Proximally, subcutaneous tissues above the proximal limb of the TCL and DVFF are mobilized to about 2 cm proximal to the wrist flexion crease to create a plane for the fine long nasal turbinate speculum. The nasal turbinate speculum is then inserted into this plane above the proximal limb of the TCL and DVFF (Figure 3). Once inserted to the level of the confluence of the TCL and the DVFF, the speculum is opened.
Topside visualization is now encountered with the ulnar neurovascular bundle protected by the ulnar blade of the speculum. A long-handle scalpel is used to incise the TCL and the DVFF under direct visualization from proximal to distal in line with the previously completed distal release (Figure 4). As the nasal turbinate speculum is stretching the TCL and putting it under tension, the TCL can be heard splitting as it is being incised. Once the TCL and the DVFF are divided, the speculum is slowly closed and removed. Wide diastasis of the radial and ulnar leaflets of the TCL and the DVFF is directly visualized. Complete decompression of the median nerve from the distal forearm fascia to the superficial palmar arch is confirmed.
Adhesions between the undersurface of the radial leaflet and the flexor tendons and median nerve are mobilized. The median nerve is assessed for “hourglass” morphology or atrophy. The flexor tendons can be swept radialward with a free elevator to inspect the floor of the carpal tunnel. Flexor tenosynovectomy is not routinely performed. The incision is closed with interrupted simple sutures using 4-0 nylon.
Study Results
This study was conducted at Hand Surgery PC, Newton-Wellesley Hospital, Tufts University School of Medicine. Over a 10-month interval, 101 consecutive mini-OCTRs (63 right hands, 38 left hands) were performed with this proximal release modification in 88 patients (51 females, 37 males) by Dr. Ruchelsman and Dr. Belsky (Table). CTRs performed in the setting of wrist and/or carpal trauma were excluded. Mean age was 62.8 years. Mean follow-up was 11.3 weeks (~3 months). For isolated cases of CTR, mean tourniquet time was 16 minutes. CTS symptoms were relieved in all patients with a high degree of satisfaction as measured with history and examination findings at follow-up visits. There were no major complications (eg, infection, neural or vascular damage, severe residual pain). Four patients reported minor residual numbness in the fingers at latest follow-up but nevertheless had major improvement over preoperative baseline. These 4 patients had preoperative electromyograms or nerve conduction studies documenting the extent of their disease. There was 1 case of minor wound complication. Three weeks after surgery, the patient had a 1-cm wound opening, which closed with local wound care. The patient did not develop any drainage, infection, bleeding, or neurologic symptoms.
Discussion
Open release of the TCL—the gold standard of surgical treatment for CTS—produces reliable symptom relief in the vast majority of patients.25,30 Given that the most common complication of carpal tunnel surgery is incomplete release of the TCL,31,32 this technique, which uses a nasal turbinate speculum to better visualize the median nerve, could potentially reduce the reoperation rate. The nasal turbinate speculum allows the surgeon to see the confluence of the TCL and the DVFF. In addition, as the complete release can be visualized, there is minimal chance of injury.
The 2007 Cochrane review3 found no strong evidence supporting replacing OCTR with endoscopic techniques. Previous investigators have questioned the utility of ECTR given that it is higher in cost and more resource-intensive than OCTR1,33,34 and is associated with higher rates of certain complications.5,22,35-37 A 2004 meta-analysis of 13 randomized, controlled trials found a higher rate of reversible nerve damage with an odds ratio of 3.1 for ECTR versus OCTR.35 A more recent (2006) review of more than 80 studies found transient neurapraxias in 1.45% of ECTR cases and 0.25% of OCTR cases.5 The same study reported overall complication rates (reversible and major neurovascular structural injuries) of 0.74% for OCTR and 1.63% for ECTR (P < .005). Another limitation of ECTR is that endoscopic techniques require a higher degree of surgical skill, which makes teaching residents and fellows more challenging.
The novel nasal turbinate speculum technique presented here is easily reproducible and allows first-time surgeons to visualize all important structures. Given that this technique does not require an endoscope or an endoscope-viewing tower, it is likely more cost-effective and requires less time for turnover between cases. Patients obtain good relief of their CTS symptoms with this technique, and most return to their daily activities within weeks after operation.