Outcomes After Aortic Valve Replacement for Asymptomatic Severe Aortic Regurgitation and Normal Ejection Fraction.

We investigated long-term outcomes following aortic valve replacement (AVR) in asymptomatic patients with severe aortic regurgitation (AR) and normal left ventricular (LV) function. We reviewed 268 patients who underwent isolated AVR for chronic severe AR from 1991 to 2010 and enrolled 162 asymptomatic patients with normal LV ejection fraction (≥50%) preoperatively. They were divided into 2 groups according to LV dimension at surgery, the early stage C group (indexed LV end-systolic diameter ≤25 mm/m2 and LV end-diastolic diameter ≤65 mm, n = 61), and late stage C group (indexed LV end-systolic diameter >25 mm/m2 and/or LV end-diastolic diameter >65 mm, n = 101). Survival was compared with that of an age- and gender-matched Japanese general population using a one-sample log-rank test. Subgroup analysis was performed for patients who survived >10 years after AVR. The mean age of all patients was 59 ± 14 years and mean follow-up period was 10 ± 5 years. Survival after AVR for the early and late stage C groups was not statistically different (P = 0.57). Furthermore, survival for both groups was not statistically different from that of the general population (early stage C, P = 0.63; late stage C, P = 0.14). However, subgroup analysis showed that survival >10 years after AVR was significantly worse for the late stage C group as compared to that of the general population (P < 0.001). Long-term survival following AVR for asymptomatic AR with normal LV ejection fraction was excellent. However, survival more than 10 years after surgery might be dependent on LV dimension at surgery.

Intermediate-term outcomes of our original multiple-knot technique using ePTFE sutures for anterior mitral leaflet prolapse.

PURPOSE: To define the outcomes of our original simple chordal replacement technique using ePTFE sutures for mitral regurgitation. METHODS: Between January, 2004 and March, 2014, 38 patients underwent mitral valve repair using our chordal replacement technique for anterior leaflet prolapse. The mitral regurgitation was caused by degenerative disease in 34 patients and infective endocarditis in 4 patients. RESULTS: The follow-up period was 66 ± 37 months and the 5-year survival rate was 95 ± 4%. Two patients had recurrent mitral regurgitation, caused by degenerative change not associated with the procedure. The 5-year rate of freedom from recurrent mitral regurgitation was 94 ± 4%. In the late postoperative period, 15 (42%) patients had a mean pressure gradient > 5 mmHg. Stepwise logistic regression analysis showed that the use of a full ring (odds ratio 8.9; 95% confidence interval 1.2-64; p = 0.031) and a 26 mm annuloplasty (odds ratio 7.5; 95% confidence interval 1.1-50; p = 0.037) were significant independent risk factors for a mean pressure gradient > 5 mmHg. CONCLUSION: The intermediate-term outcomes of our original chordal replacement technique were not inferior to those in previous reports, although a 26 mm annuloplasty was found to be associated with a higher mitral valve gradient at rest.

Beneficial effects of restrictive annuloplasty on subvalvular geometry in patients with functional mitral regurgitation and advanced cardiomyopathy.

OBJECTIVES: The effects of restrictive mitral annuloplasty (RMA) on subvalvular geometry remains unknown. We evaluated changes in left ventricular (LV) function, severity of mitral regurgitation (MR), and leaflet tethering parameters after RMA and clarified their associations. METHODS: In 44 patients with clinically relevant functional MR who underwent RMA, distances between papillary muscle (PM) tips and anterior mitral annulus (PM tethering distance), leaflet angles relative to lines connecting annuli, and interpapillary muscle distance (IPMD) were serially quantified. RESULTS: One month after surgery, LV function and MR severity improved with decreased anterior (34 ± 5 to 30 ± 4 mm) and posterior PM tethering distance (37 ± 4 to 32 ± 4 mm), anterior leaflet angle (32 ± 8° to 22 ± 7°), and IPMD (31 ± 6 to 25 ± 5 mm), whereas these variables remained abnormal and posterior leaflet angle increased (34 ± 8° to 48 ± 14°; P < .01 for all). During follow-up (66 ± 37 months), these effects were maintained in 33 patients without MR recurrence, whereas 11 with it showed worsened tethering with less LV function recovery. Multiple linear regression analyses identified that change in MR severity from baseline to 12-month examination independently associated with corresponding change in IPMD (parameter estimate of 0.100 with standard error of 0.039; P = .019) and that in posterior PM tethering distance (parameter estimate of -0.104 with standard error of 0.045; P = .035), whereas not with change in posterior-leaflet angle. The IPMD change was independently associated with change in LV end-systolic dimension (parameter estimate of 0.299 with standard error of 0.110; P = .013). CONCLUSIONS: The RMA procedure partially relieved leaflet tethering, evidenced by decreased tethering distances and IPMD; the latter was the main determinant of MR. These beneficial effects might be mainly attributed to post-RMA reverse LV remodeling, potentially offsetting the negative effect of augmented posterior leaflet angle in selected patients.

Complete removal of infected devices and simultaneous implantation of new devices for infective endocarditis after pacemaker implantation.

Two cases of infective endocarditis after pacemaker implantation were reported. Complete removal of infected devices was performed under cardiopulmonary bypass, and simultaneous implantation of new devices was performed using epicardial leads and generator on the abdominal wall. The postoperative course was uneventful and recurrence was not recognized. These procedures may be suitable for the patients who depend on the pacemaker or who have repeat bacteremia with other infectious disease or conditions.

[Papillary fibroelastoma derived from the left ventricular wall just under the mitral leaflet; report of a case].

A 74-year-old male was referred to our department due to a mobile solid mass of 10 mm in diameter on the left ventricular interior wall just below the posterior leaflet of the mitral valve. Mild mitral regurgitation and moderate tricuspid regurgitation were also detected. A high serum level of IL-6 was detected(33.0 pg/ml), and myxoma was suspected. The tumor, which was bright yellowish brown with a partly jelly-like surface, was successfully removed surgically through the mitral valve under cardiopulmonary bypass. Pathological findings of the mass was papillary fibroelastoma. Papillary fibroelastoma derived from the left ventricular wall is very rare.

Impact of Subxiphoid Video Pericardioscopy with a Rigid Shaft on Cardiac Hemodynamics in a Porcine Model.

OBJECTIVE: Single-port subxiphoid videopericardioscopy with a rigid shaft is useful for left atrial exclusion, left ventricular pacing lead implantation, and epicardial mapping, but it may interfere with the cardiac rhythm and adversely alter hemodynamics. We examined the impact of this technique on hemodynamic indices in a porcine model. METHODS: The videopericardioscopy device was introduced into the pericardial space of 5 pigs (35-45 kg) via a subxiphoid approach and navigated to 6 anatomical targets (right atrial appendage, superior vena cava, ascending aorta, left atrial appendage (anterior and posterior approaches), transverse sinus, and atrioventricular groove). After successful target acquisition, the device was withdrawn through the subxiphoid port. When the hemodynamics stabilized, the device was navigated to another target. The heart rate, arterial blood pressure, central venous pressure, pulmonary arterial pressure, and mixed venous oxygen saturation were measured at every pre-target (subxiphoid incision) and target point. After the navigation trials, the animals were sacrificed and the mediastinum space was examined for procedure-related injuries. RESULTS: The device afforded a good view, and the navigation trials were successfully performed on the beating heart. Four animals tolerated the procedures, while 1 died of device-induced ventricular fibrillation after the trials. Hemodynamics were severely compromised at all anatomical targets except the left atrial appendage (anterior approach). CONCLUSIONS: Subxiphoid videopericardioscopy significantly interferes with the cardiac rhythm, causing life-threatening arrhythmia and hemodynamic compromise, when the target is located deep and far from the pericardiotomy. A flexible or highly articulated device would enable intrapericardial navigation without hemodynamic compromise.

Newly developed tissue-engineered material for reconstruction of vascular wall without cell seeding.

BACKGROUND: We have developed a tissue-engineered patch for cardiovascular repair. Tissue-engineered patches facilitated site-specific in situ recellularization and required no pretreatment with cell seeding. This study evaluated the patches implanted into canine pulmonary arteries. METHODS: Tissue-engineered patches are biodegradable sheets woven with double-layer fibers. The fiber is composed of polyglycolic acid and poly-L-lactic acid, and compounding collagen microsponges. The patches (20- x 25-mm) were implanted into the canine pulmonary arterial trunks. At 1, 2, and 6 months after implantation (n = 4), they were explanted and characterized by histologic and biochemical analyses. Commercially available patches served as the control. No anticoagulant therapy was administered postoperatively. RESULTS: No aneurysm or thrombus was present within the patch area in all groups. The remodeled tissue predominantly consisted of elastic and collagen fibers, and the endoluminal surface was covered with a monolayer of endothelial cells and multilayers of smooth muscle cells beneath the endothelial layer. The elastic and collagen fibers and smooth muscle cells kept increasing with a maximum at 6 months, while a monolayer of endothelial cells was preserved. The expression levels of messenger RNA of several growth factors in the tissue-engineered patches were higher than those of native tissue at 1 and 2 months and decreased to normal level at 6 months. No regenerated tissue was found on the endoluminal surface in the control group. CONCLUSIONS: The novel tissue-engineered patches showed in situ repopulation of host cells without prior ex vivo cell seeding. This is promising material for repair of the cardiovascular system.

Modified maze procedure combined with mitral valve surgery via septal-superior approach.

Although a septal-superior approach provides excellent exposure of the mitral valve, it requires novel strategies for concomitant ablation in patients with atrial fibrillation. Utilizing a combination of bipolar radiofrequency and cryothermy, we developed a novel technique for creating a biatrial lesion set via a septal-superior approach during mitral valve surgery. We treated 10 patients with functional mitral regurgitation and permanent atrial fibrillation with rhythm disturbance for a mean 87 months. A modified maze was successfully accomplished via a septal-superior approach in all. The mean follow-up period was 18 months, during which permanent pacemaker implantation was necessary for one due to sinus bradycardia. Sustained sinus rhythm, including atrial or atrial-based paced rhythm, was present in all immediately after surgery, in 70% at discharge, in 80% at 1 year after surgery, and in 90% at the latest follow-up examination. Our novel technique using a modified maze procedure in combination with mitral valve surgery via a septal-superior approach was safe and useful for eliminating atrial fibrillation, with a relatively low frequency of sinus node dysfunction.

In situ tissue regeneration using a novel tissue-engineered, small-caliber vascular graft without cell seeding.

OBJECTIVE: Various types of natural and synthetic scaffolds with arterial tissue cells or differentiated stem cells have recently attracted interest as potential small-caliber vascular grafts. It was thought that the synthetic graft with the potential to promote autologous tissue regeneration without any seeding would be more practical than a seeded graft. In this study, we investigated in situ tissue regeneration in small-diameter arteries using a novel tissue-engineered biodegradable vascular graft that did not require ex vivo cell seeding. METHODS: Small-caliber vascular grafts (4 mm in diameter) were fabricated by compounding a collagen microsponge with a biodegradable woven polymer tube that was constructed in a plain weave pattern with a double layer of polyglycolic acid (core) and poly-L-lactic acid (sheath) fibers. We implanted these tissue-engineered vascular grafts bilaterally into the carotid arteries of mongrel dogs (body weight, 20-25 kg). No anticoagulation regimen was used after implantation. We sacrificed the dogs 2, 4, 6, and 12 months (n = 4 in each group) after implantation and evaluated the explants histologically and biochemically. RESULTS: All of the tissue-engineered vascular grafts were patent with no signs of thrombosis or aneurysm at any time. Histologic and biochemical examinations showed excellent in situ tissue regeneration with an endothelial cell monolayer, smooth muscle cells, and a reconstructed vessel wall with elastin and collagen fibers. CONCLUSION: Our study indicated that this novel tissue-engineered vascular graft promoted in situ tissue regeneration and did not require ex vivo cell seeding, thereby conferring better patency on small-caliber vascular prostheses.

Novel technique for reimplantation of intercostal arteries using tailored patch graft.

We developed a simple and secure technique for reimplantation of the intercostal arteries (ICAs) using a patch graft during thoracoabdominal aneurysm repair. With our procedure, a sidearm branch with its base is tailored from a 24 mm one-branch Dacron graft, and then sutured as a patch graft to the trimmed wall of the descending aorta to cover the ICA orifices between Th9 and Th12. The proximal end of the patch graft is then anastomosed to the main tube graft, while the graft is perfused. With this technique, the entire suture lines are clearly visible and hemostasis is secured without difficulty. We used this technique in 6 patients, in whom 2.3+/-0.8 pairs of ICAs were reimplanted. The time required for reimplantation of the ICAs was 14+/-6 min and none of 6 patients developed paraplegia. Our results indicate that this novel technique is a simple method to obtain secure hemostasis under direct vision, which may contribute to reduce the risk of paraplegia during thoracoabdominal aneurysm repair.

[A case of peritoneal metastasis of gastric cancer responding to TS-1, administered for four consecutive weeks with two-week rests].

We treated a patient with gastric cancer considered to be unresectable due to peritoneal metastasis, who responded remarkably to treatment with TS-1. The patient was a 62-year-old male. His diagnosis was gastric cancer, for which he underwent surgery on February 22, 2001. Laparotomy disclosed many nodules measuring 2-3 mm in diameter in the abdominal cavity, so rapid pathological tests were conducted during the operation. The test results indicated peritoneal metastasis from gastric cancer. Therefore, simple laparotomy was employed as the best option. On day 13 after surgery, oral administration of TS-1, bid., at a daily dose of 120 mg was commenced. In our outpatient clinic, he was given 3 courses, each comprising 4 weeks' medication and 2 weeks' discontinuation. Subsequently, upper digestive tract endoscopy was performed but only scars in the gastric vestibular area were observed. Biopsy could not detect any malignant findings. Medication was discontinued due to the patient's preference and he died of gastric cancer 10 months after operation.

Usefulness of continuous air tonometry for evaluation of splanchnic perfusion during cardiopulmonary bypass.

Although gastric mucosal tonometry has been reported as a useful method to assess splanchnic perfusion during cardiovascular surgery, the conventional discontinuous method of tonometry (saline tonometry) was cumbersome and prone to systematic errors. A new automated system of air tonometry (Tonocap; Datex Ohmeda, Helsinki, Finland) allows for frequent (every 10 minutes) measurement of gastric regional CO2 (PrCO2) and may be more suitable as a monitoring system in cardiac patients. We evaluated the usefulness of continuous air tonometry as a marker of splanchnic perfusion during cardiopulmonary bypass (CPB). In 19 patients (53-79 years, mean 63 years) who underwent cardiovascular surgery under standard CPB with mild hypothermia (32 degrees C) from January 2001 to May 2002, the PrCO2 and calculated intramucosal pH (pHi) of gastric tonometry was monitored using Tonocap, and their relation to postoperative visceral organ function was evaluated. The pHi significantly increased after initiation of CPB from 7.32 +/- 0.07 to 7.43 +/- 0.10 (p < 0.05) and then consistently decreased in all patients to 7.39 +/- 0.09 at the end of CPB. The value of PrCO2 significantly (p < 0.01) correlated with the value of pHi. The lowest value of pHi during CPB was significantly related to blood urea nitrogen (r = -0.75, p < 0.05), serum creatinine (r = -0.78, p < 0.05), creatinine clearance (r = 0.68, p < 0.05) on postoperative day 1, and blood urea nitrogen (r = -0.84, p < 0.01) on day 3. In contrast, arterial blood lactate level, venous oxygen saturation, and routinely measured hemodynamics (e.g., pump flow, arterial pressure) during CPB were unrelated to the postoperative visceral organ function. These results suggest that continuous monitoring of gastric regional CO2 and pHi by air tonometry system is useful for the evaluation of splanchnic perfusion during CPB and may contribute to improve CPB technique by allowing the early detection of visceral malperfusion.

An alternative approach using long elephant trunk for extensive aortic aneurysm: elephant trunk anastomosis at the base of the innominate artery.

BACKGROUND: Although a staged elephant trunk procedure has been widely used, the early mortality of the first stage operation as well as the interval mortality between operations remains unsatisfactory. We developed an alternative elephant trunk procedure to reduce mortality and morbidity. METHODS AND RESULTS: Ascending aorta and arch vessels were minimally dissected. During systemic cooling, a four-branched arch graft with a sewing "collar" and a long "elephant trunk" was prepared. The ascending aorta was opened under selective brain perfusion with moderate hypothermia (25 degrees C), and the elephant trunk was then pulled down into the descending aorta using the catching catheter introduced via a femoral artery. The elephant trunk anastomosis using the collar was made at the base of the innominate artery. The arch vessels were divided and closed at aortic stump, and grafted separately as a consequence of the very proximal site for the elephant trunk anastomosis. Between October 1998 and September 2001, 17 patients, ranging in age from 25 to 79 years (mean 67 years) with extensive aortic aneurysm underwent this operation. Preoperative cardiac complications included coronary artery disease in 5, aortic regurgitation in 3, and 3 of these 8 patients had poor left ventricular function with an ejection fraction less than 40%. Nine patients underwent a second stage operation, in 1 of them the permanent elephant trunk procedure was initially attempted but the second stage procedure was done because of increasing endo-leakage. The mean interval between operations was 8 days (range 1 to 14 days) in the remaining 8 patients. In 5 of 6 patients who underwent the permanent elephant trunk procedure, a decrease in the size of the aneurysm based on thromboexclusion was observed using serial computed tomography scans. A single stage repair was performed in 1 patient. The 30-day survival rate of all operations was 100%, however, there was 1 in-hospital death (6%) after the second operation. There was no stroke, however, paraplegia occurred after the first operation in 1 patient (6%) of the in-hospital death. No new phrenic or recurrent laryngeal nerve palsy occurred as a result of surgery. CONCLUSIONS: The present technique using a modification of the elephant trunk technique for extensive aortic aneurysm provides acceptable mortality and morbidity. The present strategy would be an alternative for the standard elephant trunk procedure in some high-risk patients with advanced age and comorbidities.