Intraoperative Neuromonitoring of Sacral Reflexes to Predict Post Operative Function in Patients Undergoing Sacrectomy for Pelvic Bone Malignancy or Patients Undergoing Spinal Procedures Without Sacral Root Involvement

Phase 2a Prospective Study of Intraoperative Neuromonitoring of the Bulbocavernosus and External Urethral Sphincter Reflexes

This clinical trial tests how well monitoring the sacral reflexes during surgery (intraoperatively) works to predict the post operative function for patients undergoing removal of the lowest part of the spine (sacrectomy) for pelvic bone cancers or patients undergoing spinal procedures. These surgical procedures can lead to damage to sacral root nerves which can result in impairment to the lower extremities, bowel, bladder, and sexual function. Intraoperative monitoring of sacral reflexes can provide objective, real-time information about pelvic nerve function during surgery. This can aid surgical decision-making and help surgeons better prepare patients to understand the changes that may have occurred to their function as a result of surgery. Intraoperative neuromonitoring may work well to predict postoperative function in patients undergoing sacrectomy for pelvic bone malignancy or patients undergoing spinal procedures.

PRIMARY OBJECTIVE:

I. To evaluate the feasibility of acquiring analyzable sacral reflex neuromonitoring data at baseline and case closure during surgery.

SECONDARY OBJECTIVES:

I. To characterize sacral reflex parameters amplitude, latency, waveform morphology, and Nerveana Power Index (NPI) at baseline under standardized intraoperative neuromonitoring conditions in patients undergoing spinal procedures without sacral nerve root involvement and patients undergoing sacrectomy.

II. To describe intraoperative changes in sacral reflex parameters from baseline to end-of-case during standardized intraoperative neuromonitoring in patients undergoing sacrectomy.

III. To characterize the relative contribution of individual sacral nerve roots to sacral reflex responses during intraoperative stimulation in patients undergoing sacrectomy.

IV. To characterize longitudinal changes in postoperative functional outcomes in patients undergoing sacrectomy.

EXPLORATORY OBJECTIVES:

I. To explore the association between intraoperative sacral reflex changes and postoperative functional outcomes in patients undergoing sacrectomy.

II. To explore the association between sacrifice of higher- versus lower-contributing sacral nerve roots and postoperative functional outcomes in patients undergoing sacrectomy.

OUTLINE:

Patients undergo neuromonitoring of the sacral reflexes at predefined time points during standard of care surgery.

After completion of study treatment, patients are followed up at 21 days, 6 weeks and 3, 6 and 12 months.

Inclusion Criteria:

• Documented informed consent of the participant and/or legally authorized representative.

  • Assent, when appropriate, will be obtained per institutional guidelines

• Age: ≥ 18 years

• Ability to complete study questionnaires

• Willingness to comply with all study procedures, including postoperative patient-reported outcome (PRO) assessments

• Undergoing surgery at City of Hope involving either:

  • Complete or partial sacrectomy for primary or metastatic bone tumors, or
  • Thoracolumbar intervention in which the sacral roots are not exposed or manipulated (reference cohort)

Exclusion Criteria:

• Prior sacrectomy or prior surgery resulting in complete sacral nerve transection
• For thoracolumbar cohort patients, prior diagnosis or patient report of bowel or bladder dysfunction
• Cognitive or psychiatric conditions preventing reliable completion of PRO instruments