Seminars in Thoracic and Cardiovascular Surgery

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Emerging Treatment for Stage I Non-Small Cell Lung Cancer: Introduction

Arjun Pennathur

This issue of Seminars in Thoracic and Cardiovascular Surgery includes a series of articles which highlight newer technologies and advances in the treatment of stage I non-small cell lung cancer (NSCLC) with a focus on the high-risk patient. Thoracic surgery is rapidly evolving, and it is critical that surgeons are apprised of new technological advances, as well as some of the controversies surrounding them. Here, the management of early-stage NSCLC, including risk assessment for pulmonary resection, newer techniques and concepts for lung resection in high-risk patients, and emerging new technologies, is featured.

Risk Assessment for Pulmonary Resection

Alessandro Brunelli

Risk assessment for pulmonary resection must include a preliminary cardiac evaluation. Patients deemed at prohibitive cardiac risk should be evaluated and treated as per American Heart Association/American Society of Cardiology guidelines. Those with low cardiac risk or with optimized treatment can proceed with pulmonary assessment. A systematic measurement of lung carbon monoxide diffusing capacity is recommended. In addition, predicted postoperative forced expiratory volume in 1 second should not be used alone for patient selection because it is not an accurate predictor of complications, particularly in patients with chronic obstructive pulmonary disease. The use of exercise testing should be emphasized. Low-technology tests, such as stair climbing, can be used whenever a formal cardiopulmonary exercise test is not readily available. However, in case of suboptimal performance (ie, <22 m in the stair-climbing test) patients should be referred to cardiopulmonary exercise testing with measurement of Vo2max for a better definition of their aerobic reserve. A Vo2max less than 10 mL/kg/min (or <35% of predicted) indicates a high risk for major lung resection.

Thoracoscopic Lobectomy for Stage I Non-Small Cell Lung Cancer

Rafael S. Andrade, Michael A. Maddaus

Lobectomy via video-assisted thoracoscopic surgery (VATS) has a lower rate of morbidity and is less immunosuppressive than open lobectomy. Compared with open lobectomy, VATS lobectomy appears to have equivalent oncological results. We review the literature on perioperative outcomes, biological impact, and oncological results. Most published reports to date—although retrospective—suggest significant perioperative advantages to VATS lobectomy over open lobectomy. Data on acute phase reactants and cellular immunity show that VATS lobectomy causes less of an inflammatory response and is less immunosuppressive than open lobectomy. Mid- to long-term oncological results of patients with early-stage non-small cell lung cancer (NSCLC) appear to be equivalent for VATS and open lobectomy. Clinical evidence indicates that VATS lobectomy for early-stage NSCLC is associated with fewer postoperative complications and less negative biological impact than open lobectomy. Furthermore, all data to date strongly suggest oncological equivalence between VATS and open lobectomy for patients with early-stage NSCLC.

Sublobar Resection for Early-Stage Lung Cancer

The use of sublobar resection techniques (anatomic segmentectomy; extended wedge) in the treatment of early-stage non-small cell lung cancer has been associated with increased local recurrence rates compared with lobectomy. Recent data, however, have suggested that sublobar resection of smaller tumors (especially those ≤2 cm) can be performed with no significant difference in local recurrence or long-term survival. These findings have particular relevance in elderly patients and in those patients who may be at high risk for lobectomy because of underlying medical comorbidities. Careful patient selection on the basis of individualized assessment of specific patient and tumor characteristics will aid in selecting the optimal approach. For larger tumors, or when adequate surgical margins are not obtainable, lobectomy should be performed. Currently, active, prospective, randomized studies (Cancer and Leukemia Group B [CALGB] 140503 and American College of Surgeons Oncology Group [ACOSOG] Z4032) will provide critical insights in delineating the efficacy of sublobar resection techniques in early-stage non-small cell lung cancer.

Sublobar Resection with Brachytherapy Mesh for Stage I Non-Small Cell Lung Cancer

David D. Odell, Michael S. Kent, Hiran C. Fernando

Lobar resection is currently the standard approach for the treatment of stage I non-small cell lung cancer. Sublobar resection is generally considered a compromise, reserved for high-risk patients because of greater rates of local recurrence compared with lobar resection. Adjuvant radiation therapy may decrease these increased local recurrence rates, but because of respiratory motion and difficulties in identifying the staple line, radiation delivery can be challenging with an external beam approach. Adjuvant intraoperative brachytherapy with the use of low-dose rate iodine-125 seeds placed alongside the surgical staple has been used with success in several centers. A randomized multicenter North American study has also recently completed accrual, but the results of this are not yet available. In the following review, we outline the techniques used, safety considerations, and currently available outcomes of sublobar resection with adjuvant brachytherapy for non-small cell lung cancer.

Surgical Resection in Combination With Lung Volume Reduction Surgery for Stage I Non-Small Cell Lung Cancer

Wael N. Yacoub, Bryan F. Meyers

Surgical resection remains the favored option of treatment for stage I lung cancer patients. Co-existing obstructive lung disease can reduce lung function and increase the risk of surgery. Severe emphysema may preclude resection of lung cancer due to concerns about low values of postoperative lung function. However, many patients will experience stable or improved lung function simply by resecting hyper-expanded and relatively functionless lung. This so-called “lung volume reduction effect” may occur after standard resection or after rare instances of formal lung volume reduction surgery concurrent with pulmonary resection of the tumor. This review explores these possibilities and informs the readers of pioneering work in this area.

Fractionated Radiotherapy for High-Risk Patients with Early-Stage Non-Small Cell Lung Cancer

Jeffrey A. Bogart

The treatment of patients with early-stage non-small cell lung cancer and cardiopulmonary dysfunction has rapidly evolved during the past decade. Although fractionated radiotherapy has been the most frequently used alternative treatment, additional approaches, including limited resection with or without brachytherapy, stereotactic body radiotherapy, and radiofrequency ablation are increasingly used and have now been studied prospectively. This review will focus on the potential current role of fractionated radiotherapy for high-risk patients with particular consideration of altered fractionation schemes and recent advances in treatment related technology.

Image-Guided Radiofrequency Ablation for the Treatment of Early-Stage Non-Small Cell Lung Neoplasm in High-Risk Patients

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.

Stereotactic Radiosurgery for Lung Tumors

Richard I. Whyte

Lung cancer remains the most common cause of cancer-related deaths in the United States, and although surgery remains the standard treatment for early-stage tumors, stereotactic radiation is gaining an increasing role as an alternative form of therapy. Initially a form of treatment designed for neurosurgical applications, during the past decade stereotactic radiosurgery (SRS) has gone from a novel treatment for patients deemed to be prohibitive candidates for surgical resection to the point that there is now an international, randomized, multicenter trial to compare SRS to lobectomy in otherwise-healthy patients. This article reviews the history of SRS as applied to lung tumors, summarizes the currently available data on efficacy and toxicity, and describes some of the current controversial aspects of this treatment.

Functional Tricuspid Regurgitation: Introduction

Ani C. Anyanwu

Functional or secondary tricuspid regurgitation typically refers to tricuspid regurgitation occurring secondary to left-sided heart disease, or pulmonary hypertensive disease, in the absence of organic lesions of the tricuspid valve. Until recently, “surgical abstention” has been the norm in dealing with functional tricuspid regurgitation, with the assumption that tricuspid regurgitation should resolve once the primary cause (typically mitral stenosis or regurgitation) is eliminated. This historical conservative approach to tricuspid regurgitation continues to tailor surgical practice to the present day, and tricuspid valve annuloplasty remains an infrequent operation in most surgical practices. Increasingly, however, there are reports in the literature supporting a more aggressive role for surgery in the prevention and treatment of functional tricuspid regurgitation. We have dedicated the cardiac section of this issue of the Seminars in Thoracic and Cardiovascular Surgery to exploring the pathophysiological, epidemiologic, and clinical basis for a more aggressive approach to management of functional tricuspid regurgitation. In 6 articles, invited experts in valvular heart disease have provided a thorough review of the current state of opinion and practice as regards functional tricuspid valve regurgitation. Although the articles are written mostly from the perspective of treating the patient with mitral valve disease, the principles apply to other causes of functional tricuspid regurgitation.

Functional Tricuspid Regurgitation in Mitral Valve Disease: Epidemiology and Prognostic Implications

Ani C. Anyanwu, David H. Adams

In this review we summarize the data on epidemiology and natural history of functional tricuspid valve regurgitation as it applies to surgery for mitral valve disease. Tricuspid regurgitation in the context of mitral valve disease is frequent and is associated with substantial reduction in survival and quality of life. In many patients, the correction of left-sided cardiac lesions does not lead to resolution of tricuspid regurgitation. Significant tricuspid regurgitation after mitral valve surgery portends a poor prognosis, a course that is often not altered by subsequent surgical therapy. Although a liberal approach to tricuspid annuloplasty is widely practiced, the evidence that this approach alters the natural history of functional tricuspid regurgitation is not yet available, so it is not certain how much of the negative impact of tricuspid regurgitation is causative, rather than confounding, and to what degree we will improve long-term outcomes of mitral valve surgery by liberal tricuspid annuloplasty.

The Pathogenesis of Functional Tricuspid Regurgitation

Judy Hung

Functional tricuspid regurgitation (TR) is a common etiology of TR. Functional TR results from geometrical distortion of the normal spatial relationships of the tricuspid leaflets, annulus, chords, papillary muscles, and right ventricular (RV) walls. Functional TR results most commonly from left-sided heart disease, including mitral valve abnormalities and cardiomyopathy and RV dysfunction secondary to pulmonary disease (Cor pulmonale). The tricuspid annulus, which has a normal bimodal or saddle shape, becomes larger, flatter, and more circular with the development of functional TR. RV dilation can lead to papillary muscle displacement and tethering of the tricuspid leaflets, resulting in incomplete coaptation and development of functional TR.

Basis for Intervention on Functional Tricuspid Regurgitation

Shahzad G. Raja, Gilles D. Dreyfus

Functional tricuspid regurgitation is a complex valvular lesion. Its optimal management remains controversial in the current era as the result of uncertainties regarding accurate diagnosis, surgical indication, the appropriate surgical procedure, and the late results of surgical treatment. It is no longer regarded a benign problem and does not resolve spontaneously after correction of left-sided heart valve lesions as once believed. It carries a significant morbidity and has an adverse impact on survival. Current techniques to repair functional tricuspid regurgitation are associated with a significant degree of residual or recurrent regurgitation mainly because of failure to address all the components of this challenging entity. This review article highlights emerging concepts and advances that provide an insight into the understanding of this perplexing lesion and attempts to define the basis of intervention on functional tricuspid regurgitation.

Valve Repair for Functional Tricuspid Valve Regurgitation: Anatomical and Surgical Considerations

Jason H. Rogers, Steven F. Bolling

Functional tricuspid regurgitation (TR) primarily arises from asymmetric dilation of the tricuspid annulus in the setting of right ventricular dysfunction and enlargement in response to left-sided myocardial and valvular abnormalities. Even if TR is not severe at the time of mitral valve surgery, TR can worsen and even appear late after successful mitral valve surgery, which portends a poor prognosis. Despite data demonstrating inferior outcomes in the presence of residual TR, surgical repair for functional TR remains underused. However, “benign neglect” of TR, especially in the presence of tricuspid annular dilation, is unacceptable. Surgical repair should consist of placement of a rigid or semirigid annular ring, which has been shown to provide superior durability compared with suture and flexible band-based therapies. Finally, minimally invasive and percutaneous approaches for correcting functional TR may increase the delivery of therapy and allow treatment of patients with recurrent TR at high risk for reoperation.

Surgical Strategies for Functional Tricuspid Regurgitation

Joanna Chikwe, Ani C. Anyanwu

Functional or secondary tricuspid regurgitation commonly is found in the setting of left-sided heart disease and, when severe, is associated with substantially poorer functional outcomes and survival if untreated. The traditional view that functional tricuspid regurgitation generally resolves with surgical correction of the primary lesions is no longer held. Data showing late development of severe tricuspid regurgitation in patients with mild regurgitation at time of mitral valve surgery have heralded a new era of aggressive intervention on the tricuspid valve. Tricuspid ring annuloplasty can be performed with minimal incremental morbidity and negligible additional mortality. Therefore, in addition to patients with severe regurgitation, annuloplasty is now also recommended for patients with risk factors for developing late tricuspid insufficiency (typically patients with moderate tricuspid regurgitation or severe annular dilation at time of left-sided cardiac procedures). In this work we review the current indications for tricuspid valve repair in patients undergoing other cardiac surgery operations and also the various options available to the surgeon.

Durability of Functional Tricuspid Valve Repair

Virna L. Sales, Patrick M. McCarthy

Current tricuspid repair techniques have variable and disappointing durability. The authors of several studies have shown the superiority of ring (rather than suture or pericardial) annuloplasties; however, others suggest equal or superior results with suture or pericardial repair techniques. Indeed, recurrent significant tricuspid regurgitation has been reported consistently after repair; it is therefore unclear which technique provides the best long-term outcomes and in which patients. In this study, we evaluated the outcomes of different tricuspid repairs regarding durability and analyzed the risk factors for repair failure. We also presented our current approach to surgical management of functional tricuspid regurgitation on the basis of recent studies and our experience treating patients with heart failure.