Current issues for hernia repair
The goalposts have changed over recent times for groin hernia repair. Once, the main concern was whether the repair lasted the test of time. The main area of interest was surgeons' recurrence rates. Most experienced surgeons nowadays have low recurrence rates for hernia repair, around 1-2%. We are now focusing on other aspects of hernia repair. These include speed of recovery, wound infection rate, and incidence of chronic groin pain. The last of these is of particular interest lately because it appears that technique is very important to reduce the incidence of chronic pain. The good news is that all these parameters are better achieved through laparoscopic repair, with modern techniques. Other operations can be done at the same time as laparosocpic groin hernia repair. For example, through he same incisions, a hernia at the umbilicus can be repaired as well as a groin hernia. More to follow....
Towards better colonoscopy
Colonoscopic techniques have changed over the last few years. Here are some of the important factors that have recently been shown to improve colonoscopy. Firstly, good bowel preparation is extremely important. There is no use having up-to-the minute equipment if the operator cannot see. Nowadays, we use split preparation, with the last volume of purgative taken just two hours before the procedure. It is important that the endoscopy nurse is consulted immediately prior to the procedure to check on the quality of the preparation. The procedure is nowadays done "underwater". Instead of using gas to inflate the bowel during insertion of the colonoscope, water is instilled via the colonoscope to gently fill the colon and permit navigation of the scope through to the terminal ileum. The colonoscopist should enter the terminal ileum which is the last part of the small intestine before it joins that large intestine. That way, not only can diseases of the last part of the small bowel be diagnosed but also, it is proof that the entire colon has been examined. Carbon dioxide is insufflated into the bowel during withdrawal of the scope, which is when the careful examination of the colon is done. This gas is absorbed by the body and results in less bloating and discomfort after the procedure than when air is used as it used to be. It has been shown that the longer the operator spends examining the colon, the more chance there is of picking up abnormal things such as polyps. We time the operator now to ensure that at least 6 minutes has been taken to withdraw the scope and examine the bowel. It is important that high definition scopes are used and high definition monitors to ensure that subtle lesions are not missed. It is thought that that many of the cancers that appear in the two or three years after colonoscopy actually represent benign polyps that were inadvertently missed and then grew cancerous. This type of very subtle polyp is more common on the right side. The current standard is that the operator should examine the right side of the colon twice or bend the scope backwards to look back behind the bowel folds to double-check little polyps are not hidden. Sometimes polyps can hide behind folds on the bowel and the operator can only see them by what we call retroflexing the scope. At the end of the day, what we are looking for are benign polyps that might later become cancerous. Ideally, the operator should keep a record of how often he or she finds a benign polyp. In a screening colonoscopy, polyps should be found in about 30-40% of cases. Otherwise there is a risk that polyps have not been discovered and were missed. The operator should be skilled at removing polyps. The modern trend is to remove polyps using cold snares for small polyps rather than cauterising the polyps as we used to. The operator should be skilled at using modern techniques to remove large polyps too - ones that we used to refer for surgery. Techniques have improved such that now many patients are saved major surgery by having expert endoscopic polypectomy. The endoscopist should be expert at interpreting the appearances of a polyp. With modern technology and proper training, the endoscopist nowadays should be able to to tell in most cases if a polyps is benign or malignant by looking at it.
Bowel cancer screening
Screening for bowel cancer New Zealand is a leader in bowel cancer. We and Australia have the highest incidence of bowel cancer in the world. It is the second highest cause of cancer death in New Zealand. Yet it is one of the most preventable forms of cancer in a population that receives adequate and timely screening. And the latest studies show that there is an increasing incidence of bowel cancer in younger people, who are below the screening age group. This month the Minister of Health, David Clark, apologised to the country for the recently-discovered shock failing of the National Bowel Screening Programme as reported by the Ministry of Health. Piloted in Waitemata, the report established that 15,000 citizens who should have been tested in the pilot did not receive invitations for screenings. 30 people later developed cancer and one died. Terrible as this is, there are two issues that have been either glossed over or concealed. The true failing here is that our Ministry of Health has failed to act and has procrastinated for 20 years. As early as the 1990’s it was shown that bowel cancer screening saved lives and screening was being implemented overseas. The media have been alarmed by the tragedy in Waitemata but failed to recognise that three quarters of a million other New Zealanders living outside the pilot areas have been denied the opportunity to have bowel cancer screening. Over the twenty years, hundreds of people throughout New Zealand have died because their bowel cancer was not diagnosed until too late. Bowel cancer screening is highly cost-effective and is considered the modern standard of care. For decades in other countries, screening has been freely available, and government programmes have been established. Despite this, New Zealand, with the highest incidence of bowel cancer in the world, is still running pilot programmes, and these are even faulty. It has just been announced that Wellington citizens will not be screened until 2020. This is outrageous. Virtually every other country where screening is undertaken is offering screening to everyone over the age of 50 (as in Australia, and England has recently decided to begin screening at age 50). But the latest recommendation from the American Cancer Society is that everyone over the age of 45 should be screened. But screening in the New Zealand pilot programmes only begins at 60 years old. By screening, which detects polyps and by then removing these pre-cancerous polyps, we can prevent bowel cancer developing. Where screening has been available, the incidence of bowel cancer has been falling and continues to fall. That is, in countries where those aged over 50 have been screened, there are fewer people being diagnosed with bowel cancer and fewer people dying. However, the latest studies show that there is an increasing incidence of bowel cancer in younger people, who are below the screening age group. That is why the American Cancer Society has recently changed its recommendations – to initiate screening at an earlier age. New Zealand needs to catch up - quickly.
Bowel cancer screening - the future
Screening for bowel cancer – the future in the genomic era Currently our plan in New Zealand is to screen for bowel cancer by testing faeces for blood and proceeding to colonoscopy if the test is positive. In many parts of the world screening is done by simply going straight to colonoscopy as the first step. However there are newer ways of bowel cancer screening on the horizon. These new methods use gene testing. Although most cancers are not caused by an inherited genetic defect, all cancers have some abnormality of their DNA or the way the DNA is works so that the faulty DNA actually allows cancers to grow instead of doing the normal policing and ridding the body of abnormal cells. Blood tests One promising technique is to screen people’s blood for various elements. There are modern techniques (transcriptomics) that pick up abnormal DNA or copies of DNA in the white blood cells in the circulated blood. This is possible because the cells can be multiplied millions of times over in the laboratory until they are detectable. There is now a commercial blood test approved by the FDA that detects what is called methylation of a certain gene. Methylation is a process that alters the gene and changes its capability. Cancer could be screened for by picking up these changed genes. Combining the search and looking for several mutated genes will increase the accuracy of the tests. Other faeces tests By testing faeces it is also possible to detect abnormal mutant genes that are inappropriately switched on and permit cancer cells to grow. These genes are found in cells that have been shed by tumours in the bowel, even benign tumours that would later become malignant. Urine tests Urine tests are also becoming available to test for methylated genes. Other urine markers exist such as prostaglandins (molecules that are produced by cells) Cancer cell metabolites, which are small molecules that are produced by cells’ metabolism can also be detected in the urine. One study showed that a combination panel of these metabolites could detect cancer more often that our current faecal blood testing. Another promising avenue is the detection of VOMs ( volatile organic metabolites). These are gases that are produced by cancer and can be detected in the breath, urine and faeces and other body fluids. These molecules can be detected by smell and this is the basis for the way dogs can literally sniff out cancer. Studies have shown that dogs can smell cancer in their owner before it is clinically apparent. Pill tests Nanotechnology has been studied too. There is a nanopill that can detect methylated genes in a person’s intestinal fluid. Gene testing Cancer genomics is also promising. We already know that a few bowel cancers are hereditary and genetic abnormalities can be detected in these patients’ genome (the complete set of genes or genetic material present in a cell). It might even be possible to run a genetic test on genetic predisposition genes at birth, leading to closer monitoring of these individuals. The future None of these markers of cancer or imminent cancer have the potential at present of mass screening because they are either expensive or not quite accurate enough. However, in time it may be possible and economic to use a combination panel of these tests to screen the general population in a more accurate and efficient way than we are doing now. As these tests become more available, they will almost certainly improve the uptake of screening by our citizens because they are non-obtrusive.