| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Eur J Cardiothorac Surg 1999;16:S13-S16
© 1999 Elsevier Science NL
Division of Thoracic Surgery, University of Maryland Hospital, 22 South Greene Street, Rm N4W94, Baltimore, MD 21201, USA
Key Words: Pulmonary metastases • Video-assisted thoracic surgery
Surgical resection has come to be accepted as standard treatment for patients with isolated pulmonary metastases. Although no prospective studies have ever been performed to clearly assess the benefit of pulmonary metastasectomy, there is an abundance of retrospective data that indicates long term survival benefits of complete pulmonary metastasectomy over historical controls without resection. This data has been used to support aggressive unilateral and bilateral open explorations for resection. Despite this aggressive approach, there is still a recurrence rate of over 50%. However, the long term survival of patients undergoing repeat metachronous metastasectomy has been unchanged compared to patients who did not require repeat metastasectomy after primary resection. Thus, patients with pulmonary metastases may face multiple surgical explorations with ‘curative' intent. These patients may be ideally suited to have their pulmonary resections performed with the aid of minimally invasive video assisted thoracic surgical techniques.
Concurrently, the techniques, indications and training of video-assisted thoracic surgery (VATS) have significantly developed. A number of surgeons have begun to apply VATS procedures to patients with pulmonary metastases in both diagnostic and therapeutic settings. Other surgeons, however, oppose the use of VATS as a therapeutic modality. To date, no prospective or significant retrospective data exist to support either opinion. Currently, the National Cancer Institute (NCI) sponsored US inter-group trial is conducting a Phase III multinational cooperative study comparing open resection (thoracotomy or median sternotomy) to minimally invasive (video-assisted) resection. The primary objective will be to determine the overall, failure-free survival difference between VATS and open approaches in the treatment of pulmonary metastases. It is the groups hypothesis that VATS resection will yield the same disease-free survival as open approach but with less overall morbidity, cost and pain to the patient. This will allow surgeons and oncologists, for the first time, to prospectively study the prognostic indicators and survival of patients with surgically resectable pulmonary metastases. It will also enable the prospective evaluation of a new surgical technique in relation to quality of life, cost, and oncologic outcome.
The justification of pulmonary metastasectomy and the need for prospective analysis of this procedure become clear when available data is analyzed. The surgical resection of pulmonary metastases has come to be accepted as standard treatment for patients with isolated pulmonary metastases. Although no prospective studies have ever been performed to clearly assess the benefit of pulmonary metastasectomy, there is an abundance of retrospective data that indicates long term survival benefits of complete pulmonary metastasectomy over historical controls without resection [1–13]. The strongest prognostic variable from these retrospective studies has been complete resection of all identifiable lesions. This data has been used to support aggressive unilateral and bilateral open explorations for resection. Despite this aggressive approach, there is still a recurrence rate of over 50%. However, the long term survival of patients undergoing repeat metachronous metastatectomy has been unchanged compared to patients who did not require repeat metastatectomy after primary resection [3,14,15]. Thus, occult metastases, that are clinically undetectable and ‘missed' at the time of pulmonary metastatectomy, may simply represent the natural biology of slow growing pulmonary metastases, and do not necessarily indicate a poor prognosis. Thus, patients with pulmonary metastases may face multiple surgical explorations with ‘curative' intent, or may represent with unresectable disease. In either case, these patients may be ideally suited to have their pulmonary resections performed with the aid of minimally invasive video assisted resection.
The first reports of pulmonary metastasectomy came as early as the late 1800s (Winlechner, Kronlein), and the first report of a long term survivor was by Barney and Churchill [4], who resected a solitary renal cell metastasis in a patient who subsequently survived 23 years and died of unrelated causes. Pulmonary metastasectomy was then primarily applied to carefully selected patients with single pulmonary metastases and long disease free intervals [5]. Martini et al. [2] ushered in the current approach to pulmonary metastasectomy, reporting long term survival in patients with multiple unilateral and bilateral metastases who underwent aggressive primary and repeat pulmonary metastatectomy. Since that time, there have been numerous retrospective reports of the application of aggressive pulmonary metastasectomy [1]. The general criteria accepted as requirements in selecting patients for pulmonary metastatectomy include: (i) primary neoplasm must be completely controlled or imminently controllable; (ii) metastatic lesions must be limited to the lung without evidence of other distant organ involvement; (iii) all metastases must be resectable with adequate pulmonary reserve; and (iv) non-availability of other effective therapy. Using these criteria for the resection of pulmonary metastases, long-term survival rates have been reported to be in the range of 30% and 58% for patients with soft tissue and osteogenic sarcomas respectively [7,8]. Similar cure rates have been reported with the resection of isolated pulmonary metastases from colon cancer (30.5%), [9] renal cell carcinoma (52.4%), [10] head and neck cancers (48%) [11], and germ cell tumors (59%). Although some patients with solitary melanoma metastases may benefit from pulmonary metastasectomy, the vast majority of patients with this disease do not survive long-term despite aggressive resection of metastases [13].
Data collected from patients with soft tissue and bony sarcomas, and more recently a collective review by the International Registry of Lung Metastases (a collective review of 5207 patients from multiple institutions) support the use of multiple resections for recurrent pulmonary metastases. It has been shown that the percentage of patients surviving long term is not adversely affected by the need for multiple surgical procedures [3,8,15]. Additionally, a retrospective study by Roth et al. [14] comparing median sternotomy to open, unilateral thoracotomy showed no difference in patient survival despite the finding that bilateral exploration, with only evidence of unilateral metastases, found additional tumor in approximately 40% of the patients. This implies that each patient originally developed a finite number of metastases that, when removed (even if serial resections were required), resulted in long-term survival. The literature, therefore, supports the potential use of lower morbidity procedures (VATS) in patients with isolated pulmonary metastases.
Recently, video-assisted thoracic surgery (VATS) has gained in popularity due to the excellent visualization of the pleural space with modern optics. VATS procedures have been applied to a number of common thoracic problems with success. Early reports have been both favorable and disapproving [16–19]. Early VATS enthusiasm has been tempered by reports of local tumor recurrences both at the original resection site and in thoracoscopic port sites [20]. This problem has been addressed by making an adequate sized incision and by placing the specimen in a bag prior to removal from the chest. Experience has also improved surgical technique so that close or positive margins can be more reliably avoided. An additional argument against a VATS approach is that malignant nodules may be missed, which was shown to be true by McCormack, et al. [21,22]. Their data led to the early closure of Cancer and Leukemia Group B (CALGB) 9336, a study directly comparing the ability of VATS versus thoracotomy to detect metastatic lesions not identified on pre-operative screening. However, these studies were done before the availability of high resolution, spiral CT scanners. Spiral CT scanners have been found to reliably detect additional pulmonary nodules when directly compared to traditional CT scanners, detecting an additional 40% more lesions. A similar number was documented to be found by open technique in Remy-jardin's study [23]. In addition, this argument would demand the use of bilateral, open exploration for all patients undergoing metastatectomy. Such an approach was found by Roth not to impact on survival, nor does it address the biology of metastatic disease.
The biology of pulmonary metastases may favor VATS resection based on the following arguments: (i) metastases have been present prior to treatment of the primary lesion and in that sense have been ‘missed' for a significant period of time already, (ii) as noted above multiple resections do not adversely affect the overall outcome of patients with metachronously detected metastases, (iii) patients who recur with unresectable disease will not be subject to a larger operation, and (iv) VATS resection may be less stressful for patients and therefore result in less immunosuppressive factor production resulting in a more favorable disease course, (v) VATS may allow patients to return to their regular work or family schedules significantly earlier than an open approach. This effect may be multiplied in a patient who requires multiple resections. Currently, there is no evidence that resection of pulmonary metastases, at the time that they become radiographically apparent, is any less efficacious than open procedures that remove all nodules, benign and malignant, prior to their radiologic identification.
Other considerations include quality of life and cost of treatment. The decrease in the quality of life in patients undergoing VATS procedures may be substantially less than those undergoing full thoracotomy/median sternotomy. If more frequent procedures are required, however, the open procedures may be preferred from this standpoint. Although the cost of VATS procedures are not clearly less expensive than open procedures, they have not been compared in the context of pulmonary metastases. These lesions generally are peripheral and often ideal nodules for VATS wedge resection. Often these patients can be discharged in 24–48 h and are able to return to work in 1–2 weeks. This differs substantially from the 3–7 days hospitalization often required following a median sternotomy or thoracotomy, and cessation of work for up to 6 weeks. These issues are ideally assessed in the context of a randomized trial of minimally-invasive techniques, such as VATS, and standard open procedures.
Historical data, tumor biology and recent advances in radiology and surgical techniques support the use of video assisted surgery in the resection of pulmonary metastases. With these factors in mind, a minimally-invasive approach may very well accomplish the same outcome as a more radical, open approach when resecting pulmonary metastases, but with less overall morbidity. Currently, a large, prospective randomized trial, involving North America and possibly Europe, comparing video assisted thoracic surgery versus open surgery for pulmonary metastases is moving forward to answer these questions. A study of this important population of oncology patients will therefore be undertaken, for the first time, in a prospective manner to corroborate survival and prognostic variables previously collected in a retrospective manner.
 |
Footnotes |
|---|
Presented at the 2nd MITSIG International Symposium: Controversies in Cardiothoracic Surgery, Hong Kong, November 20–21, 1998.
1 Tel.: +1-410-328-6366; fax: +1-410-328-0693 
|
References |
|---|
 Top References |
|---|
This article has been cited by other articles:
|
|
 |
|
  A. Nakas, M. N. Klimatsidas, J. Entwisle, A. E. Martin-Ucar, and D. A. Waller Video-assisted versus open pulmonary metastasectomy: the surgeon's finger or the radiologist's eye? Eur. J. Cardiothorac. Surg., September 1, 2009; 36(3): 469 - 474. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. C. Kang, C. H. Kang, H. J. Lee, J. M. Goo, Y. T. Kim, and J. H. Kim Accuracy of 16-channel multi-detector row chest computed tomography with thin sections in the detection of metastatic pulmonary nodules Eur. J. Cardiothorac. Surg., March 1, 2008; 33(3): 473 - 479. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M. Parsons, F. C. Detterbeck, and L. A. Parker Accuracy of Helical CT in the Detection of Pulmonary Metastases: Is Intraoperative Palpation Still Necessary? Ann. Thorac. Surg., December 1, 2004; 78(6): 1910 - 1918. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
