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SummaryPurpose: Successful development of a vascular prosthesis lined with endothelial cells (EC) may depend on the ability of the attached cells to resist shear forces after implantation. The present study was designed to investigate EC detachment from extracellular matrix (ECM) precoated vascular prostheses, caused by shear stress in vitro and to test the performance of these grafts in vivo. Methods: Bovine aortic endothelial cells were seeded inside untreated polytetrafluoro-ethylene (PTFE) vascular graft (10 X 0.6 cm), PTFE graft precoated with fibronectin (FN), or PTFE precoated with FN and a naturally produced ECM (106 cells/graft). Sixteen hours after seeding the medium was replaced and unattached cells counted. The strength of endothelial cell attachment was evaluated by subjecting the grafts to a physiologic shear stress of 15 dynes/cm2 for 1 h. The detached cells were collected and quantitated. PTFE or EC preseeded ECM coated grafts were implanted in the common carotid arteries of dogs. Results: While little or no differences were found in the extent of endothelial cell attachment to the various grafts (79%, 87% and 94% of the cells attached to PTFE, FN precoated PTFE, or FN+ECM precoated PTFE, respectively), the number of cells retained after a shear stress was significanly increased on ECM coated PTFE (20%, 54% and 85% on PTFE, FN coated PTFE, and FN+ECM coated PTFE, respectively, p

Background: The chest cage is a common target for traumatic damage. Although relatively rare, it is considered to be a serious condition with significant reported mortalities. As most flail injuries are accompanied by severe extrathoracic injuries, it is often difficult to pinpoint a single injury responsible for the patient’s death. Aim: To investigate the factors related to mortality when flail injury is diagnosed. Methods: Data from the Israel National Trauma Registry between 1998 and 2003 included 11 966 chest injuries (262 flail chest injuries) out of a total of 118 211 trauma hospitalisations. Mortality figures were analysed to determine which factors, singly or in combination, influenced flail chest mortality. Results: Road crashes accounted for most flail injuries (76%). The total mortality was 54 (20.6%) of 262 patients with flail chest injuries. 13 (20.4%) of the deaths occurred soon after admission to the emergency room and 37 (68.5%) within the first 24 h. Mortality in moderate to severe injuries (injury severity score (ISS) 9–24) was 3.6% and that in critical injuries 28.5% (ISS >24). Mortality increased with age: 17% in those aged 65 years. Age remained a risk for inpatient death when adjusted for severity. Mortality in isolated unilateral flail injury was not more than 6%. Total mortality for traumatic brain injury (TBI) and flail was 34%. Flail, TBI and other major injuries increased the mortality to 61.1%. Conclusions: Advanced age is associated with higher mortality. Isolated unilateral bony cage instability infrequently leads to death in patients who make it to the emergency department but rather its combination with additional extrathoracic trauma.

Studies in myocardial ischemia and reperfusion have demonstrated damage to endothelium, impaired production and release of vasoactive substances such as nitric oxide, and marked alteration in endothelium-dependent relaxatin of the coronary vasculature. This study was designed to examine the cardioprotective effect of exogenous administration of L-arginine, a precursor of nitric oxide, during ischemia and reperfusion, particularly using oxygenated crystalloid cardioplegia.Seventy energy-depleted isolated working rat hearts were arrested by cardioplegia and subjected to 60 min normothermic global ischemia followed by 10 min nonworking and 30 min working reperfusion (Gr 1). L-arginine (3mM or 10mM) was added to the cardioplegic solution (Gr 2,3 respectively), reperfusion (Gr 6,7 respectively), throughout the experiment (Gr 4,5 respectively), and with Nw-nitro-L-arginine methyl ester (L-NAME), a competitive inhibitor of nitric oxide synthase (Gr 8).At 30 min of working heart reperfusion, compared to control all arginine containing groups (Gr 2-7) exhibited a significant improved recovery of cardiac output (64.7+/-21.2, 98.1+/-21.1, 90.9+/-11.7, 88.9+/-16.2, 83.1+/-7.4, and 90.8+/-10.6, mean +/- SD% Gr 2 to 7 respectively, vs Gr 1 36.3+/-20%, p0.01). Significant recovery improvement was observed also in other hemodynamic parameters (coronary flow, aortic peak pressure), as well as biochemical recovery assessed by O2 consumption ratio, release of lactic dehydrogenase at reperfusion and regeneration of ATP. The L-NAME group had a significant poorer hemodynamic and biochemical recovery. L-arginine had no effect on the preischemic hemodynamic parameters.These results support the cumulative data considering L-arginine as a cardioprotective agent in postischemic reperfusion injury.

Four collaborating centers pooled their results with the Sorin Bicarbon Bileaflet valve.Between 6/91 and 11/95, 431 patients, 235 males and 196 females, underwent valve replacement using the new Sorin prosthesis; age range: 16-88, mean 61.4 yrs.AVR - 206, MVR - 177, TVR - 1, DVR - 47. Additional procedures - 139: CAB -117, valve repair - 22. AV sizes: 19-27, MV sizes: 21-33.Thirty day mortality was 4.3%. Early complications included: CVA - 1.4%, +ve blood culture - 2%, reop for bleeding - 5%. Late complications: infective endocarditis - 2.3%, valve thrombosis - 0.2%, thromboemboli - 2.5%, major bleeding - 1.6%, reoperation - 3%, late deaths (all causes) - 4.3%. No structural deterioration has been reported with this valve and acceptable gradients have been observed. Hemolysis is negligible.Based on this intermediate experience the Sorin Bicarbon prosthesis is well-designed with good hemodynamic properties, and an acceptably low incidence of complications.

A solution for prolonged cold storage of the heart has been developed. The Jerusalem-Cape Town Solution (JCT) is an "intracellular" type cardioplegic solution and is formulated to (1) minimize hypothermic-induced cell swelling, (2) diminish intracellular acidosis, (3) prevent the expansion of the interstitial space during the reperfusion, (4) protect against oxygen free radical injury during early reperfusion, and (5) provide substrates for regenerating high-energy phosphates.With a Langendorff model, rat hearts were subjected to 15 minutes of perfusion with Krebs-Henseleit, 10 minutes of cardioplegic infusion and 20 hours of cold storage (5 degrees to 6 degrees C). Hearts were reperfused for 60 minutes and hemodynamic recovery was assessed. The hearts were assigned to three groups (eight hearts in each), according to the cardioplegic solution used: group 1, JCT; group 2, Bretschneider's HTK cardioplegic solution; and group 3 University of Wisconsin cold storage solution.After 60 minutes of reperfusion, the recovery of the coronary artery flow in group 1 (JCT) was significantly better than in group 2, and slightly better than in group 3 (64% +/- 8.9%, 47.2% +/- 11.6%, 52.5% +/- 19.9%, mean +/- SD, respectively; group 1 versus group 2, p0.01). The recovery of the left ventricular developed pressure (LVDP) was significantly better in group 1 compared with group 2 and group 3 (60.2% +/- 14.5%, 41.1% +/- 12.6% and 36.5% +/- 10.1%, respectively; p0.01). The recovery of the heart contractility expressed by the product of LVDP and the heart rate (LVDP x heart rate) was significantly higher in group 1 than in group 2 and group 3 (47.5% +/- 3.4%, 23.6% +/- 9.6%, and 28.7% +/- 8.3%, respectively, p0.001). In hearts stored for 12 hours in JCT or HTK, the recovery of the heart contractility did not differ significantly (73.4% +/- 12.7% or 70.8% +/- 30.8%, respectively). Modified reperfusion aimed to improve postischemic heart recovery did not bring significant changes in cardiac mechanical function but resulted in an increase in postischemic coronary artery flow recovery in hearts reperfused with amino acid-enriched buffer.The JCT solution is effective (as well as HTK) in preserving the ischemic hearts for up to 12 hours. It is superior to HTK or University of Wisconsin solution at 20 hours of isolated ischemic storage.

Successful development of a vascular prosthesis lined with endothelial cells (EC) may depend on the ability of the attached cells to resist shear forces after implantation. The present study was designed to investigate EC detachment from extracellular matrix (ECM) precoated vascular prostheses, caused by shear stress in vitro and to test the performance of these grafts in vivo.Bovine aortic endothelial cells were seeded inside untreated polytetrafluoro-ethylene (PTFE) vascular graft (10 x 0.6 cm), PTFE graft precoated with fibronectin (FN), or PTFE precoated with FN and a naturally produced ECM (10(6) cells/graft). Sixteen hours after seeding the medium was replaced and unattached cells counted. The strength of endothelial cell attachment was evaluated by subjecting the grafts to a physiologic shear stress of 15 dynes/cm2 for 1 h. The detached cells were collected and quantitated. PTFE or EC preseeded ECM coated grafts were implanted in the common carotid arteries of dogs.While little or no differences were found in the extent of endothelial cell attachment to the various grafts (79%, 87% and 94% of the cells attached to PTFE, FN precoated PTFE, or FN+ECM precoated PTFE, respectively), the number of cells retained after a shear stress was significantly increased on ECM coated PTFE (20%, 54% and 85% on PTFE, FN coated PTFE, and FN+ECM coated PTFE, respectively, p0.01). Implantation experiments in dogs revealed a significant increase in EC coverage and a reduced incidence of thrombus formation on ECM coated grafts that were seeded with autologous saphenous vein endothelial cells prior to implantation.ECM coating significantly increased the strength of endothelial cell attachment to vascular prostheses subjected to shear stress. The presence of adhesive macromolecules and potent endothelial cell growth promoting factors may render the ECM a promising substrate for vascular prostheses.

Between 1.6.1991 and 31.5.1995, 62 patients underwent heart valve replacement with Sorin Bicarbon bileaflet prosthetic valve, age 16-83 years (mean 60.5). The valve disease was rheumatic in 37 cases, degenerative in 17, congenital in 4 and miscellaneous etiologies in the other 4. The valve lesion was AS in 24 patients, AR in 5, AR+MS in 2, MS in 13, MR+MS in 6, MR in 6, tricuspid prosthetic stenosis in 1, A+M disease in 3, and a clotted prosthetic valve (Sorin disc) in 1. CAD was present in 14 patients (23%) and AF in 19 (31%). 11 had moderate pulmonary hypertension and 4 severe. Preoperatively 6 patients were in FC II, 40 in FC III and 16 in FC IV. Operative procedures included AVR 18, AVR+CABG 13, AVR+T annuloplasty 1, AVR and open M valvotomy 1, MVR 7, MVR+T annuloplasty 7, MVR+AVR (Medtronic) 1, MVR+AVR 1, TVR, prosthetic valve replacement 1, and MVR+CABG 1. Hospital mortality was 3 (4.8%) -- one due to ruptured A-V groove and two due to LoCO. Postoperative complications: LoCO necessitating IABP -- 3 patient; 3 transient CVA and 1 CVA with hemiplegia. One patient had aortic prosthetic valve endocarditis 18 months following the operation necessitating reoperation. Other cases were treated for positive blood cultures. One patient had CVA after anticoagulant were discontinued. 28 patients are in FC I, 22 in H, 4 in III and 1 in IV. 4 patients are lost to follow-up. These data suggest that the Sorin Bicarbon Prosthetic valve can be safely and effectively used for heart valve replacement.

Several observations provide some clues as to the possible mode of the regulatory action of thyroid hormone (TH) in the heart, indicating delayed action at the level of the nucleus and acute effects on the plasma membrane. Here we present evidence for a direct and rapid stimulatory effect of TH in the intact normal heart. In the isolated perfused rat heart, 3,5,3′-tri-iodothyronine (T3) produced a positive inotropic effect increasing both the left ventricular peak systolic pressure (P) and +dP/dt values, but had no significant effect on heart rate. This effect of T3 was: (1) very rapid in onset (starting after 15 s) and transient, increasing gradually to reach a maximum (80% above control) at about 20 min, and declining progressively 20 to 30 min later; (2) dose-related and biphasic, occurring at physiological concentrations as low as 1 pm (+dP/dt) and 10 pm (P), reaching a maximum at 1 nm, and decreasing at higher concentrations; and (3) thyroid hormone specific, as shown by the effects of several TH analogs (l-T3>l-thyroxine (T4)=d-T3>d-T4; 3,3′,5′-tri-iodothyronine (rT3), 3,5,-l-di-iodothyronine and dl-thyronine had no effect). The calcium blockers nifedipine and verapamil, at concentrations of 10−8–10−5 m given before or after the addition of T3 (10−9–10−6 m), inhibited the T3-induced increase in cardiac inotropic activity in a time- and dose-related fashion. We suggest that the acute effect of TH in the heart is plasma membrane-mediated and calcium-dependent. Journal of Endocrinology (1996) 149, 73–80

Ward blood cardioplegia (WBC) has recently been reported to improve myocardial protection in adult open heart surgery, especially in high risk cases. However, WBC has been reported to have some disadvantages including narrow safety margins concerning brain and kidney perfusion. We therefore modified our technique to utilize luke-warm blood cardioplegia (LWBC). We carried out 470 open heart procedures using luke-warm cardioplegia (anterograde + retrograde perfusion) from 1/2/1991 - 30/9/1992; 94 had LVEF30% and form the basis of this study. Other major risk factors in this group included:70 yrs - 26 patients, L main50% - 14 patients, emergencies - 11 patients, redo's - 3 patients. Eightyone patients underwent CAB only; 3 had additional MVR, 3 additional closure acute VSD of whom one underwent additional LV aneurysmectomy, one additional AVR; 4 patients underwent AVR only, and 2 MVR. Average number of grafts/patient for the 81 isolated CAB's was 4.5. IABP was necessary postbypass in 4 patients (9 emergencies were on IABP support at time of operation). Thirty day mortality was 3 patients (3.2%). Late mortality was 5 cases. These results are superior to those achieved using cold protection and warm blood cardioplegia. LWBC is a safe method for myocardial protection in patients undergoing CAB, particularly when LV function is severely compromised.

A study of the protective efficiency imparted by intermittent warm blood cardioplegia (WBCP) using perfused rat heart model.Hemodynamic parameters were monitored simultaneously with metabolic changes in high-energy phosphates using 31P-NMR spectroscopy. Following 30 min perfusion with Krebs-Henseleit (KH) buffer, all hearts were arrested for one hour (G1 and G2) and than reperfused with KH for 30 minutes. A warm oxygenated crystalloid cardioplegia (WCCP, modified St Thomas' hospital solution) was used for the control group (G1). The second group of hearts (G2) were arrested with oxygenated WBCP (K+ = 15 mM; Hct = 15-20%) and the third group (G3), was subjected to a protocol consisting of 4 periods (10 min each) of WBCP interspersed by 10 min of global ischaemia.The post-arrest percentage recoveries of LVDP, +dP/dt and HR were respectively: 88, 93 and 90 for G1 (n = 8); 97, 100 and 98 for G2 (n = 10); 76, 79 and 91 for G3 (n = 12). The corresponding metabolic recoveries of ATP and PCr were respectively, 85 and 90 for G1; 91 and 98 for G2 and 73 and 85 for G3. The PCr level declined during the arrest period in G1 contrasting with elevated PCr level (140%) during the WBCP arrest in G2. After an initial rise to approximately 140%, PCr level gradually decreased during the intermittent WBCP interval (G3).At normothermia, with equal CF rates, continuous WBCP provides better myocardial protection, through an effective oxygen supply, compared with WCCP. During the intermittent periods of ischaemia, certain metabolic and hemodynamic dysfunction occurs.

Dobutamine and Nitrate Radionuclide Angiography (RNA) may help to distinguish viable from nonviable myocardium and to predict revascularization effects on LV function.Ambulatory.Prospective.We studied 12 patients (11 male, 1 female; mean age 56 +/- 10 years) with three-vessel disease, severe LV dysfunction, and prior MI for a mean follow-up time of 10 +/- 3.4 months. Thallium-201 scintigraphy favored potential viability in all patients: inducible ischemia with satisfactory perfusion in more than one coronary arterial territory. Global and regional LVEF's were calculated from preoperative RNA (baseline rest study and with continuous dobutamine infusion with gradual rate increase plus oral nitrates) and postoperative RNA at 1 and 6 months.There was no operative mortality, but two late deaths occurred. Symptomatically, most patients showed improvement. Global LVEF increased during dobutamine and nitrates preoperatively (p0.01), but not at 1 and 6 months postoperatively (without pharmacological intervention). Mean LVED volume was not significantly changed postoperatively. Regional EF improvement was found in 4 out of 9 LV wall segments under dobutamine and nitrates, and this increase persisted postoperatively at 1 and 6 months.Mild but significant increase in global LVEF during dobutamine and nitrates administration is not predictive of postoperative LVEF improvement. However, regional EF improvement appears to be predictive of post-revascularization LV functional improvement.

Acute, massive pulmonary embolism is life-threatening and must be treated immediately. Since the early 1970's when thrombolytic therapy was shown to hasten resolution of pulmonary emboli, there has been a debate in the literature as to new indications for surgical pulmonary embolectomy. Some authors believed that there are no longer any indications for embolectomy, while others justify surgery for certain indications. Although the debate is still on, this operation is very rarely performed today. We present a patient who developed massive pulmonary embolism, with continuing extreme hemodynamic and respiratory disturbances despite full thrombolytic treatment. Embolectomy was successfully performed.

Low-porosity woven Dacron grafts have been used extensively as an extracardiac conduit in the surgical treatment of congenital and acquired heart diseases involving total heparinization. Caution is still warranted in their use, however, because of long-term complications, including calcification and development of obstructive fibrous peel. In contrast, high-porosity grafts offer much better tissue anchorage and healing but cannot be used under heparinization. We have developed a compound vascular prosthesis in which a knitted Dacron graft is coated with a polymeric biodegradable sealant. Polyethylene oxide-polylactic acid-segmented copolymers comprised the degradable component of the graft. In vitro studies showed that the coated prosthesis exhibited a highly flexible elastomer-like mechanical response. The prostheses were completely watertight, and significant degradation started after 1 week, with absorption completed after 3 weeks. Seven woven and six knitted polyethylene oxide-polylactic acid-coated Dacron grafts used as extracordiac conduits (16 mm), connecting the right ventricle and the pulmonary artery were implanted in dogs. The dogs were killed after 12 to 18 months, and the results are reported. Scanning electron microscopy examination showed peel detachment and nonhomogenous intimal surface with fenestrations in the woven graft group, but complete healing and incorporation of the pseudointima with homogenous, thin lining of the luminal surface in the polyethylene oxide-polylactic acid-coated group. Histologic studies indicated much superior healing and anchorage of the periprosthetic tissue and the pseudointima in the polyethylene oxide-polylactic acid-coated grafts. The biodegradable polymer was fully degraded and exhibited a complete incorporation of the compound vascular prosthesis. This study indicates the superior healing properties of these selectively biodegradable grafts, which might increase long-term patency and decrease complications of right ventricular conduits.

SUMMARY A method of general anaesthesia using thiopentone, nitrous oxide and oxygen, with full muscular relaxation, using suxamethonium, was employed in 120 patients undergoing bronchoscopy. After orotracheal intubation the lungs were ventilated by manual compression of the reservoir bag. This method was found to provide excellent conditions for the bronchoscopist Blood gas measurements in seven patients on samples taken before and at the end of bronchoscopy indicated that satisfactory pulmonary ventilation is obtained by this method.

Five selected cases of successful prolonged resuscitation (up to 16 hours) after open heart surgery are presented. Four had undergone prosthetic valve insertion, two being double replacements. External cardiac massage did not produce any demonstrable damage to the heart or the implanted valve prostheses, the competent prostheses probably assuring the haemodynamic effectiveness of the massage. Intermittent positive pressure breathing via an endotracheal tube providing 100% oxygen was begun immediately in all cases. The continuous monitoring of blood pressure through an intra-arterial cannula during resuscitation was of great value. It indicated the minimum amount of force that had to be applied to obtain satisfactory perfusion and enabled frequent arterial blood sampling for pH and blood gas analyses. Thus acidosis could rapidly and effectively be corrected. Comment is made upon the use of bretylium tosylate and chlorpromazine during resuscitation. The value of the continuous presence of a physician at the bedside of patients after open heart surgery and an aggressive, stubborn approach to cardiopulmonary resuscitation as long as vital signs are present is stressed.

Subvalvular pseudo-aneurysm is a rare and potentially lethal complication of aortic valve replacement. The demonstration of such pathology by cardiac catheterization should be considered an indication for surgery. Recommendations for prevention of this false aneurysm and for surgical repair of the left ventricular outflow tract are discussed in this case report.

This study was designed to test the effect of glucose and a formulation enriched with branched chain amino acids as additives to oxygenated crystalloid cardioplegic solution in the ischemic heart. Energy-depleted isolated working rat hearts were subjected to 68 minutes of normothermic global ischemia during which oxygenated cardioplegic solution was used to protect them. The hearts were then reperfused in the nonworking mode for 10 minutes and for a further 30 minutes in the working mode. The hearts were randomly divided into three groups, in which various oxygenated cardioplegic solutions were perfused. Group 1 (control) was subjected to modified St. Thomas' Hospital cardioplegic solution and groups 2 and 3 to the same solution with the addition of glucose (11.1 mmol/L) and glucose (11.1 mmol/L) and branched chain amino acids, respectively. Recovery of aortic flow, coronary flow, cardiac output, aortic pressure, adenosine triphosphate, creatine phosphate, and oxygen consumption was significantly better in group 2 than in group 1. In addition, recovery of aortic flow, coronary flow, cardiac output, aortic pressure, stroke volume, minute work, adenosine triphosphate, and creatine phosphate was found to be significantly enhanced in group 3. Release of adenine catabolites and lactic dehydrogenase from these hearts during postischemic reperfusion was significantly decreased. Thus, during global ischemia in the energy-depleted heart, the presence of glucose and branched chain amino acids in oxygenated crystalloid cardioplegic solution enhanced myocardial protection.

Left ventricular (LV) function was studied by echocardiography in 28 patients with volume overload of the LV before and after valve replacement. Of the 28 subjects, 19 had mitral valve disease (eight with mitral incompetence and 11 with mitral incompetence and stenosis) and nine patients had aortic incompetence. Patients with chronic mitral and aortic incompetence had marked LV enlargement with normal or slightly depressed systolic function; in those with acute mitral incompetence the degree of cardiomegaly was less and the state of LV function depended on the underlying cause of valvular incompetence. Valve replacement was followed by a decrease in LV end-diastolic volume and this occurred in the first week after operation. There was a gradual improvement in LV function in some patients, as measured by normalized mean velocity of posterior LV wall motion. Paradoxical septal motion occurred in many patients after operation but improved in the late postoperative period.

Large and small platelets are present in the bloodstream in nearly equal proportions and comprise about 30 per cent of the normal platelet population. The assumption that cardiopulmonary bypass may alter this platelet population distribution was investigated. Platelet volume distribution curves during and after cardiopulmonary bypass were examined in 12 patients undergoing various intracardiac operation by an electronic particle-sizing apparatus based on the Coulter counter. Mean platelet volume (MPV) was 8.6 +/- 0.7 cubic microns prior to cardiopulmonary bypass. Ten minutes after commencement of cardiopulmonary bypass the MPV decreased to 85 per cent of control levels. A further decrease, reaching a plateau at 75 per cent of prebypass MPV, was reached after 50 minutes on bypass. MPV returned to 87 per cent of prebypass levels 2 hours after discontinuation of cardiopulmonary bypass. Since it is known that platelet count is markedly reduced on cardiopulmonary bypass, a simultaneous 25 per cent decrease in MPV can be explained only by a highly selective disappearance of the large platelets from the circulation. As the larger platelets are younger and functionally more potent than the smaller ones, the selective disappearance of large platelets may thus provide an explanation for the observed alteration in platelet adhesiveness caused by cardiopulmonary bypass.

The protective effect of a branched chain amino acid (BCAA) formulation on the ischemic myocardium was determined in four groups of passively perfused normothermic (37 C) isolated rat hearts perfused with Krebs-Henseleit (KH) or KH + BCAA. Time to ischemic contracture was significantly increased by the infusion of BCAA compared with KH (19.4 +/- 2.3 vs. 15.9 +/- 1.7 min). In a second set of experiments, rat hearts were perfused with KH or KH + BCAA solution followed by 2 min of glucose-free KH buffer. After 17 min of ischemia, both groups were reperfused for another 15 min. Percent of pressure recovery was significantly better with KH + BCAA (90.1 +/- 8.4) than with KH (56.4 +/- 40.0). Percent +dP/dt (time derivative of pressure at contraction) recovery was also significantly improved with KH + BCAA (96.5 +/- 26.9 vs. 58.1 +/- 44.0). Furthermore, arrhythmias were minimized by BCAA. There was no difference in change of coronary flow between these two groups. Thus, BCAAs appear to protect the heart against myocardial ischemic injury and to delay the time to ischemic contracture, particularly in the depleted ischemic heart. BCAAs enhance postischemic pressure recovery and improve postischemic systolic and diastolic myocardial function.

This is a report of successful management of a traumatic rupture of the thoracic aorta in pregnancy. Both mother and daughter are alive and well 24 months after the injury. The various aspects of the surgical and supportive treatment are discussed.

Acute myocardial ischemia is a serious complication of percutaneous transluminal coronary angioplasty (PTCA). Between September 1981 and September 1985, 240 patients underwent 260 PTCAs at the Hadassah University Hospital. Thirteen patients (5%) developed signs of acute ischemia during or immediately after the procedure. In 10 patients (4.2%) emergency coronary artery bypass grafting was performed. The left anterior descending artery in nine cases and the right coronary artery in one case were occluded. In eight patients intraaortic balloon counterpulsation (IAB) was begun prior to surgery. On the average 1.8 grafts per patient were performed. Two patients who were transferred to surgery while being resuscitated died from myocardial rupture, one during surgery and the other 4 days postoperatively. Perioperative infarction rate was 50% (5/10). Six patients are angina-free 3 to 46 months postoperatively. Better patient selection, performance by an experienced team, early use of IAB, and immediate surgery might reduce the current periprocedure morbidity and mortality rate of PTCA.

We studied 40 patients with preoperative ejection fraction (EF) of 0.35 or less who underwent aortocoronary bypass. An average of 3.1 saphenous vein grafts per patient were inserted and revascularization was considered complete in 33 (82%) of the subjects in the group. Mean follow-up period was 29 months (range 12-65 months). Early mortality was 5% (2 patients) and there were 7 late deaths (3 cardiac and 4 non-cardiac). The 5-year cardiac actuarial survival rate was 74 +/- 13% (+/- SEM). Angina has improved in 29 (94%) of the 31 long-term survivors with 23 (74%) being totally asymptomatic. Twenty-two of the long-term survivors performed an exercise test at the end of their follow-up period. These tests revealed that bypass surgery in such patients results in significantly enhanced myocardial oxygen consumption with concomitant increase in effort level and duration. The exercise ability is probably directly related to the degree of revascularization.

Sixty patients underwent repair or replacement of the tricuspid valve, 58 for acquired and two for congenital lesions. In 59 of the cases, the tricuspid surgery formed part of multiple valve surgery. Preoperatively, 33 patients (55%) were in New York Heart Association class IV and 25 in class III functional capacity. The tricuspid valve was replaced in 42 patients and repaired in 18. Forty-seven patients (78%) survived operation, but 10 of these died during a follow-up period of two to seven years. Thirty-four of the 37 long-term survivors show marked improvement. Operative mortality was 26% for tricuspid valve replacement and 11% for repair; late mortality was 14% and 22%, respectively. It should be stressed that the tricuspid valve replacement group consisted of patients whose preoperative condition was worse and whose valvular pathology was more severe than that of those who had tricuspid repair. In view of this, and the better long-term results of tricuspid valve replacement, it is concluded that the procedure of choice for serious organic disease of the tricuspid valve is valve replacement.

Severe pathological changes in the cardiac valves are often observed at an early age in children in the developing countries. Mitral stenosis is best managed by closed commissurotomy. However, mitral insufficiency, aortic insufficiency and tricuspid lesions may lead to life-threatening hemodynamic effects which necessitate valve replacement. This differs from experience in the developed countries where surgery for rheumatic valvular disease is limited to the adult. Our experience includes 33 children aged 5 to 16 years. Twenty-four children underwent single valve replacement, eight had two valves replaced and one had triple valve replacement. All were classified Grade IV or late Grade III (New York Heart Association). Four children had to be operated on despite known rheumatic activity. Two children in shock and pulmonary edema underwent emergency operation. There were two hospital deaths and eight late deaths. Patients have been followed for up to eight years. Twenty children are now classified as Grade I and lead completely normal lives and the remaining three are classified as Grade II. Postoperative catheterization studies have documented improvement from severe preoperative hemodynamic changes to near normal values at rest after operation. The cardiothoracic ratio has decreased impressively. We conclude that the natural history of rheumatic heart disease in children with severely damaged heart valves is favorably modified by valve replacement.

In 13 patients, sternal closure was delayed at the end of open heart procedures. Seven patients underwent coronary artery bypass surgery (CAB), 5 valve replacements, and one left ventricular aneurysmectomy and closure of post myocardial infarction VSD. In all, primary closure of the sternum was considered impossible or inadvisable. The major indications for delaying sternal closure were: cardiac dilatation with tamponade-like behaviour upon attempted sternal closure (8 patients); intractable bleeding (2); intractable arrhythmia (1); insertion of mediastinal assist devices (3) and intraoperative non-cardiogenic pulmonary edema (1). In all, only the skin was closed. Delayed sternal closure (DSC) was performed 36-120 hours later on 10 of the patients, when their condition had stabilized. Nine patients are long term survivors. None of these patients has developed mediastinitis, wound infection, osteomyelitis or instability of the sternum. The judicious use of DSC in selected situations has several advantages: hemodynamic deterioration from pressure upon the heart may be prevented; a quick access to the heart in case of tamponade or intractable arrhythmia is obtained; insertion of mediastinal assist devices is facilitated. With careful technique the risk of infection is low.

Computer simulation was used to compare flow characteristics through Starr-Edwards and Björk-Shiley valves in the mitral and aortic positions. Pressure and velocity determinations were mathematically computed with the use of a model based on the recognition that blood is a non-Newtonian fluid. The results were displayed in two-dimensional graphic form. In both the mitral and aortic positions the Björk-Shiley prosthesis showed a more favorable laminar flow pattern, producing fewer eddies and smaller pressure and velocity gradients through the occluder. Computer simulation is a valuable adjunct in the comparative testing of the hemodynamic properties of artificial heart valves and offers several advantages over physical simulators.

Rheumatic valvular disease in children is common in underprivileged countries and often damages the tricuspid valve (in addition to the mitral and aortic valves). Fifteen children aged 12 to 16 years underwent tricuspid valve surgery. Fourteen were graded as Class IV disability; five were operated during rheumatic activity. The tricuspid valve was replaced in ten patients, four had annuloplastic procedures and one underwent tricuspid commissurotomy. There was one operative death and four late deaths. Eight of the ten long-term survivors are in Class I and the remainder in Class II functional ability. It may be concluded that in children who can be protected from additional bouts of carditis and thromboembolism, the surgical treatment of advanced multivalvular disease including the tricuspid valve is most rewarding, and dramatic clinical improvement with return to normal or near-normal hemodynamics may be expected.

Blood viscosity, hematocrit and plasma protein concentrations were determined simultneously in five different vessels of the systemic and pulmonary circulations, before and immediately after cardiopulmonary bypass and again after surgery. There was a reduction in all these measurements after bypass and a lesser reduction one day after operation. At any one stage, however, values in the pulmonary artery and pulmonary vein were not significantly different from those in the superior vena cava, radial artery and a peripheral vein.

The protective effect of hydrocortisone on the myocardium during anoxic arrest was investigated in nonworking, isolated rat heart preparations subjected to cardioplegia. In control preparations (no cardioplegia) there was no inotropic effect of hydrocortisone. After both 60 and 120 min of anoxic arrest, recovery of contractility in hearts treated with cardioplegia and hydrocortisone was significantly better than that of hearts treated with cardioplegia only--98 vs. 85%, respectively, at 60 min, and 100 vs. 87% at 120 min. The addition of hydrocortisone to cardioplegia solution apparently results in better protection of the myocardium during anoxic arrest.

Primary blast injury of the chest is a potentially lethal entity. Immersion blast is even more damaging than that incurred out of water. Illustrative cases of a group of patients injured by an underwater explosion are presented. The pathogenesis, clinical manifestations and diagnosis of the entity are described. Complications include arterial occlusion by air emboli, affecting the central nervous system and heart, and respiratory insufficiency and failure. Conventional management of respiratory failure with intermittent positive pressure breathing may further aggravate the air embolism. An attempt to circumvent this conflict with the aid of the membrane oxygenator and hyperbaric facilities is discussed. It is suggested that expeditious compression with oxygen in a one-man chamber might be the most favorable emergency measure, to be followed later by more extensive and definitive treatment in a major hospital equipped for such contingencies.

Thirty-nine patients received aortic valve replacement prostheses. The 19 patients who received Starr-Edwards (SE) caged-ball valve prostheses and the 20 patients who received Björk-Shiley (BS) tilting-disc valve prostheses were followed up for a mean period of 20 and 19 mo, respectively. The cumulative mortality rate was 5.3% in the SE group and 15% in the BS group. The clinical improvement was more remarkable in the BS than in the SE series. Major thromboembolic complications developed in three patients in each group, and two patients in each group developed infectious endocarditis. Tests for intravascular hemolysis indicated a higher rate in the SE than in the BS group. The serum haptoglobin levels were 39 +/- 22 and 102 +/- 63 g/dl (mean +/- SD), respectively (P less than 0.001). The hemoglobin level was 12.4 +/- 1.8 g/dl in the SE group and 13.4 +/- 0.6 g/dl in the BS group (P less than 0.03). The BS tilting-disc valve caused less hemolysis and the smaller size led to greater clinical improvement.

The malignant type of rheumatic fever rampant in the young in countries with poor socioeconomic conditions most commonly damages the mitral valve. Juvenile mitral stenosis in these regions is often encountered, and mitral commissurotomy in children is frequently carried out [1–4]. In most children, the closed approach is preferred, yieldieng excellent results (see chapter on “Closed mitral commissurotomy in children”) and necessitating less sophisticated surgical facilities. Furthermore, the demand for expert manpower and the financial outlay are significantly reduced - factors of considerable importance in the less affluent countries. Mitral insufficiency and certain cases of mitral stenosis considered unsuitable for closed commissurotomy must be managed by direct vision surgery using total cardiopulmonary bypass. The choice of operation, i.e., conservative repair or valve replacement, depends not only on the pathologic condition of the valve but also on the experience of the surgical team with a particular method. Results should be compared and conclusions drawn, bearing in mind that the ultimate aim of the surgeon is to relieve or alleviate suffering and prolong life.