What is the difference between the endoscopic surgery of the carpal tunnel syndrome and opern surgery?
The similarity of these two operational methods is that the roof of the carpal tunnel is divided.
How does the division of the carpal tunnel’s roof (expanding the carpal tunnel) take place with the endoscopic surgery treatment?
A small skin incision is made.The incision is usually located at the entrance of the carpal tunnel, directly at the end of the forearm.
The surgeon then enters the carpal canal with a special tool via the skin incision. After the tool is placed within the carpal canal, the roof of the carpal tunnel can be split from below with a telescopic knife.
Is this approach always the same?
No, several methods are possible with the endoscopic splitting of the carpal tunnel. Agee’s method needs only one incision directly before the carpal canal to split the roof of the carpal tunnel.
Chow’s method needs two incisions to split the roof of the carpal tunnel: a small incision at the entry of the carpal canal and a second small incision at the exit of the carpal tunnel.
The illustration shows the small skin incisions for the endoscopic surgery of the carpal tunnel, marked in red.
What is the advantage of the endoscopic splitting of the carpal tunnel?
The skin incision for the open surgery for splitting the carpal tunnel’s roof takes place in a very sensitive area of the hand. With some people, small skin nerves run through the area of the fat tissue. Cutting those nerves can lead to constant sensitivity of the scar. The endoscopic surgery avoids these disadvantages.
The supporters of the endoscopic splitting of the carpal tunnel see the advantages mainly in the possibility for the patient to start again the daily activities during work and sport earlier compared to the open method.
With those advantages, the endoscopic treatment of the carpal tunnel syndrome should be the standard method?
No, this is not the case. The advantages of the endoscopic method are coming with a number of disadvantages.
The risk of injuring (or partly injuring) the median nerve if higher with the endoscopic splitting than with the open splitting of the carpal tunnel’s roof. Injuries of vessels, palmar arches or even injuries of the ulnar nerve were found with the endoscopic splitting of the carpal tunnel’s roof.
How can those major complications be explained?
The illustration shows a partly cut through the median nerve (arrow) after previous endoscopic splitting of the carpal tunnel.
The photo was taken during a second operation, which has been performed with the open method.
In the shown case, the median nerve is anatomical variant. The median nerve usually splits into several side branches at the exit of the carpal tunnel. Here, the splitting already took place at the entry of the carpal tunnel.
The (partly) injury of the median nerve is a very serious complication, which can not be reconstructed (even with a correct treatment with micro-surgical nerve sutures) in a way, no substantial damages remain for the patient.
Often, a lifelong tingling discomfort remains at the damaged nerve: the so called neuroma pain.
Cause of these complications with endoscopic treated carpal tunnel syndrome is a very limited visibility compared to the open method, where the surgeon can identify all structures easily.
As individuals can have rare variants in the courses of nerves, even an experienced surgeon can hurt a nerve in the carpal canal due to limited visibility and an anatomic variant in the courses of nerves.
How frequent are those complications?
This question can not really be answered. There are sequences of more than 1000 surgeries published in specialized literature, which describe carpal tunnel syndromes treated with the endoscopic method, without any major complications.
On the otherhand, there is a significant number of individual case reports, which describe a full section of the median nerve, a partly section if the median nerve, sections of the ulnar nerve, as well as reports about incomplete splits of the roof of the carpal tunnel.
How to behave if one is considering the endoscopic splitting of a carpal tunnel syndrome?
As a patient one should be aware, that this method comes with some specific risks (never damaged), which can not even be excluded by an experienced surgeon.
The risks of injuries in the area of the median nerve are higher, even with the same experience of the surgeon, compared to an open decompression of the carpal canal.
The endoscopic splitting of the carpal tunnel syndrome should only be performed by a doctor, which has extensive experience in performing this method. It is absolutely legitimate to ask the surgeon about the experience with the method.
What else should be known about the endoscopic splitting of the carpal tunnel syndrome?
The endoscopic perfomed splitting of the carpal tunnel’s roof is significantly more expensive in regards to material costs, than the open splitting. The major cost factor if the knife which can only be used once to split the roof of the carpal tunnel.
Possible additional costs for the patient need to be checked with the treating physician before the surgery.
Additionally it should be known, that there is hardly a comparable controversial debate between hand surgeons like the endoscopic splitting of the roof of the carpal tunnel.
As a patient, one will find supporters for this method, which highlight advantages like the small skin incision, quick capacity of the hand, and so on. But one will also find hand surgeons which – for good reasons – absolutely reject this method.
Those hand surgeons surely are afraid of the rare complication of a nerve damage, which is so severe, that they are not willing to take the risk.