BMI over 35 and DIEP Flap Surgery

Risks Associated with High BMI for DIEP Flap Surgery Patients

DIEP flap surgery, or Deep Inferior Epigastric Perforator flap surgery, is a sophisticated breast reconstruction technique that utilises a patient’s own tissue to recreate the breast after mastectomy. This method has gained popularity due to its natural look and feel, along with the absence of synthetic implants.

However, one significant factor that influences the success and complication rates of this surgery is the patient’s Body Mass Index (BMI). Recent studies, including a comprehensive analysis conducted between 2004 and 2021, have highlighted how increased BMI can affect surgical outcomes. Understanding these risks is essential for patients with a BMI over 35 who are considering DIEP flap surgery. In this blog, Sydney Specialist Plastic Surgeon Dr Bish Soliman aims to provide an in-depth look at these findings and offer valuable insights for patients considering DIEP flap surgery.

Overview of the DIEP Flap Surgery

DIEP flap surgery stands out as a preferred option for breast reconstruction due to its use of autologous tissue, meaning tissue sourced from the patient’s own body. Unlike other reconstruction techniques that might rely on implants, DIEP flap surgery uses skin, fat, and blood vessels taken from the lower abdomen to form the new breast. The procedure involves microsurgery to connect the blood vessels of the transplanted tissue to those in the chest, ensuring a robust blood supply and better integration.

The primary benefit of DIEP flap surgery is its ability to provide a more natural appearance and sensation compared to implant-based reconstruction. Additionally, since no muscle is removed from the donor site, patients generally experience less postoperative pain and a quicker recovery period. However, it is important to note that not every patient is an ideal candidate for this procedure. Factors such as overall health, body weight, and previous abdominal surgeries play a crucial role in determining eligibility.

For patients with a BMI over 35, the considerations become even more critical. Higher BMI can increase the risk of complications such as infections, delayed wound healing, and flap failure.

The Impact of BMI on DIEP Flap Surgery

The impact of Body Mass Index (BMI) on DIEP flap surgery outcomes is a critical consideration for both patients and surgeons. BMI, a measure of body fat based on height and weight, is a significant predictor of surgical risk and complication rates. For patients with a BMI over 35, understanding the implications of their weight on the surgery and recovery process is essential for making informed decisions and achieving the best possible outcomes.

BMI and Surgical Outcomes

BMI is categorised into several ranges: underweight (BMI <18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25-29.9), and obese (BMI ≥30). Within the obese category, further distinctions are made: class I (BMI 30-34.9), class II (BMI 35-39.9), and class III (BMI ≥40). These classifications help in assessing the potential risks associated with surgical procedures, including DIEP flap surgery.

Studies have consistently shown that higher BMI is associated with increased surgical risks. Specifically, for DIEP flap surgery, a retrospective chart review conducted at the University of California, San Francisco, spanning from 2004 to 2021, revealed significant findings regarding the relationship between BMI and surgical outcomes.

Key Findings from the Study

1. Complication Rates and BMI Thresholds:

1. • Any Breast Complication: The study found that the rate of any breast complication significantly increased for patients with a BMI greater than 30 kg/m².
   • Unplanned Reoperations: Patients with a BMI over 35 kg/m² were more likely to require unplanned reoperations.
   • Fat Necrosis: The incidence of fat necrosis, where fatty tissue within the reconstructed breast dies, was notably higher in patients with a BMI exceeding 40 kg/m².
   • Wound Breakdown: Wound breakdown requiring reoperation was significantly more common in patients with a BMI above 35 kg/m².
   • Infections: Both general infection rates and severe infections requiring intravenous antibiotics increased markedly in patients with a BMI over 30 kg/m². Infections treated with oral antibiotics were more frequent in patients with a BMI over 25 kg/m².
   • Mastectomy Flap Necrosis: This severe complication, where the skin flap over the mastectomy site dies, was more prevalent in patients with a BMI over 35 kg/m².

2. Abdominal Complications:

1. • Delayed Wound Healing: Patients with a BMI over 30 kg/m² experienced significantly higher rates of delayed wound healing at the donor site.
   • Wound Breakdown and Infection: Similar to breast complications, the donor site also showed increased rates of wound breakdown and infections in patients with higher BMI.

Optimal BMI Cut-offs for Minimising Complications

The study utilised receiver-operating characteristic analysis to determine optimal BMI cut-offs for minimising complications. An optimal BMI cut-off of 32.7 kg/m² was identified to minimise the occurrence of any breast complication, while a cut-off of 30.0 kg/m² was optimal for reducing abdominal complications. These thresholds provide valuable benchmarks for assessing surgical candidacy and guiding preoperative preparations.

Implications for Patients with a BMI Over 35

For patients with a BMI over 35, these findings underscore the importance of recognising and addressing the heightened risks associated with DIEP flap surgery. Increased BMI can lead to a range of complications that not only affect surgical outcomes but also impact overall recovery.

1. Surgical Planning and Candidacy:

1. • Patients with a higher BMI may need more rigorous preoperative assessments to evaluate their suitability for DIEP flap surgery.
   • Dr Soliman might recommend weight management strategies before proceeding with surgery.

2. Infection Control and Wound Care:

1. • Given the increased risk of infections, meticulous infection control protocols are essential. This includes preoperative skin preparation, intraoperative antibiotic prophylaxis, and postoperative wound care.
   • Enhanced monitoring and early intervention for signs of infection can help mitigate these risks.

3. Optimising Healing and Recovery:

1. • Strategies to promote optimal wound healing, such as adequate nutrition, avoiding smoking, and managing comorbid conditions like diabetes, are crucial.
   • Close follow-up care to monitor wound healing and address any complications promptly is necessary to ensure a smooth recovery.

Risks Associated with High BMI

Body Mass Index (BMI) is an important determinant of surgical outcomes, particularly in complex procedures like DIEP flap surgery. Patients with a high BMI (over 35) face increased risks due to several physiological and anatomical factors.

Infection Risks

Infections are a significant concern for patients with a high BMI. The increased adipose tissue in obese patients can create a conducive environment for bacterial growth, leading to a higher likelihood of both superficial and deep infections. This risk is compounded by impaired immune responses often observed in obese individuals. Studies have shown that patients with a BMI over 30 are at a significantly higher risk of developing postoperative infections, with the severity and frequency increasing with BMI.

Wound Healing Complications

Delayed wound healing is another major risk. The excess fat tissue can lead to poor blood circulation, which impedes the supply of oxygen and nutrients necessary for wound healing. This can result in prolonged recovery times and a higher risk of wound dehiscence, where the surgical wound reopens, necessitating additional surgical interventions. For patients with a BMI over 35, the rate of delayed wound healing is notably higher, complicating the postoperative recovery process.

Surgical Site Complications

Specific complications related to the surgical site, such as seromas (accumulation of fluid) and haematomas (accumulation of blood), are more common in patients with high BMI. These complications can cause discomfort, delay healing, and increase the risk of infection. Additionally, the increased tension on surgical incisions due to excess body weight can lead to wound breakdown, requiring further surgical correction.

Flap Failure and Fat Necrosis

In DIEP flap surgery, the risk of flap failure and fat necrosis (death of fatty tissue) is elevated in patients with a high BMI. The excess fat tissue can compromise the blood supply to the transplanted tissue, increasing the risk of partial or complete flap loss. Fat necrosis can cause hard lumps, pain, and may necessitate additional surgical procedures to remove the necrotic tissue.

Anaesthesia-Related Risks

Patients with a high BMI are at increased risk of complications related to anaesthesia. These include difficulties with intubation, increased risk of aspiration, and challenges in maintaining adequate ventilation during surgery. The prolonged anaesthesia time required for complex surgeries like DIEP flap procedures further heightens these risks.

Cardiovascular and Respiratory Complications

Obese patients are more likely to suffer from comorbid conditions such as hypertension, diabetes, and obstructive sleep apnoea, which can complicate both the surgery and the recovery process. These conditions increase the risk of cardiovascular events, such as heart attacks and strokes, during and after surgery. Respiratory complications, including postoperative pneumonia and hypoxemia (low blood oxygen levels), are also more common in this patient population.

Strategies to Mitigate Risks

Mitigating the risks associated with high BMI in DIEP flap surgery involves a multi-faceted approach, focusing on preoperative, intraoperative, and postoperative strategies. These strategies aim to optimise patient health, improve surgical outcomes, and enhance recovery.

Preoperative Strategies

1. Weight Management and Preoperative Weight Loss:

1. • Achieving a healthier BMI before surgery can significantly reduce the risk of complications. Even a modest weight loss can improve cardiovascular health, enhance immune function, and decrease the risk of infections.
   • Collaborating with dietitians and nutritionists to develop personalised weight loss plans that include balanced diets, portion control, and regular physical activity is crucial.
   • Structured weight loss programmes or bariatric surgery may be considered for patients with very high BMI who face severe health risks.

2. Optimising Comorbid Conditions:

1. • Managing chronic conditions such as diabetes, hypertension, and obstructive sleep apnoea is essential. Ensuring these conditions are well-controlled can reduce the risk of perioperative complications.
   • Regular monitoring and adjusting medications as needed, in consultation with primary care physicians and specialists, can help stabilise these conditions before surgery.

3. Smoking Cessation:

1. • Smoking significantly impairs wound healing and increases the risk of complications. Patients will be encouraged to quit smoking well before surgery.

4. Nutritional Optimisation:

1. • Adequate nutrition is vital for wound healing and recovery.
   • Supplements such as vitamin C, zinc, and iron may be recommended to boost immune function and support tissue repair.

5. Physical Conditioning:

1. • Improving physical fitness through regular exercise can enhance cardiovascular health and improve respiratory function. Even light to moderate exercise can be beneficial.
   • Tailoring exercise programmes to individual capabilities and limitations can ensure they are both effective and safe.

Intraoperative Strategies

1. Enhanced Surgical Techniques:

1. • Using advanced surgical techniques and technologies can reduce operative time and minimise tissue trauma. This includes meticulous handling of tissues and precise microsurgical techniques to ensure adequate blood supply to the transplanted flap.
   • Employing intraoperative imaging tools, such as Doppler ultrasound, can help in assessing blood flow and ensuring the viability of the flap.

2. Optimised Anaesthesia Management:

1. • Working closely with anaesthesiologists to develop customised anaesthesia plans that consider the specific needs and risks of obese patients is crucial. This includes strategies for safe intubation, maintaining adequate ventilation, and monitoring for potential complications.
   • Using regional anaesthesia techniques where appropriate can reduce the need for general anaesthesia and its associated risks.

3. Prophylactic Measures:

1. • Administering prophylactic antibiotics to prevent infections and using techniques such as sterile draping and proper aseptic methods can reduce the risk of surgical site infections.
   • Implementing measures to prevent deep vein thrombosis (DVT), such as the use of compression stockings and anticoagulant medications, can mitigate the risk of postoperative blood clots.

Postoperative Strategies

1. Intensive Monitoring and Early Intervention:

1. • Close postoperative monitoring in a high-dependency unit can ensure early detection and management of complications. Regular assessments of the surgical site, vital signs, and overall health status are essential.
   • Prompt intervention at the first sign of complications, such as infections or wound breakdown, can prevent more severe outcomes.

2. Enhanced Wound Care:

1. • This includes guidance on dressing changes, signs of infection, and when to seek medical attention.
   • Using advanced wound care products, such as antimicrobial dressings and negative pressure wound therapy, can promote healing and reduce the risk of infections.

3. Rehabilitation and Physical Therapy:

1. • Engaging in postoperative rehabilitation and physical therapy can aid in recovery. Tailored exercises can improve mobility, enhance strength, and prevent complications such as pneumonia and DVT.

4. Nutritional Support and Continued Weight Management:

1. • Continuing to focus on nutrition and weight management postoperatively can support long-term health and prevent complications. Patients should maintain a balanced diet and follow any dietary recommendations provided by healthcare professionals.
   • Regular follow-up appointments to monitor weight and provide ongoing support for weight management can help sustain the benefits achieved preoperatively.

FAQs about BMI over 35 an DIEP Flap Surgery

Can a patient with a BMI over 35 still be a candidate for DIEP flap surgery?

• Yes, patients with a BMI over 35 can still be candidates for DIEP flap surgery. However, they may face increased risks of complications. It is essential for these patients to undergo thorough preoperative evaluations and discuss the potential risks and benefits with their surgeon. Weight management and addressing comorbid conditions before surgery can improve outcomes and make the procedure safer.

What lifestyle changes can help reduce surgical risks for high-BMI patients?

• High-BMI patients can reduce surgical risks by making several lifestyle changes, including adopting a balanced diet, engaging in regular physical activity, quitting smoking, and managing stress. These changes can help improve overall health, enhance immune function, and promote better wound healing.

How does obesity affect the recovery time after DIEP flap surgery?

• Obesity can extend the recovery time after DIEP flap surgery due to increased risks of complications such as infections, delayed wound healing, and wound breakdown. High-BMI patients may require more frequent follow-up visits, additional wound care, and longer periods of rest and rehabilitation.

Further Reading about DIEP Flap Surgery with Sydney Specialist Plastic Surgeon Dr Bish Soliman

• Read Dr Bish Soliman’s Blog about Returning to Exercise after DIEP Surgery
• Read Dr Bish Soliman’s Blog about What to Expect during Recovery after DIEP surgery
• Read Dr Bish Soliman’s Blog about How to Reduce Scars after DIEP Surgery
• Read Dr Bish Soliman’s Blog about Secondary Procedures after DIEP
• Read Dr Bish Soliman’s Blog about Combining DIEP Flap with Other Reconstructive Techniques

Medical References about BMI and DIEP Flap Surgery

• Higher BMI Ups Complications After Flap Reconstruction – BreastCancer.org
• Impact of body mass index on free DIEP flap breast reconstruction: A multicenter cohort study
• Patient Selection For DIEP Flap Breast Reconstruction In The Obese Population: Stratifying Surgical Risk Factors For Patient Inclusion Or Exclusion
• Obesity Affects DIEP Flap Outcomes and Donor Site Complications
• Retrospective Review of Obesity and Its Impact on Complications in Patients Undergoing Autologous Abdominal Free Flap for Breast Reconstruction