Name: Stromal Vascular Fraction-enriched Fat Grafting for the Treatment of Symptomatic End-neuromata (Video) | JoVE Journal
Uploaded: 2017-11-23T13:00:00.000+00:00
Duration: 7 min 58 s
Description: Learn SVF-enriched fat grafting for treating painful end-neuromas through neuroma excision and biological grafting. This technique reduces pain recurrence using mechanical and cellular mechanisms in peripheral nerve surgery.

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5 minutes

The authors have no acknowledgements.

The protocol follows the guidelines of the University Hospital Zurich Human Research Ethics Committee.
1. Diagnoses of Neuromata and Patient Selection
<ol>
	<li>Perform preoperative nerve blocks proximal to the neuroma in order to confirm the diagnoses. Assess the blocks in the middle third of the forearm and exclude potential triggers of the overlapping innervation areas of the SBRN, such as the lateral antebrachial cutaneous nerve (LACN), posterior interosseous nerve (PIN), and a dorsal branch of ulnar nerve10.</li>
	<li>Perform surgery only in patients with considerable pain reduction (at least 5 points on the Visual Analog Scale (VAS) for pain)11.</li>
</ol>
2. Surgical Preparation
<ol>
	<li>Forbid the patient any food or liquid intake 6 h prior to the surgery.</li>
	<li>Place the patient in the middle of the surgical suite on a universal operative table in a beach chair position.</li>
	<li>Place the affected arm/hand on an arm rest.</li>
	<li>Ask the anesthetists to perform endotracheal anesthesia (fentanyl 2 &#181;g/kg, rocuronium 0.6 mg/kg, propofol 150 - 250 mg).</li>
	<li>Disinfect the skin with povidone iodine in the area of liposuction (e.g. inner thigh and/or upper/lower abdomen) and the site of neuroma excision.</li>
	<li>Cover the patient with sterile surgical drapes, leaving exposed the site of liposuction and the surgical site.</li>
</ol>
3. Tumescent Liposuction
<ol>
	<li>Make several small stab (puncture) incisions of approximately 3 - 5 mm diameter with a #11-blade scalpel in the area of liposuction. Incise as far as the subcutaneous layer is reached.</li>
	<li>Inject the tumescent solution containing a dilute lidocaine and epinephrine (500 mL Ringer&#39;s lactate solution, 20 mL of 1% lidocaine, and 1 mg epinephrine) via the 14-gauge infiltrator (infiltrating cannula) into the subcutaneous fat layer (3 mm in depth) in the region of fat harvesting.</li>
	<li>Wait for at least 20 min allowing the tumescent solution to take effect.</li>
	<li>Hook the 3 mm-collecting cannula (outer diameter 3 mm, length 26 cm) to a 60-mL Toomey syringe and start harvesting adipose via the stab incisions. 
	NOTE: The nondominant hand continually controls placement and course of the cannula.</li>
	<li>Pull back the plunger of the Toomey syringe to the 60-mL mark and place a mosquito clamp along the withdrawn plunger in order to maintain negative pressure in the syringe and avoid a continuous vacuum creation by the dominant hand.</li>
	<li>Harvest a minimum of 220 mL of adipose tissue by positioning the Toomey syringes in a vertical position in the provided Toomey syringe stand; this allows the sedimentation of the fat and separation from the fluid.</li>
	<li>Take special care to obtain a good quality fat graft without substantial amount of blood. 
	NOTE: Change the region of liposuction when augmented blood content is noticed.</li>
	<li>Suture the stab incisions with simple stitches and apply pressure as required (e.g. compressive belt).</li>
	<li>Transfer the lipoaspirate into a single-use sterile disposable set of the isolation system.</li>
	<li>Keep one Toomey syringe with lipoaspirate in the provided stand in order to obtain the fat fraction for later lipofilling.</li>
</ol>
4. Adipose Tissue Processing
<ol>
	<li>Close the sterile consumable set. 
	NOTE: The isolation system (see Table of Materials) confirms the completeness by performing a wet test.</li>
	<li>Follow the instructions on the display. 
	NOTE: The process is mostly software controlled and only requires the manual confirmation for the listed steps below by pressing the buttons &#34;next&#34; or &#34;back&#34; on the control panel. The lipoaspirate is transferred into the tissue collection canister. In the tissue collection canister, the lipoaspirate is weighed and automatically cleaned with Ringer&#39;s lactate solution in order to remove the residual blood cells and wetting solution.</li>
	<li>Add more fat if required. 
	NOTE: Depending on the weight of harvested adipose tissue the isolation system asks the user to add more fat or it calculates the amount of additional enzyme reagent to add.</li>
	<li>Add the required amount of enzyme reagent when prompted by the isolation system. 
	NOTE: During the process of enzymatic digestion, separation of lipid and the SVF is achieved. Thereby, the tissue is in oscillating motion. After the enzymatic digestion is completed, the SVF is automatically transferred into the centrifuge chamber for cell concentration. In the centrifuge chamber, the SVF is concentrated to a cell pellet (centrifuge speed is approximately 3,000 x g) . Finally, the cell pellet undergoes a series of washes with Ringer&#39;s lactate solution to reduce residual enzyme levels in the output. When the process is completed, 5 mL of clear fluid (SVF) is obtained.</li>
</ol>
5. Surgical Procedure
<ol>
	<li>To approach the neuroma, make a skin incision over the previously diagnosed neuroma site in the distal third of the forearm.</li>
	<li>Under the usage of surgical binocular loupes magnifier glasses (2.5 - 3.5X), continue to dissect the subcutaneous tissue and identify the involved nerve proximal to the neuroma.
	<ol>
		<li>Subsequently, follow the nerve distally and identify the neuroma (based on visual inspection).</li>
	</ol>
	</li>
	<li>Once the full extension of the neuroma is clear, begin to excise the neuroma by a straight trans-neural scissor cut. If no neuroma is identified, only neurolysis of the nerve is performed.</li>
	<li>Continue with the neurolysis of the remaining nerve stump until 3 cm proximal to the wrist. 
	NOTE: The end of the nerve stump should be located in the middle of the principal incision.</li>
	<li>Arrange two to four small puncture (stab) incisions (1 mm in diameter) with a scalpel through epidermal and dermal cutis around the principal approach.</li>
	<li>Place two to four blunt cannulas (16-gauge, length 9 cm) via the stab incisions perineural to the stump. 
	NOTE: The tip of the cannulas should be directed towards the nerve stump.</li>
	<li>Secure the cannulas in place by adhesive dressing.</li>
	<li>Place the stitches around the cannulas and leave the suture material in situ without securing the node.</li>
	<li>Suture the main incision tightly in order to prevent the outflow of grafting. 
	NOTE: Ensure that cannulas remain in situ.</li>
</ol>
6. Application of the SVF-enriched Fat Graft
NOTE: After approximately 1.5 h of processing, the 5 mL of the processed SVF is ready for further use.
<ol>
	<li>Aspirate 5 mL of SVF in a 10-mL communicating syringe.</li>
	<li>In the same manner, aspirate 2 mL of the sedimented lipid fraction in the opposing 10-mL syringe.</li>
	<li>Mix the 5 mL of SVF with the 2 mL of the sedimented lipid fraction by alternating pulling back the plunger of one syringe and pulling down the plunger of the communicating, opposing syringe until sufficient mixing is obtained.</li>
	<li>Divide the SVF-enriched fat graft equally in two to four 10 mL syringes.</li>
	<li>Distribute the prepared SVF-enriched fat graft one after the other equally around the nerve stump by connecting the syringes to the blunt cannulas. 
	NOTE: Before applying the graft, ensure that the cannulas are secured in the correct position and be careful not to dislocate the cannulas while applying the fat graft.</li>
	<li>Remove the cannulas carefully.</li>
	<li>Then, tape the small puncture incisions with steri-strips.</li>
	<li>Immobilize the hand by applying a splint in the intrinsic plus position (metacarpophalangeal (MCP) joints flexed at 60 -&#160;70&#176;, the interphalangeal (IP) joints fully extended, thumb in the fist projection, wrist in dorsal flexion of 25&#176;).&#160;If only neurolysis of the nerve is performed, no splint is needed and arm and wrist are bandaged for 10 days.</li>
</ol>
7. Postoperative Patient Handling
<ol>
	<li>Transfer the patient to the post-anesthesia recovery unit post-surgery, and allow for sufficient monitoring in the ward.</li>
	<li>Continue to immobilize the wrist for 10 days after the surgery.</li>
	<li>Perform the first change of bandages after 48 h post-surgery and continue at regular intervals (i.e. every second day until discharge).</li>
	<li>Remove the sutures 12 - 14 days postoperatively.</li>
	<li>Perform clinical assessment of pain during follow-up at 2, 6, 12, and 36 months.</li>
</ol>

<ol><li>Mackinnon, S. E., Dellon, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Results+of+treatment+of+recurrent+dorsoradial+wrist+neuromas%5BTitle%5D)+AND+%22Ann+Plast+Surg%22%5BJournal%5D)">Results of treatment of recurrent dorsoradial wrist neuromas.</a> Ann Plast Surg. 19 (1), 54-61 (1987).</li>
<li>Hazari, A., Elliot, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Treatment+of+end-neuromas%2C+neuromas-in-continuity+and+scarred+nerves+of+the+digits+by+proximal+relocation%5BTitle%5D)+AND+%22J+Hand+Surg+Br%22%5BJournal%5D)">Treatment of end-neuromas, neuromas-in-continuity and scarred nerves of the digits by proximal relocation.</a> J Hand Surg Br. 29 (4), 338-350 (2004).</li>
<li>Goldstein, S. A., Sturim, H. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Intraosseous+nerve+transposition+for+treatment+of+painful+neuromas%5BTitle%5D)+AND+%22J+Hand+Surg+Am%22%5BJournal%5D)">Intraosseous nerve transposition for treatment of painful neuromas.</a> J Hand Surg Am. 10 (2), 270-274 (1985).</li>
<li>Koch, H., Haas, F., Hubmer, M., Rappl, T., Scharnagl, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Treatment+of+painful+neuroma+by+resection+and+nerve+stump+transplantation+into+a+vein%5BTitle%5D)+AND+%22Ann+Plast+Surg%22%5BJournal%5D)">Treatment of painful neuroma by resection and nerve stump transplantation into a vein.</a> Ann Plast Surg. 51 (1), 45-50 (2003).</li>
<li>Vaienti, L., Merle, M., Battiston, B., Villani, F., Gazzola, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Perineural+fat+grafting+in+the+treatment+of+painful+end-neuromas+of+the+upper+limb%3A+a+pilot+study%5BTitle%5D)+AND+%22J+Hand+Surg+Eur%22%5BJournal%5D)">Perineural fat grafting in the treatment of painful end-neuromas of the upper limb: a pilot study.</a> J Hand Surg Eur. 38 (1), 36-42 (2013).</li>
<li>Zuk, P. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Multilineage+cells+from+human+adipose+tissue%3A+implications+for+cell-based+therapies%5BTitle%5D)+AND+%22Tissue+Eng%22%5BJournal%5D)">Multilineage cells from human adipose tissue: implications for cell-based therapies.</a> Tissue Eng. 7 (2), 211-228 (2001).</li>
<li>Fraser, J. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+Celution+System%3A+Automated+Processing+of+Adipose-Derived+Regenerative+Cells+in+a+Functionally+Closed+System%5BTitle%5D)+AND+%22Adv+Wound+Care+%28New+Rochelle%29%22%5BJournal%5D)">The Celution System: Automated Processing of Adipose-Derived Regenerative Cells in a Functionally Closed System.</a> Adv Wound Care (New Rochelle). 3 (1), 38-45 (2014).</li>
<li>Guo, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Stromal+vascular+fraction%3A+A+regenerative+reality%3F+Part+2%3A+Mechanisms+of+regenerative+action%5BTitle%5D)+AND+%22J+Plast+Reconstr+Aesthet+Surg%22%5BJournal%5D)">Stromal vascular fraction: A regenerative reality? Part 2: Mechanisms of regenerative action.</a> J Plast Reconstr Aesthet Surg. 69 (2), 180-188 (2015).</li>
<li>Lutz, B. S., Ma, S. F., Chuang, D. C., Chan, K. H., Wei, F. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Interposition+of+a+pedicle+fat+flap+significantly+improves+specificity+of+reinnervation+and+motor+recovery+after+repair+of+transected+nerves+in+adjacency+in+rats%5BTitle%5D)+AND+%22Plast+Reconstr+Surg%22%5BJournal%5D)">Interposition of a pedicle fat flap significantly improves specificity of reinnervation and motor recovery after repair of transected nerves in adjacency in rats.</a> Plast Reconstr Surg. 107 (1), 116-123 (2001).</li>
<li>Calcagni, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+novel+treatment+of+SVF-enriched+fat+grafting+for+painful+end-neuromas+of+superficial+radial+nerve%5BTitle%5D)+AND+%22Microsurgery%22%5BJournal%5D)">The novel treatment of SVF-enriched fat grafting for painful end-neuromas of superficial radial nerve.</a> Microsurgery. , (2016).</li>
<li>Hawker, G. A., Mian, S., Kendzerska, T., French, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Measures+of+adult+pain%3A+Visual+Analog+Scale+for+Pain+%28VAS+Pain%29%2C+Numeric+Rating+Scale+for+Pain+%28NRS+Pain%29%2C+McGill+Pain+Questionnaire+%28MPQ%29%2C+Short-Form+McGill+Pain+Questionnaire+%28SF-MPQ%29%2C+Chronic+Pain+Grade+Scale+%28CPGS%29%2C+Short+Form-36+Bodily+Pain+Scale+%28SF-36+BPS%29%2C+and+Measure+of+Intermittent+and+Constant+Osteoarthritis+Pain+%28ICOAP%29%5BTitle%5D)+AND+%22Arthritis+Care+Res+%28Hoboken%29.+63+Suppl%22%5BJournal%5D)">Measures of adult pain: Visual Analog Scale for Pain (VAS Pain), Numeric Rating Scale for Pain (NRS Pain), McGill Pain Questionnaire (MPQ), Short-Form McGill Pain Questionnaire (SF-MPQ), Chronic Pain Grade Scale (CPGS), Short Form-36 Bodily Pain Scale (SF-36 BPS), and Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP).</a> Arthritis Care Res (Hoboken). 63 Suppl. 63, Suppl 11. S240-S252 (2011).</li>
<li>Stokvis, A., van der Avoort, D. J., van Neck, J. W., Hovius, S. E., Coert, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Surgical+management+of+neuroma+pain%3A+a+prospective+follow-up+study%5BTitle%5D)+AND+%22Pain%22%5BJournal%5D)">Surgical management of neuroma pain: a prospective follow-up study.</a> Pain. 151 (3), 862-869 (2010).</li>
<li>Kolle, S. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Enrichment+of+autologous+fat+grafts+with+ex-vivo+expanded+adipose+tissue-derived+stem+cells+for+graft+survival%3A+a+randomised+placebo-controlled+trial%5BTitle%5D)+AND+%22Lancet%22%5BJournal%5D)">Enrichment of autologous fat grafts with ex-vivo expanded adipose tissue-derived stem cells for graft survival: a randomised placebo-controlled trial.</a> Lancet. 382 (9898), 1113-1120 (2013).</li>
<li>Zhu, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Adipocyte+regeneration+after+free+fat+transplantation%3A+promotion+by+stromal+vascular+fraction+cells%5BTitle%5D)+AND+%22Cell+Transplant%22%5BJournal%5D)">Adipocyte regeneration after free fat transplantation: promotion by stromal vascular fraction cells.</a> Cell Transplant. 24 (1), 49-62 (2015).</li>
<li>Eto, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Characterization+of+human+adipose+tissue-resident+hematopoietic+cell+populations+reveals+a+novel+macrophage+subpopulation+with+CD34+expression+and+mesenchymal+multipotency%5BTitle%5D)+AND+%22Stem+Cells+Dev%22%5BJournal%5D)">Characterization of human adipose tissue-resident hematopoietic cell populations reveals a novel macrophage subpopulation with CD34 expression and mesenchymal multipotency.</a> Stem Cells Dev. 22 (6), 985-997 (2013).</li>
<li>Premaratne, G. U., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Stromal+vascular+fraction+transplantation+as+an+alternative+therapy+for+ischemic+heart+failure%3A+anti-inflammatory+role%5BTitle%5D)+AND+%22J+Cardiothorac+Surg%22%5BJournal%5D)">Stromal vascular fraction transplantation as an alternative therapy for ischemic heart failure: anti-inflammatory role.</a> J Cardiothorac Surg. 6, 43(2011).</li>
<li>Paik, K. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Studies+in+Fat+Grafting%3A+Part+V.+Cell-Assisted+Lipotransfer+to+Enhance+Fat+Graft+Retention+Is+Dose+Dependent%5BTitle%5D)+AND+%22Plast+Reconstr+Surg%22%5BJournal%5D)">Studies in Fat Grafting: Part V. Cell-Assisted Lipotransfer to Enhance Fat Graft Retention Is Dose Dependent.</a> Plast Reconstr Surg. 136 (1), 67-75 (2015).</li>
</ol>

The authors have nothing to disclose.

The purpose of the present study is to methodically illustrate the technical aspects of SVF-enriched fat grafting as a novel treatment for symptomatic end-neuromata.
Neuromata of the SBRN are associated with a surgical success rate of only 33%12. Vaienti et al. presented a series of favorable results in early follow-up using perineural fat grafting (PFG) without adding the SVF in 8 patients with painful neuromata of the upper limb<sup c...

The management of symptomatic end-neuromata of the SBRN remains challenging with a multitude of existing surgical treatments. Principally, the neuroma is excised and the remaining nerve stump is relocated into neighboring structures such as muscles1,2, bone3, or veins4. This is assumed to prevent the out-sprouting of the regenerating neural fascicles by mimicking the ambience of an end-organ. However, none of these techniques proved superior, as high rates of pain relapse and insufficient pain reduction were often observed.
Recently, fat grafting around the remaining nerve stump yielded promising results and was advocated as a new treatment option for painful end-neuromata of the upper limb5. Besides acting as a mechanical barrier to prevent continuing motion and tap pain, the beneficial aspect of fat grafting is rather attributed to the cellular level. Human adipose tissue contains multiple cell types, including preadipocytes, mast cells, pericytes, endothelial cells, vascular smooth muscle cells, fibroblasts, and adipose derived stem cells (ADSCs) along with hematopoietic stem cells6. This heterogeneous cell population is referred to as Adipose-Derived Regeneration Cells (ADRCs) or SVF, and can be obtained from the lipoaspirate by an isolation system (see the Table Of Materials) and applied enzyme reagent (see Table of Materials)7. The exact mechanism of action is still not fully understood; however, SVF has been associated with improvements in angiogenesis, immunomodulation, differentiation, and secretion of extracellular matrix8.
The concentrated cell population of the SVF is added to the fat graft with the purpose to reduce the resorption rate and to increase the regenerative potential of the fat graft, as recent studies revealed pain relapse after 12 months with fat grafting without added SVF5. Moreover, the biological action also provides beneficial effects on the nerve itself by reducing disorganized axonal sprouting of the stump9 and subsequent scar adherences which might result in nerve entrapment.
The first clinical study to describe SVF-enriched fat grafting as a novel surgical option for the treatment of symptomatic end-neuromata of SBRN has been recently published10. In general, the technique can be applied to any neuroma occurring after accidental or iatrogenic nerve injury. The aim of the present subsequent study is to methodically illustrate the technical aspects of this procedure.

<table><tbody><tr><td>Cytori Celution System</td><td>Cytori</td><td></td><td>isolation system</td></tr><tr><td>Celase</td><td>Cytori</td><td></td><td>enyzme reagent</td></tr><tr><td>liposuction system</td><td></td><td></td><td></td></tr><tr><td>tumescent solution (500 ml Lactated Ringers, 20 ml of 1% lidocaine and 1 mg epinephrine)</td><td></td><td></td><td></td></tr><tr><td>14-gauge infiltrator</td><td></td><td></td><td></td></tr><tr><td>3 mm-collecting cannula (15, 26, 32 cm)</td><td></td><td></td><td></td></tr><tr><td>60 mL Tommey syringes</td><td></td><td></td><td></td></tr><tr><td>mosquito clamp</td><td></td><td></td><td></td></tr><tr><td>Toomey syringe stand</td><td></td><td></td><td></td></tr><tr><td>4 cannulas (fat injecting cannulas 1.5 mm, syringe NO.2, 90 mm)</td><td>Chalybs</td><td></td><td></td></tr><tr><td>10 mL syringes</td><td></td><td></td><td></td></tr><tr><td>connecting device for syringes</td><td></td><td></td><td></td></tr><tr><td>#11- and #15-blade scalpel</td><td></td><td></td><td></td></tr><tr><td>stevens scissors</td><td></td><td></td><td></td></tr><tr><td>pins pincette</td><td></td><td></td><td></td></tr><tr><td>bipolar electrocautery</td><td></td><td></td><td></td></tr><tr><td>suture material</td><td></td><td></td><td></td></tr><tr><td>adhesive dressing</td><td></td><td></td><td></td></tr><tr><td>binocular loupes magnifier glasses (2.5-3.5x)</td><td>Carl Zeiss</td><td></td><td></td></tr><tr><td>Statistical Package for Social Sciences, version 22</td><td>IBM</td><td></td><td></td></tr></tbody></table>

stromal vascular fraction-enriched fat grafting for the treatment of symptomatic end-neuromata

Stromal Vascular Fraction-enriched Fat Grafting for the Treatment of Symptomatic End-neuromata

The purpose of this study was to methodically illustrate and highlight the crucial steps of stromal vascular fraction (SVF)-enriched fat grafting as a novel treatment of symptomatic end-neuromata of peripheral sensory nerves, and in this study, specifically of the superficial branch of the radial nerve (SBRN). Despite a multitude of existing treatments, persistent postoperative pain and common pain relapse are still very common, independent of the procedure assessed. The neuroma is microsurgically excised accordingly to standardized protocol. Instead of the relocation of the regenerating nerve stump in neighboring anatomical structures, such as muscle or bone, a fat graft is applied perifocally and acts as a mechanical barrier. In order to reduce the fat resorption rate and boost the regenerative potential of the graft, the highly concentrated SVF is integrated in the grafting. The SVF is isolated from subcutaneous fat by enzymatic and mechanic separation of the lipoaspirate by a specific commercial isolation system. The SVF-enriched fat graft provides both a mechanical barrier and various biological effects at the cellular level, including improving angiogenesis, inflammation, and fibrosis. Both mechanical and biologic effects help to reduce the disorganized axonal outgrowth of the nerve stump during nerve regeneration and hence prevent the recurrence of painful end-neuromata.

Data were analyzed using statistical software and presented as means ± standard deviations. The Kolmogorov-Smirnov test was applied to verify the nonparametric distribution of the study population and confirmed a negative empirical distribution. Based on the nonparametric nature of the study population, the Wilcoxon's test for related samples was employed to compare preoperative and postoperative outcomes. Statistical significance was regarded at p-values less than 0.05<sup class=...

The purpose of the study is to illustrate the technical procedure of stromal vascular fraction (SVF)-enriched fat grafting as a novel treatment of symptomatic end-neuromata. This technique provides advantages of both the mechanical barrier and the biological action at the cellular level by the processed and concentrated SVF.

The purpose of this study was to methodically illustrate and highlight the crucial steps of stromal vascular fraction (SVF)-enriched fat grafting as a ...

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.

stromal-vascular-fraction-enriched-fat-grafting-for-treatment

Research

JoVE Journal

Medicine

Source: Zimmermann, S., et.al. Stromal Vascular Fraction-enriched Fat Grafting for the Treatment of Symptomatic End-neuromata. J. Vis. Exp. (2017)This video demonstrates the surgical procedure for neurolysis and stromal vascular fraction (SVF)-enriched fat grafting in the management of symptomatic neuroma. Neurolysis removes adhesion tissue to restore nerve gliding, while SVF-enriched fat grafting is applied around the nerve to create a protective barrier, support nerve healing, and enhance...

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