Sperm Retrieval and Fertility in Men with SCI

Men with SCI may not be able to ejaculate via partner sexual practices or masturbation alone; if they have a goal of becoming biological fathers, many may require medical assistance to obtain sperm. Two most common methods used in men are for sperm retrieval are penile vibrostimulation (PVS) and the electroejaculation procedure (EEP). PVS is performed using a specialized vibrator placed on the penis to induce reflex ejaculation, whereas EEP uses a rectal probe to deliver electrical current to the periprostatic nerves, eliciting seminal emission. In the first months after injury, semen can only be attained by EEP, since PVS is not effective until spinal shock has resolved. Meanwhile, if PVS or EEP do not work, minimally invasive techniques such as testicular sperm aspiration (TESA) are available which allow sperm to be retrieved directly from the testicle for fertility.

Discussion

Brackett et al. (2010) determined in one of the largest studies of its kind (N=500) that most men with SCI can obtain sperm without surgical procedures.  The studies have mainly reported cumulative ejaculatory success rates and suitability of using techniques such as vibrostimulation, electroejaculation, and operative sperm retrieval for assisted reproduction (Dahlberg et al. 1995; Nehra et al. 1996; Brinsden et al. 1997; Chung et al. 1997; Löchner-Ernst et al. 1997; Le-Chapelain et al. 1998; Hibi et al. 2008; Kanto et al. 2009). Simple prostatic massage alone has been successfully used to obtain sperm in 32% of 69 men with SCI, typically those with lesions above the T10 level (Arafa et al. 2007).

A commonly used method of non-invasive sperm retrieval is PVS. Frequency and amplitude are important variables to optimize outcomes when using PVS. The application of a specialized vibrator, with settings of approximately 70-100 Hz with 2.5-3.5 mm amplitude (Brindley 1984; Ohl et al. 1997; Sønsken et al. 1994) on the penis (usually frenulum) can cause antegrade, retrograde, and some mixed semen samples. After each interval, it is important to examine the penile skin for early detection of skin abrasions or edema, which will warrant termination of the stimulation session (Sinha et al. 2017).

Vibrostimulation worked most reliably in men with lesions above T10, men who had a reflex hip flexion with scratching the soles of the feet, and with injuries over 6 months in duration (Brindley 1984; Sonsken et al. 1994; Löchner-Ernst et al. 1997; Sonsken et al. 1997) or in patients with incomplete lesions (Taylor et al. 1999). Recent research has shown greater success with PVS in SCI patients less than 3.5 years since injury (77%) than 3.5 years since injury (14%) (Čechová et al. 2014). A retrospective chart review found that successful ejaculation with PVS was greater in C5–T6 injuries (50-67% success) and was less likely with caudal injuries (complete L4 injury of 2.6%; 12% when any of the sacral segments was injured; Chéhensse et al. 2016).

Vibrostimulation application for 30 sec to 20 minutes (most occurring in less than 3 min) resulted in ejaculation in 60-100% of patients (Beretta et al. 1989; Rawicki & Hill 1991; Sønksen et al. 1994; Rutkowski et al. 1995; Chung et al. 1997; Sønksen et al. 1997). Several recent studies have reported methods to “salvage” some of the ejaculatory failures with PVS. Brackett et al. (2007) reported success in recovering semen in an additional 22% of men with SCI who failed on several occasions to respond to high amplitude PVS with 1 vibrator, as well as 38% of inconsistent responders, using a technique that sandwiched the glans penis between two vibrators presumably by increasing afferent input. Ibrahim et al. (2021) found in a small study that 2 participants responded to 2 devices at 2.5mm after failure to ejaculate with 1 device at the 2.5mm and 4.0mm setting.

PVS paired with midodrine has mixed results in producing ejaculation in men with SCI. Soler et al. (2007) reported that 65% of 158 men who failed to respond to PVS alone were able to ejaculate when treated with midodrine (average dose of 18.7 mg) 30-120 minutes prior to applying PVS. They found antegrade ejaculation was more frequent in patients with complete (73%) and UMN (89%) lesions. Moderate increases in blood pressure (MAP ~10mmHg) were induced by midodrine in comparison to PVS alone, with 13 patients (11 with tetraplegia) recording systolic BP > 200mmHg. In contrast, a recent double‐blind, randomized, placebo‐controlled study found no improvement in ejaculation success rates by PVS combined with midodrine vs. a placebo (Leduc et al. 2015). Another placebo‐controlled study found that vardenafil had significantly greater ejaculation success rate than placebo (19% vs. 10%) (Giuliano et al. 2008).

As a caution, vibrostimulation has been shown to also induce pronounced levels of AD, increases of +70-90mmHg in mean arterial pressure (SBP ~190±20mg, DBP ~130±10mg, SBP ~150±10mg) especially in men with tetraplegia (Sheel et al. 2005; Claydon et al. 2006In EEJ techniques nifedipine can control the severity of AD, allowing for better sperm retrieval using electroejaculation technique (VerVoort et al. 1988; Brackett et al. 2002; Elliott & Krassioukov 2006). This requires careful monitoring during vibratory stimulation and EEJ, screening for safe home use particularly for silent AD.

Electroejaculation is often utilized when PVS fails particularly for people with lower lesions (Ohl et al. 2001; Taylor et al. 1999). Since an ejaculate was almost always attainable by PVS or electroejaculation (EEJ), the need for surgical retrieval was rare (Dahlberg et al. 1995; Löchner-Ernst et al. 1997; Shieh et al. 2003). Retrograde ejaculation of semen into the bladder, which frequently accompanies EEJ and affects sperm quality, can be prevented by simply applying a technique of gentle bladder neck tamponade which uses a non-toxic all-silicone Foley catheter and the balloon filled with 10mls of saline (Lim et al. 1994). Electroejaculation is considered more invasive and painful than PVS for men with incomplete SCI, and patients prefer PVS if sperm quality was equal between the two techniques (Ohl et al. 1997). A small group of men (4–5%) will require anesthesia during EEJ, because of their retained pelvic sensation (Brackett et al. 2010).

Operative methods should be reserved for those men who do not respond to non-invasive sperm retrievals. Operative retrieval commits a couple to expensive, higher-level interventions such as intracytoplasmic sperm injection (ICSI), where a single sperm is injected directly into the egg for fertilization. Such high-level interventions with operative sperm retrieval, i.e. using fresh testicular sperm (Kanto et al. 2009) or aspirated retrograde vasal sperm (Hibi et al. 2008) do result in better conception rates per cycle from the male SCI population.

Conclusion

There is level 4 evidence (Beretta et al. 1989; Sønksen et al. 1994; Le Chapelain et al. 1998; Brackett et al. 2007b, 2010; Kathiresan et al. 2012; Qiu et al. 2012; Sønksen et al. 2012; Chéhensse et al. 2016; Čechová et al. 2014) that semen retrieval may be assisted by vibrostimulation in men with lesions above T10.

There is level 4 evidence (Ohl et al. 1989; Löchner-Ernst et al. 1997; Le Chapelain et al. 1998; Kolettis et al. 2002) that semen retrieval may be assisted by electroejaculation in men who failed vibrostimulation.

There is level 4 evidence (Brindley et al. 1989) that surgical aspiration may be used to retrieve sperm if vibrostimulation and electroejaculation are not successful.

There is level 4 evidence (Arafa et al. 2007) that prostatic massage thru the rectum to push the sperm out through the ejaculatory ductal system is one technique to retrieve semen in some men and is more successful with lesions above T10.

There is level 4 evidence (Hibi et al. 2008) that retrograde vasal sperm aspiration can retrieve sperm of sufficient motility to afford pregnancy.