Superior Cavopulmonary Connections Research Articles

The so-called "one-and-a-half" ventricular repair: where are we after 40 years?

The indications, timing, and results of the so-called "one-and-a-half ventricle repair", as a surgical alternative to the creation of the Fontan circulation, or high-risk biventricular repair, currently remain nebulous. We aimed to clarify these issues. We reviewed a total of 201 investigations, assessing selection of candidates, the need for atrial septal fenestration, the fate of an unligated azygos vein and free pulmonary regurgitation, the concerns regarding reverse pulsatile flow in the superior caval vein, the growth potential and function of the subpulmonary ventricle, and the role of the superior cavopulmonary connections as an interstage procedure prior to biventricular repair, or as a salvage procedure. We also assessed subsequent eligibility for conversion to biventricular repair and long-term functional results. Reported operative mortalities ranged from 3% to 20%, depending on the era of surgical repair with 7% risk of complications due to a pulsatile superior caval vein, up to one-third incidence of supraventricular arrhythmias, and a small risk of anastomotic takedown of the superior cavopulmonary connection. Actuarial survival was between 80% and 90% at 10 years, with two-thirds of patients in good shape after 20 years. We found no reported instances of plastic bronchitis, protein-losing enteropathy, or hepatic cirrhosis. The so-called "one-and-a-half ventricular repair", which is better described as production of one-and-a-half circulations can be performed as a definitive palliative procedure with an acceptable risk similar to that of conversion to the Fontan circulation. The operation reduces the surgical risk for biventricular repair and reverses the Fontan paradox.

Pediatric Single Ventricle VADs: A Single Center Review

<h3>Purpose</h3> Single ventricular assist device (SVAD) support in with children with single ventricle (SV) physiology remains challenging. We hypothesized that an individualized approach to SV patients—particularly those with superior cavopulmonary connections (SCPCs)—including changing the "stage" of palliation at the time of VAD support would promote improved outcomes. <h3>Methods</h3> We performed a single-center retrospective chart review of all SVADs implanted 2006 to 2021. We evaluated implant strategy, outcomes, and adverse events (AEs, ACTION-defined). A successful VAD course was defined as still on support, 180 days on support, or transplanted. <h3>Results</h3> A total of 20 SV patients were supported on VAD (7 prior to 2017, 13 after). Devices have varied (Berlin 5, Thoratec PVAD 1, HVAD 1, PediMag 9, HM3 4). SV stage of palliation prior to VAD support included 2 stage 1, 12 SCPC, and 7 Fontan patients. Among the 12 patients with pre-VAD SCPC: 9 were supported as a SCPC, 2 following biventricular conversion, and 1 as a Fontan. Successful support occurred in 13/20 (65%) patients (9 transplanted, 2 180 days of support, 2 alive on support). AE rates were high and success rate lower among SCPC patients, but all patients with BiVAD or Fontan were successfully supported (Table). Among patients on durable devices, 2/5 (40%) were discharged to home on support. Patients with pre-VAD ECMO had a lower likelihood of success when supported as a SCPC (0/4, 0%) than when supported as a BiVAD (2/2, 100%). <h3>Conclusion</h3> Data compiled from our center shows SV patients can be supported successfully on VADs. Stage 1 and SCPC patients remain challenging, but conversion to biventricular circulation or Fontan completion improves outcomes

Thromboprophylaxis strategies for children with single-ventricle circulations (superior or total cavo-pulmonary connections) after stent implantation.

To define optimal thromboprophylaxis strategy after stent implantation in superior or total cavopulmonary connections. Stent thrombosis is a rare complication of intravascular stenting, with a perceived higher risk in single-ventricle patients. All patients who underwent stent implantation within superior or total cavopulmonary connections (caval vein, innominate vein, Fontan, or branch pulmonary arteries) were included. Cohort was divided into aspirin therapy alone versus advanced anticoagulation, including warfarin, enoxaparin, heparin, or clopidogrel. Primary endpoint was in-stent or downstream thrombus, and secondary endpoints included bleeding complications. A total of 58 patients with single-ventricle circulation underwent 72 stent implantations. Of them 14 stents (19%) were implanted post-superior cavopulmonary connection and 58 (81%) post-total cavopulmonary connection. Indications for stenting included vessel/conduit stenosis (67%), external compression (18%), and thrombotic occlusion (15%). Advanced anticoagulation was prescribed for 32 (44%) patients and aspirin for 40 (56%) patients. Median follow up was 1.1 (25th-75th percentile, 0.5-2.6) years. Echocardiograms were available in 71 patients (99%), and advanced imaging in 44 patients (61%). Thrombosis was present in two patients on advanced anticoagulation (6.3%) and none noted in patients on aspirin (p = 0.187). Both patients with in-stent thrombus underwent initial stenting due to occlusive left pulmonary artery thrombus acutely post-superior cavopulmonary connection. There were seven (22%) significant bleeding complications for advanced anticoagulation and none for aspirin (p < 0.001). Antithrombotic strategy does not appear to affect rates of in-stent thrombus in single-ventricle circulations. Aspirin alone may be sufficient for most patients undergoing stent implantation, while pre-existing thrombus may warrant advanced anticoagulation.

Factors associated with systemic to pulmonary arterial collateral flow in single ventricle patients with superior cavopulmonary connections

ObjectiveSystemic to pulmonary arterial collateral flow (CollF) is common in single ventricle patients with superior cavopulmonary connections (SCPC), although associations with CollF are not well understood. We previously described a...

Status of Systemic to Pulmonary Arterial Collateral Flow After the Fontan Procedure

The investigators recently validated a method of quantifying systemic-to-pulmonary arterial collateral flow using phase-contrast magnetic resonance imaging velocity mapping. Cross-sectional data suggest decreased collateral flow in patients with total cavopulmonary connections (TCPCs) compared with those with superior cavopulmonary connections (SCPCs). However, no studies have examined serial changes in collateral flow from SCPCs to TCPCs in the same patients. The aim of this study was to examine differences in collateral flow between patients with SCPCs and those with TCPCs. Collateral flow was quantified by 2 independent measures from 250 single-ventricle studies in 219 different patients (115 SCPC and 135 TCPC studies, 31 patients with both) and 18 controls, during routine studies using through-plane phase-contrast magnetic resonance imaging. Collateral flow was indexed to body surface area, aortic flow, and pulmonary venous flow. Regardless of indexing method, SCPC patients had significantly higher collateral flow than TCPC patients (1.64 ± 0.8 vs 1.03 ± 0.8L/min/m(2), p <0.001). In 31 patients who underwent serial examinations, collateral flow as a fraction of aortic flow increased early after TCPC completion. In TCPC patients, indexed collateral flow demonstrated a significant negative correlation with time from TCPC. In conclusion, SCPC and TCPC patients demonstrate substantial collateral flow, with SCPC patients having higher collateral flow than TCPC patients overall. On the basis of the paired subset analysis, collateral flow does not decrease in the short term after TCPC completion and trends toward an increase. In the long term, however, collateral flow decreases over time after TCPC completion.

Accuracy of Conventional Oximetry for Flow Estimation in Patients With Superior Cavopulmonary Connection

Cardiac catheterization is routinely used as a diagnostic tool in single ventricle patients with superior cavopulmonary connection. This physiology presents inherent challenges in applying the Fick principle to estimate flow. We sought to quantitatively define the error in oximetry-derived flow parameters using phase-contrast cardiac MRI (CMR) as a reference. Thirty patients with superior cavopulmonary connection who underwent combined CMR and catheterization between July 2008 and June 2012 were retrospectively analyzed. Estimates of flow and resistance calculated using the Fick equation were compared with CMR measurements. Oximetry underestimated CMR-measured pulmonary blood flow (Qp) by an average of 1.1 L/min per m(2) or 32% of the CMR value (P<0.0001). Oximetry overestimated systemic blood flow (Qs) by an average of 0.5 L/min per m(2) or 15% of the CMR value (P=0.009). There was no correlation between the Qp:Qs ratio derived by Fick and that measured by CMR (ρ(c)=0.01). The error in the Fick Qp correlated moderately with the measured systemic-to-pulmonary arterial collateral flow (r=0.39). The median total oxygen consumption calculated using combined CMR and oximetry data was 173 mL/min per m(2), higher than the assumed values used to calculate flows by the Fick equation. The upper body circulation received on average 51% of systemic blood flow while conducting only 39% of total body metabolism. Fick-derived estimates of flow are inherently unreliable in patients with superior cavopulmonary connections. Integrating flows measured by CMR and pressures measured by catheter will provide the best characterization of superior cavopulmonary connection physiology.

Urgent Hepatic to Azygous Vein Connection for Thrombosis of Hepatic Vein to Pulmonary Artery Conduit

We report on an emergent use of hepatic-to-azygous vein connection using a 10-mm polytetrafluoroethylene graft in a 6-year-old girl who developed acute thrombosis of an extracardiac graft conduit from the hepatic veins to the pulmonary arteries. She had left atrial isomerism, interrupted inferior vena cava with azygous continuation, and had undergone surgical creation of bilateral superior cavopulmonary connections 5 years earlier. The emergency procedure to create hepatic-to-azygous connection resulted in successful salvage of the patient who was subsequently able to maintain stable oxygen saturations and experienced rapid regression of hepatic congestion and pleural effusions. Six months following the procedure, oxygen saturation was above 90%. Repeated echocardiography and computed tomography angiography showed patency of the hepatic-to-azygous connection.

Current Spectrum of Surgical Procedures Performed for Ebstein's Malformation: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database

Ebstein's malformation is a rare congenital cardiac anomaly. Available data are limited to individual reports demonstrating highly variable approaches. We sought to understand the spectrum of surgical treatment of Ebstein's anomaly across institutions. A retrospective review of surgical procedures performed on patients with primary diagnosis of Ebstein's malformation (2002 through 2009) in The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) was conducted. A total of 595 operations on 498 patients with Ebstein's anomaly were included: 116 on neonates (19%), 122 on infants (21%), 264 on children (44%), and 93 on adults (16%). Average annual institutional case volumes were low (median, 1 per year; range, 0 to 8 per year). Neonates had a high rate of palliative procedures: systemic-to-pulmonary artery shunts with or without tricuspid valve closure (43; 37.1%) and tricuspid valve closure (10; 8.6%); Ebstein's repair or tricuspid valvuloplasty was performed in 32%. The most common procedures among infants were superior cavopulmonary connections (62; 50.8%) and systemic-to-pulmonary shunt (10; 8.2%). Among older patients, procedures were primarily in three categories: tricuspid valve surgery (children, 54.5%; adults, 68.8%), arrhythmia procedures (children, 8.7%; adults, 17.3%), and Fontan (children, 14.8%). In-hospital mortality was high in neonatal patients (23.4%) in comparison with infants (4.1%), children (0.7%), and adults (1.1%). Surgery for Ebstein's anomaly consists of a wide range of procedures, with low individual institutional volumes. Mortality is highest among neonates. A prospective multicenter inception cohort study would be valuable to better define indications for specific strategies of surgical management.

Acute Effects of Embolizing Systemic-to-Pulmonary Arterial Collaterals on Blood Flow in Patients With Superior Cavopulmonary Connections

The significance and optimal treatment of systemic-to-pulmonary arterial collateral (SPC) vessels in single ventricle patients are poorly understood. The acute efficacy of SPC embolization has not been demonstrated in a quantifiable fashion. We sought to assess the acute efficacy of SPC embolization on blood flow as quantified by phase contrast magnetic resonance imaging and hypothesized that embolization acutely decreases SPC flow and increases systemic blood flow (Q(S)). Six superior cavopulmonary connection patients underwent SPC flow quantification by phase contrast magnetic resonance imaging, including quantification of superior and inferior caval, total pulmonary artery, total pulmonary vein, ascending and descending aortic flows (Q(SVC), Q(IVC), Q(PA), Q(PV), Q(Ao), and Q(Dao), respectively), both immediately before and after cardiac catheterization with coil and particle embolization of angiographically evident SPC vessels. All studies were performed under a single anesthetic. After embolization, we found a significant decrease in SPC flow of 0.9 (range, 0.6-1.3) L/(min·m(2)) (P=0.03); a median reduction of 47% (range, 32-60). There was a significant decrease in the median Q(P):Q(S) from 1.3 before to 0.8 after embolization (P=0.03), and an increase in Q(S) from a median of 3.4 to 4.4 L/(min·m(2)) (P<0.05), and Q(SVC) from a median of 1.7 to 2.3 L/(min·m(2)) (P=0.03). We report on the acute efficacy of SPC embolization, demonstrating a significant decrease in SPC flow and Q(P):Q(S) and increase in Q(SVC) and Q(S). Further studies are needed to assess the durability of the procedure and the effect on Fontan and longer-term outcomes.

Extracardiac Fontan with direct cavopulmonary connections: midterm results

The aim of this study was to analyse the midterm results following superior and inferior direct cavopulmonary connections (DCPC) to create a Fontan circulation in patients with functionally univentricular hearts. A retrospective review of patients operated on between January 2005 and December 2011 was carried out. Thirty consecutive patients who underwent this type of operation were retrospectively reviewed. There were 18 (60%) males and 12 (40%) females, with a median age of 69 months (range 16-150 months) and median weight of 23 kg (range 11-46 kg). Aortic cross-clamping was used in 10 patients, with a median cross-clamp time of 40 min (range 23-99) and a median cardiopulmonary bypass (CPB) time of 135 min (range 76-179 min). The remaining 20 patients were operated on without aortic cross-clamping. Their median CPB time was 104 min (range 78-139 min). Fenestration was performed in 16 patients. The associated intracardiac procedures were performed in 10 patients. The follow-up period ranged from 2 months to 6 years. Operative mortality and late mortality after discharge was zero. The major postoperative complications included supraventricular tachycardia in one patient, oliguria and peritoneal dialysis in one and chest drainage (>30 ml/day) persisting >7 days in five (20%). One patient developed sinus bradycardia in association with sinus pauses 2 months after discharge. One patient developed pericardial effusion 1 month after discharge. A computational fluid dynamic study was performed in one patient. The computational fluid dynamic study showed that DCPC may have a better power efficiency. Superior and inferior DCPCs to create a Fontan circulation in appropriately selected patients with functionally univentricular hearts can be performed with a low risk and a low rate of reinterventions. The midterm results are favourable.

Extracardiac Fontan With Direct Cavopulmonary Connections: Midterm Results

The aim of this study was to analyze the midterm results following direct superior and inferior cavopulmonary connections (DCPC) to create Fontan circulation in patients with functionally univentricular hearts. Retrospective review of patients operated between January 2005 and May 2011. The 25 consecutive patients who underwent this type of operation were retrospectively reviewed. There were 15 (60%) males and ten (40%) females, with median age of 73 months (range: 16-150 months) and median weight of 25kg (range: 11-46kg). Aortic cross-clamping used in ten patients, with median cross-clamp time of 40 minutes (range: 23-99) and median cardiopulmonary bypass (CPB) time of 135 minutes (range: 76-179 minutes). The remaining 15 patients were operated without aortic cross-clamping. Their median CPB time was 112 minutes (range: 82-139 minutes). Fenestration was performed in 15 cases. Associated intracardiac procedures were performed on ten patients. The follow-up period ranged from two months to six years. Operative mortality and late mortality after discharge were zero. Major postoperative complications included supraventricular tachycardia in one patient, oliguria and peritoneal dialysis in one patient, chest drainage persisting more than seven days in five patients (20%). One patient developed sinus bradycardia in association with sinus pauses two months after discharge. One patient developed pericardial effusion one month after discharge. Direct superior and inferior cavopulmonary connections to create Fontan circulation in appropriately selected patients with functionally univentricular hearts can be performed with low risk and a low rate of reintervention. The midterm results are favorable.

Inhaled Nitric Oxide for Elevated Cavopulmonary Pressure and Hypoxemia After Cavopulmonary Operations

Background. Elevated cavopulmonary pressure early after surgical creation of cavopulmonary connections is an important hemodynamic problem with grave prognostic significance. We examined the effect of administration of inhaled nitric oxide (iNO) to patients with elevated cavopulmonary pressure in the early postoperative period. Methods. We retrospectively reviewed data pertaining to all 14 patients with superior (n = 6) and total (n = 8) cavopulmonary connections who were treated with iNO in the early postoperative period during an interval of six years. Changes in the cavopulmonary pressure, the transpulmonary gradient, and the oxygen saturation after the institution of iNO were evaluated. The preoperative characteristics of the patients were compared to those of a control group of patients with cavopulmonary operations not treated with iNO postoperatively. Results. Twelve hours after the initiation of iNO therapy, significant reduction in the cavopulmonary pressure (16.6 ± 3.5 mm Hg vs 18.1 ± 2.3 mm Hg, P = .006), reduction in the cavopulmonary gradient (7.0 ± 3.5 mm Hg vs 9.8 ± 3.7 mm Hg, P = .009), and elevation of the arterial oxygen saturation (84.5% ± 6.0% vs 78.7% ± 5.9%, P = .001) were observed. Linear correlation analysis confirmed tendencies for reduction in the cavopulmonary pressure (P = .13), reduction in the cavopulmonary gradient (P = .02), and elevation of the oxygen saturation (P = .10). Compared to the control group, the treated patients tended to have higher preoperative pulmonary arterial pressures (PAPs) 17 (11-30) mm Hg versus 12 (10-25) mm Hg, P = .10; higher pulmonary vascular resistance (PVR) 2.04 (0.27-6.94) Wood units versus 1.02 (0.49-5.20) Wood units, P = .37; and longer bypass times 154 (41-218) versus 91 (15-276) minutes, P = .13. Conclusions. Administration of iNO was associated with diminuition of cavopulmonary pressure and transpulmonary gradient and increasing oxygen saturation in our small group of patients. In our experience selected patients with preoperatively elevated PAP above 17 mm and PVR above 2 Wood units can undergo cavopulmonary operations with iNO treatment early postoperatively.

Challenges of Univentricular Physiology in Heterotaxy

Patients with heterotaxy syndrome exhibit an extensive constellation of congenital cardiac malformations, making these patients a challenging group to manage surgically. Many of these patients' hearts do not lend themselves to separation of the pulmonary and systemic circulations except by some modification of the Fontan procedure. Palliative procedures early in life are directed at creating a satisfactory balance of pulmonary and systemic blood flow and at the same time ensuring unobstructed pulmonary venous return. Early conversion from parallel pulmonary and systemic circulations to superior cavopulmonary connections is important, to reduce volume work of the systemic ventricle. Heterotaxy patients are generally considered a high-risk population with respect to eventual Fontan procedure. It is important to appreciate the unique and variable anatomy of the sinus node and conduction system and the potential for occult pulmonary venous obstruction, atrioventricular valve regurgitation, and recurrent cyanosis, which may be related to the development of pulmonary arteriovenous malformations.

Histomorphometric analysis of intrapulmonary vessels in patients undergoing bidirectional Glenn shunt and total cavopulmonary connection

The purposes of this study were to elucidate the histomorphometry of the intrapulmonary arteries in patients undergoing univentricular type of repairs and to identify the histomorphometric characteristics, if any, that may predispose patients to postoperative Fontan failure. Operatively resected wedges of lung tissue from 44 patients undergoing univentricular type of repairs (aged 17 months to 34 years; mean, 83.52 ± 75.90 months) was subjected to histomorphometric analysis. Despite pulmonary arterioplasty, a low Nakata index was associated with 9.61 (95% confidence interval: 1.01-91.5; P = .003) times increased risk of death after the operation. A statistically significant difference in the mean indexed diameter of the intra-acinar pulmonary arteries (P = .03) was observed between patients undergoing superior and total cavopulmonary connections. Overall, there were 8 (8.2%), 4 (9.1%), 13 (29.5%), and 29 (65.9%) instances of intrapulmonary arterial intimal lesions, thrombosis, smooth muscle extension, and interstitial fibrosis, respectively. Among patients undergoing total cavopulmonary connection, only low Nakata index was significantly associated with the presence of severe intimal lesions, abnormal smooth muscle extension, intra-acinar pulmonary arterial thrombus, and smaller intra-acinar pulmonary arteries. A low Nakata index is significantly associated with the presence of severe intimal lesions, thrombus, abnormal smooth muscle extension, a lower mean indexed area of the intrapulmonary arteries, and poor postoperative outcome. However, none of the histomorphometrically derived parameters could conclusively predict the outcome after univentricular repair.

Correction

HomeCirculation: Cardiovascular ImagingVol. 3, No. 1Correction Free AccessResearch ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessResearch ArticlePDF/EPUBCorrection Originally published1 Jan 2010https://doi.org/10.1161/HCI.0b013e3181cc5045Circulation: Cardiovascular Imaging. 2010;3:e1In the article by Whitehead et al., “Noninvasive Quantification of Systemic-to-Pulmonary Collateral Flow: A Major Source of Inefficiency in Patients With Superior Cavopulmonary Connections,” which appeared in the September 2009 issue of the Journal (Circulation: Cardiovascular Imaging 2009;2:405-411), the following correction must be made.During the copyediting of this article, the term SCPC (superior cavopulmonary connection) was incorrectly changed to SPCF (systemic-to-pulmonary collateral flow) throughout the article.Equation 1 was also incorrect and should read: equationDownload figureThis error has been corrected in the current online version of the article (http://circimaging.ahajournals.org/cgi/content/full/2/5/405). The publisher regrets the error. Previous Back to top Next FiguresReferencesRelatedDetails January 2010Vol 3, Issue 1 Advertisement Article InformationMetrics https://doi.org/10.1161/HCI.0b013e3181cc5045 Originally publishedJanuary 1, 2010 PDF download Advertisement

Noninvasive Quantification of Systemic-to-Pulmonary Collateral Flow

Background— Systemic-to-pulmonary collateral flow (SPCF) is common in single-ventricle patients with superior cavopulmonary connections (SCPC). Because no validated method to quantify SPCF exists, neither its hemodynamic burden nor its clinical impact can be systematically evaluated. We hypothesize that (1) the difference in total ascending aortic (Ao) and caval flow (superior vena cava [SVC]+inferior vena cava [IVC]) and (2) the difference between pulmonary vein and pulmonary artery flow (PV−PA) provide 2 independent estimators of SPCF. Methods and Results— We measured Ao, SVC, IVC, right (RPA) and left (LPA) PA, and left (LPV) and right (RPV) PV flows in 17 patients with SCPC during routine cardiac MRI studies using through-plane phase-contrast velocity mapping. Two independent measures of SPCF were obtained: model 1, Ao−(SVC+IVC); and model 2, (LPV−LPA)+(RPV−RPA). Values were normalized to body surface area, Ao, and PV, and comparisons were made using linear regression and Bland-Altman analysis. SPCF ranged from 0.2 to 1.4 L/min for model 1 and 0.2 to 1.6 L/min for model 2, for an average indexed SPCF of 0.5 to 2.8 L/min/m 2 : 11% to 53% (mean, 37%) of Ao and 19% to 77% (mean, 54%) of PV. The mean difference between model 1 and model 2 was 0.01 L/min ( P =0.40; 2-SD range, −0.45 to 0.47 L/min). Conclusions— We present a noninvasive method for SPCF quantification in patients with SCPC. It should provide an important clinical tool in treating these patients. Furthermore, we show that SPCF is a significant hemodynamic burden in many patients with bidirectional Glenn shunt physiology. Future investigations will allow objective study of the impact of collateral flow on outcome.

Extracardiac Fontan With Direct Cavopulmonary Connections

In order to optimize the Fontan circulation, a technique for direct superior and inferior cavopulmonary connections was devised. Such pathways retain growth potential, obviate suture lines within the right atrium, and avoid prosthetic implants. They thus enable definitive, single-stage ventricular unloading, regardless of patient size or great artery position.

Unifocalization of Major Aortopulmonary Collaterals in Single-Ventricle Patients

Unifocalization of major aortopulmonary collateral arteries (MAPCAs) in pulmonary atresia with ventricular septal defect and intracardiac repair has become the standard of care. However, there are no reports addressing unifocalization of MAPCAs in single-ventricle patients. It is unknown whether their pulmonary vascular bed can be reconstructed and low enough pulmonary vascular resistance achieved to allow for superior or total cavopulmonary connections. We reviewed data on all patients with functional single ventricles and unifocalization procedures of MAPCAs. From 1997 to 2005, 14 consecutive children with various single-ventricle anatomies were operated on. Patients had a median of three surgical procedures (range, 1 to 5). Two patients had absent, all others diminutive central pulmonary arteries, with an average of 3.5 +/- 1.2 MAPCAs. Seven patients (50%) had bidirectional Glenn procedures, and 3 of these had Fontan procedures. Median postoperative pulmonary artery pressures measured 12.5 mm Hg (Glenn) and 14 mm Hg (Fontan), respectively. Six patients are alive today (46%), with 1 patient lost to follow-up. Three patients died early and 3 late after initial unifocalization to shunts. One other patient survived unifocalization, but was not considered a candidate for a Glenn procedure and died after high-risk two-ventricle repair. Another patient with right-ventricle-dependent coronary circulation died of sepsis late after Glenn. In selected patients with functional single ventricles and MAPCAs, the pulmonary vascular bed can be reconstructed sufficiently to allow for cavopulmonary connections. Venous flow to the pulmonary vasculature decreases cardiac volume load and is likely to increase life expectancy and quality of life for these patients.

Nitric Oxide in Pulmonary Arteriovenous Malformations and Fontan Procedure

Pulmonary arteriovenous malformations are a well documented complication of superior cavopulmonary (Glenn) connections. We report the successful management of a case of severe hypoxemia in the early postoperative period of a patient who underwent the Fontan operation. The patient had previously been diagnosed with pulmonary arteriovenous malformations; the use of inhaled nitric oxide was followed up with reversal of life-threatening hypoxemia. At 6-month postoperative follow-up, the patient was asymptomatic with near normal aortic saturation.

Predicting the identity of decompressing veins after cavopulmonary anastomoses

D veins are an important cause of unanticipated cyanosis after cavopulmonary anastomosis (CPA). Venous connections between the superior and inferior vena caval pathways result in cyanosis after bidirectional CPA (hemi-Fontan and bidirectional Glenn), whereas connections between the systemic and pulmonary venous pathways lead to cyanosis after either bidirectional CPA or total cavopulmonary connection (Fontan operation). Previous studies have focused on hemodynamic settings in which decompressing channels are likely to occur after bidirectional CPA. However the spectrum of anatomic variations resulting in significant venous decompression after total as well as superior cavopulmonary connections has not been well characterized. In this study, we defined the anatomy of significant decompressing veins occurring after CPA, determined the incidence of significant decompressing veins by reviewing angiograms in all patients after CPA, and determined whether cardiac anatomy or clinical parameters were predictive of decompressing venous anatomy. The cardiology database from The Children’s Hospital of Philadelphia was reviewed to identify patients with CPAs who had undergone cardiac catheterization between January 1987 and January 1998. Patients whose angiograms could be obtained and were of adequate quality for interpretation were included in the analysis. Echocardiographic diagnoses were reviewed. The anatomy of the underlying heart defect was classified into 1 of 4 categories: (1) hypoplastic left heart syndrome, (2) other functional single right ventricle (including double-outlet right ventricle), (3) functional single left ventricle (including tricuspid atresia and pulmonary atresia), and (4) heterotaxy syndrome. Hemodynamic information including arterial oxygen saturation, pulmonary artery pressures, and ventricular end-diastolic pressures was recorded. Angiograms were reviewed noting anatomy and size of decompressing veins. Magnification correction was based on the known diameter of the angiographic catheter. Decompressing vessels were deemed significant if they were 3 mm in diameter or associated with arterial oxygen saturation 1 SD below the mean for each group (superior or total CPA). In many patients, right azygos veins were intentionally left patent by the surgeon at the time of bidirectional CPA. The significance of decompressing right azygos veins was determined solely by saturation criteria. Finally, in patients with other sources of arterial desaturation after total cavopulmonary connection (baffle leak, fenestration, or partial hepatic vein exclusion), only size was considered in determining the significance of decompressing veins. Differences between groups were evaluated by Student’s t test or Wilcoxon rank-sum test for numerical data, and chi-square distribution for categorical variables. A p value 0.05 was considered statistically significant. Five hundred fifty patients were identified with CPA. Angiograms adequate for review were obtained for 298 of these patients. Hypoplastic left heart syndrome was present in 170 patients (47%), single left ventricle in 101 (28%), single right ventricle in 60 (17%), and heterotaxy syndrome in 32 (8%). Data were collected on 208 patients who had undergone hemi-Fontan or bidirectional Glenn procedures. The median age at catheterization was 19 months (range 4 months to 17 years). Thirty-three of these patients (16%) had significant decompressing veins. Pulmonary artery pressures were higher, and (partially by definition) arterial oxygen saturations were lower in patients with decompressing veins (p 0.05; Table 1). Four types of decompressing veins occurred after bidirectional CPA. Most common were azygos connections; 19 cases accounted for 58% of the total. This type included azygos veins to either the right or left superior vena cava (SVC), hemiazygos veins, and accessory hemiazygos veins (Figure 1A). Left SVC decompressing to a coronary sinus occurred in 8 paFrom the Department of Pediatrics, University of Pennsylvania School of Medicine and Division of Cardiology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania. Dr. Rome’s address is: Division of Cardiology, The Children’s Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, Pennsylvania 19104. E-mail: rome@email.chop.edu. Manuscript received February 19, 2001; revised manuscript received and accepted July 23, 2001. TABLE 1 Hemodynamic Data from Patients With Bidirectional Cavopulmonary Anastomosis