Neurolytic Block Techniques In Abdominal Visceral Cancer Pain

Double-blind randomized clinical trial.

The objective of the study is to compare the analgesic efficacy of splanchnic nerve neurolysis with alcohol to celiac plexus block with alcohol, with pain relief as the primary outcome. It also aims to quantify the adverse effects of the techniques as secondary outcomes. The sample size calculation will be based on comparing the mean pain scores on the Numerical Rating Scale of patients in the Control Group and the Intervention Group, evaluated after completing the second month of treatment. A two-tailed t-test will be sufficient and will require an adequate sample size. Therefore, for the chosen sample design with a significance level of α=5%, a power of 1-β=80%, assuming M1=5.0 and M2=3.5 and a standard deviation of 2.0, the sample size required is n=58. the sample size required is n=58. Considering a 10% dropout rate, the final sample size will be increased to 64 participants. Convenience sampling (a non-probabilistic sampling method) will be used. Participants will be randomly allocated to the groups using a list generated by a program obtained at https://www.randomizer.org. The proportion between the participants in the groups will be 1:1, with 32 patients allocated to the Intervention arm and 32 to the Control arm. The allocation of the total 64 participants will be determined by randomly assigned sequential letters (A or B) generated by the computer (website https://www.randomizer.org), randomly assigning numbers from 0 to 64 to each group: Control Group (Celiac Block) and Intervention Group (Splanchnic Nerve Block). The Control Group will receive celiac plexus neurolysis with absolute alcohol, and the Intervention Group will receive splanchnic nerve neurolysis with alcohol. The statistical analysis will be performed in program R version 3.5.1. The results obtained will be presented as mean + standard deviation for continuous data or absolute frequency for described data. For quantitative variables, the Student's t-test will be used for normally distributed data, or the Mann-Whitney test for non-normally distributed data. For qualitative variables, the chi-square test will be used or Fisher's exact test. Significant difference is defined as p < 0.05. Data will be collected and managed using REDCap data capture tools.

Inclusion criteria

Patients aged 18 years or older Presence of localized visceral pain in the upper abdomen originating from cancer of the stomach, duodenum, distal esophagus, ascending or transverse colon, liver, biliary tract, or pancreas

Ineffectiveness of analgesic treatment with third-step opioids according to the WHO analgesic ladder, including:

Opioids (≥ 60 mg/day of morphine equivalents) Antidepressants (tricyclic or dual-action), at any dosage Gabapentinoids, at any dosage Presence of side effects from analgesics that are difficult to manage with medication

Exclusion criteria

Presence of ascites Presence of deep vein thrombosis Presence of hepatic failure: Child-Pugh class B or C Presence of renal failure: estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m² Use of any anticoagulant medication

Clinical coagulation disorder, defined as:

INR > 1.5 Prothrombin activity < 70% or prothrombin time > 13.5 seconds aPTT > 40 seconds Cardiovascular failure: NYHA class III