Full-root aortic valve replacement with stentless xenograft achieves superior regression of left ventricular hypertrophy compared to pericardial stented aortic valves

BACKGROUND

Full-root aortic valve replacement with stentless xenografts has potentially superior hemodynamic performance compared to stented valves. However, a number of cardiac surgeons are reluctant to transform a classical stented aortic valve replacement into a technically more demanding full-root stentless aortic valve replacement. Here we describe our technique of full-root stentless aortic xenograft implantation and compare the early clinical and midterm hemodynamic outcomes to those after aortic valve replacement with stented valves.

METHODS

We retrospectively compared the pre-operative characteristics of 180 consecutive patients who underwent full-root replacement with stentless aortic xenografts with those of 80 patients undergoing aortic valve replacement with stented valves. In subgroups presenting with aortic stenosis, we further analyzed the intra-operative data, early postoperative outcomes and mid-term regression of left ventricular mass index.

RESULTS

Patients in the stentless group were younger (62.6 ± 13 vs. 70.3 ± 11.8 years, p < 0.0001) but had a higher Euroscore (9.14 ± 3.39 vs.6.83 ± 2.54, p < 0.0001) than those in the stented group. In the subgroups operated for aortic stenosis, the ischemic (84.3 ± 9.8 vs. 62.3 ± 9.4 min, p < 0.0001) and operative times (246.3 ± 53.6 vs. 191.7 ± 53.2 min, p < 0.0001) were longer for stentless versus stented valve implantation. Nevertheless, early mortality (0% vs. 3%, p < 0.25), re-exploration for bleeding (0% vs. 3%, p < 0.25) and stroke (1.8% vs. 3%, p < 0.77) did not differ between stentless and stented groups. One year after the operation, the mean transvalvular gradient was lower in the stentless versus stented group (5.8 ± 2.9 vs. 13.9 ± 5.3 mmHg, p < 0.0001), associated with a significant regression of the left ventricular mass index in the stentless (p < 0.0001) but not in the stented group (p = 0.2).

CONCLUSION

Our data support that full-root stentless aortic valve replacement can be performed without adversely affecting the early morbidity or mortality in patients operated on for aortic valve stenosis provided that the coronary ostia are not heavily calcified. The additional time necessary for the full-root stentless compared to the classical stented aortic valve replacement is therefore not detrimental to the early clinical outcomes and is largely rewarded in patients with aortic stenosis by lower transvalvular gradients at mid-term and a better regression of their left ventricular mass index.

Left ventricular mass regression following implantation of MIRA bileaflet valves in patients with severe aortic stenosis

The aim of this study was to evaluate the factors that determine the course of left ventricular mass regression in a homogeneous group of patients following aortic valve replacement by use of the mechanical Edwards MIRA bileaflet prosthesis. Furthermore, we examined if the 19-mm valve leads to an equally good outcome when compared with larger 21- and 23-mm valves. We included 79 patients (49 men) with a mean age of 65+/-9 years operated on for isolated aortic valve replacement with the MIRA valve prosthesis. The analyses included preoperative and postoperative echocardiograms during a follow-up of at least 18 months (995+/-439 days) after valve surgery. Indication for valve replacement was aortic stenosis in 59 and combined disease (aortic stenosis and regurgitation) in 20 patients. Concomitant coronary artery bypass grafting was performed in 28 patients. Left ventricular mass index declined from 155.6+/-47 g/m(2) to 128.8+/-35 g/m(2) (P<0.001) at final visit and normalized in 49% of the patients. Female sex and a preoperatively highly elevated left ventricular mass index were identified as risk factors for residual hypertrophy. However, age and valve size did not have a predictive value for completeness of left ventricular mass regression. This study supports the evidence that an extensive preoperative left ventricular hypertrophy results in an incomplete postoperative mass regression in patients with aortic bileaflet valves. It shows that the slightly elevated pressure gradient in MIRA 19-mm valves does not affect left ventricular mass regression.

[Management concept for acute traumatic aortic rupture based on a case report]

Acute traumatic rupture of the thoracic aorta (ATRRA) is mainly a consequence of high-speed travel or fall from great altitude. Most of the victims die at the accident scene. Only 10-20% reach the hospital alive. Because of the extremely high mortality, emergency repair seems to be indicated. Taking into consideration that the hemorrhage into the mediastinum may remain constained and the patient usually suffers from a wide variety of life-threatening causes of injury the aforementioned option is probably not the best one. We report on a patient whose "stable" aortic rupture was surgically corrected after stablization of the circulation, coagulation and respiratory problems.

Lung resection for invasive pulmonary aspergillosis in neutropenic patients with hematologic diseases

Invasive pulmonary aspergillosis (IPA) is associated with a high mortality. In 27 consecutive neutropenic patients who underwent lung resection for suspected IPA, we analyzed preoperative diagnostic evaluation, operative procedure, perioperative management, histological findings, outcome concerning recurrence of aspergillosis, and survival to evaluate the morbidity and mortality of a surgical treatment of IPA. Seventeen patients with hematologic diseases had previously undergone high-dose chemotherapy and four stem cell transplantation. Six patients with aplastic anemia were treated with antilymphocyte globulin. IPA was suspected if localized infiltrates developed on thoracic CT scan, and fever persisted under antibiotic therapy in neutropenic patients. In only one case a diagnosis of IPA could be made preoperatively. Twenty patients underwent lobectomy and seven wedge resection. At day of surgery the neutrophil count was below 500 x 10(9)/L in 78% of patients, and the platelet count below in 50 x 10(9)/L in 58% of patients. Invasive fungal infection was confirmed histologically in 22 of 27 patients (81.5%); in five patients no fungal infection was documented. The median duration of surgery was 120 min. Postoperatively, patients stayed one night in the intensive care unit, and chest tubes were removed after 2 d. Within 7 d a median of four erythrocyte packs and two platelet packs per patient were replaced. Major surgical complications occurred in two patients (bronchial dehiscence; pleural aspergillosis). Minor surgical complications included prolonged chest tube drainage (recurrent pneumothorax, n = 2; air leakage, n = 1; hematothorax, n = 1), pleural effusion (n = 4), and seroma (n = 2). Postoperatively, two patients suffered from histologically proven disseminated aspergillosis (pleural aspergillosis, renal aspergilloma) and another patient from suspected orbital aspergillosis. At 30 d postoperative mortality was 11% and 3-mo survival was 77%. After lung resection, seven patients underwent stem cell transplantation without recurrence of IPA. In conclusion, we suggest lung resection is a therapeutic option for invasive pulmonary aspergillosis in neutropenic patients with hematologic diseases and is associated with a low surgery-related morbidity and mortality.

Quantitative monitoring of blood supply to knee joint transplants in dogs

BACKGROUND

Transplantation of vascularized knee joints has become technically feasible, but graft rejection as well as failures of the vascular anastomoses remain critical hazards. We therefore tested the potential of repetitive non-invasive duplex sonography to detect changes of the arterial blood flow following canine knee joint transplantation.

METHODS

Four transplantations and, as controls, 4 replantations of intact canine knee joints were performed. The follow-up was 6 months. During this period, repetitive duplex sonography measurements as well as tests of knee joint function were performed. Six months postoperatively, angiographies were performed and all joints were explanted for histological investigation.

RESULTS

The luminal diameters of the implanted popliteal artery remained constant in the transplanted animals (preop. 2.6 +/- 0.2 mm, 6 months postop. 2.7 +/- 0.2 mm) but decreased in the autografted controls (preop. 2.9 +/- 0.3 mm, postop. 2.0 +/- 0.3 mm). The time-averaged velocity of the popliteal artery blood flow decreased in both groups 1 month postoperatively. Subsequently, blood flow velocity recovered in transplanted animals but remained low in replanted controls. Significant arterial wall thickening was also detected in transplanted animals as compared to controls. Six months postoperatively, hypervascularization of transplanted joints was confirmed by angiography and thickening of the arterial wall by histology. Furthermore, histology identified mild to chronic allograft rejection in all transplanted joints in spite of controlled cyclosporin A trough level immunosuppression.

CONCLUSIONS

Chronic rejection of transplanted vascularized knee joints appears to be associated with vessel wall thickening and hypervascularization rather than with vascular rarefaction (picture of the 'arbre mort') that is characteristic of the rejection of most parenchymatous organs. Duplex sonography appears to be sensitive in detecting the corresponding changes of blood supply.

Cardiac metastasis of an epitheloid leiomyoblastoma of the lung

A 73-year-old patient underwent an extended pneumonectomy on the left side on account of a central malignant epitheloid leiomyoblastoma of the upper lobe. During this operation a tumor invasion of the pulmonary vein was discovered by chance. During the postoperative course the patient suffered from a tumor-caused morbus embolicus which led to his death. The autopsy showed cardiac metastasis. Four aspects are discussed: the morphology and biology of the malignant leiomyoblastoma, the incidence of cardiac metastases and their clinical diagnosis as well as the intraoperative embolism of tumor masses during lung resections.

[Functional and morphological results of transplantation of vascularized knee joints in a dog model--a preliminary report]

Functional and morphological results of transplantation (n = 3) and replantation (n = 4) of vascularised total knee joints were compared in a canine model. Follow up time was 6 months. All vascular anastomoses remained patent and all osteotomies healed. Replanted animals displayed normal static weight bearing in contrast to the transplant recipients, which showed reduced weight bearing after 6 months compared to preoperative values. Mild to moderate signs of chronic allograft rejection were detected in all transplanted animals. Functional results were correlated with morphological outcome demonstrating the relevance of adequate control of rejection.

[Surgical technique in vascularized auto- and allotransplantation of the knee joint in a dog model]

Experimental transplantation of vascularized canine knee joints has so far been associated with high complication rates in both auto- and allografts. We have now compared 4 autografts and 4 allografts that were successfully performed at our institution. This report details our surgical technique. Stable internal fixation enabling immediate postoperative weight bearing, microsurgical end-to-end anastomoses of popliteal artery and vein and postoperative control of immunosuppression in transplanted animals are crucial. Thus, an interdisciplinary approach of experts in microsurgery, orthopedic and trauma surgery and immunologists appears to be a prerequisite for successful joint transplantation.

Decision making in the surgical treatment of massive pulmonary embolism

Pulmonary embolectomy in the treatment of acute massive pulmonary embolism (PE) is the subject of considerable controversy with regard to indication, technique of embolectomy and perioperative management. Since 1968 50 patients have undergone surgery for massive PE in our unit. Inflow occlusion technique and cardiopulmonary bypass were used in 33 and 17 patients, respectively. The overall operative mortality was 46%. Univariate analysis disclosed age (< 60 vs > 60), preoperative hemodynamics (cardiogenic shock vs cardiac arrest), location of emboli (peripheral vs central), duration of symptoms (hours vs days vs weeks) and number of episodes (first episode vs recurrent pulmonary emboli) as predictive factors of the post-operative outcome. The results of the retrospective analysis show that pulmonary embolectomy remains an acceptable procedure in patients with acute massive pulmonary emboli who are in refractory cardiogenic shock or who need intermittent resuscitation.

[External fixator as primary and definitive treatment of tibial fracture with severe soft tissue damage]

The initial treatment of choice of fractures with severe soft tissue damage of the leg is the stabilization with an external fixator. After successful healing the question arises whether to continue the initial treatment with the external fixator to bone union or to change the initial concept by an internal fixation. Our experience with 62 fractures of the tibia (follow-up of 59 fractures) from 1985 to 1989 shows that 72% of the fractures were healed by the external fixator alone. Delayed union or pseudoarthrosis occurred in 17% and were mostly treated by late internal fixation. An analysis of the fracture types (new AO classification) did not show certain fracture types, that did not respond to the external fixator treatment alone. We conclude that the reason for a delayed union or pseudoarthrosis is less a morphological than a biological one. We recommend the first and final external fixator as treatment for fractures with severe soft tissue damage of the leg.