Specific in vitro binding of radiolabeled antibodies to cell surface antigens: interaction of antihuman thymocyte globulin with human target cells.

We have developed a highly sensitive and reproducible in vitro method to measure the rate and amount of binding of radiolabeled antibodies to target cells. We reduced non-specific binding of the antibodies to the target cells approx. 92% by removing protein aggregates from the antibody solutions. Using a specially designed cup that simultaneously allows washing and collection of target cells, cell loss was eliminated. This method was used to study the in vitro binding properties of the IgG fraction of anti-human thymocyte globulin (ATG) to nucleated human cells and to cells of other species. We found the initial rapid uptake of labeled ATG-IgG slowed with prolonged incubation. Incubation temperature and ATG concentration increased the rate of uptake. Sequential absorption studies indicated that initial uptake was due to rapidly binding antibodies. After these antibodies were removed, the rate of binding for antibodies that remained was several fold less than that of the antibodies removed by the initial absorption. Since temperature and the concentration of antibody and target cells can be rigidly controlled, this in vitro model system is ideally suited to quantify optimal conditions and kinetics of antibody binding to cell membrane antigens. Furthermore, the binding properties of antibody subpopulations in an antiserum may be determined by this technique. The maximum antibody binding capacity of various cell types can also be measured using the technique with a precision of +/- 14% on replicate determinations.

The exposed cardiac pacemaker. Treatment by subfascial pocket relocation.

Ten patients were treated for skin erosion and exposure of chronically implanted pacemakers. The pulse generators had been implanted either subcutaneously or in the subpectoral, submammary location. All patients were treated either by primary or secondary relocation of the pulse generator to deeper subfascial planes. Pacemakers relocated primarily to subfacial planes healed without resurfacing. Those pacemakers relocated to other superficial planes resurfaced but healed in a second subfascial translocation. Bacteriologic studies on these patients revealed that the organisms cultured or antibiotics utilized did not influence the fate of the relocated pulse generator. The subfascial location was the only determinant of the ultimate healing of the exposed pacemaker. We conclude that subfascial relocation of well-functioning pacemaker generators should be considered as an alternative to complete replacement of the unit.

Aneurysm of the sinus of Valsalva producing obstruction of the left main coronary artery.

An aneurysm of the left sinus of Valsalva compressed the left main coronary artery and the patient experienced anginal pain. Surgical correction consisted of obliteration of the orifice of the aneurysm, aortic valve replacement, and a saphenous vein bypass from the ascending aorta to the distal left anterior descending coronary artery. Postoperative studies revealed excellent function of the prosthetic valve, no recurrence of the aneurysm and retrograde filling of the left anterior descending and circumflex coronary arteries. Three years after the operation, the patient is asymptomatic.

Surgical management of the bleeding aortopulmonary fistula.

A technique utilizing endobronchial intubation with a Carlens tube and a TDMAC-heparinless shunt is described for management of the actively bleeding aortopulmonary fistula. An illustrative case report is presented.

Expanded polytetrafluoroethylene surgical membrane for pericardial closure. An experimental study.

This experimental study summarizes our experience with the use of a new polytetrafluoroethylene surgical membrane as a pericardial substitute in 24 dogs. Group I consists of 10 dogs who underwent simple pericardial closure with this membrane, and in Group II, 14 dogs had pericardial closure with this membrane after cardiac procedures. There were three early deaths. Two dogs that had undergone an associated right heart procedure developed endocarditis at 4 and 7 months, respectively. Postmortem examinations were performed in all 21 surviving dogs. The pericardial membranes were found to be acellular and to have maintained their initial characteristics. The epicardium was normal and the coronary arteries easily visible. Seven of the eight 0.2 mm thick membranes caused filmy pericardial adhesions. None of the 0.1 mm thick membranes formed adhesions or had any structural change. We conclude that this new 0.1 mm thick polytetrafluoroethylene surgical membrane should be clinically tested to see if it will reduce or eliminate pericardial adhesions and facilitate cardiac reoperation.

Generation of chordae tendineae with polytetrafluoroethylene stents. Results of mitral valve chordal replacement in sheep.

Surgical repair of ruptured or elongated chordae tendineae of the mitral valve is one of the most complex reconstructive techniques in cardiac surgery. Various surgical procedures have been described to repair chordal abnormalities of the anterior leaflet of the mitral valve with unpredictable results. Mitral valve replacement is usually recommended in that situation. This report describes a simple repair technique that we have devised. We resected one or two marginal chordae of the anterior leaflet of the mitral valve in 35 sheep and replaced them with a double-armed, pledget-supported, expanded polytetrafluoroethylene suture. The 30 surviving animals were studied hemodynamically and were electively put to death 3, 6, 9, 18, and 24 months after the operation. Mitral insufficiency did not develop in any of the sheep. All specimens had a normal mitral valve without thrombosis. The polytetrafluoroethylene suture remained pliable and was incorporated into the anterior leaflet and papillary muscle. Scanning and transmission electron microscopy showed that the suture was completely covered by a sheath of tissue with a collagen structure remarkably similar to that of a native chorda. Calcification was not detected in the new chordae. This reproducible and safe technique may considerably simplify the difficult repair of chordal abnormalities.

Successful repair of a transected intrathoracic trachea after chest trauma.

A 28-year-old man had a transection of the intrathoracic trachea in a head-on collision. Prompt diagnosis with a flexible bronchoscope, expeditious thoracotomy, and distal tracheal intubation proved lifesaving and allowed for meticulous repair of the disrupted trachea. The patient is asymptomatic 1 year later.

The Ionescu-Shiley valve: a solution for the small aortic root.

Valve replacement in patients with a small aortic anulus can cause difficult technical problems or leave the patient with a significant residual transvalvular gradient. Between August, 1977, and June, 1983, 35 patients with a small aortic root (21 mm or less) underwent aortic valve replacement with Ionescu-Shiley pericardial xenograft valves. They ranged in age from 29 to 76 years (mean 52.8 years) and in weight from 64 to 91 kg (mean 76.3 +/- 3.6 kg). Preoperatively, 26 patients were in New York Heart Association Functional Class III-IV. The valve sizes used were 17 mm in three cases, 19 mm in 16 cases, and 21 mm in 16 cases. There were four hospital deaths (11.4%) resulting from sepsis or low cardiac output. There were no late deaths. Cumulative duration of follow-up was 819.4 patient-months. Twenty-four (78%) of the 31 surviving patients are asymptomatic. Up to the time of review, there have been no episodes of thromboembolism, infective endocarditis, perivalvular leak, valve thrombosis, or primary tissue valve failure. Fifteen patients were hemodynamically evaluated 2 to 47 months (mean 14.3 months) after operation. The average resting transvalvular gradients for 19 and 21 mm valves were 15.1 and 10.8 mm Hg, respectively. Our experience suggests that the Ionescu-Shiley pericardial xenograft valve is a valid alternative in the surgical treatment of patients with a small aortic root.

Congenital partial pericardial defect: surgical correction by partial pericardiectomy through a median sternotomy.

A case of symptomatic congenital pericardial defect with herniation of the left atrial appendage is reported. The patient had experienced increasing fatigue, chest pain, shortness of breath, and slight cyanosis. A partial pericardiectomy through a median sternotomy was performed and the patient made an uneventful recovery.

Myocardial revascularization prior to subsequent major surgery in patients with coronary artery disease.

Of our series of patients undergoing direct myocardial revascularization, we selected 60 patients who had subsequent major surgical and cardiovascular operative procedures. Thirteen of these patients had a second subsequent operative procedure, and four of the original 60 patients had a third subsequent operation. None of the patients died during the subsequent operation and none sustained a myocardial infarction. During the 77 subsequent procedures, there were eight different episodes of cardiac complications: seven patients had supraventricular arrhythmias and one patient had acute pulmonary edema. All patients responded to medical therapy. These results are suggestive that myocardial revascularization should be performed prior to other major indicated operative procedures in patients with documented coronary artery disease.

Intestinal obstruction due to phytobezoars. Observations in two patients with hypothyroidism and previous gastric surgery.

Two patients had small-bowel obstruction due to phytobezoars. Both patients were hypothyroid. One patient had undergone a previous pyloroplasty for pyloric stenosis and the other a truncal vagotomy and a pyloroplasty for a duodenal ulcer. Similarities and differences between the two cases and the possible predisposing factors in the formation of the phytobezoars are discussed. The recognition of high-risk patients, and their education to prevent phytobezoars are emphasized.

Aneurysm of the main pulmonary artery: long-term survival after aneurysmorrhaphy and closure of a ventricular septal defect.

Pulmonary artery aneurysm (PAA) usually carries an ominous prognosis due to the associated pulmonary hypertension. Six years ago a patient with a PAA secondary to cystic medial necrosis and pulmonary hypertension due to a ventricular septal defect (VSD) was treated by aneurysmorrhaphy and closure of the VSD. Although the patient had early postoperative cardiac failure, his cardiopulmonary status stabilized, and he has done well without recurrence of his aneurysm or cardiac failure. This report summarizes the patient's clinical course, operative treatment, and long-term follow-up.

A technique for spot application of fibrin glue during open heart operations.

Several techniques have been described for preparing and applying fibrin glue to control surgical bleeding. However, these methods tend to be cumbersome, expensive, or messy. Furthermore, commercial kits have not been approved by the Food and Drug Administration because of the potential risk of hepatitis contamination. Therefore, we have devised a modified, simpler technique that enables the precise, pinpoint application of fibrin glue. The risk of hepatitis transmission is substantially reduced by using cryoprecipitate plasma instead of fibrinogen from pooled donors. This technique is especially well suited for anastomoses of small vessels or for sealing suture holes in nonporous grafts.

Mersilene ribbon closure of the median sternotomy: an improvement over wire closure.

With the increased utilization of median sternotomy in thoracic surgery, some difficulties have arisen with closure of the sternum. This article presents a simple, easy-to-perform method of sternal closure utilizing reinforcement of the sternal halves with a material that is less likely to cut through the sternum and that is readily available.

Tricuspid commissurotomy.

The technique of tricuspid commissurotomy is based on principles different from those employed in mitral valve commissurotomy. In performing tricuspid commissurotomy, it is essential to identify and split the fan chordae, which are always fused and which clearly delineate the fused commissures. Failure to do this can result in an incorrect commissurotomy and secondary massive insufficiency. Our technique of tricuspid commissurotomy, employed in 205 patients, is presented.

Implantation of pericardial substitutes.

Pericardial substitutes have been shown to decrease the formation of pericardial adhesions. For a pericardial substitute to be properly implanted, it must lie over the heart smoothly without buckling and prevent the accumulation of blood under its surface. The technique we describe prevents buckling of the pericardial substitute and consequently reduces the formation of pericardial adhesions.

Pancreatic pseudocyst of the mediastinum.

A patient with pancreatic pseudocyst of the mediastinum is presented. Weight loss, chest or abdominal pain, and dyspnea are the most frequent symptoms of mediastinal pseudocyst. Chest roentgenogram frequently demonstrates a posterior mediastinal mass, and esophagogram always shows esophageal displacement. The diagnosis is confirmed by computerized axial tomography of the chest and abdomen. Cyst-gastrostomy is the operation of choice for this condition.

Repair of posterior coronary lacerations.

Posterior lacerations of the coronary arteries that occur during arteriotomy should be repaired if significant. We describe a modification of the standard technique to repair posterior coronary artery lacerations. This technique avoids distortion and narrowing of the coronary artery.

Simplified aortic cannulation.

Cannulation of the ascending aorta for cardiopulmonary bypass can be complicated by excessive bleeding or improper (too low) placement. A simple method of cannulation that avoids these problems is presented. This technique has been utilized in more than 1,000 patients without untoward complications.

Surgical treatment of aortic dissections: initial experience with the adventitial inversion technique.

BACKGROUND: The adventitial inversion technique obliterates the false lumen and converts a dissected aorta into a conduit with tough adventitia on the inside and outside. Dacron grafts can be anastomosed to the aorta with fine sutures, which hold without tears. METHODS: From August 1995 to March 1997, we treated 6 patients with acute dissecting aneurysms. Three aneurysms were type I (A) involving the entire aorta, two type II (A) involving the ascending aorta, and one type III (B) involving the thoracoabdominal aorta. Circulatory arrest was used in 3 patients, 1 with type I aneurysm (A), 1 type II (A), and 1 type III (B). RESULTS: All Dacron-aorta anastomoses held sutures well and did not bleed intraoperatively or postoperatively. One patient (type II [A]) died of intraoperative low cardiac output. In patients with type I (A) aneurysms, the false lumen was obliterated, but 1 patient required resection of a 6-cm abdominal aortic aneurysm. CONCLUSIONS: The adventitial inversion technique is a safe technique for the treatment of acute dissecting aneurysms, which facilitates operation and solves the problem of intraoperative or postoperative bleeding due to tissue friability.