Efficacy and Safety of Sodium Hyaluronate Gel Combined With Sodium Bicarbonate Versus Sodium Bicarbonate Alone in Prevention of Failed Back Surgery Syndrome

Hypothesis:

We hypothesize that Sodium Hyaluronate Jell combined with Sodium Bicarbonate provides a safer and more efficient barrier in preventing Postoperative adhesions in spine surgery than spraying of Sodium Bicarbonate alone on the surface of dura and nerve roots after lumber spine surgery (Laminectomy) for L4-5 and /or L5- S1 disc prolapse.

Ethical Considerations

Before we start the study, we will take approval of the research ethical committee. Informed written consent will be obtained from study participants or their legally authorized representative.

Methodology using

I. Study design

Randomized controlled study

II. Study setting and location

The study will be conducted at the operative theatre of Souad Kafafi University Hospital-Misr University for science and Technology (MUST)

III. Study population:

Patients aged from 18 to 70 years old scheduled for Lumber Spine Surgery (Laminectomy) for L4-5 and/or L5-S1 disc prolapse.

Subjects presenting for Lumber Spine surgery will be randomized in a 1:1:1 ratio to either:

Group A(SH):

Receiving a prefilled syringe with Sodium Hyaluronate Gel after spraying a mixture of Sodium Bicarbonate 8.4%, lidocaine 2% and bupivacaine 0.5% on the surface of dura and nerve roots before closure of the wound.

Group B(SB):

Spraying a mixture of Sodium Bicarbonate 8.4%, lidocaine 2% and bupivacaine 0.5% on the surface of dura and nerve roots before closure of the wound. .

Group C:

Spraying a mixture of lidocaine 2% and bupivacaine 0.5% on the surface of dura and nerve roots before closure of the wound. .

IV. Eligibility Criteria

• Inclusion criteria

• Patients scheduled for Lumbar Spine surgery (L4-5 and/or L5-S1 Laminectomy) for disc prolapse.
• Patients aged >18 years old and below 70 years old.
• Patients with American Society of Anesthesia (ASA) classification I or II (i.e. ASA classification I: A normal healthy patient, for example: no chronic disease, non-smoking, no or minimal alcohol consumption, BMI<30). (ASA classification II: patients with mild systemic disease, for example: well controlled diabetes/hypertension, smokers, obesity (30 < BMI < 35 )
• Exclusion criteria

• Patients aged < 18 years old and above 70 years old.
• Patients who refuse to participate
• Patients on Chronic opioid use (addicts, cancer patients receiving palliative treatment,)
• Patients with ASA classification III or more: patients with life threatening medical conditions, for example: recent myocardial infarction, sepsis, severe cardiac valve dysfunction.
• Patients with coagulopathy or full anticoagulation.
• Patients with history of aggressive scar formation.
• Patients with causes of low back pain other than disc prolapse.
• Patients with previous lumbar spine surgery.
• Patients with anemia or acid base disturbances or electrolyte disorders.

V.Study Procedures

• Randomization Patients will be randomly allocated by a computer-generated table into one of the study groups; the randomization sequence will be concealed in sealed opaque envelopes.
• Study Protocol

• All Patients will have a pre-operative assessment visit, which will include; history taking, complete physical examination and review of all the results of the routine investigations (CBC, Coagulation profile, renal functions, liver functions, electrolytes).
• On Arrival to the preparation room, they will receive the following premedication via intravenous (IV) route: Midazolam 0.03 mg/kg, ondansetron 4 mg & omeprazole 40 mg iv infusion.
• Upon Arrival to the operating room, the standard Monitoring will be applied which include: Pulse Oximeter, Noninvasive Blood Pressure & Six-lead electrocardiogram (ECG).

The General Anesthesia will be induced using: Propofol 1-2mg/kg, Fentanyl1-2 μg/kg, morphine 0.1mg/kg and Atracurium 0.5 mg/kg. General anesthesia will be maintained using Sevoflurane 1-2 MAC (Mean Alveolar Concentrations) in O2/ Air 50% / 50%, Paracetamol 1gm iv infusion, ketolac 30 mg iv and incremental doses of Atracurium 0.1mg/kg/30 minutes.

At end of the surgery and before wound closure the surgeon will spray the medications on the surface of the dura and nerve roots according to each patient group class.

The patients will be randomly classified into three groups Group A (SH): (Sodium Hyaluronate Gel and Sodium Bicarbonate);

Group B (SB): (Sodium Bicarbonate only);

Group C : control group

VI.Study outcomes

Primary Outcome Measures:

● Grade of epidural fibrosis: as measured by lumbar MRI with contrast at 3 and 6 months after surgery compared with the preoperative lumber MRI.

Scar score ratings will be graded according to the degree of dural scar score in the spinal canal [11]. For each subject, five cross-sectional MR images will be checked, and each cross-sectional image will be divided into four quadrants, so that a total of 20 quadrant cross-sectional MR images per subject will be evaluated.

0= No scar

• 0-25% of quadrant filled with scar
• 25-50% of quadrant filled with scar
• 50-75% of quadrant filled with scar
• >75% of quadrant filled with scar

Secondary Outcome Measures:

• Postoperative pain score; will be measured by Numerical Rating Scale (NRS) score (0=no pain, 1-3=mild, 4-6=moderate 7-9=severe, 10=most severe) [10]
• Patient and doctor satisfaction with the results of surgery.
• Risk of complications from this technique.

Statistical Analysis

• Sample size:

Sample size calculation was based on mean Efficacy and Safety of Sodium Hyaluronate Gel combined with Sodium Bicarbonate in Prevention of Failed Back Surgery Syndrome retrived from previous research ( Ji et al., 2015) [12] . Using G power program version 3.1.9.4 to calculate sample size based on effect size 0.747 ,using 2-tailed test , α error =0.05 and power = 90.0%, the total calculated sample size will be 20 cases at least in each group.

• statistical analysis: Data will be analyzed using SPSS (statistical package for social sciences) version 22. Qualitative data will be presented as number and percent, Quantitative data will be tested for normality by Kolmogrov-Smironv test then described as mean and standard deviation for normally distributed data and median and range for non-normally distributed. The appropriate statistical test will be applied according to data type with the following suggested tests: Chi-Square for categorical variable, Student t test and Mann Whitney U test for continuous variables.

Inclusion criteria

This study will include patients scheduled for Lumbar Spine surgery (L4-5 and/or L5-S1 Laminectomy) for disc prolapse, Patients aged >18 years old and below 70 years old and Patients with American Society of Anesthesiologists (ASA) classification I or II.

Exclusion criteria

Patients aged < 18 years old and above 70 years old, Patients who refuse to participate, Patients on Chronic opioid use (addicts, cancer patients receiving palliative treatment), Patients with ASA classification III or more, Patients with coagulopathy or full anticoagulation, Patients with history of aggressive scar formation, Patients with causes of low back pain other than disc prolapse, Patients with previous lumbar spine surgery and Patients with anemia or acid base disturbances or electrolyte disorders will be excluded from this study.

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