Coagulation factor abnormalities in patients with single-ventricle physiology immediately prior to the Fontan procedure

Background. Coagulation abnormalities have been reported following the Fontan operation and have been attributed to various aspects of Fontan-associated physiology. Using age-matched controls, this study evaluated coagulation abnormalities in children who had undergone a bidirectional Glenn procedure to test the hypothesis that coagulation abnormalities are present before the Fontan operation.

Methods. Coagulation factors were assayed in 38 children (mean age 34.4 ± 15 months) immediately before the Fontan operation; 37 healthy children (mean age 33 ± 17 months) were assayed as controls. Concentration of factors II, V, VII, VIII, IX, and X and of antithrombin III, plasminogen, proteins C and S, fibrinogen, serum albumin, and liver enzymes were measured. Normal reference intervals based on the control patients were determined using 95% confidence limits. Patient demographic data, hemodynamic variables, and elapsed time after the Glenn procedure were evaluated as possible predictors of coagulation abnormalities.

Results. Concentrations of protein C; factors II, V, VII, and X; plasminogen; and antithrombin III were significantly lower before the Fontan operation compared with age-matched controls (p < 0.01); no specific hemodynamic variables were predictive of a pro- or anticoagulant deficiency. There were significant positive correlations between patients who had abnormally low factor VII, protein S, and protein C levels and a longer interval between the bidirectional Glenn procedure and the Fontan operation (p < 0.001).

Conclusions. Coagulation abnormalities that could predispose patients to increased risk for clotting or bleeding are evident early in the course of staged single-ventricle repair.     

Coagulation abnormalities in patients with hip osteonecrosis

The relatively high frequency of coagulation abnormalities in patients with hip osteonecrosis might represent increased risk factors for the development of bone necrosis by predisposing these patients to thromboembolic phenomena. The recognition of this association may increase as more patients with osteonecrotic lesions are tested for haemostatic abnormalities.Early diagnosis of hypercoagulability in the group of patients at risk may allow pharmacologic intervention that may prevent this devastating process from developing.     

Coagulation abnormalities in patients with head injury

The Authors have studied five coagulation parameters (platelets count, prothrombin time, activated partial thromboplastin time, fibrinogen and fibrinogen degradation products) in 60 head traumatized patients. These parameters were alterated in a high percentage of patients. Moreover 5 patients presented laboratory values indicative of disseminated intravascular coagulation (DIC). DIC could be an important factor of mortality in the head traumatized patients. So coagulation system must be carefully evaluated in any patient with head injury.     

Experience with the Fontan procedure

From 1975 to the present, 45 patients have undergone modifications of the Fontan procedure for complex congenital heart disease. There were 30 males and 15 females ranging in age from 2 to 38 years (mean 13 years). Primary diagnoses were tricuspid atresia in 19, univentricular heart in 24, and pulmonary atresia with intact ventricular septum in two. Right atrial-pulmonary arterial connections were performed in 32 patients, 11 with conduits (seven with valves and four without) and 21 by direct anastomosis with patch augmentation. Right atrial-right ventricular connections were made in 13 patients, six with valved conduits and seven without conduits. Follow-up ranged from 0.1 to 9 years, with a mean of 2.3 years. There were three early deaths (less than 30 days) (7%) and two late deaths (5%) in this series, all in patients with a univentricular heart. The late deaths were both related to venous hypertension. A venous assist device was used in eight patients in the immediate postoperative period and was effective in improving cardiac output and reducing fluid accumulation. Postoperative Doppler flow studies in 15 patients revealed biphasic pulmonary artery flow in all without distinction between the type of connection or the presence of a valve. Cardiac catheterization was performed in 16 patients a mean of 14 months postoperatively (range 1 to 42 months) and revealed a reduced cardiac index at rest. Exercise testing in eight patients demonstrated a marked rise in right atrial pressure with a reduced rise in the cardiac index, even in those without functional limitations. With a mean follow-up of 2.3 years, 78% of patients were in New York Heart Association Class I, 17% in Class II, and 5% in Class III. We conclude that the Fontan procedure is an excellent operation in carefully selected patients with tricuspid atresia and other forms of complex congenital heart disease.     

The modified Fontan procedure: physiology and anesthetic implications.

The modified Fontan operation has gained wide acceptance as a functional corrective procedure for patients with CHD with single ventricle physiology. Long-term survival and palliation of symptoms are excellent with most patients able to lead normal lives. The absence of a pulmonary contractile ventricle means that the single ventricle is responsible for perfusion of both the pulmonary and systemic circulations. Elevated systemic venous pressure is required to overcome PVR and this state of systemic venous hypertension has a significant impact on the anesthetic and postoperative care of these patients.     

A staged Fontan approach in patients initially unsuitable for the primary Fontan procedure.

OBJECTIVE: To determine the efficacy of the Glenn procedure in terms of establishing the Fontan procedure. METHODS: Surgical results were investigated in 248 patients undergoing either the total or partial right heart bypass. Of these, the conventional and the bidirectional Glenn procedures were employed in 27 and 58 patients, respectively. RESULTS: Conversion to the Fontan circulation was attempted in 32 of 58 patients initially considered unsuitable for the Fontan circulation and undergoing the bidirectional Glenn procedure, with 2 operative deaths. Of the 27 undergoing the conventional Glenn procedure, 13 have undergone conversion with 2 deaths. Actuarial survival rate after the staged Fontan approach did not statistically differ from that after the primary Fontan procedure. Catheterization in 130 patients with the established Fontan circulation showed no significant differences in ejection fraction, end diastolic volume, and end diastolic pressure of the systemic ventricle, as well as in Cardiac Index, between the group of patients treated with the primary Fontan procedure and the group treated with the staged Fontan procedure. When achieving the bidirectional Glenn procedure, the size of the additional channel from the ventricles to the pulmonary arteries was correlated with the postoperative change in pulmonary arterial size, but such additional forward flow produced insufficient ventricular offloading in 9 of 16 patients with significant atrioventricular valvar regurgitation. CONCLUSION: The staged Fontan strategy has an advantage in patients with complicated circumstances. Whether the primary or the staged Fontan procedure was used, however, did not affect the Fontan circulation itself when once the Fontan circulation was established. The additional forward flow in the bidirectional Glenn physiology, if employed, should be appropriately adjusted, considering both the advantages and the disadvantages of the option.     

Results of the Fontan procedure for patients with univentricular heart.

One hundred twenty-four consecutive patients with univentricular heart undergoing the Fontan operation were reviewed. Patients with tricuspid atresia or biventricular heart with hypoplasia of one ventricle were excluded. Eighty-four patients had left ventricular morphology. Atrioventricular connection was double-inlet (n = 76), common (n = 29), absent left atrioventricular connection (n = 14), and absent right atrioventricular connection (n = 5). Actuarial survival was 77% (70% confidence limits, 73% to 81%) at 1 year, 66% (70% confidence limits, 60% to 72%) at 5 years, and 49% (70% confidence limits, 36% to 61%) at 10 years, indicating a continuing risk for premature death. Multivariate analysis identified preoperative ventricular function and hypertrophy as risk factors for survival. High postrepair right atrial pressure (greater than 15 mm Hg) emerged as a strong intraoperative predictor of survival. Logistic regression analysis of these factors predicts high probability of death for certain subgroups of patients after the Fontan operation. Forty-four percent (n = 53) of these original 124 patients are alive and in New York Heart Association class I at follow-up. Thirty-eight percent (n = 33) of survivors have worse ventricular function than preoperative. Long-term survival is disappointing. Certain identifiable subgroups of patients with univentricular heart have unacceptable risks for the Fontan operation and should have alternate management. High postrepair right atrial pressure is an ominous sign, and if it persists the Fontan should be fenestrated or taken down.     

Laparoscopic surgery in a patient with Fontan physiology

Laparoscopic surgery represents a significant advance in surgical technique, but a number of physiologic sequelae result from positioning and insufflation. These physiologic changes may be more significant in patients with complex congenital heart disease. We present the anesthetic management of a patient with Fontan physiology who successfully underwent two separate laparoscopic procedures.     

Coagulation abnormalities in patients undergoing myocardial revascularization.

One hundred patients were screened for hypercoagulability preoperatively and on the third, seventh, tenth, fourteenth, and twenty-first days postoperatively. Patients found to have hypercoagulability were treated with heparin, aspirin, and Coumadin. When the abnormality was present preoperatively, treatment was continued for the duration of the patient's life. Those patients in whom abnormalities developed postoperatively were given anticoagulants until cardiac catheterization 6 months following their operation. Twenty-four of the 100 patients had no coagulation abnormalities preoperatively or postoperatively. Fifteen patients were found to have abnormality prior to operation. Their predominant abnormality was low antithrombin III activity. Sixty-one patients became hypercoagulable postoperatively. Predominant abnormality in this group of patients was increased thrombin generation and increased platelet adhesiveness. Evaluation of patients in this study group revealed a decrease in the incidence of pulmonary embolism, an increase in the patency of vein grafts, and the elimination of anticoagulant therapy in 24 percent of the patients.     

Atrioventricular valve repair in patients with single-ventricle physiology: mechanisms, techniques of repair, and clinical outcomes

Significant atrioventricular (AV) valve insufficiency in patient with single ventricle-physiology is strongly associated with poor survival. Herein we discuss the etiology and mechanism of development of significant AV valve insufficiency in patients with single-ventricle physiology, surgical indication and repair techniques, and clinical outcomes along with our 10-year surgical experience. Our recent clinical series and literature review indicate that it is of prime importance to appreciate the high incidence and clinical effect of the structural abnormalities of AV valve. Valve repair at stage II palliation may minimize the period of volume overload, thereby potentially preserving post-repair ventricular function. Since 85% of the AV valve insufficiency was associated with structural abnormalities, inspection of an AV valve that has more than mild to moderate insufficiency is recommended because they are not likely to be successfully treated with volume unloading surgery alone.