Hiroki Mizoguchi

Morphological analysis and preoperative simulation of a double-chambered right ventricle using 3-dimensional printing technology

We present a case of a double-chambered right ventricle in adulthood, in which we tried a detailed morphological assessment and preoperative simulation using 3-dimensional (3D) heart models for improved surgical planning. Polygonal object data for the heart were constructed from computed tomography images of this patient, and transferred to a desktop 3D printer to print out models in actual size. Medical staff completed all of the work processes. Because the 3D heart models were examined by hand, observed from various viewpoints and measured by callipers with ease, we were able to create an image of the complete form of the heart. The anatomical structure of an anomalous bundle was clearly observed, and surgical approaches to the lesion were simulated accurately. During surgery, we used an incision on the pulmonary infundibulum and resected three muscular components of the stenosis. The similarity between the models and the actual heart was excellent. As a result, the operation for this rare defect was performed safely and successfully. We concluded that the custom-made model was useful for morphological analysis and preoperative simulation.

Which valve and which size should we use in the valve-on-valve technique for re-do mitral valve surgery?

The valve-on-valve (VOV) technique is that a mechanical valve is implanted on the sewing cuff of the previous bioprosthesis after removing degenerated leaflets. We conducted an in vitro study to determine the size-match of the valves for VOV technique. The Carpentier-Edwards pericardial (CEP) valve and Mosaic valve were used. We measured the inner diameter of the bioprosthesis after removing the leaflets. We investigated five mechanical mitral valves and two mechanical aortic valves (inverted use). The mitral valves used in this study were the ATS valve (ATS), the CarboMedics standard valve (CMS), the CarboMedics OptiForm valve (CMO), the On-X valve, and the St Jude valve (SJM). Two aortic mechanical valves, CarboMedics and St Jude Regent valves, were investigated for inverted use. After removing the tissue leaflets, the inner diameter of the Mosaic valve was 3 mm smaller than that of the CEP valve even in the same catalogue labeling size. The outer diameters of the housing of the ATS, CMS, CMO, On-X, and SJM valves of the same catalogue size (25 mm) were 25.7, 25.8, 22.0, 25.0, and 23.2 mm, respectively. SJM and CMO valves are the favorite mechanical valve for the VOV technique in terms of the profile and size-match.

Clinical management of lower limb ischemia secondary to a persistent sciatic artery aneurysm: Report of a case

A persistent sciatic artery (PSA) is a rare congenital malformation, frequently complicated by atherosclerotic changes such as aneurysmal formation. Optimal treatment is dependent on the individual situation. We report a case of a PSA aneurysm complicated by lower limb ischemia. Graft interposition with distal balloon angioplasty and thrombectomy from the posterior transgluteal approach was performed successfully, without any complications.

Quadricuspid aortic valve complicated with infective endocarditis: report of a case

Congenital quadricuspid aortic valve is a rare cardiac malformation with an unknown risk of infective endocarditis. We report a case of quadricuspid aortic valve complicated with infective endocarditis. A 53-year-old Japanese woman was hospitalized with leg edema and a fever of unknown origin. Corynebacterium striatum was detected in the blood culture. Echocardiography demonstrated a quadricuspid aortic valve with vegetation and severe functional regurgitation. The condition was diagnosed as a quadricuspid aortic valve with infective endocarditis, for which surgery was performed. The quadricuspid aortic valve had three equal-sized cusps and one smaller cusp (type B according to Hurwitz classification). We dissected the vegetation and infectious focus and implanted a mechanical valve. Following the case report, we review the literature.

Surgical Treatment of Complications Associated with the Angio-Seal Vascular Closure Device: Report of Three Cases

The Angio-Seal arterial closure device consists of several bioabsorbable components and is used for hemostasis of arterial puncture sites. We report 3 cases of hemorrhagic and ischemic complications related to Angio-Seal use. Two cases were treated successfully by surgical removal of the device. In the third case surgical removal of the device failed and additional intervention was necessary. The unique structure of the Angio-Seal and the most likely cause of failure should be considered when treating device-related complications.

Surgical approach to left subclavian artery aneurysm in Marfan syndrome

We present a case of left subclavian artery aneurysm in a 48-year-old man with Marfan syndrome. Aneurysmectomy and interposition with an artificial graft were successfully performed through an infraclavicular incision by dividing the clavicle at its midshaft. The clavicle bone was reconstructed with a steel plate, and the postoperative course was uneventful. Because the arterial wall is fragile in cases of connective tissue disorders such as Marfan syndrome, our surgical approach was considered to be helpful for gentle maneuvering in an adequate operative field.

Inverted Intercostal Hernia of Soft Tissue Manifested as Slow-Growing Chest Wall Tumor After Thoracotomy

An 80-year-old woman had an asymptomatic chest wall tumor. She had undergone thoracotomy to treat a benign lesion 11 years previously. Chest computed tomography revealed a convex lens-shaped mass 7 cm in diameter in the chest wall. Positron emission tomography demonstrated mild accumulation of F-deoxyglucose. We performed an exploratory thoracotomy; however, no mass lesion was found. Therefore, we thought that the soft tissue of the back was drawn into the pleural cavity through the widened intercostal space during the previous thoracotomy. We simply aligned the ribs using heavy surgical sutures. The patient has experienced good recovery, with no recurrence since the surgery.

Mid-term results of small-sized St. Jude Medical Regent prosthetic valves (21 mm or less) for small aortic annulus

Prosthesis–patient mismatch (PPM) is always of concern when performing aortic valve replacement (AVR) in patients with a small aortic annulus. Although bioprosthetic AVR is preferred in patients older than 65 years, we have experienced cases in elderly patients with a small aortic annulus whereby we could not implant small-sized bioprosthetic valves. We have implanted St. Jude Medical Regent (SJMR) mechanical valves (St. Jude Medical, St. Paul, MN, USA) as necessary, even in elderly patients with no aortic annulus enlargement. We investigated our experiences of AVR with SJMR mechanical valves of 21 mm or less in size. Between January 2006 and December 2009, 40 patients underwent AVR with SJMR mechanical valves ≤21 mm in size: 9 patients received 21-mm valves, 19 received 19-mm valves, and 12 received 17-mm valves. The mean age was 65.9 ± 9.5 years, and 25 patients (62.5 %) were 65 years or older. We evaluated the clinical outcome and the echocardiographic data for each valve size. There was no operative or hospital mortality. The mean duration of clinical follow-up was 31.2 ± 17.6 months. During follow-up, there were no hospitalizations due to heart failure. The cumulative valve-related event-free survival was 93 % at 33 months, and the cumulative hemorrhagic event-free survival was 93 % at 33 months and 84 % at 43 months, using the Kaplan–Meier method. At follow-up, the mean values of the measured effective orifice area (EOA) for the 21-, 19-, and 17-mm prostheses were 2.00 ± 0.22, 1.74 ± 0.37, and 1.25 ± 0.26 cm2, and the mean measured EOA index (EOAI) were 1.17 ± 0.12, 1.11 ± 0.21 and 0.90 ± 0.22 cm2/m2, respectively. A PPM (EOAI ≤0.85) was documented in 5 patients, all of whom had received a 17-mm SJMR valve. AVR with SJMR valves of 21 mm or less in size appears to show satisfactory clinical and hemodynamic results.

Surgical reconstruction for intrathoracic aneurysm originating from proximal part of the right subclavian artery.

Subclavian artery aneurysms are comparatively rare in peripheral aneurysms. We experienced a case of intrathoracic aneurysm originating from the proximal part of the right subclavian artery. A 78 year-old man was referred to our hospital with the diagnosis of a right subclavian artery aneurysm. Enhanced computed tomography demonstrated an intrathoracic aneurysm, originating from the right subclavian artery just proximal of its origin. Through a median sternotomy and supra-infraclavicular incision, we reconstructed the brachiocephalic and right common carotid arteries and bypassed to the distal part of the right subclavian artery by using a T-shaped vascular graft and the aneurysm was excluded.

Thoracic Aortic Aneurysm With Aortic Pseudocoarctation Involving the Left Subclavian Artery

A 39-year-old man with a thoracic aortic aneurysm and pseudocoarctation underwent graft replacement of the distal arch. The left subclavian artery, which rose just after the aneurysm, was also reconstructed at surgery. The aneurysmal wall was extremely thin, and the adventitia and a small amount of medial tissue were found on histologic examination. Thus, surgical treatment was recommended due to risk of rupture. Furthermore, because aneurysms involved the cervical branch, separate reconstruction was also performed. Endovascular intervention is not appropriate for this group of patients because of the complex kinking of the aorta and the extremely thin aneurysmal wall.