Discussion
Tonsillectomy is one of the most common operations in otolaryngology and the number is increasing per year over recent decades(5). In the past century, a variety of modern techniques have emerged to replace traditional CD tonsillectomy to make the surgery more fast, safe, and efficient.
Postoperative pain is the main factor affecting patients’ quality of life of in the short-term. Although the VAS score of the CD group was significantly higher than other two groups on the1st postoperative day, the VAS score of the HS group was higher than the other two groups on the 3rd and 7th postoperative day, and the VAS score of coblation group was lower throughout the recovery period. We believe that coblation tonsillectomy has lower postoperative pain compared with HS and CD tonsillectomy. There are many factors that affect the level of postoperative pain in patients. Ragabet al. reported that higher VAS scores in CD group on the first day after surgery may be related to more intraoperative bleeding resulting in unclear operation fields and longer operation time(6). Postoperative pain is mainly caused by inflammation, tissue damage and stimulation of mucous membranes, muscles, and nerve endings by mechanical movements such as swallowing. HS tonsillectomy has more severe thermal damage, leading to more obvious inflammation and a slower recovery rate. Coblation tonsillectomy reduces both intraoperative mechanical and thermal injury, which leads to lesspostoperative pain. Mitic et al. reported that coblation tonsillectomy has less postoperative pain than CD tonsillectomy(7). Polites et al. reported that the application of coblation tonsillectomy on only the first three days after surgery has less postoperative pain than CD tonsillectomy(8).
According to the results of our study, two cases of secondary bleeding occured in each group. It is worth noting that the mean time to occur secondary bleeding was 7.8th days after surgery in the three groups. As epithelial cells grow inward from the wound edge, the epithelial contracture causes the fibrinous clot to separate and expose the granulation tissue on the 7th day after surgery(9). Meantime, as patient’s pain getting greatly reduced, patients are eager to return to a normal diet, subconscious mechanical stretching is more likely to cause secondary bleeding. The stimulation of repeated inflammation can cause necrosis and fibrosis of the surrounding tissues to make the tonsils adhere to the surrounding tissues(10, 11), and because of the large diameter of blood vessels in the lower tonsils, bleeding is more dangerous if they occur. In order to avoid severe bleeding, we suggest that active postoperative care and surgical proficiency are very important, the tonsils should be carefully separated along the capsule, especially the lower pole of the tonsils.
To compared with CD tonsillectomy, both HS tonsillectomy and coblation tonsillectomy can significantly reduce operative time and intraoperative bleeding loss, which is also recognized by many other scholars(6, 12, 13).
Pseudomembrane is a fibrin clot that includes inflammatory cells and bacteria(14). HS tonsillectomy has high thermal damage to the tissue. The heat energy denatures the collagen in the tissue, and the pseudomembrane is thicker, which makes the pseudo-membrane grow and fall off time for a longer time(15).
Our study shows that HS tonsillectomy has stronger thermal damage to tonsil tissue, while CD tonsillectomy has no thermal damage. The necrosis depth is not related to postoperative pain and postoperative bleeding rate. Boğrul et al. reported that necrosis depth was positively correlated with the degree of postoperative pain(16). However, we believe that the necrosis depth is related to the healing time of surgery.