Intrathecal Pump Refill: Reservoir Fill Port Identification by Palpation Versus Ultrasound,a Mono-centre Prospective Comparison Study in Patients Undergoing Regular Intrathecal Pump Refill

The primary purpose of this study is to assess the accuracy of the ultrasound-guided technique for the refill procedure compared to the blind technique in subjects undergoing regular refills of their intrathecal pumps for the treatment of chronic non-malignant pain or spasticity.

Study design: Mono-center prospective efficacy and reliability study comparing two approaches to enter the fill port. Study population: The investigators will include patients with an intrathecal pump for the treatment of chronic non-malignant pain or spasticity, undergoing regular refills of their intrathecal pumps at our Centro Terapia del Dolore at the Ospedale Italiano a Viganello(EOC, Switzerland). Intervention: Two different experienced clinicians will perform one time the blind technique and two times the ultrasound-guided technique on all patients.sample size calculations can be performed. The sample size i.e. n=25 patients in NSI-TD-001 Protocol v. 1.0 Final: August 4th, 2014 Confidential Page 31 of 40 total assessed 6 six times is therefore based on practical grounds related feasibility to duration of inclusion (i.e. one year). This would imply 50 paired assessments for both fill port accuracy assessment and intra-rater reliability. The investigators believe based on clinical experience that this number would suffice to detect a difference between methods. Likewise, although no formal power calculation are available for ICC based reliability assessment, as a rule of thumb 50 paired assessments are usually considered adequate to evaluate intra-rater liability.