Outcomes of Barlow mitral valve repaired by robot-assisted keyhole surgery.

Objective: To present our strategy and the clinical outcomes of robot-assisted Barlow mitral valve keyhole surgery. Methods: From May 2015 to March 2022, a total of 1281 patients underwent mitral valve repair at our institution, including 763 with robotics surgeries. Of these, 124 patients with Barlow mitral valve (49 ± 12 years, male/female ratio = 81:43) were treated using robotic assistance and included in this study. Results: All operations were completed using 3 to 5 keyholes. Neochordae implantation using the loop technique was the first option, and resection was performed only in cases with an intrinsic risk of developing systolic anterior motion. Neochordae implantation was performed in 118 cases (95.1%) using 6.6 ± 3.0 neochordae. Posterior leaflet resection was performed in 27 (21.7%) patients. Operation time was 177 ± 42 minutes, cardiopulmonary bypass time was 127 ± 25 minutes, and aorta crossclamp time was 76 ± 16 minutes. Blood transfusion was required in 5 cases (4%). None of the patients required a conversion to valve replacement. The postoperative complications included bleeding (n = 4), stroke (n = 1), and infection (n = 2). Mitral valve regurgitation 1 week after repair was none or trivial in 122 cases (98.3%), mild in 2 cases (1.7%), and more than moderate in 0 cases. Freedom from reoperation was 99.2% during the follow-up period of 36 ± 21 months. One patient required reoperation due to infective endocarditis. Conclusions: Robot-assisted keyhole surgery using the loop-first concept was adequate to help achieve satisfactory and safe perioperative outcomes for Barlow mitral valve.

Commissure leaflet prolapse closely mimics anterior mitral leaflet perforation in 2-D image of transesophageal echocardiography.

BACKGROUND: Precise diagnosis of mitral valve regurgitation is challenging, particularly for distinguishing between commissure leaflet prolapse and anterior leaflet perforation, based exclusively on 2-dimensional (2-D) imaging by transesophageal echocardiography. CASE 1: Two mitral regurgitation jets suggesting anterior leaflet perforation, but no regurgitation orifices, were observed in the mid esophageal (ME) 4-chamber view. Multiple 2-D and 3-dimensional (3-D) images revealed prolapse of the anterior (A3) leaflet and posterior commissure, not anterior leaflet perforation. CASE 2: A regurgitation jet suggesting an anterior leaflet prolapse with a regurgitation orifice was observed in ME long-axis view. Multiple 2-D and 3-D images showed only anterior commissure prolapse, but no signs of anterior leaflet perforation. CONCLUSIONS: A regurgitant jet caused by commissure leaflet prolapse closely resembles anterior leaflet perforation in 2-D imaging. Careful evaluation of multiple 2-D and 3-D images, as well as of the regurgitation orifices, is crucially important for making an accurate diagnosis.

Off-Pump Neochordae Implantation via Left Minithoracotomy for Recurrent Regurgitation Following Mitral Valve Repair: The First Case in Japan.

Surgical fixation after recurrent regurgitation following surgical mitral repair has been technically demanding and associated with high morbidity and mortality. Avoiding reopening the adhesive site or limiting the usage of cardiopulmonary bypass are solutions for reducing the operative risk. We report a case of recurrent mitral regurgitation treated by off-pump neochordae implantation via left minithoracotomy. A 69-year-old woman with a history of conventional mitral repair via median sternotomy developed heart failure due to mitral regurgitation from recurrent posterior leaflet P2 prolapse. Four neochordaes were implanted off-pump via left minithoracotomy using a NeoChord DS1000 in the seventh intercostal space. No transfusion was required. The patient was discharged a week after the procedure with no complications. The regurgitation remains trivial 6 months after the NeoChord procedure.

Transesophageal echocardiography for cardiac herniation occurring during robotic-assisted mitral valve repair: a case report.

BACKGROUND: Cardiac herniation has been reported in thoracic trauma and after pneumonectomy; however, it is sporadic in cardiac surgery. CASE PRESENTATION: A 35-year-old male patient underwent an elective totally endoscopic robotic-assisted mitral valve repair (TERMVR). His hemodynamics were stable after weaning from cardiopulmonary bypass, and no residual mitral valve regurgitation was observed. However, during suturing of the port wound, the patient developed hypotension, which improved with phenylephrine administration. Four-chamber transesophageal echocardiography (TEE) images showed cardiac deformity, and postoperative chest radiography confirmed the dextrocardia. The cardiac herniation was repaired by deflating the left lung and over-inflating the right lung using a double-lumen tube, allowing selective ventilation without re-thoracotomy. The patient was discharged on the sixth postoperative day without complications. CONCLUSIONS: This was a very unusual case of cardiac herniation during TERMVR visualized using distinct TEE images. The cardiac herniation was successfully repaired using a double-lumen tube without re-thoracotomy.

A routine de-airing method for total endoscopic robot-assisted mitral valve repair.

Intraoperative water testing is essential for assessing mitral valve morphology and degree of residual mitral regurgitation during mitral valve repair. However, in some cases, evacuating intracardiac air is challenging. Herein, we report the routine de-airing method during total endoscopic robot-assisted mitral valve repair at our institute and discuss its effectiveness. In brief, our de-airing methods involve the following steps: after restricting the blood flow of the cardiopulmonary bypass, intracardiac air was pushed out into the pulmonary veins by drawing blood from the right ventricle. The left atrium, left ventricle, and ascending aorta were filled with blood to remove air from the root cannula. Retrograde blood flow from the coronary sinus was used to remove air from the coronary arteries. At 10 min after cardiopulmonary bypass weaning, transesophageal echocardiography revealed that residual intracardial air was absent in 99% of patients in all three chambers (ascending aorta, left atrium, and left ventricle).

Robotic mitral valve plasty for isolated clefts of mitral valve leaflets.

A 21-year-old female patient referred to our institute had been suffering from severe mitral valve regurgitation due to a rare anomaly: a typical cleft at the posterior mitral leaflet and the other partial one at the anterior leaflet. We successfully fixed the mitral valve using the robot-assisted totally endoscopic technique which could perform suture closure of both leaflets and annuloplasty. This communication is the first report of the robotic and totally endoscopic procedure which could treat this rare mitral anomaly.

Safety of perioperative period in robot-assisted atrial septal defect repair under hyperkalemic arrest.

BACKGROUND: Various attempts have been made to meet patient desires, especially among younger and otherwise healthy individuals, for cosmetically satisfying incision with atrial septal defect (ASD) repair. One of procedures was a robotic-assisted totally endoscopic ASD repair via only two ports under hyperkalemic arrest without aortic cross-clamping. This study investigated perioperative management and safety for robotic-assisted total endoscopic ASD repair surgery under hyperkalemic arrest. METHODS: We retrospectively reviewed perioperative management of thirty patients who underwent total endoscopic robot-assisted ASD repair under hyperkalemic arrest. All procedures were performed under general anesthesia using robotic-assisted total endoscopic for ASD repair via two or three ports under hyperkalemic arrest without aortic cross-clamping. RESULTS: A total of 30 patients (mean age 45 ± 17 years, 8 male, 22 female) underwent successful ASD repair with the total endoscopic robotic-assisted procedures under hyperkalemic arrest. Hyperkalemic arrest was achieved and maintained by intravenous administration of mean potassium dose of 91±32 mEq (1.4±0.6 mEq/kg) with the lowest bladder temperature was 31.9±1.4 °C during hyperkalemic arrest. In all cases, serum potassium concentration was <5.0 mEq/L after weaning from cardiopulmonary bypass, although two cases who developed hyperkalemia >6 mEq/L after operation. At other time points, no patient exceeded 6 mEq/L of serum potassium concentration. At admission to the intensive care unit, mean serum creatine phosphokinase-MB level was 32±7mg/dL. There were no cases of arrhythmia or other cardiac complications during recovery. CONCLUSIONS: Perioperative management of robotic-assisted total endoscopic ASD repair under hyperkalemic arrest is safe and is not associated with fatal arrhythmia due to hyperkalemia.

Two patterns of the "crossed swords sign" for the accurate diagnosis of diverse mitral valve regurgitations.

The "crossed swords sign," demonstrating the divergent jet, is visualized on 2-dimensional color Doppler imaging and indicates complicated mitral regurgitation (MR). We describe the cases of two patients with varying patterns of the crossed swords sign. In the first patient, the crossed swords sign was detected during the holosystolic phase. In the second patient, the direction of the MR jet changed according to the phase of systole: The crossed swords sign was formed by two regurgitation jets during different phases of systole. The crossed swords sign implies two patterns and is useful for the accurate diagnosis of complex MR.

Additional cleft mitral valve diagnosed by a combination of 2-D and 3-D echocardiography using transesophageal echocardiography during mitral valve prolapse: a case report.

BACKGROUND: A mitral cleft may be an important etiological factor for significant mitral regurgitation. We diagnose an additional cleft mitral valve by a combination of 2-dimensional (2-D) and 3-dimensional (3-D) echocardiography. CASE PRESENTATION: We describe the case of a severe mitral regurgitation due to posterior leaflet prolapse (P2). In the 2-D view, which is obtained after turning the probe clockwise from the mid-esophageal long-axis view, TEE showed a moderate central regurgitation jet. In the 3-D en face view, a cleft between P2 and P3 was identified, and we found that the cause of mitral regurgitation was not only P2 prolapse but also a cleft between P2 and P3. CONCLUSION: A complex mitral valve lesion was detected by a combination of 2-D and 3-D TEE. The presence of a cleft could affect the surgical procedure because of the possibility that an enlarged cleft would increase with leaflet resection.

Intraoperative detection of stuck leaflet after implantation of a mechanical aortic valve: a case report.

BACKGROUND: Mechanical aortic valve dysfunction is a rare but potentially fatal complication. It is usually caused by thrombosis, vegetation, and pannus overgrowth. However, it very rarely occurs immediately after the cardiopulmonary bypass weaning period. CASE PRESENTATION: We describe a case of stuck leaflet after the implantation of a mechanical aortic valve because of residual suture materials interfering with mechanical aortic valve leaflet closure, which is a very rare cause and has not been reported until now. CONCLUSION: The residual suture materials for mechanical aortic valve replacement could cause mechanical valve dysfuction indicated as stuck leafet.

First Major Clinical Outcomes of Totally Endoscopic Robotic Mitral Valve Repair in Japan　- A Single-Center Experience.

BACKGROUND: In 2018, Japan became the first country to have robotic cardiac surgery covered under the national health insurance. The number of patients undergoing robotic mitral valve (MV) repair has been estimated to increase remarkably, but no reports in Japan have yet described the outcomes of robotic MV repair. This study aimed to analyze the early clinical outcomes of patients undergoing totally endoscopic robotic MV repair (TERMVR) as a landmark national study for this procedure.Methods and Results:A total of 213 patients (152 men; mean age, 55±11 years) underwent TERMVR during May 2014 to December 2018. Preoperative demographics, operative profiles, and postoperative outcomes, including follow-up echocardiography, were analyzed. Successful TERMVR was achieved in all patients. Operation, cardiopulmonary bypass, and aortic cross-clamp times were 192±49.8, 127±23.8, and 70.1±16.2 min, respectively. Intraoperative transfusion was performed in 20 patients (10%). There were no in-hospital deaths. All patients were alive during the median follow-up period of 255 days (interquartile range, 32.5-208 days). Freedom from recurrence of MR >grade 2+ was 97.3%, 95.0%, and 90.7% at 6, 12, and 24 months, respectively. CONCLUSIONS: TERMVR is an effective and safe procedure with acceptable early postoperative outcomes.

Risk factors to predict leg ischemia in patients undergoing single femoral artery cannulation in minimally invasive cardiac surgery.

BACKGROUND: In peripheral cannulation for cardiopulmonary bypass, there is always a risk of ischemia in the extremities, caused by femoral artery cannulation. This report aimed to evaluate the outcome and the risk factors in patients undergoing minimally invasive cardiac surgery in mitral valve surgery. METHODS: We retrospectively reviewed all minimally invasive mitral valve surgery at our institute from May 2014 to December 2016. Operative outcomes and intra-operative monitoring for distal leg saturation were measured by the near-infrared spectroscopy values. For post-operative outcomes, the creatinine phosphorus kinase level was measured for the assessment of leg ischemia. Risk factors were evaluated for the elevation of post-operative creatinine phosphorus kinase. RESULTS: There were 162 patients who underwent single femoral artery cannulation for minimally invasive mitral valve surgery. The mean operation, cardiopulmonary bypass and aortic cross-clamp time were 212±44, 124±30, 76.6±22 minutes (min), respectively. The factors related to increased creatinine phosphorus kinase were male, body mass index, larger cannula size, operation time, cardiopulmonary bypass time and aortic cross-clamp time. The measurement of minimum near-infrared spectroscopy values did not show any association with creatinine phosphorus kinase elevation. There were significant associations between body mass index, cannula size and operation time and post-operative creatinine phosphorus kinase increase by multiple regression analysis. Two male patients had extremely high post-operative creatinine phosphorus kinase (18188 U/L and 16831 U/L) and they had high body mass index, large cannula size and longer operation time. CONCLUSIONS: In peripheral cannulation for minimally invasive cardiac surgery, body mass index, cannula size and operation time can be considered as risk factors for leg ischemia.

Inverted left atrial appendage during minimally invasive mitral valve repair.

Inverted left atrial appendage (LAA) is a rare complication in cardiac surgery. The echocardiographic appearance often leads to misdiagnosis of thrombus or some other cardiac mass. Patients misdiagnosed in this way often undergo unnecessary anticoagulation or surgical treatment. Recently, minimally invasive mitral valve surgery (MIMVS) has become more widespread. However, as the incision for MIMVS through the right thoracotomy is very small, the inverted LAA is not within the surgical field of the cardiac surgeon. We present a case of inverted LAA during MIMVS and provide images from transesophageal echocardiography.

[Vasoplegic Syndrome after Aortic Valve Replacement].

We report a case of vasoplegic syndrome (VS) after aortic valve replacement in a 65 year old male with aortic stenosis. The patient developed hypotension after separation from cardiopulmonary bypass (CPB). Transesophageal echocardiography revealed well-maintained cardiac function and normal prosthetic valve function. However, his cardiac index was 3.0 l x min(-1) x m(-2) and systemic vascular resistance index (SVRI) was 1100 dynes x sec(-1) x cm(-5) x m(-2). Diagnosing VS, norepinephrine administration was commenced. Since his respiratory status was good, the patient was extubated on the day of surgery. Two days after surgery, catecholamines were discontinued with the stabilization of his circulatory status. However, his respiratory status showed gradual deterioration, and he was re-intubated. Chest X-ray showed bilateral pleural effusion, which was treated by drainage and fluid restriction. With this, his oxygenation improved and he could be extubated 5 days after surgery. Vasoplegic syndrome is a potentially life-threatening complication following cardiac surgery. Hypotension at the time of separation from CPB can be due to multiple factors. Despite an incidence rate of 10%, little is known about VS. We hope that, in future, tailored therapeutic protocols for VS will be developed.

[Anesthetic Management of Robotic Cardiac Surgery].

Traditional cardiac surgery is performed via median sternotomy to approach the mediastinum and coronary structures. Recently, the use of minimal invasive car- diac surgery (MICS) via right mini-thoracotomy has become introduced. Furthermore, robotic-assisted car- diac surgery, with da Vinci® Surgical System, has been introduced. We herein summarize anesthetic manage- ment for robotic-assisted mitral valve surgery. After the induction of anesthesia, the venous cannula was maintained through the right internal jugular vein. Intraoperative transesophageal echo (TEE) is important for guiding the cannula to the right position. Moreover, anesthesiologists must evaluate the myocardial function and the mitral valve before and after the surgical pro- cedure. One-lung ventilation is required to produce ports for the robotic arms. If hypoxemia occurs before beginning the robotic procedure, then bilateral lung ventilation is needed. As robotic cardiac surgery is a completely endo- scopic mitral valve surgery, anesthesiologists must understand the details of the surgical procedure and the findings of the TEE examination.

[A Case of Mitral Valvular Re-repair in a Patient with Hemolytic Anemia after Mitral Valvular Repair].

A 54-year-old woman was admitted for mitral valvular repair. After folding plasty to A3, a 30 mm Cosgrove-Edwards ring was placed. There was no mitral regurgitation jet observed by transesophageal echocardiography (TEE) during the operation. However, high blood pressure was monitored and treated in the intensive care unit, hemolytic anemia developed, and the serum lactate dehydrogenase level was elevated. Two weeks after the operation, serum lactate dehydrogenase was again elevated. TEE showed mild mitral regurgitation and the regurgitation jet colliding with the annuloplasty ring. Multiple transfusions of red blood cells were required. Repeat surgery was therefore undertaken. Lam and associates previously studying patients on hemolysis after mitral valvular repair noted high grade mitral regurgitation jets fragmented or accelerated. In the present case, mitral regurgitation was mild, but the high velocity and manner of regurgitation (collision with the annuloplasty ring) could cause hemolytic anemia. In the present case, high blood pressure might have caused chordae rupture. Furthermore, a flexible ring, such as the Cosgrove-Edwards ring, is likely to cause hemolytic anemia. As contributing factors to hemolysis after mitral valvular repair, perioperative blood pressure management and type of ring are significant.

[Perioperative management of off-pump CABG for a 93-year-old man].

In recent years, the aging population has been growing, and the operative techniques and anesthetic methods have advanced. With these developments and medical support, the number of operations on very elderly patients has been increasing. We report the perioperative management of off-pump CABG for a 93-year-old man. When the heart was displaced during the operation, hypotension was induced and a marked reduction of his bispectral index (BIS) to "1" appeared. During the perioperative period, the patient developed delirium that was difficult to manage, but he was discharged from the hospital without any complications on POD 21. As part of the perioperative management, intraoperative cerebral circulatory management with attention to cerebral perfusion and prevention of postoperative delirium is crucial.

[Intensive care for CKD patients].

In Japan, the number of patients with chronic kidney disease (CKD) has increased. Hence, the opportunities for intensive care management of patients with CKD have also increased. Acute kidney injury (AKI) easily develops following CKD, and conversely, it can be a risk factor for CKD. At the time when CKD patients require ICU admission, their disease is already very severe, and the mortality rate tends to be high due to a number of associated complications. During the hemodynamic management of these patients, not only static indices such as CVP, but also dynamic indices such as stroke volume variation (SVV) should be used, since their circulation is very precariously balanced. While "goal-directed" hemodynamic management, which targets particular hemodynamic variables, might be useful in CKD patients, there is no evidence to prove its efficacy. Renal Replacement Therapy (RRT) is usually started after metabolic acidosis, hyperkalemia, ingestion of dialyzable toxin, volume overload and uremia have occurred. However, it is not clear whether continuous or intermittent RRT is beneficial in these patients.