Comparison of two topical collagen-based hemostatic sponges during cardiothoracic procedures.

The need for topical hemostasis during cardiothoracic procedures continues to fuel the development of additional hemostatic products with a focus on minimizing cost and increasing efficacy. The efficacy of a recently approved collagen-based topical hemostatic agent (Hemostagene, Coletica, S.A., Lyon, France) was tested in a prospective randomized trial of 60 consecutive patients undergoing cardiothoracic surgical procedures. Comparisons to a control collagen sponge (Helistat, Integra Life Sciences, Inc., Plainsboro, NJ) were made and hemostasis was considered successful if bleeding was controlled in 10 min or less. We employed a unique hemorrhage grading scale to more closely assess the relative effectiveness of these different topical agents. Overall, Hemostagene and Helistat achieved a successful hemostasis rate of 75% and 77%, respectively, with no statistically significant difference. The Hemostagene sponge was deemed easier to handle when compared to control. During the study, neither of the products was associated with complications attributable to the topical sponge. In conclusion, Hemostagene had improved handling characteristics yet was equal to Helistat at topical hemostasis, adding an alternative to the topical hemostatic market.

Acute normovolemic red cell exchange for cardiopulmonary bypass in sickle cell disease.

A patient with sickle cell disease (hematocrit, 28.5%; hemoglobin S fraction, 79%), required mitral valve repair. Partial red cell removal and blood component sequestration with an autotransfusion device before cardiopulmonary bypass initially decreased the sickle red cell mass. This was followed by an acute one-volume whole blood exchange transfusion performed upon the initiation of cardiopulmonary bypass, resulting in a further reduction. Both techniques yielded fresh autologous plasma for use; sequestration yielded a platelet-pheresis product. Adequate postbypass hemostasis was demonstrated.

Automatic internal cardioverter-defibrillator patch erosion into the upper airway presenting as a cavitary lesion.

Erosion of an automatic internal cardioverter-defibrillator (AICD) patch into the lingular bronchus occurred 4 years after implantation; the erosion presented as a cavitary mass associated with hemoptysis and weight loss. On bronchoscopy to evaluate for suspected carcinoma, a cavity was entered through a bronchial defect and the AICD patch clearly identified. The complication was successfully treated with patch removal and fistula closure.

Relation of unstable angina and myocardial infarction to progression of coronary narrowing in patients undergoing coronary artery bypass grafting (utilizing an internal mammary artery).

We examined the relation of an ischemic syndrome with the progression of coronary disease early (<3 years) after multiple bypass grafting utilizing an internal mammary artery and saphenous vein grafts. Data indicate that an ischemic syndrome is associated with progression of native coronary disease distal to the graft or total occlusion of the saphenous vein graft in most cases.

Adverse effects of postoperative infusion of shed mediastinal blood.

BACKGROUND: Postoperative infusion of shed mediastinal blood has been used in an effort to decrease blood usage after cardiac operations. Recent experience has suggested that this practice may actually lead to a delayed increase in bleeding. METHODS: In a prospective, randomized study, 40 patients undergoing coronary artery bypass grafting with shed mediastinal blood collected in a cardiotomy reservoir were divided into two equal groups and studied during their first 4 hours in the intensive care unit. Shed mediastinal blood was directly infused in group I (n = 20), whereas in group II (n = 20), it was not. In group II, if a sufficient volume of red cells was present to allow processing (n = 5), washed red cells were infused. Variables studied before and after infusion were the amount of blood lost and infused, homologous blood transfused, complete blood count and differential, serum fibrinogen, fibrin split products, D-dimers, clotting factors, prothrombin time, activated partial thromboplastin time, thromboelastograms, plasma-free hemoglobin, complement factors C3 and C4, creatine kinase and its MB isoenzyme, and body temperature. RESULTS: After infusion of shed mediastinal blood, elevated levels of fibrin split products and D-dimers were found in significantly more patients in group I. The thromboelastogram index was normal in 76% of patients in group II but in only 12.5% in group I. Group I also had an increase in band neutrophils, a greater number of febrile patients, higher serum levels of creatine kinase, its MB isoenzyme, and plasma-free hemoglobin, and greater blood loss during hours 3, 4, and 5 in the intensive care unit. The volume of red cells in shed mediastinal blood (hematocrit, 9% to 10%) was small, resulting in clinically insignificant autotransfusion when infused directly, and insufficient for cell processing in most patients. CONCLUSIONS: These data support those in previous studies that direct infusion of shed mediastinal blood does not save substantial amounts of autologous red cells and can cause a delayed coagulopathy and other adverse effects that may be harmful to patients postoperatively.

Percutaneous tamponade of inadvertent transthoracic catheterization of the aorta.

During routine placement of a subclavian central venous catheter for cancer chemotherapy, a sheath was inadvertently placed into the aortic arch, through the left lung. We describe a technique for transthoracic compression of the aortic injury using the sheath in conjunction with an occlusion balloon catheter.

Transient ischemia cannot precondition the rabbit heart against postischemic contractile dysfunction.

BACKGROUND: The rat heart is preconditioned against postischemic contractile dysfunction by a brief period of transient ischemia before a prolonged ischemic period. However, the rabbit heart does not receive such cardio-protection from pretreatment with a single transient ischemia periods. We hypothesized that in the rabbit heart, a multiple cycle of transient ischemia is required to reach a threshold necessary to precondition against postischemic contractile dysfunction. METHODS: To test this hypothesis, we subjected isolated, perfused rabbit hearts to either one 5-minute transient ischemic period or three 5-minute transient ischemic periods followed by a 40-minute period of warm ischemia and 30 minutes of reperfusion. Control hearts (no pretreatment with transient ischemia) were examined simultaneously. Left ventricular developed pressure was measured with an intraventricular balloon. RESULTS: Postischemic recoveries (expressed as percent of preischemic values) of left ventricular developed pressure for the group with one ischemic period and the group with three ischemic periods were 43% +/- 5% (n = 5) and 38% +/- 6% (n = 6), respectively. These values were not significantly different from control values. CONCLUSIONS: Neither one nor three periods of transient ischemia protect the isolated, perfused rabbit heart from postischemic contractile dysfunction. Therefore, the rabbit heart may not have the capacity to be ischemically preconditioned against postischemic contractile dysfunction.

Simple technique of left heart bypass.

Left heart bypass is typically established by left atrial appendage cannulation. We report a technique using inferior pulmonary vein cannulation, which is technically simpler. We have used this technique in 20 cases with reliable venous inflow.

Attenuation of postischaemic dysfunction by ischaemic preconditioning is not mediated by adenosine in the isolated rat heart.

OBJECTIVE: The aim was to test the hypothesis that adenosine mediates the cardioprotective effects of ischaemic preconditioning in the isolated rat heart. METHODS: Transient exposure of the hearts to adenosine and the A1 selective agonist, PIA, were tested for the ability to mimic the cardioprotective effects of ischaemic preconditioning in hearts that underwent 40 min normothermic ischaemic followed by 30 min reperfusion. Treated hearts were perfused with 10 or 50 microM adenosine or 10(-7) M R-phenylisopropyladenosine (PIA) for 5 min followed by a 5 min washout period. Preconditioned hearts underwent 5 min of ischaemia and 5 min of reflow prior to the 40 min ischaemic period. The ability of the adenosine receptor antagonist, BW A1433U, to inhibit the cardioprotective effects of ischaemic preconditioning was also tested. The effects of these treatments on metabolite levels and postischaemic haemodynamic function were assessed. RESULTS: Adenosine (50 microM), but not PIA, resulted in enhanced accumulation of lactate after 40 min ischaemia: 122(SEM 8) v 96(5) nmol.mg-1 protein in control hearts (p < 0.002). Adenosine and PIA treatments did not significantly affect myocardial acidosis during ischaemia. Postischaemic contractile function (as assessed by percent recovery of the heart rate x developed pressure) was lower in 50 microM, but not 10 microM, adenosine treated hearts [8.8(2.2)] and PIA treated hearts [11.9(2.5)] than in control hearts [20.4(3.6)] (p < 0.01). Ischaemic preconditioning (1) lowered glycogen levels prior to the 40 min ischaemic period [57(6) v 110(18) nmol glucosyl units.mg-1 protein; p < 0.01]; (2) lowered lactate levels at the end of the 40 min ischaemic period [61(4) v 104(5) nmol.mg-1 protein]; (3) preserved myocardial pH during ischaemia [6.69(0.07) v 6.40(0.07); p < 0.01]; and (4) enhanced recovery of postischaemic contractile function [42.3(4.4)% v 19.7(6.0)%; p < 0.02]. BW A1433U did not prevent these effects of ischaemic preconditioning. CONCLUSIONS: The cardioprotective effects of ischaemic preconditioning are not mediated by adenosine released during the preconditioning period in the isolated rat heart. Also, transient treatment of the heart with A1 adenosine receptor agonists can exacerbate postischaemic contractile dysfunction.

Postischemic recovery of mitochondrial adenine nucleotides in the heart.

BACKGROUND: Adenine nucleotides (AdNs) are lost from the mitochondrial fraction of the heart cell during ischemia. It is unknown whether this pool of AdNs can be replenished after reperfusion. The purpose of this study was to evaluate the postischemic recovery of the mitochondrial AdN pool. METHODS AND RESULTS: The left anterior descending coronary artery (LAD) of the canine heart was occluded for 30 minutes followed by either no reflow, 30-minute reflow, 1-day reflow, or 7-day reflow. Systolic shortening in the LAD-supplied region was absent during occlusion but recovered to approximately 30% of preocclusion values during early reperfusion. Mitochondrial and tissue AdNs (ATP, ADP, and AMP) were determined in the LAD-supplied and left circumflex-supplied (control) regions of the heart. The AdN content (expressed as percent of control values) of mitochondria from the LAD region was 55 +/- 10% (p less than 0.002), 64 +/- 7% (p less than 0.001), 81 +/- 6% (p less than 0.03), and 94 +/- 8% for the no-reflow, 30-minute-reflow, 1-day-reflow, and 7-day-reflow groups, respectively. The AdN content (expressed as percent of control values) of tissue samples from the LAD region was 52 +/- 9% (p less than 0.002), 48 +/- 12% (p less than 0.02), 68 +/- 5% (p less than 0.002), and 70 +/- 9% for the no-reflow, 30-minute-reflow, 1-day-reflow, and 7-day-reflow groups, respectively. There was a good correlation between mitochondrial and tissue AdN (r = 0.95). Using initial exchange rates, adenine nucleotide translocase activities of mitochondria from the LAD and control regions were not significantly different. State 3 respiration of LAD mitochondria was depressed (approximately 25%, p less than 0.05) only in the no-reflow group. Acceptor control ratios of the LAD mitochondria were not significantly different from control values in any group. CONCLUSIONS: After 30 minutes of regional ischemia, postischemic restoration of the mitochondrial AdN pool occurs between 1 and 7 days; this restoration is preceded by recovery of respiratory and adenine nucleotide translocase functions. Although the abnormally low levels of AdN persist in the mitochondrial compartment during the early reperfusion period, postischemic contractile dysfunction cannot be explained by depressed mitochondrial respiratory activity.

Cardiac surgery for inmates in the Texas Department of Corrections.

All Texas prison inmates requiring hospitalization since 1983 have been transferred to a separate prison hospital adjacent to a tertiary care university hospital. We reviewed and analyzed the data regarding one major tertiary care service, namely cardiac surgery, to describe the rate of utilization of this service and its results. From January 1, 1984, to June 30, 1988, 73 inmates underwent 74 cardiac operations, 50 of which were coronary revascularizations. The age-adjusted rates of utilization for coronary artery bypass grafting were substantially higher for inmates over age 45 than for that described for the general population, whereas the utilization rates for valve surgery were comparable. There were no perioperative or late deaths, and 86% of the inmate patients are currently employed within the Texas Department of Corrections system or were employed at the time of their release. The utilization rates and the results of this representative tertiary medical care service for the state's prison population are comparable to those achieved in the private sector, and may have a substantial beneficial effect on inmate rehabilitation.

Intermittent ischemia produces a cumulative depletion of mitochondrial adenine nucleotides in the isolated perfused rat heart.

The purpose of the present study was to determine if repetitive myocardial ischemia would result in the cumulative loss of mitochondrial adenine nucleotides. Isolated perfused rat hearts were subjected to continuous or intermittent ischemia. A single 5-minute period of continuous ischemia did not result in a significant decrease in the mitochondrial adenine nucleotide pool; a single 10-minute period of ischemia resulted in a decrease of approximately 17%. Next, the adenine nucleotide content of mitochondria from preischemic and 30-minute continuous ischemic hearts was compared with two groups of hearts undergoing intermittent ischemia (both groups receiving a total of 30 minutes of ischemia). One group received three 10-minute episodes of ischemia interrupted by 5-minute periods of reperfusion (3 x 10-minute intermittent ischemia); the other intermittent ischemic group received six 5-minute episodes of ischemia interrupted by 5-minute periods of perfusion (6 x 5-minute intermittent ischemia). The mitochondrial adenine nucleotide content (expressed as nanomoles per nanomole cytochrome a) for the preischemic and 30-minute continuous ischemic hearts was 14.7 +/- 0.6 and 8.0 +/- 0.4, respectively. The mitochondrial adenine nucleotide content of the 3 x 10-minute intermittent ischemia group (8.5 +/- 0.5) was not significantly different from the 30-minute continuous ischemic group. The mitochondrial adenine nucleotide content of the 6 x 5-minute intermittent ischemia group (11.0 +/- 0.6) was significantly larger than that of the 30-minute continuous and the 3 x 10-minute intermittent ischemia groups (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood conservation in coronary artery bypass surgery: prediction with assistance of a computer model.

A computer assisted model was created with the data from 514 consecutive coronary bypass patients in order to predict the potential need of a blood transfusion. During this time period strict management protocols were used. In this series 261 (55.9%) patients were never and 46 (9.9%) were only intraoperatively transfused. Intra- and postoperative transfusions were necessary for 160 (34.2%) patients. Preoperative hematocrit, age, sex, and weight were the statistically significant parameters in the development of the model.

Viable cryopreserved aortic homograft for aortic valve endocarditis and annular abscesses.

Six consecutive patients with active aortic valve endocarditis, including 2 with extensive subannular aortic root abscess, were successfully treated with viable cryopreserved homograft aortic valve replacement. Two patients required extensive aortic root reconstruction with an appropriately trimmed aortic homograft to cover large abscess cavities. All patients showed resolution of infection with no perioperative mortality or clinically significant morbidity. Three patients had a minor degree of aortic insufficiency on postoperative echo-Doppler study. On follow-up at 6 to 48 months, all patients were in New York Heart Association functional class I. The resistance of the unstented homograft to infection makes it an attractive choice for patients requiring aortic valve replacement for active endocarditis. The results of surgical intervention in patients with extensive aortic root involvement may be further improved by the flexibility afforded by the homograft to be "custom-fit" to the abnormal aortic root and the ability to achieve secure abnormal aortic root and the ability to achieve secure valve fixation without use of prosthetic material.

Vascular sling with tracheomalacia: surgical management.

Surgical repair of pulmonary artery sling without concomitant correction of associated tracheal abnormalities has yielded poor results in the past. We combined vascular sling repair done during cardiopulmonary bypass through a median sternotomy incision with tracheopexy for severe associated tracheomalacia in 2 infants. Neither experienced substantial postoperative respiratory difficulties and both had patent vascular anastomoses at 1 year after repair, thus supporting this approach when this combination of lesions is present.