Needle Placement: A Guide to Predictable Sensory and Motor Responses Based on Variations in Needle Placement During Sacral Neuromodulation Procedures

Crites-Bachert, Melanie; Clark, Casey

Abstract

PURPOSE
Providing practitioners with an adjunctive guide that will aid implanters in the ability to predict and, immediately recognize, what suboptimal needle placement looks like (based on visualization of needle/lead placement and the patient's sensory and motor responses), allow cultivation of a more complete and comprehensive level of understanding of the sacral neuromodulation procedure as a whole, and inversely provide a guide for what true optimal needle/lead placement should currently demonstrate (based on current International Continence Society guidelines).
METHODS
More than 400 patients underwent sacral neuromodulation procedures from 2011-2018 by a practitioner who is in the top 5% of implanting physicians in the United States. Common stimulation patterns with motor and sensory responses were observed in patients with suboptimal needle placement intraoperatively.
RESULTS
Reproducible stimulation patterns were observed with common suboptimal needle placement intraoperatively. This allowed the implanting practitioner to immediately identify and correct the needle placement intraoperatively to achieve optimal needle placement and optimal motor and sensory responses for the patients.
CONCLUSIONS
By considering the 3-dimensional spatial trajectory of the S3 nerve, and following this presented guide, the most optimal lead placement with consistently reproducible outcomes that include S3 motor and sensory response on all 4 leads at less than, or equal to, 2 volts can be achieved and can potentially maximize the life of the device while potentially affording patients a more successful outcome.