle to pulmonary artery (RV-PA) conduits is limited due to calcification and degeneration of non-viable structures. Xenografts are commonly used because of the restricted availability of cryopreserved homografts. Tissue-engineered (de-cellularised) pulmonary valves (TEPVs) were thought to be a valuable alternative to cryopreserved pulmonary homografts due to postoperative seeding with viable autologous vascular endothelial cells.

METHODS

From July 2007 to December 2008, xenogenous TEPV (Matrix P plus) were implanted in 16 patients in the right ventricular outflow tract for different indications, related to congenital heart disease. Mean age at operation was 14+/-11 years, including three patients younger than 1 year. The median conduit size was 22 mm (range: 13-26 mm).

RESULTS

The early and late survival rates were 100%. At a median follow-up of 10 months (range: 2-17 months), six patients (38%) had to be re-operated upon due to obstructed grafts. Five of these patients were older than 13 years (range: 13-26 years); one patient was younger than 1 year. On echocardiography before re-operation, mean systolic gradient in the main PA was 66+/-18 mmHg. In explanted conduits, we found a predominantly peripheral conduit narrowing without leaflet calcification. Histological examination revealed stenosis formation, due to inflammatory infiltration and severely fibrogenic pseudo-intimal reaction.

CONCLUSIONS

On the basis of our short-term results, the Matrix P plus de-cellularised tissue-engineered pulmonary valve cannot be regarded as an ideal conduit for right ventricular outflow tract reconstruction, as the widespread use of these grafts may increase the possibility of frequent early conduit failures.

The Norwood procedure - does the type of shunt determine outcome?

BACKGROUND

Stage I palliation of hypoplastic left heart syndrome (HLHS) and its variants is usually performed by a Norwood operation. The management of pulmonary blood flow during this procedure remains controversial. The RV-to-PA conduit (RVPAC) has been proposed as the better alternative compared to a systemic-to-pulmonary shunt (SPS).

METHODS

A retrospective single center chart review of consecutive patients who underwent a Norwood I procedure between 01/1997 and 09/2006 was performed. All patients were operated in deep hypothermia, with or without circulatory arrest, using different shunt modifications according to surgeon's preference. Patients were divided into two groups depending on surgical management for pulmonary blood flow (modified BT shunt [BT] and non-valved RVPAC [Sano]).

RESULTS

Fifty-four patients were included in the study (BT: 31 patients vs. Sano: 23 patients). Diastolic blood pressure during the first 24 hours postoperatively was significantly lower in the BT group (BT: 38.6 +/- 6.9 mmHg vs. Sano: 42.4 +/- 7.2 mmHg; P < 0.01) with a trend towards a higher systolic blood pressure (BT: 74.1 +/- 13.5 mmHg vs. Sano: 69.8 +/- 12.1 mmHg; P = 0.08). Mean circulatory arrest time in the BT group was significantly longer compared to the Sano patients (BT: 41 +/- 21 min vs. Sano: 25 +/- 23 min; P < 0.01). The mean hospital stay was 18.5 days for BT patients and 20 days for Sano patients ( P = 0.45). Early mortality for the total cohort was 14.8 % (n = 8) (BT 19.4 % [n = 6] vs. Sano 8.7 % [n = 2]; P = 0.12). There was no significant difference in inter-stage mortality between the two groups (BT: 18.2 % vs. Sano: 21.1 %; P = 0.47).

CONCLUSION

The results for both established surgical methods (BT and Sano) for the palliation of HLHS and its variants have improved over time and are reaching acceptable early mortality rates. There was a trend towards a favorable early outcome for Sano patients, which did not reach statistical significance in this study due to the low patient numbers.

High-risk mitral valve replacement in severe pulmonary hypertension--30 years experience

OBJECTIVE

In the past 30 years, 2316 patients underwent mitral valve replacement (MVR) at our institution; 382 of them had severe pulmonary hypertension (pulmonary artery pressure (PAP) > 50 mmHg; pulmonary vascular resistance (PVR), 690 +/- 46 dyn/s per m2). We reviewed our early and late results in this high-risk subgroup.

METHODS

We used 336 mechanical and 46 biological devices for MVR. The follow-up was 95%, with an observation period of 3208 patient-years and a mean of 8.4 +/- 0.2 years per patient. The overall early mortality rate was 10.5% (n = 40) and stayed at about the same level over the years, although patients characteristics have changed to much older patients and more reoperations. To clarify this fact we divided our data in results according to the decades in which the operations were carried out. The clinical preoperative status and results were as follows (*P < 0.05; **P < 0.01 compared with previous decade). In the decades between 1963 and 1973 (I), 1974 and 1983 (11) and 1984 and 1993 (III) we operated on n = 95 (I), n = 185 (II), and n = 102 (III) patients with a mean age of 43 +/- 1 (I), 50 +/- 1** (II), and 58 +/- 1** (III) years. The incidence of reoperations among these patients was 3.2 (I), 4.9 (II), and 22.6%** (III). The early mortalities were 13.7 (I), 8.6* (II) and 10.8% (III); late mortalities lowered from 5.77 (I), over 4.95 (II), and up to 3.39%** (III) patients/year. The mean functional status according to New York Heart Association (NYHA) class improved from preoperatively 3.0 +/- 0.1 (I), 3.2 +/- 0.1 (II) and 3.3 +/- 0.1 (III) to 2.4 +/- 0.2 (I), 2.4 +/- 0.1 (II) and 2.3 +/- 0.1 (III) postoperatively.

RESULTS

Compared with routine elective MVR with a mortality rate of 3.6% (P < 0.01), early mortality is high. But once the patient survives the perioperative course, late results show no difference compared with patients without pulmonary hypertension. The functional results as well are not significantly different. In spite of on average 15 years older multimorbid patients with therefore higher complication rates, early results improved slightly, which could be explained by better operative techniques, perioperative treatment and nursing (online monitoring with immediate therapeutic substitution). Surprisingly the increased number of reoperations had no negative impact on patients' outcomes.

CONCLUSION

According to our results, we recommend MVR in severe pulmonary hypertension even in the elderly, with a high but acceptable risk and good long-term results.

Posttraumatic aneurysm of the right atrium

We report on an acquired right atrial false aneurysm, which was removed under extracorporeal circulation. The patient remembered three occasions of blunt chest trauma with rib fractures. Clinical symptoms were ongoing dyspnea, chest pain, and atrial fibrillation.