Devices to stop organs from sticking together

SINGAPORE - For months after the births of her first two children through caesarean sections, Ms Geline Poh, 34, put up with an intense pulling pain in her abdomen.

The clinic assistant said it felt like something was pulling her organs apart, especially when she made sudden, large movements.

She dismissed it as residual pain from childbirth and never saw a doctor about it.

It was only during her third such operation to have her baby delivered through cuts in her uterus and abdomen that the problem became clear. Her doctor in Mount Elizabeth Medical Centre, Dr Suresh Nair, found that the previous operations had caused her bladder to adhere in some places to her uterus.

Such adhesions are bands of scar tissue that join two internal body surfaces that are not normally connected together.

They develop in up to nine out of every 10 people after any kind of pelvic or abdominal surgery, but can also be caused by endometriosis (a condition in which cells that usually line the uterus grow abnormally outside of it), appendicitis (infection of the appendix) or a pelvic infection.

Before he could deliver Ms Poh's baby, Dr Nair had to cut through the adhesions to separate the uterus from the bladder.

Though removal of the adhesions, called adhesiolysis, put her at greater risk of bladder perforation, bleeding and infections, it had to be done as it was the only way Dr Nair could reach the uterus and deliver the baby.

To reduce the risk of adhesions forming again, he used an implant known as an adhesion barrier to physically separate her internal tissue and organs while they healed.

Ms Poh, who now has four children aged between five months old and eight years old, said this made a big difference to her last two deliveries.

"The pain was much reduced and my recovery was faster in my subsequent deliveries," she said.

Greater demand for barriers

Greater demand for barriers

The pain and damage caused by adhesions has been lessened a great deal through the use of adhesion barriers by at least four hospitals and three private clinics in their bid to prevent adhesions forming after surgery.

Adhesion barriers come in the form of a mesh, film or gel, which physically block adhesions from forming between tissue and organs. The barriers are later broken down and absorbed or excreted by the body.

Patients undergoing abdominal surgery are at greatest risk, though some have more of a genetic predisposition than others towards scar formation.

The use of adhesion barriers also tends to be greatest in gynaecological clinics, because women tend to undergo abdominal surgery more frequently.

Dr Tan Yew Ghee, a specialist in obstetrics and gynaecology and a consultant at Raffles Women's Centre at Raffles Hospital, said he uses adhesion barriers in six out of 10 women who undergo gynaecological surgery now, compared with fewer than five in 10 a decade ago.

He tends to use them in surgery in which there is more bleeding and tissue trauma, such as in myomectomy (fibroid removal) and surgery for endometriosis and chronic pelvic inflammatory disease.

At KK Women's and Children's Hospital, Associate Professor Bernard Chern, head and senior consultant at the department of obstetrics and gynaecology, said he uses them in the majority of his patients undergoing major gynaecologic surgery.

He said the trend is fuelled by an increasing awareness by doctors and patients about the benefits of adhesion barriers, as well as more published data supporting its use.

For instance, a study has shown that an adhesion barrier reduces the risk of small bowel obstruction by 47 per cent in patients who have had colorectal surgery.

However, despite studies which show, for instance, that 3 per cent of readmissions in the 10 years after gynaecological surgery are due to adhesions, barriers are not yet routinely used because they can add hundreds of dollars to a patient's bill, though subsidies are available for some patients.

The trouble with adhesions

The trouble with adhesions

Adhesions, like all scars, form as the body heals, said Dr Stephen Chew, a senior consultant at the department of obstetrics and gynaecology at National University Hospital.

Any trauma or irritation to the peritoneum, the lining of the abdomen, induces a repair response which causes a protein called fibrin in the blood to build up in and around tissue and organs.

Fibrin is eventually broken down by the body. But when incompletely broken down, it will cause tissue and organs to stick together and form adhesions.

Dr Wendy Teo, a consultant obstetrician and gynaecologist at Thomson Women's Clinic in AMK Hub, said in diseases such as endometriosis, pelvic inflammatory disease and appendicitis, tissue became inflamed, which predisposes a person to adhesions.

Most people have mild adhesions which do not result in any symptoms. Fewer than 10 per cent will require surgery too. Others, like Ms Poh, can suffer from chronic pelvic pain because the nerves are being pulled.

Dr Teo said if the adhesion is located near the vagina, it may even cause pain during sex.

An adhesion itself contains nerve fibres and is sensitive to touch, hence a patient may feel pain when the bowels are moving during digestion. The pain may become worse when the adhesion thickens over time.

It can also lead to abdominal colic, a disorder in the flow of intestinal contents along the intestinal tract.

If it becomes severe enough to cause the bowels to be blocked, the patient will require immediate medical attention.

Adhesions can also affect a woman's fertility, warned Dr Nair. They can twist and block fallopian tubes, preventing them from picking up eggs from the ovaries.

If adhesions narrow the neck of the uterus and cause liquid and blood to build up inside, they will prevent pregnancy. If adhesions occur inside the uterus, they can prevent implantation of the embryo.

Adhesions can also obscure the ovaries and make it difficult for the embryologist to retrieve eggs during in-vitro fertilisation (IVF), Dr Nair added.

In IVF, egg cells are fertilised by sperm outside the body and the resulting embryos are placed in the womb to produce "test-tube babies".

Adhesions do not show up in ultrasound scans and can be confirmed only via a camera inserted into the abdomen. Often, they are picked up incidentally during surgery.

Even with the use of adhesion barriers, Associate Professor Tan Hak Koon, head and senior consultant at the department of obstetrics and gynaecology at Singapore General Hospital, said nothing beats good surgical techniques by the doctor to prevent adhesions from forming.

These involve careful tissue handling, keeping tissue moist and stemming bleeding during surgery, among others.

He added that laparoscopic surgery, which involves operating with small tools through a few, small abdominal incisions instead of a large one in open surgery, also lowers the chance of adhesions forming, though the risk cannot be completely eliminated.

Types of barriers

1. HYACORP ENDO GEL

What it is: This is a sterile, transparent and viscous gel obtained by condensation of hyaluronic acid, one of the main components of human connective tissue, epithelial tissue and mesothelial tissue.

Epithelial tissue covers the whole surface of the body, while the mesothelium is a membrane that covers and protects most of the internal organs of the body.

How it works: The gel is applied to the operative site through a syringe.

It stays effective as a barrier for seven days and is then reabsorbed by the body.

Its Germany-based manufacturer, BioScience, said this is a long enough time to avoid the formation of adhesions.

The gel received approval from the Health Sciences Authority (HSA) on Nov 9 last year and is currently being used by six hospitals and 30 private clinics.

How much it costs: In private clinics, it can cost $400 to $500 per injection. At the National University Hospital (NUH), it costs $272.50 per injection for a private patient.

What studies show: Dr Liselotte Mettler at the University Hospital Schleswig-Holstein in Germany studied 35 patients who underwent a second look through a scope two to three months after an initial procedure.

The study, published in January in Minimally Invasive Therapy & Allied Technologies, found 31 patients either had no adhesions, or adhesions that were separated with minimal effort.

Only four patients had adhesions that required effort to separate.

2. SEPRAFILM

What it is: This is a membrane composed of chemically modified sodium hyaluronate and carboxymethylcellulose.

Sodium hyaluronate is naturally found in connective tissue, the synovial fluid in the joints and the umbilical cord.

Carboxymethylcellulose is commonly used in food, cosmetics and pharmaceuticals and has no known toxic effects.

Seprafim is manufactured by Genzyme Corp, which was acquired by France-based Sanofi in 2011.

How it works: Seprafilm changes from a film to a gel between 24 and 48 hours after application. It is slowly absorbed within a week and excreted by the body within four weeks.

It received approval from the United States Food and Drug Administration (FDA) in 1996 and from HSA on June 18, 2011.

How much it costs: A Sanofi spokesman said a small sheet, measuring 7.6 by 12.7cm, costs $300 and a sheet twice that size costs $400. At NUH, a small piece of Seprafilm costs $230, while a large one costs $355 for a private patient.

What studies show: The April 2012 edition of the scientific journal, Gynecological Surgery, reviewed the clinical data on Seprafilm.

In one study of 183 patients who underwent surgery to remove all or part of the colon, 51 per cent of patients treated with Seprafilm had no adhesions, compared with 6 per cent of those in the control group.

Results of another trial showed that Seprafilm treatment reduced the relative risk of a first adhesive small bowel obstruction by 47 per cent in colorectal patients.

3. INTERCEED

What it is: This is a barrier consisting of oxidised regenerated cellulose. It comes in two sizes: 7.6 by 10.2cm, and 12.7 by 15.2cm.

Interceed is manufactured by Ethicon, part of the US-based pharmaceutical company Johnson & Johnson, and received FDA approval in 1993 and HSA approval in 2006.

How it works: The mesh-like product is designed to be placed over or between injured surfaces, which have to be free of blood before it is applied.

Otherwise, the product will be rendered ineffective as an adhesion barrier.

It is absorbed by the body within four weeks of application.

How much it costs: A spokesman for Johnson & Johnson said Interceed costs between $160 and $300, depending on its size. At NUH, a piece of Interceed costs $280 for a private patient.

What studies show: The 2009 issue of Reviews In Obstetrics & Gynecology reported that a meta-analysis of 10 randomised, controlled studies, involving more than 500 patients, showed a 24 per cent reduction in adhesion formation on surgical sites treated with Interceed, compared with untreated sites.

Sources: www.hyacorp-endogel.com, www.seprafilm.com, www.ethicon.com

joanchew@sph.com.sg


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