Drainage is commonly implemented as a post-thyroidectomy protocol with the primary objective of minimizing dead space and reducing or preventing postoperative complications, such as fluid accumulation, which is a potential serious source that could lead to respiratory obstruction and endanger patients' lives. However, an increasing body of research suggests that drainage may not be necessary, as it does not appear to significantly reduce the risk rate [4–9]. Consequently, the use of drainage remains a topic of ongoing controversial. Similar to the results of previous research, drain use in our study did not affect the development of postoperative complications, indicating that the procedure of abandoning drainage is safe for patients as there was no statistically significant difference in the rate of postoperative complications between patients with and without drains. There was a statistically significant difference in the rate of recurrent laryngeal nerve injury (p = 0.038)(Table 2).
Owing to the highly vascular structure and trachea-ahead location of the thyroid, postoperative neck hematoma could be a potentially life-threatening complication with a heightened risk of respiratory obstructionis [9]. Although drain placement is considered effective in preventing post-thyroidectomy hematoma and early detection of bleeding [10–11], studies have indicated its ineffectiveness in reducing hematoma formation [4, 6, 12]. Some studies even suggested that drain usage may increase the risk of hematoma [13]. According to Table 2, the presence of a drain did not significantly reduce the occurrence of hematoma (p = 0.075), which suggests that the effect of drainage on preventing hematoma formation may be limited. This indicates that any potential benefit of drainage in reducing hematoma seems minimal. This may be caused by clotted blood, which can block the drain tube. Therefore, it hardly prevents hematoma formation, as expected. Although drains do not prevent hematoma, observing blood flow from the drains in the immediate postoperative period can facilitate early diagnosis of significant hemorrhage.
Wound infection is a severe postoperative complication that poses a significant threat. Patients who develop infections may experience prolonged hospital stays, higher readmission rates, and increased hospital costs [14, 15]. Despite the intended purpose of drainage to prevent infection, as shown in Table 2, no statistical significance was observed in the cases of wound infection between the two groups(p = 1.000). This suggests that the absence of drainage does not increase the incidence of wound infections. No wound infections were observed in the non-drained group, whereas several cases occurred in the drained group, suggesting a possible association between drainage use and increased infection risk. Several studies have corroborated these findings, indicating that drainage may increase the risk of wound infection, possibly due to the introduction of external pathogens or prolonged wound exposure [4, 5, 7, 13].
Hypoparathyroidism and recurrent laryngeal nerve injury are among the most serious and common complications associated with thyroid surgery [16]. Transient recurrent laryngeal nerve injury occurs in 5–11% of cases, while permanent injury develops in 1-3.5%. Similarly, transient hypoparathyroidism is observed in 20–30% of cases, with 1–4% developing permanent hypoparathyroidism [17]. Several factors influence the risk of nerve injury, including the type of surgery, underlying thyroid pathology, and the extent of resection. Additionally, the surgeon's practice also plays a crucial role in determining the risk [18]. As shown in Table 2, the incidence of recurrent laryngeal nerve injury significantly decreased when postoperative drainage was not used (p = 0.038). Therefore, avoiding drainage may reduce the risk of serious complications. Furthermore, a randomized clinical trial confirmed that drainage significantly increases the risk of recurrent laryngeal nerve injury and hypoparathyroidism (p < 0.05) [4]. This evidence suggests that abandoning drainage in certain cases may be a safer approach to reduce these risks.
The safety of avoiding drainage during thyroidectomy has been a topic of interest, particularly with respect to various postoperative complications. In addition to hematoma, infection, hypoparathyroidism, and recurrent laryngeal nerve injury, Table 2 demonstrates that other complications were also unaffected by the absence of drainage. These findings suggest that avoiding drainage is a safe practice for patients undergoing thyroidectomy.
In addition to its questionable impact on complication rates, drainage may negatively affect patient comfort and recovery time. Drainage appeared to increase patient pain, as evidenced by significantly lower NRS scores in those without drainage (p < 0.001) [Table 3]. Meta-analyses [7], retrospective clinical reports [9], and systematic reviews [13] have supported the notion that patients with drainage experience higher pain scores and greater suffering during their hospital stay. Furthermore, patients without drains are typically discharged earlier (Table 2), and there is mounting evidence that drainage extends the length of the postoperative hospital stay [4, 6–9, 13]. Additionally, patients without drainage reported higher postoperative satisfaction (p = 0.0001) [4], shorter operation times [4, 9], and lower medical costs [19]. These findings further suggest the need to reconsider the routine use of drainage in thyroidectomy.
A prospective randomized study demonstrated that the size of the gland, diagnosis, type of surgery, transoperative bleeding, and complications are invalid arguments to leave an external drain in thyroid surgery [20]. A comparative study between patients with drainage who underwent lobectomies and total thyroidectomies showed that the type of surgery and mass size cannot be used as indicators for drain insertion or predictors of postoperative bleeding [21]. Therefore, the diagnosis and type of surgery were not considered as factors affecting drain insertion. Other factors, such as the surgeon’s training, experience, and personal preference might also affect the use of drains [21]. The latest data from the largest cohort across the United States demonstrated that otolaryngologists were 6.98 times more likely to place a drain after thyroidectomy than general surgeons [22]. These findings collectively suggest that traditional indicators, such as gland size or type of surgery, may not be reliable predictors for drain necessity, pointing to the need for individualized decision-making based on the surgeon's expertise and patient-specific factors.
Despite these findings, the present study had several limitations. As this was a retrospective study, it was subject to inherent bias. Moreover, the smaller sample size in the non-drained group may have introduced an additional bias, potentially skewing the results. Therefore, a large-scale prospective clinical study is recommended to validate these findings and to ensure their applicability in broader clinical settings. Potential confounding factors, such as variations in surgical techniques or postoperative care protocols, were not fully controlled for, which might have influenced the outcomes. Another limitation is the lack of long-term follow-up data, which restricts the ability to assess the persistence of complications or long-term outcomes of patients without drainage. Additionally, because this study was conducted at a single center, the findings may not be generalizable to other hospital settings or populations.