Neutron scattering study of novel magnetic order in Na0.5CoO2.

We report polarized and unpolarized neutron scattering measurements of the magnetic order in single crystals of Na0.5CoO2. Our data indicate that below TN=88 K the spins form a novel antiferromagnetic pattern within the CoO2 planes, consisting of alternating rows of ordered and nonordered Co ions. The domains of magnetic order appear to be closely coupled to the domains of Na ion order, consistent with such a twofold symmetric spin arrangement. Magnetoresistance and anisotropic susceptibility measurements further support this model for the electronic ground state.

Conventional coronary artery bypass grafting: why women take longer to recover.

BACKGROUND: Recovery following successful coronary artery bypass grafting (CABG) has been dramatically improved with the use of fast-track methods. Although data exist that demonstrate a significant gender difference in survival following CABG, little is known about factors influencing gender-specific recovery. This report describes a series of consecutive patients undergoing isolated CABG to determine gender-associated factors that may impact outcomes and recovery. METHODS: Five hundred and seventeen consecutive patients underwent isolated CABG utilizing cardiopulmonary bypass and were retrospectively reviewed. The outcomes of 351 men in the study were compared to the group of 160 women. A rapid recovery protocol focused on reduced cardiopulmonary bypass time, aggressive preoperative intra-aortic balloon pump use, early extubation, perioperative administration of corticosteroids and thyroid hormone, aggressive diuresis and atrial fibrillation prevention was applied to all patients. RESULTS: The 30-day mortality rate for the women was 4.2% (Parsonnet risk 16.3+/-9.0) compared with 3.4% (Parsonnet risk 9.9+/-7.5) for the men. There were no statistically significant differences in the 30-day mortality rates or postoperative complication rates between the women and men. The women, however, were found to be older (71+/- years versus 65+/- years, p<0.001), and to have a higher incidence of acute myocardial infarction (31% versus 20%, p<0.05), obesity (23% versus 10%, p <0.05), diabetes (31% versus 22%, p<0.05), hypertension (65% versus 48%, p<0.001), and symptomatic vascular disease (20% versus 12%, p<0.05). The women required fewer bypass grafts (2.9 versus 3.5 grafts, p<0.001), and consequently, had shorter cross and cardiopulmonary bypass times. Rapid recovery with discharge before the fifth postoperative day was achieved in 30% of the women, in comparison to 44% of the men (p<0.01). The postoperative hospital length of stay was longer for the women in comparison to the men (7.2+/-7.1 versus 5.8+/-5.2 days, p<0.05). CONCLUSIONS: Women had similar operative mortality and postoperative complication rates to men under a rapid recovery protocol. However, women have a longer recovery interval compared to men, which may be a reflection of their higher preoperative risk profile.

Reoperative coronary bypass surgery using normothermic cardiopulmonary bypass: comparison with first-time procedures.

Redo coronary artery bypass grafting (CABG) is characterized by increased patient risk compared with first-time CABG. The reason for higher risk is not completely understood but it is logically related to inadequate myocardial preservation evidenced by the higher incidence of postoperative low-output syndrome. We compared normothermic cardiopulmonary bypass with cold blood maintenance cardioplegia in both first-time and redo CABGs to determine whether this single approach is appropriate for both instances. Five hundred seventeen consecutive CABG patients were retrospectively reviewed. Four hundred fifty-four first-time CABG procedures were compared with 44 redo procedures. All aspects of the operation were identical including myocardial preservation. Retrospective univariant analysis of both groups followed. Three clinical features distinguished first-time versus redo CABG. These were previous percutaneous transluminal coronary angioplasty (first-time 19% vs redo 71%; P < 0.001), preoperative intra-aortic balloon pump (first-time 38% vs redo 71%; P < 0.001), and Parsonnet risk score (first-time 11.7+/-8.2 vs redo 19.2+/-8.8; P < 0.001). Operative mortality for redo CABG was higher than in first-time procedures (3.4% vs 6.4%; P = not significant), although small sample size limited statistical significance. The length of stay was statistically longer in redo patients (8.7+/-10.8 vs 6.0+/-5.1 days; P < 0.01) and is related to a higher Parsonnet score, increased postoperative pneumonia, and failed percutaneous transluminal coronary angioplasty before redo CABG. We conclude that redo CABG is a different operation from first-time procedures and requires enhanced myocardial preservation. Normothermic cardiopulmonary bypass with cold blood maintenance cardioplegia does not appear to achieve this goal.

Simplified Parsonnet risk scale identifies limits to early patient discharge.

BACKGROUND: Fast-track recovery after coronary artery bypass surgery has influenced patient care positively. Predicting patients who fall off track and require prolonged (> or =7 days) hospitalization remains uncertain. The Parsonnet risk assessment score is effective in predicting length of stay, but is limited by inaccurate subdivision of risk categories. We simplified the Parsonnet risk scale to better identify patients eligible for fast-track recovery. METHOD: The cases of 604 consecutive patients who underwent isolated coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) were reviewed retrospectively. A rapid recovery protocol emphasizing reduced CPB time, preoperative intra-aortic balloon pump (IABP) criteria, and atrial fibrillation prophylaxis was applied to all patients. The five original divisions of the Parsonnet risk scale were reduced to three risk categories: Low (0-10; Group A), Intermediate (11-20; Group B), High (> 20; Group C). Comparisons of progressive risk categories were analyzed to identify predictive factors associated with fast-track outcomes. RESULTS: The thirty-day operative mortality for the entire group was 3.6%. Three clinical features were identified that distinguished risk progression-female gender, reoperative CABG, and increased age. Additionally, the presence of diabetes (p < 0.05), congestive heart failure (p < 0.01), and peripheral vascular disease (p < 0.001) distinguished Groups A and B, while acute myocardial infarction (p < 0.05) influenced outcomes in Group C. Group A (48%) mean risk score 5.9+/-3.2 was compared to Group B (34%) 14.8+/-2.6, which was further compared to Group C (18%) 26.4+/-2.8. The mean length of stay for Group A (5.3+/-4.1 days) was notably less than Group B (6.1+/-4.7 days; p < 0.05); however, both groups responded favorably to fast-track techniques. Group C did not respond comparably (9.2+/-9.2 vs 6.1+/-4.7 days; p < 0.001) and experienced prolonged recovery. The simplified Parsonnet risk scale did not identify differences in operative mortality and revealed only pneumonia (p < 0.05) and atrial fibrillation (p < 0.01) to be greater in Group C. As risk increased, significantly less revascularization was performed (Group A 3.6+/-1.2 grafts/patient vs Group B 3.3+/-1.2 [p < 0.01]; Group B 3.3+/-1.2 vs Group C 2.5+/-1.0 [p < 0.001]). CONCLUSION: A simplified Parsonnet risk scale (three categories) is an effective tool in identifying factors limiting fast-track recovery. Low- and intermediate-risk patients represent the majority (82%) and respond well to fast-track methods. High-risk patients (18%) are limited by a greater percentage of female patients, reoperative CABG, and the very elderly, resulting in fast-track failure. Strategies to improve recovery in high-risk patients may include evolving off-pump techniques.

Initial experience with beating heart surgery: comparison with fast-track methods.

Cardiopulmonary bypass (CPB) in coronary artery bypass grafting (CABG) may increase postoperative complications in high-risk patients. The goal of this study is to retrospectively review a series of consecutive patients undergoing conventional CABG using a fast-track recovery method and to compare this series with the initial series of patients undergoing beating heart surgery using either the single-vessel minimally invasive approach or the off-pump multivessel bypass technique with a median sternotomy. One hundred fifty-eight consecutive patients underwent CABG. One hundred four patients underwent conventional CABG using CPB with a short-pump fast-track recovery method (Group A). Twenty-nine patients underwent a single-vessel bypass via a left anterior thoracotomy off pump [Group B, minimally invasive direct coronary artery bypass (MIDCAB)]. Twenty-five patients underwent multivessel CABG with a median sternotomy off pump (Group C). Short-pump fast-track (Group A) patients exhibited minimal complications and expedient recovery and received extensive revascularization. Off-pump multivessel patients (Group C) received fewer bypass grafts, had more preoperative comorbidity, and recovered as quickly as lower-risk fast-track short-pump patients (Group A). Single-vessel off-pump patients (Group B, MIDCAB) were younger elective patients and demonstrated no recovery advantage. The overall mortality was 1.8 per cent. The conversion rates from beating heart surgery to CPB for groups B and C were 10.3 and 16 per cent, respectively. The postoperative hospital length of stay for groups A, B, and C were 4.8+/-2.4, 3.9+/-1.8, and 5.2+/-2.3 days, respectively. Eliminating CPB is not as important as reducing exposure for minimizing operative risk. Beating heart surgery is an adjunct to conventional CABG with CPB. The off-pump multivessel bypass technique is best suited for high-risk patients requiring three grafts or fewer, whereas MIDCAB is best suited for single-vessel bypass that cannot be managed using interventional percutaneous techniques; however, the recovery advantage with MIDCAB is not apparent. Patients requiring more than three bypass grafts should undergo conventional CABG with CPB.

Aggressive preoperative use of intraaortic balloon pump in elderly patients undergoing coronary artery bypass grafting.

BACKGROUND: The use of the intraaortic balloon pump (IABP) in patients undergoing coronary artery bypass grafting has been traditionally associated with a high complication rate and adverse outcomes. However, recent reports show that many of these catastrophic outcomes can be avoided by preoperatively placing the IABP in high-risk patients. To further validate these reports, we defined a set of liberal criteria for preoperative IABP insertion and applied them to a series of elderly patients (70 years or older) undergoing isolated coronary artery bypass grafting. METHODS: Two hundred six consecutive patients who underwent isolated coronary artery bypass grafting with cardiopulmonary bypass were retrospectively reviewed. A rapid recovery protocol emphasizing reduced cardiopulmonary bypass time, an anesthetic protocol for early extubation, perioperative administration of corticosteroids and thyroid hormone, and aggressive diuresis was applied to all patients. Patients who required an urgent operation because of failed percutaneous transluminal coronary angioplasty, a critical left main stenosis (70% or greater), pronounced left ventricular dysfunction (left ventricular ejection fraction 40% or less), or unstable angina refractory to medical therapy or who required an emergency reoperation received preoperative IABP support. RESULTS: The 30-day mortality rate for the entire group was 4.4%. There were 97 patients (47%) who received a preoperative IABP (group II) in comparison with 109 patients (53%) who did not fulfill the preoperative insertion criteria (group I). Patients in group II had a lower left ventricular ejection fraction (mean, 46% versus 59%, p<0.001) and a higher incidence of congestive heart failure (35% versus 17%, p<0.01) and acute myocardial infarction (37% versus 17%, p<0.01) than patients in group I. The average postoperative hospital length of stay for patients in group II was slightly longer than for those in group I (9.0+/-10.5 versus 6.0+/-3.7 days, p<0.01). However, there were no statistically significant differences in complication or mortality rates between the two groups. Only 2 patients (2.2%) had complications related to IABP insertion. Lower extremity ischemia occurred in both patients, and both were treated successfully with thromboembolectomy. CONCLUSIONS: Liberal preoperative insertion of the IABP can be performed safely in high-risk elderly patients undergoing coronary artery bypass grafting, with results comparable to those in lower risk patients.

Reduced postoperative atrial fibrillation using multidrug prophylaxis.

BACKGROUND: Atrial fibrillation (AFIB) is the most common complication following coronary artery bypass grafting (CABG). Despite three decades of recognition, efforts to reduce the high incidence reported (15%-30%) have been largely unsuccessful. Reasons for postoperative AFIB are likely multifactorial. As a result, we defined a multidrug prophylaxis based on agents known to be individually effective. This method was applied prospectively to a series of consecutive CABG patients with the goal of reducing the incidence of new-onset postoperative AFIB. METHODS: Isolated CABG with cardiopulmonary bypass was performed on 517 consecutive patients. A rapid recovery protocol emphasizing AFIB multidrug prophylaxis was applied to all patients. All patients received 10 microg of triiodothyronine intraoperatively when the clamp on the aorta was released. Immediately following CABG, parenteral magnesium was administered to assure a serum magnesium > 2.2 mEq/dL. Thyroxine 200 microg was administered parenterally to all patients on postoperative days 1 and 2. Metoprolol (25 mg to 100 mg/day) was begun on all patients after extubation provided: heart rate > 85 beats/min and systolic blood pressure > 130 mmHg. Parenteral procainamide (12 mg/kg) loading dose, followed by a maintenance dose (2 mg/min), was used for patients who developed premature atrial contractions (> 1/min), nonsustained supraventricular tachycardia, or any episodes of atrial fibrillation. All patients also received postoperative digitalization, steroids, and aggressive diuresis. RESULTS: The 30-day operative mortality was 3.7%. The overall incidence of new-onset postoperative AFIB was 10.3% (53 patients). There was no major difference in operative mortality (7.5% vs 3.2%, p = 0.23), Parsonnet risk score, or intraoperative variables between AFIB patients and the non-AFIB patients. Patients presenting with a preoperative acute myocardial infarction (p < 0.05), left main stenosis > or = 70% (p < 0.01), and advanced age > or = 70 years (p < 0.05) were at increased risk of developing AFIB. The length of stay for patients with AFIB was 9.9 +/- 9.6 days versus 5.9 +/- 5.2 days (p < 0.001). CONCLUSION: Application of a multidrug prophylaxis can reduce postoperative AFIB to a low incidence. Identification of associated clinical features can help predict patients at risk for postoperative AFIB. Additional strategies to target postoperative AFIB may include treatment at the earliest recognition of atrial rhythm instability.

Coronary artery bypass grafting "on pump": role of three-day discharge.

BACKGROUND: A new emphasis has been directed toward "off-pump" coronary artery bypass grafting to avoid the morbidity of cardiopulmonary bypass and further reduce the postoperative hospital length of stay. With the intent of achieving a hospital discharge for "on-pump" coronary artery bypass grafting procedures comparable with the same procedures "off pump," we applied a rapid-recovery protocol with particular attention paid to patients eligible for discharge on the third postoperative day. METHODS: The cases of 104 consecutive patients who underwent isolated coronary artery bypass grafting using cardiopulmonary bypass were retrospectively reviewed. A rapid-recovery protocol emphasizing reduced cardiopulmonary bypass time, an anesthesia protocol for early extubation, perioperative administration of corticosteroids and thyroid hormone, and aggressive diuresis was applied to all patients. The goal during the first 24 hours postoperatively was to achieve early extubation as well as a mild state of negative fluid balance and to ensure absence of postoperative bleeding and a safe transfer from the intensive care unit to a monitored floor. On the second postoperative day, chest drains were discontinued, and aggressive ambulation therapy was instituted. If at 72 hours postoperatively the patient was walking without assistance, had return of normal bowel function, and had no atrial fibrillation, a 3-day discharge home was planned. RESULTS: The 30-day mortality rate for the entire group was 1.9%. The average postoperative hospital length of stay for the entire series was 4.8 +/- 2.4 days. Of the 102 survivors, 30 patients (29%) were discharged within 3 days postoperatively (group 1), and 72 patients (71%) were discharged after the third postoperative day (group 2). Patients in group 1 were younger and had fewer comorbid conditions. Compared with group 2, group 1 had fewer patients with diabetes (7% versus 28%; p < 0.05), congestive heart failure (7% versus 18%), symptomatic vascular disease (0% versus 11%), chronic obstructive pulmonary disease (0% versus 10%), ambulatory difficulties (0% versus 10%), and the requirement of an intraaortic balloon pump preoperatively (13% versus 35%). Group 1 patients also had almost no complications and a lower readmission rate (3.3% versus 6.9%). CONCLUSIONS: With the application of a rapid-recovery protocol to patients undergoing "on-pump" coronary artery bypass grafting, discharge home within 3 days postoperatively is attainable and safe for patients who have minimal comorbid conditions.

Rapid recovery after coronary artery bypass grafting: is the elderly patient eligible?

BACKGROUND: Rapid recovery protocols after coronary artery bypass grafting have been applied successfully to young patients with normal ventricular function. However, the success of such protocols when applied to the elderly population has not been thoroughly validated, and at some centers there is still reluctance in allowing elderly patients to be discharged early from the hospital. METHODS: One hundred fifty-two consecutive younger patients (< 70 years) were compared retrospectively with 167 consecutive elderly patients (> or = 70 years) who underwent isolated coronary artery bypass grafting using cardiopulmonary bypass. A rapid recovery protocol emphasizing an anesthetic protocol for early extubation, reduced cardiopulmonary bypass time, and perioperative administration of corticosteroids and thyroid hormone was applied to all patients. The protocol also emphasized early identification and management of postoperative atrial fibrillation, a proactive negative fluid balance, rapid return of bowel function, mobilization of the patient, and aggressive use of the intraaortic balloon pump preoperatively. RESULTS: The 30-day mortality rate for the younger group of patients was 3.3% (Parsonnet risk 7.2 +/- 6.2), compared with 4.2% (Parsonnet risk, 17.7 +/- 6.8) for the elderly group of patients. There were no statistically significant differences in the 30-day mortality rates or postoperative complications between the elderly and younger patient groups. Rapid recovery with discharge before the fifth postoperative day was achieved in 19% of the elderly, in comparison with 48% of the younger patients (p < 0.001). The younger patients were discharged earlier after operation than the older patients (5.7 +/- 5.2 versus 8.0 +/- 8.5 days; p < 0.01). CONCLUSIONS: Application of the rapid recovery protocol helped expedite recovery for all patients regardless of age, acuity of illness, or associated conditions. Although younger patients had a significantly shorter postoperative length of hospital stay, older patients performed well and are suitable candidates for rapid recovery protocols.

Rapid recovery of octogenarians following coronary artery bypass grafting.

BACKGROUND: Rapid recovery protocols for coronary artery bypass grafting (CABG) have resulted in major decreases in postoperative hospital length of stay (LOS) when applied to younger patients undergoing elective procedures. However, the effectiveness of rapid recovery protocols when applied to octogenarians has not been thoroughly studied. METHODS: Thirty-seven consecutive octogenarians underwent isolated CABG utilizing cardiopulmonary bypass (CPB). A protocol emphasizing preoperative placement of the intra-aortic balloon pump, reduced CPB time, early extubation, perioperative steroids, thyroid hormone, and aggressive postoperative diuresis was used. RESULTS: The 30-day operative mortality for the entire series was 5.4%. Twenty-five patients (71%, group I) were discharged in < 10 days postoperatively (average LOS of 6.3 +/- 1.6 days), while ten patients (29%, group II) were discharged at 10 or more days postoperatively (average LOS of 20.3 +/- 8.0, p < 0.001). Patients in group II were found to have a higher incidence of obesity (50% vs 4%, p < 0.01), symptomatic peripheral vascular disease (60% vs 8%, p < 0.01), and preoperative ambulatory difficulties (50% vs 0%, p < 0.01). The incidence of complications was 31% for the entire series, with no differences between the groups. CONCLUSION: Octogenarians performed well under a rapid recovery protocol, with 71% being discharged in < 10 days postoperatively, while patients with obesity, symptomatic peripheral vascular disease, and ambulatory difficulties rehabilitated more slowly.

Video-thoracic surgery for treatment of end-stage bullous emphysema and chronic obstructive pulmonary disease.

Surgical treatment of emphysema and chronic obstructive pulmonary disease (COPD) has received renewed attention because of advances in instrumentation and techniques. Our approach includes video-assisted thoracotomy, neodymium-Yag and KTP laser plication of emphysematous bullae, pulmonary resection using reinforced stapling, and pleurodesis: reduction pneumonoplasty. In a 9-month period, 28 patients (age 52 to 78, 23 men and 5 women) with end-stage disease underwent reduction pneumonoplasty. Oxygen therapy was required in 82 per cent, steroid therapy was used in 86 per cent, and the preoperative FEV1 averaged 0.68 +/- 0.05. The most severely diseased lung was determined by physical, chest film, and CT scan, and this lung had reduction pneumonoplasty. There were no hospital mortalities. Prolonged postoperative air leaks occurred in 42 per cent of patients. Postoperatively FEV1 was 0.91 +/- 0.35. Lung size (chest film) showed 21.6 per cent reduction in volume. Subjective improvement was noted in 78.6 per cent (22/28) of patients, and no patient reported worse symptoms. Half of the steroid-using patients required a reduced steroid dose or no steroid therapy, and 5/23 (21.7%) patients had reduced oxygen requirements. Reduction pneumonoplasty can improve the symptoms of severe emphysema and COPD. Our results with treatment of one lung suggest that further improvement may be anticipated by proceeding with surgery for the contralateral lung.

Concepts in the application of pneumatic ventricular assist devices for ischemic myocardial injury.

The clinical results of "bridge-to-recovery" from ischemic myocardial injury using pneumatic ventricular assist devices (VADs) have been disappointing, because no significant improvement in the hospital discharge rate (25%) has been observed during the past 10 years. Interestingly, similar results have been reported using the less sophisticated and more widely available centrifugal pumps. It is well recognized that appropriate patient selection and early device implantation are important determinants of patient survival; however, it is less clear why there is a lack of difference in the results between pneumatic VADs and the centrifugal pumps. The reasons for the lack of difference in the results between pneumatic VADs and centrifugal pumps are multifactorial, and to some extent may be due to a conservative approach in the application of the more capable pneumatic VADs. In an effort to provide a more effective approach to the clinical application of pneumatic VADs for bridge-to-recovery, two pneumatic devices (the Jarvik 7-70 total artificial heart and the Symbion acute VAD) were functionally characterized using an in vitro mock circulatory system. The performance under pneumatic VAD asynchronous pumping compared to electrocardiogram synchronous counterpulsation was also evaluated. Based upon the results obtained, a two phase approach was developed. In the initial phase (i.e., the first 12-48 hrs), device output is maximized through asynchronous pumping to rapidly reverse the effects of cardiogenic shock. During the second phase (i.e., after hemodynamic stabilization and early evidence of end-organ recovery), electrocardiogram synchronous counterpulsation is used to focus more specifically on recovery of the heart.(ABSTRACT TRUNCATED AT 250 WORDS)

Emergency thoracotomy with lung resection following trauma.

Over a 7-year period, 9443 trauma patients were evaluated with 2934 (31%) sustaining chest trauma. Of these, 347 (12%) patients required thoracotomy, with 12 patients undergoing emergency lung resection. Mean age was 23.1 years with mean Injury Severity Score of 32. Mechanism of injury was blunt in three (25%), gunshot wound in seven (58%), and stab wound in two (17%). Associated injuries included head injury in two (17%), intra-abdominal injury requiring laparotomy in four (33%), cardiac injury in three (25%), and great vessel injury in one (8%). Indications for operation included persistent hemorrhage in 11 and suspected tracheobronchial disruption in one. Non-anatomic lung resection was performed in five patients, lobectomy in three patients, and pneumonectomy in four patients. Overall mortality was 33 per cent: 20 per cent for non-anatomical lung resection, 33 per cent for lobectomy, and 50 per cent for pneumonectomy. All survivors fully recovered except for one patient with an associated head injury. Our experience supports the selective use of lung resection, including pneumonectomy, to immediately control hemorrhage and to impact survival in severe chest trauma.

Techniques for optimization of pulsatile ventricular assist device support.

For some time now researchers have argued the efficacy of pulsatile versus nonpulsatile hemodynamic support. Pulsatile systems, while providing a more physiological pumping source, are burdened with a multiparametric output function that can greatly affect the utility of such ventricular assist device (VAD) support. A simplified approach to the optimization of the pulsatile VADs' output function has been developed. This approach yields device outputs of approximately 5.5 L/min at physiologic pressures while demonstrating clinically acceptable blood chemistry. Obtaining this optimal operating point involves the determination of the VAD system output function for a range of fill-enhancing vacuum settings. A quantitative method for evaluating synchronous versus asynchronous pumping modes as related to coronary perfusion is also demonstrated.

A simple method to avoid thrombus formation at the de-airing port of the acute ventricular assist device.

De-airing of the acute ventricular assist device using the designed port has resulted in thrombus formation at the site of device puncture in three of four ventricular assist devices in place during long-term (more than 72 hours) support. Disruption of the inner biomer coating by blunt needle insertion for de-airing of the prosthetic ventricle is the apparent underlying cause. Because of the obvious hazard of subsequent embolization, we describe a simple and effective method of de-airing the acute ventricular assist device with use of a jejunostomy kit.

Ventricular fibrillation complicating endomyocardial biopsy of a cardiac allograft.

Transvenous endomyocardial biopsy remains the most useful diagnostic aid in assessing rejection in the transplanted heart. Although invasive, the complications associated with endomyocardial biopsy are few, and the procedure is generally regarded as safe. We report a case of apparent ventricular fibrillation complicating transvenous endomyocardial biopsy. Histologic section revealed evidence of moderate acute rejection. This case represents the first report of a life threatening ventricular dysrhythmia following routine endomyocardial biopsy in a cardiac transplant recipient.

Successful treatment of acute allograft failure using pneumatic biventricular assistance.

A 61-year-old man underwent orthotopic heart transplantation complicated by acute allograft failure. Management entailed placement of two ventricular assist devices, and there was subsequent hemodynamic stabilization. Ventricular assistance continued for 8 days, at which time graft recovery resulted in successful explanation of the devices. Subsequent recovery was uneventful, and the patient was discharged on the 28th postoperative day. Methods of optimizing interoperative device cardiac output and synchronous-mode weaning are discussed.

Initial clinical evaluation of carotid artery laser endarterectomy.

Clinical study of carotid artery laser endarterectomy began April 15, 1988. This report describes the first 10 cases that were performed in nine patients (five men and four women, mean age 70 years). Indications were asymptomatic stenosis (5), transient ischemic attacks (4), and stroke in evolution (1). There were two emergency cases and eight elective cases (including one reoperative case). Surgical exposure, systemic heparinization, vascular control, and a longitudinal arteriotomy were used. The cleavage plane between atheromas and media was developed with argon ion laser radiation (488 and 514.5 nm) directed through a 300 microns quartz fiber at power 1.0 W. Laser radiation was used to cut the atheromas out of the arteries and weld the end points. Residual atheromatous debris were vaporized with individual laser exposures. Arteriotomies were closed with sutures, and blood flow was restored. The endarterectomies were 3.9 +/- 1.1 cm long and required 330 +/- 97 joules. Mean clamp time was 22.5 +/- 7.9 minutes. Shunts were used in two cases. There were no arterial perforations or injuries as a result of laser light. Complications were hematoma (1), respiratory arrest (1), and transient neurologic deficit (1). Carotid endarterectomy is technically feasible with argon ion laser radiation. In the present series, postoperative observations, averaging 12 months and ranging from 5 to 19 months, have shown satisfactory results. No angiographic follow-up examinations were carried out.