Pilonidal Sinus Recurrence Rates in Young Adults—Similar to Children or Adults?

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Sirs,

 

The manuscript compares the outcomes of pilonidal sinus treatment in children and adults. Furthermore, the authors divide adult age into young adults and older adults. 

They compare the recurrence rates among the 3 groups. 

It is difficult to understand why the authors create 2 groups in the adult age. 

It would be of benefit if the authors include figures illustrating the methods of treatment in children and in adults. This will rendrer the article clearer and more attractive for the reader. 

There are 2 basic strategies for the radical treatment of pilonidal sinus: excision and closure or excision and healing by secondary intention. 

Which is the treatment strategy in children? This is not clear from the text. 

Wchich is the treatement strategu in young adults? 

Wchich is the treatment strategy in older adults? 

All these questions should be clarified since the various treatment strategies are the keystone of the article. 

This should be illustrated by drawings or other figures. 

 

 

 

Author Response

We thank the reviewer for his insightful comments that helped us to better shape our line of argument, especially in introduction. The comments demonstrated that we had insufficiently explained the rationale for our study and its aim. We therefore introduced substantial changes in our manuscript, which are marked in yellow. We also had our manuscript revised by a native speaker to improve the clarity of the manuscript and the use of the English language.

The manuscript compares the outcomes of pilonidal sinus treatment in children and adults. Furthermore, the authors divide adult age into young adults and older adults. 

They compare the recurrence rates among the 3 groups. 

It is difficult to understand why the authors create 2 groups in the adult age. 

Recently, several minimally-invasive treatment approaches have been extended beyond 18 years of age into young adulthood. These minimally-invasive treatment protocols had been developed to address the increased recurrence rates of children and adolescents compared to adults. They aim to reduce the burden of disease by repeated minimally-invasive procedures in order to avoid excisional procedures before adulthood. The recurrence dynamics in adults are substantially different and thus exicisional procedures are more likely to be successful in avoiding a recurrence. But, their success is higher if previous surgeries were not substantially changing the anatomy. At present, it is unclear whether young adults had a similar recurrence rates as children and adolescents or recurrence dynamics that were more similar to adults.

The term young adults was coined because the age of adulthood differs between societies. While some use the cut-off of 18 years, others had preserved the traditional limit of 21 years of age. Consequently, there are two definitions of being adult differing by society/country. We there found it reasonable to investigate if these young adults could be considered adults based on the recurrence dynamics of pilonidal sinus disease.

We have incorporated this into the line of argument in the introduction and covered it in the discussion.

It would be of benefit if the authors include figures illustrating the methods of treatment in children and in adults. This will rendrer the article clearer and more attractive for the reader.

We agree with the reviewer that this might likely be the case. However, as we provide a database article and not an original investigation with our own patients, this might be considered misleading by some readers. This is especially the case, because we included crude recurrence rates from the database into our analysis irrespective of the surgical therapy. We have however amended the introduction by describing the historical approach and the several current ones.

There are 2 basic strategies for the radical treatment of pilonidal sinus: excision and closure or excision and healing by secondary intention. 

Which is the treatment strategy in children? This is not clear from the text. 

Wchich is the treatement strategu in young adults? 

Wchich is the treatment strategy in older adults? 

All these questions should be clarified since the various treatment strategies are the keystone of the article. 

This should be illustrated by drawings or other figures. 

As explained in the responses above, we felt this would not be appropriate for our database study. However, we have included several references that provide the reader with a detailed technical description accompanied by drawings or step-by-step photographs of the respective procedures. This has been included in a shorter form in the introduction and more detailed in the first paragraph of the discussion. We have now clearly differenteriated between the several approaches that were extended from children and adolescents to young adults.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors performed a literature survey on the recurrence-free healing of pilonidal sinus surgery in children, young aults 18-21 yo, and adults over 21 years. They found the highest recurrence risk is in children. Unfortunately, the authors did not discuss why a pilonidal sinus develops, the role of hair growth in the intergluteal cleft, etc.

The analysis showed that young adults had approximately the same recurrence rate like older adults, but children still have the highest risk of recurrence after pilonidal sinus surgery. 

Line 113: "In the direct comparison between children and young adults, the latter had a much lower recurrence free outcome (log rank test P<0.001) [Figure 3]. "  I do not really understand: in the text you say that recurrences are much less frequent in young adults, but here you claim the opposite.

Line 139: "...increased recurrence rate observed in children, which forms the basis of preferring minimally-invasive approaches ..." Actually, this might be the reason for the high recurrence rate: in children, often minimally invasive approaches are used followed by recurrence.

Comments on the Quality of English Language

There are some minor linguistic issues to be corrected.

Author Response

We thank the reviewer for his insightful comments that helped us to better shape our line of argument. The comments demonstrated that we had insufficiently explained the rationale for our study and its aim. We therefore introduced substantial changes in our manuscript, which are marked in yellow. We also had our manuscript revised by a native speaker to ensure adequate clarity and appropriate use of the English language.

The authors performed a literature survey on the recurrence-free healing of pilonidal sinus surgery in children, young aults 18-21 yo, and adults over 21 years. They found the highest recurrence risk is in children. Unfortunately, the authors did not discuss why a pilonidal sinus develops, the role of hair growth in the intergluteal cleft, etc.

We have included the pathogenesis into the fourth paragraph of the discussion.

The analysis showed that young adults had approximately the same recurrence rate like older adults, but children still have the highest risk of recurrence after pilonidal sinus surgery.

Line 113: "In the direct comparison between children and young adults, the latter had a much lower recurrence free outcome (log rank test P<0.001) [Figure 3]. "  I do not really understand: in the text you say that recurrences are much less frequent in young adults, but here you claim the opposite.

Thank you for pointing this out. We have corrected the apparent mistake. It is indeed the case that the young adults had a much higher recurrence free outcome. This has been corrected. Likewise, we also had our manuscript revised by a native speaker for improvements to increase the understandability of our text.

Line 139: "...increased recurrence rate observed in children, which forms the basis of preferring minimally-invasive approaches ..." Actually, this might be the reason for the high recurrence rate: in children, often minimally invasive approaches are used followed by recurrence.

Based on the two systematic reviews by Grabowski et al. (J Pediatr Surg. 2019;54(11):2210-2221) and Hardy et al. (J Pediatr Surg. 2019;54(11):2222-2233), it is the other way round. Although Grabowski et al. see a potential role for flaps, this has been based on studies in adults, which are likely to be non-transferrable. This has clearly be demonstrated by Hardy et al., who only summarise results from studies of children. They found open healing to have inacceptable recurrence rates of 26%, midline closure of 12%, and of minimally-invasive methods of 6%. These systematic reviews prompted the substantial changes away from more invasive approaches. If their recurrence rates are similar or even higher than those of minimally-invasive approaches, the latter would be favourable to reduce the burden of disease. Moreover, it does not increase the chances for failed excisional approaches in adulthood by having a failed major procedure, because major excisional procedures in adults are successful. We have adapted our line of argument to reflect the aforementioned evidence from systematic reviews accordingly.

Reviewer 3 Report

Comments and Suggestions for Authors

This study investigated the recurrence rates of pilonidal sinus disease among different age groups. Overall, the study is clearly presented, includes a well-structured discussion, and provides valuable insights into this area.

My comments:

1. In the inclusion criteria, does “surgical approach” refer specifically to a single procedure using off-midline flap closure, or does it encompass multiple surgical techniques? Are minimally invasive or office-based procedures included in the children group?
2. Line 114: The word “lower” should be corrected to “higher.”
3. Lines 120–121 should be revised for clarity and precision.
4. Line 127: How did you define “the number at risk”? Please clarify how you calculated the values at different time points.
5. Lines 164–165: It is unclear how this conclusion was drawn from your data, could you provide a brief explanation?

Author Response

We thank the reviewer for his insightful comments that helped us to improve our manuscript, especially with regard to methodologic details. We therefore introduced substantial changes in our manuscript, which are marked in yellow. We also had our manuscript revised by a native speaker to ensure adequate clarity and appropriate use of the English language.

This study investigated the recurrence rates of pilonidal sinus disease among different age groups. Overall, the study is clearly presented, includes a well-structured discussion, and provides valuable insights into this area.

My comments:

• In the inclusion criteria, does “surgical approach” refer specifically to a single procedure using off-midline flap closure, or does it encompass multiple surgical techniques? Are minimally invasive or office-based procedures included in the children group?

We have not differentiated between surgical approaches, because that would further diminish the available patient numbers. This has been added to the methods and as a limitation in the discussion.

• Line 114: The word “lower” should be corrected to “higher.”

This has been corrected.

• Lines 120–121 should be revised for clarity and precision.

The sentence has been revised and does now better convey the meaning we intended in drafting the sentence: Pilonidal sinus disease protocols were developed to improve surgical care for children and adolescents to diminish the impact the disease has on their formative live phases without impairing future definitive therapy as an adult.

• Line 127: How did you define “the number at risk”? Please clarify how you calculated the values at different time points.

This information has been added to the methods in the sentence just before the statistical analysis.

• Lines 164–165: It is unclear how this conclusion was drawn from your data, could you provide a brief explanation?

Considering your comment, we agree with you that this claim might not be backed by our data due to its inherent uncertainty. We therefore opted to remove the sentence.