Microsurgical DREZotomy for pain of spinal cord and Cauda equina injury origin: clinical characteristics of pain and implications for surgery in a series of 26 patients.

The result of the DREZotomy procedure used for the treatment of chronic intractable neuropathic pain caused by injuries at the T9-L4 spine level in 26 patients has been reported. For the purpose of identifying the most favorable pain pattern for DREZ surgery we retrospectively analyzed the effectiveness of surgical treatment on different forms of pain in the follow-up period of 13-50 months, 37 months on average. All pain forms were classified according to subjective sensory pain expression including the rhythm and topography of the pain. Three groups of pain were formed according to subjective sensory equivalents: pain of thermal quality (burning, boiling, baking, warm etc.), pain of mechanical-nonthermal quality (shooting, cutting, stabbing, sharp, incisive, cramping, constriction, distraction, throbbing etc.). The third group was the combination of the previous two. Success in pain relief has been defined as a 50% or greater reduction in pain after surgery such that pain no longer interferes with patient activities of daily living and sleeping pattern and no longer requires routine analgesic pain medication. Our results revealed that the pain of mechanical-nonthermal nature and intermittent rhythm, confined to segmental topography was the most responsive to the DREZ surgical treatment so that 90% patients suffering from this pain pattern experienced a good long-term pain relief (70% had complete long term pain relief). Neuropathic pain of thermal quality with the diffuse infralesional distribution and steady rhythm was the most resistant to the DREZ surgical treatment: neither patient had long-term relief of this pain pattern. In the group of patients suffering from pain consisting of combined mechanical and thermal sensory components with confined pain territory, 75% experienced a good long-term pain relief (50% had complete long-term pain relief). Immediate pain relief was obtained in 88% of patients and was long lasting in 69% of the total series. Our results pointed to confined territory, intermittent rhythm and mechanical nature of the pain as the most relevant predictors of the expected pain relief achieved by the DREZ surgery.

Repeat radiosurgery for refractory trigeminal neuralgia.

OBJECTIVE: Stereotactic radiosurgery has become an important and minimally invasive alternative for patients with refractory trigeminal neuralgia. When a second procedure is necessary, the outcomes are unknown. The degree of pain relief and morbidity after repeat radiosurgery were studied. METHODS: Thirty-one patients underwent a second gamma knife radiosurgery procedure because of unsatisfactory or unsustained relief of pain after the first procedure. Twenty-seven patients were assessable at median follow-up periods of 42.7 and 20.4 months after the first and second procedures, respectively. Most patients had undergone multiple previous operations of other types (microvascular decompression, radiofrequency rhizotomy, glycerol rhizotomy, balloon compression). The median target doses of the first and second radiosurgeries were 75 and 64 Gy, respectively. All patients were evaluated by a physician who did not participate in patient treatment. RESULTS: After the first radiosurgical procedure, 13 patients had an excellent response initially (complete relief without any medication), 3 had a good response (complete relief with some medication), 7 had a fair response (>50% relief), and 4 had a poor response (<50% pain relief or treatment failure). Repeat radiosurgery was performed in patients with recurrent or residual pain. After the second radiosurgical procedure, 5 patients had an excellent response, 8 had a good response, 10 had a fair response, and 4 had a poor response. Thirteen patients (48%) achieved complete pain relief (with or without medication). Two patients (7.4%) experienced new sensory symptoms after the first radiosurgical procedure, and three (12.7%, actuarial) experienced new sensory symptoms after the second procedure. CONCLUSION: Repeat radiosurgery provided a similar rate of pain relief as the first procedure, despite a modest dose reduction. The risk of new sensory symptoms was increased, but no other morbidity was identified. For patients who experience recurrent pain and choose to undergo a second procedure, our current procedure is to deliver a maximum dose of 50 to 60 Gy to a trigeminal target anterior to the root entry zone near the entrance of the nerve beneath the petrous dura.

Buprenorphine-soaked absorbable gelatin sponge: an alternative method for postlaminectomy pain relief.

There have been several reports of instillation of buprenorphine in the intact epidural space in an attempt to control postoperative pain, but none in which an absorbable gelatin sponge soaked with buprenorphine is placed directly in the epidural space. In the present study, carried out on 30 patients (study group) undergoing noncervical laminectomies, 0.3 mg buprenorphine diluted to 5 mL with normal saline soaked into an absorbable gelatin sponge was placed in the epidural space under direct vision. In 30 other patients (control group) undergoing laminectomies, absorbable gelatin sponge soaked with 5 mL normal saline was placed in the epidural space. Pulse rate, mean arterial pressure, respiratory rate, pain score by visual analog scale, duration of analgesia, and adverse effects, if any, were noted preoperatively and postoperatively at 1, 2, 3, 4, 5, 6, 12, 18, and 24 hours. The presence of any neurologic symptoms was also assessed at these time intervals as well as on the seventh postoperative day. The authors observed that changes in pulse rate, mean arterial pressure, and respiratory rate were not statistically significant between the control and the study groups. The pain relief score, duration of pain relief (14.8 +/- 0.77 hours in the study group vs. 0.66 +/- 0.15 hours in the control group), and sedation were significantly better in the study group. No patient demonstrated any respiratory depression (respiratory rate <12/min), bradycardia, pruritus, or neurologic pressure symptoms, although the incidence of nausea was higher in the study group.

The use of surgical sympathectomy in the treatment of chronic renal pain.

OBJECTIVE: To assess the efficacy of renal sympathetic denervation in the treatment of chronic renal pain. PATIENTS AND METHODS: In a 10-year period, 21 patients suffering from chronic renal pain underwent 27 renal denervation operations, six of which were bilateral. The cause of pain was the loin pain haematuria syndrome in 18 patients. RESULTS: Four operations resulted in complete pain relief to date (median follow-up 53.5 months). pain relief after the other 23 operations in 18 patients lasted a median of 6 months. Assuming that recurrent pain was due to neuronal regeneration, nine of the 18 patients with recurrent pain underwent a total of 10 re-explorations of the renal pedicle, stripping it of all nerve fibres and areolar tissue. Three of these re-explorations produced complete pain relief to date (median follow-up 40 months). The median pain-free interval of the other seven re-explorations in six patients was 19 months. CONCLUSION: Renal denervation cures severe intractable pain in about 25% of patients. Recurrence of pain could be prevented in more patients if there was a way of preventing re-innervation.