Hemoglobin A2 quantification by capillary zone electrophoresis.

Hemoglobin A2 (HbA2) comprises about 2.2% of the total hemoglobin in the erythrocytes. The separation and quantitation of this minor hemoglobin by capillary electrophoresis (CE) using an arginine Tris buffer is described. Some of the variables affecting the accuracy and precision of HbA2 quantification are investigated. Furthermore, the quantification of this hemoglobin by CE is compared to that of a microcolumn chromatography method. The CE method is better suited than the microcolumn method for measuring HbA2 in the sickle cell trait.

"Half and half" woven and knitted Dacron grafts in the aortoiliac and aortofemoral positions: seven and one-half years follow-up.

One-hundred fifty-eight patients received specially manufactured aortoiliac or aortofemoral bifurcated grafts with one limb woven, the other knitted from Dacron. During an observation period ranging from 1,567 to 2,555 days (average 2,130 days) no statistically significant difference was found in either platelet adherence (30 patients studied) or in clinical patency. According to the results of the study, the type of graft (woven or knitted) did not seem to influence either platelet adherence or patency rate in the aortoiliac or aortofemoral positions.

Traumatic tears of the thoracic aorta: improved results using the Bio-Medicus pump.

Traumatic disruption of the descending thoracic aorta is a relatively rare but dramatic injury. Controversy remains regarding the use of shunts during operative repair. Discouraged by our results using the "no shunt" technique, we adopted the recently reported technique using the Bio-Medicus pump for left atrium-femoral artery bypass without heparin sodium. At Charlotte Memorial Hospital and Medical Center, 39 patients were treated for tears of the descending thoracic aorta between January 1979 and October 1988. Eight patients died before repair could be completed. Four patients underwent repair using femorofemoral bypass with 1 death and no instances of paraplegia. Fifteen patients had repair using the no-shunt technique with 4 deaths and three instances of paraplegia. Since January 1986, 12 patients have been treated using the Bio-Medicus heparinless pump with no deaths and no instances of paraplegia. We present our experience to confirm the reports of others regarding the efficacy of this technique. We believe it reduces the morbidity and mortality associated with this serious injury and aids in the hemodynamic management of the patient during aortic clamping.

Rapidly growing nontuberculous mycobacteria: a new enemy of the cardiac surgeon.

A review of atypical mycobacterial infections complicating cardiac operations is presented. Proven sources of infections at different institutions include contaminated porcine valves and municipal water supply, but the mode of transmission in the great majority of patients remains unclear. There are two principal clinical forms of atypical mycobacterial infections after cardiac operations--endocarditis and sternal osteomyelitis. The latter has characteristics resembling tuberculotic "cold abscess." Specialized laboratory testing is necessary to confirm the diagnosis, and surgeons may have to take the initiative to request special microbiological investigation in cases where infection is clinically suspected but routine cultures are reported as "negative." The prognosis for patients who have any atypical mycobacterial infection after a heart operation is severe. Those infected with the strain chelonei and those whose cardiac chambers were entered during operation fare worse. This dim clinical prognosis may be improved by appropriate and aggressive antibiotic and surgical therapy. Awareness of the urgency of special bacteriological studies is the key to successful management.

Balloon valvuloplasty in calcified aortic stenosis: a cause for caution and alarm.

Balloon dilation by the percutaneous route has recently been recommended as an alternative to surgical intervention in the management of calcified aortic valvular stenosis. To investigate the validity of balloon valvuloplasty, this procedure was carried out in the operating room under direct vision in 30 patients just prior to excision and replacement of the ossified aortic valve. Changes induced by balloon dilation were evaluated by visual inspection as well as by geometric measurements. By visual observation, balloon valvuloplasty did not have a detectable impact on the valvular anatomy in about 19 of the patients and induced enlargement of the functional aortic orifice judged as "minimal" or "moderate" in only 11. In no patient was there a substantial increase in the functional orifice size. These findings were supported by geometrical measurements. Therefore, we believe that the virtues of this procedure have been grossly overstated by its proponents and that it should be offered only to patients who present a truly forbidding risk by standards of modern surgery.

A new instrument to facilitate myectomy in subaortic hypertrophic stenosis.

A new instrument, a modified "back-biting" Kerrison rongeur, is presented and recommended for the treatment of hypertrophic subvalvular aortic stenosis. The spike of the instrument allows the instrument to be engaged accurately and effectively into the anterior surface of the muscular ridge and appropriate obstructing tissue to be removed.

Indium 111-labeled platelet deposition in woven and knitted Dacron bifurcated aortic grafts with the same patient as a clinical model.

A study was designed to compare platelet deposition between knitted and woven Dacron grafts in the same patient. Twenty patients received aortoiliac or aortofemoral bifurcated Dacron grafts, each composed of one woven and one double-velour knitted limb. External nuclear graft imaging was carried out after injection of autologous platelets labeled with indium 111. The patients were studied postoperatively in time periods ranging from 6 days to 42 months. Platelet accumulation was almost identical in knitted and woven limbs in all patients. This study appears to indicate that there is no difference in thrombogenicity between knitted and woven bifurcated Dacron grafts in the aortoiliac or aortofemoral positions measured by platelet accumulation.

Patency rate of bifurcated aortic grafts: comparative analysis of woven versus knitted prostheses in the same patient.

To investigate the difference in patency rate between woven and knitted aortofemoral or aortoiliac prosthetic grafts, a special vascular prosthesis was manufactured with one limb of the graft knitted and the other, woven. The prosthesis was implanted in 143 consecutive patients with occlusive aortoiliac arteriosclerotic disease or aneurysms. Detailed statistical analysis failed to reveal any difference in the patency rate between the woven and knitted limbs of the grafts during an observation period ranging from one month to two years.

The value of thermography in the early diagnosis of postoperative sternal wound infections.

Peristernal skin temperatures were recorded postoperatively by infrared thermography in 150 patients. Persistent elevation of peristernal skin temperature during the 3rd and 4th post-operative week was found in 5 patients, all of whom developed sternal wound infection. A further group of 18 patients, all suspected to have occult wound infection, showed persistent temperature elevation in 7 patients, 6 of these patients were proven later to have manifest infection and needed treatment. Close thermographic scruting of the incision in patients with suspected but not proven infection appears to be useful in deleting early stages of deep seated infections.

Massive chest trauma due to impalement.

It is concluded in cases of thoracic impalement after arrival to the hospital the chances of survival are high because the probability is dominant that organ injury is most probably limited to severe contusion of the lung and that the cardiovascular system is largely spared by the penetrating object. The case histories of two patients surviving massive thoracic impalement are presented. Factors influencing initial survival and principles of surgical management are discussed.

Long-term observations on a crimped Dacron aortic bypass graft in the growing child.

Nineteen years of clinical and angiographic observations are presented on a patient with congenital stricture of the upper abdominal aorta who underwent thoracic-to-abdominal aorta bypass grafting using a woven crimped Dacron vascular prosthesis. These observations indicate that if such a prosthesis is properly applied, i.e., attached in a proper angle and is not stretched as it is usually done in the adult, then it will be capable of gradual "lengthening" through the years and thus adapt to the needs of a growing child.

Technical options in repairing the diseased ascending aorta with aortic valve involvement.

Operative repair of the diseased ascending aorta with aortic valve involvement consists of replacement of the ascending aorta and the aortic valve plus reconstitution of coronary arterial flow. Two basic techniques are presently available. The conventional technique involves separate replacement of the aorta and valve above and below a small segment of retained aorta including the coronary orifices. The second method consists of replacement of the entire ascending aorta and aortic valve with reconstitution of coronary flow by approximation of the coronary orifices to the Dacron conduit or with saphenous vein bypasses. Each method has its merits depending on the exact pathological anatomy encountered near the coronary orifices. Other pathological variables exist that demand additional intraoperative choices in technique. The present report details the operative repair of this lesion and outlines the technical options available for solution of the various problems encountered.

Simultaneous revascularization for complex brachiocephalic and coronary artery disease.

We have recently encountered two patients with significant coronary artery disease in addition to complex and extensive brachiocephalic occlusive disease. Both were operated upon successfully with simultaneous repair of both anatomic areas. These cases form the basis of this article. Fourteen additional patients with combined coronary and conventional carotid disease have been operated upon successfully with a simultaneous approach to both lesions. We conclude, until convincing prospective data are available possibly indicating otherwise, that a simultaneous approach to these combined lesions is indicated.

Thoraco-abdominal aortic aneurysm. Simplified surgical management according to Hardy. A case report.

The case of a middle-aged woman with an extensive thoraco-abdominal aneurysm who underwent exclusion-bypass grafting (Hardy procedure) is presented. The patient had an uneventful recovery. Studies one year after surgery showed all grafts to be well functioning and the aneurysm thrombosed. In the authors' opinion, the method is a valuable alternative to more radical operations designed for treatment of thoraco-abdominal aneurysm.

Sinus venosus type of atrial septal defect with partial anomalous pulmonary venous return.

This report describes our method of repairing the sinus venosus type of atrial septal defects. The superior vena cava is compartmentatlized by means of a single double-armed suture. Caval catheters are used as temporary internal shunts, and a vertical U-shaped patch is incorporated into the atriotomy suture line. The experiences with 27 cases are presented.