Seminars in Thoracic and Cardiovascular Surgery

Published by WB Saunders
Print ISSN: 1043-0679
Stem cell therapy holds promise as a therapeutic option for cardiovascular disease. As the field of cellular transplantation matures, novel methodologies are needed to longitudinally track and evaluate the functional effects of transplanted cells. At present, available techniques that hold the greatest promise for tracking cell fate include radionuclide labeling, ferromagnetic particle labeling, and genetic modification with reporter genes. This review describes the benefits and limitations of each technique and provides a summary of critical issues regarding stem cell transplantation that have been addressed by each imaging modality.
•Conduit preparation and its lie are the crucial elements in esophagectomy•Pyloric drainage of some sort is preferred to the use of Botox.•The use and timing of conduit preconditioning remains unanswered.•Significant postoperative reflux is seen in a minority of cases.•Surgery use or not as part of a multimodality treatment package should be decided prior to the inception of therapy.
The first experience with endoventricular circular patch plasty (EVCPP) was reported in 1984 as a surgical method to rebuild left ventricular (LV) geometry made more spheric after myocardial infarction. The consequence is dilated ischemic cardiomyopathy. In anterior infarction, the free LV wall and septum are scarred and become dyskinetic or akinetic. The fundamental approach excludes the noncontractile (asynergy) and nonresectable regions to restore more normal size and shape. The current experience of our group in 2001, includes 1,011 patients, and confirmation of our results by others, including an international team. The basic components are LV reconstruction, revascularization, and mitral repair (when needed), which form an integrated method of surgical management. Endocardiectomy and cryoablation are used with spontaneous and inducible ventricular arrhythmias. This article reviews these results and summarizes 10 important points concerning the surgical treatment of ischemic dilated cardiomyopathy that may provide guidelines for the future. These data indicate EVCPP, and its variations, form the central theme in surgical treatment of congestive heart failure.
We present the current optimal uses and limitations of positron emission tomography/computed tomography (PET/CT) as it relates to the diagnosis and staging of non-small cell lung cancer (NSCLC). PET/CT demonstrates increased accuracy in the workup of solitary pulmonary nodules for malignancy compared with CT alone, and we discuss its benefits and limitations. We review pitfalls in measured standardized uptake values of lung lesions caused by respiratory artifacts, the lower sensitivity for detection of small lung nodules on non-breath-hold CT, and the benefits of obtaining an additional diagnostic CT for the maximum sensitivity of lung nodule detection. There are limitations of quantitatively comparing separate PET/CT examinations from different facilities with standardized uptake values. As for staging, we describe how PET/CT supplements clinical tumor-nodes-metastases (ie, TNM) staging, as well as mediastinoscopy, endobronchial ultrasound, and endoscopic ultrasound, which are the gold standard pathologic staging methods. We touch on the 7th edition TNM staging system based on the work by the International Association for the Study of Lung Cancer, an anatomically based staging method.
Allograft aortic root replacement for primary aortic valve or ascending aortic root pathology is the favored method of technical implantation. Results in 418 patients over 15 years demonstrate exceedingly low early mortality (<1%), complete eradication of preoperative endocarditis but poor long-term durability in the young age group of 20 years or less.
The aim of this study was to determine long-term results from one unit of subcoronary homograft aortic valve replacement (AVR) using the same sterilization and preservation techniques in each case. Between 1973 and 1983, 200 patients underwent AVR using an unstented homograft previously sterilized in antibiotics and preserved at 4 degrees C. Surviving patients were monitored for a minimum of 15 years to the end of 1998. Mean age was 50.0+/-14 (1 standard deviation) years; 121 patients were men (60.5%). Mean patient follow-up time was 15.6+/-6.7 years, with a total follow-up time of 3,115 patient years. Follow-up was 95.6% complete. There were three early deaths (1.5%). At autopsy, the homograft was anatomically normal and in a satisfactory position. Kaplan-Meier survival, including early death, was 81.2%+/-2.8% (1 standard error) at 10 years, 68.1%+/-3.4% at 15 years, and 58.0%+/-3.7% at 20 years. Repeat AVR was undertaken in 74 patients, giving a freedom from reoperation for any reason of 86.5%+/-2.6%, 69.6%+/-3.8%, and 38.8%+/-5.3% at 10, 15, and 20 years, respectively. Freedom from structural valve degeneration at 10, 15, and 20 years was 81.1%+/-2.9%, 61.7%+/-3.9%, and 31.2%+/-4.7%, respectively. Freedom from endocarditis at 10, 15, and 20 years was 98.7%+/-0.9%, 96.0%+/-1.8%, and 94.6%,+/-2.3%, respectively. Homograft AVR with an antibiotic-sterilized valve stored at 4 degrees C and implanted in the subcoronary position offers low operative mortality and good long-term outcome for patients.
The increased applicability and excellent results with left ventricular assist devices (LVADs) have revolutionized the treatment options available for patients with end-stage heart failure. Until recently, most patients who have undergone LVAD implantation have been supported by pulsatile devices. Unfortunately, the use of the latter devices is associated with significant comorbidity, primarily as a result of their large size and limited durability. The HeartMate II and the Jarvik 2000 pumps, both of which incorporate axial-flow and rotary pump technology represent the next generation of devices. The clinical use of these newer axial-flow pumps have resulted in superior outcomes, including significantly reduced complication rates with improved durability. However, as with all new technology, axial-flow LVADs have also introduced a different set of management issues, as well as certain complications, into the mechanical circulatory support arena--issues and complications that were previously absent or unimportant with pulsatile LVADs. Concerns include the effects of continuous-flow on the systemic circulation and end-organ function, risk of thromboembolism and pump thrombosis, increased incidence of gastrointestinal bleeding and ventricular arrhythmias, as well as the effects of partial unloading on pulmonary hemodynamics. Different strategies are required to optimize outcomes with these newer devices.
Medical treatment for patients with stable chronic obstructive pulmonary disease (COPD) has evolved significantly over the past 2 decades. Current World Health Organization recommendations suggest a stepwise approach to therapy depending upon disease severity. As-needed use of short-acting bronchodilators is recommended for patients with mild disease. Scheduled dosing of bronchodilators is recommended for patients with more advanced disease. Inhaled beta-agonists and anti-cholinergic agents in combination have proved to be more effective than either agent alone. Long-acting preparations are associated with better disease control and have not been associated with tachyphylaxis. Inhaled corticosteroids are useful for reducing the frequency of exacerbations in patients who experience one or more episodes per year. Oxygen therapy is clearly beneficial in patients with advanced COPD and chronic respiratory failure, and its potential benefits in less severe disease are currently being studied. Pulmonary rehabilitation benefits patients with mild-to-severe disease, although the greatest benefits have been demonstrated in those with moderate COPD. New ultra-long-acting inhaled bronchodilators, phosphodiesterase inhibitors, protease inhibitors, and retinoids intended to promote tissue regeneration are currently being evaluated in clinical trials as future therapeutic agents.
Despite advances in percutaneous coronary intervention, coronary artery bypass grafting remains the most effective intervention for complex coronary artery disease in survival, freedom from reintervention, and cost-effectiveness. To ensure that patients have access to this "gold-standard" treatment, a multidisciplinary team approach, rather than an individual cardiologist acting as a "gatekeeper," should be the standard of care when intervention is necessary, to ensure transparency, real patient choice, and genuine informed consent.
Patients in the cardiothoracic surgical intensive care unit are generally critically ill and undergoing a systemic inflammatory response to cardiopulmonary bypass, ischemia/reperfusion, and hypothermia. This presents several metabolic challenges: hyperglycemia in need of intensive insulin therapy, catabolism, and uncertain gastrointestinal tract function in need of nutritional strategies. Currently, there are controversies surrounding the standard use of intensive insulin therapy and appropriate glycemic targets as well as the use of early enteral nutrition ± parenteral nutrition. In this review, an approach for intensive metabolic support in the cardiothoracic surgical intensive care unit is presented incorporating the most recent clinical evidence. This approach advocates an IIT blood glucose target of 80-110 mg/dL if, it can be implemented safely, with early nutrition support (using parenteral nutrition as needed) to prevent a critical energy debt.
The purpose of this paper is to review the current literature and practice of the Ross concept of using the autologous pulmonary valve to replace a diseased aortic valve. The potential advantages and disadvantages of these operations will be evaluated in the context of alternative options and relative risks. The different surgical techniques of subcoronary and full root methods will be discussed and important technical aspects reviewed. Long-term outcomes will be described to the extent these are available, including recent publications describing a survival advantage for the Ross. Brief discussions will be presented regarding hemodynamics, child-bearing, endocarditis, and the use of the Ross in pediatric patients as well as biological adaptability of the living pulmonary autograft.
Early results after aortic valve replacement (AVR) with three different types of stentless xenografts suggested less satisfactory outcome with a simplified implant model (Cryolife-O'Brien) compared with two standard implant models (Biocor PSB, Toronto SPV). To assess the impact of experience on mid-term outcome after stentless AVR, results with 322 implants were reviewed. Between July 1992 and February 1999, 106 patients underwent operations to implant the Biocor PSB (group 1), 139 patients the Toronto SPV (group 2), and 77 patients the Cryolife-O'Brien valve (group 3). Mean age (70+/-6 years; 70+/-7 years; 71+/-7 years; P = .7), prevalence of male gender (56 patients, 53%; 72 patients, 55%; 38 patients, 49%; P = .4), prevalence of aortic stenosis (72 patients, 68%; 77 patients, 55%; 38 patients, 49%; P = .7), and need for associated procedures (51 patients, 48%; 54 patients, 39%; 33 patients, 43%; P = .7) were similar among all three groups, respectively. Mean aortic cross-clamp time was shorter in group 3 (96+/-24 min; 98+/-24 min; 78+/-22 min; P = .02). Early deaths (3/106, 3%; 4/139, 3%; 2/77; 3%, P = .8) and late survival were comparable (89%+/-5%, 93%+/-4%, and 85%+/-7% at 5 years, P = .1) among groups. Follow-up ranged from 1 to 84 months (mean 52+/-20 months). Five-year freedom from valve deterioration (95%+/-5%, 96%+/-3%, and 85%+/-7%, P = .008) and from reoperation (98%+/-2%, 98%+/-2%, 92%+/-4%, P = .01) was significantly poorer in group 3 patients. When valve failure resulting from technical mishaps (none in the last 60 implants) with the Cryolife-O'Brien valve was excluded, no significant difference in freedom from valve deterioration was noted (98%+/-2%, 96%+/-3%, and 95%+/-4%, P = .1). Late functional status of 290 survivors was satisfactory and comparable among groups (1.3+/-0.8, 1.1+/-0.4, and 1.4+/-0.7 New York Heart Association class, P = .5). After an initial learning curve, simplified implant stentless xenografts offer satisfactory mid-term results, which are comparable to two-suture-line implant valves. Owing to the shorter grafting time, simplified implant xenografts such as the Cryolife-O'Brien may be particularly suited for complex operations where associated procedures are required.
Three-dimensional echocardiography has emerged as an essential tool for visualizing cardiac anatomy and for making more accurate measurements of cardiac structure and function. Recently, improvements in 3D beam-forming and transducer technologies have allowed higher resolution imaging from a transesophageal echocardiographic probe. This is creating new avenues for real-time visualization of intracardiac procedures without the need for cardiopulmonary bypass or opening the beating heart. Evolutions in visualization will allow a wider array of reparative procedures to be performed minimally invasively within a beating heart.
Left ventricular assist device (LVAD) therapy has become an established treatment option for patients with advanced heart failure. Broader application of this therapy has been limited by the risk profile of the current generation of devices. The development of continuous-flow rotary pump technology with noncontact bearing design offers the promise of improved device durability and safety profile. Clinical evaluation of these innovative pump designs are currently underway.
Long-term success in lung transplantation continues to be challenged by chronic graft dysfunction, which is manifest as bronchiolitis obliterans syndrome (BOS). The mechanisms of BOS involve both immune-mediated pathways (rejection, autoimmune-like mechanisms), and alloimmune-independent pathways (infection, aspiration, ischemia, primary graft failure), which lead to a fibroproliferative responses. BOS correlates histologically with obliterative bronchiolitis in terminal bronchioles and evidence of aberrant remodeling in the airway epithelium, vasculature, stroma, and lymphoid system. A potentially important mechanism that supports the progressive and therapy-resistant nature of BOS is a continuous cycle of ongoing injury and aberrant remodeling. Namely, anatomical and functional abnormalities induce and exacerbate immune-mediated and alloimmune-independent pathways through various mechanisms (e.g., epithelial remodeling decreases mucociliary clearance that exacerbates aspiration-related injury). From this viewpoint, we review current therapeutic strategies and revisit the role of transplant surgeons in attenuating the initial transplant-related injuries to prevent the lung grafts from entering the remodeling-injury cycle.
Lung cancer is the most common cause of cancer-related mortality in the United States. Surgical resection with a lobectomy is the standard treatment for stage I non-small cell lung cancer. With an aging population, however, there are a significant number of patients who have other comorbidities that preclude surgical resection. Image-guided radiofrequency ablation is a new emerging modality of treatment which may be applicable in this high-risk group of patients. In this article, we review the principles of radiofrequency ablation, the common devices in use, the results of ablate and resect studies, future directions, and the results of treatment for stage I non-small cell lung neoplasm.
Traditional approaches to small pulmonary nodules have ranged from serial radiographic surveillance to transthoracic needle aspiration to surgical resection for diagnosis. Once the diagnosis of non-small-cell lung cancer is secured, lobectomy remains the gold standard treatment. Nevertheless, advances in image-guided technology and radiofrequency thermal ablation techniques have allowed for diagnostic sampling of lesions with concomitant therapeutic thermal ablation. The role these techniques will play in the treatment of patients with primary lung cancer remains undefined. This review (1) examines the basic technology of radiofrequency ablation; (2) provides an update on current clinical experience with this technique; and (3) explores the role of radiofrequency ablation in the treatment scheme of patients with non-small-cell lung cancer.
Lung cancer is the most common cause of cancer related mortality in the United States. Surgical resection is the standard treatment for stage I non-small cell lung cancer (NSCLC). However, many patients who have resectable cancer may have significant comorbidities precluding surgical resection. Radiofrequency ablation is an emerging modality of treatment and may be applicable in this high-risk group of patients. In this article, we review the principles of radiofrequency ablation, the common devices in use, and the results of treatment for stage I non-small cell lung neoplasm.
The metaplastic change of the normal squamous epithelium of the distal esophagus into a specialized columnar epithelium is known as Barrett's esophagus (BE) and is associated with an increased risk of adenocarcinoma of the esophagus. It is a frequent complication of gastroesophageal reflux disease (GERD) and up to 10% of patients with GERD suffer from BE. The progression to dysplasia increases the risk of cancer development and the annual risk of developing cancer in Barrett's esophagus is estimated to be 0.5% per year. The management of BE with high grade dysplasia (HGD) is controversial. Recent innovations in endoscopic therapy have allowed for the development of multiple endoscopic techniques, such as photodynamic therapy (PDT), argon plasma coagulation (APC), and endoscopic mucosal resection. In this article, we will discuss primarily photodynamic therapy, and other ablative technologies such as argon plasma coagulation in the treatment of BE.
The purpose of this article is to present and evaluate the various technologies recently developed for the surgical treatment of atrial fibrillation as alternatives or adjuncts to the traditional Maze III procedure and other "cut and sew" techniques. The discussion contains a detailed consideration of the biophysical background of the most common ablation techniques, their mode of tissue injury, the methods of use, and the related complications through a review of the existing literature and analysis of experimental results. All of the current technologies presented are still being tested to augment the success rates and reduce the incidence of complications, although all are not available for clinical use. Radiofrequency and cryoablation have been used clinically on large numbers of patients with varying results. Microwave technology has been used in small groups of patients, and the results are to be evaluated. Laser technology is still in an experimental phase, and the clinical results are forthcoming. True transmurality, reduction of operative time, friendly use of ablation devices, and substantial reduction of complications appear to be the key factors for broad adoption of alternative energy sources for surgical ablation.
Atrial fibrillation is present in approximately 35% of patients presenting for mitral valve surgery and in 1 to 6% of adult patients undergoing other forms of cardiac surgery. If left untreated, atrial fibrillation is associated with increased morbidity, and, in some subgroups, increased mortality. Therefore, concomitant management of the arrhythmia is indicated in most cardiac surgery patients with preexisting atrial fibrillation. Although the cut-and-sew Cox-maze III procedure is extremely effective, it has been supplanted by newer operations that rely on alternate energy sources to create lines of conduction block. Early and mid-term results are good with a variety of technologies. Choice of lesion set remains a matter of debate, but results of ablation appear to be enhanced by a biatrial lesion set. Targeted areas for improvement in concomitant ablation include acceptance of uniform standards for reporting results, development of improved technology for ablation and intraoperative assessment, and creation of instrumentation that facilitates minimally invasive approaches.
The presence of intestinal metaplasia (IM) of the esophagus is associated with an elevated risk for developing high-grade dysplasia and invasive adenocarcinoma. Historically, IM has been surveyed with a lifetime of serial endoscopy and biopsy procedures to monitor for the development of high-grade dysplasia and cancer, the early detection of which would permit intervention with surgery. Several nonsurgical endoscopic procedures have been developed with the intent to eradicate IM and dysplasia and halt progression to invasive cancer. However, many of these techniques have been associated with significant morbidity and unacceptable efficacy outcomes. Radiofrequency ablation (RFA) has more recently been studied to eradicate IM and dysplasia of the esophagus. This manuscript will review the technique, clinical results, and recommendations for RFA.
Twenty-three patients underwent endocardial radiofrequency ablation of atrial fibrillation (AF) during mitral valve procedures with a previously described left atrial lesion pattern. A temperature-controlled 7-coil surgical probe delivered 60-second lesions at 80 degrees C. The left atrial appendage was oversewn after ablation. Ages ranged from 28 to 88 years. Nineteen patients had chronic AF that was present for over 1 year in 74%; 12 patients had rheumatic mitral stenosis. Mean left atrial diameter was 5.4 +/- 0.7 cm. There was 1 operative death unrelated to the ablation, and no strokes or ablation-related complications were observed. At mean follow-up of 32.5 weeks, 86% of the 22 survivors were in sinus rhythm. All 18 patients with left atrial diameter <6 cm are in sinus rhythm. All postoperative atrial flutter was transient, and no patients required subsequent transcatheter ablation. This lesion pattern is safe and effective when applied in the method described here. It appears to be a reasonable alternative to the complete Maze 3 lesion pattern in patients with mitral valve disease.
Dr. Mahmood Mirhoseini from Milwaukee, WI, transformed transmyocardial revascularization (TMR) into transmyocardial laser revascularization (TMLR) more than 2 decades ago. The controversial nature of this laser procedure and the prospect of its successful application to refractory cases of chronic debilitating angina have created spirited interest in TMLR. As a natural component of this interest, various laser modalities have been proposed and employed during the performance of the TMLR procedure both in the experimental and the clinical setting. However, it is the nature of laser-tissue interactions that is primarily responsible for the long-term fate of the channels, the angiogenesis that occurs in the vicinity of these laser channels, and the resulting increase (if any) in myocardial perfusion. These interactions with tissue are, in turn, determined by laser variables such as photonic absorption and scattering by the target tissue, pulse energy and duration, and the peak power generated. The CO2 laser has the advantages of producing high-energy pulses that create a transmural channel with a single pulse, low-peak power that minimizes structural tissue trauma, and high photonic absorption to minimize thermal damage. The holmium:YAG and excimer lasers, in turn, have the advantage of being coupled to a fiber optic catheter for transluminal endocardial delivery. Importantly, long-term clinical and perfusional data showing a cause and effect relationship between the use of TMLR and these end-points are available for the CO2 laser only. Prospective randomized trials are, therefore, warranted to delineate the use of each laser modality in relation to that of the CO2 laser in the TMLR setting.
Microwave (MW) interstitial thermoablation offers several advantages over the more commonly applied thermal ablative technique of radiofrequency (RF) ablation for targeted tumor destruction, such as higher ablation temperature, faster treatment time, reduced heat-sink effect, effective ablation of cystic lesions, a technologically easier multi-applicator approach, no necessity for grounding pads, and no risk of skin burns. The technique may be used in different treatment approaches, including imagingguided percutaneous, laparoscopic, and open surgical access. MW ablation constitutes one of the most recent developments in interstitial tumor ablation techniques; however, as yet no FDA-approved commercial device is available. In MW ablation, electromagnetic MW irradiation applied to the tumor tissue causes water molecules to vibrate and rotate, resulting in tissue heating and subsequently cell death via thermal-induced protein denaturation. In first pilot studies, MW ablation has shown immense potential for the treatment of primary and secondary liver tumors, primary and secondary lung cancer, renal cell carcinoma, and bone metastases.
Recent years have seen many developments in the field of alternative energy sources for arrhythmia surgery. The impetus behind these advances is to replace the traditional, "cut-and-sew" Cox maze III procedure with lesion sets that are simpler, shorter, and safer but just as effective. There is demand for technology to make continuous, linear, transmural ablations reliably with a versatile energy source via an epicardial approach. This would make minimally invasive endoscopic surgical ablation of atrial fibrillation (AF) without cardiopulmonary bypass and with a closed chest feasible. These advances would shorten cardio-pulmonary bypass and improve outcomes in patients having surgical ablation and concomitant cardiac surgery. This review summarizes the technology behind alternative energy sources used to treat AF. Alternative energy sources include hypothermic sources (cryoablation) and hyperthermic sources (radiofrequency, microwave, laser, ultrasound). For each source, the biophysical background, mode of tissue injury, factors affecting lesion size, and advantages and complications are discussed.
Microwave energy is a relatively new energy modality that is being used for surgical atrial ablation as a treatment of atrial fibrillation. Microwave energy works by dielectric heating and has a favorable thermal profile that permits both rapid endocardial and epicardial ablation. The device is also extremely flexible and can be easily adapted to minimally invasive applications. The device has been used in over 600 patients with a success ranging from 70% to 90% and without any device-related complications. Many of these patients have had their ablations performed from the epicardium on the beating heart without the aid of cardiopulmonary bypass. Microwave atrial ablation is likely to become an important part of the surgical armamentarium, particularly for those performing minimally invasive approaches to cure atrial fibrillation.
Atrial fibrillation is present in close to 50% of all patients undergoing surgery for mitral valve disease.(1-3) However, surgical correction of atrial fibrillation in patients with other cardiac pathology that requires surgical intervention such as mitral valve disease was never considered as a standard approach. The Maze procedure for the treatment of atrial fibrillation was introduced in 1987 and was performed safely in hundreds of patients with excellent outcomes.(4-7) As a result, several centers have begun to combine the Maze procedure with other cardiac procedures, especially mitral valve surgery, without adding undue operative risk to patients.(8) When properly performed, the results with this combined approach have been excellent.(9,10)
Stereotactic ablative radiotherapy, also known as stereotactic body radiation therapy, has been developed as an innovative therapy for stage I non-small cell lung cancer and has now emerged as a standard treatment option for medically inoperable patients through careful analysis using prospective multi-institutional trials. We review and update the evidence for use of stereotactic ablative radiotherapy in medically inoperable patients with stage I lung cancer, and its possible extension of use to operable patients, from the perspectives of an experienced radiation oncologist and a thoracic surgeon.
Excessive sweating interferes considerably with daily life; the problem has become more serious because of the increasing popularity of electronic devices. This disorder also affects social activities and can ultimately lead to psychological withdrawal. Treatment for this embarrassing condition is in high demand.
The incidence of left ventricular (LV) diastolic abnormalities in adult cardiac surgical patients has not previously been adequately investigated. The present study was performed to characterize LV diastolic filling patterns by performing transesophageal Doppler echocardiographic (TEE) studies in patients undergoing cardiac surgical procedures and thus indirectly assess diastolic function in these patients. Doppler TEE studies were performed and transmitral flow (TMF) and pulmonary venous flow (PVF) velocities were recorded in 104 patients intraoperatively. Peak early (E) and late (A) TMF velocities and systolic (S) and diastolic (D) forward PVF velocities were assessed and deceleration time (DT) was measured in all patients. For analysis, the study patients were classified into three groups according to the ratio of the TMF E to A velocity curves: group I with E/A ratio less than 1.0, group II with E/A ratio of 1.0 to less than 2.0, and group III with E/A ratio of 2.0 or greater. A filling pattern of abnormal LV relaxation was found in 73 patients (E/A < 1.0), a normal or pseudonormal pattern was present in 27 patients (1.0 < or = E/A < or = 2.0), and restrictive filling in 4 patients (E/A > 2.0). Patients with impaired relaxation had a greater incidence of recent myocardial infarction and congestive heart failure (CHF) than those with normal or pseudonormal filling patterns. Within group II, patients with CHF had higher TMF E deceleration rates and lower PVF S/D ratios compared with those without CHF (P < .05). Doppler echocardiographic examination of TMF and PVF velocities suggests that abnormalities in diastolic function are prevalent in adult cardiac surgical patients.
The problems of lung abscess and empyema were recognized by physicians in ancient times, and continue to pose a challenge for contemporary practitioners. Until the current century, anaerobic bacterial infections were undoubtedly the most common cause of lung abscess and empyema. However, other infectious causes are becoming increasingly common as more patients present with complex comorbidities and/or severe immunosuppression. Most lung abscesses respond to appropriate antimicrobial therapy; only about 10% of patients require external drainage or surgical therapy. Noninfected parapneumonic effusions usually respond to systemic antibiotic therapy alone. However, complete drainage of the pleural space is indicated if an effusion is infected or has the characteristics of frank pus. Some parapneumonic effusions that are not grossly turbid and that have negative cultures are nevertheless "complicated"; that is, these effusions have a high risk for causing pleural loculations unless drained early in their course. Over the past 20 years, it has been demonstrated that chemical analysis of parapneumonic effusions (eg, pH, glucose, LDH) is helpful in identifying apparently noninfected, but nevertheless "complicated," parapneumonic effusions. Optimum diagnosis and management of lung abscess and empyema require the coordinated efforts of thoracic surgeons and medical specialists.
Stent mounting of xenografts induces a loss of mobility and reduces the effective valve orifice. By contrast, the higher surgical technical expertise required for stentless procedures is a major obstacle for many surgeons. To facilitate the insertion of the Toronto SPV (St Jude Medical Inc, St Paul, Minneapolis, MN) stentless aortic valve, we tried to alter the porcine design by lowering the invasive profile at the depth of the sinuses on both coronary sites. This technique could theoretically facilitate implantation of the modified stentless valve with an easygoing single-layer suture at the challenging subcoronary level and make it more attractive for the surgeon. The standard model was modified by lowering the profile at the depth of the sinuses on both coronary sites, whether by plication (in 3 specimens, one of each size) or excision (in 3 others) of the protruding porcine aortic wall at the nadir of each coronary sinus. Animal implants in juvenile sheep (6 standard Toronto versus 6 modified valves of 21, 23, and 25 mm) were studied for durability and biocompatibility for 3 to 6 months. All valves were evaluated by postoperative echocardiography and after explantation examined macroscopically, radiographically, histologically, and electron microscopically. The standard valves performed well, although at 6 months after implantation, marked fibrosis was found at the outflow parts with scattered calcifications, essentially in the porcine aortic wall. The leaflets remained mobile and contained scant mineralization. By contrast, the modified specimen showed markedly accelerated fibrosis and significant cusp calcifications at distance from the altered zones. Severe restriction of the mobility of the leaflets was visible 3 months after implantation in the juvenile sheep model. The more pronounced the deformation of the modified scaffold, the faster and more intense the degradation and calcification of the leaflets far from the altered zones (worse in the heavily deformed, plicated cusps). Because all valve types were prepared by identical preservation techniques, this study shows that loss of mobility by distortion of the natural scaffold induces early failure. It is extremely important to correct implantation of stentless valves to prevent early degeneration.
We report a case of a 68-year-old woman with a basal postmyocardial infarction ventricular septal defect that recurred 4 months after initial surgical repair. Successful transcatheter closure using an Amplatzer Muscular VSD Occluder was facilitated by direct percutaneous left ventricular access.
A right thoracotomy is a well-known alternative for midsternotomy to have access to the left atrium. The Port-Access (Heartport, Inc, Redwood City, CA) approach is an invaluable option to avoid cracking of ribs and cartilage. EndoCPB (Heartport, Inc) and Endo-Aortic Clamp (Heartport, Inc) allows installation of the extracorporeal circulation and cardiac arrest from the groin. Videoassistance and shafted instruments help the surgeon to perform the surgery through a 5 x 2-cm port and fulfill the main goals of minimally invasive cardiac surgery, comfort, cosmesis, and fast rehabilitation. From February 1997 to November 1998, 75 patients (40 men/35 women) had either Port-Access mitral valve repair (n = 41) or replacement (n = 33) for a variety of reasons: myxoid degeneration (n = 45), rheumatic disease (n = 21), chronic endocarditis (n = 4), annular dilatation (n = 2), and sclerotic disease (n = 2). One valve was replaced because of an ingrowing myxoma. There was one closure of a paravalvular leak. The mean age was 59.3 years of age (range, 32 to 83 years). Most patients had normal ejection fractions but different grades of mitral valve insufficiency and were in NYHA class II. One 71-year-old patient died after reoperation on postoperative day 1 for failed repair. Two patients had conversion to sternotomy and conventional ECC for repair of a dissected aorta. One patient died, one patient suffered a minor cerebrovascular deficit. Three patients had prolonged intensive care unit (ICU) stays for respiratory insufficiency, 5 patients underwent revision for bleeding. Mean ICU stay was 2.5 days; and mean hospital stay, 9 days (range, 4 to 36). A significant difference between the first 30 and last 38 patients in terms of length of stay in the ICU and the hospital was noticed. Two late mitral valve replacements for chronic endocarditis after repair occurred. One patient had medical therapy for endocarditis after mitral valve replacement. The debut of Port-Access mitral valve surgery may be nerve-racking; the routine is a smooth and sure surgery with maximum comfort, a very discrete scar, and a fast rehabilitation. There were no paravalvular leakages nor myocardial infarctions. Cerebrovascular accidents owing to thromboembolic phenomena, vascular lower limb or wound complications were not seen. Port-Access mitral valve surgery is a very important investment in the future of cardiac surgery. Some learning curve pitfalls were associated with the process of starting this revolutionary technique.
The continued evolution of surgical revascularization has resulted in much less invasive alternatives for patients undergoing coronary artery bypass grafting. In particular, techniques and technologies have been developed to allow for the grafting of coronary arteries through limited access incisions without the circulatory support of cardiopulmonary bypass. The conduits are generally arterial rather than the venous alternatives used originally, and the harvesting of these conduits is performed through limited access incisions described in another article in this review. The result of these efforts is sternal-sparing solutions for the off-pump coronary artery bypass grafting of all the various coronary locations on the heart. This is accomplished through a spectrum of small incisions that can directly expose any specific area of interest for focal bypass grafting. The surgical insult is greatly reduced and the patient's recovery is significantly enhanced. These efforts continue to bring us closer to the ultimate goal of 24-hour hospital stays for coronary artery bypass grafting patients.
We reviewed our experience with minimally invasive direct-access mitral valve surgery in 207 patients through February 1999. Three patients underwent associated procedures, a coronary artery bypass graft (CABG) with right internal mammary artery to right carotid artery (RIMA-RCA), a left ventricular outflow tract (LVOT) debridement for endocarditis, and a primum atrial septal defect (ASD) repair, and were excluded from analysis. Of the 204 remaining patients, 120 (59%) patients were men, aged 58.7 +/- 13.2 years, functional class of 2.3 +/- 0.5. The cause was myxomatous in 162 (79%) patients, rheumatic in 28 (14%) patients, endocarditis in 8 (4%) patients, congenital in 3 (2%) patients, and ischemic in 3 (2%) patients. Mean preoperative EF was 60% +/- 10%, with 184 (90%) patients showing ejection fraction (EF) greater than 50%. The valve was approached through a 5- to 8-cm right parasternal (n = 180, 88%) or right inframammary (n = 24, 12%) incision. One hundred nineteen (58%) patients had open femoral artery-femoral vein cannulation, and 85 (42%) patients had direct cannulation of the aorta and percutaneous cannulation of the femoral vein. One hundred seventy (83%) patients underwent successful valve repair, and 34 (17%) patients required valve replacement. The mean duration of aortic clamping and cardiopulmonary were, respectively, 100 +/- 34 and 146 +/- 44 minutes. There were 2 (1%) surgical deaths. Nonfatal perioperative complications included 3 (1.5%) ascending aortic complications, 3 (1.5%) reoperations for bleeding, 4 (2%) strokes, 2 (1%) transient ischemic attacks (TIAs), 2 (1%) myocardial infarctions, 3 (1.5%) pericardial effusions requiring drainage, 9 (4.5%) vascular complications, and 3 (1.5%) wound complications. Mean length of stay (LOS) was 6.1 +/- 3 days, with 63 (31%) patients being discharged in less than 5 days. One hundred twenty-nine (63%) patients did not require blood transfusions. Follow-up was complete in 165 (81%) patients, with mean follow-up of 13.2 +/- 8 months. Late complications included 1 (0.5%) myocardial infarction, 3 (1.5%) reoperations, all converting repairs to replacements, 3 (1.5%) wound hernias requiring reoperation and repair with mesh, 5 (2.5%) thromboembolic events, and 3 (1.5%) deaths of suicide, pneumonia, and sudden death, respectively. Mean follow-up New York Heart Association (NYHA) functional class was 1.2 +/- 0.5. We conclude that minimally invasive direct-access mitral valve surgery is safe, effective, and applicable for most patients presenting for isolated mitral valve surgery. We now consider it the standard of care for selected patients.
The range of minimal-access cardiac surgery approaches has many implications in intraoperative management. A modified anesthetic regimen is required to deal with the type of surgical exposure, hemodynamic instability, whether cardiopulmonary bypass is used, and early extubation. Intraoperative considerations include hemodynamic monitoring, one-lung ventilation, pharmacological stabilization of the myocardium, pacing, hypothermia, bleeding, and rapid emergence with a minimum of postoperative mechanical ventilation. As a result, anesthetic methods and intraoperative management were modified to meet these specific needs of minimally invasive cardiac procedures.
New techniques for minimally invasive cardiac surgery have recently emerged. This report describes the Port-Access technique for coronary artery bypass grafting, which involves a small left anterior thoracotomy, femoral cannulation for endovascular cardiopulmonary bypass, and cardioplegic arrest using an endoaortic occlusion catheter and cardioplegia delivery system. This technique allows for minimally invasive single or multivessel revascularization in an arrested, protected heart, while maintaining a high level of anastomotic precision. The Port-Access surgical techniques are described, along with the indications and contraindications for this procedure. The initial New York University clinical results with Port-Access coronary bypass grafting are presented.
An era of increasing budgetary constraints, misaligned payers and providers, and a competitive system where United States health outcomes are outpaced by less well-funded nations is motivating policy-makers to seek more effective means for promoting cost-effective delivery and accountability. This article illustrates an effective working model of regional collaboration focused on improving health outcomes, containing costs, and making efficient use of resources in cardiovascular surgical care. The Virginia Cardiac Surgery Quality Initiative is a decade-old collaboration of cardiac surgeons and hospital providers in Virginia working to improve outcomes and contain costs by analyzing comparative data, identifying top performers, and replicating best clinical practices on a statewide basis. The group's goals and objectives, along with 2 generations of performance improvement initiatives, are examined. These involve attempts to improve postoperative outcomes and use of tools for decision support and modeling. This work has led the group to espouse a more integrated approach to performance improvement and to formulate principles of a quality-focused payment system. This is one in which collaboration promotes regional accountability to deliver quality care on a cost-effective basis. The Virginia Cardiac Surgery Quality Initiative has attempted to test a global pricing model and has implemented a pay-for-performance program where physicians and hospitals are aligned with common objectives. Although this collaborative approach is a work in progress, authors point out preconditions applicable to other regions and medical specialties. A road map of short-term next steps is needed to create an adaptive payment system tied to the national agenda for reforming the delivery system.
The durability of current bioprosthetic heart valves is diminished by glutaraldehyde-associated leaflet calcification or by the associated absence of a cellular component capable of repair of wear-related damage. As a novel tissue engineering approach to improving replacement heart valve durability, we have developed a decellularization process to replace the use of cross-linking to limit xenograft antigenicity. The effectiveness of this process was assessed in a weanling sheep right ventricular outflow tract reconstruction model where valve function, calcification, and recellularization were examined. Porcine aortic valves were decellularized by a process designed to remove all histologically demonstrable leaflet cells. Stentless, bioprosthetic valves were fabricated from acellular tissues, cryopreserved, sterilized, and then implanted as pulmonary valve replacements in 4- to 6-month old female Suffolk sheep. Sheep aortic valves were implanted as allograft control subjects. After 150 days, the grafts were explanted and assessed histologically and by atomic absorption spectrophotometry for calcium content. All valves were hemodynamically functional at explant. Histological examination showed intact leaflets with in-growth of host fibroblastoid cells in all explanted porcine valves and no evidence of calcification. Porcine leaflet calcium content was unchanged over the duration of the implant (1.0+/-1.2 vs 1.5+/-1.8 mg/g dry weight, P = ns). Decellularization can stabilize xenogenic heart valves. Lack of calcification of acellular aortic leaflets suggests that prolonged durability of such valves is attainable without the use of cross-linking agents. The repopulation of the leaflet matrix offers additional promise of durability based on revitalization of the graft in vivo.
Top-cited authors
James L Cox
  • Washington University in St. Louis
Alan Marc Gillinov
  • Cleveland Clinic
Tirone E David
  • University Health Network
Johan Suyderhoud
  • Wake Forest School of Medicine
Hartzell Schaff
  • Mayo Foundation for Medical Education and Research