Vasectomy is the injection of contrast into the vas deferens by incision or percutaneous puncture to show the vas deferens, seminal vesicles, ejaculatory ducts and other tissue structures to understand whether the vas deferens is open and whether there are pathological changes in the seminal vesicle glands, etc., and to clarify the causes of male infertility. A plain film is routinely taken before the examination to exclude stones or calcified shadows in the prostate, lower urinary tract or pelvis to avoid confusion with contrast. Preoperative clean enema and skin preparation, iodine allergy test and bladder evacuation are performed. The main indications for vas deferens and seminal vesicle imaging: ① Testicular biopsy to confirm normal spermatogenesis of azoospermia to clarify the site and nature of obstruction. ② To understand whether there are congenital malformations, cysts, tumors or chronic inflammation of the seminal vesicles. Under normal circumstances, vasovasography should show symmetry of the vas deferens channels bilaterally, and the tissues of the vas deferens, vas deferens potbelly, seminal vesicles, and ejaculatory ducts should be shown. Common abnormal sperm duct images are as follows: 1. Vas deferens obstruction: common causes include vas deferens tuberculosis, scar formation after inflammation, prostate cancer infiltrating the vas deferens, congenital partial defect of the vas deferens, etc. Spermography can clarify the site and scope of vas deferens obstruction. If the ejaculatory duct is incompetent or completely obstructed, the ejaculatory duct often does not appear, and the jugular abdomen is obviously dilated. 2. Seminal vesicle diseases: 1) Stones or calcification of seminal vesicles and vas deferens: before imaging, take a plain film of the bladder area to exclude stones or calcification outside the seminal tract, and compare it with the X-ray film after imaging. Sperm vesicle imaging is obstructed by stones, and the passage of contrast agent is obstructed. In the case of stones at the end of the vas deferens, it is difficult to inject the contrast medium and there is high resistance, and the subject has no sensation of urination. Calcification of the vas deferens also affects the contrast. 2) Seminal vesicle tuberculosis: If the clinical diagnosis of epididymal tuberculosis is confirmed, seminal vesicle imaging should be contraindicated to prevent the spread of the lesion. The seminal vesicle tuberculosis imaging shows curvature and dilatation of seminal vesicles, morphological atrophy, visible destruction of images, and the phenomenon of ejaculatory duct reflux, and the lumen at the end of the ejaculatory duct becomes smaller. If there is cavity formation, worm-like edges are seen due to the mixing of contrast with caseous material. In case of severe destruction of the seminal vesicle, the lumen of the duct may be completely occluded and the affected side of the seminal vesicle cannot be visualized. 3) Non-specific seminal vesiculitis: if there is inflammatory secretion or bleeding in the lumen of the vesicle, the contrast is not well developed, and the viscosity of the inflammatory secretion is directly related to the intensity of the contrast agent. In addition, irregularities in the edges of the seminal vesicles, some showing partial or complete dilatation of the seminal vesicles, and the phenomenon of contrast spillage are unique to non-specific seminal vesiculitis, but not in diseases such as seminal vesicle tuberculosis and prostate cancer. 4) Seminal cysts, seminal vesicles diverticula: Rarely, the imaging shows dilatation of seminal vesicles, disappearance of the complex normal structure of seminal vesicles and terminal branches of the vas deferens, a single sac-like enlargement, and dilatation of part or all of the seminal vesicles. 3. Diseases of adjacent organs: 1) In prostatitis, the seminal vesicles may be dilated or reduced in size, spherical in shape, and poorly filled. The distal potbelly has diverticulum-like changes, and the ejaculatory ducts are mostly unchanged. 2) In prostatic hyperplasia, the seminal vesicles and the abdomen of the jug are enlarged, symmetrical and elevated upward on both sides, with smooth edges. The ejaculatory ducts can be several times larger than normal, and the lumen of the ducts is lengthened and brought closer to the midline. The normal concave surface turns inward to concave surface outward. 3) In prostate cancer, the edges of the ejaculatory duct are irregular and changes such as defect, deformation, narrowing or sudden truncation are seen. In severe cases, the seminal vesicles and the jugular abdomen are deformed, the images are mutilated or all of them are not visible, and the vas deferens stumps show rigid rat-tail-like changes. 4. Endocrine disorders: endocrine disorders have a greater impact on the development of the vas deferens and can cause changes in morphology and weight, and morphological changes can be shown by sperm ductography, and weight changes can be determined by quantitative methods of biology. In addition to determining obstruction and congenital malformation of the vas deferens, vasectomy is also useful for diagnosing various anatomical disruptions caused by inflammation, tumor, trauma, etc. It is also useful for understanding lesions of adjacent tissues. In order to reduce unnecessary suffering of patients, it is necessary to carefully select cases and make a thorough examination beforehand, and only perform this examination when it is confirmed that the development of spermatogenic epithelium is normal or when anatomical abnormalities really need to be excluded. Anatomy of the vas deferens The vas deferens is part of the spermatic cord within the scrotum and inguinal canal and is the main structure within the spermatic cord. The vas deferens is tough like a rope, and can be molded to the spermatic cord below the outer ring of the inguinal canal and across the pubic wall by itself. The vas deferens is left and right, 35-45 cm long, with an outer diameter of about 2 mm and an inner lumen of less than 1 mm in diameter. The vas deferens extends from the epididymis to the neck of the seminal vesicle gland and is directly continuous with the epididymal duct, which is the final discharge duct of the testes. It begins at the caudal part of the epididymis, travels up through the inner part of the epididymis along the posterior margin of the testis, crosses the external inguinal ring, passes through the inguinal canal to the level of the internal inguinal ring, and finally ends in the ejaculatory duct. It enters the inguinal canal through the external inguinal ring, and after entering the internal inguinal ring, it advances posteriorly and inferiorly along the lateral wall of the small pelvis, then turns inward and crosses above the end of the ureter, between the bladder and rectum to the bottom of the bladder, and at the upper end of the seminal vesicles, along the inner side of the seminal vesicles and downward inward, it expands in the shape of a pike and becomes the vas deferens potbelly, and the lower end of the potbelly tapers and joins the seminal vesicle excretory duct at the posterior top of the prostatic base to form the ejaculatory duct. Indications for vasectomy The patency of the sperm duct is directly related to ejaculation and fertility. The main indications for vasovasography are: (1) Clinical features of vasovaginal obstruction with normal epididymis and vas deferens on palpation. (2) Clinical features of vasovaginal obstruction with normal epididymis on palpation and normal sperm production on testicular biopsy. (3) Clinical features of vas deferens obstruction, but no abnormality is found on intra-scrotal exploration; (4) Vasectomy or epididymal vas deferens anastomosis is required. There are various methods of vasovasography, and Dr. Yuan Weiqing and Dr. Jia Yuchun of the Fertility Department of Minquan County Hospital have worked out a set of simple and easy methods of vasovasography with minimal damage after years of clinical experience. After local anesthesia, the vas deferens together with the taut scrotal skin is clamped into the fixation ring with extracutaneous fixation forceps. The handle of the fixation glucoside is directed toward the lower extremity of the patient. The operator pinches both sides of the vas deferens in front of the wrong head with the thumb and index finger of the left hand, and holds a vas deferens puncture needle (No. 8 sharp-tipped needle) in the right hand at the middle of the most prominent part of the vas deferens, piercing the anterior wall of the vas deferens in an approximately vertical direction to a depth of about 2 mm. The needle is then punctured at the middle of the vas deferens in an approximately vertical direction, about 2 mm deep. The bevel of the needle must be consistent with the direction of the longitudinal axis of the vas deferens when puncturing, otherwise there is a possibility of puncturing or cutting the vas deferens. 3, remove the No. 8 needle, fix the vas deferens fingers do not move, immediately insert the No. 6 blunt needle into the distal testicular end of the vas deferens along the orifice that has been pierced. When the needle enters the hole in the anterior wall of the vas deferens, there is often a tightening sensation, and with a little force, there is a feeling of stabbing hollow, indicating that it has entered the lumen. 4, to determine whether the puncture is successful, in addition to the operator’s subjective feeling, the following methods can be used to identify: (1) seminal vesicle perfusion test: the operator with the left thumb and index finger gently pinch the vas deferens near the subcutaneous ring, the syringe containing 1% procaine 5ml connected to the inserted 6 blunt needle seat, suddenly inject 2 to 3ml, if the needle in the lumen, pinch the vas deferens finger, that is, feel the sudden expansion of the vas deferens, hardening and pressure increase of the impact feeling, if the needle in the lumen, the vas deferens. If the needle is in the lumen, pinch the finger of the vas deferens and feel the sudden swelling and hardening of the vas deferens and the shocking sensation of increased pressure, continue to inject several milliliters, the patient often has the feeling of urination and no local edema. (2) Vas deferens blind end pressure injection test: the assistant pinches the vas deferens near the subcutaneous ring with the thumb and index finger, the operator pinches the vas deferens in front of the needle hole with the same method, after drawing back no blood, inject 2 ml of air, and relax the finger pushing the injection after a few seconds. If the puncture is successful, the syringe core will automatically return to the original scale due to pressure; if the vas deferens at the spermatophore is not pinched tightly, the air will be injected into the sperm duct and the patient will have a strong feeling of urination, indicating a successful puncture. Conversely, if the puncture fails, there will be obvious signs of subcutaneous air accumulation around the needle and no sense of urination. The procedure of percutaneous vasectomy is like this: the vas deferens is firmly fixed under the skin of the scrotum, and then the needle is inserted directly from the skin into the vas deferens, which is very difficult because the lumen of the vas deferens is very thin, and then the needle is inserted through the skin, but as long as the technique is mastered, it can be successfully punctured at once. However, if you do not master the technique, it is difficult to puncture successfully, so the doctor needs to repeatedly puncture, which increases the patient’s pain and more importantly, increases the damage to the vas deferens, which is not conducive to the recovery of the patient’s condition. Image analysis of the normal seminal tract The vas deferens is normally about 40-50 cm long, with an inner lumen diameter of about 1 mm. Before the vas deferens migrates to the abdomen, a small section of the vas deferens becomes thin and seems to form an isthmus. The two sides of the vas deferens into the pelvis are mostly symmetrical. The abdominal region of the vas deferens is located above the shadow of the seminal vesicles. It is irregularly twisted and bar-shaped. The main ducts are about 2-3 mm in diameter and 3-7 mm in length, with a 1.5 mm segment first running transversely downward and then longitudinally downward, merging at the end with the seminal vesicle excretory duct to form the ejaculatory duct. The margins of most of the pots are irregular and may have diverticulosis-like changes, forming a feathery shape, while a few have smooth margins. The two lateral pots are mostly symmetrical. The spermathecae are normally smooth and irregularly leaf-shaped, in which a sinuous strip of dark shadow made of coiled spermathecal ducts can be seen, located outside and below the abdomen, with a gap between the two in most cases and partial overlap between the two images in a few cases. The morphology of spermathecae can be broadly divided into three types: ① grape-shaped with multiple round dark shadows; ② curved and monotonous curved ducts; and ③ coiled ducts with more curves and overlapping each other. The diameter of the seminal vesicles is basically the same except for the excretory duct which is thin, and the maximum width is about 4-5 mm. The normal ejaculatory duct is a long conical shape or a rod shape of similar width on the X-ray, about 1.6s0.6cm long and 1.5s0.6mm wide, with a smooth outer edge and most of the inner edges have more or less folds or serrated images, and both sides are basically symmetrical. The morphology can be roughly divided into four categories: ① “V” type: the ejaculatory duct is straight, and the spacing between the two is wide at the top and narrow at the bottom (accounting for 22.1%); ② “11” type: the spacing between the two ducts is basically equal (accounting for 47.1%); ③ “X “type: the two ducts were mildly curved outward (25.5%); ④ “()”: the two ducts were significantly curved inward (5.3%). The abdomen of the vas deferens showed irregular distorted stripes on X-ray, first transversely downward, then longitudinally downward, with the end converging with the seminal vesicle excretory duct as the ejaculatory duct. The edges of the jugular abdomen are mostly irregular in the form of diverticula or villi, and a few edges are smooth. Before connecting to the ejaculatory duct, the main tube of the pot belly is mostly dilated and widened, and the end of the tube becomes thin again and then connects to the ejaculatory duct, and the angle between it and the vesicoureteral duct is clear. Epididymis The vasectomy reversal technique is an art that requires high technical skills. A good vasectomy reversal image of the epididymis needs to show the epididymal end of the vas deferens at the scrotal end, the lumen of which is the same as that of the seminal vesicles, and starts to become significantly thinner and more curved when the epididymal duct is shown. Editorial abnormal sperm duct image analysis Common causes of vas deferens obstruction include bilateral inguinal hernia surgical injury, scrotal surgery, gonorrhea, vas deferens tuberculosis, post-inflammatory scar formation, prostate cancer infiltrating the vas deferens, congenital partial defect of the vas deferens, etc. Sperm ductography can clarify the site and scope of vas deferens obstruction, especially the bilateral vas deferens blockage caused by bilateral inguinal hernia surgery injury can clearly locate the vas deferens dissection site and provide valuable diagnostic basis for future vas deferens anastomosis. If the ejaculatory ducts are incompetent or completely obstructed, the ejaculatory ducts are often unremarkable, and the abdomen is obviously dilated. Sperm vesicle diseases 1) Stones or calcification of seminal vesicles and vas deferens: before imaging, a plain film of the bladder area should be taken to exclude stones or calcification outside the seminal tract and to compare with the X-ray film after imaging. Sperm vesicle imaging is obstructed by stones, and the passage of contrast agent is obstructed. In the case of stones at the end of the vas deferens, contrast injection is difficult, resistance is high, and the subject does not feel the urge to urinate. Calcification of the vas deferens also affects the contrast. 2) Seminal vesicle tuberculosis: If the clinical diagnosis of epididymal tuberculosis is confirmed, seminal vesicle imaging should be contraindicated to prevent the spread of the lesion. The seminal vesicle tuberculosis imaging shows distortion and dilatation of the seminal vesicles, morphological atrophy, visible destruction of images, and the phenomenon of ejaculatory duct reflux, and the lumen at the end of the ejaculatory duct becomes smaller. If there is cavity formation, worm-like edges are seen due to the mixing of contrast with caseous material. In case of severe destruction of the seminal vesicle, the lumen of the duct may be completely occluded and the affected side of the seminal vesicle cannot be visualized. 3) Non-specific seminal vesiculitis: if there is inflammatory secretion or bleeding in the lumen of the vesicle, the contrast is not well developed, and the viscosity of the inflammatory secretion is directly related to the intensity of the contrast agent. In addition, irregularities in the edges of the seminal vesicles, some showing partial or complete dilatation of the seminal vesicles, and the phenomenon of contrast spillage are unique to non-specific seminal vesiculitis, but not in diseases such as seminal vesicle tuberculosis and prostate cancer. 4) Seminal cysts, seminal vesicles diverticula: Rarely, the contrast shows dilatation of seminal vesicles, disappearance of the complex normal structure of seminal vesicles and terminal branches of the vas deferens, a single sac-like enlargement, and dilatation of part or all of the seminal vesicles. Epididymal diseases Due to epididymal tuberculosis and gonorrhea, the epididymal ducts are often not visualized, and even in a significant number of patients, the epididymal ducts and the vas deferens in the scrotal area are completely blocked, resulting in failure of imaging. However, in most cases, the epididymal duct is blocked at the epididymal end of the vas deferens and is blocked at the junction of the epididymal duct and the varicocele. If this problem is not clear, it often causes doctors and patients to understand that the testicular biopsy shows normal testicular spermatogenesis and obstructive azoospermia, while the vas deferens and epididymal end of the vas deferens are both well developed. In fact, it is because of the poor understanding of the pathology and imaging. Neighboring organ disease 1) In prostatitis, the seminal vesicles may be dilated or reduced in size, spherical in shape, and poorly filled. The distal jugular has diverticulum-like changes, and the ejaculatory ducts are mostly unchanged. 2) In prostatic hyperplasia, the seminal vesicles and the abdomen of the jug are enlarged, symmetrical and elevated on both sides, with smooth edges. The ejaculatory ducts can be several times larger than normal, and the lumen of the ducts is lengthened and brought closer to the midline. The normal concave surface turns inward to concave surface outward. 3) In prostate cancer, the edges of the ejaculatory duct are irregular and changes such as defects, deformation, narrowing or sudden truncation are seen. In severe cases, the seminal vesicles and the abdomen of the jug are deformed, the image is mutilated or not visible at all, and the vas deferens stump shows stiff rat-tail-like changes. 4) Endocrine disorders: endocrine disorders have a greater impact on the development of the vas deferens and can cause changes in morphology and weight, morphological changes can be shown by sperm ductography and weight changes can be determined by quantitative methods of biology. In addition to determining the obstruction and congenital malformation of the vas deferens, vasectomy is also useful for the diagnosis of various anatomical disruptions caused by inflammation, tumor and trauma. It also helps to understand the lesions of adjacent tissues. Vasectomy is mainly used for male infertility suspected to be caused by obstruction of the vas deferens. If there is no sperm in the semen but the testicular biopsy is normal, vasectomy can clarify whether the vas deferens is obstructed and the specific site of obstruction so that corresponding treatment measures can be taken. Vasectomy vesiculography is mainly used for: 1. Sperm discharge disorder: male infertility semen examination without sperm but testicular biopsy with spermatogenic ability (sperm exist in the varicocele), vasectomy vesiculography can be done to observe whether there is discharge disorder in the vas deferens, its abdomen and the lumen of the ejaculatory duct and seminal vesicles. Through the angiography, we can pay attention to the obstruction site, the degree and scope of narrowing, and whether both sides of the sperm ducts are inaccessible. 2.Seminal vesicle diseases: aspermatism and retrograde ejaculation are often diagnosed by vasovaginal seminal vesicle imaging, and are differentiated from infertility caused by seminal vesicle tuberculosis, seminal vesicle stones, seminal cysts, and non-specific chronic seminal vesicle infection. 3. Endocrine dynamic observation: seminal vesicle is a male genital system paraphilic organ, which is closely related to sexual function. Changes in the endocrine function of an individual can prevent the development of seminal vesicles or cause congenital malformations, thus leading to infertility. Changes in the morphology of seminal vesicles can be inferred from seminal vesiculography.