Historically, textbooks recommended the use of two chest tubes after mayor pulmonary resections: one placed inferiorly to drain fluids and one towards the apex to facilitate lung expansion (7). A 1999 survey showed that more than 90% of thoracic surgeons in the United Kingdom used two drains after anatomical or non-anatomical pulmonary resections (8).
In the last decades, many studies reported that a single chest tube could be adequate (9). Four randomized clinical trials (1–4) compared the use of one chest tube with the standard two chest tubes in patients undergoing lobectomy and/or bilobectomy. All the studies concluded that one chest tube was “non-inferior” compared to two chest tubes, without statistically significant differences in terms of hospital stay, pleural drain capability and post-removal complications. Furthermore, Alex et al (1) and Okur et al. (3) observed a significantly decrease in postoperative pain and Gomez-Caro et al. (2) reported a reduction of analgesic drugs administration.
A recent meta-analysis (10) showed that the use of a single chest drain is more effective than two to reduce postoperative pain and facilitate patients to adhere to postoperative physiotherapy, resulting in a shorter hospitalization.
Despite that, the majority of institutions still prefer to insert two tubes to optimize fluid and air drainage (11, 12). Tube clotting is observed in up to 5.8% of the patients with one chest tube (5, 13). Other complications are loculated pleural effusion and inefficient fluid drainage of the costophrenic angle.
Recently, a new flexible coaxial drain was developed to combine the benefits of two separate chest drains with the proved advantages of one chest tube. It is made of biocompatible silicone and is composed by four external fluted channels for fluids drainage and an internal section which allows separate air evacuation from appropriate distal bores. Compared with STs, the draining surface area provided by SDC is considerably wider and resistant to clot occlusion. Furthermore, Guerrera et al. showed that SDC provides a satisfactory air evacuation even in patients with significant air leaks (14).
In 2017, Rena et al. (5) retrospectively compared 52 patients treated with SDC with 104 patients with standard two chest tubes after open or VATS lobectomy: SDC resulted “non-inferior” in fluid and air evacuation, hospital stay and rate of postoperative complications. However, one of the limitations of that study was the retrospective nature and the absence of randomization.
We have performed the first randomized clinical trial comparing the use of two standard tubes with one SDC. As primary endpoint, SDC resulted as an effective option after pulmonary lobectomy. Regarding fluid drainage, the CT group showed a lower fluid evacuation compared to ST group, in particular during the first three PODs. However, at CXR there was no difference between the groups in terms of pleural effusion, suggesting that one SDC tube provides sufficient cleaning of the chest cavity. The draining surface provided by SDC is wider than both superior and inferior STs. This is supported by the analysis of the pleural fluid retention rate: even if there are no statistically significant differences (p = 0.13), the CT group showed a lower rate of 2-grade or 3-grade pleural effusion at POD1 compared with the ST group (18,8% vs 32%). Thus, the higher fluid evacuation provided by two ST, estimated at approximately 50 mL per day, could be the effect of pleural irritation due to the presence of the additional chest tube.
Concerning air aspiration, SDC appears “non-inferior” to STs. The air leaks rate is similar between the groups, as well as the rate of PALs. SDC provides adequate air evacuation even in presence of large air leaks. The rate of fixed pleural space (15), defined as incomplete re-expansion of the lung after resection in absence of air leaks, is similar in the two groups and it seems more related to patients’ characteristics than to inadequate air evacuation.
In our series, CT group showed a significantly shorter hospitalization. This could be explained with the tendency of patients to promptly adhere to mobilization and physiotherapy. In fact, even if the mean postoperative pain showed no significant differences between the groups, the CT group showed a significantly lower pain in POD1. This topic is crucial in the era of enhanced recovery after surgery (ERAS). Late mobilization has been proved to be an independent factor correlated to delayed discharge and increased morbidity (16). Furthermore, in our series, ST patients had more often required additional analgesic drugs suggesting an inadequate pain control, despite no differences in VAS score.
Finally, although it is remarkable that the cost of a single SDC is higher respect to STs, the reduction of hospital stay and adjunctive analgesic drugs administration break down health costs.
This study presents some limitations: although it is a randomized study, the number of patients is relatively small; different surgeons performed the surgical procedures and no information about intraoperative prevention of air leaks are available. Finally, this is a single center experience and larger multicenter studies are required to validate our results.