Thoracic duct lesions in thyroid surgery: An update on diagnosis, treatment and prevention based on a cohort study.

INTRODUCTION: Thoracic duct fistula at the cervical level is a severe but rare complication following thyroid surgery, particularly associated to lateral dissection of the neck and to mediastinal goiter. METHODS: we retrospectively analyzed chylous fistulas observed in a cohort of 13.224 patients underwent surgery for thyroid disease since 1986 to 2014, in the Unit of Endocrine Surgery, S. Maria University Hospital, Terni, Italy. RESULTS: We observed 20 cases of chylous fistula. Thirteen patients underwent primary surgery in our institution while the remaining 7 cases had been referred to our Department from other hospitals for an already diagnosed lymphatic leak. Surgical procedures carried out included total thyroidectomy for mediastinal goiter in 4 patients, total thyroidectomy for cancer in 2 patients, unilateral functional lymphadenectomy in 11 patients and bilateral in 3. Intraoperative repair was carried out in 4 cases. Of the remaining 16 cases, 4 of the 6 fistulas with low flow leakage healed in about 30 days of conservative treatment, 2 cases instead required surgical repair. All 10 patients with "high-flow" fistula underwent surgery. Despite surgery was performed later, postoperative course in patients with late surgical repair is similar to what observed in those patients with early surgical repair. Both groups underwent cervical drainage removal in post-operative day 4. CONCLUSION: Healing of a cervical chylous fistula can be achieved by conservative medical therapy (nutritional and pharmacological) but in case of therapeutic failure with rapid decrease of general condition, the surgical approach is necessary. In our experience, duct ligation after unsuccessful conservative treatment, is the only resolutive treatment.