Focus on therapeutic endoscopy

Interview with Dr. V.G. Mohan Prasad, gastroenterologist.

"The therapeutic use of endoscopy, a revolution in treatment and cure, is yet to gain acceptance in India though it has tremendous potential," says Coimb- atore-based Dr. V.G. Mohan Prasad, consultant gastroenterologist, hepatologist and endoscopist, who recently released a CD-Rom on therapeutic endoscopy. The CD-Rom, which details the procedures of various therapeutic uses of endoscopy, is a pioneering effort in the medical world.

Dr. Mohan Prasad has undergone training in the United States (Granada Hills Community Hospital, Los Angeles), Japan (Chiba University, Kyoto) and the Netherlands (Academic Medical Centre, Amsterdam), and is a member of the International Association for the Study of Liver and the American Gastroenterologic Association. He has published several research papers on liver diseases, dyspepsia, cancer and therapeutic endoscopy procedures. In Chennai, Dr. Mohan Prasad spoke to Asha Krishnakumar of the various types of jaundice as also ulcers, their causes and treatment methods, of pharmacological developments made in the treatment of liver diseases, and of the uses of therapeutic endoscopy. Excerpts from the interview:

What are the common liver disorders in India and how do they manifest themselves?

Among the most common liver disorders are hepatitis, alcoholic liver diseases and liver carcinoma. Jaundice is an important manifestation of most liver disorders and is of three types: haemolytic, which occurs rarely and has a genetic predisposition; obstructive jaundice; and hepatitis. In haemolytic jaundice the red blood corpuscles (RBCs) swell and start breaking down into sclerocytes. This releases haemoglobin, which gets converted by the liver into a yellow pigment called bilirubin. The excess bilirubin enters the bloodstream giving a yellow colour to the sclera (the white fibrous outer layer of the eyeball) and urine. People with haemolytic jaundice have a higher chance of developing gall-bladder stones.

The 'obstructive' type occurs when there is an obstruction in the flow of bile. The bile secreted in the liver is taken to the gall bladder through bile ducts and stored there. The gall bladder releases it into the intestine through the common bile duct, to aid in digestion. A block in this pathway - from the liver down to the duodenum - can cause obstructive jaundice. Roundworm or stones in the gall bladder can migrate into the bile duct, run amok in the intestine and cause problems. Obstruction can also be caused by cancer of the bile duct, duodenum or pancreas, thus leading to obstructive jaundice.

Hepatitis ('hepar' means liver and 'ites', inflammation) or liver inflammation is the most common type. The immune system attacks liver cells, which then break down releasing bilirubin. This mixes in the bladder and the patient develops yellowness of the sclera.

What are the common causes of hepatitis?

The most common cause is virus attack. Some 80 virus types can affect the liver and cause jaundice. But many are rare and some specific to certain regions such as Africa, Italy (Europe) and so on. A group of viruses called Hepatotropic viruses is very fond of the liver. Introduced anywhere in the body they find their way to the liver, multiply and live on for years. Six such viruses - A, B, C, D, E and G - are well-defined. While A and E are water-borne, B, C, D and G are parenterally transmitted just like the Human Immunodeficiency Virus (HIV), which causes AIDS, through improperly sterilised needles, shared razors, unprotected sex, homosexual activity and blood and blood products. But Hepatitis B, unlike AIDS, can be prevented and cured. Now effective vaccines are also available.

What is the incidence of hepatitis in India?

We have a national carriage of 4 per cent, or 4.2 million. All carriers are not diseased people. Over 90 per cent of those afflicted with Hepatitis B, when treated, get cured completely. Only 5-10 per cent of the acute cases become chronic carriers. That is, they carry the virus after six months and also develop complications. It is this group that needs attention.

Has the development of drugs kept pace with the advances made in understanding the disease?

For long, the only drug available for treating chronic Hepatitis B was Interferon, a biological response modifier. It is still the sheet anchor of therapy all over the world. But its cure rate is only 25 per cent. In 1992, I combined Riboviron with Interferon to treat chronic Hepatitis B patients. Riboviron, introduced in India in 1990, is a broad-spectrum antiviral and is effective against viruses in the ribonucleic acid (RNA) and the deoxyribonucleic acid (DNA).

This created ripples in the treatment of Hepatitis B. Even those who initially criticised me endorsed the treatment later. Now everyone agrees that there is the need for cocktail therapy.

I am convinced that if a chronic case of Hepatitis B is recognised early - before the liver gets cirrhotic, shrinks and the patient develops portal hypertension and varices - the progress of the disease can be halted.

How serious are the diseases caused by other Hepatitis viruses and can they be cured?

The D, or the Delta, virus is incomplete in the sense that it cannot survive in the liver without the surface coat of the B virus. So, if we take care of the B virus, D would also be taken care of. In India, the virus is very rare, existing only in some pockets.

The C virus is more common. It has a 1-1.7 per cent spread in the country. There is as yet no vaccine for the C virus as it mutates rapidly and a single vaccine cannot take care of it. Cocktail therapy can probably help.

Whether or not G virus is harmful is still being debated. But what is clear is that if C and G co-exist, the damage to the liver is very high. Not many commercial tests have been done in this field.

In India, A and E viruses (both water-borne) are the most common causes of jaundice. Fifty per cent of acute jaundice in adults is caused by the E virus. In children, 80 per cent of the cases are because of the A virus. If both attack together, the liver could be severely damaged and it could even lead to death. The A virus is dangerous for the aged and for infants, and the E virus for pregnant mothers. A third of the pregnant mothers affected by jaundice caused by the E virus die, and 50 per cent of the foetuses are also lost.

But Hepatitis A and E are easily preventable. If drinking water is boiled, chlorinated or purified before use, they can be prevented. Ultra-violet filtration or deradiation, and ozone treatment can also destroy the A and E viruses. It is important to use protected water not only for drinking but also in the preparation of chutneys, salads, juices and buttermilk.

The incubation period of these viruses is usually four to six weeks. There is a vaccine for the A virus now. But as it is genetically engineered, it is very expensive - Rs.1,000 for a dose (three doses have to be administered).

Why is the vaccine for the Hepatitis A virus expensive?

The primary reason is that the A virus is not widely prevalent in the West, except in a few countries such as Italy. So, not much money has been invested on research into it. If India manufactures this vaccine, costs can come down dramatically. This is amply demonstrated by the production of the Hepatitis B vaccine by Shanta Biotech and some other companies. The genetically engineered recombinant Hepatitis B vaccine is now available for Rs.40-50 a dose for children.

There is fear in the U.S. and Europe that the administration of the Hepatitis B vaccine causes autism and multiple sclerosis in children. Is this fear real?

The International Viral Hepatitis Research Board has found no evidence to show that there is a relationship between the Hepatitis B vaccine and autism or multiple sclerosis in children. It has categorically stated that at this point of time there is no scientific basis to believe that there is a relationship between the two.

What are your other areas of interest?

I am also working on the causes and treatment of ulcers. For long, it was believed that erratic timing of food intake or spicy/oily food caused peptic ulcers. Thirteen years ago, B. Marshall and Warren from Australia found a spiral bacteria, Helicobacter pylori, to be the cause of 90 to 95 per cent of duodenal ulcers. In the developing world, where its incidence is high, it spreads mainly through polluted water. The use of the Berkefield Candle Filter can remove this bacteria from drinking water. Ozonisation and ultra-violet deradiation can also kill the bacteria. If the bacteria get into the stomach, they stay there for as long as 30 years.

How can H. pylori be diagnosed?

It can be done by using endoscopy and performing a biopsy of the stomach. Two methods are used for this. One is the "rapid urea test". Unfortunately, many endoscopists do not do this.

Other specialised histopathology tests can also identify H. pylori by scanning the stomach tissues. Although there is no vaccine for H. pylori, 95 per cent of the bacteria in an infected person can be eradicated by combining two antibiotics for a week. In six weeks' time, the patient would be completely cured. Thus, endoscopy has various uses.

Apart from diagnostics, what are the other uses of endoscopy?

Endoscopy is commonly used for diagnostics. But it can be used for therapeutic procedures as well. There are over 4,000 endoscopists in India, but only some 50 use it for therapeutic procedures.

What are the therapeutic procedures that can be done using endoscopy?

Several out-patient procedures can be done using an endoscope. For instance, cancer in the foodpipe produces strictures needing a dilatation - balloon or the rigid type. Endoscopy can be used for this. Stents can be put in the foodpipe using endoscopy. Early stages of cancer in the oesophagus can be removed using endoscopy. The method employed is called Endo Mucosal Resection (EMR). It is 100 per cent cure if treated early. Using endoscopy lasers can melt cancers in the foodpipe. Reflux diseases can be treated by chromoscopy using colouring agents such as Lugol's Iodine. Several surgical procedures in the stomach, bile duct and colon can be done using endoscopy. All these and many more can be done using endoscopy without anaesthesia. The only problem is that not many doctors do it as it is not taught in classrooms. Very soon we will have the endoscopy suturing device. This will be a revolution in the treatment and cure of several disorders.

How expensive is therapeutic endoscopy?

It is expensive now. But if more people use it and if the required equipment is produced indigenously, costs will come down. Awareness and education on precautions and treatment methods is important to reduce diseases relating to gastroenterology, including ulcers. The public healthcare system should be strengthened in order to generate this awareness.