Canaletto implant in revision surgery for carpal tunnel syndrome: 21 case series

Clinical outcomes following neurolysis and porcine collagen extracellular matrix wrapping of scarred nerves in revision carpal tunnel decompression

Scar tether after primary nerve decompression can impair physiological nerve glide and vascularity of the nerve. Revision decompression in the setting of neurostenalgia should address the scarred mesoneurium in order to prevent further entrapment and tether. This study reports on the clinical outcomes of 12 patients with neurostenalgia following carpal tunnel decompression (CTD), treated with revision CTD and a porcine submucosa extracellular matrix nerve wrap (PECM) (Axoguard® nerve protector, Axogen Inc., Alachua, FL). Eleven patients had one primary decompression procedure prior to revision surgery; one patient previously had two operations for CTD. There was a significant reduction in visual analogue pain scores (VAS) and improvement in patients' satisfaction rating and symptom resolution. Patient-reported outcome measures were recorded using the Impact of Hand Nerve Disorders (I-HaND) Scale (Version 2), which demonstrated a significant reduction in hand disability. There were no complications attributable to the procedure and no re-revision procedures necessary at the latest follow-up.

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.

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

The aim of this study was to assess the value of using a Canaletto® implant in combination with a gel composed of carboxymethylcellulose and polyethylene oxide in the surgical treatment of recurrent carpal tunnel syndrome (CTS). The case series included 31 patients with 32 hands operated for the second time for recurrent (22 cases) or recalcitrant (9 cases) CTS by neurolysis. The average patient age was 62 years. Dynavisc® gel alone was applied around the median nerve in the first 16 cases (Group I). The Canaletto® implant combined with Dynavisc® gel was used in the last 16 cases (group II). With an average follow up of 8 months (for group I) and 11 months (for group II), the pre/postoperative variation in pain assessed with a visual analog scale was 1.38/10 (group I) and 2.04/10 (group II), the QuickDASH score was 20.1/100 (Group I) and 20.48/100 (Group II), grip strength was 8% (Group I) and 20% (Group II), sensory nerve conduction speed was 23.20 m/s (group I) and 15.51 m/s (group II) and distal motor latency was 1.55 m/s (group I) and 1.21 m/s (group II). Ten patients recovered from hypoesthesia in both groups, 6 patients in group I and 2 patients in group II regained good trophicity of their superficial thenar muscles. Two patients from group II had not improved clinically although their electromyography had become normal. One patient from group II suffered a postoperative infection that required removal of the Canaletto® implant. He subsequently improved slightly. Our study found that for recurrent or recalcitrant CTS, the combination of Dynavisc® anti-adhesion gel around the median nerve and a Canaletto implant® after neurolysis results in outcomes that are as good as Dynavisc® alone, with a significant improvement of the QuickDASH score without the Canaletto®. In conclusion, the use of Dynavisc® gel alone around the median nerve after neurolysis seems to be as effective as other techniques described in literature but less invasive or time-consuming, and not associated with donor site morbidity such as the flexor tendon sheath.

Recurrent and persistent carpal tunnel syndrome: "Triple-therapy approach"

Background

Various procedures have been described for patients undergoing a revision carpal tunnel release. These can include repeat open decompression with external or internal neurolysis, tenosynovectomy, endoscopic release, various flap techniques, saphenous vein wrapping and use of prosthetic implants. This study reports a case series of 30 consecutive patients who underwent revision carpal tunnel release at single institution from 2012 to 2018. Our surgical plan in all the patients involved a combination of these three techniques (triple therapy approach): neurolysis (external or internal) and tenosynovectomy, collagen matrix conduit wrap (NeuraWrap; Integra LifeSciences or Axoguard Nerve Protector, AxoGen Inc), and hypothenar fat flap.

Materials and methods

A total of 30 patient records were identified. The index surgery was performed by a variety of surgeons at varied private institutions as well as the VA hospital. However, all of the revision interventions in this series were performed by the senior author (Z.J.P.). Demographic data (age, sex, hand dominance, comorbidities, alcohol, and smoking history) were collected. Preoperative and postoperative symptoms were recorded for all patients, including: subjective outcomes, need for additional surgery and complications. Mean VAS preoperatively and postoperatively were compared using a paired t-test. All statistical analyses were performed with SPSS 20 (IBM, Chicago, IL).

Results

Patient reported measures of resolution of symptoms and VAS scores documented at 3 months. Of the 30 patients who underwent surgery for persistent or recurrent carpal tunnel syndrome, symptoms resolved completely in 25 patients. 2 patients were lost to follow up. 3 patients showed no improvement. The mean preoperative VAS score was 4.37 and declined to 1.23 after surgery (P < .0001).

Conclusion

Our study demonstrates that a combination of neurolysis and tenosynovectomy along with a nerve wrap and hypothenar fat flap should be considered in patients presenting with recurrent or persistent carpal tunnel syndrome.

Which surgery should be offered for carpal tunnel syndrome in a patient who was previously treated for recurrence on the contralateral side? Preliminary study of 13 patients with the Canaletto® implant

There are no published studies on the management of carpal tunnel syndrome (CTS) patients who have already been operated for recurrent CTS on the contralateral side. The aim of this study was to evaluate 13 patients with CTS who underwent primary release using a Canaletto^® implant. The 13 patients had all been operated for recurrent CTS previously. On the contralateral side, they all had subjective signs, and two of them already had complications. All were operated with the Canaletto^® implant according to Duché's technique, in a mean of 20minutes. After a mean 19.3-month follow-up, paresthesia, pain, and QuickDASH scores were significantly improved, even in one patient who underwent revision at another facility. This preliminary study suggests that use of a Canaletto^® implant as first-line treatment for CTS in patients who already underwent revision surgery on the other side is a simple and safe technique, without worsening of symptoms. These findings should be assessed with a prospective randomized controlled trial.

Arterial vascularization of the flexor digitorum superficialis synovial flap. An anatomical study

Among the various techniques proposed to protect the median nerve from scarring and to provide it with a vascular supply, the synovial flap represents a simple and effective method. The flap is taken from the flexor tendons sheath and results in a thin and richly vascularized tissue that will act as a barrier to scarring and provide neovascularization to improve nerve regeneration and gliding. The aim of this study was to evaluate the arterial vascularization of this flap to assess its reliability. An anatomic study was carried out on 24 fresh upper limbs infused with colored and radiopaque solutions before or after flap elevation. Anatomical findings showed the synovial flap to be supplied by a consistent vascular pedicle arising from the ulnar artery 2 to 5 centimeters proximal to the pisiform bone and running between the flexor tendons of the ring and little fingers. The synovial flap is known to be a simple and effective method for protecting the median nerve. The present study shows that its consistent vascularization makes it a reliable technique. We believe this procedure is relevant for the treatment of recurring carpal tunnel syndrome.

Collagen nerve wrap for median nerve scarring

Nerve wrapping materials have been manufactured to inhibit nerve tissue adhesions and diminish inflammatory and immunologic reactions in nerve surgery. Collagen nerve wrap is a biodegradable type I collagen material that acts as an interface between the nerve and the surrounding tissues. Its main advantage is that it stays in place during the period of tissue healing and is then gradually absorbed once tissue healing is completed. This article presents a surgical technique that used a collagen nerve wrap for the management of median nerve tissue adhesions in 2 patients with advanced carpal tunnel syndrome due to median nerve scarring and adhesions. At last follow-up, both patients had complete resolution with no recurrence of their symptoms. Complications related to the biodegradable material were not observed.

A systematic review of the literature on the outcomes of treatment for recurrent and persistent carpal tunnel syndrome

BACKGROUND

Recurrent and persistent carpal tunnel syndrome is an uncommon but potentially difficult surgical dilemma. Many surgical treatment options have been described in the literature without comparative data on outcome.

METHODS

A systematic review on recurrent carpal tunnel syndrome was performed for all articles from 1946 to 2012 in MEDLINE, EMBASE, CENTRAL, and hand-searched reference lists from all identified articles. Twenty-three articles were screened and identified from the time period 1972 to 2012, representing two general treatment groups: decompression with flap interposition and repeated open decompression. A meta-analysis was then performed, generating forest and funnel plots of the data.

RESULTS

In total, 294 patients from 14 studies in the flap arm of the meta-analysis had a weighted success rate of 86 percent (95 percent CI, 0.75 to 0.96), and 364 patients from nine studies in the nonflap arm had a weighted 75 percent success rate (95 percent CI, 0.66 to 0.84). Heterogeneity was statistically analyzed and revealed low heterogeneity with the I statistic. Forest plots were created and analyzed between subgroups, and chi-square analysis revealed a highly statistically significant difference (p = 0.001). The odds ratio of success in the nonflap group was 0.50 (95 percent CI, 0.33 to 0.75).

CONCLUSIONS

Decompression with the use of vascularized flap coverage appears to have a higher success rate over simple repeated decompression. The relevance of these data is pertinent to all hand surgeons, as they could have an impact on treatment guidelines for this relatively uncommon but problematic condition, but further prospective study is needed.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Revision carpal tunnel surgery: a 10-year review of intraoperative findings and outcomes

PURPOSE

To evaluate intraoperative findings and outcomes of revision carpal tunnel release (CTR) and to identify predictors of pain outcomes.

METHODS

We performed a retrospective cohort study of all adult patients undergoing revision CTR between 2001 and 2012. Patients were classified according to whether they presented with persistent, recurrent, or new symptoms. We compared study groups by baseline characteristics, intraoperative findings, and outcomes (strength and pain). Within each group, we analyzed changes in postoperative pinch strength, grip strength, and pain from baseline. Predictors of postoperative average pain were examined using both multivariable linear regression analyses and univariable logistic regression to calculate odds ratios of worsened or no change in pain.

RESULTS

We performed revision CTR in 97 extremities (87 patients). Symptoms were classified as persistent in 42 hands, recurrent in 19, and new in 36. The recurrent group demonstrated more diabetes and a longer interval from primary CTR, and was less likely to present with pain. Incomplete release of the flexor retinaculum and scarring of the median nerve were common intraoperative findings over all. Nerve injury was more common in the new group. Postoperative pinch strength, grip strength, and pain significantly improved from baseline in all groups, apart from strength measures in the recurrent group. Persistent symptoms and more than 1 prior CTR had higher odds of not changing or worsening postoperative pain. Higher preoperative pain, use of pain medication, and workers' compensation were significant predictors of higher postoperative average pain.

CONCLUSIONS

Carpal tunnel release may not always be entirely successful. Most patients improve after revision CTR, but a methodical approach to diagnosis and adherence to safe surgical principles are likely to improve outcomes. Symptom classification, number of prior CTRs, baseline pain, pain medications, and workers' compensation status are important predictors of pain outcomes in this population.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

Evaluation and treatment of failed carpal tunnel release

Treatment failure and complications are encountered in 1% to 25% of all carpal tunnel releases. Besides hematoma, infection, skin necrosis, and intraoperative iatrogenic injuries, persistence and recurrence should be included in this discussion. Persistence is often related to incomplete release. Similar symptoms recurring after a symptom-free interval of 6 months are considered recurrent and may be caused by intraneural or perineural scarring. Adequate diagnosis and treatment of these failures can be challenging. Operative release is the main treatment consisting of complete decompression of the median nerve. In some circumstances, coverage of the median nerve may be necessary.