Off pump treatment of aortic arch rupture: extraanatomic hybrid reconstruction.

We present a possible alternative technique to treat the rupture of aortic arch aneurysms on beating heart without necessity of cardiopulmonary bypass (CPB), hypothermic circulatory arrest and cerebral protection, using a bifurcated vascular prosthesis to revascularize the subclavian and carotid arteries and an endovascular prosthesis to repair the aortic arch. We report the case of a 78-year-old woman successfully treated with this technique. Since in our institution endovascular prostheses are placed by the interventional cardiologists, the operation was done in cooperation between cardiac surgeons and interventional cardiologists.

Automated protamine dose assay in heparin reversal management after cardiopulmonary by pass.

BACKGROUND: To evaluate the impact of automated Protamine Dose Assay (PDA) performed with Hemochron 8000 (International Technodyne Company, Edison, NJ) on the management of heparin reversal after cardiopulmonary bypass (CPB). PDA was compared with empirical protamine to heparin ratio with regard to calculation of the protamine dose, and the sensitivity of PDA and ACT to residual circulating heparin after protamine administration was investigated too. DESIGN: prospective and randomized study. SETTING: cardiac surgical center of a General Hospital. PARTICIPANTS: 50 patients undergoing elective cardiac surgery with CPB. INTERVENTIONS: after CPB patients randomly received protamine according to our standard empirical ratio of 1 mg. protamine/100 U. heparin (group S, 24 patients), or to PDA result (group T, 26 patients) based on protamine titration method of determining circulating heparin. After protamine administration ACT and PDA were performed to assess heparin reversal and detect residual circulating heparin. Based on the PDA result, additional protamine was administered in both groups when required. MEASUREMENTS: in both groups basal and post-heparin ACT values, protamine doses, ACT and PDA after protamine administration were measured. RESULTS: The protamine dose was significantly lower (30%) in patients treated according to PDA. In 20% of patients showing normal ACT PDA revealed still circulating heparin, and additional protamine was required. In all other cases ACT and PDA both confirmed heparin reversal. CONCLUSIONS: PDA allowed us to administer a significantly lower amount of protamine. This can reduce incidence of adverse effects of over- and under-infusion of protamine. PDA also proved to be more sensitive than ACT in detecting residual circulating heparin after protamine administration.

Influence of transesophageal echocardiography on intraoperative decision making for toronto stentless prosthetic valve implantation.

BACKGROUND AND AIM OF THE STUDY: Intraoperative transesophageal echocardiography (TEE) is commonly used during aortic valve surgery. In aortic valve replacement (AVR), this permits measurement of the aortic annulus, study of the anatomy of aortic valve components, and prediction of prosthesis valve size. After cardiopulmonary bypass (CPB), echocardiography is valuable in checking prosthesis function. In this study, we evaluated the impact of intraoperative TEE on the decision-making process of aortic Toronto stentless prosthetic valve (TSPV) implantation. METHODS: Fifty-two consecutive patients undergoing elective AVR were collected prospectively. Multiplane TEE was performed before CPB to determine diameters of the aortic valve annulus and sinotubular junction. This was to evaluate the feasibility of TSPV implantation in the aortic position and to predict prosthesis size. Further TEE evaluation was carried out after CPB to assess prosthetic valve function. RESULTS: TEE allowed measurement of the aortic annulus and sinotubular junction, and enabled correct prediction of prosthesis size. Ultrasonic evaluation also revealed contraindications to TSPV implantation in five patients. In one case, color-Doppler examination led to immediate successful surgical correction of prosthetic incompetence. CONCLUSION: Intraoperative multiplane TEE examination is useful in the decision-making process in AVR with the TSPV by selecting patients suitable for the stentless valve, predicting prosthesis size, and checking prosthesis function.

Left ventricular remodeling after aortic valve replacement with the Toronto-SPV prosthesis.

The remarkable hemodynamic features of the aortic Toronto SPV prosthesis have been reported. To assess the efficacy of these characteristics to produce a favorable left ventricular remodeling and to test the limits of the dobutamine stress test to check these results, 25 consecutive patients, who had undergone aortic valve replacement with Toronto SPV, were monitored with dobutamine and exercise stress tests for 1 year. Among the prosthetic and left ventricular morphological and functional parameters evaluated, dobutamine infusion produced an overestimation of prosthetic and left ventricular outflow tract gradients, effective orifice area, and prosthetic resistance compared with the more physiological exercise test (P<.01). These misleading results were probably due to the inotropic and unloading effects of dobutamine in still hypertrophied hearts. Indexed myocardial mass and wall thickness decreased significantly during the follow-up period (P<.01), whereas left ventricular diastolic diameter and ejection fraction showed no significant variations. These data show that the positive left ventricular remodeling is due only to the regression of the hypertrophy and not to the reduction of left ventricular diameters. Based on results from this study, the dobutamine stress test should be avoided to evaluate patients with aortic valve prostheses and still present left ventricular hypertrophy. The Toronto SPV produces a favorable left ventricular remodeling during the first year of follow-up, and is likely to improve.

Artificial chordae in the treatment of anterior mitral leaflet pathology.

This report describes the authors' clinical experience with expanded polytetrafluorethylene (e-PTFE) sutures to replace the anterior mitral leaflet chordae for valve repair. Between November 1986 and July 1995, 203 patients underwent operations with e-PTFE chordae insertion. Among these, 122 had artificial chordae utilized for anterior mitral leaflet repair. Four patients had the valve replaced during the same operation because of an unsatisfactory result. One patient died from respiratory insufficiency 16 days after operation. Transoesophageal echocardiography at discharge from hospital showed no evidence of regurgitation in 81 cases, and trivial regurgitation in 36. During a mean follow-up of 36.6 (range 1-106) months two other patients died from causes unrelated to the valve repair, while one patient had a transient ischaemic attack returning to sinus rhythm. Two patients were reoperated on 12 and 18 months respectively after their initial operation for progression of valvular degeneration causing natural chordae rupture. Among the remaining 113 patients, 111 are in New York Heart Association functional class I and yearly transoesophageal echocardiography has shown absent or trivial regurgitation. The utilization of e-PTFE as artificial chordae for anterior mitral leaflet pathology is a safe and reliable procedure, yielding excellent results and increasing the number of candidates for valve repair.

Hemodynamic evaluation of 23 mm Pericarbon and 23 mm Hancock II bioprostheses in the aortic position at mid-term follow up.

BACKGROUND AND AIMS OF THE STUDY: Pericardial xenografts were introduced for clinical use following evidence of their good hemodynamic characteristics in laboratory tests; however, their efficiency in comparison with porcine valves has not been fully assessed. Pericarbon, a new type of pericardial bioprosthesis, has been recently developed in order to provide better hemodynamic performances and longer durability than such bioprostheses currently in use. METHODS: Fifteen patients operated on for aortic valve replacement with a 23 mm Pericarbon and a sex- and age-matched group operated on with a 23 mm Hancock II bioprosthesis were submitted to echocardiographic and Doppler examinations in order to compare the hemodynamic performance of the two devices. RESULTS: Peak transvalvular gradients for Pericarbon and Hancock II bioprostheses (38.9 +/- 13.0 vs. 33.9 +/- 13.0 mmHg; p = 0.294) and mean transvalvular gradients (24.7 +/- 7.6 vs. 20.8 +/- 9.9 mmHg, p = 0.24) showed no significant difference. However, the indexed effective prosthetic dynamic area was significantly larger for the Hancock II device (0.73 +/- 0.14 vs. 0.62 +/- 0.13 cm2; p < 0.05). CONCLUSIONS: When installed as 23 mm pericardial bioprostheses, the Pericarbon device appears not to demonstrate superior hemodynamic performance to that of the Hancock II; however, additional studies are needed to provide a definitive conclusion.

Different applications of ePTFE valve chordae: surgical technique.

BACKGROUND AND AIMS OF THE STUDY: Artificial chordae made of ePTFE have been used for mitral valve repair for 10 years. The positive results obtained in experimental and clinical series have led to the extension of their clinical indications to mitral valve replacement and tricuspid valve repair. The different technical aspects of each of these applications are illustrated. MATERIALS, METHODS AND RESULTS: Artificial chordae were implanted in 223 patients undergoing mitral valve repair. Seven of them had the valve replaced during the same operation due to an unsatisfactory result. Two patients died in the postoperative period. During a mean follow up of 38.1 months (range 2-114 months), two more patients died, while three reoperations were required; one thromboembolic event was reported and the actuarial rates of patient survival and event-free survival were 98.0% and 95.8%, respectively, at nine years. In 31 cases of mitral valve replacement, with unavoidable removal of the entire subvalvular apparatus, ventricular wall-mitral annulus continuity was restored with the insertion of artificial chordae. None of these patients died early or during a mean follow up of 25.2 months (range 2-110 months), in which only one thromboembolic event was reported. In five cases of tricuspid valve insufficiency in which traditional techniques of repair were inadequate, valve replacement was avoided with the application of artificial chordae. None of these patients experienced any early or late complications. CONCLUSION: Based on this experience these procedures are safe, reproducible and reliable. They are a valuable support for other traditional techniques, allowing the indications for mitral and tricuspid valve repair to be extended, and restoring the ventricular-annular continuity in case of mitral valve replacement.

Artificial chordae.

One hundred and eighty-seven patients had mitral valve repair and 28 mitral valve replacement using 5-0 expanded polytetrafluoroethylene (e-PTFE). A mean of 6.7 (range 2-24) artificial chordae were utilized in each patient, associated with an autologous pericardium reinforced suture annuloplasty in most cases. Six patients required mitral valve replacement during the same operation, and one after 48 hours for unsatisfactory operative result. There was one operative death due to respiratory insufficiency. NO early valve-related complications were reported. At a mean follow up of 35.6 months (range 1-99 months), two more patients died because of cardiomyopathy and multi-organ failure, respectively, while only one patient experienced a TIA, returning to sinus rhythm two months after operation. Three patients required reoperation for rupture of natural chordae, traditionally shortened at operation in one case; for technical error in tying the artificial chordae in the second, and for progression of the degenerative disease in the third. At reoperation the artificial chordae appeared partially covered by a fibrous sheath, without any sign of thrombosis or calcification. Transesophageal echocardiography revealed a satisfactory long term result in 97% of the cases, while four patients showed a recurrence of mild mitral regurgitation, probably due to the progression of rheumatic valve pathology. Ninety-five percent of the patients are in NYHA class I. This surgical technique appears to be reproducible and reliable, improving the results of mitral valve repair, increasing the number of valves repaired, and optimizing left ventricular function in the case of mitral valve replacement with unavoidable removal of the entire subvalvular apparatus.

Seven-year experience with chordal replacement with expanded polytetrafluoroethylene in floppy mitral valve.

Among 106 patients operated on for implantation of artificial mitral chordae (expanded polytetrafluoroethylene), usually associated with other traditional procedures, 82 had degenerative valve disease. Two of them had the valve replaced during the same operation because of residual regurgitation, and one patient died (1.3%) of respiratory insufficiency. Seventy-nine patients left the hospital and were followed up to 84 months. No late deaths and only one valve-related complication were reported. This occurred in a patient who required reoperation after 18 months for sudden recurrence of mitral regurgitation caused by the rupture of natural chordae, which had been shortened during the first procedure, whereas the artificial chordae had retained their function. The clinical experience confirms positive experimental data, because this technique was reliable with lasting results. Application of artificial chordae, associated with other traditional techniques, is useful to improve the results and to extend the indications for mitral valve repair.

The replacement of the ascending aorta and aortic valve with a new design composite graft: a six-year experience.

The problems encountered in coronary artery reattachment when the ascending aorta and aortic valve are replaced with a composite graft induced Gallucci and one of the authors to develop a new aortovalvular prosthesis in clinical practice. The unique transverse ovoidal shape of this graft is intended to conform to the natural aortic root and facilitate the coronary anastomoses and minimize bleeding. We present our 6-year experience with 56 patients operated upon with this prosthesis. In all patients we were able to connect the coronary arteries directly to the graft without complications including hemorrhage or distortion of the coronary ostia. The survivors were evaluated with chest X ray, two-dimensional echocardiography, and conventional or digital subtraction angiography to detect the presence of pseudoaneurysms at the site of the coronary anastomosis, reported by others that have used the composite graft technique. The notable absence of this complication in our patients at a mean follow-up of 41 months (range 3-71) documents that this ovoidal composite graft is a reliable tool in the treatment of aortic root pathology.

Surgical technique for artificial mitral chordae implantation.

Failure of reconstructive procedures of the mitral valve is often ascribed to diffuse alteration of the subvalvular apparatus, which prevents the utilization of well-established techniques such as chordal transposition or shortening. For this reason, in 1986 after 2 years of animal experiments, we started the clinical use of expanded-polytetrafluoroethylene mitral chordae. Details of the surgical procedure are presented. Our experience is based on 51 patients with a mean follow-up of about 20 months (range 3-57). Four patients had the valve replaced during the same operation: one patient died later of cardiac failure and two underwent reoperation, 8 and 18 months after operation. Forty-one patients are in New York Heart Association Functional Class I and three in Class II. We suggest this technique in association with other traditional procedures to increase the number of mitral valves repaired, mostly because of degenerative etiology.

Surgical correction of posttraumatic VSD via the right atrium.

We report the cases of four patients seen with ventricular septal defects (VSDs) resulting from penetrating chest trauma; initial surgical management was via left thoracotomy and comprised relief of tamponade and suture of the surface cardiac wound. A VSD was suspected in all four patients postoperatively on the basis of a holosystolic murmur as confirmed with two-dimensional echo and angiography. Elective surgical repair was undertaken on cardiopulmonary bypass with bicaval cannulation and cardioplegic arrest. The interventricular septum was approached through the right atrium (no attempt was made to free the anterior surface of the right ventricle from adhesions). Three defects were closed directly and one was closed with a pericardial patch. The surgical correction of posttraumatic VSD from a penetrating injury can be safely and effectively achieved via a right atrial approach.

Surgical treatment of left-ventricular outflow-tract obstruction guided by intraoperative transesophageal echocardiography.

Transesophageal echocardiography may provide additional morphologic information in many cases of cardiovascular disease when compared with the traditional transthoracic approach. In our department 3 male patients underwent surgical treatment with preoperative diagnosis of left-ventricular outflow-tract obstruction. We describe the intraoperative transesophageal echocardiographic findings and in which way they guided the surgical strategy.

Chordal replacement in mitral valve repair.

Chordal replacement greatly extends the possibility of repair of atrioventricular valves. Both glutaraldehyde-tanned xenograft pericardial chordae (GTXP) and extruded polytetrafluorethylene chordae (ePTFE) heal to papillary muscles and cusps. Neither type elongates or shrinks. GTXP may thicken and stiffen with time. ePTFE is covered by a normal fibrosa and intima (a new chorda is grown around the ePTFE suture) experimentally and in small sizes (e.g., CV 5), retains flexibility. The results of late follow-up (5-10 years) with GTXP chordae and early follow-up (6-58 months) with ePTFE chordae are encouraging.

Artificial mitral valve chordae: experimental and clinical experience.

Failure of mitral valve reconstructive procedures often may be ascribed to severe or progressive alterations of subvalvar apparatus. Expanded polytetrafluoroethylene sutures were used to replace anterior leaflet mitral valve chordae in 8 animals (hypertensive dogs and growing sheep). After the positive results obtained during a 13-month follow-up, 5-0 sutures of the same material were introduced in clinical practice to replace mitral valve chordae. Twelve patients had two to six anterior leaflet chordae replaced for degenerative or rheumatic disease. In 3 patients, the intraoperative result was not acceptable and a prosthetic valve was inserted during the same operation. One case of late failure has been recorded so far (18 months after the procedure), owing to rupture of a natural chorda shortened at operation. Since that event, we have implanted supportive artificial chordae in case of diffuse alteration of natural chordae. The remaining patients show satisfactory hemodynamic results, and no valve-related events have been recognized up to 30 months after operation. We suggest use of 5-0 polytetrafluoroethylene sutures in replacing anterior leaflet chordae in degenerative, rheumatic, and congenital mitral valve diseases.

Efficacy and safety of predeposit blood autodonation in 500 cases of myocardial revascularization.

Since 1985 all patients scheduled for coronary artery bypass grafting have been evaluated for admission to a program of predeposited blood autodonation. From a total of 816 consecutive patients, 505 were admitted to the program (group 1). The other 311 (group 2) were excluded on the basis of one or more of the following criteria: 1) emergency surgical indication, 2) hemoglobin less than 12 g/dl, or 3) uncontrolled angina or clinically manifest cardiac failure. Postoperative use of homologous blood products was required by 16% of the group 1 and 44% of the group 2 patients (p less than 0.001). Altogether 597 patients (73%) had no contact with homologous blood products. There was no intergroup difference in the incidence of postoperative complications. Non-A, non-B hepatitis developed in three group 1 and four group 2 patients. Its incidence was 0.9% among all discharged patients and 3.2% of the homologous blood recipients. The findings emphasize the safety and value of the autodonation with predeposit program in significantly reducing the requirement for homologous blood in coronary artery bypass grafting.