Surgical results of pulmonary thromboendarterectomy for chronic pulmonary thromboembolism

Chronic pulmonary thromboembolism may produce severe respiratory insufficiency and progressive pulmonary hypertension resulting in an intractable right ventricular failure. Although the pathogenesis of this syndrome has not been completely understood, medical treatment usually has little effect and only surgery can be a life saving remedy. Since 1986, seven patients with this syndrome have had pulmonary thromboendarterectomy at the First Department of Surgery, Chiba University Medical Center. Surgery is indicated mainly for patients who present with a mean pulmonary arterial pressure greater than 30 mmHg. All procedures were performed through a unilateral thoracotomy with a cardiopulmonary bypass on stand-by use. Two patients (#1 and #6) needed bilateral surgery which was carried out in two stages, in the remainder only a right side being operated on. When a major pulmonary artery was clamped, the systolic pulmonary arterial pressure rose to equalize or even exceeded that of systemic artery, however since no further hemodynamic deterioration was observed, cardiopulmonary bypass was not used in any case. Although the key feature of this procedure is commonly said to establish an exact cleavage plane between thrombus and arterial wall, it can be carried out without difficulty through thoracotomy approach. Grasping the thrombus, blunt dissection is further proceeded until the entire thrombotic material comes free as a cast of the vessels. All patients survived the operation without major complications including severe reperfusion pulmonary edema. Postoperative catheterization, performed one month following surgery, demonstrated a marked reduction of pulmonary arterial pressure with significantly reduced pulmonary arterial resistance (PAR).     

Prostaglandin E1 and intrapulmonary shunt in cardiac surgical patients with pulmonary hypertension

Unlike many other vasodilators, prostaglandin E1 may reduce pulmonary vascular resistance without changing intrapulmonary shunt in patients with adult respiratory distress syndrome. Whether the same is true for surgical patients with cardiogenic pulmonary hypertension but normal gas exchange remains unclear. Data from the intraoperative records of 8 patients with pulmonary hypertension and elevated pulmonary vascular resistance were used for the study. Hemodynamic variables had been monitored through radial arterial cannulas and pulmonary arterial catheters. Arterial and mixed venous oxygen tension, carbon dioxide tension, oxygen saturation, and hemoglobin level, as well as cardiac output and pulmonary capillary wedge pressure, had been determined in each patient before prostaglandin E1 infusion was started and again when the desired pulmonary vascular response had been achieved. Pulmonary and systemic vascular resistances and intrapulmonary shunt were calculated from standard formulas. Infusion rates of prostaglandin E1 ranged from 7 to 135 ng/kg/min. Prostaglandin E1 reduced mean pulmonary arterial pressure, pulmonary vascular resistance, and pulmonary capillary wedge pressure but did not change intrapulmonary shunt. Heart rate and mean arterial and right atrial pressures were not changed, whereas systemic vascular resistance decreased and cardiac output increased. The present study shows that prostaglandin E1 reduces pulmonary arterial pressure and pulmonary vascular resistance without dramatic changes in intrapulmonary shunt in patients with pulmonary hypertension secondary to cardiac disease.     

Quantitative analysis of pulmonary vascular disease in total anomalous pulmonary venous connection in sixty infants.

A quantitative analysis of small pulmonary arteries, pulmonary veins, and lymphatic vessels was conducted in autopsy cases of total anomalous pulmonary venous connection. The materials were obtained from 60 cases of total anomalous pulmonary venous connection without asplenia or pulmonary stenosis, ages ranging from 2 days to 19 months at the time of death (mean age 2.2 months). Pulmonary arterial pressure had been measured in 32 of these patients before death. Twenty cases of ventricular septal defect with pulmonary hypertension and 15 normal individuals were used as the control group. The mean thickness of the media of small pulmonary arteries and veins was 12.7 and 7.6 microns, respectively, in the total anomalous pulmonary venous connection cases, both values being significantly larger than those for normal and ventricular septal defect cases. No changes in thickness with aging were found. Medial thickness in the arteries and veins was greater in the cases of pulmonary venous obstruction than in those without such obstruction. The medial thickness of small pulmonary arteries in total anomalous pulmonary venous connection cases correlated with increased pulmonary arterial pressure. When the patients with the same pulmonary arterial pressure levels were compared, the medial thickness was always greater in those who had total anomalous pulmonary venous connection than in those who had ventricular septal defect. The medial thickness of pulmonary veins was also highly correlated with increased pulmonary arterial pressure in total anomalous pulmonary venous connection. The severity of the intimal lesions was milder in those who had total anomalous pulmonary venous connection than in those who had ventricular septal defect, suggesting the protective role of the thickened pulmonary arterial media against development of intimal lesions. Intimal fibrous thickening of pulmonary veins was not seen in the cases of ventricular septal defect, but it was present in 45% of the total anomalous pulmonary venous connection cases. Lymphangiectasia was characteristically present in 62% of the total anomalous pulmonary venous connection cases. Interstitial emphysema was often a complication of lymphangiectasia, and it led to eight postoperative deaths.     

Left ventricle is better suited as pulmonary ventricle in simple transposition with severe pulmonary hypertension

BACKGROUND: The conventional treatment of transposition of great arteries with prepared left ventricle is an arterial switch operation. This, in our experience, does not hold for patients with transposition of great arteries with intact ventricular septum where the left ventricle continues to be prepared secondary to severe pulmonary arterial hypertension without an immediately reversible cause. METHODS: Ten infants with D-transposition of the great arteries with essentially intact interventricular septum and severe pulmonary arterial hypertension underwent surgical treatment. Age ranged from 3 to 6 months (mean, 4.2 months). One of these patients had a large ductus with left to right shunting but the others had no intra- or extracardiac shunt to account for their pulmonary hypertension. All 10 had "prepared" left ventricles. The first 4 children underwent an arterial switch operation. Uneventful surgery was followed by prolonged ventilator dependence in all 4 with occurrence of severe pulmonary arterial hypertension every time weaning from ventilator was attempted. This was accompanied by metabolic acidosis and features of right heart failure. Only 1 patient with large ductus could be extubated and discharged from hospital. Subsequently, the other 6 infants underwent a Senning repair. RESULTS: There was no early mortality. All patients were separated from mechanical ventilation within 48 hours of surgery without blood gas derangement or heart failure despite elevated pulmonary artery pressure in all. The child with the arterial switch operation has pulmonary artery pressure of 50% systemic 4 years following repair; although among the Senning group, 2 patients continue to have pulmonary artery pressure more than 60% of systemic and 4 have normal pulmonary artery pressure at a mean follow-up of 1 year. CONCLUSIONS: Atrial level repairs seem to perform better than arterial level repairs in children having TGA with persistent pulmonary artery hypertension without a correctable cause. Better tolerance of pulmonary arterial hypertension in this group is probably consequent to the superior ability of the left ventricle to tolerate a pressure load in the early postoperative period.     

Origin of the right pulmonary artery from the ascending aorta.

Origin of the right pulmonary artery from the aorta is a congenital malformation usually associated with serious symptoms in the first year of life and characterized by a poor prognosis. Sixty-five patients with this disorder have been reviewed in the literature, and 95% presented during the first year with signs of congestive heart failure. All had cardiomegaly by radiographic and electrocardiographic examination. An accurate diagnosis was established by cineangiography, and associated cardiovascular anomalies were present in 85%. Origin of the right pulmonary artery from the ascending aorta is much more common than origin of the left pulmonary artery from this vessel (8 to 1). Twenty-three patients were managed without operation with a 30% 1-year survival rate. Among those patients managed surgically, the survival rate was 84% at 1 year. It is now clear that operation should be done as early as possible to prevent irreversible changes occurring in the pulmonary arterial vasculature since microscopic features of pulmonary hypertension have been seen during the first month of life. One patient was operated on at 5 months with correction of the deformity. The pulmonary arterial pressure decreased to normal after operation. This child is now asymptomatic and his 10-year postoperative follow-up is the longest found in the literature.     

Expanded selection criterion for Fontan's operation based on the size of distal pulmonary arteries

This study examined pulmonary arterial size to clarify a quantitative selection criterion for Fontan's operation in six cases without pulmonary hypertension. Pulmonary arterial size was angiographically assessed before and after the operation. No enlargement of the artery was observed, even after the procedure, confirming the importance of preoperative pulmonary arterial size. All three cases with preoperative PAa/N-RPAa of more than 0.5 survived the operation, whereas two of the remaining three cases (less than 0.5) died due to low cardiac output. The only survivor in the latter group had previously received Glenn's anastomosis. Hemodynamic study was done simultaneously, and a significant exponential correlation was obtained between preoperative PAa/N-RPAa and perioperative post-repair right atrial pressure (p less than 0.025). It was concluded that the selection criterion based on pulmonary arterial size could be expanded to a PAa/N-RPAa value of 0.5 when no Glenn's anastomosis had previously been done and the rudimentary right ventricle was not to be utilized. The exponential curve is useful for postoperative care in Fontan's operation, since it indicates the central venous pressure necessary to sustain the circulation at a level corresponding to the preoperative pulmonary arterial size.     

A case of microscopic pulmonary tumor emboli 14 months after total cystectomy

A 70-year-old man was admitted with slight dyspnea and fever up. The patient had had total cystectomy for urothelial carcinoma of urinary bladder 14 months earlier and had a ureterocutaneostomy. At 2 days after the admission, he had a sudden attack of dyspnea. He was transferred to the intensive care unit, and mechanical ventilation was initiated. The pulmonary arterial pressure was measured at 65/30 mmHg, but the etiology for the pulmonary hypertension was unclear. Although highly suggestive of pulmonary embolism, chest roentgenogram and chest computed tomography (CT) showed clear lung fields. Pulmonary angiography disclosed no evidence of embolism. Despite anticoagulation therapy he died of respiratory failure. Autopsy revealed diffuse microscopic pulmonary tumor embolism with urothelial cacinoma in the pulmonary arterial vasculature. Microscopic pulmonary tumor embolism has rarely been reported with urothelial carcinoma.     

A new method of predicting pulmonary capillary wedge pressure: the arterial pressure ratio

The response of arterial blood pressure to an increase in intrathoracic pressure has been shown to be predictive of pulmonary capillary wedge pressure. We devised a new method, which we termed the arterial pressure ratio. We defined arterial pressure ratio as the ratio of systolic blood pressure of the final beat during the strain phase of the Valsalva manoeuvre to that during apnoea before the manoeuvre, and tested the accuracy of arterial pressure ratio in predicting pulmonary capillary wedge pressure. In 30 patients scheduled for elective abdominal aortic reconstruction, following induction of general anaesthesia and tracheal intubation, a 20-G catheter and pulmonary artery catheter were inserted through the radial artery and right internal jugular vein, respectively. Pulmonary capillary wedge pressure was then measured during a brief period of apnoea and the Valsalva manoeuvre was performed by application of pressure to the reservoir bag. Airway pressure was maintained at 30 cmH2O for 10 s and then released. Radial arterial pressure and airway pressure were recorded simultaneously, and arterial pressure ratio was calculated. There was a close linear correlation between arterial pressure ratio and pulmonary capillary wedge pressure (r = 0.88, p < 0.0001).     

Therapeutic effects of thromboembolectomy and caval Günther filter insertion in chronic pulmonary embolism

Two cases of chronic-stage pulmonary embolism which had occurred at least one month before the operation were presented. Pulmonary thromboembolectomy under the cardiopulmonary bypass was performed and followed by the insertion of Günther filter to prevent recurrence of embolism. Both cases revealed severe obstruction occupying over 50% of the pulmonary arteries which were presented by the remarkable increase of pulmonary arterial systolic pressures up to 100 and 80 mmHg respectively. After thrombectomy the pulmonary artery pressure declined to 45 and 28 mmHg, even though the pulmonary embolism was in subchronic state. The respiratory symptoms and abnormal findings on the ECG and chest X-ray were also improved. Since the phlebothrombosis of the inferior limb might be the cause of pulmonary embolism, the insertion of the filter in the inferior vena cava was thought to be indispensable for the prevention of recurrence.     

Reduction in pulmonary varix size after mitral valve replacement

A 48-year-old female was admitted to our hospital for examination of an abnormal shadow in the right lung field. She had a systolic murmur (4/6) over the apex and the chest radiograph revealed cardiac enlargement with three round opacities in the right lung field. Cardiac catheterization showed marked mitral regurgitation and large pulmonary varices. Pulmonary varix caused by mitral regurgitation was diagnosed. The size of the pulmonary varix was reduced with improvement of pulmonary artery wedge pressure one month after mitral valve replacement. We conclude that pulmonary varices can decrease in size secondary to lowering of left atrial pressure within one month after operation.     

Outpatient inhaled nitric oxide in a patient with idiopathic pulmonary fibrosis: a bridge to lung transplantation.

Inhaled nitric oxide (INO) has been shown to improve oxygenation and decrease intrapulmonary shunt and pulmonary hypertension in various lung diseases. In this study we report a patient with end-stage idiopathic pulmonary fibrosis and pulmonary hypertension who received INO after coronary artery bypass surgery, with significant improvement in arterial oxygenation and pulmonary arterial pressure. Using a pulsing delivery system, the patient continued to receive outpatient INO for 30 months while waiting for lung transplantation. Exercise study and two-dimensional echocardiogram, after 3 months of inhaled NO, demonstrated continued benefits of INO for improvement of arterial oxygenation, pulmonary arterial pressure and exercise tolerance.     

Total anomalous pulmonary venous drainage

Forty-four patients with total anomalous pulmonary venous drainage underwent repair between 1979 and 1987. The anomalous drainage was supracardiac in 16, cardiac in 12, and infracardiac in 16. Median age at repair was 15 days and median weight, 3.3 kg. In 22 patients (50%) the venous drainage was obstructed. Emergency operation was necessary in 12 patients, and the condition of seven additional patients deteriorated while they were awaiting semiurgent operation. There was one hospital death (mortality rate 2.3%), occurring in a 2-week-old premature neonate with infracardiac drainage. In 17 of 44 patients, mean pulmonary artery pressure equaled or exceeded systemic arterial pressure immediately after repair. Four patients have required reoperation and two of these have died as a result of peripheral extension of pulmonary vein sclerosis. In the review period of from 1 month to 7 years, all survivors are well and receiving no medication.     

Fatal pulmonary bile embolism following acute acalculous cholecystitis

A 52-year-old man died during reoperation for bleeding after the development of acute postoperative acalculous cholecystitis. While the liver was being manipulated during surgery, the pulmonary artery diastolic pressure increased suddenly, cardiac output and blood pressure decreased, and soon afterward the patient had a cardiac arrest from which he could not be resuscitated. During resuscitative efforts, the maximum partial arterial oxygen pressure achieved was only 55 mm Hg despite 100% inspired oxygen. At autopsy, bile aggregates were found within necrotic liver parenchyma, portal and central vein branches, and numerous pulmonary arterioles and capillaries. The pulmonary arterial bile most likely resulted from embolization of inspissated hepatic bile aggregates during surgical manipulation.     

Outcome after reconstruction of discontinuous pulmonary arteries

OBJECTIVE: This study was undertaken to determine outcomes of and optimal treatment strategies for reconstruction of congenital or acquired discontinuity of branch pulmonary arteries. METHODS: Between 1985 and 2000 pulmonary artery continuity was established in 102 patients with discontinuous central pulmonary arteries and normal peripheral arborization. Data were obtained retrospectively. RESULTS: Techniques to connect both pulmonary arteries included direct pulmonary artery-pulmonary artery anastomosis (n = 33), tube graft interposition (n = 47), or pulmonary arterial implantation in right ventricular-pulmonary arterial conduits (n = 22). Among patients with biventricular repair (n = 66), survival was 85% +/- 8% at 5 years, and freedom from surgical or interventional pulmonary arterioplasty was 31% +/- 11%. At most recent follow-up, mean branch pulmonary arterial z scores were -0.5 +/- 1.6 (right pulmonary artery) and -1.4 +/- 1.3 (left pulmonary artery). Mean right to left ventricular pressure ratio was 0.61 +/- 0.26, and this value was more than 0.75 in 13 of 58 cases. Fifteen of 51 had a lung perfusion mismatch of more than 75:25, and in 9 of 58 one branch pulmonary artery was occluded. Twenty-two patients who underwent primary establishment of antegrade pulmonary artery flow without previous shunt procedures had comparable survival and reintervention rates, with a tendency toward higher pulmonary arterial z scores and lower right to left ventricular pressure ratios. Among patients with single-ventricle repair (n = 33), 5-year survival was 93% +/- 8% and freedom from pulmonary arterioplasty was 39% +/- 9%. Ten of 19 patients had a lung perfusion mismatch, and one branch pulmonary artery was occluded in 4 of 31. Overall, a direct pulmonary artery anastomosis was associated with better survival (P =.006). The presence of aortopulmonary collaterals was a risk factor for pulmonary artery occlusion (P =.03). CONCLUSION: Good survival can be achieved for patients with pulmonary artery discontinuity, but this requires frequent reinterventions. Direct pulmonary artery- pulmonary artery anastomoses and control of all collateral vessels may further improve outcome.     

A successful arterial switch operation for a patient with pulmonary venous obstruction and pulmonary hypertension five years after the Mustard procedure

A five year and six month old boy, who had undergone Mustard operation for complete transposition of the great arteries with intact ventricular septum at two months of age, was reoperated on for pulmonary venous obstruction and pulmonary hypertension (PLV/RV = 0.96). The other complications which he had were moderate tricuspid regurgitation and various supra-ventricular arrhythmias. After the atrial baffle of the Mustard procedure was taken down, atrial septum was reconstructed and arterial switch operation was performed at the same time. One month after the operation, Pp/Ps was 0.41 and no tricuspid regurgitation and arrhythmias were found. He was discharged and his quality of life was ameliorated surprisingly.     

Aerosolised iloprost improves pulmonary haemodynamics in patients with primary pulmonary hypertension receiving continuous epoprostenol treatment

BACKGROUND: Continuous intravenous treatment with epoprostenol significantly improves pulmonary haemodynamics and survival in patients with primary pulmonary hypertension (PPH). Its beneficial effect, however, may be blunted due to adverse effects such as catheter sepsis and systemic hypotension. Recent investigations have shown that inhaled iloprost is effective in the treatment of PPH. Based on their different pharmacokinetics, we hypothesised that the combination of intravenous epoprostenol and inhaled iloprost would be more efficacious than epoprostenol alone during acute testing in patients with PPH. METHODS: The effect of a single dose of inhaled iloprost (30 microg total over 15 minutes) on pulmonary haemodynamics was examined in eight patients with PPH (initial non-responders to nitric oxide) who had considerable adverse effects during treatment with epoprostenol. RESULTS: The combination of inhaled iloprost and intravenous epoprostenol significantly improved mean pulmonary artery pressure (MPAP), cardiac index (CI), mixed venous oxygen saturation (SvO2), and systemic arterial oxygen pressure (PaO2) compared with epoprostenol treatment alone. Mean systemic arterial pressure (MSAP) and pulmonary capillary wedge pressure (PCWP) remained unchanged. CONCLUSIONS: The pulmonary vasoreactivity shown by additional iloprost inhalation during effective epoprostenol treatment suggests that an improvement of treatment for pulmonary hypertension may be possible by combining vasoactive substances.     

Selective pulmonary vasodilation with inhaled aerosolized milrinone in heart transplant candidates

PURPOSE: Selective pulmonary vasodilation is an advantageous method for testing the responsiveness of the pulmonary vasculature of heart transplant candidates. A pilot study was under-taken to test the hypothesis that inhaled aerosolized milrinone may cause selective pulmonary vasodilation. METHODS: 18 consecutive male heart transplant candidates with either dilated or ischemic cardiomyopathy were included in this open clinical study. Nine of the patients had significant pulmonary hypertension with a mean pulmonary arterial pressure > 30 mmHg. After baseline measurements, 2 mg of milrinone was administered by ultrasonic nebulization. Pulmonary and systemic hemodynamics were measured ten, 30, and 60 min after inhalation. RESULTS: After inhalation for ten minutes, milrinone induced a significant reduction of mean pulmonary arterial pressure (32.7 +/- 9.1 vs 37.7 +/- 7.5 mmHg, P = 0.01), pulmonary vascular resistance index (296 +/- 150 vs 396 +/- 151 dyn.sec(-1).cm(-5).m(2), P = 0.02) and transpulmonary gradient (10.6 +/- 5.5 vs 15 +/- 4.9, P = 0.01) only in patients with significant pulmonary hypertension. There was no significant effect on mean arterial pressure or systemic vascular resistance at any time after inhalation in either group. Furthermore, there was no influence on extravascular lung water or intrathoracic blood volume. CONCLUSIONS: We conclude that inhaled aerosolized milrinone for a short period selectively dilates the pulmonary vasculature in heart transplant candidates with elevated pulmonary arterial pressure, without producing systemic side effects. Further comparative studies are necessary to evaluate possible advantages of milrinone compared to other inhaled vasodilators.     

Progressive pulmonary vascular disease after pulmonary artery banding and total correction in a case of ventricular septal defect and pulmonary hypertension

A 7-month-old infant with ventricular septal defect and pulmonary hypertension underwent pulmonary artery banding, which resulted in a decrease in the pulmonary arterial peak pressure from 102 to 54 mmHg. Lung biopsy findings showed at most an early grade 3 Heath-Edwards classification, and an index of pulmonary vascular disease of 1.4, both of which indicated operability for total correction. Small pulmonary arteries less than 100 μm in diameter, however, showed marked hydropic changes in the medial smooth muscle cells. Total correction was performed at the age of 2 years, but the pulmonary arterial pressure failed to decrease. A lung biopsy taken just after the closure of the ventricular septal defect contraindicated operability due to progressive pulmonary vascular disease at a grade 6 Heath-Edwards classification and an index of pulmonary vascular disease of 2.4. The patient died at 8 months after the operation, and an autopsy revealed still more advanced pulmonary vascular disease at a grade 6 Heath-Edwards classification and an index of pulmonary vascular disease of 2.8. The pathogenesis of arterial changes is discussed.     

The effect of phenylephrine and norepinephrine in patients with chronic pulmonary hypertension*

In this study the effect of phenylephrine and norepinephrine for the treatment of systemic hypotension were evaluated in patients with chronic pulmonary hypertension. When systemic hypotension (systolic arterial pressure < 100 mmHg) occurred following induction of anaesthesia, either phenylephrine or norepinephrine were infused in a random manner to raise the systolic blood pressure by 30% and 50% above baseline values. Norepinephrine decreased the ratio of pulmonary arterial pressure to systemic blood pressure without a change in cardiac index. However, phenylephrine did not increase arterial blood pressure by more than 30% from baseline in one-third of patients and decreased cardiac index without a significant decrease in ratio of pulmonary arterial pressure to systemic blood pressure. These vasoconstrictors showed different systemic and pulmonary haemodynamic effects in patients with chronic pulmonary hypertension as compared to acute pulmonary hypertension. Norepinephrine was considered to be preferable to phenylephrine for the treatment of hypotension in patients with chronic pulmonary hypertension.     

Unsuccessful anesthetic management for cesarean section in a patient with primary pulmonary hypertension

A 31-year-old woman with primary pulmonary hypertension presented for an elective cesarean section at the 34-week gestation. After monitoring pulmonary artery, systemic artery blood pressures and an electrocardiogram, continuous lumbar epidural anesthesia was performed. Uneventful delivery was followed by a sudden decrease in systemic pressure and loss of consciousness. Her trachea was intubated and administration of epinephrine was started. Nitroprusside and milrinone were infused to decrease pulmonary artery pressure and to maintain systemic arterial pressure. However, she died after 16 hours due to an impairment of right ventricular function. Although the patient with PPH had been managed successfully using continuous epidural analgesia until delivery, sudden hemodynamic alterations following delivery could not be controlled by pharmacological interventions.