Preoperative assessment and planning for patients undergoing spine surgery

1

What are some factors which influence complication rates associated with spinal procedures?

• Type of procedure

• Whether elective or emergency

• Chronologic age of the patient

• General health status of the patient and medical comorbidities

• Institution where surgery is performed

2

What are some examples of types of elective spinal procedures that are associated with a relatively low risk of complications and perioperative morbidity?

When performed in patients without significant medical comorbidities, elective spinal procedures associated with a relatively low-risk profile include:

• Lumbar microdiscectomy

• Lumbar laminectomy

• Anterior cervical discectomy and fusion

• Single-level lumbar spinal instrumentation and fusion (anterior or posterior)

3

What are some examples of types of spinal procedures associated with a relatively high risk of complications and perioperative morbidity?

Spinal procedures associated with a relatively high-risk profile, often referred to as complex spinal procedures, include:

• Surgery involving >6 spinal levels or lasting >6 hours

• Revision spinal deformity procedures

• Same-day or staged multilevel anterior-posterior spinal procedures or circumferential multilevel spinal procedures performed through a single posterior surgical approach.

• Emergent spinal procedures for trauma, infections, and tumors, especially if associated with preoperative neurologic deficit.

• Spine surgery in patients with significant medical comorbidities (coronary artery disease, congestive heart failure, cirrhosis, dementia, emphysema, renal insufficiency, pulmonary hypertension, stroke, age >80 years, chronic steroid use, pediatric spinal deformities due to neuromuscular or syndromic disorders).

4

How is the surgical invasiveness of spinal procedures quantified?

Increased surgical invasiveness is correlated with higher intraoperative blood loss, longer surgical times, and increased risk of developing a surgical site infection requiring return to the operating room for treatment. Mirza et al. (5) developed an index to characterize the invasiveness of spine surgery and quantify spine surgery complexity. Points are assigned per vertebral unit (defined as one vertebra and the caudal intervertebral disc) based on each surgical component performed at each vertebral unit: anterior decompression (ad), anterior fusion (af), anterior instrumentation (ai), posterior decompression (pd), posterior fusion (pf), and posterior instrumentation (pi). For example:

• L4–L5 posterior discectomy: invasiveness score is 1 (pd = 1)

• C6–C7 anterior cervical discectomy, fusion, and plating: invasiveness score is 5 (ad = 1 [one disc] + af = 2 [two vertebra] + ai = 2 [two vertebra]).

• L4–L5 laminectomy, posterolateral fusion, posterior pedicle instrumentation, and interbody fusion: invasiveness score is 10 (pd = 2 [two vertebra] + pi = 2 [two vertebra] + pf = 2 [two vertebra] + af = 2 [two vertebra] + ai = 2 [two vertebra]).

5

What tools may assist surgeons in stratifying spine surgery risks as a guide to counseling patients regarding their procedure-specific risks for complications prior to deciding to have surgery?

Patients considering spinal surgery may be counseled regarding their specific risk for medical complications, infection, and dural tear, based on their personal comorbidity profile and the surgical invasiveness of the proposed operative intervention using an online risk calculator (SpineSage™). Risk factors considered in this predictive model include chronic obstructive pulmonary disease (COPD), asthma, congestive heart failure, prior cardiac complications, body mass index (BMI), diabetes, renal conditions, age, gender, spinal diagnosis, prior spine surgery, and whether the surgery is a revision procedure. Surgical invasiveness is determined based on the number of spinal levels that are decompressed, fused, or instrumented, and whether the surgical approach is anterior or posterior. Additional surgical risk calculators are available online and include the Seattle Spine Score and the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) Surgical Risk Calculator. Recently, frailty scores rather than chronologic age have been suggested for use in preoperative risk stratification prior to adult spinal deformity surgery, as frailty has been shown to be a better predictor of adverse events compared to chronologic age.

6

Once a patient and surgeon decide to pursue spine surgery, what are some important areas to address to optimize the patient for surgery?

The details and sequence for presurgical assessment varies based on multiple factors, including patient age, medical comorbidities, procedure type and magnitude, surgical acuity, and whether the surgical procedure is performed in an inpatient or outpatient facility. Patients undergoing major spine surgery are increasingly evaluated and managed using systems-based protocols, which comprehensively evaluate patients prior to surgery and guide intraoperative and postoperative management to optimize surgical outcomes. Such protocols often include:

• (1)

  Comprehensive assessment by the spine surgeon who:

  • performs a detailed preoperative medical history and physical examination

  • obtains appropriate radiographs and spinal imaging studies

  • develops and finalizes a detailed surgical plan

  • coordinates equipment and personnel required for the surgical procedure

  • obtains informed consent for surgical procedure

  • orders appropriate preoperative testing according to when the specific test has a reasonable pretest probability of being abnormal, and when the abnormal test result would directly impact perioperative care. These tests may include:

    • i.

      complete blood count (CBC)

    • ii.

      comprehensive metabolic panel (CMP)

    • iii.

      hemoglobin (hgb) A1c

    • iv.

      albumin and prealbumin levels (baseline nutritional status)

    • v.

      chest x-ray (CXR)

    • vi.

      electrocardiogram (ECG)

    • vii.

      bleeding profile (prothrombin time, partial thromboplastin time, bleeding time)

    • viii.

      urine analysis

    • ix.

      type and screen or type and cross-match if blood transfusion may be required

    • x.

      pregnancy (as indicated)

    • xi.

      urine screening for nicotine use and controlled substances (select patients)

• (2)

  Multidisciplinary spine conference (for complex spine surgery cases) to confirm that the patient is a reasonable candidate for the proposed surgical procedure from medical, anesthesia, rehabilitation medicine, and surgical perspectives.

• (3)

  Preoperative anesthesia consultation.

• (4)

  Appropriate subspecialty medical consultations as indicated for specific medical comorbidities.

• (5)

  Optimization of modifiable conditions such as nutritional status, diabetes control, tobacco use, alcohol abuse, osteoporosis, and opioid use to decrease risk of related complications.

• (6)

  Patient education course with patient and caregivers to review surgery preparation and postoperative care details.

• (7)

  Presurgical conference with surgeon, patient, and family members, which covers a range of topics, including presurgical education, diagnosis, available treatment options, informed consent, and expectations regarding recovery, including discharge planning.

7

List key areas to assess during the preoperative medical evaluation of a patient undergoing major spinal reconstructive surgery.

• Cardiovascular: Assess for risk factors such as coronary artery disease history, congestive heart failure, hypertension, carotid disease, history of transient ischemic attacks (TIAs), peripheral vascular disease and/or vascular claudication, history of thromboembolic disease, presence and types of stents or pacemaker, use of antiplatelet therapy or anticoagulants. Investigate for presence of cardiac disease in patients with congenital spinal deformities.

• Pulmonary: Recognize patients at risk for pulmonary complications, including patients with severe neuromuscular disorders, severe thoracic scoliosis, COPD, asthma, sleep apnea, emphysema, poor exercise tolerance, and tobacco use.

• Neurologic: Document preoperative neurologic status and baseline cognitive status. Check antiseizure medication levels when appropriate.

• Hematologic: Inquire regarding history of abnormal bruising or bleeding, or conditions associated with coagulopathy, including renal and hepatic disorders. Assess issues regarding blood donation and blood transfusion. Determine plan for management of nonsteroidal antiinflammatory drugs (NSAIDs), aspirin, antiplatelet and other anticoagulant medications in the perioperative period.

• Endocrine: Assess risk factors for osteoporosis and order testing as indicated (DEXA scan, Vitamin D level), optimize control of blood glucose in diabetic patients, determine need for perioperative steroids in chronic steroid users or adrenal insufficiency.

• Renal: Document history of chronic renal insufficiency. Additional precautions and preoperative consultations required for patients potentially requiring or in need of dialysis.

• Hepatic : Document history of chronic or active liver disease due to association with thrombocytopenia, coagulopathy, encephalopathy, sepsis, renal failure, and increased perioperative morbidity.

• Rheumatologic : Assess for cervical instability, especially in rheumatoid arthritis patients. Consultation indicated for perioperative management of disease-modifying antirheumatic drugs as appropriate.

• Immune status : Caution is required if surgery is planned for immunocompromised patients (e.g., oncology, human immunodeficiency virus [HIV], rheumatology patients) due to associated comorbidities.

• Nutritional status : Assess nutritional status and correct any deficits prior to elective surgery due to association with impaired wound healing and increased risk of infection.

• Orthopedic : Assess for extremity contractures, presence of total joint replacements, cervical instability, or previously undiagnosed cervical myelopathy, which may influence safe patient positioning prior to and during spine surgery.

• Medications : Obtain a list of all medications and nutritional supplements, evaluate potential impact on spine surgery and hemostasis, and determine a plan for perioperative medication management in coordination with medical subspecialists.

• Patient habits : Inquire regarding history of smoking, alcohol use, narcotic use, and address these areas prior to surgery by referral to a smoking cessation program, psychosocial evaluation, or pain management specialist.

• Psychological and social factors : Assess barriers to recovery including depression, chronic pain, and lack of home/family support, and refer for psychosocial evaluation as appropriate.

• Rehabilitation : Refer patients with poor exercise tolerance to preoperative rehabilitation program (prehabilitation) to improve ambulation, strength, and facilitate postoperative recovery.

• Weight-management : Morbidly obese patients (>40 kg/m ² ) are referred to a nutritionist for a weight-loss program consisting of diet and exercise, or to bariatric surgery.

8

What are the three leading causes of death after noncardiac surgery?

Cardiac events, major bleeding, and sepsis in the perioperative period are the three leading cause of death after noncardiac surgery.