The significance and prevention of air emboli with the total artificial heart.

Embolism remains a significant complication of the total artificial heart (TAH). The ineffectual deairing of the TAH can allow embolization of the retained air. The standard needle aspiration of TAH air (Group A) was compared with a new protocol (Group B) that included standard needle TAH aspiration plus simultaneous pumping of the TAH against an occluded ascending aorta and main pulmonary artery with vacuum applied to a needle in the proximal aorta and pulmonary artery. There were 4 calves in each group. There was no premortem evidence of systemic or pulmonary emboli. Both groups of animals were electively terminated less than 2 weeks postoperatively Postoperative mean aortic and pulmonary artery pressures were recorded for each animal. Animals in Group B had a significant decline in pulmonary artery pressures (43 +/- 12 vs. 33 +/- 8 mm Hg) 1 h after TAH implantation when compared with Group A. All other aortic and pulmonary artery pressure differences between Groups A and B were not statistically significant within 24 h of the operation. Group A animals had a 75% incidence, and Group B animals had 100% incidence of TAH thrombus. This very small thrombus was found exclusively at the inflow valve-TAH housing interface. Evaluation of the kidneys postmortem was used to identify embolic injury. All animals in Group A had evidence of acute, hemorrhagic injury, but none of the Group B animals had similar injury. Half of the animals in each group had small, fibrotic chronic renal cortical injury, which did not develop during TAH implantation.(ABSTRACT TRUNCATED AT 250 WORDS)

A limited axillary thoracotomy as primary treatment for recurrent spontaneous pneumothorax.

Recurrent spontaneous pneumothorax often requires surgical treatment following variable periods of chest tube therapy. A limited axillary thoracotomy provides sufficient exposure to isolate or excise pulmonary blebs and perform a pleurodesis. Prompt use of this surgical approach in lieu of the initial placement of a thoracostomy tube avoids prolonged hospitalization and a significant failure rate of thoracostomy tubes to resolve this problem. This operation can also prevent recurrence, a significant problem for this pathologic process. Fourteen patients with recurrent spontaneous pneumothorax underwent an axillary thoracotomy as either primary treatment or within 72 h of thoracostomy tube placement. The average follow-up was 38 months for the initial 10 patients and 23 months for the entire group. The procedure averaged 66 min in duration. The average incision was 3.3 cm in length. There was an equal male/female ratio and right-left distribution. The patients were discharged an average of 4.2 days after surgery. There were no complications. The most recent six patients with a recurrent pneumothorax were surgically treated on the day of admission without a preoperative chest tube. The other eight patients had a thoracostomy tube for control of the pneumothorax, with surgery performed within 72 h of tube placement. A limited axillary thoracotomy corrected the underlying pathology, hastened hospital discharge, limited pain, prevented short-term recurrence, and was cosmetically acceptable. A limited axillary thoracotomy is the operation of choice when a spontaneous pneumothorax requires surgery. This surgical approach has become our primary treatment for recurrent pneumothorax, avoiding the use of a preoperative thoracostomy tube and unnecessary delay, with excellent results for the patient.

Remnant atrial function in human and animal recipients of a total artificial heart.

The native atria remains intact after total artificial heart (TAH) implantation. The electrical activity of the recipient's atria can be recorded from wires placed during TAH implantation. Regulating TAH heart rate by coupling it with native atrial activity has the potential for a more physiologically responsive TAH. The reactivity of the atrial impulse rate is a critical component of this link, but little is known about atrial responsiveness after TAH placement. Two human and three animal TAH recipients had recordable atrial electrical activity. Human atrial impulse rate after TAH was relatively constant at rest but unresponsive to physiologic stimuli. Analysis of human atrial contraction provided no discernable effect on ventricular filling. Animal atrial impulse rate at rest was more rapid than calves without a TAH. The bovine TAH recipients had an atrial impulse rate that responded to catecholamine stimulation and blockade. Isoproterenol caused a significant rise in atrial impulse rate (152 +/- 16 impulses per minute to 216 +/- 24 impulses per minute; p < 0.05) and propranolol caused a decrease in atrial impulse rate (142 +/- 20 impulses per minute to 122 +/- 19 impulses per minute; p > 0.05). Despite beta blockade, the atrial impulse rate remained abnormally elevated secondary to unknown factors. Animal atrial contraction did appear to intermittently augment TAH ventricular filling. These data indicate that the atria remains electrically intact after TAH implantation. The human atrial impulse rate was unresponsive to physiologic stimuli although the animal atrial impulse rate was affected by exogenous catecholamine administration, but the rate remained abnormally rapid.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine nucleotide content in cold preserved human donor hearts and subsequent cardiac performance after orthotopic heart transplantation.

Myocardial high-energy phosphate content has been used as a parameter to evaluate the adequacy of donor organ preservation. The purpose of this study was to assess current techniques of preservation by measuring high-energy phosphates in cold preserved (4 degrees C) human donor hearts. Endomyocardial biopsy samples of the donor heart right ventricular septum (n = 24) were compared with samples from patients with normal cardiac function evaluated before chemotherapy (n = 12). Left ventricular and right ventricular ejection fractions were measured by means of radionuclide angiography early (24 to 72 hours) and late (mean 42 days) postoperatively. Mean total cold ischemic time was 146 +/- 54 minutes (range, 89 to 340 minutes). ATP nmol/mg noncollagenous protein in donor hearts was 38.2 +/- 10.7 and 31.9 +/- 13.6 (p = NS) in normal hearts. Early postoperative left ventricular and right ventricular ejection fraction was 55% +/- 14% and 40% +/- 9%, respectively. Late postoperative left ventricular and right ventricular ejection fraction was 64% +/- 14% and 50% +/- 10%, respectively; both represent significant increases in right and left ventricular ejection fraction (p less than 0.05). No correlation was found between ischemic time and donor ATP, ischemic time and ejection fraction, or ejection fraction and ATP. Three patients with normal donor heart ATP content had severe, but reversible, early graft dysfunction. In summary, currently used human donor heart preservation techniques are associated with normal values of high-energy phosphates and usually excellent early and late postoperative graft function.(ABSTRACT TRUNCATED AT 250 WORDS)

Platypnea-orthodeoxia: an unusual indication for surgical closure of a patent foramen ovale.

Platypnea-orthodeoxia is an infrequently reported clinical form of position dependent dyspnea and oxygen desaturation. There are several diverse etiologies for this syndrome. This case report of a patient with platypnea-orthodeoxia is the first known presentation of a case secondary to a patent foramen ovale and idiopathic hemidiaphragm paralysis. A major problem with this disease is the clinical recognition of its existence. Full recovery is possible with proper assessment of clinical signs and symptoms, appropriate noninvasive diagnostic tests, and corrective surgery in selective cases.

Left recurrent laryngeal nerve paralysis: an unusual presentation of histoplasmosis.

A case of histoplasmosis seen as left recurrent laryngeal nerve paralysis in a 49-year-old man is described. The patient had roentgenographic findings of a solitary, noncalcified left upper lobe mass and mediastinal adenopathy. Tissue diagnosis of histoplasmosis was obtained using a thoracotomy, allowing institution of appropriate treatment.

Correlation of gross and microscopic appearance of skin buttons in total artificial heart animals.

Pneumatic artificial hearts are powered by compressed air that is delivered through percutaneous tubes. A stress relief device, termed a skin button, surrounds these tubes as they exit from the recipient's tissues. The skin button is designed to protect the tissues from damage and provide a secure material-tissue interface. Prevention of superficial and invasive infection is the primary goal of the skin button. Eight calves were studied prospectively to identify gross or microscopic infection with the skin button. All animals who survived more than sixty days (62-136) had both gross and microscopic evidence of infection. All animals surviving less than 60 days (13-43) had no gross evidence of infection but one had subcutaneous microscopic abscess formation. No animal died secondary to a skin button infection. Skin buttons cannot prevent infection but they can contain the pathologic process in the superficial tissues with no evidence of systemic effects.

Combined blunt traumatic rupture of the heart and aorta: two case reports and review of the literature.

Blunt chest trauma resulting in combined aortic disruption and cardiac rupture, although a common autopsy finding, was found reported only once previously in a surviving patient. We report two cases repaired through a left posterolateral thoracotomy in which the cardiac injury was unsuspected and presented as an intraoperative finding of hemopericardium. With improved emergency resuscitation in the field and faster transport of these cases to tertiary care centers, this combination of lesions may be seen more frequently. Suggestions for their diagnosis and management are presented.

Effect of a total artificial heart on adaptive hormonal responses in humans with end-stage heart failure.

The J-7 total artificial heart (TAH) can restore normal vascular hemodynamics in humans treated for end-stage heart failure, but less is known regarding its effect on hormones elevated under these conditions. A 49-year-old man with NYHA Class IV end-stage heart failure received a J-7-70 TAH as a bridge to transplantation. Pre-TAH cardiac index was less than 2 L/min/m2 with end organ dysfunction, increased venous and pulmonary pressures, and a low arterial pressure. The TAH provided an immediate cardiac index greater than 3 L/min/m2 with normal hemodynamics and organ function. Pre-TAH renin, aldosterone, and atrial natriuretic factor (ANF) levels were markedly elevated: 147 ng/dl, 29.4 ng/dl, and 380 pg/ml, respectively. All values declined dramatically by the fifth postoperative day, with the aldosterone and ANF values returning to normal at 11.5 ng/dl and 37 pg/ml, respectively. Renin levels reached normal values by the fourth postoperative week. Once normal values were obtained, they remained in this range for the 57 days of TAH function. The TAH, used in end-stage heart failure, restores normal hemodynamics and compensatory hormonal levels. These hormones can be used as indicators of proper TAH function in such patients.

The effect of graded exercise on cardiac output of the Jarvik-7-70 total artificial heart in humans.

Animal exercise studies have shown a self-regulated change in cardiac output (CO) with the J-7 total artificial heart (TAH). A 49-year-old, 75 kg patient received a J-7-70 TAH as a bridge to transplant. During bicycle exercise, the TAH heart rate, drive pressures, percent systole, and vacuum were unchanged. Cardiac output was measured by analysis of diastolic air exhaust. Mean arterial pressure (MAP) was measured via a radial artery catheter. Daily recordings of hemodynamics were made from TAH day 35 to 56 at rest, cycling with zero resistance, 18 watts resistance, return to zero resistance, and at rest. Values were as follows: baseline MAP, 75.7 +/- 9.7; LCO, 6.4 +/- 0.2; RCO, 6.8 +/- 0.2. For zero watts resistance MAP was 92.2 +/- 7.2*; LCO, 7.1 +/- 0.2*; RCO, 7.8 +/- 0.3*. For eighteen watts resistance MAP was 101.3 +/- 6.2*; LCO, 7.6 +/- 0.3*; RCO, 8.4 +/- 0.4*. For zero watts resistance MAP was 98.5 +/- 4.9*; LCO, 7.2 +/- 0.4*; RCO, 8.0 +/- 0.4*. The postexercise MAP was 86.4 +/- 4.1*; LCO, 6.2 +/- 0.2; RCO, 6.9 +/- 0.2. For all but baseline and postexercise MAPs, the average response was over a 4 minute interval. The starred values were significant compared to baseline p less than 0.05. Exercise resulted in an autoregulated change in TAH CO in man. Increasing the work of exercise produced an increased CO, reflecting changes in venous return. A TAH patient can exercise for more than 30 minutes with an autoregulated CO and no deleterious effects.

The role of beta receptors in the peripheral vasculature of calves with a total artificial heart.

Drugs given to a total artificial heart (TAH) calf isolate their vascular effects independent of the myocardium. During experiments, the TAH maintains full ejection, constant heart rate, and percent systole, and uses no vacuum. Cardiac output (CO) varies solely and directly with preload. Six calves received an infusion of isoproterenol, a beta agonist, and three calves received propranolol, a beta antagonist. The isoproterenol was resumed after beta blockade. Isoproterenol alone caused a significant increase in CO, an effect that was attenuated but not eliminated with beta blockade. Both isoproterenol and propranolol decreased AoP, but only isoproterenol increased preload. Beta receptors play a significant role in decreasing venous capacitance with increased preload and CO, independent of the myocardium.

Peripheral venous bullet embolization to the heart. Case report and review of the literature.

Peripheral venous bullet embolization to the heart is a rare event. We report our experience with one patient who suffered peripheral venous bullet embolization to the right ventricle and review the 38 patients with this phenomenon previously reported in the literature. The clinical presentation of patients with peripheral venous bullet embolization to the right ventricle is discussed. In addition, the indications for surgery and the therapeutic approaches available to patients with bullet embolization are discussed.

The effect of ischemia on canine carotid endothelial permeability.

The effect of ischemia on arterial endothelial permeability was assessed by surgically interrupting arterial blood flow for 45 min in the left carotid artery of 12 foxhounds. The right carotid artery served as control. Twenty-four hours before sacrificing the animals at 1 day, 1 week, 1 month, and 3 months postoperatively. Evans blue dye (1.5 ml/kg) was administered intravenously. Carotid arteries were harvested, opened, and scanned with a reflectometer to measure Evans blue dye uptake, and scanning electron microscopy was performed on a section of tissue from each harvested vessel. A statistically significant increase in permeability of the ischemic vessel occurred at 1 day (79 +/- 42% (SD], 1 week (186 +/- 75%), and 1 month (229 +/- 125%), but was not present at 3 months (7 +/- 8%) postinjury. Scanning electron microscopic examination of all specimens was essentially normal. This study demonstrates that arterial endothelium has increased permeability at 1 month following a brief ischemic period. What effect this ischemia-induced endothelial dysfunction will have on lipid uptake by the arterial wall will be the subject of future study.

Pedunculated left ventricular rhabdomyoma.

A patient with an unusual left ventricular outflow tract obstruction caused by a solitary pedunculated left ventricular rhabdomyoma is described. Diagnosis was based on two-dimensional echocardiographic findings alone. The obstructive portion of the tumor was successfully removed from the interventricular septum by an aortic root approach.