H. Victor Moore

Thirteen year experience with aortic valve replacement

Abstract Two hundred forty-one patients (163 male, 78 female) underwent isolated aortic valve replacement at the Medical College of Georgia from 1963 to 1976. The mean age was 46 years (range 12 to 72). Thirty-seven percent had aortic stenosis, 39 percent aortic regurgitation and 24 percent mixed valve lesions. One hundred ninety-eight were in New York Heart Association functional class III or IV. Forty-three were in functional class I or II and underwent surgery for endocarditis, severe regurgitation with rapidly increasing heart size or appearance of angina or electrocardiographic signs of ischemia. The long-term clinical characteristics of five models of Starr-Edwards valves (1000, 1200, 2300, 2310 and 2320) and the Bjork-Shiley prosthesis were defined by rates of survival, complications and rehabilitation. In 212 patients who survived operation, the annual valve-related cardiac mortality rate calculated by the life table method was 4.8 percent for those with model 1000, 3.6 percent for those with model 1200, 7.1 percent for those with model 2300, 6.1 percent for those with model 2310, 3.7 percent for those with model 2320 and 4.0 percent for those with the Bjork-Shiley prosthesis. Complications were most frequent among patients with models 2300 and 2310. The model 2320 valves have posed the greatest embolism risk (7.1 episodes/100 patient years compared with 3.3/100 for the entire group). One hundred twelve current survivors (90 percent) are in functional class I or II. No patient in class IV preoperatively survived the full study period. Thirty-nine percent of those in class III and 91 percent of those in classes I and II preoperatively survived 13 years. Successful management of patients with an aortic valve prosthesis is based upon knowledge of the natural history of individual prostheses. Longevity and rehabilitation depend upon aortic valve replacement before severe myocardial decompensation occurs plus meticulous management to avoid lethal complications inherent in individual prostheses. Assessment of functional durability of hemodynamically adequate valve designs requires long-term evaluation.

Esophageal mucocele: a complication of blind loop esophagus

Mucocele of the bypassed esophagus is an unusual complication of esophageal replacement and has been described only in isolated references. This report is based on our experience with 6 patients in whom a mucocele developed following esophageal replacement. Esophageal replacement was performed on 37 patients over a 10-year period at the Medical College of Georgia Hospital. A symptomatic mucocele requiring excision developed in 3 patients with achalasia, 1 with congenital tracheoesophageal fistula, 1 with esophageal atresia, and 1 with inflammatory stricture. Conduits used included stomach (4), reversed gastric tube (1), and colon (1). Our experience indicates that conversion of a closed-loop esophagus into a symptomatic mucocele is more likely in the presence of functioning, chronically irritated mucosa. The clinical features were referable to the mucocele itself or respiratory embarrassment therefrom. Thoracic roentgenograms and computed tomographic scans were diagnostic in verifying the presence of the esophageal mucocele. All five mucoceles arose from squamous epithelium. One of 3 patients with achalasia in whom a mucocele developed following esophageal replacement had premalignant changes in the mucosa. Based on this experience, our treatment of choice is early, complete excision of the mucocele.

Absent Pulmonary Valve with Atrial Septal Defect and Patent Ductus Arteriosus

SummaryThe case of a newborn with “absent pulmonary valve,” atrial septal defect, and patent ductus arteriosus is reported. He underwent surgical repair at five weeks of age, with closure of the patent ductus arteriosus and porcine pulmonary valve insertion. The clinical course leads us to suggest that reduction of pulmonary artery pressure and pulmonary valve competence will lead to prompt improvement in tracheobronchial compression and respiratory symptoms; no pulmonary arterioplasty is needed.

Apico-aortic conduits in children with severe left ventricular outflow tract obstruction

BACKGROUND Infrequently, congenital heart defects are complicated by left ventricular outflow tract obstruction (LVOTO) not amenable to conventional reconstruction. Apico-aortic conduits provide a means of palliating such patients until definitive repair is possible. The purpose of this study was to review a single institutions current experience with apico-aortic conduits. METHODS The medical records of pediatric patients receiving apico-aortic conduits were reviewed. Demographics, operative techniques, preoperative and postoperative physiologic variables, morbidity, mortality, and functional class were recorded. Off-pump and on-pump procedures were categorized for comparison. RESULTS Ten cases of apico-aortic conduits for left ventricular outflow tract obstruction were identified. Indications included congenital aortic stenosis, aortic atresia, and subaortic stenosis. Six procedures were performed off-pump and four required median sternotomy with cardiopulmonary bypass as necessitated by concomitant procedures. There was one operative death. The remaining patients demonstrated hemodynamic improvements and are all alive to date. One patient required conduit valve replacement. All patients are in New York Heart Association classification I or II at the time of last follow-up. CONCLUSIONS Apico-aortic conduits provide a safe and effective treatment alternative for select cases of left ventricular outflow tract obstruction. Off-pump techniques are feasible in the majority of cases. This valuable adjunct should be considered whenever conventional repair of left ventricular outflow tract obstruction is considered prohibitive.

Permanent Cardiac Pacemakers: Twelve-Year Experience with 287 Patients

Our total pacemaker experience was evaluated to determine survival, complications, effectiveness of follow-up techniques, and future goals for surveillance. A retrospective review of 287 patients with 570 pulse generators revealed 164 alive and 104 dead; 3 recovered normal conduction, 14 transferred care, and 2 have been lost to follow-up. Average age at initial implantation was 67 years. Overall mean generator life has been 22 months. The one-, three-, five-, and ten-year survival is 84, 71, 60, and 39%, respectively. The 738 operations performed averaged 2.6 procedures per patient. Of the total survivors, 108 (66%) had no complications; 56 (34%) have had at least one complication, 70% during the first year of the initial implantation. Fifty episodes of premature interruption of pacing service were detected. Ninety-one patients (32% of the group) have required an operative procedure on their pacemaker system more frequently than every two years. Of the replacements, 89 (29%) were for reasons other than end of generator life; 66 (63%) of the deaths occurred before replacement of the first generator. Mortality in the first two years was 23%. Once survival exceeded two years the average annual death rate was 3.7% (expected, 3.2%). Survival in our series compares favorably with that of other groups who report by the actuarial method. These data suggest that some deaths, reduced patient productivity, and the high cost to health care providers may be due in part to inadequate follow-up after the first pacemaker implantation. If follow-up observation is done frequently during the first year after initial implantation and once minimum generator longevity has passed, the goals of pacemaker therapy may be achieved.

Twelve-year experience with mitral valve replacement.

Between 1962 and 1974, 203 mitral prostheses were implanted in 201 patients. Of the 102 survivors, 29 have Beall, 25 Kay-Shiley, 22 Starr-Edwards (SE) 6000, and 27 SE 6320 valves. Full rehabilitation was achieved in 25 patients with Beall and 23 with SE 6320 valves. Sixteen with SE 6000 valves remain normally active. Only 8 with Kay-Shiley prostheses have resumed normal activities. Systemic embolization occurred with the following frequencies per 1,000 patient-months: 13.7 for those receiving the Kay-Shiley valve; 7.2 in the SE 6000 group; 4.3 after SE 6320 implantations; and 3;1 for the Beall group. Other prosthesis-related complications that were much less frequent included detachment (10), bacterial endocarditis (5), and hemolysis (10). Three Kay-Shiley valves malfunctioned. Life table analyses reveal the following survival rates: 33% after 11 years in the SE 6000 patients, 50% after 7.5 years in the Kay-Shiley group, 69% 2.5 years after SE 6320 implantation, and 65% 3.5 years after replacement with a Beall valve. Evidence is presented to support the extension of operative treatment to patients with less advanced valvular heart disease. Postoperative anticoagulation remains an unresolved issue despite lower rates of thromboembolism. More cumulative analyses of survival and morbidity and follow-up hemodynamic data are needed to assess the Beall and SE 6320 prostheses now employed in our valve replacement program.

Assessment of cardiac and renal function in children immediately after open-heart surgery: The significance of a reduced radionuclide ejection fraction (postoperative ejection fraction)

SummaryVentricular ejection fractions, calculated from radionuclide studies, and inulin clearance, were determined in 33 infants and children immediately after surgical repair of their congenital or rheumatic heart defects. Of these children, the seven whose surgery did not require a period of ischemic arrest served as controls.The immediate postoperative ejection fractions in the 26 children who did undergo a period of ischemic arrest were significantly less than their preoperative values (P≥0.001), but this decline was not observed in the control group. Ejection fraction tended to be depressed, transiently, in children 3–5 h after open-heart surgery. Early postoperative ejection fraction was significantly related to aortic cross-clamp time even when controlling for preoperative ejection fraction (r=0.74,n=25,P≤0.001). Some striking declines in ejection fraction were observed among children whose aortic cross-clamp time exceeded 42 min. The decline in ejection fraction was transient; late postoperative (>1 week) ejection fraction was not significantly different from preoperative values.Though glomerular filtration rates (GFRs) were often above normal, they were significantly correlated with ejection fraction (r=0.74,n=19,P≤0.01). The lower GFRs were associated with the lower early postoperative ejection fractions.

Assessment of Fontan graft patency by radionuclide perfusion pulmonary scan in tricuspid atresia with previous Glenn shunt

(superior vena cava to right pulmonary artery anastomosis).” Lung scanning with an upper extremity injection (Fig. 1, left panel) in this circumstance results in paradoxical filling of the left lung (Fig. 1, right panel).“-” A case is presented in which a Fontan procedure (insertion of a valve-containing prosthetic conduit between the right atrium and pulmonary artery) was assessed with radionuelides in a patient with a previous Glenn shunt. A lower extremity injection resulted in paradoxical filling of the right lung, confirming obstruction of the Fontan graft. Venous collaterals were in this case beneficial. They provided a pathway for systemic venous return. Lung scanning from a lower extremity provided quantitation of graft obstruction, as evidenced by reduced blood flow to the left lung, with most of the flow reaching the right lung via venous collaterals. CA, a 22.year-old woman with tricuspid atresia, ventric-

124 IMMEDIATE EFFECTS OF CARDIAC SURGERY ON MYOCARDIAL AND RENAL FUNCTION IN CHILDREN

The purpose of this study was to assess the extent of intraoperative myocardial compromise during cardiopulmonary bypass. A radionuclide ejection fraction (EF), cardiac output (CO), and left ventricular volume (V) determination, and inulin clearance were performed on 20 children (1-19 years old) 2-3 hours after total surgical repair of their congenital heart defects. Three measurements of EF, CO, and V were made at hourly intervals in 7/20 patients post-op. In spite of changes in CO and V, EF and heart rate did not change significantly. The duration of aortic cross clamp time (CT) reflects the potential for intraoperative myocardial insult. Immediately after surgery EF correlated with CT (r=−.77, p <.001) but not with pre-op EF. Late post-op (1 month-1 year) EF correlated with pre-op EF (r=.71, p <.05). Glomerular filtration rate correlated with EF (r=.76, p <.01). EF in the immediate post-op period reflected intraoperative myocardial compromise. Late post-op EF showed recovery from immediate post-op lows and was most influenced by pre-op EF. Low immediate post-op EF was associated with reduced renal function independent of the effect of altered cardiac output.