Specialized Thoracic Adapted Recovery Model for Thoracic Organ Recovery: a 15-Year Review

BACKGROUND

To review outcomes from a regionalized heart and lung transplant service over a 15-year period.

METHODS

Data on organ procurements made by the Specialized Thoracic Adapted Recovery (STAR) team. The STAR team staff recorded data from November 2, 2004 to June 30, 2020, were reviewed.

RESULTS

The STAR teams recovered thoracic organs from 1118 donors between November 2004 and June 2020. The teams recovered 978 hearts, 823 bilateral lungs, 89 right lungs and 92 left lungs, and 8 heart and lung sets. A total of 79% of hearts and 76.1% of lungs were transplanted, whereas 2.5% of hearts and 5.1% of lungs were declined; the remainder were used for research, valves, or abandoned. A total of 47 transplantation centers received at least 1 heart, and 37 centers received at least 1 lung during this period. The 24-hour graft survival among organs recovered by STAR teams was 100% for lungs and 99% for hearts.

CONCLUSIONS

A specialized regional thoracic organ procurement team may improve transplantation rates.

Simulated Regionalization of Heart and Lung Transplantation in the United States

We simulated the impact of regionalization of isolated heart and lung transplantation within United Network for Organ Sharing (UNOS) regions. Overall, 12 594 orthotopic heart transplantation (OHT) patients across 135 centers and 12 300 orthotopic lung transplantation (OLT) patients across 67 centers were included in the study. An algorithm was constructed that "closed" the lowest volume center in a region and referred its patients to the highest volume center. In the unadjusted analysis, referred patients were assigned the highest volume center's 1-year mortality rate, and the difference in deaths per region before and after closure was computed. An adjusted analysis was performed using multivariable logistic regression using recipient and donor variables. The primary outcome was the potential number of lives saved at 1 year after transplant. In adjusted OHT analysis, 10 lives were saved (95% confidence interval [CI] 9-11) after one center closure and 240 lives were saved (95% CI 209-272) after up to five center closures per region, with the latter resulting in 1624 total patient referrals (13.2% of OHT patients). For OLT, lives saved ranged from 29 (95% CI 26-32) after one center closure per region to 240 (95% CI 224-256) after up to five regional closures, but the latter resulted in 2999 referrals (24.4% of OLT patients). Increased referral distances would severely limit access to care for rural and resource-limited populations.

Risk Factors for De Novo Malignancy Following Lung Transplantation

Risk factors for non-skin cancer de novo malignancy (DNM) after lung transplantation have yet to be identified. We queried the United Network for Organ Sharing database for all adult lung transplant patients between 1989 and 2012. Standardized incidence ratios (SIRs) were computed by comparing the data to Surveillance, Epidemiology, and End Results Program data after excluding skin squamous/basal cell carcinomas. We identified 18 093 adult lung transplant patients; median follow-up time was 1086 days (interquartile range 436-2070). DNMs occurred in 1306 patients, with incidences of 1.4%, 4.6%, and 7.9% at 1, 3, and 5 years, respectively. The overall cancer incidence was elevated compared with that of the general US population (SIR 3.26, 95% confidence interval [CI]: 2.95-3.60). The most common cancer types were lung cancer (26.2% of all malignancies, SIR 6.49, 95% CI: 5.04-8.45) and lymphoproliferative disease (20.0%, SIR 14.14, 95% CI: 9.45-22.04). Predictors of DNM following lung transplantation were age (hazard ratio [HR] 1.03, 95% CI: 1.02-1.05, p < 0.001), male gender (HR 1.20, 95% CI: 1.02-1.42, p = 0.03), disease etiology (not cystic fibrosis, idiopathic pulmonary fibrosis or interstitial lung disease, HR 0.59, 95% CI 0.37-0.97, p = 0.04) and single-lung transplantation (HR 1.64, 95% CI: 1.34-2.01, p < 0.001). Significant interactions between donor or recipient smoking and single-lung transplantation were noted. On multivariable survival analysis, DNMs were associated with an increased risk of mortality (HR 1.44, 95% CI: 1.10-1.88, p = 0.009).

Incorporating Molecular Identification of Meloidogyne spp. into a Large-scale Regional Nematode Survey

A regional nematode survey of potato fields was conducted in the central United States during 2002 and 2003. The survey encompassed seven states and included a morphological and molecular examination of nematodes of regulatory concern from 1,929 soil samples. No regulated pest species were recovered during this survey. Meloidogyne juveniles extracted from soil were identified by mitochondrial and 18S ribosomal molecular markers. Eighty-two DNA sequences representing the two marker regions for Meloidogyne species were submitted to GenBank to facilitate evaluation of marker variability. Sufficient 18S variation was observed among some Meloidogyne species to aid in identification; however, nucleotide sequence from this highly conserved region of 18S did not discriminate among M. arenaria, M. incognita, and M. javanica. The mitochondrial gene region provided greater species discrimination and revealed intraspecific variation among many isolates. One nucleotide substitution found in a subset of M. hapla isolates from west Texas and New Mexico affected a DraI restriction site used in the PCR/RFLP diagnostic protocol. None of the mitochondrial sequence variants observed in this study compromised the PCR/RFLP identification protocol for M. chitwoodi. Additional sequence analysis is recommended for validation and evaluation of genetic markers used in diagnostic decisions.

Technique to prevent limb ischemia during peripheral cannulation for extracorporeal membrane oxygenation

Prolonged extracorporeal support using femoral cannulation may cause limb ischemia. A technique is described using antegrade, retrograde arterial perfusion and venous drainage to prevent limb ischemia.

Bronchogenic carcinoma in lung transplant recipients

Although lung transplant recipients have a higher prevalence of non-melanoma skin cancers and lymphoma than the general population, the same has not been noted for bronchogenic carcinoma. If an increased prevalence of bronchogenic carcinoma exists, contributing factors may include the high rate of previous tobacco use in this population and/or the chronic immunosuppression used to prevent allograft rejection. With time, the incidence of bronchogenic carcinoma in the lung transplant population is likely to parallel the increasing longevity and number of transplanted individuals. We describe 2 cases of bronchogenic carcinoma in lung transplant recipients that demonstrate the morbidity associated with the discovery or development of bronchogenic carcinoma in this population.

Airway complications after lung transplantation: treatment and long-term outcome

BACKGROUND

Airway complications are a significant cause of morbidity after lung transplantation. Effective treatment reduces the impact of these complications.

METHODS

Data from 123 lung (99 single, 24 bilateral) transplants were reviewed. Potential risk factors for airway complications were analyzed. Stenoses were treated with expanding metal (Gianturco) stents.

RESULTS

Mean follow-up was 749 days. Thirty-five complications developed in 28 recipients (complication rate: 23.8%/anastomosis). Mean time to diagnosis was 47 days. Only Aspergillus infection and airway necrosis were significantly associated with development of complications (p < 0.00001 and p < 0.03, respectively). Stenosis was diagnosed an average of 42 days posttransplant. Average decline in forced expiratory volume in 1 second (FEV1) was 39%. Eighteen patients (13 single and 5 bilateral) required stent insertion. Mean increase in FEV1 poststenting was 87%. Two stent patients died from infectious complications. Six patients required further intervention. Long-term survival and FEV1 did not differ from nonstented patients.

CONCLUSIONS

Aspergillus and airway necrosis are associated with the development of airway complications. Expanding metal stents are an effective long-term treatment.

Heart transplant for dilated cardiomyopathy associated with polymyositis

Cardiac involvement is one of the most significant factors in the poor clinical outcome of polymyositis. The case of a 39 year old African American woman with polymyositis, cardiomyopathy, and severe heart failure who had orthotopic heart transplantation is described. Review of the literature reveals that cardiac manifestations of polymyositis are frequent and include conduction system abnormalities, myocarditis, cardiomyopathy, coronary artery atherosclerosis, valvar disease, and pericardial abnormalities.

Novel, ultraslow inactivating sodium current in human ventricular cardiomyocytes

BACKGROUND

Alterations in K+ channel expression and gating are thought to be the major cause of action potential remodeling in heart failure (HF). We previously reported the existence of a late Na+ current (INaL) in cardiomyocytes of dogs with chronic HF, which suggested the importance of the Na+ channel in this remodeling process. The present study examined whether this INaL exists in cardiomyocytes isolated from normal and failing human hearts.

METHODS AND RESULTS

A whole-cell patch-clamp technique was used to measure ion currents in cardiomyocytes isolated from the left ventricle of explanted hearts from 10 patients with end-stage HF and from 3 normal hearts. We found INaL was activated at a membrane potential of -60 mV with maximum density (0.34+/-0.05 pA/pF) at -30 mV in cardiomyocytes of both normal and failing hearts. The steady-state availability was sigmoidal, with an averaged midpoint potential of -94+/-2 mV and a slope factor of 6.9+/-0.1 mV. The current was reversibly blocked by the Na+ channel blockers tetrodotoxin (IC50=1.5 micromol/L) and saxitoxin (IC50=98 nmol/L) in a dose-dependent manner. Both inactivation and reactivation of INaL had an ultraslow time course (tau approximately 0.6 seconds) and were independent of voltage. The amplitude of INaL was independent of the peak transient Na+ current.

CONCLUSIONS

Cardiomyocytes isolated from normal and explanted failing human hearts express INaL characterized by an ultraslow voltage-independent inactivation and reactivation.

Donor cerebral tissue pulmonary emboli in a functioning transplanted lung

Cerebral tissue pulmonary embolus (CTPE) is a rare event following severe blunt or penetrating head trauma and is often complicated by coagulation disturbances and hemorrhage. Donor cerebral tissue pulmonary embolism has been reported to cause lethal, early graft dysfunction in lung transplant recipients. We report a case of donor cerebral tissue pulmonary embolism in a 41-year-old female single lung transplant recipient with excellent post-operative graft function.

Does age limit the effectiveness of clinical pathways after coronary artery bypass graft surgery?

BACKGROUND

Clinical pathways have been shown to be effective in reducing the length of hospital stay after isolated CABG. Few studies, however, have focused specifically on the outcomes of the pathways in regard to the elderly population.

METHODS AND RESULTS

We reviewed our experience with 445 consecutive patients (299 < 70 years old [mean age, 58.2 +/- 0.5 years] and 146 > or = 70 years old [mean age, 75.6 +/- 0.3 years]) who underwent isolated CABG with the expectation of progressing through the same 5-day postoperative pathway. Preoperatively, the elderly had a smaller body surface area (1.87 +/- 0.02 versus 2.00 +/- 0.01; P < 0.001) and a higher incidence of female gender (45.9% versus 26.8%; P = 0.001), cerebrovascular disease (13.7% versus 7.0%; P = 0.022), congestive heart failure (22.6% versus 13.4%; P = 0.013), and 3-vessel coronary artery disease (76.7% versus 65.9%; P = 0.024). Postoperatively, the elderly had a higher incidence of red blood cell transfusion (28.8% versus 9.0%; P = 0.001), atrial fibrillation (37.6% versus 11.7%; P = 0.001), and overall rate of complications (46.6% versus 23.4%; P = 0.001). Mortality rate and length of stay were 5.5% and 7.9 +/- 0.4 days for the elderly versus 1.0% and 6.4 +/- 0.4 days for those < 70 years old (P = 0.004 and P = 0.008), respectively. Of those > or = 70 years old, 34% were discharged in < or = 5 days, 64% in < or = 7 days, and 82% in < or = 10 days versus 64%, 85%, and 93%, respectively, for younger patients (P = 0.001 for all). Multivariate analysis of preoperative variables identified age (P < 0.001), female gender (P < 0.001), hypertension (P = 0.017), chronic obstructive pulmonary disease (P = 0.002), preoperative intra-aortic balloon pumping (P = 0.002), and body surface area (P = 0.003) as significantly related to length of stay. However, when the postoperative variables found to be different by univariate analysis are added to the model, age is only marginally significant (P = 0.079), and red blood cell transfusion and atrial fibrillation are the strongest predictors of increased length of stay, along with intra-aortic balloon pumping and pneumonia (P < 0.001 for all).

CONCLUSIONS

These data suggest that extraordinary modifications of clinical pathways are not needed for success with elderly patients. The increased length of stay is largely attributable to the increased incidence of atrial fibrillation.

Effect of payer status on outcomes of coronary artery bypass surgery in blacks

BACKGROUND

Black patients with coronary artery disease have a higher mortality rate than white Americans. They also have a higher prevalence of hypertension, diabetes mellitus, and renal disease, which may have an effect on mortality rates. The deleterious effect of these comorbidities may be exacerbated by impaired access to secondary prevention strategies and longitudinal care. Therefore, the presence or absence of comprehensive care as indicated by payer status may then affect survival on surgically treated patients. In this study we examined the role of cardiovascular risk factors and insurance carrier status on early outcomes of coronary artery bypass grafting (CABG) surgery in blacks versus white Americans.

METHODS AND RESULTS

From January 1990 to December 1996, 2776 patients (2003 men, 773 women; mean age 63 +/- 10 years), underwent isolated CABG in a multispecialty practice serving a major metropolitan population. There were 494 (17.8%) black patients and 2282 (82.2%) white patients. The proportion of black patients in each payer category was 17.8% commercial, 14.1% managed care, 52.9% Medicaid, and 19.5% Medicare. The effect of preoperative risk factors, including status of operation (elective, urgent, or emergent), sex, race, redo CABG, presence of renal disease, diabetes mellitus, congestive heart failure, myocardial infarction, the completeness of revascularization, age, and left ventricular ejection fraction were analyzed with the chi 2 test for categorical variables and the Student t test for age and ejection fraction. A multiple logistic regression analysis was performed to assess the effect of all variables on mortality rates simultaneously. Black patients had a higher incidence of diabetes mellitus, hypertension, and renal disease than white patients (P < 0.001). Overall, 30-day mortality rate was 2.5% (58 of 2282) in white patients versus 5.5% (25 of 494) for black patients (P < 0.003). Multivariate analysis showed that only emergency surgery status (OR 3.59, P < 0.01), redo CABG (OR 3.78, P < 0.001), hypertension (OR 2.32, P < 0.03), history of congestive heart failure (OR 2.1, P < 0.004), older age (OR 1.07, P < 0.001), and low ejection fraction (OR 0.98, P < 0.003) correlated with mortality rates. Race and payer status were not significant predictors of death.

CONCLUSIONS

These data on CABG surgery in black patients suggest that early death is due to associated risk factors and not due to race or insurance payer status.

Atrial fibrillation after bypass surgery: does the arrhythmia or the characteristics of the patients prolong hospital stay?

STUDY OBJECTIVES

The goal of this study was to determine whether prolonged hospital stay associated with atrial fibrillation or flutter (AF) after coronary artery bypass graft (CABG) surgery is attributable to the characteristics of patients who develop this arrhythmia or to the rhythm disturbance itself.

DESIGN

An investigation was conducted through a prospective case series.

SETTING

Patients were from a single urban teaching hospital.

PARTICIPANTS

Consecutive patients undergoing isolated CABG surgery between December 1994 and May 1996 were included in the study.

INTERVENTIONS

No interventions were involved.

RESULTS

Of 436 patients undergoing isolated CABG surgery, 101 (23%) developed AF. AF patients were older and more likely to have obstructive lung disease than patients without AF, but both patients with and without AF had similar left ventricular function and extent of coronary disease. ICU and hospital stays were longer in patients with AF. Multivariate analysis, adjusted for age, gender, and race, demonstrated that postoperative hospital stay was 9.2+/-5.3 days in patients with AF and 6.4+/-5.3 days in patients without AF (p<0.001).

CONCLUSIONS

Although AF is strongly associated with advanced age, most of the prolonged hospital stay appears to be attributable to the rhythm itself and not to patient characteristics.

A randomized, double-blind comparison of intravenous diltiazem and digoxin for atrial fibrillation after coronary artery bypass surgery

BACKGROUND

Atrial fibrillation (AF) after coronary bypass graft surgery may result in hypotension, heart failure symptoms, embolic complications, and prolongation in length of hospital stay (LOHS). The purpose of this study was to determine whether intravenous diltiazem is more effective than digoxin for ventricular rate control in AF after coronary artery bypass graft surgery. A secondary end point was to determine whether ventricular rate control with diltiazem reduces postoperative LOHS compared with digoxin.

METHODS AND RESULTS

Patients with AF and ventricular rate > 100 beats/min within 7 days after coronary artery bypass graft surgery were randomly assigned to receive intravenous therapy with diltiazem (n = 20) or digoxin (n = 20). Efficacy was measured with ambulatory electrocardiography (Holter monitoring). Safety was assessed by clinical monitoring and electrocardiographic recording. LOHS was measured from the day of surgery. Data were analyzed with the intention-to-treat principle in all randomly assigned patients. In addition, a separate intention-to-treat analysis was performed excluding patients who spontaneously converted to sinus rhythm. In the analysis of all randomly assigned patients, those who received diltiazem achieved ventricular rate control (> or = 20% decrease in pretreatment ventricular rate) in a mean of 10 +/- 20 (median 2) minutes compared with 352 +/- 312 (median 228) minutes for patients who received digoxin (p < 0.0001). At 2 hours, the proportion of patients who achieved rate control was significantly higher in patients treated with diltiazem (75% vs 35%, p = 0.03). Similarly, at 6 hours, the response rate associated with diltiazem was higher than that in the digoxin group (85% vs 45%, p = 0.02). However, response rates associated with diltiazem and digoxin at 12 and 24 hours were not significantly different. At 24 hours, conversion to sinus rhythm had occurred in 11 of 20 (55%) patients receiving diltiazem and 13 of 20 (65%) patients receiving digoxin (p = 0.75). Results of the analysis of only those patients who remained in AF were similar to those presented above. There was no difference between the diltiazem-treated and digoxin-treated groups in postoperative LOHS (8.6 +/- 2.2 vs 7.7 +/- 2.0 days, respectively, p = 0.43).

CONCLUSIONS

Ventricular rate control occurs more rapidly with intravenous diltiazem than digoxin in AF after coronary artery bypass graft surgery. However, 12- and 24-hour response rates and duration of postoperative hospital stay associated with the two drugs are similar.

Reoperative mitral valve surgery via right thoracotomy: decreased blood loss and improved hemodynamics

BACKGROUND AND AIMS OF THE STUDY

Reoperative mitral surgery via sternotomy can be associated with significant complications, including excessive blood loss and injuries to the heart, great vessels and patent coronary artery grafts. The right antero-lateral thoracotomy offers excellent exposure with less risk from re-entry.

MATERIALS AND METHODS

Between 1982 and 1992, 221 patients had repeat mitral valve procedures at our institution. Fifteen of these 221 underwent mitral valve replacement via right thoracotomy. Indications for surgery in each group included bioprosthetic valve failure, paravalvular leak and bacterial endocarditis. Fifteen patients having reoperative mitral valve surgery via right thoracotomy approach were compared with a control group of 33 patient who underwent surgery via repeat sternotomy. All thoracotomy patients underwent mitral replacement or repair with ventricular fibrillation without aortic cross-clamping. Operative time, cardiopulmonary bypass time, requirement for inotropic support, blood loss within the first six postoperative hours, number of blood units transfused, length of ICU stay, days to discharge, and 30-day survival were compared between the two groups. In addition, the preoperative PaO2/FiO2 (P/F) ratio was evaluated as a prognostic indicator.

RESULTS

Bypass time (162 +/- 43 min thoracotomy group vs. 131 +/- 34 min sternotomy group), operative time (389 +/- 100 min thoracotomy group vs. 450 +/- 25 min sternotomy group), ICU stay (6 +/- 8 days thoracotomy group vs. 5 +/- 6 days sternotomy group), P/F ratio (352 +/- 142 thoracotomy group vs. 423 +/- 108 sternotomy group), and 30-day survival (93% thoracotomy group vs. 91% sternotomy group) were not found to be significantly different between groups. Of great significance was the reduction in blood loss (277 +/- 152 ml thoracotomy vs. 651 +/- 504 ml sternotomy, p < 0.05) and blood transfused (2.0 +/- 1.7 units thoracotomy vs. 6.5 +/- 3.3 units sternotomy, p < 0.01) with the thoracotomy approach. Also of significance was a reduction in frequency with which significant inotropic support was needed to separate from cardiopulmonary bypass (26% vs. 63%, p < 0.05). Despite decreased access to the heart for de-airing maneuvers, no cerebrovascular events whatsoever were noted with the thoracotomy approach.

CONCLUSION

The right thoracotomy approach is recommended for redo mitral valve surgery. Despite these advantages, severe pulmonary dysfunction (as indicated by a P/F ratio less than 300) correlated with a prolonged hospital course in four thoracotomy patients; such patients should have repeat sternotomy.

Enrollment in the Health Alliance Plan HMO is not an independent risk factor for coronary artery bypass graft surgery

BACKGROUND

Henry Ford Hospital is the sole provider of cardiac surgical services for the Health Alliance Plan, a health maintenance organization (HMO) that presently serves 450,000 enrollees.

METHODS AND RESULTS

To determine the effect of managed care referral patterns on the outcome of coronary artery bypass graft (CABG) surgery, we retrospectively reviewed two concurrent groups of patients, 569 HMO patients and 225 patients with free-for-service (FFS) insurance, who had undergone isolated primary CABG surgery between January 1, 1990 and January 31, 1994. The 605 patients with Medicare operated on during the same time frame were excluded to obviate age bias. Age, sex, use of cardiac medications, history of prior percutaneous transluminal coronary angioplasty or thrombolytic therapy, history of recent and remote myocardial infarction, extent of coronary disease, presence of preexisting comorbid conditions, and incidence of unstable clinical syndromes and left ventricular dysfunction (ejection fraction < 40%) were comparable for both groups. In hospital mortality (HMO group, 1.9%; FFS group, 2.2%), mean ICU stay (HMO, 2.6 +/- 0.3 days; FFS, 2.3 +/- 0.3 days), and total hospital length of stay (HMO, 9.8 +/- 0.8 days; FFS, 8.6 +/- 0.6 days) were likewise similar.

CONCLUSIONS

These data refute the notion that the gate-keeper mentality often associated with managed-care health insurance vehicles results in delayed referral of patients with coronary artery disease and results in suboptimal outcome.

Use of neodymium yttrium aluminum garnet laser in long-term palliation of airway obstruction

Palliation of acute airway obstruction using the neodymium yttrium aluminum garnet (Nd-YAG) laser was studied in 54 patients who presented over a 42-month period to the Yale cardiothoracic surgery service. Thirty-seven patients had bronchogenic carcinoma; 27 had stage IIIB or IV disease. Nine patients had endobronchial metastases from a primary nonbronchogenic carcinoma. Eight patients had benign disease. A total of 109 Nd-YAG laser tumor ablations were performed. In addition, 32 patients underwent postoperative brachytherapy. Median survival for all patients was 12 months. Patients with bronchogenic carcinoma had a median survival of five months. Fifteen of 20 patients (75%) alive at the time of follow-up reported continued palliation as shown by an improved postoperative Karnofsky score. There was no survival benefit from Nd-YAG laser ablation of endobronchial bronchogenic carcinoma; however, the Nd-YAG laser provided good to excellent palliation in the majority of patients on long-term follow-up.

Culture of intraluminal thrombus during abdominal aortic aneurysm resection: significant contamination is rare

The significance of positive bacterial cultures from intraluminal thrombus in patients undergoing repair of abdominal aortic aneurysm remains controversial. Over the last 4 years, thrombus was cultured during aneurysm repair in 116 patients. All patients received cephalosporin antibiotic before and for 48 h after operation. Although none of the aneurysms appeared to be clinically infected, six patients (5.2%) had positive cultures. Four groups were identified based on the bacteria cultured: group I, coagulase-negative staphylococci, light growth (three patients); group II, coagulase-negative staphylococci, light growth and 'Streptococcus viridans' (one patient); group III, Bacillus sp., heavy growth (Gram-negative stain) (one patient); group IV, Clostridium perfringens, occasional growth (one patient). One of the six patients died during resection; the other five are alive without graft infection at 5-24 (mean 12) months after operation. The absence of graft infection suggests that positive cultures were not clinically significant or were adequately covered by the antibiotic prophylaxis. The incidence of positive cultures was lower than previously reported. Routine culture of aneurysm thrombus in the absence of clinical infection is probably not cost-effective.

Improved ultrastructural lung preservation with prostaglandin E1 as donor pretreatment in a primate model of heart-lung transplantation

Donor pretreatment with prostaglandin E1 as a pulmonary vasodilator has developed as a simple, effective means to provide excellent preservation in heart-lung transplantation. This study was undertaken to investigate the degree of ultrastructural preservation of the lung with prostaglandin E1 and other pulmonary vasodilators in a primate heart-lung transplantation model. Heart-lung transplantation was performed in 14 African green monkeys. Donor cardiac preservation was achieved with cold crystalloid cardioplegic solution (10 ml/kg). Lung preservation was achieved with cold, modified Euro-Collins solution delivered into the main pulmonary artery (60 ml/kg total). Vasodilator agents were administered intravenously 15 minutes before aortic crossclamping. The heart-lung grafts were stored at 4 degrees C for 6 hours. Three groups of animals were studied: five donors with prostaglandin E1 (0.1 to 4.0 micrograms/kg per minute), five donors with prostacyclin (0.1 to 0.35 micrograms/kg per minute), and four donors with nitroprusside (0.8 to 5.0 micrograms/kg per minute). After transplantation, arterial blood gas measurements and lung biopsies were performed at 1- and 3-hour intervals. Five formalin blocks per specimen were sectioned for hematoxylin and eosin staining. Cellular preservation and endothelial cell swelling were evaluated with electron microscopy. The specimens were graded for alveolar hemorrhage, endothelial cell swelling, and cellular preservation (grade 0, minimal, to grade 3, severe) and a mean score was obtained for each preservative agent. Prostaglandin E1-treated specimens demonstrated the least amount of endothelial swelling (mean score of 1.0) compared with prostacyclin- and nitroprusside-treated specimens (mean scores of 1.4 and 2.7, respectively). All nitroprusside-treated specimens demonstrated moderate to severe endothelial cell swelling. Interstitial and alveolar hemorrhage was noted in poorly preserved specimens, but there were no significant differences between groups. We conclude that prostaglandin E1 provides improved cellular preservation by decreasing the extent of endothelial cell swelling as observed on electron microscopy.

Mechanical circulatory support decreases neurologic complications in the treatment of traumatic injuries of the thoracic aorta

The surgical treatment of traumatic injuries of the thoracic aorta is controversial because a number of technical approaches have been recommended. Despite the technique employed, spinal cord ischemia continues to be a persistent problem. Nineteen patients with confirmed aortic injuries secondary to blunt trauma were treated at the Yale-New Haven (Conn) Medical Center from 1984 to 1991. The patients were analyzed in two groups: group 1 (n = 10) underwent repair using mechanical circulatory support and group 2 (n = 9) underwent repair without mechanical circulatory support. Sixteen patients survived. Three patients died of complications of multiple trauma. The groups were comparable with respect to aortic cross-clamp time, preoperative systolic blood pressure, and Injury Severity Score. Three patients in the nonmechanical support group developed neurologic complications (P less than .05). No patient in the mechanical support group had a neurologic complication. We believe that mechanical circulatory support reduces the incidence of neurologic complications following traumatic injuries of the thoracic aorta and should be used whenever clinically feasible.

Right ventricular assist devices and the surgical treatment of right ventricular failure

Treatment of patients with severe right ventricular dysfunction follows a continuum of progressive therapies. If optimization of volume status and inotropic support do not adequately improve right ventricular function, higher levels of mechanical circulatory support are required. A right-sided intraaortic balloon pump has been helpful in such circumstances. The centrifugal pump and the artificial ventricle provide the most effective long-term circulatory support for patients with right ventricular or biventricular failure after cardiopulmonary bypass, myocardial infarctions, or as a bridge to cardiac transplantation. All of these support measures still carry a high morbidity and mortality. Survival in approximately one third of these high-risk patients can be expected with the use of right ventricular assist devices. Cardiopulmonary bypass has also been effective for circulatory support of patients with massive pulmonary emboli.

Skin grafting for repair of a cardiac laceration

Rupture of the right ventricle has been reported as a complication of closed catheter irrigation in poststernotomy mediastinitis. We report the case of a right ventricular rupture that was repaired with a deepithelialized dermal skin graft. The technique is described and management options for these difficult wounds are discussed.

Computed tomographic scan confirmation of paraprosthetic enteric fistula

Aortoenteric anastomotic fistulae and paraprosthetic graft infections are rare but devastating complications following aortic graft surgery. Although the incidence of these complications is reported to be less than 2%, the difficulty in diagnosis and management has led to high mortality rates and extensive morbidity. The majority of patients present with either groin infection or significant gastrointestinal tract bleeding. There is, however, a subset of patients with nonspecific clinical findings in whom routine studies are not diagnostic. Computed tomography was a useful adjunct to the diagnosis of retroperitoneal infection in these patients by demonstrating small collections of periaortic gas or "black dots." The presence of periaortic gas in each instance proved to be a specific sign of a paraprosthetic-enteric fistula, as opposed to a graft infection without intestinal communication.

The management of aortoenteric and paraprosthetic fistulae

Aortoenteric and aortic paraprosthetic fistulae are devastating complications. Most authors recommend total excision of the graft and revascularization of the lower extremities by extra-anatomic bypass. We reviewed the University of Pittsburgh experience with these fistulae in 15 patients between 1977 and 1987. There were 9 aortoenteric fistulae (AEF) and 6 paraprosthetic fistulae (PPF). Seven of the 9 AEF had no abscess surrounding the graft, but communication of the intestine with the aortic anastomosis. One patient died during operation. Six patients underwent a local repair or in situ replacement of the graft. All 6 of those patients survived operation without limb loss. Two of the 9 patients with AEF had evidence of graft infection and underwent total excision of the graft and extra-anatomic reconstruction. Both patients died, one of sepsis and one of aortic stump rupture. All 6 patients with PPF had clinical and operative evidence of overt graft infection and underwent total graft excision and extra-anatomic bypass. Two of these patients died secondary to sepsis. We conclude that AEF, without evidence of graft infection, were safely treated by local repair. Patients with PPF had infected grafts requiring graft removal with significant morbidity and mortality.

Effect of lidocaine treatment on acute spinal cord injury

The effect of continuous infusion of lidocaine on acute spinal cord trauma in cats was studied. Intravenous and subarachnoid administration of lidocaine did not alter generation and conduction of the spinal evoked responses (SERs) in intact animals. The cortical somatosensory evoked responses and SERs were abolished after weight drop injuries of 120 and 400 g-cm. No return of the evoked responses occurred within 4 hours after trauma in either the lidocaine- or the saline-treated groups. Loss of SERs and appearance of an evoked injury potential were sensitive determinants of spinal cord injury. We concluded that lidocaine treatment did not facilitate the return of spinal cord function in this model of acute spinal cord injury.