Relationship between fragmented QRS complex and early left ventricular dysfunction after mitral valve repair.

BACKGROUND: Preoperative left ventricular (LV) ejection fraction (PreLVEF) and preoperative LV end-systolic diameter (PreESD) are known predictors for postoperative LV dysfunction after mitral valve repair (MVR). Fragmented QRS (fQRS) evaluated in 12-derivation electrocardiography has widely been accepted as a sign of myocardial fibrosis. In the present study, we aimed to evaluate the relationship between fQRS in preoperative 12­lead electrocardiography (ECG) and postoperative LV dysfunction that develop after MVR in patients with severe primary mitral regurgitation (MR) due to mitral valve prolapse (MVP). METHODS: From 2019 to 2022, 49 patients who had undergone successful MVR surgery for severeMR caused by MVP were enrolled in the study. The preoperative and postoperative echocardiographic data were collected retrospectively. We analyzed the demographic, echocardiographic, operative and postoperative parameters to assess the relationship between fQRS and early postoperative LV dysfunction, defined as an LVEF<60%. RESULTS: PreLVEF of all patients were ≥ %65. A total of 22 patients had fQRS (44.9%) and postoperative LV dysfunction was found to be 36.7%. A significantly higher rate of fQRS was observed in the group with postoperative LV dysfunction compared to the group without (12 (66.7%) vs 10 (32.3%), p: 0.036). In multivariate analysis for fQRS, PreESD, preoperative pulmonary artery systolic pressure (PrePASP), preoperative atrial fibrillation (PreAF), and male gender, only fQRS was found to be a significant predictor of postoperative LV dysfunction (p: 0.003, OR: 4.28, 95% CI (1.15-15.96). CONCLUSION: fQRS was found to be a predictor of postoperative LV dysfunction in the early period after MVR. fQRS may be a readily available and cost-effective test that can be used in clinical practice to predict postoperative LV dysfunction in patients undergoing MVR.

Quasi-static and dynamic Brazilian testing and failure analysis of a deer antler in the transverse to the osteon growth direction.

The transverse tensile strength of a naturally fallen red deer antler (Cervus Elaphus) was determined through indirect Brazilian tests using dry disc-shape specimens at quasi-static and high strain rates. Dynamic Brazilian tests were performed in a compression Split-Hopkinson Pressure Bar. Quasi-static tensile and indirect Brazilian tests were also performed along the osteon growth direction for comparison. The quasi-static transverse tensile strength ranged 31.5-44.5 MPa. The strength increased to 83 MPa on the average in the dynamic Brazilian tests, proving a rate sensitive transverse strength. The quasi-static tensile strength in the osteon growth direction was however found comparably higher, 192 MPa. A Weibull analysis indicated a higher tensile ductility in the osteon growth direction than in the transverse to the osteon growth direction. The microscopic analysis of the quasi-static Brazilian test specimens (tensile strain along the osteon growth direction) revealed a micro-cracking mechanism operating by the crack deflection/twisting at the lacunae in the concentric lamellae region and at the interface between concentric lamellae and interstitial lamellae. On the other side, the specimens in the transverse direction fractured in a more brittle manner by the separation/delamination of the concentric lamellae and pulling of the interstitial lamellae. The detected increase in the transverse strength in the high strain rate tests was further ascribed to the pull and fracture of the visco-plastic collagen fibers in the interstitial lamellae. This was also confirmed microscopically; the dynamically tested specimens exhibited flatter fracture surfaces.

Scimitar syndrome: a complex form of anomalous pulmonary venous return.

Scimitar syndrome, or pulmonary venolobar syndrome, is a rare congenital anomaly, in which all the right pulmonary veins drain into the inferior vena cava. In this study, we review the diagnostic features, clinical management, and surgical strategy in the Scimitar syndrome and discuss the significance of new generation diagnostic imaging methods for this rare anomaly.

The disappearance of nonsustained ventricular tachycardia after surgical repair in a patient with mitral annular disjunction and mitral valve prolapse.

Mitral annular disjunction (MAD) is a structural abnormality defined as the separation of the ventricular myocardium between the mitral valve annulus and the left atrial wall. It is present in some patients with mitral valve prolapse (MVP) and is associated with papillary muscle fibrosis and ventricular arrhythmia. Although it is easy to diagnose, it can be overlooked in daily practice. This study presents the case of a 42-year-old patient who was admitted to the cardiology clinic with complaints of palpitation and syncope. The patient was diagnosed with bileaflet MVP, MAD, and severe mitral regurgitation using transthoracic echocardiography and cardiac magnetic resonance imaging, in which ventricular tachycardia disappeared following subsequent surgical repair.

Rare variation in partial anomalous venous drainage in 2 cases: diagnosis, assessment methods, and surgical approach.

Where pulmonary veins drain and their relationship with an atrial septal defect (ASD) are important. A sinus venosus (high venosum) type of defect is the most common pathology accompanying partial anomalous pulmonary venous connection. Typically, the right superior pulmonary vein and occasionally the middle pulmonary vein drain into the junction of the superior vena cava (SVC) and the right atrium (RA), and a sinus venosus type of ASD usually accompanies these anomalies. In this report, we assess a very rare pathology in which 3 right pulmonary veins (superior, middle, and inferior) drain into the SVC-RA junction with respect to diagnostic methods and in the light of 2 cases involving patients in 2 different age groups.

An alternative method for cardioplegia delivery during totally endoscopic robotic surgery.

The optimal technique for myocardial protection and cardioplegia delivery during totally endoscopic robotic surgery is still under evolution. Cardioplegia delivery with endovascular clamping of the aorta is a common method used for this purpose but has several disadvantages and may lead to serious complications. Here we describe an alternative cardioplegia delivery method during totally endoscopic atrial septal defect closure and mitral valve repair. The method using a transthoracic aortic clamp and an antegrade cardioplegia cannula without any thoracotomy seems to be a safe and reproducible technique, which may enhance myocardial protection and prevent some of the complications of the endoclamp technique during robotically assisted cardiac surgery.

Durability of mitral valve repair: A single center experience.

BACKGROUND: This study aims to present clinical outcomes of mitral valve repair in patients with different etiologies. METHODS: Between June 2006 and August 2017, a total of 421 consecutive patients (266 males, 155 females; mean age 53.1±15.6 years; range, 5 to 89 years) who underwent mitral valve repair with or without concomitant cardiac procedures were retrospectively analyzed. All pre-, intra-, and postoperative data were collected. Echocardiographic examinations were performed at discharge and during follow-up. Kaplan-Meier analysis was used to estimate overall survival and from residual severe mitral regurgitation, endocarditis and reoperation-free survival rates. RESULTS: The mean follow-up was 58.9±35.1 months. Of the patients, 12 (2.8%) had previous cardiac operations. The most predominant pathology was degenerative disease in 265 patients (62.9%). Repair techniques included ring annuloplasty (n=366, 86.9%), artificial chordae implantation (n=185, 44%), and commissurotomy (n=38, 9%). Overall in-hospital mortality rate was 1.2% (n=5). Echocardiography before discharge showed no/trivial mitral regurgitation in 64.9% (n=270) and mild mitral regurgitation in 34.85% (n=145) of the patients. At the late postoperative period, transthoracic echocardiography revealed moderate mitral regurgitation in 23 patients (5.7%) and severe in 11 patients (2.7%). The mean late survival and freedom from endocarditis, reoperation, and recurrent severe mitral regurgitation rates were 92±0.03%, 98.5±0.07%, 98.1±0.01%, and 94.7±0.02%, respectively. CONCLUSION: Our study results suggest that mitral valve repair is a safe and effective procedure associated with favorable longterm outcomes in experienced centers.

Effectiveness of Artificial Neochordae Implantation in Tricuspid Valve Repair.

Various techniques for treating tricuspid regurgitation have been described; however, because of scarce data about the long-term outcomes of different repairs, the optimal technique has not been established. We evaluated the effectiveness and durability of artificial neochordae implantation in the treatment of tricuspid regurgitation. From 2009 through 2014, 507 patients underwent tricuspid valve repair at our institution. Of those, 48 patients implanted with artificial neochordae were included in our study. The median age of the participants was 62 years (range, 4-77 yr) and 50% were women. Thirty patients (63%) were in New York Heart Association functional class III, and 11 (23%) were in class II. The cause of tricuspid regurgitation was functional in 33 patients (69%) and rheumatic in 15 (31%). In 46 patients, neochordae implantation was performed in addition to Kay annuloplasty (n=13) or ring annuloplasty (n=33). Forty-two patients were discharged from the hospital with absent or mild tricuspid regurgitation. The mean follow-up period was 44.3 ± 20.2 months. Follow-up echocardiograms revealed that tricuspid regurgitation was absent, minimal, or mild in 38 patients (80.8%), moderate in 7, and severe in 2. Our results indicate that the use of artificial neochordae implantation as an adjunct procedure to annuloplasty leads to effective and durable repair in comparison with conventional techniques for treating tricuspid regurgitation.

Coronary air embolism in off-pump surgery caused by blower-mister device.

Gaseous emboli caused by the blower-mister result in air locks within coronary vessels. We describe the case of a coronary air embolism caused by a blower-mister device on off-pump surgery. The tip of the device unexpectedly entered the coronary artery through arteriotomy and caused the air emboli. Air locks in the coronary circulation led to hemodynamic deterioration, and cardiopulmonary bypass was started following the emergency cannulation.

Stuck mechanical valve in pregnancy.

Mechanical heart valve thrombosis during pregnancy is a challenging condition. We present a pregnant patient with stuck mechanical mitral valve. During the 36th week of pregnancy, she was admitted to our emergency clinic because of aggravated dyspnea, tachypnea, and cyanosis. Echocardiography revealed stuck mechanical valve in mitral position and she was diagnosed with acute left ventricular heart failure due to mechanical valve thrombosis. Reoperative mitral valve replacement was performed in emergency conditions immediately following Cesarean section. She and her baby were discharged 11 days after surgery without complications.

[The surgical treatment of atrial fibrillation]. / Atriyal fibrilasyonun cerrahi tedavisi.

The surgical treatment of atrial fibrillation (AF) has entered a new era with the development of new tools and advanced techniques. The Maze III operation remains as the gold standard for the surgical treatment of AF. However new energy sources have been adopted for treating this arrhythmia in an effort to reduce the invasiveness and technical concerns with the original procedure. Success rates ranging between 70-98% have been reported using these new techniques. On the other hand, interventional cardiologists have further improved their techniques so that percutaneous techniques are competing with minimally invasive ablation techniques for the treatment of drug resistant and symptomatic lone AF. These developments have aroused the interest of cardiac surgeons in AF surgery and have found themselves a wide application. It has been estimated that thirty thousand patients have undergone surgical ablation for AF so far. Inevitably, procedure related complications have occurred and caused skepticism by some groups. However, surgical ablation has become a widely accepted treatment modality for AF patients undergoing concomitant cardiac surgery. The aim of this text is to make an overall review of the surgical treatment of AF and evaluate the current situation in view of the literature and the personal experience of the authors.

Microhardness and fracture toughness of dental materials by indentation method.

The main objective of this study was to measure the fracture toughness of the human teeth enamel using the microindentation technique and to compare the results calculated from the equations developed for Palmqvist and radial-median cracks. Vickers microhardness measurements of dental ceramic (alumina) and human teeth were performed using indentation fracture method. The fracture toughness of enamel was calculated using different equations reported in the literature. Vickers microhardness of the sintered alumina specimen (98.8% theoretical density) was measured to be 14.92 GPa under 9.8 N indentation load. Three equations based on the radial-median cracks were found to be applicable for the fracture toughness determination of the enamel. Results show that indentation fracture method is adequate to measure microhardness and fracture toughness of dental materials. However the calculation of fracture toughness depended on the nature of the cracks and also on the location of the indentation. Therefore, it is necessary to identify the crack profile and to select the appropriate equation for accurate fracture toughness values.

Staphylococcus epidermidis adhesion on surface-treated open-cell Ti6Al4V foams.

The effect of alkali and nitric acid surface treatments on the adhesion of Staphylococcus epidermidis to the surface of 60% porous open-cell Ti6Al4V foam was investigated. The resultant surface roughness of foam particles was determined from the ground flat surfaces of thin foam specimens. Alkali treatment formed a porous, rough Na2Ti5O11 surface layer on Ti6Al4V particles, while nitric acid treatment increased the number of undulations on foam flat and particle surfaces, leading to the development of finer surface topographical features. Both surface treatments increased the nanometric-scale surface roughness of particles and the number of bacteria adhering to the surface, while the adhesion was found to be significantly higher in alkali-treated foam sample. The significant increase in the number of bacterial attachment on the alkali-treated sample was attributed to the formation of a highly porous and nanorough Na2Ti5O11 surface layer.

Clinical experience with the Novare Enclose II manual proximal anastomotic device during off-pump coronary artery surgery.

OBJECTIVE: The aim of this study was to assess the feasibility and safety of a new proximal anastomotic device during off-pump coronary surgery. METHODS: The Novare Enclose II is a manual proximal anastomotic device that enables the surgeon to perform proximal anastomoses without side-biting clamps in a fully pressurized aorta. The device was used in 30 off-pump coronary artery bypass graft (CABG) patients (Group A) for performing 25 vein, 10 free right internal thoracic artery and 14 radial artery anastomoses to the aorta. The number of proximal anastomoses varied between 1 and 3 per patient. Intraoperative transcranial Doppler measurements were performed to detect cerebral microemboli during the use of the device and were compared with transcranial Doppler measurements of 30 off-pump patients where a partial side clamp was used for proximal anastomoses (Group B). The aorta was evaluated using transesophageal echocardiography (TEE) and epiaortic echocardiography (EAE) in both groups before the procedure and patients with a calcified aorta were excluded. RESULTS: In Group A, 49 proximal anostomoses were performed as planned with the device using conventional hand-sewn methods. Twenty-four of these were arterial conduits. In Group B, 32 proximal anastomoses were performed using 25 veins and 7 arterial grafts. There were no procedure related to adverse events or complications in both groups. The median number of microemboli was 15 (range 5-48) in Group A and 68 (range 35-290) in Group B (P<0.05). CONCLUSION: The Enclose II device can be a valuable tool to perform venous or arterial proximal anastomoses during off-pump CABG. Transcranial Doppler results suggest that the device seems to be less traumatizing than side clamping and may reduce clamp-associated complications during off-pump coronary artery surgery.

Mitral valve surgery using video-assisted right minithoracotomy and deep hypothermic perfusion in patients with previous cardiac operations.

BACKGROUND: Redo-sternotomy for mitral valve (MV) surgery may be complex and attendant complications can be avoided using anterolateral right thoracotomy, deep hypothermia (20°C, nasopharyngeal) with low flow cardiopulmonary perfusion. Video-assisted minithoracotomy technique is a further improvement. METHODS: We performed 20 consecutive MV operations in patients with previous cardiac surgery using video-assisted right minithoracotomy, femoro-femoral bypass, deep hypothermia, low flow cardiopulmonary bypass without aortic cross-clamping. The mean follow-up was 30 ± 17.8 mo. Data is presented as the mean ± standard deviation of the mean. RESULTS: There were 11 males and 9 females (age, 62.3 ± 12.1; ejection fraction 50.1 ± 11.2). Operations included MV replacement (n = 11), MV repair (n = 5), and MV re-replacement (n = 4). There were no hospital deaths, and the mean hospital stay was 8 ± 2.9 days. There were no postoperative strokes or need for mechanical circulatory support. The mean cardiopulmonary bypass time was 152 ± 28 minutes. Two patients (10%) required inotropic support beyond 24 hrs. All patients were free from inotropic support at 48 hours. The mean number of transfused red cell units was 2.8 ± 0.8 (range, 2 to 4). One patient died in another institution six months postoperatively following surgery for acute type III aortic dissection. At 30 ± 17.8 months follow-up all patients were found to be in NYHA Class I or II. CONCLUSIONS: Minimally invasive video-assisted MV surgery using deep hypothermia, low-flow cardiopulmonary bypass without aortic clamping can result in excellent clinical outcomes in patients with previous cardiac surgery via a median sternotomy. This technique offers reproducible results, good myocardial protection (as evidenced by the low rate of inotropic support that patients needed postoperatively), and low rates of complications.

Intraoperative saline-irrigated radiofrequency modified Maze procedure for atrial fibrillation.

BACKGROUND: This study was conducted to evaluate the effectiveness of the saline-irrigated radiofrequency modified Maze operation for treatment of chronic atrial fibrillation, and to compare the results of the left and biatrial procedures. METHODS: During a period of 11 months, 62 patients with chronic atrial fibrillation who were having concomitant cardiac surgery underwent the procedure. The mean age of the patients was 52 +/- 14 years. Patients underwent either a biatrial (group A; n = 39) or left atrial (group B; n = 23) procedure. RESULTS: Two patients (3.2%) died early in the postoperative period. Three patients (4.8%) required reoperation for bleeding. One patient in group A (1.6%) received a permanent pacemaker. Patients in both groups were free of atrial fibrillation at the end of the procedure (group A: sinus 86.9%, pacemaker 13%; group B: sinus 90.5%, pacemaker 9.5%) (p > 0.05). At 1-month and longer-term follow-up, sinus rhythm was maintained in 92% and 95% of cases in group A, respectively, whereas this rate was 71% and 81% in group B (p > 0.05). Holter monitor surveillance revealed a higher rate of atrial fibrillation, atrial arrhythmias, and atrial flutter in group B (p < 0.05). Transthoracic echocardiography revealed improvement over time in left atrial transport function in both groups (p < 0.05). CONCLUSIONS: The saline-irrigated radiofrequency modified Maze procedure was performed safely and efficiently. Both the left and biatrial procedures were successful in terms of restoring sinus rhythm during short-term follow-up. Long-term follow-up with more cases is needed to show the superiority of one method over the other.

Does off-pump CABG reduce gastrointestinal complications?

BACKGROUND: The aim of this study was to compare gastrointestinal complications and associated risk factors among patients undergoing cardiac surgery using off- and on-pump revascularization techniques. METHODS: A total of 1146 adult patients who underwent coronary artery surgery during a 6-year period were evaluated retrospectively. Group 1 consisted of 546 patients operated using off-pump techniques and group 2 consisted of 600 cases operated with cardiopulmonary bypass. Patients were compared and evaluated for gastrointestinal complications and possible associated risk factors using univariate and multivariate logistic regression analysis. RESULTS: Overall mortality was 1.6% in group 1 and 2.2% in group 2 (p = 0.523). Mortality due to gastrointestinal complications was 38.5% and 35.7% respectively in group 1 and group 2. The mean EuroSCORE value was 5.1 +/- 2.8 in group 1 and 3.8 +/- 2.4 in group 2 (p < 0.001). The most common gastrointestinal complication in the off-pump group was gastrointestinal bleeding. The leading complication in group 2 was intestinal ischemia. CONCLUSIONS: The incidence rates of gastrointestinal complications were similar in the on- and off-pump coronary artery bypass groups, the type of gastrointestinal complications, however, was different. Mortality rate due to these complications was also similar and remained high, regardless of the type of surgery. Cardiopulmonary bypass did not emerge as a risk factor for gastrointestinal complications, but prolonged cardiopulmonary bypass (longer than 98 minutes) resulted in a high incidence of such complications. Old age and advanced arteriosclerosis emerged as risk factors in both groups resulting in gastrointestinal complications suggesting the ischemic nature of the injury.

Vertebral osteomyelitis after cardiac surgery.

BACKGROUND: Mediastinitis after open-heart surgery is a serious complication that has a decreasing incidence but still a significantly high mortality rate. Back pain may develop during the course of treatment for mediastinitis, and this should suggest vertebral osteomyelitis in the differential diagnosis. Diagnosis of vertebral osteomyelitis may be difficult because of the insidious onset and delayed diagnosis, and treatment may result in serious neurologic compromise and even death of the patient. METHODS: This retrospective study involves 5 patients who had open-heart surgery and mediastinitis that was further complicated by vertebral osteomyelitis. Average delay in diagnosis was 18 days after the onset of symptoms. Magnetic resonance imaging was the most helpful tool for diagnosis. Methicilline-resistant Staphylococcus aureus was identified as the responsible microorganism in all patients. Neurologic compromise occured (one paraplegia and one paraparesia) in 2 patients during medical treatment. RESULTS: Along with the medical treatment, all patients were surgically treated due to either one or more of the following reasons: unresolving symptoms, sudden neurologic compromise, or impaired spinal column stability despite appropriate conservative treatment. One patient died 10 days postoperatively. The mean follow-up period for the remaining 4 patients was 47 (12 to 95) months. Complete recovery was achieved, and they were able to return to their routine daily activities. CONCLUSIONS: Vertebral osteomyelitis should be borne in mind when a patient develops back pain during the course of mediastinitis. Suspicion, early diagnosis with appropriate imaging, and proper treatment are crucial to prevent catastrophic complications.

Combined radiofrequency modified maze and mitral valve procedure through a port access approach: early and mid-term results.

OBJECTIVE: The aim of this study was to assess the feasibility and effectiveness of irrigated radiofrequency (RF) modified Maze procedure through a port access approach during mitral valve surgery and evaluate early and mid-term results. MATERIAL AND METHOD: During a 16 months time period, 67 patients with chronic atrial fibrillation (AF) eligible for port access mitral valve surgery were randomly assigned to either Group A, in which they underwent a combined procedure (N = 33) or Group B, in which a valve procedure alone was performed (N = 34). Both groups were similar in terms of age, sex, valve pathology, duration of AF left atrial diameter and left ventricle function (P > 0.05). Four had undergone previous operations. RESULTS: Median follow-up was 10 months for both groups, 95% CI (9.18-10.8). One patient in each group died early postoperatively (3 and 2.9%). Two patients required reoperation for bleeding, one in each group (3 and 2.9%). There were two conversions to right thoracotomy. In Group A, freedom from AF was 100% at the end of the operation (76% sinus, 24% pacemaker) Six and twelve months freedom from AF was 87.2 and 93.6%, respectively. In Group B, freedom from AF at the end of operation was 41%. At the end of 6 and 12 months, freedom from AF was 9.4% (P = 0.0001). One patient in Group A required a permanent pacemaker (3%). During follow-up, one patient in Group A died of non-cardiac causes (3%). In Group B, there were two late deaths: one cardiac (2.9%) and one neurologic (2.9%). There were no thromboembolic events detected in Group A during follow-up, whereas two patients in Group B suffered this complication (6%, P = 0.081). At 12 months, functional capacity had improved for patients in both groups (P < 0.0001). CONCLUSION: The combination of mitral valve surgery and irrigated RF Maze procedure was safe and efficient through a port access approach. There were no procedure related complications like esophageal or coronary artery injury. Early and mid-term results were favourable with 93.6% of patients free of AF at 1 year in comparison to the 9.4% of the control group. The data is not sufficient to reach any conclusions in terms of thromboembolic rates, despite favourable results for the RF Maze group. Nevertheless, in terms of feasibilty, sinus rhythm restoration and overall outcome, early results are encouraging and we advocate the use of the combined procedure through a port access approach.