A modified technique for supra-annular implantation of prosthetic tricuspid valve.

In conventional tricuspid valve replacement, there is a risk of valve detachment because stitches are placed on relatively fragile tissues. In the supra-annular implantation technique, stitches are placed lateral to the triangle of Koch and the coronary sinus instead of the anterior and septal leaflets as in conventional tricuspid valve replacement. This procedure relieves stress at the antero-septal commissural area, as well as avoids injury to the conduction system. However, there are a few drawbacks: (1) the valve sits obliquely at the annular surface, (2) the suture line becomes extremely long, and (3) the venous return to the coronary sinus may be impeded. We modified the suture line, which travels lateral to the triangle of Koch and medial to the coronary sinus, to solve these problems. We herein report the technique and results of four cases.

[Total Arch Replacement with Frozen Elephant Trunk for Treatment of Traumatic Aortic Injury with Stanford Type A Aortic Dissection].

An 83-year-old woman was injured in a traffic accident. Enhanced computed tomography (CT) showed aortic injury on the isthmus, Stanford type A aortic dissection and intracranial hemorrhage. Neurological deficit was not noted. We immediately started to lower the blood pressure, and her hemodynamic status remained stable. Although intracranial bleeding had not worsened on the next day, a false lumen of the aortic arch was newly enhanced on CT. Emergency total arch replacement with frozen elephant trunk was performed under deep hypothermia and selective cerebral perfusion. Intraoperative angiography showed no endoleak at the descending aorta. Postoperative course was uneventful, and the patient was discharged on the 21st postoperative day. This procedure is useful for aortic injury involving the ascending aorta and the arch.

Migrations and Catalytic Action of Water Molecules in the Ionized Formamide-(H2O)2 Cluster.

Isomerization dynamics involving the migrations, proton transfer reaction, and catalytic actions of water molecules upon vertical ionization of the formamide (FA)-(H2O)2 cluster is investigated by the infrared spectroscopy and theoretical reaction path search calculation. The infrared spectroscopic result indicates the [FA-(H2O)2]+ cation has the hydrogen-bonded structure of the enol isomer cation of formamide and the water dimer. This structure is formed by proton transfer from the CH bond to the carbonyl group through the catalytic action of the water molecules. The isomerization paths involving this enolization in ionized FA-(H2O)2 are explored by using the anharmonic downward distortion following method. We found multiple enolization paths which accompany proton exchanges among the formamide moiety and water molecules through the catalytic actions of the water molecules.

Saphenous Vein Graft Aneurysm Repaired with Radial Artery Graft Pre-Sewn Vascular Prosthesis Patch.

Saphenous vein graft aneurysms are rare but are potentially fatal and their optimal management is not clearly established. Herein, we report a case of a saphenous vein graft aneurysm that was successfully treated with surgical intervention, including aneurysmal resection and re-grafting. The aneurysm, detected 36 years after coronary artery bypass grafting, was located at the proximal part of the saphenous vein graft to the posterolateral branch; the flow of the left anterior descending coronary artery was limited due to compression of the left internal thoracic artery by the adjacent aneurysm. The proximal anastomotic site was reconstructed under deep hypothermic circulatory arrest using a radial artery graft pre-sewn vascular prosthesis patch.

Implementation of bundled interventions greatly decreases deep sternal wound infection following cardiovascular surgery.

OBJECTIVE: Surgical site infection (SSI), particularly deep sternal wound infection (DSWI), is a serious complication after cardiovascular surgery because of its high mortality rate. We evaluated the effectiveness of an SSI bundle to reduce DSWI and identify the risk factors for DSWI. METHODS: During the period January 2004 to February 2012, 1374 consecutive patients undergoing cardiovascular surgery via sternotomy were included. The cohort was separated into periods from January 2004 through February 2007 (period I, 682 patients) and March 2007 through February 2012 (period II, 692 patients). During period II, all preventive measures for DSWI were completed as an SSI bundle. We compared the DSWI rate between the 2 periods. Univariate and multivariate analyses were performed for the entire period to identify the risk factors for DSWI. RESULTS: DSWI occurred in 13 patients (1.9%) during period I and in 1 patient (0.14%) during period II. The DSWI rate during period II was significantly decreased by 93%, compared with period I (P=.001). Independent risk factors for DSWI included obesity (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.00-11.75; P=.049), the use of 4 sternal wires (OR, 8.2; 95% CI, 1.39-48.14; P=.020), long operative time (OR, 4.4; 95% CI, 1.20-16.23; P=.026), and postoperative renal failure (OR, 9.0; 95% CI, 2.44-33.30; P=.001). CONCLUSIONS: Complete implementation of simple multidisciplinary prevention measures as a bundle can greatly decrease the incidence of DSWI.

Retrograde cardioplegia revisited: open technique for long aortic cross clamping.

BACKGROUND: The efficacy of retrograde cardioplegia for myocardial protection is still controversial. In our institution, we exclusively use intermittent administration of tepid, undiluted blood supplemented with potassium and magnesium for the cases with aortic insufficiency, requiring aortotomy, or undergoing mitral valve repair. In using this retrograde technique, we make a point of cannulating a retrograde perfusion catheter under direct vision following right atriotomy. The purpose of this retrospective study is to evaluate the clinical outcome of using this technique. METHODS: This study comprises 49 patients who underwent elective valve surgery using direct-vision retrograde cardioplegia exclusively, requiring more than 3h aortic cross-clamping. Their clinical outcome was reviewed retrospectively. RESULTS: There was no hospital mortality in this study. No patient was noted to have evidence of mediastinitis, myocardial infarction, or cerebral complications in the postoperative period. The case requiring the longest aortic cross-clamping time (380 min) survived the operation without the use of intra-aortic balloon pumping or percutaneous cardiopulmonary support, and the postoperative course was uneventful. CONCLUSIONS: Our result suggests that direct-vision retrograde cardioplegia is a safe and effective method of cardioplegia delivery, and provides a longer period of myocardial protection than previously thought.

[Surgical strategy for mitral regurgitation in ischemic cardiomyopathy].

OBJECTIVE: Surgical strategy for the mitral regurgitation (MR) in patients with ischemic cardiomyopathy (ICM) still remains controversial. The purpose of this study is to evaluate the operative outcome and long-term survival in patients with ICM, MR. METHODS: Perioperative data and surgical results of 35 patients with ischemic MR were collected. Mitral annuloplasty with artificial ring (MAP) was performed in 27 patients and mitral valve replacement (MVR) in 8 patients. Preoperative left ventricular ejection fraction (LVEF) in MVR was significantly lower (23.1 +/- 11.8 : 33.4 +/- 10.3%, p < 0.05) and the left ventricular diastolic dimension (LVDd) was dilated (73.7 +/- 9.3: 64.2 +/- 7.0 mm, p < 0.01). Concomitant procedures including coronary artery bypass grafting and/or left ventricular reconstruction were performed in more than half patients. RESULTS: No operative death was observed in both groups. Postoperative data showed that MVR still remained in low left ventricular (LV) function. Six of 27 patients in MAP developed more than grade 2 MR during follow up period and 1 required reoperation. No significant difference was observed in survival and in freedom rate from cardiac event between groups. CONCLUSIONS: MAP had no impact on operative outcome and long-term survival in patients with ICM, MR. MVR should be considered in patients with severely impaired LV function to avoid the risk of recurrence of MR.

Pathogenesis of paravalvular leakage as a complication occurring in the late phase after surgery.

Paravalvular leakage (PVL) remains an unavoidable late complication after valve surgery. We indicate surgery only cases with progressive congestive heart failure and/or hemolytic anemia. We review our clinical experiences of PVL surgery. Between 1992 and 2009 we experienced 8 cases of aortic PVL-6 subjects after primary aortic valve replacement (AVR) and 2 subjects after re-AVR-and 10 subjects with mitral PVL-5 cases after primary mitral valve replacement (MVR) and 5 cases after re-MVR. Mitral PVL began in the later phases after surgery and had more severe symptoms, because of heart failure and/or hemolytic anemia, than aortic PVL. Aortic PVL occurred more frequently because of laxation of sutured threads without frequent sites. Conversely, mitral PVL was mainly caused by cutting annulus tissue around the anterior commisurae after primary MVR, and by a valve-on-valve structure on the middle scallop of the posterior leaflet or circumferentially after re-MVR. All operations were performed safely and all patients were discharged uneventfully. No cases experienced recurrence of PVL in the follow-up period. The symptoms of PVL became exacerbated, and our surgical indications based on these symptoms were validated. Valve-on-valve replacement, which was a major cause of PVL after re-MVR, should be avoided in a re-MVR procedure. Cautious follow-up is necessary, even in the late phase after surgery, especially for patients who have undergone MVR.

Long-range migration of a water molecule to catalyze a tautomerization in photoionization of the hydrated formamide cluster.

The dynamics on the vacuum-ultraviolet one-photon ionization of a formamide-water cluster is investigated by a combination of theoretical reaction-path search and infrared spectroscopic methods. A keto-enol tautomerization of the formamide moiety occurs after photoionization by a catalytic action of the water molecule accompanied with its long-distance migration; the water molecule in the cluster migrates almost one turn around the formamide moiety. During the migration, the water molecule abstracts the proton of CH in the formamide moiety and carries it to the O atom side in the carbonyl group through a "catch and release"-type catalytic action.

[Comparative study between cryoablation and radiofrequency ablation for surgical intervention of atrial fibrillation associated with mitral valve disease].

OBJECTIVES: Recently, bipolar radiofrequency (RF) ablation has been introduced as a potential option to replace many of the Cox-maze incisions. We compared the surgical outcomes of maze procedures in patients who had undergone cryoablation and RF ablation and mitral valve surgery. METHODS: From January 2004 to August 2009, a total of 40 patients underwent the maze procedure and concomitant mitral operation as a 1st operation. Of these, the cryoablation maze procedure (n = 20) and RF ablation procedure (n = 20) were performed in the patients with similar background, although more patients in the RF group had undergone mitral valve repair (n = 15) compared to the cryoablation group (n = 8) [p = 0.025]. RESULTS: The peri-operative data, such as operative duration, cardiopulmonary bypass time, aortic cross-clamp time, postoperative ventilation time, and the duration of intensive care unit (ICU) stay did not show any significant difference between cryoablation group and RF group. Both ablation procedures were similarly effective in restoring sinus rhythm at the early post-operative period (cryoablation: 80%, RF: 70%). Nine patients in the cryoablation group and 13 patients in the RF ablation group required anti-arrhythmic medication. CONCLUSIONS: The RF ablation technique is simpler and equally effective in controlling atrial fibrillation compared to the cryoablation for the maze procedure of concomitant mitral valve surgery.

On-pump beating-heart coronary artery bypass: a propensity matched analysis.

BACKGROUND: It remains unclear how cardioplegic arrest affects surgical results after coronary artery bypass grafting surgery (CABG). This study compares early outcomes after on-pump beating-heart CABG and conventional CABG. METHODS: From 2002 to 2005, 114 patients underwent on-pump beating-heart CABG. Multivariate logistic regression revealed five characteristics according to which technique is liable to be used: history of cerebral infarction, urgent or emergent operation, lower ejection fraction, preoperative creatine kinase, and lower number of diseased vessels. The early clinical outcome for these patients was compared against 114 conventional CABG patients, matched using a propensity score constructed with these five significant variables and with two nonsignificant variables: history of diabetes mellitus and hypertension. RESULTS: On-pump beating-heart CABG significantly reduced the duration of operation and cardiopulmonary bypass, total blood loss, and peak creatine kinase (p < 0.05). The number of patients requiring additional intra-aortic balloon pump support was significantly lower in the on-pump beating-heart CABG group (2 versus 13, p < 0.01). No patients required percutaneous cardiopulmonary support after on-pump beating-heart CABG, whereas 4 patients needed it after conventional CABG. Complete revascularization was significantly lower (42.1% versus 77.2%, p < 0.0001), but in-hospital mortality was less in the on-pump beating-heart CABG group (2.6% versus 9.6%, p < 0.05). No significant difference was found in morbidity including stroke, renal failure, mediastinitis, and prolonged ventilation. CONCLUSIONS: On-pump beating-heart CABG can be performed safely, including on high-risk patients. Use of cardiopulmonary bypass and the elimination of cardioplegic arrest may be of most benefit to hemodynamically unstable patients.

Hyperkalemic cardioplegia-induced myocyte swelling and contractile dysfunction: prevention by diazoxide.

BACKGROUND: Hyperkalemic cardioplegia (9 degrees C) results in significant myocyte swelling and reduced contractility, representing a possible mechanism of myocardial stunning. Adenosine triphosphate-sensitive potassium channel (KATP) openers have been shown to ameliorate stunning. This study evaluated the hypothesis that a KATP opener would prevent hyperkalemic cardioplegia-induced myocyte swelling and reduced contractility. METHODS: Isolated rabbit myocytes were perfused with 37 degrees C Tyrode's solution for 20 minutes, followed by test solution (9 degrees C or 37 degrees C) including control Tyrode's, Tyrode's + 100 micromol/L diazoxide (KATP opener), St. Thomas's solution; or 9 degrees C St. Thomas's + 100 micromol/L diazoxide or St. Thomas's + 100 micromol/L diazoxide + 20 micromol/L HMR1098 or 50 micromol/L 5-hydroxydeconoate (KATP blockers) for 20 minutes (n = 8 per group). Myocytes were then reexposed to 37 degrees C Tyrode's solution for 20 minutes. Volume and contractility were measured by videomicroscopy and video-based edge detection, respectively. RESULTS: St. Thomas's solution (9 degrees C) caused significant myocyte swelling and associated reduced contractility (p < 0.05). The addition of diazoxide abolished myocyte swelling (p < 0.0001), and eliminated the associated reduced contractility (p < 0.05). Findings were unchanged by the addition of HMR 1098 and 5-hydroxydeconoate. CONCLUSIONS: Diazoxide prevented myocyte swelling and reduced contractility secondary to hyperkalemic cardioplegia, and this was unchanged by the addition of either KATP channel blocker. Prevention of myocyte swelling was associated with improved contractility, consistent with the hypothesis that myocyte swelling may be a mechanism of myocardial stunning. Diazoxide may play a role in myocyte volume homeostasis by means of a mechanism separate from opening the KATP channel.

Progress towards a more physiologic approach to donor heart preservation: the advantages of hyperpolarized arrest.

BACKGROUND: The University of Wisconsin (UW) solution is the gold standard for heart preservation but has limitations in terms of both duration and adequacy of protection. Our laboratory has been interested in a more physiologic approach to heart preservation by maintaining the heart at its resting membrane potential (hyperpolarized arrest) with the K(ATP) channel agonist pinacidil. This study compared our extracellular solution (WashU) with the UW intracellular depolarizing solution and quantified the protective effect of pinacidil in both solutions. METHODS: Thirty-two rabbit hearts received 1 of 4 solutions in a crystalloid-perfused Langendorff apparatus: (1) UW, (2) WashU containing 0.5 mmol/liter pinacidil, (3) UW with 0.5 mmol/liter pinacidil, or (4) WashU without pinacidil. Thirty minutes of perfusion was followed by data acquisition consisting of left ventricular pressure-volume curves generated by inflating an intraventricular balloon. All hearts were placed in cold storage for 8 hours, followed by 1 hour of reperfusion before data acquisition. RESULTS: Post-ischemic developed pressure (DP) was better preserved by WashU (76.8% +/- 3.8%) than by UW (48.3% +/- 2.5%). Diastolic compliance was better preserved by WashU (239.9% +/- 77.2%) compared with UW (711.1% +/- 193.1%). Removing pinacidil from our solution resulted in decreased DP (46.6% +/- 3.2%) and diastolic compliance (688.8% +/- 158.2%) Adding pinacidil to UW had a limited effect on DP and compliance. CONCLUSIONS: Our results support the superiority of the WashU hyperpolarizing solution for heart preservation over UW. Pinacidil was beneficial in maintaining cardiac function and compliance. This benefit was not observed when pinacidil was placed into the UW depolarizing solution.

Myocyte volume and function in response to osmotic stress: observations in the presence of an adenosine triphosphate-sensitive potassium channel opener.

BACKGROUND: Hypothermic hyperkalemic cardioplegia results in significant myocyte swelling and impaired contractility. These detrimental effects may be eliminated by the addition of an adenosine triphosphate-sensitive potassium (KATP) channel opener. This study evaluated the hypothesis that a KATP channel opener (diazoxide) would benefit volume homeostasis by limiting volume and subsequent contractility changes during osmotic stress. METHODS AND RESULTS: Isolated rabbit ventricular myocyte volume and contractility were evaluated using video microscopy and field stimulation after exposure to osmotic stress at 37 degrees C. Myocytes were exposed to Tyrode's physiological solution for 20 minutes and test solution for 20 minutes, and then reexposed to Tyrode's for 20 minutes. Test solutions included control Tyrode's (1T) and osmotically altered Tyrode's (2.6T, 0.9T, and 0.6T) solutions with or without the KATP channel opener diazoxide. Severe osmotic stress (2.6T and 0.6T) resulted in significant cell shrinkage and swelling, respectively. This was unchanged by the addition of diazoxide. Mild hyposmotic stress (0.9T) resulted in significant cell swelling that was eliminated by the addition of diazoxide. Cell swelling was associated with reduced contractility. CONCLUSIONS: Cell swelling, but not shrinkage, was detrimental to myocyte contractility. Diazoxide eliminated volume change due to mild hyposmotic stress, similar to that previously noted with hyperkalemic cardioplegia, but did not alter volume change secondary to severe osmotic stress.

Management of intraoperative aortic dissection with a direct cannulation on the intimal flap.

We report a case of severe aortic stenosis in which intraoperative aortic dissection developed from aortic cross-clamp. The patient showed symptoms of malperfusion, but was successfully managed by direct inflow cannulation on the intimal flap into the true lumen. She then recovered well without further incident.

The value of caval division in the maze procedure with valve surgery.

Operative predictors for successful elimination of atrial fibrillation (AF) following the maze procedure are not yet known. We have often divided the superior vena cava (SVC) during the maze procedure, not to eliminate AF but in order to explore the mitral valve. However, in multivariate analysis of 79 patients, the division of SVC, as well as the duration of AF, was found to be the strongest predictor of AF elimination. The explanation of this observation is not clear, but denervation of the cardiac autonomic nervous system or the existence of paroxysmal AF originating from the SVC could be involved.

Optimal size of prostheses for functioning of the aortic prosthetic valve in aortic and mitral valve replacement with annular enlargement through Manouguian's technique.

There is not yet agreement about the optimal size of the prostheses in aortic and mitral valve replacement with Manouguian's technique. In this technique, the aortic prosthetic valve can be pushed upon the mitral prosthesis which may cause dysfunction of the aortic prosthetic valve. The aim of this study was to clarify the size of the prostheses needed to avoid dysfunction of the aortic prosthetic valve. Three patients underwent aortic and mitral valve replacement through this procedure. Two of them had active aortic and mitral valve endocarditis. Aortomitral continuity involved with abscesses could be approached and completely excised using this technique. All patients survived the operation, but 1 of them suffered aortic mechanical valve dysfunction for the reason stated. Anatomical analysis of the geometrical relation of the 2 prosthetic valves suggests that the mitral annulus should be enlarged less than 25 mm to avoid dysfunction of the aortic prosthetic valve.

Repetitive atrial flutter as a complication of the left-sided simple maze procedure.

BACKGROUND: Of 41 patients who had undergone a left-sided simple maze procedure, 4 (9.8%) developed repetitive tachycardia due to atrial flutter, and required radiofrequency catheter ablation. Linear ablation of the right atrial isthmus was effective to treat atrial flutter. METHODS: We conducted an electrophysiologic study of atrial flutter and determined its reentry circuit on the atrium. We consider how to reduce atrial flutter after the left-sided simple maze procedure. RESULTS: Common atrial flutter through the right atrial isthmus was induced in all 4 patients, and linear ablation on the right atrial isthmus was effective in 3 of these. An incisional atrial flutter around the right atriotomy was also induced in 2 of 4 patients; both were successfully treated by linear ablation between the right atriotomy and the inferior vena cava. CONCLUSIONS: Common atrial flutter through the right atrial isthmus is a risk after the left-sided simple maze procedure. When a left-sided simple maze procedure is performed, sufficient cryoablation on the right atrial isthmus of the arrested heart should be administered to prevent postoperative atrial flutter.