FROM THE JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
Large and complex airway defects that primary repair cannot fully close require alternative surgical approaches and techniques that are far more difficult to perform, but bioprosthetic materials may be an option to repair large tracheal and bronchial defects that has achieved good results, without postoperative death or defect recurrence, in a small cohort of patients at Massachusetts General Hospital, in Boston.
Brooks Udelsman, MD , and his coauthors reported their results of bioprosthetic repair of central airway defects in eight patients in the Journal of Thoracic and Cardiovascular Surgery ( 2016 Nov;152:1388-97 ). “Although our results are derived from a limited number of heterogeneous patients, they suggest that closure of noncircumferential large airway defects with bioprosthetic materials is feasible, safe and reliable,” Dr. Udelsman said. He previously reported the results at the annual meeting of the American Association for Thoracic Surgery, May 14-18, 2016, in Baltimore.
These complex defects typically exceed 5 cm and can involve communication with the esophagus. For repair of smaller defects, surgeons can use a more conventional approach that involves neck flexion, laryngeal release, airway mobilization, and hilar release, but in larger defects, these techniques increase the risk of too much tension on the anastomosis and dehiscence along with airway failure. Large and complex defects occur in patients who have had a previous airway operation or radiation exposure, requiring alternative strategies, the researchers wrote. “Patients in this rare category should be referred to a high-volume center for careful evaluation by a surgeon experienced in complex airway reconstruction before the decision to abandon primary repair is made,” he said. Among the advantages that bioprosthetic materials have over synthetic materials for airway defect repair are easier handling, minimal immunogenic response, and potential for tissue ingrowth, Dr. Udelsman and his coauthors said.
All eight patients in this study, who underwent repair from 2008 to 2015, had significant comorbidities, including previous surgery of the trachea, esophagus, or thyroid. The etiology of the airway defect included HIV-AIDS–associated esophagitis, malignancy, mesh erosion, and complications from extended intubation. Three patients had previous radiation therapy to the neck or chest. Five patients had defects localized to the membranous tracheal wall, two had defects of the mainstem bronchus or bronchus intermedius, and one patient had a defect of the anterior wall of the trachea.
Dr. Udelsman and his coauthors used both aortic homograft and acellular dermal matrix to repair large defects. Their experience confirmed previous reports of the formation of granulation tissue with aortic autografts, underscoring the importance of frequent bronchoscopy and debridement when necessary. And while previous reports have claimed human acellular dermis resists granulation formation, that wasn’t the case in this study. “The exact histologic basis of bioprosthetic incorporation and reepithelialization in these patients is still elusive and will require further study,” the researchers said.
This study also employed the controversial muscle buttress repair in six patients, which helped, at least theoretically, to secure the repairs when leaks occur, to separate suture lines when both the airway and esophagus were repaired and to support the bioprosthetic material to prevent tissue softening, Dr. Udelsman and his coauthors said.
Postoperative examinations confirmed that the operations successfully closed the airway defects in all eight patients. Long term, most resumed oral intake, but three did not for various reasons: one had a pharyngostomy; another had neurocognitive issues preoperatively; and a third with a tracheoesophageal fistula repair and cervical esophagostomy could resume oral intake but depended on tube feeds to meet caloric needs.
All patients developed granulation at the repair site, two of whom required further debridement and one who underwent balloon dilation. Pneumonia was the most common complication within 30 days of surgery, occurring in two patients. Three patients died within 120 days from metastatic disease, and a fourth patient progressed to end-stage AIDS 6 years after the operation and eventually died.
Dr. Udelsman and his coauthors reported having no financial disclosures.