Time-domain analysis of scrotal thermoregulatory impairment in varicocele

Paolo Pompa,Giuseppe Orlando,Arcangelo Merla,Luigino Di Donato,Daniela Cardone,Daniela Gabrielli,Enas Ismail

doi:10.3389/fphys.2014.00342

Paolo Pompa, Giuseppe Orlando + Show 5 more

Open Access

https://doi.org/10.3389/fphys.2014.00342

Copy DOI

Abstract

Varicocele is a common male disease defined as the pathological dilatation of the pampiniform plexus and scrotal veins with venous blood reflux. Varicocele usually impairs the scrotal thermoregulation via a hemodynamic alteration, thus inducing an increase in cutaneous temperature. The investigation of altered scrotal thermoregulation by means of thermal infrared imaging has been proved to be useful in the study of the functional thermal impairment. In this study, we use the Control System Theory to analyze the time-domain dynamics of the scrotal thermoregulation in response to a mild cold challenge. Four standard time-domain dynamic parameters of a prototype second order control system (Delay Time, Rise Time, closed poles locations, steady state error) and the static basal temperatures were directly estimated from thermal recovery curves. Thermal infrared imaging data from 31 healthy controls (HCS) and 95 varicocele patients were processed. True-positive predictions, by comparison with standard echo color Doppler findings, higher than 87% were achieved into the proper classification of the disease stage. The proposed approach could help to understand at which specific level the presence of the disease impacts the scrotal thermoregulation, which is also involved into normal spermatogenesis process.

Highlights

Varicocele is defined as the pathological dilatation of the pampiniform plexus and of the scrotal veins with venous blood reflux (Herman, 1975)
The rise time values measured at ppl showed statistical significant differences (Table 6) for the vr2 and vr3 with respect to healthy controls (HCS), without any differences shown within varicocele groups
The assessment of varicocele is usually performed by evaluating the venous blood reflux by using echo color Doppler (Pauroso et al, 2011), the functional assessment of alterations in scrotal thermoregulation could provide new insights about its pathophysiology

Summary

Introduction

Varicocele is defined as the pathological dilatation of the pampiniform plexus and of the scrotal veins with venous blood reflux (Herman, 1975). Varicocele may cause subfertility or infertility and testicular pain (Masson and Brannigan, 2014). The left internal spermatic vein enters the left renal vein perpendicularly; while on the right, the internal spermatic vein drains obliquely into the inferior vena cava. These combined anatomic features may result into increased hydrostatic pressure transmitted to the venous drainage system of the left testicle, resulting in the occurrence of venous dilatation and varicocele formation (Nagler and Grotas, 2009). Varicocele can be diagnosed by Echo Color Doppler imaging and categorized in five grades according to Pauroso et al (2011) (see Table 1)

Objectives

Methods

Results

Conclusion