Search

Background Surgical pulmonary embolectomy (SPE) has been sparingly used for the successful treatment of massive and submassive pulmonary emboli. To date, all data regarding SPE have been limited to single-center experiences. The purpose of this study was to document short-term outcomes after SPE for acute pulmonary emboli (PE) at four high-volume institutions. Methods A retrospective review of multiple local Society of Thoracic Surgeons databases of adults undergoing SPE from 1998 to 2014 for acute PE was performed (n = 214). Demographic, operative, and outcomes data were collected and analyzed. Patients were summarily categorized as having either massive or submassive PEs based on the presence or absence of preoperative vasopressors. Results A total of 214 patients with acute PE were treated by SPE. The mean age was 56.0 ± 14.5 years, and 92 (43.6%) patients were female. Of those, 176 (82.2%) PEs were submassive and 38 (17.8%) were massive. Fifteen (7.0%) patients underwent concomitant cardiac procedures, with 10 (4.7%) having simultaneous valvular interventions and 5 (2.4%) undergoing concomitant bypass grafting. Cardiopulmonary bypass (CPB) was used for all cases. Cardioplegic arrest was used for 80 (37.4%) patients. The median CPB and aortic cross clamp times were 71.5 (interquartile range [IQR], 47.0–109.5) and 46.0 (IQR, 26.0–74.5), respectively. Notably, only 25 (11.7%) patients died in the hospital. Mortality was highest among the 28 patients who experienced preoperative cardiac arrest (9, 32.1%) Conclusions These data represent the first multicenter experience with SPE for acute pulmonary emboli. Surgical pulmonary embolectomy for acute massive and submassive PE is safe and can be performed with acceptable in-hospital outcomes; the procedure should be included in the multimodality treatment of life-threatening pulmonary emboli.

Background Rigid bone fixation is the standard of care for all bone reconstructions except that after sternotomy. Sternal reconstruction after median sternotomy using rigid fixation with plates may improve bone healing and reduce pain when compared with wire cerclage. Methods One-hundred forty patients at six centers who were determined preoperatively to be at high risk for sternal wound complications were randomly assigned to sternal closure with rigid plate fixation (n = 70) or wire cerclage (n = 70). Sternal healing was evaluated at 3 or 6 months by a core laboratory using computed tomography. Pain and function were evaluated at postoperative day 3 through discharge, 3 weeks, 6 weeks, 3 months, and 6 months. Results Sternal healing was superior in rigid plate fixation patients at both 3 and 6 months. Mean computed tomography scores in the rigid plate fixation and wire cerclage groups at 3 months were 1.7 ± 1.1 and 0.9 ± 0.8 ( p = 0.003). At 6 months, the scores were 3.2 ± 1.6 and 2.2 ± 1.1, respectively ( p = 0.01). At 6 months, 70% of rigid plate fixation patients had achieved sternal union, compared with 24% of conventional wire cerclage patients ( p = 0.003). Pain scores and narcotic usage were lower in rigid plate fixation patients. Significant differences in pain scores were observed at 3 weeks for total pain ( p = 0.020) and pain with coughing ( p = 0.0084) or sneezing ( p = 0.030). Complication rates were similar in both groups. Conclusions Sternal reconstruction using rigid fixation with plates improved bone healing and reduced early postoperative pain compared with wire cerclage.

An increasing number of patients are being referred for mitral valve repair in the redo cardiac surgery setting. The most common clinical scenarios involve prior coronary bypass surgery or aortic valve replacement, each presenting special challenges in terms of gaining valve exposure to enable repair while limiting dissection as much as possible. A right anterior thoracotomy approach is preferred in most patients, coupled with hypothermic fibrillatory arrest. A repeat sternotomy may be favored in select circumstances such as when there is a need for bypass grafting or moderate aortic insufficiency is present. Special attention to cannulation techniques, perfusion conditions, valve exposure, and de-airing maneuvers are all important to ensure good clinical results. Using a tailored approach we have performed mitral valve repair in 22 patients with a patent left internal mammary artery graft following coronary artery bypass grafting between July 1992 and February 2000 with acceptable morbidity and low mortality.

Objective We sought to assess the feasibility of performing sutureless distal coronary artery bypass anastomoses with a novel magnetic coupling device. Methods From May 2000 to April 2001, single-vessel side-to-side coronary artery bypass grafting on a beating heart was performed in 39 domestic white pigs (35-60 kg) without the use of mechanical stabilization, shunts, or perfusion bridges. Animals were divided into 2 groups. Seventeen pigs underwent right internal thoracic artery to right coronary artery bypass grafting through a median sternotomy (group 1) with a novel magnetic vascular positioning system (MVP system; Ventrica, Inc, Fremont, Calif). Twenty-two pigs underwent left internal thoracic artery to left anterior descending artery grafting with the MVP anastomotic device through a left anterior minithoracotomy (group 2). This system consists of 2 pairs of elliptical magnetic implants and a deployment device. One pair of magnets forms the anastomotic docking port within the graft; the other pair forms an identical anastomotic docking port within the target vessel. The anastomosis is created when the 2 docking ports magnetically couple. Anastomotic patency was evaluated by means of angiography during the first postoperative week and at 1 month. Histologic studies were performed at different time points as late as 6 months. Results Right internal thoracic artery to right coronary artery anastomoses and left internal thoracic artery to left anterior descending artery anastomoses were successfully performed with the system in all animals. The self-adherent and self-aligning properties of the implants allowed for immediate and secure approximation of the arteries (total anastomotic time between 2-3 minutes). Anastomoses were constructed without a stabilization platform. Five nondevice-related deaths occurred postoperatively. One-week angiography, performed in 35 surviving animals, showed a patent graft and anastomosis in all cases. The patency rate at 1 month was 97% (33/34). Histologic studies as late as 6 months demonstrated neointimal coverage of the magnets without any significant luminal obstruction. Histology also confirmed the presence of viable tissue between magnets. Conclusion The MVP anastomotic system uses magnetic force to create rapid and secure distal coronary artery anastomoses, which might facilitate minimally invasive and totally endoscopic coronary artery bypass surgery.

Over the past 5 years, many coronary artery surgeons have embraced technology and advanced the field of beating heart surgery to the point where off-pump coronary artery bypass (OPCAB) is becoming a mature procedure. Enabling technologies are now available for all stages of the procedure, including cardiac positioning, coronary artery stabilization, coronary artery visualization, and performance of the proximal and distal anastomoses. Despite these successes, only a minority of cardiac surgeons performs this procedure routinely. Proponents of OPCAB and the medical device industry will need to continue to develop new technologies to make OPCAB less technically challenging and more widely accepted. Progress towards routine single-vessel off-pump totally endoscopic coronary artery bypass has been slow. Translating the benefits of multivessel OPCAB to an endoscopic setting remains a formidable challenge that will require further technologic breakthroughs. © 2003 Elsevier Inc. All rights reserved.

Background — Acute pulmonary embolism confers a high mortality rate despite advances in diagnosis and therapy. Thrombolysis is often effective but has a high frequency of major bleeding complications, especially intracranial hemorrhage. Therefore, we liberalized our criteria for acute pulmonary embolectomy and considered operating on patients with anatomically extensive pulmonary embolism and concomitant moderate to severe right ventricular dysfunction despite preserved systemic arterial pressure. Methods and Results — We report 29 (17 men and 12 women) consecutive patients who underwent embolectomy from October 1999 through October 2001. Twenty-six patients (89%) survived surgery and were alive more than 1 month postoperatively. Median follow-up is 10 months. Conclusion — The high survival rate of 89% can be attributed to improved surgical technique, rapid diagnosis and triage, and careful patient selection. We hope that other tertiary centers will evaluate pulmonary embolism patients with an algorithm that includes surgical embolectomy as one of several therapeutic options. Our contemporary approach to pulmonary embolectomy no longer confines this operation to a treatment of last resort reserved for clinically desperate circumstances.

Background . Aortic valve surgery after coronary artery bypass grafting (CABG) in the setting of patent pedicled internal mammary artery (IMA) grafts poses a high risk because of the underlying ischemic and valve disease. Unlike mitral valve surgery or CABG, in which aortic clamping (AoX) may be optional, aortic valve surgery uniformly requires AoX unless circulatory arrest is used. Management of the IMA graft in these circumstances has traditionally involved dissection and clamping to prevent regional myocardial warming and cardioplegia "washout" during AoX. An alternative strategy involves avoiding dissection of the IMA, leaving the IMA graft open and establishing moderate-to-deep hypothermia during AoX and cardioplegic arrest. To date, no study has been published documenting the safety and efficacy of the latter practice. Methods . A total of 94 patients who had patent IMA graft and underwent aortic valve surgery under AoX and cardioplegia between April 1992 and March 2001 were analyzed. The IMA was avoided and left open during AoX, and the patients were cooled systemically (median 20°C). Patients ranged in age from 55 to 90 years (median 73.5 years). Ejection fraction was 15% to 83% (median 50%). Of the patients, 18 (19%) underwent minimally invasive upper hemi-resternotomy. Analysis for predictors of outcome was performed. Results . The operative mortality, perioperative myocardial infarction (MI), and stroke rates were 6.4%, 7%, and 11%, respectively. No significant independent predictors of operative mortality or MI could be identified in the multivariate analysis, although a trend was shown for operative mortality with urgent procedures and patients requiring concomitant surgery of the ascending or arch aorta or aortic root. Advanced age and prolonged cardiopulmonary bypass predicted stroke in the multivariate analysis. There were five (5%) IMA injuries, all occurring during reentry or mediastinal dissection, but none in the subgroup of patients who underwent minimally invasive procedures. All patients survived. Conclusions . Patients undergoing aortic valve surgery after CABG in the presence of patent IMA represent a potentially high-risk group. Because AoX is almost uniformly required, a decision regarding the management of the IMA pedicle is needed. We have found that leaving the IMA undissected and unclamped is a reasonable strategy, provided that systemic cooling for myocardial protection is established to prevent regional warming and to compensate for cardioplegia washout effect during AoX.

For more than three decades, conventional coronary artery bypass grafting (full sternotomy, cardiopulmonary bypass, and cardioplegic arrest) has been the treatment of choice for patients with multi-vessel coronary artery disease. However, neurologic injury secondary to ascending aortic manipulation and systemic inflammatory reaction related to cardiopulmonary bypass are major causes of morbidity. During the past decade research efforts have been focused on the development of innovative revascularization techniques to minimize these deleterious effects. Minimally invasive direct coronary artery bypass surgery was developed to reduce chest trauma and to accelerate patient recovery. The relatively recent introduction of mechanical stabilizers and positioning devices has allowed for the safe performance of off-pump coronary artery bypass for patients with multi-vessel disease. Robotic technology has offered the possibility of myocardial revascularization through limited access using endoscopic principles. Recently, emphasis has been placed on the development of new sutureless anastomotic devices that may revolutionize the field of myocardial revascularization and allow a broader acceptance of minimally invasive CABG. Despite the increasing availability of new technologies, the validity of these procedures must be evaluated carefully. Prospective randomized studies and longitudinal follow-up will be required.

Background . Reoperative coronary artery bypass grafting (CABG) through a left thoracotomy is a challenging operation with no one dominant approach. We developed a tailored strategy for this difficult group of patients, integrating the currently available newer technologies for each patient indication. Methods . Between October 1991 and October 1999, 50 consecutive patients underwent reoperative CABG through a left thoracotomy. Age was 65 ± 9 years, 40 (80%) were men, and preoperative ejection fraction was 40 ± 13. In 36 patients (72%) the left internal mammary artery had been placed to the left anterior descending coronary artery during the primary CABG and in 25 of 36 patients (70%) this left internal mammary artery–left anterior descending coronary artery graft was patent. The mean duration from previous CABG was 8.0 ± 4.8 years. Three approaches were used: (1) conventional cardiopulmonary bypass using fibrillatory or circulatory arrest (n = 33, 66%); (2) Heartport endoaortic balloon occlusion (n = 4, 8%); and (3) off-pump beating heart techniques (n = 13, 26%). Results . The off-pump CABG technique was used in the majority of recent patients and 1 (7.7%) had to be converted to cardiopulmonary bypass due to hemodynamic instability. When cardiopulmonary bypass was used its duration was 122 ± 59 minutes and mean temperature on bypass was 24° ± 6°C. In the 4 patients in whom the Heartport system was used, the median endo-aortic occlusion duration was 49 minutes. Patients received an average of 1.4 grafts/patient. In 60 of 70 patients (89%) distal anastomoses were performed to an anterolateral coronary target. There were 3 of 50 (6%) operative deaths, 2 in the conventional group and 1 in the endo-aortic balloon occlusion group. The mean length of stay in the 47 survivors was 7.8 ± 3.9 days (median, 7 days). Conclusions . Reoperative CABG by left thoracotomy remains a challenging operation. Several techniques, including off-pump CABG, conventional cardiopulmonary bypass, circulatory arrest, and endoaortic balloon occlusion, should be in the surgeon's armamentarium to allow a tailored approach for each operation based on patient indications.

Surgical pulmonary embolectomy has a definite role to play in the management of selected patients with acute, Major pulmonary embolism. Rapid noninvasive diagnostic modalities allow proper patient selection based on anatomic location of the emboli, right heart function, and contraindications to thrombolysis. Operative results are a direct reflection of the preoperative hemodynamic status, the degree of underlying cardiopulmonary disease, and attention to minimizing surgical trauma and protecting the right heart. An operative mortality of 10% or less and excellent long-term outcomes can be expected if the procedure is performed, before cardiovascular collapse, as part of a multidisciplinary strategy that emphasizes careful patient selection, rapid diagnosis, triage, and transport.

Objectives: Our objective was to determine whether direct-access minimally invasive mitral valve surgery can improve recovery and cost while maintaining the efficacy of conventional surgery. Methods: Minimally invasive mitral valve operations were performed on 106 patients, 58% male, average age 58.1 years, with good ventricular function. Ninety underwent repair of a regurgitant, myxomatous valve, and 16 underwent mitral valvuloplasty for prematurely calcified mitral stenosis. The valve was approached with standard instruments through a 5- to 8-cm right parasternal incision. Eighty-five had open femoral artery–femoral vein cannulation, but this technique has recently been replaced by direct cannulation of the aorta and percutaneous cannulation of the femoral vein for most patients. Results: There were no operative deaths. The mean mitral regurgitation score (0-4) decreased from 3.7 to 0.7 after the operation. Although ischemic and bypass times were increased, postoperative recovery was accelerated. Ventilatory support time, intensive care unit stay, hospital stay, need for rehabilitation, and return to "normal activities" all improved. Hospital charges, pain medications, and blood transfusions were also reduced. New atrial fibrillation contributed significantly to increased length of stay and charges. There were no deep wound infections. Other complications included re-exploration for bleeding (n = 1), transient ischemic attacks (n = 2), stroke (n = 1), femoral artery injury (n = 5), pseudoaneurysm (n = 2), and antegrade dissection of the ascending aorta (n = 1). Two patients died and 1 required reoperation during a mean follow-up of 8.8 months. Conclusions: Direct-access minimally invasive mitral valve surgery can accelerate recovery, decrease charges, and decrease pain, while maintaining overall surgical efficacy. It has become our standard approach for isolated primary mitral valve operations. (J Thorac Cardiovasc Surg 1998;116:705-15)

Dynamic cardiomyoplasty (DCM) is an emerging surgical procedure for heart failure in which the patient's latissimus dorsi (LD) muscle is wrapped around the heart and stimulated to contract in synchrony with the heartbeat as a cardiac assist measure. A 6 week training protocol of progressive electrical stimulation renders the normally fatigueable skeletal muscle fatigue-resistant and suitable for chronic stimulation. To date, over 500 procedures have been performed in worldwide clinical trials. Investigators typically report symptomatic improvement and modest hemodynamic improvement in patients. Controversy exists regarding the exact mechanism of DCM. To test the hypothesis that DCM augments cardiac stroke volume through improvement in systolic function, we formulated an engineering model of dynamic cardiomyoplasty to predict stroke volume. The heart and the LD were modeled as nested (series) elastance chambers, and the vasculature was represented by a two-element Windkessel model. Using five healthy goats, we verified model predictions of stroke volume for both stimulator ON beats (y = 1.00x-0.08, r = 0.87, p0.0001) and OFF beats (y = 1.01x+1.06, r = 0.91, p0.0001), where x and y are the measured and predicted stroke volumes, respectively. The model confirms that using untrained latissimus dorsi applied to the normal myocardium produces only moderate increases in stroke volume and suggests that future research should focus on increasing LD strength after training.

Venous occlusive disease encompasses a variety of clinical entities that range the spectrum from being catastrophic and life threatening, such as massive pulmonary embolism, to disease states that may have an occult presentation, such as inferior vena cava occlusion. Other examples of veno-occlusive disease states include deep venous thrombosis and right atrial masses. When venous occlusion is characterized by an overwhelming volume of offending material, clinical therapy may be a significant challenge. This chapter examines the historical background of therapy directed at venous occlusion, and outlines a simplified technique for addressing the occurrence of major undesirable intravascular material.

Angiography has been considered the gold standard, for the diagnosis of acute dissection of the ascending aorta, but it may increase mortality by imposing an unnecessary delay before surgical repair. In addition, coronary angiography has often been considered essential as well. From 1988 to 1993, 37 patients (median age 61 years, 30 men and 7 women) had acute dissection of the ascending aorta. All of the initial 15 patients (group I) had angiography, even though the diagnosis , of aortic dissection had already been made noninvasively in 14; six (40%) of 15 died, three of aortic rupture and none of complications of coronary artery disease. Among the next 22 patients (group 11), 21 had a noninvasive diagnosis of acute dissection of the ascending aorta (eight by echocardiography; 13 by computed tomography), and 19 (86%) were operated on without angiography; two died (9%, p = 0.03 versus group I) and neither death was due to aortic rupture ,or coronary artery disease. Overall, either root or selective coronary angiography was attempted in 18 of 37 patients, but it documented coronary artery disease in only two patients (11%). Coronary artery disease was found in four other patients at autopsy; three of them, including two that died of aortic rupture, had angiography that failed to reveal the coronary artery disease. Noninvasive diagnosis of acute dissection of the ascending aorta is reliable and avoids the risks and delays inherent in invasive angiography. Rapid noninvasive diagnosis of aortic dissection and avoidance of routine angiography appear to improve survival by expediting surgical intervention and thus decreasing the risk of aortic rupture.

The effect of complement activation on the pulmonary vascular system and on right ventricular function was studied in sheep (n = 12) by injection of cobra venom factor. Animals were instrumented for measurement of pulmonary flow, mean pulmonary artery pressure, right ventricular stroke work, arterial blood gases, and systemic vascular resistance. Blood was sampled from the left atrium and pulmonary artery to measure thromboxane B2, the metabolite of thromboxane A2, by radioimmunoassay. After baseline measurements, animals were randomly assigned to receive a selective thromboxane receptor antagonist SQ30741 as a 10 mg/kg bolus with an infusion of 10 mg/kg per hour or else to receive vehicle. Cobra venom factor was then injected (30 U/kg) in all animals, and data were recorded at 15, 30, 60, 90, and 120 minutes. In control animals there was a 2.4-fold increase in mean pulmonary artery pressure and a 76% increase in right ventricular stroke work at 15 minutes from baseline (p < 0.05); these values remained elevated for 30 minutes and returned to baseline by 1 hour with no change in systemic vascular resistance. Arterial oxygenation decreased by 124% at 15 minutes and remained depressed through the experiment, but in treated animals oxygen tension remained unchanged from baseline. Thromboxane B2 increased 95% from baseline in the control group and 1.5 fold in treated animals and followed a similar time course as the functional measurements (p < 0.05). A pulmonary vascular thromboxane B2 gradient of approximately 1000 pg/ml was measured at 15 and 30 minutes in both control and treated groups. (p < 0.05) We conclude that after complement activation in this model pulmonary hypertension and decreased oxygen tension are mediated by thromboxane release from the pulmonary vascular bed. This increased afterload causes a stress on the right ventricle as demonstrated by the increased right ventricular stroke work. Selective thromboxane receptor antagonism may be a beneficial therapy for pulmonary hypertension in patients after cardiopulmonary bypass.

We describe a patient who underwent off-pump coronary artery bypass graft surgery performed with an aortic connector. The patient developed a malignant deep sternal wound infection that subsequently led to an aortic pseudoaneurysm at the site of proximal anastomosis.

The conductance catheter method for measuring right ventricular (RV) volume changes was assessed in seven excised porcine hearts. A 5-FG conductance catheter was placed within a latex balloon and positioned in the RV cavity of seven freshly excised porcine hearts. Conductance was recorded while saline was withdrawn from the intraventricular balloon in 2 ml decrements. Linear regression analysis of measured conductance versus reference volumes was computed. The effect of left ventricular (LV) filling and catheter length on conductance derived RV volume was also determined. Conductance derived volumes were highly correlated with reference volumes [R 2 0.976, standard deviation (SD) 0.035]. The mean gradient of regression was 0.97 (SD 0.10), and it was not significantly affected by LV volume alterations. However, when we analyzed LV filling, a small but significant increase in the y-intercept was observed (LV empty 3.11 ml, SD 1.71; LV full 4.58, SD 2.39; p = 0.008). Introduction of the catheter through either the tricuspid or pulmonary orifices were both effective in ventricular volume measurement. The effect of mismatch between the catheter length and the RV long axis dimension was evaluated by changing the position of the active sensing electrodes along the catheter body. Conductance measurements, obtained from catheters shorter than the long axis of the RV, still maintained a highly linear correlation with real volume, but regression gradients were significantly reduced (long 0.975, SD 0.087; medium 0.787, SD 0.094; small 0.589, SD 0.091; p < 0.001). These results show that a conductance catheter of appropriate length can accurately measure RV volume, despite the complex shape and geometric changes associated with ventricular filling. ASAIO Journal 2002; 48:514-519.

Background . The purpose of this retrospective study was to evaluate the current incidence, survival, and predictors of mortality for open chest management at our center. Methods . Our database was analyzed to identify adult postcardiotomy patients who left the operating room without primary sternal closure. Medical records were reviewed to determine mortality, postoperative complications, and pertinent hemodynamic data. Results . From November 1997 to June 2000, 5,177 adults underwent cardiac procedures at our center. The incidence of open chest management was 1.7% (87 of 5,177), including 0.7% (16 of 2,254) for isolated coronary artery bypass grafting, 1.6% (15 of 912) for isolated valve, and 5.6% (47 of 839) for combined valve/coronary bypass. Hospital survival was 76% (66 of 87). Major complications included deep sternal infection (n = 4), stroke (n = 8), and dialysis (n = 13). Predictors of mortality by univariate analysis included ventricular assist device insertion ( p = 0.003), new onset hemodialysis ( p p = 0.002), sternal infection ( p = 0.042), mean length of delay before sternal closure (survivors = 3.2 days, nonsurvivors=6.2 days; p = 0.031), higher mean dose of epinephrine at the time of chest closure (2.5 μg versus 0.9 μg, p = 0.011), and longer duration of high dose inotropic therapy (110 hours versus 43 hours, p = 0.002). Multivariate analysis showed ventricular assistance and reoperation for bleeding as independent predictors of in-hospital death with odds ratios of 3.8 and 3.4, respectively. Conclusions . Liberal use of open chest management is useful in patients with postcardiotomy shock, and can be carried out with a relatively low incidence of sternal complications. Patients who require ventricular assistance or exploration for ongoing mediastinal bleeding continue to have a high mortality rate.

Performing a precise inferior vena caval (IVC) anastomosis during bicaval orthotopic heart transplantation can sometimes be challenging because of crowding of the operative field by the venous cannula and tourniquet. We performed bicaval orthotopic heart transplantation in 10 patients using an open IVC anastomotic technique with vacuum-assisted venous drainage. A long venous cannula was passed into the IVC through the femoral vein. The IVC anastomosis was performed after removing the IVC tourniquet under vacuum-assisted venous drainage. A precise edge-to-edge IVC anastomosis was successfully performed in all patients. This technique may result in greater anastomotic precision and improved outcomes.

Background: Right heart failure after cardiopulmonary bypass can result in severe hemodynamic compromise with high mortality, but the underlying mechanisms remain poorly understood. After ischemia-induced right ventricular failure, alterations in the interventricular septal position decrease left ventricular compliance and limit filling but may also distort left ventricular geometry and compromise contractility and relaxation. This study investigated the effect of acute isolated right ventricular ischemia on biventricular performance and interaction and the response of subsequent right ventricular unloading by use of a modified Glenn shunt. Methods: In 8 pigs isolated right ventricular ischemic failure was induced by means of selective coronary ligation. A modified Glenn circuit was then established by a superior vena cava–pulmonary artery connection. Ventricular performance was determined by conductance catheter–derived right ventricular pressure-volume loops and left ventricular pressure-segment length loops. Hemodynamic data at baseline, after right ventricular ischemia, and after institution of the Glenn circuit were obtained during inflow occlusion, and the load-independent contractile indices were derived. Results: Right ventricular free-wall ischemia resulted in acute right ventricular dilation (118 ± 81 mL vs 169 ± 70 mL, P =.0008) and impairment of left ventricular contractility indicated by the reduced end-systolic pressure-volume relation slope (50.0 ± 19 mm Hg/mm vs 18.9 ± 8 mm Hg/mm, P =.002) and preload recruitable stroke work index slope (69.6 ± 26 erg · cm –3 · 10 3 vs 39.7 ± 13 erg · cm –3 · 10 3 , P =.003). In addition, left ventricular relaxation (τ) was significantly prolonged (33.3 ± 10 ms vs 53.0 ± 16 ms, P =.012). Right ventricular unloading with the Glenn shunt reduced right ventricular dilation and significantly improved left ventricular contraction, end-systolic pressure-volume relation slope (18.9 ± 8 mm Hg/mm vs 35.8 ± 18 mm Hg/mm, P =.002), preload recruitable stroke work index slope (39.7 ± 26 erg · cm –3 · 10 3 vs 63.0 ± 22 erg · cm –3 · 10 3 , P =.003), and diastolic performance (τ 53.0 ± 16 ms vs 43.5 ± 13 ms, P =.001). Conclusions: Right ventricular ischemia-induced dilation resulted in acute impairment of left ventricular contractility and relaxation. A modified Glenn shunt attenuated the left ventricular dysfunction by limiting right ventricular dilation and restoring left ventricular cavity geometry. J Thorac Cardiovasc Surg 2001;122:80-91

We review our experience with minimally invasive direct access (MIDA) heart valve surgery in 518 patients. Two hundred fifty-two patients underwent MIDA aortic valve replacement (AVR) or repair and 266 underwent MIDA mitral valve repair or replacement. Among the 250 AVRs, 157 (63%) were men, aged 63.2 +/- 14.6 years, NYHA functional Class 2.4 +/- 0.8. The surgical approach was right parasternal in 36 (14%) or upper hemisternotomy in 216 (86%). There were four (2%) operative deaths. Perioperative complications included 14 (5.6%) reexplorations for bleeding, 7 (3%) chest wound infections, 5 (2%) strokes, and 1 (0.4%) external iliac vein injury. Follow-up was complete in 193 (77%) patients, with a mean follow-up of 12 +/- 8 months. Late complications included 2 (0.8%) nonfatal myocardial infarctions, 4 (2%) reoperations for, respectively, 2 pericardial complications, 1 paravalvar leak, and 1 infected valve. There were five (2%) late deaths from congestive heart failure, pneumonia, hemorrhage, aneurysm, and cancer. Mean follow-up NYHA Class was 1.4 +/- 0.6. For the 266 mitral patients, 145 (54.5%) were men, age 58.7 +/- 13.6 years, functional Class 2.3 +/- 0.5. The surgical approach was right parasternal in 195 (73%), lower hemisternotomy in 53 (20%), right submammary thoracotomy in 9 (3.4%), or full sternotomy through a small skin incision in 9 (3.4%). There were 2 (0.8%) operative deaths. Perioperative complications included 4 (1.5%) reoperations for bleeding, 4 (1.5%) strokes, and 5 (2%) wound infections, and 3 (1%) ascending aortic complications. Follow-up was complete in 202 (76%) patients with a mean follow-up of 9.5 +/- 6.4 months. Late complications included one (0.4%) nonfatal myocardial infarction and three (1%) reoperations all converting repairs to replacements. There were three (1%) late deaths from suicide, pneumonia, and sudden death, respectively. Mean follow-up NYHA functional Class was 1.3 +/- 0.5. We conclude that MIDA heart valve surgery is safe and effective for the majority of patients requiring isolated elective aortic or mitral valve surgery. Language: en

Objective: We developed techniques for ‘inverted T’ partial upper re-sternotomy for aortic valve replacement (AVR) or re-replacement (AVreR) after previous cardiac surgery. We previously reported on decreased blood loss, transfusion requirements and total operative duration when compared to conventional full re-sternotomy. This report updates our series, one of the few to document a substantial benefit from a ‘minimally-invasive’ approach, refines a number of technical aspects of this new approach and reports follow-up. Methods: Between November 1996 and December 1999, we performed 34 AVRs or AVreRs after previous cardiac surgery by use of an ‘inverted T’ partial upper re-sternotomy. There were 25 (74%) men. Median ejection fraction was 54%, range 15‐80%. Median age was 72, range 38‐93. All were New York Heart Association functional class (NYHA) functional class II or III. Twenty-one (62%) had previous coronary artery bypass grafts (CABG) while 14 (41%) had previous valve surgery. Follow-up was 100% complete for a total of 593 patient months (median 19 months). Results: Twenty-three (66%) underwent AVR of the native aortic valve while 11 (33%) underwent AVreR of a prosthetic aortic valve. There were no intraoperative or valve-related complications, and no conversion to full re-sternotomy was necessary. There were two (5.9%) operative deaths from an arrhythmia on postoperative day 4 and a large stroke during surgery, respectively. Twenty-four (75%) patients were free of major complications. There was no need for reoperation for bleeding and patients required a median of two units of packed red blood cells. Complications included new atrial fibrillation (na 3, 9%), pacemaker implantation (na 3, 9%) and deep sternal wound infection (na 2, 6%). Median lengths of stay in the intensive care unit (ICU) and in the hospital were 1 and 7 days, respectively. There was one (3%) late deep sternal wound infection and 2/32 (6%) late deaths due to congestive heart failure at 22 months and myocardial infarction at 23 months, respectively. Conclusions: Partial upper re-sternotomy presents a safe and effective alternative approach to AVR and AVreR after previous cardiac surgery, and is associated with low morbidity and mortality. q 2000 Elsevier Science B.V. All rights reserved.

Previously, a modification to the Sunagawa engineering model for the isolated left ventricle and arterial system was proposed and validated for dynamic cardiomyoplasty in an acute goat preparation. To test the hypothesis that this model may be applied to the clinical scenario in cardiomyoplasty patients, we predicted human stroke volume using the model with human clinical data from the literature. Predicted stroke volume correlated well with published stroke volume in patients who have had the dynamic cardiomyoplasty procedure. These results suggest that the modest hemodynamic improvement commonly reported after the procedure is performed may be due to diminished latissimus dorsi strength after transformation. The validity of both the original Sunagawa model and the previously proposed modification for dynamic cardiomyoplasty is further supported with these results. A nomogram methodology for predicting stroke volume after dynamic cardiomyoplasty for any particular patient is presented.

Background. The mechanism by which cardiomyoplasty appears to enhance left ventricular (LV) function is not well understood. We applied the time-varying elastance model to study the effect of cardiomyoplasty on LV function, ventriculovascular coupling, and LV energetics in an acute canine model. Methods. Right latissimus dorsi cardiomyoplasty was performed in 5 dogs. The end-systolic pressure-volume relation was generated by using brief caval occlusions. End-systolic elastance, effective arterial elastance, stroke work, internal work, total mechanical work, and stroke work efficiency (stroke work/total mechanical work) were calculated from these pressure-volume data. Myocardial oxygen consumption and overall mechanical efficiency (stroke work/myocardial oxygen consumption) were predicted using the myocardial oxygen consumption-total mechanical work relation. Results. Skeletal muscle contraction significantly increased end-systolic elastance, an index of contractility. Although stroke work did not change significantly, the increase in end-systolic elastance led to a 29% decrease in total mechanical work, a 50% decrease in internal work, and an increase in stroke work efficiency from 53% to 66%. This was consistent with the observed 29% decrease in effective arterial elastance/end-systolic elastance, an indicator of ventriculovascular coupling that is related inversely to stroke work efficiency. Predicted myocardial oxygen consumption decreased by at least 22%, and predicted overall mechanical efficiency increased at a minimum from 16.1% to 18.4%. Conclusions. These results support the theory that cardiomyoplasty unloads the LV by decreasing LV volumes and increasing contractility. These effects appear to improve LV energetics by decreasing total mechanical work without significantly affecting stroke work, resulting in improved stroke work efficiency. The decrease in total mechanical work strongly suggests a decrease in myocardial oxygen consumption and an increase in overall mechanical efficiency.

Background. We introduce the use of a fluid-filled balloon, interposed between myocardium and latissimus dorsi (LD), as a new technique to measure transmural myocardial pressure in an acute goat model of dynamic cardiomyoplasty. Methods. A half-ellipsoidal balloon, composed of polychloryl vinyl layers, was sutured to the atrioventricular groove in 5 goats, thereby completely enveloping both ventricles. Left LD dynamic cardiomyoplasty was then performed, anchoring the LD to the felt sewing skirt of the balloon so that the LD completely covered the balloon. Left ventricular pressure and balloon pressure were measured with the stimulator in the 1:2 mode as balloon volume was varied. Results. Average transmural myocardial pressure, defined as left ventricular pressure minus balloon pressure, decreased from 34.4 mm Hg to 15.6 mm Hg during stimulator-on beats ( p Conclusion. These results support the conclusion that dynamic cardiomyoplasty unloads to the left ventricle by decreasing wall stress. Furthermore, transmural myocardial pressure decreased more when balloon volume was increased, implying that the LD sarcomere length has an effect on wall stress. A balloon may therefore allow optimization of LD sarcomere length and thus assisted cardiac performance.

Background: Coronary artery hemostasis during off-pump coronary artery bypass (OPCAB) may be achieved with extraluminal coronary occlusion or intraluminal coronary shunting. We sought to determine with a normal porcine beating-heart model whether coronary shunting preserves regional myocardial perfusion and function compared with coronary occlusion. Methods: Six pigs (50-60 kg) underwent sternotomy and instrumentation. Two pairs of ultrasonic crystals were placed in the distribution of the left anterior descending (LAD) and left circumflex (LCx) arteries for measurement of fractional change in area (FCA), an index of regional contractility. Regional myocardial blood flow (RMBF) was determined with radiolabeled microspheres. Data were recorded for each animal at baseline and after LAD arteriotomy and vascular control with (1) a 1.5-mm intraluminal shunt, (2) proximal occlusion, and (3) proximal and distal occlusion. Results: One pig experienced ventricular fibrillation during LAD manipulation and was excluded from the study. Data were summarized for the remaining 5 animals. Coronary shunting maintained RMBF and function (FCA) compared with baseline. Proximal occlusion led to 50% (P = .05) and 47% (P = .04) decreases in RMBF and FCA, respectively, in the LAD region. Proximal and distal occlusion led to 55% (P = .03) and 51% (P = .02) decreases in RMBF and FCA, respectively, in the LAD region. There were no significant changes in RMBF or FCA in the LCx (control) region. Conclusion: Intraluminal coronary shunting is capable of preserving distal myocardial perfusion and function in a normal porcine heart. Coronary occlusion, in contrast, significantly reduces regional perfusion and function. More frequent use of intracoronary shunting may facilitate OPCAB by minimizing ischemia and hemodynamic compromise.

Background The optimal management of moderate (3+ on a scale of 0 to 4+) ischemic mitral regurgitation (MR) remains controversial. Some advocate CABG alone, whereas others favor concomitant mitral annuloplasty. To clarify the optimal management of these patients, we evaluated the early impact of isolated CABG on moderate ischemic MR. Methods and Results Between January 1992 and August 1999, 136 patients (54% male, mean age 70.5 years, mean New York Heart Association class 2.7, mean ejection fraction 38.1%) with a preoperative diagnosis of moderate ischemic MR, without leaflet prolapse or pathology, underwent isolated CABG. Thirty-eight (28%) of 136 patients had intraoperative transesophageal echocardiography (TEE) before CABG, and 68 (50%) had postoperative transthoracic echocardiography (TTE) within 6 weeks of surgery. The subgroups of patients undergoing intraoperative TEE and postoperative TTE had preoperative characteristics similar to the overall group. The 30-day operative mortality was 2.9% ( \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\frac{4}{136}\) \end{document} ). Intraoperative TEE downgraded the severity of MR to mild or less (0 to 2+) in 89% ( \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\frac{34}{38}\) \end{document} ). On postoperative TTE, 40% ( \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\frac{27}{68}\) \end{document} ) continued to have at least moderate MR (3 to 4+), 51% ( \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\frac{35}{68}\) \end{document} ) improved somewhat to mild (2+) MR, and only 9% ( \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\frac{6}{68}\) \end{document} ) had resolution of their MR (0 to 1+). The mean preoperative, intraoperative, and postoperative MR grades were 3.0±0.0, 1.4±1.0, and 2.3±0.8, respectively ( P Conclusions CABG alone for moderate ischemic MR leaves many patients with significant residual MR and may not be the optimal therapy for most patients. Intraoperative TEE may significantly underestimate the severity of ischemic MR. A preoperative diagnosis of moderate MR may warrant concomitant mitral annuloplasty.

Objectives This study retrospectively reviews an aggressive multidisciplinary approach to the treatment of massive pulmonary embolism, centering on rapid diagnosis with contrast-enhanced computed tomography of the chest to define the location and degree of clot burden and transthoracic echocardiography to document right ventricular strain followed by immediate surgical intervention when appropriate. Methods Between October 1999 through February 2004, 47 patients (30 men and 17 women; median age, 58 years; age range, 24–86 years) underwent emergency surgical embolectomy for massive central pulmonary embolism. The indications for surgical intervention were (1) contraindications to thrombolysis (21/47 [45%]), (2) failed medical treatment (5/47 [10%]), and (3) right ventricular dysfunction (15/47 [32%]). Preoperatively, 12 (26%) of 47 patients were in cardiogenic shock, and 6 (11%) of 47 were in cardiac arrest. Results There were 3 (6%) operative deaths, 2 with preoperative cardiac arrest; 2 of these 3 patients required a right ventricular assist device. In 38 (81%) patients a caval filter was placed intraoperatively. Median length of stay was 11 days (range, 3–75 days). Median follow-up was 27 months (range, 2–50 months); follow-up was 100% complete in surviving patients. There were 6 (12%) late deaths, 5 of which were from metastatic cancer. Actuarial survival at 1 and 3 years' follow-up was 86% and 83%, respectively. Conclusion An aggressive approach to large pulmonary embolus, including rapid diagnosis and prompt surgical intervention, has improved results with surgical embolectomy. We now perform surgical pulmonary embolectomy not only in patients with large central clot burden and hemodynamic compromise but also in hemodynamically stable patients with right ventricular dysfunction documented by means of echocardiography.