Autologous Fat Transfer in Secondary Carpal Tunnel Release.

Median nerve compression in carpal tunnel syndrome (CTS) is currently the most common hand neuropathy. The symptoms depend on the advancement of the disease and increase gradually, beginning with paresthesias and pain (especially during the night) and culminating in hypesthesia of the hand accompanied by weakness and a loss of precision and strength.1 The disease stage is confirmed by electrodiagnostic (electromyography, EMG) evaluation. Both conservative and surgical treatments are used for the management of CTS. Conservative treatments include wrist splints, corticosteroid injections, and rehabilitation. These conservative approaches are effective during the early phase of the disease and sometimes allow for the postponement of surgical interventions.2 CTS is most successfully treated with operative techniques (endoscopic, mini-invasive, or open).3–7 The aim of surgical treatment is nerve decompression by dividing the transverse canal ligament and the distal part of the antebrachial fascia (AF). Consequently, the pressure in the canal is decreased, and the volume of the tunnel space is increased. Under such conditions, the median nerve fibers are able to regenerate.8,9 After surgical treatment, most patients confirm immediate or delayed improvement. In case of advanced disease accompanied by prolonged numbness in the fingers and hand weakness due to substantial thenar muscle atrophy, recovery can be delayed for months or even up to a year. In addition, due to severe nerve damage, only partial regeneration of the fibers may occur. Some patients must accept that neither entire sensory nor motor abilities can be restored. However, even if some functions are irreversibly lost, most patients report positive aspects of the treatment (such as the resolution of night pains and the progressive improvement of manual function). Although the results of the treatment of CTS are mostly satisfactory, there is a small but significant group of patients who experience persistent or recurrent symptoms even after surgical management.10,11 In few cases, a patient may not experience any relief after treatment (persistent symptoms). Usually, patients confirm the partial amelioration of symptoms, for example, the resolution of night pains but with persistent numbness. Practically, recurrence is diagnosed after a period (usually some months) of actual improvement of symptoms. In patients with prolonged symptoms who have undergone surgery, other reasons for the recurrence or persistence of symptoms that are not related to CTS should also be excluded. It is important to consider that various general disorders can produce similar symptoms.12 Because postoperative recovery requires time, we usually observe a decreasing intensity of symptoms. However, the duration of observation required for patients lacking improvement is unclear. No consensus has been reached among authors with regard to this time period, and most patients undergo repeated surgical interventions between 12 and 30 months after the first intervention.11 Most likely, an observation period of 6–9 months is adequate for further electromyographic examination. A patient who presents clinical symptoms and a confirmed lack of recovery based on electrodiagnostic criteria may be qualified for a secondary revision. Two main reasons for recurrence or persistence have been hypothesized by some authors, including a technical mistake and/or scarring; however, the pathogenesis of symptom recurrence or persistence remains unclear. Because abundant scarring (ABS) is usually observed in the carpal tunnel, we propose the use of autologous fat transfer (AFT) during secondary revision, which has been motivated by encouraging outcomes achieved with other applications of fat grafting for tissue regeneration, skin quality improvement, and scarring inhibition. This is a pilot study to demonstrate the feasibility and application of AFT during secondary carpal tunnel release (SCTR).