Understanding What Are Considered High-Risk Surgeries?

According to the Royal College of Surgeons, patients with a predicted hospital mortality of $\ge$5% are often classified as undergoing a high-risk surgery. Understanding what are considered high-risk surgeries is crucial for patients and their families to prepare for complex procedures and manage health expectations.

Quick Summary

An examination of high-risk surgeries, exploring the interplay between patient health conditions and procedural factors. It details various high-risk procedures, like complex cardiac and abdominal surgeries, and discusses how patient age, comorbidities, and the emergency nature of an operation significantly impact risk levels. This guide explains risk assessment and patient preparation strategies.

Key Points

• Risk is Multifactorial: A surgery's risk level depends on both the complexity of the procedure and the patient's individual health, age, and existing medical conditions.

• High-Risk Procedures Have Higher Complication Rates: Surgeries classified as high-risk are typically associated with an estimated mortality rate of over 5% and a higher incidence of major complications.

• Emergency Surgery Is Inherently Riskier: Operations performed on an emergency basis carry a significantly higher risk than elective procedures due to time constraints for patient optimization.

• Vascular, Cardiac, and Complex Abdominal Surgeries are High-Risk: Procedures on the aorta, heart, liver, and pancreas are consistently listed as high-risk due to their invasive nature and potential for large fluid or blood shifts.

• Patient Optimization is Key: Preoperative steps like managing chronic diseases, improving functional capacity, and quitting smoking are critical for mitigating risk in high-risk patients.

• Hospital Experience Matters for Complex Procedures: For certain intricate operations, better patient outcomes are observed in larger medical centers that perform these surgeries more frequently.

Surgical risk is a complex issue influenced by a combination of a patient's health status and the nature of the procedure itself. Healthcare providers classify surgeries into categories like low, intermediate, and high risk to help inform decision-making, manage expectations, and allocate resources effectively. What constitutes a high-risk procedure is not a single factor but a multifactorial assessment.

Defining High-Risk Surgery

Medical guidelines define high-risk surgery as any procedure associated with a significantly elevated risk of adverse outcomes, such as major adverse cardiac events (MACE) or mortality. While definitions may vary, a commonly accepted benchmark for high risk is a predicted mortality rate of $\ge$5%. These procedures typically involve substantial hemodynamic shifts, large fluid shifts, or significant potential for blood loss. The urgency of a surgery also plays a critical role, as emergency procedures are inherently riskier than elective ones, regardless of the procedure type.

Patient-Specific Risk Factors

Individual patient health can significantly influence the level of surgical risk. Some key factors include:

• Age: Older adults, particularly those over 65, face higher risks due to reduced physiological reserve and the increased likelihood of underlying health conditions. Frailty, a condition of reduced function and reserve, is also an important risk predictor, especially in older patients.
• Comorbidities: Pre-existing health issues are a major contributor to surgical risk. Critical conditions include:
  • Heart disease (e.g., ischemic heart disease, heart failure, severe valvular disease)
  • Chronic kidney disease
  • Insulin-dependent diabetes
  • Chronic pulmonary disease
• Obesity: An elevated body mass index (BMI) can increase the risk of complications such as infections, blood clots, and breathing problems.
• Lifestyle Choices: Smoking and excessive alcohol consumption are well-documented risk factors that can lead to poor wound healing and infections.
• Functional Capacity: A patient's physical reserve, or functional capacity, is a strong predictor of outcomes. Reduced functional status, often measured in Metabolic Equivalents (METs), is associated with increased perioperative risk.

Procedure-Specific Risk Factors

Beyond the patient's health, characteristics of the surgery itself determine risk levels. Factors include:

• Urgency: Emergency surgery is considerably riskier than elective surgery due to the patient's acute illness and the lack of time for preoperative optimization.
• Complexity and Duration: More extensive and lengthy procedures increase the likelihood of complications.
• Location: Surgeries involving major body cavities, such as the chest (intrathoracic) and abdomen (intraperitoneal), or major vascular structures (suprainguinal) are typically classified as high risk.
• Surgical Center and Volume: Studies show that for certain complex interventions, outcomes are better when performed in high-volume hospitals with experienced surgeons.

Examples of High-Risk Surgeries

Examples of procedures that fall into the high-risk category include:

• Vascular Surgery: Procedures on the aorta (abdominal or thoracic), peripheral vascular surgery.
• Complex Abdominal Surgery: Includes pancreatectomy, esophagectomy, bowel resections, and complex procedures involving the stomach or esophagus.
• Cardiac Surgery: Open-heart procedures, coronary revascularization, heart valve repair, and heart transplantation.
• Neurosurgery: Complex procedures on the brain and nervous system, such as cerebrovascular surgery for aneurysms or arteriovenous malformations.
• Organ Transplantation: Major transplant surgeries for organs like the heart, lung, liver, or kidney.
• Major Orthopedic Surgery: Complex joint revisions or spinal reconstruction.

Surgical Risk Classification Comparison

To understand the spectrum of risk, medical bodies like the ACC/AHA classify procedures based on estimated cardiac risk.

Feature	Low-Risk Surgery	Intermediate-Risk Surgery	High-Risk Surgery
Estimated Cardiac Risk	< 1%	1-5%	> 5%
Common Examples	Endoscopic procedures, cataract removal, superficial procedures, breast surgery	Orthopedic, urologic, uncomplicated abdominal or thoracic, head and neck	Aortic surgery, organ transplantation, complex abdominal, major vascular
Surgical Duration	Often short with minimal fluid shifts	Moderate duration with potential for some hemodynamic changes	Prolonged with large fluid and hemodynamic shifts
Invasiveness	Minimally invasive, superficial	Moderate invasiveness	Highly invasive

Managing and Mitigating High-Risk Surgery

Management for high-risk patients begins well before the operation, with careful preoperative assessment and optimization.

• Preoperative Assessment: This involves a thorough evaluation of the patient's overall health, including cardiovascular and pulmonary status, functional capacity, and frailty.
• Comorbidity Management: Optimizing pre-existing conditions like diabetes, hypertension, and heart failure is crucial for improving outcomes.
• Lifestyle Modification: Patients may be advised to quit smoking and moderate alcohol use in the weeks leading up to surgery to reduce complications.
• Goal-Directed Therapy: Intraoperatively, hemodynamic parameters can be managed to ensure adequate tissue oxygenation throughout the procedure.
• Postoperative Care: These patients often require close monitoring in a specialized unit, such as an Intensive Care Unit (ICU), to manage potential complications and support recovery.
• Informed Decision-Making: For elective procedures, patients should have detailed discussions with their surgical team about the risks and benefits to make informed decisions about their care.

Conclusion

While a variety of procedures can be classified as high-risk surgeries, the true measure of risk is a combination of the procedure's inherent complexity and the patient's underlying health and functional status. Open communication with the surgical team, diligent preoperative preparation, and comprehensive postoperative care are the cornerstones of ensuring the best possible outcome for patients facing complex operations. Awareness of these factors empowers patients and their families to navigate the surgical process with greater understanding.

For more detailed information on cardiac risk assessment in noncardiac surgery, consult the National Institutes of Health(https://www.ncbi.nlm.nih.gov/books/NBK537146/).

Frequently Asked Questions

What is the primary factor that determines if a surgery is high-risk?

The primary factor is a combination of the complexity and invasiveness of the procedure and the patient's health status, including comorbidities, age, and functional capacity.

Are older patients automatically considered high-risk for surgery?

Not automatically, but advanced age, especially over 65, is a significant risk factor because older adults often have less physiological reserve and may have more pre-existing health conditions.

Does an emergency procedure make a surgery high-risk?

Yes, emergency surgery is an independent and significant risk factor. The urgent nature of the procedure prevents adequate time for preparing and optimizing the patient's health beforehand.

What kind of vascular surgeries are considered high-risk?

Major vascular surgeries are considered high-risk, including procedures on the aorta (abdominal or thoracic) and peripheral vascular surgery involving large vessels above the groin.

How do doctors assess a patient's risk before surgery?

Doctors use several methods, including reviewing the patient's medical history, conducting a physical exam, assessing functional capacity (often using METs), evaluating frailty, and using risk prediction tools like the ASA-PS classification.

What is the difference between a high-risk and intermediate-risk surgery?

High-risk surgeries typically have an estimated cardiac complication rate above 5%, while intermediate-risk procedures have an estimated rate between 1% and 5%.

What steps can a patient take to reduce their surgical risk?

A patient can reduce risk by managing chronic health conditions, quitting smoking, abstaining from heavy alcohol use, and adhering to all preoperative instructions from their healthcare team.