Saturday, December 18, 2010

Robotic Surgery

There has been a flood of people requesting robotic surgery, especially men with prostate cancer, and I fear that they are not aware of all the pertinent facts. These men seem to think that robotic surgery is superior (i.e. more curative), and therefore have greater disappointment when the cancer returns. I have certain biases against robotic surgery, both medical and economic, and I would like to explain these to you, with reference to both general (open) and laparoscopic ("mini") surgery.

First some background, and an explanation of what robotic surgery really entails. The first surgery, of course, was "regular" surgery, which left a long scar because the surgeon needs adequate exposure to visualize the surgical field and its surroundings, and thereby minimize the chance of transecting the common bile duct during gall bladder surgery, etc. The need for adequate field of view was drilled into the heads of all surgical residents. The result for cholecystectomies was usually a long (8 to 12 inch) scar under and parallel to the lowest right rib, and a 10 day recovery period in the hospital. The surgery was almost always done after a severe gallbladder attack, with the idea of preventing a second severe attack and possible ascending cholangitis.

Laparoscopic surgery  typically involves only four small incisions in the abdomen, each no longer than an inch. Lights and a TV camera are  inserted, and the surgeon then directly manipulates his/her instruments to remove the gall bladder. They have gotten so skilled at this that last year a surgeon removed a gall bladder through the superior vaginal wall (!), leaving no abdominal scar whatsoever. In addition, because of minimal incisional tissue damage, the time in the hospital after a laparoscopic cholecystectomy was reduced from ten to three days, and now it may be as little as two. Therefore there  is less trauma and faster healing than under the old method, and it was thought that with fewer days in the hospital, the nationwide annual cost of cholecystectomies would decrease. Unfortunately, as shown by an article in NEJM 10-15 years ago, this was not the case. The surgery was so "easy" that  satisfied patients informed their friends, and  more and more patients with asymptomatic gall stones elected to have the laparoscopic cholecystectomy. The overall result was that the annual total cost of gall bladder surgery increased in the United States.

Now we come to robotic surgery. It is essential to remember that the FDA does NOT have to clear or approve of any new surgical technique, unless a medical device (artificial hip, heart valve) is implanted. If I wanted to drill a hole in your head to let the "evil humors" escape,, and you were agreeable, then it is a go.
If I wanted to remove your gall bladder through an endoscope, it is also a go. In robotic surgery, several  things are true that are not true for laparoscopic surgery:

(1)  There is an extra $3,000 added to the cost of the surgery,---$1500 for the instruments that have to be disposed, and $1500 to amortize the cost of the equipment. Whether or not Medicare or your HMNO will pay the extra expense is a separate question.

(2) There is no direct tactile feel by the surgeon on your organs. Even with laparoscopic surgery, the instruments are directly moved by his hands, and he can feel resistance, texture, etc. But in robotic surgery, he types in commands to a computer console, and the computer then moves the instruments. It is true that the computer has finer motions than human hands, but it has no "feel", and the patient also has to hope that the program was properly entered, not like the CT scans of the brain or the gamma-ray vs. electron beam treatment of tumors where the wrong button was pushed or the wrong program entered, and the patient's tissues were fried. So the robotic surgeon is deprived of tactile feedback.

(3) Most important of all: There is a sharp learning curve in robotic surgery, precisely because of the lack of tactile feedback. It has been estimated that it takes between 50 to 100 robotic operations on the prostate for the surgeon to become proficient enough so that the results and the time of robotic surgery equals that of non-robotic surgery. Skin-to-skin prostate surgery takes 2 to 2.5 hours, and the first time a surgeon uses the robot it can take 4.5 to 5.0 hours, and the depressive effect of anesthesia on your heart and lungs increases after 2.5 hours. Therefore, the first question you should ask any surgeon who wants to to robotic prostate or heart valve or any other critical surgery on you is : HOW MANY OF THESE ROBOTIC OPERATIONS HAVE YOU DONE? If the answer is fewer than 50, I, for one, would not let him/her touch me. It makes you wonder: Who "volunteered" to be the surgeon's first robotic surgery patient, and did the patient know that he/she was the first? Did the surgeon tell the patient?

Friday, December 10, 2010

Aspirin and Colon Cancer

There have been reports in the news lately about two different articles in medical journals: (1) whether daily aspirin use reduces the incidence of colon cancer, and (2) the expense and morbidity of robotic surgery as opposed to standard laparoscopic ("keyhole" or "mini") surgery. Since I am an internist and neither article will affect my practice or income, I feel  can comment on them without bias (outside my usual inquisitorial examination of the evidence presented in research papers, a habit than has only been intensified by my over 20 years of reviewing articles). This blog will discuss the possible aspirin-colon cancer reduction link, and the next will discuss robotic surgery.

Let us look at the aspirin-colon cancer article first. As some background, let me inform my non-medical readers that it appears that it takes 5 years from the time a polyp first develops in the colon until it becomes cancerous (and I am here excluding any familial cases). Since as the polyps enlarge they tend to put drops of blood into the stool, the first screening for colon cancer that was shown to reduce the death rate from colon cancer was the annual test for blood in the stool. When I started practice in the early 1980"s, it was known that  five year examinations of the distal 25 centimeters of the colon by a rigid proctoscope detected enough cancers to reduce the death rate from colon cancer, and this became a standard practice for me. One curious fact that was noted and unexplained was that even though only a minute part of the distal colon was examined, fatal cancers originating in the proximal colon were also reduced (although not by as much). The proctoscope, or rigid signoidoscopy was soon replaced by the flexible sigmoidoscope, which reached further into the distal colon. This examination, if given every 5 to 10 years, also reduced colon cancer deaths in the proximal as well as the distal colon, but, again the incidence of cancers in the distal colon were much more strongly affected, than that  of cancers in the proximal colon .

A few years ago, a 5 year retrospective study of 5,000 female American nurses was published. The study showed that the frequent use of NSAID's (usually Advil or Alleve) reduced the incidence of and death from colon cancer. (I might here mention that a parallel 5 year study of females placed on a low fat diet showed no reduction in the incidence of either colon or breast cancer, but people still seem to think, without any hard evidence, that animal fat is carcinogenic for humans.)  This study led to the Vioxx study, where Merck hoped that they could show that Vioxx, another NSAID, also reduced the incidence of colon cancer, so they could get FDA approval to market it as such. Unfortunately, the initial data showed an increase in cardiovascular events, so the study  was terminated, as was Vioxx. I leave it to the audience to search the published reports to see which NSAID is the safest and which is the most apt to produce cardiac events. The last time I reviewed the subject (and this may not be true now) prescription Celebrex was the safest anti-inflammatory , and OTC Alleve/Naprosyn had the highest incidence of cardiac events.

So now we come to the latest study, published in Lancet (Vol. 376, Nov. 20, 2010, pp1741-1750). The study found that a dose of 75 mg. of daily aspirin (a baby aspirin has 81 mg) reduced the incidence and mortality of colon cancer, and the benefit was highest for proximal cancers. A few caveats. This article was the result of pooling 5 different studies, and in none of the studies was colon cancer the endpoint. Furthermore, the pooling showed a much greater effect in men than in women.We also think we know that aspirin reduces the incidence of colon polyps by suppressing COX-2, and tumors in the distal colon seem to have greater interaction with COX-2 receptors than do proximal tumors. It also did not compare the use of daily aspirin with q. 5 year colonoscopes with regard to reduction in the incidence of colon cancer.

Now when my patients ask me about  how to apply the results of this study to their own medical lives, I will reply as follows: There is now some evidence that taking a daily 81 mg. (children's) aspirin will reduce your chance of getting colon cancer, but no one has compared the % reduction achieved with aspirin with that achieved by either an annual stool-for-blood test or q. 5-10 years colonoscopy, and daily aspirin use increases your risk of GI bleeding. We also have absolutely no idea if adding daily ASA to the suggested routine of colonoscopy plus stool-for-blood  will have a positive synergistic effect. On the other hand, it is evident that if aspirin does have a preventive effect, it is greater for proximal colon tumors than distal tumors, and proximal tumors are the ones least likely to be detected by either colonoscopy or stool-for-blood. I would also suggest that if they absolutely refuse to ever have a colonoscopy then a daily children's aspirin is probably a good idea.