Biosil Limited

Introduction

Faecal Incontinence affects men and women of all age groups and with a reported incidence rate averaging 2% of the adult population of the recognised western world progressing upto 7% of healthy independent adults over the age of 65 years.

Often described as a common distressing condition, faecal incontinence can have a devastating impact upon an individual's quality of life. Biosil's Prosthetic Anal Sphincter (PAS) has been developed over a period of 10 years and is based on studies of the normal function of the anal sphincter and pelvic floor, to manage the condition of faecal incontinence. The performance of the PAS device was assessed in a mixed-sex human clinical investigation study which concluded that the device was successful in achieving/restoring continence without causing damage to the bowel.

The PAS device is an inflatable, fluid filled, silicone device which is designed for the management of severe faecal incontinence in adult men and women. It is implanted entirely within the body. The device functions by gently flattening and angulating the bowel, thereby simulating the normal function of the anal sphincter muscles as illustrated below.

The PAS device is composed of 3 main parts described below. Each of the parts are joined together by tubing that allows the flow of saline (salt water) solution between each part:

The Sphincter Cuff is implanted around the anal canal where the rectum joins the anus. It is composed of a soft cushioning pillow filled with cohesive silicone gel which is attached by fixation straps to an inflatable expander. When the inflatable expander is filled with saline, it gently compresses the bowel whilst the soft cushioning pillow protects the area of the bowel which is being compressed, and continence is maintained.

The Reservoir is implanted within the pelvis and is the storage/pressure regulating balloon for the saline solution that provides the pressure to drive the system and open and close the Sphincter Cuff. The saline flows to and from the Reservoir to the Sphincter Cuff along a length of connecting tubing via the Pump.

The Pump is implanted under the skin in the lower half of the abdomen and controls the movement of saline solution to and from the Reservoir and Sphincter Cuff. Its contours can be felt through the skin enabling easy operation by locating and pressing the pump bulb and pump dome button.

When you feel the need to defecate, the PAS Sphincter Cuff can be deflated EITHER by:

(a) Feeling and locating the Pump through the skin and grasping both sides of the pump bulb with the forefinger and thumb and squeezing the two sides together 4-8 times as illustrated below:

OR (b) Feeling and locating the Pump through the skin and pressing down onto the top side of the pump bulb 4-8 times against the abdominal wall/pelvis to depress the top side of the pump bulb as illustrated below:

When defecation is complete the PAS Sphincter Cuff is inflated by depressing the Control Pump's dome button against the abdominal wall/pelvis as illustrated below. It should be noted that the Sphincter Cuff inflatable expander will inflate steadily, taking a few minutes before it is fully closed and continence has been restored.

The operation to implant the PAS device takes approximately 2 hours. An incision is made in the lower half of the abdominal wall allowing the surgeon to place the artificial sphincter around the rectum, close to the join with the anus.

After implantation, a period of approximately 2 weeks is typically required to be spent in hospital although this period will vary from patient to patient.

You should expect to be away from work for approximately 6 weeks after implantation although this timeframe will again differ from patient to patient.

It is strongly recommended that vigorous exercise and heavy lifting should be avoided for at least 3 months after implantation.

It will take approximately 6-12 weeks for the Control Pump site to feel comfortable to the touch and before the PAS device can be activated. Admission to hospital will be required for a few days at the time of activation to ensure that the device is working properly and that you fully understand how to use the device.

As with any type of invasive surgery there are possible complications associated with the operative procedure such as:

As with any invasive surgical procedure infection may occur after the operation. If infection occurs, it is most often shortly after the operation and less common at a later stage, i.e. after healing. Signs of infection include redness of the skin, tenderness, high temperature and pain or swelling around the infected site.

In some cases, if the infection does not respond to antibiotic therapy it may be necessary to remove the PAS device. Subsequent re-implantation may, or may not, be possible.

Haematoma and serous fluid accumulation (seroma) are complications associated with any type of invasive surgery. Haematoma is a collection of blood contained within the body and this can cause swelling, pain and bruising and occurs in the area of the operation site. Small haematomas can be reabsorbed by the body but larger aematomas may have to be drained away as they can delay wound healing and may contribute to infection.

Serous fluid is produced by the body at the site of the operation in response to the body tissues being cut and may collect in the tissues around the device. This fluid is normally reabsorbed by the body but if produced in sufficient quantity may require drainage.

It is possible that you may be allergic to medication administered before, during or after surgery.

Any known allergies to medication, especially antibiotics, should be discussed with your surgeon prior to surgery.

As with any other major abdominal operation, patients may experience pain and discomfort after surgery.

However, persistent or excessive post-operative pain may indicate a complication and should be reported to your surgeon immediately.

As with any mechanical device, the PAS device is subject to wear and tear over time and may include component disconnection, Control Pump failure etc.

If any problems with the performance and effectiveness of the PAS device are experienced, you are advised to contact your surgeon immediately.

Constipation/faecal impaction may be experienced after implantation of the PAS device. This is a common problem which may be treated by using gentle laxatives or if necessary, an enema. Advice on the management of this problem will be given to you by your surgeon or medical staff after the operation.

The design of the PAS device is intended to avoid the risk of tissue ischaemia - damage to the blood flow. Although such a scenario did not occur during the clinical investigation of the PAS device, this is a theoretical and therefore potential complication of any implanted device which encircles the bowel.

If you experience symptoms such as severe abdominal pain, fever, or the passing of blood you should contact your surgeon without delay.

The PAS Pump could be subject to trauma/impact damage due to contact sports such as rugby, football, karate, judo etc. You should be aware of this possibility and take due care. However, it should not inhibit you from participating in sporting activities in general.

It is possible that a radio-opaque solution may be used as an alternative to the sterile saline solution to fill the device, enabling the device to be viewed by X-ray. However, allergies to this solution have been reported and it is therefore important you should discuss any known allergies with your surgeon prior to surgery.

Some patients may also complain of occasional minor staining. This is usually due to failure to fully evacuate the rectum prior to closing the PAS device. With practise this can be avoided.

Most patients find the Pump site cosmetically acceptable, but in thin patients the Pump may be visible as a small protrusion under the skin.

In the event of infection or failure of the component parts of the PAS device, replacement of individual components or the entire system may be required. However, due to post-operative scarring, infection or other factors, revision surgery may not be possible and instead the entire PAS device may need to be removed.

Listed below are a number of frequently asked questions that patients have asked when discussing the PAS device ...

How do I know that I have fully opened the Sphincter Cuff?
When the Cuff has been fully deflated/opened, the bulb in the Pump will be depressed and feel flat to the touch.
Is there a specific squeezing technique that I should use?
Prior to leaving hospital you will be given specific instructions how to operate the Pump. Experience has shown that once at home, patients frequently develop a technique of their own, that is personally convenient and successful for them. However, it is important to note that whichever technique you employ, the Sphincter Cuff must be allowed to fully empty.
What happens if I develop constipation / faecal impaction?
Experience has shown that the PAS device is very successful in achieving continence. Constipation is the most common complaint and this can be treated by using gentle laxatives or an enema. After implantation you will receive full instructions on how to deal with this occurrence. If the problem persists you should contact your surgeon.
How good should I expect my continence to be after implantation of the PAS device?
Experience to date has shown that the majority of patients are continent to formed stool. It should be noted that the PAS device is not designed to control liquid stool/diarrhoea. Therefore, if you develop diarrhoea the PAS device will not maintain continence and it is recommended that the condition should be medically treated. Some patients may also complain of occasional minor staining. This is usually due to failure to fully evacuate the rectum prior to fully closing the PAS device and is minimised with experience of using the PAS device correctly.
Can I expect to carry on with normal exercise and sexual activities post operatively?
Following the normal post-operative recovery period, it is expected that you will be able to resume the majority of activities - e.g. walking, jogging, cycling, tennis etc. You should however, be careful not to damage or create trauma to the Pump site by contact sports such as rugby, football, karate judo etc. There have been no reported restrictions concerning sexual activity, although it should be noted that anal sex is not recommended.
How long might I expect the PAS device to last - does it wear out?
As with any performing biomedical device that is subject to wear and tear, it is not possible to accurately predict the life expectancy of the PAS device as several factors influence how long a device will function in any particular individual. Design verification bench-test studies have showed that the PAS device should successfully work for a minimum of 11,000 cycles. This equates to a minimum product life expectancy of 10 years (3 uses per day) up-to 30 years (1 use per day). The saline solution within the PAS device system may require topping-up after approximately 2 years of use. The need for top-up is indicated by a deterioration in the effectiveness of the PAS's performance. Top up is effected by a painless injection into the fill port site in the control Pump.
What problems could I experience after implantation of the PAS device?
As with any invasive surgical procedure, the PAS device site might become infected. If infection occurs it is usually soon after surgery and is unusual as a late event. Signs of infection include redness of the skin, tenderness, high temperature and pain or swelling around the infected site. In severe cases, infection may lead to the removal of the PAS device. In addition to infection, other unexpected problems may develop and it is recommended that you immediately contact your surgeon if you have any doubts.
What material is the PAS device made from?
The PAS device is comprised of a number of materials including silicone elastomers and silicone gel. It should be noted that silicone has been widely used in many other medical applications for over 40 years e.g. artificial heart valves, pacemakers, artificial joints, intraocular eye lenses, hypodermic syringes as well as in food, cosmetics and a wide array of consumer products.

In order to address recent public concerns regarding the use of silicones in implants, several studies and comprehensive independent reviews of currently available scientific data have concluded that...
* there is no epidemiological evidence for any link between silicone containing implants and any established connective tissue disease or increased risk of cancer.
* the overall biological response to silicone is consistent with a normal response to any foreign material in the body.