BMI and Plastic Surgery

Body Mass Index (BMI) is a crude guide to determining someone’s health based on their weight and height. It is used to categorise people into different weight categories, and thus indirectly reflect their general health. BMI is often used by surgeons to determine an individual’s suitability to undergo elective surgery.

 What is BMI?

BMI is calculated by dividing a person’s weight in kilograms by the square of their height in meters (kg/m²). The scoring system is as follows:

It provides a simple numerical measure to classify individuals into different weight categories:

• < 18.5 – Underweight
• 5 – 24.9 – Healthy weight range
• 25 – 29.9 – Overweight
• 30 – 39.9 – Obese
• ≥ 40 – Morbidly obese

The importance of BMI in surgery

Risk Profile:

• Anesthesia Risks: Higher BMI is associated with increased potential anaesthetic risks
• Surgical Risks: Individuals with a high BMI are at a greater risk for complications such as infection, poor wound healing, and blood clots.

Healing:

• Wound Healing: Patients with a higher BMI can have a reduced ability to heal efficiently, leading to increased risk of wound complications.
• Immune Function: A higher BMI can affect the immune system, making the body more susceptible to post-surgery infections.

Results:

• Aesthetic Results: Achieving desired aesthetic outcomes can be more challenging in individuals with higher BMI. However, ensuring realistic expected outcomes are discussed prior to surgery is vital and would thus avoid this issue.

Suitability for Surgery:

• Eligibility: Many plastic surgeons set BMI thresholds to determine an individual suitability for elective surgery. These surgeons will deny surgery to patients who are above a certain BMI.

People who have a high BMI but could still be offered surgery

Examples include:

• They have already lost a massive amount of weight, there weight has stabilised, and they now have significant excess skin problems.
• They have developed a large fatty apron which is a major functional and medical burden and are in urgent need of treatment.
• They have always been large, and will always have a higher BMI, yet they have areas of excess skin that proves to be a major medical and functional burden and need appropriate care.

People who have a high BMI and should have surgery denied

Examples include:

• They are actively losing weight and have yet to reach a realistic sustainable weight goal
• They have a high BMI and want to lose weight but don’t know how to. Have their GP manage their weight through the various means available – whether that be through medical management or referral to a bariatric surgeon to consider if they are suitable to gastric surgery.
• They have a high BMI, yet don’t have any major excess skin functional issues that surgery can address. These patients need advice and referrals to the appropriate healthcare professionals to help them lose weight.

Problems with using BMI as a guide for surgery

Many surgeons use a BMI guide of 30 for patients to determine whether they are suitable to have surgery.

This is based on studies demonstrating an increased surgical risk profile of such patients.

However, using a single number as a guide of the importance and value of a surgical procedure to a patient is unfortunately poor decision making.

Yes, as mentioned earlier, a higher BMI does equate to an increased risk profile.

However, every treatment in medicine and surgery involves a careful assessment of risks versus benefits.

If upon assessment the potential benefit of a treatment far outweighs any potential risks, and those risks are openly discussed, then treatment should be offered.

Denying a patient treatment that could have an enormous positive impact on their life because the BMI is deemed too high is poor patient care.

The following is a few examples of patients with high BMI’s that are still deemed suitable to have surgery:

Example 1.

A classic example of this are patients who have lost a massive amount of weight and have significant amounts of excess skin.

Often these patients have already had elective surgery to help them lose weight – such as gastric sleeve or gastric bypass surgery. These surgeries were performed when they were much heavier and therefore has a much greater surgical risk profile.

They have lost massive amounts of weight and have plateaued. They are not going to lose more weight and are now comfortable with their weight. However, the now excess skin is a major physical, functional and medical burden and body contouring surgery will clearly be a major benefit to them.

However, a BMI assessment on many of these patients will still yield a number well over 30. Should these patients be denied surgery? Dr Dona firmly believes that these patients should be offered surgery as it is a genuine reconstructive procedure that will have potentially significant medical and lifestyle benefits to them.

Example 2.

Another example is someone that has a large functionally debilitating fatty abdominal apron that is a major medical and functional burden to them. Such an individual will often have a very high BMI, well above 30, yet they are in desperate need for surgical care. Should such a patient be denied treatment? Dr Dona believes that as long as they are well informed, as all patients should be, then they should be offered treatment.

Example 3.

Patients presenting with excessively large breasts (bilateral hypermastia) often have a BMI above 30. Should these patients be denied surgical care?

Bilateral hypermastia is a major physical burden and it is a well known amongst plastic surgeons that patients who have undergo breast reduction surgery are typically the most satisfied plastic surgery patients. This is because the surgery is designed to first and foremost address the many functional and medical concerns that excessively large breasts cause. As a secondary bonus, the breasts are aesthetically enhanced, however that is only a secondary issue. Should such a deserving and in need individual be denied surgery specialist care because they have a high BMI?

The ideal BMI for elective surgery

A BMI in the range of 18.5–24.9 is generally considered ideal for most elective plastic surgery procedures. However, many individuals are not within that range, and most individuals in need of specialist plastic surgery care are not within that range.

How to Achieve a Healthy BMI

As per always, the keys to a healthy weight and lifestyle follows the below basic principles:

1. Diet and Nutrition:

• Balanced Diet
• Portion Control
• Hydration

1. Exercise:

• Regular Physical Activity
• Cardio Training
• Strength Training: Any exercise program should also incorporate strength training exercises to build muscle
• Consistency: This is the key.

Points 1 & 2 all relates to calories in versus calories out. To lose weight, you need to burn more calories than you consume – simple.

1. Lifestyle Changes:

• Sleep: Adequate quality sleep is vital to all aspects of your health.
• Stress Management: Through whatever means works best for you.

1. Healthcare Guidance:

• Healthcare Professionals: Seek assistance from a healthcare professional or nutritionist for personalised advice.
• Personal Trainer: They are often required to help start and maintain a healthier version of you.

Conclusion

Whilst BMI can be an important number in determining an individual’s health, it should be used to exclude a person from surgery when it is desperately needed.

Every treatment in medicine and surgery involves a careful assessment of risks versus benefits.

If upon assessment the potential benefit of a treatment far outweighs any potential risks, and those risks are openly discussed, then treatment should