|
|
NewsletterOctober 2002 Newsletter Synthetic Sealants for Preventing Air Leaks after Pulmonary Resection
Andrew Ochroch, MD and Rebecca A. Barnett, MBChB
Postoperative air leaks are a major complication from pulmonary resection. Air leaks lasting longer than 7 days are reported to occur in greater than 15% of patients [1]. Risk factors for prolonged air leak include non-anatomical resection, emphysematous lung parenchyma, poor nutritional status, radiation therapy, infection, and trauma.[2] Prolonged air leakage leads to increased morbidity due to prolonged chest tube drainage which is associated with increased pain, decreased mobility and prolonged hospital stay. At worst, continued air leak can necessitate pleurodesis, mechanical ventilation, and reoperation. [2,3]
Surgical techniques to decrease intensity and duration of air leak include suturing and stapling. In the last few years stapling devices have improved to include multiple rows of smaller staples and padding materials (often bovine pericardium) that more evenly distribute the pressure of the staples across the lung tissue. Unfortunately, these advances have only decreased and not eliminated air leaks.
Recently, the FDA has approved FocalSeal-L Surgical Sealant. The sealant is a water-soluble polyethylene glycol-based gel that is applied and photo-polymerized in a three step process. After the lung resection is complete and the tissue is dry, a primer is applied to the lung. Next, the sealant, a pro-drug, is applied, and then a special light source is used to cause photopolymerization. It forms a strong seal that withstands pressures up to 40cm H20, and yet is flexible and compliant enough to move with normal respiration.
FocalSeal-L Surgical Sealant has been studied prospectively in only one randomized trial.[4] That study was a multicenter open label study with twice as many patients (117) in the treatment group as compared to the control group (58). 39% of the treatment group remained leak free from surgery to discharge as compared to 11% in the control group. There was no significant difference in the duration of thoracostomy tube use or discharge, but this was not a primary end-point of the study. During the 6 month follow up morbidity and mortality did not differ between the groups. There was a non-statisitically significant, but concerning trend where 7.2% of the treated patients had postoperative pulmonary infection as compared to 3.6% of the control population. Finally, there was a strict enrollment criteria which may cause difficulty in generalizing their findings to common thoracic surgical patients.
A significant issue with FocalSeal is the cost. The special light source is expensive, as are the primer and sealant. The primer and sealant must be kept frozen. This means that the drugs must be thawed and prepared 45 to 60 minutes prior to their usage. Consequently, their use can not be dictated by a test for air leak at the end of surgery. The use of this system must be anticipated based on known risk factors for air leak. This raises the possible further increase in cost of wasting product.
Other new products that do not require the somewhat time-intensive thawing and three part application process are beginning early phase trials. Further study of these products is necessary to ensure that their meaningful clinical benefit is not outweighed by complications or cost. References
© Society of Cardiovascular Anesthesiologists Questions or comments? Please send email to webmaster@scahq.org |