Can bilateral chest drainage prevent buffalo chest after minimally invasive repair of pectus excavatum (MIRPE)?

In their publication, Donati et al. (1) presented the results of a survey they conducted to assess how much experts in pectus surgery consider minimally invasive repair of pectus excavatum (MIRPE) to be a risk factor for buffalo chest and what recommendations they would make to avoid this potentially fatal complication.

Despite the high number of respondents (62 surgeons) who represent a significant portion of Chest Wall International Group (CWIG) members, the preventive measures presented in the Conclusion are limited to indicating the treatment of pulmonary blebs and providing guidance to families on the problem.

Even agreeing with the proposed measures, and admitting in advance that the suggestions presented lack scientific evidence to support them, we will present a hypothesis about what could be done to minimize this potentially fatal complication.

The etiology of the problem is a consequence of the fact that during MIRPE, retrosternal mediastinal dissection is performed to create a tunnel for the insertion of the metal bars, and this results in opening the pleura on both sides, creating a communication between pleural cavities and establishing iatrogenic buffalo chest. Starting from the principle that it is the opening of the mediastinal pleura that causes the problem, our intention is to create conditions that can potentially lead to the occlusion of the retrosternal tunnel as early as possible. To this end, two simple measures are proposed.

Theoretically, the smaller the diameter of the communication between the pleural cavities, the greater the chance that an occlusion of the tract will occur. In this sense, the first precaution to be taken is not to extend the dissection of the retrosternal tunnel more than necessary to safely implant the bars.

The most important measure is to perform bilateral drainage of the thoracic cavities with pigtail drains. The rationale for this is to achieve full lung expansion in the immediate postoperative period, when the inflammatory process in the tissues is even more intense due to recent manipulation. The idea is that if the lungs expand rapidly and occupy the retrosternal space, there may be a greater chance of adhesions forming between the pleura and of the retrosternal tunnel being occluded by the expanded lungs. In order to increase the effectiveness of bilateral drainage, pigtail drains are aspirated with a syringe postoperatively until all residual air has been evacuated.

It should be remembered that simply evacuating residual air with a tube at the end of MIRPE, or draining unilaterally, has not been sufficient to prevent residual air from remaining within the pleural cavities. It is not uncommon that when the patient undergoes a standing chest X-ray, there is still residual air in one or both hemithoraces.

The lack of scientific evidence may lead to resistance in implementing this proposal. However, it should be noted that conducting a clinical study to test the hypothesis runs into a technical problem: there are, to the best of our knowledge, no imaging methods that can be used to assess the retrosternal tunnel and thus confirm or refute this hypothesis.

On the other hand, it must be considered that even if the present proposal has no proven usefulness in helping to occlude the retrosternal tunnel, it has potential advantages for patient outcomes. It should be remembered that pleural complications (pneumothorax and pleural effusions) are among the most frequent post-MIRPE (2).

In addition, groups that have specific material for fixing two or more metal bars such as bridges (3), have increasingly performed MIRPE with at least two metal bars implanted in the thoracic cavity and this may increase the risk of pleural complications (4).

Furthermore, patients undergoing MIRPE also experience significant pain and have considerable difficulty walking, performing respiratory physiotherapy, and even coughing, which hinders the reabsorption of air or residual fluid in the pleural cavity. Therefore, in this scenario, bilateral pleural drainage with a pigtail has the potential to keep the lungs fully expanded from the immediate postoperative period, which can contribute to reducing the risk of pleural complications and ensuring better patient outcomes.

Finally, we would like to emphasize that, in essence, this proposal for bilateral thoracic drainage does not differ from what thoracic surgeons have always done in their surgical practice: draining the thorax after opening and manipulating the pleural cavity. Due to what has been presented, and until it is possible to conduct a randomized trial, we suggest that colleagues who operate on pectus consider performing bilateral thoracic drainage with a pigtail after all cases of MIRPE.

Once again, we want to congratulate Donati et al. for their contribution to the evolution of pectus surgery.

Supplementary

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Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.