DETECTION OF HYPOXIA AND ISCHEMIA WITHIN THE DETRUSOR USING NEAR INFRARED SPECTROSCOPY (NIRS)

DETECTION OF HYPOXIA AND ISCHEMIA WITHIN THE DETRUSOR USING NEAR INFRARED SPECTROSCOPY (NIRS)

600 THE JOURNAL OF UROLOGY® Vol. 181, No. 4, Supplement, Tuesday, April 28, 2009 1664 DETECTION OF HYPOXIA AND ISCHEMIA WITHIN THE DETRUSOR USING N...

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THE JOURNAL OF UROLOGY®

Vol. 181, No. 4, Supplement, Tuesday, April 28, 2009

1664 DETECTION OF HYPOXIA AND ISCHEMIA WITHIN THE DETRUSOR USING NEAR INFRARED SPECTROSCOPY (NIRS). Lynn Stothers, Andrew J Macnab*, Babak Shadgan, Vancouver, BC, Canada

CONCLUSIONS: There is considerable variability in suggested management based on the interpretation of the CMG / VCMG, even in specialist hands. Management consistency doubled when all components of VCMG including video imaging were reviewed for patients with incontinence or neuropathic dysfunction, but not outflow obstruction. Video cystometry is an essential component of decision-making for patients with complex incontinence or neuropathic dysfunction Source of Funding: None

1663 ULTRASOUND IMAGING FOR FEMALE URODYNAMICS TECHNIQUE, FEASIBILITY AND PATIENT ACCEPTANCE Lewis W Chan*, Sydney, Australia INTRODUCTION AND OBJECTIVES: There is increasing interest in the use of ultrasound for assessment of voiding dysfunction. The aim of this study was to evaluate the technique, feasibility, patient acceptance and the learning curve of adopting ultrasound imaging for urodynamics. METHODS: 270 female patients underwent urodynamics with ultrasound imaging between 2004 and 2008. Transabdominal ultrasound was carried out to image the bladder and kidneys during the filling phase. Transperineal ultrasound was conducted with the patient in the standing position prior to leak point pressure measurements. Imaging findings including bladder neck position, urethral mobility and pelvic organ prolapse were recorded into a prospective database. A cohort of 28 patients completed a 22 item questionnaire assessing their discomfort and emotional responses to the procedure. Responses were rated on a 10 point scale and compared to 28 patients who underwent fluoroscopic urodynamics. During this period 4 trainees with no prior ultrasound experience were taught the technique and the learning curve assessed with a 12 point checklist for competency. RESULTS: Of 270 patients, 117 had evaluation for stress or mixed incontinence, 90 had overactive bladder symptoms, 41 had neurogenic bladder and 22 had voiding dysfunction. Bladder neck and urethral mobility were satisfactorily assessed in all patients with incontinence except 4 who had significant detrusor overactivity. All 15 patients with a suburethral sling had good visualization of the sling on transperineal ultrasound. 5 patients with neurogenic bladder had hydronephrosis on renal imaging. Patients rated ultrasound urodynamics less troublesome than fluoroscopic urodynamics on all 22 items of the questionnaire. Patients who underwent ultrasound urodynamics reported less trouble in “pain”(0 vs 18% scoring q7,p=0.026),“discomfort” (4 vs 21% scoring q7,p=0.045), “feeling embarrassed”(7 vs 32% scoring q7,p=0.02) compared to those who had fluoroscopic urodynamics. All 4 trainees were able to learn the technique within 3 supervised urodynamic sessions and demonstrated competence in instrumental controls, image acquisition and identification of anatomical features. CONCLUSIONS: Ultrasound is a good modality of imaging for female urodynamics. The technique is easy to learn and allows assessment of the bladder, urethra and urethral mobility. Patients who underwent ultrasound urodynamics reported significantly less discomfort and embarrassment compared to those who had fluoroscopic urodynamics. Source of Funding: None

INTRODUCTION AND OBJECTIVES:Near infrared spectroscopy (NIRS) monitors changes in tissue concentration of oxy and deoxy hemoglobin, and total hemoglobin (O2Hb, HHb, tHb). Simultaneous studies with NIRS and urodynamics (UDS) have evaluated patients with lower urinary tract symptoms (LUTS). Hypoxia is a suggested etiology for LUTS. A method to detect bladder hypoxia non-invasively has been lacking. Since NIRS detects hypoxia and ischemia in other organs the objective was to confirm the ability of NIRS to detect the presence of hypoxia and ischemia in the detrusor. METHODS: Simultaneous collection of UDS (Laborie Medical) and NIRS (Artinis BV) data (O2Hb, HHb &tHb), at 10 Hz in 10 anesthetized female New Zealand rabbits, with NIRS optodes in reflectance mode a) on the abdominal skin over the bladder (skin) or b) directly on the bladder surface after surgical exposure using interoptode distances of 2 and 1 cm respectively to provide photon penetration into the detrusor. Episodes of hypoxia (SaO2 down to 80% via re-breathing circuit and back to 100% via restored spontaneous respiration) or bladder ischemia (vascular clamping) were generated. RESULTS: During 3 repetitive cycles of hypoxia NIRS patterns of change from skin optodes were reproducible and consistent with characteristic hypoxic patterns documented in other tissues. The optodes directly on the bladder gave the same data. Vascular clamping with skin and direct detrusor optode placement detected the immediate fall in O2Hb and equal and opposite rise in HHb with stable tHb characteristic of the onset of ischemia. Fig. 1 shows 3 cycles of hypoxia with chromophore concentration (umol/100ml) plotted against time (sec.), a gradual fall in O2Hb and equal rise in HHb occurs reversed by return to normoxia, and stable tHb throughout indicates stable blood volume.

CONCLUSIONS: NIRS optodes placed on the abdominal skin or directly on the bladder both detected patterns of change in O2Hb, HHb and tHb compatible with hypoxia or ischemia during each event that compromised oxygenation. Because the patterns seen from both sites were characteristic of those seen in other tissue this supports the hypothesis that NIRS monitors physiologic change in detrusor oxygenation, can detect bladder hypoxia and ischemia, and has potential for study of LUTS etiology. Source of Funding: Vancouver Hospital Foundation

1665 WIRELESS NEAR-INFRARED SPECTROSCOPY (NIRS) OF THE BLADDER DETRUSOR DURING UROFLOW IN AMBULANT CHILDREN AND ADULTS. Andrew J Macnab*, Lynn Stothers, Babak Shadgan, Vancouver, BC, Canada INTRODUCTION AND OBJECTIVES: NIRS non-invasively measures absolute changes of detrusor oxygenated, deoxygenated and total hemoglobin concentration (O2Hb, HHb & tHb) during the voiding cycle. Conventional NIRS instruments require fiber-optic cables to link the cutaneous patient interface to the device and are used simultaneously