Video-assisted Thoracic Surgery versus Thoracotomy for Non-small-cell Lung Cancer

Video-assisted thoracic surgery (VATS) has been recommended as more optimal surgical technique than traditional thoracotomy for lobectomy in lung cancer, but it is not well defined. Here, we compared VATS and traditional thoracotomy based on clinical data. From November 2008 to November 2010, 180 patients underwent lobectomy for non-small-cell lung cancer (NSCL) identified by computerized tomography. Of them, 83 cases were performed with VATS and 97 by thoracotomy. Clinical parameters, consisting of blood loss, operating time, number of lymph node dissection, days of pleural cavity drainage, and length of stay were recorded and evaluated with t test. No significant difference was observed between the VATS and thoracotomy groups in the average intraoperative blood loss, number of lymph node dissections, and days of pleural cavity drainage. While the average operating time in the VATS group was significantly longer than that in thoracotomy group, recurrence was only present in one case, as opposed to 7 cases in the thoracotomy group In conclusion, similar therapeutic effects were demonstrated in VATS and thoracotomy for NSCL. However, VATS lobectomy was associated with fewer complications, recurrence and shorter length of stay.


Introduction
Lung cancer is the leading cause of cancer-related death worldwide.Conventional thoracotomy has been widely adopted as standard surgical approaches for treatment of lung cancer.However, it often requires dissection of several major chest wall muscles and the use of rid spreaders, both of which may lead to serious postoperative morbidity, like chronic pain and compromised pulmonary function (Moffatt et al., 2002).More recently, videoassisted thoracoscopic surgery (VATS) has been demonstrated as a safe and feasible alternative for the treatment of lung cancer with the advantage of minimally invasive, less pain, less blood loss and faster recovery (Flores et al., 2009).Nevertheless, this approach is still not popular among thoracic surgeons in China because of the technical difficulties and operative risks.VATS also constituted only 20% of lobectomies performed between 1999 and 2005 by high-level practitioners in the United States as represented by the Society of Thoracic Surgeons (STS) General Thoracic Surgery database (Boffa et al., 2008).Importantly, the long-term oncological validity of VATS is still under study (Thomas et al., 2002;Sakuraba et al., 2007;Yang et al., 2009).Therefore, the objective of this study is to further confirm the superiority of VATS lobectomy for non-small-cell lung cancer (NSCLC) to thoracotomy.

Clinical data
We retrospectively analyzed results in our patients who underwent VATS lobectomy (83 cases) and thoracotomy lobectomy (97 cases) between November 2008 and November 2010.Mean postoperative follow-up was 13.2 months with the range from 3 to 27.Preoperatively, all the patients were diagnosed with lung cancer through routine examination of the tumor location, tumor size, lymph node status and the adjacent relations.Pre-, peri-, and postoperative patient details and outcome variables, including blood loss, operating time, number of lymph node dissection, days of pleural cavity drainage, and length of stays, were collected by means of clinical assessment.The detail preoperative clinical data was listed in table 1 (Table 1).

Operative technique
The lobectomy is performed under general anesthesia with single-lung ventilation, which may be accomplished with double-lumen endotracheal tubes.The patient is placed in the full lateral decubitus position with the upper arm suspended on a crossbar.Three incisions were performed to accomplish this procedure: A 4 cm utility incision was placed in the fourth intercostal space at mid axillary line using standard thoracic instruments without rib spreading; a 1 cm anterior thoracostomy port was obtained at the eighth intercostal space at the anterior axillary line for camera; a 1-cm posterior port was used for retraction and stapler insertion (Yang et al., 2009).Subcutaneous tissue and muscle bundles were shoved off by incision retractor to enable the easy entrance of surgical instruments.Anterograde or one way lung vessel and bronchus treatment were performed to dissect the lung lobe.

Statistical analysis
All data were analyzed by SPSS17.0 and the results were measured by average ± standard deviation ( ±s).All the peri-, and postoperative clinical parameters between these two groups were evaluated with t test.P < 0.05 was considered as statistically significant.

Results
No significant difference was observed between VATS group and thoracotomy group in the average intraoperative blood loss, number of lymph node dissection, and days of pleural cavity drainage (Table 2).The average operating time in VATS group was significantly longer than that in thoracotomy group, but otherwise in the length of stays.Besides, in VATS group, one case showed incision metastasis and one case of III a patient with lung cancer recurrence.In thoracotomy group, recurrence was present in 7 cases.

Discussion
Lung cancer is the most common cause of cancer death in the developed world and the incidence is rising steeply in the developing world, such as China (Saunders et al., 1997).Therefore, the accurate diagnose and treatment of lung cancer is critical for reducing the death rate.Because of lack of clinical symptom, chest computerized tomography (CT) scan is highly preferential for early diagnose of lung cancer (Swensen et al., 2005;Bach et al., 2007).However, studies show high frequency of missed diagnose and misdiagnose in CT scan (Porte et al., 1999;Swensen et al., 2002).High-cost and limited equipment popularity of position emission tomography (PET) and single photon emission computerized tomography (SPECT) also results in their confined application in clinic (Pieterman et al., 2000).Percutaneous core needle biopsy (PCNB) and fibrobronchoscopy also seem not to be applicable for lung cancer diagnose due to isolated and minute lesion.Moreover, it is unacceptable for patients and clinician to perform exploratory thoracotomy owing to high invasiveness (Debevec et al., 2006).However, recent researches have demonstrated that VATS could overcome all the above shortcomings, and significantly improve the diagnose rate of isolated small nodule concurrently removing the corresponding lesions.Thus, it is more acceptable for patients and clinician.
In this study, all the patients were diagnosed as malignant lung cancer through CT scan and postoperative pathologic study.Therefore, it is essential to carry out operative treatment to remove the lesion (VATS or thoracotomy).Postoperatively, we found no significant difference was present between VATS group and thoracotomy group in the average intraoperative blood loss, number of lymph node dissection, and days of pleural cavity drainage.These results indicate the similar effect between VATS and thoracotomy treatment, which both could minimize the trauma.
Nevertheless, VATS incision is obviously smaller than that in thoracotomy, not affecting latissimus dorsi, serratus anterior, and pectoralis major, not cutting and shoving off the rib, but only dividing the intercostals and supracostal.Thus, VATS treatment could cause less pains, shorter hospital stays, and reduced the respiratory comorbid illness (Demmy et al., 2008).These advantages have also been demonstrated in our study.Our results indicated the length of stays was significantly shorter than that in thoracotomy group.After VATS treatment, the upper limbs activities and function in injury side could restore to normal within a month.And the wound is relatively perfect.Therefore, VATS is, in particular, suitable for the young patients and older patients with marginal lung function.Further, the less time in bed after VATS treatment made the patient vigorously coughing and spitting which decrease the complication occurrence of lung infection and atelectasis.However, some reports indicated the reduced complication is only present within two weeks after surgery, and this superiority would weaken after two weeks (Muraoka et al., 2006).
Importantly, major trauma could lead to serious acute phase response which may damage the organism immune system and cause decreased anti-tumor ability.Griag et al showed that VATS pulmonary lobectomy is associated with reduced peri-operative changes in acute phase responses compared with thoracotomy, with significant lower expression of C-reactive protein (CRP) interleukin (IL)-6, tumour necrosis factor (TNF) receptors (TNF-sR55, TNF-sR75) and P-selectin (Craig et al., 2001).Whitson et al. (2008) also proposed that VATS lobectomy for NSCL cancer was associated with less impairment of cellular cytotoxicity, as compared with thoracotomy.This less immune damage after VATS may lay a better basis for quicker recovery and further treatment.
For example, patients undergoing thoracoscopic lobectomy had significantly fewer delayed and reduced chemotherapy doses (Petersen et al., 2007).Nicastri et al. (2008) showed VATS lobectomy could improve the improved tolerance of chemotherapy.The overall survival rates 5 years after surgery were 85% and 90% in the thoracotomy and VATS groups, respectively (Sugi et al., 2000).Recent study also revealed that VATS could significantly improve the quality of life for the patients.Patients in VATS group had higher scores in physical functioning and emotional role in Medical Outcomes Study Short Form 36 (SF-36) Health Survey.Moreover, the results for chest pain, arm/shoulder pain and peripheral neuropathy scores were better preserved in the VATS group (Baysungur et al., 2011).
Besides, in our study, one case developed incisions metastasis.We predicted the reason may be that the incision was so small that iatrogenic dissemination and incision implanting due to broken tumor and lymph nodes transfer during removing the tumor process.McKenna et al also found 5 patients developed incisions metastasis in 1,100 case (McKenna Jr et al., 2006).Therefore, we suggest careful operation and endo-pouch should be used when removing the tumor.
Shiraishi et al found VATS lobectomy for c-stage I NSCLC may have no survival disadvantage over thoracotomy procedures.It might, however, increase the risk of local recurrence when used to treat pathologically N1 or N2 node-positive disease (Shiraishi et al., 2008).Identically, in this study, we found one case of IIIa patient with recurrence after thoracoscopic lobectomy, but seven cases after thoracotomy.Thus, caution should be used when treating those cases with thoracoscopic surgery.
The need for conversion to a thoracotomy is possible after VATS.Our result found conversion to a thoracotomy occurred in 6 patients, which seemed to be in accordance with previous study (approximately 10%) (Walker, 1998;Shennib et al., 2005).The major causes for conversion were bleeding, adhesion of calcified lymph node and carcinoma invasion to the adjacent organs (Sagawa et al., 2002;Ohtsuka et al., 2004).
In conclusion, we suggest VATS is effective and irreplaceable for early diagnosis and treatment of lung cancer.Although similar therapeutic effect exists after VATS and thoracotomy, VATS could significantly reduce the postoperative complication and length of stay, minimize the trauma, and improve the quality of life.