Tonsillar stones are caused by pathological calcifications within the tonsillar crypts. The condition may present with chronic halitosis, dysphagia, cough and ear pain and is usually treated by tonsillectomy.[1]While, tonsillectomy is the most common surgery in the field of otolaryngology, the procedure isn’t without drawbacks and multiple surgical techniques and instruments have been developed to shorten and operative time and reduce complications rate. [2] In this context, it was suggested that coblation tonsillectomy can provide quicker patients’ recovery and short hospitalization time [3] the technique uses bipolar radiofrequency energy for soft tissue dissolution. It avoids trauma to pharyngeal muscles and related vessels and improves wound healing.[4] The procedure became popular in the late 1980s because it caused less pain, had easier recovery, and allowed greater retention of immune function[5]. In spite of the fact that a plethora of studies assessed the outcomes of coblation tonsillectomy, no randomized studies were conducted on the particular group of patients with tonsillar stones. So, we proposed to contribute to the build-up of rigorous clinical evidence investigating the role of coblation tonsillectomy by conducting this randomized study on a group of patients with tonsillar stones. The study aimed to compare the peri-operative outcomes in patients submitted to coblation cryptolysis, monopolar bipolar dissection and cold dissection techniques.

The present randomized study was conducted at a private hospital in Jeddah, Kingdom of Saudi Arabia in the period from September, 2016 through December, 2019. The study protocol was approved by the Ethical Committee of Saudi German Hospital, Kingdom of Saudi Arabia and all patients signed informed consent before participation. The study included 105 adult patients with tonsillar stones indicated for tonsillectomy. Patients with bleeding disorder or contraindications to general anesthesia were excluded. The recruited patients comprised three groups: GI (n=35) was subjected to cold dissection, GII (n=35) was subjected to monopolar bipolar dissection and GIII (n=35) was subjected to coblation cryptolysis. Randomization was performed using computer generated numbers and sealed envelope technique. Patients allocation was achieved by an independent researcher who wasn’t aware of the nature of the study.

Surgical technique: All procedures were performed under general anesthesia through endotracheal intubation. Patients were positioned in the Rose position and a Crow-Davis mouth gag was inserted. The tonsil was taken and mediatized with an Allis clamp. Cold dissection (CD) was performed using scissors to enter the superior peritonsillar space, and blunt dissection was used to remove the tonsil from superior to inferior pole. Hemostasis was performed by packing or suturing bleeding points with absorbable suture. In monopolar bipolar dissection group, the incision was made with monopolar cautery at the anterior and superior parts of the anterior pillar. Dissection was performed at the peritonsillar cleavage plane with monopolar diathermy and bleeding points were coagulated with bipolar cautery. Coblation cryptolysis was made using coblation radiofrequency through a saline medium by cryptolysis through the crypts up to pharyngeal muscles [Figure 1]. Two electrodes were immersed in a medium of normal saline, which produces a plasma field of sodium ions. Many highly ionized particles are contained in the plasma field resulting in coagulation of vessels and vaporization of tissues. In contrast to electrocautery, which works at a temperature of up to 400°C, coblation devices work at a temperature of 60°C. [3] Irrigation and suction were employed at all times and coagulation of vessels was done with the same instrument, Coblation® which is a registered trademark of ArthroCare Corporation, Sunnyvale, CA, USA Postoperative care Most patients were discharged the day after the surgical procedure. We prescribed paracetamol 1 gram IV every 8 hours in the day of admission and 3 tablets daily of paracetamol (500 mg) + codeine (8 mg) + caffeine (30 mg) in subsequent days until pain subsided

Outcome parameters: Outcome parameters included operative time, intraoperative bleeding, postoperative analgesics consumption, time to normal food intake and postoperative complications. Postoperative pain was assesses using visual analogue scale (VAS) on a scale of 0–10, with 0 representing no pain at all and 10 worst possible pain. When pain level exceeds 3, patients were given additional analgesics. Patients were followed for two weeks postoperatively.

Statistical analysis: Results of the present study were presented as number and percent or mean and standard deviations. Numerical data were compared using one-way ANOVA while categorical data were compared using chi-square test. All statistical calculations were achieved using SPSS 25 (IBM, USA). P value less than 0.05 was considered statistically significant.

Figure 1. Coblation Cryptolysis.

The present study included 105 patients with tonsillar stones. They comprised 47 males and 58 females with an age range of 19-36 years. They included three groups: GI (n=35) was subjected to cold dissection of tonsillar stone, GII (n=35) was subjected to monopolar bipolar diathermy tonsillectomy and GIII (n=35) was subjected to coblation cryptolysis. All groups were matched regarding age and sex distribution (Table 1).

Table 1. Baseline characteristics of the studied groups.

Data expressed as mean and SD or number (n)

Table 2. Operative time in the studied groups.

Data expressed as mean ± SD

Comparison between the studied groups regarding the operative time showed significantly shorter intraoperative time in GIII (11.24 ± 6.76 versus 10.76 ± 5.95 and 7.81 ± 3.14 minutes, p< 0.001) (Table-2). Also, GIII patients had significantly less intraoperative bleeding when compared to GI and GII (57.4 ± 27.99 versus 44.3 ± 22.85 and 11.8 ± 6.14 ml, < 0.001) (Table 3).

Table 3. Intraoperative bleeding in the studied groups.

Data expressed as mean ± SD

Table 4. Postoperative pain in the studied groups.

Data expressed as mean ± SD

Moreover, GIII patients experienced significantly less consumption of analgesics in the first postoperative 5 day (Table 4). All patients achieved normal food intake within 15 postoperative days but analysis implicated that coblation cryptolysis might be associated with fewer recovery days in comparison to the other two groups (Figure 2). No significant differences were found between the studied groups regarding postoperative complications including postoperative hemorrhage, nausea and vomiting (Table 5).

Table 5. Postoperative complications in the studied groups.

Data presented as number (n) and percent (%)

Figure 2. Time to normal diet.

Coblation tonsillectomy has been proven as a safe and effective in previous studies and is widely used for tonsillectomy in both adults and children. In addition, coblation tonsillectomy is associated with better postoperative morbidity in comparison to other techniques based on the postoperative pain, and use of postoperative analgesia [6]. However, few studies compare coblation cryptolysis to CD and MBD in adults with tonsillar stones. Results of the present study showed significantly shorter intraoperative time of coblation cryptolysis in comparison to the other two techniques in agreement with previous studies[7, 8] Moreover, our study reported less intraoperative blood loss in coblation cryptolysis as compared to other procedures in line with the conclusions of other report [9] which concluded that in most patients submitted to coblation tonsillectomy, estimated blood loss was less than that reported in the cold dissection method. Also, in the study of Timms and Temple[10], and Dwyer-Hemmings[11] the reported blood loss in coblation tonsillectomy was 19.10 ± 8.6 ml in comparison to 67.85 ± 33.95 ml in cold dissection method. In addition, our study noted significantly less postoperative analgesics consumption in the coblation group in comparison to the other two groups in harmony with the findings of Polites et al.[12] and Mudd et al.[13] who documented significantly less pain in coblation during first three days post-operatively as compared to the cold dissection method. On the other hand, Philpott et al.[14] and Mitic et al.[9] found no significant differences between coblation and cold dissection regarding the postoperative pain. In our study, time to normal food intake was found to be shorter in coblation cryptolysis in agreement with Zhou et al.[15] they noted that coblation led to a 1.80-day reduction in the time required to return to normal food intake.

In conclusion, coblation cryptolysis is superior to the other two techniques It was associated shorter operative time, less intraoperative bleeding, less post-operative pain and shorter time to normal food intake.

Declarations

Ethics approval and consent to participate: The Ethical Committee of Saudi German Hospital, Kingdom of Saudi Arabia on June 22, 2016, approved the study protocol and all patients signed informed consent before participation.

Consent for publication: Not applicable.

Availability of data and materials: The datasets during and/or analyzed during the current study available from the corresponding author on reasonable request.

Competing interests: The authors declare that they have no competing interests.

Funding: None.

Authors' contributions: All authors equally contributed to this manuscript. All authors read and approved the final manuscript

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