In the literature, only one study by Mutus et al. was found to focus on wound infection after pilonidal sinus disease surgical treatment (13). However, the authors studied a cohort of adolescents with a median age of 16 years old with a shorter follow-up (7 days- 49 months) compared to our study (1-124 months). Their study showed that 36 patients out of 268 (13.4%) had wound complications, including infection and dehiscence, during the first month after surgery. Mutus et al. have a complication rate significantly higher than ours (whatever group of hygiene) which encompasses all complication types (bleeding, infection, dehiscence). We explain this difference by our strategy of close wound hygiene monitoring with small interventions at follow-up such as perineal/wound irrigation and/or perineal showers, fibrin removal, application of silver nitrate etc. These small interventions can influence cost management but will be always less expensive than the cost management of complications with in addition potential stress of an other surgery.
Interestingly, significant differences of follow-up between hygiene groups were found with group G1 having the longest follow-up. However, the range obtained for G1 was the most important reflecting the possibility that patients in the initially G1 group, for lack of monitoring instructions (because G1 group significates to be at the least-risk hygiene group and therefore initially receiving fewer monitoring replicates and wound care instructions) were able to switch to a poorer hygiene group, resulting in an increase in the duration of the follow-up.
So far we could not find in the current literature mention of an hygiene score. As consequence, it has led our surgical team to direct the wound monitoring message to the clinic: poor hygiene groups were then encouraged to perform more showers and specific hygiene instructions were administered to them. Thus, recurrence rates between the different hygiene groups were similar. Furthermore, this highlights that the recognition of wounds’ dirt degree after surgery is predictive of the time of recovery (with significant difference of median time off work between hygiene groups) but did not alter the surgical technique .
In 2010, Mc Callum et al. (14), performed a Cochrane review to compare open versus closed surgical treatments of pilonidal sinus disease. No significant difference was found in the rate of infection between the two types of procedures (risk ratio 1.31, 95% CI 0.93 to 1.85). These results are difficult to compare with ours because they take into account several types of open surgical treatments, including the technique we are using.
Milone et al. (9) performed a review of the literature gathering 15 studies with different surgical approaches to treat pilonidal sinus disease. The overall incidence of recurrence of pilonidal sinus disease after surgery was 13.8% with a mean follow-up from 58.36 to 240 months. In this review, only 2 studies (15) (16) were focusing on sinusectomy such as in our study. These studies were published in 1995 (Matter et al.) (15) and 2008 (Gips et al.) (16). Matter et al. included 50 patients with a mean age of 25 years old, with a mean follow-up of 72 months and described 18 recurrences (36%). The study of Gips et al. (16) included 1165 patients and reported 189 recurrences (16.2%) for a mean follow-up of 82.8 months. These recurrence rates are higher than the incidence of 7.2% we reported in this study with a median follow-up of 24 months.
The lowest and highest recurrence rates by grade of wound hygiene in the present study were found in respectively G1 (4.5%) and G2 (9.2%). These results have to be compared to a 2010 Cochrane review including studies with different surgical approaches were the recurrence rate for open healing approach (without cutaneous bridges) was 5.3% and global recurrence rate was 7% (8).
This study has some drawbacks. Firstly, the design was retrospective and based on records of wound aspects described by key words for the purpose of documenting the patient’s visit on his file and not to collect data for a study. We did not have the possibility to retrieve the name of surgeons who evaluated each patient. However, due to the limited number of surgeons involved in patient follow-up, the variability between observers would be low. Secondly, some important and potentially confounding variables were missing in patients’ files, such as diabetes, smoking, BMI etc.. Thus, this report should be completed with a prospective study with direct classification of wound aspect according to the grade we used and assessor training with wound pictures. Moreover, all variables of interest should be collected.
Many studies have focused on the priority of hair removal after surgery. A recent literature review published in 2018 by Pronk et al. (17) has underlined lower recurrence rates of pilonidal disease after laser hair removal compared to other methods of hair removal. However, the quality of methodology was limited. It would be interesting to incorporate in a future score, hair removal characteristics (extent of hair removal, technique etc.).
Wound hygiene is predictive of infection (18) (19). So far we could not find in the current literature mention of wound hygiene classification after pilonidal sinus disease surgery. We herein demonstrated that with a strategy of close wound monitoring and feedback interventions on wound hygiene we reach lower complication rates compared to the current literature and similar outcomes of complications and recurrence for dirty and clean wounds.