Technique for blood conservation in ABIOMED BVS 5000 ventricular assist device exchange.

We describe a technique for blood conservation when ABIOMED BVS 5000 blood pumps require exchange because of thrombus formation in the blood pumps. The technique is simple in concept but requires careful planning and coordination between surgeon and perfusionist.

Five-year clinical experience with Abiomed BVS 5000 as a ventricular assist device for cardiac failure.

Mechanical support for the failing heart has interested and challenged cardiac specialists for decades. In the United States alone, there are close to 375,000 cardiac surgical procedures performed each year, and, despite the recent advances in myocardial protection, surgical techniques, intra-aortic balloon therapy and maximal pharmacological support, postoperative ventricular dysfunction continues to occur in 0.5-1.0% of all patients undergoing cardiac surgery. This retrospective review describes our 5-year clinical experience at the Brigham and Women's Hospital with the Abiomed BVS 5000 as a means of ventricular support. During the period of 1994 to present, 7,428 cardiac surgical operations were performed at our institution. The Abiomed BVS 5000 has been implanted in 47 patients exhibiting ventricular failure. There were 38 patients in the bridge-to-recovery group and nine patients in the bridge-to-transplantation group. Twenty-five patients (66%) in the bridge-to-recovery group were weaned and 16 patients (42%) went on to discharge. In the bridge-to-transplantation group, one patient actually recovered myocardial function and one expired on the device. The remaining seven patients (77%) underwent cardiac transplantation with post-transplant survival at 66%. Overall, patients were supported in the isolated left ventricular mode (28%), in the biventricular mode (45%) and in the isolated right ventricular mode (28%). The Abiomed BVS 5000 has been shown to be a safe and simple cardiac support system with no mechanical failure. Our experience shows that a substantial number of patients suffering from ventricular failure will benefit from the use of this device. The results also justify the use of this device in groups of patients other that of postcardiotomy ventricular failure.

Electrophysiology and anatomic characterization of an epicardial accessory pathway.

Pericardial access permitted epicardial catheter mapping and ablation of a rapidly conducting posteroseptal accessory pathway (AP) that had failed repeated ablation attempts. Transient block was achieved at the site of an AP potential. The AP was visible at surgery and resected. Histologic examination revealed cells typical of specialized cardiac conduction tissue. The location, size, and presence of conduction tissue likely account for failure of catheter ablation and resistance to drug therapy.

Partial upper re-sternotomy for aortic valve replacement or re-replacement after previous cardiac surgery.

OBJECTIVE: We developed techniques for 'inverted T' partial upper re-sternotomy for aortic valve replacement (AVR) or re-replacement (AVreR) after previous cardiac surgery. We previously reported on decreased blood loss, transfusion requirements and total operative duration when compared to conventional full re-sternotomy. This report updates our series, one of the few to document a substantial benefit from a 'minimally-invasive' approach, refines a number of technical aspects of this new approach and reports follow-up. METHODS: Between November 1996 and December 1999, we performed 34 AVRs or AVreRs after previous cardiac surgery by use of an 'inverted T' partial upper re-sternotomy. There were 25 (74%) men. Median ejection fraction was 54%, range 15-80%. Median age was 72, range 38-93. All were New York Heart Association functional class (NYHA) functional class II or III. Twenty-one (62%) had previous coronary artery bypass grafts (CABG) while 14 (41%) had previous valve surgery. Follow-up was 100% complete for a total of 593 patient months (median 19 months). RESULTS: Twenty-three (66%) underwent AVR of the native aortic valve while 11 (33%) underwent AVreR of a prosthetic aortic valve. There were no intraoperative or valve-related complications, and no conversion to full re-sternotomy was necessary. There were two (5.9%) operative deaths from an arrhythmia on postoperative day 4 and a large stroke during surgery, respectively. Twenty-four (75%) patients were free of major complications. There was no need for reoperation for bleeding and patients required a median of two units of packed red blood cells. Complications included new atrial fibrillation (n=3, 9%), pacemaker implantation (n=3, 9%) and deep sternal wound infection (n=2, 6%). Median lengths of stay in the intensive care unit (ICU) and in the hospital were 1 and 7 days, respectively. There was one (3%) late deep sternal wound infection and 2/32 (6%) late deaths due to congestive heart failure at 22 months and myocardial infarction at 23 months, respectively. CONCLUSIONS: Partial upper re-sternotomy presents a safe and effective alternative approach to AVR and AVreR after previous cardiac surgery, and is associated with low morbidity and mortality.

Minimally invasive direct access heart valve surgery.

We review our experience with minimally invasive direct access (MIDA) heart valve surgery in 518 patients. Two hundred fifty-two patients underwent MIDA aortic valve replacement (AVR) or repair and 266 underwent MIDA mitral valve repair or replacement. Among the 250 AVRs, 157 (63%) were men, aged 63.2 +/- 14.6 years, NYHA functional Class 2.4 +/- 0.8. The surgical approach was right parasternal in 36 (14%) or upper hemisternotomy in 216 (86%). There were four (2%) operative deaths. Perioperative complications included 14 (5.6%) reexplorations for bleeding, 7 (3%) chest wound infections, 5 (2%) strokes, and 1 (0.4%) external iliac vein injury. Follow-up was complete in 193 (77%) patients, with a mean follow-up of 12 +/- 8 months. Late complications included 2 (0.8%) nonfatal myocardial infarctions, 4 (2%) reoperations for, respectively, 2 pericardial complications, 1 paravalvar leak, and 1 infected valve. There were five (2%) late deaths from congestive heart failure, pneumonia, hemorrhage, aneurysm, and cancer. Mean follow-up NYHA Class was 1.4 +/- 0.6. For the 266 mitral patients, 145 (54.5%) were men, age 58.7 +/- 13.6 years, functional Class 2.3 +/- 0.5. The surgical approach was right parasternal in 195 (73%), lower hemisternotomy in 53 (20%), right submammary thoracotomy in 9 (3.4%), or full sternotomy through a small skin incision in 9 (3.4%). There were 2 (0.8%) operative deaths. Perioperative complications included 4 (1.5%) reoperations for bleeding, 4 (1.5%) strokes, and 5 (2%) wound infections, and 3 (1%) ascending aortic complications. Follow-up was complete in 202 (76%) patients with a mean follow-up of 9.5 +/- 6.4 months. Late complications included one (0.4%) nonfatal myocardial infarction and three (1%) reoperations all converting repairs to replacements. There were three (1%) late deaths from suicide, pneumonia, and sudden death, respectively. Mean follow-up NYHA functional Class was 1.3 +/- 0.5. We conclude that MIDA heart valve surgery is safe and effective for the majority of patients requiring isolated elective aortic or mitral valve surgery.

Reoperative aortic valve replacement: partial upper hemisternotomy versus conventional full sternotomy.

OBJECTIVE: We developed techniques for partial upper hemisternotomy for reoperative aortic valve replacement and compared the results with those of reoperative aortic valve replacement by way of conventional full resternotomy. METHODS: We retrospectively analyzed data from 19 patients who underwent conventional full sternotomy and 20 patients who underwent partial hemisternotomy for isolated elective reoperative aortic valve replacements performed between November 1996 and September 1998. Univariable and multivariable analyses were used to document the differences between the groups. RESULTS: The 2 groups were similar with respect to age, sex, New York Heart Association functional class, valve pathologic characteristics, and numbers and types of previous operations. There were neither any operative deaths nor any postoperative valve-related morbidities in either group. There was 1 injury to a cardiac structure, which occurred in the conventional full sternotomy group. Univariable analysis documented that patients in the conventional full sternotomy group were significantly more likely to have at least 1000 mL blood loss during the first 24 hours after the operation (odds ratio 8.1, P =.02), were more likely to require transfusion of more than 5 units of packed red blood cell (odds ratio 3.6, P =.08), and were more likely to have a total operative duration longer than 5 hours (odds ratio 3.6, P =.08). In the multivariable analysis conventional full resternotomy remained a risk factor for greater blood loss (odds ratio 5.7, P =.06), greater transfusion requirement (odds ratio 2.4, P =.25), and longer total operative duration (odds ratio 7.7, P =.03). CONCLUSIONS: Partial upper hemisternotomy for reoperative aortic valve replacement avoids unnecessary lower mediastinal dissection, thereby reducing blood loss, transfusion needs, and total operative duration. These beneficial effects, which are accomplished without compromising the efficacy of the valve operation, make the partial upper hemisternotomy an excellent alternative to conventional full resternotomy for reoperative aortic valve replacement.

Impact of body mass index and albumin on morbidity and mortality after cardiac surgery.

OBJECTIVE: Extremely thin and overly obese patients may not tolerate cardiac surgery as well as other patients. A retrospective study was conducted to determine whether the extremes of body mass index (weight/height(2) [kg/m(2)]) and/or cachexia increased the morbidity and mortality associated with cardiac operations. METHODS: Body mass index was used to objectively measure "thinness" (body mass index < 20) and "heaviness" (body mass index > 30); preoperative serum albumin was used to quantify nutritional status and underlying disease. Data were gathered between 1993 and 1997 from 5168 consecutive patients undergoing coronary artery bypass or valve operations, or both. RESULTS: No significant correlations were observed between body mass index and preoperative albumin levels. Low body mass index (<20) and low albumin level (<2.5 g/dL) were each independently associated with increased mortality after cardiopulmonary bypass (P

The logistics and cost-effectiveness of circulatory support: advantages of the ABIOMED BVS 5000.

BACKGROUND: In 1994, the ABIOMED BVS 5000 was incorporated into our acute cardiac assist armamentarium. This report is a general overview of our experience. A hypothetical cost analysis focusing on specific devices and device-related personnel contrasted the BVS 5000 with our prior model of centrifugal pump use. METHODS: In 3 years, 22 patients were supported with the BVS 5000, as a biventricular assist device in 40%, right ventricular assist device in 27%, and left ventricular assist device in 32%. Indications were postcardiotomy support in 12, acute myocarditis in 2, bridge to transplant in 4, and failed heart transplant in 4. The cost analysis was performed retrospectively. The actual cost of disposable blood pumps, including replacement pumps, and cannulae constituted the BVS cost. The hypothetical centrifugal costs included the disposables, replacement cones, as well as the labor costs of the continuous perfusionist coverage. RESULTS: Of the 22 patients, 10 (45%) were weaned and 13 (59%) were successfully discharged. Five patients were transplanted while on BVS 5000 support, accounting for a higher rate of discharge. Comparison of "actual" BVS costs with "projected" centrifugal costs revealed differences based upon the intended application of the BVS. In bridge-to-transplant patients with long duration of support, the daily cost of support was dramatically lower with the BVS 5000. For short-term postcardiotomy support, acute myocarditis, or failed transplant, the differences were small. CONCLUSIONS: Because the BVS 5000 was readily managed by the intensive care unit nursing staff, this system displaced centrifugal systems in our program. Outcome measures of weaning and successful discharge were improved relative to our prior experience with centrifugal pumps. Even without taking indirect costs into account, the hypothetical cost analysis supported continued use of the BVS system for acute cardiac assistance.

Minimally invasive direct access mitral valve surgery.

We reviewed our experience with minimally invasive direct-access mitral valve surgery in 207 patients through February 1999. Three patients underwent associated procedures, a coronary artery bypass graft (CABG) with right internal mammary artery to right carotid artery (RIMA-RCA), a left ventricular outflow tract (LVOT) debridement for endocarditis, and a primum atrial septal defect (ASD) repair, and were excluded from analysis. Of the 204 remaining patients, 120 (59%) patients were men, aged 58.7 +/- 13.2 years, functional class of 2.3 +/- 0.5. The cause was myxomatous in 162 (79%) patients, rheumatic in 28 (14%) patients, endocarditis in 8 (4%) patients, congenital in 3 (2%) patients, and ischemic in 3 (2%) patients. Mean preoperative EF was 60% +/- 10%, with 184 (90%) patients showing ejection fraction (EF) greater than 50%. The valve was approached through a 5- to 8-cm right parasternal (n = 180, 88%) or right inframammary (n = 24, 12%) incision. One hundred nineteen (58%) patients had open femoral artery-femoral vein cannulation, and 85 (42%) patients had direct cannulation of the aorta and percutaneous cannulation of the femoral vein. One hundred seventy (83%) patients underwent successful valve repair, and 34 (17%) patients required valve replacement. The mean duration of aortic clamping and cardiopulmonary were, respectively, 100 +/- 34 and 146 +/- 44 minutes. There were 2 (1%) surgical deaths. Nonfatal perioperative complications included 3 (1.5%) ascending aortic complications, 3 (1.5%) reoperations for bleeding, 4 (2%) strokes, 2 (1%) transient ischemic attacks (TIAs), 2 (1%) myocardial infarctions, 3 (1.5%) pericardial effusions requiring drainage, 9 (4.5%) vascular complications, and 3 (1.5%) wound complications. Mean length of stay (LOS) was 6.1 +/- 3 days, with 63 (31%) patients being discharged in less than 5 days. One hundred twenty-nine (63%) patients did not require blood transfusions. Follow-up was complete in 165 (81%) patients, with mean follow-up of 13.2 +/- 8 months. Late complications included 1 (0.5%) myocardial infarction, 3 (1.5%) reoperations, all converting repairs to replacements, 3 (1.5%) wound hernias requiring reoperation and repair with mesh, 5 (2.5%) thromboembolic events, and 3 (1.5%) deaths of suicide, pneumonia, and sudden death, respectively. Mean follow-up New York Heart Association (NYHA) functional class was 1.2 +/- 0.5. We conclude that minimally invasive direct-access mitral valve surgery is safe, effective, and applicable for most patients presenting for isolated mitral valve surgery. We now consider it the standard of care for selected patients.

Innominate vein cannulation for venous drainage in minimally invasive aortic valve replacement.

Minimally invasive aortic valve or aortic root replacement may be carried out through a mini-hemisternotomy. Venous cannulation of the right atrium may be difficult, at best, and obstruct the limited operative field. We have carried out cannulation of the innominate vein with 25F or 27F thin-walled femoral venous cannulae in 20 patients. Transesophageal echocardiographic guidance is invaluable in safely passing the guidewire and subsequently the cannula into the right atrium. This approach results in an unobtrusive method of complete intrathoracic cannulation through a mini-hemisternotomy with the risks of femoral cannulation.

Minimally-invasive aortic root replacement.

PURPOSE: We retrospectively analyzed our early results with minimally invasive aortic root replacement. METHODS: Between August 1996 and April 1999, our center performed 137 aortic root replacements. Thirty-seven (27%) were accomplished through a 5 to 8 cm minimally invasive upper hemi-sternotomy incision. All minimally invasive operations were elective. The mean age for this cohort was 46 +/- 12 yrs. Thirty one (84%) of the patients were male and 3 (8%) were reoperations. The average preoperative NYHA classification was 2.4 +/- 0.6 and ejection fraction (EF) was 58% +/- 12%. Valve pathology was congenitally bicuspid in 19 (51%), endocarditis (SBE ) in 5 (14%), calcific degeneration in 4 (11%), annuloaortic ectasia in 3 (8%), rheumatic in 2 (5%) and other etiologies in 4 (11%). Nine patients (24%) had associated ascending aortic or arch aneurysms. RESULTS: The surgical techniques performed through mini-hemisternotomy consisted of 1) full root replacement in 31 (84%), 2) subcoronary replacement in 4 (11%), and 3) hemiroot in 2 (5%). Valve implants consisted of a homograft in 30 (81%), "Freestyle" bioprosthesis in 4 (11%) and a St Jude valved conduit in 3 (8%). Mean cardiopulmonary bypass duration was 193 +/- 47 min. and aortic cross-clamp duration was 157 +/- 40 min. Myocardial protection included systemic hypothermia in all (24 +/- 4 degrees C), antegrade cardioplegia (CP) in 35 (95%) with supplemental retrograde CP in 23 (62%). Three patients (8%) experienced postoperative low cardiac output syndrome (LCO). There was one operative death (3%). There was one (3%) reoperation for bleeding and 13 patients (35%) required blood transfusions. New onset atrial fibrillation occurred in 7 patients (19%) and there were 3 (8%) minor complications. Hospital length of stay (LOS) was 6.7 +/- 4.3 days and LOS was less than 7 days in 29 patients (78%). CONCLUSIONS: Minimally invasive aortic root replacement is feasible for a broad range of aortic valve pathology, can incorporate full root, hemiroot and subcoronary techniques, can be used for homografts and "Freestyle" valves as well as valved conduits, and can be accomplished with acceptable morbidity and mortality. However, the operation takes longer through the smaller incision and therefore requires more careful attention to myocardial protection.

Mitral valve surgery after previous CABG with functioning IMA grafts.

BACKGROUND: Mitral valve surgery after previous coronary artery bypass grafting presents a challenging problem for the cardiac surgeon. An injury to patent coronary artery bypass grafts, especially internal mammary artery grafts, during reoperation via a redo sternotomy, may be fatal. Therefore, a reliable alternative to the redo sternotomy is desirable to minimize potential injury to internal mammary artery grafts. METHODS: Between February 1987 and October 1998, we performed 59 consecutive mitral valve operations after previous coronary artery bypass grafting surgery (CABG). A total of 24 patients (41%) had functioning internal mammary artery (IMA) grafts and represent the population for this study. No patients were excluded for any reason. Of the 24 patients, 20 (83%) were men. Mean age was 66+/-13 years (range 41 to 83 years) and the mean duration from CABG was 5.3+/-3.6 years (range 0.1 to 12 years). Four (17%) had functioning bilateral internal mammary artery grafts. All had 3 to 4+ mitral regurgitation (MR) at the time of mitral valve surgery and the mean preoperative ejection fraction (EF) was 40%+/-14% (range 20% to 74 %). RESULTS: Twenty-one (88%) patients underwent mitral valve surgery through an anterolateral right thoracotomy and 3 (12%) through a redo sternotomy. Twenty-two (92%) patients, including the 3 patients in whom a redo sternotomy was used, had cannulation of the femoral artery and vein. Two patients required axillary artery cannulation. All 21 patients in whom the mitral valve was approached through a right thoracotomy underwent deep hypothermia (19.6 degrees+/-2.1 degrees C, range 14 degrees to 25 degrees C) without aortic clamping, with a mean duration of CPB of 138+/-46 minutes (range 65 to 249 minutes). In 18 (75%), the MR was ischemic in origin and in 6 (25%) there was myxomatous degeneration. Nine (34%) required valve replacement and 15 (66%) underwent repair. There were no operative or hospital deaths and all patients were discharged to home or to a rehabilitation facility. There were 4 (17%) major complications. Two patients suffered respiratory failure requiring tracheotomy, 1 patient developed a perioperative MI requiring an intraaortic balloon pump and 1 developed heart block requiring a permanent pacemaker. There were no neurologic, peripheral vascular, bleeding, or wound complications. CONCLUSIONS: Reoperative mitral valve surgery in the setting of functioning IMA grafts, even in the face of depressed LV function, can be done safely and with minimal morbidity.

Salvage of externally exposed ventricular assist devices.

Although externally exposed ventricular assist devices are associated with extremely high mortality rates, salvage may be accomplished by early aggressive wound debridement, transposition of a well-perfused autologous tissue (such as omentum), dead space obliteration, and adequate external coverage using vascularized tissue. The temporary suppression rather than the total eradication of the infection should be the goal of these procedures.

Mitral valve repair in cardiomyopathy.

BACKGROUND: Volume overload secondary to mitral regurgitation (MR) in cardiomyopathy is considered critical in the pathogenesis of subsequent ventricular dysfunction. Open mitral valve repair (OMVP) is hypothesized to improve symptomatology and ventricular function by reducing the volume overload of the left ventricle. METHODS AND RESULTS: All patients who underwent OMVP with a left ventricular ejection fraction (EF) of < 0.30 (n = 81) from 1984 through 1997 were reviewed (1 patient was lost to follow-up). Fifteen operations (18.5%) were repeat operations after previous coronary artery bypass graft surgery. Preoperative and postoperative EFs and NYHA class were compared. Survival probabilities were calculated, and multivariate analysis was performed. The average age of all patients was 67.1 years (range, 41 to 83 years). Mean follow-up was 1.7 years (range, 2 months to 8.5 years). The most common mitral repair was ring annuloplasty. Sixty-two patients (77%) had concomitant coronary artery bypass graft surgery. The surgery mortality rate was 11% (9 of 81); 6 of these 9 patients were > 70 years old. The overall Kaplan-Meier survival probability rate at 1, 2, 3, 4, and 5 years was 0.73, 0.68, 0.58, 0.50, and 0.38, respectively. EF improved significantly (0.24 to 0.32; P < 0.0001), as did the NYHA class (3.2 to 1.6; P < 0.0001), at follow-up. There was no difference in late survival between patients with an EF of < 0.20 (21 patients) and those with an EF between 0.20 and 0.30 (P = NS). Risk factors for death included heart failure and old age. CONCLUSIONS: OMVP for MR in the setting of ischemic cardiomyopathy and low EF appear to improve ventricular function, medium-term patient symptomatology, and survival.

Techniques and results of direct-access minimally invasive mitral valve surgery: a paradigm for the future.

OBJECTIVES: Our objective was to determine whether direct-access minimally invasive mitral valve surgery can improve recovery and cost while maintaining the efficacy of conventional surgery. METHODS: Minimally invasive mitral valve operations were performed on 106 patients, 58% male, average age 58.1 years, with good ventricular function. Ninety underwent repair of a regurgitant, myxomatous valve, and 16 underwent mitral valvuloplasty for prematurely calcified mitral stenosis. The valve was approached with standard instruments through a 5- to 8-cm right parasternal incision. Eighty-five had open femoral artery-femoral vein cannulation, but this technique has recently been replaced by direct cannulation of the aorta and percutaneous cannulation of the femoral vein for most patients. RESULTS: There were no operative deaths. The mean mitral regurgitation score (0-4) decreased from 3.7 to 0.7 after the operation. Although ischemic and bypass times were increased, postoperative recovery was accelerated. Ventilatory support time, intensive care unit stay, hospital stay, need for rehabilitation, and return to "normal activities" all improved. Hospital charges, pain medications, and blood transfusions were also reduced. New atrial fibrillation contributed significantly to increased length of stay and charges. There were no deep wound infections. Other complications included re-exploration for bleeding (n = 1), transient ischemic attacks (n = 2), stroke (n = 1), femoral artery injury (n = 5), pseudoaneurysm (n = 2), and antegrade dissection of the ascending aorta (n = 1). Two patients died and 1 required reoperation during a mean follow-up of 8.8 months. CONCLUSIONS: Direct-access minimally invasive mitral valve surgery can accelerate recovery, decrease charges, and decrease pain, while maintaining overall surgical efficacy. It has become our standard approach for isolated primary mitral valve operations.

An engineering model of dynamic cardiomyoplasty. I.

Dynamic cardiomyoplasty (DCM) is an emerging surgical procedure for heart failure in which the patient's latissimus dorsi (LD) muscle is wrapped around the heart and stimulated to contract in synchrony with the heartbeat as a cardiac assist measure. A 6 week training protocol of progressive electrical stimulation renders the normally fatigueable skeletal muscle fatigue-resistant and suitable for chronic stimulation. To date, over 500 procedures have been performed in worldwide clinical trials. Investigators typically report symptomatic improvement and modest hemodynamic improvement in patients. Controversy exists regarding the exact mechanism of DCM. To test the hypothesis that DCM augments cardiac stroke volume through improvement in systolic function, we formulated an engineering model of dynamic cardiomyoplasty to predict stroke volume. The heart and the LD were modeled as nested (series) elastance chambers, and the vasculature was represented by a two-element Windkessel model. Using five healthy goats, we verified model predictions of stroke volume for both stimulator ON beats (y = 1.00x-0.08, r = 0.87, p < 0.0001) and OFF beats (y = 1.01x+1.06, r = 0.91, p < 0.0001), where x and y are the measured and predicted stroke volumes, respectively. The model confirms that using untrained latissimus dorsi applied to the normal myocardium produces only moderate increases in stroke volume and suggests that future research should focus on increasing LD strength after training.

An engineering model of dynamic cardiomyoplasty. II. Clinical applications.

Previously, a modification to the Sunagawa engineering model for the isolated left ventricle and arterial system was proposed and validated for dynamic cardiomyoplasty in an acute goat preparation. To test the hypothesis that this model may be applied to the clinical scenario in cardiomyoplasty patients, we predicted human stroke volume using the model with human clinical data from the literature. Predicted stroke volume correlated well with published stroke volume in patients who have had the dynamic cardiomyoplasty procedure. These results suggest that the modest hemodynamic improvement commonly reported after the procedure is performed may be due to diminished latissimus dorsi strength after transformation. The validity of both the original Sunagawa model and the previously proposed modification for dynamic cardiomyoplasty is further supported with these results. A nomogram methodology for predicting stroke volume after dynamic cardiomyoplasty for any particular patient is presented.

Twenty-year follow-up of the Hancock modified orifice porcine aortic valve.

BACKGROUND: The entire experience with the Hancock modified orifice porcine bioprosthetic aortic valve from 1976 to 1996 at the Brigham and Women's Hospital has been reviewed. Eight hundred forty-three patients received this valve with a total follow-up of 61,114 months, and a mean follow-up of approximately 72.5 months. There were 490 men and 353 women, and the predominate lesion was aortic stenosis (636 of 843); 365 (43%) patients required a concomitant coronary artery bypass graft operation. METHODS: Patients were followed prospectively in the Brigham Cardiac Valve Data Registry, and the data were analyzed by the SAS statistical package, using actuarial survival curves and incidence per patient-year of morbidity and mortality. RESULTS: The overall operative mortality was 45 of 843 (5.3%) with 23 of 478 (4.8%) for isolated aortic valve replacement and 22 of 365 (6.0%) for aortic valve plus coronary artery bypass graft operation. The major morbidity of this valve was structural valve dysfunction, which was significantly related to the age of the patient in whom the valve was placed. Actuarial probability of freedom from structural valve degeneration at 5, 10, and 15 years overall was 99%+/-1%, 79%+/-3% and 57%+/-4%, at 15 years, respectively. In patients younger than 50 years, freedom from structural valve dysfunction was 16%+/-8%, whereas in the age group older than 70 years it was 87%+/-5% (p = 0.0005). Thromboembolism at 10 and 15 years was 81%+/-3% overall, 84%+/-2% in patients in normal sinus rhythm, and 57%+/-13% in patients with chronic atrial fibrillation. CONCLUSIONS: The Hancock modified orifice aortic valve, despite its more complicated fabrication, has been a reliable porcine bioprosthetic valve and can be used reliably in patients older than 70 years because of its low structural valve degeneration rate, and protection from stroke and anticoagulant hemorrhage in those patients in sinus rhythm.

Ablation of ventricular tachycardia due to a postinfarct ventricular septal defect: identification and transection of a broad reentry loop.

INTRODUCTION: Ventricular tachycardia (VT) after postinfarct ventricular septal defect (VSD) repair has not been well characterized. METHODS AND RESULTS: A 55-year-old man developed refractory VT after inferior wall infarction and VSD repair. Entrainment demonstrated a broad reentry circuit path (outer loop) between the tricuspid annulus and VSD patch. A series of radiofrequency (RF) lesions transected this path, abolishing VT and producing conduction block between the inferior and superior aspects of the basal right ventricular septum. CONCLUSION: Some VTs have broad reentry loops requiring ablation by a series of RF lesions across the path to create a line of block. This approach is analogous to that for atrial flutter.