European Journal of Cardiovascular Medicine

The median nerve entrapment at the wrist, which defines carpal tunnel syndrome (CTS), represents the most common compressive neuropathy which is encountered clinically with a prevalence of up to 4-7% in. (1) Common comorbid conditions associated with increased risk of developing CTS include advanced age, female gender, obesity, diabetes, and pregnancy. A variety of additional etiologic conditions have been implicated, including hypothyroidism, rheumatologic and autoimmune diseases, alcoholism, and renal failure. Compression may also result from space-occupying lesions within the canal such as proliferative tenosynovitis, hematoma, tumors, or ganglion cysts. Displaced distal radius or carpal injuries may also diminish canal volume. Patients predominantly complain of paraesthesias and numbness, in the distribution of median nerve. The paraesthesias may be aggravated on wrist movement or prolonged wrist posture in a flexed position, such as holding a baby or driving a car. With progression of the disease, patients may complain of weakness of grasp and pinch and later thenar muscle atrophy may also develop.

The diagnosis is primarily clinical based on a combination of symptoms and characteristic physical signs. The Phalen test (wrist flexion test) and Tinel sign (nerve percussion test) are frequently positive. Nerve conduction studies (NCV) may demonstrate; increased distal median nerve sensory latency (>3.5 msec), increased distal median nerve motor latency (>4.5 msec), and decreased conduction velocity (demyelination) or amplitude (axonal loss). Denervation of thenar muscles on EMG (fibrillation potentials, sharp waves, increased insertional activity) will predict post operative recovery in advanced disease. MRI is a sensitive tool but rarely used, ultrasound is easy to perform and frequently used as a first-line tool to assist diagnosis.

Carpal tunnel release (CTR) is one of the most frequently performed hand surgery worldwide (2)^. The traditional open technique requires a longitudinal incision extending between the distal end of the transverse carpal ligament (TCL) and distal wrist flexion crease. Whereas this access provides a complete exposure of the median nerve, it carries the risk of scar tissue and scar sensitivity, along with a possible flexion contracture in the wrist. All these conditions can significantly delay a complete functional recovery (3,4,5)^. To avoid such complications, less invasive techniques have been proposed, such as the endoscopic-assisted release or mini-palmar incision surgery, sometimes by using innovative surgical instruments. CTR surgery with a single limited or small incision is becoming more widely accepted. A better recovery, less pillar pain, less scarring, and an earlier return to work are the key benefits of single limited incision (6,7)^.

Despite these premises, all the techniques mentioned above could result in several complications, such as vascular, nerve, and tendon damages, or the incomplete release of the transverse ligament, leading to recurrence (7).

When adopting a less invasive procedure, the final aim is to reduce surgical time and possible complications (including the extent of the incision and post-operative scar), providing faster recovery and an earlier return to work and daily activities. This study describes our surgical technique and outcome of single limited incision (1cm) minimally invasive carpal tunnel release for CTS, with easily available, routinely used instruments. This technique has all the advantages of ECTR and has significantly overcome all the disadvantages of major open surgical techniques (Classical open technique, Palmar crease approach, mini open single incision palmar approach and minimally invasive Distal wrist crease approach (13,14,15). We describe a minimally invasive surgery for carpal tunnel release with the traditionally available instruments

The study was conducted in the department of Plastic and Reconstructive surgery GMC Srinagar. The patients who underwent treatment for carpal tunnel syndrome from March -2018 to Feb -2022 were the subjects of study.

Surgical Technique

Minimally invasive (Mini Open) surgical technique using routine instruments (Mushtaq’s Technique). The technique is performed under regional anesthesia, under tourniquet control.

Step 1: Incision

A 1cm transverse skin incision is made in the proximal wrist flexion crease, medial to Palmaris Longus tendon (Fig 1).

Double blunt Senn retractors are used to retract the skin.

Step 2: Identification and Incision of antebrachial fascia

After dissection of subcutaneous tissues, antebrachial fascia is identified and incised (Fig 2).

Step 3: Delineation of the distal edge of antebrachial fascia

Delineation of distal edge of antebrachial fascia, which is distally continuous with TCL (Fig 3).

Step 4: Identification of median nerve and dilatation of Carpal Tunnel

After incising antebrachial fascia, median nerve is identified passing distally under TCL through Carpal Tunnel into palm. Then serial Urethral dilators (28-32 F) are used to dilate carpal tunnel, for making space to safely use instruments in step. Serial dilatations are done with dilators pointing towards the distal end of the TCL, at the junction of a line drawn from the centre of third web space and another line drawn from distal part of the fully abducted thumb, this strategy prevents possible damage branches of median nerve that may originate at this level (Fig 4).

Step 5: Creation of a subcutaneous tunnel superficial to TCL

Tenotomy scissors are used to dissect distally just superficial to the transverse carpal ligament, to clear upper surface of TCL (subcutaneous tunnel is created), up to its distal end to accommodate one blade of Metzenbaum scissors.

Step 6: Safeguarding median nerve and division of TCL

Distal edge of antebrachial fascia which is distally continuous with TCL, is grasped firmly with a toothed Addison’s Forceps, a metallic guard (freer) safeguarding median nerve in carpal tunnel, a medium sized sharp Metzenbaum scissor is introduced with one blade in CT and another blade in superficial subcutaneous tunnel, TCL is cut from proximal to distal direction end. TCL cuts with a gritty sound, cessation of which suggests complete division of TCL. The complete division of TCL is confirmed by visualizing the cut ends of TCL by throwing light with a torch into the incision (Fig 5).

Finally, complete release is verified by direct visual observation using a probe or a freer. The transverse carpal ligament can be clearly seen through the limited incision. Proximal release of antebrachial fascia (1-2cm) is also done. The final result is a wide release of the nerve. The metallic guard is then retracted. The skin is closed with a single horizontal mattress suture, using a 5- 0 Prolene (Fig 6). A soft bulky and compressive dressing is applied. Tourniquet is released and hand is kept in elevated position in an arm pouch.

Postoperative Care

Elevation and finger motion are encouraged. Light activity is encouraged when comfortable.  The dressing can be removed in 3 to 4 days, and hand washing is encouraged. At 2 weeks the patient can gradually resume full activity.

The study included 63 patients, majority of patients were females (55 patients), and median age was 45 years. 16 patients had bilateral disease; right hand was predominantly involved. All the procedures were done under regional anesthesia under Tourniquet control. Average time taken was 15-20 minutes. Most patients returned to normal routine work in 2 to 3 weeks, with immediate and significant relief of symptoms. Scar was fine, non-tender and almost invisible in most cases. No patient developed hypertrophy or Keloid formation. There was no case of flexion contracture, or pillar pain. We did not observe any case of median nerve injury or its branches, or injury to any other important structures. Complications were recorded in 3 patients, which included mild scar tenderness in two patients and minor hematoma in one patient. Follow up ranged from 6 months to 2 years. No patient required any repeat surgery for incomplete release of carpal tunnel.

Nonoperative treatment options range from wrist splinting to corticosteroid injections. If the symptoms are mild with no thenar muscle atrophy, splinting the wrist in neutral or serial steroid injections frequently decreases symptoms (8). If signs and symptoms persist or progress after conservative treatment, especially if thenar atrophy develops, surgical decompression of the median nerve is indicated. For acute CTS after trauma, such as carpal bone dislocation, crush injury, or forearm compartment syndrome, immediate surgical release is always indicated. Surgical management is now recognized to be more effective than non-surgical treatment (10,11). Standard conventional open surgery is a routine procedure that under direct visualization through a large incision (5–7 cm), the transverse carpal ligament is divided and nerve decompressed. It results in effective CTR.

In 1989, Okutsu and colleagues (9) described an Endoscopic technique for carpal tunnel release (ECTR) using a single small incision 3 cm proximal to wrist crease. They released the transverse carpal ligament longitudinally under endoscopic visualization using a hook knife. Several modifications of ECTR have come up lately. Endoscopic techniques avoid midpalm incisions, preserving the palmar musculature and skin. Their shorter incisions also mean less scar tenderness and pillar pain. However, postoperative wound complications with conventional open surgery are more common than with minimally invasive carpal tunnel surgery (12). Wound infection, inflammation, wound dehiscence, and painful scarring are the most frequent wound consequences of open surgery. The disadvantages of ECTR are its learning curve and higher cost. Several new minimally invasive surgical procedures have been developed and are currently “competing” for the title of most effective method of CTR. Surgeons have modified various approaches to minimize wound problems, painful scars, and other complications. Multiple randomized controlled trials have showed limited open procedures and endoscopic approach to have similar rates of complications. Immediate postoperative advantages of the endoscopic technique in grip strength and pain relief disappeared after 12 weeks.  The limited incision carpal tunnel release approach and technique has been shown to have increased the efficacy compared to the standard incision of open release for CTS and has proven both practical and productive (7,12). 

In the author’s technique the limited open carpal tunnel syndrome (mini-OCTR), through small incision (1cm) median nerve decompression is done, patient recovery is rapid, no specific and costly equipment is required and is an ideal procedure where endoscopic equipment and expertise is not available. It has all the advantages of ECTR, while it has significantly overcome all the major disadvantages and complications of conventional open surgical Technique.

Ethical approval: This study has been waived ethical approved for this clinical case study by the ethical committees in accordance with the declaration of Helsinki.

Acknowledgement: The authors would like to thank all the technical staff from our department who provided invaluable support for the study and the patients for devoting their time and effort.

Financial support and sponsorship: None

Conflict of interest: The authors declare no competing conflict of interest

Funding: None

CTR surgery with a single limited or small incision is becoming more widely accepted as it involves less scarring, less pillar pain, rapid recovery, and an earlier return to work, key benefits of a single limited incision. The commercially available endoscopic equipment, of course, is very expensive and not readily available in most centers. This technique which we would like to name it as Mushtaq’s Technique, is a simple minimally invasive, mini open technique. It is a simple, easy and effective technique, in a setup with limited resources (fig 7), with all the advantages of an ECTR and having significantly reduced the complications of conventional open surgical techniques.  

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