Joint Drainology Session at EACTS 2022 in Milan – Summary
Drainology: Where Cardiac and Thoracic surgeons meet
Session outcomes:
- Early chest drain removal is not associated with post-op complications.
- Standardised drain management will allow the prediction and prevention of postoperative complication risks.
A recent focus session at the 36th European Association for CardioThoracic Surgery (EACTS) annual meeting in Milan introduced the new scientific concept of ‘Drainology’. The session was chaired by Francesco Di Chiara (Thoracic Surgeon from Oxford, UK), who highlighted that this is a new area of interest for scientific work and there is a desperate need to have evidence-based practice.
Prof Daniel Engelman (Springfield, USA) framed the concept of Drainology, candidly admitting that there is very little known on the subject, with many more questions than answers. Clinical tradition, passed down by mentors, usually dictates individual surgeons’ choices regarding the type, number, placement, and duration of drains. A scientific approach is needed to investigate a multitude of variables. How best to maintain drain patency, and whether this can be achieved by active clearance technology? Are digital drains more efficacious than standard drains? It is crucial to define outcome measures in future trials, such as reoperation rates, length of stay, acute kidney injury (AKI), tamponade, the incidence of effusions, readmission, retained blood syndrome (RBS), postoperative atrial fibrillation (POAF), and patient-reported outcomes. The lack of answers to these questions and the lack of consensus are hindering progress in the care of patients undergoing cardiothoracic surgery.
The lack of answers to many questions and the lack of consensus are hindering progress in the care of patients undergoing cardiothoracic surgery.
Prof Stephen Cassivi (Mayo Rochester, USA) discussed the variations in chest drain management between cardiac and thoracic surgery. He highlighted the disparate and similar uses of chest drains between the two disciplines. Published information on the management of drains in thoracic surgery is contrasting, with serious gaps in the data. The work of the Drainology task force is to find and curate the data that is out there and to prioritise the outcome measures required to find common ground between the two medical disciplines.
Prof Theodor Fischlein (Nuremberg, Germany) discussed the impact of digital drains in cardiac surgery. Nearly 40% of drains clog, 86% of which occlude beneath the skin, unseen by care staff[1]. The clogging leads to retained blood in the pericardial space, subsequent haemolysis, activation of the inflammatory response, and POAF[2]. Data presented suggest that active maintenance of chest drain patency has benefits over traditional chest tubes, showing significant reductions in the risk of cardiac tamponade, RBS, POAF, and reduced patient mortality[3],[4]. Clinical data from Barozzi (2020) shows higher drainage volumes in the early postoperative period with digital drain, which could indicate more effective drainage and potentially earlier drain removal. This, in turn, may lead to a shorter duration of ICU and hospital stays and reduced transfusion requirements, all of which reduce the economic burden[5]. Further retrospective analysis of over 1000 patients comparing digital against conventional drainage supports the published claims that improved drainage reduces POAF. The analysis also revealed reductions in rates of re-exploration, RBS, and deep sternal wound infection.
Dr Bo Laksáfoss Holbek (Copenhagen, Denmark) discussed evidence-based chest drain management from the thoracic surgeon’s perspective, where the core problem is air leaks. He presented the data from a randomised controlled trial, assessing the optimal level of suction for digital chest drains after lobectomy using video-assisted thoracoscopic surgery (VATS). The results showed that lower suction (-2 cmH2O compared to -10 cmH2O) led to shortened air leak and drainage duration, reduced fluid production and shorter hospital stay[6]. Studies on respiratory mechanics and fluid dynamics after lung surgery have shown that the more suction is applied, the more fluid is produced, supporting these findings[7],[8],[9]. The unknown variables are: the safest level of suction (if any) and data are lacking on the optimal management of prolonged air leaks. Dr Holbek also made a compelling case for conducting adequately powered, non-inferiority, multi-centre trials run according to the ERAS protocol.
Data are lacking on the optimal management of prolonged air leaks.
Prof Bernd Niemann (Germany) retained blood syndrome after cardiac surgery. The incidence of RBS in cardiac surgery is between 13.7 and 22.8%. The retention of blood clots generates thrombin and fibrin that leads to the compression of the heart and lungs. The generation of thrombin and fibrin also induces an inflammatory activation and fibrosis[10]. RBS may be subacute and chronic, developing up to a month following surgery, affecting the quality of life and survival[11]. As mentioned by Prof Fischlein, active chest tube clearance following cardiac surgery was associated with a significant reduction in re-exploration rates. However, the data also revealed certain predictors of RBS, including shorter in-hospital stay, obesity, female gender, and preoperative corticoids[12]. The incidence of RBS was also higher in younger patients, patients who have undergone surgery on the aorta, and patients with higher-urgency surgeries. While the exact pathophysiological mechanism of RBS remains unclear, certain mitigation measures would include precise blood-dry procedures, training medical staff on drain management, improving drainage techniques, and anti-inflammatory medications.
The exact patho-physiological mechanism of RBS remains unclear.
Dr Giovanni Comacchio (Padua, Italy) presented results from their single-centre retrospective study assessing the impact of a standardised protocol for chest tube management after VATS pulmonary resections on postoperative outcomes. A traditional chest drain system was used, with early cessation of suction. The threshold for drain removal was <500 ml/day of non-chylous, non-bloody fluid. The tube management protocol was followed from the operation to the fifth post-operative day. Patients in the standardised protocol group had a statistically significant reduction in their length of hospital stay compared to patients assigned to clinician choice management, independent of the type of surgery. Early chest drain removal was not associated with an increase in post-operative complications.
No protocol is widely accepted, and standardisation is fundamental in the development of an ERAS protocol for lung surgery. They concluded that using a digital chest drain system could further improve these outcomes.
Standardisation is fundamental in the development of an ERAS protocol for lung surgery.
Dr Patrick Dorn (Bern, Switzerland). Evaluation of fluid output threshold for safe chest tube removal after pulmonary surgery – A potential way to improve postoperative care and decrease length of stay? Dr Dorn presented as yet unpublished data from a single-centre, controlled trial in adult patients undergoing elective open or minimally invasive lung resection. Patients were randomised to two criteria for chest drain removal based on the volume of effusion per kilogram of body weight over a 24-hour period. We await the publication of these results to fill further gaps in Drainology science.
Conclusion: Thus, the session announced the birth of new ‘Drainology’ science that is gaining momentum. Building scientific evidence to support the consensus use of drains will ultimately save lives and lower costs. Call to cardiac and thoracic surgeons to start collecting data on drain management.
The comprehensive agreement from the session was the need for standardised best practices in thoracic and cardiac drain management. The use of digital drains allows for the collection of quantitative data on many important outcomes that can be applied to the science of Drainology, potentially eliminating the ongoing problems with the current heterogeneous data available with regard to procedures, suction levels, devices used, and overall treatment protocols.
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