Aortic Valve Reconstruction Using Autologous Pericardium for Aortic Stenosis.

BACKGROUND: To determine the feasibility of original aortic valve reconstruction (AVRec) for patients with aortic stenosis (AS), 416 consecutive cases were reviewed. METHODS AND RESULTS: AVRecs for AS were performed for 416 patients from April 2007 through April 2013. All 416 patients were retrospectively reviewed. One hundred and fourteen patients had bicuspid valves and 16 had unicuspid valves. There were 182 men and 234 women. Mean age was 71.2±12.0 years old. On preoperative echocardiography, peak pressure gradient averaged 79.0±33.6 mmHg. Surgical annular diameter was 20.1±2.8 mm. The procedure is based on independent tricuspid replacement by autologous pericardium using original sizing apparatus and template. There was no conversion to prosthetic valve replacement. There were 8 in-hospital mortalities due to non-cardiac cause. On postoperative echocardiography, peak pressure gradient averaged 21.2±10.7 mmHg 1 week after surgery and 14.3±5.0 mmHg 5.5 years after surgery. Four reoperations were done for infective endocarditis. The other 412 patients had less than mild regurgitation. No thrombo-embolic events were recorded. The mean follow-up period was 25.2±17.5 months. Freedom from reoperation was 96.7% with 73-month follow-up. CONCLUSIONS: Medium-term results were excellent. Original AVRec was feasible for the patients with AS. Long-term data will be presented in the future.

Reconstruction of bicuspid aortic valve with autologous pericardium--usefulness of tricuspidization.

BACKGROUND: This study describes the surgical treatment of bicuspid aortic valve with original aortic valve reconstruction. METHODS AND RESULTS: Aortic valve reconstruction was done in 102 patients with bicuspid aortic valve from April 2007 through September 2011. Thirty-four patients with ascending aortic diameter >45 mm underwent hemi-arch aortic replacement concomitantly. Seventy-seven patients had aortic stenosis, and 25 had aortic regurgitation (AR). Mean age was 63.7±10.0 years old. There were 55 men and 47 women. Harvested pericardium is treated with 0.6% glutaraldehyde solution. The distance between commissures is measured with an original sizing instrument. For bicuspid valve with raphe, the raphe is considered as a commissure in order to measure the distance between each commissure. Without a raphe, we create a new annular margin and commissure using coronary ostium and the sizing instrument as a guide. Then, pericardium is trimmed with original template. Three cusps are sutured independently. The preoperative averaged peak pressure gradient of 71.1±39.0 mmHg was decreased to 16.2±8.8, 13.3±6.0, and 13.9±5.6 mmHg, respectively 1 week, 1 year, and 3 years after operation. AR was trivial. One reoperation was recorded. Mean follow-up was 733 days. There were 5 late mortalities. No thromboembolic event was recorded. CONCLUSIONS: Medium-term results were excellent. Tricuspidization gave good opening and closure of aortic valve with excellent hemodynamics.

Ozaki procedure-re-construction of aortic valve leaflets using autologous pericardial tissue: a review.

The Ozaki procedure has emerged as a valuable option for treating various aortic valve pathologies. This review article delves into the intricacies of this innovative surgical approach by exploring its adaptation to the complex anatomy and physiology of the aortic root. The diverse etiologies of aortic valve diseases, ranging from congenital anomalies to degenerative changes, make treatment selection a complex challenge. Aortic valve replacement has traditionally been the gold standard, but emerging evidence supports valve repair techniques, emphasizing the importance of preserving native tissue. Nevertheless, issues like lifelong anticoagulation with mechanical valves and patient-prosthetic mismatch remain. The Ozaki procedure offers a compelling alternative by utilizing autologous pericardium or a tissue substitute to construct new aortic valve leaflets. This technique, standardized by Dr. Ozaki in 2007, provides a customizable and adaptable solution. The article highlights the anatomy of the aortic root, emphasizing the critical role of the sinus of Valsalva and interleaflet triangles in maintaining proper valve function. The procedure's unique adaptation to aortic root dynamics allows for reduced mechanical stress during systole and diastole, mimicking the natural valve's behavior. Furthermore, Ozaki leaflets exhibit promising hemodynamics and reduced risks of complications, such as permanent pacemaker implantation and patient-prosthetic mismatch. The use of autologous pericardium in the Ozaki procedure presents advantages, including enhanced tissue strength, minimal immunogenicity, and reduced risk of immune-mediated calcification. These factors contribute to the longevity and resilience of the reconstructed valve. This comprehensive review aims to shed light on the procedure's intricacies, its alignment with aortic root anatomy and physiology, and its potential as a valuable tool in the armamentarium of aortic surgeons.

Aortic Valve Reconstruction With Autologous Pericardium Versus a Bioprosthesis: The Ozaki Procedure in Perspective.

Background We assessed the Ozaki procedure, aortic valve reconstruction using autologous pericardium, with respect to its learning curve, hemodynamic performance, and durability compared with a stented bioprosthesis. Methods and Results From January 2007 to January 2016, 776 patients underwent an Ozaki procedure at Toho University Ohashi Medical Center. Learning curves, aortic regurgitation (AR), and peak gradient, assessed by serial echocardiograms, valve rereplacement, and survival were investigated. Valve performance and durability were compared with 627 1:1 propensity-matched patients receiving stented bovine pericardial valves implanted from 1982 to 2011 at Cleveland Clinic. Learning curves were observed for aortic clamp and cardiopulmonary bypass times, AR prevalence, and early mortality. Decreased aortic clamp time was observed over the first 300 cases. New surgeons performing parts of the procedure after case 400 resulted in a slight increase in aortic clamp and cardiopulmonary bypass times. Among matched patients, the Ozaki cohort had more AR than the PERIMOUNT cohort (severe AR at 1 and 6 years, 0.58% and 3.6% versus 0.45% and 1.0%, respectively; P[trend]=0.006), although with a steep learning curve. Peak gradient showed the opposite trend: 14 and 17 mm Hg for Ozaki and 24 and 28 mm Hg for PERIMOUNT at these times (P[trend]<0.001). Freedom from rereplacement was similar (P=0.491). Survival of the Ozaki cohort was 85% at 6 years. Conclusions Patients undergoing the Ozaki procedure had lower gradients but more recurrent AR than those receiving PERIMOUNT bioprostheses. Although recurrent AR is concerning, results confirm low risk and good midterm performance of the Ozaki procedure, supporting its continued use.

Primary cardiac synovial sarcoma: a case report and literature review.

Primary cardiac synovial sarcoma is a rare disease. A 51-year-old man visited our hospital with the chief complaint of palpitations and shortness of breath while exercising. Copious bloody pericardial effusion and a multicystic intrapericardial tumor were detected. A primary cardiac malignant tumor was suspected, an open-chest tumor resection was performed with the objectives of diagnosis and treatment. Histologically, the tumor cells were uniformly spindle-shaped with an ovoid or oval nucleus, they had proliferated in fascicular fashion. In addition myxoid degeneration, a hemangiopericytomatous vascular pattern and pseudorosette formation were seen in some areas of the tumor. Based on the histopathological and immunohistochemical findings and reverse transcription polymerase chain reaction detection of SS18-SSX1 fusion transcripts, a monophasic fibrous type synovial sarcoma was diagnosed. Postoperative radiation therapy was administered and there had been no recurrence 9 months after the surgery.

Mechanical characterization of an in-body tissue-engineered autologous collagenous sheet for application as an aortic valve reconstruction material.

The reconstruction of the aortic valve using glutaraldehyde-treated autologous pericardium is known as "aortic valve neo-cuspidization" (AVNeo). In-body tissue architecture (iBTA), a cell-free, in vivo tissue-engineering technology that can form autologous implantable tissues of the desired shape by subcutaneous embedding specially designed molds, was used to prepare sheet-like collagenous tissues called "Biosheets". Cylindrical molds with several line slits arranged in an alternating (n = 30) or parallel (n = 36) pattern were subcutaneously embedded in goats (n = 12) for 2 or 3 months. The tubular tissues formed in the molds were dried and then cut in the longitudinal direction, thus obtaining Biosheets (5 × 7 cm). The success rate was 97.6% when using the alternating-pattern molds and 97.2% for the parallel molds. Thickness mapping of the Biosheets showed that their entire surface, except for the line-projection portions, was smooth without any defects. The average wall thickness could be controlled over a range of ca. 0.2-0.5 mm by changing the size of the gap (0.75-1.5 mm) in the molds. The alternating slit-patterned Biosheets were found to be almost isotropic in their mechanical properties (ultimate tensile strength, fracture strain, and Young's modulus). Although the composition of the Biosheet wall was heterogeneous in terms of its density (which varied with the thickness), the breaking strength of all the alternating-patterned Biosheets increased almost linearly with the thickness within the range of the thickness of clinically used glutaraldehyde-treated pericardium as a control, and was larger than that of human aortic valve leaflets. Therefore, the alternating-patterned Biosheets have potential for use in an alternative aortic leaflet material in AVNeo.

Midterm outcomes after aortic valve neocuspidization with glutaraldehyde-treated autologous pericardium.

OBJECTIVE: We had previously reported the short-term results of the aortic valve neocuspidization (AVNeo) procedure. We have now evaluated the midterm results with the longest follow-up of 118 months. METHODS: From April 2007 through December 2015, 850 patients were treated with AVNeo using autologous pericardium. Medical records of these patients were retrospectively reviewed. The procedure was on the basis of independent tricuspid replacement using autologous pericardium. The distances between the commissures were measured with an original sizing device, the pericardial cusp was trimmed using an original template, and then sutured to the annulus. RESULTS: There were 534 patients with aortic stenosis, 254 with aortic regurgitation, 61 with aortic stenoregurgitation, 19 with infective endocarditis, and 5 with a previous aortic valve procedure. Besides 596 patients with tricuspid aortic valve, 224 patients had bicuspid valve, 28 had unicuspid valve, and 2 had quadricuspid valve. There were 444 male and 406 female patients. The median age was 71 (range, 13-90) years old. Preoperative echocardiography revealed a peak pressure gradient average of 68.9 ± 36.3 mm Hg with aortic stenosis. Surgical annular diameter was 20.9 ± 3.3 mm. There was no conversion to a prosthetic valve replacement. There were 16 in-hospital mortalities. Postoperative echocardiography revealed a peak pressure gradient average of 19.5 ± 10.3 mm Hg 1 week after surgery and 15.2 ± 6.3 mm Hg 8 years after surgery. Fifteen patients needed reoperation (13 infective endocarditis, 1 break of thread, and 1 tear of cusp case). The mean follow-up period was 53.7 ± 28.2 months. Actuarial freedom from death, cumulative incidence of reoperation, and that of recurrent moderate aortic regurgitation or greater was 85.9%, 4.2%, and 7.3%, respectively, with the longest follow-up of 118 months. CONCLUSIONS: The midterm outcomes of AVNeo using autologous pericardium were satisfactory in 850 patients with various aortic valve diseases. However, further randomized, multicenter prospective studies are needed to confirm the results of the current study.

Notes on the application of the Matsui-Kitamura stent-graft for endovascular repair of abdominal aortic aneurysm.

Abdominal aortic and left common iliac aneurysms in a 79-year-old man who had undergone Miles' operation for rectal carcinoma were treated with endovascular repair of an abdominal aortic aneurysm (EVAR), taking into consideration the age, surgical history, and wishes of the patient and his family. The Matsui-Kitamura stent-graft (MK-SG) was designed based on preoperative angiographic mapping. At EVAR, the right leg of the MK-SG was caught at the aortic bifurcation because of unexpected contraction of the MK-SG. To resolve the problem, the body of the MK-SG was dilated with a balloon, slightly lifted while being gradually shortened, and eventually successfully connected to the leg of the MK-SG. Made of nitinol mesh, the MK-SG is stable and flexible enough to make it one of the best stent-grafts for EVAR. A serious drawback, however, is the high contraction rate of the MK-SG itself. It is difficult to estimate the appropriate length of the stent-graft owing to unpredictable contraction. It is important to understand its characteristics and to carefully design and acquire sufficient skills in manipulating MK-SG.

Trileaflet aortic valve reconstruction with a decellularized pericardial patch in a sheep model.

BACKGROUND: The purpose of this study was to provide a preliminary assessment of the performance of a decellularized pericardial patch in a trileaflet aortic valve reconstruction in a long-term juvenile sheep model. METHODS: A sheep surgical model was used to perform a complete trileaflet reconstruction (Ozaki technique) of the aortic valve with 3 separate pericardial patches. Valve function was assessed 1 week, 3 months, and 6 months after surgery via transthoracic echocardiography. Calcification resistance and host cell infiltration of the pericardial material were assessed at 6 months after surgery. RESULTS: Three of 6 sheep with implanted pericardial neo-cusps survived until the planned time of sacrifice after surgery, whereas 3 animals had a successful implant but died shortly after the procedure as the result of a bad recovery from cardiopulmonary bypass. Echocardiography at 6 months revealed a high coaptation area with only minimal regurgitation. In all explanted leaflets, cusp tissue was soft. There was only minimal calcification in 8 of 9 leaflets. CONCLUSIONS: Aortic valves reconstructed with a decellularized pericardial patch demonstrated adequate diastolic function with minimal regurgitation and resistance to calcification. Combining the Ozaki technique with this decellularized pericardial scaffold showed adequate hemodynamics, sustained mechanical integrity of the patch and limited calcification of the material. These results, together with earlier experimental and clinical data, indicate the potential of this material for aortic valve repair.

A Case of Severe Unicuspid Aortic Valve Stenosis: Valve Repair With Tricuspidization in an Adult.

A 33-year-old male was referred to our institute with acute heart failure. The patient was found to have a unicuspid aortic valve (UAV) and severe aortic stenosis. He had been followed at a local university hospital during childhood. However, he stopped visiting the outpatient clinic after becoming an adult. His condition subsequently worsened, and he ultimately presented to our hospital with cardiogenic shock. In Japan, some adult congenital heart disease (ACHD) patients continue to be followed by pediatric cardiologists, though the patterns of practice are variable. This report describes the case of a patient who became lost to follow-up in early adulthood. We thus focus on this ACHD case as an example of the effects of inadequate communication among doctors and the need to establish better ACHD management protocols for treating this patient population.

Valved jugular vein segments for right ventricular outflow tract reconstruction in young sheep.

OBJECTIVE: This study was undertaken to investigate the degeneration and calcification of valved bovine jugular vein segments for right ventricular outflow tract reconstruction in juvenile sheep. METHODS: Seven valved bovine jugular vein conduits (Contegra model 220; VenPro Corporation, Irvine, Calif) and 3 control conduits (MH100; Medtronic, Inc, Minneapolis, Minn) were implanted in the pulmonary artery in young sheep. After 20 weeks the conduits were explanted and qualitatively analyzed by epicardial echocardiography, gross examination, x-ray analysis, light microscopy, and transmission electron microscopy. Calcification was determined quantitatively by flame atomic absorption spectrometry. RESULTS: Two Contegra conduits could not be analyzed because of endocarditis. All other Contegra conduits functioned well, with preserved structure and minimal calcification. The control MH100 conduits exhibited extensive fibrous sheathing, with calcification of the aortic wall portion and the commissural part of the Hancock valve. CONCLUSIONS: The Contegra conduit's performance was clearly superior to that of the control MH100 conduit when implanted in the pulmonary artery position in juvenile sheep for 5 months.

Bioprosthetic tissue calcification: influence of blood contact and arterial pressure. an experimental study in rats and sheep.

BACKGROUND AND AIM OF THE STUDY: Several animal models are currently used to study bioprosthetic tissue calcification. The study aim was to evaluate the influence of species and environmental factors (blood contact and arterial pressure) on valve tissue mineralization. METHODS: Glutaraldehyde-fixed porcine cusps and aortic wall samples were implanted subcutaneously in rats (n = 6) and sheep (n = 18). In sheep, similar samples were also implanted into the jugular vein (blood contact) and carotid artery (blood contact and arterial pressure). Tissue was explanted at intervals up to three months and evaluated macroscopically, and by X-radiography, light and electron microscopy and calcium content measurement. RESULTS: After eight weeks in the subcutaneous position, glutaraldehyde-fixed cusps were severely calcified in rats, but not in sheep (78.6 +/- 28.3 and 0.3 +/- 0.5 microg Ca/mg, respectively; p <0.001). Aortic wall samples were calcified in both species, but less in sheep (p <0.001). In sheep, blood contact without arterial pressure (venous implants) significantly increased the calcification of cusp and even more of aortic wall tissue. Arterial pressure had no effect on calcification of aortic wall tissue. CONCLUSION: Major inter-species inconsistencies were found in valve tissue calcification after subcutaneous implantation. In sheep, blood contact increased tissue calcification significantly, mainly in aortic wall samples. Arterial pressure did not enhance mineralization of aortic wall tissue.

A new model to test the calcification characteristics of bioprosthetic heart valves.

BACKGROUND: Tissue degeneration and calcification are the two chief obstacles to the successful application of bioprosthetic heart valves. To enable the study of the durability of bioprosthetic heart valves and the efficacy of anti-calcification treatment, it has become necessary to develop animal models. The aim of this study is to validate a new model for implantation in the pulmonary position. METHODS: Three juvenile sheep underwent implantation of Carpentier-Edwards pericardial valves in the pulmonary position (experimental group). These three valves were compared with three Carpentier-Edwards pericardial valves in the aortic position in patients which had been explanted due to primary tissue failure (clinical group). The valves were analyzed. RESULTS: The findings of macroscopic, X-ray and light microscopic examination were very similar between the two groups. Scattered irregular calcification was seen near the commissures and at the base of the cusps in both groups. Quantitative calcium content analysis showed that calcification of the cusps had progressed to almost the same degree in both groups (experimental group, 3.7+/-0.2 micro g/mg dry tissue; clinical group, 4.3+/-0.3; p>0.05). In the experimental group, calcification in the commissural area of the cusp was pronounced (6.5+/-1.0). In the clinical group, calcification had also progressed in the commissural area of the cusp (6.0+/-1.5), and extended to the base area of the cusp (6.6+/-1.2). CONCLUSIONS: This model is promising for preclinical evaluation of bioprosthetic heart valves. The degree of calcification is not significantly different between our experimental results after three months of implantation in sheep and clinical results after 10 years of implantation in elderly patients. However, the pattern of calcification is somewhat different between the two groups.

Influence of blood contact on the calcification of glutaraldehyde-pretreated porcine aortic valves.

BACKGROUND: The rat subcutaneous model reproduces clinically observed mineralization of bioprosthetic tissues. However, the effectiveness of antimineralization treatment can be overestimated in subcutaneous implants, since specimens using this model are not subjected to mechanical and dynamic stress or blood-surface contact. The purpose of this study was to evaluate the influence of blood contact on the calcification of bioprosthetic valves. METHODS: Glutaraldehyde-pretreated porcine aortic valves were prepared. Aortic wall and cusp discs were implanted subcutaneously in six rats for 8 weeks and were implanted within the jugular vein wall in six sheep for 3 and 6 months (blood contact model). Tissue discs were analyzed by gross inspection, radiography and light microscopy. Calcium content was determined by atomic absorption spectrometry. RESULTS: X-ray and light microscopic examination showed calcification in the cusps to be higher than that in the aortic wall in the rat subcutaneous model. On the other hand, in the blood contact model, the cusps were slightly calcified and calcification in the aortic wall was more pronounced. Calcium analysis in rats revealed more calcium in the cusp than in the aortic wall (71.5+/-9.7 g/mg dry tissue vs. 53.7+/-2.6, p=0.09). Tests for calcium content of the jugular vein samples in sheep showed significantly more calcium in the aortic wall than in the cusp (3 months, 7.9+/-1.5 vs. 0.3+/-0.1, p<0.0001; 6 months, 77.2+/-6.1 vs. 27.2+/-10.2, p=0.0002). In addition, aortic wall and cusp calcification significantly increased with time. CONCLUSIONS: These data suggest that the results from the rat subcutaneous model were completely opposite to those for the blood contact model. This study confirms the need to include blood contact as a factor in in vivo pre-clinical valve testing.

Tissue engineering of an auto-xenograft pulmonary heart valve.

To improve the durability of stentless valves without losing their excellent hemodynamic function, a new-generation auto-xenograft was developed and evaluated. A piece of vein was harvested from 3 juvenile sheep 6 weeks before implantation of the valve. Endothelial cells from the vein material were cultivated and used to reendothelialize a decellularized porcine pulmonary valve. The tissue-engineered valve was implanted into the right ventricular outflow tract of the juvenile sheep. It was explanted after 100 days and assessed macroscopically as well as by x-ray, light microscopy (hematoxylin and eosin staining and von Kossa staining), and scanning electron microscopy. Calcium content of the cusps was determined quantitatively by atomic absorption spectrometry. The sheep implanted with the valve recovered quickly without any problems during the observation period. X-ray examination of the 3 explanted valves showed no cusp calcification, which was confirmed by histological study. Atomic absorption spectrometry showed low tissue calcium content. A clinical safety and feasibility trial with an allograft valve prepared the same way showed excellent short-term results in 6 patients.

Modified stentless porcine valve enhances accelerated cuspal calcification in the juvenile sheep model.

OBJECTIVE: Stent mounting of any bioprosthesis, induces a loss of mobility and reduces the effective valve orifice. By contrast, for stentless procedures, the higher surgical technicality remains a major obstacle for many surgeons. In an attempt to facilitate the insertion of the stentless porcine aortic valve (Toronto SPV), we tried to alter the design by lowering the invasive profile at the depth of the sinuses on both coronary sites. This could theoretically facilitate the implant of the modified stentless valve with an easygoing single layer suture at the challenging subcoronary level and make it more attractive for every surgeon. METHODS: Modifications of the standard model were done by lowering the profile at the depth of the sinuses on both coronary sites, whether by plication or excision of the protruding porcine aortic wall at the nadir of each coronary sinus. Nine juvenile sheep underwent implantation of stentless porcine aortic valves in pulmonary position: 3 standard Toronto SPV, 3 plicated Toronto SPV and 3 excised Toronto SPV. In each series, valves were explanted after 3 months. Valves were analyzed. RESULTS: The cusps of standard Toronto SPV were perfectly functioning and pliable, without visible calcification after three months. The calcium content of the cusps was less than those in the plicated and excised Toronto SPV (2.4 +/- 0.7 microg/mg versus 10.8 +/- 5.9 and 6.7 +/- 3.4 microg/mg). In the plicated and excised valves, calcification of the cusp was more pronounced in the commissural region (3.9 +/- 1.9, 29.0 +/- 16.7, 13.8 +/- 9.5 microg/mg in the standard, plicated and excised Toronto SPV, respectively). On the other hand, the aortic wall from the plicated Toronto SPV had more calcium than that from the other groups (53.6 +/- 6.3, 41.2 +/- 7.1, 45.2 +/- 7.4 microg/mg in the plicated, standard and excised Toronto SPV, respectively). CONCLUSIONS: The modification of stentless porcine valve enhanced accelerated cuspal calcification in the commissural region. It accentuated that the correct implantation technique for stentless procedures is extremely important in order to prevent early degeneration.