Vitamin C prophylaxis for posttransfusion hepatitis: lack of effect in a controlled trial.

In vitro data suggest that vitamin C alters numerous parameters of immune function and might have potential as an agent which prevents infection. When an uncontrolled Japanese trial claimed efficacy of vitamin C in preventing posttransfusion hepatitis, a randomized double-blind controlled trial was initiated to determine if this claim of vitamin C efficacy could be confirmed. For 2 days before surgery and 2 wk after operation, cardiac surgery patients received orally either a lactose placebo or 800 mg of vitamin C four times daily. One hundred seventy-five patients completed the study. Highly significant elevations of plasma vitamin C were seen in the vitamin C treatment group as compared to the placebo group (p < 0.0005), but no significant difference in the incidence of posttransfusion hepatitis (p < 0.50) or the clinical course of hepatitis was seen between the two treatment groups.

Use of atrial epicardial electrodes to diagnose and treat postoperative arrhythmias in children.

Temporary Teflon-coated stainless steel wires were placed on the right atrium of 100 consecutive infants and children undergoing open heart surgery. The patients' ages ranged from 1 day to 17 years. The wires were used for diagnosis or treatment 40 times in 30 patients. Atrial electrograms were recorded 14 times to diagnose arrhythmias and conduction disturbances that were unsuspected or misdiagnosed from the standard electrocardiogram. In 10 patients, atrial pacing was used to treat postoperative arrhythmias. Atrial pacing was also used as an adjunct to therapy in 16 children with postoperative low cardiac output and bradycardia with intact atrioventricular conduction. The wires were removed before discharge and no complications resulted from their use. Previous studies have demonstrated the usefulness of temporary atrial wires after cardiac surgery in adults. This experience confirms that the technique is easy and safe and can be of great diagnostic and therapeutic value in children.

Total tracheal reconstruction in a three-month-old infant.

Total tracheal reconstruction with a reversed segment of left bronchus was attempted in a 3-month-old infant with an extensive tracheal stenosis. The patient survived for 48 hours. The details of the procedure and its potential applications are discussed.

Partial anomalous pulmonary venous connection to the azygous vein with intact atrial septum.

A five-year-old girl with partial anomalous pulmonary venous connection to the azygous vein with intact atrial septum is reported. The clinical and roentgenographic features suggested the correct diagnosis. Surgical correction of this previously unreported defect was accomplished by creating an atrial septal defect and constructing a baffle to direct the blood flow from the azygous vein to the left atrium.

Observations on flow characteristics of passive external aortic shunts.

Extraluminal heparin-bonded shunts have been recommended to support the distal circulation and decompress the proximal vascular bed during procedures that require interruption of flow through the thoracic aorta. Shunts that originate in either the left ventricle or the proximal aorta are generally viewed as hemodynamically similar, despite incomplete documentation of their flow characteristics. The present study was conducted to further define these hemodynamic properties. Identical extraluminal shunts were placed from the left ventricular apex and aortic arch to the distal thoracic aorta in mongrel dogs. Simultaneous pressure and Doppler flow velocities were recorded in the carotid and femoral arteries. Computer-enhanced composite waveforms were used to assist data analysis. When compared to ventricular cannulation, aortic cannulation provided improved proximal decompression and increased mean distal flow. In addition, significant diastolic flow reversal was recorded in the distal circulation when ventricular cannulation was employed. On the other hand, ventricular cannulation was associated with the preservation of pulsatile flow, whereas flow generated by aortic cannulation was linear. It is concluded that extraluminal shunts that originate in the left ventricle and the proximal aorta have distinct hemodynamic properties. These differences may be clinically important in specific situations.

Unusual complication of direct left atrial pressure monitoring line.

We are here reporting the case of a left atrial pressure monitoring line that caused mechanical interference with the functioning of a Björk-Shiley mitral valve. The catheter wedged the disc into a closed position and caused the patient's death.

Bedside evaluation of postoperative sinus node function in children.

Sinus node dysfunction in children frequently results from the surgical correction of congenital heart defects. We evaluated postoperative sinus node function at the bedside in 25 children by utilizing atrial epicardial electrodes which were placed near the sinus node at the time of operation. Sinoatrial conduction times (SACTs) and corrected sinus node recovery times (CSNRTs) were determined within 3 days of operation in each patient. Group 1 consisted of 20 patients (aged 1 month to 13 years) with normal postoperative sinus node function. Mean (+/- SD) SACTs and CSNRTs were 122 +/- 33 msec (range 61 to 187 msec) and 165 +/- 54 msec (range 52 to 253 msec), respectively. Preoperative evaluation of sinus node function during cardiac catheterization showed that preoperative and postoperative SACTs and CSNRTs were not significantly different (p greater than 0.05) in any of nine patients. Group 2 was composed of five children (aged 1 to 14 years) with postoperative sinus node dysfunction. Three had abnormal SACTs of 230 msec or greater and two children had first-degree sinus node entrance block. Two patients had prolonged CSNRTs. Electrocardiographic (ECG) monitoring revealed evidence of sinus node dysfunction in four of the five patients in Group 2. This report describes a simple and safe means of evaluating postoperative sinus node function at the bedside. The data are comparable to those obtained using more conventional methods during cardiac catheterization.

Clinical experience with the activated clotting time for the control of heparin and protamine therapy during cardiopulmonary bypass.

The clinical experience with the activated clotting time (ACT) for the control of heparin and protamine therapy during cardiopulmonary bypass in 70 patients (50 adults and 20 children) is reviewed. After a standard dose of 2 mg/kg of body weight of heparin, the patient's ACT ranged from 210 to more than 600 seconds. The heparin dose required to accomplish an ACT of 500 seconds ranged from 1.3 to 4.7 mg/kg for adults and from 2 to 4.5 mg/kg for children. At the termination of bypass, the assessment of the patient's heparin level with the ACT allowed a more accurate reversal with protamine and markedly reduced the protamine requirements. Although the postoperative drainage was not significantly decreased, the total amount of blood transfusion and fresh-frozen plasma and platelet requirements were reduced by 30%, 20%, and 20% respectively. The simple, easy-to-use protocol is presented in detail.

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 micrograms/ml (range, 13.1 to 40.3 micrograms/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 micrograms/ml (range, 11.4 to 28.9 micrograms/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.

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.

A new method of tracheal reconstruction.

When resection of more than 50% of the trachea is necessary, tracheal reconstruction becomes a very difficult problem. We tested a new method of tracheal reconstruction using the left main bronchus. The procedure was performed in 6 adult mongrel dogs. Through a midline sternotomy, a left pneumonectomy is performed, preserving as much of the left main bronchus as possible. The carina is preserved and mobilized, and the left main bronchus is passed under the aortic arch and reversed. The distal end of the bronchus is anastomosed to the proximal end of the resected trachea. The distal end of the resected trachea is closed by stapling. Four animals survived the procedure without apparent functional difficulty and remained healthy until they were killed five to ten months postoperatively. The anastomosis was well healed without stenosis. Anatomical measurements in 10 human cadavers revealed that the length of the left main bronchus to the level of the upper lobe takeoff is approximately 50% that of the trachea. The diameter of the left main bronchus is approximately 75% that of the trachea. We believe that the technique described can extend the limits of tracheal resection in a selected group of patients for whom there is currently no good alternative.

Use of a sagittal oscillating saw for repeat sternotomy: a safer and simpler technique.

A method of repeat sternotomy using a microsagittal oscillating saw is described. We have found this method to be safer and simpler than previously described techniques. We have used this technique in more than 50 repeat sternotomies without a single complication related to the mediastinal reentry procedure.

Bacterial wound colonization after broad-spectrum versus narrow-spectrum antibiotics.

Broad-spectrum versus narrow-spectrum antibiotic prophylaxis for patients who undergo cardiac operations is variously advocated to reduce the incidence of all infections or, conversely, to prevent resistant superinfections. Previous studies of prophylaxis have shown a reduction in the incidence of staphylococcal infections with some increased resistance. We studied preoperative and postoperative wound colonization as a surrogate for infection. Among 78 patients undergoing cardiac procedures, the type of prophylaxis was allocated as follows: narrow-spectrum (nafcillin), 24 patients; midspectrum (cephapirin), 26 patients; and broad-spectrum (ceftriaxone), 28 patients. Seventeen patients who underwent other procedures received no antibiotics and served as controls. Cultures of the operative site were done preoperatively, and 3 and 6 days postoperatively. The incidence of preoperative skin colonization with staphylococci was identical (95%) in all groups. Postoperatively, more patients receiving nafcillin (48%) were culture-negative for all organisms than were either of the other groups receiving antibiotics (27% and 22%) (p < 0.05). Gram-negative bacilli were infrequent colonizers and neither did the incidence of infection with these organisms increase nor did resistance develop in any group. The infection rates were not different among the treatment groups. Thus, a narrow-spectrum antistaphylococcal penicillin may offer an advantage in terms of both prophylaxis for cardiac operations and hospital costs.

Surgical repair of an anterior mitral subvalvular aneurysm.

An individual with a ruptured congenital subvalvular aneurysm is presented. The anterior location in the mitral annulus compromised the intervalvular fibrosa shared by the aortic valve. Aortic and mitral valve replacement were required to obliterate the resulting fistula between the left ventricle and left atrium.

Alternative method of ultrafiltration after cardiopulmonary bypass.

A revised circuit design for modified ultrafiltration is presented rendering the technique more convenient for use after cardiopulmonary bypass when blood cardioplegia is used. The procedure employs a hollow-fiber ultrafiltration device attached to the cardioplegia circuit. A bubble trap, heat exchanger, and a pressure monitor are incorporated as safety features. The technique has been used in 80 patients (30 pediatric and 50 adult) and has been associated with relevant increases in colloid osmotic pressure and hematocrit.

Arteriovenous and capillary hemangiomas of the interventricular septum.

The case of a patient with two extremely unusual types of hemangioma is presented. The arteriovenous and capillary hemangiomas of the interventricular septum were discovered on coronary angiography performed for chest pain. Echocardiography confirmed the diagnosis. Successful surgical excision was performed.

A reliable bridge to cardiac transplantation: the TCI left ventricular assist device.

The Thermo Cardiosystems (TCI) HeartMate, a pneumatically driven, implantable left ventricular assist device, was designed for long-term support of the failing heart. Between February 1990 and August 1992, the HeartMate was implanted in 11 heart transplant candidates because of profound deterioration of left ventricular function. Patients had a mean cardiac index of 1.6 L.min-1 x m-2 and a mean pulmonary capillary wedge pressure of 33 mm Hg despite maximal pharmacologic support with at least three inotropic medications. In addition, 5 patients were being supported with an intraaortic balloon pump. Nine patients were bridged successfully to cardiac transplantation. The mean cardiac index after implantation of the left ventricular assist device was 3.2 L.min-1 x m-2. Support ranged from 2 to 143 days (mean duration, 60 days). One patient died early of low output secondary to right heart failure, and a second died of air embolism, which occurred intraoperatively. All surviving patients became fully ambulatory. There were no thromboembolic complications during a total of 658 patient-days of support on a regimen of only 80 mg of aspirin daily. The 9 bridged patients are currently alive 4 to 34 months after transplantation. The TCI HeartMate provides safe and effective hemodynamic support with low risk of complications and virtual freedom from thromboembolism on a regimen of minimal anticoagulation.

Role of different methods of lung biopsy in the diagnosis of lung lesions.

Bronchoscopic biopsy and percutaneous needle biopsy were retrospectively compared with open biopsy. No procedure resulted in mortality. Nonfatal complications were similar in incidence. Bronchoscopic biopsy approached the accuracy of open biopsy only when applied to infiltrates. Percutaneous needle biopsy approached the accuracy of open biopsy only when applied to nodules. Nonspecific results of either bronchoscopic biopsy or percutaneous needle biopsy were unacceptable as definitive diagnoses.

Carotid endarterectomy: Is a shunt necessary?

Seventy-seven carotid endarterectomies performed on fifty-nine patients, using induced systemic hypertension during carotid artery clamping, were reviewed. The risk of cerebral ischemia is reduced to a minimum by this technic. The measurement of the internal carotid artery stump pressure is an excellent guideline for the need of additional brain protection. An internal shunt is rarely necessary. Thromboembolic phenomena contributed to the major neurologic complications encountered (two deaths and one stroke). Extreme gentleness and careful surgical technic cannot be overemphasized.

Bilateral bleb excision through median sternotomy.

We believe that when the indications for operation for spontaneous pneumothorax are met, the procedure of choice is bilateral resection of apical blebs and pleural abrasion through a median sternotomy. This approach allows easy access to both lungs and pleural spaces for a condition that is bilateral 100 per cent of the time. The operative morbidity is minimal and it essentially eliminates both ipsilateral and contralateral recurrence of pneumothorax with an operation that is of lesser rather than greater magnitude.