Thrombelastographic changes in OPCAB surgical patients

The purpose of this study was to determine whether thrombelastography could detect hypercoagulability in the off-pump coronary artery bypass (OPCAB) patient. Seventeen OPCAB and six cardiopulmonary bypass (CPB) patients were studied pre- and postprocedure, as well as on each of the first three postoperative days (POD). In the OPCAB patients, there was a small reduction in the postprocedure coagulation index (CI). This was followed by an increase in the CI on each of the next three POD, reaching a level exceeding the mean preprocedure CI by 2.32 units, indicative of a state of relative hyper- coagulability. The mean CI for the CPB patients decreased significantly in the postprocedure sample. Over the next 72 h, the CI increased to a level that nearly equaled the preprocedure ‘baseline’. We concluded that our study identified a state of relative hypercoagulability in the OPCAB patient 72 h after surgery. The mechanism of this hypercoagulation, as well as the clinical significance of this finding, is yet to be determined.

The role of echocardiography in mitral valve dysfunction after repair

The echocardiographer responsible for the intraoperative evaluation should be familiar with the transesophageal echocardiography (TEE) views of mitral valve morphology as well as the the repair procedure(s) in order to assess postoperative results. The most frequent immediate mitral valve repair failures are a result of extensive valve disease, calcification, suture dehiscence, ischemia, technical misadventures, stenosis, or systolic anterior motion. Systolic anterior motion with left ventricular outflow tract obstruction and an associated posteriorly directed jet of mitral regurgitation is the most common cause of immediate failure after mitral valve repair. The incidence of this potentially devastating complication has decreased dramatically since the introduction of preoperative measures (sliding annuloplasty and anterior leaflet valvuloplasty) in those patients at risk. Intraoperative TEE is extremely valuable in evaluating the competency of the mitral valve following repair. In fact the results of this modality have a predictive valve in determining long-term outcomes in these patients.

Anatomic lung resections using minimally invasive thoracic surgery (MITS)

We have designed a minimally invasive thoracic surgery (MITS), which, in this report, we compare to the conventional muscle-sparing thoracotomy (MST). We retrospectively compared 70 consecutive MITS patients (mean age, 65 years) and 70 consecutive MST patients (mean age, 60 years) who underwent thoracotomies for similar pathologies between 1995 and 1997. All comparisons between the MITS and MST groups were made using the Student's t-test. Extubation times, intensive care unit (ICU) stays, analgesia requirements, morbidities/mortalities, hospital lengths of stay (LOS), and cost analyses were all compared. Nine of the 70 planned MITS procedures were converted intraoperatively to MST. All nine of these patients were admitted to the ICU. All of the MST patients spent a minimum of 24 hours in the ICU. The mean LOS in the MITS group was 2.87 days with a mean hospital cost of 6,480.00 dollars, while in the MST group it was 8.28 days (P = 0.003) and 11,490.00 dollars (P = 0.006). There were no deaths and 6 complications in the MITS series. There were two mortalities and 15 complications in the MST patients. Our MITS procedure not only may be performed with low morbidity and cost, it also allows early ambulation and early hospital discharge.

Creative arterial bypass grafting can be performed on the beating heart

BACKGROUND

To demonstrate that compromise is unnecessary in either the design or performance of beating heart surgery, we report our experience, over 1 year, of total arterial revascularization where composite or creative grafting was utilized.

METHODS

We performed 321 off-pump coronary artery bypass operations, of which, 290 (90%) were done with only arterial conduits. The mean number of distal anastomoses was 2.48, with a range of 1 to 5. There were no aortic anastomoses. One hundred eighty-nine patients (65%) were male, and 101 (35%) were female, with a mean age of 67 years. Comorbidities included chronic renal failure (CRF), 21 (7%); diabetes, 92 (32%); obesity, 68 (23%); hypertension, 212 (73%); chronic obstructive pulmonary disease, 189 (65%); cerebral vascular accident (CVA), 39 (13%); smoking, 164 (56%); and hypercholesterolemia, 151 (52%). The mean ejection fraction was 56%, with a range of 21% to 71%. All procedures were performed with external stabilizers with or without vacuum assist. The complete arterial revascularizations included a T-graft (internal thoracic [ITA]/radial arteries [RA]), 130 (45%); a sequential graft (ITA +/- RA), 118 (41%); a U-graft (coronary-coronary graft perfused by the ITA or right gastroepiploic artery), 5 (2%); an I-graft (ITA/RA), 4 (1%); an X-graft (ITA/RA), 2 (12); and a Y-graft (ITA/RA), 31 (10%).

RESULTS

The postoperative incidence of atrial fibrillation was 80 of 290 (27%); CVA, 5 of 290 (2%); bleeding resulting in take-back, 5 of 290 (2%); CRF, 8 of 290 (3%); deep sternal infection, 4 of 290 (1%); and readmission (30-day) for angina, 4 of 290 (1%). The observed perioperative (30-day) mortality was 9 of 290 (3.1%), with the STS predicted rate of 3.82%.

CONCLUSIONS

Our experience indicates that once the operating surgeon has learned to safely expose the lateral and inferior walls of the heart, the type of conduit and the method of revascularization should be no different than that used with cardiopulmonary bypass. However, we still recommend conventional methods of revascularization (on-pump with saphenous vein conduits) for the ischemic patient.

Regulation of integrin-mediated adhesion by muscarinic acetylcholine receptors and protein kinase C in small cell lung carcinoma

STUDY OBJECTIVES

Improved understanding of the phenotypic characteristics of small cell lung cancer (SCLC) cells may facilitate the development of new therapies for this bronchogenic malignancy with early metastases. Herein we investigate whether activation of the M3 subtype of muscarinic acetylcholine receptor (mAChR) expressed on SCLC cells affects beta1-integrin-mediated adhesion of these cells.

DESIGN

Adhesion of the SCLC cell lines SCC-9 and NCI-H345 to extracellular matrix (ECM) proteins was investigated. Cell adhesion was quantified by labeling the cells with either toluidine blue dye and measuring optical density or 3H-thymidine and measuring beta-activity. Fluorescence-activated cell sorting was used to quantify the SCLC cell surface expression of beta1-integrins.

SETTING

Experiments were conducted in the Molecular Pharmacology Laboratory, Guthrie Research Institute.

MEASUREMENTS AND RESULTS

Activation of mAChR with the agonist carbachol (10 microM, 1.5 h) significantly increases adhesion of the SCC-9 SCLC cell line to the ECM proteins laminin and collagen types I and IV. In contrast, mAChR activation does not alter the adhesion of SCC-9 cells to vitronectin, fibronectin, poly-L-lysine, or bovine serum albumin. Carbachol also does not alter the adhesion of NCI-H345 SCLC cells that lack functional mAChR. Preincubation of SCC-9 cells with the AIIB2 blocking antibody to beta1-integrin inhibits mAChR-induced adhesion to ECM proteins. Immunofluorescence analysis indicates that mAChR activation does not alter the surface expression of beta1-integrins by SCC-9 cells. Direct stimulation of protein kinase C (PKC) by treatment with phorbol 12-myristate 13-acetate (PMA) (10 nM, 1.5 h) increases the adhesion of both the SCC-9 and NCI-H345 cell lines to ECM proteins. These results indicate that direct activation of PKC or stimulation of M3 mAChR (which results in increased PKC activity) increases the binding activity of beta1-integrins, resulting in increased adhesion of SCLC cells to ECM proteins.

CONCLUSIONS

The ability of mAChR to regulate SCLC proliferation and adhesion suggests that activation of these receptors may be used to alter SCLC tumorigenesis and metastasis.

Coronary artery bypass with "snake" grafts: fifteen-year follow-up

BACKGROUND

Since 1970 we have used the "snake" graft in more than 8000 cases of coronary artery bypass grafting (CABG). We followed, for over 15 years, 214 patients who underwent CABG in 1981 with only a "snake" graft by one surgeon (William H. Sewell, M.D.).

METHODS

Eighty-four percent (180/214) were male and 16% (34/214) were female with an average age of 58 and 66 years, respectively. The average left ventricular ejection fraction (LVEF) was > 55% in 63% (135/214) of the patients and < 55% in 37% (79/214); 15% (33/214) had diabetes and 77% (164/214) were smokers. The mean preoperative New York Heart Association (NYHA) functional class was 3.1+/-0.6 (range I-IV). Diagnostic arteriography demonstrated two vessel disease in 5% (9/214), three vessel disease in 89% (191/214), and left main disease in 6% (14/214). The average number of distal grafts per patient was 3.4. Coronary arteriography was performed 8-weeks postoperatively. Annual follow-up with a questionnaire determined incidence of redo procedures and survival.

RESULTS

The perioperative 30-day mortality was 1% (2/214). At 8 weeks there was a graft patency rate end-to-side of 85%, side-to-side 97%, and the proximal segment of 95%. Four percent (9/214) had redo surgery while 6% (13/214) underwent angioplasty during the 15 years. Sixty-seven percent (144/214) were alive at 15 years with a significantly improved mean NYHA functional class of 1.2+/-0.9 (p < 0.001). Twenty-four percent of those 166 live patients (35/144) had an average LVEF of 50% by echocardiography. There were 34 (16%) noncardiac deaths, 32 (15%) cardiac deaths, and 2 (1%) unknown causes.

CONCLUSIONS

The results of this study suggest that survival using the "snake" graft conduit is competitive with that observed using the internal mammary artery.

A coronary artery bypass "fast-track" protocol is practical and realistic in a rural environment

BACKGROUND

In this study we determine retrospectively whether assignment of all patients undergoing coronary artery bypass grafting to a "fast-track" protocol (FT) is practical and realistic in our rural institution.

METHODS

We compared the outcome of 266 consecutive patients undergoing coronary artery bypass grafting who were fast-tracked in 1996 with that of 266 consecutive patients who were managed conventionally (NFT) in 1994. The surgical techniques were comparable in both groups; however, FT anesthesia used inhalational agents and short-acting narcotics. All comparisons were performed using the Student's t test or the chi 2 test.

RESULTS

Postoperatively 95% of the FT group were extubated by 24 hours compared with 0% in the NFT group (p < 0.0001). The mean intensive care unit length of stay in the FT group was 1.7 +/- 0.8 days, whereas it was 2.6 +/- 0.6 days in the NFT group (p < 0.001). The mean postoperative length of stay was 6.4 +/- 1.2 days in the FT group compared with 7.5 +/- 0.9 days in the NFT group (p < 0.001). There were no significant differences in 30-day morbidity/mortality. There was a substantial cost savings in the FT group.

CONCLUSIONS

The fast-track protocol can be successful without any compromise of patient care. Early discharge from the hospital, however, is not always feasible.

Passive retrograde cerebral perfusion during routine cardiac valve surgery reverses middle cerebral artery blood flow and reduces the risk of stroke

BACKGROUND AND AIMS OF THE STUDY

Cerebral complications constitute a major source of morbidity and disability after cardiac valve surgery. These may be the result of macroembolization (air/debris) or inadequate perfusion pressure. In an attempt to reduce the incidence of cerebral vascular accident (CVA)/transient ischemic attack (TIA), we have routinely performed three minutes of passive retrograde cerebral perfusion (PRCP) on all valve cases. Here, we retrospectively determined our perioperative (0-30 day) incidence of CVA/TIA.

METHODS

In all cases, the extracorporeal circuit consisted of an ascending aortic cannula and either one two-stage or two single-stage venous cannulae. Three minutes of PRCP was instituted in all cases upon discontinuation of anterograde cardiopulmonary bypass (CPB) via a shunt distal to the heart/lung machine between the arterial and venous cannulae. Mean systemic blood pressure was maintained at 60 mmHg with Neo-Synephrine. Central venous pressure never exceeded 25 mmHg. In 10 cases, transcranial Doppler ultrasonography (TCD) was used to assess middle cerebral artery (MCA) blood flow. In total, 209 consecutive valve procedures with PRCP (group A) were compared with 164 consecutive valve procedures with no PRCP (group B). All data were compared using Fisher's exact probability test. The incidence of CVA/TIA was also compared with published retrospective and prospective data.

RESULTS

TCD demonstrated blood flow reversal in the MCA after a minimum of 30 s. The incidence of CVA/TIA was 0% (0/209) in group A, and 2.4% (4/165) in group B (p = 0.0386). The incidence of CVA/TIA in published retrospective data is 0.7-3.8% and 4.8-5.2% in prospective data.

CONCLUSIONS

We have demonstrated in 209 consecutive valve cases that, upon discontinuation of CPB, routine three-minute PRCP not only reversed MCA blood flow, but also reduced the incidence of neurologic events.

A modified thoracotomy for minimally invasive coronary artery bypass grafting

The optimal technique of minimally invasive coronary artery revascularization using the in situ internal thoracic artery (ITA), without extracorporeal circulation, is yet to be defined. To obtain adequate exposure for both ITA harvest and left anterior descending coronary artery anastomosis, an anterior chest wall defect is created which can be difficult to reconstruct. Based on the vascular anatomy of the acromiothoracic axis and three described osteocutaneous composite tissue flaps, we present a novel dissection that not only improves exposure, but also preserves chest wall integrity.

Acute dilutional anemia and critical left anterior descending coronary artery stenosis impairs end organ oxygen delivery

OBJECTIVE

Limited cardiac reserve, secondary to coronary disease, may be associated with end organ morbidity. In this study, we investigate the significance of anemia in the pathogenesis of this phenomenon.

DESIGN

Nonrandomized controlled animal trial.

SETTINGS

Animal laboratory in a university hospital.

SUBJECT

Anesthetized dogs. INTERVENTIONS/MEASUREMENTS: Fourteen anesthetized dogs underwent isovolemic hemodilution with 6% hetastarch from a baseline hematocrit of 40 to 20%. Radioactive microspheres were used to evaluate regional blood flow and cardiac index. Systemic oxygen delivery, consumption, serum lactate, and systemic vascular resistance were recorded during each experiment. Arterial venous oxygen difference was determined from arterial and mixed venous blood. Seven dogs had an iatrogenic critical stenosis of their left anterior descending coronary artery (experimental group); seven dogs did not (control).

MAIN RESULTS

Only in the control animals, the cardiac index increased by 35% with hemodilution to 20%. Systemic oxygen delivery decreased in both the control and the experimental animals. Systemic oxygen consumption and lactate levels were unchanged in both groups. In the renal cortex, spleen, distal colon, ileum, gallbladder, and stomach body, regional O2 delivery was significantly decreased with hemodilution to 20% in both groups. This finding was also observed in the left ventricle and cervical spinal cord in the experimental group. In addition, regional O2 delivery was reduced in the spleen, distal colon, and gallbladder with hemodilution to only 30%. Regional blood flow in the stomach body, gallbladder, ileum, renal cortex, and distal colon, in both groups, and the spleen in the control group was unchanged from baseline with hemodilution to 20%. However, regional blood flow under all other circumstances (control or experimental) was significantly increased with hemodilution to 20% with the exception of the spleen, which showed significant regional blood flow decrease in the experimental group only.

CONCLUSIONS

These data suggest that with limited cardiac reserve, anemia may compromise aerobic splanchnic circulation. These observations may further our understanding of the pathogenesis of cholecystitis, gastric stress ulcers, ileal endotoxin translocation, and ischemic colitis in critically ill patients with coronary artery disease.

A technique of positive-pressure single-lung ventilation via a silicone T-Y stent

Airway control and protection, in any operation, is the first priority. The presence of a T-Y stent in the proximal airway can complicate this fundamental principle. Here we describe an effective and safe technique for positive-pressure single-lung ventilation via a T-Y stent for a lung lobectomy.

Immediate hemodynamic effects of thrombolytic therapy on the ischemic myocardium

Thrombolytic agents are used to restore coronary artery perfusion and limit the size of a myocardial infarction. The systemic effects of these drugs, streptokinase (SK), urokinase (UK), and recombinant tissue plasminogen activator (rtPA), have been studied extensively. Although their effects on rheology and late myocardial performance have been well-documented to date, there have not been any studies evaluating the acute hemodynamic consequences of thrombolytics immediately after administration. In this report we use an isolated Langendorf rodent heart preparation to evaluate the acute hemodynamic effects of thrombolytic therapy on both the normal and the ischemic myocardium. We quantified performance by documenting cardiac output, coronary blood flow, and blood pressure. Although each thrombolytic agent significantly transiently impairs cardiac performance, differences in effect between the agents were statistically insignificant. This was also the case with both the normal as well as the ischemic myocardium. The results of this study would not support favoring the use of one of these agents over the other with regards to primary myocardial performance.

The effect of leukocytes on adhesion molecules. An explanation of blood transfusion enhancement of tumor growth

OBJECTIVE

To determine the mechanism of the adverse relationship between perioperative blood transfusion and lung cancer recurrence, by focusing on endothelial cell adhesion molecules (CAMs), which are thought to play a role in distant tumor cell implantation.

DESIGN AND OUTCOME MEASURES

Murine endothelial cells were cocultured with allogeneic leukocytes, syngeneic leukocytes, and syngeneic lung carcinoma cells for 60 hours. The percentage of endothelial cells expressing vascular CAMs (VCAMs) and intercellular CAMs (ICAMs) was quantified during this time using indirect immunofluorescence and flow cytometry. Tumor cell adhesion to the endothelium was quantified for 6 hours using cells labeled with sulfur 35 and a scintillation counter.

SETTING

Laboratory.

MATERIALS

C57/BL and Balb/C mice.

RESULTS

Vascular CAM was not expressed on the endothelium, but ICAM was preferentially expressed without stimulation. Tumor-cell adhesion and endothelial ICAM expression were inversely related. After 15 hours of coculture, tumor cell adhesion was four-fold greater in the experimental group than in the control, and coincident endothelial ICAM expression was fourfold lower.

CONCLUSION

Endothelial cell ICAM expression is negatively correlated with metastatic potential.

Migration of an automatic implantable cardioverter-defibrillator patch causing massive hemothorax

The automatic implantable cardioverter-defibrillator is composed of shocking electrodes (patches or coils), sensing electrodes, and a generator implanted in the abdominal wall. A number of complications with defibrillators have been reported, including migration of the various components. We describe a patient in whom one of the patches, originally sutured extrapericardially, migrated in the right hemithorax and eroded into the ipsilateral lung. The resultant massive hemothorax necessitated urgent thoracotomy, patch removal, and hematoma evacuation. A hybrid implantable cardioverter-defibrillator system was created as a replacement to minimize surgery while protecting the patient from sudden death.

Modulation of alloreactivity in transplant recipients by phenotypic manipulation of donor endothelium

Phenotypic manipulation of allograft endothelium to reduce immunogenicity would have a significant impact on transplantation. In this study we have demonstrated that random seeding of a heart allograft with endothelium, of host origin, not only promotes long-term survival, but reduces the requirement for pharmacologic immunosuppression. We propose that this simple technology could easily be extrapolated to the clinical arena where hypothermia and preservation solutions have allowed allografts to remain ex vivo for extended periods.

The haemostatic effectiveness of autologous platelet rich plasma sequestered after heparin administration and institution of cardiopulmonary bypass

Preoperative harvesting and postoperative reinfusion of autologous platelet rich plasma (PRP) has been reported to decrease blood loss as well as the requirement for homologous blood transfusion following cardiopulmonary bypass (CPB). We have developed a technique of intraoperative PRP sequestration which occurs during the initial period of CPB after the patient's circulation is supported and heparin has been given (PRP+). This process does not require any additional hardware, personnel or expense and it is performed without difficulty or complication. To evaluate the effect of PRP+ sequestration and reinfusion on blood loss and homologous blood requirement after CPB, we randomly assigned 126 consecutive patients undergoing elective open heart surgery into the experimental group 1 (PRP+) (n = 64) or the control (no platelet pheresis) group 2 (n = 52). A third group (n = 10) were not included in the randomization. Patients in group 3 had PRP prepared by conventional techniques (PRPc) prior to heparin administration and given to the patient after protamine infusion. Aggregation and activation studies were performed on the PRP+, PRPc, and blood bank platelets (BBP). Per cent aggregation of PRP in response to ADP was superior to that of BBP. There were no significant differences in ADP induced aggregation between PRP+ and PEPc. There was no significant difference in platelet activation (CD62) or number between the three groups. Patients infused with PRP+ showed significantly increased aggregation to ADP when compared with untreated patients 120 minutes after return to the ICW. Furthermore, more homologous haemostatic components (platelets/fresh frozen plasma) were required in the control group. We have demonstrated that collection of autologous PRP+ after administration of heparin does not interfere with its haemostatic effectiveness compared with PRPc prepared before the initiation of bypass. Moreover, this can be performed universally in haemodynamically unstable patients without any additional costs.

Alternative approach to the repair of a floppy anterior mitral valve leaflet

Increased exertional dypsnea developed in a 25-year-old female with a long standing history of a myxomatous mitral valve. Transesophageal echocardiography demonstrated left atrial and ventricular dilatation and no significant functional impairment. In addition, there was prolapse of a voluminous anterior mitral valve leaflet as well as prolapse of the posterior leaflet. To avoid the risks of long term anticoagulation therapy including fetal teratogenicity, efforts were made to repair rather than replace this degenerated valve. Here we report a new technique of anterior or mitral valvuloplasty complementing a quadrangular resection of the mural leaflet and a ring annuloplasty. The elliptoid excision of the redundant anterior leaflet resulted in a competent valve apparatus without any significant gradient. This technique would not apply, however, when the chordae tendinae to the anterior leaflet were significantly stretched as a result of the myxomatous process. In that situation the valve would be replaced with a prosthesis.

Cardiopulmonary bypass with adequate flow and perfusion pressures prevents endotoxaemia and pathologic cytokine production

Endotoxin and cytokine inflammatory mediators comprise the afferent and efferent limbs of the 'acute phase response'. During cardiopulmonary bypass (CPB) there may be gut translocation of endotoxin and contact activation of lymphocytes. It has been hypothesized that the haemodynamic instability encountered following CPB is caused by the 'acute phase response'. In this study we attempted to quantify the acute phase response in patients undergoing open-heart surgery and determine the influence of these cytokines on perioperative morbidity. Four perioperative blood samples were drawn from 20 consecutive patients undergoing coronary artery bypass grafting (CABG). These samples were assayed for endotoxin and four cytokines. In all cases the cardiac index was maintained > 2.4 l/min/m2 during nonpulsatile normothermic bypass (37 degrees C) and > 1.8 l/min/m2 during nonpulsatile hypothermic bypass (28 degrees C), and the perfusion pressure > 60 mmHg. Endotoxin was not detected in any of the test samples despite positive nonpatient controls. Interleukin 6 (IL-6) and tumour necrosis factor (TNF) were not detected despite an assay sensitivity of 80 and 10 pg/ml, respectively. TNF was detectable with an assay sensitivity of 0.5 pg/ml although there were no significant differences within the group. Interleukin 1 (IL-1) was detected (range = 0.98 - 9.09 ng/ml) in patients and again there were no trends within the group. The platelet activating factor (PAF) values peaked at crossclamp release (1.3 ng/ml versus a baseline of 0.2 ng/ml); however, there was no significant difference within the study.

Thoracentesis and chest tube drainage

Thoracentesis can be used as both a diagnostic and a therapeutic tool. Tube thoracostomy can be life saving. Each technique requires familiarity with the principles of pulmonary and pleural anatomy and physiology. It is mandatory that all pulmonary and critical care practitioners be familiar with the indications, benefits, and risks of these interventions to prevent devastating complications.

Management of massive pulmonary thromboembolism complicating diabetic ketoacidosis

Intravascular volume depletion secondary to diabetic ketoacidosis may result in thrombosis of major blood vessels. Without anticoagulation these thrombi can embolize to the lungs and compromise cardiopulmonary function. When this occurs early surgical pulmonary embolectomy is indicated to salvage a failing right heart.

A case of retrograde jejunoduodenal intussusception caused by a feeding gastrostomy tube

A case is presented of migration of a gastrostomy feeding tube (Foley type) through the pylorus with duodenal obstruction and subsequent retrograde intussusception. Although feeding tube migration is not uncommon, retrograde intussusception of the jejunum into the duodenum is rare. In this case, surgery was required with resection of a segment of necrotic bowel. Recommendations are given for treatment of this unusual complication with emphasis on its avoidance through use of a retaining bar or disc at the tube's skin exit site.

Application of the popliteal lymph node assay to evaluate an immunosuppression protocol

There exists a variety of experimental techniques which are used to evaluate host immunity. None of these in vitro assay systems are optimal, since they are performed ex vivo. Here is described an in vivo model, using four rat strain combinations and a modification of the popliteal lymph node assay, which quantifies the immune response to blood transfusion, in a sensitive and reproducible fashion. The subcutaneous injection of a 5 x 10(5) or 10 x 10(5) (depending on the rat strain) X-irradiated allogeneic lymph node cells into the hind footpad of a rat results in an increase in the weight of the draining popliteal lymph node harvested 7 days later. Injection of 100 x 10(5) X-irradiated cells results in the maximum nodal enlargement (fourfold). A dose of 50 x 10(5) cells results in lymph node enlargement just shy of maximum and so was selected for use in all experiments. When 50 x 10(5) nonirradiated allogeneic lymph node cells are injected, there is up to an eightfold increase in nodal size. To eliminate the effects of non-specific inflammation, as well as variation in node weights, a stimulation index (SI) was established. Transfusion of a rodent with blood from the same strain as the lymph node donor, 1 week prior to subcutaneous injection, resulted in a significantly lower SI, compared to the SI observed in untreated animals challenged with the same inoculum or third-party controls (P < 0.05). The significance of all comparisons was assessed by the Students' t test. This simple method of in vivo quantification of the immune response has obvious application to the evaluation of any experimental immunosuppression regimen.

Prognosis and management of anterolateral myocardial infarction in patients with severe left main disease and cardiogenic shock. The left main shock syndrome

BACKGROUND

To identify the determinants of survival in patients with severe (> 75%) stenosis of the left main coronary artery (LM) and an acute (48 hours) anterolateral myocardial infarction (AAMI), we retrospectively analyzed the course of 34 such patients who presented to our institution over the last decade.

METHODS AND RESULTS

LM disease was diagnosed arteriographically at presentation, and AAMI was determined by ECG, enzymatic, and kinetic criteria. Of the nine patients (26%) managed medically, seven patients (78%) were in cardiogenic shock (cardiac index < 2.0, left ventricular end-diastolic pressure > 25, and pulmonary edema), and all seven died in hospital. Twenty-five (74%) of the 34 patients were managed surgically or with angioplasty. Nine of these patients, of whom eight were in cardiogenic shock, also died in hospital. Regardless of the method of treatment, the presence of cardiogenic shock in this population was reproducibly a grave prognostic indicator. That is, 15 (94%) of the 16 patients in cardiogenic shock at presentation died in hospital, and only 1 (5%) of the 18 patients without cardiogenic shock died (P < .001).

CONCLUSIONS

Thus, we propose that, because patients presenting with AAMI, severe LM stenosis, and cardiogenic shock (left main shock syndrome) have such a grave prognosis regardless of management, conservative measures may be indicated.

Intraoperative procurement of autologous fibrin glue

A method of intraoperative procurement of autologous fibrin glue is described. The relative efficacy of our autologous preparation is compared with that of fibrin glue made with homologous cryoprecipitate. Experimentally, the fibrinogen content and the strength are less than those found in cryoprecipitate and appear related to the fibrinogen content of the autologous plasma used as substrate in the fibrin glue reaction. Clinically, no significant differences are noted in the performance of autologous fibrin glue. We believe the absence of the risk of blood-borne infection with the autologous product is a major advantage.

Delayed presentation of a mitral annular perforation complicating Staphylococcus aureus infective endocarditis

This report describes a patient who presented with congestive heart failure secondary to a mitral annular-left atrial fistula. There was a remote history of Staphylococcus aureus endocarditis involving the mitral valve which was treated medically 30 years previously. The sterile fistula was managed surgically with an annuloplasty.

Primary hypertrophic pyloric stenosis in the adult

Analysis of 100 consecutive patients with pyloric outlet obstruction revealed that 37% of the obstructions were secondary to peptic ulcer disease and 42% were caused by malignant neoplasm. Only a single patient with primary hypertrophic pyloric stenosis was identified, and whether this lesion is a cause or effect of peptic ulcer disease remains unclear. Similarly, the association of this entity with congenital pyloric stenosis is unknown.

The relative roles of major and minor histocompatibility antigens in the induction of immunologic unresponsiveness by blood transfusion

Renal allograft survival may be prolonged indefinitely in some strains of rats following preoperative transfusion with whole blood from the organ donor. Similarly donor-specific transfusion results in a reduction in the proliferative response of lymph node (LN) white cells (WBCs) to donor-specific stimulators in mixed-lymphocyte culture (MLC). To determine the relative roles of major and minor histocompatibility antigens in the depression of the proliferative response, in vitro lymphocyte proliferation assays were performed using congenic rat strains as blood donors. Unidirectional MLCs were set up between haplotype-disparate responder and stimulator LN cells, in cases in which the responding cells had been harvested from rats transfused with blood that shared either some, all, or none of the major histocompatibility complex genes with the stimulator strain. The proliferative response of LN cells harvested from rats transfused with blood sharing major (class I or II) or minor antigens, or both, with the in vitro stimulator cells was significantly less than the response of cells harvested from nontransfused controls. No single-locus product was more or less effective than whole blood in depressing cell proliferation. These data suggest that the beneficial effect of preoperative random blood transfusions observed in clinical transplantation may arise from the fortuitous sharing by the blood donor and the subsequent organ donor of not only a single major histocompatibility antigen but also of minor histocompatibility antigens.

Mediation of the induction of immunologic unresponsiveness following antigen pretreatment by a CD4 (W3/25+) T cell appearing transiently in the splenic compartment and subsequently in the TDL

We have previously demonstrated in a rat renal allograft model, using adoptive transfer studies, that a single blood transfusion results in the generation of blood donor-specific W3/25+ (CD4) T suppressor cells detectable in the thoracic duct lymph, but not in the spleen, 7 days after transfusion. In this study, again using the LEW-to-DA strain combination, we have investigated the time of appearance of suppressor activity in different lymphoid compartments in vivo and in vitro following a single blood transfusion. Cells (5 x 10(7) unfractionated TDL or 1 x 10(8) unfractionated spleen cells) were harvested from DA rats on days 1-6 after a single LEW blood transfusion and were adoptively transferred into syngeneic (DA), lightly irradiated (200 rads) hosts. The following day these animals received a kidney allograft (LEW or PVG). Specific suppressor activity, as demonstrated by the prolongation of survival of LEW, but not PVG, renal allografts was noted in the spleen 4 days after transfusion (MST greater than 100 days). Suppressor cells were not found in the TDL at this stage--but 6 days after transfusion suppressor activity could be detected in the TDL (median survival time [MST]greater than 100 days), while at this time no such activity was demonstrable in the spleen. The suppressor activity in the spleen on day 4 after transfusion was shown to be mediated by a W3/25+ (CD4) T cell. The proliferative response in a mixed lymphocyte culture of DA spleen cells, prepared 4 days after transfusion, or TDL cells prepared 6 days after transfusion, to LEW stimulator cells was significantly suppressed when compared with the response of cells harvested from untreated controls. In contrast, the proliferative response of spleen cells examined 6 days after transfusion, when no suppressor activity was detected in vivo, was significantly augmented in comparison with untreated controls. Thus we have demonstrated that a DST results in the generation of W3/25-positive (CD4) T cells capable of suppressing renal allograft rejection that appear transiently in the splenic compartment (4 days after transfusion) and subsequently in the TDL (six days after transfusion).

Mediation of antigen-induced suppression of renal allograft rejection by a CD4 (W3/25+) T cell

The mechanism of induction of specific immunosuppression by preoperative donor-specific blood transfusion in the rodent remains unclear. In a previous study we demonstrated that a single LEW blood transfusion in a DA rat results in the generation of donor-specific suppressor cells in the lymph node and thoracic duct lymph, detectable both in vivo and in vitro 7 days after DST. In contrast, no such activity was found in the splenic compartment. In this study lymphoid cells were harvested from either untreated DA rats or DA rats transfused 7 days previously with LEW blood and purified by rosette depletion using appropriate monoclonal antibodies. The purified lymphocyte subpopulation from transfused rats, of splenic or TDL origin, was adoptively transferred into syngeneic, lightly irradiated (200 rads) DA rats, where the adoptive transfer of 4.25 x 10(7) T (OX12-negative) cells (98.9% pure) or 2.5 x 10(7) CD4 (i.e., W3/25-positive, OX8 and OX12-negative) cells (97.9% pure), both of TDL origin, resulted in the indefinite survival of a LEW kidney (median survival time [MST]greater than 100 days), but not a PVG kidney (MST = 11 days). In contrast lymphocytes of splenic origin, regardless of the phenotype, did not prolong graft survival. Thus we have phenotypically characterized a CD4 (W3/25+) T suppressor cell that is generated after a single DST and is detectable 7 days later in the TDL but not the splenic compartment. Although there was no significant difference in the lymphocyte subset composition of lymphoid organs from transfused and untreated hosts, as determined by flow cytometry, the mean channel fluorescence of the lymphocyte population markers of cells harvested from transfused animals was significantly less than that observed with untreated controls, a finding which remains unexplained.

Transfusion induces blood donor-specific suppressor cells

Transfusion with blood from the organ donor before transplantation can prolong the survival of renal allografts in the rat. To determine if the beneficial effect of preoperative blood transfusion was due to the generation of donor-specific suppressor cells, in vivo and in vitro adoptive transfer experiments were performed. Lymphoid cells were harvested from transfused and untreated rats. These cells were then either (1) transferred to lightly irradiated (200 R) syngeneic hosts which were subsequently challenged with a kidney allograft (in vivo assay) or (2) titrated as regulator cells into naive unidirectional MLC such that the regulator and responder populations were syngeneic. In the LEW-RT1 to DA-RT1av1 strain combination, the adoptive transfer of thoracic duct lymph (TDL) or lymph node (LN) cells (5 x 10(7) to 7.5 x 10(7) cells) from DA animals transfused with LEW blood, 7 days previously into syngeneic (DA), lightly irradiated (200 R) hosts resulted in the indefinite survival of LEW kidney allografts. The phenomenon was blood donor-specific and dose-dependent. In contrast the adoptive transfer of spleen cells (10(7) to 10(8] from blood transfused hosts 7 days after transfusion had no effect on renal allograft survival. In vitro the addition of LN or TDL regulator cells, harvested from DA rats transfused with LEW blood, to a unidirectional MLC (DA responders, LEW stimulators) resulted in a significant depression of the proliferative response when compared with the proliferation of these same cells without the addition of these regulator cells or with the addition of LN or TDL regulator cells from a DA rat transfused with third party (PVG-RT1c) blood. The depression of the proliferative response observed in vitro, was blood donor specific. When LN or TDL regulator cells from a DA rat transfused with PVG-RT1c blood were added to a unidirectional MLC between DA responders and PVG stimulators, a significant depression in the proliferative response was observed. These in vitro findings were confirmed in two other strain combinations (LEW-PVG, and DA-PVG). Thus a single blood transfusion results in the induction of donor-specific suppressor cells detectable both in vivo and in vitro 7 days after transfusion in some but not all lymphoid compartments.

Transfusion induces blood donor-specific suppressor cells

Transfusion with blood from the organ donor before transplantation can prolong the survival of renal allografts in the rat. To determine if the beneficial effect of preoperative blood transfusion was due to the generation of donor-specific suppressor cells, in vivo and in vitro adoptive transfer experiments were performed. Lymphoid cells were harvested from transfused and untreated rats. These cells were then either (1) transferred to lightly irradiated (200 R) syngeneic hosts which were subsequently challenged with a kidney allograft (in vivo assay) or (2) titrated as regulator cells into naive unidirectional MLC such that the regulator and responder populations were syngeneic. In the LEW-RT1 to DA-RT1av1 strain combination, the adoptive transfer of thoracic duct lymph (TDL) or lymph node (LN) cells (5 x 10(7) to 7.5 x 10(7) cells) from DA animals transfused with LEW blood, 7 days previously into syngeneic (DA), lightly irradiated (200 R) hosts resulted in the indefinite survival of LEW kidney allografts. The phenomenon was blood donor-specific and dose-dependent. In contrast the adoptive transfer of spleen cells (10(7) to 10(8] from blood transfused hosts 7 days after transfusion had no effect on renal allograft survival. In vitro the addition of LN or TDL regulator cells, harvested from DA rats transfused with LEW blood, to a unidirectional MLC (DA responders, LEW stimulators) resulted in a significant depression of the proliferative response when compared with the proliferation of these same cells without the addition of these regulator cells or with the addition of LN or TDL regulator cells from a DA rat transfused with third party (PVG-RT1c) blood. The depression of the proliferative response observed in vitro, was blood donor specific. When LN or TDL regulator cells from a DA rat transfused with PVG-RT1c blood were added to a unidirectional MLC between DA responders and PVG stimulators, a significant depression in the proliferative response was observed. These in vitro findings were confirmed in two other strain combinations (LEW-PVG, and DA-PVG). Thus a single blood transfusion results in the induction of donor-specific suppressor cells detectable both in vivo and in vitro 7 days after transfusion in some but not all lymphoid compartments.

Investigation of the mechanism of active enhancement of renal allograft survival by blood transfusion

Transfusion with donor blood before transplantation can prolong the survival of renal allografts in the rat. The phenomenon is donor specific. We have investigated the effect of blood transfusion on both lymphocyte proliferation and the generation of donor-specific cytotoxic cells. In the first instance the kinetics of the proliferative responses of lymph node, spleen and thoracic duct lymph (TDL) leucocytes (harvested 7 days after transfusion of donor-specific blood, third-party allogeneic blood, syngeneic blood or no treatment) to lymph node stimulator cells were determined in a one-way mixed lymphocyte culture (MLC). Four strain combinations (LEW to DA, LEW to PVG, PVG to DA and DA to PVG) were investigated in this study. Maximal proliferation was observed at 4 days in the MLC and this was not altered by prior blood transfusion. When lymph node and TDL cells from transfused recipients were used as responders and stimulation was provided by cells from the same strain of rat as the blood donor, there was a significant depression of the MLC response compared to the response of cells harvested from untreated animals or animals given a syngeneic blood transfusion. This correlated with the behaviour of renal allografts in the same strain combinations. Lymph node and TDL cells harvested from rats that had received a third-party blood transfusion produced variable results in the MLC, ranging from a normal to a depressed response. No prolongation of allograft survival was noted in any animals pretreated with third-party blood. In contrast, when spleen cells were used as responder cells there was a donor-specific increase in the proliferative response on Day 4 in all strain combinations tested. In the second instance, specific cytotoxic activity was generated by in vitro (MLC) stimulation of lymph node or TDL, but not spleen, cell responders harvested from transfused or untreated rats. The activity of cytotoxic cells generated in MLC was quantified in a 51Cr-release assay, using Con A blast lymph node target cells prepared from animals of the same strain as the blood donor or a third-party strain. The specific cytotoxic activity generated was significantly increased when the responding cells were harvested from an animal that had received a donor-specific transfusion and then been restimulated by the blood donor in MLC.(ABSTRACT TRUNCATED AT 400 WORDS)