Clarence S. Weldon

Percutaneous Transthoracic Aspiration Needle Biopsy

An experience based on 1,211 patients has shown aspiration needle biopsy to be a valuable technique for diagnosing bronchogenic carcinoma and other localized intrathoracic lesions that are beyond the reach of the fiberoptic bronchoscope. In 896 patients with malignant intrathoracic neoplasm, the aspirate demonstrated malignant cells in 96%. A false cytological diagnosis of carcinoma occured in 2 patients, for a true positive rate of 99%. However, the true negative rate was only 87%. In 77% of 31 immunosuppressed patients, the causative agent of a focal infectious process was diagnosed. Pneumothorax was the only notable complication, occuring in 24% of patients, with 14% requiring chest tube drainage. The procedure is relatively simple and rapid, generally causes little patient discomfort, and can be performed in virtually any hospital.

A Simple, Safe, and Rapid Technique for the Management of Recurrent Coarctation of the Aorta

Abstract Six patients treated in infancy for coarctation of the aorta developed severe stenosis of the end-to-end aortic anastomosis that produced marked collateral circulation and upper extremity hypertension. Operation relieved the anastomotic obstruction in all 6 patients. A resection of the stenotic anastomosis with end-to-end aortic anastomosis was performed in 2 patients, bypass grafting between the transverse aortic arch and the distal aorta was done in 3 patients, and bypass grafting between the enlarged left subclavian artery and the distal aorta was performed in 1 patient. Interposed graft segments were short and had a diameter equal to or greater than the diameter of the aorta above or below the stenosis. Insertion of such short graft segments over an anastomotic obstruction provides an easy, rapid, and safe method for relieving hypertension and restoring distal pulsatile blood flow. Bypass grafting should be reserved for patients in whom anatomical considerations present an unusual hazard for a second aortic resection.

The use of the TDMAC-heparin shunt in replacement of the descending thoracic aorta.

The use of a flexible polyvinyl tube bonded with tridodecylmethylammonium-heparin (Gott) as a temporary shunt during the resection of lesions of the descending thoracic aorta has proven a safe and simple means of providing adequate circulation to the abdominal viscera and spinal cord. This technique avoids the metabolic consequences of ischemia to the lower body, diminishes left ventricular afterload during aortic clamping, and obviates the requirement for systemic anticoagulation associated with pump bypass. Between September 1970 and October 1974, 24 patients have been operated using the TDMAC shunt. There were two deaths (9%) among the 22 patients undergoing elective resections. Two patients with acutely dissecting and ruptured aneurysms expired. Followup data has been obtained on all patients from one to 46 months postoperative. The ease with which the shunt is inserted and its adaptability to varied clinical and anatomic situations is stressed. We feel that TDMAC-Heparin shunt provides the best method of circulatory support for elective operative procedures on the descending thoracic aorta.

Thoracic Aneurysmectomy Utilizing the TDMAC-Heparin Shunt

Abstract Clear heparin-bonded polyvinyl shunts were used during resection of descending thoracic aortic aneurysms for one year from July, 1970, through June, 1971. Eight patients were operated upon with 7 survivors; the single death was that of a patient with a rupture into the left pleural cavity. In our experience the use of this shunt is superior to techniques of temporary support that require systemic anticoagulation and pump bypass. The TDMAC-heparin shunt is simple and safe to use and adaptable to many anatomical situations; it provides ample distal blood flow and eliminates the need for systemic heparinization. Based on this initial rewarding experience, we believe this shunt offers advantages over all other techniques now being used for intraoperative circulatory support during descending thoracic aneurysmectomy.

Clinical experience with the use of a valve bearing conduit to construct a second left ventricular outflow tract in cases of unresectable intra-ventricular obstruction

Two patients, ages 7 and 17, with unresectable obstructions within the left ventricular cavity, have been managed by interposing a conduit bearing a porcine aortic valve between the apex of the left ventricle and the infra-renal abdominal aorta. The younger child had idiopathic hypertrophic subaortic stenosis (IHSS) recognized in infancy. At age three, a right ventricular myomectomy and a trans-aortic left ventricular myotomy were performed. Symptoms were progressive with congestive failure, diaphoresis, syncope, and angina pectoris. Following construction of a second left ventricular outflow tract with relief of intraventricular obstruction, the patient has become asymptomatic. The second patient has fibrous tunnel obstruction of the left ventricular outflow trading providing a 100 mm Hg gradient. Fibrous tissue was resected in part through the transaortic route, and a second outflow tract was constructed. A postoperative cardiac catheterization revealed an obliteration of the previous intraventricular gradients and an equal distribution of left ventricular output through the two available outflow tracts. She remains asymptomatic.

Laboratory and initial clinical studies of nifedipine, a calcium antagonist for improved myocardial preservation.

This report summarizes five years of laboratory investigations and the initial six-month clinical experience with a calcium antagonist, nifedipine, added to a cold hyperkalcmic cardio-plcgic solution for enhancement of myocardial protection. Regional ischemia was created in 112 dogs and global ischemia in 98 dogs, under normothermic and two hypothermic states. Control solutions, two clinical cardioplegic solutions, and nifedipine solutions were compared. Infusion of nifedipine during regional ischemia and repcrfusion intervals resulted in a two-to-thrccfold reduction in injury volume and maintenance of normal left ventricular function in contrast to infusion of nitroprusside. Nifedipine solutions (0.2 μ/ml) provided superior preservation of left ventricular function in comparison to the two cardioplegic solutions after one hour of global ischemia at 37 C and two hours at 18 C. In a clinical trial of nifedipine in cold potassium cardioplegia, 38 high risk patients with poor ventricular function have been treated; 22 of which were intensively studied serially with radionuclide ventriculography and pyrophosphate scans, myocardial isoenzyme determinations, 24 hour EKG recordings and intra-and postoperative hemodynamic studies. Of the 35 patients admitted to the intensive care unit (ICU), 33 have survived. Stroke work and cardiac indices return promptly to near normal levels after operation. The time-isoenzyme activity curves are low and radionuclide determined ejection fractions show no change for the study group. Death from acute postischemic cardiac failure did not occur in treated patients and the usage of intra-aortic balloon pump (IABP) has decreased threefold in comparison with 40 similar high risk patients treated concurrently with cardioplegic solution alone. It is concluded that nifedipine is a potent adjunct to cold hyper-kalemic cardioplegic solution in high risk patients.

Considerations in the surgical management of infantile coarctation of aorta

The results of a recent 5 year experience with resection of coarctation of the aorta in infants less than 1 year of age are compared with those of an earlier series from the same institution. The significant improvement in mortality and morbidity statistics is attributed to modifications in operative and postoperative care. Operative mortality has decreased from 38 to 17 percent and the incidence rate of significant restenosis has diminished from 60 to 33 percent. It is suggested that in patients with large associated intracardiac shunt banding of the main pulmonary artery should be performed before resection of the coarctation. Three of five patients have survived procedures performed in this sequence. Microsurgical techniques and careful approximation of the aortic lumen with interrupted sutures are the major factors responsible for the reduced incidence of recoarctation. Prolonged ventilatory support postoperatively with the occasional addition of controlled positive airway pressure and continued aggressive medical therapy for heart failure are recommended.

Treatment of d-transposition of the great arteries: Management of hypoxemia after balloon atrial septostomy

Between 1975 and 1979, a group of 43 patients with d-transposition of the great arteries were diagnosed and underwent Rashkind balloon atrial septostomy at the time of initial catheterization. Thirty-six (88 percent) survived to the time of intraatrial baffle repair, and 31 (72 percent) are long-term survivors, 2 of them now awaiting repair. Palliative operations were performed in nine patients before definitive surgery; four of these patients are long-term survivors. Prostaglandin E1 infusion improved oxygenation and relieved acidosis in four patients. It is concluded that most patients with d-transposition of the great arteries will survive to elective intraatrial baffle repair between 6 and 12 months without surgical palliation in spite of significant hypoxemia. Prostaglandin E1 infusion may be lifesaving and provide sufficient palliation in patients with persistent hypoxemia and acidosis after balloon atrial septostomy.

Late Clinical Problems with Beall Model 103 and 104 Mitral Valve Prostheses: Hemolysis and Valve Wear

The purpose of this study was to determine the influence on hemolysis of the spatial orientation of the struts in the Beall mitral valve prosthesis, Models 103 and 104. Thirteen pairs of patients were selected to match struts oriented parallel and perpendicular to the left ventricular outflow tract axis. The average time after operation was 3.73 years. Complete blood counts and relative serum chemistry values were determined.

Results of surgery for congenital supravalvular aortic stenosis.

Of eight children aged 3 to 15 years with surgical correction of severe supravalvular aortic stenosis, 6 were evaluated 7 to 44 months later by repeat cardiac catheterization and aortography. Prosthetic patch angioplasty was performed in all cases. Preoperative systolic gradients ranged from 40 to 90 mm Hg (average 70); postoperative gradients ranged from 0 to 20 mm Hg (average 11). The postoperative anglographic appearance of the ascending aorta was near normal in all six patients, and none had new aortic valve insufficiency. These results of surgery for supravalvular aortic stenosis are judged to be excellent.