Diabetes is responsible for more than 60% of all non-traumatic lower limb amputations and losing a limb is a devastating event in a person’s life. There is often a significant loss of independence in one’s daily activities. A more sedentary lifestyle often comes with increased health problems including increased risk of blood clots, obesity, cardiovascular disease, infection, and stroke. Disability comes in many forms. Amputees suffer a higher incidence of depression, loss of financial independence, and inability to care for family members.
In the field of limb salvage, doctors and specialists equate saving a limb with saving a life. If an amputation can be avoided, there is better survival, fewer hospitalizations, and better quality of life. Why is that thousands of patients receive amputations, while standard available treatments are withheld? Let’s start by defining the problem.
Peripheral Arterial Disease
According to the National Institutes of Health, peripheral arterial disease (PAD) affects 8 to 12 million people in the United States. PAD develops when the arteries that supply blood to the internal organs, arms and legs become completely or partially blocked as a result of atherosclerosis. There are many possible side effects of atherosclerosis including angina and heart attacks if the coronary arteries are involved; strokes and transient ischemic attacks if the carotid and vertebral arteries are involved; and claudication, non-healing leg ulcers and critical limb ischemia (CLI) if the lower extremity arteries are involved.
The 2 million people with CLI are at imminent risk of amputation. Over HALF of patients with CLI are dead within 5 years. To contrast, this far exceeds the mortality of most forms of cancers including breast, prostate and colorectal cancer. Awareness remains at an all-time low for PAD and CLI with only 1 in 4 people over age 50 aware of its existence.
The most common risk factors for developing PAD are smoking, high blood pressure, diabetes, and high cholesterol. Those who smoke or have a history of smoking have up to four times greater risk of PAD. The most important risk factor for limb amputation is PAD which leads to impaired arterial circulation to the extremity, which impairs wound healing, leading to gangrene and ultimately amputation.
Prevention is possible
Type 2 diabetes is caused by genetics and lifestyle factors. Currently, you can’t change your genetics. However, you can change your lifestyle to prevent PAD, which is what leads to amputation of limbs. Controlling diabetes, blood pressure, and cholesterol requires a commitment to yourself and your loved ones to adhere to your medication, diet, and exercise before it’s too late.
I tell my patients not to expect that medication will do all the work; moderate exercise at least 30 minutes a day is critical and a healthy diet with whole grains, vegetables, and fruits is just as important. If my patients are overweight or obese, a weight loss plan is not a choice, it’s a necessity. If my patient is diabetic, this means reducing sugar intake. The American Heart Association recommends no more than six teaspoons (25 grams or 100 calories) per day for women and no more than nine teaspoons (36 grams, 150 calories) per day for men. Your overall sugar intake should be less than 5 percent of your caloric intake.
For a diet of 2,000 calories per day, you should also aim for 28 grams daily of soluble fiber which is essential for blood sugar regulation. Soluble fibers are found in fresh fruits, beans, carrots, and oatmeal.
Eating and drinking healthy, exercising regularly, and controlling blood sugar level and avoiding tobacco can help prevent complications that lead to amputation.
Taking care of oneself requires a multidisciplinary care team approach that includes:
- Eating the right foods
- Taking medications
- Injecting insulin
- Checking blood sugar (glucose) levels
- Seeing an endocrinologist
- Working with a dietician to help with a meal plan, and
- Regular visits with a podiatrist to inspect the patient’s feet to ensure that even so much as a blister or nick is treated.
Unfortunately, even minor skin injuries can lead to a non-healing ulcer which can quickly turn to gangrene and necessitate amputation. If the patient has diabetic neuropathy, he/she may not feel an injury.
Blocked arteries require evaluation and treatment
When a patient has diabetes, his/her chances of heart disease go up. Therefore, a cardiologist can order tests to see if the patient has signs of heart trouble. Symptoms such as shortness of breath or chest pain could indicate blocked arteries to the heart which can be treated with angioplasty to open up the blockage with a stent or flexible tube put in place to prevent it from coming back. Blockages in arteries to the heart that can’t be treated with angioplasty may require a cardiothoracic surgeon to do coronary artery bypass graft surgery.
Blocked arteries to the brain or lower extremities may require evaluation by a vascular specialist, and angioplasty or bypass can be done in these arteries too. Taking care of the heart reduces the chances of getting to the point of amputation.
Finally, any patient with PAD and CLI who is at risk for limb amputation should see a vascular interventional specialist prior to any surgical amputation. We can do both invasive and noninvasive studies to determine if a revascularization procedure is needed. Often times, restoring blood flow to the affected extremity can result in a total limb salvage or a much smaller amputation.
Why Innovation is Needed
Genetics that cause diabetes cannot be controlled. However, American scientists have adapted a gene editing technology known as CRISPR (clustered, regularly interspaced, short palindromic repeat) to successfully treat mouse models of type 1 diabetes, kidney disease, and muscular dystrophy. CRISPR enables scientists to edit the genetic material of an organism allowing for DNA sequences to be easily altered and gene function to be modified. However, rather than cutting DNA, scientists at the Salk Institute for Biological Studies have repurposed CRISPR to kick-start the activity of other genes. Upon doing this, they were able to create new insulin-producing beta cells in mouse models of type 1 diabetes. Research like this must continue to find a cure for the complex disease.
UC Davis Vascular Center has launched a stem cell study to reduce amputations from vascular disease and diabetes using a patient’s own stem cell to increase blood circulation to the lower leg with the hope of preventing amputation due to severe arterial disease or diabetes.
Many advances are being made in the field of interventional vascular medicine as well. Smaller catheters and devices are used to remove plaque from affected arteries (atherectomy). There are new companies using sound and lithotripsy (Shockwave Medical) to help break up calcium in arteries affected with arteriosclerosis. Research is also being done using drug-eluting balloons that help open arteries and reduce the chance of them closing again.
Cardiologists like me who see patients every day with serious medical conditions also want to do something to help. We often see that there might be a better way. I am fortunate to have the opportunity to work with The Innovation Institute and their Innovation Lab in Newport Beach, California, to develop my own innovation related to improving patient outcomes. I hope to one day help provide hope for those stricken with diabetes.