Sufficient mesh polyhedral intralesional injection for treatment of keloids

The recurrence of keloids after intralesional injections is significant, and a review of the literature shows an inconsistent range of success rates. In this study, the modified medical proportion and intralesional injection method were intended to enhance the treatment effect.

It is advocated to treat them in a timely and effective manner.
A wide variety of modalities have been used to treat keloids, as no "gold standard" has been determined for an ideal treatment. 9stepwise algorithm for the treatment of keloids based on the characteristics and responsiveness of the scar presents the best management strategy.Combination therapy, including steroid injections, 5-fluorouracil (5-FU), and pulsed dye laser, has proven to be the optimal option for the nonsurgical management of keloids. 10 the past, injection therapy often required multifrequency treatments at an interval of 1-4 weeks for 1-2 years, which increased the pain and cost of the patients.This method was adopted to increase injection efficiency through the improvement of the injection method.

| MATERIAL S AND ME THODS
The study protocol conformed to the guidelines of the 1975 Declaration of Helsinki and was approved by the IRB.Twenty patients were enrolled in this study.Informed consent was obtained from all subjects.Patients who had previously been treated within the past 12 months, pregnant patients or recently planned pregnancy, lactating women, patients aged <15 years, patients with chronic renal failure, or patients with abnormal liver function or blood cell counts were excluded from the study.
The patients were administered regional block anesthesia before intralesional injection.Lidocaine (20 mg/mL), ropivacaine (7.5 mg/mL), and normal saline were configured in the ratio of 1:1:1 with local anesthetics.Local infiltration injection was performed at the base of the scar and the junction between the skin and the scar with 1-mL spiral syringe and 30-gauge needle.Next, triamcinolone acetonide (TAC) (40 mg/mL), 5-FU (25 mg/mL), and ropivacaine (7.5 mg/mL) were configured in a 2:1:4 ratio.The horizontal fan-shaped stratified injection and the vertical shaking pressurized injection of the intralesional solutions were administered in the keloid using a 1-mL spiral syringe and a 30-gauge needle.The injections were administered approximately 2 mm away from the scar base and the surface.The minimum volume of injection per square centimeter was approximately 3.5 mL.The delivered dose was adjusted according to the extent of the lesions but did not exceed 14 mL.
Assessments were carried out on the basis of patient satisfaction, observations and measurements of a blinded observer, and photographic records before and after the treatment.The Vancouver Scar Scale (VSS) was used to assess the scar before and after treatment.The full scores of the table included 15 points.VSS included four evaluation indexes of scars: melanin (m), 0-3 points; height (H), 0-4 points; vascular distribution (V), 0-3 points; and flexibility (P), 0-5 points.A higher score indicated a more serious scar.The Visual Analog Scale (VAS) was used to evaluate the degrees of pain and pruritus.The VAS includes two 10-point scales, in which 0 indicates no pain, 10 indicates severe pain, 0 indicates no pruritus, and 10 indicates severe pruritus.The observer also interviewed the patients and asked them about symptoms and any adverse events encountered during the study.The patient started the next injection when there was any sign of recurrence or scar residue after treatment.

TA B L E 2
The histogram of assessment of the keloids at end of the study.

| DISCUSS ION
There is no universally accepted treatment resulting in permanent keloid ablation. 4,11The ideal treatment must have a low side effect profile, be cost effective, and be easy to administer without the need for elaborate hardware. 9Because surgical methods are associated with trauma and a high risk of recurrence, patients are more likely to accept minimally invasive methods.The standard and most commonly used treatment is intralesional steroid injection. 1rticosteroids have powerful and long-lasting anti-inflammatory and anti-allergic effects. 12The corticosteroid inhibits an α2-macroglobulin, which, in turn, inhibits collagenase.Once this pathway is blocked, collagenase is elaborated, enabling collagen degeneration. 1C is one of the most widely used first-line drugs. 13A review of the literature yields an inconsistent range of success rates of TAC treatment.A series of literature reported that intralesional steroids can have improved efficacy and decreased adverse effects when combined with 5-FU. 4,9,115-FU, a pyrimidine analog with antimetabolite activity, has been shown in tissue culture to inhibit fibroblast proliferation. 14It also has an inhibitory effect on TGF-b-induced type I collagen gene expression in human fibroblasts. 15In conventional treatment, the dosages of TAC and treatment intervals have arbitrarily varied from 10 to 40 mg/mL administered at intervals of 4-6 weeks for several months or until the scar is flattened. 4,16In the combined treatment using TAC and 5-FU, the dosage of TAC was 4 mg/mL, and that of 5-FU was 45 mg/mL. 4,11The maximum volume of injection per square centimeter should not exceed 0.5 mL.The delivered dose was adjusted according to the extent of the lesions but did not exceed 2 mL per session. 4,11,16e combination of TAC, 5-FU, and ropivacaine plays a multidimensional therapeutic and inhibitory effect on scars, and it also  In an adequate intralesional injection, the minimum volume of injection per square centimeter was approximately 3.5 mL, and the total amount should not exceed 14 mL.The dosage of TAC was 40-160 mg, and that of 5-FU was 12.5-50 mg.The dosage of TAC was increased, whereas the dose of 5-FU was similar to that in previous literature, which reduces the number of treatments and improves treatment efficiency.In addition, the solution dose was increased to provide a carrier for sufficient mesh polyhedral injection, rendering more uniform drug effect.
In terms of injection method, a sufficient mesh polyhedral injection was performed.The core of a keloid is solid, hard, and inelastic.When the drug is excessive, it is more evenly distributed in the scar.According to mechanical theory, the keloid can be regarded as a uniform, continuous, and isotropic deformable fixed material in a relatively balanced state.The result of its horizontal force, vertical force, and bending movement is equal to 0. Therefore, when an external force is applied to the pathological scar, the resultant tensile fracture (fracture failure) and shear dislocation (flow failure) destroy its balanced and stable state.At the outermost edge of the scar, where the section changes suddenly, and the stress is concentrated, pressure shaking needle injection can effectively penetrate the scar tissue and cause artificial damage to the fibers and scar surface.This method can not only promote the uniform effect of drugs but also reduce the material strength of the pathological scar and cause fatigue and damage.This treatment did not increase the number of adverse reactions.
The most prominent reaction is menstrual disorder, but it returns to normal after a period of time following treatment.In traditional intralesional injection, problems such as normal tissue atrophy and injection pain cannot be ignored.In our method, regional block anesthesia (lidocaine, ropivacaine) was performed at the base of the scar and the junction between the skin and scar.It can effectively block sensory nerve conduction into the pathological scar and reduce the pain of follow-up injection.In addition, local anesthetics can block subsequent drugs from normal tissue to a certain extent.Long-acting and slow-onset ropivacaine mixed with short-acting and fast-onset lidocaine can speed up the onset time and reduce toxic reactions.

| CON CLUS ION
The method of sufficient mesh polyhedral injection can effectively enhance the effects of treatment and reduce treatment frequency for keloids.
reduces side effects.Corticosteroids inhibit immunity by affecting cell material metabolism, inhibiting transcription factors, and inducing lymphocyte apoptosis.Local corticosteroids injection may lead to redness, swelling, blistering, skin atrophy, and necrosis.5-FU is an anti-metabolic drug, which can interfere with the intracellular material metabolism of fibroblasts and vascular endothelial cells in scars.Consequently, it can inhibit the adverse reactions caused by corticosteroids injection.Ropivacaine can not only dilute the solution but also increase the duration of the analgesic effect.

F I G U R E 1
Outcome of once intralesional injection treatment for chest keloid.F I G U R E 2 Outcome of once intralesional injection treatment for chest keloid.F I G U R E 3 Outcome of twice treatments for multiple keloids in the chest.
Demographic features and assessment of the keloids at end of the study.Note: VSS/VAS 1, the scores of VSS/VAS before treatment.VSS/VAS 2, the scores of VSS/VAS at the end of the study.