Pregnancy and mechanical valve prostheses: a high-risk situation for the mother and the fetus

Thirty-eight women with mechanical valve prostheses had a total of 47 pregnancies. All patients were on oral anticoagulants before pregnancy. A high incidence of complications was seen in both the mothers and the fetuses. The rate of spontaneous abortion was 23.4% (11/47), and 2 of the 36 newborns had chondrodysplasia punctata. Three of the women (7.9%) had acute valvular thrombosis; 1 died after replacement of the thrombosed valve. Thus, the overall mortality for the series was 2.6%. More complications were observed in the fetuses and infants of women treated with oral anticoagulants during pregnancy than in women treated with heparin. However, the mothers had more complications with heparin anticoagulation. Neither heparin nor oral anticoagulants clearly proved superior as the anticoagulation regimen of choice for pregnant women with mechanical valves. Counseling before conception occurs and avoidance of pregnancy are recommended for women with mechanical valve prostheses because of the high risk of serious or fatal complications in the mother and fetus. Use of tissue valves in women of childbearing age who desire to have children also seems advisable, even with the possibility of having to undergo another operation as a result of degeneration of the valve tissue.     

Is there a suitable method of anticoagulation in pregnant patients with mechanical prosthetic heart valves?

A best evidence topic was written according to a structured protocol in order to identify the mode of anticoagulation that has the best safety profile for both the mother and the foetus in pregnant patients with mechanical prosthetic heart valves. A total of 281 papers were identified using the reported search, of which eight represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results are tabulated. The reported measures were foetal mortality, maternal mortality, congenital abnormalities and embryopathy, and maternal thromboembolic and haemorrhagic complications. The medical orthodoxy has warned of the combination of oral anticoagulation and pregnancy due to the well-documented warfarin embryopathy. Yet only one of the reported papers identified a greater incidence of foetal aberrations among warfarin use, with the highest reported rate being 6.4% and two of the assessed papers reporting no embryopathy at all. Foetal mortality with oral anticoagulation use ranged from 1.52 to 76%. All reported publications demonstrated a superior maternal outcome with warfarin use, with a range of thromboembolic events from 0 to 10% in comparison with 4 to 48% where heparin was used. Thus, it is concluded that warfarin is a more durable anticoagulant with a better maternal outcome despite it carrying a greater foetal risk. Although, in contrast to previous teaching, the risks of embryopathy are not the major drawback of oral anticoagulation. Heparin is consistently less effective, but may be preferred for the superior foetal outcome. Heparin usage during the first trimester reduces the foetal risk but is still associated with an adverse maternal outcome. While the focus for clinicians looking after pregnant women with mechanical heart valves may be to prevent maternal thromboembolic complications, the overriding concern for many women is to avoid any harm to their unborn child, even when this places their health at risk. Thus women with mechanical heart valves must be fully informed of the risks involved with different anticoagulation for an informed decision to be made.     

Management of anticoagulant therapy during pregnancy in patients with prosthetic heart valves

We describe two patients with Starr-Edwards mitral valve replacements who underwent pregnancy on oral anticoagulants and who were successfully delivered of live babies. The literature on pregnancy with prosthetic heart valves is reviewed. It is suggested that properly controlled oral anticoagulation should be continued until the onset of labour; the anticoagulant effect should then be reversed by an intravenous infusion of fresh-frozen plasma and the patient maintained on intravenous heparin injections six-hourly. Oral anticoagulants should be restarted immediately after delivery and the heparin withdrawn only when their effect has been re-established.     

Pregnancy in patients with prosthetic cardiac valve. A 10-year experience

Pregnancy after valve replacement has been considered hazardous because of maternal and fetal complications secondary to anticoagulant medication, in addition to basic myocardial problems. Of 229 females aged 15-45 years with prosthetic valve replacement, 37 (including 34 with Bj?rk-Shiley valve and anticoagulants) subsequently had a total of 47 pregnancies. Fullterm delivery of a normal infant was achieved in 40 cases. There were three premature births, two spontaneous abortions, one stillbirth and one ectopic pregnancy. The fetal mortality was 8.5%. Valve thrombosis developed in two cases, but surgical treatment was successful. Oral anticoagulants (acenocoumarin and dipyridamole) were continued throughout pregnancy. Heparin was substituted before labour began, but discontinued after delivery, when effective oral anticoagulation was resumed. Our experience showed that pregnancy in women with mechanical heart valve prosthesis and continued oral intake of anticoagulants is safe and successful in most cases.     

Prophylactic effects of systemic oral ephedrine in spinal anesthesia-induced hypotension during transurethral prostatectomy

OBJECTIVE: We investigated the prophylactic effects of systemic oral ephedrine in spinal anesthesia-induced hypotension during transurethral prostatectomy. MATERIAL AND METHODS: Sixty American Society of Anesthesiologists Grade II and III patients scheduled for spinal anesthesia were randomized into one of two groups. Patients in Group I (n = 30) received oral ephedrine 50 mg in addition to premedication whilst those in Group II (n = 30) received only premedication 30 min before spinal anesthesia. Pre-infusion values were measured in order to obtain baseline readings after oral ephedrine administration in Group I and after premedication in Group II. Systolic arterial pressure (SAP) and heart rate (HR) were recorded before and after infusion, during and 5 min after spinal anesthesia and intraoperatively. Hypotension was defined as SAP <100 mmHg and <20% of baseline value. Hypotension was treated with 3 mg ephedrine and bradycardia was corrected with atropine 0.5 mg, given as an i.v. bolus. RESULTS: SAP values were significantly lower in Group II during the spinal anesthesia, post-spinal and intraoperative periods (p < 0.0001). Fifteen patients received ephedrine in Group II and seven in Group I. Supplemental ephedrine was used at doses of 3.42 +/- 0.97 mg in Group I and 8.86 +/- 1.24 mg in Group II. The incidence of hypotension was halved in Group I compared to Group II (23.33% vs 50%, p = 0.003). Six patients received atropine in Group II because of severe bradycardia. Mean HR values were lower in Group II than Group I during the spinal anesthesia, post-spinal and intraoperative periods. CONCLUSIONS: We conclude that a prophylactic oral dose of ephedrine 50 mg is effective for minimizing and managing spinal anesthesia-induced hypotension during transurethral prostatectomy.     

Pregnancy in patients with mechanical prosthetic heart valves. Our experience regarding 98 pregnancies in 57 patients

Ninety-eight pregnancies in 57 patients with mechanical (ball or tilting disc) prosthetic heart valves are described. Sixty-one pregnancies developed in 36 patients with a mitral prosthesis, 12 pregnancies in 9 patients with an aortic prosthesis, 17 pregnancies in 10 patients with both mitral and aortic prostheses and 8 pregnancies in 2 patients with mitral and tricuspid prostheses. All patients were in I or in II NYHA class at conception and no significative change was noted during pregnancy. All the patients were treated with oral anticoagulant therapy at conception. Different kinds of antithrombotic and antiembolic prophylaxis were employed. There were 13 voluntary interruptions of pregnancy and 37 spontaneous abortions. In the 47 newborn 2 malformation complications (1 warfarin syndrome, 1 cleft palate) and 4 haemorrhagic complications (without sequelae) were noted. Two fatal thromboses of a mitral prosthesis occurred; systemic embolic complications were noted in 7 cases. These observations suggested different incidences of complications regarding the antithrombotic and anti-embolic prophylaxis. The authors point out the high risk of thrombotic and embolic complications and the low rate of successful outcome of pregnancy in these patients.     

A Swine model for long-term evaluation of prosthetic heart valves

BACKGROUND: The objective of this study was to develop a porcine model of mitral valve replacement (MVR) for long-term evaluation of prosthetic heart valves. METHODS: Sixteen 25-kg male Bama miniature pigs underwent MVR using St Jude Medical valve (21 mm). Each animal was allocated to an anticoagulation protocol after surgery (group I, s.c. heparin injection and warfarin (n = 8); group II, s.c. low-molecular-weight heparin and warfarin (n = 8)) and was followed for up to 20 weeks. Terminal studies were carried out on all animals having survived for more than 140 days or died. RESULTS: Fourteen animals survived for more than 1 month without signs of heart failure. One of group I animals died from haemorrhagic (haemopericardium) complications on the 9th postoperative day, and another animal of group I died on the 18th postoperative day because of valve thrombosis. CONCLUSIONS: Compared with other species, humans and pigs show remarkable anatomical and physiological similarities. This model is promising for long-term preclinical evaluation of prosthetic heart valves and evaluation of postoperative anticoagulant agents.     

Toward a better understanding of the hemodynamic effects of protamine and heparin interaction

Hemodynamic changes have been documented during protamine infusion into heparinized but not unheparinized pigs and suggest that a protamine-heparin interaction might be responsible. This hypothesis was tested in four groups of pigs by varying the dosage and order of administration of these two drugs: Group I (n = 9) received heparin (3 mg/kg) followed by protamine (3 mg/kg); Group II (n = 9) received protamine (3 mg/kg) followed by heparin (3 mg/kg); Group III (n = 9) received protamine (25 mg/kg) followed by heparin (3 mg/kg); and Group IV (n = 16) received protamine-heparin complex (protamine 3 mg/kg and heparin 3 mg/kg mixed immediately prior to injection). Systemic and pulmonary arterial pressures, systemic and pulmonary vascular resistances, left ventricular end-diastolic pressure, central venous pressure, cardiac output, and heart rate were measured before and at 1.0, 2.5, 5.0, and 15 minutes after protamine, heparin, or protamine-heparin complex infusions. Immediately following protamine infusion, Group I pigs exhibited transiently but significantly increased pulmonary artery pressure, pulmonary vascular resistance, systemic vascular resistance, and central venous pressure and decreased cardiac output with (Group Ib, n = 5) or without (Group Ia, n = 4) systemic hypotension. The fact that no hemodynamic changes occurred in Group II confirms that infusion of clinical doses of protamine produces no hemodynamic changes in unheparinized pigs. Protamine alone in high doses (Group III) produced hemodynamic changes similar to clinical-dose protamine reversal of heparin (Group I). This effect suggests that the presence of heparin in the circulation lowers the threshold for protamine-mediated hemodynamic responses. Infusion of heparin (3 mg/kg) into pigs 15 minutes after treatment with high (25 mg/kg) (Group III) but not clinical (3 mg/kg) (Group II) doses of protamine produced hemodynamic effects similar to clinical-dose protamine reversal of heparin (Group I), suggesting that a protamine-heparin interaction may be responsible. These results also suggest a rapid inactivation in vivo of clinical doses (3 mg/kg) (Group II) of infused protamine. Protamine-heparin complex formed in vitro (Group IV) also produced hemodynamic changes similar to clinical-dose protamine reversal of heparin (Group I), suggesting that formation of this complex in vivo may be the protamine-heparin interaction responsible. Protamine-heparin complex may well be a useful tool in further elucidating the full effects of protamine reversal of heparin.     

Preclinical assessment of a trileaflet mechanical valve in the mitral position in a calf model

BACKGROUND: The bileaflet valve is currently the mechanical replacement valve of choice. Though durable, it does not closely mimic native valve hemodynamics and remains potentially thrombogenic. METHODS: Prototype trileaflet valves (T1 and T2) were implanted in the mitral position in calves. Group I calves received either a T1 valve (n = 12) or a control bileaflet valve (n = 5); Group II, either a T2 valve (n = 7) or a control bileaflet valve (n = 5). Valve function, perivalvular leakage, and transvalvular pressure gradients were evaluated. Also, long-term prototype leaflet wear was evaluated in vivo in one Group I calf (502 days) and two Group II calves (385 and 366 days). Calves were euthanized and necropsied at study termination, and major organs weighed and examined. RESULTS: Valve function was excellent and hematologic parameters remained normal in all calves that survived to study termination. Mean peak transvalvular pressure gradients were 10 +/- 7 mm Hg for T1 valves, 6 +/- 3 mm Hg for T2 valves, and 12 +/- 4 mm Hg for bileaflet control valves. Clinically insignificant valvular regurgitation was observed in both prototypes. Explanted valves showed no thrombus-impaired leaflet motion, except in two T1-fitted calves and one T2-fitted calf. Major organs showed no evidence of clinically significant thromboembolic events. There were no other significant differences between the results of experimental and control groups. CONCLUSIONS: Prototype trileaflet valves performed safely and effectively in the mitral position in calves, even without long-term anticoagulation. This warrants their evaluation as an equivalent alternative to bileaflet valves.     

Deep-vein thrombosis in pregnancy. A case report

The incidence of thrombo-embolic complications in pregnancy varies between 2 and 5 per 1000 deliveries. Deep-vein thrombosis (DVT) is classically associated with pulmonary embolism and chronic venous insufficiency, which are leading causes of maternal morbidity and mortality. An accurate diagnosis of iliofemoral or calf vein thrombosis should be confirmed by either Doppler ultrasonography, impedance plethysmography or ascending phlebography. Full-dose continuous intravenous heparin for 5-10 days is the established method of therapy for acute DVT and pulmonary embolism occurring during pregnancy or in the puerperium. Thereafter, long-term treatment with self-administered subcutaneous injections of heparin in low doses is feasible and effective. During pregnancy, coumarin administration results in embryopathy as it readily crosses the placenta; it should be avoided until after delivery. In view of its safety and effectiveness, low-dosage intravenous heparin or heparin by subcutaneous injection seems to be the anticoagulant of choice for the expectant mother.     

Peripheral venous thrombophlebitis during pregnancy

The treatment of peripheral venous thrombosis during pregnancy presents difficult problems not encountered under usual circumstances. Since the coumarin derivatives are small molecules which readily traverse the placenta, hazards to the fetus have been considered a contraindication to the use of these drugs. Thrombectomy is usually followed by rethrombosis and is not recommended except for the massively swollen limb with impending gangrene. Femoral vein ligation seems suitable for the patient with calf thrombophlebitis seen early in pregnancy, in whom prolonged hospitalization for heparin therapy would be required. Non-operative treatment with bed rest for five to seven days and intravenous administration of heparin, which does not cross the placenta, is based on sound pathophysiologic considerations. A four and a half year experience with this form of therapy is presented. Heparin is continued post-partum until oral anticoagulants, begun at the time of delivery, become effective. Vitamin K antagonists are then continued for three to six months. Thrombophlebitis during pregnancy is infrequent despite the similarities in physiology to other states with a much higher incidence of thromboembolic disease (puerperium and oral contraceptive agents).     

Comparison of 5-, 10-, and 15-Point Laparoscopic Ovarian Electrocauterization in Patients With Polycystic Ovarian Disease: a Prospective, Randomized Study

Objective:

We compared 12-month pregnancy and live birth rates in patients with polycystic ovarian disease undergoing 5-, 10-, and 15-point laparoscopic ovarian electrocauterization.

Methods:

This was a prospective, randomized study performed at the Dabirashrafi Fertility and Endoscopy Research Center, Tehran, Iran. The study included 187 patients with polycystic ovarian disease who were randomly assigned to 3 groups. Group I comprised 67 patients whose ovaries received 5-point electrocauterization. Group II comprised 57 patients whose ovaries received 10-point electrocauterization. Group III comprised 63 patients whose ovaries received 15-point electocauterization.Laparoscopic ovarian electrocauterization with a unipolar current was used. The main outcome measures were 12-month pregnancy and live birth rates.

Results:

Patients were homogeneous for age, body mass index, and type and duration of infertility. Twenty pregnancies resulted in Group I, with a pregnancy rate of 29.9% (20/67) and a live birth rate of 20.9% (14/57). Eighteen pregnancies resulted in Group II, with a pregnancy rate of 31.6% (18/57), and a live birth rate of 28.1% (16/57).Thirty-three pregnancies resulted in group III, with a pregnancy rate of 52.4% (33/63), and a live birth rate of 47.6% (30/63). Comparison of Group III with Groups I and II revealed a statistically significant increase in pregnancies (P=0.016) and live birth rates (P=0.004).

Conclusion:

We recommend 15-point electrocauterization of ovaries in patients with polycystic ovarian disease.     

Long-term evaluation of bovine pericardial bioprostheses in young women

Objectives: To avoid the fetal and maternal risks associated with anticoagulant therapy during pregnancy, the use of bioprostheses has been advocated for young women with cardiac valve disease during the childbearing years. Several reports have suggested the probability of pregnancy-related accelerated structural valve deterioration (SVD). The aim of this study was to assess the effect of pregnancy and delivery on bovine pericardial bioprostheses. Methods: Between 1986 and 2004,13 female patients received 14 bioprostheses. The women were segregated into two groups based on whether pregnancy occurred during follow-up: eight in the Pregnant Group (Group P) (including one case who underwent two operations), and six in the Nonpregnant Group (Group NP). Result: Early mortality was not observed. Late mortality was 12.5% for Group P and 16.7% for Group NP. There were a total of ten valve-related reoperations (seven in Group P and three in Group NP); the major reason was SVD in 64.3% of the cases. Freedom from valve-related reoperation at nine years was 28.6% in Group P and 33.3% in Group NP (p=0.338). Overall time from primary surgery to reoperation was 111±24.7 months, with no significant difference between the two groups (p=0.615). The Group P of eight patients had 12 pregnancies: ten deliveries and two abortions. There were no maternal or neonatal deaths. Conclusion: Pregnancy did not significantly influence the incidence of SVD and reoperation. The bioprostheses appears to provide female patients with more opportunity for uncomplicated pregnancies, deliveries and normal children than mechanical valves.     

Anticoagulation for prosthetic heart valves during pregnancy: is low-molecular-weight heparin an alternative?

We report on the treatment failure of low molecular weight heparin (LMWH) for anticoagulation in a pregnant woman that underwent artificial mitral valve replacement 10 years prior to her pregnancy. Until she became pregnant warfarin was administered for anticoagulation, but due to the often mentioned increased risk for warfarin-induced maternal and fetal complications, at gestational week 5 the anticoagulation regimen was switched to subcutaneous application of low molecular weight heparin. At gestational week 24 our patient developed acute life-threatening pulmonary edema and hemodynamic instability due to acute mitral valve thrombosis and underwent emergency valve re-replacement with a biological porcine valve. She recovered uneventfully and gave birth to a healthy child at gestational week 35. In addition to our case presentation we review the sparse evidence in the literature regarding anticoagulation in pregnant women with mechanical heart valves and discuss the rational of different anticoagulation regimens with regards to maternal and fetal outcome. Special consideration is directed towards LMWH administration as an alternative to oral anticoagulation during pregnancy in women with mechanical heart valves.     

Increased prostacyclin and adverse hemodynamic responses to protamine sulfate in an experimental canine model

Prostanoid activity was correlated with the hemodynamic effects of protamine sulfate reversal of heparin in 24 dogs undergoing three different pretreatment regimens: Group I (n = 8) received saline, Group II (n = 8) received the thromboxane synthetase inhibitor U63,557A (30 mg/kg), and Group III (n = 8) received indomethacin (10 mg/kg). Pretreatment substances were administered as 5-min intravenous infusions 20 min before anticoagulation with intravenous heparin (150 IU/kg). Protamine sulfate (1.5 mg/kg) was subsequently given as a 10-sec intravenous infusion 30 min after heparin had been administered. Hemodynamic data, as well as prostacyclin (PGI2) and thromboxane (TxA2) activity in aortic, venous, and pulmonary artery blood samples, were assessed over a 30-min time period following protamine administration. Group III indomethacin pretreatment provided the most protection from declines in blood pressure, heart rate, cardiac output, venous oxygen saturation, oxygen consumption, and elevations in pulmonary pressures and was accompanied with actual declines in PGI2. Group II U63,557A pretreatment was associated with the most severe hemodynamic changes and the greatest increase in PGI2 (+576%). Elevated PGI2 correlated with hypotension at 1 and 3 min (P less than 0.01), as well as pulmonary artery pressure declines at all times following protamine reversal. TxA2 changes did not correlate with hemodynamic changes. Protamine's adverse hemodynamic responses were attenuated with cyclooxygenase blockade by indomethacin, but were worsened with selective TxA2 blockade with U63,557A. Excess arachadonic acid precursors in the latter setting may increase PGI2 production. This study, for the first time, raises the possibility that PGI2 contributes to the adverse effects accompanying protamine reversal of heparin anticoagulation.     

Preliminary result of an algorithm to select proper ventricular assist devices for high-risk patients with extracorporeal membrane oxygenation support.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is not suitable for long-term support because of its high incidence of complications. Conversion from ECMO to ventricular assist device (VAD) is reasonable, and we have developed a simple algorithm for selecting proper VADs for these ECMO-supported patients. METHODS: We converted 12 patients who were receiving ECMO support to VAD for bridge to transplantation. Group I (n = 6) was converted directly from ECMO to VAD. Group II (n = 6) underwent stage conversion. We added left atrial drainage to ECMO because of lung edema or marked left heart distension. We discontinued drainage after recovery of right heart function. Group II had more unfavorable risk factors for VAD before ECMO. RESULTS: Three patients (50%) in Group I received biventricular VADs. The other 3 patients were converted to left ventricular assist device (LVAD), but only 1 (16.7%) experienced successful conversion. We successfully converted 5 patients (83.3%) in Group II to LVAD without right VAD, and 4 of them could be weaned from the ventilator. The multiple-organ dysfunction score gradually improved in Group II despite additional surgery. Two patients in each group received heart transplantation and survived long term. CONCLUSION: Using a conversion protocol provides a good guideline for making decisions. According to the protocol, right heart and pulmonary function can be clearly assured before shifting to LVAD in these critical ECMO-supported patients.     

The effect of intravenous fixed-dose heparin during total hip arthroplasty on the incidence of deep-vein thrombosis. A randomized, double-blind trial in patients operated on with epidural anesthesia and controlled hypotension

Heparin was given in fixed doses intravenously during unilateral primary total hip-replacement operations in a prospective, double-blind trial to assess the effect on the incidence of deep-vein thrombosis. One hundred and fifty patients were randomly assigned to one of two groups before the operation. Twenty-four patients were excluded from the study, leaving 126 patients. Group I consisted of sixty-six patients who received saline solution intravenously, and Group II comprised sixty patients who received heparin. All patients had epidural anesthesia with controlled hypotension. Fixed doses of heparin were administered five minutes before the operative incision was made and every thirty minutes throughout the operation. Mean arterial pressures were maintained at between fifty and sixty millimeters of mercury in all patients. Ascending venography was done on the seventh day after the operation. The incidence of deep-vein thrombosis was 24 per cent (sixteen of sixty-six patients) in Group I and 8 per cent (five of sixty patients) in Group II; the difference is significant (p = 0.03). The intraoperative loss of blood averaged 220 +/- 79 milliliters in Group I compared with 269 +/- 109 milliliters in Group II. An average of less than one unit of blood was transfused for each patient in each group. Postoperatively, there was no difference between the groups with regard to the amount of drainage that was collected in a Hemovac device or the values for hematocrit.     

Reversal of depressed oxygen consumption accompanying in vivo protamine sulphate-heparin interactions by the prostacyclin analogue, iloprost.

Oxygen consumption (VO2) is known to be depressed 50 to 60% during protamine sulphate reversal of heparin anticoagulation. Accompanying this event are systemic hypotension, pulmonary artery hypertension and thrombocytopaenia. The effect of a pro-stacyclin analogue, iloprost, on protamine-induced changes in VO2 was assessed in this investigation. Three groups of anaesthetised adult mongrel dogs were studied: Group I--control subjects received i.v. normal saline infusions (n = 10); Group II--subjects received low-dose i.v. iloprost infusions (25-50 ng/kg/min) over 30 min (n = 7); and Group III--subjects received high-dose i.v. iloprost infusions (175 ng/kg/min) over 30 min (n = 7). All dogs initially received sodium heparin, 150 IU/kg i.v. Protamine sulphate, 1.5 mg/kg i.v., was subsequently administered over 10 s following the first 20 min of saline or iloprost infusion. Continuous measurements included: mixed venous (SvO2) and arterial (SaO2) oxygen saturation, arterial blood pressure, pulmonary artery pressure, heart rate and carotid artery flow (CaQ). Thermodilution cardiac output (CO) allowed calculation of VO2. Platelet counts were performed before and 3 min after protamine infusion. The VO2 declines in Group II and III subjects compared to Group I controls were markedly less. Maximum VO2 declines in Group I control dogs of -38.2 +/- 26.7% and Group II dogs of -34.1 +/- 36.8% at 75 to 90 s post-reversal contrasted to -2.9 +/- 31.9% in Group III animals at the same time interval. VO2 increases occurred 3 to 10 min after protamine exposure in Group III animals, as did attenuation of systemic hypotensive and pulmonary hypertensive responses in this group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Recent improvements in outcome with the Novacor left ventricular assist device.

BACKGROUND: The Novacor implantable, electrically powered, wearable, left ventricular assist device (LVAD) has been used as a bridge to transplantation at our institution since 1994. Recent changes in protocol have resulted in a decreased incidence of infections, thromboembolism, and mortality. METHODS: We reviewed the medical records of all 43 patients who received implantable LVADs at the Mount Sinai Medical Center. After 1998, a number of protocol modifications were instituted. Vascular grafts were changed from a low-porosity, woven polyester (Cooley) to a gelatin-sealed, knitted polyester graft (Vascutek), the devices were implanted pre-peritoneally rather than in the posterior rectus sheath, and extensive drainage of the chest and pre-peritoneal pocket was used. The following anti-coagulation regimen was used: low-molecular-weight Dextran for 1 day, initiated after chest tube drainage <50 cc/hour; then IV heparin for 10 to 14 days, beginning at 500 U/hour, slowly increasing partial thromboplastin time to 1.5 to 2 x control; and finally Coumadin, maintaining the international normalized ratio at 2.5 to 3.5. Daily aspirin, 325 mg, was begun on post-operative Day 7. We compared 22 patients who electively underwent surgery before the changes, Group I, with 18 patients treated thereafter, Group II. RESULTS: Groups I and II were well matched with regard to age (47 vs 44 years); cause of heart failure (idiopathic, 50% vs 44%; ischemic, 50% vs 56%), and duration of support (79 vs 76 days). The incidence of thromboembolic cerebrovascular events was significantly less in Group II (6%) than in Group I (23%), p = 0.025. The incidence of bleeding increased mildly in Group I. Pocket infections occurred in 27% of Group I patients vs 11% of Group II patients, p = 0.018. Only 2 patients (11%) in Group II died while receiving device support, vs 7 (32%) in Group I, p = 0.019. CONCLUSIONS: Our results indicate that pre-peritoneal implantation, use of a new generation of vascular grafts, extensive drainage, and a more restricted anti-coagulation regimen improve outcome after Novacor LVAD implantation for advanced heart failure.     

Pulmonary artery thromboendarterectomy: a comparison of two different postoperative treatment strategies

Pulmonary artery thromboendarterectomy (PTE) is a potentially curative surgical procedure for chronic thromboembolic pulmonary hypertension. It is, nevertheless, associated with considerable mortality caused by postoperative complications, such as reperfusion pulmonary edema (RPE) (i.e., pulmonary infiltrates in regions distal to vessels subjected to endarterectomy) and right heart failure (RHF). However, there are no reports about the influence of different postoperative treatment strategies on complications and mortality. Therefore, we compared two different treatment strategies. In Group I (n = 33), positive inotropic catecholamines and vasodilators were avoided during termination of cardiopulmonary bypass (CPB) and thereafter, and mechanical ventilation was performed with low tidal volumes < 8 mL/kg, duration of inspiration:duration of expiration = 3:1, and peak inspiratory pressures < 18 cm H(2)O. In Group II (n = 14), positive inotropic catecholamines and vasodilators were regularly used for termination of CPB and thereafter, and ventilation was performed with high tidal volumes (10-15 mL/kg) and peak inspiratory pressures up to 50 cm H(2)O. Hemodynamics, the incidence of RPE and RHF, duration of ventilation, morbidity, and mortality were recorded. Cardiac index was comparable before surgery (2.11 +/- 0.09 vs 2.08 +/- 0.09 L. min(-1). m(-2)) and 20 min after CPB (2.26 +/- 0.09 vs 2.60 +/- 0.20 L. min(-1). m(-2)). RPE occurred in 6.1% (Group I) versus 14.3% (Group II), and RHF was observed in 9.1% (Group I) versus 21.4% (Group II). Mortality was 9.1% (Group I) versus 21.4% (Group II). Thus, the avoidance of positive inotropic catecholamines and vasodilators in combination with nonaggressive mechanical ventilation after PTE was associated with a low incidence of RPE, RHF, duration of ventilation, and mortality after PTE. IMPLICATIONS: The avoidance of positive inotropic catecholamines and vasodilators in combination with nonaggressive mechanical ventilation was associated with a low incidence of reperfusion pulmonary edema and/or right heart failure after pulmonary artery thromboendarterectomy.