Sperm retrieval techniques and cryopreservation in men with spinal cord injury

Schalk W Wentzel, MB ChB, MMed (Urol)

Professor and Head, Department of Urology, University of the Free State, Bloemfontein

Correspondence to: S Wentzel (wentzelS@ufs.ac.za)

Men with spinal cord injury (SCI) have several problems with regard to fertility and conception.

The extent of these problems falls outside the scope of this article, but can include:

• Problems with ejaculation due to interruption of sympathetic, parasympathetic and somatic nerves during the SCI. In a large study it was shown that only 15% of men with all types of SCI ejaculate normally.1

• Abnormal sperm parameters including low sperm count2 and especially low sperm motility.3

The availability and development of sperm retrieval techniques and cryopreservation have improved the chances of conception in men with SCI. A few of these techniques are discussed here, but much more detail is available in the literature.4

Sperm retrieval techniques

Non-surgical sperm recovery

Pharmaceutical agents

The first pharmaceutical agents used to induce spontaneous ejaculation in men with SCI were cholinesterase inhibitors.5 These drugs had a success rate of about 58% but also had severe side-effects, including autonomic dysreflexia (AD), cerebral haemorrhage and death. Another drug, the alpha-1 agonist midodrine, can be used orally and has shown promise in the treatment of anejaculation and retrograde ejaculation and has a lower incidence of AD.6

Prostate massage

Several authors have reported efficient retrieval of sperm by rigorous prostatic massage with the male in the lateral decubitus position.7

Penile vibratory stimulation (PVS)

This technique has been used since 1965 but was later refined by Brindley.8 A hand-held vibrator is held against the dorsum of the glans penis or the frenulum of the penis. The mechanical stimulation activates afferent fibres in the dorsal nerve of the penis and subsequently leads to ejaculation.9

To decrease the incidence of AD, the patient receives oral nifedipine and/or sublingual nitroglycerine before starting the procedure. If the patient has a history of retrograde ejaculation, it is necessary to prepare the bladder by emptying it and installing a buffer appropriate for spermatozoa washing before starting the procedure.10 Alkalinisation of the urine needs to start at least 48 hours before the PVS session. During the session it is important to monitor the patient’s blood pressure (BP) continuously and terminate the procedure if the BP rises to a dangerously high level. Somatic responses such as contraction of the abdominal muscles, or knee or hip flexion indicate that either antegrade or retrograde ejaculation has taken place.4 If there is no antegrade ejaculation or there are low volumes of antegrade ejaculation, bladder washings should be done to retrieve viable sperm. The overall success rate of PVS is between 49% and 54% if injuries below T10 are excluded.11

Electro-ejaculation

This technique was initially described by Learmonth in 193112 and is said to produce successful ejaculation after 15 - 35 stimulations of the anterior rectal wall.13 Before the start of the procedure, the bladder is emptied and buffer solution installed to protect the sperm in the case of retrograde ejaculation. If the patient has preserved sensation of the rectum, spinal or epidural analgesia will be needed and precautions must be taken to protect the patient in case of AD. The success rate of electro-ejaculation may range from 63% (patients with upper motor neuron lesions) to 93% (patients with lower motor neuron lesions).14 Some investigators have shown that electro-ejaculation may affect sperm motility and that PVS is a better method for preserving sperm motility.15

Surgical techniques for sperm retrieval

If assisted ejaculation procedures fail to produce motile and/or viable sperm for in vitro fertilisation, several surgical techniques can be employed to retrieve sperm. These procedures can be done percutaneously or during open surgical procedures. The complete description of these techniques falls outside the scope of this article, but readers are referred to an excellent review by Schlegel.16

Percutaneous techniques

There are several successful techniques that may be used under local or general anaesthesia. These techniques include percutaneous epididymal sperm aspiration (PESA), percutaneous testicular sperm aspiration (TFNA) and percutaneous testis biopsy.

Open surgical sperm retrieval

Open microsurgical techniques are used to retrieve sperm from the testis or epididymis. The two best-known techniques are microsurgical epididymal sperm aspiration (MESA) and testicular sperm extraction (TESE).

Cryopreservation of sperm

After retrieval, cryopreserved sperm can be stored for long periods and still be used successfully. There are different techniques for cryopreservation of sperm.17

Freezing

Cryoprotectants such as glycerol and sucrose or other saccharides are added to sperm. Thereafter sperm can be frozen using slow programmable freezing or a new flash-freezing technique called vitrification.18

Thawing

Thawing of sperm at 40ºC has minimal effect on sperm viability and DNA quality.19

More information about cryopreservation can be found on the website of the South West Centre for Reproductive Medicine at: www.plymouthhospitals.nhs.uk. More information about sperm banking and available sperm banks in South Africa can be obtained at the following website: www.giftovlife.com

References available at www.cmej.org.za