Cleft closure (the Bascom cleft lift) for 714 patients—treatment of choice for complex and recurrent pilonidal disease (a cohort study)

Pilonidal disease is a benign condition that affects mainly the young. In existing literature, there is no consensus for best treatment, with multiple operative techniques described, some complex, resulting in a high proportion of failure and/or morbidity. The cleft closure (or cleft lift) described by Bascom and Bascom (Arch Surg, 137, 2002, 1146−50), by comparison, is a simple operation, resulting in healing in the majority and good cosmesis.

months, if not years, to heal, requiring regular dressings or in some cases multiple operations.Sometimes they do not heal at all.
Recurrent disease can often be more difficult to treat; replicate midline excisional surgery for recurrence has been quoted to fail in nearly 50% of patients [6].Other techniques reported in the literature for management of recurrent pilonidal disease include the Karydakis and Limberg operations and plastic surgical techniques such as split myocutaneous flaps [7].These procedures often involve extensive mobilization and dissection down to the sacrococcygeal fascia and are performed under general anaesthesia.
The cleft closure (also known as cleft lift) was initially described by Bascom and Bascom in 2002 [8].It is a simple technique that does not require extensive mobilization and can be employed in both primary and recurrent disease.Its advantages are that it has a high success rate, low morbidity, can be done as a day case usually under local anaesthesia and has a good cosmetic outcome.We have performed a retrospective analysis of a prospectively collected database on a large series of patients who underwent a cleft closure operation under one surgeon on two sites (St Mark's Hospital, London, and Queen Alexandra Hospital, Portsmouth).

ME THOD
This is an observational cohort study, examining consecutive patients treated with a cleft closure (operative technique as previously described by Senapati et al. [9]) for extensive disease and recurrent or unhealed pilonidal disease after previous definitive surgery, between 1995 and 2021.This is also a retrospective analysis of prospectively collected data over many years, for which patients gave written consent for the collection of their clinical outcomes.No additional procedures were done, nor information gathered outside the standard clinical care given to them.Ethical approval was therefore not considered to be required.The study has been reported in adherence to the STROBE statement guidelines.
Treatment selection for patients is based on examination findings preoperatively.Patients with pits in the midline and no evidence of secondary sinus are offered trephine surgery (or the Gips procedure) in the first instance.Patients with midline pits and at least one secondary discharging sinus or evidence of an abscess cavity within 5 cm of the nearest pit are routinely offered the Bascom pit picking surgery.The cleft closure is the preferred technique for patients with more complex or extensive disease: either a secondary sinus >5 cm from nearest midline pits, evidence of pilonidal disease extending below the natal cleft towards the anal verge, bilateral disease or recurrent disease.It is also recommended for patients presenting with unhealed wounds in the natal cleft.
Data were collected prospectively onto a Microsoft Access database.Multiple variables and outcomes were recorded, including age, sex, disease description, type of anaesthesia, primary healing, time to complete healing, length of follow-up, early and late postoperative complications and recurrence.
Patients were managed by day case surgery unless their social situation stipulated otherwise, and all received perioperative antibiotics.All had one dose intra-operatively.After September 2017 patients also received a 5-day course in keeping with that observed in other centres.
All patients were followed up until fully healed and then reviewed 6 months later.Patients whose wounds had not healed primarily were reviewed in clinic every 6 weeks, with clinical assessment of the wound until it had completely healed.For the few patients who did not heal, further surgery was offered after 4 months.Patients were asked to report if they had recurrent symptoms in the future, even if they were treated elsewhere or moved home.
Primary wound healing was defined as complete healing of the wound with no evidence of wound breakdown.Recurrence was defined as patients who developed further pilonidal infections after initial closure of the wound, requiring further surgery.

S TATIS TIC AL ME THODS
Data were recorded using a Microsoft Access database.Comparisons between groups were performed using Pearson's χ 2 tests.Data were analysed using the program IBM® SPSS® Statistics for Windows, Version 28.0; Armonk, NY, IBM Corp. Non-parametric data were expressed as median, range and interquartile range.In total, 398 (60.7%) patients achieved initial primary healing with no wound breakdown.By 12 weeks, 88.5% (n = 581) of patients had achieved complete healing of their cleft closure wounds, and this had risen to 91.8% (n = 602) by 16 weeks (Figure 1).Only 19

Characteristics
(2.9%) patients had failure of their cleft closure surgery and required further surgery.
No statistical difference was observed in primary healing between men and women (61.4% vs. 56.6%,χ 2 p = 0.364).Twenty-three Just over one in four (n = 169) of the cohort had reported having at least one previous presentation of a pilonidal abscess in the past, treated with either antibiotics or incision and drainage.However, there was no difference in primary healing following cleft closure between those who had a previously treated abscess and those who did not (62.1% vs. 60.1%,χ 2 p = 0.652).45% of the cohort had previous attempted curative surgery for pilonidal disease.Primary healing occurred in 57.3% of patients who had at least one previous curative surgery (n = 168) compared to those who had none (63.4%, n = 230); no significant difference was observed between the two groups (χ 2 p = 0.116).
All patients received intra-operative antibiotics.In addition, 206 patients received postoperative antibiotics for 5 days due to a change in policy, whereas 450 patients received no routine postoperative antimicrobial therapy.No significant difference was found in rates of primary healing between those who received postoperative antibiotics (57.9%, n = 125) and those who did not (57.8%,n = 273), χ 2 p = 0.919.Overall healing occurred in 98.1% with antibiotics and 96.7% without antibiotics, and no significant difference was observed (χ 2 p = 0.317).Recurrence rates, however, were lower in the cohort who received antibiotics (2.4% vs. 6.7%, χ 2 p = 0.024).

DISCUSS ION
The cleft closure technique described by Bascom and Bascom [8] is often employed in more extensive pilonidal disease or disease recurrence where patients have had at least one previously attempted curative operation.From this case series we have observed that 97% of patients healed either by primary or secondary intention, and only 2.9% patients required further surgery for failure of the cleft closure wounds to heal.A similar series by Immerman reported a revision rate of 3.4% [10]; cohort studies evaluating the Limberg flap have reported 4.3% [11] of patients requiring revisional surgery.
Complete wound healing (primary or secondary) was reported in 97% of patients, and wounds healing by secondary intention required little intervention by way of dressings.No difference was observed in primary healing rates between men and women.Complex negative pressure wound therapy is not required.This has obvious benefits to the patient by reducing the frequency of visits for wound review and improved quality of life.
This series has a recurrence rate of 5.3%.A single centre experience of cleft closure series by Hatch et al. [12]  Limberg procedure compared with another technique, recurrence was quoted as 4.2% [14], 5.9% [15] and 6.3% [16].Previous cohorts of primary midline closure have exhibited long-term recurrence of up to 68% [4].
The cleft closure procedure has many advantages over other techniques for pilonidal disease.It is quick, usually taking 30-40 min.
In a cohort of 15 patients in whom it was measured accurately, it was a mean of 36 min (range 23-86 min).In the majority of cases, it can be performed as a day case procedure under sedation with local anaesthesia.It is a simplified asymmetrical closure technique; other flap techniques, such as the Limberg flap, are far more extensive procedures, usually requiring general or spinal anaesthesia [17], and take a great deal longer to perform even though they have similar results [5,18].A recent systematic review also demonstrated that patients have less postoperative pain, increased satisfaction and an earlier return to work having undergone local anaesthesia for curative pilonidal surgery [19].
The cleft lift operation results in an asymmetrical linear scar when fully healed, in comparison to some other flap techniques aiming to obliterate the cleft which result in a scar over the buttocks.
However, further work needs to be conducted in the form of a patient cosmetic satisfaction score to definitively conclude that the cleft lift leaves a more satisfactory scar for patients.
A course of postoperative antibiotics was given routinely from September 2017, due to a change in practice in keeping with that observed in other centres.It is of interest and not altogether surprising that healing was not improved by giving antibiotics, as these patients did not have acute infections at the time of their surgery.This outcome concurs with a previous systematic review evaluating the use of prophylactic antibiotics following pilonidal surgery, which found no improvement in primary surgical wound healing or reduction in recurrence rates [20].We have shown a reduction in the recurrence rate after postoperative antibiotics, however.
There are some limitations of this study.Follow-up of patients once they have healed is difficult, as they are reluctant to attend if they are well.We followed up patients for at least 6 months after full healing, which we considered to be the time when patients were most likely to agree to be followed up when they were asymptomatic.Symptomatic patients invariably kept their follow-up appointments.We conducted a patient driven follow-up programme, with patients being asked to report any recurrence.They most probably would have done so since they would be keen to have further treatment.There is no perfect method for follow-up and this low loss to follow-up rate (8.1%) should not affect the overall validity of our results.Nonetheless, this series would benefit from a more structured longer term follow-up to observe for further recurrence, as late recurrences can occur, although it is accepted that most recurrences occur within 2 years of surgery [21].

CON CLUS ION
We have demonstrated that the Bascom cleft closure has a very good overall healing rate (97%) with minimal morbidity.The operation is safe and easy to perform and could be easily adopted without special equipment or anaesthetic requirements.It is in our view preferable to wide local excision and primary midline closures, which are still employed in many centres despite the adverse literature about the technique.In the medium term it has comparable results to other flap techniques including the Karydakis and Limberg, with low levels of morbidity and good cosmesis [22].
It is the authors' recommendation that the cleft closure procedure described by Bascom can be taught as a possible alternative to primary midline closure and could be considered prior to complex flap operations, to improve patient outcomes, morbidity and recovery.
paper add to the literature?This is a large cohort series, demonstrating that patients with extensive or recurrent pilonidal disease can achieve healing without complex or full thickness flap surgery.The cleft closure technique can prove to be a preferable alternative, as it does not require extensive dissection or tissue mobilization (e.g., in the Limberg procedure).In all, 714 patients underwent cleft closure surgery, of whom 58 patients did not return to clinic and were therefore lost to follow-up.656 patients (86 at St Mark's) underwent cleft closure surgery (557 men) and had documented follow-up.Their median age was 25 years (range 12-61).The median duration of disease was 2 years (range 6 weeks to 32 years) and 293 (45%) patients had previously had at least one failed curative operation for pilonidal disease.Overall, 6.7% (n = 44) had disease extending beyond the navicular area of the natal cleft at the time of their cleft closure.The operation was performed under local anaesthesia with sedation whenever possible and was the case in 402 patients (61.3%).In the most recent 5 years this proportion rose to 73%.The median follow-up was 9 months (interquartile range 5-14 months).

patients ( 3 .
5%) had developed short-term complications postoperatively requiring a further procedure.Fourteen patients developed an abscess requiring an incision and drainage.Eight patients required marsupialization of an abscess, and one patient required evacuation of a haematoma.Recurrence occurred in 35 patients (5.3%) after a median of 12 months (mean 18.8; interquartile range 17 months).
Most operations were performed by a single surgeon and represent 20 years of incremental improvement in technique and growth of experience.Patient selection, operative technique and perioperative management are likely to have adjusted over time.A new surgeon undertaking the cleft closure may not be able to achieve the same results immediately, but the technique is simple to learn and we do not consider that it has a long learning curve.A lack of clear classification, especially in the early years of this study, and a change in the way outcomes are considered by clinicians and patients in recent years mean that important outcome measures such as patient satisfaction and quality of life were not studied.This will be remedied in the future by our own work on identifying core outcomes and developing a disease-specific quality of life score, both in progress.

F I G U R E 1
Kaplan−Meier curve demonstrating the length of time to heal following cleft lift surgery for the 97% of patients who healed.Mean length of time to complete healing was 6.3 weeks (95% CI: 5.5−7.2weeks), median 2 weeks (range 2−108 weeks).weeks Length of time to complete healing following Cleft Lift surgery Proportion of healed wounds | 1843 OJO et al.