On Table Prevention of Airleaks: A Protocol from Previous Studies Mr Syed Mohiyaddin1, Dr Nathan Tyson1, Dr Mohamed Sherif1 1Department of Cardiothoracic Surgery, Morriston Hospital Background The Protocol for on table prevention of Airleaks postoperatively Prolonged Air Leak Post-operative air leak is well recognised in thoracic surgery, and complicates up to 50% of all lung resections, with the highest incidence in the immediate post-operative period (approximately 28-60%)1. Prolonged air leaks (PALs) have been defined as any air leak persisting for ≥7 days post-operatively. The development of PAL is associated with considerable mortality and increased hospital stay2. A number of factors have been implicated in the development of PAL. Amongst these factors are anatomical factors affecting resection (such as incomplete or absent interlobar fissure), upper lobe lobectomy and low predicted post-operative FEV13. Lung Volume Reduction Surgery (LVRS) more commonly results in PAL (39-45.2%) than lung resection in emphasematous (5.4-44%) or non-emphasematous patients (4.2-18.2%). Male gender and % emphysema have also been shown to be independent risk factors2,4. Prevention and Management A number of strategies have been reported in order to prevent PALs from occurring. Traditionally, suction drainage has been the management of choice to prevent PAL, although studies suggest this approach has no benefit over water-sealed drainage5. Interestingly, a previous study by Mohiyaddin and colleagues demonstrated delayed drain removal was associated with an air leak ≥437mL as measured using the anaesthetic apparatus intra-operatively6. A number of strategies aimed at preventing PAL have been reported in the literature, in addition to meticulous surgical technique and minimal handling of lung tissues. These include the use of fissureless surgical techniques, pulmonary sealants, pericardial patches and the use of buttressed suture methods. Meta-analysis shows that all methods effectively prevent PAL7. Identification of patients at high risk of developing PAL (adapted from Lee et al, 2011) Variable Score Wedge Resection only (Baseline Score) 0 (risk of PAL 4.8%) Presence of Pleural Adhesions +2 FEV1 (% Predicted) +1 per 10% below 100% Carbon Monoxide Diffusing Capacity (DLCO, % Predicted) Score of ≥5 indicates high risk, and patient should be considered for measures below Intra-operative measures to prevent PAL In patients undergoing LVRS or who have extensive emphysematous change Use of stapling devices, such as ET45 (Ethicon) or EndoGIA (Medtronic) for resection, buttressed with a running suiture preferably with ethelon 3-0. Anatomical Resection (Wedge / Lobectomy) Site of resection/stapling to be treated with fibrin based-sealants. 28F Chest drain placed on suction drainage until no evidence of airleak Aim To produce a protocol for prevention of PAL in lung resection surgery which may be introduced into clinical practice, and which is based on currently available literature. Significant Air Leak Intraoperatively Saline instilled into pleural cavity and lung inflated to 15-25cm H2O pressure Grade 0 – No air leak Grade 2 – Stream of bubbles Grade 1 – Countable bubbles Grade 3 – Coalesced bubbles Methods A search was performed of a number of databases to find studies which examined prevention of PAL post-operatively in patients undergoing wedge resection, lobectomy, anatomic resection or lung volume reduction surgery. A protocol was then designed using best evidence from the available literature. Patients Undergoing Upper Lobectomy Consider performing pleural tent procedure, post-lobectomy. Procedure as described by Brunelli et al. 28F Chest drain placed on suction drainage until no evidence of airleak Patients Undergoing Lower-, mid-lobectomy / Wedge resection Grade 1-2: Consider using instillation of autologous, non-heparinised blood into pleural space. Body weight dependant, volume of 1mL/Kg Grade 3: Consider use of free pericardial fat pad sealant. Follow-up CT thorax required to exclude fat masses. The Evidence for Intervention A number of studies have been published which report both intra-operative and post-operative strategies for the management of PAL: The use of fibrin glue was shown to completely resolve air leaks (mean 15.7 post-operative days) within one day of application in 91.7% of thoracic surgery patients. Lack of resolution was the result of poor identification of airleak site8. Additionally, the use of free pericardial fat pad sealants reduced the mean duration of air leak to 2.3 days in severe leaks, whilst autologous blood instillation was shown to successfully obliterate smaller leaks9,10. Upper lobe leaks, due to their anatomical location, have been shown to be amenable to resolution by the formation of pleural tent immediately post-resection11. In LVRS for emphysema, buttressing of staple lines in lung tissues using bovine pericardium reduces initial air leak by up to 50%, with a significant reduction in mean post-operative air leak duration (2.5 ±0.7 days versus 5.2 ±0.75 days in the control group). However, there was no impact on the length of hospital stay12. Therapeutic pneumoperitoneum was performed on patients with persistent air leak at post-operative day 7, and obliteration of the pleural space was seen after 4 days, with no complications or sequelae13. Lee and colleagues have suggested a model for prediction of prolonged air leak in thoracic surgery (see opposite). The model is effective at predicting those at high risk of PAL and who may benefit from the above adjuncts3. Development of Prolonged Airleak (≥7 Days Post-Operatively) For All Patients: Return to theatre may be indicated, with general anaesthesia or sedation using midazolam and with full anaesthetic monitoring. Following per-umbilical local anaesthetic infiltration, air is insufflated into the abdomen with a veress needle at 30mL/Kg Those with still persistent air leak may be discharged with a Heimlich valve in situ. Further work is required in this area before such a protocol may be used in clinical practice. The next step in this project would be a clinical trial of the above protocol as a pilot study. References Okereke, I., et al., Characterization and importance of air leak after lobectomy. Ann Thorac Surg, 2005. 79(4): p. 1167-73. Thistlethwaite, P.A., et al., Ablation of persistent air leaks after thoracic procedures with fibrin sealant. Ann Thorac Surg, 1999. 67(2): p. 575-7. Cerfolio, R.J., et al., Predictors and treatment of persistent air leaks. Ann Thorac Surg, 2002. 73(6): p. 1727-30; discussion 1730-1. Lee, L., et al., Estimating the risk of prolonged air leak after pulmonary resection using a simple scoring system. J Am Coll Surg, 2011. 212(6): p. 1027-32. Matsumoto, I., et al., Free pericardial fat pads can act as sealant for preventing alveolar air leaks. Ann Thorac Surg, 2005. 80(6): p. 2321-4. Petrella, F., et al., Predicting prolonged air leak after standard pulmonary lobectomy: computed tomography assessment and risk factors stratification. Surgeon, 2011. 9(2): p. 72-7. Cao, G., et al., Intrapleural instillation of autologous blood for persistent air leak in spontaneous pneumothorax in patients with advanced chronic obstructive pulmonary disease. Ann Thorac Surg, 2012. 93(5): p. 1652-7. Alphonso, N., et al., A prospective randomized controlled trial of suction versus non-suction to the under-water seal drains following lung resection. Eur J Cardiothorac Surg, 2005. 27(3): p. 391-4. Brunelli, A., et al., Pleural tent after upper lobectomy: a randomized study of efficacy and duration of effect. Ann Thorac Surg, 2002. 74(6): p. 1958-62. Mohiyaddin, S., et al., Air Leak Following Lung Resections as measured by the Anaesthetic Machine Correlates with Length of Chest Drainage, in SCTS Annual Meeting & Cardiothoracic Forum. 2014: Edinburgh. Stammberger, U., et al., Buttressing the staple line in lung volume reduction surgery: a randomized three-center study. Ann Thorac Surg, 2000. 70(6): p. 1820-5. Malapert, G., et al., Surgical sealant for the prevention of prolonged air leak after lung resection: meta-analysis. Ann Thorac Surg, 2010. 90(6): p. 1779-85. De Giacomo, T., et al., Pneumoperitoneum for the management of pleural air space problems associated with major pulmonary resections. Ann Thorac Surg, 2001. 72(5): p. 1716-9.