Venoocclusive Disease With Both Hepatic and Pulmonary Involvement

Pulmonary venoocclusive disease (PVOD) is a rare form of pulmonary vascular disease with pulmonary hypertension characterized by preferential involvement of the pulmonary venous system. Hepatic venoocclusive disease (HVOD), also known as sinusoidal obstruction syndrome, is a condition that occurs in 13% to 15% of patients after hematopoietic stem cell transplantation (HSCT). Although hepatic and pulmonary venoocclusive diseases may share some pathologic features as well as some etiologies such as HSCT, these two disorders have never been described together in a single adult patient. We report the case of a patient who received HSCT and developed HVOD and PVOD within 9 months. Despite their differences, PVOD and HVOD share common risk factors and associated conditions, suggesting that in the context of HSCT, the two diseases share common pathophysiological mechanisms. Optimal treatment for HSCT-related PVOD remains to be determined.

Pulmonary venous thrombosis in a patient with COVID-19 infection

Objectives

Infection with the SARS-COV2 virus (COVID-19) may be complicated by thrombotic diathesis. This complication often involves the pulmonary microcirculation. While macrovascular thrombotic complications of the lung may include pulmonary artery embolism, pulmonary artery thrombus in situ has also been hypothesized. Pulmonary vein thrombosis has not been described in this context.

Methods/Results

Herein, we provide a case of an otherwise healthy male who developed an ischemic stroke with left internal carotid thrombus. Further imaging revealed pulmonary emboli with propagation through the pulmonary veins into the left atrium. This left atrial thrombus provides a source of atypical “paradoxic arterial embolism”.

Conclusions

Thrombotic outcomes in the setting of severe COVID 19 pneumonia may include macrovascular venous thromboembolism, microvascular pulmonary vascular thrombosis and arterial thromboembolism. Pulmonary vein, herein described, provides further mechanistic pathway for potential arterial embolic phenomenon.

Use of vasodilators for the treatment of pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis: A systematic review

BACKGROUND

There are several medications available to treat pulmonary arterial hypertension (PAH): PAH-targeted drugs. However, in patients with pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis (PVOD/PCH), rare diseases that cause pulmonary hypertension, the effectiveness and safety of vasodilators, including PAH-targeted drugs, are unclear.

METHODS

We searched English-language publications listed in three electronic databases (PubMed, Cochrane Library, and the Japan Medical Abstracts Society). Reports with efficacy outcomes (survival, improvement in 6-minute walk distance, and pulmonary vascular resistance) and data on development of pulmonary edema after administration of vasodilators to patients with PVOD/PCH were selected (1966 to August 2015).

RESULTS

We identified 20 reports that met our criteria. No randomized controlled or prospective controlled studies were reported. The survival time ranged from 71 minutes to 4 years or more after initiation of vasodilators. Most of the reported cases showed an improvement in the 6-minute walk distance and pulmonary vascular resistance. Pulmonary edema was reported in 15 articles, some cases of which were lethal.

CONCLUSIONS

The present study demonstrates the potential efficacy and difficulties in the use of vasodilators in patients with PVOD/PCH; however, drawing a firm conclusion was difficult because of the lack of randomized controlled trials. Further research is needed to ascertain if vasodilator use is beneficial and safe in patients with PVOD/PCH.

[Echocardiography and Respiratory Function Testing for Pulmonary Arterial Hypertension]

Pulmonary hypertension (PH) is a hemodynamic and pathophysiologic condition characterized by elevated pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR), defined as an increase in the mean PAP of more than 20 mmHg at rest. PH can be a progressive and fatal disease if not treated appropriately. In the advanced stage of PH, the right ventricular (RV) function may be impaired, and it is associated with poor outcomes in PH. PH, however, can be easily misdiagnosed until the disease is at an advanced stage, because of its nonspecific and subtle symptoms in the early stages. PH is also a multi-factorial disease, it can be due to a primary elevation of pressure in the pulmonary arterial system alone (pulmonary arterial hypertension), or secondary to elevations of pressure in the pulmonary venous and pulmonary capillary systems (pulmonary venous hypertension). Establishing its etiology is also important for the early diagnosis of PH. Echocardiography is an important modality to assess the presence or absence of PH and its etiology, and it has been used to screen for this disease, determine the left and right heart structure and function, and assess the response to therapy in persons with PH. The pulmonary function test is also useful in PH, especially PH in chronic lung disorders. PH patients may also display mild to moderate ventilatory impairment in the absence of any evidence of lung airway or parenchymal disease, mainly in the form of airway obstruction. In this review, we discuss the diagnostic and prognostic role of clinical echocardiography and pulmonary function testing in clinical practice for pulmonary hypertension in this modern era.

Pulmonary vein stenosis and necrotising enterocolitis: is there a possible link with necrotising enterocolitis?

OBJECTIVES

While acquired pulmonary vein stenosis (PVS) is an often lethal anomaly with poor long-term prognosis and high mortality, little is known about the causes of this disease process. The purpose of this study was to describe the possible association between acquired PVS and necrotising enterocolitis (NEC) in premature infants.

STUDY DESIGN

We performed a retrospective review of all premature infants (<37 weeks' gestation) diagnosed with acquired PVS in our institution. Babies with congenital heart disease with known association with PVS were excluded. The hospital records were reviewed for prior history of NEC, as defined by Bell's staging criteria. We also reviewed serial echocardiograms performed during their hospitalisation. Outcomes assessed were worsening or resolution of the PVS and death.

RESULTS

Twenty patients met inclusion criteria and were diagnosed with acquired PVS. The median gestational age was 27 weeks. 50% (10/20) of the infants had NEC during their hospital course. The NEC group had significantly lower birth weights in comparison to the non-NEC group. There was no difference between groups with regards to the age at diagnosis of PVS. The mean gradient across the pulmonary veins was higher in the NEC group, as was mortality.

CONCLUSIONS

There appears to be a high incidence of NEC in premature infants who are diagnosed with acquired PVS. Future large controlled studies are needed to further analyse this association and to evaluate the possible role of abdominal inflammation in the development of PVS in premature infants.

Outcome predictors and implications for management of scimitar syndrome

BACKGROUND

Scimitar syndrome is a rare congenital anomaly. We evaluated risk factors for postoperative pulmonary vein stenosis or death and predictive factors for survival without scimitar vein surgery in patients with scimitar syndrome.

METHODS

The records of patients with scimitar syndrome evaluated at our medical center between 1964 and 2011 were reviewed.

RESULTS

Scimitar syndrome was identified in 80 patients, with a median follow-up of 4.5 years. Patients presenting less than 1 year of age had a higher incidence of symptoms, aortopulmonary collaterals, coexisting congenital heart disease (CHD), extracardiac anomalies, and pulmonary hypertension. Of 36 patients having scimitar vein surgery, 18 had postoperative pulmonary vein obstruction that occurred with similar frequency after baffle or reimplantation procedures, early or late in the study period, and tended to be more common in infants (P = .10). Overall, 19 (24%) of 80 died. Multivariate risk factors for death included systolic pulmonary pressure >0.5 systemic level (P = .007) and left pulmonary vein stenosis (P = .009). Pulmonary artery systolic pressure <0.5 systemic level (P = .01) and absence of CHD excluding atrial septal defect (P = .01) were predictive factors in 28 patients who survived and did not have scimitar vein surgery; these patients had no or mild right ventricular dilation and a ratio of pulmonary-to-systemic flow <1.6 either at baseline, after coiling aortopulmonary collaterals or nonscimitar vein intervention.

CONCLUSIONS

Postoperative pulmonary vein obstruction is common after scimitar vein surgery regardless of redirection technique. Pulmonary hypertension and left pulmonary vein stenosis are risk factors for death, whereas patients without significant pulmonary hypertension or associated CHD did well without scimitar vein surgery. These observations may guide management decisions in patients with scimitar syndrome.

Assessment of pulmonary veins after atrio-pericardial anastomosis by cardiovascular magnetic resonance

BACKGROUND

The atrio-pericardial anastomosis (APA) uses a pericardial pouch to create a large communication between the left atrium and the pulmonary venous contributaries in order to avoid direct suturing of the pulmonary veins during the repair of congenital cardiac malformations. Post-operative imaging is routinely performed by echocardiography but cardiovascular magnetic resonance (CMR) offers excellent anatomical imaging and quantitative information about pulmonary blood flow. We sought to compare the diagnostic value of echocardiography and CMR for assessing pulmonary vein anatomy after the APA.

METHODS

This retrospective study evaluated all consecutive patients between October 1998 and January 2010 after either a primary or secondary APA followed by post-repair CMR.

RESULTS

Of 103 patients who had an APA, 31 patients had an analyzable CMR study. The average time to CMR was 24.6 ± 32.5 months post-repair. Echocardiographic findings were confirmed by CMR in 12 patients. There was incomplete imaging by echocardiography in 7 patients and underestimation of pulmonary vein restenosis in 12, when compared to CMR. In total, 19/31 patients (61%) from our cohort had significant stenosis following the APA as assessed by CMR. Our data suggest that at least 18% (19/103) of all patients had significant obstruction post-repair.

CONCLUSIONS

Echocardiography incompletely imaged or underestimated the severity of obstruction in patients compared with CMR. Pulmonary vein stenosis remains a sizable complication after repair, even using the APA.

Lengthy diagnostic challenge in a rare case of pulmonary veno-occlusive disease: case report and review of the literature

Pulmonary veno-occlusive disease (PVOD) is a rare and usually survival poor disorder. We report a patient with a long history of progressive dyspnea of over 8 years, who with a diagnosis of chronic cor pulmonale confirmed elsewhere, was ultimately diagnosed as PVOD via histological analysis of a lung biopsy. After treatment with combined bosentan, diuretics and digoxin, his symptoms and function improved. This case highlights that PVOD is an under-recognised and often misdiagnosed disease, especially in its chronic form. Understanding its pathogenesis, its poor response to medical therapy and its dismal prognosis remain challenges for the treatment of PVOD.

Surgical management of post-repair pulmonary vein stenosis

Obstructed pulmonary venous drainage - either in association with total anomalous pulmonary venous drainage, congenital stenosis, or post-repair stenosis - is associated with poor outcome. Post-repair stenosis typically involves fibrotic scar tissue extending from the site of anastomosis. "Sutureless" repair techniques avoid direct left atrial-pulmonary vein suture lines by instead reconstituting atrial tissue to posterior pericardium. Hence, the repair leaves widely decompressed pulmonary veins in the posterior mediastinum draining directly into the left atrium as a 'controlled bleed.' In our experience, late outcomes are significantly more favorable with sutureless repair techniques versus conventional pulmonary vein surgery. Therefore, after these encouraging results, we have now extended the application of this repair strategy to all scenarios of pulmonary vein surgery, including primary repair of unobstructed total anomalous pulmonary venous connection. The sutureless repair is versatile and facile. In particular, complex geometry of multiple decompressed veins can be easily accommodated by wide left atrial-pericardial suture lines. Common pitfalls can be avoided by mobilizing and protecting the phrenic pedicle and preserving the integrity of the areolar connective tissue and pleuro-parietal membrane. Overall, sutureless repair of anomalous or stenotic pulmonary veins appears safe and effective. Furthermore, in patients known to be at high risk of recurrent stenosis, sutureless techniques appear to offer improved freedom from recurrent stenosis.

Idiopathic pulmonary veno-occlusive disease

We report a case of idiopathic pulmonary veno-occlusive disease (PVOD). The patient experienced progressively worsening dyspnea. Heart catheterization revealed severe pulmonary hypertension. High-resolution computed tomography (HRCT) showed diffuse, poorly identified centrilobular ground-glass opacities. Surgical lung biopsy led to the diagnosis of PVOD. A microscopic examination revealed occlusions of pulmonary veins and venules over a wide area with prominent loop-like capillary dilatations. These pathological findings may be correlated with the radiological characteristics of HRCT in this case.

Pulmonary veno-occlusive disease: clinical, functional, radiologic, and hemodynamic characteristics and outcome of 24 cases confirmed by histology

Pulmonary veno-occlusive disease (PVOD) is defined by specific pathologic changes of the pulmonary veins. A definite diagnosis of PVOD thus requires a lung biopsy or pathologic examination of pulmonary explants or postmortem lung samples. However, lung biopsy is hazardous in patients with severe pulmonary hypertension, and there is a need for noninvasive diagnostic tools in this patient population. Patients with PVOD may be refractory to pulmonary arterial hypertension (PAH)-specific therapy and may even deteriorate with it. It is important to identify such patients as soon as possible, because they should be treated cautiously and considered for lung transplantation if eligible. High-resolution computed tomography of the chest can suggest PVOD in the setting of pulmonary hypertension when it shows nodular ground-glass opacities, septal lines, lymph node enlargement, and pleural effusion. Similarly, occult alveolar hemorrhage found on bronchoalveolar lavage in patients with pulmonary hypertension is associated with PVOD. We conducted the current study to identify additional clinical, functional, and hemodynamic characteristics of PVOD. We retrospectively reviewed 48 cases of severe pulmonary hypertension: 24 patients with histologic evidence of PVOD and 24 randomly selected patients with idiopathic, familial, or anorexigen-associated PAH and no evidence of PVOD after meticulous lung pathologic evaluation. We compared clinical and radiologic findings, pulmonary function, and hemodynamics at presentation, as well as outcomes after the initiation of PAH therapy in both groups. Compared to PAH, PVOD was characterized by a higher male:female ratio and higher tobacco exposure (p < 0.01). Clinical presentation was similar except for a lower body mass index (p < 0.02) in patients with PVOD. At baseline, PVOD patients had significantly lower partial pressure of arterial oxygen (PaO2), diffusing lung capacity of carbon monoxide/alveolar volume (DLCO/VA), and oxygen saturation nadir during the 6-minute walk test (all p < 0.01). Hemodynamic parameters showed a lower mean systemic arterial pressure (p < 0.01) and right atrial pressure (p < 0.05), but no difference in pulmonary capillary wedge pressure. Four bone morphogenetic protein receptor II (BMPR2) mutations have been previously described in PVOD patients; in the current study we describe 2 additional cases of BMPR2 mutation in PVOD. Computed tomography of the chest revealed nodular and ground-glass opacities, septal lines, and lymph node enlargement more frequently in patients with PVOD compared with patients with PAH (all p < 0.05). Among the 16 PVOD patients who received PAH-specific therapy, 7 (43.8%) developed pulmonary edema (mostly with continuous intravenous epoprostenol, but also with oral bosentan and oral calcium channel blockers) at a median of 9 days after treatment initiation. Acute vasodilator testing with nitric oxide and clinical, functional, or hemodynamic characteristics were not predictive of the subsequent occurrence of pulmonary edema on treatment. Clinical outcomes of PVOD patients were worse than those of PAH patients.

Massive systemic-to-pulmonary collateral arteries in the setting of a cavopulmonary shunt and pulmonary venous stenosis

We report a patient in whom a cavopulmonary anastomosis had been constructed, along with repair of anomalous pulmonary venous drainage. Left-sided pulmonary venous obstruction led to redistribution of the flow to the right lung. The reversal of flow in the left pulmonary artery was accentuated by flow through collateral arteries feeding the left lung. Within 14 months, the collateral flow increased six-fold, resulting in a doubling of the cardiac output.

Pulmonary venous flow assessed by Doppler echocardiography in the management of atrial fibrillation

Pulmonary venous blood flow (PVF) visualized by Doppler echocardiography exhibits a pulsatile behavior, which is related to left atrial pressure and function, mitral valve function, and left ventricular compliance. In atrial fibrillation (AF), the disappearance of atrial reverse flow, a decrease in systolic flow with a greater diastolic than systolic flow, a prolonged onset of systolic flow and the appearance of an early systolic reverse flow are characteristic findings. A reduction in systolic PVF expressed by reduced peak velocity, reduced velocity-time integral of systolic flow, and reduced systolic fraction of PVF has been found to be associated with reduced left atrial appendage flow, left atrial spontaneous echo contrast formation, frequency of AF paroxysms and propensity for AF recurrence following restoration of sinus rhythm. Ablation techniques targeting pulmonary vein ostia and adjacent left atrium are promising treatment options to cure AF. Monitoring the PVF response to and adjusting of ablation procedures has been suggested to optimize outcome and prevent complications such as pulmonary vein stenosis. In conclusion, assessment of PVF variables and patterns by Doppler echocardiography seems useful in the management of AF patients. Especially the reduction in systolic PVF may be used as marker for left atrial dysfunction which favors thrombus formation and AF reinitiation. Finally, PVF monitoring has the potential to an increasing role in AF ablation procedures.

Acquired pulmonary vein stenosis after radiofrequency ablation treated by angioplasty and stent implantation

OBJECTIVE

Pulmonary vein (PV) stenosis is a late complication of radiofrequency ablation for atrial fibrillation. Although frequently asymptomatic, it can be associated with severe respiratory symptoms that cause significant morbidity. This study evaluated the role of angioplasty and stent implantation in patients affected by acquired PV stenosis.

METHODS

Between June 2003 and June 2004, six patients with seven acquired iatrogenic PV stenoses, documented by multislice computed tomography scanning, underwent catheterisation and angiography at the St. Ambrogio Clinical Institute, Milan, Italy.

RESULTS

The median duration between radiofrequency ablation and the reported onset of respiratory symptoms was 13.5 months (interquartile range 6.7-22.2 months). All of patients were symptomatic (New York Heart Association functional class II or III). Five PV stenoses were treated by angioplasty and stent implantation. In one patient, the procedure was not performed because of endoluminal thrombosis and in another one recanalisation of occluded PV was unsuccessful. At angiography overall vessel diameter increased from 1.7 +/- 0.5 to 8.2 +/- 0.8 mm (P < 0.05). There were no procedure-related major adverse events. Immediate follow-up by multislice computed tomography scanning showed patency of the PV. At a median follow-up of 17.1 months (interquartile range 10.6-22.2 months), all patients have no or minimal persistent symptoms; multislice computed tomography showed patency of the PV followed at a median time of 16.4 months (interquartile range 10.3-22.3 months).

CONCLUSIONS

The treatment of PV stenosis by angioplasty with stent implantation is feasible and safe. The majority of patients undergoing this procedure showed symptomatic improvement and patency of the PV.

Epidemiology of Pulmonary Arterial Hypertension

Progress in understanding the basic biology and the development of new therapies for pulmonary arterial hypertension have led to improvements in survival. This article reviews clinically important changes in the classification of the pulmonary hypertensive diseases, as well as the epidemiology of various forms of pulmonary hypertension. The risk factors for the development of pulmonary arterial hypertension, prognostic markers, and the effects of current therapies on survival are discussed.

Novel surgical approach 'intrapulmonary-artery septation' for Fontan candidates with unilateral pulmonary arterial hypoplasia or pulmonary venous obstruction

It is difficult to manage patients with single ventricular physiology and unbalanced pulmonary arteries. Since 1998, we started a novel approach [Intrapulmonary-artery Septation (IPAS)] to improve the result for those with severe unbalanced pulmonary arteries consisting of a well-grown pulmonary artery and an inadequately-grown pulmonary artery. The inadequately-grown pulmonary artery includes severe pulmonary arterial hypoplasia and pulmonary venous obstruction. This approach is based on the following concepts: (1) A reliable blood source should be secured to recover the inadequately-grown pulmonary artery; (2) Wasteful volume-load should be prevented for the heart; (3) Long stenosis or non-confluence of pulmonary artery should be avoided. IPAS primarily consists of (A) a Glenn shunt; (B) a systemic-pulmonary artery shunt; and (C) a septation-patch. Both (A) and (B) are adjoined on a well-grown pulmonary artery, and (C) is placed between (A) and (B). PAS brings two separate blood flows of a Glenn shunt to the well-grown side and SPS on the inadequately-grown side. IPAS was performed in 20 patients. Seventeen reached the Fontan operation. Eleven underwent postoperative catheterization and seven had acceptable-balanced pulmonary blood flow distribution. IPAS can pilot more complicated cases having severe unbalanced pulmonary arteries to the Fontan circulation.

Sildenafil as Adjunct Therapy to High-Dose Epoprostenol in a Patient with Pulmonary Veno-Occlusive Disease

Pulmonary veno-occlusive disease is refractory to medical treatment and is generally associated with a poor prognosis. Treatment with vasodilators, such as prostacyclin, of patients with PVOD is controversial because of concerns regarding hemodynamic deterioration. Although a preferential pulmonary vasodilatory effect of a specific phosphodiesterase-5 inhibitor, sildenafil, has recently been reported in patients with primary pulmonary hypertension, little information is available regarding the effect of sildenafil on patients with pulmonary veno-occlusive disease. In the present case, remarkable improvement of hemodynamics and of clinical course was produced by adjunctive use of oral sildenafil in association with intravenous high-dose epoprostenol. These findings suggest that sildenafil may be a therapeutic option in the medical treatment of pulmonary veno-occlusive disease.

Visualization of pulmonary vein stenosis after radio frequency ablation using multi-slice computed tomography: initial clinical experience in 33 patients

PURPOSE

Radio frequency ablation (RFA) of the pulmonary veins (PV) is an established technique for treatment of atrial fibrillation (AF). However, stenoses within the treated areas are well known complications. Thus, a reliable non-invasive diagnosis of PV stenosis would be an important step forward in the care of these patients (pts). Aim of the present study was the diagnostic accuracy of new multi-slice detected computed tomography (MSCT) in visualization of PV and in detecting PV stenosis.

MATERIAL AND METHODS

A total of 33 pts (17 male, 16 female, mean age 57+/-10.2 years [40-71]) were included. Retrospectively ECG-gated CT angiography (CTA) was performed within 1 day to a maximum of 380 days after RFA with a MSCT scanner. Interpretation of the scan was performed on conventional contrast enhanced axial slices and on 3D volume rendering images (maximum intensity projection: MIP, multi-planar reconstruction: MPR). Lesion severity was determined on a semi-quantitative scale (mild: <20%, intermediate: 20-50%, severe >50%) and compared to conventional angiography which had been performed at the beginning and at the end of RFA.

RESULTS

MSCTA was applied without any complications, and all treated pulmonary veins (n=73) could be visualized. Diagnostic image quality was obtained in all examinations. A significant stenosis was detected by conventional angiography in 26/73 (36%) PV (2/73 (3%) severe, 14/73 (19%) intermediate, 10/73 (14%) mild). Using MSCTA, only 13 stenosis in 73 treated PV could be visualized (1/73 (1%) severe, 6/73 (8%) intermediate, 6/73 (8%) mild).

CONCLUSIONS

Multi-slice-detector CT is able to visualize PV and to detect PV stenoses. However, stenosis severity seems to be underestimated and not all lesions could be accurately detected. Larger studies have to be performed to further assess the diagnostic accuracy and clinical reliability of this new non-invasive method and to focus on the incidence of PV stenosis following RFA especially in long-time follow up.

Significance of pulmonary venous obstruction in total anomalous pulmonary venous return

BACKGROUND

Total anomalous pulmonary venous return (TAPVR) is an uncommon congenital cardiovascular anomaly with poor natural prognosis. It has been detected more frequently in recent year due to the advent of echocardiography and cardiovascular magnetic resonance imaging (MRI). The aim of this study was to evaluate the clinical manifestations and outcomes in TAPVR patients with or without pulmonary venous obstruction (PVO).

METHODS

From January 1985 to December 2002, a total of 27 cases with TAPVR at our institution were reviewed. Accurding to the preseace or assence of PVO, patients were divided into PVO group and non-PVO group. Patients' sex, age at diagnosis, types of TAPVR, clinical manifestations, surgical treatment and outcomes were evaluated.

RESULTS

All of them had received 2-dimensional (2-D) and color Doppler echocardiography examination. Cardiac catheterization was performed in all but 1 patient who died at the first day of birth. In addition, 10 of 27 cases had cardiovascular MRI for further study. The number of cases in PVO group and non-PVO group were 15 (56%) and 12 (44%), respectively. There was no significant difference in sex or pulmonary venous drainage sites between both groups. Cyanosis was more prevalent in the PVO group (80% vs. 30%, p = 0.038). Four (27%) cases PVO group and 3 (25%) cases of the non-PVO group had of the non-isolated cardiac lesions. Pulmonary hypertension was present in 18 (69%) of 26 cases who had received cardiac catheterization. Among them, 10 had PVO and 5 had systemic level of pulmonary arterial pressure. Seven (30%) of 23 patients who had received operation died; in contrast, 3 of 4 patients without operation expired. The remaining 1 did not had surgery because of complex heart disease. There was no significant difference in surgical mortality between PVO and non-PVO groups (33% vs. 27%).

CONCLUSIONS

Cyanosis is an obvious clinical symptom of obstructed TAPVR. Surgical mortality made no significant difference between obstructed and non-obstructed groups. Early detection and surgical treatment for TAPVR are important. Although cardiac catheterization and angiocardiography is the golden standard for the diagnosis, 2-D and color Doppler echocardiography can also provide quick and accurate diagnostic images of TAPVR.

Total anomalous pulmonary venous return with the circular pulmonary venous connection: outcome of common pulmonary venous agenesis

A rare case of total anomalous pulmonary venous return, in which the right and left peripheral pulmonary veins connected circularly and there was no central part of the pulmonary vein or the common pulmonary vein, is presented. To our knowledge, total anomalous pulmonary venous return with circular pulmonary venous connection has not been reported previously in the literature. It is thought that the complex connection between peripheral pulmonary veins with the absence of the central part of the pulmonary vein as well as the common pulmonary vein results from common pulmonary venous agenesis.

Acquired coropulmonary and bronchopulmonary anastomoses occurring in association with pulmonary arterial occlusion and veno-occlusive disease generating potential coronary steal

The development of collateral circulation is a general vascular response which is well characterised in the heart. The most common precipitant of this is ischaemia and the most common manifestation is intra coronary collateralisation. Collateral flow between the heart and other thoracic structures is also documented albeit rarely and can be congenital or acquired. In this case report we define a unique case of collateral flow between the coronary and pulmonary circulations in a complex case of mediastinal fibrosis.

[New surgical approach "intrapulmonary septation technic" for Fontan candidates with unilateral pulmonary arterial hypoplasia and/or pulmonary venous obstruction]

Unilateral pulmonary arterial hypoplasia and/or pulmonary venous obstruction are serious hazards for Fontan candidates. For these patients, we have started new surgical approach "intrapulmonary septation technic". This consists of 3 components; (A) partial right heart bypass to well-grown side, (B) mandatory pulmonary blood flow to low-capacity side, (aorto-pulmonary shunt or others) and (C) a patch between partial right heart bypass and mandatory pulmonary blood flow. Thirteen patients underwent the approach. The source of partial right heart bypass was brought from superior vena cava (11 patients), inferior vena cava (1 patient) and fenestrated Fontan (1 patient). The mandatory pulmonary blood flow was supplied by aorto-pulmonary shunt (11 patients), pulmonary arterial banding (1 patient) and native pulmonary valve stenosis (1 patient). We added pulmonary artery enlargement (9 patients), release of pulmonary venous obstruction (8 patients) and/or atrio-ventricular valve plasty (5 patients), simultaneously. No hospital death. Early post-operative course was uneventful in all cases except 1, as pulmonary blood flow to low-capacity side had increased gradually after this intervention. Eight patients had reached Fontan operation. In this approach, nearly whole pulmonary artery can grow without any affect of volume overload through well-grown side from collateral arteries of low-capacity side. All procedures of "intrapulmonary septation technic" and reconstruction of pulmonary artery in Fontan operation can be easily performed in larger pulmonary artery of well-grown side, eliminating need for extensive dissection.

Single arterial occlusion to locate resistance in patients with pulmonary hypertension

The purpose of this study was to determine the site of increased resistance using the arterial occlusion technique in patients with severe pulmonary hypertension. Pulmonary vascular resistance was partitioned in arterial and venous components based on double exponential fitting analysis of the pulmonary artery pressure decay curve: after balloon occlusion in 36 patients with pulmonary arterial hypertension (PAH); at baseline and during the inhalation of 20 parts per million of nitric oxide (NO); in four patients with chronic thromboembolic pulmonary hypertension; and in two patients with pulmonary veno-occlusive disease. In the patients with PAH, at baseline, mean pulmonary artery pressure was 56+/-2 mmHg (mean+/-SE), with an arterial component of resistance of 63+/-1%. Inhaled NO did not change the partition of resistance. The arterial component of resistance amounted on average to 42% and 77% in the patients with veno-occlusive disease and the patients with thromboembolic pulmonary hypertension, respectively. However, the partitioning of resistance did not discriminate between these three diagnostic categories. The occlusion technique may help to locate the predominant site of increased resistance in patients with severe pulmonary hypertension, but does not allow for a satisfactory differential diagnosis on an individual basis.

Use of intracardiac echocardiography for prediction of chronic pulmonary vein stenosis after ablation of atrial fibrillation

INTRODUCTION

Measurements of pulmonary vein (PV) flow with intracardiac echocardiography (ICE) immediately before and after PV isolation may be a useful method for predicting which patients will develop chronic PV stenosis.

METHODS AND RESULTS

We assessed preablation and postablation flows in each of the four PVs using a phase-array ICE catheter in 95 patients (mean age 52 +/- 13) undergoing atrial fibrillation ablation. The ostium of each of the PVs was defined using angiography, electrical mapping, and ICE imaging. Ostial electrical isolation of all PVs was achieved using a 4-mm cooled-tip radiofrequency ablation catheter. Change in PV flow, when present, was examined as both an absolute value and as a percentage of the baseline flow. All patients underwent spiral computed tomography (CT) scans of the PVs 3 months after the procedure for detection of stenosis. The average preablation diastolic flows for the left superior, left inferior, right superior, and right inferior veins were 0.56, 0.54, 0.47, and 0.45 m/sec, respectively. These values increased to 0.74, 0.67, 0.58, and 0.59 m/sec postablation (P < 0.001). Of 380 PVs ablated, the CT scans revealed 2 (1%) with severe (>70%) stenosis, 13 (3%) with moderate (51%-70%) stenosis, and 62 (16%) with mild (< or = 50%) stenosis. The r value between flow and stenosis was only 0.09 (P = NS).

CONCLUSION

Acute changes in PV flow immediately after ostial PV isolation do not appear to be a strong predictor of chronic PV stenosis.

Pulmonary vascular changes induced by unilateral pulmonary venous obstruction

The relation of pulmonary hemodynamics to pathological change in the pulmonary vasculature was examined in a model of unilateral pulmonary venous (PV) obstruction. The left upper pulmonary vein (A group, n=6) or both the left upper and left lower pulmonary veins (B group, n=6) of two-week-old piglets were banded; the control group (n=6) was sham operated. At eight weeks after PV banding, mean pulmonary arterial pressure was highest in the B group, intermediate in the A group and lowest in the control group. In all groups, the media of the pulmonary artery was equally thickened in both lungs, whereas the media of the pulmonary vein was thickened only in those lung lobes having stenotic pulmonary veins. For all animals from three groups, left pulmonary arterial wedge pressure (PAWP) correlated with medial thickness of the pulmonary arteries of the right lung (r=0.76, p=0.003), the left upper lobe (r=0.54, p<0.03), the left lower lobe (r=0.49, p=0.04). This finding suggests that the pathogenesis of PAWP-related medial thickening of the bilateral lung pulmonary artery begins with the sensing by the bilateral lung of PV pressure buildup in the unilateral lung.

Successful arterial switch operation for post-Mustard pulmonary venous obstruction and secondary pulmonary hypertension

A 16-year-old girl presented with dyspnea 15 years after the Mustard operation for transposition of the great arteries with intact ventricular septum. An echocardiogram revealed secondary pulmonary hypertension due to pulmonary venous obstruction. Cardiac catheterization showed the left (pulmonary) ventricular pressure was over the systemic level. We performed a successful one-stage switch conversion. The patient is doing well 1 year after the switch conversion.

Major pulmonary embolism: review of a pathophysiologic approach to the golden hour of hemodynamically significant pulmonary embolism

Major pulmonary embolism (PE) results whenever the combination of embolism size and underlying cardiopulmonary status interact to produce hemodynamic instability. Physical findings and standard data crudely estimate the severity of the embolic event in patients without prior cardiopulmonary disease (CPD) but are unreliable indicators in patients with prior CPD. In either case, the presence of shock defines a threefold to sevenfold increase in mortality, with a majority of deaths occurring within 1 h of presentation. A rapid integration of historical information and physical findings with readily available laboratory data and a structured physiologic approach to diagnosis and resuscitation are necessary for optimal therapeutics in this "golden hour." Echocardiography is ideal because it is transportable, and is capable of differentiating shock states and recognizing the characteristic features of PE. Spiral CT scanning is evolving to replace angiography as a confirmatory study in this population. Thrombolytic therapy is acknowledged as the treatment of choice, with embolectomy reserved for those in whom thrombolysis is contraindicated.

Acquired pulmonary vein stenosis after radiofrequency catheter ablation of paroxysmal atrial fibrillation

INTRODUCTION

Elimination of the initiating focus within the pulmonary vein (PV) using radiofrequency (RF) catheter ablation is a new treatment modality for treatment of drug-refractory atrial fibrillation. However, information on the long-term safety of RF ablation within the PV is limited.

METHODS AND RESULTS

In 102 patients with drug-refractory atrial fibrillation and at least one initiating focus from the PV, series transesophageal echocardiography was performed to monitor the effect of RF ablation on the PV. There were 66 foci in the right upper PV and 65 foci in the left upper PV. Within 3 days of ablation, 26 of the ablated right upper PVs (39%) had increased peak Doppler flow velocity (mean 130+/-28 cm/sec, range 106 to 220), and 15 of the ablated left upper PVs (23%) had increased peak Doppler flow velocity (mean 140+/-39 cm/sec, range 105 to 219). Seven patients had increased peak Doppler flow velocity in both upper PVs. No factor (including age, sex, site of ablation, number of RF pulses, pulse duration, and temperature) could predict PV stenosis after RF ablation. Three patients with stenosis of both upper PVs experienced mild dyspnea on exertion, but only one had mild increase of pulmonary pressure. There was no significant change of peak and mean flow velocity and of PV diameter in sequential follow-up studies up to 16 (209+/-94 days) months.

CONCLUSION

Focal PV stenosis is observed frequently after RF catheter ablation applied within the vein, but usually is without clinical significance. However, ablation within multiple PVs might cause pulmonary hypertension and should be considered a limiting factor in this procedure.

The role of infectious agents in pulmonary and systemic vascular disease

With emphasis on the pulmonary circulation, three general types of vascular disease are discussed: fibroproliferative (atherosclerosis), cellular proliferative (endothelial neoplasms) and inflammatory (granulomatous vasculitis). The causes of these phenotypic responses are invariably multifactorial, but infectious agents including viruses, Chlamydia, Helicobacter, Rickettsia, mycobacteria and other infectious agents have been increasingly implicated in the pathophysiology. The classifications of vascular diseases are complicated and confusing and many eponymous diseases are specific variations of more general disease processes. The pivotal role of the monocyte/macrophage and T-cells is discussed, particularly with regard to intracellular infections. In addition to antimicrobial therapy, modifications of macrophage function by IFN-gamma and blockade of TNF are attractive areas for therapeutic research. Diseases with many synergistic causes will probably also require multifaceted therapeutic interventions.

Hypoxia and cold stress on pulmonary venous obstruction

Hemodynamic changes induced by hypoxia and cold stress were examined on the model of pulmonary venous obstruction (PVO) to investigate the mechanism of pulmonary hypertensive crisis. Bilateral pulmonary venous stenosis was surgically created in 7 newborn piglets of the PVO group. Sham operations were performed on 6 piglets of the control group. Following the baseline hemodynamic measurement (FiO2 = 0.3) at 8 weeks after the operation, the piglets were exposed to hypoxia (FiO2 = 0.14) for 10 minutes, and were also exposed to cold stress for 20 minutes. Hypoxia significantly increased mean pulmonary arterial pressure in the PVO group. Hypoxia increased not only pulmonary arterial resistance, but also pulmonary venous resistance in the PVO group. Cold stress did not change pulmonary arterial resistance or pulmonary venous resistance in each group. In the lungs of the PVO group, the medial muscular layer of the pulmonary arteries and pulmonary veins were thickened. This probably accelerates hypoxia-induced vasoconstriction, which in turn increases pulmonary arterial and venous resistances.

Pulmonary veno-occlusive disease: a case series and new observations

STUDY OBJECTIVES

The aim of this study was to describe our experience at one institution with pulmonary veno-occlusive disease (PVOD) during the past 10 years, with particular reference to new findings and long-term outcome.

SETTING

Tertiary care, academic medical center.

PATIENTS AND METHODS

Eleven patients who were evaluated and treated for PVOD at our institution were retrospectively studied. Included were all available clinical, radiographic, hemodynamic, and pathologic data.

RESULTS

All 11 patients in our series had at least one symptom or clinical finding that, in conjunction with known pulmonary hypertension, suggested the diagnosis of PVOD. Digital clubbing, not previously reported in PVOD, was found in 5 patients, rales in 6, and increased interstitial markings on chest radiograph in 10. Half of the 10 patients who underwent acute vasodilator testing exhibited a decrease in pulmonary artery pressure of > 20%, although one patient died shortly after receiving IV calcium-channel blockers. Three patients have demonstrated sustained clinical improvement with therapy, which includes calcium-channel blockers, epoprostenol, and lung transplantation in one patient each. However, outcome was generally poor, with a 72% mortality within 1 year of diagnosis.

CONCLUSION

The diagnosis of PVOD requires a high clinical suspicion. However, both physical examination findings and radiographic studies often provide clues to the diagnosis, which may obviate the need for lung biopsy in the majority of cases. Although there may be patients who respond to medical therapy, the use of vasoactive medications in patients with PVOD should be undertaken with great caution. Long-term survival is poor, and lung transplantation remains the only proven therapy.

Pulmonary veno-occlusive disease

Pulmonary veno-occlusive disease (PVOD) is a rare cause of pulmonary hypertension that mainly affects children and young adults. Its cause is unknown, although viral infections and drugs have been implicated. Patients with PVOD present with symptoms of right-sided heart failure. Radiologic examination shows prominent pulmonary arteries with Kerley B lines, pleural effusion, and mediastinal adenopathy. The definite diagnosis is made by histologic examination. Eccentric intimal fibrosis and recanalized thrombi in pulmonary veins and venules, arterialized veins, alveolar edema, and medial hypertrophy of arteries are seen on lung biopsy. No effective treatment is available; lung transplantation has been tried. The prognosis associated with PVOD is poor.

Bronchial responsiveness to inhaled histamine in canine pulmonary congestion

To elucidate the role of bronchial hyperresponsiveness (BHR) in pulmonary congestion, an inhaled histamine provocation test was performed in dogs with acute pulmonary congestion, and the role of vagal nerve activity and arachidonic acid metabolites on bronchial responsiveness was evaluated. We assessed BHR with the provocation concentration of histamine causing a 100% increase in pulmonary resistance (PC100) in an openchest anesthetized and tracheotomized canine model before and after left atrial balloon inflation. Twenty-two mongrel dogs (8-14 kg) were anesthetized with sodium thiopental (15-20 mg/kg) and mechanically ventilated with positive end-expiratory pressure at 3 cmH2O. A Foley catheter was inserted into the left atrium to cause pulmonary congestion, in which mean left atrial pressure was increased to 18 mmHg. In 6 dogs, histamine provocation was examined before and after pulmonary congestion was effected. Intravenous indomethacin (1 mg/kg) administration and vagotomy were performed in 5 dogs. In pulmonary congestion, PC100 was significantly decreased both before and after vagotomy and after indomethacin administration. We conclude that pulmonary congestion augments bronchial responsiveness to inhaled histamine and that neither vagotomy nor indomethacin administration prevents bronchial hyperresponsiveness in pulmonary congestion. These findings suggest that bronchial hyperresponsiveness in pulmonary congestion is related to another factor such as bronchial edema.

Down syndrome as a factor influencing hemodynamic response to pulmonary artery banding

The hemodynamic response to pulmonary artery banding (PAB) in relation to the preoperative pulmonary/systemic vascular resistance (Rp/Rs) ratio and to the timing of surgery, with special regard to Down syndrome, was investigated in 56 nonconsecutive pediatric patients aged 3 days to 6 months (mean 2.5 months) with simple and complex congenital shunt-related cardiac malformations. Among the non-Down patient group (39 patients; mean age 6.9 weeks) there was a good hemodynamic response in all but three cases, irrespective of the preoperative Rp/Rs ratio; these three poor responders had preoperatively normal or nearly normal Rp/Rs ratios (Rp/Rs < 0.3) and were affected postoperatively by lung complications. In the Down patient group (17 patients; mean age 8.2 weeks) the mean preoperative as well as the mean postoperative Rp/Rs ratio was higher than in the non-Down patient group (preoperative Rp/Rs 0.49 versus 0.32; postoperative Rp/Rs 0.31 versus 0.18). There was a good hemodynamic response in all five patients with Down syndrome who had preoperative normal or nearly normal pulmonary vascular resistance ratios (Rp/Rs < 0.3). Among 12 patients with Down syndrome and preoperative increased resistance ratios (Rp/Rs > 0.3) PAB did not cause a reduction in pulmonary vascular resistance (PVR) in five patients (postoperative Rp/Rs 0.49-1.00), all operated on at more than 6 weeks of age. PAB resulted in effective reduction of postoperative Rp/Rs ratios (range 0.10-0.27) in seven patients, six of them younger and one older than 6 weeks at the time of the banding procedure. In conclusion, patients with Down syndrome and shunt-related cardiac malformations (predominantly total atrioventricular canal cases) in general have higher pre- and postoperative Rp/Rs ratios than non-Down children and also have a higher potential for developing pulmonary vascular obstructive disease despite hemodynamically effective PAB. Especially in children with Down syndrome and pathologically high resistance ratios, PAB, if indicated, should be performed as early as possible.

Effect of prostacyclin on microvascular pressures in a patient with pulmonary veno-occlusive disease

Continuous-infusion prostacyclin improves symptom scores and decreases mortality in patients with primary pulmonary hypertension, but use of prostacyclin in patients with pulmonary veno-occlusive disease may precipitate pulmonary edema. A patient with pulmonary veno-occlusive disease received a graduated intravenous infusion of prostacyclin and pulmonary capillary pressures were calculated during prostacyclin dose ranging. Calculated capillary pressure increased with low-dose prostacyclin (< or = 6 ng/kg/min) but decreased with higher doses. These data suggest that the post-capillary pulmonary venules in our patient had reversible vasomotor tone, but required a higher dose of prostacyclin to vasodilate than did the precapillary arterioles.

Lung function in relation to haemodynamic status after atrial redirection for transposition of the great arteries

To assess the interplay between haemodynamic sequelae and lung function after atrial redirection for transposition of the great arteries, we investigated 15 Mustard (age 12.0-22.0 years), and 15 Senning patients (age 7.2-12.1 years). As diagnosed at cardiac catheterization and ultracardiography, 16 (11 Mustard) had major haemodynamic sequelae, including systemic ventricle dysfunction, pulmonary hypertension, pulmonary venous obstruction, systemic venous obstruction and atrial septal defects. Static and dynamic lung volumes, ventilation distribution and diffusion capacity were assessed by body plethysmography, spirometry, the single-breath nitrogen test (N2slope) and the single-breath method for diffusion capacity (DLCO) respectively. Apart from DLCO, our own reference values were used for comparison. We found small lung volumes, a high functional residual capacity, a high N2slope and a low DLCO. Tests of > 2SD in the abnormal direction were more prevalent in the Mustard group (P = 0.06) and significantly more prevalent in patients with pulmonary hypertension. Six had normal lung function tests, 15 had unclassified abnormalities, three had small lungs and three had central airway obstruction. Peripheral airway obstruction was only present in three of four subjects with moderate or severe pulmonary hypertension. The study confirms some previous reports indicating a high frequency of lung function abnormalities in these patient groups and discusses a possible relationship to haemodynamic status.

Pulmonary vascular disorders masquerading as interstitial lung disease

During the acquisition of a series of 92 children with interstitial lung disease (ILD) over a 14 year period, a significant minority (8/92 or 9%) were initially diagnosed as having ILD, but were subsequently found to have a variety of arterial, venous, and/or capillary disorders that explained their initial pulmonary findings. This subgroup of patients has had a very high morbidity and mortality, with only three of eight patients currently surviving. The presentation, evaluation, and natural history of these eight children were reviewed. We developed a strategy of cardiac and pulmonary evaluation for children presenting with clinical and radiographic features of ILD that helped us to identify rapidly those with pulmonary vascular disorders.

Evaluation of pulmonary vein stenosis by transesophageal echocardiography

Pulmonary vein stenosis was diagnosed by transesophageal echocardiography in five patients who underwent the study for different clinical indications. Stenosis was encountered in the right upper pulmonary vein in two patients, the right lower pulmonary vein in two patients, and at the confluence of the left pulmonary veins in one patient. In only one patient was the diagnosis suspected on transthoracic echocardiography. Contralateral normal veins from the same patient served as the control. Vessel diameter and peak flow velocity were measured and compared. The diameter of the stenosed veins ranged from 0.3 to 0.8 cm (mean 0.4 +/- 0.09 cm [SEM]), whereas for normal veins the diameter was 0.9 to 1.2 cm (mean 1.0 +/- 0.05 cm [SEM]; p < 0.001). Peak flow velocity in the stenosed veins ranged from 1.1 to 1.6 m/sec (mean 1.4 +/- 0.1 m/sec [SEM]), whereas in normal veins peak flow velocity ranged from 0.4 to 0.7 m/sec (mean 0.6 +/- 0.04 m/sec [SEM]; p < 0.001). There was a strong negative correlation between vessel diameter and peak flow velocity (R = 0.89; p < 0.001). Peak flow velocity of 0.8 m/sec appears to provide the best separation between normal and stenosed pulmonary veins. We conclude that pulmonary vein stenosis is associated with increased flow velocity and turbulence and deformity of the flow signal. Transesophageal echocardiography is a powerful tool in the study of pulmonary vein stenosis.

Responses of systemic and pulmonary veins to the presence of an intravascular stent in a swine model

The outcome of stent implantation for children with pulmonary venous obstruction has been characterized by late reocclusion associated with a marked vessel neointimal proliferation. The purpose of this study was to compare the responses of the systemic vein and pulmonary vein to the presence of an intravascular stent, using a Yorkshire swine (N = 10) model. Under cardiopulmonary bypass, a single Palmaz stent was placed in the inferior vena cava (IVC) and right lower pulmonary vein (PV) with sacrifice at 4.9-6.1 months. Angiography and hemodynamic data were determined at 1 and 3 months post-stent implant and prior to euthanasia. All stents were found to be patent, with no difference in degree of thrombosis or neointimal formation. No statistical difference was found in the initial and final stent diameter for both inferior vena cava and pulmonary vein stents (PV initial 6.8 +/- 0.9; final 7.1 +/- 0.6) (IVC initial 10.4 +/- 1.2; final 10.4 +/- 1.2). Electron microscopy demonstrated smooth endothelialization of both pulmonary and systemic venous stent devices. No thrombosis was found on gross morphology. The data indicate that there is no intrinsic difference in the response of the pulmonary vein to the presence of a stent device. The clinical experience of restenosis following stent implantation for pulmonary vein stenosis appears to be more related to variables of final stent diameter combined with the marked intrinsic abnormal vessel architecture, as seen with this condition.

[Pulmonary vein stenosis. Report of 2 cases and review of the literature]

Topical congenital pulmonary vein stenosis is a uncommon defect, both isolated or associated to other cardiac abnormalities. Only the localization of the lesions seems to affect the survival, because 60% of survival cases has unilateral stenosis; the severity of associated cardiac lesions become the prognosis poor. We describe two cases: 1st case, a 43 days old boy presented with heart failure and convulsion and had a diagnosis of pulmonary hypertension, atrial septal defect and tricuspid regurgitation, without pulmonary abnormalities. He had recurrent pulmonary infections and a cerebral ischemia in the following months, and died at 15 months of age for sepsis. Autopsy revealed stenosis and atresia in all pulmonary veins, with venous and arterial hypertension. There was also aortic hypoplasia and aortic and tricuspid valves indifferentiation; 2nd case, a 7 days old girl had a diagnosis of aortic coarctation and atrial and ventricular septal defects. Surgical corrections, at 38 and 46 days old, firstly of the aortic coarctation and after for the septal defects, disclosed and relief a supra-valvar mitral stenosis, but she remained on heavy respiratory insufficiency. At 6 months old, she returned to the hospital with dyspnea and cianosis, heart failure and hemoptisis; a sepsis developed and she died. At autopsy, there were severe pulmonary vein stenosis on the left and in the superior right veins, with pulmonary hypertension and hemorrhage.

Orthotopic transplantation for total anomalous pulmonary venous connection associated with complex congenital heart disease

BACKGROUND

When total anomalous pulmonary venous connection is associated with other complex cardiac malformations, early and late postsurgical morbidity and mortality are excessive.

METHODS

In an attempt to modify this outcome, twelve children (4 days to 6.8 years of age) with total anomalous pulmonary venous connection and various congenital cardiac defects were treated with orthotopic heart transplantation. Associated cardiac diagnoses included the following: hypoplastic left heart syndrome (n = 2), unbalanced atrioventricular canal with pulmonary atresia (n = 2), and single ventricle with severe pulmonary stenosis (n = 3) or atresia (n = 5). Two patients had situs inversus, and two had dextrocardia with situs ambiguous. Eight patients had asplenia and one had polysplenia. Palliative pretransplantation procedures in five patients included the following: systemic to pulmonary artery shunt (n = 5), atrioventricular valve annuloplasty (n = 1) and classical Glenn shunt (n = 1). The donor left atrium was anastomosed directly to a common pulmonary venous pool in nine patients; whereas three children required complex reconstruction to baffle the pulmonary venous flow to the donor left atrium.

RESULTS

There was one operative death related to an oversized heart and vena caval thrombosis. Follow-up ranged from 16 months to 4.5 years (average 3 years). In two patients (18%) pulmonary venous obstruction developed 3 and 4 months after transplantation. Reoperation to relieve the obstruction was successful in one patient. The second patient underwent three such reoperations and died of sepsis 10 months after orthotopic heart transplantation.

CONCLUSION

Orthotopic transplantation is a viable option for children with complex total anomalous pulmonary venous connection that precludes a biventricular repair. Transplantation may improve the dismal prognosis of those children, but it does not eliminate the potential for late pulmonary venous obstruction.

Stenosis of pulmonary veins with ventricular septal defect: visualization of the pulmonary veins after pulmonary arterial banding

A case of 'absent' left pulmonary vein with ventricular septal defect was diagnosed based on echocardiography, magnetic resonance imaging and cardiac catheterization at newborn stage. Pulmonary arterial banding was performed at the age of 1 month to ameliorate the pulmonary flow. At a cardiac catheterization 1 year later, the left pulmonary veins were visualized with moderate stenosis at their entrance into the left atrium. The patient has been stable after surgical repair of the ventricular septal defect and dilation of the pulmonary venous stenosis.

[Relief of pulmonary venous obstruction for asplenia syndrome associated with total anomalous pulmonary venous connection in neonates and infants]

Five patients of asplenia syndrome with pulmonary venous obstruction underwent TAPVC repair in the period of neonates (4 patients) and infant (1 patient). They also underwent associated procedures to reconstruct or adjust pulmonary blood flow (systemic-pulmonary shunts in 2, bilateral PDA banding in 1, pulmonary artery banding in 1) in accordance with individual anatomy of the pulmonary arteries. In four of them, they required subsequent surgical procedures for reduction of pulmonary blood flow because of intractable heart failure due to increase in pulmonary blood flow mostly at the early postoperative period. The increasing pulmonary blood flow was successfully controlled by early reduction procedures (1 patient: extrathoracically adjustable PA banding, 1 patient: tightening of shunt graft) in two patients. However, one patient died in the early postoperative period because of moribund preoperative condition. The remaining one patient underwent PA banding three month after the first operation, but died in late period due to heart failure. These results suggest that the adjustment of pulmonary blood flow is critically important for management of the patients of asplenia syndrome with TAPVC after the operation, and early decision of PA band re-adjustment (or other procedures to decrease pulmonary blood flow) is mandatory to improve the results.

Respiratory response to pulmonary vascular congestion in intact conscious dogs

Clinical disorders associated with pulmonary venous hypertension frequently result in tachypnea and hyperpnea. The response to pulmonary vascular congestion (PVC) in anesthetized or decerebrate animals has consisted of modest and bidirectional changes in respiratory rate with no hyperpnea. We hypothesized that anesthesia or decerebration in previous animal experiments may have attenuated the hyperpneic response that would otherwise have been evident. A conscious dog model was developed in which the left lower lobe (LLL) pulmonary circulation could be reversibly isolated and pressurized. Occluders were placed outside the LLL pulmonary artery (PA) and vein. Two fine catheters were introduced through the wall of the LLLPA distal to the arterial occluder. A pleural catheter was used to monitor pleural pressure swings. After recovery from surgery PVC was initiated by inflation of the occluders and injection of warm saline or fresh warm blood through one of the catheters. PVC resulted in decreased breathing frequency and hypopnea in six of seven intact unanesthetized dogs. The remaining dog exhibited a transient rapid shallow breathing pattern. In four dogs tested using the same preparation under anesthesia, the response to PVC was an increase instead of a decrease in breathing frequency. We conclude that the presence of higher brain function does not promote tachypnea or hyperpnea in response to PVC. Mechanisms other than PVC, per se, likely account for the tachypnea and hyperpnea observed in clinical disorders associated with pulmonary venous hypertension.