The Acceptance, Safety, and Efficacy of Needle-free Jet Anaesthetic Technique (MadaJet) Versus Needle Injection for Sperm Retrieval in Patients With Azoospermia

Azoospermia is found in 1-3% of general population and 10-15% of men presenting with infertility. In this scenario, there are no spermatozoa in the patient's semen after centrifugation, and pregnancy may be achieved through IVF/ Intracytoplasmic sperm injection (ICSI) combined with sperm retrieval techniques (e.g. PESA, testicular sperm extraction - TESE, TESA). These techniques are commonly conducted under local anesthesia, which a 10-15 mL solution of 2% lidocaine hydrochloride injected around the spermatic cord near the external inguinal ring. However, needle fear is prevalent in both children (~33-63%) and adults (~14-38%) and can contribute to negative experiences with needle procedures and health care for patients, caregivers, and health professionals. In clinical practice, patients often concern about the pain, trauma and possible complication (i.e. wheal, hematoma, infection) of needle injection of local anaesthesia into and through the scrotal wall when performing sperm retrieval. It not only interferes with clinicians' abilities to carry out procedures (e.g. due to flailing and attempts to escape), but also undermines the efficacy of pain interventions at the time of the needle. Therefore, receiving local anaesthesia without a needle is easily well accepted by the patients with azoospermia.

The needleless jet injector (MadaJet Medical Injector) has been widely used in the fields of dermatology, cosmetic and plastic surgery, gynecology, dentistry, and podiatry as well as for immunization. It was also employed for no-scalpel vasectomy in Urology/Andrology. The first studies using needleless jet injector for spermatic cord block was reported by Wilson in 2001 and Weiss in 2005. The next studies showed that MadaJet has better outcomes (e.g. cost, pain scores, onset time) than traditional needle anaesthesia (16-18). Unlike a conventional spermatic cord block with needle injection, there is no wheal on the patients' skin and local edema after administering injection. A mist of solution with a high-pressure injector will be rapidly delivered and absorbed through the skin to the tissue beneath around the cord with much less trauma. As a consequence, it is less painful than the needle injection.

For those reasons, a needle-free jet anaesthetic technique for sperm retrieval will be described for local anaesthesia, which may minimize the fear of the needle. The acceptance, safety, and efficacy of this technique will also be compared with needle injection for sperm retrieval in azoospermia patients.