Rhizotomy for Truncal or Extremity Neuralgia and Lumbar Facet Syndrome

Initial success rates were around 60% but declined on long-term follow-up. Despite the variability in treated pain syndromes, number of sectioned roots, outcome measures, and follow-up, the results were sufficiently discouraging that the procedure was relatively abandoned and replaced with modified rhizotomies directed at facet denervation for the treatment of lumbar facet syndrome.⁴⁴

Four randomized, blinded controlled trials compared RF rhizotomy of the medial branch of the dorsal root with sham treatment (3 studies) or intrafacetal versus extrafacetal rhizotomy (1 study). Outcome measures and patient selection differed sufficiently between the groups to preclude meta-analysis.⁷⁰ Modest long-term improvement in pain scores in the treated group was observed in all three studies comparing rhizotomy with sham treatment. In the last study, intrafacetal rhizotomy was superior to extrafacetal procedures. Complications were minimal in all four studies. Of the remaining 14 papers, 4 were prospective. The proportion of patients with “good outcomes” varied from 41% to 75% in long-term follow-up. The remaining 7 series are classified as class III studies and reported long-term success rates of 40% to 60% (see Table 169-2, 14 studies^34–47).

Rhizotomy for Chronic Diskogenic Back Pain

One RCT (see Table 169-3) evaluated the effects of RF lesions of the ramus communicans for the treatment of single-level chronic diskogenic back pain.⁴⁸ All selected patients had previously failed an intradiskal electrothermal procedure and had a good response to local nerve blockade of the ramus communicans. At 1 and 4 months of follow-up, the treated group showed significant improvement in visual analog scale (VAS) scores and the medical outcomes study short-form health survey (MOS 36).

Rhizotomy for Cervical Pain

RF rhizotomy was compared with sham procedures for the treatment of cervical pain or cervicogenic headache in three RCTs.^50,56,57 One prospective class II clinical trial⁵¹ and four case series also addressed rhizotomy for cervical pain. The number of patients in each RCT was small, ranging from 12 to 24.⁵⁶ Two of the RCTs demonstrated a significant treatment effect for RF lesions,^56,57 although one did not (an underpowered study).⁵⁰ The class II study also reported durable reduction in validated pain scores.⁵⁰ Both studies with long-term follow-up demonstrated similar median time to recurrence^51,56 (see Table 169-4, nine studies^49–57).

Rhizotomy for Trigeminal Neuralgia

No controlled trials were found that reviewed the treatment of TN by rhizotomy. The best evidence consisted of two class II and three class III studies that prospectively monitored TN patients treated by RF rhizotomy or glycerol rhizolysis, as well as a large (1600 patients) case series.¹⁸ Three studies evaluated pain recurrence rates by life-table analysis,^18,30,59 and two of these studies prospectively compared separate cohorts of patients defined by symptomatology²¹ or treatment protocol.¹⁶

Overall, these studies demonstrate a significant long-term benefit from rhizotomy for TN. Reported recurrence rates concurred, 40% to 60% at 5 years. Several authors have suggested that patients with facial pain other than typical or type I TN had higher recurrence rates or poorer patient satisfaction⁷¹ (see Table 169-1, 20 studies^{14–25,26–33}).

Neurectomy for Trigeminal Neuralgia

Five additional case series involving the treatment of TN were found with the search word “neurectomy” and are summarized in Table 169-1.^{17,22,23,27,33}

Rhizotomy and Neurectomy for Cluster Headache and Facial Pain

Two retrospective studies (19 patients)^59,60 and one prospective study (18 patients) were reviewed. In the prospective study, 83% of patients had immediate pain relief but also demonstrated a 39% recurrence rate at long-term follow-up⁵⁸ (see Table 169-5, three studies^58–60).

Rhizotomy for Cancer Pain

Ten case series were identified and the majority evaluated the effects of dorsal root rhizotomy for malignant pain of the extremities. The largest series contained 71 patients and was one of the earliest papers.⁴⁴ Reported outcomes were generally favorable initially but faded quickly with time. The open nature of the procedure, the fading effect, and the presence of more effective procedures all contributed to abandonment of this procedure (see Table 169-6, 10 studies^44,61–69).

Ganglionectomy for Lumbar and Cervical Radicular Pain

Geurts and colleagues in 2003 randomized 83 patients to either RF lesioning (45 patients) or needle placement without RF lesioning (38 patients) of selected lumbar ganglia.⁷² Evaluators and patients were blinded to the protocol used. Despite adequate power, no statistical difference was found between the groups.

Slappendel and associates in 1997 found no difference in outcomes between patients receiving an RF lesion at 60° C (group I) or 40° C (group II) for cervicobrachialgia.⁷³ In a case series of 61 patients with sciatica,⁷⁹ 59% had “markedly reduced” postoperative pain at follow-up ranging between 1 month and 15 years. Definite conclusions concerning long-term outcomes are difficult given the variability in follow-up data. The remaining studies were small and inconsistent.

Ganglionectomy for Occipital Neuralgia

The largest case series evaluated the efficacy of C2 ganglionectomy for occipital neuralgia.⁷⁵ These authors found that 80% of patients had significant relief from symptoms. Unfortunately, long-term follow-up data were unclear, thus rendering any conclusions difficult. The second largest series of patients with occipital neuralgia compared ganglionectomy performed on patients with occipital pain described as either “sharp, burning, jabbing, electrical, or exploding” (group I) or “dull, aching, throbbing, or pressure-like” (group II).⁷⁶ Patients in group I tended to have a higher prevalence of a traumatic history (74%) and had the best response, nearly 80%. Overall, group II patients had a poor response. Follow-up was between 19 and 48 months. Other published series on occipital neuralgia were small and without standardized follow-up data.

One retrospective paper evaluated the effects of occipital neurectomy for the treatment of occipital neuralgia of various causes.⁸⁷

Ganglionectomy for Other Causes

One study evaluated sphenopalatine ganglionectomy for cluster headache and found that patients with intermittent headache (group A) had a 67% response rate whereas chronic, continuous headache sufferers had only a 24% response.⁴¹ Mean follow-up was 24 and 29 months, respectively.

Two small series, one with 4 patients⁸² and another with 10 patients,⁸⁶ reported patients treated by thoracic ganglionectomy for a variety of symptoms. Both claimed some success. Ganglionectomy articles are listed in Table 169-7 (17 articles^41,72–87).

Dorsal Root Entry Zone Lesions

A total of 31 (26 noncancer pain, 5 cancer pain) case series were obtained for DREZ lesions. No class I or II studies were found. These reports included between 3 and 124 patients and had a wide range of follow-up time points. For noncancer pain, all studies reported greater than 50% relief of pain in the majority of patients, and these results tended to be durable.⁸⁸ Patients with brachial plexus avulsion (BPA) injuries and traumatic spinal cord injury tended to have the best response to DREZ lesions in studies that compared different initial causes directly, whereas patients with postherpetic neuralgia and peripheral neuropathy had the worst response.^89,90 Outcomes for patients with BPA injury were quite consistent across series, with 54% to 86% of patients having a greater than 50% reduction in reported pain levels. Table 169-8, 26 studies, is a summary of the articles obtained for DREZ lesions.^88–113

Only four (Tables 169-9 and 169-10) papers were identified that addressed the use of DREZ lesions for cancer pain.^114–117 Two were case series that claimed long-lasting pain relief in patients with mixed cancer pain causes. Specific follow-up and outcome measures were not reported. For facial pain from craniofacial malignancies, three of the four papers were small case series that reported some benefit from DREZ lesions of the nucleus caudalis.^114,116,117

Trigeminal Tractotomy for Facial Pain

Eight pertinent articles were found for tractotomy of noncancer pain, including the oldest article retrieved for this review.¹¹⁸ No class I data were found for this topic. Instead, all papers were case series. The largest case series was reported by Schvarcz in 1975, who found that excellent pain relief was achieved in 16 of 17 patients.¹¹⁹ Interestingly, all case series reported good to excellent results, even in patients with postherpetic neuralgia. In one series, for example, deep pain was eliminated or significantly decreased in 6 of 6 patients with postherpetic craniofacial dysesthesia.¹²⁰ Table 169-11, eight case series, presents an overview of the articles just reviewed.^118–125

Seven papers were found that involved tractotomy for cancer facial pain (Table 169-12).^{119,122,126–130} All were cases series with one exception,¹²⁶ an open label prospective study. In this prospective class II study, a standardized outcomes measure (VAS), Karnofsky Performance Scale, activities of daily living, and sleep duration were assessed at 6 months. The authors reported sustained relief of pain in 80% of patients at 6 months. Although the study was categorized as class II, the number of tractotomy patients included was limited (10 patients). We did not consider this sufficient to claim class II evidence for the efficacy of tractotomy in relieving facial cancer pain. The current literature supports only class III evidence for tractotomy for cancer pain.

Cordotomy

A review of cordotomy for patients with noncancer pain produced 11 case series published between 1958 and 1990. No class I or II studies were found. The number of patients in these case series ranged from 13 to 72, and follow-up was between 1 month and 10 years. Outcome data from these studies generally demonstrated an overall improvement in patient-reported pain postoperatively over preoperative values.

In general, for studies with long-term follow-up, surgical benefits declined with time. However, determining significance was difficult because neither outcome nor follow-up was standardized for these patients. Furthermore, outcome measures were inconsistent among studies, thus complicating any attempts to make generalized recommendations. The articles that were included in this review are outlined in Table 169-13, 11 case series.^{100,131–140}

For cancer pain, cordotomy is the invasive procedure most often reported in the literature. Forty-seven papers qualified under our search criteria (Table 169-14).^{65,126,132,134–136,141–181} Many reports included more than 100 patients, many with long-term follow-up. A surge in publications followed the introduction of percutaneous cordotomy in the mid-1960s, followed by a gradual decline in published reports and patients in the late 1990s. Kanpolat introduced CT guidance for percutaneous cordotomy in the late 1980s, which was considered a major contribution to the field of pain surgery. However, intrathecal opioid use was also introduced at around the same time and gained widespread popularity.

One prospective trial was identified; this trial used a standardized outcome measure (VAS), Karnofsky Performance Scale, activities of daily living, and total sleeping hours. This prospective trial reported statistically significant improvement in all outcomes measures with respect to postprocedure and baseline pain levels. Three papers involved retrospective cohorts with survival analysis of pain relief of the whole cohort until death.^64,158,159 Many other papers consisted of retrospective cohorts with large numbers (>100 patients) and 6 months’ follow-up.^{145,153,163,164,179} There were no RCTs.

Despite the heterogeneity of outcome measures, the vast majority reported excellent lasting relief within the context of cancer longevity. Reported cordotomy outcomes in cancer pain patients contrast with outcomes for noncancer pain patients, in whom pain relief was moderate, short-lived, and often complicated by dysesthesias.

Within the medical literature there is limited class II evidence for cordotomy as an effective treatment modality in cancer pain patients.

Myelotomy

Three articles examining the use of myelotomy for noncancer pain were found. They were small case series (3 to 14 patients) with variable follow-up periods and causes of pain. The largest series reported that 64% of patients experienced a complete or marked reduction in deep “background” pain.¹⁸² Table 169-15, three case series, represents a summary of the articles.^182–184

For cancer pain, 19 papers were identified (Table 169-16).^{124,185–202} These articles were all case series and included papers about commissural as well as extralemniscal myelotomy, both open and percutaneous. With the exception of 3 papers,^198–200 most reports involved a small number of patients (<20).

Outcome measures and follow-up periods were heterogeneous. In general, reported outcomes were less favorable when compared with cordotomy. However, a consistent observation was that myelotomy was most effective in treating midline visceral cancer pain syndromes (i.e., cervical, pancreatic, or gastric cancer).

The current literature supports only class III evidence for myelotomy for pain relief.

Mesencephalotomy

Using the criteria described earlier, nine relevant articles on the use of mesencephalotomy for noncancer pain were reviewed. All these articles were case series, and most had relatively small numbers of patients. The most recent publication reported the effects of lesions made in one of two locations in 27 patients with central pain after stroke.²⁰³ Long-term pain relief was achieved in 75% of patients with lesions created at the level of the superior colliculus, although significant ocular side effects occurred. These side effects were reduced with lesions adjacent to the inferior colliculus. Long-term pain relief was achieved in 58% of patients in this latter group. Follow-up ranged between 3 months and 5 years. In a separate study, good pain relief was reported in 23 patients (67%) with thalamic syndrome and tabes dorsalis monitored for 3 to 70 months.²⁰⁴ Table 169-17, nine case series, provides a summary of articles pertaining to mesencephalotomy.^203–211

Mesencephalotomy and pontine tractotomy for cancer pain were reported in seven papers (Tables 169-18 and 169-19).^{207,212–217} All were case series with variable outcome measures and follow-up. Outcome varied between extreme success (92% until death)²¹⁵ to very poor success (1 of 12 had lasting pain relief).²⁰⁷ There was agreement on the frequency of side effects, specifically those related to ocular mobility.

Thalamotomy

All published articles describing thalamotomy were limited to small case series with heterogeneous patient populations. Similar to cingulotomy, the largest case series (N = 85) was not published in a peer-reviewed article but in book format²¹⁸ and was not included here; however, a subset of patients was described earlier.²¹⁹ Follow-up, outcome measures, target site, and cause of pain were inconsistent within or among series, thus making definite conclusions difficult. Dougherty and associates²²⁰ and Tasker²²¹ have provided thorough discussions of thalamotomy. Please refer to Table 169-20, 12 case series, for a summary of articles.^{133,205,219,222–230}

Sixteen papers on thalamotomy for cancer pain were found (Table 169-21)^{133,205,222,226,229,231–241} (some articles are included in the noncancer pain tables). All were case series with variable outcome measures and follow-up. Most reported lasting benefits in more than 50% of patients. In some instances, bilateral pain relief was achieved with unilateral thalamotomy. Effects tended to fade with time and were often accompanied by persistent psychiatric complications.²³⁸

Cingulotomy

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