Лечение боли у онкологических пациентов с использованием стимуляции спинного мозга

At least one-third of patients with cancer have pain at the time of their diagnosis and nearly 75% of the patients experience moderatesevere pain in the advanced and terminal stages of their disease [1]. Unfortunately, 10-15% of patients with cancer-related pain do not achieve acceptable levels of pain relief with opiates alone or in combination with conventional adjuvant analgesics [2], which negatively affects patient’s quality of life. In an attempt to provide increased pain relief for patients with intractable cancer pain, unconventional agents and interventional management approaches have received considerable attention. Spinal cord stimulation (SCS) has been used with increased frequency for the treatment of intractable cancer pain. It has been estimated that approximately 15-40% of chronic cancer pain has a neuropathic component [3], and this type of pain often responds poorly to opioids. Moreover, the side effect profile of opioids and other analgesics warrant consideration of other interventional pain management approaches in the treatment of cancer pain. In this article we present several cases of cancer related pain which were successfully treated with SCS, supporting the use of SCS is a treatment option for cancer pain [4-6].

Methods

Between March 2005 and June 2014, 24 patients suffering from intractable chronic back, groin, abdominal and chest pain underwent spinal cord stimulator placement. These patients were diagnosed with lung, breast, colon and anal cancer and subsequently underwent mastectomy, thoracotomy, laparotomy, anterior-posterior resection and postoperative radiation therapy. All of the patients had no evidence of local recurrences or metastases. Seventeen of them were males 70.8% and seven were females 29.2% aged from 39 to 72 with mean age 59 years. Most of the patients, 87.5%, had over 12 month’s pain duration. No patients were involved in active litigation. 25% of patients had distant history of drug and alcohol abuse. The patients experienced constant burning, aching, stabbing pain over the groin, lower back, abdominal or chest wall. All of them on physical examination had tenderness on palpation and fifteen patients were found allodynia and hyperpathia along post-operative scars. The patients failed conservative therapy and had short lasting pain relief after ilioinguinal, intercostal nerve blocks and epidural steroid blocks. Chronic pain medication regimen had included gabapentin, pregabalin, darvocet, oxycodone, hydrocodone, morphine, hydromorphone, fentanyl patch, nonsteroidal anti-inflammatory medications, lidocaine patches, and topical ointments, none of which provided the patients significant pain relief. Each of the patients was counseled on treatment options including continuing with current treatment, or SCS therapy. The patients elected to proceed with SCS therapy.

They underwent successful 2 day trial of percutaneous placement of two 8-electrode epidural leads (Medtronic Inc., Minneapolis, MN) after passing a psychological evaluation for an implantable device. Epidural access was gained with C-arm guidance at the T12/L1 or T11/T12 intervertebral space with two 14 gauge Touhy needles after local infiltration of 1% lidocaine (Figure 1). Two 8-electrode standard Octad Leads (Medtronic Inc., Minneapolis, MN) were inserted through 14 gauge Touhy needles with final leads positioned in posterior epidural space at T2-T3-T4 level (Figure 2) for the patients with chest wall pain, at T5-6-7 level for abdominal and groin pain. Patients with pain in the lower back had the leads at the level T8-9-10. Both leads were connected to a temporary extension cord and to an external stimulator. During the 2 day SCS trial the patients reported greater than 50% improvement in pain. Two to three weeks later the patients underwent implantation with permanent leads and RestorePRIME non-rechargeable or RestoreULTRA (Medtronic Inc., Minneapolis, MN) rechargeable generators. Preoperatively we discussed with the patients the options for location of the implanted generator and they chose the right or left supragluteal area. Both permanent leads were anchored in the wound created in upper lumbar area (Figure 3) to fibroaponeurotic tissue with 2-0 non-absorbable suture of braided polyester (Ethibond) and Titan Anchors (Medtronic Inc., Minneapolis, MN). The leads were tunneled to the left or right supragluteal areas where the subcutaneous pocket was created (Figure 4) for the generator. Leads were then connected to RestorePRIME non-rechargeable or RestoreUltra (Medtronic Inc., Minneapolis, MN) rechargeable generator. The procedures were performed in an ambulatory surgery center with intravenous sedation and local anesthesia administered by the surgeon. The post-operative courses were uneventful for each patient. The initiation of spinal cord stimulation after implantation was uneventful.

The implanted stimulators were programmed using a guarded electrode configuration with a pulse width of 240 to 450 microseconds and a rate of 50 to 80 Hz. The amplitude use ranged from 1.5 to 4.2 Volts. The patients each reported that the stimulation covered one-hundred percent of their painful areas following the initial programming.

As theories continue to evolve, so does the use of SCS for various chronic pain conditions. Since its first use over 3 decades ago when electrodes were placed epidurally over the dorsal columns of the spinal cord, SCS has been further refined and multiple studies have demonstrated its efficacy in the treatment of intractable, chronic pain with a variety of causes [10]. SCS has been used to successfully treat chronic pain in patients with failed back syndrome [11, 12], ischemic limb pain [13], angina pectoris [14], painful peripheral neuropathies [15, 16], visceral abdominal pain syndrome [17], chronic non-alcoholic pancreatitis, generalized abdominal pain, abdominal wall neuromas, and post-traumatic splenectomy [18-23], and cancer related pain [24].

SCS provides a safe, effective, and convenient treatment option for patients suffering from cancer related pain. SCS has many advantages over conservative treatments as well as more invasive techniques. There are no side effects created by SCS as there are with many medications. There is a high rate of success with permanent implant due to the fact that a trial is performed during which the patient evaluates the efficacy of the device. The therapy is completely reversible if for some reason therapy becomes contraindicated or is no longer needed. Patient programmers permit patients to control the level of stimulation they feel based on their degree of pain. This enables patients to take a more active role in their pain management.

We present the group of patients with cancer related pain which was successfully treated with SCS. This technique may be a safe and effective treatment for patients who have failed to find relief with more conservative measures or who are not appropriate candidates for opioid pain medications, more invasive interventional pain procedures or surgical procedures based on their co-morbid health conditions. In our opinion, SCS offers a safe and effective treatment method that is completely reversible should a patient lose its pain-alleviating effect. This study provides support for SCS as an alternative treatment option for patients with cancer related pain and will hopefully inspire interest in prospective studies comparing SCS to other therapies. Our preliminary data from the group of patients with intractable cancer related pain will provide groundwork for potential prospective studies including comparison with other less invasive interventions to control the pain.

Литература

1. Gralow I. Cancer pain: an update of pharmacological approaches in pain therapy. Cur Opin Anaesth. 2002; Vol. 15 (5): 555-61.

9. Linderoth B., Gaxelius B., Franck J., et al. Dorsal column stimulation induced release of serotonin and substance P in the cat dorsal horn. Neurosurgery. 1992; Vol. 31: 289-96.

24. Yakovlev A.E., Resch B.E., Karasev S.A. Treatment of can- cer-related chest wall pain using spinal cord stimulation. Am J Hosp Palliat Med. 2010; Vol. 27 (8): 552-6.