The Journal of thoracic and cardiovascular surgery

Published by Elsevier
Print ISSN: 0022-5223
Between June 1978 and June 1989, superficial or deep mediastinitis (or both) developed in only five (0.16%) of 3118 consecutive patients. All patients studied underwent cardiac procedures through a median sternotomy and survived more than 7 postoperative days. The surgical team disciplined itself to divide presternal soft tissues with a scalpel and used electrocautery for pinpoint hemostasis only. This 0.16% infection rate was statistically significantly lower than those in 28 previously published studies (Pearson's chi 2 test, p less than 0.05). Twenty-four predisposing factors were evaluated by Fisher's exact test. Among these only an operating time longer than 3 hours is related to sternotomy infections (p = 0.0208), and this effect was not a strong one. Statistical evidence strongly suggests that discriminate use of electrocautery is a major reason for the lowest median sternotomy infection rate reported to date.
Objective: The rate of complete resection (50%) and the 5-year survival (30%) for non-small cell lung carcinomas of the superior sulcus have not changed for 40 years. Recently, combined modality therapy has improved outcome in other subsets of locally advanced non-small cell lung carcinoma. This trial tested the feasibility of induction chemoradiation and surgical resection in non-small cell lung carcinoma of the superior sulcus with the ultimate aim of improving resectability and survival. Methods: Patients with mediastinoscopy-negative T3-4 N0-1 superior sulcus non-small cell lung carcinoma received 2 cycles of cisplatin and etoposide chemotherapy concurrent with 45 Gy of radiation. Patients with stable or responding disease underwent thoracotomy 3 to 5 weeks later. All patients received 2 more cycles of chemotherapy and were followed up by serial radiographs and scans. Survival was calculated by the Kaplan-Meier method and prognostic factors were assessed for significance by Cox regression analysis. Results: From April 1995 to September 1999, 111 eligible patients (77 men, 34 women) were entered in the study, including 80 (72.1%) with T3 and 31 with T4 tumors. Induction therapy was completed as planned in 102 (92%) patients. There were 3 treatment-related deaths (2.7%). Cytopenia was the main grade 3 to 4 toxicity. Of 95 patients eligible for surgery, 83 underwent thoracotomy, 2 (2.4%) died postoperatively, and 76 (92%) had a complete resection. Fifty-four (65%) thoracotomy specimens showed either a pathologic complete response or minimal microscopic disease. The 2-year survival was 55% for all eligible patients and 70% for patients who had a complete resection. To date, survival is not significantly influenced by patient sex, T status, or pathologic response. Conclusions: (1) This combined modality treatment is feasible in a multi-institutional setting; (2) the pathologic complete response rates were high; and (3) resectability and overall survival were improved compared with historical experience, especially for T4 tumors, which usually have a grim prognosis.
Objective: The study objective was to evaluate the long-term survival of patients with radiographically determined noninvasive lung adenocarcinomas. Methods: A prospective, multi-institutional study on image diagnosis to define early (noninvasive) adenocarcinomas of the lung (Japan Clinical Oncology Group 0201) has shown that a consolidation/tumor ratio on thin-section computed tomography 0.25 or less in cT1a (≤2.0 cm) could be used as a better radiologic criterion for a noninvasive pathology than a consolidation/tumor ratio 0.50 or less in cT1a-b (≤3.0 cm). From the prognostic viewpoints, these criteria were evaluated for 545 patients with adenocarcinoma who underwent lobectomy and lymph node dissection. Results: The subjects consisted of 233 men and 312 women with a median age of 62 years. The median follow-up period among overall patients was 7.1 years (range, 0-8.5 years). The overall and relapse-free 5-year survivals of the overall patients were 90.6% and 84.7%, respectively. When a consolidation/tumor ratio 0.5 or less in cT1a-b was used as a cutoff, the 5-year overall survivals of radiologic noninvasive (121 patients, 22.2%) and invasive (424 patients, 77.8%) adenocarcinomas were 96.7% and 88.9%, respectively, and the difference was statistically significant (P < .001, log-rank test). With the use of a consolidation/tumor ratio 0.25 or less in cT1a, the 5-year overall survivals of radiologic noninvasive (35 patients, 12.1%) and invasive (254 patients, 87.9%) adenocarcinomas were 97.1% and 92.4%, respectively, and the difference was not statistically significant (P = .259). Conclusions: The radiologic criteria of a consolidation/tumor ratio 0.25 or less in cT1a (≤2.0 cm) and 0.50 in cT1a-b (≤3.0 cm) were both able to define a homogeneous group of patients with an excellent prognosis before surgery.
Objective: The purpose of the present study was to compare the selection criteria and short-term outcomes among 3 prospective clinical trials using stereotactic body radiotherapy (Radiation Therapy Oncology Group [RTOG] trial 0236), sublobar resection (American College of Surgeons Oncology Group [ACOSOG] trial Z4032), and radiofrequency ablation (ACOSOG trial Z4033). Methods: The selection criteria and outcomes were compared among RTOG 0236 (n = 55), ACOSOG Z4032 (n = 211), and ACOSOG Z4033 (n = 51). Age, Eastern Cooperative Oncology Group performance status, percentage of predicted forced expiratory volume in 1 second, and percentage of predicted carbon monoxide diffusing capacity of the lung were used to perform a propensity-matched analysis among patients with clinical stage 1A in RTOG 0236 and ACOSOG Z4032. Results: The patients in ACOSOG Z4033 undergoing radiofrequency ablation were older (75.6 ± 7.5 years) than those in RTOG 0236 (72.5 ± 8.8 years) and ACOSOG Z4032 (70.2 ± 8.5 years; P = .0003). The pretreatment percentage of predicted forced expiratory volume in 1 second was 61.3% ± 33.4% for RTOG 0236, 53.8% ± 19.6% for ACOSOG Z4032, and 48.8% ± 20.3% for ACOSOG Z4033 (P = .15). The pretreatment percentage of predicted carbon monoxide diffusing capacity of the lung was 61.6% ± 30.2% for RTOG 0236, 46.4% ± 15.6% for ACOSOG Z4032, and 43.7% ± 18.0% for ACOSOG Z4033 (P = .001). The overall 90-day mortality for stereotactic body radiotherapy, surgery, and radiofrequency ablation was 0%, 2.4% (5/211), and 2.0% (1/51), respectively (P = .5). Overall, the unadjusted 30-day grade 3+ adverse events were more common with surgery than with stereotactic body radiotherapy (28% vs 9.1%, P = .004), although no difference was between the 2 groups at 90 days. Among the patients with clinical stage IA in ACOSOG Z4032, 29.3% had a more advanced pathologic stage at surgery. A propensity-matched comparison showed no difference between stereotactic body radiotherapy and surgery for 30-day grade 3+ adverse events (odds ratio, 2.37; 95% confidence interval, 0.75-9.90; P = .18). Conclusions: Among appropriately matched patients, no difference was seen in early morbidity between sublobar resection and stereotactic body radiotherapy. These results underscore the need for a randomized trial to delineate the relative survival benefit of each modality and to help stratify patients considered high risk.
We analyzed the long-term results of valve replacement with the St. Jude Medical bileaflet valve (St. Jude Medical, Inc., St. Paul, Minn.) in our first 1000 implantations between 1978 and 1992. A total of 399 patients had mitral valve replacement, 471 aortic valve, and 130 double (mitral and aortic) valve replacement. The average patient age was 64 +/- 15 years and the majority of patients (52%) had concomitant coronary disease. With 4328 patient-years of follow-up, 83% of the mitral group, 76% of the aortic group, and 77% of the double valve group were free of thromboembolism at 10 years after operation, and 87% of the mitral group, 82% of the aortic group, and 85% of the double valve group were free of valve-related hemorrhage. At 10 years, 91% of the mitral group, 84% of the aortic group, and 84% of the double valve group were free of valve-related death. However, overall survival at 10 years was only 42% +/- 4% for the mitral group, 43% +/- 4% for the aortic group, and 43% +/- 6% for the double valve group. For all three groups, age was a highly significant factor stratifying survival (p < 0.001), as was the presence of coronary disease (all p < 0.001). The excellent freedom from valve-related death at 10 years of 84% to 91% is in striking contrast to the overall survivals of 42% to 43% at 10 years. This difference suggests that the primary factors limiting long-term survival after valve replacement with the St. Jude Medical valve are not valve-related factors, but other patient factors such as age and concomitant coronary disease.
A series of 1,000 specimens of the esophagus was examined grossly and microscopically. The most interesting finding was 3 instances of carcinoma in situ (0.3%). A leiomyoma was found in 5%, dilated veins in 20%, acute esophagitis in 27%, and chronic esophagitis in 76%. In a collateral study of 200 esophagi from newborn infants, one was lined by columnar epithelium.
All surviving patients between 18 and 88 years of age receiving biological or mechanical prosthetic heart valves at the Yale-New Haven Hospital from January 1974 through January 1985 were analyzed for thromboembolism, anticoagulation-related hemorrhage, endocarditis, perivalvular leak, valve failure, need for reoperation, late cardiac death, and valve-related death. The rates of these events were analyzed in linear and actuarial terms over the 11 year period. A total of 533 patients received 606 biological valves (328 aortic, 252 mitral, 24 tricuspid, and two pulmonary, consisting of 482 Carpentier-Edwards, 108 Hancock, 15 Ionescu-Shiley, and one other), with a mean follow-up of 2,571 patient-years and 2,935 valve-years. They were compared with 479 patients with 510 mechanical valves (330 aortic, 175 mitral, and five tricuspid, consisting of 178 Starr-Edwards, 166 St. Jude Medical, 164 Björk-Shiley, and two others), which were implanted for 2,247 patient-years and 2,392 valve-years. We found a significantly increased incidence of thromboembolism (p less than 0.001) and reoperation for perivalvular leak (p less than 0.05) in the mechanical valves compared with the biological valves, but a significantly increased rate of valve failure (p less than 0.001) in the biological valves compared with the mechanical valves. The overall analysis comparing total morbidity and valve-related mortality significantly (p less than 0.01) favored the biological valves in the first 5 years of the study and the mechanical valves (p less than 0.001) in the second 5 years of the study. However, the net 10 year results showed no significant difference between the two types of valves. In summary, we found little direct evidence to strongly support the generalized use of one type of valve over another.
A total of 1,179 vein grafts were studied angiographically in 353 (45%) unselected survivors (male, mean age 45.5 years) of 786 coronary bypass operations. Studies were conducted early (0.96 months), 1 year (12.8 months), and 5 years (59.7 months) postoperatively. A previously described technique was used to grade the patency of the grafts, and a new technique was used to assess intimal irregularity, presumably caused by atherosclerosis; this new technique indicated both intimal surface distribution of disease and profile (relief or elevation). Ten percent, 17%, and 26% of grafts were occluded early, at 1 year, and at 5 years, respectively. Distal anastomotic defects were the commonest cause for low grades in the patency classification. Irregularities in patent grafts increased from 9% at 1 year to 42% at 5 years, with 11% of all the 1 year lesions and 20% of all the 5 year lesions having a high profile (more than 50% graft stenosis); of the lesions categorized as showing the widest surface spread, 17% were in high relief at 1 year and 34% at 5 years. Thus, the lesions we believed to be atherosclerotic proliferated in both surface spread and elevation. All severely diseased grafts at the 1 year study had been normal in outline early; 79% at the 5 year study had been disease free at 1 year. All newly occluded grafts at the 1 year study had been normal in outline and 82% had had good patency early; 78% of newly occluded grafts at the 5 year study had been disease free at 1 year and 77% had had good patency. Normal appearance of the intima in grafts studied at 1 year had no prognostic value for 5 year findings. However, 62% of all grafts with the appearance of intimal disease at 1 year showed deterioration by 5 years, and 28% were occluded. The differences between these outcomes are highly significant (p less than 0.0005). In conclusion, the appearance of intimal irregularity compatible with atherosclerosis in a coronary bypass graft 1 year after operation carried a poor prognosis for adverse angiographic change at 5 years. On the other hand, normally appearing intima at 1 year had no predictive valve for the 5 year study despite a generally better prognosis for nondiseased grafts.
We evaluated the effect of pretreatment with nitric oxide precursor before ischemia on recovery with reperfusion in rat hearts. Isolated rat hearts were perfused with Krebs-Henseleit buffer without (C group) or with 3 mmol/L L-arginine (A group) before 30 minutes of ischemia. The left ventricular function, including heart rate, developed pressure, maximal dp/dt, and coronary flow, were measured before pretreatment and after 10 and 30 minutes of reperfusion. Cyclic guanosine monophosphate (by radioimmunoassay), calcium (by absorption spectrophotometry), and inositol 1,4,5-triphosphate synthesized from tritiated myo-inositol (by ion-exchange chromatography preceding counting) were measured at the same times and immediately after ischemia. Recovery of ventricular function was significantly greater in the A group than in the C group. Pretreatment increased postischemic cyclic guanosine monophosphate content compared with the preischemic level (from 1.06 +/- 0.12 to 1.94 +/- 0.09 pmol/mg protein, p < 0.05). No change in cyclic guanosine monophosphate was evident in the C group. In the C group, inositol triphosphate content increased after 10 minutes of reperfusion beyond the preischemic level (from 0.53 +/- 0.023 to 1.15 +/- 0.045 cpm x 10(-3)/gm, p < 0.05) as did calcium at 30 minutes (from 4.12 +/- 0.164 to 6.86 +/- 0.544 mmol/gm dry weight). In the A group, both of these increases were significantly attenuated. These data suggest that L-arginine pretreatment may reduce calcium overload by increasing cyclic guanosine monophosphate production, which in turn downregulates inositol triphosphate synthesis during reperfusion.
The influence of 35 preoperative and intraoperative characteristics on operative mortality risk after 1,479 isolated aortic valve replacement procedures (1967 to 1981) was investigated utilizing univariate and multivariate logistic regression analyses. Mean age at operation was 58 +/- 13 years; 72% of patients were men. Physiology was classified as aortic stenosis (58%), regurgitation (30%), or both (9%). The overall operative mortality rate was 7% +/- 1%, but there were substantial differences in operative mortality rates among physiological subgroups (aortic regurgitation, 10% +/- 2%; aortic stenosis, 6% +/- 1%; stenosis/regurgitation, 5% +/- 2%). Independent determinants of operative mortality rate in the entire group were advanced New York Heart Association functional class, renal dysfunction, physiological subgroup, atrial fibrillation, and older age. In the aortic regurgitation subgroup, functional class, atrial fibrillation, and operative year were independent predictors. In the aortic stenosis subgroup, the significant determinants were functional class, renal dysfunction, age, prosthetic valve dysfunction, and absence of angina. Concomitant coronary bypass grafting, previous operation, endocarditis, and ascending aortic replacement had no independent predictive effect on operative mortality rate. Thus, the early results of aortic valve replacement can be related to several specific variables describing the functional and physiological status of the patient. Operative mortality rate is not independently related to previous operation or concomitant operative procedures. Specific differences in risk factors exist among the various physiological subgroups, probably reflecting the pathophysiology of the different hemodynamic lesions. This information should provide for a more rational approach to aortic valve replacement, at least in terms of early risk/benefit deliberations.
Through a thoracotomy with surrounding tissue protected, single-dose ; radiation was administered in 10 dogs directly to freshly sutured bronchial ; stumps and esophageal anastomosis in 1500-r doses. Two dogs died as a direct ; result of the radiation. Three animals died, probably of unrelated causes, ; between 197 and 333 days postirradiation, The remaining 5 dogs were sacrificed ; between 699 and 722 days postirradiation. In no instance did the radiation ; prevent healing of the suture lines. Of the 2 dogs that died of the effects of ; radiation, one showed necrosis of the trachea with hemorrhage and the other a ; tracheo-atrial fistula. Of the 3 dogs that died as the result of infection, one ; had empyema with spontaneous drainage but parenchymal necrosis was not present ; and the bronchial stump and esophageal anastomosis were intact. The second ; developed an abscess in the axilla opposite the side operated upon and the ; remaining animal had bilateral pneumonitis. It is doubtful that radiation was a ; contributory cause of death. Thus only 2 of the 8 dogs died as a direct result ; of the radiation. The variable response of the animals in the series is ; difficult to explain. However, the technique and dose did not seriously impair ; healing of the bronchial stump or esophageal anastomosis. (TCO);
Fructose-1,6-bisphosphate is a high-energy intermediate in the anaerobic metabolism. It enhances glycolysis, preserves cellular adenosine triphosphate, and prevents the increase of intracellular calcium during ischemia. The potential neuroprotective effect of fructose-1,6-bisphosphate during hypothermic circulatory arrest was evaluated in a surviving porcine model. Twenty-four pigs were randomly assigned to receive two intravenous infusions of either fructose-1,6-bisphosphate (500 mg/kg) or saline solution. The first infusion was given immediately before a 75-minute period of hypothermic circulatory arrest and the second was given immediately after hypothermic circulatory arrest. The 7-day survivals were 83.3% in the fructose-1,6-bisphosphate group and 41.7% in the control group (P =.09). The treated animals had significantly better postoperative behavioral scores. The administration of fructose-1,6-bisphosphate was associated with higher venous phosphate and sodium levels, lower venous ionized calcium levels, higher blood osmolarity, and a better fluid balance. Intracranial pressure and venous creatine kinase isoenzyme MB were significantly lower in the fructose-1,6-bisphosphate group during rewarming (P =.01 and P =.001, respectively). Among the treated animals, brain glucose, pyruvate and lactate levels tended to be higher, brain glycerol levels tended to be lower, and the histopathologic score of the brain was significantly lower (P =.04). Intravenous administration of fructose-1,6-bisphosphate at 500 mg/kg before and after hypothermic circulatory arrest in a surviving porcine model was associated with better survival, behavioral outcome, and histopathologic score. The observed lower blood creatine kinase isoenzyme MB and brain glycerol levels and the higher brain glucose, pyruvate, and lactate levels in the fructose-1,6-bisphosphate group suggest that this drug has supportive effects on myocardial and brain metabolisms.
Fructose-1,6-diphosphate is a glycolytic intermediate that has been shown experimentally to cross the cell membrane and lead to increased glycolytic flux. Because glycolysis is an important energy source for myocardium during early reperfusion, we sought to determine the effects of fructose-1,6-diphosphate on recovery of postischemic contractile function. Langendorff-perfused rabbit hearts were infused with fructose-1,6-diphosphate (5 and 10 mmol/L, n = 5 per group) in a nonischemic model. In a second group of hearts subjected to 35 minutes of ischemia at 37 degrees C followed by reperfusion (n = 6 per group), a 5 mmol/L concentration of fructose-1,6-diphosphate was infused during the first 30 minutes of reperfusion. We measured contractile function, glucose uptake, lactate production, and adenosine triphosphate and phosphocreatine levels by phosphorus 31-nuclear magnetic resonance spectroscopy. In the nonischemic hearts, fructose-1,6-diphosphate resulted in a dose-dependent increase in glucose uptake, adenosine triphosphate, phosphocreatine, and inorganic phosphate levels. During the infusion of fructose-1,6-diphosphate, developed pressure and extracellular calcium levels decreased. Developed pressure was restored to near control values by normalizing extracellular calcium. In the ischemia/reperfusion model, after 60 minutes of reperfusion the hearts that received fructose-1,6-diphosphate during the first 30 minutes of reperfusion had higher developed pressures (83 +/- 2 vs 70 +/- 4 mm Hg, p < 0.05), lower diastolic pressures (7 +/- 1 vs 12 +/- 2 mm Hg, p < 0.05), and higher phosphocreatine levels than control untreated hearts. Glucose uptake was also greater after ischemia in the hearts treated with fructose-1,6-diphosphate. We conclude that fructose-1,6-diphosphate, when given during early reperfusion, significantly improves recovery of both diastolic and systolic function in association with increased glucose uptake and higher phosphocreatine levels during reperfusion.
Repair of Ebstein anomaly and impaired right ventricular function pose challenges for the cardiac surgeon. The bidirectional cavopulmonary shunt may improve early outcomes. We reviewed our experience with the 1.5-ventricle repair in this patient population. Between July 1999 and March 2006, 169 patients underwent operations to repair Ebstein anomaly. Fourteen patients had a bidirectional cavopulmonary shunt constructed. The median age at operation was 6 years (17 months-57.8 years). All of the patients had severe Ebstein anomaly with dilated right-sided chambers and/or right ventricular dysfunction. The mean left ventricular ejection fraction was 54.5% (range 35%-72%). Three patients were initially referred for heart transplantation, and the bidirectional cavopulmonary shunt allowed a conventional repair. Procedures included bidirectional cavopulmonary shunting (14), tricuspid valve replacement (11), tricuspid valve repair (2), and right ventricular resection (3). Shunting was planned preoperatively in 9 patients; the indication in 5 other patients was hemodynamic instability after separation from cardiopulmonary bypass. One patient died of multiple organ failure. Median follow-up in 10 patients was 18 months (3 months-6.5 years). The preoperative left ventricular ejection fraction of less than 50% improved in 3 patients to greater than 50% postoperatively. The 1.5-ventricle repair can be utilized in patients with severe Ebstein anomaly and impaired right ventricular function who are at high risk for surgical treatment. We believe the bidirectional cavopulmonary shunt may be considered as a planned procedure, as an intraoperative salvage maneuver, or as an alternative to cardiac transplantation in selected patients.
Aneurysms and dissections of the descending thoracic aorta represent a complex substrate with a variety of therapeutic options. The introduction of thoracic endovascular aortic repair (TEVAR) has revolutionized the treatment of thoracic aortic disease. However, longitudinal analyses of post-TEVAR outcomes appropriately stratified by aortic disease remain limited. A total of 11,996 patients undergoing TEVAR from 2005-2010 were identified from the Medicare/Centers for Medicare and Medicaid Services database. Patients were stratified by underlying aortic disease and the presence of Current Procedural Terminology (CPT) codes. Survival was assessed using Kaplan-Meier analysis. Cox proportional hazards analysis determined predictors of survival from TEVAR. After TEVAR, patients had a median survival of 57.6 months (95% confidence interval, 54.9-61.3 months). Although patients without CPT codes had significantly fewer recorded comorbidities, TEVAR survival was comparable between patients with and without CPT codes (56.3 vs 59.5 months, P = .54). The early and late incidence of death varied significantly by aortic disease. Patients with aortic rupture, acute aortic dissection, and aortic trauma had the highest early incidence of death, whereas late survival was highest in patients with acute aortic dissection, aortic trauma, and isolated thoracic aortic aneurysm. Although hospital TEVAR volume was not associated with survival, an independent hospital effect (determined by using a mixed-effect Cox model) associated certain hospitals with a hazard for death 50% of what it was at other hospitals. TEVAR has been applied to a multitude of aortic diseases in the Medicare population; early and late post-TEVAR survival varies by aortic disease. The late incidence of death remains high in TEVAR recipients, although certain aortic diagnoses such as acute aortic dissection, aortic trauma, and isolated thoracic aortic aneurysm were associated with improved late survival. An independent hospital effect, but not hospital volume, is correlated with post-TEVAR survival. Future analyses of TEVAR outcomes using the Medicare database should adjust for underlying aortic diagnoses and the presence of CPT codes. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.
Destination therapy experience using long-term left ventricular assist devices was analyzed relative to the benchmark Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure trial to evaluate the potential for improving outcomes with this groundbreaking therapy for advanced heart failure. The largest single-center experience with destination therapy in the United States (Utah Artificial Heart Program, LDS Hospital, Salt Lake City, UT) was retrospectively analyzed. All destination therapy recipients (n = 23) presented with chronic, advanced heart failure, meeting indications for destination therapy adopted from the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure trial. All received HeartMate left ventricular assist devices (Thoratec Corp, Pleasanton, Calif), with 87% receiving an improved XVE model. Advanced practice guidelines were implemented using a multidisciplinary approach. Survivals (Kaplan-Meier, log-rank analyses) and adverse events (Poisson regression) were compared with those of the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure left ventricular assist device group (n = 68). Survival in the destination therapy group was significantly increased (P = .007), with an overall reduction in mortality of 66%. The 2-year survival was 77% for destination therapy compared with 29% for the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure left ventricular assist device group (P < .0001). The 1-year survival was 77% for destination therapy compared with the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure left ventricular assist device rate of 52% (P = .036). Adverse events decreased by 38% (3.90 per patient-year in the destination therapy group compared with the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure left ventricular assist device rate of 6.32). Factors related to severity of illness met Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure-like criteria for both groups. This analysis provides evidence that long-term destination therapy can be improved well beyond the pioneering experience of the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure trial. With continued evolution of devices, management, and patient selection, outcomes approaching those of heart transplantation may be possible.
Between May 1980 and December 1984, 1000 Medtronic Hall prostheses (538 mitral and 462 aortic) were implanted in 852 patients (mean age 30 +/- 15 years) of a third-world type of population group. The most common valve lesions were aortic and mitral regurgitation, and 32% of the patients were in New York Heart Association class IV or greater. Double valve (aortic and mitral) operations were performed in 209 patients. The 782 operative survivors were followed up for 2 to 6.5 years (mean 3.5 years) for a cumulative 2676 patient-years. Valve performance was analyzed in each position separately for valve-related complications. Results for the whole group for the following events are expressed in both linearized (percent/patient-year) and actuarial (percent +/- standard error of the mean freedom at 5 years) terms, respectively: valve-related mortality, 2.9 and 92 +/- 2; reoperation, 1.9 and 90 +/- 2; systemic thromboembolism, 3.3 and 85 +/- 2; thrombotic obstruction, 1.2 and 95 +/- 1; prosthetic valve endocarditis, 0.7 and 97 +/- 1; anticoagulant-related hemorrhage, 0.7 and 98 +/- 1; and periprosthetic leak, 0.7 and 97 +/- 1. Corresponding composite figures for valve failure were 4.3 and 85 +/- 2, and for all valve-related morbidity and mortality were 6.7 and 75 +/- 3. Thrombotic obstruction (fatal in 71% of the cases), anticoagulant-related hemorrhage (61% fatal), and prosthetic endocarditis (44% fatal) were the most lethal complications. Although the differences did not reach statistical significance, aortic prostheses appeared to have a higher incidence of complications than the mitral prostheses. When analyzed against the background of an essentially noncompliant population group, the Medtronic Hall prosthesis proved to be reliable and remarkably free from structural failure. The high incidence of thromboembolism and thrombotic obstruction still mandates anticoagulation.
Brachial plexus injury is a typical complication after median sternotomy. A prospective study was performed on 1000 consecutive patients to determine whether preventive actions, including lower position and least possible opening of the sternal retractor, help to reduce the complication rate. Twenty-seven patients were observed with postoperative brachial plexus injury. Nerve conduction measurements and electromyography were performed. Patients without preparation of the internal mammary artery had a complication rate of less than 1%, whereas the complication rate of those patients with preparation of the internal mammary artery was as high as 10.6%. The main symptoms were continuous pain and motor and sensory disturbances. Most frequent were lesions corresponding to the roots C8-T1. Six patients had Horner's syndrome; three had ptosis only with no other signs of Horner's syndrome. Symptoms persisted in eight patients more than 3 months after the operation, and one patient still had intractable pain. Increasing use of internal mammary artery grafts in coronary artery bypass demands measures to protect the brachial plexus.
Operative transluminal coronary artery balloon angioplasty has been used for over 3000 lesions in 1000 patients since 1980. Initially it was only used for distal stenoses not accessible to coronary bypass grafting in 200 patients. Recatheterization of patients who had intraoperative transluminal balloon angioplasty of the proximal left anterior descending, right, and circumflex coronary arteries 3 years previously revealed excellent patency of both the bypass grafts and the dilated native coronary arteries. This observation supports the thesis that with properly constructed bypass anastomoses competitive flow does not significantly mandate graft thrombosis. Subsequently, intraoperative balloon angioplasty has been performed for both proximal and distal stenoses in 800 patients to improve native coronary artery perfusion and maximize revascularization. Follow-up from 1 to 7 years revealed perioperative myocardial infarction in 21 patients (2.1%) and death in 19 patients (1.9%). Recatheterization from 1 to 7 years after the operation in 51 patients (41 with symptoms) revealed that patency was almost as prevalent in arteries subjected to angioplasty (82%; 137/167) as in bypass grafts (84%; 102/122). Intraoperative balloon angioplasty appears to improve coronary artery perfusion without detrimental competitive flow when used with bypass grafts.
Coronary artery bypass grafting (CABG) with incomplete revascularization (ICR) is thought to decrease survival. We studied the survival of patients with ICR undergoing total arterial grafting. In a consecutive series of all-comer 1000 patients with isolated CABG, operative and midterm survival were assessed for patients undergoing complete versus ICR, with odds ratios and hazard ratios, adjusted for European System for Cardiac Operative Risk Evaluation category, CABG urgency, age, and comorbidities. In this series of 1000 patients with 98% arterial grafts (2922 arterial, 59 vein grafts), 73% of patients with multivessel disease received bilateral internal mammary artery grafts. ICR occurred in 140 patients (14%). Operative mortality was 3.8% overall, 8.6% for patients with ICR, and 3.2% for patients with complete revascularization (P = .008). For operative mortality using multivariable logistic regression, after controlling for European System for Cardiac Operative Risk Evaluation category (P < .001) and CABG urgency (P = .03), there was no evidence of a statistically significant increased risk of death due to ICR (odds ratio, 1.73; 95% confidence interval, 0.80-3.77). For midterm follow-up (median, 54 months [interquartile range, 27-85 months]), after controlling for European System for Cardiac Operative Risk Evaluation category (P < .001) and comorbidities (P = .017) there was a significant interaction between age ≥ 80 years and ICR (P = .017) in predicting mortality. The adjusted hazard ratio associated with ICR for patients older than age 80 years was 5.7 (95% confidence interval, 1.8-18.0) versus 1.2 (95% confidence interval, 0.7-2.1) for younger patients. This is the first study to suggest that ICR in patients with mostly arterial grafts is not associated with decreased survival perioperatively and at midterm in patients younger than age 80 years. Arterial grafting, because of longevity, may balance survival between complete revascularization and ICR.
Intraoperative pleural lavage cytology for lung cancer has not been widely accepted. The prognostic significance of this procedure has yet to be intensively analyzed because the reports published thus far have involved small patient populations. We therefore performed a large prospective trial of pleural lavage cytology to elucidate its importance. Cytologic status of pleural lavage fluid before any manipulation of the lung was examined in 1000 consecutive patients with non-small cell lung cancer but no pleural effusion who underwent tumor resection. Forty-five (4.5%) of 1000 patients had positive cytologic findings. Positive cytologic findings were observed more frequently in patients with adenocarcinoma, advanced stage, higher involvement of lymph nodes, pleural involvement of the tumor, lymphatic permeation, vascular invasion, high level of serum carcinoembryonic antigen, and male sex. The survival rate for 5 years was 28% in patients with positive findings and 67% in patients with negative findings (P <.0001). Among 587 patients with stage I disease, 13 (2.2%) had positive findings, and their 5-year survival was 43%, which was significantly poor compared with that of patients with negative findings (81%, P =.0009). Multivariable analysis demonstrated that pleural lavage cytology was an independent prognostic determinant (P =.0290). Regarding the recurrence pattern in patients with positive findings, distant metastases (19/45 [42.2%]) were observed more frequently rather than local recurrences (19/45 [22.2%]). Cytologic status of pleural lavage fluid immediately after thoracotomy, an independent significant prognostic factor, constitutes valuable information to detect patients at a high risk of recurrence. Therefore cytology should be performed at the time of curative resection for non-small cell lung cancer.
Lung transplantation has become accepted therapy for end-stage pulmonary disease. The objective of this study was to review a single-institution experience of adult lung transplants. We reviewed 1000 adult lung transplants that were performed at Washington University between July 1988 and January 2009. Transplants were performed for emphysema (52%), cystic fibrosis (18.2%), pulmonary fibrosis (16.1%), and pulmonary vascular disease (7.2%). Overall recipient age was 48 ± 13 years with an increase from 43 ± 12 years (July 1988-November 1993) to 50 ± 14 years (June 2005-January 2009). Overall incidence of primary graft dysfunction was 22.1%. Hospital mortality was higher for patients who had primary graft dysfunction (primary graft dysfunction, 13.6%; no primary graft dysfunction, 4%; P < .001). Freedom from bronchiolitis obliterans syndrome was 84% at 1 year, 38.2% at 5 years, and 12.2% at 10 years. Survival at 1, 5, 10, and 15 years was 84%, 56.4%, 32.2%, and 17.8%, respectively. Five-year survival improved from 49.6% (July 1988-November 1993) to 62.1% (October 2001-June 2005). Primary graft dysfunction was associated with lower survival at 1, 5, and 10 years (primary graft dysfunction: 72.8%, 43.9%, and 18.7%, respectively; no primary graft dysfunction: 87.1%, 59.8%, and 35.7%, respectively, P < .001) and lower rates of freedom from bronchiolitis obliterans syndrome (primary graft dysfunction: 78%, 27.5%, and 8.5%, respectively; no primary graft dysfunction: 85.4%, 40.7%, and 13.1%, respectively, P = .007). Five-year survival has improved over the study period, but long-term outcomes are limited by bronchiolitis obliterans syndrome. Primary graft dysfunction is associated with higher rates of bronchiolitis obliterans syndrome and impaired short- and long-term survival. A better understanding of primary graft dysfunction and bronchiolitis obliterans syndrome is critical to improve outcomes.
The first generation of aortic ball-valve prostheses, used until 1965, was associated with poppet damage owing to fatty infiltration of the silicone rubber ball, a phenomenon termed ball variance. For the Model 1000 Starr-Edwards valves, almost all cases were discovered before 8 years. However, a review of our patients still at risk with the original valve and poppet, prompted by other recent reports of late ball variance, has shown that severe variance can exist up to 20 years after implantation. There is a relationship between the year of valve implantation and the timing and severity of ball variance for the overall series of patients surviving operation, but for the subgroup currently at risk the sample sizes are too small to detect any difference, if one still exists. Only three of 12 patients in the current subset were found to have severe variance. Simple ball change has been the operation of choice. Prophylactic reoperation is not indicated in the current subset, but patients require careful follow-up and should be considered for reoperation should symptoms develop.
Trends in mean velocity of circumferential fiber shortening (mVCFc) after patent ductus arteriosus ligation. #P < .05 versus baseline, analysis of variance.
Trends in left ventricular (LV) exposed vascular resistance after patent ductus arteriosus ligation. #P < .05 versus baseline, analysis of variance.
Perioperative cardiorespiratory physiology and degree of respiratory support in neonates undergoing PDA ligation
Stress-velocity relationship for all patients (neonates weighing 1000 g and >1000 g)
Comparison of neonatal demographics and morbidities, characteristics of the PDA, and status at surgical ligation in neonates with postoperative abnormal versus normal LV performance
Patent ductus arteriosus ligation is often complicated by systemic hypotension and oxygenation failure. The ability of the immature myocardium to compensate for altered afterload is poorly understood. The aim of this study was to characterize the effects of patent ductus arteriosus ligation on myocardial performance in preterm infants. Serial echocardiographic analysis was performed before and after patent ductus arteriosus ligation. Characteristics of the patent ductus arteriosus, myocardial performance (fractional shortening, mean velocity of circumferential fiber shortening, and left ventricular output) and left ventricular afterload (end-systolic wall stress) were assessed. The stress-velocity relationship was measured as a preload-independent, afterload-adjusted measure of myocardial contractility. Forty-six preterm infants were assessed at 28.5 +/- 11.3 days and a weight of 1058 +/- 272 g. Patent ductus arteriosus ligation was followed by increased left ventricular exposed vascular resistance temporally coinciding with reduced left ventricular preload, decreased left ventricular contractility, and low left ventricular output. Neonates weighing 1000 g or less had a higher rate of low fractional shortening (<25%) or low left ventricular output (<170 mL x kg(-1) x h(-1)) and increased need for cardiotropes and demonstrated a trend toward an impaired stress-velocity relationship. Neonates with impaired left ventricular systolic performance were more likely to require cardiotropes and have low systolic arterial pressure, increased heart rate, and abnormal base deficit. Patent ductus arteriosus ligation is sometimes associated with impaired left ventricular systolic performance, which is most likely attributable to altered loading conditions. Neonates weighing 1000 g or less are at increased risk of impaired left ventricular systolic performance, which might relate to maturational differences and decreased tolerance to altered loading conditions.
The use of selective antegrade cerebral perfusion (ACP) makes deep hypothermia nonessential for aortic arch replacement. Consequently, a growing tendency to increase the body temperature during circulatory arrest with ACP has recently been reported from various institutions. However, very little is known about the clinical effect of different modes of ACP (unilateral vs bilateral) on neurologic morbidity. Also, the safe limits of this approach for spinal chord and visceral organ protection are yet to be defined. Between January 2000 and January 2011, 1002 consecutive patients underwent aortic arch repair during ACP (unilateral, 673; bilateral, 329) with mild systemic hypothermia (30°C ± 2°C; range, 26°-34°C) at 2 centers in Germany. The mean patient age was 62 ± 14 years, 663 patients (66%) were men, and 347 patients (35%) had acute type A dissection. Hemiarch replacement was performed in 684 patients (68%), and 318 (32%) underwent total arch replacement. The cardiopulmonary bypass time accounted for 158 ± 56 minutes and the myocardial ischemic time, 101 ± 41 minutes. Isolated ACP was performed for 36 ± 19 minutes (range, 9-135). We observed new postoperative permanent neurologic deficits in 28 patients (3%; stroke in 25 and paraplegia in 3) and transient neurologic deficits in 42 patients (4%). All 3 cases of paraplegia occurred in patients with acute type A dissection and a broad range of ACP times (24, 41, and 127 minutes). A trend was seen toward a reduced permanent neurologic deficit rate after unilateral ACP (P = .06), but no difference was seen in the occurrence of transient neurologic deficits (P = .6). Overall, the early mortality rate was 5% (n = 52). Temporary dialysis was necessary primarily after surgery in 38 patients (4%). When corrected for the unequal distribution of type A dissection, neurologic morbidity, early mortality, and the need for temporary dialysis were independent of the duration of ACP and were not affected by unilateral versus bilateral ACP. Current data suggest that ACP and mild systemic hypothermic circulatory arrest can be safely applied to complex aortic arch surgery even in a subgroup of patients with up to 90 minutes of ACP. Unilateral ACP offers at least equal brain and visceral organ protection as bilateral ACP and might be advantageous in that it reduces the incidence of embolism arising from surgical manipulation on the arch vessels.
Recently, some studies have focused on the tumor angiogenesis and its prognostic value. We studied the expression of vascular endothelial growth factor, microvessel counts, and serum concentrations of vascular endothelial growth factor to investigate their association with clinicopathologic factors and prognosis in non-small-cell lung cancer. The expression of vascular endothelial growth factor was determined by an immunohistochemical analysis from 91 paraffin specimens of completely resected non-small-cell lung cancers using anti-growth factor polyclonal antibody. Microvessel staining was performed by immunohistochemical analysis with anti-factor VIII-related antigen polyclonal antibody. Measurement of the serum concentrations of vascular endothelial growth factor used the sandwich enzyme-linked immunosorbent assay technique. Expression of vascular endothelial growth factor was detected in 48 of the 91 tumors. The positive ratio was significantly higher in patients with adenocarcinoma than in those with squamous cell carcinoma. The microvessel counts were significantly higher in the patients with nodal metastasis than in those without nodal metastasis. The serum concentrations of vascular endothelial growth factor were also significantly higher in the patients with T3-4 disease than in those with T1-2 disease. The microvessel counts were closely associated with expression of vascular endothelial growth factor. The prognosis of patients with a positive growth factor ratio was significantly worse than that of the patients with a negative ratio (p = 0.002), especially in squamous cell carcinoma. According to a multivariate analysis, only nodal status and expression of vascular endothelial growth factor were found to be independent prognostic factors. The expression of vascular endothelial growth factor was one of the most important prognostic factors in completely resected non-small-cell lung cancer, especially in squamous cell carcinoma.
Our study describes the results from surgical slide tracheoplasty (STP) in children with long segment tracheal stenosis. Demographic and preoperative conditions, operative details, and outcome measures, including the need for endoscopic airway intervention and mortality, were collected for children undergoing STP between February 1995 and December 2012. One hundred one patients (median age, 5.8 months; range, 5 days-15 years) underwent STP. Seventy-two patients (71.3%) had associated cardiovascular anomalies. Preoperative ventilation was necessary in 56 patients (55.4%), whereas extracorporeal membrane oxygenation was required in 10 patients (9.9%). Abnormal bronchial arborization was present in 39 children (38.6%), which included 13 patients (12.8%) with an anomalous right upper lobe bronchus and 17 patients (16.8%) with tracheal trifurcation. Airway stenosis extended into 1 or both bronchi in 24 patients (23.7%) and preoperative malacia was present in 24 patients (23.7%). STP was extended into the bronchus in 47 patients (46.5%). Overall survival was 88.2% (mortality in 12 patients). Post-STP balloon dilation was necessary in 45 patients (44.6%) and stenting was required in 22 patients (21.8%). Multivariate analysis revealed preoperative extracorporeal membrane oxygenation (P < .05), preoperative malacia (P < .001), and bronchial stenosis (P < .05) to be adverse predictors of survival. Preoperative malacia was a significant risk factor for stenting (P < .05). STP is a versatile and reliable technique associated with low morbidity and mortality when compared with previous strategies for children with long segment tracheal stenosis. The presence of preoperative bronchomalacia is a significant risk factor for death and postoperative stenting.
Published data suggest that low birth weight is a risk factor for poor outcome in corrective surgery for many cardiac defects. Congenital heart defects in low birth weight infants are typically managed with supportive therapy or palliative operations, with definitive repair delayed. The morbidity associated with such approaches is high. Since 1990 complete repair of congenital heart defects (other than patent ductus arteriosus) has been performed in 102 infants no larger than 2500 g (median 2100 g, range 700-2500 g), including 16 no larger than 1500 g. Defects included ventricular septal defect (n = 22), tetralogy of Fallot complexes (n = 20), transposition complexes (n = 13), aortic coarctation (n = 12), interrupted arch (n = 10), truncus arteriosus (n = 8), atrioventricular septal defect (n = 6), total anomalous pulmonary venous return (n = 5), and other (n = 6). Preoperative morbidity was more common among patients referred late for surgical correction. There were 10 early deaths (10%) attributable to cardiac failure (n = 4), arrhythmia (n = 1), multiorgan failure (n = 1), sepsis (n = 1), idiopathic coronary artery intimal necrosis (n = 1), foot gangrene (n = 1), and pulmonary hemorrhage (n = 1). No patient had postbypass intracerebral hemorrhage. At follow-up (median 36 months) there were 8 late deaths, and 8 patients underwent 10 reinterventions. There was no evidence of neurologic sequelae attributable to the operation. In general, delaying repair of congenital heart defects in low birth weight infants does not confer a benefit and is associated with higher preoperative morbidity. Complete repair of both simple and complex lesions can be achieved in such cases with good results. Growth after repair approximates the normal curve for low birth weight infants without heart disease. It is recommended that such infants, especially when they have symptoms, undergo early surgical repair rather than prolonged medical management or other forms of palliation.
Malignant pleural mesothelioma is usually a fatal cancer for which operation has been the mainstay of treatment because chemotherapy and radiation are relatively ineffective. The choice of operation for malignant pleural mesothelioma remains controversial. Extrapleural pneumonectomy has been advocated because it allows complete removal of gross tumor and can be associated with long-term survival. To evaluate extrapleural pneumonectomy, we conducted a prospective multiinstitutional trial in patients with biopsy-proved previously untreated malignant pleural mesothelioma. Criteria for extrapleural pneumonectomy were (1) potentially completely resectable unilateral disease by computed tomography scan, (2) predicted postresection forced expiratory volume in 1 second greater than 1 L/sec, and (3) no other major medical problems. Patients who were not candidates for extrapleural pneumonectomy had a more limited operation with or without adjuvant therapy or had nonsurgical treatment. From September 1985 to June 1988 83 eligible patients (64 male, 19 female) were entered. The mean age for all patients was 59.7 years. Only 20 of the 83 patients (24%) underwent extrapleural pneumonectomy. Three of these 20 patients (15%) died postoperatively. The recurrence-free survival was significantly longer for the patients undergoing extrapleural pneumonectomy than for the other two groups (p = 0.03), but there was no difference in overall survival among the three groups. In univariate analyses, epithelial versus sarcomatoid and mixed histologic findings and platelet count less than 400,000 were associated with a better overall survival (p = 0.02), and performance status (Karnofsky less than 80) was predictive of recurrence (p = 0.02). In a multivariate analysis, histologic findings, sex, age, extrapleural pneumonectomy, weight loss, and performance status all had no significant impact on survival. Extrapleural pneumonectomy was associated with a greater likelihood of relapse in distant sites than were limited operation and nonsurgical treatment. We conclude that (1) only a small proportion of all patients with malignant pleural mesothelioma are candidates for extrapleural pneumonectomy, (2) extrapleural pneumonectomy carries a significant operative mortality and does not seem to improve overall survival compared with more conservative forms of treatment, (3) extrapleural pneumonectomy alters the patterns of relapse, and (4) factors previously thought to have an impact on survival in other series did not affect outcome in this trial.
During the past decade, tremendous interest has arisen in the use of nonoperative therapies for patients with non-small cell lung cancer. Of these therapies, stereotactic body radiotherapy has become established as an effective modality for treating peripheral cancer in medically inoperable patients. Toxicity is low, and the treatment is effective, with excellent local control rates. Several investigators have suggested that stereotactic body radiotherapy could be effective for high-risk operable patients (usually treated with sublobar resection) and even perhaps for standard-risk operable patients (usually treated with lobectomy); however, this is less accepted. A direct comparison of stereotactic body radiotherapy and sublobar resection is difficult for a number of reasons. These include different definitions of recurrence, different populations of patients in these studies (with those undergoing stereotactic body radiotherapy tending to be the medically inoperable group), and different methods of classifying morbidity in the surgical and radiation oncology studies. Imaging follow-up has also not been standardized among the studies. Thus, a randomized study is necessary and timely. Investigators from the American College of Surgeons Oncology Group and the Radiation Therapy and Oncology Group have collaborated to develop a phase III randomized study comparing stereotactic body radiotherapy and sublobar resection (with or without brachytherapy) for high-risk operable patients with non-small cell lung cancer. This study (American College of Surgeons Oncology Group Z4099/Radiation Therapy Oncology Group 1021) has recently opened for accrual. It is hoped that this will help to better define the role of these therapies for patients with non-small cell lung cancer.
A total of 103 patients, age range 2 to 77 years, had some type of Carpentier reconstruction for mitral insufficiency. The mitral insufficiency resulted from ruptured chordae in 52, prolapse in 13, rheumatic fever in 16, coronary disease in eight, congenital disease in nine, and endocarditis in five. Multiple abnormalities were usually present. Four patients had severe calcification of the anulus. A reconstruction was accomplished in almost all patients. A ring annuloplasty was performed in all but two small children, but annuloplasty alone was adequate in only 17 patients. Fifty-eight had resection of 1 to 4 cm of diseased mitral leaflet. In 23 patients, chordal transposition or shortening was employed. Aortic leaflet repair was done in 28. Shortened, fused chordae (one to eight) were divided in 13 patients. Additional procedures performed in 28 patients included coronary bypass in 14. A successful repair was accomplished in all but one patient (moderate residual insufficiency). Two late hospital deaths were unrelated to the mitral repair. Following hospital discharge, ring dehiscence necessitated repeat operation in one patient. Thromboembolism produced a permanent minor neurological deficit in only one patient. There have been no late recurrences of insufficiency. Recurrent endocarditis necessitated valve replacement in three patients. A late Doppler evaluation of 95 patients for mitral insufficiency revealed none in 82, a trace in 12, and moderate insufficiency in one. Late catheterization in 16 patients revealed no insufficiency. The data suggest that reconstruction, rather than prosthetic valve replacement, can be successfully performed in over 90% of patients with nonrheumatic, noncalcified mitral valves. A much wider use of the technique seems strongly indicated.
The effect of temperature on cerebral blood flow and metabolism was studied in 41 adult patients scheduled for operations requiring cardiopulmonary bypass. Plasma levels of midazolam and fentanyl were kept constant by a pharmacokinetic model-driven infusion system. Cerebral blood flow was measured by xenon 133 clearance (initial slope index) methods. Cerebral blood flow determinations were made at 27 degrees C (hypothermia) and 37 degrees C (normothermia) at constant cardiopulmonary bypass pump flows of 2 L/min/m2. Blood gas management was conducted to maintain arterial carbon dioxide tension (not corrected for temperature) 35 to 40 mm Hg and arterial oxygen tension of 150 to 250 mm Hg. Blood gas samples were taken from the radial artery and the jugular bulb. With decreased temperature there was a significant (p less than 0.0001) decrease in the arterial venous-oxygen content difference, suggesting brain flow in excess of metabolic need. For each patient, the cerebral metabolic rate of oxygen consumption at 37 degrees C and 27 degrees C was calculated from the two measured points at normothermia and hypothermia with the use of a linear relationship between the logarithm of cerebral metabolic rate of oxygen consumption and temperature. The temperature coefficient was then computed as the ratio of cerebral metabolic rate of oxygen consumption at 37 degrees C to that at 27 degrees C. The median temperature coefficient for man on nonpulsatile cardiopulmonary bypass is 2.8. Thus reducing the temperature from 37 degrees to 27 degrees C reduces cerebral metabolic rate of oxygen consumption by 64%.
The mechanism of higher incidence of ischemic mitral regurgitation in patients with inferior compared with anterior myocardial infarction despite less global left ventricular remodeling and dysfunction is controversial. We hypothesized that inferior myocardial infarction causes left ventricular remodeling, which displaces posterior papillary muscle away from its normal position, leading to ischemic mitral regurgitation. In 103 patients with prior myocardial infarction (61 anterior and 42 inferior) and 20 normal control subjects, we evaluated the grade of ischemic mitral regurgitation on the basis of the percentage of Doppler jet area, left ventricular end-diastolic and end-systolic volumes, midsystolic mitral annular area, and midsystolic leaflet-tethering distance between papillary muscle tips and the contralateral anterior mitral annulus, which were determined by means of quantitative echocardiography. Global left ventricular dilatation and dysfunction were significantly less pronounced in patients with inferior myocardial infarction (left ventricular end-systolic volume: 52 +/- 18 vs 60 +/- 24 mL, inferior vs anterior infarction, P<.05; left ventricular ejection fraction: 51% +/- 9% vs 42% +/- 7%, P <.0001). However, the percentage of mitral regurgitation jet area and the incidence of significant regurgitation (percentage of jet area of 10% or greater) was greater in inferior infarction (percentage of jet area: 10.1% +/- 7.5% vs 4.4% +/- 7.0%, P =.0002; incidence: 16/42 (38%) vs 6/61 (10%), P <.0001). The mitral annulus (area = 8.2 +/- 1.2 cm2 in control subjects) was similarly dilated in both inferior and anterior myocardial infarction (9.7 +/- 1.7 vs. 9.5 +/- 2.3 cm2, no significant difference), and the anterior papillary muscle-tethering distance (33.8 +/- 2.6 mm in control subjects) was also similarly and mildly increased in both groups (35.2 +/- 2.4 vs 35.2 +/- 2.8 mm, no significant difference). However, the posterior papillary muscle-tethering distance (33.3 +/- 2.3 mm in control subjects) was significantly greater in inferior compared with anterior myocardial infarction (38.3 +/- 4.1 vs 34.7 +/- 2.9 mm, P =.0001). Multiple stepwise regression analysis identified the increase in posterior papillary muscle-tethering distance divided by body surface area as an independent contributing factor to the percentage of mitral regurgitation jet area (r2 = 0.70, P <.0001). It is suggested that the higher incidence and greater severity of ischemic mitral regurgitation in patients with inferior compared with anterior myocardial infarction can be related to more severe geometric changes in the mitral valve apparatus with greater displacement of posterior papillary muscle caused by localized inferior basal left ventricular remodeling, which results in therapeutic implications for potential benefit of procedures, such as infarct plication and leaflet or chordal elongation, to reduce leaflet tethering.
Top-cited authors
Eugene H Blackstone
  • Cleveland Clinic
Richard Jonas
  • Children's National Medical Center
James L Cox
  • Washington University in St. Louis
Hartzell Schaff
  • Mayo Foundation for Medical Education and Research
Tirone E David
  • University Health Network