Revision surgery in carpal tunnel syndrome: a retrospective study comparing the Canaletto® device alone versus a combination of Canaletto® and Dynavisc® gel

Dual-Polymer Carboxymethyl Cellulose and Poly(Ethylene Oxide)-Based Gels for the Prevention of Postsurgical Adhesions

Postsurgical adhesions are a common complication associated with surgical procedures; they not only impact the patient's well-being but also impose a financial burden due to medical expenses required for reoperative surgeries or adhesiolysis. Adhesions can range from a filmy, fibrinous, or fibrous vascular band to a cohesive attachment, and they can form in diverse anatomical locations such as the peritoneum, pericardium, endometrium, tendons, synovium, and epidural and pleural spaces. Numerous strategies have been explored to minimize the occurrence of postsurgical adhesions. These strategies include surgical approaches, adhesiolysis, antiadhesive agents, and mechanical barriers which have demonstrated the most promise in terms of efficacy and breadth of indications. In this review, we discuss the use of physical/mechanical barriers for adhesion prevention and outline the most commonly used, commercially available barriers. We then focus on a synthetic, dual-polymer gel composed of carboxymethyl cellulose (CMC) and poly(ethylene oxide) [PEO], which, unlike the more commonly used single-polymer hydrogels, has demonstrated higher efficacy across a greater range of indications and surgical procedures. We review the formulation, mechanical properties, and mechanisms of action of the CMC + PEO dual-polymer gel and summarize findings from clinical studies that have assessed the efficacy of CMC + PEO gels in multiple surgical settings in clinics across the world. In conclusion, the CMC + PEO dual-polymer gel represents an approach to preventing postsurgical adhesions that has been commonly used over the last 20 years and could therefore serve as a foundation for research into improving postsurgical outcomes as well as a drug delivery device to expand the use of gels in surgical settings.

Prevention of Adhesions after Bone Fracture Using a Carboxymethylcellulose and Polyethylene Oxide Composite Gel in Dogs

The formation of adhesions is a common complication following traumatic injuries and surgical procedures, often resulting in pain, stiffness, and loss of function. This study aimed to evaluate the feasibility and safety of using a composite material comprising of carboxymethylcellulose (CMC), polyethylene oxide (PEO), and calcium chloride, for preventing adhesions between muscle and bone during the healing stage, as well as its effect on the bone healing process. Ten healthy purpose-bred laboratory Beagle dogs were randomly subjected to two consecutive operations with a 6-month interval, alternating between left and right forelimbs. On the left forelimb an osteotomy at the ulna was performed, while on the right forelimb the same procedure was supplemented by the application of the anti-adhesion agent in the osteotomy site prior to closure. Clinical, diagnostic imaging, macroscopic, and histological evaluations were performed at various time points. The results showed no significant differences in surgical site perimeter (p = 0.558), lameness (p = 0.227), and radiographic bone healing (p = 0.379) between the two groups. However, the macroscopic (p = 0.006) and histological assessments revealed significantly lower adhesion scores (p = 0.0049) and better healing (p = 0.0102) in the group that received the anti-adhesion agent. These findings suggest that the CMC/PEO composite material is a safe and potentially effective intervention for preventing post-traumatic and post-surgical adhesions in canine patients without compromising bone healing. Further research is warranted to fully characterize the clinical benefits of this approach.

Management of Recurrent Carpal Tunnel Syndrome: Systematic Review and Meta-Analysis

PURPOSE

Few comparisons have been performed between the outcomes of surgical techniques for recurrent carpal tunnel syndrome. Using a meta-analysis, this study aimed to compare the outcomes of different surgical techniques using the Boston Carpal Tunnel Questionnaire (BCTQ) and visual analog scale (VAS) for pain as outcomes.

METHODS

The following categories were used to define the study's inclusion criteria: population, intervention, comparator, outcomes, and study design. Studies were examined by 2 reviewers, and the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines were followed. The studies were assigned to 1 of the following treatment groups: decompression with or without neurolysis, autologous fat transfer, hypothenar fat pad, pedicled or free flap, and "other." For our primary outcome, we compared improvement using the BCTQ and VAS for pain between the treatment groups. For our secondary outcome, postoperative BCTQ and VAS pain values were compared.

RESULTS

Fourteen studies were included: 5 case series with postoperative data only and 9 pre-post studies without a control group. With regard to our primary outcome, the studies reported an average improvement of 1.2 points (95% confidence interval [CI][1.5, 0.9]) on a scale of 1-5 on the symptoms severity scale (SSS) of the BCTQ, 1.9 points (95% CI [1.37, 0.79]) on a scale of 1-5 on the function severity scale of the BCTQ, and 3.8 points (95% CI [4.9, 2.6]) on a scale of 1-10 on the VAS for pain. We only found significantly lesser improvement in the "other" treatment group than in the hypothenar fat pad group and autologous fat transfer group using the SSS. The hypothenar fat pad group had the best reported postoperative SSS score of 1.75 (95% CI [1.24, 2.25]), function severity scale score of 1.55 (95% CI [1.20, 1.90]), and VAS pain score of 1.45 (95% CI [0.83, 2.07]).

CONCLUSIONS

All the techniques showed clinically important improvements in all the outcomes. We found lesser improvement in the "other" treatment group than in the hypothenar fat pad group and autologous fat transfer group using the SSS. We found that the hypothenar fat pad group had the best reported postoperative values in our secondary analysis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Systematic review and meta-analysis of surgical options for recurrent or persistent carpal tunnel syndrome: simple decompression versus coverage of the median nerve

We performed a systematic review on the success of different surgical techniques for the management of recurrent and persistent carpal tunnel syndrome. Twenty studies met the inclusion criteria and were grouped by the type of revision carpal tunnel release, which were simple open release, open release with flap coverage or open release with implant coverage. Meta-analysis showed no difference, and pooled success proportions were 0.89, 0.89 and 0.85 for simple open carpal tunnel release, additional flap coverage and implant groups, respectively. No added value for coverage of the nerve was seen. Our review indicates that simple carpal tunnel release without additional coverage of the median nerve seems preferable as it is less invasive and without additional donor site morbidity. We found that the included studies were of low quality with moderate risk of bias and did not differentiate between persistent and recurrent carpal tunnel syndrome.

Preventive Effect of Alginate Gel Formulation on Perineural Adhesion

Background: Perineural adhesion is a potential complication of manipulating peripheral nerves. Using a model of median nerve manipulation in the carpal tunnel, perineural adhesion preventive effects of an alginate gel formulation were examined. Methods: After exposing carpal tunnels of Japanese white rabbits and dissecting the median nerve, the gliding floor was excised as much as possible and the transverse carpal ligament was repaired to induce a perineural tissue reaction. Prior to wound closure, 0.5 ml of alginate gel formulation was administered into the right carpal tunnel (formulation group) and 0.5 ml of physiological saline was administered into the left carpal tunnel (control group). At 1, 2, 3, and 6 weeks after treatment, electrophysiological evaluation of thenar distal latency, macroscopic evaluation with adhesion score, and pathological evaluation of carpal tunnel cross sections were performed (N = 4-5 at each time point). Results: Although distal latency tended to be low in the formulation group, there was no significant difference between the groups according to electrophysiological evaluation. Macroscopic evaluation revealed that the adhesion score was always lower in the formulation group than in the control group; over the course of treatment, it remained unchanged in the formulation group, but peaked at 3 weeks after treatment in the control group. In pathological evaluation, neural perfusion peaked at 2-3 weeks after treatment in both groups; neural perfusion tended to be lower in the formulation group than in the control group. Conclusions: Results suggested that the peak tissue response associated with nerve dissection occurred 2-3 weeks after treatment and that the repair process started subsequently. The alginate gel formulation modified the surrounding environment of the nerve and promoted repair by acting as a physical barrier against perineural fibrosis. The preventive effect of alginate gel on perineural adhesion may improve treatment outcomes of constrictive neuropathy.

Decompression for recurrent carpal tunnel syndrome provides significant functional improvement and patient satisfaction

This prospective single-centre study describes the functional outcomes, satisfaction and health-related quality of life after open revision carpal tunnel decompression for recurrent carpal tunnel syndrome. The QuickDASH, patient satisfaction and EuroQol-5 dimensions questionnaires were collected preoperatively and postoperatively over a 5-year period (2013-2018). The median time to revision was 13.3 years (range 3.9-35.4 years; interquartile range 7.2-15.9 years). Outcomes were available for 14 hands in 13 patients at a mean of 20 months after revision surgery. The mean preoperative and postoperative QuickDASH scores were 55 and 29, respectively, and the mean improvement in QuickDASH was 26. The mean improvement in EuroQol-5 dimensions score was 0.1, and 13 of the 14 patients were satisfied. The net promoter score was 85. This study confirms that patients undergoing revision open carpal tunnel decompression for recurrent carpal tunnel syndrome experience a significant improvement in function and health-related quality of life. Level of evidence: IV.

Dynavisc as an Adhesion Barrier in Finger Phalangeal Plate Fixation—a Prospective Case Series of 8 Patients

Purpose

Adhesion problems are common after plate fixation of finger phalanges and often lead to stiffness and reoperations with plate removal and tenolysis. The aim of this prospective case series was to study the effect of the adhesion barrier gel Dynavisc on total active motion (TAM), postoperative pain, and grip strength after plate fixation of phalangeal fractures. Total active motion at 3 months after surgery was the primary outcome.

Methods

Eight patients with a fracture of the proximal phalanx underwent surgery with open reduction and plate fixation. The adhesion barrier Dynavisc was applied between plate and extensor tendon and between tendon and skin. Results in terms of pain, grip strength, and TAM at 2 weeks, 3 months, and 1 year after surgery were collected. Results on TAM were classified according to Page and Stern.

Results

After 3 months, only 2 patients had a result classified as excellent. After 1 year, 3 patients fulfilled the criteria for an excellent result. There were no adverse events. Patients with long-standing postoperative pain had a worse outcome on TAM.

Conclusions

The antiadhesive effect of Dynavisc in this prospective case series was unconvincing. Only 2 patients had an excellent result on TAM at 3 months. Because the gel is resorbed within 30 days after application, it is questionable whether the gel had a role in improvement that occurred later in the postoperative course. Larger, randomized studies would be required to show any anti-adherent effect of Dynavisc definitively in finger fracture surgery.

Type of study/level of evidence

Therapeutic IV.

A case series of seven patients with recurrent median nerve neuropathy treated by the revision surgery of median nerve neurolysis and wrapping with radial artery perforator adipose flap

Adhesion neuropathy of the median nerve with persistent pain can be a challenging problem. Currently, coverage of the median nerve with a well-vascularized soft tissue is deemed necessary after secondary neurolysis. Herein, we reviewed the outcomes of seven patients with a persistent median nerve neuropathy after a primary open carpal tunnel release or a median nerve repair, treated with neurolysis and median nerve wrapping with radial artery perforator adipose flaps. During the revision surgery, after a careful and complete neurolysis of the scarred median nerve, the distally based radial artery perforator adipose flap without its fascia was raised and rotated to wrap the median nerve. The mean size of the perforator flap was 1146 mm², which was enough to wrap the median nerve in all patients. At 26 months postsurgery, both the visual analog scale score for pain with tingling, and the patient-reported outcome measures improved. There was no recurrence of the median nerve adhesion neuropathy and no major complications were noted. Tinel's sign at the palmar wrist completely disappeared in four patients and was relieved in three patients. The median distal motor latency becomes recordable, and closer to a normal compound motor action potential postoperatively in all patients. Secondary neurolysis and median nerve wrapping with a radial artery perforator adipose flap, which was modified to be softer and thinner than the radial artery perforator adipofascial flap, was a successful treatment for the recurrent median nerve neuropathy in terms of both pain relief and restoration of the hand function.