Discussion

Clinical efficacy of supraclavicular decompression in nTOS

In our study cohort, patients with nTOS treated according to recent consensus recommendations benefitted substantially from surgical decompression via the supraclavicular approach with significant improvement in pain, hypesthesia, and motor symptoms. Our data show that this approach was beneficial for improvement of QoL in patients with nTOS. This is not only true for the individually rated health related QoL, but also for the different dimensions in terms of activity, self-care, pain, and anxiety. Moreover, a significant positive impact of surgery on individual return to work at was observed.

Surgical strategy and anatomical considerations

Studies specifically addressing the surgical outcome of nTOS are limited and former TOS classifications systems are generally used heterogeneously (Dengler et al., 2022a; Rochkind et al., 2023). A recent consensus on classification reached by neurosurgeons now allows for more differentiated patient evaluation and categorization (Dengler et al., 2022b; Rochkind et al., 2023).

According to our data, most patients were classified as nTOS 2. A structured analysis of nTOS outcome reports after microsurgical decompression via the supraclavicular route without routine resection of the first rib is currently lacking given that most studies examine mixed TOS populations as well as transaxillary approaches and surgical strategies with routine first rib resection (Thompson, 2012; Peek et al., 2017; Nejim et al., 2017):

Alternative surgical strategies for nTOS include the transaxillary approach and infraclavicular or combined approaches, most commonly in combination with routine first rib resection (Thompson, 2012). While the transaxillary approach provides direct access to the first rib, visualization of the brachial plexus and associated anatomical variations is more limited compared with the supraclavicular microsurgical approach (Thompson, 2012; Peek et al., 2017). In contrast, the supraclavicular approach allows comprehensive exposure of the brachial plexus, identification of anatomical abnormalities, targeted neurolysis, and selective first rib resection only when persistent compression remains after soft tissue decompression. As comparative evidence between these surgical strategies remains limited and no randomized studies are available, superiority of one approach over another cannot currently be established. Surgical approach should therefore be individualized according to anatomical findings and surgeon expertise (Peek et al., 2017; Nejim et al., 2017).

In our cohort, first rib resection was performed only if compression was still present after resection of anatomic variabilities such as a cervical rib or a prominent C7 transverse process, and after the transection of fibrous bands, muscles or other soft tissues. This was the case in three patients that had a persistent compression of the brachial plexus after resection of fibrous bands and muscular decompression due to the individual anatomy of the topographic relation between first rib and brachial plexus. In our cohort, a benefit from surgery was detected in 94% of subjects. Our results indicate that a significant reduction in pain levels (NRS improvement from 8 to 4) was achieved post-surgery. No complications such as pneumo- or chylothorax occurred in our patient cohort. Our data has to be interpreted in the context of other reports on patients, which were not treated according to the recent consensus recommendations used in our series (Povlsen et al., 2014; Rochlin et al., 2013). For example, in the study by Rochlin and colleagues in patients treated with transaxillary scalenectomy and routine first rib resection symptom improvement was detected in only 72% of patients and pneuromothoraces occurred in about 22% of patients while EQ-5D-5L scores were not examined (Hinz et al., 2014). In a series published by Bosma and colleagues nTOS surgery failed to improve QoL to ranges of healthy people (Rochlin et al., 2013).

Quality of life and impact on mental health

Chronic pain is known to have a profound impact on the physiological and psychological well-being, often leading to increased levels of stress, reduced activity, anxiety, and depression (Wyns et al., 2023;Bosma et al., 2010). Outcome reporting for nTOS patients including factors associated with well-being in daily life is scarce (Peek et al., 2017).

The EQ-5D-5L, which was used in our analysis allows for comparisons with the general population as well as for cross-country comparisons due to previous validation studies (Wilson et al., 2024;Marten and Greiner, 2021). In our cohort, the individual health-related QOL prior to surgery ranged at a median of 65, which is remarkably below the German average population, for which it ranges between 73 and 9225. The significant increase to 85 observed after surgery showed that nTOS patients operated on using h microsurgery via the supraclavicular approach, can reestablish or even surpass normal QOL scores.

The substantial improvement in activity and mobility observed in our cohort after surgery may be interpreted as a direct result of decompression of the affected neural structures. This may enhance the ability to perform daily activities but also empower patients them to engage in physical activities previously avoided (Pesser et al., 2021; Ludwig et al., 2018).

Evidence on patients afflicted with chronic pain syndromes or peripheral nerve compression syndromes established a link between mental health and the postoperative recovery process (Alnahhal et al., 2023; Córdoba-Mosqueda et al., 2023; Beith et al., 2011). Anxiety decreased significantly after surgery in our cohort of nTOS patients. This is in line with the reduction of pain and the decrease and thus improvement of the sensorimotor deficits and reintegration into daily life. Nevertheless, these results should be discussed cautiously, as, to date, there is no other study addressing the issue of anxiety in patients with nTOS undergoing surgery.

Given that the average age of patients with nTOS ranges between 30 and 40 years, thre is relevant impact on the working demographic, making return to work a pivotal outcome parameter in this patient group (Laulan et al., 2011; Ludwig et al., 2018). A notable challenge associated with nTOS lies in the protracted duration required for diagnosing the condition. This may leads to severe limitations in daily activities and an incapacity to work during the prolonged diagnostic process preceding definitive treatment (Dengler et al., 2022b; Thompson, 2012). The predominant symptomatic manifestations of nTOS, characterized by pain and sensorimotor deficits, underscore the considerable challenges faced by patients with chronic pain when attempting to re-enter the workforce (Córdoba-Mosqueda et al., 2023). Our data show that a substantial amount of patients were able to return to work after surgery.

A major strength of our study is the selection of patients based on a a recently reached consensus for classification of nTOS and usage of a standardized questionnaire allowing for structural comparisons with the general population as well as for cross-country comparisons. However, the generalizability of our results may be limited due to the retrospective single-center design as well as the relatively limited patient number. Also, a longer follow-up interval could have been able to give a broader picture in terms of potential recurrence risks.