Surgery · Medical Literature
Efficacy of Sapylin in endoscopic thyroid cancer surgery: a double-blind, randomized, controlled trial.
Abstract
Postoperative exudation after thyroidectomy can compromise healing. Although Sapylin (Group A Streptococcus pyogenes) promotes wound repair, its efficacy and safety in endoscopic thyroid cancer surgery remain unclear. This randomized controlled trial evaluated Sapylin's impact on postoperative drainage and complications. Ninety-two patients were randomized (1:1) to receive 10 KE Sapylin in 20 ml saline (treatment group) or saline alone (control group) via the drainage tube. Endpoints included drainage volume, inflammatory markers, and assessment of short-term and long-term complications, specifically vocal function. The treatment group showed significantly lower drainage volumes on Day 1 (P = 0.026), Day 2 (P = 0.014), and in total (P = 0.009). Inflammatory markers were transiently elevated in the treatment group (P < 0.01) but normalized rapidly. Notably, the incidence of hoarseness was significantly higher in the treatment group (16 vs. 6 cases, P = 0.015). Crucially, long-term follow-up confirmed that all cases of hoarseness were transient. All affected patients achieved complete recovery of vocal cord mobility, and no cases of permanent vocal cord paralysis were observed. Sapylin significantly reduces postoperative drainage volume following endoscopic radical thyroidectomy. However, its application is associated with a systemic inflammatory response and an increased risk of transient postoperative hoarseness. Although this nerve dysfunction is reversible, given the potential for neural irritation, its application should be restricted or approached with extreme caution, carefully weighing the benefits of drainage reduction against the risk of transient hoarseness. This study was registered with the Chinese Clinical Trial Registry (accessible by logging in at https://www.chictr.org.cn/ ), registration number ChiCTR2500103444.
Clinical relevance
In patients undergoing endoscopic thyroid cancer surgery, does intraoperative instillation of Sapylin (Group A Streptococcus pyogenes immunomodulator, 10 KE in 20 ml saline) via the drainage tube reduce postoperative drainage volume compared with saline alone, without incurring unacceptable complications? __SNAPSHOT__ {"studyDesign":"Double-blind, randomized, controlled trial","setting":"Not reported (single or multi-center status and country not specified in the abstract)","sampleSize":"n=92 (treatment: 46, control: 46)","population":"Adult patients undergoing endoscopic thyroid cancer surgery; specific staging, histologic subtype, extent of resection (lobectomy vs. total thyroidectomy), age range, and sex distribution not reported in the abstract","intervention":"Sapylin (Group A Streptococcus pyogenes preparation) 10 KE in 20 ml normal saline instilled via the surgical drainage tube postoperatively","comparator":"Normal saline (20 ml) instilled via the surgical drainage tube (placebo control)","primaryOutcome":"Postoperative drainage volume (assessed on Day 1, Day 2, and as cumulative total); secondary endpoints included inflammatory marker levels and incidence of short-term and long-term complications, specifically vocal function (hoarseness)","followUp":"Long-term follow-up duration for vocal cord recovery was performed but the exact duration is not reported in the abstract","fundingSource":"Not reported"}
Key findings
The treatment group demonstrated statistically significantly lower postoperative drainage volumes at Day 1 (P=0.026), Day 2 (P=0.014), and for the cumulative total (P=0.009); absolute drainage volumes and effect sizes (mean differences, confidence intervals) are not reported in the abstract. Inflammatory markers were transiently but significantly elevated in the treatment group (P<0.01) and subsequently normalized; specific markers, magnitude of elevation, and time to normalization are not reported. A clinically important safety signal was identified: the incidence of hoarseness was significantly higher in the treatment group versus control (16 vs. 6 cases; crude rates: 34.8% vs. 13.0% [calculated]; absolute risk increase 21.7% [calculated]; relative risk approximately 2.67 [calculated]; NNH approximately 5 [calculated]). However, long-term follow-up confirmed that all 16 cases of hoarseness in the treatment group were transient, with complete recovery of vocal cord motility reported; the timeframe for recovery is not reported in the abstract. No other adverse event data (e.g., infection, hematoma, hypocalcemia, serosal reaction) are reported.
Practice implications
This double-blind RCT provides preliminary evidence that intradrainage-tube instillation of Sapylin after endoscopic thyroidectomy significantly reduces postoperative drainage volume over the first two postoperative days compared with saline. However, several critical interpretive constraints apply. First, only an abstract is available for review; full methods, patient characteristics, surgical details, statistical tables, and adverse event profiles cannot be independently verified. Second, the most striking finding is a nearly three-fold increase in the relative incidence of postoperative hoarseness (NNH approximately 5 [calculated])—a rate that is clinically alarming in the short term even if ultimately transient. The mechanism is not explained in the abstract; plausible hypotheses include local inflammatory edema affecting the recurrent laryngeal nerve or adjacent soft tissue, consistent with the documented transient inflammatory marker elevation. Third, it is not established whether reduced drainage volume translates into clinically meaningful patient outcomes (e.g., shorter drain duration, reduced reoperation for fluid accumulation, shorter hospital stay, or cost savings). Fourth, the sample size of 92 patients is modest, limiting power for rare but serious complications. Fifth, the population of applicability is incompletely defined: thyroid cancer histology, tumor stage, nodal dissection extent, and whether total versus partial thyroidectomy was performed are not described—each of these factors substantially influences baseline drainage and complication risk. The finding that hoarseness was universally transient is reassuring but must be interpreted cautiously given the absent denominator for follow-up duration and the inherent risk of reporting bias in an industry-sponsored (unknown) context. Practice should not change on the basis of this single small trial; the transient hoarseness rate alone warrants prospective safety monitoring before broader adoption. __LIMITATIONS__ Only an abstract is available; full methodology, allocation concealment procedures, blinding integrity, and complete adverse event data cannot be assessed.,Small sample size (n=92) provides limited statistical power for detecting rare but serious complications and may inflate observed effect sizes.,Absolute drainage volumes and effect sizes (mean differences with confidence intervals) are not reported, preventing assessment of clinical magnitude of benefit.,Duration of long-term follow-up for vocal cord recovery is not specified; 'complete recovery' cannot be contextualized without time-to-recovery data.,Patient population is incompletely characterized: histologic subtype, tumor stage, extent of lymph node dissection, type of thyroidectomy (total vs. lobectomy), age, and sex are not described, severely limiting generalizability.,The mechanism of Sapylin-associated hoarseness is not discussed; whether this reflects direct drug toxicity, inflammatory nerve compression, or procedure-related factors is unknown.,Funding source is not reported; potential industry conflicts of interest cannot be assessed.,No correction for multiple comparisons across numerous endpoints (drainage day 1, day 2, total, inflammatory markers, hoarseness), raising the risk of Type I error.,The study appears to be conducted in a single surgical technique/endoscopic approach context, limiting generalizability to other operative settings or open thyroidectomy.,No patient-reported outcomes, quality-of-life measures, or health economic data are presented. __BOTTOM_LINE_CATEGORY__ not_ready_for_clinical_application __BOTTOM_LINE__ In this small double-blind RCT (n=92), intradrainage Sapylin instillation after endoscopic thyroidectomy significantly reduced postoperative drainage volumes but was associated with a nearly three-fold higher rate of transient postoperative hoarseness (34.8% vs. 13.0%; NNH ≈5 [calculated]) that fully resolved on long-term follow-up. Given the modest sample size, absence of clinically contextualized effect sizes, incompletely characterized patient population, and a concerning short-term complication signal, this intervention is not ready for routine clinical adoption. Larger confirmatory trials with rigorous safety monitoring, defined recovery timelines, and patient-centered outcomes are required before Sapylin can be considered for integration into perioperative endoscopic thyroidectomy protocols.