Aneurysmal bone cyst of the sternum.

A very rare case of aneurysmal bone cyst of the sternum is described. Aneurysmal bone cyst is a tumorlike bone lesion occumng commonly in the metaphysis of long bones and in the vertebrae. This report is one of the very few cases in the literature of aneurysmal bone cyst of the sternum. Total resection of the tumor and reconstruction of the sternal defect using autogenous fibula are presented     

Management of Ascending Aortic Aneurysm Complicating Coarctation of the Aorta

Four patients with coarctation of the aorta complicated by an aneurysm of the ascending aorta are described. One patient, treated only medically, died suddenly. For the 3 patients who underwent operation, management was similar. Pharmacological control of blood pressure and repair of the aortic coarctation to achieve anatomical reduction in afterload (stage I) were followed after an interval of one to five weeks by surgical repair of the ascending aortic aneurysm (stage II).Initial repair of the coarctation relieves proximal hypertension, thereby decreasing the chance of progressive dissection or rupture of the aneurysm. It also permits safe arterial cannulation for perfusion during correction of the aneurysm in the second stage. In patients not requiring valve replacement in stage II, continued long-term follow-up for progression of aortic valvular disease appears to be necessary.     

Serum Cefazolin Levels during Cardiopulmonary Bypass

This study was done to assess the adequacy of a regimen using cefazolin as a prophylactic antibiotic for patients undergoing open-heart operation. At the time of the preoperative medication, adult patients received 1 gm of cefazolin intramuscularly, and pediatric patients were given a dose of 20 mg per kilogram of body weight. Group I consisted of 10 adults undergoing a variety of cardiac procedures. The mean serum cefazolin level after institution of cardiopulmonary bypass was 27.36 μg/ml (range, 13.1 to 40.3 μg/ml). This level remained fairly stable throughout cardiopulmonary bypass. Group II consisted of 10 pediatric patients undergoing cardiac procedures for repair of a variety of congenital anomalies. The mean serum cefazolin level after institution of cardiopulmonary bypass was 20.01 μg/ml (range, 11.4 to 28.9 μg/ml) and remained stable for the duration of the procedure. In both groups perfusion pressure, urinary output, and body temperature did not seem to have any influence on these levels.It is concluded that the administration of one dose of cefazolin intramuscularly before operation results in an adequate and stable serum cefazolin level in patients undergoing cardiopulmonary bypass for up to three hours, possibly longer.     

Individualized fluid resuscitation based on haemodynamic monitoring in the management of extensive burns

An evaluation has been made on the effectiveness and feasibility of the individualized fluid replacement programme based on intensive haemodynamic monitoring using a Swan-Ganz catheter. Twenty-one extensively burned patients with an average burn of 60·8 per cent BSA were resuscitated with lactated Ringer's and colloid solutions. The rate of fluid administration was adjusted to maintain the optimal ranges of the various haemodynamic parameters including cardiac index and left ventricular stroke work index. Two patients failed to respond to fluid resuscitation possibly due to inadequate emergency procedures given before arrival at our institute. The remaining patients survived the shock phase, with the amount of fluid given to the 18 adult patients being (3·38 ±1·02 ml/kg) × (percentage burn) for the first 24 hours. A negative correlation existed between the amounts of lacated Ringer's solution and colloid solution used for the fluid resuscitation. Dopamine was effective in 4 out of 5 patients who showed depressed myocardial function. The individualized fluid programme was shown to be effective and reliable for the management of critically burned patients.     

Pulmonary blastoma in a child.

Pulmonary blastoma is a very rare type of lung tumor. In 1952 Barnard¹ described the first report of a rare pulmonary neoplasm which histologically resembled fetal lung tissue. He named it pulmonary embryoma. Spencer² reported four similar cases which he called pulmonary blastoma because they resembled the histologic pattern of nephroblastoma. Since then there have been 25 reported cases of this type of neoplasm but only two were in children.^3,4 We have recently treated a 10-yr-old girl with this neoplasm.     

Stride length of elderly patients with lumbar spinal stenosis: Multi-center study using the Two-Step test

BackgroundShort stride length is one of clinical symptoms associated with lumbar spinal stenosis (LSS). Short stride is a risk factor for falls; therefore, identification of factors associated with short stride is critical for fall prevention in LSS patients. Although the Two-Step test can conveniently assess maximal stride length, it has not become widely used; therefore, its data are limited. We identified the potential factors associated with short stride of elderly LSS patients using Two-Step test.MethodsClinical data of patients aged >65 years who planned to undergo surgery for LSS were prospectively collected at multiple institutions. Patients were assessed with the Two-Step test and Timed Up-and-Go Test prior to surgery; 357 consecutive patients were enrolled. We determined the cut-off value of the Two-Step test score for short stride, referring to the Timed Up-and-Go Test score of 13.5 s, used to indicate high risk of falls in elderly individuals. Logistic regression model was constructed to identify factors associated with short stride.ResultsThe Two-Step test score showed moderate-to-strong inverse correlation with that of Timed Up-and-Go Test (r = ?0.65, p < 0.001). Using the tentative Two-Step test cut-off value (0.93) for short stride, multivariable analysis showed that age ≥80 years (OR = 2.3, 95% CI:1.1–4.8), a score of <60 for lumbar function in Japanese Orthopedic Association Back Pain Evaluation Questionnaire (OR = 2.7, 95% CI:1.5–4.7), motor deficit (OR = 2.7, 95% CI:1.2–6.1), and sagittal vertical axis ≥50 mm (OR = 2.1, 95% CI:1.2–3.5) were factors significantly associated with short stride in elderly patients with LSS.ConclusionsUsing the Two-Step test, we found that 80 years old and over, lumbar dysfunction, motor deficit of the lower extremities, and forward-bent posture were associated with short stride in LSS patients. Therefore, elderly LSS patients with these conditions may have a higher risk for falls.     

Effects of Pulsatile Assistance and Nonpulsatile Flow on Subendocardial Perfusion During Cardiopulmonary Bypass

We compared the effects of pulsatile and nonpulsatile perfusion in 12 dogs on extracorporeal circulation. In beating empty and fibrillating hearts at 37° and 28°, coronary blood flow was measured by flowmeter and microspheres at diastolic pressures ranging between 50 and 130 mm Hg.At fixed systemic flow rates (range, 600 to 2,400 ml/min), pulsatile perfusion produced a transient (3 to 4 second) augmentation of diastolic pressure and then resulted in the following: (1) decreased peripheral vascular resistance (p < 0.05); (2) unchanged peak diastolic pressure (compared with nonpulsatile perfusion); (3) decreased mean aortic pressure (6 to 37%) (p < 0.05); (4) decreased coronary blood flow (10 to 45%) (p < 0.05); and (5) decreased subendocardial blood flow (from 512 to 438 ml/100 gm/min) (p < 0.05). Pulsatile perfusion in beating hearts (37° or 28°) did not reduce subendocardial vascular resistance, but did improve subendocardial perfusion by 27% and 36% in fibrillating hearts at 37° and 28°, respectively.We conclude that with the exception of ventricular fibrillation, pulsatile assistance offers no advantage over nonpulsatile perfusion and has the potential disadvantage of requiring higher pump flow rates to achieve any desired level of coronary and subendocardial flow.     

Method for Replacement of the Ascending Aorta and Aortic Valve with Reimplantation of the Coronary Arteries

A method for replacing the entire ascending aorta and aortic valve is described that employs direct anastomosis of the coronary ostia to the graft, facilitated by appropriately timed periods of hypothermic ischemic cardiac arrest. The advantages of this technique are that proper placement of sutures around the coronary ostia is simplified and that hemostasis at the aortic annulus and coronary anastomosis can be evaluated before the aortic clamp is removed and suture lines become inaccessible.     

Cardiopulmonary Dynamics during Arteriovenous Perfusion: Cardiac Output,Pulmonary Arterial Resistance,and Right Ventricular Stroke Work

The effects of arteriovenous perfusion on myocardial performance, pulmonary circulatory dynamics, and organ preservation were studied in dogs in order to evaluate the applicability of arteriovenous extracorporeal membrane oxygenation for partial respiratory support. Studies were made on normally oxygenated dogs, on dogs made hypoxic by oxygen deprivation and ventilatory depression, and on dogs with pulmonary injury and moderate pulmonary hypertension induced by injection of oleic acid into the right ventricle. The latter two groups were included to assess the changes that occur in cardiopulmonary dynamics in the presence of hypoxia and pulmonary hypertension. A micro-channel membrane oxygenator was employed to provide partial respiratory support to the group of animals with pulmonary injury. The results indicate that no deleterious hemodynamic changes occurred in any of the groups of animals with arteriovenous flow for periods of up to 5 hours at rates corresponding to 20 to 35% of the total cardiac output. Adequate systemic oxygenation was provided by the microchannel oxygenator at these rates of arteriovenous perfusion.     

Lumbar spinal canal stenosis leads to locomotive syndrome in elderly patients

Background

Locomotive syndrome is a condition in which the ability to lead a normal life is restricted owing to a dysfunction in one or more of the parts of the musculoskeletal system. Although lumbar spinal canal stenosis (LSS) is considered to cause locomotive syndrome, a detailed assessment of the association between two pathologies has not yet been reported.

Coarctation of the Aorta in Infants and Children: 25 Years of Experience

Repair of coarctation of the aorta was performed in 334 patients ranging from less than a year to 16 years of age at Children's Hospital of Pittsburgh from 1953 to 1977. Resection and end-to-end anastomosis were performed in 310, interposition grafts in 7, and other procedures in 17. There were 41 operative deaths among the 95 infants less than 1 year old (43% mortality); all of these infants had associated cardiac anomalies. Only 1 operative death occurred in patients older than a year (0.4% mortality). No hospital deaths occurred in patients with isolated coarctation of the aorta. Eleven late deaths were due to associated anomalies (7) and unrelated or unknown causes (4). Postoperatively, hemorrhage occurred in 7, paradoxical or persistent hypertension in 128, postcoarctectomy syndrome in 32, neurological problems in 14, pulmonary complications in 53, and infections in 12 patients. Restenosis occurred in 26 patients (8%); only 10 have required reoperation. Residual hypertension was present in 28 of 264 patients (11%). Mortality from coarctation resection remains high in infants, but is minimal in children older than 1 year. Based on minimizing the risk of restenosis and residual hypertension, elective repair of coarctation is recommended when the patient is about 6 years of age.     

Enhancing Survival of Human Hepatocytes by Neonatal Thymectomy and Partial Hepatectomy in Micro-miniature Pigs

Background

With the goal of in vivo cultivation of human hepatocytes that have not been sufficient in full differentiation in vitro, the advantage of neonatal thymectomy was verified on expansion of xenogeneic human hepatocyte in the micro-miniature pig (MMP).

Preferential Atherosclerosis at the Aortic Junction of the Ligamentum Arteriosum: Clinical Significance and Pathological Correlation

Clinical experience with 5 patients who had complications of atherosclerosis within the aorta at the site of the obliterated ductus arteriosus suggested the occurrence of clinically significant preferential atherosclerosis at this location. To examine this hypothesis, the clinical findings in these patients (4 with saccular aneurysm and 1 with systemic emboli from an ulcerated plaque at this location) were correlated with postmortem examination of the aortic isthmus in 40 consecutive cadavers.The point of ductal closure was the area of most severe atheromatous involvement in 32 of the 40 cadavers, and 25 of the 40 specimens demonstrated ulcerated plaques at this location. Microscopical examination consistently demonstrated intimal irregularity or disruption and thinning of the aortic media in this area. These studies indicate that preferential atherosclerosis occurs at the aortic end of the obliterated ductus arteriosus and that these atherosclerotic changes can be a clinically significant development.     

The Ascending Aortic Aneurysm: Replacement or Repair?

Between 1971 and 1980, 100 patients underwent operation for ascending aortic aneurysm. Acute dissection was present in 29, chronic dissection in 11; 56 had dilatation only, and 4 had inflammatory disease of the ascending aorta. Four different operative procedures were applied independent of the type of disease: repair and reduction aortoplasty (21), reduction aortoplasty reinforced by nylon net (17), supracoronary graft replacement (42), and composite graft replacement with reimplantation of both coronary ostia (20). Early mortality was 10%, and late mortality was 12% after a mean follow-up of 45 months.Retrospective comparative analysis of the four operative methods led to the following conclusion: reduction aortoplasty supported by a tightly wrapped synthetic net is a suitable method in patients with a normal sinus of Valsalva and without dissection or inflammatory disease. Particular attention needs to be drawn to the proximal anchor stitches to avoid late net displacement. Compared with supracoronary or composite graft replacement, this method carried a lower complication rate, particularly in regard to cerebrovascular accidents and myocardial infarction. For patients with acute and chronic dissection with intact aortic root, supracoronary graft replacement is preferred, whereas in those with annuloaortic ectasia with dilated sinus of Valsalva and in all patients with Marfan's syndrome, composite graft replacement has become the procedure of choice.     

Hyperkalemia Complicating Cardiopulmonary Bypass: Analysis of Risk Factors

This study was undertaken to assess the hyperkalemic effect of several factors, including cardioplegia containing 25 mEq K⁺ per liter. We measured potassium balance at termination of cardiopulmonary bypass (CPB) in each of 20 patients with hyperkalemia (minimum K⁺, 6.0 mEq/L) and 20 patients with normal potassium levels (K⁺ up to 5.5 mEq/L) by subtracting urinary excretion of potassium from the sum of contributions from cardioplegia, hemolysis, and transfusion. The effects of potassium balance, diabetes, blood glucose, catecholamines, and propranolol on the degree of potassium change during CPB were assessed by multiple linear regression.We found no effect of potassium load on potassium change in either the hyperkalemic or normal group. This suggested that derangement of potassium homeostasis was more important than exogenous potassium loading as a hyperkalemic stimulus. Use of catecholamines reduced the potassium change in the hyperkalemic group (p < 0.048), but any effect of propranolol on potassium change was not significant.A striking finding was the frequency of diabetics in the hyperkalemic group (12 of 20 patients) compared with the control group (2 of 20) (p < 0.001). In addition, the preoperative serum glucose level in the hyperkalemic group (mean, 154 ± 75 mg/dl) exceeded that of the normal group (mean, 103 ± 13 mg/dl) (p < 0.001).It is concluded that dangerous hyperkalemia is related to derangements of potassium homeostasis rather than excessive potassium loads, and that the use of cardioplegic solutions containing 25 mEq/L of potassium is safe. Known diabetics or patients noted preoperatively to have abnormal elevations of serum glucose deserve special attention during CPB, as many hyperkalemic patients require pacing or prolongation of bypass to manage the resulting electromechanical disturbance.     

Controlled Trial of Routine Administration of Platelet Concentrates in Cardiopulmonary Bypass Surgery

Prophylactic administration of platelet concentrates to patients undergoing their first cardiopulmonary bypass operation (coronary artery bypass grafting or uncomplicated valve replacement) was evaluated in a controlled randomized study of 28 patients. Four units of platelet concentrates administered at the end of bypass prevented prolongation of the bleeding time seen in patients not receiving platelets. However, chest tube blood loss, transfusion requirements, and clinical outcome were not improved. Moreover, thrombocytopenia and prolongation of bleeding time did not correlate with blood loss or transfusion needs. Mild thrombocytopenia (to 58,000 platelets per microliter) and transient platelet dysfunction after bypass do not require administration of platelet concentrates, and prophylactic use of this blood component in the surgical setting of bypass is not indicated.