Palliation For Single Ventricle Physiology Research Articles

Commentary: Extracardiac conduit-total cavopulmonary connection for heterotaxy-Is going the "extra" mile worth it.

Extracardiac conduit-total cavopulmonary connection (EC-TCPC) represents the latest evolution in Fontan palliation for single ventricle physiology. Here, we review a manuscript by Pan et al. in the Journal of Cardiac Surgery detailing a retrospective, single-center cohort study of patients with and without heterotaxy syndrome undergoing EC-TCPC. Although lacking a comparison to other techniques for single ventricle palliation, this approach appears to offer excellent outcomes for this complex patient cohort.

Incidence and impact of acute kidney injury in patients with hypoplastic left heart syndrome following the hybrid stage 1 palliation.

Acute kidney injury leads to worse outcomes following paediatric cardiac surgery. There is a lack of literature focusing on acute kidney injury after the Hybrid stage 1 palliation for single ventricle physiology. Patients undergoing the Hybrid Stage 1, as a primary option, may have a lower incidence of kidney injury than previously reported. When present, kidney injury may increase the risk of post-operative morbidity and mortality. A retrospective, single centre review was conducted in patients with hypoplastic left heart syndrome who underwent Hybrid Stage 1 from 2008 to 2018. Acute kidney injury was defined as a dichotomous yes (meeting any injury criteria) or no (no injury) utilising two different criteria utilised in paediatrics. The impact of kidney injury on perioperative characteristics and 30-day mortality was analysed. The incidence of acute kidney injury is 13.4-20.7%, with a severe injury rate of 2.4%. Patients without a prenatal diagnosis of hypoplastic left heart syndrome have a higher incidence of kidney injury than those prenatally diagnosed, (40% versus 14.5%, p = 0.024). Patients with acute kidney injury have a significantly higher incidence of 30-day mortality, 27.3%, compared to without, 5.6% (p = 0.047). The incidence of severe acute kidney injury after the Hybrid Stage 1 palliation is low. A prenatal diagnosis may be associated with a lower incidence of kidney injury following the Hybrid Stage 1. Though uncommon, severe acute kidney injury following Hybrid Stage 1 may be associated with higher 30-day mortality.

MRI Evaluation of Lymphatic Abnormalities in the Neck and Thorax after Fontan Surgery: Relationship with Outcome.

Background The Fontan operation is performed for surgical palliation of single ventricle physiology. This operation is usually preceded by a superior cavopulmonary connection (SCPC); lymphatic abnormalities after SCPC may be demonstrated at MRI and prior to the Fontan operation. Purpose To determine if the degree of neck and thoracic lymphatic abnormalities at T2-weighted MRI in patients after superior cavopulmonary connection (SCPC) correlated with surgical outcomes from the Fontan procedure. Materials and Methods Patients for whom SCPC was performed for palliation of single ventricle disease who underwent chest MRI between July 2012 and May 2015 at a single institution were retrospectively reviewed. T2-weighted images were scored as lymphatic type 1 (little or no T2 mediastinal and supraclavicular signal) to type 4 (T2 signal into both the mediastinum and the lung parenchyma). Fontan takedown, duration of post-Fontan hospitalization and pleural effusion, postoperative plastic bronchitis, need for transplant, and mortality were tabulated. The relationship between lymphatic type and clinical outcomes was evaluated by using analysis of variance (ANOVA), the Kruskal-Wallis H test, and the Fisher exact test. Results A total of 83 patients (mean age, 7.9 years ± 2.6) were evaluated. Among these 83 patients, 53 (64%) were classified with type 1 or 2 lymphatic abnormalities, 17 (20%) with type 3, and 12 (16%) with type 4. The rate of failure of Fontan completion was higher in patients with type 4 than in type 1 or 2 (54% vs 2%, respectively; P = .004). Need for cardiac transplant (one of 13 [8%]) and death (three of 13 [23%]) occurred only in type 4. Median postoperative length of stay was longer for patients with type 4 than for those with types 1 or 2 (29 days vs 9 days, respectively; P < .01). Conclusion Greater MRI-based severity of lymphatic abnormalities in patients prior to planned Fontan procedure was associated with failure of Fontan completion and longer postoperative stay. © RSNA, 2019 Online supplemental material is available for this article.

Focal liver lesions following Fontan palliation of single ventricle physiology: A radiology‐pathology case series

Patients who have undergone Fontan palliation of single ventricle physiology congenital heart disease are prone to developing focal liver lesions. In our experience, the variety of lesions occurring in this population is greater than that described in the literature. The purpose of this study was to describe the breadth of biopsy-proven liver lesions in patients post-Fontan palliation of single ventricle physiology cared for at our institution. We retrospectively identified patients who had previously undergone the Fontan operation and had a focal liver lesion biopsied between January 2000 and June 2018. Medical records were reviewed for lesion pathology, background liver findings, pertinent laboratory data, and demographic data. CT and MRI images were reviewed to describe imaging findings of the reported lesions. Twelve patients met inclusion criteria; 58% (7/12) of which were female. Fifteen lesions were biopsied including four macroregenerative/benign hepatocellular hyperplastic nodules, two hepatocellular adenomas, two hepatocellular carcinomas, two intrahepatic cholangiocarcinoma (in the same patient), one venous malformation, and one focus of vascularized scar tissue. Two additional lesions in patients postcardiac transplant were posttransplant lymphoproliferative disorder. Patients who have undergone Fontan palliation of single ventricle physiology are prone to develop a variety of liver lesions, both benign and malignant.

Simultaneous Systemic to Pulmonary Shunt and Pulmonary Artery Banding is a Viable Option for Neonatal Palliation of Single Ventricle Physiology

A subset of neonates with single ventricle (SV) physiology has antegrade pulmonary blood flow that is deemed unlikely to be reliable until Glenn. We have used systemic to pulmonary shunt (SPS) with pulmonary artery banding (PAB) to optimize pulmonary blood flow while maintaining reserve antegrade flow. We hypothesize that this is an effective strategy that can be accomplished without the routine need for cardiopulmonary bypass. We retrospectively reviewed the records of 60 neonates who underwent combined SPS + PAB between 2004 and 2015. Data are presented as median with quartiles. Children were 8 (4-19) days old at surgery and included 38 (63%) boys. Atresia or severe stenosis of the subpulmonary atrioventricular (AV) valve associated with pulmonary blood flow across a bulboventricular foramen was present in 37 (62%). In 20 (33%), heterotaxy-associated unbalanced AV canal with pulmonary stenosis with or without anomalous pulmonary venous drainage was present. First-stage palliation was accomplished without cardiopulmonary bypass in 44 patients (73%). There were 7 (12%) hospital deaths, 4 among the 20 (20%) with heterotaxy. Fifty-three children were followed for a median 5.1 (1.8-8.2) years. Three early reinterventions were required after initial palliation (1 PAB adjustment, 2 SPS balloon angioplasties). Five additional heterotaxy patients experienced late mortality during follow-up. There were no early or emergent Glenn. Thirty-nine patients have reached Fontan circulation with a median pre-Fontan PA pressure of 14 (12-18) mm Hg. One patient converted to biventricular physiology and the remaining await completion Fontan. Heterotaxy was the only independent predictor of mortality (hazard ratio 10 (2.3-44, P < 0.001). In SV patients with unreliable antegrade PA flow, SPS + PAB is an effective first-stage palliation. SV patients with heterotaxy are at increased risk for mortality.

Incidence of Immediate Extubation After Pediatric Cardiac Surgery and Predictors for Reintubation.

The objectives were to assess the incidence of immediate tracheal extubation in the operating room after pediatric cardiac surgery and to investigate predictors for subsequent reintubation. This is a single institutional retrospective study including all patients who had a cardiac operation with cardiopulmonary bypass from 2011 to 2016. Patients who required preoperative ventilator support, postoperative open chest, or mechanical support were excluded. Predictors for reintubation after immediate extubation were analyzed only for patients with stage II palliation for single ventricle physiology. Nine hundred nine qualifying operations were identified. Immediate extubation was performed in 590 (64.9%) operations. A multivariable logistic regression model showed that the identities of anesthesiologist ( P = .0003), year of the operation performed ( P < .001), cardiopulmonary bypass time ( P < .001), and type of operations ( P < .001) were significantly associated with immediate extubation. Reintubation was significantly less frequent in patients with immediate extubation compared to those without (6.1% vs 15.0%; P < .001). A subgroup analysis for stage II palliation showed that reintubation after immediate extubation was significant for younger age (0.42 vs 0.54 years, P = .044), lower Po2/Fio2 and Po2 at the last blood gas analysis (66 vs 98 mm Hg, P = .032 and 39 vs 47 mm Hg, P = .008), and higher inotropic score (2 vs 0, P = .034). A multivariable logistic regression model showed that only inotropic score was significantly associated with reintubation ( P = .018). Immediate extubation in the operating room after pediatric cardiac surgery can be performed in most patients. Inotropic score is a predictor for reintubation in stage II palliation.

Staged Palliation for Single Ventricle Physiology: The Influence of Specialization and Shunt Type

Staged Palliation for Single Ventricle Physiology: The Influence of Specialization and Shunt Type

Fontan completion in reverse order out of necessity: secondary Glenn after primary extracardiac inferior cavopulmonary artery connection

The primary extracardiac inferior cavopulmonary connection is an unusual novel palliation for single-ventricle physiology, which we first performed in the setting of unfavourable upper-body systemic venous anatomy for a standard bi-directional Glenn, and in lieu of leaving our patient with shunt-dependent physiology. After an initial 16-month satisfactory follow-up, increasing cyanosis led to the discovery of a veno-venous collateral that was coiled, but, more importantly, to impressive growth of a previously diminutive superior caval vein, which allowed us to perform completion Fontan with a good outcome. Performing the single-ventricle staging in a reverse manner, first from below with a primary inferior cavopulmonary connection, followed by Fontan completion from above with a standard superior caval vein bi-directional Glenn, is also possible when deemed necessary.

When the bi-directional Glenn is an unfavourable option: primary extracardiac inferior cavopulmonary connection as an alternative palliation

The superior cavopulmonary anastomosis - bi-directional Glenn - is the standard palliation for single ventricle physiology. When upper body systemic venous anatomic concerns such as superior caval vein stenosis, hypoplasia, or inadequate collateral tributaries are present, a Glenn may be precluded or have a high risk of poor outcome. A primary inferior cavopulmonary connection with an extracardiac conduit is an alternative palliation that provides a generous pathway for pulmonary blood flow, with the additional benefit of including hepatic venous return. We report a case of primary extracardiac inferior cavopulmonary connection in a patient unsuitable for Glenn, with successful post-operative outcome and early follow-up.

Early Cyanosis After Stage II Palliation for Single Ventricle Physiology

In the early postoperative period after stage II palliation, patients with single ventricle physiology can have cyanosis due to a variety of causes. This cyanosis can be significant and necessitate cardiac catheterization to determine etiology and attempt treatment. Our objective was to determine the etiology of early postoperative cyanosis and outcomes in patients referred to the catheterization laboratory from the cardiac intensive care unit (CICU) after stage II palliation. We performed a retrospective analysis of all patients referred for cardiac catheterization from the CICU for evaluation of early cyanosis after stage II palliation. Etiology for hypoxemia, treatment strategy, and patient outcomes were examined for each patient. Between January 1, 2006, and December 31, 2011, 244 patients underwent stage II palliation of which 22 required cardiac catheterization during the early postoperative period because of severe cyanosis. The etiologies for cyanosis were venovenous collaterals (n = 12), cavopulmonary pathway thrombosis (n = 3), hemi-Fontan pathway baffle leak (n = 2), and undetermined (n = 5). Overall, transplant-free survival to hospital discharge was 50% and survival to hospital discharge with stage II physiology was 32%. Venovenous collateral occlusion, cavopulmonary anastomosis takedown, and addition of a second source of pulmonary blood flow were not associated with improved outcome. Regardless of the etiology or treatment strategy, severe cyanosis in the early postoperative period after stage II palliation imparts high mortality and usually indicates failing stage II physiology. Venovenous collateral occlusion and thrombectomy are usually futile, and those who survive have a low likelihood of having stage II physiology at hospital discharge.

Feeding and nutritional challenges in infants with single ventricle physiology

Adequate enteral nutrition and growth are vital to recovery and survival of infants following palliation for univentricular hearts. This group of patients experiences frequent feeding complications that may impede adequate delivery of enteral nutrition. This review presents the most recent data related to feeding practices, growth patterns and outcomes. It also explores management strategies for delivering enteral nutrition safely and effectively to this high-risk group of infants. Infants following palliation for single ventricle physiology have persistent growth failure until at least 14 months of life. Greater daily caloric intake attenuates this growth failure. Persistent growth failure is associated with increased mortality following cardiac surgery. Management of enteral nutrition varies widely both pre and postoperatively. Data suggest that standardizing feeding practices improves delivery of enteral nutrition and decreases feeding complications. Evidence-based international feeding guidelines do not exist. Delivery of adequate nutrition in infants with single ventricle physiology is essential to improve outcomes but is often difficult to achieve. Evidence-based feeding guideline development is crucial to improve outcomes in this group of patients.

Orthotopic Heart Transplantation in Patients with Univentricular Physiology

Parallel advancements in surgical technique, preoperative and postoperative care, as well as a better understanding of physiology in patients with duct-dependent pulmonary or systemic circulation and a functional single ventricle, have led to superb results in staged palliation of most complex congenital heart disease (CHD) [1]. The Fontan procedure and its technical modifications have resulted in markedly improved outcomes of patients with single ventricle anatomy [2,3,4]. The improved early survival has led to an exponential increase of the proportion of Fontan patients surviving long into adolescence and young adulthood [5]. Improved early and late survival has not yet abolished late mortality secondary to myocardial failure, therefore increasing the referrals for cardiac transplantation [6]. Interstage attrition [7] is moreover expected in staged palliation towards completion of a Fontan-type circulation, while Fontan failure represents a growing indication for heart transplantation [8]. Heart transplantation has therefore become the potential “fourth stage” [9] or a possible alternative to a high-risk Fontan operation [10] in a strategy of staged palliation for single ventricle physiology. Heart transplant barely accounts for 16% of pediatric solid organ transplants [11]. The thirteenth official pediatric heart transplantation report- 2010 [11] indicates that pediatric recipients received only 12.5% of the total reported heart transplants worldwide. Congenital heart disease is not only the most common recipient diagnosis, but also the most powerful predictor of 1-year mortality after OHT. Results of orthotopic heart transplantations (OHT) for failing single ventricle physiology are mixed. Some authors advocate excellent early and mid-term survival after OHT for failing Fontan [9], while others suggest that rescue-OHT after failing Fontan seems unwarranted [10]. Moreover, OHT outcome appears to be different according to the surgical staging towards the Fontan operation and surgical technique of Fontan completion [12].The focus of this report is a complete review of the recent literature on OHT for failing single ventricles, outlining the clinical issues affecting Fontan failure, OHT listing and OHT outcome. These data are endorsed reporting our experience with OHT for failing single ventricle physiology in recent years.

Performance of Cavopulmonary Palliation at Elevated Altitude

Outcomes of patients undergoing cavopulmonary palliation for single ventricle physiology may be impacted by living at altitude, as the passive pulmonary circulation is dependent on the resistance of the pulmonary vascular bed. The objective of this study is to identify risk factors for failure of cavopulmonary palliation at elevated altitude. Between January 1995 and March 2007, 122 consecutive patients living at a mean altitude of 1600 m (range 305 to 2570) underwent a bidirectional Glenn (BDG). There was one in-hospital mortality and 7 late deaths. 52 have proceeded to the Fontan procedure. Survival after BDG was 92.4% at 5 years. Freedom from palliation failure, defined as death, transplant, BDG/Fontan takedown, or revision was 81% at 5 years. At a mean follow-up of 39.8 months, 90 patients (75%) were in New York Heart Association class I. Patients with failing cavopulmonary circulation had higher pre-BDG pulmonary artery pressure (PAP) (18.3+/-6.1 mm Hg versus 14.8+/-5.1 mm Hg, P=0.016) and higher pre-BDG transpulmonary gradient (TPG) (11.2+/-6.2 mm Hg versus 7.7+/-4.3 mm Hg, P=0.014). Post-BDG, patients with palliation failure had increased PAP (15.0+/-5.7 mm Hg versus 10.8+/-2.8 mm Hg, P=0.008) and indexed pulmonary vascular resistance (PVRI) (2.43+/-1.0 Wood U . m(2) versus 1.52+/-0.9 Wood U . m(2), P=0.007). The majority of patients at moderate altitude have favorable outcomes after BDG or Fontan palliation. Risk factors for palliation failure at elevated altitude include PAP >15 mm Hg, TPG >8 mm Hg, and PVRI >2.5 Wood U . m(2).

Fontan Fenestration Closure Has No Acute Effect on Exercise Capacity but Improves Ventilatory Response to Exercise

The aim of this study was to prospectively examine the effects of elective Fontan fenestration closure upon exercise capacity and ventilatory abnormalities. For patients undergoing Fontan procedures as palliation of single ventricle physiology, the addition of a fenestration to the procedure mitigates perioperative morbidity. Although some fenestrations may close spontaneously, many remain patent and subject patients to arterial hypoxemia and risk for paradoxical emboli. For these reasons fenestration closure is routinely performed post-operatively in the cardiac catheterization laboratory. Although closure of Fontan fenestrations typically results in an immediate improvement in systemic arterial oxygen saturation, it is also associated with an acute decrease in cardiac index and systemic O(2) delivery. The sum result of these physiologic changes upon exercise capacity has not been examined. Twenty consecutive patients, age 5 to 46 (median 10) years, underwent pre- and post-fenestration closure exercise testing with expiratory gas analysis. Before fenestration closure, peak oxygen consumption (VO(2)) was depressed and there was systemic desaturation at rest that worsened with exercise. The ventilatory response to exercise was also abnormal, characterized by elevation of the minute ventilation (VE)/CO(2) elimination slope (VE/VCO(2)), a low end-tidal CO(2), and high end-tidal O(2) at the ventilatory anaerobic threshold. Although arterial saturation improved significantly after fenestration closure, there was no change in peak VO(2) (70.9 +/- 18.6% to 74.0 +/- 18.6%, p = NS), heart rate, or O(2) pulse at peak exercise. In contrast, ventilatory abnormalities (VE/VCO(2)) improved considerably (44.4 +/- 10.9 to 33.3 +/- 5.5, p <or= 0.001). Fontan fenestration closure does not significantly improve peak VO(2). However, ventilatory abnormalities improve considerably.

Abstract 2138: Fontan Fenestration Closure Has No Effect On Exercise Capacity But Improves The Ventilatory Response To Exercise

Introduction: For patients undergoing Fontan procedures for palliation of single ventricle physiology the addition of a fenestration to the procedure, which permits intracardiac right-to-left shunting, mitigates perioperative morbidity. While some fenestrations may close spontaneously, many remain patent and subject patients to arterial hypoxemia and risk for paradoxical emboli. For this reason fenestration closure is routinely performed post-operatively in the cardiac catheterization laboratory. Fenestration closure typically results in improved arterial oxygenation, but decreased cardiac index. We assessed the hypothesis that sum effect of these physiologic changes would have not improve exercise capacity. Methods: Nineteen consecutive patients, age 4.8–46 (median 10) years underwent pre and post-fenestration closure exercise testing with expiratory gas analysis. Results: Prior to fenestration closure, peak oxygen consumption (VO2) was low. Arterial desaturation was present at rest and worsened with exercise. The ventilatory response to exercise was excessive, characterized by elevation of the minute ventilation vs. CO2 production slope (VE/VCO2 slope) and a low end tidal pCO2 at the ventilatory anaerobic threshold (pETCO2). Following fenestration closure, arterial saturation (at rest and at peak exercise) improved significantly. However, there was no change in VO2, heart rate, or oxygen pulse at peak exercise. In contrast, ventilatory abnormalities improved considerably. The VE/VCO2 slope fell 25% and pETCO2 rose from 27.9+/−4.2 to 34.1+/−3.2 mmHg. Conclusion: Elective Fontan fenestration closure does not improve peak VO2. However, the reduction in right-to-left intracardiac shunting improves arterial oxygen saturation during exercise and reduces the patient’s need to ventilate during exercise. These changes may reduce the Fontan patient’s perception of dyspnea during exercise. Pre and Post-Fenestration Exercise Data

Off pump bidirectional Glenn performed through a thoracotomy

Introduction The bidirectional Glenn shunt has become an accepted method of palliation for single ventricle physiology and an intermediate step prior to the Fontan type operations. Attempts have been made to perform this operation without the use of cardiopulmonary bypass thereby eliminating its deleterious effects. The aim of this study was to review our experience with bidirectional Glenn shunt performed via thoracotomy without cardiopulmonary bypass.

Anesthetic Implications of the Fontan Procedure for Single Ventricle Physiology

The Fontan procedure is the operation of choice for patients considered to be candidates for definitive palliation of single ventricle physiology. Anesthetic technique for the Fontan procedure is not well described in the literature, and the medical and surgical treatment of these patients is rapidly evolving. With an understanding of the anatomy and phys iology of the Fontan patient, a safe and effective anesthetic can be executed. An understanding of the changes that occur during the perioperative period is critical. This article focuses on a review of single ventricle physiology and Fon tan physiology, preoperative assessment and risk factors for the Fontan procedure, intraoperative management, and management of low cardiac output in the postbypass period.