Complications of Cartilage Sparing Otoplasty: A Systematic Review and Meta-Analysis

Abstract

Objective:

To study the prevalence of complications in patients who have undergone cartilage sparing otoplasty.

Methods:

On December 26, 2021, the authors searched 8 databases using the search term “(otoplasty) AND (cartilage sparing OR cartilage sparing)” for collecting the most appropriate studies. The authors used R software version 4.1.2 for conducting the meta-analysis.

Results:

Of the 414 records screened, the authors included 14 studies. Recurrence/reoperation was the most common reported complication with a prevalence of 4.27% (95% CI: 2.93–6.22), followed by suture erosion 2.46% (95% CI: 0.86–7.07) and hematoma/hemorrhage 1.34% (95% CI: 0.79–2.27). The authors did not find any significant difference between cartilage sparing and cartilage scoring in terms of recurrence/reoperation [odds ratio (OR): 0.92; 95% CI: 0.53–1.60; P = 0.766], hematoma/hemorrhage (OR: 1.39; 95% CI: 0.28–7.01; P = 0.688), and wound infection (OR: 0.37; 95% CI: 0.06–2.24; P = 0.279).

Conclusion:

Various complications have been reported, including recurrence and reoperation, hematoma, wound infections, suture erosions, keloid formation, and skin necrosis. However, the prevalence of these events is not high, although significant heterogeneity was reported for some outcomes. Therefore, it can be concluded that cartilage sparing otoplasty is a safe and reproducible technique.

Estimates from epidemiological data indicate that the prevalence of prominent ear is relatively high, with an estimated rate of 5%.¹ Patients usually present an increase in auriculomastoid angle and absent deep concha and antihelix.² Accordingly, the different management approaches aim to reduce the concha and formation of the antihelix.³ Although the physiological burden in the affected patients is negligible, studies indicate that these patients are usually liable to severe social and psychogenic traumas, particularly when affecting children. Accordingly, management of the disorder and surgery is usually recommended at an early age.^1,4

Various techniques were reported in the literature for correcting prominent ears. Managing the different types of congenital ear deformities requires certain techniques, and some even require integrated approaches to achieve proper management and enhanced outcomes. For example, fixation of the ear using mastoid sutures was first reported in 1848 by Dieffenbach, who performed the first otoplasty.⁵ These include around 200 techniques, including perichondroplasty, cartilage splitting, cartilage sparing, percutaneous, and endoscopic and incision-less techniques. These approaches can be generally divided into 2 main categories, including cartilage cutting and cartilage sparing techniques.⁶ However, the outcomes of these techniques are hugely variable among the different studies, including a wide range of safety, complications, and recurrence rates.⁷ Accordingly, many modifications to these techniques were reported in the literature to enhance the safety and efficacy of these surgeries.^8–11

Cartilage sparing otoplasty is one technique that has shown to be highly efficacious with a favorable safety profile. It was first reported by Furnas¹² and Mustardé¹³ who indicated the acceptable safety and efficacy of these approaches. However, some studies reported various complications that might develop after this operation. Some of these complications include recurrence and need to reoperate, development of hematoma, residual pain, suture extrusion, and others.¹⁴ However, the rates of these complications are not consistent among these studies as some of the relevant investigations estimate a high prevalence rate of complications, whereas others concluded that minimal or no events of complications were detected.^15–18 Accordingly, we aimed to conduct the current meta-analysis to estimate the overall rates of different complications among patients undergoing cartilage sparing otoplasty based on the results of relevant studies.

METHODS

Search Strategy

By following the well-known PRISMA guideline for performing systematic reviews, we searched 8 databases named: Web of Science, PubMed, Google Scholar, Clinical trial.gov, the WHO International Clinical Trials Registry Platform, metaRegister of Controlled Trials, Virtual Health Library, and The New York Academy of Medicine.¹⁹ The search term “(otoplasty) AND (cartilage sparing OR cartilage sparing)” was used on December 26, 2021, in the 8 databases and was modified according to the search process of each individual database for collecting the most appropriate studies. Moreover, we did an extensive manual search across PubMed and Google Scholar to gather any relevant missed papers during the systematic search process.

Inclusion Criteria

We included papers that reported the complications of cartilage sparing otoplasty. We did not settle limitations regarding the age or sex of patients, study design, and sample size.

Exclusion Criteria

We excluded papers where the number of ears is not described (unilateral or bilateral otoplasty in the same patient), review articles, duplicate studies, including the same patients, presented in other included papers, editorials, and review papers

The systematic search was performed by the most experienced member according to the recommendations of the senior author. Then, at least 2 authors did the title and abstract screening by using the previously reported inclusion and exclusion criteria. Furthermore, the full-text screening was conducted by at least 3 authors to avoid the exclusion of any relevant paper. At each step of the title and abstract screening and full-text screening, the senior author was consulted in each conflict between members.

Data Extraction

The senior author made a pilot extraction of full texts for developing an extraction sheet then the extraction was performed by at least 3 authors and a fourth author, if necessary. We included several outcomes in our study (recurrence/reoperation, hematoma/hemorrhage, wound infection, scarring, keloid, suture erosion, and skin necrosis). Demographics of the included studies were also extracted such as age, compared groups, sample size, and follow-up duration. After performing the extraction, all authors did an extensive revision of the extracted data to minimize the bias of the wrong extracted data.

Risk of Bias

We assessed the risk of bias according to the study design of the included papers. The National Institute of Health quality assessment tool was used to evaluate the quality of each study.²⁰ Two authors ranked the quality of each study and revised by a third author, if necessary.

Statistical Analyses

Using R software version 4.1.2, we calculated pooled prevalence rates and odds ratios (ORs), with their corresponding 95% CIs. Heterogeneity was assessed using Q statistics and the I ² test, where I ² >50% or P value <0.05 were considered statistically significant, and a random model was adopted.²¹ Whenever 10 or more studies were available, publication bias (Egger regression test) and the impact of sample size (meta-regression) were tested.²² Whenever publication bias was found, funnel plots were drawn, and the trim and fill method was used to calculate the adjusted effect size.²³

RESULTS

Search Results and Study Selection

The systematic search through the 8 databases yielded 414 records after removing duplicate records. Title and abstract screening and full-text screening resulted in an exclusion of 385 and 45 records, respectively. Manual search trials yielded another 3 papers. In total, we included 14 papers for this systematic review and meta-analysis (Supplemental Digital Content, Table 1, http://links.lww.com/SCS/F804, Fig. 1).^24–37

FIGURE 1.

PRIMSA flow diagram of the study process.

We included 9 prospective cohort studies and 5 retrospective cohort studies. The sample size was 1295 patients who had undergone cartilage sparing otoplasty, whereas 998 patients had undergone cartilage scoring otoplasty. Follow-up duration was reported in 12 studies and ranged from 8 weeks to 4.5 years.

Recurrence/Reoperation

A total of 14 studies of 2008 ears have reported the recurrence/reoperation rates among patients who underwent cartilage sparing otoplasty, with a pooled prevalence of 4.27% (95% CI: 2.93–6.22). The prevalence reported among individual studies ranged from 0% to 9.01%, which may explain the significant heterogeneity among studies (I ² = 57%; P = 0.004; Fig. 2A). Egger regression test showed funnel plot asymmetry (P = 0.002), and using the trim and fill method, the adjusted prevalence rate was 5.72% (95% CI: 3.90–8.40; Supplemental Digital Content, Fig. 1, http://links.lww.com/SCS/F805). On further exploration of heterogeneity sources and testing, the impact of variable sample sizes on the effect size, we found no significant effect (P = 0.993) and did not account for any of the heterogeneity (R ² = 0%). In addition, there was no significant difference in the recurrence/reoperation outcomes of cartilage sparing and cartilage scoring procedures (OR: 0.92; 95% CI: 0.53–1.60; P = 0.766), with no considerable heterogeneity present among different studies (I ² = 27%; P = 0.254; Fig. 2B).

FIGURE 2.

Recurrence/reoperation in cartilage sparing otoplasty. (A) Prevalence rates (represented by the pooled event rate and the corresponding 95% CI). (B) Comparison with cartilage scoring otoplasty (represented by OR and the corresponding 95% CI). OR indicates odds ratio.

Hematoma or Hemorrhage

A total of 12 studies of 1440 ears have reported the hematoma/hemorrhage rates among patients who underwent cartilage sparing otoplasty, with a pooled prevalence of 1.34% (95% CI: 0.79–2.27). The prevalence reported among individual studies was <1% among the majority of the included studies, with no heterogeneity detected (I ² = 0%; P = 0.687; Fig. 3A). Egger regression test showed funnel plot asymmetry (P = 0.019), and using the trim and fill method; the adjusted prevalence rate was 1.83% (95% CI: 1.13–2.95; Supplemental Digital Content, Fig. 2, http://links.lww.com/SCS/F807). On further exploration testing, the impact of variable sample sizes on the pooled prevalence, we found no significant effect (P = 0.993). In addition, there was no significant difference in the hematoma/hemorrhage rates of cartilage sparing and cartilage scoring procedures (OR: 1.39; 95% CI: 0.28–7.01; P = 0.688), with no significant heterogeneity present among different studies (I ² = 20%; P = 0.263; Fig. 3B).

FIGURE 3.

Hematoma in cartilage sparing otoplasty. (A) Prevalence rates (represented by the pooled event rate and the corresponding 95% CI). (B) Comparison with cartilage scoring otoplasty (represented by OR and the corresponding 95% CI). OR indicates odds ratio.

Wound Infection

A total of 10 studies of 1550 ears have reported the wound infection rates among patients who underwent cartilage sparing otoplasty, with a pooled prevalence of 0.63% (95% CI: 0.29–1.40). The prevalence reported among individual studies was <1% in almost all of the included studies, with no heterogeneity detected (I ² = 0%; P = 0.560; Fig. 4A). Egger regression test showed funnel plot symmetry (P = 0.112). On further exploration testing, the impact of variable sample sizes on the pooled prevalence, we found no significant effect (P = 0.053). In addition, there was no significant difference in the wound infection rates of cartilage sparing and cartilage scoring procedures (OR: 0.37; 95% CI: 0.06–2.24; P = 0.279), with no heterogeneity present among different studies (I ² = 0%; P = 0.780; Fig. 4B).

FIGURE 4.

Wound Infection in cartilage sparing otoplasty. (A) Prevalence rates (represented by the pooled event rate and the corresponding 95% CI). (B) Comparison with cartilage scoring otoplasty (represented by OR and the corresponding 95% CI). OR indicates odds ratio.

Other Complications

A variety of complications were less common among the included studies. Suture erosion had the highest prevalence of 2.46% (95% CI: 0.86–7.07), as pooled from eight studies of 862 ears. Noteworthy, 6 of these studies reported a 0% prevalence, which might explain the high heterogeneity found among different studies (I ² = 77%; P < 0.001; Fig. 5A). Moreover, the pooled prevalence of scarring was 1.14% (95% CI: 0.66–3.03) with no heterogeneity found among the included studies (I ² = 0%; P = 0.810; Fig. 5B). The least prevalence rates were found in keloid formation 0.95% (0.24–3.76), and skin necrosis 0.35% (0.12–1.00), with no heterogeneity found for both outcomes (Fig. 5C, D).

FIGURE 5.

Prevalence of other complications in cartilage sparing otoplasty (represented by the pooled event rate and the corresponding 95% CI). (A) Suture erosion. (B) Scarring. (C) Keloid formation, (D) Skin necrosis.

DISCUSSION

This is the first meta-analysis that provides evidence regarding the overall rates of different complications associated with cartilage sparing otoplasty operations based on evidence from relevant studies in the literature. Overall, our results indicate that the modality is relatively safe, reproducible, and efficient with minimal complications.

The significant heterogeneity estimated for recurrence rates and rates of hematomas among the different studies is probably attributed to the wide variations in otoplasty techniques, which can remarkably affect postoperative outcomes.³⁸ Moreover, the great diversity in the sample size of included studies and different epidemiological data of included populations might also be another reason for this heterogeneity.³⁹

It should be noted that some studies reported a minimal number of cases of bleeding and hematoma (<1%). This can be attributed to the enhanced approaches by some authors, which reported using bipolar coagulation for better control of bleeding, in addition to preoperative infiltration, enhancing the efficacy and safety of the technique. Some authors further reported that intraoperative lack of adequate hemostasis might be attributed to the development of postoperative hemorrhage.^38–42 Furthermore, the risk of bleeding and hematoma can be further reduced by avoiding early dressing change, as reported by Binet et al.³⁹

The estimated rate of wound infection was also very low based on our pooled analysis, with no significant heterogeneity among the results of the included studies. Although infections are commonly encountered during otoplasty, some reasons might explain the low rates of infections in this setting. For instance, the excellent blood supply of the ear might partially explain this.^42,43 Moreover, prophylactic regimens of antibiotics are usually administered perioperatively, which can dramatically provide adequate protection against these events. Scarring complications (such as keloid formation and skin necrosis) were also reported in the different studies. However, these events are not commonly encountered based on our pooled analysis with no significant heterogeneity. A previous study reported that the development of postoperative scarring complications might be attributed to neglecting the skin type of the included patients.³⁹ Evidence indicates that type I and type V of skin are more liable to developing hypertrophic scars.^44–46 Moreover, it has been evidenced that the type of surgical technique might be another potential for developing these events. For instance, Sadhra et al³⁸ estimated that the incidence of skin/wound healing complications is usually higher with cartilage manipulation than with suture-based techniques. However, it should be noted that the authors also reported that the latter approach is usually associated with a higher rate of reoperation and recurrence rates.

It should also be noted that there were no significant differences in terms of overall complications (including rates of hematoma, recurrence and reoperation, and wound infections) between cartilage cutting and cartilage sparing techniques. However, it has been evidenced that reoperation is usually easier with cartilage sparing techniques. Besides, evidence indicates that it is impossible to reoperate with cartilage irregularity, reported with cartilage cutting techniques.¹⁵ Therefore, cumulative evidence from the current analysis and results of previous investigations show that the incidence of these complications after cartilage sparing otoplasty is a significant indication for performing postoperative follow-up of patients to provide early management of the different potential pathologies.

The major limitation of the current meta-analysis is probably the limited number of included studies, which included variable numbers of included patients. Besides, the significant heterogeneity among the included studies might be another limitation. Accordingly, further well-designed studies are encouraged to overcome these limitations and potentially identify the definite causes of the reported complications to enhance the safety and outcomes of cartilage sparing otoplasty.

CONCLUSION

The current meta-analysis provides evidence regarding the prevalence of different complications after cartilage sparing otoplasty. Various complications have been reported, including recurrence and reoperation, hematoma, wound infections, suture erosions, keloid formation, and skin necrosis. However, the prevalence of these events is not high, although significant heterogeneity was reported for some outcomes. Therefore, it can be concluded that cartilage sparing otoplasty is a safe and reproducible technique.