Chitwood Clamp Research Articles

EARLY RESULTS OF MINIMALLY INVASIVE CORONARY ARTERY BYPASS GRAFTING

Abstract Coronary artery bypass grafting (CABG) is the benchmark in elective revascularization for Coronary Artery Disease (CAD), particularly for complex or multivessel CAD, left main coronary involvement, diabetes, or impaired heart function. Traditional CABG, via median sternotomy using cardiopulmonary bypass (CPB), has limitations like CPB–related morbidity and sternal complications. Alternatives like Minimally Invasive Cardiac Surgery (MICS CABG) and Hybrid Revascularization (HR) aim to address these drawbacks. We present a series of 215 consecutive patients (mean age 67±9 years, 27.9% females, EuroSCORE II 1.5±1.3%) between 2017–2023 who underwent elective minimally invasive surgical revascularization. Among the cohort, 164 (76.3%) had Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) via anterolateral left mini–thoracotomy (ALMT) at the fifth intercostal space (IS), with 140 (85.4%) receiving a single left internal thoracic artery (LITA) graft to the left anterior descending (LAD) artery and 24 (14.6%) an additional distal anastomosis. Thirty–four (20.7%) had HR via percutaneous coronary intervention (PCI) on the right coronary artery (RCA). Of the total cohort, 35/215 patients (16.3%) underwent multivessel MICS CABG via ALMT, with mean 2.3±0.5 distal anastomoses using LITA, right ITA, radial artery, or saphenous vein. Heart manipulation was via a subxiphoid device. Four MICS CABG patients (11.4%) had HR. More than half of MICS CABG cases were performed with planned peripheral CPB, without cross–clamping the Aorta. Of the total cohort, 16/215 patients (7.4%) received MICS CABG in an endoscopic fashion, using 3D thoracoscopy for LITA and RITA harvesting via bilateral ports in the 2nd, 3rd, and 4th IS, employing peripheral CPB and aortic clamping by Chitwood clamp at the second IS, with cardioplegia delivery via a 4 cm right anterior MT. Distal anastomoses were performed via left anterior MT, with easy subxiphoid manipulation of the emptied heart. Transit time flowmetry was used in all cases. Conversion to sternotomy was needed in 3 cases, all were MIDCAB. Thirty–day mortality was 1.4%, median ventilation was 4 [2–5] hours, and Intensive Care Unit–stay was 1 [1–2] days. All patients received graft evaluation via computerized tomography before hospital discharge. Mean follow–up was 2.9±1.9 years (max 5 years), with no deaths and 4 (1.9%) requiring follow–up PCI. MICS CABG is a promising future technique for heart revascularization by dedicated teams.

MID–TERM OUTCOMES OF ENDOSCOPIC MITRAL VALVE REPAIR VIA RIGHT ANTERIOR MINI–THORACOTOMY

Abstract The adoption of less–invasive mitral repair (MVr) surgery is increasing, backed by evidence of satisfactory short–term results and lower major morbidity. We assessed mid–term follow–up results of our experience, and compared two techniques: isolated leaflet resection and neochord implantation for posterior leaflet (PML) prolapse. Between 2012–2021, 700+ operations were performed with a video–assisted right mini–thoracotomy (RMT) approach. We report 309 consecutive patients who had endoscopic MVr, including those receiving concomitant tricuspid repair, ablation for atrial fibrillation, closure of patent foramen ovale and/or left atrial appendage. The early and mid–term follow–up results were ascertained. Primary outcome was the incidence of mortality and significant mitral regurgitation (MR) during follow–up which were summarized by Kaplan–Meier estimator and compared between treatment arms via log–rank test. Secondary outcomes were the early–postoperative results including 30–days mortality and major complications. All patients had endoscopic MVr via RMT at the 3rd/4th intercostal space (IS). A soft–tissue retractor is used, accompanied or not by a rib spreader, and two ports in the fourth and sixth IS are used for 3D thoracoscopy and carbon dioxide insufflation. Femoral vessels exposure through a right groin incision and echo–guided cannulation sec. Seldinger is achieved post–heparinization. Thoracic fascia bisection is performed during single–lung ventilation using a double–lumen endotracheal tube, integral to our anesthetic management, including percutaneous right internal jugular vein cannulation. The pericardium is opened and an aortic root cannula for cardioplegia delivery and venting is placed via working incision. After establishing cardiopulmonary bypass, a Chitwood clamp is passed through the second IS and cardioplegia is delivered. Endoaortic balloon clamping is primarily used in redo cases. With ring annuloplasty, 136 (44%) patients received PML resection (122 isolated) and 97 (31%) PML chords implantation (88 isolated). Forty–nine patients had annuloplasty alone. In–hospital mortality was 1.0%. Mean follow–up was 29±22 months (max 8.3 years). Kaplan–Meier 5–year survival was 97.3±1.0%. MR (3/4+) free–survival at 5 years was 94.5±2.3%. Subgroup time–to–event analysis for the indexed outcomes showed no statistical significance between techniques. In conclusion, endoscopic MVr is safe with excellent mid–term outcomes.

Endovascular Vena Cavae Occlusion Technique in Minimally Invasive Tricuspid Valve Surgery in Patients With Previous Cardiac Surgery

The aim of the present study was to describe a bicaval endovascular occlusion technique in minimally invasive tricuspid valve (TV) surgery in patients with previous cardiac surgery. Case series. Single tertiary university center. The study comprised ten patients. Endovascular occlusion of vena cavae for minimally invasive TV redo surgery. Between 2008 and 2017, ten patients with previous cardiac surgery underwent TV minimally invasive surgery (repair or replacement; isolated or with concomitant procedures) using the Coda balloon catheter (Cook Medical, Bloomington, IN) to occlude both vena cavae. Data were collected retrospectively from electronic medical records. Superior and inferior vena cava occlusion with Coda balloon catheters was successful with no complications. The drainage of the vena cavae was optimal with excellent surgical exposure. Cardiopulmonary bypass time was 131 ± 119 minutes, with 30% of patients undergoing aortic clamping (two with a Chitwood clamp, one with an endoaortic balloon). Intensive care unit length of stay was 3.9 ± 2.7 days, and the in-hospital mortality rate was 30%. Bicaval endovascular occlusion of vena cavae is a feasible and effective technique in patients with previous cardiac surgery who are undergoing a minimally invasive TV procedure. The high mortality rate is associated with the inherent risk of a redo surgery involving the TV.

Multivessel Arterial Revascularization via Left Anterior Thoracotomy

To present the technique and to evaluate the outcomes of the multivessel minimally invasive coronary revascularization through the left anterior thoracotomy. From July 2017 to March 2019 in 229 consecutive patients with isolated multivessel coronary artery disease we performed complete coronary revascularization through the left anterior minithoracotomy (6-8 cm skin incision). In 47 of them we performed multiarterial revascularization using left internal mammary artery and T-shunt with left radial artery or right internal mammary artery. Cardiopulmonary bypass (CPB), Chitwood clamp and blood cardioplegia were used in all patients. Heart strings, encircling tapes and Chitwood clamp were used to reduce the distance from skin to coronary targets. Usual coronary instruments were used. The perioperative outcomes of multiarterial graft strategy group were compared with uniarterial graft strategy group. There were no mortality, no perioperative myocardial infarcts, and no conversion to sternotomy with either graft strategy groups. The mean number of distal anastomoses, CPB time, and total hospital stay were not different between the groups. Aortic cross-clamp time ((83.8 ± 17.4 (45;121) vs 67.8 ± 17.4 (35;146), P < 0.0001) and total operation time (283.5 ± 45 (205;495) vs 254.3 ± 48.6 (175;590), P = 0.0003) were longer in patients with multiarterial revascularization compared to uniarterial revascularization using left internal mammary artery and veins. Multivessel coronary bypass grafting using CPB and cardioplegia can be routinely performed minimally invasively through the left anterior thoracotomy. In selected patients multiarterial revascularization could be done with excellent procedural outcomes.

Minimally Invasive Endoscopic Aortic Valve Replacement: Operative Results

To describe our endoscopic aortic valve replacement (E-AVR) technique and to evaluate its early results regardless of the type of prosthetic valve implanted and the patients' characteristics. From July 2013 to September 2018, 125 patients (76 males, mean age 68.8 ±10.9 years, mean EuroScore II 1.51 ±1.39) underwent isolated E-AVR due to a severe stenosis in 99 cases and insufficiency in 26 cases. The surgical access was a 3-4 cm working port in the second right intercostal space with no rib-spreading and 3 additional 5 mm miniports for the introduction of a 30-degree thoracoscope, the Chitwood clamp, and the vent line. Cardiopulmonary bypass (CPB) was achieved through a femoro-femoral cannulation. All patients successfully underwent E-AVR. Stended bioprostheses were implanted in 56 cases, Rapid Deployment and Sutureless valves in 23 and 46 cases, respectively. Mean cross-clamping and CPB times were 87.5 ±22.1 and 126.1 ±28.4 minutes, respectively, and a significant difference between the types of prostheses was observed: 69.1 ±15.1 and 106.2 ±21.8 minutes (Sutureless) vs 93.2 ±15.1 and 135.5 ±21.8 minutes (Rapid Deployment) vs 100.6 ±17.2 and 138.9 ±21.9 minutes (Stented). Mean ventilation and ICU times and hospital stay were 10.9 ±39.3 hours, 45.9 ±58.4 hours, and 8.3 ±9.3 days, respectively. Thirty-day mortality was 0.8%. One patient (0.8%) needed a re-exploration for bleeding and 3 patients (2.4%) required a new permanent pacemaker implantation. No major neurologic events were observed. No paravalvular leakage was detected at discharge. E-AVR is associated with low mortality and few complications. Sutureless bioprostheses significantly reduce cross-clamping and CPB times. In dedicated centers, this approach may become a valid alternative to other minimally invasive techniques.

Complete Coronary Revascularization via Left Anterior Thoracotomy.

Our aim was to develop the minimally invasive coronary artery bypass grafting (CABG) technique, which is equally effective and safe compared with conventional coronary grafting technique, is reproducible, and can be applied in the vast majority of patients with isolated coronary artery disease. From July 2017 to November 2018 a total of 170 nonselected consecutive patients underwent minimally invasive on-pump multivessel CABG through the left anterior minithoracotomy in the fourth intercostal space using a Chitwood clamp and blood cardioplegia. We named this technique total coronary revascularization via left anterior thoracotomy. The mean number of grafts was 3.1 ± 0.7. Left internal mammary artery was used in 159 (93.5%) patients, right internal mammary artery in 4 (2.4%) patients, radial artery in 25 (14.7%) patients, and veins in 148 (87%) patients. We had no mortality, no postoperative myocardial infarcts, and no conversion to sternotomy. There were 2 postoperative strokes without residual neurological deficit and 2 revisions for postoperative bleeding. The total operation time was 258.8 ± 43.9 minutes, cardiopulmonary bypass time 135.8 ± 26.6 minutes, and aortic cross-clamp time 71.2 ± 19.4 minutes. The mean intensive care stay was 2.1 ± 0.56 days and mean total hospital stay 6.3 ± 1.3 days. Complete coronary revascularization could be routinely performed using the above-mentioned technique. No patient selection, based on number of grafts, quality and location of coronary vessels, left ventricle function, age, gender, or body mass index, is required.

RF47 MINIMALLY INVASIVE AORTIC VALVE REPLACEMENT (MIAVR) THROUGH A RIGHT ANTERIOR MINI THORACOTOMY IN A TOTALLY FREE OPERATIVE FIELD.

Background: MIAVR through a right anterior minithoracotomy has excellent results. This approach has technical challenges related to a smaller working space. The operation requires learning curve, longer operative time and is routinely performed only by skilled surgeons. We describe our technique for MIAVR through a right anterior mini thoracotomy, making the procedure simple and reproducible. Methods: From February 2016 we have performed MIAVR in 29 patients with aortic stenosis. A preoperative CT scan was performed for detailed operative planning. EndoVent pulmonary catheter was pre-positioned; in case of significant aortic regurgitation ProPlege peripheral retrograde cardioplegia device was used. A 6 centimeters incision was made over the 2 nd right intercostal space. The right mammarian vessels were divided and the 3 rd rib cartilage was transected. Working view was enhanced pulling the tip of the right appendage with a snare. Right femoral vessels were cannulated. CPB was started. A Chitwood clamp was inserted through a chest tube incision. After such a preparation, a complete free operative filed makes possible aortic valve replacement, using suturless prosthesis or standard valves, with CoreKnot ligation system Results: Mortality rate was 0%; aortic cross clamp time was 59 min (+/- 5 min). In 4 patients femoral cannulation was not possible and we performed a central percutaneous aortic cannulation. In 1 patient, at the end of the operation we had to convert to sternotomy due to bleeding from the epicardial wire insertion. Conclusions: A totally free operative field make MIAVR more “surgeon friendly” and reproducible.

OC58 PRELIMINARY RESULTS OF MITRAL VALVE SURGERY IN OCTOGENARIANS: A GIROC MULTICENTER STUDY

Objective: In this multicenter prospective study we sought to analyze preliminary results of high risk old patients who underwent mini-invasive mitral valve surgery. Methods: From January 2016 to March 2018, 38 patients ≥80 years old underwent MV surgery: mean EuroSCORE II was 4.5 ± 3.7, mean predictive mortality according to logistic Euroscore was 15.4 ± 11.2%. Male were 47.4%, mean BMI was 23.8 ± 3.5. Main MV etiology was degenerative (76.3%). Comorbidities included: diabetes (13.2%), COPD (10.5%), CRF (15.8%), peripheral vasculopathy (21.1%) and AF (60.5%). Mean pre-operative EF was 59.9 ± 10.1% and severe pulmonary hypertension (≥ 55 mmHg) was present in 36.8% of the cases. Patients who underwent previous cardiac operation were 2.6 %. A preoperative vascular screening of the aorta was perfomed in 81.6% patients. Results: All patients except one (97.4%) underwent mini-invaive mitral valve surgery. Mitral repair was obtained in 12 out of 38 patients. Main associated procedures were TV repair (15.8%), ASD closure (13.2%) and AF-crioablation (7.9%). Mean cardiopulmonary and cross-clamping time were respectively 122.7 ± 34.4 and 85.2 ± 24.5 minutes. Aortic clamping was obtained with either Chitwood clamp (94.5%) or endoballoon (5.5%). Conversion to sternotomy was necessary in only one case. Operative mortality was 0%. Reoperation for bleeding, aortic dissection and major neurologic events were not reported. 34.2% of the patients required blood transfusion, 5.3% emodyalisis and 5.3% PM implantation. Mean ventilatory support, ICU and hospital stay were respectively 14.5 ± 14 h, 3.3 ± 5.7days and 10.0 ± 5.8days. 30-day mortality was 2.6%. Preliminary Conclusions: mini-invasive approach allows acceptable morbidity and mortality in octogenarian patients.

Mid-Term Results of Peripheral Cannulation After Robotic Cardiac Surgery.

IntroductionVarious surgical procedures for minimally invasive cardiac surgery have been described in recent decades as alternatives to median sternotomy. Cardiopulmonary bypass via femoral arterial and venous cannulation is the foundation of these procedures. In this study, we evaluated the mid-term outcomes of femoral cannulation performed with U-suture technique in patients undergoing robotic heart surgery.MethodsA total of 216 patients underwent robotic-assisted cardiac surgery between January 2013 and April 2017. Cardiopulmonary bypass was performed via femoral artery, jugular, and femoral vein cannulation, and a Chitwood clamp was used for aortic occlusion. A total of 192 patients attended the outpatient follow-up, and femoral arterial and venous flow pattern was examined using Doppler ultrasound (DUS) in 145 patients.ResultsHospital mortality occured in 4 of the 216 (1.85%) cases, but there was no late mortality in this patient group. Postoperatively, seroma (n=9, 4.69%) and cannulation site infection (n=3, 1.56%) were managed with outpatient treatment. DUS in 145 patients revealed triphasic flow pattern in the common femoral arteries in all patients except for 2 (1.38%). These patients were determined to have asymptomatic arterial stenosis. Chronic recanalized thrombus in the common femoral vein was also detected in 2 (1.38%) patients.ConclusionFemoral artery cannulation with the U-suture technique can be successfully performed in robotic-assisted cardiac surgery, with good mid-term results.

Unequal pressure distribution along the jaws of currently available vascular clamps: do we need a new aortic clamp?

The pressure along vascular clamp jaws may be unequally distributed, with greater pressure near the clamp hinge than at its top. Such unequal pressure distribution may cause aortic injury, especially in large aortas. We evaluated pressure distribution along different currently availably clamp jaws. Seven descending thoracic aortas from pigs (diameter 2.0-3.0 cm) were plainly dissected and all side arteries closed. Aortas were filled up with water and cross-clamped. The pressure inside the aorta was raised to 100 mmHg and the aorta was clamped so tightly that no water exited from the distal aortic end. Each aorta was clamped seven times at different sites with the following clamps: DeBakey, Satinsky, femoral, iliac, Chitwood, angled handle Fogarty and straight handle Fogarty. The pressure along the clamp jaws was measured with a pressure-detecting film placed between the clamp jaws and aorta. The collagen-fibre disorganization was examined in haemotoxylin-eosin- and Elastica van Gieson-stained tissue samples. The DeBakey clamp revealed the lowest maximum pressure along the clamp jaws after complete aortic occlusion (1.43 ± 0.49 MPa), whereas the Chitwood clamp's pressure was the highest (3.26 ± 1.93 MPa, P < 0.001). The angled handle Fogarty clamp displayed the lowest difference between maximum pressures across the jaws (33%), with the greatest difference measured in the iliac (72%) and Chitwood (66%) clamps. The highest collagen-fibre disorganization score was observed in the proximal-to-the-clamp-hinge quartile after clamping with the angled handle Fogarty (2.8 ± 0.4), straight handle Fogarty (2.3 ± 0.8) and Chitwood (2.3 ± 0.5) clamps. The pressure along clamp jaws is unequally distributed in all the currently available vascular clamps. The Chitwood clamp is associated with the highest maximum pressure during complete aortic occlusion and with the most unequal pressure distribution along the jaws.

Port Access Cardiac Operations Can Be Safely Performed With Either Endoaortic Balloon or Chitwood Clamp

Minimally invasive, right thoracotomy (port access) approaches to intracardiac operations (mitral valve, tricuspid valve, atrial septal defect, intracardiac tumors) are becoming increasingly accepted by surgeons, cardiologists, and patients alike. Standard techniques for cardioplegic arrest of the heart have included endoaortic balloons and Chitwood clamps. Concerns have been raised regarding the potential increased risk of vascular adverse events (embolization, dissection, stroke, lower extremity ischemia) associated with endoaortic balloon occlusion. We undertook this study to evaluate the vascular risk associated with endoaortic balloon use. All patients undergoing minimally invasive, port access, right thoracotomy operations from 1998 to 2012 at our institution were retrospectively analyzed. Patients undergoing aortic occlusion with the Chitwood clamp (n=189) were compared with patients undergoing occlusion with the endoaortic balloon (n=875). There was no statistical difference in the rate of dissection between patients undergoing aortic occlusion with an endoaortic balloon (1.03%) and those receiving a Chitwood clamp (1.06%). Similarly, there was no difference in the rate of type A dissection between aortic occlusion strategies (endoaortic balloon=0.57%, n=5, vs Chitwood clamp=1.06%, n=2, p=0.28). No difference in the incidence of stroke was identified between the endoaortic balloon and the Chitwood clamp (2.2% vs 2.1%, p=1.0). Minimally invasive cardiac operations using a peripheral cannulation strategy can be safely performed with minimal vascular adverse events incorporating either endoaortic balloon or Chitwood clamp aortic occlusion. As experience with the endoaortic balloon is gained, the incidence of vascular adverse events can be reduced to nearly negligible rates.

Totally robotic atrial septal defect closure: 7-year single-institution experience and follow-up.

Robotic technology has been applied to atrial septal defect (ASD) repair for more than 10 years, but the number of cases reported is limited and results of long-term follow-up are not clear. This study reports on a large group of patients who underwent totally robotic ASD repair on an arrested or beating heart at a single institution with a 7-year follow-up. From 2007 to 2013, 160 patients (median age, 36 years; range, 11-66 years) at our centre underwent selective repair of secundum-type ASD using the da Vinci robotic system. The first 54 cases were performed on an arrested heart (arrested-heart group, n = 54) and the remainder on a beating heart (beating-heart group, n = 106). The mean diameter of defects was 2.9 cm (range, 1.1-4.1 cm). Cardiopulmonary bypass was achieved via cannulation of the femoral vessels and the right internal jugular vein. Blood cardioplegic arrest was induced using a transthoracic Chitwood clamp in the arrested-heart group. With the assistance of a robotic surgical system, atrial septal defect repairs were performed with or without tricuspid valvuloplasty via three 8-mm ports, a camera port and a working port in the right chest. Transoesophageal echocardiography was used to evaluate surgical results and follow-up. Complete ASD closure was verified by intraoperative transoesophageal echocardiography in all patients. None of the procedures was converted to an alternate technique and there were no major complications. There were significant learning curves for cross-clamp time, operative duration and cardiopulmonary bypass time. The beating-heart group had significantly shorter operative and cardiopulmonary bypass durations than the arrested-heart group (P = 0.000). The two groups had similar durations of mechanical ventilation and intensive care unit and hospital stays, and similar drainage volumes. During the 39 ± 21 months of follow-up, no patient required reoperation because of a residual shunt or tricuspid valve regurgitation. ASD can be performed safely and effectively on an arrested or beating heart with the assistance of robotic technology. This totally endoscopic approach represents an option for patients seeking a reliable, minimally invasive ASD repair with an excellent long-term result.

Minimally Invasive Mitral Valve Surgery Utilizing Heart Port Technology

To determine operative outcomes of right mini-thoracotomy mitral valve surgery utilizing port access technology in first-time and reoperative cardiac surgery patients. From 2002 to 2011, 881 patients underwent minimally invasive mitral valve surgery. Of these, 154 patients had previous cardiac operations via sternotomy (Group 1), of which 18 (12%) had two previous operations. Seven hundred and twenty-seven patients had no previous cardiac operations (Group 2). Patient demographics were similar in both groups. In Group 1, 76 (49%) patients had previous coronary artery bypass grafting, 13 (8%) had previous aortic valve surgery, and 57 (37%) had previous mitral valve surgery. Preoperative echo findings for Groups 1 and 2 included severe mitral regurgitation (MR) (88%, n = 135; 94%, n = 687), mitral stenosis (MS) (4%, n = 6; 2%, n = 12), MS + MR (8%, n = 13; 4%, n = 28), and ejection fraction (48%, 56%). Operative procedures in Groups 1 and 2 were MV repair (54%, n = 84; 89%, n = 645) and MV replacement (46%, n = 70; 11%, n = 82). Circulatory management techniques for Groups 1 and 2 included endoballoon (75%, n = 116; 79%, n = 576), Chitwood clamp (8%, n = 12; 20%, n = 147), and fibrillatory arrest (17%, n = 30; 0.5%, n = 4). Perioperative outcomes were: stroke: 2.5%, 1.6%; reoperation for bleeding: 5%, 6%; valvular reoperation rate: 0.6%, 2%; aortic dissection: 2.5%, 1%; and wound infection: 0%, 0%. Transfusion requirement was 49% (n = 76) and 31% (n = 232), respectively. Median hospital stay was seven and seven days, respectively. On postoperative echocardiography, 98% (n = 151) and 99% (n = 718) of patients had zero or trace MR (1+) with 100% freedom from MR > 2+. In-hospital mortality was 3% (n = 5) and 1% (n = 8). Operative outcomes with minimally invasive mitral valve surgery utilizing port access technology can be performed safely. Stroke rate was higher in the reoperative cases (p = NS) although similar to reports evaluating redo sternotomy in mitral valve cases.

Minimally invasive mitral valve surgery: still possible when aortic clamping is judged unsafe

We read with great interest the recent article by Vollroth et al. [1], describing their experience with conversion to sternotomy during minimally invasive mitral surgery. The authors are to be congratulated on the low incidence of conversion (1%) that they have reported. The high early mortality (23.5%) associated with conversion in their series remains a reminder of the gravity of such an occurrence, even in experienced hands. Given the fact that 14 of the 34 conversions described were related to the application of the Chitwood clamp, the authors recommend that, with any difficulty encountered during its placement, the option of elective conversion should be considered [1]. In our experience, elective conversion was seldom a consequence of difficulty clamping the aorta. Whenever clamping the aorta is judged unsafe, our alternative strategy is opting for hypothermic fibrillation (HF) as a means of myocardial protection. Over the past few years, our threshold for shifting towards HF has been increasing. We recently reported on our experience with the minimally invasive approach in patients who had a previous sternotomy, where aortic clamping is commonly judged to be unsafe due to dense adhesions. HF was used in 77% of these patients without a single incidence of conversion to sternotomy. Contrary to a common notion, there was no relationship between HF and cerebrovascular accidents [2]. Similarly, previous reports from the authors’ own institution reported exactly the same pattern of adoption of HF (77%) in redo cases [3]. Other authors also reported an increasing trend towards the use of HF in minimally invasive surgery with satisfactory results [4]. Given the demonstrated safety of HF in redo cases, it seems reasonable to extend its use to other clinical situations where aortic clamping is judged unsafe because of a diseased or a dilated aorta. As minimally invasive mitral surgery gains more ground, surgeons are likely to become increasingly exposed to similar situations. And mastering alternative means of myocardial management, rather than opting to convert to a full sternotomy, is a more practical approach. Finally, we would like to commend the authors for a fine article and look forward to their response.

Reply to Saleh et al.

With great interest, we have read the letter from Dr. Saleh et al. concerning our recently published article ‘Minimally invasive mitral valve surgery is a very safe procedure with very low rates of conversion to full sternotomy’ in the EJCTS [1]. We very much appreciate the comments from this expert group and it is our pleasure to respond. The minimally invasive approach through a right-sided minithoracotomy has developed remarkably over the past decade and has become the preferred method for mitral valve surgery in specialized centres. Despite a vast body of experience that has been gathered to date, this operation still remains a challenge, due to the limited operative space, an extended distance from the chest wall to the mitral valve and the need for specialized equipment and operative tools [2]. Chitwood et al. introduced the transthoracic aortic clamp to facilitate secure clamping of the aorta. Significant limitations of the endoaortic occlusion system have led to this innovation [3]. We have used this so-called ‘Chitwood clamp’ since its introduction into clinical practice. Our practice reconfirms the high applicability, effectiveness and safety of this technique: nevertheless, special care needs to be given to vital cardiovascular structures—such as the left atrial appendage and the pulmonary arteries—when clamping the aorta [4]. This is a well-known subject and Chitwood and his group have repeatedly alluded to this potential problem. With their letter, Chitwood and colleagues again take an active role in the continuing development of minimally invasive mitral valve surgery and refer to the valuable option of using hypothermic ventricular fibrillation, especially for redo cases without severe aortic insufficiency. We do underline this recommendation and congratulate the authors on their great experience and eminent results. As we have previously reported, we have used hypothermic fibrillation (HF) in patients undergoing redo surgery in over 40% of these patients [5]. Similarly to Chitwood’s group, using HF, we were able to achieve a very low conversion rate, low incidence of major vascular injury and superior perioperative mortality. Nevertheless, we did encounter a relatively high risk of perioperative stroke, so far for unknown reasons. An investigational study is currently being undertaken to identify the mechanism of stroke in this special subset of patients. Therefore Arcidi et al. are to be congratulated on their low incidence of cerebrovascular events [6]. Based on our vast clinical experience—and despite the low risk of aortic clamp-associated major adverse events—we do underline our recommendation to use the Chitwood clamp whenever possible: it does represent the primary technique for aortic occlusion. However in cases when aortic cross-clamping appears to be of high risk, hypothermic fibrillation provides a feasible option.

Clinical experiences on correction of congenital heart diseases with robotic technology: a report of 160 cases

To summarize the clinical experiences on correction of congenital heart disease with robotic technology at a single center. Between January 2007 and May 2012, this retrospective study recruited 160 consecutive patients undergoing robotic surgery for congenital heart diseases. There were 74 males and 86 females with a median age of 35 years (range: 11-62). The procedures included secundum-type atrial septal defect repair (n = 130), ostium primum defect repair (n = 1), perimembranous ventricular septal defect repair (n = 21), mitral valve repair for anterior leaflet cleft (n = 7) and mitral valve repair plus left atrial myxoma resection (n = 1). Cardiopulmonary bypass graft was established through cannulation of right femoral artery, vein and right internal jugular vein under the guidance of transesophageal ultrasound. Myocardial protection was performed with cold blood cardioplegic solution or HTK solution and a transthoracic Chitwood clamp was used to occlude ascending aorta. Via three 8-mm ports and one 15-mm port in right chest, the microscopic instruments were manipulated to complete defect closure or mitral valve plasty, utilizing da Vinci S or da Vinci SI robotic system. Echocardiography was performed intraoperatively and at pre-discharge. Routine follow-ups were conducted. The clinical data of operating time, cardiopulmonary bypass time and follow-up examinations were retrospectively analyzed. All cases were treated successfully without a conversion into median sternotomy. No operative mortality or severe surgical complications were observed. Seventy-six cases of secundum-type atrial septal defect were completed on beating heart. The learning curves were noted for operating time of beating heart group and cross clamp time of arrest heart group. No residual shunt, malignant arrhythmia or mitral valve regurgitation was detected on intraoperative or postoperative echocardiography and during a median follow-up period of (29.1 ± 16.3) months. Robotic minimal access is technically feasible and it may be applied in selective patients with atrial septal defect, perimembranous ventricular septal defect and mitral valve cleft.

Abstract 18025: Cryomaze for Sole-Therapy Atrial Fibrillation

Objectives: Surgical AF treatment program was started at our institution in August 2008. We report our initial results using minithoracotomy approach for endocardial cryomaze. Methods: All 30 patients undergoing Cryomaze between 8/08 and 12/10 are included. 1 patient underwent MVR while two others needed sternotomy for incidental aortic aneurysm and coronary artery disease diagnosed during preoperative workup. Surgical technique consisted of femoral cannulation for cardiopulmonary bypass and right mini-thoracotomy with video-assistance. Aortic root vent used in all cases and Chitwood clamp was used in arrested heart cases. On the left side, all pulmonary veins were isolated as an island and another line was made to the mitral annulus (LA isthmus line). On the right side, SVC was connected to IVC and this line was connected to tricuspid annulus (RA isthumus line). Left atrial appendage was oversewn in two layers, except during sternotomy, where it was stapled off with endo-GIA stapler. Beta blockers were used as tolerated and amiodarone was only used if patient developed AF. Postprocedure follow-up included spot EKG at 1, 3, 6 and 12 months and yearly thereafter. Symptomatic patients underwent three week continuous rhythm monitoring. Results: Outcomes are given in table below. 4(13%) patients required permanent pacemakers. There were 6 (20%) complications including catheter ablation for atrial tachycardia, pericardial effusion (no intervention needed), subcutaneous emphysema, lung hernia, femoral lymph leak and reopening of one LAA. There were no mortalities or strokes. Conclusions: Minimally invasive Cryomaze has acceptable morbidity and excellent short-term results in treating AF. Freedom from AF in this series was not influenced by left atrial vs biatrial ablation, beating heart vs arrested heart ablation, primary vs prior failed catheter ablation, or Paroxysmal vs Persistent AF.

Minimally invasive mitral valve surgery via right minithoracotomy

To summarize the successful experience of 45 patients with minimally invasive mitral valve surgery via right minithoracotomy. Forty-five patients with mitral valve disease were enrolled. A main surgical wound (4-6 cm)was made over the lateral border of the right breast. Cardiopulmonary bypass was established via femoral cannulation. The Chitwood clamp was inserted thlution the 2nd or 3rd intercostal space. After the cross-clamp was placed, cold blood cardioplegic solution was delivered via right minithoracotomy. The procedures of mitral valve replacement were performed via left atrialotomy. All the operations were successful. There was no death. The duration of operation and extracorporeal circulation was 80-291(139±35) min, and 25-110(49±21) min, respectively. The cross-clamped time was 18-77 (33±12) min, the ventilation time was 4.5-45(14.8±10) h, the total chest tube drainage was 50-1 050(262±110) mL, and the postoperative hospital stay was 5-14(7.5±1.8) d. Minimally invasive mitral valve surgery via right minithoracotomy is feasible, safe, and less invasive with rapid recovery,and has superior cosmetic results for patients.

Minimally invasive video-assisted approach for left atrial myxoma resection

Minimally invasive surgery has become the standard approach for several cardiac diseases. We report in the present study our ten-year experience with endoscopic cardiac surgery for left atrial myxoma resection. Between January 1998 and January 2008, 14 patients (median age: 61 years) underwent surgery for left atrial myxoma resection at our institution. The Heartport access system and the video-assistance were systematically employed to provide excellent vision and facilitate surgery. The aortic clamping was obtained with an 'EndoClamp' in 11 cases (using a central or peripheral endoaortic balloon, depending on the site of the arterial cannulation) or transthoracically with the Portaclamp system in two cases and the Chitwood clamp in one case. The average time needed for cross-clamping was 49+/-29 min, with a mean cardiopulmonary bypass (CPB) time of 88+/-57 min. There were no early or late hospital deaths. Mean intensive care unit and hospital stay were three and eight days, respectively. The mean follow-up time was 64 months and there was no evidence of residual or recurrent tumor. There were two late deaths due to acute ischemic stroke. Minimally invasive video-assisted surgery for left atrial myxoma resection is a safe, reproducible and cosmetic operation and can be considered an effective oncologic approach as an alternative to standard sternotomy.

Port-access minimally invasive surgery for atrial septal defects: A 10-year single-center experience in 166 patients

We assessed the surgical results and the benefits to the patient of a minimally invasive surgical approach for atrial septal defects. Between May 1998 and May 2008, 166 patients (median age, 44 years) had surgery for atrial septal defects in our institution. Of these patients, 118 (71%) had a patent foramen ovale (associated with atrial septal aneurysm in 48 cases), 33 (20%) had a wide ostium secundum defect, 6 (3.6%) had an ostium primum defect, 6 (3.6%) had a sinus venosus defect with abnormal pulmonary vein connection, and 1 (0.6%) had a coronary sinus defect. In 2 cases (1.2%) patients were referred to our department for surgical correction after failure of interventional occluder placement. All patients were operated on via a right minithoracotomy (mean incision, 5.5 + or - 1 cm) in the fourth intercostal space and under cardiopulmonary bypass. The HeartPort access system was used in 106 patients (64%), with an endoaortic clamp (central kit in 50 cases and peripheral kit in 56). In the remaining patients (36%), we preferred the Portaclamp system (37 cases) or the Chitwood clamp (23 cases). Average crossclamp time was 38.4 + or - 22.2 minutes with a mean cardiopulmonary bypass time of 64.9 + or - 34.5 minutes. There was no conversion in classic sternotomy. There were no early or late hospital deaths. Surgical revision was performed in 6 patients for bleeding from the thoracic wall. The mean hospital stay was 5.8 days. At 51 months mean follow-up, 4 patients died of non-cardiac-related causes. Port-access minimally invasive surgery for atrial septal defects is a safe, less-invasive, reproducible, and cosmetic operation, providing an excellent outcome and an effective correction, and could be now considered the standard approach for this type of patient.