Regarding Surgical Mortality Statistics
By G. Wesley Clark, MD, bariatric surgeon, San Diego, CA
(co. 2003, reprinted by permission of the author)
I am a weight-loss surgeon, with an experience of over 2000 operations, over the
last 17 years. I was an originator of the Laparoscopic Gastric Bypass, Roux
en-Y. My personal mortality is about 1:1000 for the laparoscopic procedure,
somewhat higher for the open operation (not because the operation is more
dangerous that way, but because more high-risk patients must be done by that
method). I have the advantage of operating in a hospital where the entire team
has experience, and where we have special equipment for the obese patient.
Mortality from surgery is usually determined by taking mortality from all causes
within 30 days of the operation. For example, if one had a minor and safe
operation, and was run down by a beer truck 27 days later, it would be
considered a surgical mortality, even though it is apparently not related to the
operation. This is a very stringent method, but eliminates any judgments about
whether or not the death was caused by the operation. This method may overstate
mortality from a safer operation: if one gets better fast, and is more active,
there is a slightly greater chance of death from an unrelated cause, due to
activity. On the other hand, a patient with severe surgical complications might
survive for several months before expiring, and not be counted. That’s the
problem with statistics.
Low mortality rates for 3 days after surgery are very misleading. Even the
patient with a severe sepsis, or a brain-death, will usually survive for that
long, and not be counted against the surgery.
The most commonly cited mortality rate for bariatric surgical operations, across
the United States, is 0.5%. That looks pretty good, till you do the math and
realize that means about 1 out of 200 patients will experience a fatal result.
This increased risk arises from numerous factors, and is not just for bariatric
surgery, but any surgery performed on a very obese patient. I call this the “fat
penalty”. The increased mortality arises from numerous factors:
- Anesthetic Risk
Most anesthesiologists shudder to see an obese person on their table. They
know it may be very difficult to insert the anesthetic tube into the airway,
and very dangerous if it comes out too soon. Ventilator pressures must be set
a lot higher, because of the weight of the chest. Drugs and anesthetic gases
may be absorbed by the fat, requiring much higher doses to take effect, and
much longer to be eliminated when they are no longer needed. Obese patients
don’t breath well to begin with (they get out-of-breath from simple daily
activities), and may have much more difficulty after surgery. Moving an
unconscious patient is always difficult and tricky, but can be much more so
when the patient weighs 400 pounds. Our hospital has special equipment to
assist with this and make it safer. You want a highly skilled
anesthesiologist, experienced with treating obese patients.
- Surgical “Degree of Difficulty”
Obese persons are much more difficult for the surgeon to operate upon.
Normally, the abdominal organs are all fitted together, with no space between
them. In order for the surgeon to see to operate, they must be separated and
held apart in some way – this is called “surgical exposure”. Exposure can be
very challenging to achieve and maintain, when there are large amounts of fat
constantly slipping and sliding about, and getting in the way. Fat on the
surface of the organs may make it harder to place sutures accurately.
The abdominal wall may be 4 – 5 inches thick in the obese patient. That means
that ordinary surgical instruments won’t reach, and we have to use extra-long
instruments, which are much harder to learn to manipulate precisely.
That’s why you want a highly skilled and experienced Bariatric Surgeon.
- Surgical Complications
Obese persons have a much higher rate of complications. Obesity is a risk
factor for Pulmonary Embolism, which is often fatal. Post-operative Pneumonia
is also more likely in the obese. Wound infections are considered more likely,
and because of the size and depth of the wound, can be very challenging to
heal. Complications can be much harder to diagnose and manage in the obese
patient. For example, X-Rays do not penetrate as well, and the pictures are
less clear. Very large patients will not fit in some equipment, such as the CT
Many surgeons with limited experience in surgery of the obese patient will
decline to operate on an obese person, even when the indications are there,
because of their perception of the increased risk, and the altered
risk/benefit ratio. Many transplant surgeons will refuse to transplant organs
in an obese patient (not overtly, they just never seem to find the right organ
match). Many orthopedic surgeons decline to do joint replacements, especially
knees, in obese persons.
All surgery carries risks, and all surgeons have patients who experience
complications, even when surgery is done "perfectly". When a complication
occurs, the most important factor in determining mortality, I believe, is the
experience, knowledge and skill of the treatment team.
What about the Benefits?
One should only seek Bariatric Surgery to protect or to restore health. It is
not a cosmetic operation, although it has some pleasant side-benefits. To decide
whether Bariatric Surgery is right for you, the risks and the benefits should be
understood, and weighed one against the other. We do that all the time in life,
usually without realizing it. (I ride a motorcycle, even though I know it’s
risky, because I get such a high from it. I don’t eat sushi, because I don’t
like it that much, and raw fish can have bad things in it).
The benefits of bariatric surgery, beyond a lighter weight and smaller dress
size, have been relatively poorly demonstrated in the surgical literature. We
found (and published) that in our first 500 Laparoscopic Gastric Bypasses, there
were 1572 major co-morbidities (health problems related to obesity) --over 3 per
patient, on the average. Following surgery, one year later, these were reduced
by 96%. Ninety-six percent of the obesity-related health problems were gone.
Of 80 diabetics, only one continued to require any medication. Risk factors for
cardiac disease were dramatically reduced. Arthritic symptoms almost
disappeared, and even when some joint pain remained, it was much lessened.
Dr. Kenneth McDonald has published a study of diabetics who undergo bariatric
surgery, and showed a 75% reduction in mortality after surgery (even including a
slightly higher than average surgical mortality).
That's the kind of results that justifies the risk of the operation -- my wife
had a Laparoscopic Gastric Bypass 3 years ago, on my recommendation, and I'd be
on the table next week myself, if I met the basic weight criteria, or if I
I started out years ago as a General Surgeon, taking out gallbladders, removing
breasts, cutting out cancers. Nothing compares to the thrill I get when my
patients return to me a year later, and want to hug me (no woman ever hugged me
for taking her breast off). They've changed into beautiful butterflies, excited
with their new lives, able to do things they never dared to dream about before.
I became a physician, because I dreamt of healing people. I found my way to
heal, and I love it.
G. Wesley Clark, MD