title: External suction versus water seal after selective pulmonary resection for lung neoplasm: a systematic review.
abstract: OBJECTIVE
  To evaluate whether external suction is more advantageous than water seal in patients undergoing selective pulmonary resection (SPR) for lung neoplasm.
  
  
  BACKGROUND
  Whether external suction should be routinely applied in postoperative chest drainage is still unclear, particularly for lung neoplasm patients. To most surgeons, the decision is based on their clinical experience.
  
  
  METHODS
  Randomized control trials were selected. The participants were patients undergoing SPR with lung neoplasm. Lung volume reduction surgery and pneumothorax were excluded. Suction versus non-suction for the intervention. The primary outcome was the incidence of persistent air leak (PAL). The definition of PAL was air leak for more than 3-7 days. The secondary outcomes included air leak duration, time of drainage, postoperative hospital stay and the incidence of postoperative pneumothorax. Studies were identified from literature collections through screening. Bias was analyzed and meta-analysis was used.
  
  
  RESULTS
  From the 1824 potentially relevant trials, 6 randomized control trials involving 676 patients were included. There was no difference between external suction and water seal in decreasing the incidence of PAL [95% confidence interval (CI) 0.81-2.16; z = 1.10; P = 0.27]. Regarding secondary outcomes, there were no differences in time of drainage (95% CI-0.36-1.56, P = 0.22), postoperative hospital stay (95% CI -.31-.54, P = 0.87) or incidence of postoperative pneumothorax (95% CI 0.18-.02, P = 0.05) between external suction and water seal.
  
  
  CONCLUSIONS
  For participants, no differences are identified in terms of PAL incidence, drainage time, length of postoperative hospital stay or incidence of postoperative pneumothorax between external suction and water seal. The bias analysis should be emphasized. To the limitations of the bias and methodological differences among the included studies, we have no recommendation on whether external suction should be routinely applied after lung neoplasm SPR. More high-quality randomized controlled trials are needed.
  
  
  BACKGROUND
  None.
authors.affiliation: Department of Thoracic Surgery, The Affiliated Hospital of Medical College, Qingdao University, Qingdao, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Qiu
authors.forename: Yi
authors.initials: Y
authors.lastname: Shen
authors.forename: Ming-zhao
authors.initials: MZ
authors.lastname: Wang
authors.forename: Yao-peng
authors.initials: YP
authors.lastname: Wang
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Zi-zong
authors.initials: ZZ
authors.lastname: Wang
authors.forename: Xiang-feng
authors.initials: XF
authors.lastname: Jin
authors.forename: Yu-cheng
authors.initials: YC
authors.lastname: Wei
mesh_terms: D004322:Drainage / Q000379:methods; D006801:Humans; D008175:Lung Neoplasms / Q000601:surgery / Q000628:therapy*; D011013:Pneumonectomy; D011030:Pneumothorax / Q000209:etiology / Q000517:prevention & control / Q000628:therapy; D011182:Postoperative Care / Q000379:methods; D011183:Postoperative Complications / Q000517:prevention & control / Q000628:therapy; D016032:Randomized Controlled Trials as Topic; D013396:Suction