Sacral neuromodulation (SNM) is commonly used as a third-line intervention for pelvic floor disorders, including overactive bladder, urgency incontinence, fecal incontinence and nonobstructive urinary retention with impressive short- and long-term success rates.^1,2 The International Continence Society best practice statement on SNM recommends achieving optimal intraoperative lead placement, defined as an appropriate motor and/or sensory response(s) at a stimulus amplitude of <2 V at all 4 electrodes.¹ Optimal lead placement increases success rates and decreases costs and adverse events.² Overall success of SNM depends on various factors with localization of the lead and its proximity to the S3 nerve being essential to achievement of optimal functional outcomes.³ Fluoroscopy has significantly improved lead placement and decreased operating room time as it allows the surgeon to identify otherwise nonvisible bony landmarks and confirm lead placement that will likely be successful.² The use of fluoroscopy to place SNM is commonly performed by female pelvic surgical specialists (both urology and gynecology trained), gynecologists, urologists, and colorectal surgeons. Formal training in fluoroscopy, along with familiarity with its techniques and safety practices, varies among surgeons. Radiation safety is a concern for patients, physicians, and staff.⁴

The Food and Drug Administration released a public health advisory encouraging physicians to limit the use of fluoroscopy and advised adherence to the ALARA (as low as reasonably achievable) principle to reduce the risks to themselves and to patients.⁵ Reduced radiation exposure can often be accomplished simply by decreasing fluoroscopy time during procedures.⁵ Fluoroscopy time is measurable and commonly used as a surrogate to quantify overall radiation exposure during fluoroscopically guided procedures.⁵ There is a paucity of data regarding radiation and safety of fluoroscopy during SNM procedures. Given optimal placement of SNM is generally dependent on fluoroscopic guidance by surgeons outside of dedicated radiology departments, the aim of our study was to characterize fluoroscopy time and dose used during SNM surgery across multiple institutions.

Electronic medical records were queried for SNM lead placement procedures from 2016-2021 at each institution based on Current Procedural Terminology codes. Demographic, clinical, and intraoperative data were collected. Demographic data included patient age, sex, BMI, and American Society of Anesthesiologists status. Clinical data included date of surgery, primary indication for procedure (urinary urgency, frequency, urgency incontinence, urinary retention, fecal incontinence, and pelvic pain), surgeon, and surgeon specialty. Intraoperative data included the operating room setting laterality of lead, presence of a resident and/or fellow, operative time, fluoroscopy time (seconds), and radiation dose (mGy). Descriptive statistics were utilized to summarize the population and data surrounding the procedures. Statistical analyses were performed using STATA/BE 17.0. A P value < .05 was considered statistically significant. Multivariable regression analyses were used to evaluate factors that may contribute to fluoroscopy dose and time.

Five hundred twenty-four procedures were performed across 3 institutions. Four hundred fifty-six were Stage 1 lead placement and 68 were full implants. Three hundred fifty-eight (68.3%) procedures had fluoroscopy details recorded. Mean surgical time was 49.2 ± 16.8(SD) minutes. The mean fluoroscopy time was 46.1 ± 48.9(SD) seconds and mean dosimetry was 36.8 ± 46.1(SD) mGy. Of all procedures, 80.5% were completed by general urologists and urology-trained Female Pelvic Medicine and Reconstructive Surgery (FPMRS) specialists (Figure 1). Surgical specialty was significantly predictive of time and dose with FPMRS-trained urologists utilizing the lowest of both (P < .001, see Table). The presence of trainees significantly increased fluoroscopy time (Figure 2). Bilateral lead testing also significantly increased both dose and time. On multivariate analysis for fluoroscopy time, both the testing of bilateral leads and FPMRS-trained urologists had a statistically significant impact (P < .001).

Table. Operative Parameters

Fluoroscopy practices in SNM procedures include significant variability in cumulative radiation dose and time based on multiple factors. These findings demonstrate the need for standardized radiation and fluoroscopy training across specialties who perform SNM procedures. Future aims include developing a survey for SNM implanters to assess baseline radiation safety knowledge and practice habits along with creation of an educational course to review basic principles of radiation safety as well as best practices for fluoroscopy during SNM. We also aim to study how surgical volume impacts fluoroscopy time and dose and further quantify radiation dose received by the surgeon and surgical staff relative to the location of the fluoroscopy unit.