Our current report aimed at comparing the outcome of coblation versus bipolar electrocautery tonsillectomy. The outcome parameters were the occurrence of postoperative bleeding, duration of healing (as indicated by the complete disappearance of the white healing membrane), postoperative pain severity, and pain duration.
The use of coblation in surgical practice is mainly dependent on chemical rather than thermal effect. This principle paved the way for the safe use of coblation during tonsillectomy procedures to reduce postoperative pain severity and duration [12].
In the current report, the difference in pain severity between both groups was statistically significant on each of the follow-up visits; however, on the first visit, the difference in the mean pain scores did not reflect a meaningful clinical difference. The authors have also found that the overall mean pain score and pain duration were significantly better for the coblation group. This comes in agreement with what has been previously reported by Omrani and associates [13]. Polites and associates agreed to the better performance of coblation over dissection tonsillectomy during the first 3 days only. Subsequent evaluation did not show statistical differences [14]. The superiority of coblation tonsillectomy over blunt dissection tonsillectomy was advocated in a report by Martin and associates in a randomized prospective study including 200 patients [15].
These findings were opposed by the results reported by Hasan et al [8]. This disagreement maybe explained by the difference in the sample size between both studies. We were able to recruit a total of 120 patients, while Hasan and associates included 80 patients in their study. Coblation tonsillectomy was compared to monopolar electrocautery tonsillectomy in a study reported by Jones and colleagues [16]. In their report, the authors concluded that coblation tonsillectomy was superior to monopolar electrocautery tonsillectomy only on the day of surgery. This difference was of limited clinical use when weighted against the higher cost of the coblation device. It is not to be neglected that they included a relatively small sample size and used both techniques for the same patient with one side acting as the control while the contralateral side resembled the interventional side. As well, they included patients with age up to 21 which is different from our study population.
In the present study, it was found that coblation tonsillectomy had better performance than bipolar tonsillectomy in terms of postoperative hemorrhage. The bipolar group had 4 patients who developed reactionary hemorrhage and two who suffered from secondary bleeding. No cases in the coblation group had any postoperative bleeding events. This difference was both statistically and clinically significant. A study by Belloso and associates agreed with our report with emphasis that this difference in postoperative hemorrhage was especially significant for the pediatric population [9]. Another study by Omrani et al showed modest results with a trend towards the superiority of coblation tonsillectomy over traditional surgical techniques; however, this difference did not reach statistical significance [13]. A meta-analysis of the published literature agreed that coblation tonsillectomy showed safe and acceptable results—similar to the standard tonsillectomy techniques—in terms of postoperative bleeding [17]. This finding was proposed by another study from Denmark. In their report, the authors conducted a non-blinded prospective study which included population different from ours [18].
The difference in the incidence of postoperative bleeding events in our study can be explained by the fact that coblation tonsillectomy produced less pain with improved swallowing ability and better oral intake in the early postoperative period. This privilege has its impact on the reduction of operative bed infection which can lead to serious hemorrhagic consequences.
In our study, the healing of the operative bed was more prompt for the coblation group. This is indicated by the complete disintegration of the whitish healing membrane and complete epithelialization of the operative bed. This advantage was statistically significant when compared against the bipolar group. This comes in agreement with what has been reported by Timms and Temple in 2002 [19] and by Matin and associates [15]. Temple and Timms agreed to our finding in their report regarding the faster healing in the coblation group. In their report, all patient showed complete sloughing of the healing membrane during the second week after the procedure [20].
In contradiction to this finding, a study by Rakesh and associates found that healing was significantly longer on the coblation group up to 1 week after the procedure. Follow-up after 3 weeks showed no difference between coblation versus dissection tonsillectomy [21].
The faster healing offered by coblation tonsillectomy is best explained by the fact that coblation produces less thermal heat during the dissection and hence less tissue trauma. This leads to faster recovery, less granulation tissue formation, and less scarring. Coblation device usually produces heat between 45 and 85 °C, while bipolar devices usually produces head around 300 and 400 °C [12, 22].
This study was affected by the effect of the outliers on the means of the outcomes. The mean tends to skew towards the outlier. To preserve the integrity of the data in this study, outliers were included and not excluded despite the fact that this may lead to contamination of the results [23]. In the present report, the mean duration of pain in the bipolar group was 25 days. This is attributed to the fact that only one patient had pain up to the 35th day postoperatively. Despite being an odd finding for the post-tonsillectomy pain to extend this long, however, this can be explained by possible personal variations between individuals with different tolerability to pain and pain threshold levels. Also, the guardians were the main source of reporting the pain indices for their children. There might be misinterpretation or exacerbation by the guardians for the duration of pain expressed by their children. Pediatric patients can also misinterpret temporomandibular joint related pain as pain related to their throat especially that both conditions are related to eating. Another example of outliers affecting our results is the presence of one patient in the coblation group with complete separation of the healing membrane on postoperative day 8 with the mean duration for complete healing in this group being 13 days. This relatively early duration of healing (postoperative day 8) may be explained by the fact that assessment of the parents was the main source for reporting the outcome in the intervals between the follow-up visits.
The main strength of this study is stemmed from its prospective nature. Effective randomization adds to its strength. The duration of the follow-up period is not only sufficient to judge early outcomes like pain severity but is also adequate to evaluate postoperative pain duration, postoperative hemorrhage, and healing of the operative bed.
The main drawback of this study is the relatively small sample size. This can be explained by the timeframe of the conduction of the study which was during the COVID-19 pandemic. Major healthcare resources were mainly directed to isolation and advanced care facilities. Many patients willingly agreed to postpone elective procedures to further save more resources to counteract the pandemic. Also, the relatively short duration of the study—7 months—have also contributed to this shortage in the number of patients. Another drawback is the method of assessment of healing, which was mainly dependent on the guardians’ observations of the white healing membrane. This is also explained by the fact that identifying the exact date of complete separation of the membrane needed examination of the patients by the surgeon every day, something that is practically unfeasible. For this, the researchers had to educate the guardians of the shape and characteristics of the white healing membrane and gave them information and training on each visit on how to observe its existence and to accurately document its disappearance. Another drawback is the lack of proper matching of the indication for tonsillectomy for both groups. This drawback also entails the lack for control for both groups regarding the extent of the procedure, i.e., whether tonsillectomy was performed alone or in combination with adenoidectomy. It is to be emphasized that usually for younger pediatric population, the procedure of tonsillectomy is usually coupled with concurrent adenoidectomy. In the current report, most of the patients had simultaneous tonsillectomy and adenoidectomy. As well, the majority of patients in our study had recurrent throat infections rather that sleep disordered breathing as the indication for the procedure. In order to confirm the diagnosis of obstructive sleep apnea, a polysomnogram is needed. In fact, the medical literature recommends against the routine use of polysomnography except in patients with syndromes affecting their craniofacial skeleton [24]. The disagreement in recommendations by three American medical societies reflects the discordance regarding the applicability of sleep studies in clinical practice [23]. Most of these patients were already excluded from our study, and hence, the guardians’ history was the source for suspecting the diagnosis of sleep-disordered breathing rather than any other tests. The relatively high cost of any investigative procedures - to confirm the diagnosis of obstructive sleep apnea - and the cultural difficulties added to the hurdles of routine testing for this indication prior to commencing on the study.
