Proteinuria and nephrotic syndrome induced by renin in patients with renal artery stenosis.

Exacerbation of hypertension and a marked excretion of protein in the urine were observed in three patients in the absence of underlying renal parenchymal disease or other causes of proteinuria. Stenosis of a renal artery and hyperreninemia were present in all three patients. Correction of the stenosis by arterial bypass or nephrectomy resulted in a rapid decrease in urinary protein excretion. The relationship between the levels of renin activity and the proteinuria in one patient and long-term follow-up in the other two patients are reported, and the mechanisms of this proteinuria are reviewed. Renal artery stenosis may be the underlying cause in some cases of idiopathic nephrotic syndrome.

Acute aortic arch dissection: reevaluation of the indications for medical and surgical therapy.

Of 42 patients with dissection of the aorta, 4 had important arch involvement. Results were good in 2 patients treated medically. In two other patients wrapping the arch with a Dacron graft successfully prevented fatal hemorrhage. This technique avoids the need for arch replacement in selected cases. From this experience and a review of others a flow sheet was developed to guide decision-making in the surgical and medical management of patients with aortic dissection.

Prosthetic replacement of the aortic arch.

Four patients are reported in whom the aortic arch and variable portions of the ascending and descending aorta were replaced with a prosthesis. In three patients the preoperative diagnosis was dissecting aneurysm of the aortic arch and in one an arteriosclerotic aneurysm of the aortic arch was present. A combination of surface cooling and cardiopulmonary bypass was utilized to produce total body hypothermia. Arch replacement was carried out during a period of total circulatory arrest. Cardiopulmonary bypass was then utilized to warm the patient and resuscitate the heart. The average duration of cerebral ischemia was 43 minutes and the average duration of myocardial ischemia was 74 minutes. The average lowest esophageal temperature was 14 degrees C., and the average lowest rectal temperature was 18 degrees C. Three patients are alive and well 4 to 13 months following surgery. One patient died 4 days postoperatively of pulmonary insufficiency. This experience indicates that by utilizing total body hypothermia and circulatory arrest aortic arch replacement can be carried out with an acceptable mortality rate. Corrective surgery could be offered to patients with life-threatening enlarging aneurysms of the aortic arch.

Preclotting of knitted Dacron prosthesis. A scanning electron microscope study.

A scanning electron microscope study of preclotting on knitted Dacron prosthesis is reported. Five steps of the interaction are well identified: (1) before any blood contact (virgin Dacron), (2) during the first 3 minutes (fibrin and platelet aggregates), (3) fifth minute of contact (clotting), (4) 15 minutes of contact with heparinized blood (thin fibrin network), and (5) the following minutes (invasion of fibrin, which enmeshes blood cells).

Arterial prosthesis of microporous expanded polytetrafluoroethylene for construction of aorta-pulmonary shunts.

A new arterial prosthesis made of polytetrafluoroethylene (OTFE) was evaluated in 10 infants with complex cyanotic congenital heart disease. All grafts used were 4 mm. in diameter and varied in length from 0.8 to 6 cm. The grafts were anastomosed to the main pulmonary artery or its bifurcation in 8 infants and to the right and left pulmonary arteries in one each. There were two early deaths, one of which was related to shunt failure. The advantages of a shunt to the main pulmonary artery are obvious, and the intraoperative procedure is facilitated with the prosthesis. Follow-up averages 9 months in the 8 survivors, and the patients have nearly doubled their preoperative weight. A shunt murmur is present in each case and the children have mild-to-moderate cyanosis at rest. Repeat aortograms in 2 patients, 8 and 10 months postoperatively, show a smooth graft without luminal narrowing. The aortic oxygen saturations were 73 per cent. The PTFE graft and/or anastomoses will not grow with the growth of the child and therefore may not accommodate growth by increased flow. This may prove to be a limiting factor in its long-term use in fants. We reserve the use of these grafts for infants with complex cyanotic defects undergoing emergency surgery or in older children in whom a conventional shunt is not possible or a previous shunt has failed.

Evaluation of right atrial-pulmonary artery conduits for tricuspid atresia. Experimental study.

Blood flow through right atrial-pulmonary artery (RA-PA) conduits was investigated. Experiments were designed to evaluate the pumping function of the right atrium, effects of the atrial versus ventricular pacing site, the necessity of a valve within the conduit, and the effect of positive-pressure ventilation on conduit flow. Twenty foxhounds were subjected to silicone patch closure of 90 percent of the tricuspid valve orifices to create stenosis. Ten dogs successfully underwent RA-PA shunting with a conduit with paralled limbs, one containing a prosthetic valve. The proximal main pulmonary artery was ligated to ensure total diversion of blood via the conduit. Valved and nonvalved conduit flow was significantly correlated with right atrial pressure (RAP): r = 0.95, p less than 0.05; r = 0.98, p less than 0.01, respectively. There was no significant effect of increasing heart rate (p = 0.19), atrial versus ventricular rhythm (p = 0.28), or the presence of a valve (p = 0.63). Increasing tidal volume resulted in increasing tidal conduit flow (expiration-inspiration) (r = 1.0, p less than 0.01), but mean flow was unaffected. Therefore, RAP is the most important factor influencing conduit flow. The absence of a valve, ventricular rhythm, and tachycardia did not significantly alter flow in this acute experimental model.

Results of aortoventriculoplasty in 21 consecutive patients with left ventricular outflow tract obstruction.

Results of aortoventriculoplasty (AVP) are reported in 21 patients with various types of left ventricular outflow tract obstruction (LVOTO). The concept of AVP is based on creating a surgical aortoseptal defect which is patched to provide the largest possible outflow tract to the left ventricle. Lesions consisted of isolated diffuse fibromuscular subaortic stenosis in six patients, diffuse subaortic stenosis and associated other cardiovascular anomalies in five, hypoplastic aortic anulus in two, idiopathic hypertrophic subaortic stenosis (IHSS) in two, and stenosis of a previously implanted aortic valvular prosthesis in three patients. Ten patients had had at least one unsuccessful previous surgical attempt to relieve the LVOTO. The coexisting mitral incompetence in IHSS disappeared after AVP alone. Immediate postoperative hemodynamic results were excellent in all cases. Postoperative death in five patients was due to advance myocardial failure in two, brain damage in one, transection of a dominant septal artery in one, and severe acidosis with renal failure in the last case. However, in the last 16 patients (17 operations) the only death (5.8 percent) was that caused by uncontrollable acidosis. Follow-up results indicate that 16 patients are clinically doing well, and hemodynamic studies in 14 patients are rated as excellent or good from 1 to 25 months postoperatively. It is concluded that AVP is an effective operation for managing all types of LVOTO and can be used routinely with an acceptably low mortality rate.

Technique for insertion of apicoaortic conduit.

A technique for insertion of an apicoaortic prosthesis is described. It provides a hemostatic aortic and ventricular anastomosis and can be performed with a minimum of bypass time and without interruption of coronary circulation. The technique requires no special instruments.

Modified technique for correction of tricuspid atresia.

This study presents a new technique for correction of tricuspid atresia. All 13 patients operated upon had the same form of the anomaly, with the great arteries normally related. The principle is to conserve the pulmonary valve and anulus of the patient in its anatomic position and to exclude the hypoplastic right ventricle. Because there is no need for closing the ventricular septal defect, the risk of heart block and residual left-to-right shunts is avoided. Deaths are related to questionable indications for two patients and to a bilateral pneumothorax for the third one. The long-term follow-up (5 years for the first patient) shows good results for the 10 survivors. Six of them are in Class 1 of the New York Heart Association and four are in Class II.

Extrathoracic bypass for stenosis of innominate artery.

Stenosis of the innominate artery usually occurs in older patients in whom the risks of conventional, corrective procedures such as transthoracic endarterectomy or aorto-innominate arterial bypass grafting are quite high. An axillo-axillary bypass procedure was performed in a high-risk patient with innominate arterial stenosis who had repeated episodes of transient cerebral ischemia due to decreased blood flow through the right carotid artery and reversal of blood flow through the right vertebral artery. Postoperatively, he has had dramatic improvement in his symptoms. Because of its simplicity, avoidance of major thoracotomy, avoidance of temporary occlusion of the carotid artery, and excellent late results, axillo-axillary bypass grafting is being proposed as the procedure of choice for stenosis of the innominate artery.

Replacement of obstructed extracardiac conduits with autogenous tissue reconstructions.

Tissue-valved prosthetic extracardiac conduits fail in 6% to 30% of patients within 5 years of implantation. Failure is caused both by valve degeneration and by conduit peel formation. This report describes a technique, performed in 16 children, in which an obstructed right ventricle-to-pulmonary artery valved conduit was removed and a new conduit constructed using the conduit bed as the posterior wall and a patch of xenograft pericardium (n = 10), homograft dura mater (n = 5), or Dacron (n = 1) as the roof of the conduit. One child with pulmonary hypertension required a Björk-Shiley pulmonary valve; in the others no valve was inserted. This technique simplifies conduit replacement, allows for a generous-sized outflow tract that may grow with patient growth, and uses material unlikely to become obstructed.

New-generation valved conduit: an experimental study.

OBJECTIVE: An ideal valved conduit to repair complex congenital heart defects is yet to be developed. In this study we have evaluated the merits of our newly developed calcification-free biologic valve incorporated in a compatible conduit of biologic origin in an animal model. METHODS: Porcine aortic valves and main pulmonary arteries were cross-linked in glutaraldehyde, followed by coupling to partially degraded heparin through an intermediate surface-bound substrate containing amino groups. Because commercially available valves are treated only with glutaraldehyde, control aortic valves and main pulmonary arteries were cross-linked in 0.625% glutaraldehyde. Valved conduits were fabricated from main pulmonary arteries, which were sewn to the aortic and ventricular ends of aortic valves. Valved conduits were examined for calcification and other pathologic changes after being implanted in the descending thoracic aorta in juvenile sheep for 5 months. RESULTS: Severe calcification was noticed in all layers of cusps (calcium, 231.86 +/- 17.90 mg/gm) and aortic wall (calcium, 123.24 +/- 24.72 mg/gm) of aortic valves and main pulmonary arteries (calcium, 135.43 +/- 26.63 mg/gm) of valved conduits treated with 0.625% glutaraldehyde. Cusps (calcium, 1.28 +/- 0.22 mg/gm) of the aortic valve of heparin-bonded conduits did not calcify at all. Only sparse calcific deposits were noticed in the medial layer of the aortic wall (calcium, 25.90 +/- 22.79 mg/gm) of aortic valves and main pulmonary arteries (calcium, 9.64 +/- 10.79 mg/gm) of the valved conduits coupled to heparin. CONCLUSION: Heparin coupling is effective in preventing calcification of glutaraldehyde cross-linked valved conduits implanted in the systemic circulation of juvenile sheep.

Surgical treatment of aneurysm of the ascending aorta with aortic insufficiency and marked displacement of the coronary ostia.

Six patients with a large aneurysm of the ascending aorta involving the root of the aorta and severe aortic valve insufficiency owing to marked annular dilatation were treated by replacement of the ascending aorta and aortic valve with a composite unit. It was also necessary to transpose the origin of the coronary arteries with the use of saphenous vein grafts. In 3 patients, the aneurysm was due to a chronic dissection. In one patient, the aneurysm extended beyond the arch of the aorta. There were no operative deaths. One patient died suddenly of pulmonary emboli 11 months after surgery. The remaining 5 patients are doing well, 5 months to 4 years postoperatively.

Repair of ventricular septal defect after pulmonary artery banding.

Since 1964, 90 patients have undergone two-stage surgical repair of ventricular septal defect (VSD) with pulmonary artery banding (PAB) in early infancy and total repair at an average age of 4 years. Reconstruction of the pulmonary artery was accomplished with a pericardial patch, woven Dacron patch, or transverse angioplasty. The VSD was closed with a knitted Dacron patch in 75 patients and by primary suture technique in 13 patients. The VSD closed spontaneously in 2 patients. The mortality rate for patients who had repair and debanding was 9 per cent (8 patients), including 4 deaths due to severe pulmonary hypertensive disease, 3 from congestive heart failure, and one from atrioventricular block. Twenty patients underwent repeat cardiac catheterization several months to 7 years after total repair. This study revealed no shunt in 16 patients and a minimal shunt not requiring operation in the other 4 children. Slight residual stenosis of the pulmonary artery was found in 2 patients and a residual infundibular stenosis in another 2 patients. We believe two-stage surgical treatment of VSD in severely ill infants under one year of age is safe and reliable.

Results of composite graft replacement for aortic root aneurysms.

From 1972 to 1980, 41 patients (aged 19 to 79) with aortic root problems have been managed surgically with a composite graft. Forty patients (97.5%) are long-term survivors who to date have had no complications related to the aortic root. This series of patients included 10 with acute dissection of the aortic root and ascending aorta. Thirty-one patients undergoing elective operations for aortic root aneurysms included three with chronic ascending aortic dissection with aortic regurgitation, three with previous operations on the aortic root, and six patients who had associated coronary artery bypass or mitral valve replacement. Follow-up to 8 years shows that patients with composite graft replacement have exhibited no early or late complications of this procedure. Two late deaths at 1 1/2 and 5 1/2 years were unrelated to the aortic root procedure. Experience seems to indicate that composite graft management of aortic root aneurysms is a most reliable and durable operation for the majority of patients with this disease.

Composite replacement of the aortic valve and ascending aorta.

This report comprises 16 consecutive patients with ascending aortic aneurysms caused by cystic medical necrosis. We replaced the ascending aorta and aortic valve with a tightly woven Dacron graft containing a Lillehei-Kaster valve prosthesis and implanted the coronary ostia in the sides of the graft. All but two patients had massive aortic insufficiency. Postoperative catheterization was performed in 13 patients, and all surviving patients have been seen within the past 6 months. There was one perioperative death (6 percent) and two late deaths. Eleven survivors are in Class I and two are in Class II (N.Y.H.A.). Angiographically demonstrated late complications have included psuedoaneurysms of the coronary ostium (two), paravalvular leak (one), and pseudoaneurysm of the distal suture line (one). Two of these four patients were asymptomatic. Two of the four patients have had successful repair of these defects and a third is awaiting operation. Compositive replacement carries a low operative risk and minimizes problems of intraoperative bleeding. In view of the incidence of late suture line problems, routine angiography 6 to 12 months postoperatively is recommended. If new symptoms occur or if there is a change in the cardiac silhousette on chest roentgenogram, the patient should be recatheterized.

Use of a ringed intraluminal graft in the surgical treatment of dissecting aneurysms of the thoracic aorta. A new technique.

An intraluminal graft made of woven tubular Dacron with cloth-covered grooved rings at both ends is used to repair dissecting aneurysms of the thoracic aorta. Six consecutive white male patients ranging in age from 31 to 69 years with an average age of 55 years were operated upon with the use of this graft. Three patients had a dissecting aneurysm of the ascending aorta and three others had a dissecting aneurysm of the descending aorta. Total cardiopulmonary bypass was utilized in repairing dissecting aneurysms of the ascending aorta and left heart bypass was used in patients with dissecting aneurymsms of the descending aorta. The basic technique consists in inserting the whole ringed graft into the true lumen of the dissected aorta and circumferentially ligating the aorta against the groove in the rings. The proximal ring of the graft effectively stabilized the flail aortic valve in two patients with aortic regurgitation associated with dissection of the ascending aorta. There were no hospital deaths. All patients are doing well 1 year, 1 month to 2 years, 8 months after the operation.

Eleven-year experience with composite graft replacement of the ascending aorta and aortic valve.

Between September, 1974, and December, 1985, 127 patients had replacement of the ascending aorta and aortic valve with a composite graft. Annuloaortic ectasia was the most common indication for operation (69 patients), followed by aortic dissection (51 patients). Twenty-four patients (19%) had the Marfan syndrome. Hospital mortality was 4.7%. Emergent operation for acute dissection was the only independent predictor of hospital death (p = 0.03). Reoperation for postoperative hemorrhage was required in 15 patients (11.8%) and for prosthesis-related complications (pseudoaneurysm, prosthetic endocarditis, technical problems, and valve thrombosis) in 16 patients (12.6%). Since we adopted a technique of preclotting the prosthesis with whole blood or albumin plus autoclaving and abandoned the inclusion technique, the reoperation rate has declined substantially. At 5 years, the actuarial freedom from reoperation for any reason on the ascending aorta or aortic valve for the 24 patients in whom this modification was used was 90% and for the remaining 103 patients, 73% (p = 0.17). No reoperations for pseudoaneurysms or technical problems were required in these 24 patients, whereas 10 reoperations for these complications were necessary in the other patients. The mean duration of follow-up was 54 months. The actuarial survival rate at 7 years for the entire group was 65%; for the patients with annuloaortic ectasia, 70%; for those with aortic dissection, 61%; for the patients with the Marfan syndrome, 57%. Actuarial freedom from operation on the remainder of the aorta at 7 years was 89%, but it was 78% for the subgroup with the Marfan syndrome. The satisfactory results with extended follow-up support the continued use of the composite graft technique as the preferred method of treatment for patients with annuloaortic ectasia or recurrent aneurysms of the sinuses of Valsalva and for patients with aortic dissection who require aortic valve replacement.

Complete repair of transposition of the great arteries with pulmonary atresia.

In this series of 13 patients undergoing repair of transposition of the great arteries with ventricular septal defect and pulmonary atresia, the operative risk and postoperative complications were greater than for repair of either transposition of the great arteries with ventricular septal defect and pulmonary stenosis or pulmonary arterial atresia with ventricular defect. Nevertheless, 6 of the 8 survivors improved clinically. Because operative and late mortality and morbidity rates are related to persistent right ventricular hypertension caused primarily by restricted pulmonary arterial outflow, results should be improved by performance of a preliminary systemic-pulmonary artery shunt for patients with hypoplastic pulmonary arteries and by use of the Hancock prosthesis, which has yielded lower gradients at both the proximal and distal anastomoses of the conduit. These improvements and the relief from cyanosis, exercise intolerance, and other symptoms seem to justify the continued application of surgical correction of transposition of the great arteries when associated with pulmonary atresia.

Resection of aneurysm of the aortic arch without cardiopulmonary bypass.

Four cases of aneurysm of the aortic arch were encountered within 1 year at the National Taiwan University Hospital, Taipei, Taiwan, Republic of China. All four patients underwent resection of the aneurysm and graft replacement of the aortic arch without cardiopulmonary bypass or hypothermia. Temporary external shunting with Tygon tube from the ascending aorta to the femoral artery, with and without permanent bypass grafts from the ascending aorta to the carotid arteries, was used in three patients. Permanent bypass grafts with multiple anastomoses was used in one patient. The over-all operative mortality rate was 25 percent. Some adjuncts are made to perfect the safe and simple technique of temporary external shunting, which has been reported previously from the same institution.