Recurrence rates of video-assisted thoracoscopic versus open surgery in the prevention of recurrent pneumothoraces: a systematic review of randomised and non-randomised trials.

BACKGROUND: Evidence supporting similar recurrence rates between video-assisted and open surgery for the treatment of recurrent pneumothorax is questionable, because the number of randomised trials is sparse and they are underpowered to detect any meaningful difference. Our aim was to do a systematic review of randomised and non-randomised studies to compare recurrence rates between the two forms of surgical access. METHODS: We did a systematic literature search for studies on pneumothorax surgery in Medline, Embase, Cochrane Library, trial registers on the internet, and conference abstracts, and identified 29 studies (four randomised and 25 non-randomised) eligible for inclusion. Meta-analysis was done by combining the results of reported recurrence rates in patients undergoing video-assisted thoracoscopic surgery compared with those having open surgery. Both fixed and random effects models were applied to the results pooled for analysis. RESULTS: In studies that did the same pleurodesis through two different forms of access, the relative risk (RR) of recurrences in patients undergoing video-assisted surgery compared with open surgery was similar between non-randomised and randomised studies (RR 4.880 [95% CI 2.670-8.922] vs 3.951 [0.858-18.193]), yielding an overall RR of 4.731 (2.699-8.291; p<0.0001). There was no evidence to suggest heterogeneity of trial results (p=0.88). The high RR of recurrence for video-assisted surgery remained robust to a random effects model (4.051 [1.996-7.465]; p<0.0001), by including all comparative studies (3.991 [2.584-6.164]; p<0.0001), with only high-quality studies used (4.016 [1.8468.736]; p<0.0001), and on a simulation biased in favour of video-assisted surgery when there were no events in either group (3.559 [2.165-5.852]; p<0.0001). INTERPRETATION: Both randomised and non-randomised trials are consistent in recurrence of pneumothoraces and show a four-fold increase when a similar pleurodesis procedure is done with a video-assisted approach compared with an open approach.

Surgical access rather than method of pleurodesis (pleurectomy or pleural abrasion) influences recurrence rates for pneumothorax surgery: systematic review and meta-analysis.

AIM: Surgery for recurrent spontaneous pneumothoraces is one of the most commonly performed procedures in thoracic surgery, but few studies have evaluated the efficacy of the surgical treatment options. We aimed to evaluate the influence of the type of pleurodesis on recurrence whilst adjusting for surgical access by systematic review and meta-regression of randomised and non-randomised trials. METHODS: A systematic literature search undertaken for studies on pneumothorax surgery in MEDLINE, EMBASE, Cochrane Library, Internet trial registers and conference abstracts identified 29 studies (4 randomised and 25 non-randomised) eligible for inclusion. Meta-regression was performed adjusting for access to screen for evidence of a difference in recurrence rates. RESULTS: Access remained the principal determinant of recurrence rates after surgery. The relative risk of recurrence was 4.731 (2.699-8.291; p < 0.001) using video-assisted thoracoscopic surgery compared to open access. After adjusting for access, the relative risk of recurrence of pleural abrasion compared to pleurectomy was observed to be 2.851 (95 % CI 0.478-17.021), but this was not statistically (p = 0.220). CONCLUSION: Surgical access remains the most important factor that influences outcome after surgery for recurrent pneumothoraces. Although the relative risk of recurrence was higher with pleural abrasion compared to pleurectomy, it was not statistically significant, and more work needs to be conducted to address this question.

A meta-analysis of minimally invasive versus traditional open vein harvest technique for coronary artery bypass graft surgery.

The long saphenous vein remains the most commonly used conduit in coronary artery bypass surgery. Vein harvest is a critical component of this operation with significant morbidity associated with large leg wounds from open techniques. Here, we analyse the available literature comparing minimally invasive techniques vs. the traditional open method for vein harvest. A systematic literature search of Medline, Embase and Cochrane databases was performed using the following terms; 'saphenous vein', 'coronary artery bypass', 'tissue and organ harvesting' and 'endoscopic'. Relevant papers were then analysed using Statsdirect software. There was significantly reduced leg wound infection, leg wound haematoma and postoperative pain in the minimally invasive group. There was no statistical difference between the groups for vein harvest time, length of hospital stay and incidence of vein injury. There was a significantly reduced long-term graft patency in veins harvested by a minimally invasive technique. The results of this meta-analysis demonstrate the operative advantages of minimally invasive techniques for the purposes of vein harvest in coronary artery bypass surgery. However, further studies are required to look at long-term graft patency following minimally invasive vein harvest as this remains a major concern.

Impact of positive pleural lavage cytology on survival in patients having lung resection for non-small-cell lung cancer: An international individual patient data meta-analysis.

OBJECTIVES: Pleural lavage cytology is the microscopic study of cells obtained from saline instilled into and retrieved from the chest during surgery for non-small-cell lung cancer. The aims of this study were to collate multi-institutional individual patient data for meta-analysis to determine independence as a prognostic marker and to characterize the impact of positive results on stage-adjusted survival. METHODS: We identified 31 publications from 22 centers/research groups that performed pleural lavage cytology during surgery for non-small-cell lung cancer and invited submission of individual patient data. Actuarial survival was calculated using Kaplan-Meier methods, and comparisons were performed using the log-rank test. Cox proportional hazards regression was used to ascertain the covariates associated with survival. RESULTS: By January 1, 2008, submissions were received internationally from 11 centers with individual data from 8763 patients. In total, 511 (5.8%) patients had a positive pleural lavage cytology result, and this was shown to be an independent predictor of adverse survival associated with a hazard ratio of 1.465 (1.290-1.665; P < .001) compared with a reference hazard ratio of 1 for a negative result. On statistical modeling, the best adjustment for patients with a positive pleural lavage cytology result was a single increase in the T category assigned to the case, up to a maximum of T4. Correction for differences in survival were obtained in stages IB (P = .315) and IIB (P = .453), with a degree of correction in stage IIIA (P = .07). CONCLUSIONS: Pleural lavage cytology should be considered in all patients with non-small-cell lung cancer suitable for resection. A positive result is an independent predictor of adverse survival, and the impact on survival suggests that it may be appropriate to upstage patients by 1 T category.

Preoperative versus postoperative chemotherapy in patients with resectable non-small cell lung cancer: systematic review and indirect comparison meta-analysis of randomized trials.

INTRODUCTION: A large number of trials have evaluated the efficacy of postoperative chemotherapy on survival after resection for lung cancer, and a smaller number have evaluated preoperative chemotherapy on survival for potentially resectable lung cancer, but no direct comparison has yet been published comparing the two approaches. METHODS: We conducted a systematic review of randomized trials, extracted time-to-event data using Parmar methods (when not reported), used random effects meta-analysis to evaluate overall and disease survival treatment effects and performed indirect comparison meta-analysis to obtain the relative hazards of postoperative to preoperative administration on survival. RESULTS: Data were abstracted from 32 randomized trials involving more than 10,000 participants, with 22 trials administering postoperative and 10 trials administering preoperative chemotherapy. For overall survival, the hazard ratios were 0.80 (0.74-0.87; p < 0.001) and 0.81 (0.68-0.97; p = 0.024) in postoperative chemotherapy group and preoperative chemotherapy group, respectively. Using indirect comparison meta-analysis, the relative hazards of postoperative compared with preoperative administration was 0.99 (0.81-1.21; p = 0.91). For disease-free survival, the hazard ratios were 0.76 (0.67-0.86; p < 0.001) and 0.79 (0.63 to 1.00; P = 0.050) in postoperative chemotherapy group and preoperative chemotherapy group, respectively. Using indirect comparison meta-analysis, the relative hazards of postoperative compared with preoperative administration was 0.96 (0.77-1.20; p = 0.70). CONCLUSIONS: In patients with resectable lung cancer, there was no evidence of a difference in overall and disease-free survival between the timing of administration of chemotherapy (postoperative versus preoperative).

A systematic review of randomized trials comparing revascularization rate and graft patency of off-pump and conventional coronary surgery.

OBJECTIVE: Although many trials have been conducted to evaluate the benefits of off-pump coronary surgery, few have concentrated on graft patency. We sought to evaluate the impact of off-pump surgery on completeness of revascularization and graft patency compared with conventional surgery. METHODS: A systematic literature search was undertaken of all randomized trials of off-pump coronary surgery in MEDLINE, EMBASE, the Cochrane Library Controlled Trials Register, the National Research Register, and abstracts from major conferences. RESULTS: In total, 132 publications were identified. From this number, we excluded 43 without a conventional surgery arm and 80 that did not evaluate graft patency. One trial was excluded for selective angiography and one abstract was excluded because of insufficient information. A total of 7 trials were eligible for overview. On initial analysis, the relative risk of graft patency in off-pump coronary surgery compared with conventional surgery was 0.959 (95% confidence interval 0.936-0.983; P = .001). The analysis was repeated after excluding one specific trial because of clinical and statistical heterogeneity (chi2(6) = 27.78; P < .001), and a relative risk of 0.953 (95% confidence interval 0.927-0.980; P = .001) was obtained with no further evidence of heterogeneity (chi2(5) = 5.35; P = .374). In 5 trials that included the mean number of grafts performed per arm, the standardized mean difference in revascularization comparing off-pump with conventional surgery was -0.164 (-0.286 to -0.043; P = .008). CONCLUSION: In a meta-analysis of randomized trials, patients undergoing off-pump coronary surgery had a lower rate of revascularization and lower graft patency than did patients undergoing conventional coronary surgery.

Indirect comparison meta-analysis of aspirin therapy after coronary surgery.

OBJECTIVES: To evaluate the efficacy of low and medium dose aspirin therapy after coronary surgery by using an indirect comparison meta-analysis. DATA SOURCES: Systematic literature search of Medline, Embase, Cochrane controlled trials register, and trial register sites on the internet. STUDY SELECTION: Outcome was evaluated by angiography and reported as graft occlusion and rate of events in patients. Trials that did not include aspirin as the sole therapy or did not have a placebo control arm were excluded. Articles were assessed for eligibility and quality and grouped according to dosage. The estimated difference in effect of low and medium dose aspirin on graft occlusion was obtained by combining the estimated log relative risks of low dose with placebo and medium dose with placebo. RESULTS: For graft occlusion, the medium dose trials yielded a relative risk reduction of 45% compared with 26% for the low dose trials. The greater effect in the medium dose trials is summarised by a relative risk ratio of 0.74 (95% confidence interval 0.52 to 1.06; P = 0.10) for graft occlusion and 0.81 (0.57 to 1.16; P = 0.25) for events in patients. CONCLUSIONS: Medium dose aspirin may more successfully reduce graft occlusion than low dose regimens within the first year after coronary surgery.