Pilonidal reality calls for action

The article by Brown et al.¹ on real-world practice and outcomes in pilonidal surgery, published in this issue, is exceptionally intriguing and highly relevant as it reveals a glaring lack of knowledge and expertise in the treatment of pilonidal sinus disease (PSD).

PSD is an acquired inflammatory condition in the upper natal cleft primarily affecting young individuals in education or employment. Although considered straightforward by most, high-risk subpopulations appear to exist, characterized by early onset, family history, stiff hair, and co-morbidities. The burden on both patients and society is substantial, yet very little is being done to improve—or even understand—outcomes. The efforts of the National Institute for Health Research and the PITSTOP management group to enhance understanding of PSD management and to guide future research are therefore highly commendable.

Population-based data

A major strength of this study is the large number of hospitals participating, generating what the authors refer to as ‘real-world data’. Although the data presented in this study are certainly more diverse than those in the average PSD study, it is unclear whether these data are indeed population-based, as some patients in the catchment area of a participating hospital may be treated elsewhere. As outlined, most PSD studies are retrospective and from a single centre, representing an ‘in my hands’ experience. Randomized trials exist, but population selection bias may be significant.

Case volume

It is striking that, across the 31 inclusion sites, 1213 patients with PSD had the patient information sheet issued over a 3-year interval. This means that each site on average saw 13 potentially eligible patients with PSD annually. Even during the COVID pandemic, this must be considered a very low annual caseload. Furthermore, most departments may have several surgeons treating PSD or even no specific surgeon at all, leaving very few cases per year per surgeon.

Classification and treatment

As expected, a broad spectrum of treatments was offered across different PSD categories. This variety in types of procedure considered appropriate for patients with different disease characteristics suggests lack of a standardized and well defined treatment strategy. Almost half of patients presented with type 2 manifestations, which represent disease with lateral extension (International Pilonidal Society classification²). This is a very heterogeneous group covering a wide spectrum of PSD ranging from simple to potentially complex disease (for example, bilateral extension or extension(s) far from the midline). This calls for further subclassification to study outcomes and tailor treatments.

Drivers of surgical decision-making were examined in this study, which, besides the identified factors, are influenced by the level of training/expertise, surgical experience with PSD, available guidelines, local practice, and perhaps resources allocated to the field. There is no information on the level of training and expertise among the surgeons participating in this trial, besides the fact that their annual caseload was low. Tools to support or guide decision-making are highly warranted. As such, treatment guidelines exceeding the Italian³ and German⁴ guidelines are currently being developed within the European Society of Coloproctology.

Follow-up

Another strength of this study is the prospective data collection and the meticulous attempt to follow up, with 71% of patients available for a very short follow-up at 6 months after surgery. This may reflect selection bias or perhaps the challenges of multicentre trials, as many of the existing specialized single-centre studies on PSD present surprisingly adherent follow-up even after 5 and more years. However, a meta-analysis⁵ has highlighted the bias that long-term recurrence rates in PSD are much higher in RCTs than in non-RCTs. With more rigorous follow-up as part of the RCT design, this suggests that the abundance of retrospective trials may have contributed to a falsely deflated risk of recurrence, as these follow-ups may, in reality, be inadequate or flawed. On the other hand, RCTs may have downsides of their own^6–8.

Endpoint

This study aimed to report patient and risk-adjusted outcomes. For the evaluation of treatment strategies, follow-up at 6 months after surgery must be considered short, representing an early outcome. The 45% complication rate aside, 20% of treatments resulted in failure within the first 6 months. Furthermore, with 25% of patients presenting with prolonged healing, more are certainly to come with a longer observation period. The authors have done readers the rare favour of defining what constitutes a failure in this study, and, although this definition may be broader than the traditionally reported ‘PSD recurrence after full healing’, the failure rate is still much higher than in existing literature. A meta-analysis conducted by Stauffer et al.⁵, encompassing nearly 90 000 patients with PSD from the global literature (including both RCTs and non-RCTs), revealed a 2% recurrence rate per year of follow-up, for comparison.

Inspiration for improvement

From this author’s own backyard, Danish patients with colorectal cancer had an inferior prognosis compared with those from neighbouring countries in the 1990s. Acknowledging this, the Danish Colorectal Cancer Group initiated meticulous monitoring of outcomes alongside multidisciplinary teaching and training. Subsequently, among colorectal surgeons, focus was increased on, among other things, surgical technique through increased training and higher volume^9–11. Implementing these initiatives has led to continuously drastic improvements in outcomes for the patients in terms of survival^12,13.

Perhaps it is time for a change? Has the time come for the surgical community to zoom in on the suffering of patients with PSD, and start setting standards for a minimum level of expertise along with a minimum caseload per centre to justify offering treatment for this condition? Indeed, high-volume centres with dedicated surgeons could improve through professional exchange and would open up to strengthened collaboration with dermatologists, paediatric and plastic surgeons, and, in selected cases, radiologists and immunologists in order to advance treatment.

This study serves as a firm reminder that the field of PSD desperately needs large and long-term prospective trials, randomized or with well defined populations and a valid disease classification, and agreement on indicators to monitor treatment quality as well as patient-reported outcomes. This study provides real-world data relevant to the design of pragmatic RCTs much needed in this field.

In summary, this study should serve as an awakening for both surgeons and decision-makers alike. This editorial’s author cannot think of any other disease treated so carelessly by the surgical community. PSD is a common condition with an increasing incidence, and it so happens that most patients are treated in ‘the real world’. On behalf of the patients, we should not accept the real-world outcomes as published in this study. Teaching, training, and specialization (and in selected patients, a multidisciplinary approach) should be the drivers of the long-awaited pilonidal revolution.

Funding

The author has no funding to declare.

Disclosure

The author declares no conflict of interest.