In this edition of “What’s Up, Doc,” I had the opportunity to speak with Dr. Lily Johnston, a vascular surgeon from Scripps in San Diego who brings a refreshingly comprehensive approach to vascular health. Unlike many specialists who focus solely on surgical interventions, Dr. Johnston combines her surgical expertise with a deep understanding of metabolic health to help patients address the root causes of their vascular issues.
Dr. Johnston’s interest in metabolic health began during the pandemic when extra time allowed her to explore new research. “I began listening to podcasts and chatting with my mom, who’s also a physician. We started talking about intermittent fasting,” she explained. This led her to discover a paper in the New England Journal of Medicine that detailed the cellular and clinical impacts of intermittent fasting.
Her exploration continued into the role of ketones as an energy supply and therapeutic carbohydrate reduction for treating various conditions, including diabetes and dysglycemic disorders. What began as a personal journey to improve her own health evolved into questioning how these approaches might benefit her patients.
The turning point came during her first job after training, where she performed lower limb amputations for a large multi-specialty group in Northern California. “I was seeing an enormous number of patients with diabetes that was out of control,” she recalled. “These were people who were trying. They were really absolutely following their instructions to the letter and kept getting worse and didn’t understand why. And it was just devastating.”
This experience motivated her to dive deeper into understanding what causes plaque formation, diabetes, and other metabolic disorders. By 2023, she had returned to Southern California and expanded her knowledge through certifications in nutrition pathways, hormone therapy, weight reduction, and lipid management.
Understanding Plaque Formation: A Multifactorial Process
Dr. Johnston emphasized that plaque formation in arteries is multifactorial, and different patients may have different root causes:
“For some patients, it’s a metabolic dysfunction like insulin resistance or diabetes. For other patients, it’s tobacco or nicotine products, other toxins that disrupt the endothelium. For some patients, it’s an inherited disorder like familial hypercholesterolemia or LP little a.”
She noted that despite cardiovascular disease being the number one killer in America, we don’t have standardized screening protocols for plaque. “We screen for breast cancer. We screen for colon cancer. But we have never come up with a screening pathway that meets all the public health epidemiology criteria for appropriate screening for heart disease.”
Dr. Johnston prefers early detection methods like carotid intimal medial thickness (CIMT) or femoral intimal medial thickness because they can detect soft plaque without radiation, making them better options for younger populations who might not show calcium deposits yet.
Taking Time with Patients
Unlike the typical rushed medical appointments, Dr. Johnston invests significant time with her patients. “My initial visits for my metabolic practice are two hours. And my office staff knows I run long. Our follow-ups are an hour.” This allows her to thoroughly understand each patient’s unique situation and develop personalized treatment plans.
The results speak for themselves. “For the first time in my medical career, people come back and say, ‘Oh my gosh, I feel so much better.’” This positive feedback reinforces her commitment to this comprehensive approach.
The Statin Debate
One of the most controversial topics in vascular health is the use of statins. Dr. Johnston takes a nuanced approach: “I sit in the middle and I make everybody unhappy.”
She explained that for most patients with metabolic disease, she recommends therapeutic carbohydrate reduction. However, she acknowledges that some patients do better with very low-fat approaches like the Ornish or Esselstyn diets.
Regarding statins, she recognizes both their benefits and potential side effects. “I don’t love statins for everybody. I absolutely acknowledge that there are some side effects that are very real, especially in terms of worsening metabolic function at high doses.”
Her approach depends on whether a patient has existing plaque and whether they’ve already had cardiovascular events. For patients with plaque who have experienced events like heart attacks or threatened limbs, she follows guidelines recommending high-intensity statin therapy.
For prevention, she often uses low-dose statin therapy along with adjuncts like ezetimibe or PCSK9 inhibitors while also addressing inflammation, oxidative stress, and metabolic dysfunction.
Most importantly, she emphasizes shared decision-making: “It’s my job to give you options, to educate you, to tell you what I think is the best evidence we have thus far, and we can try something else.”
Collateral Vessels: Nature’s Bypass System
Dr. Johnston used a traffic analogy to explain collateral vessels—the body’s natural bypass system that develops when arteries become blocked:
“Your named blood vessels are a freeway and cars are driving down that road to deliver oxygen down to your feet. If there’s major construction on the freeway, everybody starts getting off and using the county roads instead. Well, then the county wises up and says, maybe we should add a lane to the county roads. And so over time, now your county roads get bigger and they allow more cars and trucks to flow.”
The key to developing these collateral vessels is challenging the body through exercise, particularly walking. “Using your muscles, like walking, is usually the best way to develop those county roads and those collaterals because you are just asking your body to get that oxygen there and you’re doing it over and over and over again until it can’t ignore you.”
While the process can be uncomfortable due to cramping and pain, Dr. Johnston emphasized that these signals drive the growth of collateral networks that can ultimately save a limb. “If you can take the time and build that up over months to years, it’s very clear when we do angiograms who has built up these collateral networks over years.”
When asked if collaterals can disappear during periods of inactivity, she reassured that without another inciting problem, they generally stay. However, she cautioned that collateral flow might be compromised by dehydration, blood clots, or after revascularization procedures that restore normal blood flow.
The conversation turned to specific diets, with a question about the carnivore diet. Dr. Johnston again emphasized personalization: “It depends on what you’re trying to solve and whether you’re excited about it and whether you think it might be something sustainable and possible for you.”
She described how some patients find tremendous relief from joint inflammation, back pain, sleep issues, and energy problems on a carnivore diet. If these benefits come with some elevation in atherogenic particles, she suggests monitoring for plaque development and treating that separately if needed.
“If you feel amazing on it and there’s a small consequence in one system, but eight other things have gotten better that I can’t fix with any drug in the book, then maybe we deal with the one thing that’s a side effect.”
Her recommendation for anyone considering such dietary changes is to establish baseline measurements, try the diet, see how you feel, and then reassess after a few months.
When to Consider Procedures
Throughout the interview, Dr. Johnston emphasized the importance of non-surgical approaches first, but recognized that procedures are sometimes necessary. For patients considering bypasses or other interventions, she offered this advice:
“If you’re uncomfortable having your operation, get a second opinion… Don’t sign up for major high-risk surgery, which includes stenting… if you’re not comfortable with the plan and with your provider.”
She stressed that patients should fully understand why a procedure is being recommended and feel confident in both the plan and their surgeon before proceeding.
PAD: Know the Warning Signs
Peripheral Artery Disease (PAD) develops when arteries narrow or become blocked by plaque, restricting blood flow to the limbs. The most common symptoms include:
- Pain, cramping, or fatigue in the legs when walking (claudication)
- Numbness or weakness in the legs
- Cold feet or legs
- Shiny skin or hair loss on the legs
- Slow-healing wounds on the feet or toes
- Pain in the feet, even at rest (especially at night)
Dr. Johnston explained the progression of PAD symptoms: “We go from claudication or pain with walking. Then there’s this intermediate, like really short distance claudication, which is almost like rest pain. Then there’s ischemic rest pain… all the way to wounds, ulcers, tissue loss.”
Once rest pain or tissue loss occurs, this becomes limb-threatening ischemia, requiring prompt medical attention to prevent amputation.
Taking Control of Your Vascular Health
What made this conversation with Dr. Johnston so valuable was her emphasis on patient empowerment through education. Whether discussing statins, collateral vessels, nutrition, or procedures, she consistently advocated for informed, shared decision-making.
For those concerned about vascular health, her approach offers a roadmap:
- Understand your personal risk factors
- Get appropriate early detection testing
- Address metabolic health through nutrition, exercise, stress management, and sleep
- Consider medication when appropriate
- Build collateral vessels through regular walking
- Seek second opinions before major procedures
If you’re experiencing symptoms of PAD or concerned about your vascular health, contact the Global PAD Association’s Legsaver Hotline at 1-833-PAD-LEGS (1-833-723-5347). Our team can provide information, resources, and referrals to specialists like Dr. Johnston who take a comprehensive approach to vascular health.
You can also learn more about Dr. Johnston’s practice at vascularhealthinstitute.org or find her on LinkedIn under Lily Johnston, MD.
Medical Disclaimer: This article contains general information about medical conditions and treatments. The information is not advice and should not be treated as such. The medical information in this article is provided “as is” without any representations or warranties, express or implied. Always consult with your doctor or other qualified healthcare provider before undertaking a new health care regimen or if you have questions about a medical condition.