A prospective case series to evaluate subcostal nerve injury with high-resolution ultrasound in posterior retroperitoneoscopic adrenalectomy.

BACKGROUND: Posterior retroperitoneoscopic adrenalectomy has several advantages over transabdominal laparoscopic adrenalectomy regarding operating time, blood loss, postoperative pain, and recovery. However, postoperatively several patients report chronic pain or hypoesthesia. We hypothesized that these symptoms may be the result of damage to the subcostal nerve, because it passes the surgical area. METHODS: A prospective single-center case series was performed in adult patients without preoperative pain or numbness of the abdominal wall who underwent unilateral posterior retroperitoneoscopic adrenalectomy. Patients received pre- and postoperative questionnaires and a high-resolution ultrasound scan of the subcostal nerve and abdominal wall muscles was performed before and directly after surgery. Clinical evaluation at 6 weeks was performed with repeat questionnaires, physical examination, and high-resolution ultrasound. Long-term recovery was evaluated with questionnaires, and photographs from the patients were examined for abdominal wall asymmetry. RESULTS: A total of 25 patients were included in the study. There were no surgical complications. Preoperative visualization of the subcostal nerve was possible in all patients. At 6 weeks, ultrasound showed nerve damage in 15 patients, with no significant association between nerve damage and postsurgical pain. However, there was a significant association between nerve damage and hypoesthesia (p = 0.01), sensory (p < 0.001), and motor (p < 0.001) dysfunction on physical examination. After a median follow-up of 18 months, 5 patients still experienced either numbness or muscle weakness, and one patient experienced chronic postsurgical pain. CONCLUSION: In this exporatory case series the incidence of postoperative damage to the subcostal nerve, both clinically and radiologically, was 60% after posterior retroperitoneoscopic adrenalectomy. There was no association with pain, and the spontaneous recovery rate was high.

Sex Differences in Pain Sensitivity in a Dutch Cohort: Cross-Sectional and Web-Based Multidimensional Study.

BACKGROUND: Sex is an important factor influencing the development and treatment of chronic pain, but the extent of its influence is still unclear. Other demographic factors as well as nonpharmacological interventions might influence pain sensitivity differently in men and women. OBJECTIVE: In this study, we aimed to investigate the influence of sex and other demographic, lifestyle, behavioral, clinical, and environmental factors on pain sensitivity in the Dutch population. Different films were used to investigate how they would impact pain sensitivity and what influence sex and other variables have on the effect of this simple intervention. METHODS: We performed a study consisting of 2 parts: (1) a cross-sectional research to investigate pain sensitivity differences between men and women and the influence of other demographic variables on the pain sensitivity in a Dutch cohort and (2) an internet intervention study to determine whether a short film could skew pain sensitivity. RESULTS: All respondents filled in a web-based demographic questionnaire and were randomized into 4 groups. The control group filled in the Pain Sensitivity Questionnaire without watching a preliminary film. A cross-sectional analysis was performed in the control group (n=1746). The other 3 groups watched short films: one group watched a film with scenes of nature (n=2650), another group watched a film on laughing people (n=2735), and the last group watched a film on physically painful events (n=2708). Immediately after the film viewing, participants were directed to the Pain Sensitivity Questionnaire to measure their pain sensitivity. The Pain Sensitivity Questionnaire score was stated as a mean per question on the numeric rating scale from 0-1. The cross-sectional study revealed no significant differences between men and women but showed male-female differences in the Pain Sensitivity Questionnaire when specific background factors were present. Watching a short film had a positive impact on the pain sensitivity of the respondents who had chronic pain, with a higher effect observed in female respondents. CONCLUSIONS: Scientists performing pain research need to account for factors that can influence the outcome of their study and be aware that these factors can be sex-dependent, and pain sensitivity should be analyzed accordingly. Even relatively small interventions such as watching a film can impact pain sensitivity, especially in respondents with current chronic pain. This effect can vary as well when different background factors are present. Our findings warrant further explorations of the possibilities that simple interventions bring for patients in personalized medicine. TRIAL REGISTRATION: Landelijk Trial Register NTR-new NL8182; https://onderzoekmetmensen.nl/en/trial/29537.