P-741 Standard IV Cannula Aspiration (SIVCA): A step-by-step video demonstration of the minimally invasive testicular sperm aspiration technique with technical improvements after 4 years of experience

Abstract

Abstract Study question Is there room for further technical improvements in the Standard IV Cannula Aspiration (SIVCA), for a more efficient testicular issue aspiration and sperm extraction procedure? Summary answer A more efficient SIVCA procedure can be achieved by using a higher flow-rate cannula, less negative pressure aspiration and a Luer Lock syringe. What is known already Standard IV Cannula Aspiration (SIVCA) was introduced in 2022. It showed comparable sperm retrieval rates (SRR) to mTESE (56.2 vs 57.3%; McNemar P = 1.000). But given the novelty of the technique, some technical difficulties were encountered: The 14G cannula frequently kinked during the back and forth motions of aspiration, thus having to be replaced several times during the procedure; and the aspirating syringe often detached from the catheter mid-procedure, due to the absence of a lock mechanism securing it to the flashback chamber of the cannula. Study design, size, duration 224 men were enrolled in this prospective 24 months cohort study conducted at a specialized IVF center. The men had testicular tissue aspiration performed via SIVCA, either for azoospermia or increased seminal sperm DNA fragmentation, in anticipation of their partners’ ovum pick-up for an ICSI cycle. If enough testicular tissue was aspirated, it was examined for sperm. If not more than 0.2 gm of tissue could be aspirated from either testis, the patient underwent mTESE. Participants/materials, setting, methods After general anesthesia, 5cc of Xylocaine (lidocaine HCl) 2% was instilled into each spermatic cord. A standard 14-G 310 ml/min flow-rate IV cannula was introduced into the testis. After withdrawing the needle, a 3cc Luer Lock syringe was secured to the cannula. The plunger was maximally retracted to generate −250 Torr of negative pressure and clamped. Back and forth motions were performed, mapping and aspirating tissues from different regions of each testis at a time. Main results and the role of chance Out of a total of 224 cases, an adequate testicular tissue sample of more than 0.2 gm was successfully aspirated from 218 cases, with a 0.97 probability of success. Mild hematoma and pain were encountered in 5.8% of cases (n = 13/224) and subsided within two to three weeks (Grade I on the Clavien Dindo Scale). In a previous series, 130 cases of SIVCA were performed by fully retracting the plunger of a regular 20cc syringe, generating about −520 Torr of negative pressure, while the syringe was connected - but not secured - to the flashback chamber of a 270ml/min flow-rate cannula. In that series, adequate tissue samples could successfully be aspirated in 122 cases, showing a 0.93 probability of success. By using a higher flow-rate 14G IV cannula (310 ml/min vs 270 ml/min), less negative pressure (−250 Torr vs − 520 Torr) and a Luer Lock syringe; fewer number of cannulas were lost to kinking per procedure and no inconvenient disconnections occurred mid-procedure between the cannula and the aspirating syringe owing to the Luer Lock mechanism; all while maintaining a high success rate of aspiration of sufficient testicular tissue (X2 (1, N = 354) = 2.6156, p = .10582). Limitations, reasons for caution Whenever sclerosis and/or fibrosis of testicular tissue rendered aspiration of adequate amounts of testicular tissue difficult or challenging, we reverted to surgical m-TESE. Ice packs should be applied for at least 48 to 72 hours post-procedure to forestall hematomas. Further blinded randomized control studies with larger datasets are recommended. Wider implications of the findings SIVCA is a safe, efficient and easily reproducible method of testicular sperm aspiration. Its allowance for mapping different regions of the testes in order to extract sufficient amounts of tissues, makes it an ideal initial alternative to surgical m-TESE for testicular tissue aspiration and sperm searching. Trial registration number NCT05247723