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, some institutions still prefer to insert two tubes after thoracotomy to optimize fluid and air drainage (11, 12). In fact, there is still reserve in using a single chest tube after open thoracic procedure because of the possibility of avoiding suboptimal pleural space management. Concerns are still debated because tube clotting is observed in up to 5.8% of the patients with one chest tube (5, 13), along with other complications such as loculated pleural effusion and inefficient fluid drainage of the costophrenic angle. At the same time, none of clinical studies have shown the superiority of two standard chest tubes over a single chest tube after pulmonary lobectomy. In this regard, we have assumed that double chest tubes are still the most representative standard of practice worldwide.
Recently, a new flexible coaxial drain was developed to combine the benefits of two separate chest drains with the proven 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.
This is the first randomized clinical trial comparing the use of two standard tubes with one SDC. SDC resulted as an effective option after pulmonary lobectomy. Regarding fluid drainage, the SDC 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 two groups in terms of pleural effusion, suggesting that one SDC tube provides sufficient cleaning of the chest cavity. Indeed, the draining surface provided by SDC is wider than both superior and inferior STs. Thus, the higher fluid evacuation provided by two ST, estimated at approximately 50 mL per day, might be the effect of the pleural reaction to the presence of a double big bore catheters.
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 high flux 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, SDC 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 SDC 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 proven to be an independent factor correlated to delayed discharge and increased morbidity (16). Furthermore, in our series, ST patients more often required additional analgesic drugs suggesting an inadequate pain control, despite no differences in VAS score. However, the comparison between a double chest tube versus a single chest tube technique might be quite obviously associated to a better outcome after a single chest tube. This assessment could lead to a future research interest for comparing single SDC versus a single standard chest tube.
Finally, although costs of single SDC is remarkably higher compared to STs, the shorter hospital stay and lower analgesic drugs administration drop the total costs.
This study presents some limitations: although it is a randomized study, the number of patients is relatively small and different surgeons performed the surgical procedures. Finally, this is a single center experience and larger multicenter studies are required to confirm our results.