Table 3.

Advantages and disadvantages of sperm retrieval techniques.

	Advantages	Disadvantages
PESA	Fast and low cost;	Few sperm retrieved;
	Minimal morbidity, repeatable;	Limited number of sperm for cryopreservation;
	No microsurgical expertise required;	Fibrosis and obstruction at the aspiration site;
	Few instruments and materials;	Risk of hematoma/spermatocele
	No open surgical exploration
Open epididymal fine-needle aspiration	Repeatable;	Open surgical exploration required;
	No microsurgical expertise required;	Increased cost and time-demanding;
	Relatively large number of sperm for cryopreservation;	Fibrosis and obstruction at the aspiration site;
	Few instruments and materials	Postoperative discomfort;
		Not validated in a large series of patients
MESA	Large number of sperm retrieved;	Open surgical exploration required;
	High number of sperm for cryopreservation;	Increased cost and time-demanding;
	Reduced risk of hematoma;	Operating microscope required;
	Reconstruction possible1	Microsurgical instruments and expertise required;
		Postoperative discomfort
TESA	Fast and low cost;	Relatively low success rate in NOA cases;
	Repeatable;	Few sperm retrieved in NOA cases;
	No open surgical exploration;	Limited number of sperm for cryopreservation;
	No microsurgical expertise required;	Risk of hematoma/testicular atrophy
	Few instruments and materials;
	Minimal/mild postoperative discomfort
TEFNA	Fast and low cost;	Few sperm retrieved in NOA cases;
	Repeatable;	Limited number of sperm for cryopreservation;
	No open surgical exploration;	Risk of hematoma/testicular atrophy;
	No microsurgical expertise required;	Not validated in a large series of patients
	Few instruments and materials required;
	Minimal/mild postoperative discomfort
TESE	No microsurgical expertise required; Repeatable	Increased cost and time-demanding;
		Open surgical exploration required;Relatively few sperm retrieved in NOA cases;
		Risk of testicular atrophy3;
		Risk of testicular androgen production impairment3;
		Postoperative discomfort
Single seminiferous tubule biopsy	No microsurgical expertise required;	Increased cost and time-demanding;
	Repeatable	Open surgical exploration required;
		Relatively few sperm retrieved in NOA;
		Postoperative discomfort;
		Not validated in a large series of patients
Micro-TESE	Higher success rates in NOA cases2;	Surgical exploration required;
	Larger number of sperm retrieved2;	Increased cost and time-demanding;
	Relatively higher chance of sperm cryopreservation2;	Operating microscope required;
	Low risk of complications	Microsurgical instruments and expertise required;
		Postoperative discomfort

PESA: percutaneous epididymal sperm aspiration; MESA: microsurgical epididymal sperm. aspiration; TESA: percutaneous testicular sperm aspiration; TESE: conventional testicular sperm extraction; micro-TESE: microsurgical testicular sperm extraction. ¹in cases of post-vasectomy obstructions. ²compared with TESA and TESE in NOA cases. ³multiple biopsy-TESE.