[Application of a small drainage tube in transoral endoscopic thyroidectomy vestibular approach]

Objective: To examine the feasibility of small drain in transoral endoscopic thyroidectomy vestibular approach (TOETVA). Methods: A prospective research was performed in Department of Oncology Plastic Surgery/Head and Neck Surgery, Hunan Cancer Hospital, from October 2018 to March 2019. Totally 103 patients who met the inclusion and exclusion criteria, signed the operation agreement of TOETVA, had their surgery completed and followed-up over 6 months, were enrolled in analysis. A central venous catheter was used as a drain tube in all cases (outer diameter 1.7 mm, inner diameter 1.0 mm). Visual analogue scale (VAS) was applied for assessing pain scores during the first 24 hours after the operation. Vancouver scar scale (VSS) was used for assessing the scar left by the drainage. The drainage volume (minimum scale:10 ml, approximate read: 1 ml) was recorded every 2 hours during the first postoperative 12 hours, every 4 hours during 12 to 24 hours, every 8 hours during 24 to 48 hours, and once from 48 hours until extubation. The volume of drainage, the cumulative volume and the percentage of cumulative volume accounting for the total volume were calculated. The data of residual volume (subtract the cumulative volume from the total volume) in the postoperative 24, 32 and 40 hours were analyzed, and their upper one-side P(95) was calculated by percentile method. Results: There were 12 males and 91 females. The age was (36.6±9.7) years (range: 18 to 58 years). The intraoperative tube-inserting time was (10.1±2.6) minutes (range: 6 to 18 minutes). The pain score on the first day was 2.7±1.1 (range: 1 to 5). The extubation time was (2.7±0.5) days (range: 2 to 4 days). VSS scores in the postoperative 1(st) month and 6(th) month were 2.9±1.3 (range: 0 to 7) and 0(2)(M(Q(R))), respectively. The size of the scar was 0 (2.5) mm in the postoperative 6(th) month. Sixty-four patients had no visible scars. There were 5 patients who had postoperative drain-related complications (1 for air leakage, 1 for tube blockage, 3 for subcutaneous hydrop, 2 for regional infection), who were all cured after proper treatment. The total volume of drainage for 98 patients without postoperative drain-related complications was (80.1±12.2) ml (range: 58 to 131 ml). The cumulative drainage within 8 hours accounted for (53.8±4.2)% (range: 41.0% to 62.9%) of the total drainage. The volume of residual fluids in the postoperative 32 hours was estimated to (5.8±2.7) ml (range: 0 to 12 ml,P(95)=10.0 ml). Conclusions: The small drain tubecan be applied in TOETVA, providing a satisfied cosmetic appearance and a reliable drainage. The main exudation period of the wound is within 8 hours after the operation. If a residual volume less than 10 ml is considered to be self-absorbable, the shortest safe extubation point for 95% patients without drain-related complications should be 32 hours after the operation.