Surgery for Pilonidal Sinus/Abscess

What is a pilonidal sinus?

A pilonidal sinus is a small hole or tunnel in the skin. It usually appears at the top of the buttocks in the region known as the cleft.

Pilonidal sinuses can form in people that naturally develop dents in this area of the skin, often around a hair follicle which is the hole in the skin that hair grows out of.

It is not known fully why pilonidal sinuses develop, however there is evidence to suggest they can be caused by ingrown hair or when the dents in the skin become blocked with clumps of hair or skin. Other possible causes include excessive friction to the skin. Once a sinus is developed they can become infected.

Pilonidal is more common in young adults, particularly men as they have more body hair than women.

Other risk factors include:

• People who spend lots of time sitting down
• Family history of pilonidal sinus
• Frequent irritation of the skin
• Obesity
• Previous history of pilonidal sinus
• A previous injury to the skin

Symptoms of pilonidal sinus

Symptoms of an infected pilonidal sinus can develop quickly over just a few days and these can include.

• Pain
• Swelling
• Redness of the skin
• Formation of an abscess full of pus

Treatment options

If there are no symptoms of infection, individuals are advised to self-manage the condition by shaving the affected area and keeping it clean and dry.

Acute infection

If you have developed severe symptoms of an infected pilonidal sinus (pilonidal abscess) you may require surgery to drain the infection (pus) away. This is usually undertaken whilst you are asleep (general anaesthetic) and is done as a day case procedure. You will be left with an open wound that is packed with special dressings to help the healing process. This will need to be changed frequently with help from your community nurses at your GP surgery. The ward staff will advise you how to arrange this.

Chronic infections

Unfortunately an infection of a pilonidal sinus can keep coming back. The most effective treatment for this is further elective (arranged) surgery.

Wide excision

This involves cutting out the pilonidal sinus and also a margin of the skin surrounding where the sinus is positioned. The wound is left open and is left to heal by itself. This process can take several weeks to months and requires regular dressing changes by the community nurses. However its advantage is that new healthy tissue and skin is formed and lowers the chance of infection coming back.

Excision and primary closure

This involves removing the area of skin where the sinus is positioned and then stitching the skin back together. The advantage of this method is that the wound heals quickly. However the risk of infection coming back is higher than with other methods.

What are the risks of surgery?

Complications are uncommon and occur in less than 7% of patients. These include:

• Pain
• Scarring/numbness
• Bleeding
• Infection
• Risks of anaesthetic (heart and breathing problems, risk to life)
• Injury to surrounding structures
• Failure to remove the sinus
• Slow healing
• Recurrence

Are there any alternatives to surgery?

There are no other known alternatives than surgical treatment. Pilonidal sinuses cannot be removed or cured using antibiotics.

What happens after your surgery?

Your blood pressure, pulse and wounds will be monitored closely over the first few hours. You should be able to start drinking shortly after the procedure, and can start eating as soon as you are hungry. You will be able to get out of bed as soon as you feel well enough.

You may experience some pain from your wounds. If you do, you will be given painkillers. Before your discharge you will be given a supply of painkillers, dressings and post-operative instructions. Your GP will be notified of your discharge. A hospital follow-up appointment may be arranged for you.

How long will it take to recover from the anaesthetic?

Whilst most of the effects of anaesthesia wear off in a few hours, it is common to have poor concentration and memory for the first day or so. It is important therefore that you do not make important decisions, sign legal documents or operate machinery or equipment for at least 24 hours after the anaesthetic. Muscle aches or headaches may also be experienced over the first few days.

Will I feel sick after surgery?

Nausea and vomiting are not unusual after surgery, we endeavour to keep this at a minimum. Medication can be used during the anaesthetic and afterwards to control this. Take extra rest and try to drink something regularly. If you can tolerate food, eat small frequent snacks.

Looking after your wound

It is normal to have wound pain after surgery. To minimise discomfort, you should take the painkillers that you have been given, regularly (ensuring that you do not exceed the dose prescribed). After your discharge, if you have any queries or problems with your painkillers you can seek advice from your local GP or chemist.

A referral will be made to the local community nursing team as your wound will need to be cleaned and dressed frequently until it has healed. This is usually undertaken in your home or GP practice.

It is important to keep the area clean and dry. Wash regularly, wear loose fitting underwear and avoid using creams or ointments unless prescribed by your doctor.

When should I seek help?

• If you have a thick, unpleasant smelling pus coming from the wound.
• Red, swollen skin
• If you develop fever or vomiting symptoms for several days.
• Persistent pain not relieved with your prescribed painkillers.

Who can I contact if I am concerned after discharge?

If you have any concerns or feel unwell after discharge, please contact the Surgical Assessment Unit (SAU) on 01274 382505 to speak with a member of the medical team who will offer advice. The SAU can be contacted 24 hours a day, 7 days a week.