James W. Frederiksen

Clinical experience with portable cardiopulmonary bypass in cardiac arrest patients

To evaluate the use of portable cardiopulmonary bypass as a resuscitative tool and its impact on long-term survival of patients in cardiac arrest, we reviewed the results of 32 consecutive patients resuscitated by cardiopulmonary bypass for cardiac arrest or severe hemodynamic compromise at Northwestern Memorial Hospital over a 2-year period. Overall survival was 12.5%. Only 1 (3.4%) of the 29 patients who had cardiac arrest survived and left the hospital. All 3 patients who had severe hemodynamic compromise but not cardiac arrest were long-term survivors. Our study suggests that portable cardiopulmonary support systems used as a resuscitative tool do not prolong the survival of most cardiac arrest patients but may be useful for patients with shock due to mechanical causes and for those with profound hemodynamic compromise due to ischemia or myocardial infarction. Portable heart-lung machines can provide patients with excellent hemodynamic support; however, neurological or cardiac recovery is unlikely once cardiac arrest occurs.

NEW APPLICATIONS OF THE LASER IN PULMONARY SURGERY: HEMOSTASIS AND SEALING OF AIR LEAKS

In thoracic surgery, the laser has been used primarily as a destructive instrument (e.g., for extirpation of endobronchial lesions and for skin incisions). Previously, the carbon dioxide laser was used for its scalpel-like action but not for sealing. The neodymium:yttrium aluminum garnet (Nd:YAG) laser not only cuts but also seals blood vessels and bronchi. We have modified the CO2 laser technique to seal vessels and bronchi up to 3 mm on a cut surface by using low power in a defocused mode, and have evaluated the method in 12 dogs. Matched lesions in the lingula were sealed with each type of laser and compared with lesions closed by suture technique. These lesions were then evaluated at biweekly intervals up to 6 weeks following operation. All lesions demonstrated substantial air leak and bleeding prior to sealing. There was no bleeding or air leak (40 cm H2O of pressure) at any time after sealing (laser or suture). The CO2 laser sealing consistently produced the least damage both macroscopically and microscopically. However, this technique requires a relatively bloodless field. The Nd:YAG laser produced the deepest tissue destruction but functioned well under conditions of poor hemostasis. Suture closure produced large early injuries, which subsided gradually to approach the amount of damage seen with the CO2 laser. These studies demonstrate that the laser may be a useful adjunct to maximally preserve normal lung tissue and to seal bleeding, leaking, raw lung surfaces. Results of early clinical trials are also detailed.

Endocardial activation mapping and endocardial pace-mapping using a balloon apparatus☆

The relation between endocardial activation mapping and endocardial pace-mapping was evaluated in 8 dogs while they were on cardiopulmonary bypass. Pacing or recording was accomplished by using a balloon apparatus (with 32 bipolar electrodes) inserted through a left apical ventriculotomy. Ventricular tachycardia (VT) was produced by occlusion followed by reperfusion of the left anterior descending coronary artery. During each VT, activation mapping was performed and early sites determined. Pace-map correlates (sites at which endocardial pacing produced a similar QRS morphology to that of the VT) were also determined. Isochronous maps were constructed for activation mapping and pace-mapping. There was a total of 29 morphologically distinct VTs. Groups were delineated according to correlations between activation mapping and pace-mapping. In 14 episodes of VT (group 1), pace-mapping confirmed the findings of activation mapping with all early sites being pace-map correlates (total number of early sites (tES) = 19; total number of pace-map correlates (tPMC) = 88; tES same as tPMC = 19). In 9 episodes of VT (group 2), there was a partial correlation between pace-mapping and activation mapping, such that pace-mapping when used with activation mapping appeared to further delineate the region of arrhythmogenesis (tES = 31; tPMC = 59; tES same as tPMC = 14). In 6 episodes of VT (group 3), there was no correlation between pace-mapping and activation mapping (tES = 15; tPMC = 0). With the balloon apparatus, endocardial activation mapping can be performed without the need for sustained monomorphic VT, and endocardial pace-maps may be generated easily.(ABSTRACT TRUNCATED AT 250 WORDS)

Safety and efficacy of combined orthotopic liver transplantation and coronary artery bypass grafting

Advanced coronary artery disease (CAD) is increasingly common in patients awaiting orthotopic liver transplantation (OLT). Unfortunately, in patients whose coronary artery anatomy is not amenable to angioplasty, coronary artery bypass grafting (CABG) alone may precipitate hepatic decompensation. Thus, combined liver transplant and coronary artery bypass grafting (CABG‐OLT) may be required to effectively treat both conditions. Clinical records were analyzed for 5 CABG‐OLT procedures at a single institution. Operative indications, technical details, and postoperative course were determined for each patient. Patients undergoing CABG‐OLT had a mean age of 57.8 years (range, 54‐66) and were predominantly male (80%). All patients had significant 3‐vessel coronary atherosclerotic disease with preserved left ventricular function. There were no intraoperative deaths. At mean 25 months of follow‐up (range, 8.0‐25) there was an 80% graft and patient survival. Overall average length of stay was 21 days (range, 7‐59 days). In conclusion, CABG‐OLT procedure appears to be safe and effective in the population of patients with advanced CAD and liver disease. In this series, patients appear to benefit from multidisciplinary preoperative evaluation, coordination between cardiac and transplant surgeons, careful graft selection, and use of sapheno‐atrial veno‐veno bypass. (Liver Transpl 2004;10:1386–1390.)

Resection of a large arteriovenous fistula of the brain using low-flow deep hypothermic cardiopulmonary bypass: technical case report.

OBJECTIVE AND IMPORTANCE We present the second report in the literature on the use of low-flow hypothermic cardiopulmonary bypass to aide in the surgical resection of a large intraparenchymal arteriovenous fistula. CLINICAL PRESENTATION The patient was a 46-year-old man who was found to have a left sylvian arteriovenous fistula with a giant varix during a workup for chronic left frontal headaches and was referred to our center for management. A cardiac workup revealed a cardiac output of 9 L per minute. INTERVENTION Endovascular embolization of the lesion was initially attempted without success because of the high flow within the lesion and the large diameter of the feeding arteries. We then planned combined and staged endovascular and surgical approaches to gradually eliminate the fistula. Endovascular embolization, both transarterial and transvenous, could not be performed because of the high flow in the fistula. Despite the stepwise reduction of flow during the course of several weeks via surgical exposures and arterial ligations, the fistula remained difficult to remove because of its size and the turgor of the varix. Once hypothermic low-flow circulatory bypass was used, however, decompression of the sac allowed access to the afferent vasculature. CONCLUSION The use of low-flow hypothermic circulatory bypass can facilitate the surgical extirpation of certain large intraparenchymal arteriovenous fistulas.

Recombinant aprotinin in coronary artery bypass graft operations

OBJECTIVE To evaluate the role of recombinant bovine aprotinin in reducing blood loss in coronary artery bypass graft surgery. DESIGN An open-label, randomized, controlled study evaluating two dosage levels of recombinant aprotinin. SETTING Two acute care hospitals (Northwestern Memorial Hospital, Chicago, Ill., and the Scott & White Memorial Hospital, Temple, Texas). PATIENTS Patients undergoing primary and reoperation coronary artery bypass grafting were assigned to groups by means of a computer-generated table of random numbers. Treated (n = 48) and control (n = 36) patients did not differ significantly in age, sex, weight, number of grafts, or preoperative hemoglobin level. INTERVENTIONS Recombinant aprotinin was given at two dosages. Dosage level 1 consisted of a bolus of 2 mg/kg intravenously immediately after the induction of anesthesia, 1 mg/kg added to each liter of the oxygenator prime, and 0.5 mg.kg-1.hr-1 infused continuously during operation. At dosage level 2, doses were doubled. Intraoperative monitoring of anti-factor Xa activity was performed, and additional doses of heparin were given on the basis of anti-factor Xa results. MAIN OUTCOME MEASURES Preoperative and postoperative hemoglobin levels, amounts of autotransfusion device and chest tube drainage blood, and transfusions of allogeneic red blood cells. Adverse clinical events (alterations in renal function, graft thrombosis, myocardial infarction, and death) were recorded. RESULTS Additional heparin was given to 48% patients in the aprotinin group and to 44% of control patients. Overall red blood cell loss (in milliliters, mean +/- standard deviation [SD]) was decreased with aprotinin at dosage level 1 for reoperations (1040 +/- 162 vs 1544 +/- 198, p < 0.01), and at dosage level 2 for all operations (primary operations, 886 +/- 362 vs 1333 +/- 618, p = 0.02; reoperations, 1191 +/- 560 vs 1815 +/- 1116, p = 0.2). Fewer patients in the aprotinin than in the control group had transfusions of donated blood (6/48 vs 12/36, p = 0.02) or reinfusion of chest tube drainage blood (12/48 vs 20/36, p < 0.01). Among patients receiving dosage level 1, there were no myocardial infarctions or deaths. At dosage level 2, one patient had profound bradycardia and died on day 12 and two patients had late graft closures. Two control patients had hypotension after bypass necessitating intraaortic balloon pumps, and one of these patients died. Postoperative increases in blood urea nitrogen and creatinine levels were small in both aprotinin and control groups. No hypersensitivity or other allergic reactions occurred. CONCLUSION We conclude that, at the dosages given, recombinant bovine aprotinin decreases surgical blood loss and transfusion requirements in patients undergoing coronary artery bypass grafting, but its use requires appropriate monitoring of heparin use during bypass. Whether higher dosages of aprotinin increase the risk of graft thrombosis must be further assessed with a larger patient sample.

Management of Chronic Sternal Osteomyelitis

The management of 2 patients in whom chronic sternal osteomyelitis developed after apparently uncomplicated coronary artery bypass operations is described. Each patient had become totally disabled because of chronic, draining sinus tracts. Eradication of the infection required total sternectomy and excision of all infected costal cartilage. Subsequent reconstruction was accomplished by using bilateral pectoralis major myocutaneous advancement flaps without any maneuvers to stabilize the anterior chest wall. Both patients have resumed full activity and have returned to work with only minimal residual compromise of pulmonary function.

Arterial Helium Embolism from a Ruptured Intraaortic Balloon

A 67-year-old man sustained a sudden global neurological deficit immediately following rupture of an intraaortic balloon catheter. Considerable improvement in his neurological function occurred during and after three hyperbaric oxygen treatments.

Cardiopulmonary bypass in humans: bypassing unfractionated heparin.

Seven anticoagulants besides unfractionated heparin have been used for human cardiopulmonary bypass (CPB), mainly in patients with heparin-induced thrombocytopenia. The collective experience with these alternative anticoagulants provides a perspective on current efforts aimed at improving CPB anticoagulation. Unfortunately, each alternative currently lacks a standard dosing schedule and a reliable method of monitoring the adequacy of its anticoagulant effect during CPB. Most also lack proven antidotes. Thus, unfractionated heparin remains the anticoagulant of choice for standard CPB.

Topical application of bacitracin ointment is associated with decreased risk of mediastinitis after median sternotomy.

BACKGROUND The diagnosis of mediastinitis after open-heart surgery is infrequent but dreaded as it carries a high morbidity and mortality. The purpose of this study was to investigate the impact that topical antibacterials would have on the postoperative mediastinitis rate. METHODS Data were collected from 2455 consecutive patients who underwent sternotomy and cardiopulmonary bypass for both valvar and ischemic heart disease. Prior to 1999, patients (n = 1036) underwent surgery with standard perioperative intravenous antibiotics but no application of bacitracin. After 1999, patients (n = 1419) underwent surgery with intravenous antibiotics and application of bacitracin ointment to the sternotomy incision after closure. RESULTS Cases of mediastinitis occurred in 12 patients (1.2%) not treated with bacitracin, which required re-exploration, sternectomy, and soft tissue closure of the mediastinum. Alternatively, 3 patients (0.2%) in the group treated with bacitracin developed mediastinitis (P < .01). Therefore, the use of topical antibacterials was associated with a 6-fold reduction in the risk of mediastinitis after cardiac surgery. This significant difference in the infection rate was observed even though the percentage of patients with risk factors for mediastinitis was equal to greater than the group not treated with bacitracin. Non-bacitracin versus bacitracin: diabetics, 298 versus 484; emergency operations, 24 versus 50; bilateral internal thoracic grafts, 28 versus 29; and obesity (body mass index >30), 294 versus 396. CONCLUSIONS The use of topical antibacterials is associated with a decrease in the risk of mediastinitis after cardiac surgery.