] first reported reexploration for true recurrent CTS in 1963. Langloh and Linscheid [11
] subsequently detailed 34 cases of recurrent and unrelieved CTS, of which seven were true recurrences. The outcomes of these early studies are difficult to interpret, because patients with incomplete division of the transverse carpal ligament were included with patients who had true recurrence. Our technique of microneurolysis of the median nerve combined with a hypothenar pedicle flap for coverage in cases of recalcitrant CTS is a simple, effective technique that improves symptoms. However, the success of this procedure depends on distinguishing patients with true recurrent CTS and intracanal fibrosis from those with an incomplete initial release or tenosynovitis. In cases of incomplete release, the preoperative symptoms are often the same as before the operation without an intervening symptom-free period. Conversely, in cases of true recurrent CTS, symptoms are initially improved and then recur with an exacerbation of scar hypersensitivity and a significantly positive Tinel sign at the level of previous surgery. In all our patients, electrodiagnostic studies confirmed continued compression of the median nerve at the level of the wrist.
] described epineural fibrous fixations, which induced median nerve traction and resulted in traction neuropathies associated with recurrent CTS. To improve outcomes, he advocated a simple surgical mobilization of the median nerve followed by early functional nerve-gliding therapy. Louis et al. [12
] reported the results of simple neurolysis, which were disappointing in six of 26 cases with true recurrence. O’Malley et al. [17
] reported mixed results for 20 cases of repeat surgery for CTS; nine of these were incomplete releases, whereas 11 had true recurrence with fibrosis. Most authors now agree that coverage of the median nerve must be performed after any type of neurolysis [4
]. Multiple local pedicle muscle flaps for coverage of the median nerve have been described in an attempt to prevent adherence to surrounding tissue. These include flaps from the abductor digiti minimi [21
], the pronator quadratus [28
], the lumbrical [28
], and the palmaris brevis [22
]. Tham et al. [27
] described a reverse radial artery facial flap for treatment of recalcitrant CTS that had a satisfactory outcome in six patients. Varitimidis et al. [29
] treated 15 patients with recurrent compressive neuropathy of the median nerve at the wrist with autogenous saphenous vein wrapping and found significant pain relief and improvement in sensation at a mean follow up of 43 months. However, these previous reports were limited to short-term follow-up of small series of patients or were presented as technique papers alone.
Strickland et al. [25
] reported excellent results with the HTFPF in 62 hands at an average follow-up of 33 months. Mathoulin et al. [15
] used a modified HTFPF in 45 patients with recurrent symptoms of CTS and reported excellent results in 49%, good results in 45%, and average results in 4.5%; the therapy failed in only 4.5% of the 45 patients at an average follow-up of 45 months. The HTFPF has come under criticism recently for its inability to be wrapped circumferentially and its limited extent of proximal and distal coverage [8
]. Goitz and Steichen [8
] proposed microvascular omental transfer to provide more extensive coverage of the lysed median nerve. They reported high patient satisfaction in a series of nine extremities with an average follow-up of 6.6 years. However, most of these patients had already had local flaps that failed and required a laparotomy for flap harvest.
Other authors have argued that restoration of normal nerve excursion is more important than soft-tissue coverage in the treatment of recurrent CTS. Wilgis and Murphy [31
] demonstrated that nerves have longitudinal excursion, highlighting the importance of treating adherence in peripheral nerves to effectively treat the inciting lesion. Szabo et al. [26
] subsequently quantified the normal excursion of the median nerve within the carpal tunnel. Duclos and Sokolow [7
] described the treatment of 13 consecutive patients with true recurrent CTS. Their technique involved extensive neurolysis without the use of a vascularized flap. At an average follow-up of 27.5 months, 75% of their patients had complete relief of symptoms. Duclos and Sokolow suggested lack of normal nerve gliding as a major factor in symptom recurrence and recommended extensive neurolysis to help restore normal excursion.
Our approach combines many of the elements described above, namely restoration of nerve excursion and prevention of readherence, for a simple, effective treatment of recurrent CTS. The median nerve is first freed from the adherent radial leaf of the transverse ligament so that it can be brought into the operative field and inspected. This allows a determination of whether there is an hourglass deformity distorting the normal fascicular anatomy. Neurolysis is then performed under an operating microscope to remove the scarred epineurium to the level of normal fascicular alignment. Use of the microscope allows precise restoration of normal anatomy both proximally and distally to the area of scarring. Finally, use of the HTFPF through the same incision avoids a secondary donor site problem while simultaneously providing coverage to prevent readherance and create a suitable gliding bed for the nerve to restore normal excursion. Care should be taken to avoid internal neurolysis to prevent further fascicular scarring, which could be detrimental to outcome.
Our study reviewed the results of reoperation in a homogenous population of consecutive cases of true recurrent CTS treated with extensive microneurolysis and an HTFPF. Results were favorable for all patients. At latest follow-up, no patient who has undergone this procedure has had a recurrence, although recovery can average 6 to 9 months. The improvement in clinical symptoms in our patients compared with those reported previously can possibly be explained by the meticulous microneurolysis of the median nerve as well as the cushion effect of the fat flap. This technique appears to offer reliable improvement for patients with true recurrent CTS, possibly providing improved nerve gliding and increased soft-tissue coverage to protect the median nerve.