Hematospermia is a common symptom in urology, which is defined as visible blood in the ejaculate (1,2). It is commonly seen in patients <40 years old with a worldwide prevalence of one case per 5,000 urological patients (1). The exact prevalence of the condition is difficult to determine as only a few men examine their ejaculate and even less report to a clinician for a consultation (3). Hematospermia can be an isolated condition or can occur with other symptoms such as hematuria, dysuria and/or scrotal pain (3,4). It may occur only once in a life-time of an individual or can be periodic and chronic (3-5).

Hematospermia is usually benign and a self-healing condition that is less frequently associated with a underlying pathological process (5). The etiology of hematospermia is often not known in >70% cases; however, with advances in diagnostic technologies, the causes of hematospermia are more readily recognized (1). Persistent or recurrent hematospermia is often caused by non-specific inflammation or infection of the lower urinary tract, especially seminal vesiculitis and prostatitis (3,4). In some cases, pathologies such as benign urethral tumor or seminal vesicle malignancy may also present as hematospermia (5,6).

A thorough clinical work-up including the patients' medical history, sexual history, blood biochemistry, physical examination and examination of the ejaculate is recommended for assessing all patients presenting with the condition (6). In the majority of cases, hematospermia resolves without any treatment and in patients without any underlying cause of risk factors, only reassurance is sufficient to alleviate the patients anxiety (1,5,6). In the remaining patients, management of hematospermia depends on the underlying cause. In cases of infections, empirical administration of antibiotics often treat the condition successfully (4). Surgical treatment may be required in cases of pathological abnormalities like cysts, vascular anomalies or calcifications (6). While the majority of patients with hematospermia are cured in a short period of time, a small number of patients relapse with persistent symptoms, and the management of these patients can be challenging (3).

Recent advances in the field of minimally invasive surgery has led to development of trans urethral seminal vesiculoscopy for the management of recurrent hematospermia (7). However, limitations of this technique include the degree of difficulty involved with the procedure and the surgical experience required (8). A simpler technique involving image-guided puncture of seminal vesicles and irrigation with antibiotic solution has received limited attention in literature (1,5). The current study presents the results of the use of transrectal ultrasound (TRUS)-guided seminal vesicle catheterizations with continuous antibiotic infusion for the treatment of patients with persistent hematospermia.

The causes of hematospermia include inflammation, tumor formation, congenital malformations and iatrogenic injuries on seminal vesicles, prostate, testis, epididymis, bladder and urethra (7). More commonly, inflammation of the seminal vesicles and prostate is commonly associated with the condition while iatrogenic factors such as prostate biopsy, radiotherapy for prostate cancer are also frequently observed (4,5). The majority of patients with hematospermia can heal on their own within a few weeks. Certain patients exhibit a recurrent blood presence in the semen that results in persistent or refractory hematospermia (6). These symptoms can give rise to anxiety in patients, leading to erectile dysfunction and infertility in certain more severe cases (10).

Despite the varying etiologies of hematospermia, the common pathophysiology of the disease involves obstruction of the seminal vesicles owing to inflammation, and management of the inflammation usually resolves the condition (11,12). Conventional treatment includes systemic medication and topical treatment, such as prostate seminal vesicle massage, hot water bath and physiotherapy, to improve blood circulation in local tissues in order to promote the absorption and discharge of inflammatory substances (11).

For patients with refractory hematospermia, conventional treatments often yield poor efficacy (7). This is determined by the anatomy and physiological characteristics of the seminal vesicle and prostate that consists of a pair of highly folded and coiled tubular glands. The base of the mucosal folds in the lumen of the seminal vesicle is surrounded by numerous tortuous diverticula (4,10). When the seminal vesicle is inflamed, the drainage is not smooth or even obstructed due to the structural characteristics of the vesicle (11). In addition, the blood supply of the seminal vesicle comes from the small branch of the inferior bladder artery, therefore blood circulation is poor. The effects of the barrier of fibrosis around the prostate capsule limits the ability of antibiotics to access the prostate epithelium (1,3,7). In addition, antibiotics are usually water soluble and exhibit acidity that lowers their dissociation constant, rendering them able to bind easily to proteins (9). These properties additionally limit the antibiotics' accessibility to the infected area and indicate that systemic medications do not exhibit a bactericidal effect in the prostate and seminal vesicles (6,9). Therefore, the prostate and seminal vesicle bacteria are difficult to eliminate, and the lesions are not easy to heal (12). In order to solve this problem, certain researchers have used TRUS to guide the treatment of refractory hematospermia by a single injection of antibiotics, and achieved a curative effect (12-14). Topical medication can significantly increase the concentration of the drug in the lesion, so that a bactericidal effect can be achieved (14). However, since the injected antibiotics are usually quickly discharged into the bladder via the ejaculation tube, the antibiotics can only remain in the seminal vesicle for relatively short time. Therefore, the function of the antibiotics cannot be fully exerted, and the recurrence rate of hematospermia remains high (12,14). In the present study, the 24-h continuous antibiotic infusion via the seminal vesicle catheter with the guidance of TRUS was indicated to aid in maintaining an effective antibacterial concentration in the seminal vesicle and prostate for sufficiently longer time. It can be hypothesized that the potential presence of posterior urethritis and epididymitis can also be treated concomitantly with the infiltration and dispersion of the antibiotic. This also aids to prevent the recurrence of prostatitis and seminal vesiculitis caused by adjacent lesions after treatment.

Previous studies on hematospermia have indicated that recurrent hematospermia was associated with chronic inflammation of the prostate and seminal vesicles (13,14). Chronic inflammation and its secondary alterations cause obstruction, stone formation and stenosis (15-17). Moreover, the inflammation-induced formation of stones, obstruction and stenosis can worsen the inflammation rendering it more difficult to heal, as a vicious circle (15,18,19). Preoperative examination of the present group of patients revealed that secondary alterations, such as ejaculatory cysts and seminal vesicle stones among others, exhibit higher occurrence rates, which was consistent with previous research findings.

In the present study, the seminal vesicle was placed in a 24-h continuous antibiotic infusion for the treatment of refractory hematospermia. In addition to the antibacterial effect of the drug itself, it is important to continuously supply the drug with a certain pressure to aid the drainage of the seminal vesicle content, which relieves the obstruction or imperfection of the semen drainage channel and promotes the excretion of infectious substances and fine stones (14).

The treatment was indicated to be effective on both bacterial and non-bacterial inflammation. Out of 45 patients of the present study, hematospermia disappeared in 42 patients (93.33%). The efficacy of the present treatment was revealed to be higher compared with the method of antibiotic supply using a single seminal vesicle puncture (14). In parallel, secondary lesions from inflammation, such as obstructions and stones, were also alleviated to a certain degree. Moreover, reduction of the likelihood of recurrence was achieved, as only 3 patients exhibited recurrence in the current study. This may be attributed to the dissociation of the catheter in 2 patients, which led to incomplete treatment. The obstruction of the seminal vesicle may not have been relieved, or the infection of the vesicles may not have been eliminated due to incomplete treatment or presence of resistant microorganisms. Large stones in the seminal vesicles may also not be removed with catheterization and may harbor microbes leading to recurrence.

The clinical value of seminal vesicle ultrasound has gradually been recognized with its application in diseases, such as refractory hematospermia and obstruction, in recent years (20). The main goal of seminal vesicle ultrasound is to clarify the patency of the ejaculatory duct, remove the cause of obstruction or malaise and improve the excretion of the seminal vesicle for therapeutic purposes (21). Although the ultrasound-guided treatments are effective in relieving the seminal vesicle obstruction, they exhibit certain limitations (20). On the one hand, finding the ejaculatory duct opening during surgery and entering into the seminal pouch is difficult and the possibility of failure in the operation is high; on the other hand, surgery may also lead to complications, such as rectal injury, external urinary sphincter injury, retrograde ejaculation, urine reflux and secondary infection (21-26).

In the present study, it was revealed that TRUS-guided seminal vesicle catheterization was an effective and easy approach for reaching the seminal vesicle, with good success rates and a high reproducibility, since the operation can be repeated when necessary. In the present study, all 45 patients were successfully catheterized at the first attempt without any complications, except for hematuria after operation, which was indicated to be safe. One of the most critical aspects of seminal vesicle catheterization is to determine whether the puncture needle has entered the seminal vesicle. Patients with chronic seminal vesiculitis often demonstrate poor sound transmission inside the seminal vesicle (14). In the present study, the structure of the seminal vesicle in the ultrasound image could not be distinguished from that of the prostate based on the images alone, as it could be determined whether the catheter has entered the seminal vesicle. During the procedure, although there was a slight puncture when the needle passed via the prostate into the seminal vesicle, the puncture was often not evident and could not be distinguished in all procedures. When it was determined via monitoring of the ultrasonic images that the puncture needle had entered the seminal vesicle, the successful aspiration of the seminal vesicle fluid aided in indicating that the catheter was in place. If the fluid withdrawal was unsuccessful, a small amount of normal saline was injected. If the injection encountered resistance, it indicated that the puncture needle was still in the prostate area, and the needle was required to be inserted deeper. On the other hand, if saline injection was successful, it indicated that that the puncture needle had entered the seminal vesicle. The rapid expansion of the seminal vesicles, which was accompanied by a shining light spot's quick ‘rolling' motion, could be observed in the ultrasonic images. Subsequently, the liquid quickly moved into the bladder via the ejaculation tube and the patient exhibited an urge to urinate, which indicated that the puncture needle was at the correct location and the catheter could be fixed at that place. All patients were routinely indwelled with urinary catheters, which aided to promptly drain the irrigation fluid and reduce the patient activity to avoid catheter dissociation.

The present study presents certain limitations. Firstly, hematospermia cases of different etiologies were included in the current study. The actual effect of the present treatment protocol for each etiology of hematospermia should be explored in future studies. Secondly, the sample size of the present study was small with a limited follow-up. There is a need for additional studies with a larger sample size and longer follow-ups to provide in-depth evidence on the efficacy of this technique.

In conclusion, TRUS-guided seminal vesicle catheterization was indicated to be a convenient and safe procedure for the treatment of persistent hematospermia. The continuous infusion of antibiotics on the affected area was revealed to be efficient with excellent prospects for clinical application. However, this procedure is invasive for both diagnosis and treatment and should not be used in the case of non-refractory hematospermia.