The overall goal of this surgical intervention is to reduce the pain of end-neuromas by neuroma excision and fat grafting around the remaining nerve stump. SVF-enriched fat grafting can prevent the pain recurrence in peripheral neuromas. Both the mechanical and biologic features of the graft may contribute to this effect.
Specifically, painful neuromas of the superficial branch of radial nerve can be treated, but the technique can be extended to any neuroma throughout the body. This method can also provide insight into the biologic effects of the stromal vascular fraction. Furthermore, it can also be applied to scleroderma, osteoarthritis, and thermal burn injuries.
The text protocol goes over diagnosis and surgical preparations. Here, we begin with the surgery performed on a human patient. To start, make several small stab incisions in the area of liposuction, using a number 11 scalpel.
Each incision should be approximately three to five millimeters in diameter and be incised down to the subcutaneous layer. Next, inject the tumescent solution containing a dilute lidocaine and epinephrine via a 14 gauge infiltrator, three millimeters into the subcutaneous fat layer where the fat will be removed. Allow about 20 minutes for the tumescent solution to take effect before proceeding.
To harvest adipose tissue, attach three millimeter collecting cannula to a 60 milliliter Toomey syringe. Operate the cannula with the dominant hand and control placement and course of the cannula with the non-dominant hand. To prepare the syringe, pull back the plunger to the 60 milliliter mark and secure it using a mosquito clamp to maintain a vacuum therein.
Then, harvest at minimum 220 milliliters of adipose tissue. Use additional syringes, as needed, and collect from different locations to avoid taking blood. Keep the tissue-loaded syringes vertical in a dedicated stand to allow the fat to separate from the fluid.
Once enough lipoaspirate has been harvested, suture the stab incisions with simple stitches and apply pressure, as required. Then, set aside one syringe of lipoaspirate and transfer the remaining bulk of it into a single-use, disposable receptacle for the isolation system. To operate the isolation system, follow the instructions on the display.
The process is mostly software controlled and only requires user affirmation at the display prompts. The processing system moves the lipoaspirate into a collecting canister, weighs the sample, and automatically cleans it with ringers lactate solution to remove residual blood cells and wetting solution. If requested, add more fat, then, add the required volume of enzyme reagent for the digestion.
Once digested, the lipids and SVF will be separated. Next, the SVF is automatically separated by centrifugation and washed with ringers lactate solution to reduce residual enzyme levels. After 90 minutes, when the processing is completed, five milliliters of clear SVF fluid is produced.
To approach the neuroma, make a skin incision over the diagnosed site, which in this case, is three centimeters distal to the wrist. To identify the involved nerve, proximal to the neuroma, wear surgical binocular loupes and dissect the subcutaneous tissue. Once the full extent of the neuroma is exposed, use a straight, transneural scissor cut to excise the neuroma.
Proper identification of the neuroma is critical. Dissect until the nerve is visible and to identify the neuroma, simply follow the nerve distally until the neuroma formation is found. Next, perform neurolysis on the remaining nerve stump until the end of the nerve stump is located in the middle of the principle incision.
In this case, as no neuroma was present, neurolysis only was performed. Now, through epidermal and dermal cutis around the principle approach, make two to four small, one millimeter puncture incisions using a scalpel. Then, through the incisions, place four blunt cannulas paraneural to the nerve stump, with the cannula tips directed at the stump.
To ensure that the cannulas remain in situ, secure the cannulas with adhesive dressing. Special care should be taken to direct the cannulas precisely at the nerve stump and secure them in place, thus guaranteeing that the nerve stump can be totally covered by the stromal vascular fraction-enriched fat graft. Next, suture the main incision tightly so the graft solution that is to be delivered into the tissue via the cannulas will remain in situ.
Now, aspirate the five milliliters of processed SVF into one barrel of a ten milliliter communicating syringe. Then, transfer two milliliters of the sedimented lipid from the set aside Toomey syringe into the opposing barrel of the communicating syringe. Now, using the plungers, mix the SVF and lipids until the sedimented lipid is evenly distributed in the SVF.
Next, divide the seven milliliters of SVF-enriched fat graft equally into two to four 10 milliliter syringes. Then, carefully secure the two to four syringes to the cannulas and distribute the graft mixture around the nerve stump via the blunt cannulas. Once the graft has been delivered, remove the cannulas carefully.
Then, tape the small puncture incisions with Steri-Strips. Finally, the arm and wrist are bandaged for 10 days. The described procedure was implemented on the superficial branch of the radial nerve of five patients.
Their mean age was 50 years. Given the small sample size, the measured pain reductions were not statistically significant, however, there were reductions in all pain modalities at two months and at 36 months after the operation, with no reports of pain relapse. After watching this video, you should have a good understanding of the novel technique of SVF-enriched fat grafting for the treatment of painful neuromas.
Once mastered, this technique can be done in two hours, if it's performed properly. While attempting this procedure, it's important to remember that the neurolysis and/or neuroma removal needs to be done thorough in order to guarantee the maximum effect of SVF-enriched fat graft. Going forward, random trials with larger study population will be needed to demonstrate a statistically significant pain reduction.
Given the early positive results, the technique has been put to use to treat other body regions affected by painful neuromas.
