Intussuscepção e vólvulo em crianças

What is intussusception?

Intussusception is a condition where one part of the gut (small intestine/bowel) becomes sucked into the next part of the gut. It is sometimes described as the intestine being 'telescoped' - imagine a telescope, where one part slides into the part next to it.

The effect of this is that there is no longer an open tube, and the intestine becomes blocked. The blood flow to that part of the intestine is also blocked off. This needs urgent treatment.

Intussusception is more common in children than in adults. In children, it is the most common cause of a bowel blockage (obstruction) in children under the age of 3 years. It most often occurs in babies under the age of 1 year and affects more boys than girls.

Common symptoms of intussusception include:

• Tummy pain (this tends to come in spasms which last a few minutes and occur every 10-20 minutes).

• Cansaço.

• Irritabilidade.

• Becoming floppy.

• Estar vomitando (vômito). The vomit may be green in colour, and may be due to dehydration.

• Blood and/or a sticky fluid (mucus) in their poo. This is known as 'redcurrant jelly' stool as the mix of blood and mucus is said to resemble redcurrants.

• Alta temperatura (febre).

Signs of dehydration

Signs of dehydration include being tired and floppy, having fewer wet nappies than usual and the soft spot on the top of the head (fontanelle) being more sunken. The child may develop a high temperature (fever).

Usually there is no obvious reason for intussusception to occur, and the cause is unknown. It is thought that in some cases it may happen following an infection with a virus. One such virus is the rotavírus.

There is a tiny chance that the rotavirus vaccination may make intussusception more likely, but it seems to be in the region of 2 extra cases of intussusception in every 100,000 children vaccinated. To put this into context, without vaccination around 120 children per 100,000 will suffer from intussusception each year. The first dose of rotavirus vaccination should be given below the age of 15 weeks, and the second dose no sooner than four weeks after the first - these precautions reduce the risk of intussusception as an adverse reaction. It should not be given to infants with a history of intussusception or an abnormality (malformation) of the bowel which makes intussusception more likely.

Balancing that out, the vaccination prevents many cases of rotavirus infection and saves many lives. If rotavirus can cause intussusception, the vaccine may even prevent more cases than it causes, but this has not been shown in studies. Research is ongoing in this area.

Occasionally there is another abnormality already existing in the guts which makes intussusception more likely. Possible causes include pockets (diverticulae) or lumps (polyps or tumours) in the intestines, and conditions such as cystic fibrosis ou Henoch-Schönlein purpura (HSP).

The doctor will examine your baby or child and feel their tummy. If intussusception is suspected, you will be sent into hospital for further tests. Various tests might be done, but the most common would be blood tests, uma ultrassonografia and/or a tummy X-ray.

It is important that intussusception be treated urgently before any permanent damage is done to the intestines and before the child becomes too unwell.

Treatments for intussusception include:

IV drip

The child will probably need to have fluids given by a drip (intravenous or IV fluids) and a tube through their nose into their stomach (a nasogastric or NG tube) to suck out the contents of the gut while it is blocked.

Enema

The usual first treatment is a procedure called an air enema. Air is pumped through a tube placed into the child's bottom, and this pushes the bowel open again. Ultrasound or X-ray views at the same time show the progress so that the doctors can see if it is working.

Cirurgia

If this procedure does not work then an operation may be needed, involving a general anaesthetic and a small 'keyhole' cut into the tummy (a laparoscopy). This may also be needed if the condition has become very severe - for example, if the bowel has burst (perforated). If this is the case, then a larger cut to open up the tummy may be needed (a laparotomy) and a part of the bowel may need to be removed.

Outro tratamento

Studies are ongoing to establish the best way to treat intussusception. These include trying treatment with a steroid medicine called dexametasona which may help lessen the chance of the condition recurring, although it is uncertain how effective this is.

If intussusception is diagnosed early, the outlook (prognosis) is very good. The vast majority of children make a full recovery with no complications. The outlook is less good if the child is not treated until the condition has become severe and longer-lasting bowel damage has occurred.

After treatment intussusception can come back (recur) - this happens in around 5 children for every 100 who are treated, reducing to 3 if the condition is treated surgically.

Occasionally, particularly if it is not picked up early, complications can occur. Possible complications include:

• The bowel bursts (perforation), spilling bowel contents into the tummy and causing severe inflammation (peritonitis).

• A part of the bowel dies due to having its blood supply cut off. This part of the bowel would need to be removed in an operation.

• Bleeding into the bowel.

• Infection leading on to sepse.

Fortunately most cases of intussusception are picked up early enough for treatment to prevent any of these problems.

Volvulus also causes a bowel blockage (obstruction), but it is different to intussusception in that the bowel twists around itself rather than being caught up inside itself. A loop of bowel gets wound around another part of bowel along with the tissue that surrounds it (mesentery).

The twisting causes a blockage so that the contents of the bowel can no longer pass through. It can also cut off the blood supply to that part of the bowel, causing that section to die if not treated quickly.

There are several different types of volvulus with different causes. It depends which part of the intestine has been twisted.

Causes of volvulus in children

In children the most common type of volvulus occurs in the middle part of the guts, and is usually due to the child having been born with a slightly abnormally placed gut in the first place (malrotation).

Causes of volvulus in adults

In adults, the most common type of volvulus is nearer the end of the gut, in the sigmoid colon - a sigmoid volvulus. This type is very uncommon in children. Volvulus can occur in almost any part of the guts and is usually due to an underlying problem or abnormality in that part of the gut.

Malrotation occurs quite commonly (about 1 in 500 births) but in most cases does not lead to volvulus. The way a part of the gut has developed leaves it in a position which is more susceptible to being twisted and wrapped around itself. This type of volvulus tends to occur in very young babies, most often within the first month of life.

Symptoms vary slightly depending on where the gut is twisted, but in general are those of a blockage (obstruction). Possible symptoms include:

• Tummy pain (causing a baby to cry and draw his or her knees up).

• Vomiting a green liquid.

• Not passing any poo (stool) or passing very little.

• Becoming unwell rapidly, being floppy.

• A more gradual and less severe illness with recurring tummy pains, constipação, blood in the poo and poor feeding.

If volvulus is suspected, your child would be sent to hospital. Raios-X of the tummy are usually helpful in making the diagnosis. Often a substance which shows up on X-ray, called contrast medium, may be used.

A series of X-rays may be used, following the progress of the contrast through the guts to see where it gets stuck. Ultrasound scans may also be useful. Exames de sangue are also usually needed to check for the effect of the blockage on the other body systems.

An operation called a Ladd's procedure is the usual treatment. This has to be done as a matter of urgency before long-lasting damage to the gut can occur. During the operation, the gut is untwisted and positioned so that it is unlikely to twist again. Any tight bands formed around the guts are cut.

Often the appendix is removed too, as a person with malrotation may have their appendix in an unusual position which might mean a case of appendicitis could be missed in the future.

The operation involves a anestesia geral and open or keyhole surgery in the tummy area. After the operation, the child will have fluids, nutrition and painkillers through a vein (intravenously) for a few days while the gut heals.

Outlook (prognosis) depends on how quickly the condition is diagnosed and treated. If treated late, complications can occur such as:

• A part of the bowel can die due to having its blood supply cut off, and this part of the bowel may have to be removed. In some cases, it will not be possible to re-connect the ends of the bowel. If this is the case, the open upper end of the intestine is sewn so it opens on to the tummy. The poo would then empty into a pouch on the tummy wall. This is called a stoma. It may then be possible to re-connect the ends of the bowel in another operation at a later date.

• Parts of the bowel which have died or which are under pressure from the blockage can burst (perforate). Bowel contents spilling into the tummy can cause an inflammation called peritonitis.

• Infection leading to sepse.

• Inner scarring from the operation (adhesions) can cause further blockages to the intestines in the future.