Steven R. Gundry

Seven-year follow-up of coronary artery bypasses performed with and without cardiopulmonary bypass☆☆☆★

BACKGROUND There has been resurgent interest in coronary revascularization performed on the beating heart. Heretofore, there has been no long-term comparison of this technique to traditional coronary artery bypass with cardioplegia. OBJECTIVE The purpose of this study was to provide a comparison of long-term survival and intervention-free outcome between patient groups subjected to coronary bypass accomplished with or without the use of cardiopulmonary bypass. METHOD From June 1989 to July 1990, all patients treated for coronary revascularization by three surgeons were considered for coronary revascularization with the heart beating: 107 patients underwent coronary bypass on the beating heart, and 112 patients underwent revascularization with the aid of bypass with cardioplegia. Mean ages (65 +/- 10 years) and risk factors were identical. Patients operated on with the heart beating had 2.4 +/- 0.9 grafts versus 3.2 +/- 1.1 grafts for patients having cardiopulmonary bypass with cardioplegia. RESULTS At 7-year follow-up, 86 of 107 (80%) patients operated on with the heart beating were alive versus 88 of 112 (79%) patients in whom cardiopulmonary bypass with cardioplegia was used. Cardiac deaths occurred in 13 of 107 (12%) patients in the former group versus 10 of 112 (9%) patients in the latter group. However, 32 of 107 patients operated on with the heart beating (30%) needed catheterization for their symptoms versus 18 of 112 (16%) patients in the bypass with cardioplegia group (p = 0.01). This results in 21 of 107 (20%) patients in the beating heart group needing angioplasty or a second coronary bypass versus only 8 of 112 (7%) patients in the bypass with cardioplegia group. No patient in the bypass with cardioplegia group required reoperation. Most of the reinterventions for the beating heart group were percutaneous transluminal coronary angioplasty (15 of 21 [71%] patients). CONCLUSION Despite one less graft per patient, survival and cardiac death rates were similar for the two groups. However, twice as many patients in the beating heart group required recatheterization (30% versus 16%), and 20% needed a second intervention. Only 7% of the bypass with cardioplegia group required reintervention. Limited revascularization of the beating heart provides long-term results comparable to full revascularization with cardiopulmonary bypass, but at the cost of a threefold increase in reinterventions.

Transplantation as a primary treatment for hypoplastic left heart syndrome: intermediate-term results.

BACKGROUND Hypoplastic left heart syndrome is a lethal malformation. For the last 10 years, orthotopic cardiac transplantation has been our preferred treatment for infants with hypoplastic left heart syndrome. METHODS One hundred seventy-six infants with hypoplastic left heart syndrome were entered into a cardiac transplant protocol between November 1985 and November 1995. Interventional procedures to stent the ductus arteriosus or enlarge the interatrial communication were performed in 8 and 35 patients, respectively. Thirty-four patients (19%) died during the waiting period, and 142 infants underwent cardiac transplantation. Age at cardiac transplantation ranged from 1.5 hours to 6 months (median, 29 days). The majority of grafts were oversized, and the median graft ischemic time was 273 minutes (range, 60 to 576 minutes). The implantation procedure used a period of hypothermic circulatory arrest ranging from 23 to 110 minutes (median, 53 minutes). Repair of other significant defects included interrupted aortic arch and total or partial anomalous pulmonary venous connection. RESULTS There were 13 early and 22 late deaths. Patient actuarial survival at 1 month and at 1, 5 and 7 years was 91%, 84%, 76%, and 70% respectively. Half of the late deaths were due to rejection. Severe graft vasculopathy was confirmed in 8 patients. Retransplantation was performed in 5 patients for graft vasculopathy 4 and rejection 1. Lymphoblastic leukemia developed in 1 patient 3 years after cardiac transplantation. CONCLUSIONS Cardiac transplantation can be performed in infants with hypoplastic left heart syndrome with good operative and intermediate-term results. Improved survival can be achieved with increased donor availability, better management of rejection, and control of graft vasculopathy.

A Comparison of Retrograde Cardioplegia Versus Antegrade Cardioplegia in the Presence of Coronary Artery Obstruction

Cardioplegic protection is limited by nonhomogeneous distribution of solutions distal to coronary artery obstructions. Using temperature mapping and sonomicrometry crystals implanted in the distributions of the left anterior descending (LAD) and circumflex coronary arteries, we studied the effects of blood cardioplegia delivery through the aortic root versus the coronary sinus in 10 dogs with a temporarily occluded LAD. All dogs were placed on cardiopulmonary bypass and cooled to 28 degrees C; the aorta was cross-clamped for two hours with the LAD occluded. Group 1 (N = 5) had cold (4 degrees C) potassium chloride cardioplegia (20 mEq per liter of KCl) administered through the aortic root at 20-minute intervals; Group 2 (N = 5) had the same solution infused through the coronary sinus by a balloon catheter. After two hours, the LAD snare was released and the dogs were weaned from bypass. Aortic root cardioplegia resulted in very poor cooling distal to the coronary obstruction with very poor systolic function and loss of diastolic compliance. In contrast, coronary sinus cardioplegia resulted in normal cooling distal to the coronary obstruction and complete return of systolic and diastolic functions following the experimental procedure. We conclude that cardioplegia administered through the coronary sinus offers superior cooling distal to coronary artery obstructions while preserving myocardial function in all areas. In contrast, delivery of cardioplegia through the aortic root causes severe depression in the myocardium distal to obstructions.

Ultra fast track in elective congenital cardiac surgery

BACKGROUND Changes in healthcare delivery have affected the practice of congenital cardiac surgery. We recently developed a strategy of limited sternotomy, early extubation, and very early discharge, and reviewed the perioperative course of 198 pediatric patients undergoing elective cardiovascular surgical procedures, to assess the efficacy and safety of this approach. METHODS One hundred ninety-eight patients aged 0 to 18 years (median 3.2 years) underwent 201 elective cardiovascular surgical procedures over a 1-year period. All patients were admitted on the day of surgery. Patients were divided into six diagnostic groups: group 1, complex left-to-right shunts (n = 14, 7.0%); group 2, simple left-to-right shunts (n = 83, 41.3%); group 3, right-to-left shunts with pulmonary obstruction (n = 33, 16.4%); group 4, isolated, nonvalvular obstructive lesions (n = 30, 14.9%); group 5, isolated valvular anomalies (n = 20, 10.0%); and group 6, miscellaneous (n = 21, 10.4%). RESULTS After 201 procedures, 175 patients (87.1%) were extubated in the operating room and 188 (93.6%) within 4 hours from operation. Four patients (2.0%) were extubated more than 24 hours from completion of the procedure, and 2 (1.0%) died while on respiratory support (never weaned). Five patients (2.6%) failed early extubation (<4 hours). Early discharge was achieved for the vast majority of patients. Overall median length of stay (LOS, including day of surgery as day 1) was 2.0 days, with a median LOS of 3.0 days for those patients requiring circulatory arrest duration exceeding 20 minutes. Of 195 patients, 43 (24.6%), 121 (74.0%), and 159 (81.5%) were discharged, respectively, at <24, <48, <72 hours from admission. Longest and shortest mean postoperative LOS were in group 6 (9.9+/-14.5 days) and group 2 (1.6 = 0.7 days), respectively. Six patients (2.9%) died, and 11 (5.5%) suffered in-hospital complications. Thirty patients (15.4%) were either treated as outpatients (n = 11, 5.7%) or readmitted (n = 19, 9.7%) within 30 days from the time of surgery. Only 8 of 195 patients (4.1%) were readmitted with true surgical complications requiring invasive therapeutic procedures. CONCLUSIONS Selected patients with a broad spectrum of congenital heart disease may enjoy same-day admission, limited sternotomy, immediate extubation, and very early discharge with excellent outcomes and acceptable morbidity.

Cervical teratomas in the newborn

Cervical teratomas are rare neoplasms which have been infrequently reported. During the period of July 1974 to April 1982, six newborns with this lesion were seen at the Mott Childrens Hospital. There were three males and three females, all of whom presented at birth with large semicystic neck masses. In four infants, calcifications were seen on x-ray. Four patients required intubation within the first hours of life for respiratory distress. One child of 33 weeks gestation expired prior to operation because of a hypoplastic left ventricle and bilateral hypoplastic lungs. Cord blood T3 and T4 values were normal in three patients; the TSH was elevated 1.5 and 2 times normal in two of these infants. Four neonates were operated upon within 24 hours of birth and suffered no postoperative complications. One baby presented on the third day of life and expired three hours postoperatively from persistent respiratory distress. The tumors were well encapsulated and arose from or were surrounded by a lobe of the thyroid gland. In each case, the tumor was removed by performing a total thyroid lobectomy. The presence of normal thyroid tissue at the resection margin (in the isthmus) was verified by frozen section. One patient presented with cervical node metastases but is currently free of disease one year postoperatively. These six cases bring the total reported cases in the literature to 136. The 80% mortality in cases not operated upon has been reduced to 15% by prompt operation. This series substantiates the significant respiratory distress that can occur in newborns with cervical teratomas and confirms the need for emergency surgery in this group of patients.

Prospective randomized study of a protein-based tissue adhesive used as a hemostatic and structural adjunct in cardiac and vascular anastomotic repair procedures.

BACKGROUND The purpose of this study was to determine whether adjunctive use of the bovine serum albumin and glutaraldehyde tissue adhesive BioGlue (BioGlue Surgical Adhesive; CryoLife, Inc) could reduce the rate of anastomotic bleeding in patients undergoing cardiac and vascular repair procedures when compared with a standard repair control. This was a prospective multicenter, randomized, controlled clinical trial conducted in accordance with the IRB at each participating institution. STUDY DESIGN A total of 151 patients consented to participation and were randomly assigned to standard repair plus BioGlue (n = 76) or standard repair alone (n = 75). These two groups were statistically homogeneous for age, gender, race, procedure, and number of anastomoses. Patients underwent cardiac procedures (n = 49), aortic procedures (n = 105), or peripheral vascular procedures (n = 48). RESULTS Anastomotic bleeding was significantly reduced in the BioGlue group (18.8% of anastomoses) compared with the control group (42.9% of anastomoses, p < 0.001). Pledget use was reduced in the BioGlue group (26.2%) compared with the control group (35.9%, p = 0.047). Days in the ICU and total days in the hospital were slightly higher in the control group. Adverse event profiles were equivalent between the two groups except for occurrence of neurological defects, which were threefold less in the BioGlue group (p = 0.009). CONCLUSIONS This study demonstrates that using BioGlue as an adjunct to standard repair methods is safe and significantly reduces the occurrence of intraoperative anastomotic site bleeding in cardiac and vascular repair patients. Using BioGlue along suture lines reinforces anastomoses, thus minimizing pledget use.

Delayed primary repair of intrathoracic esophageal perforation: Is it safe?

The management of intrathoracic esophageal perforation with delayed diagnosis is a subject of controversy. Because of the obvious advantages of primary repair as a simple single-stage operation, this technique was preferentially used to treat 18 of 22 consecutive patients with esophageal perforation. These patients were stratified into three groups according to the time interval between perforation and repair: group A, less than 6 hours, five patients (28%); group B, 6 to 24 hours, six patients (33%); and group C, more than 24 hours, seven patients (39%). Group A patients were older (p < 0.05) and group B had fewer iatrogenic perforations (B, 17%; A, 80%; C, 57%, p < 0.1). Additional tissue was used to buttress the repair site in all three groups (A, 3/5 patients, 60%; B, 4/6 patients, 67%; C, 6/7 patients, 86%; p = not significant). In seven patients (39%), a fundic wrap was used to reinforce the site of primary repair. The outcomes of the three groups were analyzed. Group A had the lowest proportion of postoperative leaks (A, 0/4 patients, 0%; B, 4/6 patients, 67%; C, 5/6 patients, 83%; p < 0.05) and postoperative morbidity (A, 2/5 patients, 40%; B, 6/6 patients, 100%; C, 6/7 patients, 86%; p < 0.1). However the increased incidence of leak and morbidity did not lead to an increase in mortality. One death occurred in each group, with an overall mortality of 17% (A, 1/5 patients, 20%; B, 1/6 patients, 17%; C, 1/7 patients, 14%; p = not significant). We conclude that in the era of advanced intensive care capabilities, primary repair of intrathoracic esophageal perforation can be safely accomplished in most patients regardless of the time interval between perforation and operation. Leakage at the suture site is common unless primary repair is carried out without delay. Postoperative leakage, however, is usually inconsequential and does not necessarily result in an adverse outcome.

Intraoperative Trauma to Human Saphenous Veins: Scanning Electron Microscopic Comparison of Preparation Techniques

Abstract To determine optimal preparation techniques for human saphenous veins, a scanning electron microscopic comparison was made of the effects of variations in solutions, temperatures, and distention pressures on human vein morphology. Segments of saphenous veins obtained from 20 patients undergoing myocardial revascularization were divided into five groups of 5 veins each. Group 1 segments (controls) were immediately distended and perfusion-fixed with glutaraldehyde at 30 mm Hg to simulate in vivo saphenous vein hydrostatic pressure. Segments comprising Groups 2 and 3 were placed in heparinized normal saline solution at 28°C for one hour and then distended to either 100 mm Hg (Group 2) or 300 mm Hg (Group 3). Segments making up Groups 4 and 5 were immersed in heparinized blood for one hour at either 28°C (Group 4) or 4°C (Group 5), and then distended to 100 mm Hg. Except for controls, which were fixed as described, all other groups of vein specimens were perfusion-fixed at 100 mm Hg to simulate in vivo arterial pressure. Control veins showed focal intimal fractures with minimal endothelial cell loss due to harvesting manipulation. Groups 2 and 3 had marked endothelial loss, which led to exposure of basement membrane, collagen fibrils, and smooth muscle cells and was associated with intimal and medial edema. Veins prepared with blood appeared similar to controls, showing focal endothelial cell loss, but preservation of intimal and medial structure. Changes were less marked in Group 5 than in Group 4. We conclude that human saphenous veins are best preserved by immersion in cold blood and distention to a pressure of 100 mm Hg or less.

Prolonged discordant xenograft survival and delayed xenograft rejection in a pig-to-baboon orthotopic cardiac xenograft model

OBJECTIVE Our objectives were to study delayed xenograft rejection and the effectiveness of pretransplantation total lymphoid irradiation combined with immunosuppression on rejection in a pig-to-baboon cardiac xenograft model. METHODS Baboons were treated with pretransplantation total lymphoid irradiation, cyclosporine A (INN: ciclosporin), and methotrexate. Orthotopic pig-to-baboon cardiac transplantations were performed after depletion of circulating xenoreactive natural antibody by pretransplantation donor organ hemoperfusion. Tissue samples were collected for immunologic and immunopathologic evaluation. RESULTS Pig cardiac xenografts survived more than 18 and 19 days without evidence of hyperacute rejection. Immunologic analysis of serum samples demonstrated that circulating xenoreactive natural antibody levels did not return to pretransplantation levels. The production of xenoreactive natural antibodies from the recipients splenocytes was inhibited completely. Histologic examination of xenografts showed the feature of acute vascular rejection. Immunohistochemical studies demonstrated infiltration of cardiac xenografts by large numbers of macrophages, small numbers of natural killer cells, and a few T cells. The infiltrating macrophages also showed expression of interleukin-1 and tumor necrosis factor. Diffuse deposition of immunoglobulin G, C1Q, C3, and fibrin on xenograft vasculature was observed. Interleukin-2 expression was not found in rejected cardiac xenografts. Xenograft endothelial cells also showed evidence of activation (expression of cytokines interleukin-1 and tumor necrosis factor). CONCLUSIONS This study demonstrates prolonged discordant cardiac xenograft survival and delayed xenograft rejection in a pig-to-baboon model. The delayed xenograft rejection is mediated by both humoral and cellular mechanisms. Pretransplantation total lymphoid irradiation combined with cyclosporine A and methotrexate can inhibit xenoreactive natural antibody production but not elicited antipig antibody production and the xenoreactivity of macrophages.

Indications for aortography in blunt thoracic trauma: a reassessment.

The indications for aortography in patients sustaining blunt chest trauma have increased as the number of radiographic and clinical findings associated with traumatic rupture of the thoracic aorta (TRA) proliferate. No studies, however, have demonstrated whether these findings are useful in selecting patients for aortography. In order to determine the predictive value of reported associations in TRA, the presence or absence of nine radiographic and nine clinical findings associated with TRA were tabulated and tested for correlation with the results of aortography in 173 consecutive patients who underwent arch aortography from 1975 to 1980 to rule out TRA following blunt trauma. Mediastinal widening was the most reliable indicator of TRA. All patients less than 65 years old with TRA presented with mediastinal widening. In patients under 65, the reliability of mediastinal widening to predict TRA was not enhanced by any other clinical or radiographic finding studied. On the other hand, only two of six TRAs in patients over 65 had mediastinal widening. Only in this group over 65 did other publicized indications for aortography, including pulmonary contusions or multiple rib fractures including ribs 1 and 2, have any association singly or in combination with TRA. We conclude that all trauma victims who have a widened mediastinum should undergo aortography. Other reported associations by themselves are not absolute indications for aortography except in patients 65 years old or older.