Oral Sildenafil Combined With Shear Wave Elastography In Evaluation Of Vascular Erectile Dysfunction

Background and objective:Erectile dysfunction(ED),also known as impotence,is a common sexual dysfunction during male sexual maturity.According to its causes,it is divided into mental ED,psychological ED,endocrinic ED and organic ED which is the most common.In organic ED,vascular ED is the most common.Further,vascular impotence can be divided into arterial impotence and venous impotence according to its pathological changes.ED often causes serious psychological burden to patients and affects family harmony.According to different causes,there are great differences in schemes in clinical treatment;therefore,causes are closely related to the later treatment.Previously,vascular ED is mainly diagnosed by spongiosography,arteriography of the internal pudendal artery,or intracavernous injection(ICI)of vasoactive agents combined with color Doppler ultrasonography(CDU).However,spongiosography is characterized by invasive and complex operations;ICI combined with CDU needs local injection of drugs,causing patients' pain and fear and requiring patients' high coordination,and partial patients cannot continue to erect to achieve a satisfactory image.The penis consists of two penis cavernous bodies and a urethral cavernous body.The penis cavernous body is the main organ of erection and its hardness changes when it is diseased.Therefore,detecting the changes in the hardness of penis cavernous body can evaluate or diagnose lesions of the cavernous body.Ultrasound elastography can be used to evaluate the hardness of tissues.Currently,real-time strain elastography,strain-rate elastography,real-time shear wave elastography(SWE),and acoustic radiation force imaging are mainly applied.In recent years,real-time SWE is non-invasive,real-time,quantitative and rapid in imaging and has been applied in the clinic.Especially,it can accurately measure the hardness of tissues,providing a new direction for ultrasonic diagnosis.SWE is a novel elastography that does not need external force to the detected tissues,and can real-time quantitatively evaluate the elastic modulus of tissues in regions of interest.Therefore,the elastic values are objective and accurate.At present,SWE has been widely applied in the diagnosis and differential diagnosis of hepatic,breast and thyroid diseases,but it is rarely applied in the penis and erectile function.Through the observation of the maximum elastic Young's modulus(SWS-max)and mean elastic Young's modulus(SWS-Mean)in E imaging before and after erection in patients with non-vascular ED,arterial ED and venous ED,this study revealed the change rule of SWS-Max and SWS-Mean before and after erection in different patients,so as to explore the clinical value of shear wave elastography applying in the evaluation of vascular ED.Subjects and study methods:Sixty patients with ED treated in the Department of Andrology in the First Affiliated Hospital of Dalian Medical University between December 2016 and February 2018 were selected,and divided into non-vascular ED group(Group A),arterial ED group(Group B)and venous ED group(Group C)that could be included according to ICI combined with CDU.In addition,twenty healthy volunteers were selected as a control group(Group D).SWS-Max and SWS-Mean of penis cavernous body of all subjects in shear wave elastography were measured before erection,at the moment of erection completely and 13~15 minutes later for statistical analysis.Results:1.In this study,vasculogenic ED accounted for 60% of the total cases,among which arterial ED was the most,accounting for 72.2% of vasculogenic ED,and venous ED accounted for 27.8% of vasculogenic ED.2.In all types of ED,SWS-Max and SWS-Mean in erection and fatigue showed statistically significant differences(P < 0.05),which were also shown in the control group.3.SWS-Max and SWS-Mean at the moment of erection completely and 13~15minutes later showed statistically significant differences between the Group B,Group A and the Group D(P < 0.05),while no statistical significance was found in fatigue(P >0.05).SWS-Mean at the moment has the most value diagnostic.4.SWS-Max and SWS-Mean in fatigue showed statistically significant differences between the Group C,Group A and the Group D(P < 0.05),while no statistical significance was found in the moment of erection completely(P > 0.05),but 13~15minutes later the fatigue showed statistically significant differences(P < 0.05).13~15minutes later SWS-Mean has the most value diagnostic.5.No statistical significance was detected in SWS-Max or SWS-Mean in erection or fatigue between the Group A and the Group D(P > 0.05).6.In Group A,B and C,SWS-Max and SWS-Mean in fatigue were negatively correlated with PSV,namely,SWS-Max and SWS-Mean decreased with the increase of PSV.7.In the Group D,SWS-Max and SWS-Mean in fatigue were negatively correlated with age,namely,SWS-Max and SWS-Mean decreased with the increase of age.Conclusions:1.SWE can be used as an important diagnostic indicator of vasculogenic ED.For arterial ED,SWS-Mean has the highest diagnostic value when erection;for venous ED,SWS-Mean has the highest diagnostic value 13~15 min after erection;For non-vasculogenic ED,SWE examination shows no significant diagnostic value.2.Age shows a negative correlation with various indexes of SWE,and the older the age,the lower the indexes of SWE.3.There is a negative correlation between PSV and the indexes of SWE,and the higher the PSV,the lower the indexes of SWE.4.SWE technology can be used as a new index for detecting the cavernous bodies.