Impact of pleural effusion pH on the efficacy of thoracoscopic mechanical pleurodesis in patients with breast carcinoma.

OBJECTIVE: A prospective randomised study was conducted to compare the efficacy of treating malignant pleural effusions (MPE) in patients with breast carcinoma by thoracoscopic mechanical pleurodesis (TMP) as a new palliative treatment and talc pleurodesis (TP) at various pleural fluid pH levels and to determine whether at low pH values, when the success of TP is reduced, TMP is more successful.

METHODS: 87 female patients with breast carcinoma and a resulting MPE resistant to systemic therapy were divided into two groups: TMP and TP groups. In the TMP group 24 patients with pH levels above 7.3 and 21 patients with pH levels below 7.3 underwent thoracoscopic parietal and visceral pleural abrasion utilising general anaesthesia. In the TP group, 22 patients with pH levels above 7.3 and 20 patients with pH levels below 7.3 were administered 5 g of sterile talc, dissolved in 100 ml of physiological solution, via a chest tube, utilising local anaesthesia. Postoperative follow-up was performed to determine a possible recurrence of MPE with periodic radiographs, the duration of chest tube drainage and hospitalisation, occurrence of complications, and perioperative mortality. The following was used for statistical analysis: t-test for odd samples, chi2 test, logistic regression, and multiple linear regression.

RESULTS: TMP and TP were equally successful (92 and 91%) in patients with pH levels above 7.3. Differences occurred in patients with pH below 7.3 (81 and 55%) (P = 0.07). The lowest pH value at which TMP proved successful was 7.06, while for TP this value was 7.25. In TMP group the average duration of chest tube drainage amounted to 3.8 days and hospitalisation to 5.5 days, while in TP group it was 5.6 and 7.5 days, respectively. Differences were statistically significant (P < 0.05). 16% of easily treatable complications and no case of perioperative mortality were identified in TMP group, while 26% of complications and four cases of perioperative mortality were noted in TP group.

CONCLUSIONS: TMP is a safe palliative treatment for MPE in breast carcinoma, with a minimal number of complications and a short hospital stay; it is more successful than TP in patients with pH of MPE below 7.3.