PURPOSE: Various types of neck dissections exist and have proven to be an effective procedure for treating the lymphatic basins in patients with head and neck cancer. Previous authors have reported the incidence of shoulder dysfunction and nociceptive pain from spinal accessory nerve damage. However, chronic neuropathic pain (greater than six months from surgical procedure) following neck dissection is a significant complication that has not been well described. We evaluated the incidence and patient specific factors associated with nociceptive and neuropathic pain following neck dissection. We hypothesized that more extensive dissections would be associated with an increased incidence and severity of chronic neuropathic pain at the neck dissection surgical site.
METHODS: We utilized two validated surveys at follow-up appointments to assess post-surgical pain. The painDETECT survey from Freynhagen et al. (2006) and the Short Form McGill Questionnaire (sfMcGill) by Melzack et al. (1987) were used to evaluate neuropathic and nociceptive pain, respectively. Only adult patients who had undergone a neck dissection in the last three years at a single academic hospital were included in the study and offered the surveys. The surveys were voluntary and the study was approved by the institutional review board. Demographic and patient specific factors were recorded from patient charts.
RESULTS: 48 patients (32 males and 16 females, mean age 64.4 +/- 13.8 years, mean time since surgery 1.0 +/- 0.9 years) satisfied the inclusion criteria and were offered the survey. 97.9% of patients (n = 47 of 48 completed the painDETECT survey (maximum possible score 38) with an average score of 7.1 +/- 7.4 [0, 32] and 75.0% of patients (n = 36 of 48) completed the sfMcGill Pain Questionnaire (maximum possible score 45) with an average score of 5.4 +/- 9.4 [0, 35]. 6.4% of patients (n = 3 of 47) scored 18 or higher on painDETECT (PD) indicating a >90% likelihood of neuropathic pain and 87.2% of patients (n = 40 of 47) scored 12 or less, indicating <15% chance of neuropathic pain. The total incidence of chronic neuropathic pain was 4.3%, as 2 of the 3 patients with PD scores >= 18 had pain more than 6 months post-operatively. A greater amount of time since surgery was associated with less nociceptive and neuropathic pain, but not significantly, (p = 0.395, p = 0.737.) Interestingly, older age was associated with less nociceptive and neuropathic pain (R = -0.335, p = 0.046; R = -.287, p = 0.051.) The total number of nodes resected, malignant nodes resected, number of neck levels, presence of perineural invasion, angiolymphatic invasion, and gender had no significant association with pain scores.
CONCLUSION: Chronic neuropathic pain is an uncommon but important complication of neck dissection. Head and neck surgeons should be aware of this phenomenon, and consider discussing this risk with their patients preoperatively. A better understanding of chronic surgical site pain after neck dissection may also allow surgeons to direct patients to other services more suited for treatment such as pain management providers.