Wilson Ko

Cardiac Operations in Patients With Cirrhosis

BACKGROUND A retrospective review was performed to determine the outcome after cardiac operations in patients with a documented history of noncardiac cirrhosis. METHODS The charts of patients admitted to the cardiothoracic surgical service between 1990 and 1996 were reviewed, and 13 patients with a preoperative history of cirrhosis were identified. The severity of preoperative liver disease was graded according to the criteria of Child. RESULTS Most of the cases of cirrhosis were alcohol-related. Eight patients were classified as having Child class A and 5 as having Child class B cirrhosis. One hundred percent of patients with Child class B and 25% of those with Child class A cirrhosis had major complications. The postoperative chest tube output and transfusion requirements of these patients were approximately three times higher than average. The overall perioperative mortality rate was 31%. In patients with Child class B cirrhosis, the mortality rate was 80%. No patient with Child class A cirrhosis died. Deaths were related to gastrointestinal and septic complications, and not to cardiovascular failure. CONCLUSIONS These findings suggest that patients with minimal clinical evidence of cirrhosis can tolerate cardiopulmonary bypass and cardiac surgical procedures, whereas those with more advanced liver disease should not be offered operation.

Cardiopulmoitary bypass procedures in dialysis patients

To determine the operative outcome of chronic renal failure patients, we retrospectively reviewed twenty-five consecutive adult patients with chronic renal failure dependent on maintenance hemodialysis (21) or peritoneal dialysis (3), who underwent cardiopulmonary bypass procedures over a five-year period in our institution. The operations included isolated coronary artery bypass grafting in 16 patients; aortic valve replacement in 3; aortic valve replacement plus mitral valve replacement in 1; aortic valve replacement, mitral valve replacement, and coronary artery bypass grafting in 2; aortic valve replacement and coronary artery bypass grafting in 1, mitral valve replacement and coronary artery bypass grafting in 1, and repair of a thoracoabdominal aortic aneurysm in 1 patient. Fourteen operations were elective, and 11 were urgent or emergent. The number of patients with good (> 0.50), fair (0.30 to 0.50), and poor (< 0.30) left ventricular ejection fractions were 13, 9, and 3, respectively. There were 0, 7, 7, and 11 patients in New York Heart Association functional classification I, II, III, and IV, respectively. All patients were dialyzed within 24 hours before operation. All but 3 patients were managed by immediate postoperative peritoneal dialysis via a Technoff catheter placed intraoperatively (18 patients) or via a preexisting Technoff catheter (4 patients). This was then switched to hemodialysis when clinical conditions stabilized. Univariate analysis of 22 preoperative and intraoperative variables, followed by a multivariate analysis with a stepwise logistic regression model, was performed using the 30-day or in-hospital operative mortality as the dependent variable.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of shaving methods and intraoperative irrigation on suppurative mediastinitis after bypass operations

To investigate the effects of the hair removal methods and intraoperative irrigation on suppurative mediastinitis after cardiopulmonary bypass operations, 1,980 consecutive adult patients over a 2-year period in our institution were prospectively randomized to manual shaving versus electrical clipping of hair before the skin incision, and to povidone-iodine solution (0.5%) versus saline solution mediastinal and subcutaneous irrigation before wound closure. The overall incidence of suppurative mediastinitis was 0.86% (17/1,980). The infectious rate was significantly higher in the manually shaven (13/990) than in the electrically clipped patients (4/990) with an odds ratio of 3.25 (95% confidence interval, 1.11 to 9.32; p = 0.024). It was also higher in the povidone-iodine group (11/990) than in the saline group (6/990), although the difference was not statistically significant (p = 0.16). Fourteen patients were treated with operative debridement with closed tube irrigation, with one failure requiring a conversion to an open wound. Two patients were successfully treated with primary open wound procedures followed by delayed muscular flap closures, and 1 patient succumbed to rapid and profound sepsis soon after open drainage. We conclude that electrical clipping is superior to manual shaving in the prevention of suppurative mediastinitis. The routine use of povidone-iodine (0.5%) irrigation was of no benefit in this study and may increase the incidence of infection due to its known suppressive effects on local leukocytes and fibroblasts. Furthermore, operative debridement with closed tube irrigation was successful in treating the majority of cases in this series.

Retrograde Autologous Priming For Cardiopulmonary Bypass: A Safe And Effective Means Of Decreasing Hemodilution And Transfusion Requirements

OBJECTIVES The obligatory hemodilution resulting from crystalloid priming of the cardiopulmonary bypass circuit represents a major risk factor for blood transfusion in cardiac operations. We therefore examined whether retrograde autologous priming of the bypass circuit would result in decreased hemodilution and red cell transfusion. METHODS Sixty patients having first-time coronary bypass were prospectively randomized to cardiopulmonary bypass with or without retrograde autologous priming. Retrograde autologous priming was performed at the start of bypass by draining crystalloid prime from the arterial and venous lines into a recirculation bag (mean volume withdrawal: 880 +/- 150 ml). Perfusion and anesthetic techniques were otherwise identical for the two groups. The hematocrit value was maintained at a minimum of 16% and 23% during and after cardiopulmonary bypass, respectively, in all patients. Patients were well matched for all preoperative variables, including established transfusion risk factors. Subsequent hemodynamic parameters, pressor requirements, and fluid requirements were equivalent in the two groups. RESULTS The lowest hematocrit value during cardiopulmonary bypass was 22% +/- 3% versus 20% +/- 3% in patients subjected to retrograde autologous priming and in control patients, respectively (p = 0.002). One (3%) of 30 patients subjected to retrograde autologous priming had intraoperative transfusion, and seven (23%) of 30 control patients required transfusion during the operation (p = 0.03). The number of patients receiving any homologous red cell transfusions in the two groups during the entire hospitalization was eight of 30 (27%; retrograde autologous priming) versus 16 of 30 (53%; control) (p = 0.03). CONCLUSIONS These data suggest that retrograde autologous priming is a safe and effective means of significantly decreasing hemodilution and the number of patients requiring red cell transfusion during cardiac operations.

Effects of Temperature and Flow Rate on Regional Blood Flow and Metabolism During Cardiopulmonary Bypass

Eleven dogs were subjected to a 150-minute period of cardiopulmonary bypass that consisted of a high-flow, normothermic phase, a high-flow, hypothermic phase, a low-flow, hypothermic phase, and then a high-flow, rewarming phase. Regional blood flow and oxygen consumption to the brain, intestines, kidney, and hind limb were determined at baseline and at 10-minute intervals during cardiopulmonary bypass. Blood flow to the carotid artery, superior mesenteric artery, and renal artery declined significantly with hypothermic cardiopulmonary bypass whereas blood flow to the femoral artery increased significantly. Although total body oxygen consumption returned to baseline values at the end of the rewarming phase, oxygen consumption for these regions differed somewhat from their baseline values. We conclude that blood flow during hypothermic cardiopulmonary bypass is shunted to skeletal muscle, particularly with high pump flows. Additionally, the return of total body oxygen consumption to baseline after rewarming is not necessarily reflected at the regional level.

Outcomes of cardiac surgery in nonagenarians: a 10-year experience

BACKGROUND With an increasing awareness of health issues and greater emphasis on preventive medicine, the general population is living longer and healthier lives than ever before. Physicians are taking care of older patients, many of whom may require cardiac surgical procedures. Improving cardiopulmonary bypass technology allows for safer procedures with reduced morbidity and mortality even in older patients. METHODS We have performed a retrospective analysis of 42 consecutive nonagenarian patients who underwent open-heart procedures over a 10-year period (1993 to 2002) at our institution. Their demographic profiles, operative data, perioperative results, and long-term outcomes were recorded and analyzed. RESULTS Twenty-two women and 20 men with an age range of 90 to 97 years (mean, 91.4 years) had open-heart surgery over the study period. The complication rate was 67% overall, consisting of 7% respiratory (pneumonia, respiratory failure, reintubation), 7% hemorrhagic or embolic (postoperative bleeding, cerebral vascular accident), 12% infectious (wound infection, sepsis), and 31% new arrhythmia (atrial fibrillation, atrial flutter, ventricular tachycardia, ventricular fibrillation). Despite these complication rates, average hospital stay was 17.5 days (median, 11 days), with an intensive care unit stay of 12.0 days (median, 5 days). Thirty-day survival was 95% and survival to discharge was 93% (three deaths total; one cardiac arrest at hospital day 134 and two perioperative deaths; one ventricular arrhythmia, one cerebral vascular accident). The only statistically significant risk factor of mortality was emergency surgery. Currently, 81% are still alive an average of 2.53 years since surgery (range, 0.16 to 7.1 years). CONCLUSIONS With improving techniques and greater attention to detail, the select nonagenarian can safely undergo cardiac surgery.

Surgical treatment of atrial fibrillation using argon-based cryoablation during concomitant cardiac procedures.

Background—The development of ablative energy sources has simplified the surgical treatment of atrial fibrillation (AF) during concomitant cardiac procedures. We report our results using argon-based endocardial cryoablation for the treatment of AF in patients undergoing concomitant cardiac procedures. Methods and Results—Sixty-three patients with AF who were undergoing concomitant cardiac procedures had the same left atrial endocardial lesion set using a flexible argon-based cryoablative device. Mean age was 65.1±1.3 years. Sixty-two percent had permanent AF, whereas 38% had paroxysmal AF. Mean duration of AF was 30.5±4.8 months. Mean left atrial diameter was 5.5±0.1 cm. Mean ejection fraction was 45±1.4%. All endocardial lesions were performed for 1 minute once tissue temperature reached −40°C. Follow-up echocardiograms were obtained to determine freedom from AF. Kaplan-Meier analysis demonstrated an 88.5% freedom from AF rate at 12 months. Ablation time was 16.8±0.6 minutes. There were no in-hospital deaths and no strokes. Twelve patients (19%) required postoperative permanent pacemaker placement. Conclusions—Cryoablation using this flexible argon-based device for the treatment of AF during concomitant cardiac procedures was safe and effective, with 88.5% of patients free from AF at 12 months.

Cardiac Surgery in Select Nonagenarians: Should We or Shouldn’t We?

BACKGROUND Patients aged 90 years and older represent a rapidly growing subset of the population, many of whom are functionally limited by cardiovascular disease. Clinical decision making about cardiac surgical intervention in nonagenarians is hindered by a paucity of data examining survival outcomes in this population. METHODS A consecutive series of nonagenarians who underwent cardiac operations between 1995 and 2004 were retrospectively reviewed. Data collection included baseline preoperative clinical status, intraoperative characteristics, and perioperative course. Area under the Kaplan-Meier survival estimate method was used to calculate mean survival. RESULTS Cardiac surgical procedures were done in 49 patients (51% male); their mean age was 91.9 years (range, 90 to 97 years). Operative mortality was 8% (n = 4). Multivariate Cox proportional hazards models found preoperative chronic renal insufficiency (hazard ratio [HR], 4.88; 95% confidence interval [CI], 1.53 to 15.55; p = 0.007) and ejection fraction (HR, 0.96; 95% CI, 0.93 to 1.00; p = 0.033) were independently associated with death. Overall mean survival was 5.1 +/- 0.5 years (median, 5.2 years). Quality of life outcomes were similar to that of two related norm-based populations based on age and disease process. CONCLUSIONS Cardiac surgical procedures can be performed safely and with therapeutic benefit in carefully selected nonagenarians. We consider physiologic indicators, social factors, and patient preferences to be the main determinants in the patient selection process. Our results support the need for more proactive intervention in symptomatic nonagenarian patients as it relates to earlier consideration of elective, rather than emergency cardiac operations.

Outcome analysis of 245 CarboMedics and St. Jude valves implanted at the same institution

BACKGROUND Thromboembolism and valve-related death are major complications associated with prosthetic valve implants, but it is difficult to evaluate the relative incidence of these complications based on studies in which the implantation of only one valve is reported from any given institution. We therefore report the outcome of patients implanted at our institution during the same time period with either the recently released CarboMedics (CM) or the St. Jude Medical (SJ) valve prostheses. METHODS Between October 1994 and January 1996, 245 consecutive patients received either SJ (116 patients) or CM (129 patients) valves at our institution. Follow up of these patients was 99.6% complete, for a total of 318.5 cumulative patient-years (median follow-up, 1.4 years). RESULTS The 30-day mortality rates for SJ and CM implants were 3.4% and 3.1%, respectively. Actuarial survival and freedom from valve related mortality rates at 1.5 years for SJ and CM valves were 94%+/-2% versus 86%+/-3% (p = 0.03) and 100% versus 94%+/-2% (p = 0.005), respectively. There was no structural valve failure for either implant, but there were five thrombosed valves in the CM group and none in the SJ group (p = 0.04). All thrombosed valves were mitral (four mitral valve replacement, one aortic and mitral valve replacement). Two of the thrombosed valves were successfully explanted, whereas the three remaining patients died. Freedom from a thromboembolic event in the mitral position at 1.5 years, including thrombosed valves was 97%+/-3% and 83%+/-5% for SJ and CM valves, respectively (p = 0.04). CONCLUSIONS The results of this study suggest that further evaluation of thromboembolic outcomes after CM compared with SJ valve implantation is warranted.

The effects of platelet inhibitors on blood use in cardiac surgery.

Platelet inhibition via glycoprotein (GP) IIb/IIIa receptor antagonists has greatly reduced the need for emergent cardiac surgery. However, this change has come at a cost to both the patient and the cardiac surgical team in terms of increased bleeding risk. Current guidelines for patients requiring coronary artery bypass surgery include: 1) cessation of GP IIb/IIIa inhibitor; 2) delay of surgery for up to 12 h if abciximab, tirofiban, or eptafibitide is used; 3) utilization of ultrafiltration via zero balance technique; 4) maintenance of standard heparin dosing despite elevated bleeding times; and 5) transfusion of platelets as needed, rather than prophylactically. These agents present cardiac surgery teams with increased risk during CABG, although overall risk may be diminished by the substantial benefits to patients with acute coronary syndromes and percutaneous interventions, i.e., reduced infarction rates and improved vessel patency. With judicious planning, urgent coronary artery bypass can be safely performed on patients who have been treated with GP IIb/IIIa receptor inhibitors.