Aortic dissection.

Acute and chronic aortic dissection is described in terms of diagnostics, surgical indications and present day operative treatment. The need for prompt decision making and intervention is highlighted. The results to be expected from surgery are outlined.

The elephant trunk operation in complex aortic disease.

Extensive aneurysmal disease of the aorta presents considerable challenges to the cardiovascular surgeon and is generally treated with a staged approach. The elephant trunk principle, in which the downstream end of the primarily inserted graft is allowed to float freely in the downstream aorta, serves this approach. This principle greatly facilitates subsequent operation(s) and shortens the period of distal aortic occlusion. This review describes the state of the art of this technique, its various uses, and the results obtained.

Composite graft replacement of the aortic root in 335 patients with aneurysm or dissection.

The hypothesis that replacement of the aortic root with a valved composite graft is a safe and effective therapy for aneurysms involving the sino-tubular segment of the aorta was tested by a retrospective review. From September 1978 to January 1995, 335 consecutive patients underwent prosthetic aortic root replacement as the primary operation for aneurysm (222) or dissection (acute 59, chronic 54). There were 248 men (74%) and 87 women (26%) with a mean age of 50 +/- 14 years. 22 patients (6.6%) experienced hospital death primarily due to cardiac causes. Mortality was significantly higher in patients with acute dissection versus those with non-dissecting aneurysms and chronic dissection. Sex, Marfan syndrome (20.3% of patients), mitral regurgitation, coronary artery disease, and era of operation had no effect on early outcome. Mortality was significantly increased in patients aged over 50 years, in those with circulatory compromise, and in patients requiring emergency operation. Follow-up was complete in 313 survivors (97%) at a mean of 61.3 +/- 44 months. Actuarial survival was 80% at 5 and 67% at 10 years. There were no complications involving the coronary anastomoses, other than infection-related, regardless of the mode of ostial reattachment.

Surgical treatment of Marfan patients with aneurysms and dissection of the proximal aorta.

BACKGROUND: The authors retrospectively analyzed early and late results of surgical treatment for 79 Marfan patients with aneurysms and dissection of the proximal aorta. METHODS: From September 1979 to February 1996, 79 patients with Marfan syndrome underwent aortic root replacement using composite grafts (n=68, Bentall-technique 63, button-technique 5), and ascending aortic replacement with a valve-sparing procedure (n=11). There were 12 patients (15.2%) who simultaneously received partial or total arch replacement. 55 patients (69.6%) were male, and 24 female (30.4%). The average age was 33.8 years. Forty-one patient (51.9%) had non-dissecting aneurysms while the remaining 38 patients suffered from either acute (24.0%) or chronic aortic dissection (24.0%). The aortic valve was involved in 97.5% of all cases. RESULTS: The total early mortality (< or =30 days) was 3.8%, 10.5% for acute aortic dissection and 2.4% for non-dissecting aneurysms. There were no early postoperative deaths in patients after valve-sparing operation and in those with chronic aortic dissection. The follow-up rate was 98.7%. During a mean follow-up of 68+/-25 months 10 patients (13.3%) died and cardiac complications were a common cause of the late deaths. There was no late mortality in the valve-sparing operations during a mean follow-up period of 8+/-6 months, however, 1 required valve replacement. 19 (25.3%) of the 75 patients surviving late have undergone 25 secondary operations on the cardiovascular system. Reoperations at aortic sites distant from the original were much more frequent after primary repair for acute and chronic dissection when compared to non-dissecting aneurysms (p<0.005). Actuarial survival rate of all patients with composite graft replacement including early deaths was 91.2% at 1 year, 84.4% at 5 years and 75.2% at 10 years. CONCLUSIONS: Composite graft insertion has become the gold standard for treating Marfan-patients with non-dissecting and dissecting aneurysms of the aortic root. Our early experience in 11 patients with valve-sparing procedures indicated that this,variant may be the better choice in selected patients.

The role of spinal angiography in operations on the thoracic aorta: myth or reality?

BACKGROUND: The importance of preserving the artery of Adamkiewicz during replacement of the thoracoabdominal aorta is debated. We report our experience with the use of preoperative spinal angiography and modification of the surgical technique. METHODS: Between September 1993 and March 1996, 46 patients (mean age, 57 years; range, 25 to 73 years) underwent spinal angiography at our institution, 23 for an aneurysm and 23 for chronic dissection. Localization of the artery of Adamkiewicz between T-9 and L-3 was successful in 30 (65%) patients: T-9, left = 2, right = 1; T-10, left = 4; T-11, left = 10, right = 2; T-12, left = 3, right = 1; L-1, left = 1, right = 2; L-2, left = 2, right = 1; and L-3, left = 1. Thirty-one patients subsequently underwent replacement of the descending thoracic aorta and 13 underwent replacement of the thoracoabdominal aorta. Left atrial-femoral artery bypass was used in 23 patients and full extracorporeal circulation was used in 20 patients. Twelve procedures included the reimplantation of crucial intercostal/lumbar branches. RESULTS: The operative mortality rate was 6.8% (3 of 44 patients) and 1 (2.27%) patient had paraparesis. In addition to the 12 patients who underwent targeted reimplantation of the intercostal branches, evaluation of the spinal cord blood supply influenced the operative technique in 19 other patients. CONCLUSIONS: Selective angiography can demonstrate the spinal cord blood supply even in patients with complex aortic pathology. It is a helpful tool for planning extensive replacement of the thoracic and thoracoabdominal aorta.

In vivo morphology of woven, collagen-sealed Dacron prostheses in the thoracic aorta.

BACKGROUND: Long-term changes in knitted Dacron grafts inserted into the infrarenal aorta have been addressed by a number of studies indicating their potential for postoperative dilatation. In contrast, the behavior of woven, collagen-presealed, double-velour Dacron grafts used to replace the thoracic aorta is not known. METHODS: Forty-five patients were examined at a mean of 32.4 +/- 14.8 months after insertion of woven, collagen-coated, Dacron double-velour prostheses (Meadox woven with Hemashield, Meadox, Oakland, NJ) in the thoracic position under highly standardized conditions using spiral computed tomography. RESULTS: Compared with a manufactured diameter of 26 mm, all grafts showed an increase of 1 to 5 mm (mean, 3.0 +/- 1.2 mm [11.6% +/- 4.4%]; p < 0.0001) with greater enlargement of the ascending than of the descending aortic portions (p = not significant). A further statistically significant progressive dilatation failed to occur. Degenerative changes, including false aneurysm formation, could be excluded. CONCLUSIONS: Woven, collagen-coated Dacron prostheses are considered a safe replacement material for the thoracic aorta.

Intravascular ultrasound-guided percutaneous fenestration of the intimal flap in the dissected aorta.

BACKGROUND: Aortic dissection with branch obstruction is associated with high morbidity and mortality. Fenestration of the dissection flap to relieve distal vessel ischemia is at present largely performed surgically. The surgical mortality and morbidity are high, because most patients are poor candidates for anesthesia or surgery. METHODS AND RESULTS: Nine percutaneous fenestrations (one with additional stenting of the infrarenal true aortic lumen) were performed under local anesthesia in seven patients with aortic dissection. The presenting symptoms were abdominal angina or claudication. By the transfemoral approach, the intimal flap was initially punctured with a needle-catheter combination through which a guidewire was placed across the dissection flap. The fenestration was carried out with a balloon catheter introduced over the guidewire. The procedure was performed under on-line guidance with intravascular ultrasound imaging. The procedure was performed successfully and without complications in all patients. After intervention, symptoms resolved in all seven patients. CONCLUSIONS: Intravascular ultrasound-guided percutaneous fenestration of the intimal flap in symptomatic aortic dissections with distal vessel involvement is a technically feasible and safe procedure that can effectively relieve the patient's symptoms.

Exogenous surfactant treatment before and after sixteen hours of ischemia in experimental lung transplantation.

OBJECTIVE: A syngeneic, acute, double lung transplant model in the rat was used to determine the impact of exogenous surfactant treatment on graft function after prolonged cold storage. METHODS: The donor grafts were flush perfused, preserved for 16 hours, and then reperfused for 120 minutes. Untreated lungs served as controls (group I). In group II the recipient received a 200 mg/kg dose of surfactant (CuroSurf) before reperfusion. In groups III and IV, surfactant was administered before perfusion and harvesting (III, 20 mg/kg; IV, 200 mg/kg). Serial measurements of graft pulmonary vascular resistance, alveolar-arterial oxygen difference, and compliance were obtained. Final graft assessment included weight gain and histologic study. RESULTS: Repeated-measures analysis of variance showed significant improvement of graft performance in respect to compliance, alveolar-arterial oxygen difference, and pulmonary vascular resistance in donor surfactant treatment group IV (200 mg/kg) in comparison with recipient treatment (group II) and untreated controls (group I). Reducing the donor surfactant supplementation from 200 mg/kg to 20 mg/kg (group III) improved oxygenation and lung compliance as compared with untreated controls. Grafts in groups I and II had significantly more weight gain after 2 hours of reperfusion. Recipient treatment resulted in significantly more pulmonary hemorrhage in histologic sections. CONCLUSION: Donor treatment with exogenous surfactant is advantageous for preservation of graft function after extended ischemia. Positive effects may be seen with as little as 20 mg/kg of exogenous surfactant given before donor organ perfusion.

Inhibition of atrial fibrillation by pulmonary vein isolation and auricular resection--experimental study in a sheep model.

OBJECTIVE: The MAZE procedure has proven effective for surgically treating atrial fibrillation, but its acceptance has been limited due to the complex dissection pattern. A new simplified operative technique, that comprises two important components of the MAZE procedure, has been evaluated in an established animal model of induced sustained atrial fibrillation. METHODS: In eight sheep, median sternotomy was performed for cardiopulmonary bypass via femoral and bicaval cannuiation. Bipolar atrial and ventricular electrodes (16) were applied for computerized EKG-sampling. Atrial fibrillation was induced during continuous theophylline infusion (0.5 mg/kg/min) by repetitive (10x) biatrial stimulation. Atrial response was monitored and mapped. The operative procedure was accomplished in induced ventricular fibrillation: Right and left atrial appendices were resected and a circumferential transmural incision around all pulmonary veins was performed and closed. After defibrillation, the atria were stimulated again using the above protocol and EKGs were sampled. RESULTS: Sustained atrial fibrillation was inducible in all animals (80 stimulation episodes, median duration 31 s, 6 incessant episodes) prior to dissection. Post resection of the atrial appendices and pulmonary vein isolation, atrial fibrillation was not inducible in any of the eight animals (80 stimulation episodes). A significant interatrial (104 +/- 13 ms) and atrioventricular (208 +/- 19 ms) conduction delay was observed post dissection. CONCLUSION: We conclude that the described procedure is effective for the inhibition of sustained atrial fibrillation in morphologically unaltered atria. The operative approach involves less dissection than the MAZE procedure, which could facilitate its use in concomitant mitral procedures. The clinical significance of the observed AV-Delay has to be evaluated.

Previous open heart operation: a contribution to impaired outcome after cardiac transplantation?

BACKGROUND: There is still debate about whether previous cardiac operations are a risk factor for patient outcome after cardiac transplantation. As waiting lists for cardiac transplantation increase, adverse outcome criteria should be identified. METHODS: To assess this problem, we retrospectively analyzed 53 patients with previous cardiac operations before heart transplantation and compared them with 53 control patients matched for sex and age. Patient groups were analyzed regarding their preoperative, intraoperative, and postoperative variables and survival. RESULTS: Ischemic times were comparable in both groups, but the duration of the operation was significantly longer in the study group (206.5 +/- 62.5 minutes, versus 156.0 +/- 36.7 minutes in controls; p < 0.05). In addition, postoperative blood loss was greater for the patients with previous cardiac operations (1,360 +/- 260 mL, versus 730 +/- 310 mL for controls; p < 0.01). Postoperatively, the rate of rejection episodes and the incidence of graft atherosclerosis were comparable within the first 2 years. However, survival was significantly reduced in the study group (60.1%) after 4 years (versus 83.1% for controls; p < 0.05). CONCLUSIONS: Heart transplantation in patients with previous cardiac operations will lead to an impaired overall outcome. In addition, these patients have more postoperative complications.

Open heart operations after renal transplantation.

BACKGROUND: Because of the increasing number of renal transplantations performed, secondary cardiac operations in these patients are discussed concerning their impact on patient and graft survival. METHODS: We reviewed our experience in 45 patients (33 male and 12 female) who underwent open heart operations after previous renal transplantation. Thirty-one patients (group I) received coronary artery bypass grafting and 14 (group II) underwent valve replacement. Mean age at the time of operation was 55 +/- 9 years. The interval between renal transplantation and cardiac operation was 57 +/- 39 months (range, 5 days to 174 months). All patients had functioning renal allografts with preoperative serum creatinine levels ranging from 100 to 338 mol/mL (mean +/- standard deviation, 195 +/- 86). RESULTS: Overall early operative mortality (30 days) was 8.8% (group I, 1 patient; group II, 3 patients). Underlying causes of death were septic endocarditis (n = 2, group II), necrotizing enterocolitis (n = 1, group I), and myocardial infarction (n = 1, group II). One further patient in group II also died of septic endocarditis after 69 days (in-hospital death). The mean follow-up of the 40 surviving patients was 44 +/- 31 months. There was another late death (24 months postoperatively) caused by coagulopathy. Four patients had returned to hemodialysis at intervals of 27 to 83 months (mean, 51 months) because of renal transplant failure. In all patients, the function of the renal allograft was not impaired by open heart operation. CONCLUSIONS: Open heart operations in renal transplant recipients have acceptable mortality and morbidity rates. In almost all patients, function of the transplanted organ can be maintained at the preoperative level.

Extraanatomic thoracic aortic bypass grafts: indications, techniques, and results.

OBJECTIVE: Even in the age of extensive aortic replacement special circumstances may warrant the insertion of extraanatomic thoracic aortic bypass grafts. Our experience with 17 patients is analyzed. METHODS: Between 1988 and 1994, ten female and seven male patients (mean age 37.5 years, range 9-69 years) were treated for the following indications: (1) complex CoA (n = 5); (2) reoperation for CoA (n = 6); (3) extensive aortic occlusive disease (n = 4); and (4) complicated aneurysm (n = 2). Routing of the grafts was: ascending-descending aorta (8); ascending-abdominal aorta (4); left subdavian artery- descending aorta (2); descending-descending aorta (2); and descending-abdominal aorta (1). Eight procedures were reoperations. In four patients concomitant cardiac operations were performed: one aortic valve replacement, one patch plasty of the LCA, and two composite graft replacements of aortic valve and ascending aorta, one of them with CABG. RESULTS: Three early deaths occurred. two after emergency operation in thoracic aneurysm under dire conditions (one perforation, one infection), one after ascending-abdominal aortic grafting with multiple branch revascularization. The underlying pathology was relieved successfully in all 14 survivors. In the two patients with concomitant aortic valve and isthmic stenosis, critical anterior motion of the mitral valve, presumably because of the massive afterload reduction of the left ventricle, complicated the perioperative course. One patient was reoperated because of aneurysm 4 years after descending-descending aortic grafting for complex CoA with poststenotic dilatation. CONCLUSIONS: In complex aortic coarctation or hypoplasia extraanatomic bypass grafts are expedient and effective procedures, especially for reoperation. Their use in the treatment of aneurysmal lesions remains an exception.

Status of patients presently living 9 to 13 years after orthotopic heart transplantation.

BACKGROUND: Heart transplantation has a dramatic impact on both life expectancy and quality of life in patients with terminal heart failure. The aim of the study was to evaluate psychologic, social, occupational, and somatic status of patients living long-term, 9 to 13 years after orthotopic heart transplantation. PATIENTS AND METHODS: Seventy-seven of 182 patients who received transplants between July 1983 and January 1988 in Hannover (1983-1985; n = 69 patients) and Berlin (1986-1988; n = 113 patients) have survived up to now, 9 to 13 years after transplantation (mean, 10 years 4 months). The patients and their medical records (eg, cardiac catheter studies, echocardiography) were examined to assess their somatic status. Psychologic, social, and occupational status and quality of life data were assessed by combination of self-rating questionnaires (the Short Form Health Survey Questionnaire, Giessener Beschwerdebogen [the Giessen Subjective Complaints List], the Sickness Impact Profile, and the Hospital Anxiety and Depression Scale) and semistructured interviews. RESULTS: Ninety-one percent of the patients were in New York Heart Association functional class I (70%) or II (21%). The results of the psychologic investigation revealed a definite impact of the side effects of chronic immunosuppression; however, overall, the quality of life rating was within the normal range. Sixty-seven (86%) patients were married, 51 (66%) patients were retired, 17 (22%) worked full-time or part-time, and 9 (12%) were housewife or houseman. Four male patients have fathered five healthy children 1 to 10 years after the transplantation. More than 75% of the patients had normal systolic ventricular function (mean left ventricular ejection fraction, 0.63). Coronary angiograms were normal or with minor wall irregularities in 86% (n = 66 patients), and revealed severe obstructions in 14% (n = 11). Normal function of all valves was found in one-third of the patients, tricuspid valve incompetence was not found or was insignificant in 87% (n = 67 patients) and severe in 8% (n = 10). Six patients had undergone tricuspid valve replacement, invariably for structural valve defects attributable to biopsy injuries. Fifty-eight patients (75%) exhibited various degrees of compensated renal insufficiency, 7 of them were on chronic hemodialysis, and 2 patients have undergone kidney transplantation. Hepatic function was normal in 68% (n = 52) of the patients, and 1 patient has developed liver cirrhosis. Osteoporosis was diagnosed of the discrete form in 7 (9%) and of a significant degree in 24 patients (31%); 38.5% (n = 30) complained of symptoms of polyneuropathy. CONCLUSIONS: The patients surviving 9 to 13 years after orthotopic heart transplantation are mostly in good physical status, the quality of life is comparable to the general population, and only a few of them have significantly limited in their life style. They do show the substantial chronic side effects of long-term immunosuppression, remaining treatment-dependent for a lifetime.

Stentless aortic valve replacement with the biocor prosthesis: indications and outcome.

BACKGROUND AND AIMS OF THE STUDY: Due to improved hemodynamic properties stentless bioprostheses represent a new therapeutic option in the surgical treatment of aortic valve disease. MATERIALS AND METHODS: Between February 1993 and June 1995 22 patients with a small aortic root regarded as suboptimal for a stented bioprosthesis (diameter < or = 23 mm, mean 21.6 +/- 1.9 mm) underwent aortic valve replacement with a Biocor stentless prosthesis. Mean age was 63.9 +/- 15.4 years (17-85 years). Valve size ranged from 21 to 27 mm (mean 25 mm) and exceeded the root diameter by 4 mm. As compared to a control group of patients with root enlargement (n = 10) total bypass time and cross-clamp time in the stentless group were significantly shorter (83.3 +/- 12.7 and 60.9 +/- 9.2 min versus 95.8 +/- 27.1 and 69.5 +/- 16.5 min, p = 0.054 and p < 0.05), respectively. RESULTS: Three patients died postoperatively unrelated to the choice of valve. There were no late deaths. No thromboembolic or bleeding events were observed. Follow up data are available over a period of 1-25 months (mean 12.5 months, median 16 months). Echocardiographic evaluation revealed no aortic regurgitation; mean valve gradients were 9.9 +/- 4.1 mmHg (peak 19.2 +/- 6.0 mmHg). For specific root diameters these gradients were compared to established data for Hancock bioprostheses demonstrating significant differences in transvalvular gradients between the two valve designs for given root diameters. Unloading the left ventricle resulted in regression of left ventricular hypertrophy (decrease in wall thickness from 13.6 +/- 1.7 mm to 11.2 +/- 2.0 mm). Exercise capacity improved from NYHA III-IV preoperative to I-II postoperative. CONCLUSIONS: In patients with a small aortic root stentless valves represent a new option. Compared to root enlargement with standard bioprosthesis myocardial ischemia is shorter and implantation of larger valve sizes results in superior hemodynamics.

[Aortic valve reconstruction in ectasia of the aortic root and valve insufficiency]. / Aortenklappenrekonstruktion bei Ektasie der Aortenwurzel und Klappeninsuffizienz.

Aortic valve regurgitation in conjunction with ectasia of the proximal aorta is a common finding. The pathologic mechanism of valve insufficiency is mainly caused by dilatation of the aortic root at the level of the sino-tubular and the aorto-ventricular junction. Total replacement of the proximal aorta with resuspension of the aortic valve within the graft is a new alternative approach. Between July 1993 and March 1995, 17 patients were treated for root ectasia using this approach. The age ranged from 15 to 70 years. Aortic insufficiency (mean grade 3) was present in all patients. The operation consisted of total replacement of the proximal aorta with resuspension of the native valve within the graft. In five patients the aortic arch was replaced as well, one patient underwent mitral reconstruction for severe mitral regurgitation. There was no mortality; postoperative aortic regurgitation was reduced to a mean of 0.7. Aortic valve function has been stabled in 16 instances, in one patient a mild increase in regurgitation was seen. Aortic valve reconstruction in conjunction with total tubular graft replacement of the proximal aorta is a new alternative approach for patients with root ectasia. The disadvantages of mechanical heart valve replacement can be avoided.