Modified conduit preparation creates a pseudosinus in an aortic valve-sparing procedure for aneurysm of the ascending aorta.

Mechanical valved conduit replacement of the aortic root is a durable and appropriate procedure for many diseases of the ascending aorta, but may sacrifice an anatomically salvageable aortic valve. For young active patients and for patients with "systemic" arterial disease (atherosclerosis, Marfan's syndrome) who may require future operations, life-long anticoagulation with its attendant thromboembolic versus hemorrhagic risks is not ideal. Several techniques have been suggested as aortic valve-sparing options. Recently, a procedure was described that combines the freehand homograft techniques with the standard Bentall techniques (David procedure). This innovative technique replaces the ascending aorta with a Dacron cylinder, spares the aortic valve, and restores competence and thus offers an excellent alternative. The durability of this procedure that places the aortic valve inside a cylindrical conduit without sinuses of Valsalva is unknown. In selected patients, we have used this technique to spare the aortic valve. On the basis of experimental data and preliminary computer modeling, with the hope of improving the durability, we have modified the conduit to create a "pseudosinus" in our most recent nine patients. We have done the David procedure in 10 patients. The pseudosinus modification was done in the most recent nine patients. Patients' ages ranged from 37 to 71 years (mean 49.9 years). There were five female and five male patients. Five patients had Marfan's syndrome and five patients had annuloaortic ectasia. There has been no mortality and all patients have had both early and late follow-up echocardiography. Five patients have zero to trace aortic insufficiency, four patients have trace to mild aortic insufficiency, and one patient has mild or "1+" aortic insufficiency. Aortic insufficiency has not progressed in any patient during the 18 months of follow-up. The patient with 1+ aortic insufficiency has no activity limits, good ventricular function, and no evidence of congestive symptoms. One patient who had extensive thoracoabdominal aneurysmal disease has undergone subsequent replacement of the descending aorta to the level of the renal arteries and has done well. Aortic valve-sparing replacement of the aortic root is an excellent procedure for any patient with an ascending aortic aneurysm and an anatomically salvageable valve. We believe that by modifying the proximal conduit and creating a "pseudosinus" into which the leaflets can retract without contact of the cylindrical conduit we may increase the longevity of the native aortic valve in this procedure.

Infusion of autologous platelet rich plasma does not reduce blood loss and product use after coronary artery bypass. A prospective, randomized, blinded study.

Prior nonblinded studies have suggested dramatic hemostatic effects and decreased plasma after cardiopulmonary bypass. Platelet rich plasma (8 to 10 ml/kg total body weight) was obtained (Haemonetics Plasma Saver; Haemonetics Corp., Natick, Mass.) from 51 patients undergoing primary coronary artery bypass grafting before heparinization. After double-blinded randomization, the platelet rich plasma was reinfused immediately in the control group or after heparin reversal in the treatment group. Homologous blood product usage, blood loss, and the surgeon's intraoperative subjective assessment of coagulation were evaluated. Additionally, thromboelastography, prothrombin time, partial thromboplastin time, activated clotting time, fibrinogen, platelet counts, and hematocrit values were evaluated before the operation, after heparin reversal, after infusion of platelet rich plasma or control solution, and 2 hours after infusion. The surgeon's subjective assessment of coagulation was not different between control and treatment groups (p = 0.78). According to specific predetermined transfusion guidelines, no statistically significant differences were found in the use of whole blood (p = 0.07), packed red blood cells (p = 0.62), platelets (p = 0.11), total units of blood products (p = 0.45), or in the percentage of patients receiving transfusions (control group 70%, treatment group 71%, p = 0.97). Cumulative amount of blood shed through the chest tube was not significantly different between the groups at any interval but tended toward significance at 4, 6, and 12 hours (p = 0.09, 0.07, and 0.09). The prothrombin time immediately after reinfusion of platelet rich plasma was significantly lower in the treatment group (p = 0.03), but all other laboratory studies were similar at each time interval. Infusion of platelet rich plasma after cardiopulmonary bypass in patients having uncomplicated primary coronary artery bypass grafting has minimal effects on the surgeon's assessment of coagulation, total transfusion requirements, mediastinal drainage, and laboratory studies of coagulation.

Prospective trial of catheter irrigation and muscle flaps for sternal wound infection.

BACKGROUND: Sternal wound infection is a relatively rare but potentially devastating complication of open heart operations. The most common treatments after debridement are rewiring with antibiotic irrigation and muscle flaps. Here we present the results of a prospective trial to determine the appropriate roles of closed-chest catheter irrigation and muscle flap closure for sternotomy infection and to assess the effect of internal mammary artery bypass grafting on the outcome of each treatment modality. METHODS: Between 1990 and 1994, 5,658 sternotomies were performed at the University of Washington Medical Center. Sternal dehiscence occurred in 43 patients, 25 of whom had infection (overall incidence, 0.44%). Because of the infrequency of this complication, a prospective, randomized trial was developed in which the initial approach to sternal dehiscence was rewiring and catheter irrigation. Muscle flaps were used as the primary treatment if the sternum could not be restabilized or as secondary treatment if catheter irrigation failed. Wound resolution, length of hospital stay, and complications were evaluated. RESULTS: Sterile dehiscences were successfully closed with irrigation in 17 of 18 patients; the other patient required flap closure. Of the 25 patients with infection, 19 had irrigation and 6, closure with flaps primarily. In the group of infected patients, 17 of the 19 who received irrigation also had internal mammary artery bypass grafting. Irrigation failed in 15 (88.2%) of these 17 patients, and salvage was accomplished with muscle flap closure. All 6 patients with infection who were closed primarily with muscle flaps had a successful outcome. Hospitalization averaged 10.2 days when muscle flaps were used primarily and 14.3 additional days for unsuccessful irrigation. When irrigation was successful, the hospital stay averaged 11.2 days. CONCLUSIONS: Catheter irrigation should be reserved for patients without infection or patients with infection but without internal mammary artery bypass grafts in whom dehiscence occurs less than 1 month after sternotomy. All others should have closure with muscle flaps.

Washington State's model of physician leadership in cardiac outcomes reporting.

BACKGROUND: In 1993, the cardiac surgery community in Washington State opposed an effort by the state Health Care Authority (HCA) to identify "centers of excellence" for selective contracting of coronary artery bypass grafting (CABG) procedures, and proposed an alternate model that would create a statewide cardiac outcomes registry under physician governance to be used by all institutions for internal quality improvement activities. METHODS: A prospective pilot data collection effort, which examined preoperative and postoperative patient-reported health status, served as the basis for evaluating the capacity of a physician-led organization to develop a collaborative atmosphere and facilitate universal hospital participation. RESULTS: A surgical steering group met on a regular basis and reached consensus on governance issues, protocols for standardized data collection, and policies regarding data dissemination. All 14 centers that performed bypass surgery in the state participated. Patients who were surveyed reported statistically significant improvements in physical, emotional, and anginal-specific health status after bypass surgery. Baseline patient characteristics and longitudinal outcomes were compared across institutions. CONCLUSIONS: Based on the feasibility of this collaborative outcomes reporting program, the HCA revised its policy regarding selective contracting and has helped to support an ongoing physician-led and -governed cardiac outcomes reporting system that is particularly notable for the subsequent integration of both CABG surgery and catheterization-based procedures into one standardized registry.

Surgical significance of vascular changes in chronic pancreatitis.

To establish a rational approach to the diagnosis and management of pancreatitis complicated by vascular abnormalities, the records of 50 patients who underwent angiography because of pancreatitis were reviewed. The findings included splenic vein thrombosis in 11 patients, splanchnic arterial anomaly or occlusion in ten patients and arterial pseudoaneurysm in six patients. Disease duration and presence of associated splenic vein thrombosis were the only two significant predictors of pseudoaneurysm. The presence of a pseudocyst was not predictive. Gastroesophageal varices, splenomegaly, associated arterial pseudoaneurysm and chronic pancreatic disease were significant predictors of splenic vein thrombosis. Dynamic bolus computed tomography was 100 per cent sensitive in detecting arterial pseudoaneurysm and 71 per cent in detecting splenic vein thrombosis. Eight patients with splenic vein thrombosis underwent splenectomy and the remaining three patients have been observed without splenectomy. Variceal bleeding has not occurred in either group. Five of the six patients with arterial pseudoaneurysm underwent aneurysmectomy without operative mortality. We conclude that arterial and venous complications of pancreatitis are associated with long duration of disease, gastrointestinal tract bleeding, varices and splenomegaly. Dynamic bolus computed tomography will detect vascular complications in these high risk patients. In patients with chronic pancreatitis in whom an operation is indicated, preoperative knowledge of vascular abnormalities may change the planned operative approach.

Effects of halothane on calcium(2+)-activated tension of the contractile proteins and calcium(2+) uptake and release by the sarcoplasmic reticulum in skinned human myocardial fibers.

Based on studies using skinned myocardial fibers from animals, it has been postulated that one of the major mechanisms by which halothane depresses myocardial contractility is by decreasing the Ca2+ content of the sarcoplasmic reticulum (SR). In this study we examined, in skinned human myocardial fibers, the effects of halothane on Ca(2+)-activated tension development of the contractile proteins and Ca2+ uptake and release by the SR. Left ventricular muscle samples obtained from patients undergoing aortocoronary bypass operations were mechanically skinned and immersed in test solutions equilibrated with N2 and halothane preceded and followed by immersion in control solution (no halothane). To study Ca(2+)-activated tension development of the contractile proteins, free Ca2+ concentrations in the bathing solutions were buffered by EGTA. To study Ca2+ uptake and release by the SR, Ca2+ was loaded into the SR and released with caffeine and the resulting tension transients were measured. Halothane (1%-3%) depressed maximum Ca(2+)-activated tensions (pCa = -log[Ca2+](M) = 3.8) by 5% for each 1% increase in concentration. Tensions generated by submaximum Ca2+ concentrations expressed as a percentage of maximum tension were not significantly decreased by halothane except at 3%. Halothane decreased Ca2+ uptake (IC50 = 1.7%), and increased (by approximately 50%) Ca2+ release by the SR. We conclude that decreased activation of the contractile proteins and Ca2+ uptake by the SR can both contribute to the myocardial depression produced by halothane. Of these, decreased Ca2+ uptake by the SR is probably a major mechanism for halothane depression of myocardium.

Biphasic waveform defibrillation using a three-electrode transvenous lead system in humans.

INTRODUCTION: Biphasic waveform defibrillation is not always more efficacious than monophasic waveform defibrillation. METHODS AND RESULTS: Waveform efficacy appears to vary with the lead system used. In this prospective, randomized study, defibrillation efficacy with biphasic and monophasic single capacitor 120-microF, 65% tilt pulses was compared for a lead system consisting of right ventricular (RV), chest patch (CP), and superior vena cava (SVC) electrodes. Although this lead system is commonly used with monophasic pulses in transvenous defibrillators, few studies have examined the defibrillation efficacy of this lead system in man for biphasic waveform defibrillation. Fourteen cardiac arrest survivors undergoing defibrillator implantation were included in the study using pulses delivered from a cathodal RV electrode simultaneously to anodal SVC and CP electrodes. Biphasic and monophasic waveforms were recorded oscilloscopically to acquire defibrillation threshold (DFT) data on leading edge voltage requirements and for stored energy. The monophasic DFT voltage was 661 +/- 177 V compared to the biphasic DFT voltage of 451 +/- 185 V (P < 0.0001). The monophasic DFT stored energy was 28.0 +/- 13.4 J compared to the biphasic DFT stored energy of 14.1 +/- 12.4 J (P < 0.0001). The stored energy DFT was < or = 15 J in only 2 of 14 patients (15%) with monophasic defibrillation but < or = 15 J in 10 of 14 (71%) patients with biphasic defibrillation. CONCLUSION: These findings indicate that biphasic defibrillation with an RV, SVC, CP transvenous electrode system is substantially more efficient than monophasic defibrillation, allowing for higher numbers of patients to receive transvenous defibrillators with a relatively simple lead system at a satisfactory cutoff DFT safety margin of 15 J.

Nonoperative versus operative treatment of obstructive jaundice in pancreatic cancer: cost and survival analysis.

Pancreatic carcinoma is complicated by malignant obstructive jaundice in 40-70% of cases. Patients frequently are old, debilitated, unresectable, and faced with a dismal prognosis. Invasive endoscopic and radiologic procedures in the inoperable patient can provide palliation without the need for surgery, in most cases. Few studies have compared nonoperative palliation with conventional surgical biliary enteric bypass procedures. In a retrospective study of patients with pancreatic carcinoma, we found no difference between operative and nonoperative treatment in survival, total hospitalization, or morbidity and mortality. Cost analysis revealed significant savings with nonoperative treatment.