Background: Superior hypogastric plexus neurolytic (SHP-N) block is the mainstay management for
pelvic cancer pain of visceral origin when oral opioids fail due to inefficacy or intolerance to side effects.
Unfortunately, SHP-N has the potential to control pelvic pain in 62%-72% of patients at best, because
chronic pelvic pain may assume additional characteristics other than visceral.
Objective: Combining SHP-N with pulsed radiofrequency (PRF) of the sacral roots might block most of
the pain characteristics emanating from the pelvic structures and improve the success rate of SHP-N in
controlling pelvic and perineal cancer pain.
Study Design: This study was a prospective randomized controlled clinical trial.
Settings: The research took place in the interventional pain unit of a tertiary center in the university
hospital.
Methods: Fifty-eight patients complaining of cancer-related chronic pelvic and perineal pain were
randomized to either the PRF + SHP group (n = 29), which received SHP-N combined with PRF of the
sacral roots S2-4, or the SHP group (n = 29), which received SHP-N alone. The outcome variables were
the percentage of patients who showed a > 50% reduction in their Visual Analog Scale (VAS) pain score,
the VAS pain score, and global perceived effect evaluated during a 3-month follow-up period.
Results: The percentage of patients who showed a > 50% reduction in their VAS pain score was
significantly higher in the SHP + PRF group compared to the SHP group when assessed at one month
(92.9% [n = 26] vs 57.7% [n = 15]; P = .003) and 3 months (85.7% [n = 24) vs 53.8% [n = 14]; P =
.01) post procedure, respectively. However, no significant difference was observed between the 2 groups
at the 6-month evaluation (SHP + PRF [57.1% (n = 16)] vs SHP [50% (n = 13)]; P = .59). There was a
statistically significant reduction of VAS in the SHP + PRF group in comparison to the SHP group at one
month (2.8 ± 0.9 vs 3.5 ± 1.2 [mean difference, -0.7 (95% confidence interval [CI], -1.29 to -0.1), P
= .01]), 2 months (2.8 ± 0.9 vs 3.5 ± 1.2 [mean difference, -0.64 (95% CI, -1.23 to -0.05), P = .03]),
and 3 months (2.7 ± 1 vs 3.4 ± 1.2 [mean difference, -0.67 (95% CI, -1.29 to -0.05)], P = .03]) post
procedure, respectively; however, the 2 groups did not significantly differ at 2 weeks, 4, 5, and 6 months
post procedure. Regarding postprocedural analgesic consumption, there were trends towards reduced
opioid consumption at all postprocedural measured time points in the SHP+PRF group compared to the
SHP group; these differences reached statistical significance at 2 months (median, 30 [interquartile range
(IQR), 0.00-30] vs median, 45 [IQR, 30-90]; P = .046) and 3 months (median, 0.00 [IQR, 0.00-30] vs
median, 30 [IQR, 0.00-67.5]; P = .016) post procedure, respectively.
Limitations: The study follow-up period is limited to 6 months only.
Conclusions: SHP-N combined with PRF of the sacral roots (S2, 3, 4) provided a better analgesic effect
than SHP-N alone for patients with chronic pelvic and perineal pain related to pelvic cancer.
Trial Registry: ClinicalTrials.gov. NCT03228316.
Key words: Pelvic pain, pulsed radiofrequency, sacral roots, superior hypogastric plexus
A case of lung cancer who received intrathecal catheter implantation to relieve intractable cancer pain and opioid-induced delirium
