Successful treatment of acute dissection of the donor aorta after orthotopic heart transplantation.

Acute aortic dissection is one of the rare aortic complications that occur after orthotopic heart transplantation. We report the second case of successful surgical treatment of aortic dissection confined to the donor aorta in a recipient of an orthotopic cardiac allograft. A 68-year-old patient was admitted with chest pain and shortness of breath 7 years after orthotopic heart transplantation. He previously had undergone twice coronary artery bypass grafting. Echocardiography revealed acute dissection of the donor aorta. The patient underwent urgent Bentall procedure with a prosthetic conduit. The post-operative course was uneventful. The heart donor was a 40-year-old man with known arterial hypertension and who had received long-term ergotamine tartrate therapy for migraine. This case demonstrates that heart-transplant recipients with arterial hypertension and donor-related risk factors are prone to aortic complications and require careful follow-up.     

Rescue peri-operative management of the patient with giant electrical storm and severe left ventricular dysfunction: support by levosimendan and intraaortic balloon counterpulsation

We present a case of a 62-year-old male patient (coronary heart disease, and stenosis of aortic valve) with severe left ventricular dysfunction (left ventricular ejection fraction 20%, left ventricular end-diastolic diameter 80 mm, end-diastolic volume 329 ml) who developed giant electrical storm (on the whole 115 episodes of pulseless ventricular tachycardia treated by antiarrhythmics and electrical discharges) with low-elevation of cardiac biomarkers. The patient was referred to emergent cardiac surgery (double coronary bypass grafting, aortic valve replacement, and implantation of left ventricular epicardial electrode). Levosimendan and intraaortic balloon counterpulsation were used for successful weaning from the cardiopulmonary bypass; no other arrhythmia appeared in the post-bypass period. Postoperatively no arrhythmic events were detected, and repeated echocardiographic examinations of the patient in good general condition showed gradual improvement of left ventricular ejection fraction (30-35%), likewise in other parameters (left ventricular end-diastolic diameter 72 mm, end-diastolic volume 285 ml).     

Extended aortic root replacement with aortic allografts

Complex left ventricular outflow tract obstruction after operation for subaortic stenosis or with hypoplastic aortic anulus remains a challenge for pediatric cardiac surgeons. We have recently applied a new technique of extended aortic root replacement using a cryopreserved aortic allograft to treat two patients who had previously been operated on for subaortic stenosis and a third who had aortic stenosis with a hypoplastic aortic anulus. This new procedure combines the concept of aortoventriculoplasty with aortic root replacement and coronary artery reimplantation. The valved aortic homograft is used in place of an aortic valve prosthesis and the attached anterior mitral leaflet augments the interventricular septum to relieve the subvalvular left ventricular outflow tract obstruction. The coronary ostia are then reimplanted into the allograft and an anastomosis between the distal graft and the ascending aorta is completed. Allograft aortic tissue is then used to patch the right ventricular outflow tract. One patient had aortic stenosis with annular hypoplasia and did well after extended root replacement. Two patients had previous operations for subaortic stenosis before undergoing extended aortic root replacement. One required mediastinal exploration and drainage at 2 weeks for Serratia marcescens mediastinitis and bacteremia, but uncomplicated recovery followed. The other patient had complete heart block for 2 days, but normal sinus rhythm resumed and convalescence was benign. This modified technique with the aortic allograft was very helpful in treating these difficult problems, and the lack of mortality, limited morbidity, and good functional results are encouraging.     

Thoracic and cardiovascular interventions after orthotopic heart transplantation.

BACKGROUND: The long-term outcome of orthotopic heart transplantation is limited by the development of cardiac allograft vasculopathy, rejection, infection, and malignancy. METHODS: After heart transplantation, we treated patients with thoracic and cardiovascular diseases: preexisting coronary artery sclerosis in 2 patients, cardiac allograft vasculopathy in 19, valvular disease in 3, mycotic ascending aortic aneurysm in 2, superior vena cava stenosis in 2, and lung neoplasm in 10 patients. RESULTS: We successfully performed coronary artery bypass grafting for preexisting coronary artery sclerosis, valve replacement for valvular disease, and patch enlargement for superior vena cava stenosis. Percutaneous transluminal coronary angioplasty for cardiac allograft vasculopathy achieved excellent initial results, but the incidence of restenosis was high (67%). One patient who underwent coronary artery bypass grafting for cardiac allograft vasculopathy died immediately after operation. Graft replacement was performed for mycotic aortic aneurysm, but 1 patient required reoperation because of recurrent aneurysm. The long-term survival rate in patients undergoing surgical resection for lung neoplasm was poor (50%). CONCLUSIONS: The need for thoracic and cardiovascular interventions in patients after heart transplantation was low (4.7%). Use of the appropriate procedures can improve the long-term survival after heart transplantation.     

Sequentially paced heterotopic heart transplant in the left chest provides improved circulatory support for the failed left ventricle. A potential biologic bridge to orthotopic transplantation

Acute experimental transplantation of an allograft heart in a heterotopic position was performed in 14 sheep. The donor heart was implanted in the left side of the chest with left atrial, aortic, and pulmonary artery anastomoses. Hemodynamic studies were performed to evaluate the physiologic effects of the procedure, particularly when recipient left ventricular failure was produced by inflow and outflow obstruction. Pacing techniques were developed and tested to coordinate the rhythm of the two hearts either synchronously or sequentially with variable intervals between depolarization of the two hearts. Hemodynamic studies were performed to evaluate the rhythm that would most optimize the physiology. The cardiac index remained essentially unchanged when the dominant circulatory support was shifted from recipient left ventricle to donor left ventricle by producing recipient left ventricular failure (3.79 +/- 0.6 to 3.30 +/- 0.8, p = no significant difference). Consistent and reliable paced rhythms were achieved in each case. The cardiac index was significantly higher when the hearts were paced sequentially rather than synchronously (3.76 +/- 0.5 versus 3.29 +/- 0.5, p less than 0.04). Allograft donor hearts small in size or slightly inadequate otherwise, which may be unsuitable for orthotopic heart transplantation, may still be used heterotopically for short-term support. Their use would maximize the use of all donor organs and the survival of patients awaiting a suitable organ. Further, it may also be possible to use sequentially paced xenografts heterotopically for short-term left ventricular assistance as a bridge to orthotopic heart transplantation.     

Results from coronary artery bypass surgery combined abdominal aortic aneurysm repair.

OBJECTIVE: Complication from coronary artery disease is a major cause of mortality and morbidity in patients undergoing abdominal aortic aneurysm repair. We report our results from coronary artery bypass surgery performed in combination with abdominal aortic aneurysm repair in patients with coronary artery disease and abdominal aortic aneurysm, each being an indication for an emergency operation. METHODS: Seventeen patients underwent combined coronary artery bypass surgery and abdominal aortic aneurysm repair. The mean age of the patients was 67.6 +/- 5.2 years. Four had left main disease, 8 patients had triple-vessel disease, and 12 had a prior myocardial infarction. The average left ventricular ejection fraction was 0.49 +/- 0.13. The average abdominal aortic aneurysm diameter was 6.2 +/- 1.0 cm (range 4.5-8.0 cm). Thirteen patients underwent coronary artery bypass surgery followed by abdominal aortic aneurysm repair after discontinuation of cardiopulmonary bypass. In the remaining four patients, including one patient with severe left ventricular dysfunction, cardiopulmonary bypass was continued as a circulatory assist until the abdominal aortic aneurysm repair was completed. The left internal thoracic artery was used in 14 patients, and the right internal thoracic artery in one patient. RESULTS: Postoperative surgical complications occurred in three patients (bleeding in one patient requiring reoperation, abdominal subcutaneous wound infection in another and transient neural disorder in the others). There were no surgical or in-hospital death. There was no late cardiac complication and no late cardiac death after a mean of 29 months follow-up. CONCLUSIONS: We concluded that combined surgery was reasonable for selected patients with combined coronary artery disease and abdominal aortic aneurysm, each of which is an indication for an urgent operation. The aortic aneurysm repair during cardiopulmonary bypass for patients with severe left ventricular dysfunction was safe and effective.     

Successful total correction of congenital interruption of the aortic arch and ventricular septal defect

Successful surgical correction of the complex anomaly of interruption of the aortic arch and intracardiac ventricular septal defect is reported. The patient was a boy 5 years old when he first came under treatment. The total correction was performed in two stages. At the first operation, at the age of 7 years, continuity of the aortic arch was achieved by insertion of a Teflon graft, employing left heart bypass. The ventricular septal defect was closed at the age of 13 years on total cardiopulmonary bypass. Two and half years after the total correction the boy is alive and well. The difficulties in diagnosing the condition are discussed. The role of left heart bypass is emphasized.     

Circulatory Assistance with a Cardiac Allograft after Exclusion of the Canine Left Ventricle

Cardiogenic shock after myocardial infarction still carries a high mortality despite use of intraaortic counterpulsation and early surgical revascularization. An experimental canine model of left ventricular exclusion and circulation support was developed by closing the mitral valve and by interposing “in series” a cardiac allograft between pulmonary and systemic circulations. This preparation was able to support the recipient circulation after cardiopulmonary bypass in 25 animals. In 16 dogs the graft sustained life for from 1 to 32 days.It is hypothesized that such left ventricular assistance could be used to maintain the life of patients in cardiogenic shock after myocardial infarction. By providing maximal left ventricular decompression and improvement of the native coronary perfusion, this method may reverse the metabolic imbalance responsible for extension of the infarction, thereby salvaging muscle that is in jeopardy but still viable.     

On-pump beating-heart mitral valve plasty without aortic cross-clamping

Patients with ischemic cardiomyopathy often have mitral regurgitation, which should be corrected for better long-term survival. Mitral valve surgery is usually performed during cardiopulmonary bypass under the arrested heart condition. The ascending aorta is cross-clamped and the heart is arrested using a cardioplegic solution. However, because ischemic cardiomyopathy patients often have a severely atherosclerotic ascending aorta and low cardiac function, aortic cross-clamping and cardiac arrest increase the risk of postoperative thromboemboli and low cardiac output syndrome. Under the on-pump beating-heart condition, we performed mitral valve plasty concomitant with coronary artery bypass grafting, tricuspid annuloplasty, left ventricular aneurysmectomy, and the maze procedure without aortic cross-clamping for a patient with ischemic dilated cardiomyopathy and bradycardial atrial fibrillation. The patient had no postoperative complications and recovered rapidly. Thus, to prevent serious postoperative complications, on-pump beating-heart mitral valve surgery without aortic cross-clamping may be a suitable surgical option for patients with ischemic cardiomyopathy.     

Apico-aortic conduit for severe aortic stenosis in elderly

We described a case of an 84-year-old woman with end stage aortic stenosis in whom favorable results were obtained after constructing apico-aortic conduit bypass. The patient admitted due to complete atrio ventricular(AV) block and respiratory insufficiency. Although a permanent pacemaker was implanted, heart failure did not improve. Echocardiograms showed small aortic annulus and severe calcific aortic stenosis with a measured trans valve gradient of 100 mmHg. Since cardiac failure deteriorated and she lapsed into hypotension and acute renal failure, an emergency operation was performed. The left lateral thoracotomy was performed with cardiopulmonary bypass. A bioprosthetic valved conduit was anastmosed to the left ventricle apex. Another graft was anastomosed to the discending thoracic aorta. The operation was completed by anastomosing the tailored ends of the grafts together. Although the patient required hemodialysis for 2 weeks after operation, she was discharged on 57th day after operation without any complications. Apico-aortic conduit is considered to be an useful procedure for elderly patients who were not good candidates for conventional valve replacement.     

Evaluation of cardiac function during left ventricular assist by a centrifugal blood pump

In this study, the effects on varying cardiac function during a left ventricular (LV) bypass from the apex to the descending aorta using a centrifugal blood pump were evaluated by analyzing the left ventricular pressure and the motor current of the centrifugal pump in a mock circulatory loop. Failing heart models (preload 15 mm Hg, afterload 40 mm Hg) and normal heart models (preload 5 mm Hg, afterload 100 mm Hg) were simulated by adjusting the contractility of the latex rubber left ventricle. In Study 1, the bypass flow rate, left ventricular pressure, aortic pressure, and motor current levels were measured in each model as the centrifugal pump rpm were increased from 1,000 to 1,500 to 2,000. In Study 2, the pump rpm were fixed at 1,300, 1,500, and 1,700, and at each rpm, the left ventricular peak pressure was increased from 40 to 140 mm Hg by steps of 20 mm Hg. The same measurements as in Study 1 were performed. In Study 1, the bypass flow rate and mean aortic pressure both increased with the increase in pump rpm while the mean left ventricular pressure decreased. In Study 2, a fairly good correlation between the left ventricular pressure and the motor current of the centrifugal pump was obtained. These results suggest that cardiac function as indicated by left ventricular pressure may be estimated from a motor current analysis of the centrifugal blood pump during left heart bypass.     

Dipyridamole-induced coronary vasodilation in human transplanted heart: preliminary report

Coronary sinus blood flow and resistance were studied before and after intravenous dipyridamole in 4 patients with transplanted heart and normal coronary arteriogram treated by cyclosporine-prednisolone. Results were compared to those of a normal group of 7 subjects. Left ventricular endomyocardial biopsies were performed in the heart transplanted group. Mean right atrial pressure, cardiac index and left ventricular function were normal in the transplanted heart group. Mean aortic pressure and systemic vascular resistances were significantly higher in the transplanted group than in normals (p less than 0.01), but coronary resistance were similar. Dipyridamole-induced vasodilation resulted in an increased coronary sinus blood flow and a decreased coronary resistance in both groups, but these effects were reduced in 1 patient with a transplanted heart that evidenced an important perivascular fibrosis after a subacute rejection. In conclusion, this preliminary report of coronary blood flow in patients with transplanted heart indicates that the ability of coronary sinus blood flow to increase after dipyridamole is normal in the transplanted heart without allograft rejection. A major limitation in coronary vasodilation was observed in 1 patient with rejection antecedents and perivascular fibrosis, which could play a role in left ventricular function deterioration in some patients after heart transplantation.     

Extended aortic root replacement with cryopreserved allografts: do they hold up?

The extended aortic root replacement technique is used for the surgical repair of left ventricular outflow tract obstruction complicated by concurrent hypoplastic aortic annulus, multiple levels of obstruction, or aortic insufficiency. Extended aortic root replacement incorporates the concepts of aortic root replacement and aortoventriculoplasty to create a comparatively simple procedure. Unique features of the technique include the implantation of an allograft, which makes the need for anticoagulation obsolete, and use of the donor mitral leaflet to enlarge the outflow tract. Since 1985, 32 patients in Denver have undergone placement of a cryopreserved aortic valve allograft as part of extended aortic root replacement. There were four hospital deaths (13%), and 1 child underwent cardiac transplantation 30 hours after operation. In 6 months to 4.8 years of follow-up, a 14-year-old boy with familial hyperlipidemia required coronary artery bypass grafting, and 3 children experienced allograft calcification with progressive insufficiency, which prompted allograft replacement. The other 23 patients are clinically well.     

Myocardial protection by retrograde cardioplegic perfusion through the right atrium

Three types of cardioplegic delivery with ink into the isolated canine hearts were compared: (1) antegrade aortic root perfusion (AARP), (2) retrograde coronary sinus perfusion (RCSP) and (3) retrograde right atrium perfusion (RRAP). Ink was not distributed in the area distal to the coronary occlusion by AARP but well distribution in the same area by RCSP or RRAP. The right ventricular wall and ventricular septum were poorly perfused by RCSP but well perfused by RRAP. During cardiopulmonary bypass, RRAP created a fairly rapid cardiac arrest and satisfactory myocardial cooling. During Perfusion, the right heart was somewhat dilated but all the 10 canine hearts rebeat well. The left and right ventricular ejection fraction showed no significant change after bypass. No marked myocardial ultrastructural injury was found in left and right ventricles at the end of 90 minutes' ischemia. 4 patient, 1 of whom had 162 minutes' aortic cross-clamping received RRAP in operations on ascending aorta or coronary arteries and the myocardial protect ion was satisfactory. No complication was found pertaining to RRAP.     

Outcome in Cardiac Recipients of Donor Hearts With Increased Left Ventricular Wall Thickness

The ongoing shortage of donors for cardiac transplantation has led to a trend toward acceptance of donor hearts with some structural abnormalities including left ventricular hypertrophy. To evaluate the outcome in recipients of donor hearts with increased left ventricular wall thickness (LVWT), we retrospectively analyzed data for 157 cardiac donors and respective recipients from January 2001 to December 2004. There were 47 recipients of donor heart with increased LVWT >or=1.2 cm, which constituted the study group and 110 recipients of a donor heart with normal LVWT < 1.2 cm that formed the control group. At 3 +/- 1.5 years, recipient survival was lower (50% vs. 82%, p = 0.0053) and incidence of allograft vasculopathy was higher (50% vs. 22%, p = 0.05) in recipients of donor heart with LVWT > 1.4 cm as compared to LVWT 1.4 cm (p = 0.003), recipient preoperative ventricular assist device (VAD) support (p = 0.04) and bypass time > 150 min (p = 0.05) were predictors of reduced survival. Our results suggest careful consideration of donor hearts with echocardiographic evidence of increased LVWT in the absence of hypovolemia, because they may be associated with poorer outcomes; such hearts should potentially be reserved only for the most desperately ill recipients.     

Preliminary Results with an Apico-Aortic Valved Conduit (AAVC) Using Polyurethane and Aortic Allograft Valves

Stenosis of the left ventricular outflow tract is one of the most frequent congenital cardiac anomalies in dogs. The subvalvular stenosis is described as a ring of fibrous tissue located in the left ventricular outflow tract immediately below the aortic valve. The best method of surgical treatment in dogs seems to be relief of the aortic obstruction with a ventricular aortic prosthesis. A new trileaflet valve manufactured out of polyurethane has been developed. For the conduit a woven Dacron graft has been used. In 5 male dogs a valved conduit was implanted between the apex of the left ventricle and the aorta thoracica without using hypothermia and/or cardiopulmonary bypass. Four dogs survived the surgical procedure and showed no clinical symptoms postoperatively. Blood flow through the conduit was demonstrated postoperatively by angiocardiography for a maximum of 22 days, the longest surviving time being 8 weeks. Trials for the replacement of the artificial valve in the conduit by a canine aortic allograft valve are in progress. Studies were done with the cryopreservation of fresh aortic valves. Sterilization, cryoconservation, and storage methods for the allograft are described     

Aortic valve graft implantation in rats: a new functional model

BACKGROUND: Allograft heart valves used in cardiac surgery often fail at an unacceptable rate. Immune mechanisms contribute to this failure, but adequate and functional small-animal valve models to characterize this phenomenon are lacking. The objective of this study was to create native aortic valve insufficiency in recipient rats to provide for a functional abdominal aortic valve graft implant. METHODS: Lewis recipient rats underwent single-leaflet injury of their native aortic valve through a right carotid catheter injury. Animals were allowed to recover for 28 days, at which time a Lewis aortic valve graft was implanted infrarenally. Echocardiography with color flow Doppler scanning was performed before aortic injury, 1 week after aortic injury, and after abdominal implantation of a valve graft in animals with native aortic insufficiency. RESULTS: After aortic valve injury, all animals had moderate-to-severe aortic insufficiency with a significant increase in diastolic and systolic left ventricular dimensions. Color flow Doppler scanning revealed diastolic aortic flow reversal from the aortic valve extending to the infrarenal abdominal aorta. Aortic valve grafts were then implanted infrarenally in animals with created aortic valve insufficiency and resulted in 100% patency and preservation of leaflets at 4 weeks after implantation. Leaflet motion of the abdominal graft was visualized by means of M-mode echocardiography. CONCLUSION: Compensated native aortic insufficiency results in aortic diastolic flow reversal distal to the infrarenal aorta, thus allowing normal motion of the infrarenal allograft leaflets. This functional model will provide an opportunity to investigate the role of immunologic valve injury in the failure of valve allografts.     

A simultaneous operation on coronary artery disease and abdominal aortic aneurysm during extracorporeal circulation in patient with impaired left ventricular function

A 74-year-old man had an previous antero-septal and inferior myocardial infarction and an abdominal aortic aneurysm (AAA) 48 mm in diameter. Coronary angiography showed obstruction of the left anterior descending artery and of the right coronary artery, and 95% stenosis of the circumflex artery. The value of an ejection fraction of the left ventricle was 33%, measured by left venticulography. CABG and replacement of the aneurysm were performed simultaneously, because of the necessity of an intra-aortic balloon pumping (IABP) due to the impaired left ventricular function. First, CABG was performed under cardiac arrest. After declamping the ascending aorta, subsequently, replacement of AAA was performed while extracorporeal circulation (ECC) assisted heart beating. Weaning from ECC was smooth, and the operation was successful without using IABP. The patient was discharged 32 days after the operation. Consequently, cardiopulmonary bypass during AAA operation could decrease heart loads when hemodynamic states change in aortic clamping or after declamping. A simultaneous operation of CABG and AAA using ECC is safe and effective for impaired left ventricular function.     

Use of the Alfieri edge-to-edge technique to eliminate left ventricular outflow tract obstruction caused by mitral systolic anterior motion

A 68-year-old woman with concentric left ventricular hypertrophy, prosthetic valve endocarditis with aortic root abscess, and sepsis had aortic root replacement with an aortic allograft. On weaning from cardiopulmonary bypass, she had hemodynamic instability caused by systolic anterior motion of the mitral valve, which resulted in a left ventricular outflow tract obstruction; the peak pressure gradient across the left ventricular outflow tract was 130 mm Hg, and there was moderately severe (3+) mitral regurgitation. After reinstitution of cardiopulmonary bypass, a central Alfieri edge-to-edge stitch was placed between the anterior and posterior leaflets of the mitral valve. This reduced the gradient across the left ventricular outflow tract to 10 mm Hg and eliminated the mitral regurgitation, which enabled successful separation from cardiopulmonary bypass.     

The value of transesophageal echocardiography during cardiac surgery

The intraoperative use of two-dimensional transesophageal echocardiography has proved effective in the evaluation of left ventricular function after heart operations, in the assessment of adequacy of valve replacement or repair techniques, and in the detection of intracardiac air bubbles before discontinuation of cardiopulmonary bypass. We report here a patient in whom the presence of a tumor mass in the left leaflet of the aortic valve, which was missed at preoperative transthoracic echocardiogram and would have most likely been the cause of systemic embolization, was diagnosed by two-dimensional transesophageal echocardiographic monitoring. We hope that this experience may support the use of two-dimensional transesophageal echocardiography during cardiac surgery.