Extracapsular vs. Coblation intracapsular tonsillectomy: a retrospective cohort and cost analysis study

Introduction

Tonsillectomy is one of the most common paediatric surgical procedures, with over 500,000 cases performed annually in the United States alone (1). According to the American Academy of Otolaryngology–Head and Neck Surgery, tonsillectomy, with or without adenoidectomy, is recommended as a first-line treatment for children with sleep-disordered breathing (SDB) (2). Other widely recognised indications include recurrent acute tonsillitis, chronic tonsillitis, and recurrent peritonsillar abscess (2-4).

Traditionally, extracapsular tonsillectomy (ECT), using a number of surgical techniques such as bipolar diathermy or “cold steel” technique, has been the preferred technique for tonsillectomy (5-7). Post-tonsillectomy haemorrhage (PTH) is a well-recognised complication, characterised into primary PTH occurring within 24 h of surgery and secondary PTH occurring beyond 24 h (8,9). In ECT, PTH peaks in incidence between postoperative days 5–7 (9,10). The severity of PTH varies but can be life-threatening, necessitating immediate surgical intervention (9). The reported prevalence of PTH after ECT varies, with primary PTH rates reported between 0.2% and 2%, and secondary PTH rates reported between 3% and 21.8% (8,9,11-14). Postoperative pain is another common cause of patients seeking medical attention, which commonly remains a problem for up to 2 weeks postoperatively (15).

Intracapsular tonsillectomy (ICT) was popularised by Koltai and colleagues in 2003 (16). Preservation of the capsule and sparing of the underlying muscle were theorised to decrease the risk of PTH due to the smaller calibre of intracapsular vessels compared to those in the extracapsular region (17-19). Coblation (“controlled-ablation”) involves passing radiofrequency energy through a conductive medium, usually saline, thereby producing a plasma field. The charged ions break molecular bonds to allow tissue disintegration at a lower temperature than electrocautery, hence decreasing the amount of thermal damage to the surrounding structures (7,20). Reduced exposure and thermal injury to the nociceptors within the superior pharyngeal muscle have led to the hypothesis that ICT is associated with less pain (20).

A recent systematic review and meta-analysis encompassing 9,821 patients who underwent Coblation intracapsular tonsillectomy (CICT) reported a total proportion of PTH of 1.0% [95% confidence interval (CI): 0.5–1.6%] (21). The rates of primary and secondary haemorrhage were 0.1% and 0.8%, respectively. This review found that the improvement in SDB and recurrent tonsillitis following CICT was comparable to ECT. The rate of revision tonsil surgery was noted to be 1.4% (21).

One potential barrier to the uptake of CICT technique may be the cost of the disposable Coblation wand required for the procedure. A cost-benefit analysis conducted in the United States compared ECT with Coblation vs. ECT utilising electrocautery. They found that ECT with electrocautery was associated with an increased overall cost of NZ$590.67 compared to ECT with Coblation (P=0.003) (22). Furthermore, postoperative complications following tonsillectomy contribute to significant healthcare costs (23). Considering the higher rate of PTH associated with ECT, the expense of a disposable Coblation wand may be offset by the cost savings associated with reduced complications (21,23,24).

We therefore hypothesise that the total cost associated with CICT does not differ significantly from that of ECT. This study aimed to compare the surgical and overall treatment costs of ECT and CICT at a single institution.

Methods

Patients who underwent tonsillectomy at Waikato Hospital (Hamilton, New Zealand) between 1January 2022 and 30September 2023 were retrospectively identified from Waikato Hospital’s surgical database. For each patient, the electronic clinical notes were reviewed. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. This study received ethical approval from the Central New Zealand Health and Disability Ethics Committee (2023 EXP 18978), the governing ethics authority for the Waikato Hospital. Individual consent for this retrospective analysis was waived. The study is reported according to the STROBE reporting guidelines (available at https://www.theajo.com/article/view/10.21037/ajo-2025-1-100/rc) (25).

For each patient, demographic data including age, sex, ethnicity, and deprivation were collected. Deprivation was assessed using the New Zealand Deprivation Index (NZDep2013), which is a census area-based measure of socioeconomic deprivation score with a range from 1 (least deprived) to 10 (the most deprived score) (26). A prior study has shown deprivation to be relevant to PTH management (10). Additionally, travel distance (km) and travel time (in min, driving) were calculated based on the patient address using Google Maps. This information was relevant as proximity to the hospital is a criterion for same-day discharge following tonsillectomy; patients living more than an hour away typically stayed overnight. Clinical information recorded for each patient included the American Society of Anesthesiologists (ASA) score, preoperative diagnosis leading to tonsillectomy, other comorbidities including syndromes, coagulopathies and regular antiplatelet agents or anticoagulants in the peri-operative period. The surgical information recorded for each patient included the date of surgery, status of surgeon (specialist or trainee), anaesthetic time (in minutes), surgical time (in minutes), technique [CICT or ECT (bipolar, cold steel, or BiZact)], and if the surgery was combined with any other procedures such as adenoidectomy. In our department, CICT was carried out using the Smith & Nephew Procise™ XP Wand. Postoperative information such as time spent in the post-anaesthetic care unit (PACU), length of hospital stay, and any postoperative complications (defined as any unplanned hospital review, admission, or a return to operating theatre, for up to and including 30 days postoperatively) were recorded.

The cost of surgery and hospitalisation (hereafter referred to as the cost of surgery) was derived from patient-level costing data obtained from the hospital finance department. Surgical cost included all expenses associated with the index admission, including operating theatre utilisation, staffing, equipment, and postoperative recovery costs. For patients who experienced postoperative complications requiring additional healthcare utilisation, the associated expenditure was recorded as the cost of complication. The overall treatment cost was calculated as the sum of the cost of surgery and the cost of complication.

All costs incurred during 2023 were adjusted for inflation using the New Zealand Consumer Price Index (annual inflation rate, 4.7%) and recorded in Microsoft Excel (Microsoft Corporation, Redmond, WA, USA) (27). All costs are reported in New Zealand dollars (NZ$).

Exclusion criteria were: acute tonsillectomy, patients under the age of 3 years (as ECT is not routinely offered to patients under this age at our institution, and it also represents the lower age limit for day surgery tonsillectomy), patients with comorbidities impacting their surgery or hospital stay (e.g., syndromes, coagulopathy, or platelet dysfunction), patients who underwent tonsillectomy for possible or confirmed malignancy, patients undergoing additional procedures, other than adenoidectomy and/or tympanostomy tube insertion (owing to the impact of these additional procedures on the overall cost and postoperative recovery).

Statistical analysis

The demographic, clinical, and surgical data of patients in the ECT and CICT surgical groups were compared using the Student’s t-test, Fisher’s exact test, and the χ² test, as appropriate. The impact of each clinical, demographic, and surgical variable on overall mean healthcare costs was assessed using Pearson’s correlation or the Student’s t-test, depending on the data characteristics. Based on the univariate analysis results, a multivariate analysis was performed using a generalised linear model with a log-link function to evaluate the influence of preoperative and operative variables on total treatment costs. This analysis also accounted for clinically relevant factors affecting overall patient care costs and the tonsillectomy technique (ECT or CICT). Cost ratios (CR) were derived by exponentiating regression coefficients from a generalised linear model. Statistical analyses were conducted using IBM SPSS Statistics version 30 (IBM Corporation, New York), with statistical significance defined as a P value of less than 0.05.

Results

A total of 209 patients were identified from the database. Eighty-one patients were excluded: 57 due to additional procedures, 21 due to other comorbidities impacting their surgery or hospital stay, and 3 were acute tonsillectomies, leaving 128 patients in the study for analysis. The mean age was 8.2 years [standard deviation (SD): 6.0], 67 (52.3%) patients were male, SDB was the most common indication for tonsillectomy (59.4%), and 68 (53.1%) underwent CICT. The demographic, clinical, and surgical data of patients included in this study are shown in Table 1 (further details are available in Table S1). When comparing demographic, clinical, and surgical variables between the ECT and CICT surgical groups, patients in the CICT group were younger than those in the ECT group (6.2±3.9 vs. 10.8±7.1 years; mean difference 4.6 years, 95% CI: 2.6 to 6.6 years; P<0.001). The proportion of CICT procedures increased from 35% (24/64) in 2022 to 65% (44/64) in 2023, an absolute increase of 31.1% (95% CI: 14.8–47.7%; P<0.001). Additionally, a greater proportion of patients with recurrent tonsillitis underwent ECT rather than CICT [85% (17/20) vs. 15% (3/20); absolute difference 70%], while a higher proportion of patients with SDB underwent CICT [70% (53/76) vs. 30% (23/76); absolute difference 40%; P<0.001]. Among patients who underwent ECT, 10 out of 60 (16.7%) experienced a postoperative complication requiring a hospital visit, compared to 2 out of 68 (2.9%) in the CICT group. The study captured 7 cases of PTH, all of which represented secondary haemorrhage, with one requiring a return to theatre. The mean overall treatment cost for patients undergoing ECT was NZ$7,194.38 (SD: NZ$2,231.10), and for patients undergoing CICT it was NZ$7,029.19 (SD: NZ$1,107.24), with a mean difference of NZ$165.20 (95% CI: −NZ$440.18 to NZ$770.57; P=0.590).

In the univariate analysis, overall treatment cost differed significantly according to length of hospital stay. Patients discharged on the same day had a mean treatment cost of NZ$6,343.15±862.92 compared with NZ$7,475.93±1,805.67 for those requiring an overnight hospital stay, representing a mean cost difference of NZ$1,132.78 (95% CI: NZ$589.70 to NZ$1,675.86; P<0.001).

Other variables significantly associated with overall treatment cost in univariate analysis included anaesthetic duration, surgical duration, concomitant procedures (adenoidectomy and/or tympanostomy tube insertion), and the occurrence of postoperative complications. Tonsillectomy technique was generally not associated with differences in overall treatment cost. However, 4 patients underwent BiZact ECT with this tonsillectomy method being associated with significantly lower costs compared with CICT, with mean costs of NZ$5,265.54±291.90 and NZ$7,029.19±1,107.24, respectively (mean difference, −NZ$1,763.64; 95% CI: −NZ$2,876.93 to −NZ$650.36; P=0.002). The results of the univariate analysis are summarised in Table 2, with additional details provided in Table S2.

Looking at the mean cost of surgery for ECT and CICT, there was no statistically significant difference between the two groups (mean difference NZ$244.20, 95% CI: −NZ$229.94 to NZ$699.25; P=0.29), as shown in Table 3. However, the mean cost of complications was higher in the ECT group than in the CICT group (mean difference NZ$409.39, 95% CI: NZ$95.91 to NZ$722.87; P=0.011) (Table 3). This did not translate into a statistically significant difference in overall treatment cost between ECT and CICT groups (mean difference −NZ$165.20, 95% CI: −NZ$770.57 to NZ$440.18; P=0.590).

In multivariate analysis, as shown in Table 4, patients undergoing ECT incurred costs that were 3.9% higher than those undergoing CICT; however, this difference was not statistically significant [CR 1.04, 95% CI: 0.97–1.12; P=0.316]. Similarly, travel time (<1 h vs. >1 h) was not associated with a significant increase in treatment cost (CR 0.96, 95% CI: 0.87–1.05; P=0.379).

In contrast, patients undergoing tonsillectomy alone incurred costs that were 13.0% lower than those undergoing tonsillectomy combined with other procedures (CR 0.87, 95% CI: 0.79–0.96; P=0.003). Likewise, patients with ASA grades 1–2 incurred costs that were 13.1% lower than those with ASA grades 3–4 (CR 0.87, 95% CI: 0.77–0.98; P=0.022).

Discussion

To our knowledge, this is the first single-centre retrospective study comparing the costs of ECT and CICT, demonstrating no statistically significant difference between the two techniques. Prior studies comparing Coblation ECT with other extracapsular methods, or microdebrider ICT with ECT, have reported conflicting results (22). In our cohort of 128 tonsillectomy patients, the mean surgical cost was NZ$6,872.73 (SD NZ$1,298.86), with no significant cost difference between the ECT and CICT groups; however, the complication rate was notably higher in the ECT group (16.7% vs. 2.9%, P=0.012), resulting in significantly greater mean complication costs [NZ$451.38 (SD NZ$1,272.06) vs. NZ$42.00 (SD NZ$281.42)]. Despite the higher cost of complications in the ECT group, the overall treatment cost was not significantly different between the two groups, as shown in Table 3. However, the wide CI indicates uncertainty and the study may be underpowered to detect a clinically meaningful difference.

Several factors significantly impacted overall treatment costs, including hospital length of stay, surgical time, anaesthetic time, the specific ECT method (BiZact), postoperative complications, and combining tonsillectomy with adenoidectomy or tympanostomy tube insertion (Table 2). Combining tonsillectomy with tympanostomy tube insertion alone was found to be associated with a significantly higher cost than tonsil surgery alone, or tonsil surgery with adenoidectomy +/− tympanostomy tube insertion. This is likely an outlier as only one patient in this study underwent tonsil surgery and tympanostomy tube insertion.

Although no significant cost difference was identified between ECT and CICT, hospital length of stay was associated with overall treatment cost. Large international studies have demonstrated the safety and acceptability of day-case tonsillectomy in appropriately selected patients (28-31). Day-case surgery increases treatment capacity, reduces healthcare costs, and may lower the risk of hospital-acquired infections (28). Concerns for postoperative complications, in particular primary PTH, remain key barriers to same-day discharge. At our institution, eligibility for same-day discharge following tonsillectomy is determined based on the following criteria: age greater than 3 years; travel time to hospital of less than 1 h; absence of obesity or concern for severe obstructive sleep apnoea; no surgical or anaesthetic concerns (including relevant comorbidities or medication use); and, for adult patients, the requirement to remain in the care of a responsible adult for a minimum of 24 h postoperatively. Notably, CICT had lower postoperative complication rates in this study (2.9% vs. 16.7%), consistent with findings from a systematic review by Lin et al. in 2024, which reported a 1.0% overall PTH rate for CICT, including primary PTH (0.1%) and secondary PTH (0.8%) (20). Therefore, the provision of CICT may further assist the provision of same-day discharge after tonsillectomy.

Both anaesthesia time and surgical time were found to influence overall costs. While extended anaesthesia time may reflect more complex cases, strategies to reduce anaesthetic time, such as using a laryngeal mask airway instead of endotracheal intubation, when possible, could reduce costs (32). Similarly, reducing operative time may be cost-effective. BiZact ECT has been shown to decrease surgical time, which may explain the lower costs associated with this method in our study (33). However, only four patients underwent BiZact ECT, limiting conclusions. Importantly, efforts to reduce operative time must balance cost savings with patient safety, as increased complications would not only impact clinical outcomes but also drive up treatment costs.

To determine preoperative factors influencing the surgical and overall treatment costs, we conducted a multivariate analysis using a generalised linear model (Table 4). This confirmed that ECT or CICT did not significantly impact overall costs. However, two factors emerged as independent predictors of increased costs: combining tonsillectomy with adenoidectomy and/or tympanostomy tube insertion, and higher ASA scores, likely attributable to the additional cost of extra surgical equipment and increased operative time. Nonetheless, performing these procedures concurrently is likely more cost-effective than conducting separate surgeries, as it mitigates the financial and logistical burden of repeated anaesthesia on both the healthcare system and patients.

Patients with higher ASA scores (≥3) were also associated with increased treatment costs. This is likely multifactorial, as these patients often require longer anaesthetic time, extended hospital stays, and are at higher risk for complications and readmissions (34). In our study, only 12 patients had an ASA score ≥3 (7 in the ECT group, 5 in the CICT group), which limited the feasibility of further subgroup analysis.

A temporal change in surgical practice was observed in this study, with a greater proportion of patients receiving CICT in 2023 compared with 2022. While this may introduce confounding into the analysis, this is likely to represent the evolving evidence supporting CICT in the management of SDB and, more recently, tonsillitis (20).

This study had a number of limitations. Its retrospective design restricted the analysis to in-hospital care costs and precluded definitive conclusions regarding causality. Due to the structure of primary healthcare funding in New Zealand, costs incurred in primary care settings, such as general practitioner visits for pain management, could not be accounted for. Additionally, indirect costs, such as time off work for patients or caregivers, were not captured. Being non-randomised, it is also acknowledged that the treatment groups were not matched, with ECT being skewed towards older patients and those with a diagnosis of recurrent tonsillitis. This suggests that the surgical approach was strongly associated with patient age and indication. Both factors are established risk factors for PTH and may therefore introduce significant confounding by indication (35-37). These limitations restrict causal inference and may indicate that observed differences in complications are not independent of case selection, pointing to the presence of selection bias.

We recorded in-hospital costs for up to 30 days post-surgery; however, other potential expenses, such as the need for revision surgery due to regrowth, were not included. The regrowth rate is estimated to be at least 1.4% in the CICT group and lower in the ECT group (20). While we found no statistically significant difference in surgical or overall treatment costs between ECT and CICT, our relatively small sample size increases the risk of a Type II error.

Several confounding factors influenced our findings. A notable factor was the frequent combination of tonsillectomy with other procedures (e.g., adenoidectomy, tympanostomy tube insertion), particularly in the CICT group, making direct cost comparisons between tonsillectomy techniques challenging. Furthermore, as tonsillectomy was frequently performed in conjunction with other procedures, only 30% of patients in our cohort underwent tonsillectomy as a standalone operation, limiting the ability to draw meaningful comparisons. Additionally, as this study reflects the experience of a single institution, its findings should be generalised with caution.

Conclusions

In conclusion, in this single-centre retrospective cohort study, no statistically significant difference in overall treatment cost was observed between CICT and ECT. However, substantial confounding by indication and limited sample size restrict definitive conclusions. The mean complication cost was significantly higher in the ECT group. Independent predictors of overall treatment cost included combining tonsillectomy with adenoidectomy and/or tympanostomy tube insertion, as well as ASA score. Additional contributing factors were hospital length of stay, surgical time, anaesthetic time, and postoperative complications requiring unplanned hospital visits or readmission. Additionally, in a small subset of patients, the use of BiZact ECT was associated with a significantly lower cost on univariate analysis. Further research, ideally through a prospective multi-centred study with rigorous standardisation to reduce confounding and bias, would be an important next step in validating these findings and help in providing more definitive conclusions.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://www.theajo.com/article/view/10.21037/ajo-2025-1-100/rc

Data Sharing Statement: Available at https://www.theajo.com/article/view/10.21037/ajo-2025-1-100/dss

Peer Review File: Available at https://www.theajo.com/article/view/10.21037/ajo-2025-1-100/prf

Funding: None.

Conflict of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://www.theajo.com/article/view/10.21037/ajo-2025-1-100/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Central New Zealand Health and Disability Ethics Committee (2023 EXP 18978), the governing ethics authority for the Waikato Hospital. Individual consent for this retrospective analysis was waived.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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