Patient care for postamputation pain and the complexity of therapies: living experiences

Epidemiology and risk factors for phantom limb pain

Approximately 356 million limb amputations are performed globally every year. In 2005, the prevalence of limb loss in the United States was 1.6 million people; and it is estimated to increase to 3.6 million by 2050. Many post-amputation patients experience chronically altered sensations and pain associated with the amputation, such as phantom limb pain. The risk factors for phantom limb pain are widely debated in the literature due to the heterogeneity of the population being studied. This review will highlight both the non-operative and operative risk factors for phantom limb pain.

Integrating Complementary Therapies in Managing Phantom Limb Pain: A Case Review

OBJECTIVES

This paper describes phantom limb pain (PLP), its impact on patients, and the various treatment options, including pharmacologic and complementary therapies. It investigates the efficacy of incorporating complementary and alternative therapies, both invasive and noninvasive, for amputees who have not achieved satisfactory results with pharmacologic treatments and suffer from adverse drug events. Furthermore, with the predicted increase in limb amputations, it is crucial for nurses, as frontline providers, to understand PLP, be prepared to manage persistent pain and associated psychological and functional issues and educate patients and families about alternative treatment options.

APPROACH

The review includes recent studies on pharmacologic interventions for PLP, case reports, and randomized clinical trials on non-pharmacologic complementary therapies, covering both invasive and noninvasive modalities. Studies from 2013 to 2022 were identified using the PubMed search engine with terms such as "Amputation," "phantom limb pain," "invasive therapies," and "non-invasive therapies."

RESULTS AND CONCLUSION

The pathogenesis of PLP remains unclear, complicating the identification of causes and the selection of targeted therapies for each patient. Uncontrolled PLP can severely impact the quality of life, causing psychological distress and loss of productivity. Traditional pharmacologic therapy often requires supplementation with other options due to PLP's refractory nature. A comprehensive, multimodal treatment plan, including non-pharmacologic therapies, can enhance rehabilitation and reduce complications. Incorporating these therapies can decrease reliance on medications, particularly opioids, and mitigate side effects. Although many potential PLP treatments exist, further clinical studies are needed to determine their effectiveness and establish protocols for optimizing patient outcomes.

Comparative Effects of Interventions on Phantom Limb Pain: A Network Meta-Analysis

BACKGROUND

Phantom limb pain (PLP) is a common type of chronic pain that occurs after limb amputation. Many treatment approaches are available; however, the treatment of PLP is still a challenge. This study aimed to quantify and rank the efficacy of interventions for phantom limb pain.

METHODS

A comprehensive literature search was performed using the databases of PubMed, MEDLINE, Embase, Web of Science, and Cochrane. A network meta-analysis was applied to formulate direct and indirect comparisons among interventions for PLP.

RESULTS

Twenty-two studies comprising 662 patients and 13 different interventions were included in this study. The mirror therapy (MT) (-1.00; 95% confidence interval, -1.94 to -0.07) and MT + phantom exercise (PE) (-6.05; 95% confidence interval, -8.29 to -3.81) group presented significantly lower pain intensity compared with placebo. In SUCRA (surface under the cumulative ranking curve) analysis, the MT+PE and neuromodulation techniques groups had the highest SUCRA value (81.2).

CONCLUSIONS

Our results suggest that MT is the most optimal treatment for PLP, and a combination of therapies would enhance the therapeutic effect.

An Algorithm Approach to Phantom Limb Pain

Phantom limb pain (PLP) is a common condition that occurs following both upper and lower limb amputation. First recognized and described in 1551 by Ambroise Pare, research into its underlying pathology and effective treatments remains a very active and growing field. To date, however, there is little consensus regarding the optimal management of phantom limb pain. With few large well-designed clinical trials of which to make treatment recommendations, as well as significant heterogeneity in clinical response to available treatments, the management of PLP remains challenging. Below we summarize the current state of knowledge in the field, as well as propose an algorithm for the approach to the treatment of PLP.

Multicenter, Double-Blinded, Randomized, Active-Sham Controlled Clinical Study Design to Assess the Safety and Effectiveness of a Novel High Frequency Electric Nerve Block System in the Treatment of Post-Amputation Pain (The QUEST Study)

Background

Chronic pain that follows amputation of a limb is reported as “one of the most severe pains in the human experience,” due to the magnitude of tissue injury and the multiple potential of pain generators at the local peripheral, spinal, and cortical levels. The Altius® System was developed to deliver high-frequency nerve block (HFNB) therapy via a cuff electrode applied to the peripheral nerve(s) and an implantable pulse generator. We report a novel clinical trial design for the first study of an active-implantable medical device in subjects with lower-limb post-amputation pain utilizing a multicenter, double-blinded, randomized, active-sham controlled clinical study protocol called QUEST, which is an ongoing investigational device exemption study to support United States Food and Drug Administration approval.

Methods

The study enrollment of 180 subjects was completed in September 2021. Subjects were randomized 1:1 to the treatment group or the active-sham control group for the 3-month primary effectiveness and safety endpoints. After month 3, the active-sham control program group crossed over to the treatment program group and all subjects continued to the 12-month study endpoint. Study effectiveness success is determined by a superiority test between responder rates in the treatment and control groups at 3 months. A responder is defined as someone who experiences a 50% or greater reduction in pain scores – after a 30-minute treatment session – for more than 50% of all pain episodes in which the treatment was used.

Discussion

The QUEST study design employs an active-sham control group to objectively assess the effectiveness of HFNB therapy. Additionally, the electronic diary repeated measures data collection in QUEST is expected to reduce the intra-subject variation typically observed in pain treatment studies. Finally, the longitudinal measurement of health-related quality of life and use of pain medication may, for example, show effectiveness in reducing opioid use over time.

Icing the Pain-Ultrasound-Guided Cryoablation of Symptomatic Post-Amputation Stump Neuroma

Purpose

To assess the feasibility and outcome of ultrasound-guided cryoablation in patients with a sensitized stump neuroma after limb amputation.

Material and Methods

Seven patients (3 females, 4 males; mean age 42 years) were included in this retrospective study. Ultrasound-guided cryoablation of a previously identified painful stump neuroma was performed. Pain was assessed on the visual analogue scale (VAS) and compared before and after cryoablation (Wilcoxon Test). The degree of pain alleviation was correlated with patient age, duration of pain before ablation and time interval between amputation and ablation (Spearman correlation). A p-value less than 0.05 was deemed statistically significant.

Results

Nine cryoablations were performed for 8 neuromas. Technical success was 100%, there were no major complications. Mean follow-up was 27 months. There was a statistically significant decrease of pain from mean 8.3 / 10 (baseline) to 4 /10 (on day one), 2.1 / 10 (at one week) and 3 / 10 (at last follow-up) (p < 0.05). Patient satisfaction with cryoablation treatment was very high (median score 70 / 100).

Conclusion

In our small population observational study, ultrasound-guided cryoablation of a sensitized stump neuroma was effective and safe for pain alleviation with very good long-term results.

Level of Evidence

Level 2, Observational study with dramatic effect

Treatment Strategies and Effective Management of Phantom Limb-Associated Pain

PURPOSE OF REVIEW

Phantom sensations are incompletely understood phenomena which take place following an amputation or deafferentation of a limb. They can present as kinetic, kinesthetic, or exteroceptive perceptions. It is estimated that phantom limb pain (PLP) affects anywhere from 40 to 80% of amputees.

RECENT FINDINGS

Psychiatric illnesses such as depression, anxiety, and mood disorders have higher prevalence in amputees than in the general population. Pharmacologic treatment has been used as first-line therapy for amputees suffering from PLP with agents including gabapentinoids, amitriptyline, and other tricyclic anti-depressants, opioids, and local anesthetics. Non-invasive treatment modalities exist for PLP including sensory motor training, mirror visual therapy, and non-invasive neuromodulation. Non-invasive neuromodulation includes interventions like transcutaneous electrical nerve stimulation (TENS) and transcranial magnetic stimulation. While many promising therapies for PLP exist, more clinical trials are required to determine the efficacy and protocols needed for maximum benefit in patients suffering from PLP.