Diagnosis of testicular torsion using near infrared spectroscopy:

A novel diagnostic approach

Babak Shadgan, MD, MSc, PhD;* Mehdi Fareghi, MD;† Lynn Stothers, MD, FRCSC;*

Andrew Macnab, MD, FRCPCH, FRCPC, FCAHS;§ A.M. Kajbafzadeh, MD†

*Department of Urologic Sciences, University of British Columbia, Vancouver, BC;

Case Report

• 14 month old male with left scrotal swelling 1 day

• Nausea and vomiting• erythema and swelling of the left scrotal wall

with left testicular tenderness and an intact cremasteric reflex

Investigations

• Urine D/R and C/S normal• Urogenital US ---> Rt UDT; normal Lt enlarged testis with normal echogenicity• Color Doppler---> equivocal with trend towards epididymitis

Near Infra red Spectroscopy

• NRIS (SR-NIRS) device (PortaMon, Artinis, The Netherlands)

• held in place for 1 minute, data were collected in real time from the spermatic cord and the TSI% was calculated

• Rt spermatic cord vs left = 75.6% vs. 68.8%

Tissue saturation index (TSI) % difference between the affected (left) versus the normal testis (right), while TSI% values of the right and left quadriceps muscles are comparable.

Outcome

• Scrotal exploration done

Revealed 1080 degree intravaginal torsion

Left orchiectomy done.

Methods of detection of tissue hypoxia

Palpable pulse, Ankle brachial Index(ABI) by Doppler

Blood flow or perfusion by Laser Doppler Imaging(LDI)

Oxygen consumption and partial pressure by Transcutaneous oximetry.

Altered blood flow status and arterial oxygen saturation by Photo Plethysmography(PPG) and pulse oximetry

Properties of NIR light

Penetrate the biological tissue deeper

Property : Oxygenated hemoglobin and deoxygenated hemoglobin both absorb light differently in this region.

At 780 nm, deoxygenated blood has a higher absorption, whereas at 830 nm, oxygenated blood has a higher absorption.

Electromagnetic spectrum

Properties of NIR

Non-ionizing & non invasive optical technique

UV/VIS spectral region (<650), light can penetrate only superficial tissue volume [Jobsis et al 1977]

Investigates the differential absorption spectra of chromophores (oxy and deoxy hemoglobin) and functional information in tissue [Fantini et al 1999]

Measure both arterial and venous saturation because it is based on NIR wavelength(700nm-1100nm)

Healthy and diseased soft tissues can be potentially differentiated, due to their different absorption or scattering coefficients

Comparison between NIRS and Pulse oximetry

• NIRS - assessment of all the vascular compartments (Arterial, Venous and capillary).

• Measure hemo dynamics, metabolic and fast neuronal responses to brain activation

• Measure relative changes in pulsatile components of the cerebral blood flow and cerebral blood volume based on the shape of the heartbeat pulse waveform.

• Used in patients with low perfusion states and peripheral vascular. It gives exact oxygen level in the blood.

• Pulse oximeter - only the arterial compartment by time gating the measurements

• Reliable and commonly used to monitor systemic oxygen supply only.

• Pulse oximeter utilizes the arterial oscillations to extract arterial oxygen saturation SaO2 and does not exploit all of the information from the heartbeat oscillations

Different wavelengths are used in both these techniques NIRS is far more penetrating effect than Pulse oximeter because sources of light is in NIR wavelengthNIRS characterize more chromophores than Pulse oximeter

Design of NIR sensor

Three main process: – Absorption– Scattering – Reflection.

Current applications of NIR Applications :

– Non-invasive assessment of brain function in newborn [Wolf M et al 2007]

– In-vivo muscle metabolism measurement [Yuanqing Lin et al 2002]

– Monitor foetal hypoxaemia and in newborn infants to detect birth apnoea and hypoxia.

– Useful for blood analyte monitoring and non invasive imaging of tissue [E. Ciurczak & J. Drennen 2002].

– Monitor healing of burns

– Used for assessment and identification of breast cancer

Evidence has already started coming in

• NIRS has been studied in sheep, rabbit, and rat models of testicular torsion, demonstrating prompt and consistent identification of significantly lower %StO2 values in torsed versus nontorsed testes.

• Capraro GA, Mader TJ, Coughlin BF, Lovewell C, St Louis MR, Tirabassi M, et al. Feasibility of using near-infrared spectroscopy to diagnose testicular torsion: an experimental study in sheep. Ann Emerg Med 2007;49(4):520e5.

• Hallacoglu B, Matulewicz RS, Paltiel HJ, Padua H, Gargollo P, Cannon G, et al. Noninvasive assessment of testicular torsion in rabbits using frequency-domain near-infrared spectroscopy: prospects for pediatric urology. J Biomed Opt 2009;14(5):054027.

• Aydogdu O, Burgu B, Gocum PU, Ozden E, Yaman O, Soygur T, et al. Near infrared spectroscopy to diagnose experimental testicular torsion: comparison with Doppler ultrasound and immunohistochemical correlation of tissue oxygenation and viability. J Urol 2012;187(2):744e50.

Adult evidence• An adult human pilot study applying a transscrotal NIRS probe

found significantly lower %StO2 values in the affected testis compared to the contralateral, unaffected testis in 11 patients (mean age 18.27 years) with surgically confirmed torsion. Moreover, in the 5 patients without torsion, the %StO2 in the affected testis was either higher or no more than 10 points lower than the contralateral unaffected testis in all cases

• Burgu B, Aydogdu O, Huang R, Soygur T, Baker LA. Feasibility of transscrotal near-infrared spectroscopy (NIRS) in the evaluation of acute scrotum: a pilot human study. Moderated poster at 2011 AUA annual meeting and manuscript under review.

Now it has come to oximetery

Questions?

Non invasive tissue oximetry using reflection mode Near Infrared

Spectroscopy system

Periyasamy1

Research Scholar

Indian Institute of Technology Delhi 1Centre for Biomedical Engg

Dr.Ashutosh Mishra1 and Dr.Sneh Anand1

Reference